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Tom Rini83d290c2018-05-06 17:58:06 -04001# SPDX-License-Identifier: GPL-2.0+
wdenkc6097192002-11-03 00:24:07 +00002#
Wolfgang Denkeca3aeb2013-06-21 10:22:36 +02003# (C) Copyright 2000 - 2013
wdenkc6097192002-11-03 00:24:07 +00004# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
wdenkc6097192002-11-03 00:24:07 +00005
6Summary:
7========
8
wdenk24ee89b2002-11-03 17:56:27 +00009This directory contains the source code for U-Boot, a boot loader for
wdenke86e5a02004-10-17 21:12:06 +000010Embedded boards based on PowerPC, ARM, MIPS and several other
11processors, which can be installed in a boot ROM and used to
12initialize and test the hardware or to download and run application
13code.
wdenkc6097192002-11-03 00:24:07 +000014
15The development of U-Boot is closely related to Linux: some parts of
wdenk24ee89b2002-11-03 17:56:27 +000016the source code originate in the Linux source tree, we have some
17header files in common, and special provision has been made to
wdenkc6097192002-11-03 00:24:07 +000018support booting of Linux images.
19
20Some attention has been paid to make this software easily
21configurable and extendable. For instance, all monitor commands are
22implemented with the same call interface, so that it's very easy to
23add new commands. Also, instead of permanently adding rarely used
24code (for instance hardware test utilities) to the monitor, you can
25load and run it dynamically.
26
27
28Status:
29=======
30
31In general, all boards for which a configuration option exists in the
wdenk24ee89b2002-11-03 17:56:27 +000032Makefile have been tested to some extent and can be considered
wdenkc6097192002-11-03 00:24:07 +000033"working". In fact, many of them are used in production systems.
34
Robert P. J. Day7207b362015-12-19 07:16:10 -050035In case of problems see the CHANGELOG file to find out who contributed
36the specific port. In addition, there are various MAINTAINERS files
37scattered throughout the U-Boot source identifying the people or
38companies responsible for various boards and subsystems.
wdenkc6097192002-11-03 00:24:07 +000039
Robert P. J. Day7207b362015-12-19 07:16:10 -050040Note: As of August, 2010, there is no longer a CHANGELOG file in the
41actual U-Boot source tree; however, it can be created dynamically
42from the Git log using:
Robert P. J. Dayadb9d852012-11-14 02:03:20 +000043
44 make CHANGELOG
45
wdenkc6097192002-11-03 00:24:07 +000046
47Where to get help:
48==================
49
wdenk24ee89b2002-11-03 17:56:27 +000050In case you have questions about, problems with or contributions for
Robert P. J. Day7207b362015-12-19 07:16:10 -050051U-Boot, you should send a message to the U-Boot mailing list at
Peter Tyser0c325652008-09-10 09:18:34 -050052<u-boot@lists.denx.de>. There is also an archive of previous traffic
53on the mailing list - please search the archive before asking FAQ's.
54Please see http://lists.denx.de/pipermail/u-boot and
55http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
wdenkc6097192002-11-03 00:24:07 +000056
57
Wolfgang Denk218ca722008-03-26 10:40:12 +010058Where to get source code:
59=========================
60
Robert P. J. Day7207b362015-12-19 07:16:10 -050061The U-Boot source code is maintained in the Git repository at
Wolfgang Denk218ca722008-03-26 10:40:12 +010062git://www.denx.de/git/u-boot.git ; you can browse it online at
63http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
64
65The "snapshot" links on this page allow you to download tarballs of
Marcel Ziswiler11ccc332008-07-09 08:17:15 +020066any version you might be interested in. Official releases are also
Wolfgang Denk218ca722008-03-26 10:40:12 +010067available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
68directory.
69
Anatolij Gustschind4ee7112008-03-26 18:13:33 +010070Pre-built (and tested) images are available from
Wolfgang Denk218ca722008-03-26 10:40:12 +010071ftp://ftp.denx.de/pub/u-boot/images/
72
73
wdenkc6097192002-11-03 00:24:07 +000074Where we come from:
75===================
76
77- start from 8xxrom sources
wdenk24ee89b2002-11-03 17:56:27 +000078- create PPCBoot project (http://sourceforge.net/projects/ppcboot)
wdenkc6097192002-11-03 00:24:07 +000079- clean up code
80- make it easier to add custom boards
81- make it possible to add other [PowerPC] CPUs
82- extend functions, especially:
83 * Provide extended interface to Linux boot loader
84 * S-Record download
85 * network boot
Simon Glass9e5616d2019-08-01 09:47:14 -060086 * ATA disk / SCSI ... boot
wdenk24ee89b2002-11-03 17:56:27 +000087- create ARMBoot project (http://sourceforge.net/projects/armboot)
wdenkc6097192002-11-03 00:24:07 +000088- add other CPU families (starting with ARM)
wdenk24ee89b2002-11-03 17:56:27 +000089- create U-Boot project (http://sourceforge.net/projects/u-boot)
Magnus Lilja0d28f342008-08-06 19:32:33 +020090- current project page: see http://www.denx.de/wiki/U-Boot
wdenk24ee89b2002-11-03 17:56:27 +000091
92
93Names and Spelling:
94===================
95
96The "official" name of this project is "Das U-Boot". The spelling
97"U-Boot" shall be used in all written text (documentation, comments
98in source files etc.). Example:
99
100 This is the README file for the U-Boot project.
101
102File names etc. shall be based on the string "u-boot". Examples:
103
104 include/asm-ppc/u-boot.h
105
106 #include <asm/u-boot.h>
107
108Variable names, preprocessor constants etc. shall be either based on
109the string "u_boot" or on "U_BOOT". Example:
110
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
wdenkc6097192002-11-03 00:24:07 +0000113
114
wdenk93f19cc2002-12-17 17:55:09 +0000115Versioning:
116===========
117
Thomas Weber360d8832010-09-28 08:06:25 +0200118Starting with the release in October 2008, the names of the releases
119were changed from numerical release numbers without deeper meaning
120into a time stamp based numbering. Regular releases are identified by
121names consisting of the calendar year and month of the release date.
122Additional fields (if present) indicate release candidates or bug fix
123releases in "stable" maintenance trees.
wdenk93f19cc2002-12-17 17:55:09 +0000124
Thomas Weber360d8832010-09-28 08:06:25 +0200125Examples:
Wolfgang Denkc0f40852011-10-26 10:21:21 +0000126 U-Boot v2009.11 - Release November 2009
Thomas Weber360d8832010-09-28 08:06:25 +0200127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
Jelle van der Waa0de21ec2016-10-30 17:30:30 +0100128 U-Boot v2010.09-rc1 - Release candidate 1 for September 2010 release
wdenk93f19cc2002-12-17 17:55:09 +0000129
130
wdenkc6097192002-11-03 00:24:07 +0000131Directory Hierarchy:
132====================
133
Peter Tyser8d321b82010-04-12 22:28:21 -0500134/arch Architecture specific files
Masahiro Yamada6eae68e2014-03-07 18:02:02 +0900135 /arc Files generic to ARC architecture
Peter Tyser8d321b82010-04-12 22:28:21 -0500136 /arm Files generic to ARM architecture
Peter Tyser8d321b82010-04-12 22:28:21 -0500137 /m68k Files generic to m68k architecture
Peter Tyser8d321b82010-04-12 22:28:21 -0500138 /microblaze Files generic to microblaze architecture
Peter Tyser8d321b82010-04-12 22:28:21 -0500139 /mips Files generic to MIPS architecture
Macpaul Linafc1ce82011-10-19 20:41:11 +0000140 /nds32 Files generic to NDS32 architecture
Peter Tyser8d321b82010-04-12 22:28:21 -0500141 /nios2 Files generic to Altera NIOS2 architecture
Robert P. J. Day33c77312013-09-15 18:34:15 -0400142 /openrisc Files generic to OpenRISC architecture
Stefan Roesea47a12b2010-04-15 16:07:28 +0200143 /powerpc Files generic to PowerPC architecture
Rick Chen3fafced2017-12-26 13:55:59 +0800144 /riscv Files generic to RISC-V architecture
Robert P. J. Day7207b362015-12-19 07:16:10 -0500145 /sandbox Files generic to HW-independent "sandbox"
Peter Tyser8d321b82010-04-12 22:28:21 -0500146 /sh Files generic to SH architecture
Robert P. J. Day33c77312013-09-15 18:34:15 -0400147 /x86 Files generic to x86 architecture
Peter Tyser8d321b82010-04-12 22:28:21 -0500148/api Machine/arch independent API for external apps
149/board Board dependent files
Xu Ziyuan740f7e52016-08-26 19:54:49 +0800150/cmd U-Boot commands functions
Peter Tyser8d321b82010-04-12 22:28:21 -0500151/common Misc architecture independent functions
Robert P. J. Day7207b362015-12-19 07:16:10 -0500152/configs Board default configuration files
Peter Tyser8d321b82010-04-12 22:28:21 -0500153/disk Code for disk drive partition handling
154/doc Documentation (don't expect too much)
155/drivers Commonly used device drivers
Robert P. J. Day33c77312013-09-15 18:34:15 -0400156/dts Contains Makefile for building internal U-Boot fdt.
Peter Tyser8d321b82010-04-12 22:28:21 -0500157/examples Example code for standalone applications, etc.
158/fs Filesystem code (cramfs, ext2, jffs2, etc.)
159/include Header Files
Robert P. J. Day7207b362015-12-19 07:16:10 -0500160/lib Library routines generic to all architectures
161/Licenses Various license files
Peter Tyser8d321b82010-04-12 22:28:21 -0500162/net Networking code
163/post Power On Self Test
Robert P. J. Day7207b362015-12-19 07:16:10 -0500164/scripts Various build scripts and Makefiles
165/test Various unit test files
Peter Tyser8d321b82010-04-12 22:28:21 -0500166/tools Tools to build S-Record or U-Boot images, etc.
wdenkc6097192002-11-03 00:24:07 +0000167
wdenkc6097192002-11-03 00:24:07 +0000168Software Configuration:
169=======================
170
171Configuration is usually done using C preprocessor defines; the
172rationale behind that is to avoid dead code whenever possible.
173
174There are two classes of configuration variables:
175
176* Configuration _OPTIONS_:
177 These are selectable by the user and have names beginning with
178 "CONFIG_".
179
180* Configuration _SETTINGS_:
181 These depend on the hardware etc. and should not be meddled with if
182 you don't know what you're doing; they have names beginning with
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200183 "CONFIG_SYS_".
wdenkc6097192002-11-03 00:24:07 +0000184
Robert P. J. Day7207b362015-12-19 07:16:10 -0500185Previously, all configuration was done by hand, which involved creating
186symbolic links and editing configuration files manually. More recently,
187U-Boot has added the Kbuild infrastructure used by the Linux kernel,
188allowing you to use the "make menuconfig" command to configure your
189build.
wdenkc6097192002-11-03 00:24:07 +0000190
191
192Selection of Processor Architecture and Board Type:
193---------------------------------------------------
194
195For all supported boards there are ready-to-use default
Holger Freytherab584d62014-08-04 09:26:05 +0200196configurations available; just type "make <board_name>_defconfig".
wdenkc6097192002-11-03 00:24:07 +0000197
198Example: For a TQM823L module type:
199
200 cd u-boot
Holger Freytherab584d62014-08-04 09:26:05 +0200201 make TQM823L_defconfig
wdenkc6097192002-11-03 00:24:07 +0000202
Robert P. J. Day7207b362015-12-19 07:16:10 -0500203Note: If you're looking for the default configuration file for a board
204you're sure used to be there but is now missing, check the file
205doc/README.scrapyard for a list of no longer supported boards.
wdenkc6097192002-11-03 00:24:07 +0000206
Simon Glass75b3c3a2014-03-22 17:12:59 -0600207Sandbox Environment:
208--------------------
209
210U-Boot can be built natively to run on a Linux host using the 'sandbox'
211board. This allows feature development which is not board- or architecture-
212specific to be undertaken on a native platform. The sandbox is also used to
213run some of U-Boot's tests.
214
Keerthy5917d0b2019-07-29 13:52:04 +0530215See doc/arch/index.rst for more details.
Simon Glass75b3c3a2014-03-22 17:12:59 -0600216
217
Simon Glassdb910352015-03-03 08:03:00 -0700218Board Initialisation Flow:
219--------------------------
220
221This is the intended start-up flow for boards. This should apply for both
Robert P. J. Day7207b362015-12-19 07:16:10 -0500222SPL and U-Boot proper (i.e. they both follow the same rules).
Simon Glassdb910352015-03-03 08:03:00 -0700223
Robert P. J. Day7207b362015-12-19 07:16:10 -0500224Note: "SPL" stands for "Secondary Program Loader," which is explained in
225more detail later in this file.
226
227At present, SPL mostly uses a separate code path, but the function names
228and roles of each function are the same. Some boards or architectures
229may not conform to this. At least most ARM boards which use
230CONFIG_SPL_FRAMEWORK conform to this.
231
232Execution typically starts with an architecture-specific (and possibly
233CPU-specific) start.S file, such as:
234
235 - arch/arm/cpu/armv7/start.S
236 - arch/powerpc/cpu/mpc83xx/start.S
237 - arch/mips/cpu/start.S
238
239and so on. From there, three functions are called; the purpose and
240limitations of each of these functions are described below.
Simon Glassdb910352015-03-03 08:03:00 -0700241
242lowlevel_init():
243 - purpose: essential init to permit execution to reach board_init_f()
244 - no global_data or BSS
245 - there is no stack (ARMv7 may have one but it will soon be removed)
246 - must not set up SDRAM or use console
247 - must only do the bare minimum to allow execution to continue to
248 board_init_f()
249 - this is almost never needed
250 - return normally from this function
251
252board_init_f():
253 - purpose: set up the machine ready for running board_init_r():
254 i.e. SDRAM and serial UART
255 - global_data is available
256 - stack is in SRAM
257 - BSS is not available, so you cannot use global/static variables,
258 only stack variables and global_data
259
260 Non-SPL-specific notes:
261 - dram_init() is called to set up DRAM. If already done in SPL this
262 can do nothing
263
264 SPL-specific notes:
265 - you can override the entire board_init_f() function with your own
266 version as needed.
267 - preloader_console_init() can be called here in extremis
268 - should set up SDRAM, and anything needed to make the UART work
269 - these is no need to clear BSS, it will be done by crt0.S
Andreas Dannenberg14254652019-08-08 12:54:49 -0500270 - for specific scenarios on certain architectures an early BSS *can*
271 be made available (via CONFIG_SPL_EARLY_BSS by moving the clearing
272 of BSS prior to entering board_init_f()) but doing so is discouraged.
273 Instead it is strongly recommended to architect any code changes
274 or additions such to not depend on the availability of BSS during
275 board_init_f() as indicated in other sections of this README to
276 maintain compatibility and consistency across the entire code base.
Simon Glassdb910352015-03-03 08:03:00 -0700277 - must return normally from this function (don't call board_init_r()
278 directly)
279
280Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
281this point the stack and global_data are relocated to below
282CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
283memory.
284
285board_init_r():
286 - purpose: main execution, common code
287 - global_data is available
288 - SDRAM is available
289 - BSS is available, all static/global variables can be used
290 - execution eventually continues to main_loop()
291
292 Non-SPL-specific notes:
293 - U-Boot is relocated to the top of memory and is now running from
294 there.
295
296 SPL-specific notes:
297 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
298 CONFIG_SPL_STACK_R_ADDR points into SDRAM
299 - preloader_console_init() can be called here - typically this is
Ley Foon Tan0680f1b2017-05-03 17:13:32 +0800300 done by selecting CONFIG_SPL_BOARD_INIT and then supplying a
Simon Glassdb910352015-03-03 08:03:00 -0700301 spl_board_init() function containing this call
302 - loads U-Boot or (in falcon mode) Linux
303
304
305
wdenkc6097192002-11-03 00:24:07 +0000306Configuration Options:
307----------------------
308
309Configuration depends on the combination of board and CPU type; all
310such information is kept in a configuration file
311"include/configs/<board_name>.h".
312
313Example: For a TQM823L module, all configuration settings are in
314"include/configs/TQM823L.h".
315
316
wdenk7f6c2cb2002-11-10 22:06:23 +0000317Many of the options are named exactly as the corresponding Linux
318kernel configuration options. The intention is to make it easier to
319build a config tool - later.
320
Ashish Kumar63b23162017-08-11 11:09:14 +0530321- ARM Platform Bus Type(CCI):
322 CoreLink Cache Coherent Interconnect (CCI) is ARM BUS which
323 provides full cache coherency between two clusters of multi-core
324 CPUs and I/O coherency for devices and I/O masters
325
326 CONFIG_SYS_FSL_HAS_CCI400
327
328 Defined For SoC that has cache coherent interconnect
329 CCN-400
wdenk7f6c2cb2002-11-10 22:06:23 +0000330
Ashish Kumarc055cee2017-08-18 10:54:36 +0530331 CONFIG_SYS_FSL_HAS_CCN504
332
333 Defined for SoC that has cache coherent interconnect CCN-504
334
wdenkc6097192002-11-03 00:24:07 +0000335The following options need to be configured:
336
Kim Phillips26281142007-08-10 13:28:25 -0500337- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
wdenkc6097192002-11-03 00:24:07 +0000338
Kim Phillips26281142007-08-10 13:28:25 -0500339- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
Wolfgang Denk6ccec442006-10-24 14:42:37 +0200340
Kumar Gala66412c62011-02-18 05:40:54 -0600341- 85xx CPU Options:
York Sunffd06e02012-10-08 07:44:30 +0000342 CONFIG_SYS_PPC64
343
344 Specifies that the core is a 64-bit PowerPC implementation (implements
345 the "64" category of the Power ISA). This is necessary for ePAPR
346 compliance, among other possible reasons.
347
Kumar Gala66412c62011-02-18 05:40:54 -0600348 CONFIG_SYS_FSL_TBCLK_DIV
349
350 Defines the core time base clock divider ratio compared to the
351 system clock. On most PQ3 devices this is 8, on newer QorIQ
352 devices it can be 16 or 32. The ratio varies from SoC to Soc.
353
Kumar Gala8f290842011-05-20 00:39:21 -0500354 CONFIG_SYS_FSL_PCIE_COMPAT
355
356 Defines the string to utilize when trying to match PCIe device
357 tree nodes for the given platform.
358
Scott Wood33eee332012-08-14 10:14:53 +0000359 CONFIG_SYS_FSL_ERRATUM_A004510
360
361 Enables a workaround for erratum A004510. If set,
362 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
363 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
364
365 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
366 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
367
368 Defines one or two SoC revisions (low 8 bits of SVR)
369 for which the A004510 workaround should be applied.
370
371 The rest of SVR is either not relevant to the decision
372 of whether the erratum is present (e.g. p2040 versus
373 p2041) or is implied by the build target, which controls
374 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
375
376 See Freescale App Note 4493 for more information about
377 this erratum.
378
Prabhakar Kushwaha74fa22e2013-04-16 13:27:44 +0530379 CONFIG_A003399_NOR_WORKAROUND
380 Enables a workaround for IFC erratum A003399. It is only
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -0800381 required during NOR boot.
Prabhakar Kushwaha74fa22e2013-04-16 13:27:44 +0530382
Prabhakar Kushwaha9f074e62014-10-29 22:33:09 +0530383 CONFIG_A008044_WORKAROUND
384 Enables a workaround for T1040/T1042 erratum A008044. It is only
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -0800385 required during NAND boot and valid for Rev 1.0 SoC revision
Prabhakar Kushwaha9f074e62014-10-29 22:33:09 +0530386
Scott Wood33eee332012-08-14 10:14:53 +0000387 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
388
389 This is the value to write into CCSR offset 0x18600
390 according to the A004510 workaround.
391
Priyanka Jain64501c62013-07-02 09:21:04 +0530392 CONFIG_SYS_FSL_DSP_DDR_ADDR
393 This value denotes start offset of DDR memory which is
394 connected exclusively to the DSP cores.
395
Priyanka Jain765b0bd2013-04-04 09:31:54 +0530396 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
397 This value denotes start offset of M2 memory
398 which is directly connected to the DSP core.
399
Priyanka Jain64501c62013-07-02 09:21:04 +0530400 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
401 This value denotes start offset of M3 memory which is directly
402 connected to the DSP core.
403
Priyanka Jain765b0bd2013-04-04 09:31:54 +0530404 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
405 This value denotes start offset of DSP CCSR space.
406
Priyanka Jainb1359912013-12-17 14:25:52 +0530407 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
408 Single Source Clock is clocking mode present in some of FSL SoC's.
409 In this mode, a single differential clock is used to supply
410 clocks to the sysclock, ddrclock and usbclock.
411
Aneesh Bansalfb4a2402014-03-18 23:40:26 +0530412 CONFIG_SYS_CPC_REINIT_F
413 This CONFIG is defined when the CPC is configured as SRAM at the
Bin Menga1875592016-02-05 19:30:11 -0800414 time of U-Boot entry and is required to be re-initialized.
Aneesh Bansalfb4a2402014-03-18 23:40:26 +0530415
Tang Yuantianaade2002014-04-17 15:33:46 +0800416 CONFIG_DEEP_SLEEP
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -0800417 Indicates this SoC supports deep sleep feature. If deep sleep is
Tang Yuantianaade2002014-04-17 15:33:46 +0800418 supported, core will start to execute uboot when wakes up.
419
Daniel Schwierzeck6cb461b2012-04-02 02:57:56 +0000420- Generic CPU options:
421 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
422
423 Defines the endianess of the CPU. Implementation of those
424 values is arch specific.
425
York Sun5614e712013-09-30 09:22:09 -0700426 CONFIG_SYS_FSL_DDR
427 Freescale DDR driver in use. This type of DDR controller is
428 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
429 SoCs.
430
431 CONFIG_SYS_FSL_DDR_ADDR
432 Freescale DDR memory-mapped register base.
433
434 CONFIG_SYS_FSL_DDR_EMU
435 Specify emulator support for DDR. Some DDR features such as
436 deskew training are not available.
437
438 CONFIG_SYS_FSL_DDRC_GEN1
439 Freescale DDR1 controller.
440
441 CONFIG_SYS_FSL_DDRC_GEN2
442 Freescale DDR2 controller.
443
444 CONFIG_SYS_FSL_DDRC_GEN3
445 Freescale DDR3 controller.
446
York Sun34e026f2014-03-27 17:54:47 -0700447 CONFIG_SYS_FSL_DDRC_GEN4
448 Freescale DDR4 controller.
449
York Sun9ac4ffb2013-09-30 14:20:51 -0700450 CONFIG_SYS_FSL_DDRC_ARM_GEN3
451 Freescale DDR3 controller for ARM-based SoCs.
452
York Sun5614e712013-09-30 09:22:09 -0700453 CONFIG_SYS_FSL_DDR1
454 Board config to use DDR1. It can be enabled for SoCs with
455 Freescale DDR1 or DDR2 controllers, depending on the board
456 implemetation.
457
458 CONFIG_SYS_FSL_DDR2
Robert P. J. Day62a3b7d2016-07-15 13:44:45 -0400459 Board config to use DDR2. It can be enabled for SoCs with
York Sun5614e712013-09-30 09:22:09 -0700460 Freescale DDR2 or DDR3 controllers, depending on the board
461 implementation.
462
463 CONFIG_SYS_FSL_DDR3
464 Board config to use DDR3. It can be enabled for SoCs with
York Sun34e026f2014-03-27 17:54:47 -0700465 Freescale DDR3 or DDR3L controllers.
466
467 CONFIG_SYS_FSL_DDR3L
468 Board config to use DDR3L. It can be enabled for SoCs with
469 DDR3L controllers.
470
471 CONFIG_SYS_FSL_DDR4
472 Board config to use DDR4. It can be enabled for SoCs with
473 DDR4 controllers.
York Sun5614e712013-09-30 09:22:09 -0700474
Prabhakar Kushwaha1b4175d2014-01-18 12:28:30 +0530475 CONFIG_SYS_FSL_IFC_BE
476 Defines the IFC controller register space as Big Endian
477
478 CONFIG_SYS_FSL_IFC_LE
479 Defines the IFC controller register space as Little Endian
480
Prabhakar Kushwaha1c407072017-02-02 15:01:26 +0530481 CONFIG_SYS_FSL_IFC_CLK_DIV
482 Defines divider of platform clock(clock input to IFC controller).
483
Prabhakar Kushwahaadd63f92017-02-02 15:02:00 +0530484 CONFIG_SYS_FSL_LBC_CLK_DIV
485 Defines divider of platform clock(clock input to eLBC controller).
486
Prabhakar Kushwaha690e4252014-01-13 11:28:04 +0530487 CONFIG_SYS_FSL_PBL_PBI
488 It enables addition of RCW (Power on reset configuration) in built image.
489 Please refer doc/README.pblimage for more details
490
491 CONFIG_SYS_FSL_PBL_RCW
492 It adds PBI(pre-boot instructions) commands in u-boot build image.
493 PBI commands can be used to configure SoC before it starts the execution.
494 Please refer doc/README.pblimage for more details
495
York Sun4e5b1bd2014-02-10 13:59:42 -0800496 CONFIG_SYS_FSL_DDR_BE
497 Defines the DDR controller register space as Big Endian
498
499 CONFIG_SYS_FSL_DDR_LE
500 Defines the DDR controller register space as Little Endian
501
York Sun6b9e3092014-02-10 13:59:43 -0800502 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
503 Physical address from the view of DDR controllers. It is the
504 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
505 it could be different for ARM SoCs.
506
York Sun6b1e1252014-02-10 13:59:44 -0800507 CONFIG_SYS_FSL_DDR_INTLV_256B
508 DDR controller interleaving on 256-byte. This is a special
509 interleaving mode, handled by Dickens for Freescale layerscape
510 SoCs with ARM core.
511
York Sun1d71efb2014-08-01 15:51:00 -0700512 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
513 Number of controllers used as main memory.
514
515 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
516 Number of controllers used for other than main memory.
517
Prabhakar Kushwaha44937212015-11-09 16:42:07 +0530518 CONFIG_SYS_FSL_HAS_DP_DDR
519 Defines the SoC has DP-DDR used for DPAA.
520
Ruchika Gupta028dbb82014-09-09 11:50:31 +0530521 CONFIG_SYS_FSL_SEC_BE
522 Defines the SEC controller register space as Big Endian
523
524 CONFIG_SYS_FSL_SEC_LE
525 Defines the SEC controller register space as Little Endian
526
Daniel Schwierzeck92bbd642011-07-27 13:22:39 +0200527- MIPS CPU options:
528 CONFIG_SYS_INIT_SP_OFFSET
529
530 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
531 pointer. This is needed for the temporary stack before
532 relocation.
533
Daniel Schwierzeck92bbd642011-07-27 13:22:39 +0200534 CONFIG_XWAY_SWAP_BYTES
535
536 Enable compilation of tools/xway-swap-bytes needed for Lantiq
537 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
538 be swapped if a flash programmer is used.
539
Christian Rieschb67d8812012-02-02 00:44:39 +0000540- ARM options:
541 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
542
543 Select high exception vectors of the ARM core, e.g., do not
544 clear the V bit of the c1 register of CP15.
545
York Sun207774b2015-03-20 19:28:08 -0700546 COUNTER_FREQUENCY
547 Generic timer clock source frequency.
548
549 COUNTER_FREQUENCY_REAL
550 Generic timer clock source frequency if the real clock is
551 different from COUNTER_FREQUENCY, and can only be determined
552 at run time.
553
Stephen Warren73c38932015-01-19 16:25:52 -0700554- Tegra SoC options:
555 CONFIG_TEGRA_SUPPORT_NON_SECURE
556
557 Support executing U-Boot in non-secure (NS) mode. Certain
558 impossible actions will be skipped if the CPU is in NS mode,
559 such as ARM architectural timer initialization.
560
wdenk5da627a2003-10-09 20:09:04 +0000561- Linux Kernel Interface:
wdenkc6097192002-11-03 00:24:07 +0000562 CONFIG_CLOCKS_IN_MHZ
563
564 U-Boot stores all clock information in Hz
565 internally. For binary compatibility with older Linux
566 kernels (which expect the clocks passed in the
567 bd_info data to be in MHz) the environment variable
568 "clocks_in_mhz" can be defined so that U-Boot
569 converts clock data to MHZ before passing it to the
570 Linux kernel.
wdenkc6097192002-11-03 00:24:07 +0000571 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
Wolfgang Denk218ca722008-03-26 10:40:12 +0100572 "clocks_in_mhz=1" is automatically included in the
wdenkc6097192002-11-03 00:24:07 +0000573 default environment.
574
wdenk5da627a2003-10-09 20:09:04 +0000575 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
576
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -0800577 When transferring memsize parameter to Linux, some versions
wdenk5da627a2003-10-09 20:09:04 +0000578 expect it to be in bytes, others in MB.
579 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
580
Gerald Van Barenfec6d9e2008-06-03 20:34:45 -0400581 CONFIG_OF_LIBFDT
Wolfgang Denkf57f70a2005-10-13 01:45:54 +0200582
583 New kernel versions are expecting firmware settings to be
Gerald Van Baren213bf8c2007-03-31 12:23:51 -0400584 passed using flattened device trees (based on open firmware
585 concepts).
586
587 CONFIG_OF_LIBFDT
588 * New libfdt-based support
589 * Adds the "fdt" command
Kim Phillips3bb342f2007-08-10 14:34:14 -0500590 * The bootm command automatically updates the fdt
Gerald Van Baren213bf8c2007-03-31 12:23:51 -0400591
Wolfgang Denkf57f70a2005-10-13 01:45:54 +0200592 OF_TBCLK - The timebase frequency.
Kumar Galac2871f02006-01-11 13:59:02 -0600593 OF_STDOUT_PATH - The path to the console device
Wolfgang Denkf57f70a2005-10-13 01:45:54 +0200594
Marcel Ziswiler11ccc332008-07-09 08:17:15 +0200595 boards with QUICC Engines require OF_QE to set UCC MAC
596 addresses
Kim Phillips3bb342f2007-08-10 14:34:14 -0500597
Kumar Gala4e253132006-01-11 13:54:17 -0600598 CONFIG_OF_BOARD_SETUP
599
600 Board code has addition modification that it wants to make
601 to the flat device tree before handing it off to the kernel
wdenk6705d812004-08-02 23:22:59 +0000602
Simon Glassc654b512014-10-23 18:58:54 -0600603 CONFIG_OF_SYSTEM_SETUP
604
605 Other code has addition modification that it wants to make
606 to the flat device tree before handing it off to the kernel.
607 This causes ft_system_setup() to be called before booting
608 the kernel.
609
Heiko Schocher3887c3f2009-09-23 07:56:08 +0200610 CONFIG_OF_IDE_FIXUP
611
612 U-Boot can detect if an IDE device is present or not.
613 If not, and this new config option is activated, U-Boot
614 removes the ATA node from the DTS before booting Linux,
615 so the Linux IDE driver does not probe the device and
616 crash. This is needed for buggy hardware (uc101) where
617 no pull down resistor is connected to the signal IDE5V_DD7.
618
Igor Grinberg7eb29392011-07-14 05:45:07 +0000619 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
620
621 This setting is mandatory for all boards that have only one
622 machine type and must be used to specify the machine type
623 number as it appears in the ARM machine registry
624 (see http://www.arm.linux.org.uk/developer/machines/).
625 Only boards that have multiple machine types supported
626 in a single configuration file and the machine type is
627 runtime discoverable, do not have to use this setting.
628
Niklaus Giger0b2f4ec2008-11-03 22:13:47 +0100629- vxWorks boot parameters:
630
631 bootvx constructs a valid bootline using the following
Bin Meng9e98b7e2015-10-07 20:19:17 -0700632 environments variables: bootdev, bootfile, ipaddr, netmask,
633 serverip, gatewayip, hostname, othbootargs.
Niklaus Giger0b2f4ec2008-11-03 22:13:47 +0100634 It loads the vxWorks image pointed bootfile.
635
Niklaus Giger0b2f4ec2008-11-03 22:13:47 +0100636 Note: If a "bootargs" environment is defined, it will overwride
637 the defaults discussed just above.
638
Aneesh V2c451f72011-06-16 23:30:47 +0000639- Cache Configuration:
Aneesh V2c451f72011-06-16 23:30:47 +0000640 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
641
Aneesh V93bc2192011-06-16 23:30:51 +0000642- Cache Configuration for ARM:
643 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
644 controller
645 CONFIG_SYS_PL310_BASE - Physical base address of PL310
646 controller register space
647
wdenk6705d812004-08-02 23:22:59 +0000648- Serial Ports:
Andreas Engel48d01922008-09-08 14:30:53 +0200649 CONFIG_PL010_SERIAL
wdenk6705d812004-08-02 23:22:59 +0000650
651 Define this if you want support for Amba PrimeCell PL010 UARTs.
652
Andreas Engel48d01922008-09-08 14:30:53 +0200653 CONFIG_PL011_SERIAL
wdenk6705d812004-08-02 23:22:59 +0000654
655 Define this if you want support for Amba PrimeCell PL011 UARTs.
656
657 CONFIG_PL011_CLOCK
658
659 If you have Amba PrimeCell PL011 UARTs, set this variable to
660 the clock speed of the UARTs.
661
662 CONFIG_PL01x_PORTS
663
664 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
665 define this to a list of base addresses for each (supported)
666 port. See e.g. include/configs/versatile.h
667
Karicheri, Muralidharand57dee52014-04-09 15:38:46 -0400668 CONFIG_SERIAL_HW_FLOW_CONTROL
669
670 Define this variable to enable hw flow control in serial driver.
671 Current user of this option is drivers/serial/nsl16550.c driver
wdenk6705d812004-08-02 23:22:59 +0000672
wdenkc6097192002-11-03 00:24:07 +0000673- Console Baudrate:
674 CONFIG_BAUDRATE - in bps
675 Select one of the baudrates listed in
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200676 CONFIG_SYS_BAUDRATE_TABLE, see below.
wdenkc6097192002-11-03 00:24:07 +0000677
wdenkc6097192002-11-03 00:24:07 +0000678- Autoboot Command:
679 CONFIG_BOOTCOMMAND
680 Only needed when CONFIG_BOOTDELAY is enabled;
681 define a command string that is automatically executed
682 when no character is read on the console interface
683 within "Boot Delay" after reset.
684
wdenkc6097192002-11-03 00:24:07 +0000685 CONFIG_RAMBOOT and CONFIG_NFSBOOT
wdenk43d96162003-03-06 00:02:04 +0000686 The value of these goes into the environment as
687 "ramboot" and "nfsboot" respectively, and can be used
688 as a convenience, when switching between booting from
Marcel Ziswiler11ccc332008-07-09 08:17:15 +0200689 RAM and NFS.
wdenkc6097192002-11-03 00:24:07 +0000690
wdenkc6097192002-11-03 00:24:07 +0000691- Serial Download Echo Mode:
692 CONFIG_LOADS_ECHO
693 If defined to 1, all characters received during a
694 serial download (using the "loads" command) are
695 echoed back. This might be needed by some terminal
696 emulations (like "cu"), but may as well just take
697 time on others. This setting #define's the initial
698 value of the "loads_echo" environment variable.
699
Jon Loeliger602ad3b2007-06-11 19:03:39 -0500700- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
wdenkc6097192002-11-03 00:24:07 +0000701 CONFIG_KGDB_BAUDRATE
702 Select one of the baudrates listed in
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200703 CONFIG_SYS_BAUDRATE_TABLE, see below.
wdenkc6097192002-11-03 00:24:07 +0000704
Simon Glass302a6482016-03-13 19:07:28 -0600705- Removal of commands
706 If no commands are needed to boot, you can disable
707 CONFIG_CMDLINE to remove them. In this case, the command line
708 will not be available, and when U-Boot wants to execute the
709 boot command (on start-up) it will call board_run_command()
710 instead. This can reduce image size significantly for very
711 simple boot procedures.
712
Wolfgang Denka5ecbe62013-03-23 23:50:31 +0000713- Regular expression support:
714 CONFIG_REGEX
Wolfgang Denk93e14592013-10-04 17:43:24 +0200715 If this variable is defined, U-Boot is linked against
716 the SLRE (Super Light Regular Expression) library,
717 which adds regex support to some commands, as for
718 example "env grep" and "setexpr".
Wolfgang Denka5ecbe62013-03-23 23:50:31 +0000719
Simon Glass45ba8072011-10-15 05:48:20 +0000720- Device tree:
721 CONFIG_OF_CONTROL
722 If this variable is defined, U-Boot will use a device tree
723 to configure its devices, instead of relying on statically
724 compiled #defines in the board file. This option is
725 experimental and only available on a few boards. The device
726 tree is available in the global data as gd->fdt_blob.
727
Simon Glass2c0f79e2011-10-24 19:15:31 +0000728 U-Boot needs to get its device tree from somewhere. This can
Alex Deymo82f766d2017-04-02 01:25:20 -0700729 be done using one of the three options below:
Simon Glassbbb0b122011-10-15 05:48:21 +0000730
731 CONFIG_OF_EMBED
732 If this variable is defined, U-Boot will embed a device tree
733 binary in its image. This device tree file should be in the
734 board directory and called <soc>-<board>.dts. The binary file
735 is then picked up in board_init_f() and made available through
Nobuhiro Iwamatsueb3eb602017-08-26 07:34:14 +0900736 the global data structure as gd->fdt_blob.
Simon Glass45ba8072011-10-15 05:48:20 +0000737
Simon Glass2c0f79e2011-10-24 19:15:31 +0000738 CONFIG_OF_SEPARATE
739 If this variable is defined, U-Boot will build a device tree
740 binary. It will be called u-boot.dtb. Architecture-specific
741 code will locate it at run-time. Generally this works by:
742
743 cat u-boot.bin u-boot.dtb >image.bin
744
745 and in fact, U-Boot does this for you, creating a file called
746 u-boot-dtb.bin which is useful in the common case. You can
747 still use the individual files if you need something more
748 exotic.
749
Alex Deymo82f766d2017-04-02 01:25:20 -0700750 CONFIG_OF_BOARD
751 If this variable is defined, U-Boot will use the device tree
752 provided by the board at runtime instead of embedding one with
753 the image. Only boards defining board_fdt_blob_setup() support
754 this option (see include/fdtdec.h file).
755
wdenkc6097192002-11-03 00:24:07 +0000756- Watchdog:
757 CONFIG_WATCHDOG
758 If this variable is defined, it enables watchdog
Detlev Zundel6abe6fb2011-04-27 05:25:59 +0000759 support for the SoC. There must be support in the SoC
Christophe Leroy907208c2017-07-06 10:23:22 +0200760 specific code for a watchdog. For the 8xx
761 CPUs, the SIU Watchdog feature is enabled in the SYPCR
762 register. When supported for a specific SoC is
763 available, then no further board specific code should
764 be needed to use it.
Detlev Zundel6abe6fb2011-04-27 05:25:59 +0000765
766 CONFIG_HW_WATCHDOG
767 When using a watchdog circuitry external to the used
768 SoC, then define this variable and provide board
769 specific code for the "hw_watchdog_reset" function.
wdenkc6097192002-11-03 00:24:07 +0000770
771- Real-Time Clock:
772
Jon Loeliger602ad3b2007-06-11 19:03:39 -0500773 When CONFIG_CMD_DATE is selected, the type of the RTC
wdenkc6097192002-11-03 00:24:07 +0000774 has to be selected, too. Define exactly one of the
775 following options:
776
wdenkc6097192002-11-03 00:24:07 +0000777 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
Fabio Estevam4e8b7542011-10-24 06:44:15 +0000778 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
wdenkc6097192002-11-03 00:24:07 +0000779 CONFIG_RTC_MC146818 - use MC146818 RTC
wdenk1cb8e982003-03-06 21:55:29 +0000780 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
wdenkc6097192002-11-03 00:24:07 +0000781 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
wdenk7f70e852003-05-20 14:25:27 +0000782 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
Markus Niebel412921d2014-07-21 11:06:16 +0200783 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
wdenk3bac3512003-03-12 10:41:04 +0000784 CONFIG_RTC_DS164x - use Dallas DS164x RTC
Tor Krill9536dfc2008-03-15 15:40:26 +0100785 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
wdenk4c0d4c32004-06-09 17:34:58 +0000786 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
Chris Packham2bd3cab2017-05-30 12:03:33 +1200787 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
Heiko Schocher71d19f32011-03-28 09:24:22 +0200788 CONFIG_SYS_RV3029_TCR - enable trickle charger on
789 RV3029 RTC.
wdenkc6097192002-11-03 00:24:07 +0000790
wdenkb37c7e52003-06-30 16:24:52 +0000791 Note that if the RTC uses I2C, then the I2C interface
792 must also be configured. See I2C Support, below.
793
Peter Tysere92739d2008-12-17 16:36:21 -0600794- GPIO Support:
795 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
Peter Tysere92739d2008-12-17 16:36:21 -0600796
Chris Packham5dec49c2010-12-19 10:12:13 +0000797 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
798 chip-ngpio pairs that tell the PCA953X driver the number of
799 pins supported by a particular chip.
800
Peter Tysere92739d2008-12-17 16:36:21 -0600801 Note that if the GPIO device uses I2C, then the I2C interface
802 must also be configured. See I2C Support, below.
803
Simon Glassaa532332014-06-11 23:29:41 -0600804- I/O tracing:
805 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
806 accesses and can checksum them or write a list of them out
807 to memory. See the 'iotrace' command for details. This is
808 useful for testing device drivers since it can confirm that
809 the driver behaves the same way before and after a code
810 change. Currently this is supported on sandbox and arm. To
811 add support for your architecture, add '#include <iotrace.h>'
812 to the bottom of arch/<arch>/include/asm/io.h and test.
813
814 Example output from the 'iotrace stats' command is below.
815 Note that if the trace buffer is exhausted, the checksum will
816 still continue to operate.
817
818 iotrace is enabled
819 Start: 10000000 (buffer start address)
820 Size: 00010000 (buffer size)
821 Offset: 00000120 (current buffer offset)
822 Output: 10000120 (start + offset)
823 Count: 00000018 (number of trace records)
824 CRC32: 9526fb66 (CRC32 of all trace records)
825
wdenkc6097192002-11-03 00:24:07 +0000826- Timestamp Support:
827
wdenk43d96162003-03-06 00:02:04 +0000828 When CONFIG_TIMESTAMP is selected, the timestamp
829 (date and time) of an image is printed by image
830 commands like bootm or iminfo. This option is
Jon Loeliger602ad3b2007-06-11 19:03:39 -0500831 automatically enabled when you select CONFIG_CMD_DATE .
wdenkc6097192002-11-03 00:24:07 +0000832
Karl O. Pinc923c46f2012-08-16 06:20:15 +0000833- Partition Labels (disklabels) Supported:
834 Zero or more of the following:
835 CONFIG_MAC_PARTITION Apple's MacOS partition table.
Karl O. Pinc923c46f2012-08-16 06:20:15 +0000836 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
837 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
838 bootloader. Note 2TB partition limit; see
839 disk/part_efi.c
Simon Glassc649e3c2016-05-01 11:36:02 -0600840 CONFIG_SCSI) you must configure support for at
Karl O. Pinc923c46f2012-08-16 06:20:15 +0000841 least one non-MTD partition type as well.
wdenkc6097192002-11-03 00:24:07 +0000842
843- IDE Reset method:
wdenk4d13cba2004-03-14 14:09:05 +0000844 CONFIG_IDE_RESET_ROUTINE - this is defined in several
845 board configurations files but used nowhere!
wdenkc6097192002-11-03 00:24:07 +0000846
wdenk4d13cba2004-03-14 14:09:05 +0000847 CONFIG_IDE_RESET - is this is defined, IDE Reset will
848 be performed by calling the function
849 ide_set_reset(int reset)
850 which has to be defined in a board specific file
wdenkc6097192002-11-03 00:24:07 +0000851
852- ATAPI Support:
853 CONFIG_ATAPI
854
855 Set this to enable ATAPI support.
856
wdenkc40b2952004-03-13 23:29:43 +0000857- LBA48 Support
858 CONFIG_LBA48
859
860 Set this to enable support for disks larger than 137GB
Heiko Schocher4b142fe2009-12-03 11:21:21 +0100861 Also look at CONFIG_SYS_64BIT_LBA.
wdenkc40b2952004-03-13 23:29:43 +0000862 Whithout these , LBA48 support uses 32bit variables and will 'only'
863 support disks up to 2.1TB.
864
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200865 CONFIG_SYS_64BIT_LBA:
wdenkc40b2952004-03-13 23:29:43 +0000866 When enabled, makes the IDE subsystem use 64bit sector addresses.
867 Default is 32bit.
868
wdenkc6097192002-11-03 00:24:07 +0000869- SCSI Support:
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200870 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
871 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
872 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
wdenkc6097192002-11-03 00:24:07 +0000873 maximum numbers of LUNs, SCSI ID's and target
874 devices.
wdenkc6097192002-11-03 00:24:07 +0000875
Wolfgang Denk93e14592013-10-04 17:43:24 +0200876 The environment variable 'scsidevs' is set to the number of
877 SCSI devices found during the last scan.
Stefan Reinauer447c0312012-10-29 05:23:48 +0000878
wdenkc6097192002-11-03 00:24:07 +0000879- NETWORK Support (PCI):
wdenk682011f2003-06-03 23:54:09 +0000880 CONFIG_E1000
Kyle Moffettce5207e2011-10-18 11:05:29 +0000881 Support for Intel 8254x/8257x gigabit chips.
882
883 CONFIG_E1000_SPI
884 Utility code for direct access to the SPI bus on Intel 8257x.
885 This does not do anything useful unless you set at least one
886 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
887
888 CONFIG_E1000_SPI_GENERIC
889 Allow generic access to the SPI bus on the Intel 8257x, for
890 example with the "sspi" command.
891
wdenkc6097192002-11-03 00:24:07 +0000892 CONFIG_EEPRO100
893 Support for Intel 82557/82559/82559ER chips.
Marcel Ziswiler11ccc332008-07-09 08:17:15 +0200894 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
wdenkc6097192002-11-03 00:24:07 +0000895 write routine for first time initialisation.
896
897 CONFIG_TULIP
898 Support for Digital 2114x chips.
899 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
900 modem chip initialisation (KS8761/QS6611).
901
902 CONFIG_NATSEMI
903 Support for National dp83815 chips.
904
905 CONFIG_NS8382X
906 Support for National dp8382[01] gigabit chips.
907
wdenk45219c42003-05-12 21:50:16 +0000908- NETWORK Support (other):
909
Jens Scharsigc041e9d2010-01-23 12:03:45 +0100910 CONFIG_DRIVER_AT91EMAC
911 Support for AT91RM9200 EMAC.
912
913 CONFIG_RMII
914 Define this to use reduced MII inteface
915
916 CONFIG_DRIVER_AT91EMAC_QUIET
917 If this defined, the driver is quiet.
918 The driver doen't show link status messages.
919
Rob Herringefdd7312011-12-15 11:15:49 +0000920 CONFIG_CALXEDA_XGMAC
921 Support for the Calxeda XGMAC device
922
Ashok3bb46d22012-10-15 06:20:47 +0000923 CONFIG_LAN91C96
wdenk45219c42003-05-12 21:50:16 +0000924 Support for SMSC's LAN91C96 chips.
925
wdenk45219c42003-05-12 21:50:16 +0000926 CONFIG_LAN91C96_USE_32_BIT
927 Define this to enable 32 bit addressing
928
Ashok3bb46d22012-10-15 06:20:47 +0000929 CONFIG_SMC91111
wdenkf39748a2004-06-09 13:37:52 +0000930 Support for SMSC's LAN91C111 chip
931
932 CONFIG_SMC91111_BASE
933 Define this to hold the physical address
934 of the device (I/O space)
935
936 CONFIG_SMC_USE_32_BIT
937 Define this if data bus is 32 bits
938
939 CONFIG_SMC_USE_IOFUNCS
940 Define this to use i/o functions instead of macros
941 (some hardware wont work with macros)
942
Heiko Schocherdc02bad2011-11-15 10:00:04 -0500943 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
944 Define this if you have more then 3 PHYs.
945
Macpaul Linb3dbf4a52010-12-21 16:59:46 +0800946 CONFIG_FTGMAC100
947 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
948
949 CONFIG_FTGMAC100_EGIGA
950 Define this to use GE link update with gigabit PHY.
951 Define this if FTGMAC100 is connected to gigabit PHY.
952 If your system has 10/100 PHY only, it might not occur
953 wrong behavior. Because PHY usually return timeout or
954 useless data when polling gigabit status and gigabit
955 control registers. This behavior won't affect the
956 correctnessof 10/100 link speed update.
957
Yoshihiro Shimoda3d0075f2011-01-27 10:06:03 +0900958 CONFIG_SH_ETHER
959 Support for Renesas on-chip Ethernet controller
960
961 CONFIG_SH_ETHER_USE_PORT
962 Define the number of ports to be used
963
964 CONFIG_SH_ETHER_PHY_ADDR
965 Define the ETH PHY's address
966
Yoshihiro Shimoda68260aa2011-01-27 10:06:08 +0900967 CONFIG_SH_ETHER_CACHE_WRITEBACK
968 If this option is set, the driver enables cache flush.
969
Vadim Bendebury5e124722011-10-17 08:36:14 +0000970- TPM Support:
Che-liang Chiou90899cc2013-04-12 11:04:34 +0000971 CONFIG_TPM
972 Support TPM devices.
973
Christophe Ricard0766ad22015-10-06 22:54:41 +0200974 CONFIG_TPM_TIS_INFINEON
975 Support for Infineon i2c bus TPM devices. Only one device
Tom Wai-Hong Tam1b393db2013-04-12 11:04:37 +0000976 per system is supported at this time.
977
Tom Wai-Hong Tam1b393db2013-04-12 11:04:37 +0000978 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
979 Define the burst count bytes upper limit
980
Christophe Ricard3aa74082016-01-21 23:27:13 +0100981 CONFIG_TPM_ST33ZP24
982 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
983
984 CONFIG_TPM_ST33ZP24_I2C
985 Support for STMicroelectronics ST33ZP24 I2C devices.
986 Requires TPM_ST33ZP24 and I2C.
987
Christophe Ricardb75fdc12016-01-21 23:27:14 +0100988 CONFIG_TPM_ST33ZP24_SPI
989 Support for STMicroelectronics ST33ZP24 SPI devices.
990 Requires TPM_ST33ZP24 and SPI.
991
Dirk Eibachc01939c2013-06-26 15:55:15 +0200992 CONFIG_TPM_ATMEL_TWI
993 Support for Atmel TWI TPM device. Requires I2C support.
994
Che-liang Chiou90899cc2013-04-12 11:04:34 +0000995 CONFIG_TPM_TIS_LPC
Vadim Bendebury5e124722011-10-17 08:36:14 +0000996 Support for generic parallel port TPM devices. Only one device
997 per system is supported at this time.
998
999 CONFIG_TPM_TIS_BASE_ADDRESS
1000 Base address where the generic TPM device is mapped
1001 to. Contemporary x86 systems usually map it at
1002 0xfed40000.
1003
Reinhard Pfaube6c1522013-06-26 15:55:13 +02001004 CONFIG_TPM
1005 Define this to enable the TPM support library which provides
1006 functional interfaces to some TPM commands.
1007 Requires support for a TPM device.
1008
1009 CONFIG_TPM_AUTH_SESSIONS
1010 Define this to enable authorized functions in the TPM library.
1011 Requires CONFIG_TPM and CONFIG_SHA1.
1012
wdenkc6097192002-11-03 00:24:07 +00001013- USB Support:
1014 At the moment only the UHCI host controller is
Heiko Schocher064b55c2017-06-14 05:49:40 +02001015 supported (PIP405, MIP405); define
wdenkc6097192002-11-03 00:24:07 +00001016 CONFIG_USB_UHCI to enable it.
1017 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
wdenk30d56fa2004-10-09 22:44:59 +00001018 and define CONFIG_USB_STORAGE to enable the USB
wdenkc6097192002-11-03 00:24:07 +00001019 storage devices.
1020 Note:
1021 Supported are USB Keyboards and USB Floppy drives
1022 (TEAC FD-05PUB).
wdenk4d13cba2004-03-14 14:09:05 +00001023
Simon Glass9ab4ce22012-02-27 10:52:47 +00001024 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1025 txfilltuning field in the EHCI controller on reset.
1026
Oleksandr Tymoshenko6e9e0622014-02-01 21:51:25 -07001027 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1028 HW module registers.
1029
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +02001030- USB Device:
1031 Define the below if you wish to use the USB console.
1032 Once firmware is rebuilt from a serial console issue the
1033 command "setenv stdin usbtty; setenv stdout usbtty" and
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001034 attach your USB cable. The Unix command "dmesg" should print
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +02001035 it has found a new device. The environment variable usbtty
1036 can be set to gserial or cdc_acm to enable your device to
Wolfgang Denk386eda02006-06-14 18:14:56 +02001037 appear to a USB host as a Linux gserial device or a
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +02001038 Common Device Class Abstract Control Model serial device.
1039 If you select usbtty = gserial you should be able to enumerate
1040 a Linux host by
1041 # modprobe usbserial vendor=0xVendorID product=0xProductID
1042 else if using cdc_acm, simply setting the environment
1043 variable usbtty to be cdc_acm should suffice. The following
1044 might be defined in YourBoardName.h
Wolfgang Denk386eda02006-06-14 18:14:56 +02001045
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +02001046 CONFIG_USB_DEVICE
1047 Define this to build a UDC device
wdenkc6097192002-11-03 00:24:07 +00001048
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +02001049 CONFIG_USB_TTY
1050 Define this to have a tty type of device available to
1051 talk to the UDC device
Wolfgang Denk386eda02006-06-14 18:14:56 +02001052
Vipin KUMARf9da0f82012-03-26 15:38:06 +05301053 CONFIG_USBD_HS
1054 Define this to enable the high speed support for usb
1055 device and usbtty. If this feature is enabled, a routine
1056 int is_usbd_high_speed(void)
1057 also needs to be defined by the driver to dynamically poll
1058 whether the enumeration has succeded at high speed or full
1059 speed.
1060
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001061 CONFIG_SYS_CONSOLE_IS_IN_ENV
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +02001062 Define this if you want stdin, stdout &/or stderr to
1063 be set to usbtty.
1064
Wolfgang Denk386eda02006-06-14 18:14:56 +02001065 If you have a USB-IF assigned VendorID then you may wish to
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +02001066 define your own vendor specific values either in BoardName.h
Wolfgang Denk386eda02006-06-14 18:14:56 +02001067 or directly in usbd_vendor_info.h. If you don't define
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +02001068 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1069 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1070 should pretend to be a Linux device to it's target host.
1071
1072 CONFIG_USBD_MANUFACTURER
1073 Define this string as the name of your company for
1074 - CONFIG_USBD_MANUFACTURER "my company"
Wolfgang Denk386eda02006-06-14 18:14:56 +02001075
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +02001076 CONFIG_USBD_PRODUCT_NAME
1077 Define this string as the name of your product
1078 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1079
1080 CONFIG_USBD_VENDORID
1081 Define this as your assigned Vendor ID from the USB
1082 Implementors Forum. This *must* be a genuine Vendor ID
1083 to avoid polluting the USB namespace.
1084 - CONFIG_USBD_VENDORID 0xFFFF
Wolfgang Denk386eda02006-06-14 18:14:56 +02001085
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +02001086 CONFIG_USBD_PRODUCTID
1087 Define this as the unique Product ID
1088 for your device
1089 - CONFIG_USBD_PRODUCTID 0xFFFF
wdenkc6097192002-11-03 00:24:07 +00001090
Igor Grinbergd70a5602011-12-12 12:08:35 +02001091- ULPI Layer Support:
1092 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1093 the generic ULPI layer. The generic layer accesses the ULPI PHY
1094 via the platform viewport, so you need both the genric layer and
1095 the viewport enabled. Currently only Chipidea/ARC based
1096 viewport is supported.
1097 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1098 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
Lucas Stach6d365ea2012-10-01 00:44:35 +02001099 If your ULPI phy needs a different reference clock than the
1100 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1101 the appropriate value in Hz.
wdenkc6097192002-11-03 00:24:07 +00001102
1103- MMC Support:
1104 The MMC controller on the Intel PXA is supported. To
1105 enable this define CONFIG_MMC. The MMC can be
1106 accessed from the boot prompt by mapping the device
1107 to physical memory similar to flash. Command line is
Jon Loeliger602ad3b2007-06-11 19:03:39 -05001108 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1109 the FAT fs. This is enabled with CONFIG_CMD_FAT.
wdenkc6097192002-11-03 00:24:07 +00001110
Yoshihiro Shimodaafb35662011-07-04 22:21:22 +00001111 CONFIG_SH_MMCIF
1112 Support for Renesas on-chip MMCIF controller
1113
1114 CONFIG_SH_MMCIF_ADDR
1115 Define the base address of MMCIF registers
1116
1117 CONFIG_SH_MMCIF_CLK
1118 Define the clock frequency for MMCIF
1119
Tom Rinib3ba6e92013-03-14 05:32:47 +00001120- USB Device Firmware Update (DFU) class support:
Marek Vasutbb4059a2018-02-16 16:41:18 +01001121 CONFIG_DFU_OVER_USB
Tom Rinib3ba6e92013-03-14 05:32:47 +00001122 This enables the USB portion of the DFU USB class
1123
Pantelis Antoniouc6631762013-03-14 05:32:52 +00001124 CONFIG_DFU_NAND
1125 This enables support for exposing NAND devices via DFU.
1126
Afzal Mohammeda9479f02013-09-18 01:15:24 +05301127 CONFIG_DFU_RAM
1128 This enables support for exposing RAM via DFU.
1129 Note: DFU spec refer to non-volatile memory usage, but
1130 allow usages beyond the scope of spec - here RAM usage,
1131 one that would help mostly the developer.
1132
Heiko Schochere7e75c72013-06-12 06:05:51 +02001133 CONFIG_SYS_DFU_DATA_BUF_SIZE
1134 Dfu transfer uses a buffer before writing data to the
1135 raw storage device. Make the size (in bytes) of this buffer
1136 configurable. The size of this buffer is also configurable
1137 through the "dfu_bufsiz" environment variable.
1138
Pantelis Antoniouea2453d2013-03-14 05:32:48 +00001139 CONFIG_SYS_DFU_MAX_FILE_SIZE
1140 When updating files rather than the raw storage device,
1141 we use a static buffer to copy the file into and then write
1142 the buffer once we've been given the whole file. Define
1143 this to the maximum filesize (in bytes) for the buffer.
1144 Default is 4 MiB if undefined.
1145
Heiko Schocher001a8312014-03-18 08:09:56 +01001146 DFU_DEFAULT_POLL_TIMEOUT
1147 Poll timeout [ms], is the timeout a device can send to the
1148 host. The host must wait for this timeout before sending
1149 a subsequent DFU_GET_STATUS request to the device.
1150
1151 DFU_MANIFEST_POLL_TIMEOUT
1152 Poll timeout [ms], which the device sends to the host when
1153 entering dfuMANIFEST state. Host waits this timeout, before
1154 sending again an USB request to the device.
1155
wdenk6705d812004-08-02 23:22:59 +00001156- Journaling Flash filesystem support:
Simon Glassb2482df2016-10-02 18:00:59 -06001157 CONFIG_JFFS2_NAND
wdenk6705d812004-08-02 23:22:59 +00001158 Define these for a default partition on a NAND device
1159
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001160 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1161 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
wdenk6705d812004-08-02 23:22:59 +00001162 Define these for a default partition on a NOR device
1163
wdenkc6097192002-11-03 00:24:07 +00001164- Keyboard Support:
Simon Glass39f615e2015-11-11 10:05:47 -07001165 See Kconfig help for available keyboard drivers.
1166
1167 CONFIG_KEYBOARD
1168
1169 Define this to enable a custom keyboard support.
1170 This simply calls drv_keyboard_init() which must be
1171 defined in your board-specific files. This option is deprecated
1172 and is only used by novena. For new boards, use driver model
1173 instead.
wdenkc6097192002-11-03 00:24:07 +00001174
1175- Video support:
Timur Tabi7d3053f2011-02-15 17:09:19 -06001176 CONFIG_FSL_DIU_FB
Wolfgang Denk04e5ae72011-09-11 21:24:09 +02001177 Enable the Freescale DIU video driver. Reference boards for
Timur Tabi7d3053f2011-02-15 17:09:19 -06001178 SOCs that have a DIU should define this macro to enable DIU
1179 support, and should also define these other macros:
1180
1181 CONFIG_SYS_DIU_ADDR
1182 CONFIG_VIDEO
Timur Tabi7d3053f2011-02-15 17:09:19 -06001183 CONFIG_CFB_CONSOLE
1184 CONFIG_VIDEO_SW_CURSOR
1185 CONFIG_VGA_AS_SINGLE_DEVICE
1186 CONFIG_VIDEO_LOGO
1187 CONFIG_VIDEO_BMP_LOGO
1188
Timur Tabiba8e76b2011-04-11 14:18:22 -05001189 The DIU driver will look for the 'video-mode' environment
1190 variable, and if defined, enable the DIU as a console during
Fabio Estevam8eca9432016-04-02 11:53:18 -03001191 boot. See the documentation file doc/README.video for a
Timur Tabiba8e76b2011-04-11 14:18:22 -05001192 description of this variable.
Timur Tabi7d3053f2011-02-15 17:09:19 -06001193
wdenkc6097192002-11-03 00:24:07 +00001194- LCD Support: CONFIG_LCD
1195
1196 Define this to enable LCD support (for output to LCD
1197 display); also select one of the supported displays
1198 by defining one of these:
1199
Stelian Pop39cf4802008-05-09 21:57:18 +02001200 CONFIG_ATMEL_LCD:
1201
1202 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1203
wdenkfd3103b2003-11-25 16:55:19 +00001204 CONFIG_NEC_NL6448AC33:
wdenkc6097192002-11-03 00:24:07 +00001205
wdenkfd3103b2003-11-25 16:55:19 +00001206 NEC NL6448AC33-18. Active, color, single scan.
wdenkc6097192002-11-03 00:24:07 +00001207
wdenkfd3103b2003-11-25 16:55:19 +00001208 CONFIG_NEC_NL6448BC20
wdenkc6097192002-11-03 00:24:07 +00001209
wdenkfd3103b2003-11-25 16:55:19 +00001210 NEC NL6448BC20-08. 6.5", 640x480.
1211 Active, color, single scan.
1212
1213 CONFIG_NEC_NL6448BC33_54
1214
1215 NEC NL6448BC33-54. 10.4", 640x480.
wdenkc6097192002-11-03 00:24:07 +00001216 Active, color, single scan.
1217
1218 CONFIG_SHARP_16x9
1219
1220 Sharp 320x240. Active, color, single scan.
1221 It isn't 16x9, and I am not sure what it is.
1222
1223 CONFIG_SHARP_LQ64D341
1224
1225 Sharp LQ64D341 display, 640x480.
1226 Active, color, single scan.
1227
1228 CONFIG_HLD1045
1229
1230 HLD1045 display, 640x480.
1231 Active, color, single scan.
1232
1233 CONFIG_OPTREX_BW
1234
1235 Optrex CBL50840-2 NF-FW 99 22 M5
1236 or
1237 Hitachi LMG6912RPFC-00T
1238 or
1239 Hitachi SP14Q002
1240
1241 320x240. Black & white.
1242
Simon Glass676d3192012-10-17 13:24:54 +00001243 CONFIG_LCD_ALIGNMENT
1244
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001245 Normally the LCD is page-aligned (typically 4KB). If this is
Simon Glass676d3192012-10-17 13:24:54 +00001246 defined then the LCD will be aligned to this value instead.
1247 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1248 here, since it is cheaper to change data cache settings on
1249 a per-section basis.
1250
1251
Hannes Petermaier604c7d42015-03-27 08:01:38 +01001252 CONFIG_LCD_ROTATION
1253
1254 Sometimes, for example if the display is mounted in portrait
1255 mode or even if it's mounted landscape but rotated by 180degree,
1256 we need to rotate our content of the display relative to the
1257 framebuffer, so that user can read the messages which are
1258 printed out.
1259 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1260 initialized with a given rotation from "vl_rot" out of
1261 "vidinfo_t" which is provided by the board specific code.
1262 The value for vl_rot is coded as following (matching to
1263 fbcon=rotate:<n> linux-kernel commandline):
1264 0 = no rotation respectively 0 degree
1265 1 = 90 degree rotation
1266 2 = 180 degree rotation
1267 3 = 270 degree rotation
1268
1269 If CONFIG_LCD_ROTATION is not defined, the console will be
1270 initialized with 0degree rotation.
1271
Tom Wai-Hong Tam45d7f522012-09-28 15:11:16 +00001272 CONFIG_LCD_BMP_RLE8
1273
1274 Support drawing of RLE8-compressed bitmaps on the LCD.
1275
Tom Wai-Hong Tam735987c2012-12-05 14:46:40 +00001276 CONFIG_I2C_EDID
1277
1278 Enables an 'i2c edid' command which can read EDID
1279 information over I2C from an attached LCD display.
1280
wdenk7152b1d2003-09-05 23:19:14 +00001281- Splash Screen Support: CONFIG_SPLASH_SCREEN
wdenkd791b1d2003-04-20 14:04:18 +00001282
wdenk8bde7f72003-06-27 21:31:46 +00001283 If this option is set, the environment is checked for
1284 a variable "splashimage". If found, the usual display
1285 of logo, copyright and system information on the LCD
wdenke94d2cd2004-06-30 22:59:18 +00001286 is suppressed and the BMP image at the address
wdenk8bde7f72003-06-27 21:31:46 +00001287 specified in "splashimage" is loaded instead. The
1288 console is redirected to the "nulldev", too. This
1289 allows for a "silent" boot where a splash screen is
1290 loaded very quickly after power-on.
wdenkd791b1d2003-04-20 14:04:18 +00001291
Nikita Kiryanovc0880482013-02-24 21:28:43 +00001292 CONFIG_SPLASHIMAGE_GUARD
1293
1294 If this option is set, then U-Boot will prevent the environment
1295 variable "splashimage" from being set to a problematic address
Fabio Estevamab5645f2016-03-23 12:46:12 -03001296 (see doc/README.displaying-bmps).
Nikita Kiryanovc0880482013-02-24 21:28:43 +00001297 This option is useful for targets where, due to alignment
1298 restrictions, an improperly aligned BMP image will cause a data
1299 abort. If you think you will not have problems with unaligned
1300 accesses (for example because your toolchain prevents them)
1301 there is no need to set this option.
1302
Matthias Weisser1ca298c2009-07-09 16:07:30 +02001303 CONFIG_SPLASH_SCREEN_ALIGN
1304
1305 If this option is set the splash image can be freely positioned
1306 on the screen. Environment variable "splashpos" specifies the
1307 position as "x,y". If a positive number is given it is used as
1308 number of pixel from left/top. If a negative number is given it
1309 is used as number of pixel from right/bottom. You can also
1310 specify 'm' for centering the image.
1311
1312 Example:
1313 setenv splashpos m,m
1314 => image at center of screen
1315
1316 setenv splashpos 30,20
1317 => image at x = 30 and y = 20
1318
1319 setenv splashpos -10,m
1320 => vertically centered image
1321 at x = dspWidth - bmpWidth - 9
1322
Stefan Roese98f4a3d2005-09-22 09:04:17 +02001323- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1324
1325 If this option is set, additionally to standard BMP
1326 images, gzipped BMP images can be displayed via the
1327 splashscreen support or the bmp command.
1328
Anatolij Gustschind5011762010-03-15 14:50:25 +01001329- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1330
1331 If this option is set, 8-bit RLE compressed BMP images
1332 can be displayed via the splashscreen support or the
1333 bmp command.
1334
wdenkc29fdfc2003-08-29 20:57:53 +00001335- Compression support:
Kees Cook8ef70472013-08-16 07:59:12 -07001336 CONFIG_GZIP
1337
1338 Enabled by default to support gzip compressed images.
1339
wdenkc29fdfc2003-08-29 20:57:53 +00001340 CONFIG_BZIP2
1341
1342 If this option is set, support for bzip2 compressed
1343 images is included. If not, only uncompressed and gzip
1344 compressed images are supported.
1345
wdenk42d1f032003-10-15 23:53:47 +00001346 NOTE: the bzip2 algorithm requires a lot of RAM, so
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001347 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
wdenk42d1f032003-10-15 23:53:47 +00001348 be at least 4MB.
wdenkd791b1d2003-04-20 14:04:18 +00001349
wdenk17ea1172004-06-06 21:51:03 +00001350- MII/PHY support:
wdenk17ea1172004-06-06 21:51:03 +00001351 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1352
1353 The clock frequency of the MII bus
1354
wdenk17ea1172004-06-06 21:51:03 +00001355 CONFIG_PHY_RESET_DELAY
1356
1357 Some PHY like Intel LXT971A need extra delay after
1358 reset before any MII register access is possible.
1359 For such PHY, set this option to the usec delay
1360 required. (minimum 300usec for LXT971A)
1361
1362 CONFIG_PHY_CMD_DELAY (ppc4xx)
1363
1364 Some PHY like Intel LXT971A need extra delay after
1365 command issued before MII status register can be read
1366
wdenkc6097192002-11-03 00:24:07 +00001367- IP address:
1368 CONFIG_IPADDR
1369
1370 Define a default value for the IP address to use for
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001371 the default Ethernet interface, in case this is not
wdenkc6097192002-11-03 00:24:07 +00001372 determined through e.g. bootp.
Wolfgang Denk1ebcd652011-10-26 10:21:22 +00001373 (Environment variable "ipaddr")
wdenkc6097192002-11-03 00:24:07 +00001374
1375- Server IP address:
1376 CONFIG_SERVERIP
1377
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001378 Defines a default value for the IP address of a TFTP
wdenkc6097192002-11-03 00:24:07 +00001379 server to contact when using the "tftboot" command.
Wolfgang Denk1ebcd652011-10-26 10:21:22 +00001380 (Environment variable "serverip")
wdenkc6097192002-11-03 00:24:07 +00001381
Robin Getz97cfe862009-07-21 12:15:28 -04001382 CONFIG_KEEP_SERVERADDR
1383
1384 Keeps the server's MAC address, in the env 'serveraddr'
1385 for passing to bootargs (like Linux's netconsole option)
1386
Wolfgang Denk1ebcd652011-10-26 10:21:22 +00001387- Gateway IP address:
1388 CONFIG_GATEWAYIP
1389
1390 Defines a default value for the IP address of the
1391 default router where packets to other networks are
1392 sent to.
1393 (Environment variable "gatewayip")
1394
1395- Subnet mask:
1396 CONFIG_NETMASK
1397
1398 Defines a default value for the subnet mask (or
1399 routing prefix) which is used to determine if an IP
1400 address belongs to the local subnet or needs to be
1401 forwarded through a router.
1402 (Environment variable "netmask")
1403
wdenkc6097192002-11-03 00:24:07 +00001404- BOOTP Recovery Mode:
1405 CONFIG_BOOTP_RANDOM_DELAY
1406
1407 If you have many targets in a network that try to
1408 boot using BOOTP, you may want to avoid that all
1409 systems send out BOOTP requests at precisely the same
1410 moment (which would happen for instance at recovery
1411 from a power failure, when all systems will try to
1412 boot, thus flooding the BOOTP server. Defining
1413 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1414 inserted before sending out BOOTP requests. The
Wolfgang Denk6c33c782007-08-06 23:21:05 +02001415 following delays are inserted then:
wdenkc6097192002-11-03 00:24:07 +00001416
1417 1st BOOTP request: delay 0 ... 1 sec
1418 2nd BOOTP request: delay 0 ... 2 sec
1419 3rd BOOTP request: delay 0 ... 4 sec
1420 4th and following
1421 BOOTP requests: delay 0 ... 8 sec
1422
Thierry Reding92ac8ac2014-08-19 10:21:24 +02001423 CONFIG_BOOTP_ID_CACHE_SIZE
1424
1425 BOOTP packets are uniquely identified using a 32-bit ID. The
1426 server will copy the ID from client requests to responses and
1427 U-Boot will use this to determine if it is the destination of
1428 an incoming response. Some servers will check that addresses
1429 aren't in use before handing them out (usually using an ARP
1430 ping) and therefore take up to a few hundred milliseconds to
1431 respond. Network congestion may also influence the time it
1432 takes for a response to make it back to the client. If that
1433 time is too long, U-Boot will retransmit requests. In order
1434 to allow earlier responses to still be accepted after these
1435 retransmissions, U-Boot's BOOTP client keeps a small cache of
1436 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
1437 cache. The default is to keep IDs for up to four outstanding
1438 requests. Increasing this will allow U-Boot to accept offers
1439 from a BOOTP client in networks with unusually high latency.
1440
stroesefe389a82003-08-28 14:17:32 +00001441- DHCP Advanced Options:
Jon Loeliger1fe80d72007-07-09 22:08:34 -05001442 You can fine tune the DHCP functionality by defining
1443 CONFIG_BOOTP_* symbols:
stroesefe389a82003-08-28 14:17:32 +00001444
Jon Loeliger1fe80d72007-07-09 22:08:34 -05001445 CONFIG_BOOTP_NISDOMAIN
Jon Loeliger1fe80d72007-07-09 22:08:34 -05001446 CONFIG_BOOTP_BOOTFILESIZE
Jon Loeliger1fe80d72007-07-09 22:08:34 -05001447 CONFIG_BOOTP_SEND_HOSTNAME
1448 CONFIG_BOOTP_NTPSERVER
1449 CONFIG_BOOTP_TIMEOFFSET
1450 CONFIG_BOOTP_VENDOREX
Joe Hershberger2c00e092012-05-23 07:59:19 +00001451 CONFIG_BOOTP_MAY_FAIL
stroesefe389a82003-08-28 14:17:32 +00001452
Wilson Callan5d110f02007-07-28 10:56:13 -04001453 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1454 environment variable, not the BOOTP server.
stroesefe389a82003-08-28 14:17:32 +00001455
Joe Hershberger2c00e092012-05-23 07:59:19 +00001456 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1457 after the configured retry count, the call will fail
1458 instead of starting over. This can be used to fail over
1459 to Link-local IP address configuration if the DHCP server
1460 is not available.
1461
stroesefe389a82003-08-28 14:17:32 +00001462 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1463 to do a dynamic update of a DNS server. To do this, they
1464 need the hostname of the DHCP requester.
Wilson Callan5d110f02007-07-28 10:56:13 -04001465 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
Jon Loeliger1fe80d72007-07-09 22:08:34 -05001466 of the "hostname" environment variable is passed as
1467 option 12 to the DHCP server.
stroesefe389a82003-08-28 14:17:32 +00001468
Aras Vaichasd9a2f412008-03-26 09:43:57 +11001469 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1470
1471 A 32bit value in microseconds for a delay between
1472 receiving a "DHCP Offer" and sending the "DHCP Request".
1473 This fixes a problem with certain DHCP servers that don't
1474 respond 100% of the time to a "DHCP request". E.g. On an
1475 AT91RM9200 processor running at 180MHz, this delay needed
1476 to be *at least* 15,000 usec before a Windows Server 2003
1477 DHCP server would reply 100% of the time. I recommend at
1478 least 50,000 usec to be safe. The alternative is to hope
1479 that one of the retries will be successful but note that
1480 the DHCP timeout and retry process takes a longer than
1481 this delay.
1482
Joe Hershbergerd22c3382012-05-23 08:00:12 +00001483 - Link-local IP address negotiation:
1484 Negotiate with other link-local clients on the local network
1485 for an address that doesn't require explicit configuration.
1486 This is especially useful if a DHCP server cannot be guaranteed
1487 to exist in all environments that the device must operate.
1488
1489 See doc/README.link-local for more information.
1490
Prabhakar Kushwaha24acb832017-11-23 16:51:32 +05301491 - MAC address from environment variables
1492
1493 FDT_SEQ_MACADDR_FROM_ENV
1494
1495 Fix-up device tree with MAC addresses fetched sequentially from
1496 environment variables. This config work on assumption that
1497 non-usable ethernet node of device-tree are either not present
1498 or their status has been marked as "disabled".
1499
wdenka3d991b2004-04-15 21:48:45 +00001500 - CDP Options:
wdenk6e592382004-04-18 17:39:38 +00001501 CONFIG_CDP_DEVICE_ID
wdenka3d991b2004-04-15 21:48:45 +00001502
1503 The device id used in CDP trigger frames.
1504
1505 CONFIG_CDP_DEVICE_ID_PREFIX
1506
1507 A two character string which is prefixed to the MAC address
1508 of the device.
1509
1510 CONFIG_CDP_PORT_ID
1511
1512 A printf format string which contains the ascii name of
1513 the port. Normally is set to "eth%d" which sets
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001514 eth0 for the first Ethernet, eth1 for the second etc.
wdenka3d991b2004-04-15 21:48:45 +00001515
1516 CONFIG_CDP_CAPABILITIES
1517
1518 A 32bit integer which indicates the device capabilities;
1519 0x00000010 for a normal host which does not forwards.
1520
1521 CONFIG_CDP_VERSION
1522
1523 An ascii string containing the version of the software.
1524
1525 CONFIG_CDP_PLATFORM
1526
1527 An ascii string containing the name of the platform.
1528
1529 CONFIG_CDP_TRIGGER
1530
1531 A 32bit integer sent on the trigger.
1532
1533 CONFIG_CDP_POWER_CONSUMPTION
1534
1535 A 16bit integer containing the power consumption of the
1536 device in .1 of milliwatts.
1537
1538 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1539
1540 A byte containing the id of the VLAN.
1541
Uri Mashiach79267ed2017-01-19 10:51:05 +02001542- Status LED: CONFIG_LED_STATUS
wdenkc6097192002-11-03 00:24:07 +00001543
1544 Several configurations allow to display the current
1545 status using a LED. For instance, the LED will blink
1546 fast while running U-Boot code, stop blinking as
1547 soon as a reply to a BOOTP request was received, and
1548 start blinking slow once the Linux kernel is running
1549 (supported by a status LED driver in the Linux
Uri Mashiach79267ed2017-01-19 10:51:05 +02001550 kernel). Defining CONFIG_LED_STATUS enables this
wdenkc6097192002-11-03 00:24:07 +00001551 feature in U-Boot.
1552
Igor Grinberg1df7bbb2013-11-08 01:03:50 +02001553 Additional options:
1554
Uri Mashiach79267ed2017-01-19 10:51:05 +02001555 CONFIG_LED_STATUS_GPIO
Igor Grinberg1df7bbb2013-11-08 01:03:50 +02001556 The status LED can be connected to a GPIO pin.
1557 In such cases, the gpio_led driver can be used as a
Uri Mashiach79267ed2017-01-19 10:51:05 +02001558 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO
Igor Grinberg1df7bbb2013-11-08 01:03:50 +02001559 to include the gpio_led driver in the U-Boot binary.
1560
Igor Grinberg9dfdcdf2013-11-08 01:03:52 +02001561 CONFIG_GPIO_LED_INVERTED_TABLE
1562 Some GPIO connected LEDs may have inverted polarity in which
1563 case the GPIO high value corresponds to LED off state and
1564 GPIO low value corresponds to LED on state.
1565 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
1566 with a list of GPIO LEDs that have inverted polarity.
1567
Heiko Schocher3f4978c2012-01-16 21:12:24 +00001568- I2C Support: CONFIG_SYS_I2C
wdenkc6097192002-11-03 00:24:07 +00001569
Heiko Schocher3f4978c2012-01-16 21:12:24 +00001570 This enable the NEW i2c subsystem, and will allow you to use
1571 i2c commands at the u-boot command line (as long as you set
1572 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
1573 based realtime clock chips or other i2c devices. See
1574 common/cmd_i2c.c for a description of the command line
1575 interface.
1576
1577 ported i2c driver to the new framework:
Heiko Schocherea818db2013-01-29 08:53:15 +01001578 - drivers/i2c/soft_i2c.c:
1579 - activate first bus with CONFIG_SYS_I2C_SOFT define
1580 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
1581 for defining speed and slave address
1582 - activate second bus with I2C_SOFT_DECLARATIONS2 define
1583 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
1584 for defining speed and slave address
1585 - activate third bus with I2C_SOFT_DECLARATIONS3 define
1586 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
1587 for defining speed and slave address
1588 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
1589 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
1590 for defining speed and slave address
Heiko Schocher3f4978c2012-01-16 21:12:24 +00001591
Heiko Schocher00f792e2012-10-24 13:48:22 +02001592 - drivers/i2c/fsl_i2c.c:
1593 - activate i2c driver with CONFIG_SYS_I2C_FSL
1594 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
1595 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
1596 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
1597 bus.
Wolfgang Denk93e14592013-10-04 17:43:24 +02001598 - If your board supports a second fsl i2c bus, define
Heiko Schocher00f792e2012-10-24 13:48:22 +02001599 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
1600 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
1601 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
1602 second bus.
1603
Simon Glass1f2ba722012-10-30 07:28:53 +00001604 - drivers/i2c/tegra_i2c.c:
Nobuhiro Iwamatsu10cee512013-10-11 16:23:53 +09001605 - activate this driver with CONFIG_SYS_I2C_TEGRA
1606 - This driver adds 4 i2c buses with a fix speed from
1607 100000 and the slave addr 0!
Simon Glass1f2ba722012-10-30 07:28:53 +00001608
Dirk Eibach880540d2013-04-25 02:40:01 +00001609 - drivers/i2c/ppc4xx_i2c.c
1610 - activate this driver with CONFIG_SYS_I2C_PPC4XX
1611 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
1612 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
1613
tremfac96402013-09-21 18:13:35 +02001614 - drivers/i2c/i2c_mxc.c
1615 - activate this driver with CONFIG_SYS_I2C_MXC
Albert ARIBAUD \\(3ADEV\\)03544c62015-09-21 22:43:38 +02001616 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
1617 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
1618 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
1619 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
tremfac96402013-09-21 18:13:35 +02001620 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
1621 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
1622 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
1623 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
1624 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
1625 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
Albert ARIBAUD \\(3ADEV\\)03544c62015-09-21 22:43:38 +02001626 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
1627 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001628 If those defines are not set, default value is 100000
tremfac96402013-09-21 18:13:35 +02001629 for speed, and 0 for slave.
1630
Nobuhiro Iwamatsu1086bfa2013-09-27 16:58:30 +09001631 - drivers/i2c/rcar_i2c.c:
1632 - activate this driver with CONFIG_SYS_I2C_RCAR
1633 - This driver adds 4 i2c buses
1634
1635 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
1636 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
1637 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
1638 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
1639 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
1640 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
1641 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
1642 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
1643 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
1644
Nobuhiro Iwamatsu2035d772013-10-29 13:33:51 +09001645 - drivers/i2c/sh_i2c.c:
1646 - activate this driver with CONFIG_SYS_I2C_SH
1647 - This driver adds from 2 to 5 i2c buses
1648
1649 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
1650 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
1651 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
1652 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
1653 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
1654 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
1655 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
1656 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
1657 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
1658 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001659 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
Nobuhiro Iwamatsu2035d772013-10-29 13:33:51 +09001660
Heiko Schocher6789e842013-10-22 11:03:18 +02001661 - drivers/i2c/omap24xx_i2c.c
1662 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
1663 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
1664 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
1665 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
1666 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
1667 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
1668 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
1669 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
1670 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
1671 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
1672 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
1673
Naveen Krishna Che717fc62013-12-06 12:12:38 +05301674 - drivers/i2c/s3c24x0_i2c.c:
1675 - activate this driver with CONFIG_SYS_I2C_S3C24X0
1676 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
1677 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
1678 with a fix speed from 100000 and the slave addr 0!
1679
Dirk Eibachb46226b2014-07-03 09:28:18 +02001680 - drivers/i2c/ihs_i2c.c
1681 - activate this driver with CONFIG_SYS_I2C_IHS
1682 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
1683 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
1684 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
1685 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
1686 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
1687 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
1688 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
1689 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
1690 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
1691 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
1692 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
1693 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
Dirk Eibach071be892015-10-28 11:46:22 +01001694 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
1695 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
1696 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
1697 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
1698 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
1699 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
1700 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
1701 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
1702 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
Dirk Eibachb46226b2014-07-03 09:28:18 +02001703
Heiko Schocher3f4978c2012-01-16 21:12:24 +00001704 additional defines:
1705
1706 CONFIG_SYS_NUM_I2C_BUSES
Simon Glass945a18e2016-10-02 18:01:05 -06001707 Hold the number of i2c buses you want to use.
Heiko Schocher3f4978c2012-01-16 21:12:24 +00001708
1709 CONFIG_SYS_I2C_DIRECT_BUS
1710 define this, if you don't use i2c muxes on your hardware.
1711 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
1712 omit this define.
1713
1714 CONFIG_SYS_I2C_MAX_HOPS
1715 define how many muxes are maximal consecutively connected
1716 on one i2c bus. If you not use i2c muxes, omit this
1717 define.
1718
1719 CONFIG_SYS_I2C_BUSES
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001720 hold a list of buses you want to use, only used if
Heiko Schocher3f4978c2012-01-16 21:12:24 +00001721 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
1722 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
1723 CONFIG_SYS_NUM_I2C_BUSES = 9:
1724
1725 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
1726 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
1727 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
1728 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
1729 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
1730 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
1731 {1, {I2C_NULL_HOP}}, \
1732 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
1733 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
1734 }
1735
1736 which defines
1737 bus 0 on adapter 0 without a mux
Heiko Schocherea818db2013-01-29 08:53:15 +01001738 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
1739 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
1740 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
1741 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
1742 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
Heiko Schocher3f4978c2012-01-16 21:12:24 +00001743 bus 6 on adapter 1 without a mux
Heiko Schocherea818db2013-01-29 08:53:15 +01001744 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
1745 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
Heiko Schocher3f4978c2012-01-16 21:12:24 +00001746
1747 If you do not have i2c muxes on your board, omit this define.
1748
Simon Glassce3b5d62017-05-12 21:10:00 -06001749- Legacy I2C Support:
Heiko Schocherea818db2013-01-29 08:53:15 +01001750 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
wdenkb37c7e52003-06-30 16:24:52 +00001751 then the following macros need to be defined (examples are
1752 from include/configs/lwmon.h):
wdenkc6097192002-11-03 00:24:07 +00001753
1754 I2C_INIT
1755
wdenkb37c7e52003-06-30 16:24:52 +00001756 (Optional). Any commands necessary to enable the I2C
wdenk43d96162003-03-06 00:02:04 +00001757 controller or configure ports.
wdenkc6097192002-11-03 00:24:07 +00001758
wdenkba56f622004-02-06 23:19:44 +00001759 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
wdenkb37c7e52003-06-30 16:24:52 +00001760
wdenkc6097192002-11-03 00:24:07 +00001761 I2C_ACTIVE
1762
1763 The code necessary to make the I2C data line active
1764 (driven). If the data line is open collector, this
1765 define can be null.
1766
wdenkb37c7e52003-06-30 16:24:52 +00001767 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1768
wdenkc6097192002-11-03 00:24:07 +00001769 I2C_TRISTATE
1770
1771 The code necessary to make the I2C data line tri-stated
1772 (inactive). If the data line is open collector, this
1773 define can be null.
1774
wdenkb37c7e52003-06-30 16:24:52 +00001775 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1776
wdenkc6097192002-11-03 00:24:07 +00001777 I2C_READ
1778
York Sun472d5462013-04-01 11:29:11 -07001779 Code that returns true if the I2C data line is high,
1780 false if it is low.
wdenkc6097192002-11-03 00:24:07 +00001781
wdenkb37c7e52003-06-30 16:24:52 +00001782 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1783
wdenkc6097192002-11-03 00:24:07 +00001784 I2C_SDA(bit)
1785
York Sun472d5462013-04-01 11:29:11 -07001786 If <bit> is true, sets the I2C data line high. If it
1787 is false, it clears it (low).
wdenkc6097192002-11-03 00:24:07 +00001788
wdenkb37c7e52003-06-30 16:24:52 +00001789 eg: #define I2C_SDA(bit) \
wdenk2535d602003-07-17 23:16:40 +00001790 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
wdenkba56f622004-02-06 23:19:44 +00001791 else immr->im_cpm.cp_pbdat &= ~PB_SDA
wdenkb37c7e52003-06-30 16:24:52 +00001792
wdenkc6097192002-11-03 00:24:07 +00001793 I2C_SCL(bit)
1794
York Sun472d5462013-04-01 11:29:11 -07001795 If <bit> is true, sets the I2C clock line high. If it
1796 is false, it clears it (low).
wdenkc6097192002-11-03 00:24:07 +00001797
wdenkb37c7e52003-06-30 16:24:52 +00001798 eg: #define I2C_SCL(bit) \
wdenk2535d602003-07-17 23:16:40 +00001799 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
wdenkba56f622004-02-06 23:19:44 +00001800 else immr->im_cpm.cp_pbdat &= ~PB_SCL
wdenkb37c7e52003-06-30 16:24:52 +00001801
wdenkc6097192002-11-03 00:24:07 +00001802 I2C_DELAY
1803
1804 This delay is invoked four times per clock cycle so this
1805 controls the rate of data transfer. The data rate thus
wdenkb37c7e52003-06-30 16:24:52 +00001806 is 1 / (I2C_DELAY * 4). Often defined to be something
wdenk945af8d2003-07-16 21:53:01 +00001807 like:
1808
wdenkb37c7e52003-06-30 16:24:52 +00001809 #define I2C_DELAY udelay(2)
wdenkc6097192002-11-03 00:24:07 +00001810
Mike Frysinger793b5722010-07-21 13:38:02 -04001811 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1812
1813 If your arch supports the generic GPIO framework (asm/gpio.h),
1814 then you may alternatively define the two GPIOs that are to be
1815 used as SCL / SDA. Any of the previous I2C_xxx macros will
1816 have GPIO-based defaults assigned to them as appropriate.
1817
1818 You should define these to the GPIO value as given directly to
1819 the generic GPIO functions.
1820
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001821 CONFIG_SYS_I2C_INIT_BOARD
wdenk47cd00f2003-03-06 13:39:27 +00001822
wdenk8bde7f72003-06-27 21:31:46 +00001823 When a board is reset during an i2c bus transfer
1824 chips might think that the current transfer is still
1825 in progress. On some boards it is possible to access
1826 the i2c SCLK line directly, either by using the
1827 processor pin as a GPIO or by having a second pin
1828 connected to the bus. If this option is defined a
1829 custom i2c_init_board() routine in boards/xxx/board.c
1830 is run early in the boot sequence.
wdenk47cd00f2003-03-06 13:39:27 +00001831
Ben Warrenbb99ad62006-09-07 16:50:54 -04001832 CONFIG_I2C_MULTI_BUS
1833
1834 This option allows the use of multiple I2C buses, each of which
Wolfgang Denkc0f40852011-10-26 10:21:21 +00001835 must have a controller. At any point in time, only one bus is
1836 active. To switch to a different bus, use the 'i2c dev' command.
Ben Warrenbb99ad62006-09-07 16:50:54 -04001837 Note that bus numbering is zero-based.
1838
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001839 CONFIG_SYS_I2C_NOPROBES
Ben Warrenbb99ad62006-09-07 16:50:54 -04001840
1841 This option specifies a list of I2C devices that will be skipped
Wolfgang Denkc0f40852011-10-26 10:21:21 +00001842 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
Peter Tyser0f89c542009-04-18 22:34:03 -05001843 is set, specify a list of bus-device pairs. Otherwise, specify
1844 a 1D array of device addresses
Ben Warrenbb99ad62006-09-07 16:50:54 -04001845
1846 e.g.
1847 #undef CONFIG_I2C_MULTI_BUS
Wolfgang Denkc0f40852011-10-26 10:21:21 +00001848 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
Ben Warrenbb99ad62006-09-07 16:50:54 -04001849
1850 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1851
Wolfgang Denkc0f40852011-10-26 10:21:21 +00001852 #define CONFIG_I2C_MULTI_BUS
Simon Glass945a18e2016-10-02 18:01:05 -06001853 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
Ben Warrenbb99ad62006-09-07 16:50:54 -04001854
1855 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1856
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001857 CONFIG_SYS_SPD_BUS_NUM
Timur Tabibe5e6182006-11-03 19:15:00 -06001858
1859 If defined, then this indicates the I2C bus number for DDR SPD.
1860 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1861
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001862 CONFIG_SYS_RTC_BUS_NUM
Stefan Roese0dc018e2007-02-20 10:51:26 +01001863
1864 If defined, then this indicates the I2C bus number for the RTC.
1865 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1866
Andrew Dyer2ac69852008-12-29 17:36:01 -06001867 CONFIG_SOFT_I2C_READ_REPEATED_START
1868
1869 defining this will force the i2c_read() function in
1870 the soft_i2c driver to perform an I2C repeated start
1871 between writing the address pointer and reading the
1872 data. If this define is omitted the default behaviour
1873 of doing a stop-start sequence will be used. Most I2C
1874 devices can use either method, but some require one or
1875 the other.
Timur Tabibe5e6182006-11-03 19:15:00 -06001876
wdenkc6097192002-11-03 00:24:07 +00001877- SPI Support: CONFIG_SPI
1878
1879 Enables SPI driver (so far only tested with
1880 SPI EEPROM, also an instance works with Crystal A/D and
1881 D/As on the SACSng board)
1882
wdenkc6097192002-11-03 00:24:07 +00001883 CONFIG_SOFT_SPI
1884
wdenk43d96162003-03-06 00:02:04 +00001885 Enables a software (bit-bang) SPI driver rather than
1886 using hardware support. This is a general purpose
1887 driver that only requires three general I/O port pins
1888 (two outputs, one input) to function. If this is
1889 defined, the board configuration must define several
1890 SPI configuration items (port pins to use, etc). For
1891 an example, see include/configs/sacsng.h.
wdenkc6097192002-11-03 00:24:07 +00001892
Heiko Schocherf659b572014-07-14 10:22:11 +02001893 CONFIG_SYS_SPI_MXC_WAIT
1894 Timeout for waiting until spi transfer completed.
1895 default: (CONFIG_SYS_HZ/100) /* 10 ms */
1896
Matthias Fuchs01335022007-12-27 17:12:34 +01001897- FPGA Support: CONFIG_FPGA
1898
1899 Enables FPGA subsystem.
1900
1901 CONFIG_FPGA_<vendor>
1902
1903 Enables support for specific chip vendors.
1904 (ALTERA, XILINX)
1905
1906 CONFIG_FPGA_<family>
1907
1908 Enables support for FPGA family.
1909 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1910
1911 CONFIG_FPGA_COUNT
wdenkc6097192002-11-03 00:24:07 +00001912
wdenk43d96162003-03-06 00:02:04 +00001913 Specify the number of FPGA devices to support.
wdenkc6097192002-11-03 00:24:07 +00001914
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001915 CONFIG_SYS_FPGA_PROG_FEEDBACK
wdenkc6097192002-11-03 00:24:07 +00001916
wdenk8bde7f72003-06-27 21:31:46 +00001917 Enable printing of hash marks during FPGA configuration.
wdenkc6097192002-11-03 00:24:07 +00001918
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001919 CONFIG_SYS_FPGA_CHECK_BUSY
wdenkc6097192002-11-03 00:24:07 +00001920
wdenk43d96162003-03-06 00:02:04 +00001921 Enable checks on FPGA configuration interface busy
1922 status by the configuration function. This option
1923 will require a board or device specific function to
1924 be written.
wdenkc6097192002-11-03 00:24:07 +00001925
1926 CONFIG_FPGA_DELAY
1927
1928 If defined, a function that provides delays in the FPGA
1929 configuration driver.
1930
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001931 CONFIG_SYS_FPGA_CHECK_CTRLC
wdenkc6097192002-11-03 00:24:07 +00001932 Allow Control-C to interrupt FPGA configuration
1933
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001934 CONFIG_SYS_FPGA_CHECK_ERROR
wdenkc6097192002-11-03 00:24:07 +00001935
wdenk43d96162003-03-06 00:02:04 +00001936 Check for configuration errors during FPGA bitfile
1937 loading. For example, abort during Virtex II
1938 configuration if the INIT_B line goes low (which
1939 indicated a CRC error).
wdenkc6097192002-11-03 00:24:07 +00001940
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001941 CONFIG_SYS_FPGA_WAIT_INIT
wdenkc6097192002-11-03 00:24:07 +00001942
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001943 Maximum time to wait for the INIT_B line to de-assert
1944 after PROB_B has been de-asserted during a Virtex II
wdenk43d96162003-03-06 00:02:04 +00001945 FPGA configuration sequence. The default time is 500
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001946 ms.
wdenkc6097192002-11-03 00:24:07 +00001947
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001948 CONFIG_SYS_FPGA_WAIT_BUSY
wdenkc6097192002-11-03 00:24:07 +00001949
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001950 Maximum time to wait for BUSY to de-assert during
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001951 Virtex II FPGA configuration. The default is 5 ms.
wdenkc6097192002-11-03 00:24:07 +00001952
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001953 CONFIG_SYS_FPGA_WAIT_CONFIG
wdenkc6097192002-11-03 00:24:07 +00001954
wdenk43d96162003-03-06 00:02:04 +00001955 Time to wait after FPGA configuration. The default is
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001956 200 ms.
wdenkc6097192002-11-03 00:24:07 +00001957
1958- Configuration Management:
Stefan Roeseb2b8a692014-10-22 12:13:24 +02001959
wdenkc6097192002-11-03 00:24:07 +00001960 CONFIG_IDENT_STRING
1961
wdenk43d96162003-03-06 00:02:04 +00001962 If defined, this string will be added to the U-Boot
1963 version information (U_BOOT_VERSION)
wdenkc6097192002-11-03 00:24:07 +00001964
1965- Vendor Parameter Protection:
1966
wdenk43d96162003-03-06 00:02:04 +00001967 U-Boot considers the values of the environment
1968 variables "serial#" (Board Serial Number) and
wdenk7152b1d2003-09-05 23:19:14 +00001969 "ethaddr" (Ethernet Address) to be parameters that
wdenk43d96162003-03-06 00:02:04 +00001970 are set once by the board vendor / manufacturer, and
1971 protects these variables from casual modification by
1972 the user. Once set, these variables are read-only,
1973 and write or delete attempts are rejected. You can
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001974 change this behaviour:
wdenkc6097192002-11-03 00:24:07 +00001975
1976 If CONFIG_ENV_OVERWRITE is #defined in your config
1977 file, the write protection for vendor parameters is
wdenk47cd00f2003-03-06 13:39:27 +00001978 completely disabled. Anybody can change or delete
wdenkc6097192002-11-03 00:24:07 +00001979 these parameters.
1980
Joe Hershberger92ac5202015-05-04 14:55:14 -05001981 Alternatively, if you define _both_ an ethaddr in the
1982 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001983 Ethernet address is installed in the environment,
wdenkc6097192002-11-03 00:24:07 +00001984 which can be changed exactly ONCE by the user. [The
1985 serial# is unaffected by this, i. e. it remains
1986 read-only.]
1987
Joe Hershberger25980902012-12-11 22:16:31 -06001988 The same can be accomplished in a more flexible way
1989 for any variable by configuring the type of access
1990 to allow for those variables in the ".flags" variable
1991 or define CONFIG_ENV_FLAGS_LIST_STATIC.
1992
wdenkc6097192002-11-03 00:24:07 +00001993- Protected RAM:
1994 CONFIG_PRAM
1995
1996 Define this variable to enable the reservation of
1997 "protected RAM", i. e. RAM which is not overwritten
1998 by U-Boot. Define CONFIG_PRAM to hold the number of
1999 kB you want to reserve for pRAM. You can overwrite
2000 this default value by defining an environment
2001 variable "pram" to the number of kB you want to
2002 reserve. Note that the board info structure will
2003 still show the full amount of RAM. If pRAM is
2004 reserved, a new environment variable "mem" will
2005 automatically be defined to hold the amount of
2006 remaining RAM in a form that can be passed as boot
2007 argument to Linux, for instance like that:
2008
Wolfgang Denkfe126d82005-11-20 21:40:11 +01002009 setenv bootargs ... mem=\${mem}
wdenkc6097192002-11-03 00:24:07 +00002010 saveenv
2011
2012 This way you can tell Linux not to use this memory,
2013 either, which results in a memory region that will
2014 not be affected by reboots.
2015
2016 *WARNING* If your board configuration uses automatic
2017 detection of the RAM size, you must make sure that
2018 this memory test is non-destructive. So far, the
2019 following board configurations are known to be
2020 "pRAM-clean":
2021
Heiko Schocher5b8e76c2017-06-07 17:33:09 +02002022 IVMS8, IVML24, SPD8xx,
Wolfgang Denk1b0757e2012-10-24 02:36:15 +00002023 HERMES, IP860, RPXlite, LWMON,
Heiko Schocher2eb48ff2017-06-07 17:33:10 +02002024 FLAGADM
wdenkc6097192002-11-03 00:24:07 +00002025
Gabe Black40fef042012-12-02 04:55:18 +00002026- Access to physical memory region (> 4GB)
2027 Some basic support is provided for operations on memory not
2028 normally accessible to U-Boot - e.g. some architectures
2029 support access to more than 4GB of memory on 32-bit
2030 machines using physical address extension or similar.
2031 Define CONFIG_PHYSMEM to access this basic support, which
2032 currently only supports clearing the memory.
2033
wdenkc6097192002-11-03 00:24:07 +00002034- Error Recovery:
wdenkc6097192002-11-03 00:24:07 +00002035 CONFIG_NET_RETRY_COUNT
2036
wdenk43d96162003-03-06 00:02:04 +00002037 This variable defines the number of retries for
2038 network operations like ARP, RARP, TFTP, or BOOTP
2039 before giving up the operation. If not defined, a
2040 default value of 5 is used.
wdenkc6097192002-11-03 00:24:07 +00002041
Guennadi Liakhovetski40cb90e2008-04-03 17:04:19 +02002042 CONFIG_ARP_TIMEOUT
2043
2044 Timeout waiting for an ARP reply in milliseconds.
2045
Tetsuyuki Kobayashi48a3e992012-07-03 22:25:21 +00002046 CONFIG_NFS_TIMEOUT
2047
2048 Timeout in milliseconds used in NFS protocol.
2049 If you encounter "ERROR: Cannot umount" in nfs command,
2050 try longer timeout such as
2051 #define CONFIG_NFS_TIMEOUT 10000UL
2052
wdenkc6097192002-11-03 00:24:07 +00002053- Command Interpreter:
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002054 CONFIG_SYS_PROMPT_HUSH_PS2
wdenkc6097192002-11-03 00:24:07 +00002055
2056 This defines the secondary prompt string, which is
2057 printed when the command interpreter needs more input
2058 to complete a command. Usually "> ".
2059
2060 Note:
2061
wdenk8bde7f72003-06-27 21:31:46 +00002062 In the current implementation, the local variables
2063 space and global environment variables space are
2064 separated. Local variables are those you define by
2065 simply typing `name=value'. To access a local
2066 variable later on, you have write `$name' or
2067 `${name}'; to execute the contents of a variable
2068 directly type `$name' at the command prompt.
wdenkc6097192002-11-03 00:24:07 +00002069
wdenk43d96162003-03-06 00:02:04 +00002070 Global environment variables are those you use
2071 setenv/printenv to work with. To run a command stored
2072 in such a variable, you need to use the run command,
2073 and you must not use the '$' sign to access them.
wdenkc6097192002-11-03 00:24:07 +00002074
2075 To store commands and special characters in a
2076 variable, please use double quotation marks
2077 surrounding the whole text of the variable, instead
2078 of the backslashes before semicolons and special
2079 symbols.
2080
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08002081- Command Line Editing and History:
Marek Vasutf3b267b2016-01-27 04:47:55 +01002082 CONFIG_CMDLINE_PS_SUPPORT
2083
2084 Enable support for changing the command prompt string
2085 at run-time. Only static string is supported so far.
2086 The string is obtained from environment variables PS1
2087 and PS2.
2088
wdenka8c7c702003-12-06 19:49:23 +00002089- Default Environment:
wdenkc6097192002-11-03 00:24:07 +00002090 CONFIG_EXTRA_ENV_SETTINGS
2091
wdenk43d96162003-03-06 00:02:04 +00002092 Define this to contain any number of null terminated
2093 strings (variable = value pairs) that will be part of
wdenk7152b1d2003-09-05 23:19:14 +00002094 the default environment compiled into the boot image.
wdenk2262cfe2002-11-18 00:14:45 +00002095
wdenk43d96162003-03-06 00:02:04 +00002096 For example, place something like this in your
2097 board's config file:
wdenkc6097192002-11-03 00:24:07 +00002098
2099 #define CONFIG_EXTRA_ENV_SETTINGS \
2100 "myvar1=value1\0" \
2101 "myvar2=value2\0"
2102
wdenk43d96162003-03-06 00:02:04 +00002103 Warning: This method is based on knowledge about the
2104 internal format how the environment is stored by the
2105 U-Boot code. This is NOT an official, exported
2106 interface! Although it is unlikely that this format
wdenk7152b1d2003-09-05 23:19:14 +00002107 will change soon, there is no guarantee either.
wdenkc6097192002-11-03 00:24:07 +00002108 You better know what you are doing here.
2109
wdenk43d96162003-03-06 00:02:04 +00002110 Note: overly (ab)use of the default environment is
2111 discouraged. Make sure to check other ways to preset
Wolfgang Denk74de7ae2009-04-01 23:34:12 +02002112 the environment like the "source" command or the
wdenk43d96162003-03-06 00:02:04 +00002113 boot command first.
wdenkc6097192002-11-03 00:24:07 +00002114
Simon Glass06fd8532012-11-30 13:01:17 +00002115 CONFIG_DELAY_ENVIRONMENT
2116
2117 Normally the environment is loaded when the board is
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08002118 initialised so that it is available to U-Boot. This inhibits
Simon Glass06fd8532012-11-30 13:01:17 +00002119 that so that the environment is not available until
2120 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2121 this is instead controlled by the value of
2122 /config/load-environment.
2123
Wolfgang Denkecb0ccd2005-09-24 22:37:32 +02002124- TFTP Fixed UDP Port:
2125 CONFIG_TFTP_PORT
2126
Wolfgang Denk28cb9372005-09-24 23:25:46 +02002127 If this is defined, the environment variable tftpsrcp
Wolfgang Denkecb0ccd2005-09-24 22:37:32 +02002128 is used to supply the TFTP UDP source port value.
Wolfgang Denk28cb9372005-09-24 23:25:46 +02002129 If tftpsrcp isn't defined, the normal pseudo-random port
Wolfgang Denkecb0ccd2005-09-24 22:37:32 +02002130 number generator is used.
2131
Wolfgang Denk28cb9372005-09-24 23:25:46 +02002132 Also, the environment variable tftpdstp is used to supply
2133 the TFTP UDP destination port value. If tftpdstp isn't
2134 defined, the normal port 69 is used.
2135
2136 The purpose for tftpsrcp is to allow a TFTP server to
Wolfgang Denkecb0ccd2005-09-24 22:37:32 +02002137 blindly start the TFTP transfer using the pre-configured
2138 target IP address and UDP port. This has the effect of
2139 "punching through" the (Windows XP) firewall, allowing
2140 the remainder of the TFTP transfer to proceed normally.
2141 A better solution is to properly configure the firewall,
2142 but sometimes that is not allowed.
2143
Wolfgang Denk4cf26092011-10-07 09:58:21 +02002144 CONFIG_STANDALONE_LOAD_ADDR
2145
Wolfgang Denk6feff892011-10-09 21:06:34 +02002146 This option defines a board specific value for the
2147 address where standalone program gets loaded, thus
2148 overwriting the architecture dependent default
Wolfgang Denk4cf26092011-10-07 09:58:21 +02002149 settings.
2150
2151- Frame Buffer Address:
2152 CONFIG_FB_ADDR
2153
2154 Define CONFIG_FB_ADDR if you want to use specific
Wolfgang Denk44a53b52013-01-03 00:43:59 +00002155 address for frame buffer. This is typically the case
2156 when using a graphics controller has separate video
2157 memory. U-Boot will then place the frame buffer at
2158 the given address instead of dynamically reserving it
2159 in system RAM by calling lcd_setmem(), which grabs
2160 the memory for the frame buffer depending on the
2161 configured panel size.
Wolfgang Denk4cf26092011-10-07 09:58:21 +02002162
2163 Please see board_init_f function.
2164
Detlev Zundelcccfc2a2009-12-01 17:16:19 +01002165- Automatic software updates via TFTP server
2166 CONFIG_UPDATE_TFTP
2167 CONFIG_UPDATE_TFTP_CNT_MAX
2168 CONFIG_UPDATE_TFTP_MSEC_MAX
2169
2170 These options enable and control the auto-update feature;
2171 for a more detailed description refer to doc/README.update.
2172
2173- MTD Support (mtdparts command, UBI support)
Heiko Schocherff94bc42014-06-24 10:10:04 +02002174 CONFIG_MTD_UBI_WL_THRESHOLD
2175 This parameter defines the maximum difference between the highest
2176 erase counter value and the lowest erase counter value of eraseblocks
2177 of UBI devices. When this threshold is exceeded, UBI starts performing
2178 wear leveling by means of moving data from eraseblock with low erase
2179 counter to eraseblocks with high erase counter.
2180
2181 The default value should be OK for SLC NAND flashes, NOR flashes and
2182 other flashes which have eraseblock life-cycle 100000 or more.
2183 However, in case of MLC NAND flashes which typically have eraseblock
2184 life-cycle less than 10000, the threshold should be lessened (e.g.,
2185 to 128 or 256, although it does not have to be power of 2).
2186
2187 default: 4096
Simon Glassc654b512014-10-23 18:58:54 -06002188
Heiko Schocherff94bc42014-06-24 10:10:04 +02002189 CONFIG_MTD_UBI_BEB_LIMIT
2190 This option specifies the maximum bad physical eraseblocks UBI
2191 expects on the MTD device (per 1024 eraseblocks). If the
2192 underlying flash does not admit of bad eraseblocks (e.g. NOR
2193 flash), this value is ignored.
2194
2195 NAND datasheets often specify the minimum and maximum NVM
2196 (Number of Valid Blocks) for the flashes' endurance lifetime.
2197 The maximum expected bad eraseblocks per 1024 eraseblocks
2198 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
2199 which gives 20 for most NANDs (MaxNVB is basically the total
2200 count of eraseblocks on the chip).
2201
2202 To put it differently, if this value is 20, UBI will try to
2203 reserve about 1.9% of physical eraseblocks for bad blocks
2204 handling. And that will be 1.9% of eraseblocks on the entire
2205 NAND chip, not just the MTD partition UBI attaches. This means
2206 that if you have, say, a NAND flash chip admits maximum 40 bad
2207 eraseblocks, and it is split on two MTD partitions of the same
2208 size, UBI will reserve 40 eraseblocks when attaching a
2209 partition.
2210
2211 default: 20
2212
2213 CONFIG_MTD_UBI_FASTMAP
2214 Fastmap is a mechanism which allows attaching an UBI device
2215 in nearly constant time. Instead of scanning the whole MTD device it
2216 only has to locate a checkpoint (called fastmap) on the device.
2217 The on-flash fastmap contains all information needed to attach
2218 the device. Using fastmap makes only sense on large devices where
2219 attaching by scanning takes long. UBI will not automatically install
2220 a fastmap on old images, but you can set the UBI parameter
2221 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
2222 that fastmap-enabled images are still usable with UBI implementations
2223 without fastmap support. On typical flash devices the whole fastmap
2224 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
2225
2226 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
2227 Set this parameter to enable fastmap automatically on images
2228 without a fastmap.
2229 default: 0
2230
Heiko Schocher0195a7b2015-10-22 06:19:21 +02002231 CONFIG_MTD_UBI_FM_DEBUG
2232 Enable UBI fastmap debug
2233 default: 0
2234
Daniel Schwierzeck6a11cf42011-07-18 07:48:07 +00002235- SPL framework
Wolfgang Denk04e5ae72011-09-11 21:24:09 +02002236 CONFIG_SPL
2237 Enable building of SPL globally.
Daniel Schwierzeck6a11cf42011-07-18 07:48:07 +00002238
Tom Rini95579792012-02-14 07:29:40 +00002239 CONFIG_SPL_LDSCRIPT
2240 LDSCRIPT for linking the SPL binary.
2241
Albert ARIBAUD6ebc3462013-04-12 05:14:30 +00002242 CONFIG_SPL_MAX_FOOTPRINT
2243 Maximum size in memory allocated to the SPL, BSS included.
2244 When defined, the linker checks that the actual memory
2245 used by SPL from _start to __bss_end does not exceed it.
Albert ARIBAUD8960af82013-04-14 04:48:38 +00002246 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
Albert ARIBAUD6ebc3462013-04-12 05:14:30 +00002247 must not be both defined at the same time.
2248
Tom Rini95579792012-02-14 07:29:40 +00002249 CONFIG_SPL_MAX_SIZE
Albert ARIBAUD6ebc3462013-04-12 05:14:30 +00002250 Maximum size of the SPL image (text, data, rodata, and
2251 linker lists sections), BSS excluded.
2252 When defined, the linker checks that the actual size does
2253 not exceed it.
Tom Rini95579792012-02-14 07:29:40 +00002254
Scott Wood94a45bb2012-09-20 19:05:12 -05002255 CONFIG_SPL_RELOC_TEXT_BASE
2256 Address to relocate to. If unspecified, this is equal to
2257 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2258
Tom Rini95579792012-02-14 07:29:40 +00002259 CONFIG_SPL_BSS_START_ADDR
2260 Link address for the BSS within the SPL binary.
2261
2262 CONFIG_SPL_BSS_MAX_SIZE
Albert ARIBAUD6ebc3462013-04-12 05:14:30 +00002263 Maximum size in memory allocated to the SPL BSS.
2264 When defined, the linker checks that the actual memory used
2265 by SPL from __bss_start to __bss_end does not exceed it.
Albert ARIBAUD8960af82013-04-14 04:48:38 +00002266 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
Albert ARIBAUD6ebc3462013-04-12 05:14:30 +00002267 must not be both defined at the same time.
Tom Rini95579792012-02-14 07:29:40 +00002268
2269 CONFIG_SPL_STACK
2270 Adress of the start of the stack SPL will use
2271
Albert ARIBAUD \(3ADEV\)8c80eb32015-03-31 11:40:50 +02002272 CONFIG_SPL_PANIC_ON_RAW_IMAGE
2273 When defined, SPL will panic() if the image it has
2274 loaded does not have a signature.
2275 Defining this is useful when code which loads images
2276 in SPL cannot guarantee that absolutely all read errors
2277 will be caught.
2278 An example is the LPC32XX MLC NAND driver, which will
2279 consider that a completely unreadable NAND block is bad,
2280 and thus should be skipped silently.
2281
Scott Wood94a45bb2012-09-20 19:05:12 -05002282 CONFIG_SPL_RELOC_STACK
2283 Adress of the start of the stack SPL will use after
2284 relocation. If unspecified, this is equal to
2285 CONFIG_SPL_STACK.
2286
Tom Rini95579792012-02-14 07:29:40 +00002287 CONFIG_SYS_SPL_MALLOC_START
2288 Starting address of the malloc pool used in SPL.
Fabio Estevam9ac4fc82015-11-12 12:30:19 -02002289 When this option is set the full malloc is used in SPL and
2290 it is set up by spl_init() and before that, the simple malloc()
2291 can be used if CONFIG_SYS_MALLOC_F is defined.
Tom Rini95579792012-02-14 07:29:40 +00002292
2293 CONFIG_SYS_SPL_MALLOC_SIZE
2294 The size of the malloc pool used in SPL.
Daniel Schwierzeck6a11cf42011-07-18 07:48:07 +00002295
Tom Rini9607faf2014-03-28 12:03:39 -04002296 CONFIG_SPL_OS_BOOT
2297 Enable booting directly to an OS from SPL.
2298 See also: doc/README.falcon
2299
Tom Rini861a86f2012-08-13 11:37:56 -07002300 CONFIG_SPL_DISPLAY_PRINT
2301 For ARM, enable an optional function to print more information
2302 about the running system.
2303
Scott Wood4b919722012-09-20 16:35:21 -05002304 CONFIG_SPL_INIT_MINIMAL
2305 Arch init code should be built for a very small image
2306
Paul Kocialkowskib97300b2014-11-08 23:14:56 +01002307 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
2308 Partition on the MMC to load U-Boot from when the MMC is being
2309 used in raw mode
2310
Peter Korsgaard2b75b0a2013-05-13 08:36:29 +00002311 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
2312 Sector to load kernel uImage from when MMC is being
2313 used in raw mode (for Falcon mode)
2314
2315 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
2316 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
2317 Sector and number of sectors to load kernel argument
2318 parameters from when MMC is being used in raw mode
2319 (for falcon mode)
2320
Paul Kocialkowskie2ccdf82014-11-08 23:14:55 +01002321 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
2322 Partition on the MMC to load U-Boot from when the MMC is being
2323 used in fs mode
2324
Guillaume GARDETfae81c72014-10-15 17:53:13 +02002325 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
2326 Filename to read to load U-Boot when reading from filesystem
2327
2328 CONFIG_SPL_FS_LOAD_KERNEL_NAME
Peter Korsgaard7ad2cc72013-05-13 08:36:27 +00002329 Filename to read to load kernel uImage when reading
Guillaume GARDETfae81c72014-10-15 17:53:13 +02002330 from filesystem (for Falcon mode)
Peter Korsgaard7ad2cc72013-05-13 08:36:27 +00002331
Guillaume GARDETfae81c72014-10-15 17:53:13 +02002332 CONFIG_SPL_FS_LOAD_ARGS_NAME
Peter Korsgaard7ad2cc72013-05-13 08:36:27 +00002333 Filename to read to load kernel argument parameters
Guillaume GARDETfae81c72014-10-15 17:53:13 +02002334 when reading from filesystem (for Falcon mode)
Peter Korsgaard7ad2cc72013-05-13 08:36:27 +00002335
Scott Wood06f60ae2012-12-06 13:33:17 +00002336 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
2337 Set this for NAND SPL on PPC mpc83xx targets, so that
2338 start.S waits for the rest of the SPL to load before
2339 continuing (the hardware starts execution after just
2340 loading the first page rather than the full 4K).
2341
Prabhakar Kushwaha651fcf62014-04-08 19:12:31 +05302342 CONFIG_SPL_SKIP_RELOCATE
2343 Avoid SPL relocation
2344
Scott Wood6f2f01b2012-09-20 19:09:07 -05002345 CONFIG_SPL_NAND_BASE
2346 Include nand_base.c in the SPL. Requires
2347 CONFIG_SPL_NAND_DRIVERS.
2348
2349 CONFIG_SPL_NAND_DRIVERS
2350 SPL uses normal NAND drivers, not minimal drivers.
2351
Jörg Krause15e207f2018-01-14 19:26:38 +01002352 CONFIG_SPL_NAND_IDENT
2353 SPL uses the chip ID list to identify the NAND flash.
2354 Requires CONFIG_SPL_NAND_BASE.
2355
Scott Wood6f2f01b2012-09-20 19:09:07 -05002356 CONFIG_SPL_NAND_ECC
2357 Include standard software ECC in the SPL
2358
Tom Rini95579792012-02-14 07:29:40 +00002359 CONFIG_SPL_NAND_SIMPLE
Scott Wood7d4b7952012-09-21 18:35:27 -05002360 Support for NAND boot using simple NAND drivers that
2361 expose the cmd_ctrl() interface.
Tom Rini95579792012-02-14 07:29:40 +00002362
Thomas Gleixner6f4e7d32016-07-12 20:28:12 +02002363 CONFIG_SPL_UBI
2364 Support for a lightweight UBI (fastmap) scanner and
2365 loader
2366
Heiko Schocher0c3117b2014-10-31 08:31:00 +01002367 CONFIG_SPL_NAND_RAW_ONLY
2368 Support to boot only raw u-boot.bin images. Use this only
2369 if you need to save space.
2370
Ying Zhang7c8eea52013-08-16 15:16:12 +08002371 CONFIG_SPL_COMMON_INIT_DDR
2372 Set for common ddr init with serial presence detect in
2373 SPL binary.
2374
Tom Rini95579792012-02-14 07:29:40 +00002375 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
2376 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
2377 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
2378 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
2379 CONFIG_SYS_NAND_ECCBYTES
2380 Defines the size and behavior of the NAND that SPL uses
Scott Wood7d4b7952012-09-21 18:35:27 -05002381 to read U-Boot
Tom Rini95579792012-02-14 07:29:40 +00002382
2383 CONFIG_SYS_NAND_U_BOOT_OFFS
Scott Wood7d4b7952012-09-21 18:35:27 -05002384 Location in NAND to read U-Boot from
2385
2386 CONFIG_SYS_NAND_U_BOOT_DST
2387 Location in memory to load U-Boot to
2388
2389 CONFIG_SYS_NAND_U_BOOT_SIZE
2390 Size of image to load
Tom Rini95579792012-02-14 07:29:40 +00002391
2392 CONFIG_SYS_NAND_U_BOOT_START
Scott Wood7d4b7952012-09-21 18:35:27 -05002393 Entry point in loaded image to jump to
Tom Rini95579792012-02-14 07:29:40 +00002394
2395 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
2396 Define this if you need to first read the OOB and then the
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08002397 data. This is used, for example, on davinci platforms.
Tom Rini95579792012-02-14 07:29:40 +00002398
Pavel Machekc57b9532012-08-30 22:42:11 +02002399 CONFIG_SPL_RAM_DEVICE
2400 Support for running image already present in ram, in SPL binary
2401
Scott Wood74752ba2012-12-06 13:33:16 +00002402 CONFIG_SPL_PAD_TO
Benoît Thébaudeau6113d3f2013-04-11 09:35:49 +00002403 Image offset to which the SPL should be padded before appending
2404 the SPL payload. By default, this is defined as
2405 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
2406 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
2407 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
Scott Wood74752ba2012-12-06 13:33:16 +00002408
Scott Woodca2fca22012-09-21 16:27:32 -05002409 CONFIG_SPL_TARGET
2410 Final target image containing SPL and payload. Some SPLs
2411 use an arch-specific makefile fragment instead, for
2412 example if more than one image needs to be produced.
2413
Marek Vasutb527b9c2018-05-13 00:22:52 +02002414 CONFIG_SPL_FIT_PRINT
Simon Glass87ebee32013-05-08 08:05:59 +00002415 Printing information about a FIT image adds quite a bit of
2416 code to SPL. So this is normally disabled in SPL. Use this
2417 option to re-enable it. This will affect the output of the
2418 bootm command when booting a FIT image.
2419
Ying Zhang3aa29de2013-08-16 15:16:15 +08002420- TPL framework
2421 CONFIG_TPL
2422 Enable building of TPL globally.
2423
2424 CONFIG_TPL_PAD_TO
2425 Image offset to which the TPL should be padded before appending
2426 the TPL payload. By default, this is defined as
Wolfgang Denk93e14592013-10-04 17:43:24 +02002427 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
2428 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
2429 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
Ying Zhang3aa29de2013-08-16 15:16:15 +08002430
wdenka8c7c702003-12-06 19:49:23 +00002431- Interrupt support (PPC):
2432
wdenkd4ca31c2004-01-02 14:00:00 +00002433 There are common interrupt_init() and timer_interrupt()
2434 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002435 for CPU specific initialization. interrupt_init_cpu()
wdenkd4ca31c2004-01-02 14:00:00 +00002436 should set decrementer_count to appropriate value. If
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002437 CPU resets decrementer automatically after interrupt
wdenkd4ca31c2004-01-02 14:00:00 +00002438 (ppc4xx) it should set decrementer_count to zero.
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002439 timer_interrupt() calls timer_interrupt_cpu() for CPU
wdenkd4ca31c2004-01-02 14:00:00 +00002440 specific handling. If board has watchdog / status_led
2441 / other_activity_monitor it works automatically from
2442 general timer_interrupt().
wdenka8c7c702003-12-06 19:49:23 +00002443
wdenkc6097192002-11-03 00:24:07 +00002444
Helmut Raiger9660e442011-10-20 04:19:47 +00002445Board initialization settings:
2446------------------------------
2447
2448During Initialization u-boot calls a number of board specific functions
2449to allow the preparation of board specific prerequisites, e.g. pin setup
2450before drivers are initialized. To enable these callbacks the
2451following configuration macros have to be defined. Currently this is
2452architecture specific, so please check arch/your_architecture/lib/board.c
2453typically in board_init_f() and board_init_r().
2454
2455- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
2456- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
2457- CONFIG_BOARD_LATE_INIT: Call board_late_init()
2458- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
wdenkc6097192002-11-03 00:24:07 +00002459
wdenkc6097192002-11-03 00:24:07 +00002460Configuration Settings:
2461-----------------------
2462
York Sun4d1fd7f2014-02-26 17:03:19 -08002463- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
2464 Optionally it can be defined to support 64-bit memory commands.
2465
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002466- CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
wdenkc6097192002-11-03 00:24:07 +00002467 undefine this when you're short of memory.
2468
Peter Tyser2fb26042009-01-27 18:03:12 -06002469- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2470 width of the commands listed in the 'help' command output.
2471
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002472- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
wdenkc6097192002-11-03 00:24:07 +00002473 prompt for user input.
2474
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002475- CONFIG_SYS_CBSIZE: Buffer size for input from the Console
wdenkc6097192002-11-03 00:24:07 +00002476
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002477- CONFIG_SYS_PBSIZE: Buffer size for Console output
wdenkc6097192002-11-03 00:24:07 +00002478
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002479- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
wdenkc6097192002-11-03 00:24:07 +00002480
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002481- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
wdenkc6097192002-11-03 00:24:07 +00002482 the application (usually a Linux kernel) when it is
2483 booted
2484
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002485- CONFIG_SYS_BAUDRATE_TABLE:
wdenkc6097192002-11-03 00:24:07 +00002486 List of legal baudrate settings for this board.
2487
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002488- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
wdenkc6097192002-11-03 00:24:07 +00002489 Begin and End addresses of the area used by the
2490 simple memory test.
2491
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002492- CONFIG_SYS_MEMTEST_SCRATCH:
wdenk5f535fe2003-09-18 09:21:33 +00002493 Scratch address used by the alternate memory test
2494 You only need to set this if address zero isn't writeable
2495
York Sune8149522015-12-04 11:57:07 -08002496- CONFIG_SYS_MEM_RESERVE_SECURE
York Sune61a7532016-06-24 16:46:18 -07002497 Only implemented for ARMv8 for now.
York Sune8149522015-12-04 11:57:07 -08002498 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
2499 is substracted from total RAM and won't be reported to OS.
2500 This memory can be used as secure memory. A variable
York Sune61a7532016-06-24 16:46:18 -07002501 gd->arch.secure_ram is used to track the location. In systems
York Sune8149522015-12-04 11:57:07 -08002502 the RAM base is not zero, or RAM is divided into banks,
2503 this variable needs to be recalcuated to get the address.
2504
York Sunaabd7dd2015-12-07 11:05:29 -08002505- CONFIG_SYS_MEM_TOP_HIDE:
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002506 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
Stefan Roese14f73ca2008-03-26 10:14:11 +01002507 this specified memory area will get subtracted from the top
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002508 (end) of RAM and won't get "touched" at all by U-Boot. By
Stefan Roese14f73ca2008-03-26 10:14:11 +01002509 fixing up gd->ram_size the Linux kernel should gets passed
2510 the now "corrected" memory size and won't touch it either.
2511 This should work for arch/ppc and arch/powerpc. Only Linux
Stefan Roese5e12e752008-03-28 11:02:53 +01002512 board ports in arch/powerpc with bootwrapper support that
Stefan Roese14f73ca2008-03-26 10:14:11 +01002513 recalculate the memory size from the SDRAM controller setup
Stefan Roese5e12e752008-03-28 11:02:53 +01002514 will have to get fixed in Linux additionally.
Stefan Roese14f73ca2008-03-26 10:14:11 +01002515
2516 This option can be used as a workaround for the 440EPx/GRx
2517 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2518 be touched.
2519
2520 WARNING: Please make sure that this value is a multiple of
2521 the Linux page size (normally 4k). If this is not the case,
2522 then the end address of the Linux memory will be located at a
2523 non page size aligned address and this could cause major
2524 problems.
2525
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002526- CONFIG_SYS_LOADS_BAUD_CHANGE:
wdenkc6097192002-11-03 00:24:07 +00002527 Enable temporary baudrate change while serial download
2528
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002529- CONFIG_SYS_SDRAM_BASE:
wdenkc6097192002-11-03 00:24:07 +00002530 Physical start address of SDRAM. _Must_ be 0 here.
2531
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002532- CONFIG_SYS_FLASH_BASE:
wdenkc6097192002-11-03 00:24:07 +00002533 Physical start address of Flash memory.
2534
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002535- CONFIG_SYS_MONITOR_BASE:
wdenkc6097192002-11-03 00:24:07 +00002536 Physical start address of boot monitor code (set by
2537 make config files to be same as the text base address
Wolfgang Denk14d0a022010-10-07 21:51:12 +02002538 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002539 CONFIG_SYS_FLASH_BASE when booting from flash.
wdenkc6097192002-11-03 00:24:07 +00002540
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002541- CONFIG_SYS_MONITOR_LEN:
wdenk8bde7f72003-06-27 21:31:46 +00002542 Size of memory reserved for monitor code, used to
2543 determine _at_compile_time_ (!) if the environment is
2544 embedded within the U-Boot image, or in a separate
2545 flash sector.
wdenkc6097192002-11-03 00:24:07 +00002546
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002547- CONFIG_SYS_MALLOC_LEN:
wdenkc6097192002-11-03 00:24:07 +00002548 Size of DRAM reserved for malloc() use.
2549
Simon Glassd59476b2014-07-10 22:23:28 -06002550- CONFIG_SYS_MALLOC_F_LEN
2551 Size of the malloc() pool for use before relocation. If
2552 this is defined, then a very simple malloc() implementation
2553 will become available before relocation. The address is just
2554 below the global data, and the stack is moved down to make
2555 space.
2556
2557 This feature allocates regions with increasing addresses
2558 within the region. calloc() is supported, but realloc()
2559 is not available. free() is supported but does nothing.
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08002560 The memory will be freed (or in fact just forgotten) when
Simon Glassd59476b2014-07-10 22:23:28 -06002561 U-Boot relocates itself.
2562
Simon Glass38687ae2014-11-10 17:16:54 -07002563- CONFIG_SYS_MALLOC_SIMPLE
2564 Provides a simple and small malloc() and calloc() for those
2565 boards which do not use the full malloc in SPL (which is
2566 enabled with CONFIG_SYS_SPL_MALLOC_START).
2567
Thierry Reding1dfdd9b2014-12-09 22:25:22 -07002568- CONFIG_SYS_NONCACHED_MEMORY:
2569 Size of non-cached memory area. This area of memory will be
2570 typically located right below the malloc() area and mapped
2571 uncached in the MMU. This is useful for drivers that would
2572 otherwise require a lot of explicit cache maintenance. For
2573 some drivers it's also impossible to properly maintain the
2574 cache. For example if the regions that need to be flushed
2575 are not a multiple of the cache-line size, *and* padding
2576 cannot be allocated between the regions to align them (i.e.
2577 if the HW requires a contiguous array of regions, and the
2578 size of each region is not cache-aligned), then a flush of
2579 one region may result in overwriting data that hardware has
2580 written to another region in the same cache-line. This can
2581 happen for example in network drivers where descriptors for
2582 buffers are typically smaller than the CPU cache-line (e.g.
2583 16 bytes vs. 32 or 64 bytes).
2584
2585 Non-cached memory is only supported on 32-bit ARM at present.
2586
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002587- CONFIG_SYS_BOOTM_LEN:
Stefan Roese15940c92006-03-13 11:16:36 +01002588 Normally compressed uImages are limited to an
2589 uncompressed size of 8 MBytes. If this is not enough,
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002590 you can define CONFIG_SYS_BOOTM_LEN in your board config file
Stefan Roese15940c92006-03-13 11:16:36 +01002591 to adjust this setting to your needs.
2592
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002593- CONFIG_SYS_BOOTMAPSZ:
wdenkc6097192002-11-03 00:24:07 +00002594 Maximum size of memory mapped by the startup code of
2595 the Linux kernel; all data that must be processed by
Bartlomiej Sieka7d721e32008-04-14 15:44:16 +02002596 the Linux kernel (bd_info, boot arguments, FDT blob if
2597 used) must be put below this limit, unless "bootm_low"
Robert P. J. Day1bce2ae2013-09-16 07:15:45 -04002598 environment variable is defined and non-zero. In such case
Bartlomiej Sieka7d721e32008-04-14 15:44:16 +02002599 all data for the Linux kernel must be between "bootm_low"
Wolfgang Denkc0f40852011-10-26 10:21:21 +00002600 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
Grant Likelyc3624e62011-03-28 09:58:43 +00002601 variable "bootm_mapsize" will override the value of
2602 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
2603 then the value in "bootm_size" will be used instead.
wdenkc6097192002-11-03 00:24:07 +00002604
John Rigbyfca43cc2010-10-13 13:57:35 -06002605- CONFIG_SYS_BOOT_RAMDISK_HIGH:
2606 Enable initrd_high functionality. If defined then the
2607 initrd_high feature is enabled and the bootm ramdisk subcommand
2608 is enabled.
2609
2610- CONFIG_SYS_BOOT_GET_CMDLINE:
2611 Enables allocating and saving kernel cmdline in space between
2612 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2613
2614- CONFIG_SYS_BOOT_GET_KBD:
2615 Enables allocating and saving a kernel copy of the bd_info in
2616 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2617
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002618- CONFIG_SYS_MAX_FLASH_BANKS:
wdenkc6097192002-11-03 00:24:07 +00002619 Max number of Flash memory banks
2620
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002621- CONFIG_SYS_MAX_FLASH_SECT:
wdenkc6097192002-11-03 00:24:07 +00002622 Max number of sectors on a Flash chip
2623
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002624- CONFIG_SYS_FLASH_ERASE_TOUT:
wdenkc6097192002-11-03 00:24:07 +00002625 Timeout for Flash erase operations (in ms)
2626
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002627- CONFIG_SYS_FLASH_WRITE_TOUT:
wdenkc6097192002-11-03 00:24:07 +00002628 Timeout for Flash write operations (in ms)
2629
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002630- CONFIG_SYS_FLASH_LOCK_TOUT
wdenk8564acf2003-07-14 22:13:32 +00002631 Timeout for Flash set sector lock bit operation (in ms)
2632
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002633- CONFIG_SYS_FLASH_UNLOCK_TOUT
wdenk8564acf2003-07-14 22:13:32 +00002634 Timeout for Flash clear lock bits operation (in ms)
2635
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002636- CONFIG_SYS_FLASH_PROTECTION
wdenk8564acf2003-07-14 22:13:32 +00002637 If defined, hardware flash sectors protection is used
2638 instead of U-Boot software protection.
2639
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002640- CONFIG_SYS_DIRECT_FLASH_TFTP:
wdenkc6097192002-11-03 00:24:07 +00002641
2642 Enable TFTP transfers directly to flash memory;
2643 without this option such a download has to be
2644 performed in two steps: (1) download to RAM, and (2)
2645 copy from RAM to flash.
2646
2647 The two-step approach is usually more reliable, since
2648 you can check if the download worked before you erase
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002649 the flash, but in some situations (when system RAM is
2650 too limited to allow for a temporary copy of the
wdenkc6097192002-11-03 00:24:07 +00002651 downloaded image) this option may be very useful.
2652
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002653- CONFIG_SYS_FLASH_CFI:
wdenk43d96162003-03-06 00:02:04 +00002654 Define if the flash driver uses extra elements in the
wdenk5653fc32004-02-08 22:55:38 +00002655 common flash structure for storing flash geometry.
2656
Jean-Christophe PLAGNIOL-VILLARD00b18832008-08-13 01:40:42 +02002657- CONFIG_FLASH_CFI_DRIVER
wdenk5653fc32004-02-08 22:55:38 +00002658 This option also enables the building of the cfi_flash driver
2659 in the drivers directory
wdenkc6097192002-11-03 00:24:07 +00002660
Piotr Ziecik91809ed2008-11-17 15:57:58 +01002661- CONFIG_FLASH_CFI_MTD
2662 This option enables the building of the cfi_mtd driver
2663 in the drivers directory. The driver exports CFI flash
2664 to the MTD layer.
2665
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002666- CONFIG_SYS_FLASH_USE_BUFFER_WRITE
Guennadi Liakhovetski96ef8312008-04-03 13:36:02 +02002667 Use buffered writes to flash.
2668
2669- CONFIG_FLASH_SPANSION_S29WS_N
2670 s29ws-n MirrorBit flash has non-standard addresses for buffered
2671 write commands.
2672
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002673- CONFIG_SYS_FLASH_QUIET_TEST
Stefan Roese5568e612005-11-22 13:20:42 +01002674 If this option is defined, the common CFI flash doesn't
2675 print it's warning upon not recognized FLASH banks. This
2676 is useful, if some of the configured banks are only
2677 optionally available.
2678
Jerry Van Baren9a042e92008-03-08 13:48:01 -05002679- CONFIG_FLASH_SHOW_PROGRESS
2680 If defined (must be an integer), print out countdown
2681 digits and dots. Recommended value: 45 (9..1) for 80
2682 column displays, 15 (3..1) for 40 column displays.
2683
Stefan Roese352ef3f2013-04-04 15:53:14 +02002684- CONFIG_FLASH_VERIFY
2685 If defined, the content of the flash (destination) is compared
2686 against the source after the write operation. An error message
2687 will be printed when the contents are not identical.
2688 Please note that this option is useless in nearly all cases,
2689 since such flash programming errors usually are detected earlier
2690 while unprotecting/erasing/programming. Please only enable
2691 this option if you really know what you are doing.
2692
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002693- CONFIG_SYS_RX_ETH_BUFFER:
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002694 Defines the number of Ethernet receive buffers. On some
2695 Ethernet controllers it is recommended to set this value
stroese53cf9432003-06-05 15:39:44 +00002696 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2697 buffers can be full shortly after enabling the interface
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002698 on high Ethernet traffic.
stroese53cf9432003-06-05 15:39:44 +00002699 Defaults to 4 if not defined.
2700
Wolfgang Denkea882ba2010-06-20 23:33:59 +02002701- CONFIG_ENV_MAX_ENTRIES
2702
Wolfgang Denk071bc922010-10-27 22:48:30 +02002703 Maximum number of entries in the hash table that is used
2704 internally to store the environment settings. The default
2705 setting is supposed to be generous and should work in most
2706 cases. This setting can be used to tune behaviour; see
2707 lib/hashtable.c for details.
Wolfgang Denkea882ba2010-06-20 23:33:59 +02002708
Joe Hershberger25980902012-12-11 22:16:31 -06002709- CONFIG_ENV_FLAGS_LIST_DEFAULT
2710- CONFIG_ENV_FLAGS_LIST_STATIC
Robert P. J. Day1bce2ae2013-09-16 07:15:45 -04002711 Enable validation of the values given to environment variables when
Joe Hershberger25980902012-12-11 22:16:31 -06002712 calling env set. Variables can be restricted to only decimal,
2713 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
2714 the variables can also be restricted to IP address or MAC address.
2715
2716 The format of the list is:
2717 type_attribute = [s|d|x|b|i|m]
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08002718 access_attribute = [a|r|o|c]
2719 attributes = type_attribute[access_attribute]
Joe Hershberger25980902012-12-11 22:16:31 -06002720 entry = variable_name[:attributes]
2721 list = entry[,list]
2722
2723 The type attributes are:
2724 s - String (default)
2725 d - Decimal
2726 x - Hexadecimal
2727 b - Boolean ([1yYtT|0nNfF])
2728 i - IP address
2729 m - MAC address
2730
Joe Hershberger267541f2012-12-11 22:16:34 -06002731 The access attributes are:
2732 a - Any (default)
2733 r - Read-only
2734 o - Write-once
2735 c - Change-default
2736
Joe Hershberger25980902012-12-11 22:16:31 -06002737 - CONFIG_ENV_FLAGS_LIST_DEFAULT
2738 Define this to a list (string) to define the ".flags"
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08002739 environment variable in the default or embedded environment.
Joe Hershberger25980902012-12-11 22:16:31 -06002740
2741 - CONFIG_ENV_FLAGS_LIST_STATIC
2742 Define this to a list (string) to define validation that
2743 should be done if an entry is not found in the ".flags"
2744 environment variable. To override a setting in the static
2745 list, simply add an entry for the same variable name to the
2746 ".flags" variable.
2747
Joe Hershbergerbdf1fe42015-05-20 14:27:20 -05002748 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
2749 regular expression. This allows multiple variables to define the same
2750 flags without explicitly listing them for each variable.
2751
Joe Hershberger267541f2012-12-11 22:16:34 -06002752- CONFIG_ENV_ACCESS_IGNORE_FORCE
2753 If defined, don't allow the -f switch to env set override variable
2754 access flags.
2755
wdenkc6097192002-11-03 00:24:07 +00002756The following definitions that deal with the placement and management
2757of environment data (variable area); in general, we support the
2758following configurations:
2759
Mike Frysingerc3eb3fe2011-07-08 10:44:25 +00002760- CONFIG_BUILD_ENVCRC:
2761
2762 Builds up envcrc with the target environment so that external utils
2763 may easily extract it and embed it in final U-Boot images.
2764
wdenkc6097192002-11-03 00:24:07 +00002765BE CAREFUL! The first access to the environment happens quite early
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08002766in U-Boot initialization (when we try to get the setting of for the
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002767console baudrate). You *MUST* have mapped your NVRAM area then, or
wdenkc6097192002-11-03 00:24:07 +00002768U-Boot will hang.
2769
2770Please note that even with NVRAM we still use a copy of the
2771environment in RAM: we could work on NVRAM directly, but we want to
2772keep settings there always unmodified except somebody uses "saveenv"
2773to save the current settings.
2774
Liu Gang0a85a9e2012-03-08 00:33:20 +00002775BE CAREFUL! For some special cases, the local device can not use
2776"saveenv" command. For example, the local device will get the
Liu Gangfc54c7f2012-08-09 05:10:01 +00002777environment stored in a remote NOR flash by SRIO or PCIE link,
2778but it can not erase, write this NOR flash by SRIO or PCIE interface.
Liu Gang0a85a9e2012-03-08 00:33:20 +00002779
Guennadi Liakhovetskib74ab732009-05-18 16:07:22 +02002780- CONFIG_NAND_ENV_DST
2781
2782 Defines address in RAM to which the nand_spl code should copy the
2783 environment. If redundant environment is used, it will be copied to
2784 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2785
Bruce Adlere881cb52007-11-02 13:15:42 -07002786Please note that the environment is read-only until the monitor
wdenkc6097192002-11-03 00:24:07 +00002787has been relocated to RAM and a RAM copy of the environment has been
Simon Glass00caae62017-08-03 12:22:12 -06002788created; also, when using EEPROM you will have to use env_get_f()
wdenkc6097192002-11-03 00:24:07 +00002789until then to read environment variables.
2790
wdenk85ec0bc2003-03-31 16:34:49 +00002791The environment is protected by a CRC32 checksum. Before the monitor
2792is relocated into RAM, as a result of a bad CRC you will be working
2793with the compiled-in default environment - *silently*!!! [This is
2794necessary, because the first environment variable we need is the
2795"baudrate" setting for the console - if we have a bad CRC, we don't
2796have any device yet where we could complain.]
wdenkc6097192002-11-03 00:24:07 +00002797
2798Note: once the monitor has been relocated, then it will complain if
2799the default environment is used; a new CRC is computed as soon as you
wdenk85ec0bc2003-03-31 16:34:49 +00002800use the "saveenv" command to store a valid environment.
wdenkc6097192002-11-03 00:24:07 +00002801
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002802- CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
wdenk42d1f032003-10-15 23:53:47 +00002803 Echo the inverted Ethernet link state to the fault LED.
wdenkfc3e2162003-10-08 22:33:00 +00002804
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002805 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
wdenkfc3e2162003-10-08 22:33:00 +00002806 also needs to be defined.
2807
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002808- CONFIG_SYS_FAULT_MII_ADDR:
wdenk42d1f032003-10-15 23:53:47 +00002809 MII address of the PHY to check for the Ethernet link state.
wdenkc6097192002-11-03 00:24:07 +00002810
Ron Madridf5675aa2009-02-18 14:30:44 -08002811- CONFIG_NS16550_MIN_FUNCTIONS:
2812 Define this if you desire to only have use of the NS16550_init
2813 and NS16550_putc functions for the serial driver located at
2814 drivers/serial/ns16550.c. This option is useful for saving
2815 space for already greatly restricted images, including but not
2816 limited to NAND_SPL configurations.
2817
Simon Glassb2b92f52012-11-30 13:01:18 +00002818- CONFIG_DISPLAY_BOARDINFO
2819 Display information about the board that U-Boot is running on
2820 when U-Boot starts up. The board function checkboard() is called
2821 to do this.
2822
Simon Glasse2e3e2b2012-11-30 13:01:19 +00002823- CONFIG_DISPLAY_BOARDINFO_LATE
2824 Similar to the previous option, but display this information
2825 later, once stdio is running and output goes to the LCD, if
2826 present.
2827
Sascha Silbefeb85802013-08-11 16:40:43 +02002828- CONFIG_BOARD_SIZE_LIMIT:
2829 Maximum size of the U-Boot image. When defined, the
2830 build system checks that the actual size does not
2831 exceed it.
2832
wdenkc6097192002-11-03 00:24:07 +00002833Low Level (hardware related) configuration options:
wdenkdc7c9a12003-03-26 06:55:25 +00002834---------------------------------------------------
wdenkc6097192002-11-03 00:24:07 +00002835
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002836- CONFIG_SYS_CACHELINE_SIZE:
wdenkc6097192002-11-03 00:24:07 +00002837 Cache Line Size of the CPU.
2838
Timur Tabie46fedf2011-08-04 18:03:41 -05002839- CONFIG_SYS_CCSRBAR_DEFAULT:
2840 Default (power-on reset) physical address of CCSR on Freescale
2841 PowerPC SOCs.
2842
2843- CONFIG_SYS_CCSRBAR:
2844 Virtual address of CCSR. On a 32-bit build, this is typically
2845 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
2846
Timur Tabie46fedf2011-08-04 18:03:41 -05002847- CONFIG_SYS_CCSRBAR_PHYS:
2848 Physical address of CCSR. CCSR can be relocated to a new
2849 physical address, if desired. In this case, this macro should
Wolfgang Denkc0f40852011-10-26 10:21:21 +00002850 be set to that address. Otherwise, it should be set to the
Timur Tabie46fedf2011-08-04 18:03:41 -05002851 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
2852 is typically relocated on 36-bit builds. It is recommended
2853 that this macro be defined via the _HIGH and _LOW macros:
2854
2855 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
2856 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
2857
2858- CONFIG_SYS_CCSRBAR_PHYS_HIGH:
Wolfgang Denk4cf26092011-10-07 09:58:21 +02002859 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
2860 either 0 (32-bit build) or 0xF (36-bit build). This macro is
Timur Tabie46fedf2011-08-04 18:03:41 -05002861 used in assembly code, so it must not contain typecasts or
2862 integer size suffixes (e.g. "ULL").
2863
2864- CONFIG_SYS_CCSRBAR_PHYS_LOW:
2865 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
2866 used in assembly code, so it must not contain typecasts or
2867 integer size suffixes (e.g. "ULL").
2868
2869- CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
2870 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
2871 forced to a value that ensures that CCSR is not relocated.
2872
Macpaul Lin0abddf82011-04-11 20:45:32 +00002873- CONFIG_IDE_AHB:
2874 Most IDE controllers were designed to be connected with PCI
2875 interface. Only few of them were designed for AHB interface.
2876 When software is doing ATA command and data transfer to
2877 IDE devices through IDE-AHB controller, some additional
2878 registers accessing to these kind of IDE-AHB controller
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08002879 is required.
Macpaul Lin0abddf82011-04-11 20:45:32 +00002880
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002881- CONFIG_SYS_IMMR: Physical address of the Internal Memory.
wdenkefe2a4d2004-12-16 21:44:03 +00002882 DO NOT CHANGE unless you know exactly what you're
Christophe Leroy907208c2017-07-06 10:23:22 +02002883 doing! (11-4) [MPC8xx systems only]
wdenkc6097192002-11-03 00:24:07 +00002884
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002885- CONFIG_SYS_INIT_RAM_ADDR:
wdenkc6097192002-11-03 00:24:07 +00002886
wdenk7152b1d2003-09-05 23:19:14 +00002887 Start address of memory area that can be used for
wdenkc6097192002-11-03 00:24:07 +00002888 initial data and stack; please note that this must be
2889 writable memory that is working WITHOUT special
2890 initialization, i. e. you CANNOT use normal RAM which
2891 will become available only after programming the
2892 memory controller and running certain initialization
2893 sequences.
2894
2895 U-Boot uses the following memory types:
Christophe Leroy907208c2017-07-06 10:23:22 +02002896 - MPC8xx: IMMR (internal memory of the CPU)
wdenkc6097192002-11-03 00:24:07 +00002897
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002898- CONFIG_SYS_GBL_DATA_OFFSET:
wdenkc6097192002-11-03 00:24:07 +00002899
2900 Offset of the initial data structure in the memory
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002901 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2902 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
wdenkc6097192002-11-03 00:24:07 +00002903 data is located at the end of the available space
Wolfgang Denk553f0982010-10-26 13:32:32 +02002904 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
Simon Glassacd51f92016-10-02 18:01:06 -06002905 GENERATED_GBL_DATA_SIZE), and the initial stack is just
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002906 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2907 CONFIG_SYS_GBL_DATA_OFFSET) downward.
wdenkc6097192002-11-03 00:24:07 +00002908
2909 Note:
2910 On the MPC824X (or other systems that use the data
2911 cache for initial memory) the address chosen for
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002912 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
wdenkc6097192002-11-03 00:24:07 +00002913 point to an otherwise UNUSED address space between
2914 the top of RAM and the start of the PCI space.
2915
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002916- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
wdenkc6097192002-11-03 00:24:07 +00002917
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002918- CONFIG_SYS_OR_TIMING_SDRAM:
wdenkc6097192002-11-03 00:24:07 +00002919 SDRAM timing
2920
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002921- CONFIG_SYS_MAMR_PTA:
wdenkc6097192002-11-03 00:24:07 +00002922 periodic timer for refresh
2923
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002924- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2925 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2926 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2927 CONFIG_SYS_BR1_PRELIM:
wdenkc6097192002-11-03 00:24:07 +00002928 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2929
2930- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002931 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2932 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
wdenkc6097192002-11-03 00:24:07 +00002933 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2934
Andrew Sharp69fd2d32012-08-29 14:16:32 +00002935- CONFIG_PCI_ENUM_ONLY
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08002936 Only scan through and get the devices on the buses.
Andrew Sharp69fd2d32012-08-29 14:16:32 +00002937 Don't do any setup work, presumably because someone or
2938 something has already done it, and we don't need to do it
2939 a second time. Useful for platforms that are pre-booted
2940 by coreboot or similar.
2941
Gabor Juhos842033e2013-05-30 07:06:12 +00002942- CONFIG_PCI_INDIRECT_BRIDGE:
2943 Enable support for indirect PCI bridges.
2944
Kumar Galaa09b9b62010-12-30 12:09:53 -06002945- CONFIG_SYS_SRIO:
2946 Chip has SRIO or not
2947
2948- CONFIG_SRIO1:
2949 Board has SRIO 1 port available
2950
2951- CONFIG_SRIO2:
2952 Board has SRIO 2 port available
2953
Liu Gangc8b28152013-05-07 16:30:46 +08002954- CONFIG_SRIO_PCIE_BOOT_MASTER
2955 Board can support master function for Boot from SRIO and PCIE
2956
Kumar Galaa09b9b62010-12-30 12:09:53 -06002957- CONFIG_SYS_SRIOn_MEM_VIRT:
2958 Virtual Address of SRIO port 'n' memory region
2959
Simon Glass62f9b652019-11-14 12:57:09 -07002960- CONFIG_SYS_SRIOn_MEM_PHYxS:
Kumar Galaa09b9b62010-12-30 12:09:53 -06002961 Physical Address of SRIO port 'n' memory region
2962
2963- CONFIG_SYS_SRIOn_MEM_SIZE:
2964 Size of SRIO port 'n' memory region
2965
Fabio Estevam66bd1842013-04-11 09:35:34 +00002966- CONFIG_SYS_NAND_BUSWIDTH_16BIT
2967 Defined to tell the NAND controller that the NAND chip is using
2968 a 16 bit bus.
2969 Not all NAND drivers use this symbol.
Fabio Estevama430e912013-04-11 09:35:35 +00002970 Example of drivers that use it:
Miquel Raynala430fa02018-08-16 17:30:07 +02002971 - drivers/mtd/nand/raw/ndfc.c
2972 - drivers/mtd/nand/raw/mxc_nand.c
Alex Watermaneced4622011-05-19 15:08:36 -04002973
2974- CONFIG_SYS_NDFC_EBC0_CFG
2975 Sets the EBC0_CFG register for the NDFC. If not defined
2976 a default value will be used.
2977
Ben Warrenbb99ad62006-09-07 16:50:54 -04002978- CONFIG_SPD_EEPROM
Wolfgang Denk218ca722008-03-26 10:40:12 +01002979 Get DDR timing information from an I2C EEPROM. Common
2980 with pluggable memory modules such as SODIMMs
2981
Ben Warrenbb99ad62006-09-07 16:50:54 -04002982 SPD_EEPROM_ADDRESS
2983 I2C address of the SPD EEPROM
2984
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002985- CONFIG_SYS_SPD_BUS_NUM
Wolfgang Denk218ca722008-03-26 10:40:12 +01002986 If SPD EEPROM is on an I2C bus other than the first
2987 one, specify here. Note that the value must resolve
2988 to something your driver can deal with.
Ben Warrenbb99ad62006-09-07 16:50:54 -04002989
York Sun1b3e3c42011-06-07 09:42:16 +08002990- CONFIG_SYS_DDR_RAW_TIMING
2991 Get DDR timing information from other than SPD. Common with
2992 soldered DDR chips onboard without SPD. DDR raw timing
2993 parameters are extracted from datasheet and hard-coded into
2994 header files or board specific files.
2995
York Sun6f5e1dc2011-09-16 13:21:35 -07002996- CONFIG_FSL_DDR_INTERACTIVE
2997 Enable interactive DDR debugging. See doc/README.fsl-ddr.
2998
York Sune32d59a2015-01-06 13:18:55 -08002999- CONFIG_FSL_DDR_SYNC_REFRESH
3000 Enable sync of refresh for multiple controllers.
3001
York Sun4516ff82015-03-19 09:30:28 -07003002- CONFIG_FSL_DDR_BIST
3003 Enable built-in memory test for Freescale DDR controllers.
3004
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02003005- CONFIG_SYS_83XX_DDR_USES_CS0
Wolfgang Denk218ca722008-03-26 10:40:12 +01003006 Only for 83xx systems. If specified, then DDR should
3007 be configured using CS0 and CS1 instead of CS2 and CS3.
Timur Tabi2ad6b512006-10-31 18:44:42 -06003008
wdenkc26e4542004-04-18 10:13:26 +00003009- CONFIG_RMII
3010 Enable RMII mode for all FECs.
3011 Note that this is a global option, we can't
3012 have one FEC in standard MII mode and another in RMII mode.
3013
wdenk5cf91d62004-04-23 20:32:05 +00003014- CONFIG_CRC32_VERIFY
3015 Add a verify option to the crc32 command.
3016 The syntax is:
3017
3018 => crc32 -v <address> <count> <crc32>
3019
3020 Where address/count indicate a memory area
3021 and crc32 is the correct crc32 which the
3022 area should have.
3023
wdenk56523f12004-07-11 17:40:54 +00003024- CONFIG_LOOPW
3025 Add the "loopw" memory command. This only takes effect if
Simon Glass493f4202017-08-04 16:34:27 -06003026 the memory commands are activated globally (CONFIG_CMD_MEMORY).
wdenk56523f12004-07-11 17:40:54 +00003027
stroese7b466642004-12-16 18:46:55 +00003028- CONFIG_MX_CYCLIC
3029 Add the "mdc" and "mwc" memory commands. These are cyclic
3030 "md/mw" commands.
3031 Examples:
3032
wdenkefe2a4d2004-12-16 21:44:03 +00003033 => mdc.b 10 4 500
stroese7b466642004-12-16 18:46:55 +00003034 This command will print 4 bytes (10,11,12,13) each 500 ms.
3035
wdenkefe2a4d2004-12-16 21:44:03 +00003036 => mwc.l 100 12345678 10
stroese7b466642004-12-16 18:46:55 +00003037 This command will write 12345678 to address 100 all 10 ms.
3038
wdenkefe2a4d2004-12-16 21:44:03 +00003039 This only takes effect if the memory commands are activated
Simon Glass493f4202017-08-04 16:34:27 -06003040 globally (CONFIG_CMD_MEMORY).
stroese7b466642004-12-16 18:46:55 +00003041
wdenk8aa1a2d2005-04-04 12:44:11 +00003042- CONFIG_SKIP_LOWLEVEL_INIT
Rick Chen3fafced2017-12-26 13:55:59 +08003043 [ARM, NDS32, MIPS, RISC-V only] If this variable is defined, then certain
Wolfgang Denk844f07d2010-11-27 23:30:56 +01003044 low level initializations (like setting up the memory
3045 controller) are omitted and/or U-Boot does not
3046 relocate itself into RAM.
wdenk8aa1a2d2005-04-04 12:44:11 +00003047
Wolfgang Denk844f07d2010-11-27 23:30:56 +01003048 Normally this variable MUST NOT be defined. The only
3049 exception is when U-Boot is loaded (to RAM) by some
3050 other boot loader or by a debugger which performs
3051 these initializations itself.
wdenk8aa1a2d2005-04-04 12:44:11 +00003052
Simon Glassb5bd0982016-05-05 07:28:06 -06003053- CONFIG_SKIP_LOWLEVEL_INIT_ONLY
3054 [ARM926EJ-S only] This allows just the call to lowlevel_init()
yeongjun Kim90211f72016-07-20 22:56:12 +09003055 to be skipped. The normal CP15 init (such as enabling the
Simon Glassb5bd0982016-05-05 07:28:06 -06003056 instruction cache) is still performed.
3057
Aneesh V401bb302011-07-13 05:11:07 +00003058- CONFIG_SPL_BUILD
Thomas Hebb32f2ca22019-11-13 18:18:03 -08003059 Set when the currently-running compilation is for an artifact
3060 that will end up in the SPL (as opposed to the TPL or U-Boot
3061 proper). Code that needs stage-specific behavior should check
3062 this.
wdenk400558b2005-04-02 23:52:25 +00003063
Ying Zhang3aa29de2013-08-16 15:16:15 +08003064- CONFIG_TPL_BUILD
Thomas Hebb32f2ca22019-11-13 18:18:03 -08003065 Set when the currently-running compilation is for an artifact
3066 that will end up in the TPL (as opposed to the SPL or U-Boot
3067 proper). Code that needs stage-specific behavior should check
3068 this.
Ying Zhang3aa29de2013-08-16 15:16:15 +08003069
Ying Zhang5df572f2013-05-20 14:07:23 +08003070- CONFIG_SYS_MPC85XX_NO_RESETVEC
3071 Only for 85xx systems. If this variable is specified, the section
3072 .resetvec is not kept and the section .bootpg is placed in the
3073 previous 4k of the .text section.
3074
Simon Glass4213fc22013-02-24 17:33:14 +00003075- CONFIG_ARCH_MAP_SYSMEM
3076 Generally U-Boot (and in particular the md command) uses
3077 effective address. It is therefore not necessary to regard
3078 U-Boot address as virtual addresses that need to be translated
3079 to physical addresses. However, sandbox requires this, since
3080 it maintains its own little RAM buffer which contains all
3081 addressable memory. This option causes some memory accesses
3082 to be mapped through map_sysmem() / unmap_sysmem().
3083
Simon Glass588a13f2013-02-14 04:18:54 +00003084- CONFIG_X86_RESET_VECTOR
3085 If defined, the x86 reset vector code is included. This is not
3086 needed when U-Boot is running from Coreboot.
Gabe Blackb16f5212012-11-27 21:08:06 +00003087
Karicheri, Muralidharan999d7d32014-04-04 13:16:50 -04003088- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
3089 Option to disable subpage write in NAND driver
3090 driver that uses this:
Miquel Raynala430fa02018-08-16 17:30:07 +02003091 drivers/mtd/nand/raw/davinci_nand.c
Karicheri, Muralidharan999d7d32014-04-04 13:16:50 -04003092
Timur Tabif2717b42011-11-22 09:21:25 -06003093Freescale QE/FMAN Firmware Support:
3094-----------------------------------
3095
3096The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
3097loading of "firmware", which is encoded in the QE firmware binary format.
3098This firmware often needs to be loaded during U-Boot booting, so macros
3099are used to identify the storage device (NOR flash, SPI, etc) and the address
3100within that device.
3101
Zhao Qiangdcf1d772014-03-21 16:21:44 +08003102- CONFIG_SYS_FMAN_FW_ADDR
3103 The address in the storage device where the FMAN microcode is located. The
Tom Rinicc1e98b2019-05-12 07:59:12 -04003104 meaning of this address depends on which CONFIG_SYS_QE_FMAN_FW_IN_xxx macro
Zhao Qiangdcf1d772014-03-21 16:21:44 +08003105 is also specified.
3106
3107- CONFIG_SYS_QE_FW_ADDR
3108 The address in the storage device where the QE microcode is located. The
Tom Rinicc1e98b2019-05-12 07:59:12 -04003109 meaning of this address depends on which CONFIG_SYS_QE_FMAN_FW_IN_xxx macro
Timur Tabif2717b42011-11-22 09:21:25 -06003110 is also specified.
3111
3112- CONFIG_SYS_QE_FMAN_FW_LENGTH
3113 The maximum possible size of the firmware. The firmware binary format
3114 has a field that specifies the actual size of the firmware, but it
3115 might not be possible to read any part of the firmware unless some
3116 local storage is allocated to hold the entire firmware first.
3117
3118- CONFIG_SYS_QE_FMAN_FW_IN_NOR
3119 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
3120 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
3121 virtual address in NOR flash.
3122
3123- CONFIG_SYS_QE_FMAN_FW_IN_NAND
3124 Specifies that QE/FMAN firmware is located in NAND flash.
3125 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
3126
3127- CONFIG_SYS_QE_FMAN_FW_IN_MMC
3128 Specifies that QE/FMAN firmware is located on the primary SD/MMC
3129 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3130
Liu Gang292dc6c2012-03-08 00:33:18 +00003131- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
3132 Specifies that QE/FMAN firmware is located in the remote (master)
3133 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
Liu Gangfc54c7f2012-08-09 05:10:01 +00003134 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
3135 window->master inbound window->master LAW->the ucode address in
3136 master's memory space.
Timur Tabif2717b42011-11-22 09:21:25 -06003137
J. German Riverab940ca62014-06-23 15:15:55 -07003138Freescale Layerscape Management Complex Firmware Support:
3139---------------------------------------------------------
3140The Freescale Layerscape Management Complex (MC) supports the loading of
3141"firmware".
3142This firmware often needs to be loaded during U-Boot booting, so macros
3143are used to identify the storage device (NOR flash, SPI, etc) and the address
3144within that device.
3145
3146- CONFIG_FSL_MC_ENET
3147 Enable the MC driver for Layerscape SoCs.
3148
Prabhakar Kushwaha5c055082015-06-02 10:55:52 +05303149Freescale Layerscape Debug Server Support:
3150-------------------------------------------
3151The Freescale Layerscape Debug Server Support supports the loading of
3152"Debug Server firmware" and triggering SP boot-rom.
3153This firmware often needs to be loaded during U-Boot booting.
3154
York Sunc0492142015-12-07 11:08:58 -08003155- CONFIG_SYS_MC_RSV_MEM_ALIGN
3156 Define alignment of reserved memory MC requires
Prabhakar Kushwaha5c055082015-06-02 10:55:52 +05303157
Paul Kocialkowskif3f431a2015-07-26 18:48:15 +02003158Reproducible builds
3159-------------------
3160
3161In order to achieve reproducible builds, timestamps used in the U-Boot build
3162process have to be set to a fixed value.
3163
3164This is done using the SOURCE_DATE_EPOCH environment variable.
3165SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
3166option for U-Boot or an environment variable in U-Boot.
3167
3168SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
3169
wdenkc6097192002-11-03 00:24:07 +00003170Building the Software:
3171======================
3172
Wolfgang Denk218ca722008-03-26 10:40:12 +01003173Building U-Boot has been tested in several native build environments
3174and in many different cross environments. Of course we cannot support
3175all possibly existing versions of cross development tools in all
3176(potentially obsolete) versions. In case of tool chain problems we
3177recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3178which is extensively used to build and test U-Boot.
wdenkc6097192002-11-03 00:24:07 +00003179
Wolfgang Denk218ca722008-03-26 10:40:12 +01003180If you are not using a native environment, it is assumed that you
3181have GNU cross compiling tools available in your path. In this case,
3182you must set the environment variable CROSS_COMPILE in your shell.
3183Note that no changes to the Makefile or any other source files are
3184necessary. For example using the ELDK on a 4xx CPU, please enter:
wdenkc6097192002-11-03 00:24:07 +00003185
Wolfgang Denk218ca722008-03-26 10:40:12 +01003186 $ CROSS_COMPILE=ppc_4xx-
3187 $ export CROSS_COMPILE
wdenkc6097192002-11-03 00:24:07 +00003188
Peter Tyser2f8d3962009-03-13 18:54:51 -05003189Note: If you wish to generate Windows versions of the utilities in
3190 the tools directory you can use the MinGW toolchain
3191 (http://www.mingw.org). Set your HOST tools to the MinGW
3192 toolchain and execute 'make tools'. For example:
3193
3194 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3195
3196 Binaries such as tools/mkimage.exe will be created which can
3197 be executed on computers running Windows.
3198
Wolfgang Denk218ca722008-03-26 10:40:12 +01003199U-Boot is intended to be simple to build. After installing the
3200sources you must configure U-Boot for one specific board type. This
wdenkc6097192002-11-03 00:24:07 +00003201is done by typing:
3202
Holger Freytherab584d62014-08-04 09:26:05 +02003203 make NAME_defconfig
wdenkc6097192002-11-03 00:24:07 +00003204
Holger Freytherab584d62014-08-04 09:26:05 +02003205where "NAME_defconfig" is the name of one of the existing configu-
Michael Jones4d675ae2012-03-15 22:48:10 +00003206rations; see boards.cfg for supported names.
wdenk54387ac2003-10-08 22:45:44 +00003207
wdenk2729af92004-05-03 20:45:30 +00003208Note: for some board special configuration names may exist; check if
3209 additional information is available from the board vendor; for
3210 instance, the TQM823L systems are available without (standard)
3211 or with LCD support. You can select such additional "features"
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02003212 when choosing the configuration, i. e.
wdenkc6097192002-11-03 00:24:07 +00003213
Holger Freytherab584d62014-08-04 09:26:05 +02003214 make TQM823L_defconfig
wdenk2729af92004-05-03 20:45:30 +00003215 - will configure for a plain TQM823L, i. e. no LCD support
wdenkc6097192002-11-03 00:24:07 +00003216
Holger Freytherab584d62014-08-04 09:26:05 +02003217 make TQM823L_LCD_defconfig
wdenk2729af92004-05-03 20:45:30 +00003218 - will configure for a TQM823L with U-Boot console on LCD
wdenkc6097192002-11-03 00:24:07 +00003219
wdenk2729af92004-05-03 20:45:30 +00003220 etc.
wdenkc6097192002-11-03 00:24:07 +00003221
wdenkc6097192002-11-03 00:24:07 +00003222
wdenk2729af92004-05-03 20:45:30 +00003223Finally, type "make all", and you should get some working U-Boot
3224images ready for download to / installation on your system:
wdenkc6097192002-11-03 00:24:07 +00003225
wdenk2729af92004-05-03 20:45:30 +00003226- "u-boot.bin" is a raw binary image
3227- "u-boot" is an image in ELF binary format
3228- "u-boot.srec" is in Motorola S-Record format
wdenkc6097192002-11-03 00:24:07 +00003229
Marian Balakowiczbaf31242006-09-07 17:25:40 +02003230By default the build is performed locally and the objects are saved
3231in the source directory. One of the two methods can be used to change
3232this behavior and build U-Boot to some external directory:
3233
32341. Add O= to the make command line invocations:
3235
3236 make O=/tmp/build distclean
Holger Freytherab584d62014-08-04 09:26:05 +02003237 make O=/tmp/build NAME_defconfig
Marian Balakowiczbaf31242006-09-07 17:25:40 +02003238 make O=/tmp/build all
3239
Timo Ketolaadbba992014-11-06 14:39:05 +020032402. Set environment variable KBUILD_OUTPUT to point to the desired location:
Marian Balakowiczbaf31242006-09-07 17:25:40 +02003241
Timo Ketolaadbba992014-11-06 14:39:05 +02003242 export KBUILD_OUTPUT=/tmp/build
Marian Balakowiczbaf31242006-09-07 17:25:40 +02003243 make distclean
Holger Freytherab584d62014-08-04 09:26:05 +02003244 make NAME_defconfig
Marian Balakowiczbaf31242006-09-07 17:25:40 +02003245 make all
3246
Timo Ketolaadbba992014-11-06 14:39:05 +02003247Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
Marian Balakowiczbaf31242006-09-07 17:25:40 +02003248variable.
3249
Daniel Schwierzeck215bb1c2018-01-26 16:31:04 +01003250User specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by
3251setting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS.
3252For example to treat all compiler warnings as errors:
3253
3254 make KCFLAGS=-Werror
wdenkc6097192002-11-03 00:24:07 +00003255
wdenk2729af92004-05-03 20:45:30 +00003256Please be aware that the Makefiles assume you are using GNU make, so
3257for instance on NetBSD you might need to use "gmake" instead of
3258native "make".
wdenkc6097192002-11-03 00:24:07 +00003259
wdenkc6097192002-11-03 00:24:07 +00003260
wdenk2729af92004-05-03 20:45:30 +00003261If the system board that you have is not listed, then you will need
3262to port U-Boot to your hardware platform. To do this, follow these
3263steps:
wdenkc6097192002-11-03 00:24:07 +00003264
Phil Sutter3c1496c2015-12-25 14:41:18 +010032651. Create a new directory to hold your board specific code. Add any
wdenk2729af92004-05-03 20:45:30 +00003266 files you need. In your board directory, you will need at least
Phil Sutter3c1496c2015-12-25 14:41:18 +01003267 the "Makefile" and a "<board>.c".
32682. Create a new configuration file "include/configs/<board>.h" for
3269 your board.
wdenk2729af92004-05-03 20:45:30 +000032703. If you're porting U-Boot to a new CPU, then also create a new
3271 directory to hold your CPU specific code. Add any files you need.
Holger Freytherab584d62014-08-04 09:26:05 +020032724. Run "make <board>_defconfig" with your new name.
wdenk2729af92004-05-03 20:45:30 +000032735. Type "make", and you should get a working "u-boot.srec" file
3274 to be installed on your target system.
32756. Debug and solve any problems that might arise.
3276 [Of course, this last step is much harder than it sounds.]
wdenkc6097192002-11-03 00:24:07 +00003277
wdenkc6097192002-11-03 00:24:07 +00003278
wdenk2729af92004-05-03 20:45:30 +00003279Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3280==============================================================
wdenkc6097192002-11-03 00:24:07 +00003281
Wolfgang Denk218ca722008-03-26 10:40:12 +01003282If you have modified U-Boot sources (for instance added a new board
3283or support for new devices, a new CPU, etc.) you are expected to
wdenk2729af92004-05-03 20:45:30 +00003284provide feedback to the other developers. The feedback normally takes
Thomas Hebb32f2ca22019-11-13 18:18:03 -08003285the form of a "patch", i.e. a context diff against a certain (latest
Wolfgang Denk218ca722008-03-26 10:40:12 +01003286official or latest in the git repository) version of U-Boot sources.
wdenkc6097192002-11-03 00:24:07 +00003287
Wolfgang Denk218ca722008-03-26 10:40:12 +01003288But before you submit such a patch, please verify that your modifi-
3289cation did not break existing code. At least make sure that *ALL* of
wdenk2729af92004-05-03 20:45:30 +00003290the supported boards compile WITHOUT ANY compiler warnings. To do so,
Simon Glass6de80f22016-07-27 20:33:08 -06003291just run the buildman script (tools/buildman/buildman), which will
3292configure and build U-Boot for ALL supported system. Be warned, this
3293will take a while. Please see the buildman README, or run 'buildman -H'
3294for documentation.
Marian Balakowiczbaf31242006-09-07 17:25:40 +02003295
3296
wdenk2729af92004-05-03 20:45:30 +00003297See also "U-Boot Porting Guide" below.
wdenkc6097192002-11-03 00:24:07 +00003298
wdenkc6097192002-11-03 00:24:07 +00003299
wdenk2729af92004-05-03 20:45:30 +00003300Monitor Commands - Overview:
3301============================
wdenkc6097192002-11-03 00:24:07 +00003302
wdenk2729af92004-05-03 20:45:30 +00003303go - start application at address 'addr'
3304run - run commands in an environment variable
3305bootm - boot application image from memory
3306bootp - boot image via network using BootP/TFTP protocol
Marek Vasut44f074c2012-03-14 21:52:45 +00003307bootz - boot zImage from memory
wdenk2729af92004-05-03 20:45:30 +00003308tftpboot- boot image via network using TFTP protocol
3309 and env variables "ipaddr" and "serverip"
3310 (and eventually "gatewayip")
Simon Glass1fb7cd42011-10-24 18:00:07 +00003311tftpput - upload a file via network using TFTP protocol
wdenk2729af92004-05-03 20:45:30 +00003312rarpboot- boot image via network using RARP/TFTP protocol
3313diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3314loads - load S-Record file over serial line
3315loadb - load binary file over serial line (kermit mode)
3316md - memory display
3317mm - memory modify (auto-incrementing)
3318nm - memory modify (constant address)
3319mw - memory write (fill)
3320cp - memory copy
3321cmp - memory compare
3322crc32 - checksum calculation
Peter Tyser0f89c542009-04-18 22:34:03 -05003323i2c - I2C sub-system
wdenk2729af92004-05-03 20:45:30 +00003324sspi - SPI utility commands
3325base - print or set address offset
3326printenv- print environment variables
3327setenv - set environment variables
3328saveenv - save environment variables to persistent storage
3329protect - enable or disable FLASH write protection
3330erase - erase FLASH memory
3331flinfo - print FLASH memory information
Karl O. Pinc10635af2012-08-03 05:57:21 +00003332nand - NAND memory operations (see doc/README.nand)
wdenk2729af92004-05-03 20:45:30 +00003333bdinfo - print Board Info structure
3334iminfo - print header information for application image
3335coninfo - print console devices and informations
3336ide - IDE sub-system
3337loop - infinite loop on address range
wdenk56523f12004-07-11 17:40:54 +00003338loopw - infinite write loop on address range
wdenk2729af92004-05-03 20:45:30 +00003339mtest - simple RAM test
3340icache - enable or disable instruction cache
3341dcache - enable or disable data cache
3342reset - Perform RESET of the CPU
3343echo - echo args to console
3344version - print monitor version
3345help - print online help
3346? - alias for 'help'
wdenkc6097192002-11-03 00:24:07 +00003347
wdenkc6097192002-11-03 00:24:07 +00003348
wdenk2729af92004-05-03 20:45:30 +00003349Monitor Commands - Detailed Description:
3350========================================
wdenkc6097192002-11-03 00:24:07 +00003351
wdenk2729af92004-05-03 20:45:30 +00003352TODO.
wdenkc6097192002-11-03 00:24:07 +00003353
wdenk2729af92004-05-03 20:45:30 +00003354For now: just type "help <command>".
wdenkc6097192002-11-03 00:24:07 +00003355
3356
wdenk2729af92004-05-03 20:45:30 +00003357Environment Variables:
3358======================
wdenkc6097192002-11-03 00:24:07 +00003359
wdenk2729af92004-05-03 20:45:30 +00003360U-Boot supports user configuration using Environment Variables which
3361can be made persistent by saving to Flash memory.
wdenkc6097192002-11-03 00:24:07 +00003362
wdenk2729af92004-05-03 20:45:30 +00003363Environment Variables are set using "setenv", printed using
3364"printenv", and saved to Flash using "saveenv". Using "setenv"
3365without a value can be used to delete a variable from the
3366environment. As long as you don't save the environment you are
3367working with an in-memory copy. In case the Flash area containing the
3368environment is erased by accident, a default environment is provided.
wdenkc6097192002-11-03 00:24:07 +00003369
Wolfgang Denkc96f86e2010-01-17 23:55:53 +01003370Some configuration options can be set using Environment Variables.
3371
3372List of environment variables (most likely not complete):
wdenkc6097192002-11-03 00:24:07 +00003373
wdenk2729af92004-05-03 20:45:30 +00003374 baudrate - see CONFIG_BAUDRATE
wdenkc6097192002-11-03 00:24:07 +00003375
wdenk2729af92004-05-03 20:45:30 +00003376 bootdelay - see CONFIG_BOOTDELAY
wdenkc6097192002-11-03 00:24:07 +00003377
wdenk2729af92004-05-03 20:45:30 +00003378 bootcmd - see CONFIG_BOOTCOMMAND
wdenkc6097192002-11-03 00:24:07 +00003379
wdenk2729af92004-05-03 20:45:30 +00003380 bootargs - Boot arguments when booting an RTOS image
wdenkc6097192002-11-03 00:24:07 +00003381
wdenk2729af92004-05-03 20:45:30 +00003382 bootfile - Name of the image to load with TFTP
wdenkc6097192002-11-03 00:24:07 +00003383
Bartlomiej Sieka7d721e32008-04-14 15:44:16 +02003384 bootm_low - Memory range available for image processing in the bootm
3385 command can be restricted. This variable is given as
3386 a hexadecimal number and defines lowest address allowed
3387 for use by the bootm command. See also "bootm_size"
3388 environment variable. Address defined by "bootm_low" is
3389 also the base of the initial memory mapping for the Linux
Grant Likelyc3624e62011-03-28 09:58:43 +00003390 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
3391 bootm_mapsize.
3392
Wolfgang Denkc0f40852011-10-26 10:21:21 +00003393 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
Grant Likelyc3624e62011-03-28 09:58:43 +00003394 This variable is given as a hexadecimal number and it
3395 defines the size of the memory region starting at base
3396 address bootm_low that is accessible by the Linux kernel
3397 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
3398 as the default value if it is defined, and bootm_size is
3399 used otherwise.
Bartlomiej Sieka7d721e32008-04-14 15:44:16 +02003400
3401 bootm_size - Memory range available for image processing in the bootm
3402 command can be restricted. This variable is given as
3403 a hexadecimal number and defines the size of the region
3404 allowed for use by the bootm command. See also "bootm_low"
3405 environment variable.
3406
Simon Glass88fa4be2019-07-20 20:51:17 -06003407 bootstopkeysha256, bootdelaykey, bootstopkey - See README.autoboot
3408
Bartlomiej Sieka4bae9092008-10-01 15:26:31 +02003409 updatefile - Location of the software update file on a TFTP server, used
3410 by the automatic software update feature. Please refer to
3411 documentation in doc/README.update for more details.
3412
wdenk2729af92004-05-03 20:45:30 +00003413 autoload - if set to "no" (any string beginning with 'n'),
3414 "bootp" will just load perform a lookup of the
3415 configuration from the BOOTP server, but not try to
3416 load any image using TFTP
wdenkc6097192002-11-03 00:24:07 +00003417
wdenk2729af92004-05-03 20:45:30 +00003418 autostart - if set to "yes", an image loaded using the "bootp",
3419 "rarpboot", "tftpboot" or "diskboot" commands will
3420 be automatically started (by internally calling
3421 "bootm")
wdenkc6097192002-11-03 00:24:07 +00003422
wdenk2729af92004-05-03 20:45:30 +00003423 If set to "no", a standalone image passed to the
3424 "bootm" command will be copied to the load address
3425 (and eventually uncompressed), but NOT be started.
3426 This can be used to load and uncompress arbitrary
3427 data.
wdenkc6097192002-11-03 00:24:07 +00003428
David A. Longa28afca2011-07-09 16:40:19 -04003429 fdt_high - if set this restricts the maximum address that the
3430 flattened device tree will be copied into upon boot.
Shawn Guofa34f6b2012-01-09 21:54:08 +00003431 For example, if you have a system with 1 GB memory
3432 at physical address 0x10000000, while Linux kernel
3433 only recognizes the first 704 MB as low memory, you
3434 may need to set fdt_high as 0x3C000000 to have the
3435 device tree blob be copied to the maximum address
3436 of the 704 MB low memory, so that Linux kernel can
3437 access it during the boot procedure.
3438
David A. Longa28afca2011-07-09 16:40:19 -04003439 If this is set to the special value 0xFFFFFFFF then
3440 the fdt will not be copied at all on boot. For this
3441 to work it must reside in writable memory, have
3442 sufficient padding on the end of it for u-boot to
3443 add the information it needs into it, and the memory
3444 must be accessible by the kernel.
3445
Simon Glasseea63e02011-10-24 19:15:34 +00003446 fdtcontroladdr- if set this is the address of the control flattened
3447 device tree used by U-Boot when CONFIG_OF_CONTROL is
3448 defined.
3449
wdenk17ea1172004-06-06 21:51:03 +00003450 i2cfast - (PPC405GP|PPC405EP only)
3451 if set to 'y' configures Linux I2C driver for fast
3452 mode (400kHZ). This environment variable is used in
3453 initialization code. So, for changes to be effective
3454 it must be saved and board must be reset.
3455
wdenk2729af92004-05-03 20:45:30 +00003456 initrd_high - restrict positioning of initrd images:
3457 If this variable is not set, initrd images will be
3458 copied to the highest possible address in RAM; this
3459 is usually what you want since it allows for
3460 maximum initrd size. If for some reason you want to
3461 make sure that the initrd image is loaded below the
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02003462 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
wdenk2729af92004-05-03 20:45:30 +00003463 variable to a value of "no" or "off" or "0".
3464 Alternatively, you can set it to a maximum upper
3465 address to use (U-Boot will still check that it
3466 does not overwrite the U-Boot stack and data).
wdenkc6097192002-11-03 00:24:07 +00003467
wdenk2729af92004-05-03 20:45:30 +00003468 For instance, when you have a system with 16 MB
3469 RAM, and want to reserve 4 MB from use by Linux,
3470 you can do this by adding "mem=12M" to the value of
3471 the "bootargs" variable. However, now you must make
3472 sure that the initrd image is placed in the first
3473 12 MB as well - this can be done with
wdenkc6097192002-11-03 00:24:07 +00003474
wdenk2729af92004-05-03 20:45:30 +00003475 setenv initrd_high 00c00000
wdenkc6097192002-11-03 00:24:07 +00003476
wdenk2729af92004-05-03 20:45:30 +00003477 If you set initrd_high to 0xFFFFFFFF, this is an
3478 indication to U-Boot that all addresses are legal
3479 for the Linux kernel, including addresses in flash
3480 memory. In this case U-Boot will NOT COPY the
3481 ramdisk at all. This may be useful to reduce the
3482 boot time on your system, but requires that this
3483 feature is supported by your Linux kernel.
wdenk4a6fd342003-04-12 23:38:12 +00003484
wdenk2729af92004-05-03 20:45:30 +00003485 ipaddr - IP address; needed for tftpboot command
wdenkc6097192002-11-03 00:24:07 +00003486
wdenk2729af92004-05-03 20:45:30 +00003487 loadaddr - Default load address for commands like "bootp",
3488 "rarpboot", "tftpboot", "loadb" or "diskboot"
wdenkc6097192002-11-03 00:24:07 +00003489
wdenk2729af92004-05-03 20:45:30 +00003490 loads_echo - see CONFIG_LOADS_ECHO
wdenkc6097192002-11-03 00:24:07 +00003491
wdenk2729af92004-05-03 20:45:30 +00003492 serverip - TFTP server IP address; needed for tftpboot command
wdenk38b99262003-05-23 23:18:21 +00003493
wdenk2729af92004-05-03 20:45:30 +00003494 bootretry - see CONFIG_BOOT_RETRY_TIME
wdenkc6097192002-11-03 00:24:07 +00003495
wdenk2729af92004-05-03 20:45:30 +00003496 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
wdenkc6097192002-11-03 00:24:07 +00003497
wdenk2729af92004-05-03 20:45:30 +00003498 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
wdenkc6097192002-11-03 00:24:07 +00003499
Mike Frysingere2a53452011-10-02 10:01:27 +00003500 ethprime - controls which interface is used first.
wdenkc6097192002-11-03 00:24:07 +00003501
Mike Frysingere2a53452011-10-02 10:01:27 +00003502 ethact - controls which interface is currently active.
3503 For example you can do the following
wdenkc6097192002-11-03 00:24:07 +00003504
Heiko Schocher48690d82010-07-20 17:45:02 +02003505 => setenv ethact FEC
3506 => ping 192.168.0.1 # traffic sent on FEC
3507 => setenv ethact SCC
3508 => ping 10.0.0.1 # traffic sent on SCC
wdenkc6097192002-11-03 00:24:07 +00003509
Matthias Fuchse1692572008-01-17 07:45:05 +01003510 ethrotate - When set to "no" U-Boot does not go through all
3511 available network interfaces.
3512 It just stays at the currently selected interface.
3513
Wolfgang Denkc96f86e2010-01-17 23:55:53 +01003514 netretry - When set to "no" each network operation will
wdenk2729af92004-05-03 20:45:30 +00003515 either succeed or fail without retrying.
3516 When set to "once" the network operation will
3517 fail when all the available network interfaces
3518 are tried once without success.
3519 Useful on scripts which control the retry operation
3520 themselves.
wdenkc6097192002-11-03 00:24:07 +00003521
Jean-Christophe PLAGNIOL-VILLARDb4e2f892009-01-31 09:53:39 +01003522 npe_ucode - set load address for the NPE microcode
Jean-Christophe PLAGNIOL-VILLARDa1cf0272008-01-07 08:41:34 +01003523
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08003524 silent_linux - If set then Linux will be told to boot silently, by
Simon Glass8d51aac2013-07-16 20:10:00 -07003525 changing the console to be empty. If "yes" it will be
3526 made silent. If "no" it will not be made silent. If
3527 unset, then it will be made silent if the U-Boot console
3528 is silent.
3529
Albert ARIBAUD \(3ADEV\)f5fb7342015-10-12 00:02:57 +02003530 tftpsrcp - If this is set, the value is used for TFTP's
Wolfgang Denkecb0ccd2005-09-24 22:37:32 +02003531 UDP source port.
3532
Albert ARIBAUD \(3ADEV\)f5fb7342015-10-12 00:02:57 +02003533 tftpdstp - If this is set, the value is used for TFTP's UDP
Wolfgang Denk28cb9372005-09-24 23:25:46 +02003534 destination port instead of the Well Know Port 69.
3535
Wolfgang Denkc96f86e2010-01-17 23:55:53 +01003536 tftpblocksize - Block size to use for TFTP transfers; if not set,
3537 we use the TFTP server's default block size
3538
3539 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3540 seconds, minimum value is 1000 = 1 second). Defines
3541 when a packet is considered to be lost so it has to
3542 be retransmitted. The default is 5000 = 5 seconds.
3543 Lowering this value may make downloads succeed
3544 faster in networks with high packet loss rates or
3545 with unreliable TFTP servers.
3546
Albert ARIBAUD \(3ADEV\)f5fb7342015-10-12 00:02:57 +02003547 tftptimeoutcountmax - maximum count of TFTP timeouts (no
3548 unit, minimum value = 0). Defines how many timeouts
3549 can happen during a single file transfer before that
3550 transfer is aborted. The default is 10, and 0 means
3551 'no timeouts allowed'. Increasing this value may help
3552 downloads succeed with high packet loss rates, or with
3553 unreliable TFTP servers or client hardware.
3554
Wolfgang Denkc96f86e2010-01-17 23:55:53 +01003555 vlan - When set to a value < 4095 the traffic over
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02003556 Ethernet is encapsulated/received over 802.1q
wdenk2729af92004-05-03 20:45:30 +00003557 VLAN tagged frames.
wdenka3d991b2004-04-15 21:48:45 +00003558
Alexandre Messier50768f52016-02-01 17:08:57 -05003559 bootpretryperiod - Period during which BOOTP/DHCP sends retries.
3560 Unsigned value, in milliseconds. If not set, the period will
3561 be either the default (28000), or a value based on
3562 CONFIG_NET_RETRY_COUNT, if defined. This value has
3563 precedence over the valu based on CONFIG_NET_RETRY_COUNT.
3564
Jason Hobbsdc0b7b02011-08-31 05:37:28 +00003565The following image location variables contain the location of images
3566used in booting. The "Image" column gives the role of the image and is
3567not an environment variable name. The other columns are environment
3568variable names. "File Name" gives the name of the file on a TFTP
3569server, "RAM Address" gives the location in RAM the image will be
3570loaded to, and "Flash Location" gives the image's address in NOR
3571flash or offset in NAND flash.
3572
3573*Note* - these variables don't have to be defined for all boards, some
Fabio Estevamaed9fed2015-04-25 18:53:10 -03003574boards currently use other variables for these purposes, and some
Jason Hobbsdc0b7b02011-08-31 05:37:28 +00003575boards use these variables for other purposes.
3576
Wolfgang Denkc0f40852011-10-26 10:21:21 +00003577Image File Name RAM Address Flash Location
3578----- --------- ----------- --------------
3579u-boot u-boot u-boot_addr_r u-boot_addr
3580Linux kernel bootfile kernel_addr_r kernel_addr
3581device tree blob fdtfile fdt_addr_r fdt_addr
3582ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
Jason Hobbsdc0b7b02011-08-31 05:37:28 +00003583
wdenk2729af92004-05-03 20:45:30 +00003584The following environment variables may be used and automatically
3585updated by the network boot commands ("bootp" and "rarpboot"),
3586depending the information provided by your boot server:
wdenka3d991b2004-04-15 21:48:45 +00003587
wdenk2729af92004-05-03 20:45:30 +00003588 bootfile - see above
3589 dnsip - IP address of your Domain Name Server
3590 dnsip2 - IP address of your secondary Domain Name Server
3591 gatewayip - IP address of the Gateway (Router) to use
3592 hostname - Target hostname
3593 ipaddr - see above
3594 netmask - Subnet Mask
3595 rootpath - Pathname of the root filesystem on the NFS server
3596 serverip - see above
wdenka3d991b2004-04-15 21:48:45 +00003597
wdenka3d991b2004-04-15 21:48:45 +00003598
wdenk2729af92004-05-03 20:45:30 +00003599There are two special Environment Variables:
wdenkc6097192002-11-03 00:24:07 +00003600
wdenk2729af92004-05-03 20:45:30 +00003601 serial# - contains hardware identification information such
3602 as type string and/or serial number
3603 ethaddr - Ethernet address
wdenkc6097192002-11-03 00:24:07 +00003604
wdenk2729af92004-05-03 20:45:30 +00003605These variables can be set only once (usually during manufacturing of
3606the board). U-Boot refuses to delete or overwrite these variables
3607once they have been set once.
wdenkc6097192002-11-03 00:24:07 +00003608
3609
wdenk2729af92004-05-03 20:45:30 +00003610Further special Environment Variables:
wdenkc6097192002-11-03 00:24:07 +00003611
wdenk2729af92004-05-03 20:45:30 +00003612 ver - Contains the U-Boot version string as printed
3613 with the "version" command. This variable is
3614 readonly (see CONFIG_VERSION_VARIABLE).
wdenkc6097192002-11-03 00:24:07 +00003615
wdenkc6097192002-11-03 00:24:07 +00003616
wdenk2729af92004-05-03 20:45:30 +00003617Please note that changes to some configuration parameters may take
3618only effect after the next boot (yes, that's just like Windoze :-).
wdenkc6097192002-11-03 00:24:07 +00003619
stroesec1551ea2003-04-04 15:53:41 +00003620
Joe Hershberger170ab112012-12-11 22:16:24 -06003621Callback functions for environment variables:
3622---------------------------------------------
3623
3624For some environment variables, the behavior of u-boot needs to change
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08003625when their values are changed. This functionality allows functions to
Joe Hershberger170ab112012-12-11 22:16:24 -06003626be associated with arbitrary variables. On creation, overwrite, or
3627deletion, the callback will provide the opportunity for some side
3628effect to happen or for the change to be rejected.
3629
3630The callbacks are named and associated with a function using the
3631U_BOOT_ENV_CALLBACK macro in your board or driver code.
3632
3633These callbacks are associated with variables in one of two ways. The
3634static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
3635in the board configuration to a string that defines a list of
3636associations. The list must be in the following format:
3637
3638 entry = variable_name[:callback_name]
3639 list = entry[,list]
3640
3641If the callback name is not specified, then the callback is deleted.
3642Spaces are also allowed anywhere in the list.
3643
3644Callbacks can also be associated by defining the ".callbacks" variable
3645with the same list format above. Any association in ".callbacks" will
3646override any association in the static list. You can define
3647CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08003648".callbacks" environment variable in the default or embedded environment.
Joe Hershberger170ab112012-12-11 22:16:24 -06003649
Joe Hershbergerbdf1fe42015-05-20 14:27:20 -05003650If CONFIG_REGEX is defined, the variable_name above is evaluated as a
3651regular expression. This allows multiple variables to be connected to
3652the same callback without explicitly listing them all out.
3653
Heinrich Schuchardt1b040472018-07-29 11:08:14 +02003654The signature of the callback functions is:
3655
3656 int callback(const char *name, const char *value, enum env_op op, int flags)
3657
3658* name - changed environment variable
3659* value - new value of the environment variable
3660* op - operation (create, overwrite, or delete)
3661* flags - attributes of the environment variable change, see flags H_* in
3662 include/search.h
3663
3664The return value is 0 if the variable change is accepted and 1 otherwise.
Joe Hershberger170ab112012-12-11 22:16:24 -06003665
wdenk2729af92004-05-03 20:45:30 +00003666Command Line Parsing:
3667=====================
stroesec1551ea2003-04-04 15:53:41 +00003668
wdenk2729af92004-05-03 20:45:30 +00003669There are two different command line parsers available with U-Boot:
3670the old "simple" one, and the much more powerful "hush" shell:
stroesec1551ea2003-04-04 15:53:41 +00003671
wdenk2729af92004-05-03 20:45:30 +00003672Old, simple command line parser:
3673--------------------------------
wdenkc6097192002-11-03 00:24:07 +00003674
wdenk2729af92004-05-03 20:45:30 +00003675- supports environment variables (through setenv / saveenv commands)
3676- several commands on one line, separated by ';'
Wolfgang Denkfe126d82005-11-20 21:40:11 +01003677- variable substitution using "... ${name} ..." syntax
wdenk2729af92004-05-03 20:45:30 +00003678- special characters ('$', ';') can be escaped by prefixing with '\',
3679 for example:
Wolfgang Denkfe126d82005-11-20 21:40:11 +01003680 setenv bootcmd bootm \${address}
wdenk2729af92004-05-03 20:45:30 +00003681- You can also escape text by enclosing in single apostrophes, for example:
3682 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
wdenkc6097192002-11-03 00:24:07 +00003683
wdenk2729af92004-05-03 20:45:30 +00003684Hush shell:
3685-----------
wdenkf07771c2003-05-28 08:06:31 +00003686
wdenk2729af92004-05-03 20:45:30 +00003687- similar to Bourne shell, with control structures like
3688 if...then...else...fi, for...do...done; while...do...done,
3689 until...do...done, ...
3690- supports environment ("global") variables (through setenv / saveenv
3691 commands) and local shell variables (through standard shell syntax
3692 "name=value"); only environment variables can be used with "run"
3693 command
wdenkf07771c2003-05-28 08:06:31 +00003694
wdenk2729af92004-05-03 20:45:30 +00003695General rules:
3696--------------
wdenkf07771c2003-05-28 08:06:31 +00003697
wdenk2729af92004-05-03 20:45:30 +00003698(1) If a command line (or an environment variable executed by a "run"
3699 command) contains several commands separated by semicolon, and
3700 one of these commands fails, then the remaining commands will be
3701 executed anyway.
wdenkf07771c2003-05-28 08:06:31 +00003702
wdenk2729af92004-05-03 20:45:30 +00003703(2) If you execute several variables with one call to run (i. e.
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02003704 calling run with a list of variables as arguments), any failing
wdenk2729af92004-05-03 20:45:30 +00003705 command will cause "run" to terminate, i. e. the remaining
3706 variables are not executed.
wdenkf07771c2003-05-28 08:06:31 +00003707
wdenk2729af92004-05-03 20:45:30 +00003708Note for Redundant Ethernet Interfaces:
3709=======================================
wdenkf07771c2003-05-28 08:06:31 +00003710
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02003711Some boards come with redundant Ethernet interfaces; U-Boot supports
wdenk2729af92004-05-03 20:45:30 +00003712such configurations and is capable of automatic selection of a
3713"working" interface when needed. MAC assignment works as follows:
wdenkf07771c2003-05-28 08:06:31 +00003714
wdenk2729af92004-05-03 20:45:30 +00003715Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3716MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3717"eth1addr" (=>eth1), "eth2addr", ...
wdenkf07771c2003-05-28 08:06:31 +00003718
wdenk2729af92004-05-03 20:45:30 +00003719If the network interface stores some valid MAC address (for instance
3720in SROM), this is used as default address if there is NO correspon-
3721ding setting in the environment; if the corresponding environment
3722variable is set, this overrides the settings in the card; that means:
wdenkf07771c2003-05-28 08:06:31 +00003723
wdenk2729af92004-05-03 20:45:30 +00003724o If the SROM has a valid MAC address, and there is no address in the
3725 environment, the SROM's address is used.
wdenkc6097192002-11-03 00:24:07 +00003726
wdenk2729af92004-05-03 20:45:30 +00003727o If there is no valid address in the SROM, and a definition in the
3728 environment exists, then the value from the environment variable is
3729 used.
wdenkc6097192002-11-03 00:24:07 +00003730
wdenk2729af92004-05-03 20:45:30 +00003731o If both the SROM and the environment contain a MAC address, and
3732 both addresses are the same, this MAC address is used.
wdenkc6097192002-11-03 00:24:07 +00003733
wdenk2729af92004-05-03 20:45:30 +00003734o If both the SROM and the environment contain a MAC address, and the
3735 addresses differ, the value from the environment is used and a
3736 warning is printed.
wdenkc6097192002-11-03 00:24:07 +00003737
wdenk2729af92004-05-03 20:45:30 +00003738o If neither SROM nor the environment contain a MAC address, an error
Joe Hershbergerbef10142015-05-04 14:55:13 -05003739 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
3740 a random, locally-assigned MAC is used.
wdenkc6097192002-11-03 00:24:07 +00003741
Ben Warrenecee9322010-04-26 11:11:46 -07003742If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
Wolfgang Denkc0f40852011-10-26 10:21:21 +00003743will be programmed into hardware as part of the initialization process. This
Ben Warrenecee9322010-04-26 11:11:46 -07003744may be skipped by setting the appropriate 'ethmacskip' environment variable.
3745The naming convention is as follows:
3746"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
wdenkc6097192002-11-03 00:24:07 +00003747
wdenk2729af92004-05-03 20:45:30 +00003748Image Formats:
3749==============
wdenkc6097192002-11-03 00:24:07 +00003750
Marian Balakowicz3310c542008-03-12 12:13:13 +01003751U-Boot is capable of booting (and performing other auxiliary operations on)
3752images in two formats:
3753
3754New uImage format (FIT)
3755-----------------------
3756
3757Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3758to Flattened Device Tree). It allows the use of images with multiple
3759components (several kernels, ramdisks, etc.), with contents protected by
3760SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3761
3762
3763Old uImage format
3764-----------------
3765
3766Old image format is based on binary files which can be basically anything,
3767preceded by a special header; see the definitions in include/image.h for
3768details; basically, the header defines the following image properties:
wdenkc6097192002-11-03 00:24:07 +00003769
wdenk2729af92004-05-03 20:45:30 +00003770* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3771 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
Peter Tyserf5ed9e32008-09-08 14:56:49 -05003772 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3773 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3774 INTEGRITY).
Andy Shevchenkodaab59a2017-07-05 16:25:22 +03003775* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
Macpaul Linafc1ce82011-10-19 20:41:11 +00003776 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
Andy Shevchenkodaab59a2017-07-05 16:25:22 +03003777 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC).
wdenk2729af92004-05-03 20:45:30 +00003778* Compression Type (uncompressed, gzip, bzip2)
3779* Load Address
3780* Entry Point
3781* Image Name
3782* Image Timestamp
wdenkc6097192002-11-03 00:24:07 +00003783
wdenk2729af92004-05-03 20:45:30 +00003784The header is marked by a special Magic Number, and both the header
3785and the data portions of the image are secured against corruption by
3786CRC32 checksums.
wdenkc6097192002-11-03 00:24:07 +00003787
wdenkc6097192002-11-03 00:24:07 +00003788
wdenk2729af92004-05-03 20:45:30 +00003789Linux Support:
3790==============
wdenkc6097192002-11-03 00:24:07 +00003791
wdenk2729af92004-05-03 20:45:30 +00003792Although U-Boot should support any OS or standalone application
3793easily, the main focus has always been on Linux during the design of
3794U-Boot.
wdenkc6097192002-11-03 00:24:07 +00003795
wdenk2729af92004-05-03 20:45:30 +00003796U-Boot includes many features that so far have been part of some
3797special "boot loader" code within the Linux kernel. Also, any
3798"initrd" images to be used are no longer part of one big Linux image;
3799instead, kernel and "initrd" are separate images. This implementation
3800serves several purposes:
wdenkc6097192002-11-03 00:24:07 +00003801
wdenk2729af92004-05-03 20:45:30 +00003802- the same features can be used for other OS or standalone
3803 applications (for instance: using compressed images to reduce the
3804 Flash memory footprint)
wdenkc6097192002-11-03 00:24:07 +00003805
wdenk2729af92004-05-03 20:45:30 +00003806- it becomes much easier to port new Linux kernel versions because
3807 lots of low-level, hardware dependent stuff are done by U-Boot
wdenkc6097192002-11-03 00:24:07 +00003808
wdenk2729af92004-05-03 20:45:30 +00003809- the same Linux kernel image can now be used with different "initrd"
3810 images; of course this also means that different kernel images can
3811 be run with the same "initrd". This makes testing easier (you don't
3812 have to build a new "zImage.initrd" Linux image when you just
3813 change a file in your "initrd"). Also, a field-upgrade of the
3814 software is easier now.
wdenkc6097192002-11-03 00:24:07 +00003815
wdenkc6097192002-11-03 00:24:07 +00003816
wdenk2729af92004-05-03 20:45:30 +00003817Linux HOWTO:
3818============
wdenkc6097192002-11-03 00:24:07 +00003819
wdenk2729af92004-05-03 20:45:30 +00003820Porting Linux to U-Boot based systems:
3821---------------------------------------
wdenkc6097192002-11-03 00:24:07 +00003822
wdenk2729af92004-05-03 20:45:30 +00003823U-Boot cannot save you from doing all the necessary modifications to
3824configure the Linux device drivers for use with your target hardware
3825(no, we don't intend to provide a full virtual machine interface to
3826Linux :-).
wdenkc6097192002-11-03 00:24:07 +00003827
Stefan Roesea47a12b2010-04-15 16:07:28 +02003828But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
wdenkc6097192002-11-03 00:24:07 +00003829
wdenk2729af92004-05-03 20:45:30 +00003830Just make sure your machine specific header file (for instance
3831include/asm-ppc/tqm8xx.h) includes the same definition of the Board
Markus Heidelberg1dc30692008-09-07 20:18:27 +02003832Information structure as we define in include/asm-<arch>/u-boot.h,
3833and make sure that your definition of IMAP_ADDR uses the same value
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02003834as your U-Boot configuration in CONFIG_SYS_IMMR.
wdenkc6097192002-11-03 00:24:07 +00003835
Simon Glass2eb31b12014-06-11 23:29:46 -06003836Note that U-Boot now has a driver model, a unified model for drivers.
3837If you are adding a new driver, plumb it into driver model. If there
3838is no uclass available, you are encouraged to create one. See
3839doc/driver-model.
3840
wdenkc6097192002-11-03 00:24:07 +00003841
wdenk2729af92004-05-03 20:45:30 +00003842Configuring the Linux kernel:
3843-----------------------------
wdenkc6097192002-11-03 00:24:07 +00003844
wdenk2729af92004-05-03 20:45:30 +00003845No specific requirements for U-Boot. Make sure you have some root
3846device (initial ramdisk, NFS) for your target system.
wdenkc6097192002-11-03 00:24:07 +00003847
wdenkc6097192002-11-03 00:24:07 +00003848
wdenk2729af92004-05-03 20:45:30 +00003849Building a Linux Image:
3850-----------------------
wdenkc6097192002-11-03 00:24:07 +00003851
wdenk2729af92004-05-03 20:45:30 +00003852With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3853not used. If you use recent kernel source, a new build target
3854"uImage" will exist which automatically builds an image usable by
3855U-Boot. Most older kernels also have support for a "pImage" target,
3856which was introduced for our predecessor project PPCBoot and uses a
3857100% compatible format.
wdenkc6097192002-11-03 00:24:07 +00003858
wdenk2729af92004-05-03 20:45:30 +00003859Example:
wdenkc6097192002-11-03 00:24:07 +00003860
Holger Freytherab584d62014-08-04 09:26:05 +02003861 make TQM850L_defconfig
wdenk2729af92004-05-03 20:45:30 +00003862 make oldconfig
3863 make dep
3864 make uImage
wdenkc6097192002-11-03 00:24:07 +00003865
wdenk2729af92004-05-03 20:45:30 +00003866The "uImage" build target uses a special tool (in 'tools/mkimage') to
3867encapsulate a compressed Linux kernel image with header information,
3868CRC32 checksum etc. for use with U-Boot. This is what we are doing:
wdenkc6097192002-11-03 00:24:07 +00003869
wdenk2729af92004-05-03 20:45:30 +00003870* build a standard "vmlinux" kernel image (in ELF binary format):
wdenkc6097192002-11-03 00:24:07 +00003871
wdenk2729af92004-05-03 20:45:30 +00003872* convert the kernel into a raw binary image:
wdenkc6097192002-11-03 00:24:07 +00003873
wdenk2729af92004-05-03 20:45:30 +00003874 ${CROSS_COMPILE}-objcopy -O binary \
3875 -R .note -R .comment \
3876 -S vmlinux linux.bin
wdenkc6097192002-11-03 00:24:07 +00003877
wdenk2729af92004-05-03 20:45:30 +00003878* compress the binary image:
wdenkc6097192002-11-03 00:24:07 +00003879
wdenk2729af92004-05-03 20:45:30 +00003880 gzip -9 linux.bin
wdenkc6097192002-11-03 00:24:07 +00003881
wdenk2729af92004-05-03 20:45:30 +00003882* package compressed binary image for U-Boot:
wdenk24ee89b2002-11-03 17:56:27 +00003883
wdenk2729af92004-05-03 20:45:30 +00003884 mkimage -A ppc -O linux -T kernel -C gzip \
3885 -a 0 -e 0 -n "Linux Kernel Image" \
3886 -d linux.bin.gz uImage
wdenk24ee89b2002-11-03 17:56:27 +00003887
wdenk24ee89b2002-11-03 17:56:27 +00003888
wdenk2729af92004-05-03 20:45:30 +00003889The "mkimage" tool can also be used to create ramdisk images for use
3890with U-Boot, either separated from the Linux kernel image, or
3891combined into one file. "mkimage" encapsulates the images with a 64
3892byte header containing information about target architecture,
3893operating system, image type, compression method, entry points, time
3894stamp, CRC32 checksums, etc.
wdenk24ee89b2002-11-03 17:56:27 +00003895
wdenk2729af92004-05-03 20:45:30 +00003896"mkimage" can be called in two ways: to verify existing images and
3897print the header information, or to build new images.
wdenk24ee89b2002-11-03 17:56:27 +00003898
wdenk2729af92004-05-03 20:45:30 +00003899In the first form (with "-l" option) mkimage lists the information
3900contained in the header of an existing U-Boot image; this includes
3901checksum verification:
wdenk24ee89b2002-11-03 17:56:27 +00003902
wdenk2729af92004-05-03 20:45:30 +00003903 tools/mkimage -l image
3904 -l ==> list image header information
wdenk24ee89b2002-11-03 17:56:27 +00003905
wdenk2729af92004-05-03 20:45:30 +00003906The second form (with "-d" option) is used to build a U-Boot image
3907from a "data file" which is used as image payload:
wdenk24ee89b2002-11-03 17:56:27 +00003908
wdenk2729af92004-05-03 20:45:30 +00003909 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3910 -n name -d data_file image
3911 -A ==> set architecture to 'arch'
3912 -O ==> set operating system to 'os'
3913 -T ==> set image type to 'type'
3914 -C ==> set compression type 'comp'
3915 -a ==> set load address to 'addr' (hex)
3916 -e ==> set entry point to 'ep' (hex)
3917 -n ==> set image name to 'name'
3918 -d ==> use image data from 'datafile'
wdenk24ee89b2002-11-03 17:56:27 +00003919
wdenk69459792004-05-29 16:53:29 +00003920Right now, all Linux kernels for PowerPC systems use the same load
3921address (0x00000000), but the entry point address depends on the
3922kernel version:
wdenkc6097192002-11-03 00:24:07 +00003923
wdenk2729af92004-05-03 20:45:30 +00003924- 2.2.x kernels have the entry point at 0x0000000C,
3925- 2.3.x and later kernels have the entry point at 0x00000000.
wdenkc6097192002-11-03 00:24:07 +00003926
wdenk2729af92004-05-03 20:45:30 +00003927So a typical call to build a U-Boot image would read:
wdenkc6097192002-11-03 00:24:07 +00003928
wdenk2729af92004-05-03 20:45:30 +00003929 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3930 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
Stefan Roesea47a12b2010-04-15 16:07:28 +02003931 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
wdenk2729af92004-05-03 20:45:30 +00003932 > examples/uImage.TQM850L
3933 Image Name: 2.4.4 kernel for TQM850L
3934 Created: Wed Jul 19 02:34:59 2000
3935 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3936 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3937 Load Address: 0x00000000
3938 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00003939
wdenk2729af92004-05-03 20:45:30 +00003940To verify the contents of the image (or check for corruption):
wdenkc6097192002-11-03 00:24:07 +00003941
wdenk2729af92004-05-03 20:45:30 +00003942 -> tools/mkimage -l examples/uImage.TQM850L
3943 Image Name: 2.4.4 kernel for TQM850L
3944 Created: Wed Jul 19 02:34:59 2000
3945 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3946 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3947 Load Address: 0x00000000
3948 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00003949
wdenk2729af92004-05-03 20:45:30 +00003950NOTE: for embedded systems where boot time is critical you can trade
3951speed for memory and install an UNCOMPRESSED image instead: this
3952needs more space in Flash, but boots much faster since it does not
3953need to be uncompressed:
wdenkc6097192002-11-03 00:24:07 +00003954
Stefan Roesea47a12b2010-04-15 16:07:28 +02003955 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
wdenk2729af92004-05-03 20:45:30 +00003956 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3957 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
Stefan Roesea47a12b2010-04-15 16:07:28 +02003958 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
wdenk2729af92004-05-03 20:45:30 +00003959 > examples/uImage.TQM850L-uncompressed
3960 Image Name: 2.4.4 kernel for TQM850L
3961 Created: Wed Jul 19 02:34:59 2000
3962 Image Type: PowerPC Linux Kernel Image (uncompressed)
3963 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3964 Load Address: 0x00000000
3965 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00003966
wdenkc6097192002-11-03 00:24:07 +00003967
wdenk2729af92004-05-03 20:45:30 +00003968Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3969when your kernel is intended to use an initial ramdisk:
wdenkdb01a2e2004-04-15 23:14:49 +00003970
wdenk2729af92004-05-03 20:45:30 +00003971 -> tools/mkimage -n 'Simple Ramdisk Image' \
3972 > -A ppc -O linux -T ramdisk -C gzip \
3973 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3974 Image Name: Simple Ramdisk Image
3975 Created: Wed Jan 12 14:01:50 2000
3976 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3977 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3978 Load Address: 0x00000000
3979 Entry Point: 0x00000000
wdenkdb01a2e2004-04-15 23:14:49 +00003980
Guilherme Maciel Ferreiraa804b5c2013-12-01 12:43:11 -07003981The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
3982option performs the converse operation of the mkimage's second form (the "-d"
3983option). Given an image built by mkimage, the dumpimage extracts a "data file"
3984from the image:
3985
Guilherme Maciel Ferreiraf41f5b72015-01-15 02:54:40 -02003986 tools/dumpimage -i image -T type -p position data_file
3987 -i ==> extract from the 'image' a specific 'data_file'
3988 -T ==> set image type to 'type'
3989 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
Guilherme Maciel Ferreiraa804b5c2013-12-01 12:43:11 -07003990
wdenkdb01a2e2004-04-15 23:14:49 +00003991
wdenk2729af92004-05-03 20:45:30 +00003992Installing a Linux Image:
3993-------------------------
wdenkdb01a2e2004-04-15 23:14:49 +00003994
wdenk2729af92004-05-03 20:45:30 +00003995To downloading a U-Boot image over the serial (console) interface,
3996you must convert the image to S-Record format:
wdenkdb01a2e2004-04-15 23:14:49 +00003997
wdenk2729af92004-05-03 20:45:30 +00003998 objcopy -I binary -O srec examples/image examples/image.srec
wdenkdb01a2e2004-04-15 23:14:49 +00003999
wdenk2729af92004-05-03 20:45:30 +00004000The 'objcopy' does not understand the information in the U-Boot
4001image header, so the resulting S-Record file will be relative to
4002address 0x00000000. To load it to a given address, you need to
4003specify the target address as 'offset' parameter with the 'loads'
4004command.
wdenkc6097192002-11-03 00:24:07 +00004005
wdenk2729af92004-05-03 20:45:30 +00004006Example: install the image to address 0x40100000 (which on the
4007TQM8xxL is in the first Flash bank):
wdenkc6097192002-11-03 00:24:07 +00004008
wdenk2729af92004-05-03 20:45:30 +00004009 => erase 40100000 401FFFFF
wdenkc6097192002-11-03 00:24:07 +00004010
wdenk2729af92004-05-03 20:45:30 +00004011 .......... done
4012 Erased 8 sectors
wdenkc6097192002-11-03 00:24:07 +00004013
wdenk2729af92004-05-03 20:45:30 +00004014 => loads 40100000
4015 ## Ready for S-Record download ...
4016 ~>examples/image.srec
4017 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4018 ...
4019 15989 15990 15991 15992
4020 [file transfer complete]
4021 [connected]
4022 ## Start Addr = 0x00000000
wdenkc6097192002-11-03 00:24:07 +00004023
4024
wdenk2729af92004-05-03 20:45:30 +00004025You can check the success of the download using the 'iminfo' command;
Wolfgang Denk218ca722008-03-26 10:40:12 +01004026this includes a checksum verification so you can be sure no data
wdenk2729af92004-05-03 20:45:30 +00004027corruption happened:
wdenkc6097192002-11-03 00:24:07 +00004028
wdenk2729af92004-05-03 20:45:30 +00004029 => imi 40100000
wdenkc6097192002-11-03 00:24:07 +00004030
wdenk2729af92004-05-03 20:45:30 +00004031 ## Checking Image at 40100000 ...
4032 Image Name: 2.2.13 for initrd on TQM850L
4033 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4034 Data Size: 335725 Bytes = 327 kB = 0 MB
4035 Load Address: 00000000
4036 Entry Point: 0000000c
4037 Verifying Checksum ... OK
wdenkc6097192002-11-03 00:24:07 +00004038
4039
wdenk2729af92004-05-03 20:45:30 +00004040Boot Linux:
4041-----------
wdenkc6097192002-11-03 00:24:07 +00004042
wdenk2729af92004-05-03 20:45:30 +00004043The "bootm" command is used to boot an application that is stored in
4044memory (RAM or Flash). In case of a Linux kernel image, the contents
4045of the "bootargs" environment variable is passed to the kernel as
4046parameters. You can check and modify this variable using the
4047"printenv" and "setenv" commands:
wdenkc6097192002-11-03 00:24:07 +00004048
4049
wdenk2729af92004-05-03 20:45:30 +00004050 => printenv bootargs
4051 bootargs=root=/dev/ram
wdenkc6097192002-11-03 00:24:07 +00004052
wdenk2729af92004-05-03 20:45:30 +00004053 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
wdenkc6097192002-11-03 00:24:07 +00004054
wdenk2729af92004-05-03 20:45:30 +00004055 => printenv bootargs
4056 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
wdenkc6097192002-11-03 00:24:07 +00004057
wdenk2729af92004-05-03 20:45:30 +00004058 => bootm 40020000
4059 ## Booting Linux kernel at 40020000 ...
4060 Image Name: 2.2.13 for NFS on TQM850L
4061 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4062 Data Size: 381681 Bytes = 372 kB = 0 MB
4063 Load Address: 00000000
4064 Entry Point: 0000000c
4065 Verifying Checksum ... OK
4066 Uncompressing Kernel Image ... OK
4067 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
4068 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4069 time_init: decrementer frequency = 187500000/60
4070 Calibrating delay loop... 49.77 BogoMIPS
4071 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
4072 ...
wdenkc6097192002-11-03 00:24:07 +00004073
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02004074If you want to boot a Linux kernel with initial RAM disk, you pass
wdenk2729af92004-05-03 20:45:30 +00004075the memory addresses of both the kernel and the initrd image (PPBCOOT
4076format!) to the "bootm" command:
wdenkc6097192002-11-03 00:24:07 +00004077
wdenk2729af92004-05-03 20:45:30 +00004078 => imi 40100000 40200000
wdenkc6097192002-11-03 00:24:07 +00004079
wdenk2729af92004-05-03 20:45:30 +00004080 ## Checking Image at 40100000 ...
4081 Image Name: 2.2.13 for initrd on TQM850L
4082 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4083 Data Size: 335725 Bytes = 327 kB = 0 MB
4084 Load Address: 00000000
4085 Entry Point: 0000000c
4086 Verifying Checksum ... OK
wdenkc6097192002-11-03 00:24:07 +00004087
wdenk2729af92004-05-03 20:45:30 +00004088 ## Checking Image at 40200000 ...
4089 Image Name: Simple Ramdisk Image
4090 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4091 Data Size: 566530 Bytes = 553 kB = 0 MB
4092 Load Address: 00000000
4093 Entry Point: 00000000
4094 Verifying Checksum ... OK
wdenkc6097192002-11-03 00:24:07 +00004095
wdenk2729af92004-05-03 20:45:30 +00004096 => bootm 40100000 40200000
4097 ## Booting Linux kernel at 40100000 ...
4098 Image Name: 2.2.13 for initrd on TQM850L
4099 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4100 Data Size: 335725 Bytes = 327 kB = 0 MB
4101 Load Address: 00000000
4102 Entry Point: 0000000c
4103 Verifying Checksum ... OK
4104 Uncompressing Kernel Image ... OK
4105 ## Loading RAMDisk Image at 40200000 ...
4106 Image Name: Simple Ramdisk Image
4107 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4108 Data Size: 566530 Bytes = 553 kB = 0 MB
4109 Load Address: 00000000
4110 Entry Point: 00000000
4111 Verifying Checksum ... OK
4112 Loading Ramdisk ... OK
4113 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
4114 Boot arguments: root=/dev/ram
4115 time_init: decrementer frequency = 187500000/60
4116 Calibrating delay loop... 49.77 BogoMIPS
4117 ...
4118 RAMDISK: Compressed image found at block 0
4119 VFS: Mounted root (ext2 filesystem).
wdenkc6097192002-11-03 00:24:07 +00004120
wdenk2729af92004-05-03 20:45:30 +00004121 bash#
wdenkc6097192002-11-03 00:24:07 +00004122
Matthew McClintock02677682006-06-28 10:41:37 -05004123Boot Linux and pass a flat device tree:
4124-----------
4125
4126First, U-Boot must be compiled with the appropriate defines. See the section
4127titled "Linux Kernel Interface" above for a more in depth explanation. The
4128following is an example of how to start a kernel and pass an updated
4129flat device tree:
4130
4131=> print oftaddr
4132oftaddr=0x300000
4133=> print oft
4134oft=oftrees/mpc8540ads.dtb
4135=> tftp $oftaddr $oft
4136Speed: 1000, full duplex
4137Using TSEC0 device
4138TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4139Filename 'oftrees/mpc8540ads.dtb'.
4140Load address: 0x300000
4141Loading: #
4142done
4143Bytes transferred = 4106 (100a hex)
4144=> tftp $loadaddr $bootfile
4145Speed: 1000, full duplex
4146Using TSEC0 device
4147TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4148Filename 'uImage'.
4149Load address: 0x200000
4150Loading:############
4151done
4152Bytes transferred = 1029407 (fb51f hex)
4153=> print loadaddr
4154loadaddr=200000
4155=> print oftaddr
4156oftaddr=0x300000
4157=> bootm $loadaddr - $oftaddr
4158## Booting image at 00200000 ...
Wolfgang Denka9398e02006-11-27 15:32:42 +01004159 Image Name: Linux-2.6.17-dirty
4160 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4161 Data Size: 1029343 Bytes = 1005.2 kB
Matthew McClintock02677682006-06-28 10:41:37 -05004162 Load Address: 00000000
Wolfgang Denka9398e02006-11-27 15:32:42 +01004163 Entry Point: 00000000
Matthew McClintock02677682006-06-28 10:41:37 -05004164 Verifying Checksum ... OK
4165 Uncompressing Kernel Image ... OK
4166Booting using flat device tree at 0x300000
4167Using MPC85xx ADS machine description
4168Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4169[snip]
4170
4171
wdenk2729af92004-05-03 20:45:30 +00004172More About U-Boot Image Types:
4173------------------------------
wdenk6069ff22003-02-28 00:49:47 +00004174
wdenk2729af92004-05-03 20:45:30 +00004175U-Boot supports the following image types:
wdenk6069ff22003-02-28 00:49:47 +00004176
wdenk2729af92004-05-03 20:45:30 +00004177 "Standalone Programs" are directly runnable in the environment
4178 provided by U-Boot; it is expected that (if they behave
4179 well) you can continue to work in U-Boot after return from
4180 the Standalone Program.
4181 "OS Kernel Images" are usually images of some Embedded OS which
4182 will take over control completely. Usually these programs
4183 will install their own set of exception handlers, device
4184 drivers, set up the MMU, etc. - this means, that you cannot
4185 expect to re-enter U-Boot except by resetting the CPU.
4186 "RAMDisk Images" are more or less just data blocks, and their
4187 parameters (address, size) are passed to an OS kernel that is
4188 being started.
4189 "Multi-File Images" contain several images, typically an OS
4190 (Linux) kernel image and one or more data images like
4191 RAMDisks. This construct is useful for instance when you want
4192 to boot over the network using BOOTP etc., where the boot
4193 server provides just a single image file, but you want to get
4194 for instance an OS kernel and a RAMDisk image.
stroesec1551ea2003-04-04 15:53:41 +00004195
wdenk2729af92004-05-03 20:45:30 +00004196 "Multi-File Images" start with a list of image sizes, each
4197 image size (in bytes) specified by an "uint32_t" in network
4198 byte order. This list is terminated by an "(uint32_t)0".
4199 Immediately after the terminating 0 follow the images, one by
4200 one, all aligned on "uint32_t" boundaries (size rounded up to
4201 a multiple of 4 bytes).
stroesec1551ea2003-04-04 15:53:41 +00004202
wdenk2729af92004-05-03 20:45:30 +00004203 "Firmware Images" are binary images containing firmware (like
4204 U-Boot or FPGA images) which usually will be programmed to
4205 flash memory.
stroesec1551ea2003-04-04 15:53:41 +00004206
wdenk2729af92004-05-03 20:45:30 +00004207 "Script files" are command sequences that will be executed by
4208 U-Boot's command interpreter; this feature is especially
4209 useful when you configure U-Boot to use a real shell (hush)
4210 as command interpreter.
wdenk6069ff22003-02-28 00:49:47 +00004211
Marek Vasut44f074c2012-03-14 21:52:45 +00004212Booting the Linux zImage:
4213-------------------------
4214
4215On some platforms, it's possible to boot Linux zImage. This is done
4216using the "bootz" command. The syntax of "bootz" command is the same
4217as the syntax of "bootm" command.
4218
Tom Rini8ac28562013-05-16 11:40:11 -04004219Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
Marek Vasut017e1f32012-03-18 11:47:58 +00004220kernel with raw initrd images. The syntax is slightly different, the
4221address of the initrd must be augmented by it's size, in the following
4222format: "<initrd addres>:<initrd size>".
4223
wdenkc6097192002-11-03 00:24:07 +00004224
wdenk2729af92004-05-03 20:45:30 +00004225Standalone HOWTO:
4226=================
wdenkc6097192002-11-03 00:24:07 +00004227
wdenk2729af92004-05-03 20:45:30 +00004228One of the features of U-Boot is that you can dynamically load and
4229run "standalone" applications, which can use some resources of
4230U-Boot like console I/O functions or interrupt services.
wdenkc6097192002-11-03 00:24:07 +00004231
wdenk2729af92004-05-03 20:45:30 +00004232Two simple examples are included with the sources:
wdenkc6097192002-11-03 00:24:07 +00004233
wdenk2729af92004-05-03 20:45:30 +00004234"Hello World" Demo:
4235-------------------
wdenkc6097192002-11-03 00:24:07 +00004236
wdenk2729af92004-05-03 20:45:30 +00004237'examples/hello_world.c' contains a small "Hello World" Demo
4238application; it is automatically compiled when you build U-Boot.
4239It's configured to run at address 0x00040004, so you can play with it
4240like that:
wdenkc6097192002-11-03 00:24:07 +00004241
wdenk2729af92004-05-03 20:45:30 +00004242 => loads
4243 ## Ready for S-Record download ...
4244 ~>examples/hello_world.srec
4245 1 2 3 4 5 6 7 8 9 10 11 ...
4246 [file transfer complete]
4247 [connected]
4248 ## Start Addr = 0x00040004
wdenkc6097192002-11-03 00:24:07 +00004249
wdenk2729af92004-05-03 20:45:30 +00004250 => go 40004 Hello World! This is a test.
4251 ## Starting application at 0x00040004 ...
4252 Hello World
4253 argc = 7
4254 argv[0] = "40004"
4255 argv[1] = "Hello"
4256 argv[2] = "World!"
4257 argv[3] = "This"
4258 argv[4] = "is"
4259 argv[5] = "a"
4260 argv[6] = "test."
4261 argv[7] = "<NULL>"
4262 Hit any key to exit ...
wdenkc6097192002-11-03 00:24:07 +00004263
wdenk2729af92004-05-03 20:45:30 +00004264 ## Application terminated, rc = 0x0
wdenkc6097192002-11-03 00:24:07 +00004265
wdenk2729af92004-05-03 20:45:30 +00004266Another example, which demonstrates how to register a CPM interrupt
4267handler with the U-Boot code, can be found in 'examples/timer.c'.
4268Here, a CPM timer is set up to generate an interrupt every second.
4269The interrupt service routine is trivial, just printing a '.'
4270character, but this is just a demo program. The application can be
4271controlled by the following keys:
wdenkc6097192002-11-03 00:24:07 +00004272
wdenk2729af92004-05-03 20:45:30 +00004273 ? - print current values og the CPM Timer registers
4274 b - enable interrupts and start timer
4275 e - stop timer and disable interrupts
4276 q - quit application
wdenkc6097192002-11-03 00:24:07 +00004277
wdenk2729af92004-05-03 20:45:30 +00004278 => loads
4279 ## Ready for S-Record download ...
4280 ~>examples/timer.srec
4281 1 2 3 4 5 6 7 8 9 10 11 ...
4282 [file transfer complete]
4283 [connected]
4284 ## Start Addr = 0x00040004
wdenkc6097192002-11-03 00:24:07 +00004285
wdenk2729af92004-05-03 20:45:30 +00004286 => go 40004
4287 ## Starting application at 0x00040004 ...
4288 TIMERS=0xfff00980
4289 Using timer 1
4290 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
wdenkc6097192002-11-03 00:24:07 +00004291
wdenk2729af92004-05-03 20:45:30 +00004292Hit 'b':
4293 [q, b, e, ?] Set interval 1000000 us
4294 Enabling timer
4295Hit '?':
4296 [q, b, e, ?] ........
4297 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
4298Hit '?':
4299 [q, b, e, ?] .
4300 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
4301Hit '?':
4302 [q, b, e, ?] .
4303 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
4304Hit '?':
4305 [q, b, e, ?] .
4306 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
4307Hit 'e':
4308 [q, b, e, ?] ...Stopping timer
4309Hit 'q':
4310 [q, b, e, ?] ## Application terminated, rc = 0x0
wdenkc6097192002-11-03 00:24:07 +00004311
4312
wdenk2729af92004-05-03 20:45:30 +00004313Minicom warning:
4314================
wdenk85ec0bc2003-03-31 16:34:49 +00004315
wdenk2729af92004-05-03 20:45:30 +00004316Over time, many people have reported problems when trying to use the
4317"minicom" terminal emulation program for serial download. I (wd)
4318consider minicom to be broken, and recommend not to use it. Under
4319Unix, I recommend to use C-Kermit for general purpose use (and
4320especially for kermit binary protocol download ("loadb" command), and
Karl O. Pince53515a2012-10-01 05:11:56 +00004321use "cu" for S-Record download ("loads" command). See
4322http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
4323for help with kermit.
4324
wdenk85ec0bc2003-03-31 16:34:49 +00004325
wdenk2729af92004-05-03 20:45:30 +00004326Nevertheless, if you absolutely want to use it try adding this
4327configuration to your "File transfer protocols" section:
wdenk52f52c12003-06-19 23:04:19 +00004328
wdenk2729af92004-05-03 20:45:30 +00004329 Name Program Name U/D FullScr IO-Red. Multi
4330 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
4331 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
wdenk52f52c12003-06-19 23:04:19 +00004332
4333
wdenk2729af92004-05-03 20:45:30 +00004334NetBSD Notes:
4335=============
wdenkc6097192002-11-03 00:24:07 +00004336
wdenk2729af92004-05-03 20:45:30 +00004337Starting at version 0.9.2, U-Boot supports NetBSD both as host
4338(build U-Boot) and target system (boots NetBSD/mpc8xx).
wdenkc6097192002-11-03 00:24:07 +00004339
wdenk2729af92004-05-03 20:45:30 +00004340Building requires a cross environment; it is known to work on
4341NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
4342need gmake since the Makefiles are not compatible with BSD make).
4343Note that the cross-powerpc package does not install include files;
4344attempting to build U-Boot will fail because <machine/ansi.h> is
4345missing. This file has to be installed and patched manually:
wdenkc6097192002-11-03 00:24:07 +00004346
wdenk2729af92004-05-03 20:45:30 +00004347 # cd /usr/pkg/cross/powerpc-netbsd/include
4348 # mkdir powerpc
4349 # ln -s powerpc machine
4350 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
4351 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
wdenkc6097192002-11-03 00:24:07 +00004352
wdenk2729af92004-05-03 20:45:30 +00004353Native builds *don't* work due to incompatibilities between native
4354and U-Boot include files.
wdenkc6097192002-11-03 00:24:07 +00004355
wdenk2729af92004-05-03 20:45:30 +00004356Booting assumes that (the first part of) the image booted is a
4357stage-2 loader which in turn loads and then invokes the kernel
4358proper. Loader sources will eventually appear in the NetBSD source
4359tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
wdenk2a8af182005-04-13 10:02:42 +00004360meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
wdenkc6097192002-11-03 00:24:07 +00004361
4362
wdenk2729af92004-05-03 20:45:30 +00004363Implementation Internals:
4364=========================
wdenkc6097192002-11-03 00:24:07 +00004365
wdenk2729af92004-05-03 20:45:30 +00004366The following is not intended to be a complete description of every
4367implementation detail. However, it should help to understand the
4368inner workings of U-Boot and make it easier to port it to custom
4369hardware.
wdenkc6097192002-11-03 00:24:07 +00004370
4371
wdenk2729af92004-05-03 20:45:30 +00004372Initial Stack, Global Data:
4373---------------------------
wdenkc6097192002-11-03 00:24:07 +00004374
wdenk2729af92004-05-03 20:45:30 +00004375The implementation of U-Boot is complicated by the fact that U-Boot
4376starts running out of ROM (flash memory), usually without access to
4377system RAM (because the memory controller is not initialized yet).
4378This means that we don't have writable Data or BSS segments, and BSS
4379is not initialized as zero. To be able to get a C environment working
4380at all, we have to allocate at least a minimal stack. Implementation
4381options for this are defined and restricted by the CPU used: Some CPU
4382models provide on-chip memory (like the IMMR area on MPC8xx and
4383MPC826x processors), on others (parts of) the data cache can be
4384locked as (mis-) used as memory, etc.
wdenkc6097192002-11-03 00:24:07 +00004385
Wolfgang Denk218ca722008-03-26 10:40:12 +01004386 Chris Hallinan posted a good summary of these issues to the
Wolfgang Denk06682362008-12-30 22:56:11 +01004387 U-Boot mailing list:
wdenk43d96162003-03-06 00:02:04 +00004388
wdenk2729af92004-05-03 20:45:30 +00004389 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
4390 From: "Chris Hallinan" <clh@net1plus.com>
4391 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
4392 ...
wdenk43d96162003-03-06 00:02:04 +00004393
wdenk2729af92004-05-03 20:45:30 +00004394 Correct me if I'm wrong, folks, but the way I understand it
4395 is this: Using DCACHE as initial RAM for Stack, etc, does not
4396 require any physical RAM backing up the cache. The cleverness
4397 is that the cache is being used as a temporary supply of
4398 necessary storage before the SDRAM controller is setup. It's
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02004399 beyond the scope of this list to explain the details, but you
wdenk2729af92004-05-03 20:45:30 +00004400 can see how this works by studying the cache architecture and
4401 operation in the architecture and processor-specific manuals.
wdenk43d96162003-03-06 00:02:04 +00004402
wdenk2729af92004-05-03 20:45:30 +00004403 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4404 is another option for the system designer to use as an
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02004405 initial stack/RAM area prior to SDRAM being available. Either
wdenk2729af92004-05-03 20:45:30 +00004406 option should work for you. Using CS 4 should be fine if your
4407 board designers haven't used it for something that would
4408 cause you grief during the initial boot! It is frequently not
4409 used.
wdenk43d96162003-03-06 00:02:04 +00004410
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02004411 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
wdenk2729af92004-05-03 20:45:30 +00004412 with your processor/board/system design. The default value
4413 you will find in any recent u-boot distribution in
Stefan Roese8a316c92005-08-01 16:49:12 +02004414 walnut.h should work for you. I'd set it to a value larger
wdenk2729af92004-05-03 20:45:30 +00004415 than your SDRAM module. If you have a 64MB SDRAM module, set
4416 it above 400_0000. Just make sure your board has no resources
4417 that are supposed to respond to that address! That code in
4418 start.S has been around a while and should work as is when
4419 you get the config right.
wdenk43d96162003-03-06 00:02:04 +00004420
wdenk2729af92004-05-03 20:45:30 +00004421 -Chris Hallinan
4422 DS4.COM, Inc.
wdenk43d96162003-03-06 00:02:04 +00004423
wdenk2729af92004-05-03 20:45:30 +00004424It is essential to remember this, since it has some impact on the C
4425code for the initialization procedures:
wdenkc6097192002-11-03 00:24:07 +00004426
wdenk2729af92004-05-03 20:45:30 +00004427* Initialized global data (data segment) is read-only. Do not attempt
4428 to write it.
wdenkc6097192002-11-03 00:24:07 +00004429
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08004430* Do not use any uninitialized global data (or implicitly initialized
wdenk2729af92004-05-03 20:45:30 +00004431 as zero data - BSS segment) at all - this is undefined, initiali-
4432 zation is performed later (when relocating to RAM).
wdenkc6097192002-11-03 00:24:07 +00004433
wdenk2729af92004-05-03 20:45:30 +00004434* Stack space is very limited. Avoid big data buffers or things like
4435 that.
wdenkc6097192002-11-03 00:24:07 +00004436
wdenk2729af92004-05-03 20:45:30 +00004437Having only the stack as writable memory limits means we cannot use
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08004438normal global data to share information between the code. But it
wdenk2729af92004-05-03 20:45:30 +00004439turned out that the implementation of U-Boot can be greatly
4440simplified by making a global data structure (gd_t) available to all
4441functions. We could pass a pointer to this data as argument to _all_
4442functions, but this would bloat the code. Instead we use a feature of
4443the GCC compiler (Global Register Variables) to share the data: we
4444place a pointer (gd) to the global data into a register which we
4445reserve for this purpose.
wdenkc6097192002-11-03 00:24:07 +00004446
wdenk2729af92004-05-03 20:45:30 +00004447When choosing a register for such a purpose we are restricted by the
4448relevant (E)ABI specifications for the current architecture, and by
4449GCC's implementation.
wdenkc6097192002-11-03 00:24:07 +00004450
wdenk2729af92004-05-03 20:45:30 +00004451For PowerPC, the following registers have specific use:
4452 R1: stack pointer
Wolfgang Denke7670f62008-02-14 22:43:22 +01004453 R2: reserved for system use
wdenk2729af92004-05-03 20:45:30 +00004454 R3-R4: parameter passing and return values
4455 R5-R10: parameter passing
4456 R13: small data area pointer
4457 R30: GOT pointer
4458 R31: frame pointer
wdenkc6097192002-11-03 00:24:07 +00004459
Joakim Tjernlunde6bee802010-01-19 14:41:58 +01004460 (U-Boot also uses R12 as internal GOT pointer. r12
4461 is a volatile register so r12 needs to be reset when
4462 going back and forth between asm and C)
wdenkc6097192002-11-03 00:24:07 +00004463
Wolfgang Denke7670f62008-02-14 22:43:22 +01004464 ==> U-Boot will use R2 to hold a pointer to the global data
wdenkc6097192002-11-03 00:24:07 +00004465
wdenk2729af92004-05-03 20:45:30 +00004466 Note: on PPC, we could use a static initializer (since the
4467 address of the global data structure is known at compile time),
4468 but it turned out that reserving a register results in somewhat
4469 smaller code - although the code savings are not that big (on
4470 average for all boards 752 bytes for the whole U-Boot image,
4471 624 text + 127 data).
wdenkc6097192002-11-03 00:24:07 +00004472
wdenk2729af92004-05-03 20:45:30 +00004473On ARM, the following registers are used:
wdenkc6097192002-11-03 00:24:07 +00004474
wdenk2729af92004-05-03 20:45:30 +00004475 R0: function argument word/integer result
4476 R1-R3: function argument word
Jeroen Hofstee12eba1b2013-09-21 14:04:42 +02004477 R9: platform specific
4478 R10: stack limit (used only if stack checking is enabled)
wdenk2729af92004-05-03 20:45:30 +00004479 R11: argument (frame) pointer
4480 R12: temporary workspace
4481 R13: stack pointer
4482 R14: link register
4483 R15: program counter
wdenkc6097192002-11-03 00:24:07 +00004484
Jeroen Hofstee12eba1b2013-09-21 14:04:42 +02004485 ==> U-Boot will use R9 to hold a pointer to the global data
4486
4487 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
wdenkc6097192002-11-03 00:24:07 +00004488
Thomas Chou0df01fd2010-05-21 11:08:03 +08004489On Nios II, the ABI is documented here:
4490 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4491
4492 ==> U-Boot will use gp to hold a pointer to the global data
4493
4494 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4495 to access small data sections, so gp is free.
4496
Macpaul Linafc1ce82011-10-19 20:41:11 +00004497On NDS32, the following registers are used:
4498
4499 R0-R1: argument/return
4500 R2-R5: argument
4501 R15: temporary register for assembler
4502 R16: trampoline register
4503 R28: frame pointer (FP)
4504 R29: global pointer (GP)
4505 R30: link register (LP)
4506 R31: stack pointer (SP)
4507 PC: program counter (PC)
4508
4509 ==> U-Boot will use R10 to hold a pointer to the global data
4510
Wolfgang Denkd87080b2006-03-31 18:32:53 +02004511NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4512or current versions of GCC may "optimize" the code too much.
wdenkc6097192002-11-03 00:24:07 +00004513
Rick Chen3fafced2017-12-26 13:55:59 +08004514On RISC-V, the following registers are used:
4515
4516 x0: hard-wired zero (zero)
4517 x1: return address (ra)
4518 x2: stack pointer (sp)
4519 x3: global pointer (gp)
4520 x4: thread pointer (tp)
4521 x5: link register (t0)
4522 x8: frame pointer (fp)
4523 x10-x11: arguments/return values (a0-1)
4524 x12-x17: arguments (a2-7)
4525 x28-31: temporaries (t3-6)
4526 pc: program counter (pc)
4527
4528 ==> U-Boot will use gp to hold a pointer to the global data
4529
wdenk2729af92004-05-03 20:45:30 +00004530Memory Management:
4531------------------
wdenkc6097192002-11-03 00:24:07 +00004532
wdenk2729af92004-05-03 20:45:30 +00004533U-Boot runs in system state and uses physical addresses, i.e. the
4534MMU is not used either for address mapping nor for memory protection.
wdenkc6097192002-11-03 00:24:07 +00004535
wdenk2729af92004-05-03 20:45:30 +00004536The available memory is mapped to fixed addresses using the memory
4537controller. In this process, a contiguous block is formed for each
4538memory type (Flash, SDRAM, SRAM), even when it consists of several
4539physical memory banks.
wdenkc6097192002-11-03 00:24:07 +00004540
wdenk2729af92004-05-03 20:45:30 +00004541U-Boot is installed in the first 128 kB of the first Flash bank (on
4542TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4543booting and sizing and initializing DRAM, the code relocates itself
4544to the upper end of DRAM. Immediately below the U-Boot code some
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02004545memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
wdenk2729af92004-05-03 20:45:30 +00004546configuration setting]. Below that, a structure with global Board
4547Info data is placed, followed by the stack (growing downward).
wdenkc6097192002-11-03 00:24:07 +00004548
wdenk2729af92004-05-03 20:45:30 +00004549Additionally, some exception handler code is copied to the low 8 kB
4550of DRAM (0x00000000 ... 0x00001FFF).
wdenkc6097192002-11-03 00:24:07 +00004551
wdenk2729af92004-05-03 20:45:30 +00004552So a typical memory configuration with 16 MB of DRAM could look like
4553this:
wdenkc6097192002-11-03 00:24:07 +00004554
wdenk2729af92004-05-03 20:45:30 +00004555 0x0000 0000 Exception Vector code
4556 :
4557 0x0000 1FFF
4558 0x0000 2000 Free for Application Use
4559 :
4560 :
wdenkc6097192002-11-03 00:24:07 +00004561
wdenk2729af92004-05-03 20:45:30 +00004562 :
4563 :
4564 0x00FB FF20 Monitor Stack (Growing downward)
4565 0x00FB FFAC Board Info Data and permanent copy of global data
4566 0x00FC 0000 Malloc Arena
4567 :
4568 0x00FD FFFF
4569 0x00FE 0000 RAM Copy of Monitor Code
4570 ... eventually: LCD or video framebuffer
4571 ... eventually: pRAM (Protected RAM - unchanged by reset)
4572 0x00FF FFFF [End of RAM]
wdenkc6097192002-11-03 00:24:07 +00004573
4574
wdenk2729af92004-05-03 20:45:30 +00004575System Initialization:
4576----------------------
wdenkc6097192002-11-03 00:24:07 +00004577
wdenk2729af92004-05-03 20:45:30 +00004578In the reset configuration, U-Boot starts at the reset entry point
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02004579(on most PowerPC systems at address 0x00000100). Because of the reset
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08004580configuration for CS0# this is a mirror of the on board Flash memory.
wdenk2729af92004-05-03 20:45:30 +00004581To be able to re-map memory U-Boot then jumps to its link address.
4582To be able to implement the initialization code in C, a (small!)
4583initial stack is set up in the internal Dual Ported RAM (in case CPUs
Heiko Schocher2eb48ff2017-06-07 17:33:10 +02004584which provide such a feature like), or in a locked part of the data
4585cache. After that, U-Boot initializes the CPU core, the caches and
4586the SIU.
wdenkc6097192002-11-03 00:24:07 +00004587
wdenk2729af92004-05-03 20:45:30 +00004588Next, all (potentially) available memory banks are mapped using a
4589preliminary mapping. For example, we put them on 512 MB boundaries
4590(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4591on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4592programmed for SDRAM access. Using the temporary configuration, a
4593simple memory test is run that determines the size of the SDRAM
4594banks.
wdenkc6097192002-11-03 00:24:07 +00004595
wdenk2729af92004-05-03 20:45:30 +00004596When there is more than one SDRAM bank, and the banks are of
4597different size, the largest is mapped first. For equal size, the first
4598bank (CS2#) is mapped first. The first mapping is always for address
45990x00000000, with any additional banks following immediately to create
4600contiguous memory starting from 0.
wdenkc6097192002-11-03 00:24:07 +00004601
wdenk2729af92004-05-03 20:45:30 +00004602Then, the monitor installs itself at the upper end of the SDRAM area
4603and allocates memory for use by malloc() and for the global Board
4604Info data; also, the exception vector code is copied to the low RAM
4605pages, and the final stack is set up.
wdenkc6097192002-11-03 00:24:07 +00004606
wdenk2729af92004-05-03 20:45:30 +00004607Only after this relocation will you have a "normal" C environment;
4608until that you are restricted in several ways, mostly because you are
4609running from ROM, and because the code will have to be relocated to a
4610new address in RAM.
wdenkc6097192002-11-03 00:24:07 +00004611
4612
wdenk2729af92004-05-03 20:45:30 +00004613U-Boot Porting Guide:
4614----------------------
wdenkc6097192002-11-03 00:24:07 +00004615
wdenk2729af92004-05-03 20:45:30 +00004616[Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4617list, October 2002]
wdenkc6097192002-11-03 00:24:07 +00004618
4619
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04004620int main(int argc, char *argv[])
wdenk2729af92004-05-03 20:45:30 +00004621{
4622 sighandler_t no_more_time;
wdenkc6097192002-11-03 00:24:07 +00004623
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04004624 signal(SIGALRM, no_more_time);
4625 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
wdenkc6097192002-11-03 00:24:07 +00004626
wdenk2729af92004-05-03 20:45:30 +00004627 if (available_money > available_manpower) {
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04004628 Pay consultant to port U-Boot;
wdenkc6097192002-11-03 00:24:07 +00004629 return 0;
4630 }
4631
wdenk2729af92004-05-03 20:45:30 +00004632 Download latest U-Boot source;
4633
Wolfgang Denk06682362008-12-30 22:56:11 +01004634 Subscribe to u-boot mailing list;
wdenk2729af92004-05-03 20:45:30 +00004635
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04004636 if (clueless)
4637 email("Hi, I am new to U-Boot, how do I get started?");
wdenkc6097192002-11-03 00:24:07 +00004638
wdenk2729af92004-05-03 20:45:30 +00004639 while (learning) {
4640 Read the README file in the top level directory;
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04004641 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4642 Read applicable doc/*.README;
wdenk2729af92004-05-03 20:45:30 +00004643 Read the source, Luke;
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04004644 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
wdenk2729af92004-05-03 20:45:30 +00004645 }
wdenkc6097192002-11-03 00:24:07 +00004646
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04004647 if (available_money > toLocalCurrency ($2500))
4648 Buy a BDI3000;
4649 else
wdenk2729af92004-05-03 20:45:30 +00004650 Add a lot of aggravation and time;
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04004651
4652 if (a similar board exists) { /* hopefully... */
4653 cp -a board/<similar> board/<myboard>
4654 cp include/configs/<similar>.h include/configs/<myboard>.h
4655 } else {
4656 Create your own board support subdirectory;
4657 Create your own board include/configs/<myboard>.h file;
wdenk2729af92004-05-03 20:45:30 +00004658 }
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04004659 Edit new board/<myboard> files
4660 Edit new include/configs/<myboard>.h
wdenkc6097192002-11-03 00:24:07 +00004661
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04004662 while (!accepted) {
4663 while (!running) {
4664 do {
4665 Add / modify source code;
4666 } until (compiles);
4667 Debug;
4668 if (clueless)
4669 email("Hi, I am having problems...");
4670 }
4671 Send patch file to the U-Boot email list;
4672 if (reasonable critiques)
4673 Incorporate improvements from email list code review;
4674 else
4675 Defend code as written;
wdenk2729af92004-05-03 20:45:30 +00004676 }
wdenkc6097192002-11-03 00:24:07 +00004677
wdenk2729af92004-05-03 20:45:30 +00004678 return 0;
4679}
4680
4681void no_more_time (int sig)
4682{
4683 hire_a_guru();
4684}
wdenkc6097192002-11-03 00:24:07 +00004685
4686
wdenk2729af92004-05-03 20:45:30 +00004687Coding Standards:
4688-----------------
wdenkc6097192002-11-03 00:24:07 +00004689
wdenk2729af92004-05-03 20:45:30 +00004690All contributions to U-Boot should conform to the Linux kernel
Baruch Siach659208d2017-12-10 17:34:35 +02004691coding style; see the kernel coding style guide at
4692https://www.kernel.org/doc/html/latest/process/coding-style.html, and the
4693script "scripts/Lindent" in your Linux kernel source directory.
wdenk2729af92004-05-03 20:45:30 +00004694
Detlev Zundel2c051652006-09-01 15:39:02 +02004695Source files originating from a different project (for example the
4696MTD subsystem) are generally exempt from these guidelines and are not
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08004697reformatted to ease subsequent migration to newer versions of those
Detlev Zundel2c051652006-09-01 15:39:02 +02004698sources.
4699
4700Please note that U-Boot is implemented in C (and to some small parts in
4701Assembler); no C++ is used, so please do not use C++ style comments (//)
4702in your code.
wdenk2729af92004-05-03 20:45:30 +00004703
4704Please also stick to the following formatting rules:
4705- remove any trailing white space
Wolfgang Denk7ca92962011-07-27 10:59:55 +00004706- use TAB characters for indentation and vertical alignment, not spaces
wdenk2729af92004-05-03 20:45:30 +00004707- make sure NOT to use DOS '\r\n' line feeds
Wolfgang Denk7ca92962011-07-27 10:59:55 +00004708- do not add more than 2 consecutive empty lines to source files
wdenk2729af92004-05-03 20:45:30 +00004709- do not add trailing empty lines to source files
4710
4711Submissions which do not conform to the standards may be returned
4712with a request to reformat the changes.
wdenkc6097192002-11-03 00:24:07 +00004713
4714
wdenk2729af92004-05-03 20:45:30 +00004715Submitting Patches:
4716-------------------
wdenkc6097192002-11-03 00:24:07 +00004717
wdenk2729af92004-05-03 20:45:30 +00004718Since the number of patches for U-Boot is growing, we need to
4719establish some rules. Submissions which do not conform to these rules
4720may be rejected, even when they contain important and valuable stuff.
wdenkc6097192002-11-03 00:24:07 +00004721
Magnus Lilja0d28f342008-08-06 19:32:33 +02004722Please see http://www.denx.de/wiki/U-Boot/Patches for details.
Wolfgang Denk218ca722008-03-26 10:40:12 +01004723
Wolfgang Denk06682362008-12-30 22:56:11 +01004724Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
S. Lockwood-Childs1dade182017-11-14 22:56:42 -08004725see https://lists.denx.de/listinfo/u-boot
Wolfgang Denk06682362008-12-30 22:56:11 +01004726
wdenk2729af92004-05-03 20:45:30 +00004727When you send a patch, please include the following information with
4728it:
wdenkc6097192002-11-03 00:24:07 +00004729
wdenk2729af92004-05-03 20:45:30 +00004730* For bug fixes: a description of the bug and how your patch fixes
4731 this bug. Please try to include a way of demonstrating that the
4732 patch actually fixes something.
wdenkc6097192002-11-03 00:24:07 +00004733
wdenk2729af92004-05-03 20:45:30 +00004734* For new features: a description of the feature and your
4735 implementation.
wdenkc6097192002-11-03 00:24:07 +00004736
wdenk2729af92004-05-03 20:45:30 +00004737* A CHANGELOG entry as plaintext (separate from the patch)
4738
Robert P. J. Day7207b362015-12-19 07:16:10 -05004739* For major contributions, add a MAINTAINERS file with your
4740 information and associated file and directory references.
wdenk2729af92004-05-03 20:45:30 +00004741
Albert ARIBAUD27af9302013-09-11 15:52:51 +02004742* When you add support for a new board, don't forget to add a
4743 maintainer e-mail address to the boards.cfg file, too.
wdenk2729af92004-05-03 20:45:30 +00004744
4745* If your patch adds new configuration options, don't forget to
4746 document these in the README file.
4747
Wolfgang Denk218ca722008-03-26 10:40:12 +01004748* The patch itself. If you are using git (which is *strongly*
4749 recommended) you can easily generate the patch using the
Wolfgang Denk7ca92962011-07-27 10:59:55 +00004750 "git format-patch". If you then use "git send-email" to send it to
Wolfgang Denk218ca722008-03-26 10:40:12 +01004751 the U-Boot mailing list, you will avoid most of the common problems
4752 with some other mail clients.
wdenk2729af92004-05-03 20:45:30 +00004753
Wolfgang Denk218ca722008-03-26 10:40:12 +01004754 If you cannot use git, use "diff -purN OLD NEW". If your version of
4755 diff does not support these options, then get the latest version of
4756 GNU diff.
wdenk2729af92004-05-03 20:45:30 +00004757
Wolfgang Denk218ca722008-03-26 10:40:12 +01004758 The current directory when running this command shall be the parent
4759 directory of the U-Boot source tree (i. e. please make sure that
4760 your patch includes sufficient directory information for the
4761 affected files).
4762
4763 We prefer patches as plain text. MIME attachments are discouraged,
4764 and compressed attachments must not be used.
wdenk2729af92004-05-03 20:45:30 +00004765
4766* If one logical set of modifications affects or creates several
4767 files, all these changes shall be submitted in a SINGLE patch file.
4768
4769* Changesets that contain different, unrelated modifications shall be
4770 submitted as SEPARATE patches, one patch per changeset.
4771
4772
4773Notes:
4774
Simon Glass6de80f22016-07-27 20:33:08 -06004775* Before sending the patch, run the buildman script on your patched
wdenk2729af92004-05-03 20:45:30 +00004776 source tree and make sure that no errors or warnings are reported
4777 for any of the boards.
4778
4779* Keep your modifications to the necessary minimum: A patch
4780 containing several unrelated changes or arbitrary reformats will be
4781 returned with a request to re-formatting / split it.
4782
4783* If you modify existing code, make sure that your new code does not
4784 add to the memory footprint of the code ;-) Small is beautiful!
4785 When adding new features, these should compile conditionally only
4786 (using #ifdef), and the resulting code with the new feature
4787 disabled must not need more memory than the old code without your
4788 modification.
wdenk90dc6702005-05-03 14:12:25 +00004789
Wolfgang Denk06682362008-12-30 22:56:11 +01004790* Remember that there is a size limit of 100 kB per message on the
4791 u-boot mailing list. Bigger patches will be moderated. If they are
4792 reasonable and not too big, they will be acknowledged. But patches
4793 bigger than the size limit should be avoided.