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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.
Naoki Hayama6681bbb2020-10-08 13:16:18 +090054Please see https://lists.denx.de/pipermail/u-boot and
55https://marc.info/?l=u-boot
wdenkc6097192002-11-03 00:24:07 +000056
Wolfgang Denk218ca722008-03-26 10:40:12 +010057Where to get source code:
58=========================
59
Robert P. J. Day7207b362015-12-19 07:16:10 -050060The U-Boot source code is maintained in the Git repository at
Heinrich Schuchardta3bbd0b2021-02-24 13:19:04 +010061https://source.denx.de/u-boot/u-boot.git ; you can browse it online at
62https://source.denx.de/u-boot/u-boot
Wolfgang Denk218ca722008-03-26 10:40:12 +010063
Naoki Hayamac4bd51e2020-10-08 13:16:25 +090064The "Tags" links on this page allow you to download tarballs of
Marcel Ziswiler11ccc332008-07-09 08:17:15 +020065any version you might be interested in. Official releases are also
Naoki Hayamac4bd51e2020-10-08 13:16:25 +090066available from the DENX file server through HTTPS or FTP.
67https://ftp.denx.de/pub/u-boot/
68ftp://ftp.denx.de/pub/u-boot/
Wolfgang Denk218ca722008-03-26 10:40:12 +010069
70
wdenkc6097192002-11-03 00:24:07 +000071Where we come from:
72===================
73
74- start from 8xxrom sources
Naoki Hayama047f6ec2020-10-08 13:17:16 +090075- create PPCBoot project (https://sourceforge.net/projects/ppcboot)
wdenkc6097192002-11-03 00:24:07 +000076- clean up code
77- make it easier to add custom boards
78- make it possible to add other [PowerPC] CPUs
79- extend functions, especially:
80 * Provide extended interface to Linux boot loader
81 * S-Record download
82 * network boot
Simon Glass9e5616d2019-08-01 09:47:14 -060083 * ATA disk / SCSI ... boot
Naoki Hayama047f6ec2020-10-08 13:17:16 +090084- create ARMBoot project (https://sourceforge.net/projects/armboot)
wdenkc6097192002-11-03 00:24:07 +000085- add other CPU families (starting with ARM)
Naoki Hayama047f6ec2020-10-08 13:17:16 +090086- create U-Boot project (https://sourceforge.net/projects/u-boot)
87- current project page: see https://www.denx.de/wiki/U-Boot
wdenk24ee89b2002-11-03 17:56:27 +000088
89
90Names and Spelling:
91===================
92
93The "official" name of this project is "Das U-Boot". The spelling
94"U-Boot" shall be used in all written text (documentation, comments
95in source files etc.). Example:
96
97 This is the README file for the U-Boot project.
98
99File names etc. shall be based on the string "u-boot". Examples:
100
101 include/asm-ppc/u-boot.h
102
103 #include <asm/u-boot.h>
104
105Variable names, preprocessor constants etc. shall be either based on
106the string "u_boot" or on "U_BOOT". Example:
107
108 U_BOOT_VERSION u_boot_logo
109 IH_OS_U_BOOT u_boot_hush_start
wdenkc6097192002-11-03 00:24:07 +0000110
111
wdenk93f19cc2002-12-17 17:55:09 +0000112Versioning:
113===========
114
Thomas Weber360d8832010-09-28 08:06:25 +0200115Starting with the release in October 2008, the names of the releases
116were changed from numerical release numbers without deeper meaning
117into a time stamp based numbering. Regular releases are identified by
118names consisting of the calendar year and month of the release date.
119Additional fields (if present) indicate release candidates or bug fix
120releases in "stable" maintenance trees.
wdenk93f19cc2002-12-17 17:55:09 +0000121
Thomas Weber360d8832010-09-28 08:06:25 +0200122Examples:
Wolfgang Denkc0f40852011-10-26 10:21:21 +0000123 U-Boot v2009.11 - Release November 2009
Thomas Weber360d8832010-09-28 08:06:25 +0200124 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
Jelle van der Waa0de21ec2016-10-30 17:30:30 +0100125 U-Boot v2010.09-rc1 - Release candidate 1 for September 2010 release
wdenk93f19cc2002-12-17 17:55:09 +0000126
127
wdenkc6097192002-11-03 00:24:07 +0000128Directory Hierarchy:
129====================
130
Simon Glass6e73ed02021-07-10 21:14:21 -0600131/arch Architecture-specific files
Masahiro Yamada6eae68e2014-03-07 18:02:02 +0900132 /arc Files generic to ARC architecture
Peter Tyser8d321b82010-04-12 22:28:21 -0500133 /arm Files generic to ARM architecture
Peter Tyser8d321b82010-04-12 22:28:21 -0500134 /m68k Files generic to m68k architecture
Peter Tyser8d321b82010-04-12 22:28:21 -0500135 /microblaze Files generic to microblaze architecture
Peter Tyser8d321b82010-04-12 22:28:21 -0500136 /mips Files generic to MIPS architecture
Macpaul Linafc1ce82011-10-19 20:41:11 +0000137 /nds32 Files generic to NDS32 architecture
Peter Tyser8d321b82010-04-12 22:28:21 -0500138 /nios2 Files generic to Altera NIOS2 architecture
Stefan Roesea47a12b2010-04-15 16:07:28 +0200139 /powerpc Files generic to PowerPC architecture
Rick Chen3fafced2017-12-26 13:55:59 +0800140 /riscv Files generic to RISC-V architecture
Robert P. J. Day7207b362015-12-19 07:16:10 -0500141 /sandbox Files generic to HW-independent "sandbox"
Peter Tyser8d321b82010-04-12 22:28:21 -0500142 /sh Files generic to SH architecture
Robert P. J. Day33c77312013-09-15 18:34:15 -0400143 /x86 Files generic to x86 architecture
Naoki Hayamae4eb3132020-10-08 13:16:38 +0900144 /xtensa Files generic to Xtensa architecture
Simon Glass6e73ed02021-07-10 21:14:21 -0600145/api Machine/arch-independent API for external apps
146/board Board-dependent files
Xu Ziyuan740f7e52016-08-26 19:54:49 +0800147/cmd U-Boot commands functions
Simon Glass6e73ed02021-07-10 21:14:21 -0600148/common Misc architecture-independent functions
Robert P. J. Day7207b362015-12-19 07:16:10 -0500149/configs Board default configuration files
Peter Tyser8d321b82010-04-12 22:28:21 -0500150/disk Code for disk drive partition handling
Simon Glass6e73ed02021-07-10 21:14:21 -0600151/doc Documentation (a mix of ReST and READMEs)
152/drivers Device drivers
153/dts Makefile for building internal U-Boot fdt.
154/env Environment support
Peter Tyser8d321b82010-04-12 22:28:21 -0500155/examples Example code for standalone applications, etc.
156/fs Filesystem code (cramfs, ext2, jffs2, etc.)
157/include Header Files
Robert P. J. Day7207b362015-12-19 07:16:10 -0500158/lib Library routines generic to all architectures
159/Licenses Various license files
Peter Tyser8d321b82010-04-12 22:28:21 -0500160/net Networking code
161/post Power On Self Test
Robert P. J. Day7207b362015-12-19 07:16:10 -0500162/scripts Various build scripts and Makefiles
163/test Various unit test files
Simon Glass6e73ed02021-07-10 21:14:21 -0600164/tools Tools to build and sign FIT images, etc.
wdenkc6097192002-11-03 00:24:07 +0000165
wdenkc6097192002-11-03 00:24:07 +0000166Software Configuration:
167=======================
168
169Configuration is usually done using C preprocessor defines; the
170rationale behind that is to avoid dead code whenever possible.
171
172There are two classes of configuration variables:
173
174* Configuration _OPTIONS_:
175 These are selectable by the user and have names beginning with
176 "CONFIG_".
177
178* Configuration _SETTINGS_:
179 These depend on the hardware etc. and should not be meddled with if
180 you don't know what you're doing; they have names beginning with
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200181 "CONFIG_SYS_".
wdenkc6097192002-11-03 00:24:07 +0000182
Robert P. J. Day7207b362015-12-19 07:16:10 -0500183Previously, all configuration was done by hand, which involved creating
184symbolic links and editing configuration files manually. More recently,
185U-Boot has added the Kbuild infrastructure used by the Linux kernel,
186allowing you to use the "make menuconfig" command to configure your
187build.
wdenkc6097192002-11-03 00:24:07 +0000188
189
190Selection of Processor Architecture and Board Type:
191---------------------------------------------------
192
193For all supported boards there are ready-to-use default
Holger Freytherab584d62014-08-04 09:26:05 +0200194configurations available; just type "make <board_name>_defconfig".
wdenkc6097192002-11-03 00:24:07 +0000195
196Example: For a TQM823L module type:
197
198 cd u-boot
Holger Freytherab584d62014-08-04 09:26:05 +0200199 make TQM823L_defconfig
wdenkc6097192002-11-03 00:24:07 +0000200
Robert P. J. Day7207b362015-12-19 07:16:10 -0500201Note: If you're looking for the default configuration file for a board
202you're sure used to be there but is now missing, check the file
203doc/README.scrapyard for a list of no longer supported boards.
wdenkc6097192002-11-03 00:24:07 +0000204
Simon Glass75b3c3a2014-03-22 17:12:59 -0600205Sandbox Environment:
206--------------------
207
208U-Boot can be built natively to run on a Linux host using the 'sandbox'
209board. This allows feature development which is not board- or architecture-
210specific to be undertaken on a native platform. The sandbox is also used to
211run some of U-Boot's tests.
212
Naoki Hayamabbb140e2020-10-08 13:16:58 +0900213See doc/arch/sandbox.rst for more details.
Simon Glass75b3c3a2014-03-22 17:12:59 -0600214
215
Simon Glassdb910352015-03-03 08:03:00 -0700216Board Initialisation Flow:
217--------------------------
218
219This is the intended start-up flow for boards. This should apply for both
Robert P. J. Day7207b362015-12-19 07:16:10 -0500220SPL and U-Boot proper (i.e. they both follow the same rules).
Simon Glassdb910352015-03-03 08:03:00 -0700221
Robert P. J. Day7207b362015-12-19 07:16:10 -0500222Note: "SPL" stands for "Secondary Program Loader," which is explained in
223more detail later in this file.
224
225At present, SPL mostly uses a separate code path, but the function names
226and roles of each function are the same. Some boards or architectures
227may not conform to this. At least most ARM boards which use
228CONFIG_SPL_FRAMEWORK conform to this.
229
230Execution typically starts with an architecture-specific (and possibly
231CPU-specific) start.S file, such as:
232
233 - arch/arm/cpu/armv7/start.S
234 - arch/powerpc/cpu/mpc83xx/start.S
235 - arch/mips/cpu/start.S
236
237and so on. From there, three functions are called; the purpose and
238limitations of each of these functions are described below.
Simon Glassdb910352015-03-03 08:03:00 -0700239
240lowlevel_init():
241 - purpose: essential init to permit execution to reach board_init_f()
242 - no global_data or BSS
243 - there is no stack (ARMv7 may have one but it will soon be removed)
244 - must not set up SDRAM or use console
245 - must only do the bare minimum to allow execution to continue to
246 board_init_f()
247 - this is almost never needed
248 - return normally from this function
249
250board_init_f():
251 - purpose: set up the machine ready for running board_init_r():
252 i.e. SDRAM and serial UART
253 - global_data is available
254 - stack is in SRAM
255 - BSS is not available, so you cannot use global/static variables,
256 only stack variables and global_data
257
258 Non-SPL-specific notes:
259 - dram_init() is called to set up DRAM. If already done in SPL this
260 can do nothing
261
262 SPL-specific notes:
263 - you can override the entire board_init_f() function with your own
264 version as needed.
265 - preloader_console_init() can be called here in extremis
266 - should set up SDRAM, and anything needed to make the UART work
Naoki Hayama499696e2020-09-24 15:57:19 +0900267 - there is no need to clear BSS, it will be done by crt0.S
Andreas Dannenberg14254652019-08-08 12:54:49 -0500268 - for specific scenarios on certain architectures an early BSS *can*
269 be made available (via CONFIG_SPL_EARLY_BSS by moving the clearing
270 of BSS prior to entering board_init_f()) but doing so is discouraged.
271 Instead it is strongly recommended to architect any code changes
272 or additions such to not depend on the availability of BSS during
273 board_init_f() as indicated in other sections of this README to
274 maintain compatibility and consistency across the entire code base.
Simon Glassdb910352015-03-03 08:03:00 -0700275 - must return normally from this function (don't call board_init_r()
276 directly)
277
278Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
279this point the stack and global_data are relocated to below
280CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
281memory.
282
283board_init_r():
284 - purpose: main execution, common code
285 - global_data is available
286 - SDRAM is available
287 - BSS is available, all static/global variables can be used
288 - execution eventually continues to main_loop()
289
290 Non-SPL-specific notes:
291 - U-Boot is relocated to the top of memory and is now running from
292 there.
293
294 SPL-specific notes:
295 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
296 CONFIG_SPL_STACK_R_ADDR points into SDRAM
297 - preloader_console_init() can be called here - typically this is
Ley Foon Tan0680f1b2017-05-03 17:13:32 +0800298 done by selecting CONFIG_SPL_BOARD_INIT and then supplying a
Simon Glassdb910352015-03-03 08:03:00 -0700299 spl_board_init() function containing this call
300 - loads U-Boot or (in falcon mode) Linux
301
302
wdenkc6097192002-11-03 00:24:07 +0000303Configuration Options:
304----------------------
305
306Configuration depends on the combination of board and CPU type; all
307such information is kept in a configuration file
308"include/configs/<board_name>.h".
309
310Example: For a TQM823L module, all configuration settings are in
311"include/configs/TQM823L.h".
312
313
wdenk7f6c2cb2002-11-10 22:06:23 +0000314Many of the options are named exactly as the corresponding Linux
315kernel configuration options. The intention is to make it easier to
316build a config tool - later.
317
Ashish Kumar63b23162017-08-11 11:09:14 +0530318- ARM Platform Bus Type(CCI):
319 CoreLink Cache Coherent Interconnect (CCI) is ARM BUS which
320 provides full cache coherency between two clusters of multi-core
321 CPUs and I/O coherency for devices and I/O masters
322
323 CONFIG_SYS_FSL_HAS_CCI400
324
325 Defined For SoC that has cache coherent interconnect
326 CCN-400
wdenk7f6c2cb2002-11-10 22:06:23 +0000327
Ashish Kumarc055cee2017-08-18 10:54:36 +0530328 CONFIG_SYS_FSL_HAS_CCN504
329
330 Defined for SoC that has cache coherent interconnect CCN-504
331
wdenkc6097192002-11-03 00:24:07 +0000332The following options need to be configured:
333
Kim Phillips26281142007-08-10 13:28:25 -0500334- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
wdenkc6097192002-11-03 00:24:07 +0000335
Kim Phillips26281142007-08-10 13:28:25 -0500336- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
Wolfgang Denk6ccec442006-10-24 14:42:37 +0200337
Kumar Gala66412c62011-02-18 05:40:54 -0600338- 85xx CPU Options:
York Sunffd06e02012-10-08 07:44:30 +0000339 CONFIG_SYS_PPC64
340
341 Specifies that the core is a 64-bit PowerPC implementation (implements
342 the "64" category of the Power ISA). This is necessary for ePAPR
343 compliance, among other possible reasons.
344
Kumar Gala66412c62011-02-18 05:40:54 -0600345 CONFIG_SYS_FSL_TBCLK_DIV
346
347 Defines the core time base clock divider ratio compared to the
348 system clock. On most PQ3 devices this is 8, on newer QorIQ
349 devices it can be 16 or 32. The ratio varies from SoC to Soc.
350
Kumar Gala8f290842011-05-20 00:39:21 -0500351 CONFIG_SYS_FSL_PCIE_COMPAT
352
353 Defines the string to utilize when trying to match PCIe device
354 tree nodes for the given platform.
355
Scott Wood33eee332012-08-14 10:14:53 +0000356 CONFIG_SYS_FSL_ERRATUM_A004510
357
358 Enables a workaround for erratum A004510. If set,
359 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
360 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
361
362 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
363 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
364
365 Defines one or two SoC revisions (low 8 bits of SVR)
366 for which the A004510 workaround should be applied.
367
368 The rest of SVR is either not relevant to the decision
369 of whether the erratum is present (e.g. p2040 versus
370 p2041) or is implied by the build target, which controls
371 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
372
373 See Freescale App Note 4493 for more information about
374 this erratum.
375
Prabhakar Kushwaha74fa22e2013-04-16 13:27:44 +0530376 CONFIG_A003399_NOR_WORKAROUND
377 Enables a workaround for IFC erratum A003399. It is only
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -0800378 required during NOR boot.
Prabhakar Kushwaha74fa22e2013-04-16 13:27:44 +0530379
Prabhakar Kushwaha9f074e62014-10-29 22:33:09 +0530380 CONFIG_A008044_WORKAROUND
381 Enables a workaround for T1040/T1042 erratum A008044. It is only
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -0800382 required during NAND boot and valid for Rev 1.0 SoC revision
Prabhakar Kushwaha9f074e62014-10-29 22:33:09 +0530383
Scott Wood33eee332012-08-14 10:14:53 +0000384 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
385
386 This is the value to write into CCSR offset 0x18600
387 according to the A004510 workaround.
388
Priyanka Jain64501c62013-07-02 09:21:04 +0530389 CONFIG_SYS_FSL_DSP_DDR_ADDR
390 This value denotes start offset of DDR memory which is
391 connected exclusively to the DSP cores.
392
Priyanka Jain765b0bd2013-04-04 09:31:54 +0530393 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
394 This value denotes start offset of M2 memory
395 which is directly connected to the DSP core.
396
Priyanka Jain64501c62013-07-02 09:21:04 +0530397 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
398 This value denotes start offset of M3 memory which is directly
399 connected to the DSP core.
400
Priyanka Jain765b0bd2013-04-04 09:31:54 +0530401 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
402 This value denotes start offset of DSP CCSR space.
403
Priyanka Jainb1359912013-12-17 14:25:52 +0530404 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
405 Single Source Clock is clocking mode present in some of FSL SoC's.
406 In this mode, a single differential clock is used to supply
407 clocks to the sysclock, ddrclock and usbclock.
408
Aneesh Bansalfb4a2402014-03-18 23:40:26 +0530409 CONFIG_SYS_CPC_REINIT_F
410 This CONFIG is defined when the CPC is configured as SRAM at the
Bin Menga1875592016-02-05 19:30:11 -0800411 time of U-Boot entry and is required to be re-initialized.
Aneesh Bansalfb4a2402014-03-18 23:40:26 +0530412
Tang Yuantianaade2002014-04-17 15:33:46 +0800413 CONFIG_DEEP_SLEEP
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -0800414 Indicates this SoC supports deep sleep feature. If deep sleep is
Tang Yuantianaade2002014-04-17 15:33:46 +0800415 supported, core will start to execute uboot when wakes up.
416
Daniel Schwierzeck6cb461b2012-04-02 02:57:56 +0000417- Generic CPU options:
418 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
419
420 Defines the endianess of the CPU. Implementation of those
421 values is arch specific.
422
York Sun5614e712013-09-30 09:22:09 -0700423 CONFIG_SYS_FSL_DDR
424 Freescale DDR driver in use. This type of DDR controller is
Tom Rini1c588572021-05-14 21:34:26 -0400425 found in mpc83xx, mpc85xx as well as some ARM core SoCs.
York Sun5614e712013-09-30 09:22:09 -0700426
427 CONFIG_SYS_FSL_DDR_ADDR
428 Freescale DDR memory-mapped register base.
429
430 CONFIG_SYS_FSL_DDR_EMU
431 Specify emulator support for DDR. Some DDR features such as
432 deskew training are not available.
433
434 CONFIG_SYS_FSL_DDRC_GEN1
435 Freescale DDR1 controller.
436
437 CONFIG_SYS_FSL_DDRC_GEN2
438 Freescale DDR2 controller.
439
440 CONFIG_SYS_FSL_DDRC_GEN3
441 Freescale DDR3 controller.
442
York Sun34e026f2014-03-27 17:54:47 -0700443 CONFIG_SYS_FSL_DDRC_GEN4
444 Freescale DDR4 controller.
445
York Sun9ac4ffb2013-09-30 14:20:51 -0700446 CONFIG_SYS_FSL_DDRC_ARM_GEN3
447 Freescale DDR3 controller for ARM-based SoCs.
448
York Sun5614e712013-09-30 09:22:09 -0700449 CONFIG_SYS_FSL_DDR1
450 Board config to use DDR1. It can be enabled for SoCs with
451 Freescale DDR1 or DDR2 controllers, depending on the board
452 implemetation.
453
454 CONFIG_SYS_FSL_DDR2
Robert P. J. Day62a3b7d2016-07-15 13:44:45 -0400455 Board config to use DDR2. It can be enabled for SoCs with
York Sun5614e712013-09-30 09:22:09 -0700456 Freescale DDR2 or DDR3 controllers, depending on the board
457 implementation.
458
459 CONFIG_SYS_FSL_DDR3
460 Board config to use DDR3. It can be enabled for SoCs with
York Sun34e026f2014-03-27 17:54:47 -0700461 Freescale DDR3 or DDR3L controllers.
462
463 CONFIG_SYS_FSL_DDR3L
464 Board config to use DDR3L. It can be enabled for SoCs with
465 DDR3L controllers.
466
Prabhakar Kushwaha1b4175d2014-01-18 12:28:30 +0530467 CONFIG_SYS_FSL_IFC_BE
468 Defines the IFC controller register space as Big Endian
469
470 CONFIG_SYS_FSL_IFC_LE
471 Defines the IFC controller register space as Little Endian
472
Prabhakar Kushwaha1c407072017-02-02 15:01:26 +0530473 CONFIG_SYS_FSL_IFC_CLK_DIV
474 Defines divider of platform clock(clock input to IFC controller).
475
Prabhakar Kushwahaadd63f92017-02-02 15:02:00 +0530476 CONFIG_SYS_FSL_LBC_CLK_DIV
477 Defines divider of platform clock(clock input to eLBC controller).
478
York Sun4e5b1bd2014-02-10 13:59:42 -0800479 CONFIG_SYS_FSL_DDR_BE
480 Defines the DDR controller register space as Big Endian
481
482 CONFIG_SYS_FSL_DDR_LE
483 Defines the DDR controller register space as Little Endian
484
York Sun6b9e3092014-02-10 13:59:43 -0800485 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
486 Physical address from the view of DDR controllers. It is the
487 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
488 it could be different for ARM SoCs.
489
York Sun6b1e1252014-02-10 13:59:44 -0800490 CONFIG_SYS_FSL_DDR_INTLV_256B
491 DDR controller interleaving on 256-byte. This is a special
492 interleaving mode, handled by Dickens for Freescale layerscape
493 SoCs with ARM core.
494
York Sun1d71efb2014-08-01 15:51:00 -0700495 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
496 Number of controllers used as main memory.
497
498 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
499 Number of controllers used for other than main memory.
500
Prabhakar Kushwaha44937212015-11-09 16:42:07 +0530501 CONFIG_SYS_FSL_HAS_DP_DDR
502 Defines the SoC has DP-DDR used for DPAA.
503
Ruchika Gupta028dbb82014-09-09 11:50:31 +0530504 CONFIG_SYS_FSL_SEC_BE
505 Defines the SEC controller register space as Big Endian
506
507 CONFIG_SYS_FSL_SEC_LE
508 Defines the SEC controller register space as Little Endian
509
Daniel Schwierzeck92bbd642011-07-27 13:22:39 +0200510- MIPS CPU options:
511 CONFIG_SYS_INIT_SP_OFFSET
512
513 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
514 pointer. This is needed for the temporary stack before
515 relocation.
516
Daniel Schwierzeck92bbd642011-07-27 13:22:39 +0200517 CONFIG_XWAY_SWAP_BYTES
518
519 Enable compilation of tools/xway-swap-bytes needed for Lantiq
520 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
521 be swapped if a flash programmer is used.
522
Christian Rieschb67d8812012-02-02 00:44:39 +0000523- ARM options:
524 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
525
526 Select high exception vectors of the ARM core, e.g., do not
527 clear the V bit of the c1 register of CP15.
528
York Sun207774b2015-03-20 19:28:08 -0700529 COUNTER_FREQUENCY
530 Generic timer clock source frequency.
531
532 COUNTER_FREQUENCY_REAL
533 Generic timer clock source frequency if the real clock is
534 different from COUNTER_FREQUENCY, and can only be determined
535 at run time.
536
Stephen Warren73c38932015-01-19 16:25:52 -0700537- Tegra SoC options:
538 CONFIG_TEGRA_SUPPORT_NON_SECURE
539
540 Support executing U-Boot in non-secure (NS) mode. Certain
541 impossible actions will be skipped if the CPU is in NS mode,
542 such as ARM architectural timer initialization.
543
wdenk5da627a2003-10-09 20:09:04 +0000544- Linux Kernel Interface:
wdenk5da627a2003-10-09 20:09:04 +0000545 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
546
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -0800547 When transferring memsize parameter to Linux, some versions
wdenk5da627a2003-10-09 20:09:04 +0000548 expect it to be in bytes, others in MB.
549 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
550
Gerald Van Barenfec6d9e2008-06-03 20:34:45 -0400551 CONFIG_OF_LIBFDT
Wolfgang Denkf57f70a2005-10-13 01:45:54 +0200552
553 New kernel versions are expecting firmware settings to be
Gerald Van Baren213bf8c2007-03-31 12:23:51 -0400554 passed using flattened device trees (based on open firmware
555 concepts).
556
557 CONFIG_OF_LIBFDT
558 * New libfdt-based support
559 * Adds the "fdt" command
Kim Phillips3bb342f2007-08-10 14:34:14 -0500560 * The bootm command automatically updates the fdt
Gerald Van Baren213bf8c2007-03-31 12:23:51 -0400561
Wolfgang Denkf57f70a2005-10-13 01:45:54 +0200562 OF_TBCLK - The timebase frequency.
563
Marcel Ziswiler11ccc332008-07-09 08:17:15 +0200564 boards with QUICC Engines require OF_QE to set UCC MAC
565 addresses
Kim Phillips3bb342f2007-08-10 14:34:14 -0500566
Kumar Gala4e253132006-01-11 13:54:17 -0600567 CONFIG_OF_BOARD_SETUP
568
569 Board code has addition modification that it wants to make
570 to the flat device tree before handing it off to the kernel
wdenk6705d812004-08-02 23:22:59 +0000571
Simon Glassc654b512014-10-23 18:58:54 -0600572 CONFIG_OF_SYSTEM_SETUP
573
574 Other code has addition modification that it wants to make
575 to the flat device tree before handing it off to the kernel.
576 This causes ft_system_setup() to be called before booting
577 the kernel.
578
Heiko Schocher3887c3f2009-09-23 07:56:08 +0200579 CONFIG_OF_IDE_FIXUP
580
581 U-Boot can detect if an IDE device is present or not.
582 If not, and this new config option is activated, U-Boot
583 removes the ATA node from the DTS before booting Linux,
584 so the Linux IDE driver does not probe the device and
585 crash. This is needed for buggy hardware (uc101) where
586 no pull down resistor is connected to the signal IDE5V_DD7.
587
Niklaus Giger0b2f4ec2008-11-03 22:13:47 +0100588- vxWorks boot parameters:
589
590 bootvx constructs a valid bootline using the following
Bin Meng9e98b7e2015-10-07 20:19:17 -0700591 environments variables: bootdev, bootfile, ipaddr, netmask,
592 serverip, gatewayip, hostname, othbootargs.
Niklaus Giger0b2f4ec2008-11-03 22:13:47 +0100593 It loads the vxWorks image pointed bootfile.
594
Naoki Hayama81a05d92020-10-08 13:17:08 +0900595 Note: If a "bootargs" environment is defined, it will override
Niklaus Giger0b2f4ec2008-11-03 22:13:47 +0100596 the defaults discussed just above.
597
Aneesh V2c451f72011-06-16 23:30:47 +0000598- Cache Configuration:
Aneesh V2c451f72011-06-16 23:30:47 +0000599 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
600
Aneesh V93bc2192011-06-16 23:30:51 +0000601- Cache Configuration for ARM:
602 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
603 controller
604 CONFIG_SYS_PL310_BASE - Physical base address of PL310
605 controller register space
606
wdenk6705d812004-08-02 23:22:59 +0000607- Serial Ports:
Andreas Engel48d01922008-09-08 14:30:53 +0200608 CONFIG_PL011_SERIAL
wdenk6705d812004-08-02 23:22:59 +0000609
610 Define this if you want support for Amba PrimeCell PL011 UARTs.
611
612 CONFIG_PL011_CLOCK
613
614 If you have Amba PrimeCell PL011 UARTs, set this variable to
615 the clock speed of the UARTs.
616
617 CONFIG_PL01x_PORTS
618
619 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
620 define this to a list of base addresses for each (supported)
621 port. See e.g. include/configs/versatile.h
622
Karicheri, Muralidharand57dee52014-04-09 15:38:46 -0400623 CONFIG_SERIAL_HW_FLOW_CONTROL
624
625 Define this variable to enable hw flow control in serial driver.
626 Current user of this option is drivers/serial/nsl16550.c driver
wdenk6705d812004-08-02 23:22:59 +0000627
wdenkc6097192002-11-03 00:24:07 +0000628- Autoboot Command:
629 CONFIG_BOOTCOMMAND
630 Only needed when CONFIG_BOOTDELAY is enabled;
631 define a command string that is automatically executed
632 when no character is read on the console interface
633 within "Boot Delay" after reset.
634
wdenkc6097192002-11-03 00:24:07 +0000635 CONFIG_RAMBOOT and CONFIG_NFSBOOT
wdenk43d96162003-03-06 00:02:04 +0000636 The value of these goes into the environment as
637 "ramboot" and "nfsboot" respectively, and can be used
638 as a convenience, when switching between booting from
Marcel Ziswiler11ccc332008-07-09 08:17:15 +0200639 RAM and NFS.
wdenkc6097192002-11-03 00:24:07 +0000640
wdenkc6097192002-11-03 00:24:07 +0000641- Serial Download Echo Mode:
642 CONFIG_LOADS_ECHO
643 If defined to 1, all characters received during a
644 serial download (using the "loads" command) are
645 echoed back. This might be needed by some terminal
646 emulations (like "cu"), but may as well just take
647 time on others. This setting #define's the initial
648 value of the "loads_echo" environment variable.
649
Simon Glass302a6482016-03-13 19:07:28 -0600650- Removal of commands
651 If no commands are needed to boot, you can disable
652 CONFIG_CMDLINE to remove them. In this case, the command line
653 will not be available, and when U-Boot wants to execute the
654 boot command (on start-up) it will call board_run_command()
655 instead. This can reduce image size significantly for very
656 simple boot procedures.
657
Wolfgang Denka5ecbe62013-03-23 23:50:31 +0000658- Regular expression support:
659 CONFIG_REGEX
Wolfgang Denk93e14592013-10-04 17:43:24 +0200660 If this variable is defined, U-Boot is linked against
661 the SLRE (Super Light Regular Expression) library,
662 which adds regex support to some commands, as for
663 example "env grep" and "setexpr".
Wolfgang Denka5ecbe62013-03-23 23:50:31 +0000664
Simon Glass45ba8072011-10-15 05:48:20 +0000665- Device tree:
666 CONFIG_OF_CONTROL
667 If this variable is defined, U-Boot will use a device tree
668 to configure its devices, instead of relying on statically
669 compiled #defines in the board file. This option is
670 experimental and only available on a few boards. The device
671 tree is available in the global data as gd->fdt_blob.
672
Simon Glass2c0f79e2011-10-24 19:15:31 +0000673 U-Boot needs to get its device tree from somewhere. This can
Alex Deymo82f766d2017-04-02 01:25:20 -0700674 be done using one of the three options below:
Simon Glassbbb0b122011-10-15 05:48:21 +0000675
676 CONFIG_OF_EMBED
677 If this variable is defined, U-Boot will embed a device tree
678 binary in its image. This device tree file should be in the
679 board directory and called <soc>-<board>.dts. The binary file
680 is then picked up in board_init_f() and made available through
Nobuhiro Iwamatsueb3eb602017-08-26 07:34:14 +0900681 the global data structure as gd->fdt_blob.
Simon Glass45ba8072011-10-15 05:48:20 +0000682
Simon Glass2c0f79e2011-10-24 19:15:31 +0000683 CONFIG_OF_SEPARATE
684 If this variable is defined, U-Boot will build a device tree
685 binary. It will be called u-boot.dtb. Architecture-specific
686 code will locate it at run-time. Generally this works by:
687
688 cat u-boot.bin u-boot.dtb >image.bin
689
690 and in fact, U-Boot does this for you, creating a file called
691 u-boot-dtb.bin which is useful in the common case. You can
692 still use the individual files if you need something more
693 exotic.
694
Alex Deymo82f766d2017-04-02 01:25:20 -0700695 CONFIG_OF_BOARD
696 If this variable is defined, U-Boot will use the device tree
697 provided by the board at runtime instead of embedding one with
698 the image. Only boards defining board_fdt_blob_setup() support
699 this option (see include/fdtdec.h file).
700
wdenkc6097192002-11-03 00:24:07 +0000701- Watchdog:
702 CONFIG_WATCHDOG
703 If this variable is defined, it enables watchdog
Detlev Zundel6abe6fb2011-04-27 05:25:59 +0000704 support for the SoC. There must be support in the SoC
Christophe Leroy907208c2017-07-06 10:23:22 +0200705 specific code for a watchdog. For the 8xx
706 CPUs, the SIU Watchdog feature is enabled in the SYPCR
707 register. When supported for a specific SoC is
708 available, then no further board specific code should
709 be needed to use it.
Detlev Zundel6abe6fb2011-04-27 05:25:59 +0000710
711 CONFIG_HW_WATCHDOG
712 When using a watchdog circuitry external to the used
713 SoC, then define this variable and provide board
714 specific code for the "hw_watchdog_reset" function.
wdenkc6097192002-11-03 00:24:07 +0000715
Rasmus Villemoes933ada52021-04-14 09:18:22 +0200716 CONFIG_SYS_WATCHDOG_FREQ
717 Some platforms automatically call WATCHDOG_RESET()
718 from the timer interrupt handler every
719 CONFIG_SYS_WATCHDOG_FREQ interrupts. If not set by the
720 board configuration file, a default of CONFIG_SYS_HZ/2
721 (i.e. 500) is used. Setting CONFIG_SYS_WATCHDOG_FREQ
722 to 0 disables calling WATCHDOG_RESET() from the timer
723 interrupt.
724
wdenkc6097192002-11-03 00:24:07 +0000725- Real-Time Clock:
726
Jon Loeliger602ad3b2007-06-11 19:03:39 -0500727 When CONFIG_CMD_DATE is selected, the type of the RTC
wdenkc6097192002-11-03 00:24:07 +0000728 has to be selected, too. Define exactly one of the
729 following options:
730
wdenkc6097192002-11-03 00:24:07 +0000731 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
Fabio Estevam4e8b7542011-10-24 06:44:15 +0000732 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
wdenkc6097192002-11-03 00:24:07 +0000733 CONFIG_RTC_MC146818 - use MC146818 RTC
wdenk1cb8e982003-03-06 21:55:29 +0000734 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
wdenkc6097192002-11-03 00:24:07 +0000735 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
wdenk7f70e852003-05-20 14:25:27 +0000736 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
Markus Niebel412921d2014-07-21 11:06:16 +0200737 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
wdenk3bac3512003-03-12 10:41:04 +0000738 CONFIG_RTC_DS164x - use Dallas DS164x RTC
Tor Krill9536dfc2008-03-15 15:40:26 +0100739 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
wdenk4c0d4c32004-06-09 17:34:58 +0000740 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
Chris Packham2bd3cab2017-05-30 12:03:33 +1200741 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
Heiko Schocher71d19f32011-03-28 09:24:22 +0200742 CONFIG_SYS_RV3029_TCR - enable trickle charger on
743 RV3029 RTC.
wdenkc6097192002-11-03 00:24:07 +0000744
wdenkb37c7e52003-06-30 16:24:52 +0000745 Note that if the RTC uses I2C, then the I2C interface
746 must also be configured. See I2C Support, below.
747
Peter Tysere92739d2008-12-17 16:36:21 -0600748- GPIO Support:
749 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
Peter Tysere92739d2008-12-17 16:36:21 -0600750
Chris Packham5dec49c2010-12-19 10:12:13 +0000751 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
752 chip-ngpio pairs that tell the PCA953X driver the number of
753 pins supported by a particular chip.
754
Peter Tysere92739d2008-12-17 16:36:21 -0600755 Note that if the GPIO device uses I2C, then the I2C interface
756 must also be configured. See I2C Support, below.
757
Simon Glassaa532332014-06-11 23:29:41 -0600758- I/O tracing:
759 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
760 accesses and can checksum them or write a list of them out
761 to memory. See the 'iotrace' command for details. This is
762 useful for testing device drivers since it can confirm that
763 the driver behaves the same way before and after a code
764 change. Currently this is supported on sandbox and arm. To
765 add support for your architecture, add '#include <iotrace.h>'
766 to the bottom of arch/<arch>/include/asm/io.h and test.
767
768 Example output from the 'iotrace stats' command is below.
769 Note that if the trace buffer is exhausted, the checksum will
770 still continue to operate.
771
772 iotrace is enabled
773 Start: 10000000 (buffer start address)
774 Size: 00010000 (buffer size)
775 Offset: 00000120 (current buffer offset)
776 Output: 10000120 (start + offset)
777 Count: 00000018 (number of trace records)
778 CRC32: 9526fb66 (CRC32 of all trace records)
779
wdenkc6097192002-11-03 00:24:07 +0000780- Timestamp Support:
781
wdenk43d96162003-03-06 00:02:04 +0000782 When CONFIG_TIMESTAMP is selected, the timestamp
783 (date and time) of an image is printed by image
784 commands like bootm or iminfo. This option is
Jon Loeliger602ad3b2007-06-11 19:03:39 -0500785 automatically enabled when you select CONFIG_CMD_DATE .
wdenkc6097192002-11-03 00:24:07 +0000786
Karl O. Pinc923c46f2012-08-16 06:20:15 +0000787- Partition Labels (disklabels) Supported:
788 Zero or more of the following:
789 CONFIG_MAC_PARTITION Apple's MacOS partition table.
Karl O. Pinc923c46f2012-08-16 06:20:15 +0000790 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
791 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
792 bootloader. Note 2TB partition limit; see
793 disk/part_efi.c
Simon Glassc649e3c2016-05-01 11:36:02 -0600794 CONFIG_SCSI) you must configure support for at
Karl O. Pinc923c46f2012-08-16 06:20:15 +0000795 least one non-MTD partition type as well.
wdenkc6097192002-11-03 00:24:07 +0000796
797- IDE Reset method:
wdenk4d13cba2004-03-14 14:09:05 +0000798 CONFIG_IDE_RESET_ROUTINE - this is defined in several
799 board configurations files but used nowhere!
wdenkc6097192002-11-03 00:24:07 +0000800
wdenk4d13cba2004-03-14 14:09:05 +0000801 CONFIG_IDE_RESET - is this is defined, IDE Reset will
802 be performed by calling the function
803 ide_set_reset(int reset)
804 which has to be defined in a board specific file
wdenkc6097192002-11-03 00:24:07 +0000805
806- ATAPI Support:
807 CONFIG_ATAPI
808
809 Set this to enable ATAPI support.
810
wdenkc40b2952004-03-13 23:29:43 +0000811- LBA48 Support
812 CONFIG_LBA48
813
814 Set this to enable support for disks larger than 137GB
Heiko Schocher4b142fe2009-12-03 11:21:21 +0100815 Also look at CONFIG_SYS_64BIT_LBA.
wdenkc40b2952004-03-13 23:29:43 +0000816 Whithout these , LBA48 support uses 32bit variables and will 'only'
817 support disks up to 2.1TB.
818
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200819 CONFIG_SYS_64BIT_LBA:
wdenkc40b2952004-03-13 23:29:43 +0000820 When enabled, makes the IDE subsystem use 64bit sector addresses.
821 Default is 32bit.
822
wdenkc6097192002-11-03 00:24:07 +0000823- SCSI Support:
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200824 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
825 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
826 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
wdenkc6097192002-11-03 00:24:07 +0000827 maximum numbers of LUNs, SCSI ID's and target
828 devices.
wdenkc6097192002-11-03 00:24:07 +0000829
Wolfgang Denk93e14592013-10-04 17:43:24 +0200830 The environment variable 'scsidevs' is set to the number of
831 SCSI devices found during the last scan.
Stefan Reinauer447c0312012-10-29 05:23:48 +0000832
wdenkc6097192002-11-03 00:24:07 +0000833- NETWORK Support (PCI):
wdenk682011f2003-06-03 23:54:09 +0000834 CONFIG_E1000
Kyle Moffettce5207e2011-10-18 11:05:29 +0000835 Support for Intel 8254x/8257x gigabit chips.
836
837 CONFIG_E1000_SPI
838 Utility code for direct access to the SPI bus on Intel 8257x.
839 This does not do anything useful unless you set at least one
840 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
841
842 CONFIG_E1000_SPI_GENERIC
843 Allow generic access to the SPI bus on the Intel 8257x, for
844 example with the "sspi" command.
845
wdenkc6097192002-11-03 00:24:07 +0000846 CONFIG_NATSEMI
847 Support for National dp83815 chips.
848
849 CONFIG_NS8382X
850 Support for National dp8382[01] gigabit chips.
851
wdenk45219c42003-05-12 21:50:16 +0000852- NETWORK Support (other):
Rob Herringefdd7312011-12-15 11:15:49 +0000853 CONFIG_CALXEDA_XGMAC
854 Support for the Calxeda XGMAC device
855
Ashok3bb46d22012-10-15 06:20:47 +0000856 CONFIG_LAN91C96
wdenk45219c42003-05-12 21:50:16 +0000857 Support for SMSC's LAN91C96 chips.
858
wdenk45219c42003-05-12 21:50:16 +0000859 CONFIG_LAN91C96_USE_32_BIT
860 Define this to enable 32 bit addressing
861
Ashok3bb46d22012-10-15 06:20:47 +0000862 CONFIG_SMC91111
wdenkf39748a2004-06-09 13:37:52 +0000863 Support for SMSC's LAN91C111 chip
864
865 CONFIG_SMC91111_BASE
866 Define this to hold the physical address
867 of the device (I/O space)
868
869 CONFIG_SMC_USE_32_BIT
870 Define this if data bus is 32 bits
871
872 CONFIG_SMC_USE_IOFUNCS
873 Define this to use i/o functions instead of macros
874 (some hardware wont work with macros)
875
Heiko Schocherdc02bad2011-11-15 10:00:04 -0500876 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
877 Define this if you have more then 3 PHYs.
878
Macpaul Linb3dbf4a52010-12-21 16:59:46 +0800879 CONFIG_FTGMAC100
880 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
881
882 CONFIG_FTGMAC100_EGIGA
883 Define this to use GE link update with gigabit PHY.
884 Define this if FTGMAC100 is connected to gigabit PHY.
885 If your system has 10/100 PHY only, it might not occur
886 wrong behavior. Because PHY usually return timeout or
887 useless data when polling gigabit status and gigabit
888 control registers. This behavior won't affect the
889 correctnessof 10/100 link speed update.
890
Yoshihiro Shimoda3d0075f2011-01-27 10:06:03 +0900891 CONFIG_SH_ETHER
892 Support for Renesas on-chip Ethernet controller
893
894 CONFIG_SH_ETHER_USE_PORT
895 Define the number of ports to be used
896
897 CONFIG_SH_ETHER_PHY_ADDR
898 Define the ETH PHY's address
899
Yoshihiro Shimoda68260aa2011-01-27 10:06:08 +0900900 CONFIG_SH_ETHER_CACHE_WRITEBACK
901 If this option is set, the driver enables cache flush.
902
Vadim Bendebury5e124722011-10-17 08:36:14 +0000903- TPM Support:
Che-liang Chiou90899cc2013-04-12 11:04:34 +0000904 CONFIG_TPM
905 Support TPM devices.
906
Christophe Ricard0766ad22015-10-06 22:54:41 +0200907 CONFIG_TPM_TIS_INFINEON
908 Support for Infineon i2c bus TPM devices. Only one device
Tom Wai-Hong Tam1b393db2013-04-12 11:04:37 +0000909 per system is supported at this time.
910
Tom Wai-Hong Tam1b393db2013-04-12 11:04:37 +0000911 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
912 Define the burst count bytes upper limit
913
Christophe Ricard3aa74082016-01-21 23:27:13 +0100914 CONFIG_TPM_ST33ZP24
915 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
916
917 CONFIG_TPM_ST33ZP24_I2C
918 Support for STMicroelectronics ST33ZP24 I2C devices.
919 Requires TPM_ST33ZP24 and I2C.
920
Christophe Ricardb75fdc12016-01-21 23:27:14 +0100921 CONFIG_TPM_ST33ZP24_SPI
922 Support for STMicroelectronics ST33ZP24 SPI devices.
923 Requires TPM_ST33ZP24 and SPI.
924
Dirk Eibachc01939c2013-06-26 15:55:15 +0200925 CONFIG_TPM_ATMEL_TWI
926 Support for Atmel TWI TPM device. Requires I2C support.
927
Che-liang Chiou90899cc2013-04-12 11:04:34 +0000928 CONFIG_TPM_TIS_LPC
Vadim Bendebury5e124722011-10-17 08:36:14 +0000929 Support for generic parallel port TPM devices. Only one device
930 per system is supported at this time.
931
932 CONFIG_TPM_TIS_BASE_ADDRESS
933 Base address where the generic TPM device is mapped
934 to. Contemporary x86 systems usually map it at
935 0xfed40000.
936
Reinhard Pfaube6c1522013-06-26 15:55:13 +0200937 CONFIG_TPM
938 Define this to enable the TPM support library which provides
939 functional interfaces to some TPM commands.
940 Requires support for a TPM device.
941
942 CONFIG_TPM_AUTH_SESSIONS
943 Define this to enable authorized functions in the TPM library.
944 Requires CONFIG_TPM and CONFIG_SHA1.
945
wdenkc6097192002-11-03 00:24:07 +0000946- USB Support:
947 At the moment only the UHCI host controller is
Heiko Schocher064b55c2017-06-14 05:49:40 +0200948 supported (PIP405, MIP405); define
wdenkc6097192002-11-03 00:24:07 +0000949 CONFIG_USB_UHCI to enable it.
950 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
wdenk30d56fa2004-10-09 22:44:59 +0000951 and define CONFIG_USB_STORAGE to enable the USB
wdenkc6097192002-11-03 00:24:07 +0000952 storage devices.
953 Note:
954 Supported are USB Keyboards and USB Floppy drives
955 (TEAC FD-05PUB).
wdenk4d13cba2004-03-14 14:09:05 +0000956
Simon Glass9ab4ce22012-02-27 10:52:47 +0000957 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
958 txfilltuning field in the EHCI controller on reset.
959
Oleksandr Tymoshenko6e9e0622014-02-01 21:51:25 -0700960 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
961 HW module registers.
962
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200963- USB Device:
964 Define the below if you wish to use the USB console.
965 Once firmware is rebuilt from a serial console issue the
966 command "setenv stdin usbtty; setenv stdout usbtty" and
Marcel Ziswiler11ccc332008-07-09 08:17:15 +0200967 attach your USB cable. The Unix command "dmesg" should print
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200968 it has found a new device. The environment variable usbtty
969 can be set to gserial or cdc_acm to enable your device to
Wolfgang Denk386eda02006-06-14 18:14:56 +0200970 appear to a USB host as a Linux gserial device or a
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200971 Common Device Class Abstract Control Model serial device.
972 If you select usbtty = gserial you should be able to enumerate
973 a Linux host by
974 # modprobe usbserial vendor=0xVendorID product=0xProductID
975 else if using cdc_acm, simply setting the environment
976 variable usbtty to be cdc_acm should suffice. The following
977 might be defined in YourBoardName.h
Wolfgang Denk386eda02006-06-14 18:14:56 +0200978
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200979 CONFIG_USB_DEVICE
980 Define this to build a UDC device
wdenkc6097192002-11-03 00:24:07 +0000981
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200982 CONFIG_USB_TTY
983 Define this to have a tty type of device available to
984 talk to the UDC device
Wolfgang Denk386eda02006-06-14 18:14:56 +0200985
Vipin KUMARf9da0f82012-03-26 15:38:06 +0530986 CONFIG_USBD_HS
987 Define this to enable the high speed support for usb
988 device and usbtty. If this feature is enabled, a routine
989 int is_usbd_high_speed(void)
990 also needs to be defined by the driver to dynamically poll
991 whether the enumeration has succeded at high speed or full
992 speed.
993
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200994 CONFIG_SYS_CONSOLE_IS_IN_ENV
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200995 Define this if you want stdin, stdout &/or stderr to
996 be set to usbtty.
997
Wolfgang Denk386eda02006-06-14 18:14:56 +0200998 If you have a USB-IF assigned VendorID then you may wish to
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200999 define your own vendor specific values either in BoardName.h
Wolfgang Denk386eda02006-06-14 18:14:56 +02001000 or directly in usbd_vendor_info.h. If you don't define
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +02001001 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1002 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1003 should pretend to be a Linux device to it's target host.
1004
1005 CONFIG_USBD_MANUFACTURER
1006 Define this string as the name of your company for
1007 - CONFIG_USBD_MANUFACTURER "my company"
Wolfgang Denk386eda02006-06-14 18:14:56 +02001008
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +02001009 CONFIG_USBD_PRODUCT_NAME
1010 Define this string as the name of your product
1011 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1012
1013 CONFIG_USBD_VENDORID
1014 Define this as your assigned Vendor ID from the USB
1015 Implementors Forum. This *must* be a genuine Vendor ID
1016 to avoid polluting the USB namespace.
1017 - CONFIG_USBD_VENDORID 0xFFFF
Wolfgang Denk386eda02006-06-14 18:14:56 +02001018
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +02001019 CONFIG_USBD_PRODUCTID
1020 Define this as the unique Product ID
1021 for your device
1022 - CONFIG_USBD_PRODUCTID 0xFFFF
wdenkc6097192002-11-03 00:24:07 +00001023
Igor Grinbergd70a5602011-12-12 12:08:35 +02001024- ULPI Layer Support:
1025 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1026 the generic ULPI layer. The generic layer accesses the ULPI PHY
1027 via the platform viewport, so you need both the genric layer and
1028 the viewport enabled. Currently only Chipidea/ARC based
1029 viewport is supported.
1030 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1031 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
Lucas Stach6d365ea2012-10-01 00:44:35 +02001032 If your ULPI phy needs a different reference clock than the
1033 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1034 the appropriate value in Hz.
wdenkc6097192002-11-03 00:24:07 +00001035
1036- MMC Support:
1037 The MMC controller on the Intel PXA is supported. To
1038 enable this define CONFIG_MMC. The MMC can be
1039 accessed from the boot prompt by mapping the device
1040 to physical memory similar to flash. Command line is
Jon Loeliger602ad3b2007-06-11 19:03:39 -05001041 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1042 the FAT fs. This is enabled with CONFIG_CMD_FAT.
wdenkc6097192002-11-03 00:24:07 +00001043
Yoshihiro Shimodaafb35662011-07-04 22:21:22 +00001044 CONFIG_SH_MMCIF
1045 Support for Renesas on-chip MMCIF controller
1046
1047 CONFIG_SH_MMCIF_ADDR
1048 Define the base address of MMCIF registers
1049
1050 CONFIG_SH_MMCIF_CLK
1051 Define the clock frequency for MMCIF
1052
Tom Rinib3ba6e92013-03-14 05:32:47 +00001053- USB Device Firmware Update (DFU) class support:
Marek Vasutbb4059a2018-02-16 16:41:18 +01001054 CONFIG_DFU_OVER_USB
Tom Rinib3ba6e92013-03-14 05:32:47 +00001055 This enables the USB portion of the DFU USB class
1056
Pantelis Antoniouc6631762013-03-14 05:32:52 +00001057 CONFIG_DFU_NAND
1058 This enables support for exposing NAND devices via DFU.
1059
Afzal Mohammeda9479f02013-09-18 01:15:24 +05301060 CONFIG_DFU_RAM
1061 This enables support for exposing RAM via DFU.
1062 Note: DFU spec refer to non-volatile memory usage, but
1063 allow usages beyond the scope of spec - here RAM usage,
1064 one that would help mostly the developer.
1065
Heiko Schochere7e75c72013-06-12 06:05:51 +02001066 CONFIG_SYS_DFU_DATA_BUF_SIZE
1067 Dfu transfer uses a buffer before writing data to the
1068 raw storage device. Make the size (in bytes) of this buffer
1069 configurable. The size of this buffer is also configurable
1070 through the "dfu_bufsiz" environment variable.
1071
Pantelis Antoniouea2453d2013-03-14 05:32:48 +00001072 CONFIG_SYS_DFU_MAX_FILE_SIZE
1073 When updating files rather than the raw storage device,
1074 we use a static buffer to copy the file into and then write
1075 the buffer once we've been given the whole file. Define
1076 this to the maximum filesize (in bytes) for the buffer.
1077 Default is 4 MiB if undefined.
1078
Heiko Schocher001a8312014-03-18 08:09:56 +01001079 DFU_DEFAULT_POLL_TIMEOUT
1080 Poll timeout [ms], is the timeout a device can send to the
1081 host. The host must wait for this timeout before sending
1082 a subsequent DFU_GET_STATUS request to the device.
1083
1084 DFU_MANIFEST_POLL_TIMEOUT
1085 Poll timeout [ms], which the device sends to the host when
1086 entering dfuMANIFEST state. Host waits this timeout, before
1087 sending again an USB request to the device.
1088
wdenk6705d812004-08-02 23:22:59 +00001089- Journaling Flash filesystem support:
Simon Glassb2482df2016-10-02 18:00:59 -06001090 CONFIG_JFFS2_NAND
wdenk6705d812004-08-02 23:22:59 +00001091 Define these for a default partition on a NAND device
1092
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001093 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1094 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
wdenk6705d812004-08-02 23:22:59 +00001095 Define these for a default partition on a NOR device
1096
wdenkc6097192002-11-03 00:24:07 +00001097- Keyboard Support:
Simon Glass39f615e2015-11-11 10:05:47 -07001098 See Kconfig help for available keyboard drivers.
1099
1100 CONFIG_KEYBOARD
1101
1102 Define this to enable a custom keyboard support.
1103 This simply calls drv_keyboard_init() which must be
1104 defined in your board-specific files. This option is deprecated
1105 and is only used by novena. For new boards, use driver model
1106 instead.
wdenkc6097192002-11-03 00:24:07 +00001107
1108- Video support:
Timur Tabi7d3053f2011-02-15 17:09:19 -06001109 CONFIG_FSL_DIU_FB
Wolfgang Denk04e5ae72011-09-11 21:24:09 +02001110 Enable the Freescale DIU video driver. Reference boards for
Timur Tabi7d3053f2011-02-15 17:09:19 -06001111 SOCs that have a DIU should define this macro to enable DIU
1112 support, and should also define these other macros:
1113
1114 CONFIG_SYS_DIU_ADDR
1115 CONFIG_VIDEO
Timur Tabi7d3053f2011-02-15 17:09:19 -06001116 CONFIG_CFB_CONSOLE
1117 CONFIG_VIDEO_SW_CURSOR
1118 CONFIG_VGA_AS_SINGLE_DEVICE
1119 CONFIG_VIDEO_LOGO
1120 CONFIG_VIDEO_BMP_LOGO
1121
Timur Tabiba8e76b2011-04-11 14:18:22 -05001122 The DIU driver will look for the 'video-mode' environment
1123 variable, and if defined, enable the DIU as a console during
Fabio Estevam8eca9432016-04-02 11:53:18 -03001124 boot. See the documentation file doc/README.video for a
Timur Tabiba8e76b2011-04-11 14:18:22 -05001125 description of this variable.
Timur Tabi7d3053f2011-02-15 17:09:19 -06001126
wdenkc6097192002-11-03 00:24:07 +00001127- LCD Support: CONFIG_LCD
1128
1129 Define this to enable LCD support (for output to LCD
1130 display); also select one of the supported displays
1131 by defining one of these:
1132
Stelian Pop39cf4802008-05-09 21:57:18 +02001133 CONFIG_ATMEL_LCD:
1134
1135 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1136
wdenkfd3103b2003-11-25 16:55:19 +00001137 CONFIG_NEC_NL6448AC33:
wdenkc6097192002-11-03 00:24:07 +00001138
wdenkfd3103b2003-11-25 16:55:19 +00001139 NEC NL6448AC33-18. Active, color, single scan.
wdenkc6097192002-11-03 00:24:07 +00001140
wdenkfd3103b2003-11-25 16:55:19 +00001141 CONFIG_NEC_NL6448BC20
wdenkc6097192002-11-03 00:24:07 +00001142
wdenkfd3103b2003-11-25 16:55:19 +00001143 NEC NL6448BC20-08. 6.5", 640x480.
1144 Active, color, single scan.
1145
1146 CONFIG_NEC_NL6448BC33_54
1147
1148 NEC NL6448BC33-54. 10.4", 640x480.
wdenkc6097192002-11-03 00:24:07 +00001149 Active, color, single scan.
1150
1151 CONFIG_SHARP_16x9
1152
1153 Sharp 320x240. Active, color, single scan.
1154 It isn't 16x9, and I am not sure what it is.
1155
1156 CONFIG_SHARP_LQ64D341
1157
1158 Sharp LQ64D341 display, 640x480.
1159 Active, color, single scan.
1160
1161 CONFIG_HLD1045
1162
1163 HLD1045 display, 640x480.
1164 Active, color, single scan.
1165
1166 CONFIG_OPTREX_BW
1167
1168 Optrex CBL50840-2 NF-FW 99 22 M5
1169 or
1170 Hitachi LMG6912RPFC-00T
1171 or
1172 Hitachi SP14Q002
1173
1174 320x240. Black & white.
1175
Simon Glass676d3192012-10-17 13:24:54 +00001176 CONFIG_LCD_ALIGNMENT
1177
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001178 Normally the LCD is page-aligned (typically 4KB). If this is
Simon Glass676d3192012-10-17 13:24:54 +00001179 defined then the LCD will be aligned to this value instead.
1180 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1181 here, since it is cheaper to change data cache settings on
1182 a per-section basis.
1183
1184
Hannes Petermaier604c7d42015-03-27 08:01:38 +01001185 CONFIG_LCD_ROTATION
1186
1187 Sometimes, for example if the display is mounted in portrait
1188 mode or even if it's mounted landscape but rotated by 180degree,
1189 we need to rotate our content of the display relative to the
1190 framebuffer, so that user can read the messages which are
1191 printed out.
1192 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1193 initialized with a given rotation from "vl_rot" out of
1194 "vidinfo_t" which is provided by the board specific code.
1195 The value for vl_rot is coded as following (matching to
1196 fbcon=rotate:<n> linux-kernel commandline):
1197 0 = no rotation respectively 0 degree
1198 1 = 90 degree rotation
1199 2 = 180 degree rotation
1200 3 = 270 degree rotation
1201
1202 If CONFIG_LCD_ROTATION is not defined, the console will be
1203 initialized with 0degree rotation.
1204
Tom Wai-Hong Tam45d7f522012-09-28 15:11:16 +00001205 CONFIG_LCD_BMP_RLE8
1206
1207 Support drawing of RLE8-compressed bitmaps on the LCD.
1208
Tom Wai-Hong Tam735987c2012-12-05 14:46:40 +00001209 CONFIG_I2C_EDID
1210
1211 Enables an 'i2c edid' command which can read EDID
1212 information over I2C from an attached LCD display.
1213
wdenk17ea1172004-06-06 21:51:03 +00001214- MII/PHY support:
wdenk17ea1172004-06-06 21:51:03 +00001215 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1216
1217 The clock frequency of the MII bus
1218
wdenk17ea1172004-06-06 21:51:03 +00001219 CONFIG_PHY_RESET_DELAY
1220
1221 Some PHY like Intel LXT971A need extra delay after
1222 reset before any MII register access is possible.
1223 For such PHY, set this option to the usec delay
1224 required. (minimum 300usec for LXT971A)
1225
1226 CONFIG_PHY_CMD_DELAY (ppc4xx)
1227
1228 Some PHY like Intel LXT971A need extra delay after
1229 command issued before MII status register can be read
1230
wdenkc6097192002-11-03 00:24:07 +00001231- IP address:
1232 CONFIG_IPADDR
1233
1234 Define a default value for the IP address to use for
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001235 the default Ethernet interface, in case this is not
wdenkc6097192002-11-03 00:24:07 +00001236 determined through e.g. bootp.
Wolfgang Denk1ebcd652011-10-26 10:21:22 +00001237 (Environment variable "ipaddr")
wdenkc6097192002-11-03 00:24:07 +00001238
1239- Server IP address:
1240 CONFIG_SERVERIP
1241
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001242 Defines a default value for the IP address of a TFTP
wdenkc6097192002-11-03 00:24:07 +00001243 server to contact when using the "tftboot" command.
Wolfgang Denk1ebcd652011-10-26 10:21:22 +00001244 (Environment variable "serverip")
wdenkc6097192002-11-03 00:24:07 +00001245
Robin Getz97cfe862009-07-21 12:15:28 -04001246 CONFIG_KEEP_SERVERADDR
1247
1248 Keeps the server's MAC address, in the env 'serveraddr'
1249 for passing to bootargs (like Linux's netconsole option)
1250
Wolfgang Denk1ebcd652011-10-26 10:21:22 +00001251- Gateway IP address:
1252 CONFIG_GATEWAYIP
1253
1254 Defines a default value for the IP address of the
1255 default router where packets to other networks are
1256 sent to.
1257 (Environment variable "gatewayip")
1258
1259- Subnet mask:
1260 CONFIG_NETMASK
1261
1262 Defines a default value for the subnet mask (or
1263 routing prefix) which is used to determine if an IP
1264 address belongs to the local subnet or needs to be
1265 forwarded through a router.
1266 (Environment variable "netmask")
1267
wdenkc6097192002-11-03 00:24:07 +00001268- BOOTP Recovery Mode:
1269 CONFIG_BOOTP_RANDOM_DELAY
1270
1271 If you have many targets in a network that try to
1272 boot using BOOTP, you may want to avoid that all
1273 systems send out BOOTP requests at precisely the same
1274 moment (which would happen for instance at recovery
1275 from a power failure, when all systems will try to
1276 boot, thus flooding the BOOTP server. Defining
1277 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1278 inserted before sending out BOOTP requests. The
Wolfgang Denk6c33c782007-08-06 23:21:05 +02001279 following delays are inserted then:
wdenkc6097192002-11-03 00:24:07 +00001280
1281 1st BOOTP request: delay 0 ... 1 sec
1282 2nd BOOTP request: delay 0 ... 2 sec
1283 3rd BOOTP request: delay 0 ... 4 sec
1284 4th and following
1285 BOOTP requests: delay 0 ... 8 sec
1286
Thierry Reding92ac8ac2014-08-19 10:21:24 +02001287 CONFIG_BOOTP_ID_CACHE_SIZE
1288
1289 BOOTP packets are uniquely identified using a 32-bit ID. The
1290 server will copy the ID from client requests to responses and
1291 U-Boot will use this to determine if it is the destination of
1292 an incoming response. Some servers will check that addresses
1293 aren't in use before handing them out (usually using an ARP
1294 ping) and therefore take up to a few hundred milliseconds to
1295 respond. Network congestion may also influence the time it
1296 takes for a response to make it back to the client. If that
1297 time is too long, U-Boot will retransmit requests. In order
1298 to allow earlier responses to still be accepted after these
1299 retransmissions, U-Boot's BOOTP client keeps a small cache of
1300 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
1301 cache. The default is to keep IDs for up to four outstanding
1302 requests. Increasing this will allow U-Boot to accept offers
1303 from a BOOTP client in networks with unusually high latency.
1304
stroesefe389a82003-08-28 14:17:32 +00001305- DHCP Advanced Options:
Jon Loeliger1fe80d72007-07-09 22:08:34 -05001306 You can fine tune the DHCP functionality by defining
1307 CONFIG_BOOTP_* symbols:
stroesefe389a82003-08-28 14:17:32 +00001308
Jon Loeliger1fe80d72007-07-09 22:08:34 -05001309 CONFIG_BOOTP_NISDOMAIN
Jon Loeliger1fe80d72007-07-09 22:08:34 -05001310 CONFIG_BOOTP_BOOTFILESIZE
Jon Loeliger1fe80d72007-07-09 22:08:34 -05001311 CONFIG_BOOTP_NTPSERVER
1312 CONFIG_BOOTP_TIMEOFFSET
1313 CONFIG_BOOTP_VENDOREX
Joe Hershberger2c00e092012-05-23 07:59:19 +00001314 CONFIG_BOOTP_MAY_FAIL
stroesefe389a82003-08-28 14:17:32 +00001315
Wilson Callan5d110f02007-07-28 10:56:13 -04001316 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1317 environment variable, not the BOOTP server.
stroesefe389a82003-08-28 14:17:32 +00001318
Joe Hershberger2c00e092012-05-23 07:59:19 +00001319 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1320 after the configured retry count, the call will fail
1321 instead of starting over. This can be used to fail over
1322 to Link-local IP address configuration if the DHCP server
1323 is not available.
1324
Aras Vaichasd9a2f412008-03-26 09:43:57 +11001325 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1326
1327 A 32bit value in microseconds for a delay between
1328 receiving a "DHCP Offer" and sending the "DHCP Request".
1329 This fixes a problem with certain DHCP servers that don't
1330 respond 100% of the time to a "DHCP request". E.g. On an
1331 AT91RM9200 processor running at 180MHz, this delay needed
1332 to be *at least* 15,000 usec before a Windows Server 2003
1333 DHCP server would reply 100% of the time. I recommend at
1334 least 50,000 usec to be safe. The alternative is to hope
1335 that one of the retries will be successful but note that
1336 the DHCP timeout and retry process takes a longer than
1337 this delay.
1338
Joe Hershbergerd22c3382012-05-23 08:00:12 +00001339 - Link-local IP address negotiation:
1340 Negotiate with other link-local clients on the local network
1341 for an address that doesn't require explicit configuration.
1342 This is especially useful if a DHCP server cannot be guaranteed
1343 to exist in all environments that the device must operate.
1344
1345 See doc/README.link-local for more information.
1346
Prabhakar Kushwaha24acb832017-11-23 16:51:32 +05301347 - MAC address from environment variables
1348
1349 FDT_SEQ_MACADDR_FROM_ENV
1350
1351 Fix-up device tree with MAC addresses fetched sequentially from
1352 environment variables. This config work on assumption that
1353 non-usable ethernet node of device-tree are either not present
1354 or their status has been marked as "disabled".
1355
wdenka3d991b2004-04-15 21:48:45 +00001356 - CDP Options:
wdenk6e592382004-04-18 17:39:38 +00001357 CONFIG_CDP_DEVICE_ID
wdenka3d991b2004-04-15 21:48:45 +00001358
1359 The device id used in CDP trigger frames.
1360
1361 CONFIG_CDP_DEVICE_ID_PREFIX
1362
1363 A two character string which is prefixed to the MAC address
1364 of the device.
1365
1366 CONFIG_CDP_PORT_ID
1367
1368 A printf format string which contains the ascii name of
1369 the port. Normally is set to "eth%d" which sets
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001370 eth0 for the first Ethernet, eth1 for the second etc.
wdenka3d991b2004-04-15 21:48:45 +00001371
1372 CONFIG_CDP_CAPABILITIES
1373
1374 A 32bit integer which indicates the device capabilities;
1375 0x00000010 for a normal host which does not forwards.
1376
1377 CONFIG_CDP_VERSION
1378
1379 An ascii string containing the version of the software.
1380
1381 CONFIG_CDP_PLATFORM
1382
1383 An ascii string containing the name of the platform.
1384
1385 CONFIG_CDP_TRIGGER
1386
1387 A 32bit integer sent on the trigger.
1388
1389 CONFIG_CDP_POWER_CONSUMPTION
1390
1391 A 16bit integer containing the power consumption of the
1392 device in .1 of milliwatts.
1393
1394 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1395
1396 A byte containing the id of the VLAN.
1397
Uri Mashiach79267ed2017-01-19 10:51:05 +02001398- Status LED: CONFIG_LED_STATUS
wdenkc6097192002-11-03 00:24:07 +00001399
1400 Several configurations allow to display the current
1401 status using a LED. For instance, the LED will blink
1402 fast while running U-Boot code, stop blinking as
1403 soon as a reply to a BOOTP request was received, and
1404 start blinking slow once the Linux kernel is running
1405 (supported by a status LED driver in the Linux
Uri Mashiach79267ed2017-01-19 10:51:05 +02001406 kernel). Defining CONFIG_LED_STATUS enables this
wdenkc6097192002-11-03 00:24:07 +00001407 feature in U-Boot.
1408
Igor Grinberg1df7bbb2013-11-08 01:03:50 +02001409 Additional options:
1410
Uri Mashiach79267ed2017-01-19 10:51:05 +02001411 CONFIG_LED_STATUS_GPIO
Igor Grinberg1df7bbb2013-11-08 01:03:50 +02001412 The status LED can be connected to a GPIO pin.
1413 In such cases, the gpio_led driver can be used as a
Uri Mashiach79267ed2017-01-19 10:51:05 +02001414 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO
Igor Grinberg1df7bbb2013-11-08 01:03:50 +02001415 to include the gpio_led driver in the U-Boot binary.
1416
Igor Grinberg9dfdcdf2013-11-08 01:03:52 +02001417 CONFIG_GPIO_LED_INVERTED_TABLE
1418 Some GPIO connected LEDs may have inverted polarity in which
1419 case the GPIO high value corresponds to LED off state and
1420 GPIO low value corresponds to LED on state.
1421 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
1422 with a list of GPIO LEDs that have inverted polarity.
1423
Tom Rini55dabcc2021-08-18 23:12:24 -04001424- I2C Support:
Heiko Schocher3f4978c2012-01-16 21:12:24 +00001425 CONFIG_SYS_NUM_I2C_BUSES
Simon Glass945a18e2016-10-02 18:01:05 -06001426 Hold the number of i2c buses you want to use.
Heiko Schocher3f4978c2012-01-16 21:12:24 +00001427
1428 CONFIG_SYS_I2C_DIRECT_BUS
1429 define this, if you don't use i2c muxes on your hardware.
1430 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
1431 omit this define.
1432
1433 CONFIG_SYS_I2C_MAX_HOPS
1434 define how many muxes are maximal consecutively connected
1435 on one i2c bus. If you not use i2c muxes, omit this
1436 define.
1437
1438 CONFIG_SYS_I2C_BUSES
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001439 hold a list of buses you want to use, only used if
Heiko Schocher3f4978c2012-01-16 21:12:24 +00001440 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
1441 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
1442 CONFIG_SYS_NUM_I2C_BUSES = 9:
1443
1444 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
1445 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
1446 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
1447 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
1448 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
1449 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
1450 {1, {I2C_NULL_HOP}}, \
1451 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
1452 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
1453 }
1454
1455 which defines
1456 bus 0 on adapter 0 without a mux
Heiko Schocherea818db2013-01-29 08:53:15 +01001457 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
1458 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
1459 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
1460 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
1461 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
Heiko Schocher3f4978c2012-01-16 21:12:24 +00001462 bus 6 on adapter 1 without a mux
Heiko Schocherea818db2013-01-29 08:53:15 +01001463 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
1464 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
Heiko Schocher3f4978c2012-01-16 21:12:24 +00001465
1466 If you do not have i2c muxes on your board, omit this define.
1467
Simon Glassce3b5d62017-05-12 21:10:00 -06001468- Legacy I2C Support:
Heiko Schocherea818db2013-01-29 08:53:15 +01001469 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
wdenkb37c7e52003-06-30 16:24:52 +00001470 then the following macros need to be defined (examples are
1471 from include/configs/lwmon.h):
wdenkc6097192002-11-03 00:24:07 +00001472
1473 I2C_INIT
1474
wdenkb37c7e52003-06-30 16:24:52 +00001475 (Optional). Any commands necessary to enable the I2C
wdenk43d96162003-03-06 00:02:04 +00001476 controller or configure ports.
wdenkc6097192002-11-03 00:24:07 +00001477
wdenkba56f622004-02-06 23:19:44 +00001478 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
wdenkb37c7e52003-06-30 16:24:52 +00001479
wdenkc6097192002-11-03 00:24:07 +00001480 I2C_ACTIVE
1481
1482 The code necessary to make the I2C data line active
1483 (driven). If the data line is open collector, this
1484 define can be null.
1485
wdenkb37c7e52003-06-30 16:24:52 +00001486 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1487
wdenkc6097192002-11-03 00:24:07 +00001488 I2C_TRISTATE
1489
1490 The code necessary to make the I2C data line tri-stated
1491 (inactive). If the data line is open collector, this
1492 define can be null.
1493
wdenkb37c7e52003-06-30 16:24:52 +00001494 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1495
wdenkc6097192002-11-03 00:24:07 +00001496 I2C_READ
1497
York Sun472d5462013-04-01 11:29:11 -07001498 Code that returns true if the I2C data line is high,
1499 false if it is low.
wdenkc6097192002-11-03 00:24:07 +00001500
wdenkb37c7e52003-06-30 16:24:52 +00001501 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1502
wdenkc6097192002-11-03 00:24:07 +00001503 I2C_SDA(bit)
1504
York Sun472d5462013-04-01 11:29:11 -07001505 If <bit> is true, sets the I2C data line high. If it
1506 is false, it clears it (low).
wdenkc6097192002-11-03 00:24:07 +00001507
wdenkb37c7e52003-06-30 16:24:52 +00001508 eg: #define I2C_SDA(bit) \
wdenk2535d602003-07-17 23:16:40 +00001509 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
wdenkba56f622004-02-06 23:19:44 +00001510 else immr->im_cpm.cp_pbdat &= ~PB_SDA
wdenkb37c7e52003-06-30 16:24:52 +00001511
wdenkc6097192002-11-03 00:24:07 +00001512 I2C_SCL(bit)
1513
York Sun472d5462013-04-01 11:29:11 -07001514 If <bit> is true, sets the I2C clock line high. If it
1515 is false, it clears it (low).
wdenkc6097192002-11-03 00:24:07 +00001516
wdenkb37c7e52003-06-30 16:24:52 +00001517 eg: #define I2C_SCL(bit) \
wdenk2535d602003-07-17 23:16:40 +00001518 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
wdenkba56f622004-02-06 23:19:44 +00001519 else immr->im_cpm.cp_pbdat &= ~PB_SCL
wdenkb37c7e52003-06-30 16:24:52 +00001520
wdenkc6097192002-11-03 00:24:07 +00001521 I2C_DELAY
1522
1523 This delay is invoked four times per clock cycle so this
1524 controls the rate of data transfer. The data rate thus
wdenkb37c7e52003-06-30 16:24:52 +00001525 is 1 / (I2C_DELAY * 4). Often defined to be something
wdenk945af8d2003-07-16 21:53:01 +00001526 like:
1527
wdenkb37c7e52003-06-30 16:24:52 +00001528 #define I2C_DELAY udelay(2)
wdenkc6097192002-11-03 00:24:07 +00001529
Mike Frysinger793b5722010-07-21 13:38:02 -04001530 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1531
1532 If your arch supports the generic GPIO framework (asm/gpio.h),
1533 then you may alternatively define the two GPIOs that are to be
1534 used as SCL / SDA. Any of the previous I2C_xxx macros will
1535 have GPIO-based defaults assigned to them as appropriate.
1536
1537 You should define these to the GPIO value as given directly to
1538 the generic GPIO functions.
1539
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001540 CONFIG_SYS_I2C_INIT_BOARD
wdenk47cd00f2003-03-06 13:39:27 +00001541
wdenk8bde7f72003-06-27 21:31:46 +00001542 When a board is reset during an i2c bus transfer
1543 chips might think that the current transfer is still
1544 in progress. On some boards it is possible to access
1545 the i2c SCLK line directly, either by using the
1546 processor pin as a GPIO or by having a second pin
1547 connected to the bus. If this option is defined a
1548 custom i2c_init_board() routine in boards/xxx/board.c
1549 is run early in the boot sequence.
wdenk47cd00f2003-03-06 13:39:27 +00001550
Ben Warrenbb99ad62006-09-07 16:50:54 -04001551 CONFIG_I2C_MULTI_BUS
1552
1553 This option allows the use of multiple I2C buses, each of which
Wolfgang Denkc0f40852011-10-26 10:21:21 +00001554 must have a controller. At any point in time, only one bus is
1555 active. To switch to a different bus, use the 'i2c dev' command.
Ben Warrenbb99ad62006-09-07 16:50:54 -04001556 Note that bus numbering is zero-based.
1557
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001558 CONFIG_SYS_I2C_NOPROBES
Ben Warrenbb99ad62006-09-07 16:50:54 -04001559
1560 This option specifies a list of I2C devices that will be skipped
Wolfgang Denkc0f40852011-10-26 10:21:21 +00001561 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
Peter Tyser0f89c542009-04-18 22:34:03 -05001562 is set, specify a list of bus-device pairs. Otherwise, specify
1563 a 1D array of device addresses
Ben Warrenbb99ad62006-09-07 16:50:54 -04001564
1565 e.g.
1566 #undef CONFIG_I2C_MULTI_BUS
Wolfgang Denkc0f40852011-10-26 10:21:21 +00001567 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
Ben Warrenbb99ad62006-09-07 16:50:54 -04001568
1569 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1570
Wolfgang Denkc0f40852011-10-26 10:21:21 +00001571 #define CONFIG_I2C_MULTI_BUS
Simon Glass945a18e2016-10-02 18:01:05 -06001572 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
Ben Warrenbb99ad62006-09-07 16:50:54 -04001573
1574 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1575
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001576 CONFIG_SYS_SPD_BUS_NUM
Timur Tabibe5e6182006-11-03 19:15:00 -06001577
1578 If defined, then this indicates the I2C bus number for DDR SPD.
1579 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1580
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001581 CONFIG_SYS_RTC_BUS_NUM
Stefan Roese0dc018e2007-02-20 10:51:26 +01001582
1583 If defined, then this indicates the I2C bus number for the RTC.
1584 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1585
Andrew Dyer2ac69852008-12-29 17:36:01 -06001586 CONFIG_SOFT_I2C_READ_REPEATED_START
1587
1588 defining this will force the i2c_read() function in
1589 the soft_i2c driver to perform an I2C repeated start
1590 between writing the address pointer and reading the
1591 data. If this define is omitted the default behaviour
1592 of doing a stop-start sequence will be used. Most I2C
1593 devices can use either method, but some require one or
1594 the other.
Timur Tabibe5e6182006-11-03 19:15:00 -06001595
wdenkc6097192002-11-03 00:24:07 +00001596- SPI Support: CONFIG_SPI
1597
1598 Enables SPI driver (so far only tested with
1599 SPI EEPROM, also an instance works with Crystal A/D and
1600 D/As on the SACSng board)
1601
wdenkc6097192002-11-03 00:24:07 +00001602 CONFIG_SOFT_SPI
1603
wdenk43d96162003-03-06 00:02:04 +00001604 Enables a software (bit-bang) SPI driver rather than
1605 using hardware support. This is a general purpose
1606 driver that only requires three general I/O port pins
1607 (two outputs, one input) to function. If this is
1608 defined, the board configuration must define several
1609 SPI configuration items (port pins to use, etc). For
1610 an example, see include/configs/sacsng.h.
wdenkc6097192002-11-03 00:24:07 +00001611
Heiko Schocherf659b572014-07-14 10:22:11 +02001612 CONFIG_SYS_SPI_MXC_WAIT
1613 Timeout for waiting until spi transfer completed.
1614 default: (CONFIG_SYS_HZ/100) /* 10 ms */
1615
Matthias Fuchs01335022007-12-27 17:12:34 +01001616- FPGA Support: CONFIG_FPGA
1617
1618 Enables FPGA subsystem.
1619
1620 CONFIG_FPGA_<vendor>
1621
1622 Enables support for specific chip vendors.
1623 (ALTERA, XILINX)
1624
1625 CONFIG_FPGA_<family>
1626
1627 Enables support for FPGA family.
1628 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1629
1630 CONFIG_FPGA_COUNT
wdenkc6097192002-11-03 00:24:07 +00001631
wdenk43d96162003-03-06 00:02:04 +00001632 Specify the number of FPGA devices to support.
wdenkc6097192002-11-03 00:24:07 +00001633
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001634 CONFIG_SYS_FPGA_PROG_FEEDBACK
wdenkc6097192002-11-03 00:24:07 +00001635
wdenk8bde7f72003-06-27 21:31:46 +00001636 Enable printing of hash marks during FPGA configuration.
wdenkc6097192002-11-03 00:24:07 +00001637
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001638 CONFIG_SYS_FPGA_CHECK_BUSY
wdenkc6097192002-11-03 00:24:07 +00001639
wdenk43d96162003-03-06 00:02:04 +00001640 Enable checks on FPGA configuration interface busy
1641 status by the configuration function. This option
1642 will require a board or device specific function to
1643 be written.
wdenkc6097192002-11-03 00:24:07 +00001644
1645 CONFIG_FPGA_DELAY
1646
1647 If defined, a function that provides delays in the FPGA
1648 configuration driver.
1649
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001650 CONFIG_SYS_FPGA_CHECK_CTRLC
wdenkc6097192002-11-03 00:24:07 +00001651 Allow Control-C to interrupt FPGA configuration
1652
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001653 CONFIG_SYS_FPGA_CHECK_ERROR
wdenkc6097192002-11-03 00:24:07 +00001654
wdenk43d96162003-03-06 00:02:04 +00001655 Check for configuration errors during FPGA bitfile
1656 loading. For example, abort during Virtex II
1657 configuration if the INIT_B line goes low (which
1658 indicated a CRC error).
wdenkc6097192002-11-03 00:24:07 +00001659
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001660 CONFIG_SYS_FPGA_WAIT_INIT
wdenkc6097192002-11-03 00:24:07 +00001661
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001662 Maximum time to wait for the INIT_B line to de-assert
1663 after PROB_B has been de-asserted during a Virtex II
wdenk43d96162003-03-06 00:02:04 +00001664 FPGA configuration sequence. The default time is 500
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001665 ms.
wdenkc6097192002-11-03 00:24:07 +00001666
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001667 CONFIG_SYS_FPGA_WAIT_BUSY
wdenkc6097192002-11-03 00:24:07 +00001668
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001669 Maximum time to wait for BUSY to de-assert during
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001670 Virtex II FPGA configuration. The default is 5 ms.
wdenkc6097192002-11-03 00:24:07 +00001671
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001672 CONFIG_SYS_FPGA_WAIT_CONFIG
wdenkc6097192002-11-03 00:24:07 +00001673
wdenk43d96162003-03-06 00:02:04 +00001674 Time to wait after FPGA configuration. The default is
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001675 200 ms.
wdenkc6097192002-11-03 00:24:07 +00001676
1677- Configuration Management:
Stefan Roeseb2b8a692014-10-22 12:13:24 +02001678
wdenkc6097192002-11-03 00:24:07 +00001679 CONFIG_IDENT_STRING
1680
wdenk43d96162003-03-06 00:02:04 +00001681 If defined, this string will be added to the U-Boot
1682 version information (U_BOOT_VERSION)
wdenkc6097192002-11-03 00:24:07 +00001683
1684- Vendor Parameter Protection:
1685
wdenk43d96162003-03-06 00:02:04 +00001686 U-Boot considers the values of the environment
1687 variables "serial#" (Board Serial Number) and
wdenk7152b1d2003-09-05 23:19:14 +00001688 "ethaddr" (Ethernet Address) to be parameters that
wdenk43d96162003-03-06 00:02:04 +00001689 are set once by the board vendor / manufacturer, and
1690 protects these variables from casual modification by
1691 the user. Once set, these variables are read-only,
1692 and write or delete attempts are rejected. You can
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001693 change this behaviour:
wdenkc6097192002-11-03 00:24:07 +00001694
1695 If CONFIG_ENV_OVERWRITE is #defined in your config
1696 file, the write protection for vendor parameters is
wdenk47cd00f2003-03-06 13:39:27 +00001697 completely disabled. Anybody can change or delete
wdenkc6097192002-11-03 00:24:07 +00001698 these parameters.
1699
Joe Hershberger92ac5202015-05-04 14:55:14 -05001700 Alternatively, if you define _both_ an ethaddr in the
1701 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001702 Ethernet address is installed in the environment,
wdenkc6097192002-11-03 00:24:07 +00001703 which can be changed exactly ONCE by the user. [The
1704 serial# is unaffected by this, i. e. it remains
1705 read-only.]
1706
Joe Hershberger25980902012-12-11 22:16:31 -06001707 The same can be accomplished in a more flexible way
1708 for any variable by configuring the type of access
1709 to allow for those variables in the ".flags" variable
1710 or define CONFIG_ENV_FLAGS_LIST_STATIC.
1711
wdenkc6097192002-11-03 00:24:07 +00001712- Protected RAM:
1713 CONFIG_PRAM
1714
1715 Define this variable to enable the reservation of
1716 "protected RAM", i. e. RAM which is not overwritten
1717 by U-Boot. Define CONFIG_PRAM to hold the number of
1718 kB you want to reserve for pRAM. You can overwrite
1719 this default value by defining an environment
1720 variable "pram" to the number of kB you want to
1721 reserve. Note that the board info structure will
1722 still show the full amount of RAM. If pRAM is
1723 reserved, a new environment variable "mem" will
1724 automatically be defined to hold the amount of
1725 remaining RAM in a form that can be passed as boot
1726 argument to Linux, for instance like that:
1727
Wolfgang Denkfe126d82005-11-20 21:40:11 +01001728 setenv bootargs ... mem=\${mem}
wdenkc6097192002-11-03 00:24:07 +00001729 saveenv
1730
1731 This way you can tell Linux not to use this memory,
1732 either, which results in a memory region that will
1733 not be affected by reboots.
1734
1735 *WARNING* If your board configuration uses automatic
1736 detection of the RAM size, you must make sure that
1737 this memory test is non-destructive. So far, the
1738 following board configurations are known to be
1739 "pRAM-clean":
1740
Heiko Schocher5b8e76c2017-06-07 17:33:09 +02001741 IVMS8, IVML24, SPD8xx,
Wolfgang Denk1b0757e2012-10-24 02:36:15 +00001742 HERMES, IP860, RPXlite, LWMON,
Heiko Schocher2eb48ff2017-06-07 17:33:10 +02001743 FLAGADM
wdenkc6097192002-11-03 00:24:07 +00001744
Gabe Black40fef042012-12-02 04:55:18 +00001745- Access to physical memory region (> 4GB)
1746 Some basic support is provided for operations on memory not
1747 normally accessible to U-Boot - e.g. some architectures
1748 support access to more than 4GB of memory on 32-bit
1749 machines using physical address extension or similar.
1750 Define CONFIG_PHYSMEM to access this basic support, which
1751 currently only supports clearing the memory.
1752
wdenkc6097192002-11-03 00:24:07 +00001753- Error Recovery:
wdenkc6097192002-11-03 00:24:07 +00001754 CONFIG_NET_RETRY_COUNT
1755
wdenk43d96162003-03-06 00:02:04 +00001756 This variable defines the number of retries for
1757 network operations like ARP, RARP, TFTP, or BOOTP
1758 before giving up the operation. If not defined, a
1759 default value of 5 is used.
wdenkc6097192002-11-03 00:24:07 +00001760
Guennadi Liakhovetski40cb90e2008-04-03 17:04:19 +02001761 CONFIG_ARP_TIMEOUT
1762
1763 Timeout waiting for an ARP reply in milliseconds.
1764
Tetsuyuki Kobayashi48a3e992012-07-03 22:25:21 +00001765 CONFIG_NFS_TIMEOUT
1766
1767 Timeout in milliseconds used in NFS protocol.
1768 If you encounter "ERROR: Cannot umount" in nfs command,
1769 try longer timeout such as
1770 #define CONFIG_NFS_TIMEOUT 10000UL
1771
wdenkc6097192002-11-03 00:24:07 +00001772 Note:
1773
wdenk8bde7f72003-06-27 21:31:46 +00001774 In the current implementation, the local variables
1775 space and global environment variables space are
1776 separated. Local variables are those you define by
1777 simply typing `name=value'. To access a local
1778 variable later on, you have write `$name' or
1779 `${name}'; to execute the contents of a variable
1780 directly type `$name' at the command prompt.
wdenkc6097192002-11-03 00:24:07 +00001781
wdenk43d96162003-03-06 00:02:04 +00001782 Global environment variables are those you use
1783 setenv/printenv to work with. To run a command stored
1784 in such a variable, you need to use the run command,
1785 and you must not use the '$' sign to access them.
wdenkc6097192002-11-03 00:24:07 +00001786
1787 To store commands and special characters in a
1788 variable, please use double quotation marks
1789 surrounding the whole text of the variable, instead
1790 of the backslashes before semicolons and special
1791 symbols.
1792
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001793- Command Line Editing and History:
Marek Vasutf3b267b2016-01-27 04:47:55 +01001794 CONFIG_CMDLINE_PS_SUPPORT
1795
1796 Enable support for changing the command prompt string
1797 at run-time. Only static string is supported so far.
1798 The string is obtained from environment variables PS1
1799 and PS2.
1800
wdenka8c7c702003-12-06 19:49:23 +00001801- Default Environment:
wdenkc6097192002-11-03 00:24:07 +00001802 CONFIG_EXTRA_ENV_SETTINGS
1803
wdenk43d96162003-03-06 00:02:04 +00001804 Define this to contain any number of null terminated
1805 strings (variable = value pairs) that will be part of
wdenk7152b1d2003-09-05 23:19:14 +00001806 the default environment compiled into the boot image.
wdenk2262cfe2002-11-18 00:14:45 +00001807
wdenk43d96162003-03-06 00:02:04 +00001808 For example, place something like this in your
1809 board's config file:
wdenkc6097192002-11-03 00:24:07 +00001810
1811 #define CONFIG_EXTRA_ENV_SETTINGS \
1812 "myvar1=value1\0" \
1813 "myvar2=value2\0"
1814
wdenk43d96162003-03-06 00:02:04 +00001815 Warning: This method is based on knowledge about the
1816 internal format how the environment is stored by the
1817 U-Boot code. This is NOT an official, exported
1818 interface! Although it is unlikely that this format
wdenk7152b1d2003-09-05 23:19:14 +00001819 will change soon, there is no guarantee either.
wdenkc6097192002-11-03 00:24:07 +00001820 You better know what you are doing here.
1821
wdenk43d96162003-03-06 00:02:04 +00001822 Note: overly (ab)use of the default environment is
1823 discouraged. Make sure to check other ways to preset
Wolfgang Denk74de7ae2009-04-01 23:34:12 +02001824 the environment like the "source" command or the
wdenk43d96162003-03-06 00:02:04 +00001825 boot command first.
wdenkc6097192002-11-03 00:24:07 +00001826
Simon Glass06fd8532012-11-30 13:01:17 +00001827 CONFIG_DELAY_ENVIRONMENT
1828
1829 Normally the environment is loaded when the board is
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001830 initialised so that it is available to U-Boot. This inhibits
Simon Glass06fd8532012-11-30 13:01:17 +00001831 that so that the environment is not available until
1832 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
1833 this is instead controlled by the value of
1834 /config/load-environment.
1835
Wolfgang Denkecb0ccd2005-09-24 22:37:32 +02001836- TFTP Fixed UDP Port:
1837 CONFIG_TFTP_PORT
1838
Wolfgang Denk28cb9372005-09-24 23:25:46 +02001839 If this is defined, the environment variable tftpsrcp
Wolfgang Denkecb0ccd2005-09-24 22:37:32 +02001840 is used to supply the TFTP UDP source port value.
Wolfgang Denk28cb9372005-09-24 23:25:46 +02001841 If tftpsrcp isn't defined, the normal pseudo-random port
Wolfgang Denkecb0ccd2005-09-24 22:37:32 +02001842 number generator is used.
1843
Wolfgang Denk28cb9372005-09-24 23:25:46 +02001844 Also, the environment variable tftpdstp is used to supply
1845 the TFTP UDP destination port value. If tftpdstp isn't
1846 defined, the normal port 69 is used.
1847
1848 The purpose for tftpsrcp is to allow a TFTP server to
Wolfgang Denkecb0ccd2005-09-24 22:37:32 +02001849 blindly start the TFTP transfer using the pre-configured
1850 target IP address and UDP port. This has the effect of
1851 "punching through" the (Windows XP) firewall, allowing
1852 the remainder of the TFTP transfer to proceed normally.
1853 A better solution is to properly configure the firewall,
1854 but sometimes that is not allowed.
1855
Wolfgang Denk4cf26092011-10-07 09:58:21 +02001856 CONFIG_STANDALONE_LOAD_ADDR
1857
Wolfgang Denk6feff892011-10-09 21:06:34 +02001858 This option defines a board specific value for the
1859 address where standalone program gets loaded, thus
1860 overwriting the architecture dependent default
Wolfgang Denk4cf26092011-10-07 09:58:21 +02001861 settings.
1862
1863- Frame Buffer Address:
1864 CONFIG_FB_ADDR
1865
1866 Define CONFIG_FB_ADDR if you want to use specific
Wolfgang Denk44a53b52013-01-03 00:43:59 +00001867 address for frame buffer. This is typically the case
1868 when using a graphics controller has separate video
1869 memory. U-Boot will then place the frame buffer at
1870 the given address instead of dynamically reserving it
1871 in system RAM by calling lcd_setmem(), which grabs
1872 the memory for the frame buffer depending on the
1873 configured panel size.
Wolfgang Denk4cf26092011-10-07 09:58:21 +02001874
1875 Please see board_init_f function.
1876
Detlev Zundelcccfc2a2009-12-01 17:16:19 +01001877- Automatic software updates via TFTP server
1878 CONFIG_UPDATE_TFTP
1879 CONFIG_UPDATE_TFTP_CNT_MAX
1880 CONFIG_UPDATE_TFTP_MSEC_MAX
1881
1882 These options enable and control the auto-update feature;
1883 for a more detailed description refer to doc/README.update.
1884
1885- MTD Support (mtdparts command, UBI support)
Heiko Schocherff94bc42014-06-24 10:10:04 +02001886 CONFIG_MTD_UBI_WL_THRESHOLD
1887 This parameter defines the maximum difference between the highest
1888 erase counter value and the lowest erase counter value of eraseblocks
1889 of UBI devices. When this threshold is exceeded, UBI starts performing
1890 wear leveling by means of moving data from eraseblock with low erase
1891 counter to eraseblocks with high erase counter.
1892
1893 The default value should be OK for SLC NAND flashes, NOR flashes and
1894 other flashes which have eraseblock life-cycle 100000 or more.
1895 However, in case of MLC NAND flashes which typically have eraseblock
1896 life-cycle less than 10000, the threshold should be lessened (e.g.,
1897 to 128 or 256, although it does not have to be power of 2).
1898
1899 default: 4096
Simon Glassc654b512014-10-23 18:58:54 -06001900
Heiko Schocherff94bc42014-06-24 10:10:04 +02001901 CONFIG_MTD_UBI_BEB_LIMIT
1902 This option specifies the maximum bad physical eraseblocks UBI
1903 expects on the MTD device (per 1024 eraseblocks). If the
1904 underlying flash does not admit of bad eraseblocks (e.g. NOR
1905 flash), this value is ignored.
1906
1907 NAND datasheets often specify the minimum and maximum NVM
1908 (Number of Valid Blocks) for the flashes' endurance lifetime.
1909 The maximum expected bad eraseblocks per 1024 eraseblocks
1910 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
1911 which gives 20 for most NANDs (MaxNVB is basically the total
1912 count of eraseblocks on the chip).
1913
1914 To put it differently, if this value is 20, UBI will try to
1915 reserve about 1.9% of physical eraseblocks for bad blocks
1916 handling. And that will be 1.9% of eraseblocks on the entire
1917 NAND chip, not just the MTD partition UBI attaches. This means
1918 that if you have, say, a NAND flash chip admits maximum 40 bad
1919 eraseblocks, and it is split on two MTD partitions of the same
1920 size, UBI will reserve 40 eraseblocks when attaching a
1921 partition.
1922
1923 default: 20
1924
1925 CONFIG_MTD_UBI_FASTMAP
1926 Fastmap is a mechanism which allows attaching an UBI device
1927 in nearly constant time. Instead of scanning the whole MTD device it
1928 only has to locate a checkpoint (called fastmap) on the device.
1929 The on-flash fastmap contains all information needed to attach
1930 the device. Using fastmap makes only sense on large devices where
1931 attaching by scanning takes long. UBI will not automatically install
1932 a fastmap on old images, but you can set the UBI parameter
1933 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
1934 that fastmap-enabled images are still usable with UBI implementations
1935 without fastmap support. On typical flash devices the whole fastmap
1936 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
1937
1938 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
1939 Set this parameter to enable fastmap automatically on images
1940 without a fastmap.
1941 default: 0
1942
Heiko Schocher0195a7b2015-10-22 06:19:21 +02001943 CONFIG_MTD_UBI_FM_DEBUG
1944 Enable UBI fastmap debug
1945 default: 0
1946
Daniel Schwierzeck6a11cf42011-07-18 07:48:07 +00001947- SPL framework
Wolfgang Denk04e5ae72011-09-11 21:24:09 +02001948 CONFIG_SPL
1949 Enable building of SPL globally.
Daniel Schwierzeck6a11cf42011-07-18 07:48:07 +00001950
Tom Rini95579792012-02-14 07:29:40 +00001951 CONFIG_SPL_LDSCRIPT
1952 LDSCRIPT for linking the SPL binary.
1953
Albert ARIBAUD6ebc3462013-04-12 05:14:30 +00001954 CONFIG_SPL_MAX_FOOTPRINT
1955 Maximum size in memory allocated to the SPL, BSS included.
1956 When defined, the linker checks that the actual memory
1957 used by SPL from _start to __bss_end does not exceed it.
Albert ARIBAUD8960af82013-04-14 04:48:38 +00001958 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
Albert ARIBAUD6ebc3462013-04-12 05:14:30 +00001959 must not be both defined at the same time.
1960
Tom Rini95579792012-02-14 07:29:40 +00001961 CONFIG_SPL_MAX_SIZE
Albert ARIBAUD6ebc3462013-04-12 05:14:30 +00001962 Maximum size of the SPL image (text, data, rodata, and
1963 linker lists sections), BSS excluded.
1964 When defined, the linker checks that the actual size does
1965 not exceed it.
Tom Rini95579792012-02-14 07:29:40 +00001966
Scott Wood94a45bb2012-09-20 19:05:12 -05001967 CONFIG_SPL_RELOC_TEXT_BASE
1968 Address to relocate to. If unspecified, this is equal to
1969 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
1970
Tom Rini95579792012-02-14 07:29:40 +00001971 CONFIG_SPL_BSS_START_ADDR
1972 Link address for the BSS within the SPL binary.
1973
1974 CONFIG_SPL_BSS_MAX_SIZE
Albert ARIBAUD6ebc3462013-04-12 05:14:30 +00001975 Maximum size in memory allocated to the SPL BSS.
1976 When defined, the linker checks that the actual memory used
1977 by SPL from __bss_start to __bss_end does not exceed it.
Albert ARIBAUD8960af82013-04-14 04:48:38 +00001978 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
Albert ARIBAUD6ebc3462013-04-12 05:14:30 +00001979 must not be both defined at the same time.
Tom Rini95579792012-02-14 07:29:40 +00001980
1981 CONFIG_SPL_STACK
1982 Adress of the start of the stack SPL will use
1983
Albert ARIBAUD \(3ADEV\)8c80eb32015-03-31 11:40:50 +02001984 CONFIG_SPL_PANIC_ON_RAW_IMAGE
1985 When defined, SPL will panic() if the image it has
1986 loaded does not have a signature.
1987 Defining this is useful when code which loads images
1988 in SPL cannot guarantee that absolutely all read errors
1989 will be caught.
1990 An example is the LPC32XX MLC NAND driver, which will
1991 consider that a completely unreadable NAND block is bad,
1992 and thus should be skipped silently.
1993
Scott Wood94a45bb2012-09-20 19:05:12 -05001994 CONFIG_SPL_RELOC_STACK
1995 Adress of the start of the stack SPL will use after
1996 relocation. If unspecified, this is equal to
1997 CONFIG_SPL_STACK.
1998
Tom Rini95579792012-02-14 07:29:40 +00001999 CONFIG_SYS_SPL_MALLOC_START
2000 Starting address of the malloc pool used in SPL.
Fabio Estevam9ac4fc82015-11-12 12:30:19 -02002001 When this option is set the full malloc is used in SPL and
2002 it is set up by spl_init() and before that, the simple malloc()
2003 can be used if CONFIG_SYS_MALLOC_F is defined.
Tom Rini95579792012-02-14 07:29:40 +00002004
2005 CONFIG_SYS_SPL_MALLOC_SIZE
2006 The size of the malloc pool used in SPL.
Daniel Schwierzeck6a11cf42011-07-18 07:48:07 +00002007
Tom Rini9607faf2014-03-28 12:03:39 -04002008 CONFIG_SPL_OS_BOOT
2009 Enable booting directly to an OS from SPL.
2010 See also: doc/README.falcon
2011
Tom Rini861a86f2012-08-13 11:37:56 -07002012 CONFIG_SPL_DISPLAY_PRINT
2013 For ARM, enable an optional function to print more information
2014 about the running system.
2015
Scott Wood4b919722012-09-20 16:35:21 -05002016 CONFIG_SPL_INIT_MINIMAL
2017 Arch init code should be built for a very small image
2018
Paul Kocialkowskib97300b2014-11-08 23:14:56 +01002019 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
2020 Partition on the MMC to load U-Boot from when the MMC is being
2021 used in raw mode
2022
Peter Korsgaard2b75b0a2013-05-13 08:36:29 +00002023 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
2024 Sector to load kernel uImage from when MMC is being
2025 used in raw mode (for Falcon mode)
2026
2027 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
2028 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
2029 Sector and number of sectors to load kernel argument
2030 parameters from when MMC is being used in raw mode
2031 (for falcon mode)
2032
Guillaume GARDETfae81c72014-10-15 17:53:13 +02002033 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
2034 Filename to read to load U-Boot when reading from filesystem
2035
2036 CONFIG_SPL_FS_LOAD_KERNEL_NAME
Peter Korsgaard7ad2cc72013-05-13 08:36:27 +00002037 Filename to read to load kernel uImage when reading
Guillaume GARDETfae81c72014-10-15 17:53:13 +02002038 from filesystem (for Falcon mode)
Peter Korsgaard7ad2cc72013-05-13 08:36:27 +00002039
Guillaume GARDETfae81c72014-10-15 17:53:13 +02002040 CONFIG_SPL_FS_LOAD_ARGS_NAME
Peter Korsgaard7ad2cc72013-05-13 08:36:27 +00002041 Filename to read to load kernel argument parameters
Guillaume GARDETfae81c72014-10-15 17:53:13 +02002042 when reading from filesystem (for Falcon mode)
Peter Korsgaard7ad2cc72013-05-13 08:36:27 +00002043
Scott Wood06f60ae2012-12-06 13:33:17 +00002044 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
2045 Set this for NAND SPL on PPC mpc83xx targets, so that
2046 start.S waits for the rest of the SPL to load before
2047 continuing (the hardware starts execution after just
2048 loading the first page rather than the full 4K).
2049
Prabhakar Kushwaha651fcf62014-04-08 19:12:31 +05302050 CONFIG_SPL_SKIP_RELOCATE
2051 Avoid SPL relocation
2052
Jörg Krause15e207f2018-01-14 19:26:38 +01002053 CONFIG_SPL_NAND_IDENT
2054 SPL uses the chip ID list to identify the NAND flash.
2055 Requires CONFIG_SPL_NAND_BASE.
2056
Thomas Gleixner6f4e7d32016-07-12 20:28:12 +02002057 CONFIG_SPL_UBI
2058 Support for a lightweight UBI (fastmap) scanner and
2059 loader
2060
Heiko Schocher0c3117b2014-10-31 08:31:00 +01002061 CONFIG_SPL_NAND_RAW_ONLY
2062 Support to boot only raw u-boot.bin images. Use this only
2063 if you need to save space.
2064
Ying Zhang7c8eea52013-08-16 15:16:12 +08002065 CONFIG_SPL_COMMON_INIT_DDR
2066 Set for common ddr init with serial presence detect in
2067 SPL binary.
2068
Tom Rini95579792012-02-14 07:29:40 +00002069 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
2070 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
2071 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
2072 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
2073 CONFIG_SYS_NAND_ECCBYTES
2074 Defines the size and behavior of the NAND that SPL uses
Scott Wood7d4b7952012-09-21 18:35:27 -05002075 to read U-Boot
Tom Rini95579792012-02-14 07:29:40 +00002076
2077 CONFIG_SYS_NAND_U_BOOT_OFFS
Scott Wood7d4b7952012-09-21 18:35:27 -05002078 Location in NAND to read U-Boot from
2079
2080 CONFIG_SYS_NAND_U_BOOT_DST
2081 Location in memory to load U-Boot to
2082
2083 CONFIG_SYS_NAND_U_BOOT_SIZE
2084 Size of image to load
Tom Rini95579792012-02-14 07:29:40 +00002085
2086 CONFIG_SYS_NAND_U_BOOT_START
Scott Wood7d4b7952012-09-21 18:35:27 -05002087 Entry point in loaded image to jump to
Tom Rini95579792012-02-14 07:29:40 +00002088
2089 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
2090 Define this if you need to first read the OOB and then the
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08002091 data. This is used, for example, on davinci platforms.
Tom Rini95579792012-02-14 07:29:40 +00002092
Pavel Machekc57b9532012-08-30 22:42:11 +02002093 CONFIG_SPL_RAM_DEVICE
2094 Support for running image already present in ram, in SPL binary
2095
Scott Wood74752ba2012-12-06 13:33:16 +00002096 CONFIG_SPL_PAD_TO
Benoît Thébaudeau6113d3f2013-04-11 09:35:49 +00002097 Image offset to which the SPL should be padded before appending
2098 the SPL payload. By default, this is defined as
2099 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
2100 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
2101 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
Scott Wood74752ba2012-12-06 13:33:16 +00002102
Scott Woodca2fca22012-09-21 16:27:32 -05002103 CONFIG_SPL_TARGET
2104 Final target image containing SPL and payload. Some SPLs
2105 use an arch-specific makefile fragment instead, for
2106 example if more than one image needs to be produced.
2107
Marek Vasutb527b9c2018-05-13 00:22:52 +02002108 CONFIG_SPL_FIT_PRINT
Simon Glass87ebee32013-05-08 08:05:59 +00002109 Printing information about a FIT image adds quite a bit of
2110 code to SPL. So this is normally disabled in SPL. Use this
2111 option to re-enable it. This will affect the output of the
2112 bootm command when booting a FIT image.
2113
Ying Zhang3aa29de2013-08-16 15:16:15 +08002114- TPL framework
2115 CONFIG_TPL
2116 Enable building of TPL globally.
2117
2118 CONFIG_TPL_PAD_TO
2119 Image offset to which the TPL should be padded before appending
2120 the TPL payload. By default, this is defined as
Wolfgang Denk93e14592013-10-04 17:43:24 +02002121 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
2122 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
2123 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
Ying Zhang3aa29de2013-08-16 15:16:15 +08002124
wdenka8c7c702003-12-06 19:49:23 +00002125- Interrupt support (PPC):
2126
wdenkd4ca31c2004-01-02 14:00:00 +00002127 There are common interrupt_init() and timer_interrupt()
2128 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002129 for CPU specific initialization. interrupt_init_cpu()
wdenkd4ca31c2004-01-02 14:00:00 +00002130 should set decrementer_count to appropriate value. If
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002131 CPU resets decrementer automatically after interrupt
wdenkd4ca31c2004-01-02 14:00:00 +00002132 (ppc4xx) it should set decrementer_count to zero.
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002133 timer_interrupt() calls timer_interrupt_cpu() for CPU
wdenkd4ca31c2004-01-02 14:00:00 +00002134 specific handling. If board has watchdog / status_led
2135 / other_activity_monitor it works automatically from
2136 general timer_interrupt().
wdenka8c7c702003-12-06 19:49:23 +00002137
wdenkc6097192002-11-03 00:24:07 +00002138
Helmut Raiger9660e442011-10-20 04:19:47 +00002139Board initialization settings:
2140------------------------------
2141
2142During Initialization u-boot calls a number of board specific functions
2143to allow the preparation of board specific prerequisites, e.g. pin setup
2144before drivers are initialized. To enable these callbacks the
2145following configuration macros have to be defined. Currently this is
2146architecture specific, so please check arch/your_architecture/lib/board.c
2147typically in board_init_f() and board_init_r().
2148
2149- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
2150- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
2151- CONFIG_BOARD_LATE_INIT: Call board_late_init()
2152- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
wdenkc6097192002-11-03 00:24:07 +00002153
wdenkc6097192002-11-03 00:24:07 +00002154Configuration Settings:
2155-----------------------
2156
Simon Glass4d979bf2019-12-28 10:45:10 -07002157- MEM_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
York Sun4d1fd7f2014-02-26 17:03:19 -08002158 Optionally it can be defined to support 64-bit memory commands.
2159
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002160- CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
wdenkc6097192002-11-03 00:24:07 +00002161 undefine this when you're short of memory.
2162
Peter Tyser2fb26042009-01-27 18:03:12 -06002163- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2164 width of the commands listed in the 'help' command output.
2165
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002166- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
wdenkc6097192002-11-03 00:24:07 +00002167 prompt for user input.
2168
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002169- CONFIG_SYS_CBSIZE: Buffer size for input from the Console
wdenkc6097192002-11-03 00:24:07 +00002170
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002171- CONFIG_SYS_PBSIZE: Buffer size for Console output
wdenkc6097192002-11-03 00:24:07 +00002172
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002173- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
wdenkc6097192002-11-03 00:24:07 +00002174
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002175- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
wdenkc6097192002-11-03 00:24:07 +00002176 the application (usually a Linux kernel) when it is
2177 booted
2178
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002179- CONFIG_SYS_BAUDRATE_TABLE:
wdenkc6097192002-11-03 00:24:07 +00002180 List of legal baudrate settings for this board.
2181
York Sune8149522015-12-04 11:57:07 -08002182- CONFIG_SYS_MEM_RESERVE_SECURE
York Sune61a7532016-06-24 16:46:18 -07002183 Only implemented for ARMv8 for now.
York Sune8149522015-12-04 11:57:07 -08002184 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
2185 is substracted from total RAM and won't be reported to OS.
2186 This memory can be used as secure memory. A variable
York Sune61a7532016-06-24 16:46:18 -07002187 gd->arch.secure_ram is used to track the location. In systems
York Sune8149522015-12-04 11:57:07 -08002188 the RAM base is not zero, or RAM is divided into banks,
2189 this variable needs to be recalcuated to get the address.
2190
York Sunaabd7dd2015-12-07 11:05:29 -08002191- CONFIG_SYS_MEM_TOP_HIDE:
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002192 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
Stefan Roese14f73ca2008-03-26 10:14:11 +01002193 this specified memory area will get subtracted from the top
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002194 (end) of RAM and won't get "touched" at all by U-Boot. By
Stefan Roese14f73ca2008-03-26 10:14:11 +01002195 fixing up gd->ram_size the Linux kernel should gets passed
2196 the now "corrected" memory size and won't touch it either.
2197 This should work for arch/ppc and arch/powerpc. Only Linux
Stefan Roese5e12e752008-03-28 11:02:53 +01002198 board ports in arch/powerpc with bootwrapper support that
Stefan Roese14f73ca2008-03-26 10:14:11 +01002199 recalculate the memory size from the SDRAM controller setup
Stefan Roese5e12e752008-03-28 11:02:53 +01002200 will have to get fixed in Linux additionally.
Stefan Roese14f73ca2008-03-26 10:14:11 +01002201
2202 This option can be used as a workaround for the 440EPx/GRx
2203 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2204 be touched.
2205
2206 WARNING: Please make sure that this value is a multiple of
2207 the Linux page size (normally 4k). If this is not the case,
2208 then the end address of the Linux memory will be located at a
2209 non page size aligned address and this could cause major
2210 problems.
2211
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002212- CONFIG_SYS_LOADS_BAUD_CHANGE:
wdenkc6097192002-11-03 00:24:07 +00002213 Enable temporary baudrate change while serial download
2214
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002215- CONFIG_SYS_SDRAM_BASE:
wdenkc6097192002-11-03 00:24:07 +00002216 Physical start address of SDRAM. _Must_ be 0 here.
2217
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002218- CONFIG_SYS_FLASH_BASE:
wdenkc6097192002-11-03 00:24:07 +00002219 Physical start address of Flash memory.
2220
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002221- CONFIG_SYS_MONITOR_BASE:
wdenkc6097192002-11-03 00:24:07 +00002222 Physical start address of boot monitor code (set by
2223 make config files to be same as the text base address
Wolfgang Denk14d0a022010-10-07 21:51:12 +02002224 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002225 CONFIG_SYS_FLASH_BASE when booting from flash.
wdenkc6097192002-11-03 00:24:07 +00002226
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002227- CONFIG_SYS_MONITOR_LEN:
wdenk8bde7f72003-06-27 21:31:46 +00002228 Size of memory reserved for monitor code, used to
2229 determine _at_compile_time_ (!) if the environment is
2230 embedded within the U-Boot image, or in a separate
2231 flash sector.
wdenkc6097192002-11-03 00:24:07 +00002232
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002233- CONFIG_SYS_MALLOC_LEN:
wdenkc6097192002-11-03 00:24:07 +00002234 Size of DRAM reserved for malloc() use.
2235
Simon Glassd59476b2014-07-10 22:23:28 -06002236- CONFIG_SYS_MALLOC_F_LEN
2237 Size of the malloc() pool for use before relocation. If
2238 this is defined, then a very simple malloc() implementation
2239 will become available before relocation. The address is just
2240 below the global data, and the stack is moved down to make
2241 space.
2242
2243 This feature allocates regions with increasing addresses
2244 within the region. calloc() is supported, but realloc()
2245 is not available. free() is supported but does nothing.
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08002246 The memory will be freed (or in fact just forgotten) when
Simon Glassd59476b2014-07-10 22:23:28 -06002247 U-Boot relocates itself.
2248
Simon Glass38687ae2014-11-10 17:16:54 -07002249- CONFIG_SYS_MALLOC_SIMPLE
2250 Provides a simple and small malloc() and calloc() for those
2251 boards which do not use the full malloc in SPL (which is
2252 enabled with CONFIG_SYS_SPL_MALLOC_START).
2253
Thierry Reding1dfdd9b2014-12-09 22:25:22 -07002254- CONFIG_SYS_NONCACHED_MEMORY:
2255 Size of non-cached memory area. This area of memory will be
2256 typically located right below the malloc() area and mapped
2257 uncached in the MMU. This is useful for drivers that would
2258 otherwise require a lot of explicit cache maintenance. For
2259 some drivers it's also impossible to properly maintain the
2260 cache. For example if the regions that need to be flushed
2261 are not a multiple of the cache-line size, *and* padding
2262 cannot be allocated between the regions to align them (i.e.
2263 if the HW requires a contiguous array of regions, and the
2264 size of each region is not cache-aligned), then a flush of
2265 one region may result in overwriting data that hardware has
2266 written to another region in the same cache-line. This can
2267 happen for example in network drivers where descriptors for
2268 buffers are typically smaller than the CPU cache-line (e.g.
2269 16 bytes vs. 32 or 64 bytes).
2270
2271 Non-cached memory is only supported on 32-bit ARM at present.
2272
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002273- CONFIG_SYS_BOOTM_LEN:
Stefan Roese15940c92006-03-13 11:16:36 +01002274 Normally compressed uImages are limited to an
2275 uncompressed size of 8 MBytes. If this is not enough,
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002276 you can define CONFIG_SYS_BOOTM_LEN in your board config file
Stefan Roese15940c92006-03-13 11:16:36 +01002277 to adjust this setting to your needs.
2278
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002279- CONFIG_SYS_BOOTMAPSZ:
wdenkc6097192002-11-03 00:24:07 +00002280 Maximum size of memory mapped by the startup code of
2281 the Linux kernel; all data that must be processed by
Bartlomiej Sieka7d721e32008-04-14 15:44:16 +02002282 the Linux kernel (bd_info, boot arguments, FDT blob if
2283 used) must be put below this limit, unless "bootm_low"
Robert P. J. Day1bce2ae2013-09-16 07:15:45 -04002284 environment variable is defined and non-zero. In such case
Bartlomiej Sieka7d721e32008-04-14 15:44:16 +02002285 all data for the Linux kernel must be between "bootm_low"
Wolfgang Denkc0f40852011-10-26 10:21:21 +00002286 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
Grant Likelyc3624e62011-03-28 09:58:43 +00002287 variable "bootm_mapsize" will override the value of
2288 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
2289 then the value in "bootm_size" will be used instead.
wdenkc6097192002-11-03 00:24:07 +00002290
John Rigbyfca43cc2010-10-13 13:57:35 -06002291- CONFIG_SYS_BOOT_RAMDISK_HIGH:
2292 Enable initrd_high functionality. If defined then the
2293 initrd_high feature is enabled and the bootm ramdisk subcommand
2294 is enabled.
2295
2296- CONFIG_SYS_BOOT_GET_CMDLINE:
2297 Enables allocating and saving kernel cmdline in space between
2298 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2299
2300- CONFIG_SYS_BOOT_GET_KBD:
2301 Enables allocating and saving a kernel copy of the bd_info in
2302 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2303
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002304- CONFIG_SYS_MAX_FLASH_BANKS:
wdenkc6097192002-11-03 00:24:07 +00002305 Max number of Flash memory banks
2306
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002307- CONFIG_SYS_MAX_FLASH_SECT:
wdenkc6097192002-11-03 00:24:07 +00002308 Max number of sectors on a Flash chip
2309
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002310- CONFIG_SYS_FLASH_ERASE_TOUT:
wdenkc6097192002-11-03 00:24:07 +00002311 Timeout for Flash erase operations (in ms)
2312
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002313- CONFIG_SYS_FLASH_WRITE_TOUT:
wdenkc6097192002-11-03 00:24:07 +00002314 Timeout for Flash write operations (in ms)
2315
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002316- CONFIG_SYS_FLASH_LOCK_TOUT
wdenk8564acf2003-07-14 22:13:32 +00002317 Timeout for Flash set sector lock bit operation (in ms)
2318
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002319- CONFIG_SYS_FLASH_UNLOCK_TOUT
wdenk8564acf2003-07-14 22:13:32 +00002320 Timeout for Flash clear lock bits operation (in ms)
2321
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002322- CONFIG_SYS_FLASH_PROTECTION
wdenk8564acf2003-07-14 22:13:32 +00002323 If defined, hardware flash sectors protection is used
2324 instead of U-Boot software protection.
2325
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002326- CONFIG_SYS_DIRECT_FLASH_TFTP:
wdenkc6097192002-11-03 00:24:07 +00002327
2328 Enable TFTP transfers directly to flash memory;
2329 without this option such a download has to be
2330 performed in two steps: (1) download to RAM, and (2)
2331 copy from RAM to flash.
2332
2333 The two-step approach is usually more reliable, since
2334 you can check if the download worked before you erase
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002335 the flash, but in some situations (when system RAM is
2336 too limited to allow for a temporary copy of the
wdenkc6097192002-11-03 00:24:07 +00002337 downloaded image) this option may be very useful.
2338
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002339- CONFIG_SYS_FLASH_CFI:
wdenk43d96162003-03-06 00:02:04 +00002340 Define if the flash driver uses extra elements in the
wdenk5653fc32004-02-08 22:55:38 +00002341 common flash structure for storing flash geometry.
2342
Jean-Christophe PLAGNIOL-VILLARD00b18832008-08-13 01:40:42 +02002343- CONFIG_FLASH_CFI_DRIVER
wdenk5653fc32004-02-08 22:55:38 +00002344 This option also enables the building of the cfi_flash driver
2345 in the drivers directory
wdenkc6097192002-11-03 00:24:07 +00002346
Piotr Ziecik91809ed2008-11-17 15:57:58 +01002347- CONFIG_FLASH_CFI_MTD
2348 This option enables the building of the cfi_mtd driver
2349 in the drivers directory. The driver exports CFI flash
2350 to the MTD layer.
2351
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002352- CONFIG_SYS_FLASH_USE_BUFFER_WRITE
Guennadi Liakhovetski96ef8312008-04-03 13:36:02 +02002353 Use buffered writes to flash.
2354
2355- CONFIG_FLASH_SPANSION_S29WS_N
2356 s29ws-n MirrorBit flash has non-standard addresses for buffered
2357 write commands.
2358
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002359- CONFIG_SYS_FLASH_QUIET_TEST
Stefan Roese5568e612005-11-22 13:20:42 +01002360 If this option is defined, the common CFI flash doesn't
2361 print it's warning upon not recognized FLASH banks. This
2362 is useful, if some of the configured banks are only
2363 optionally available.
2364
Jerry Van Baren9a042e92008-03-08 13:48:01 -05002365- CONFIG_FLASH_SHOW_PROGRESS
2366 If defined (must be an integer), print out countdown
2367 digits and dots. Recommended value: 45 (9..1) for 80
2368 column displays, 15 (3..1) for 40 column displays.
2369
Stefan Roese352ef3f2013-04-04 15:53:14 +02002370- CONFIG_FLASH_VERIFY
2371 If defined, the content of the flash (destination) is compared
2372 against the source after the write operation. An error message
2373 will be printed when the contents are not identical.
2374 Please note that this option is useless in nearly all cases,
2375 since such flash programming errors usually are detected earlier
2376 while unprotecting/erasing/programming. Please only enable
2377 this option if you really know what you are doing.
2378
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002379- CONFIG_SYS_RX_ETH_BUFFER:
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002380 Defines the number of Ethernet receive buffers. On some
2381 Ethernet controllers it is recommended to set this value
stroese53cf9432003-06-05 15:39:44 +00002382 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2383 buffers can be full shortly after enabling the interface
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002384 on high Ethernet traffic.
stroese53cf9432003-06-05 15:39:44 +00002385 Defaults to 4 if not defined.
2386
Wolfgang Denkea882ba2010-06-20 23:33:59 +02002387- CONFIG_ENV_MAX_ENTRIES
2388
Wolfgang Denk071bc922010-10-27 22:48:30 +02002389 Maximum number of entries in the hash table that is used
2390 internally to store the environment settings. The default
2391 setting is supposed to be generous and should work in most
2392 cases. This setting can be used to tune behaviour; see
2393 lib/hashtable.c for details.
Wolfgang Denkea882ba2010-06-20 23:33:59 +02002394
Joe Hershberger25980902012-12-11 22:16:31 -06002395- CONFIG_ENV_FLAGS_LIST_DEFAULT
2396- CONFIG_ENV_FLAGS_LIST_STATIC
Robert P. J. Day1bce2ae2013-09-16 07:15:45 -04002397 Enable validation of the values given to environment variables when
Joe Hershberger25980902012-12-11 22:16:31 -06002398 calling env set. Variables can be restricted to only decimal,
2399 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
2400 the variables can also be restricted to IP address or MAC address.
2401
2402 The format of the list is:
2403 type_attribute = [s|d|x|b|i|m]
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08002404 access_attribute = [a|r|o|c]
2405 attributes = type_attribute[access_attribute]
Joe Hershberger25980902012-12-11 22:16:31 -06002406 entry = variable_name[:attributes]
2407 list = entry[,list]
2408
2409 The type attributes are:
2410 s - String (default)
2411 d - Decimal
2412 x - Hexadecimal
2413 b - Boolean ([1yYtT|0nNfF])
2414 i - IP address
2415 m - MAC address
2416
Joe Hershberger267541f2012-12-11 22:16:34 -06002417 The access attributes are:
2418 a - Any (default)
2419 r - Read-only
2420 o - Write-once
2421 c - Change-default
2422
Joe Hershberger25980902012-12-11 22:16:31 -06002423 - CONFIG_ENV_FLAGS_LIST_DEFAULT
2424 Define this to a list (string) to define the ".flags"
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08002425 environment variable in the default or embedded environment.
Joe Hershberger25980902012-12-11 22:16:31 -06002426
2427 - CONFIG_ENV_FLAGS_LIST_STATIC
2428 Define this to a list (string) to define validation that
2429 should be done if an entry is not found in the ".flags"
2430 environment variable. To override a setting in the static
2431 list, simply add an entry for the same variable name to the
2432 ".flags" variable.
2433
Joe Hershbergerbdf1fe42015-05-20 14:27:20 -05002434 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
2435 regular expression. This allows multiple variables to define the same
2436 flags without explicitly listing them for each variable.
2437
wdenkc6097192002-11-03 00:24:07 +00002438The following definitions that deal with the placement and management
2439of environment data (variable area); in general, we support the
2440following configurations:
2441
Mike Frysingerc3eb3fe2011-07-08 10:44:25 +00002442- CONFIG_BUILD_ENVCRC:
2443
2444 Builds up envcrc with the target environment so that external utils
2445 may easily extract it and embed it in final U-Boot images.
2446
wdenkc6097192002-11-03 00:24:07 +00002447BE CAREFUL! The first access to the environment happens quite early
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08002448in U-Boot initialization (when we try to get the setting of for the
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002449console baudrate). You *MUST* have mapped your NVRAM area then, or
wdenkc6097192002-11-03 00:24:07 +00002450U-Boot will hang.
2451
2452Please note that even with NVRAM we still use a copy of the
2453environment in RAM: we could work on NVRAM directly, but we want to
2454keep settings there always unmodified except somebody uses "saveenv"
2455to save the current settings.
2456
Liu Gang0a85a9e2012-03-08 00:33:20 +00002457BE CAREFUL! For some special cases, the local device can not use
2458"saveenv" command. For example, the local device will get the
Liu Gangfc54c7f2012-08-09 05:10:01 +00002459environment stored in a remote NOR flash by SRIO or PCIE link,
2460but it can not erase, write this NOR flash by SRIO or PCIE interface.
Liu Gang0a85a9e2012-03-08 00:33:20 +00002461
Guennadi Liakhovetskib74ab732009-05-18 16:07:22 +02002462- CONFIG_NAND_ENV_DST
2463
2464 Defines address in RAM to which the nand_spl code should copy the
2465 environment. If redundant environment is used, it will be copied to
2466 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2467
Bruce Adlere881cb52007-11-02 13:15:42 -07002468Please note that the environment is read-only until the monitor
wdenkc6097192002-11-03 00:24:07 +00002469has been relocated to RAM and a RAM copy of the environment has been
Simon Glass00caae62017-08-03 12:22:12 -06002470created; also, when using EEPROM you will have to use env_get_f()
wdenkc6097192002-11-03 00:24:07 +00002471until then to read environment variables.
2472
wdenk85ec0bc2003-03-31 16:34:49 +00002473The environment is protected by a CRC32 checksum. Before the monitor
2474is relocated into RAM, as a result of a bad CRC you will be working
2475with the compiled-in default environment - *silently*!!! [This is
2476necessary, because the first environment variable we need is the
2477"baudrate" setting for the console - if we have a bad CRC, we don't
2478have any device yet where we could complain.]
wdenkc6097192002-11-03 00:24:07 +00002479
2480Note: once the monitor has been relocated, then it will complain if
2481the default environment is used; a new CRC is computed as soon as you
wdenk85ec0bc2003-03-31 16:34:49 +00002482use the "saveenv" command to store a valid environment.
wdenkc6097192002-11-03 00:24:07 +00002483
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002484- CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
wdenk42d1f032003-10-15 23:53:47 +00002485 Echo the inverted Ethernet link state to the fault LED.
wdenkfc3e2162003-10-08 22:33:00 +00002486
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002487 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
wdenkfc3e2162003-10-08 22:33:00 +00002488 also needs to be defined.
2489
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002490- CONFIG_SYS_FAULT_MII_ADDR:
wdenk42d1f032003-10-15 23:53:47 +00002491 MII address of the PHY to check for the Ethernet link state.
wdenkc6097192002-11-03 00:24:07 +00002492
Ron Madridf5675aa2009-02-18 14:30:44 -08002493- CONFIG_NS16550_MIN_FUNCTIONS:
2494 Define this if you desire to only have use of the NS16550_init
2495 and NS16550_putc functions for the serial driver located at
2496 drivers/serial/ns16550.c. This option is useful for saving
2497 space for already greatly restricted images, including but not
2498 limited to NAND_SPL configurations.
2499
Simon Glassb2b92f52012-11-30 13:01:18 +00002500- CONFIG_DISPLAY_BOARDINFO
2501 Display information about the board that U-Boot is running on
2502 when U-Boot starts up. The board function checkboard() is called
2503 to do this.
2504
Simon Glasse2e3e2b2012-11-30 13:01:19 +00002505- CONFIG_DISPLAY_BOARDINFO_LATE
2506 Similar to the previous option, but display this information
2507 later, once stdio is running and output goes to the LCD, if
2508 present.
2509
Sascha Silbefeb85802013-08-11 16:40:43 +02002510- CONFIG_BOARD_SIZE_LIMIT:
2511 Maximum size of the U-Boot image. When defined, the
2512 build system checks that the actual size does not
2513 exceed it.
2514
wdenkc6097192002-11-03 00:24:07 +00002515Low Level (hardware related) configuration options:
wdenkdc7c9a12003-03-26 06:55:25 +00002516---------------------------------------------------
wdenkc6097192002-11-03 00:24:07 +00002517
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002518- CONFIG_SYS_CACHELINE_SIZE:
wdenkc6097192002-11-03 00:24:07 +00002519 Cache Line Size of the CPU.
2520
Timur Tabie46fedf2011-08-04 18:03:41 -05002521- CONFIG_SYS_CCSRBAR_DEFAULT:
2522 Default (power-on reset) physical address of CCSR on Freescale
2523 PowerPC SOCs.
2524
2525- CONFIG_SYS_CCSRBAR:
2526 Virtual address of CCSR. On a 32-bit build, this is typically
2527 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
2528
Timur Tabie46fedf2011-08-04 18:03:41 -05002529- CONFIG_SYS_CCSRBAR_PHYS:
2530 Physical address of CCSR. CCSR can be relocated to a new
2531 physical address, if desired. In this case, this macro should
Wolfgang Denkc0f40852011-10-26 10:21:21 +00002532 be set to that address. Otherwise, it should be set to the
Timur Tabie46fedf2011-08-04 18:03:41 -05002533 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
2534 is typically relocated on 36-bit builds. It is recommended
2535 that this macro be defined via the _HIGH and _LOW macros:
2536
2537 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
2538 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
2539
2540- CONFIG_SYS_CCSRBAR_PHYS_HIGH:
Wolfgang Denk4cf26092011-10-07 09:58:21 +02002541 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
2542 either 0 (32-bit build) or 0xF (36-bit build). This macro is
Timur Tabie46fedf2011-08-04 18:03:41 -05002543 used in assembly code, so it must not contain typecasts or
2544 integer size suffixes (e.g. "ULL").
2545
2546- CONFIG_SYS_CCSRBAR_PHYS_LOW:
2547 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
2548 used in assembly code, so it must not contain typecasts or
2549 integer size suffixes (e.g. "ULL").
2550
2551- CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
2552 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
2553 forced to a value that ensures that CCSR is not relocated.
2554
Macpaul Lin0abddf82011-04-11 20:45:32 +00002555- CONFIG_IDE_AHB:
2556 Most IDE controllers were designed to be connected with PCI
2557 interface. Only few of them were designed for AHB interface.
2558 When software is doing ATA command and data transfer to
2559 IDE devices through IDE-AHB controller, some additional
2560 registers accessing to these kind of IDE-AHB controller
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08002561 is required.
Macpaul Lin0abddf82011-04-11 20:45:32 +00002562
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002563- CONFIG_SYS_IMMR: Physical address of the Internal Memory.
wdenkefe2a4d2004-12-16 21:44:03 +00002564 DO NOT CHANGE unless you know exactly what you're
Christophe Leroy907208c2017-07-06 10:23:22 +02002565 doing! (11-4) [MPC8xx systems only]
wdenkc6097192002-11-03 00:24:07 +00002566
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002567- CONFIG_SYS_INIT_RAM_ADDR:
wdenkc6097192002-11-03 00:24:07 +00002568
wdenk7152b1d2003-09-05 23:19:14 +00002569 Start address of memory area that can be used for
wdenkc6097192002-11-03 00:24:07 +00002570 initial data and stack; please note that this must be
2571 writable memory that is working WITHOUT special
2572 initialization, i. e. you CANNOT use normal RAM which
2573 will become available only after programming the
2574 memory controller and running certain initialization
2575 sequences.
2576
2577 U-Boot uses the following memory types:
Christophe Leroy907208c2017-07-06 10:23:22 +02002578 - MPC8xx: IMMR (internal memory of the CPU)
wdenkc6097192002-11-03 00:24:07 +00002579
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002580- CONFIG_SYS_GBL_DATA_OFFSET:
wdenkc6097192002-11-03 00:24:07 +00002581
2582 Offset of the initial data structure in the memory
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002583 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2584 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
wdenkc6097192002-11-03 00:24:07 +00002585 data is located at the end of the available space
Wolfgang Denk553f0982010-10-26 13:32:32 +02002586 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
Simon Glassacd51f92016-10-02 18:01:06 -06002587 GENERATED_GBL_DATA_SIZE), and the initial stack is just
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002588 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2589 CONFIG_SYS_GBL_DATA_OFFSET) downward.
wdenkc6097192002-11-03 00:24:07 +00002590
2591 Note:
2592 On the MPC824X (or other systems that use the data
2593 cache for initial memory) the address chosen for
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002594 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
wdenkc6097192002-11-03 00:24:07 +00002595 point to an otherwise UNUSED address space between
2596 the top of RAM and the start of the PCI space.
2597
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002598- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
wdenkc6097192002-11-03 00:24:07 +00002599
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002600- CONFIG_SYS_OR_TIMING_SDRAM:
wdenkc6097192002-11-03 00:24:07 +00002601 SDRAM timing
2602
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002603- CONFIG_SYS_MAMR_PTA:
wdenkc6097192002-11-03 00:24:07 +00002604 periodic timer for refresh
2605
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002606- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2607 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2608 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2609 CONFIG_SYS_BR1_PRELIM:
wdenkc6097192002-11-03 00:24:07 +00002610 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2611
2612- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002613 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2614 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
wdenkc6097192002-11-03 00:24:07 +00002615 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2616
Kumar Galaa09b9b62010-12-30 12:09:53 -06002617- CONFIG_SYS_SRIO:
2618 Chip has SRIO or not
2619
2620- CONFIG_SRIO1:
2621 Board has SRIO 1 port available
2622
2623- CONFIG_SRIO2:
2624 Board has SRIO 2 port available
2625
Liu Gangc8b28152013-05-07 16:30:46 +08002626- CONFIG_SRIO_PCIE_BOOT_MASTER
2627 Board can support master function for Boot from SRIO and PCIE
2628
Kumar Galaa09b9b62010-12-30 12:09:53 -06002629- CONFIG_SYS_SRIOn_MEM_VIRT:
2630 Virtual Address of SRIO port 'n' memory region
2631
Simon Glass62f9b652019-11-14 12:57:09 -07002632- CONFIG_SYS_SRIOn_MEM_PHYxS:
Kumar Galaa09b9b62010-12-30 12:09:53 -06002633 Physical Address of SRIO port 'n' memory region
2634
2635- CONFIG_SYS_SRIOn_MEM_SIZE:
2636 Size of SRIO port 'n' memory region
2637
Fabio Estevam66bd1842013-04-11 09:35:34 +00002638- CONFIG_SYS_NAND_BUSWIDTH_16BIT
2639 Defined to tell the NAND controller that the NAND chip is using
2640 a 16 bit bus.
2641 Not all NAND drivers use this symbol.
Fabio Estevama430e912013-04-11 09:35:35 +00002642 Example of drivers that use it:
Miquel Raynala430fa02018-08-16 17:30:07 +02002643 - drivers/mtd/nand/raw/ndfc.c
2644 - drivers/mtd/nand/raw/mxc_nand.c
Alex Watermaneced4622011-05-19 15:08:36 -04002645
2646- CONFIG_SYS_NDFC_EBC0_CFG
2647 Sets the EBC0_CFG register for the NDFC. If not defined
2648 a default value will be used.
2649
Ben Warrenbb99ad62006-09-07 16:50:54 -04002650- CONFIG_SPD_EEPROM
Wolfgang Denk218ca722008-03-26 10:40:12 +01002651 Get DDR timing information from an I2C EEPROM. Common
2652 with pluggable memory modules such as SODIMMs
2653
Ben Warrenbb99ad62006-09-07 16:50:54 -04002654 SPD_EEPROM_ADDRESS
2655 I2C address of the SPD EEPROM
2656
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002657- CONFIG_SYS_SPD_BUS_NUM
Wolfgang Denk218ca722008-03-26 10:40:12 +01002658 If SPD EEPROM is on an I2C bus other than the first
2659 one, specify here. Note that the value must resolve
2660 to something your driver can deal with.
Ben Warrenbb99ad62006-09-07 16:50:54 -04002661
York Sun1b3e3c42011-06-07 09:42:16 +08002662- CONFIG_SYS_DDR_RAW_TIMING
2663 Get DDR timing information from other than SPD. Common with
2664 soldered DDR chips onboard without SPD. DDR raw timing
2665 parameters are extracted from datasheet and hard-coded into
2666 header files or board specific files.
2667
York Sun6f5e1dc2011-09-16 13:21:35 -07002668- CONFIG_FSL_DDR_INTERACTIVE
2669 Enable interactive DDR debugging. See doc/README.fsl-ddr.
2670
York Sune32d59a2015-01-06 13:18:55 -08002671- CONFIG_FSL_DDR_SYNC_REFRESH
2672 Enable sync of refresh for multiple controllers.
2673
York Sun4516ff82015-03-19 09:30:28 -07002674- CONFIG_FSL_DDR_BIST
2675 Enable built-in memory test for Freescale DDR controllers.
2676
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002677- CONFIG_SYS_83XX_DDR_USES_CS0
Wolfgang Denk218ca722008-03-26 10:40:12 +01002678 Only for 83xx systems. If specified, then DDR should
2679 be configured using CS0 and CS1 instead of CS2 and CS3.
Timur Tabi2ad6b512006-10-31 18:44:42 -06002680
wdenkc26e4542004-04-18 10:13:26 +00002681- CONFIG_RMII
2682 Enable RMII mode for all FECs.
2683 Note that this is a global option, we can't
2684 have one FEC in standard MII mode and another in RMII mode.
2685
wdenk5cf91d62004-04-23 20:32:05 +00002686- CONFIG_CRC32_VERIFY
2687 Add a verify option to the crc32 command.
2688 The syntax is:
2689
2690 => crc32 -v <address> <count> <crc32>
2691
2692 Where address/count indicate a memory area
2693 and crc32 is the correct crc32 which the
2694 area should have.
2695
wdenk56523f12004-07-11 17:40:54 +00002696- CONFIG_LOOPW
2697 Add the "loopw" memory command. This only takes effect if
Simon Glass493f4202017-08-04 16:34:27 -06002698 the memory commands are activated globally (CONFIG_CMD_MEMORY).
wdenk56523f12004-07-11 17:40:54 +00002699
Joel Johnson72732312020-01-29 09:17:18 -07002700- CONFIG_CMD_MX_CYCLIC
stroese7b466642004-12-16 18:46:55 +00002701 Add the "mdc" and "mwc" memory commands. These are cyclic
2702 "md/mw" commands.
2703 Examples:
2704
wdenkefe2a4d2004-12-16 21:44:03 +00002705 => mdc.b 10 4 500
stroese7b466642004-12-16 18:46:55 +00002706 This command will print 4 bytes (10,11,12,13) each 500 ms.
2707
wdenkefe2a4d2004-12-16 21:44:03 +00002708 => mwc.l 100 12345678 10
stroese7b466642004-12-16 18:46:55 +00002709 This command will write 12345678 to address 100 all 10 ms.
2710
wdenkefe2a4d2004-12-16 21:44:03 +00002711 This only takes effect if the memory commands are activated
Simon Glass493f4202017-08-04 16:34:27 -06002712 globally (CONFIG_CMD_MEMORY).
stroese7b466642004-12-16 18:46:55 +00002713
Aneesh V401bb302011-07-13 05:11:07 +00002714- CONFIG_SPL_BUILD
Thomas Hebb32f2ca22019-11-13 18:18:03 -08002715 Set when the currently-running compilation is for an artifact
2716 that will end up in the SPL (as opposed to the TPL or U-Boot
2717 proper). Code that needs stage-specific behavior should check
2718 this.
wdenk400558b2005-04-02 23:52:25 +00002719
Ying Zhang3aa29de2013-08-16 15:16:15 +08002720- CONFIG_TPL_BUILD
Thomas Hebb32f2ca22019-11-13 18:18:03 -08002721 Set when the currently-running compilation is for an artifact
2722 that will end up in the TPL (as opposed to the SPL or U-Boot
2723 proper). Code that needs stage-specific behavior should check
2724 this.
Ying Zhang3aa29de2013-08-16 15:16:15 +08002725
Ying Zhang5df572f2013-05-20 14:07:23 +08002726- CONFIG_SYS_MPC85XX_NO_RESETVEC
2727 Only for 85xx systems. If this variable is specified, the section
2728 .resetvec is not kept and the section .bootpg is placed in the
2729 previous 4k of the .text section.
2730
Simon Glass4213fc22013-02-24 17:33:14 +00002731- CONFIG_ARCH_MAP_SYSMEM
2732 Generally U-Boot (and in particular the md command) uses
2733 effective address. It is therefore not necessary to regard
2734 U-Boot address as virtual addresses that need to be translated
2735 to physical addresses. However, sandbox requires this, since
2736 it maintains its own little RAM buffer which contains all
2737 addressable memory. This option causes some memory accesses
2738 to be mapped through map_sysmem() / unmap_sysmem().
2739
Simon Glass588a13f2013-02-14 04:18:54 +00002740- CONFIG_X86_RESET_VECTOR
2741 If defined, the x86 reset vector code is included. This is not
2742 needed when U-Boot is running from Coreboot.
Gabe Blackb16f5212012-11-27 21:08:06 +00002743
Karicheri, Muralidharan999d7d32014-04-04 13:16:50 -04002744- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
2745 Option to disable subpage write in NAND driver
2746 driver that uses this:
Miquel Raynala430fa02018-08-16 17:30:07 +02002747 drivers/mtd/nand/raw/davinci_nand.c
Karicheri, Muralidharan999d7d32014-04-04 13:16:50 -04002748
Timur Tabif2717b42011-11-22 09:21:25 -06002749Freescale QE/FMAN Firmware Support:
2750-----------------------------------
2751
2752The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
2753loading of "firmware", which is encoded in the QE firmware binary format.
2754This firmware often needs to be loaded during U-Boot booting, so macros
2755are used to identify the storage device (NOR flash, SPI, etc) and the address
2756within that device.
2757
Zhao Qiangdcf1d772014-03-21 16:21:44 +08002758- CONFIG_SYS_FMAN_FW_ADDR
2759 The address in the storage device where the FMAN microcode is located. The
Tom Rinicc1e98b2019-05-12 07:59:12 -04002760 meaning of this address depends on which CONFIG_SYS_QE_FMAN_FW_IN_xxx macro
Zhao Qiangdcf1d772014-03-21 16:21:44 +08002761 is also specified.
2762
2763- CONFIG_SYS_QE_FW_ADDR
2764 The address in the storage device where the QE microcode is located. The
Tom Rinicc1e98b2019-05-12 07:59:12 -04002765 meaning of this address depends on which CONFIG_SYS_QE_FMAN_FW_IN_xxx macro
Timur Tabif2717b42011-11-22 09:21:25 -06002766 is also specified.
2767
2768- CONFIG_SYS_QE_FMAN_FW_LENGTH
2769 The maximum possible size of the firmware. The firmware binary format
2770 has a field that specifies the actual size of the firmware, but it
2771 might not be possible to read any part of the firmware unless some
2772 local storage is allocated to hold the entire firmware first.
2773
2774- CONFIG_SYS_QE_FMAN_FW_IN_NOR
2775 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
2776 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
2777 virtual address in NOR flash.
2778
2779- CONFIG_SYS_QE_FMAN_FW_IN_NAND
2780 Specifies that QE/FMAN firmware is located in NAND flash.
2781 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
2782
2783- CONFIG_SYS_QE_FMAN_FW_IN_MMC
2784 Specifies that QE/FMAN firmware is located on the primary SD/MMC
2785 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
2786
Liu Gang292dc6c2012-03-08 00:33:18 +00002787- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
2788 Specifies that QE/FMAN firmware is located in the remote (master)
2789 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
Liu Gangfc54c7f2012-08-09 05:10:01 +00002790 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
2791 window->master inbound window->master LAW->the ucode address in
2792 master's memory space.
Timur Tabif2717b42011-11-22 09:21:25 -06002793
J. German Riverab940ca62014-06-23 15:15:55 -07002794Freescale Layerscape Management Complex Firmware Support:
2795---------------------------------------------------------
2796The Freescale Layerscape Management Complex (MC) supports the loading of
2797"firmware".
2798This firmware often needs to be loaded during U-Boot booting, so macros
2799are used to identify the storage device (NOR flash, SPI, etc) and the address
2800within that device.
2801
2802- CONFIG_FSL_MC_ENET
2803 Enable the MC driver for Layerscape SoCs.
2804
Prabhakar Kushwaha5c055082015-06-02 10:55:52 +05302805Freescale Layerscape Debug Server Support:
2806-------------------------------------------
2807The Freescale Layerscape Debug Server Support supports the loading of
2808"Debug Server firmware" and triggering SP boot-rom.
2809This firmware often needs to be loaded during U-Boot booting.
2810
York Sunc0492142015-12-07 11:08:58 -08002811- CONFIG_SYS_MC_RSV_MEM_ALIGN
2812 Define alignment of reserved memory MC requires
Prabhakar Kushwaha5c055082015-06-02 10:55:52 +05302813
Paul Kocialkowskif3f431a2015-07-26 18:48:15 +02002814Reproducible builds
2815-------------------
2816
2817In order to achieve reproducible builds, timestamps used in the U-Boot build
2818process have to be set to a fixed value.
2819
2820This is done using the SOURCE_DATE_EPOCH environment variable.
2821SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
2822option for U-Boot or an environment variable in U-Boot.
2823
2824SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
2825
wdenkc6097192002-11-03 00:24:07 +00002826Building the Software:
2827======================
2828
Wolfgang Denk218ca722008-03-26 10:40:12 +01002829Building U-Boot has been tested in several native build environments
2830and in many different cross environments. Of course we cannot support
2831all possibly existing versions of cross development tools in all
2832(potentially obsolete) versions. In case of tool chain problems we
Naoki Hayama047f6ec2020-10-08 13:17:16 +09002833recommend to use the ELDK (see https://www.denx.de/wiki/DULG/ELDK)
Wolfgang Denk218ca722008-03-26 10:40:12 +01002834which is extensively used to build and test U-Boot.
wdenkc6097192002-11-03 00:24:07 +00002835
Wolfgang Denk218ca722008-03-26 10:40:12 +01002836If you are not using a native environment, it is assumed that you
2837have GNU cross compiling tools available in your path. In this case,
2838you must set the environment variable CROSS_COMPILE in your shell.
2839Note that no changes to the Makefile or any other source files are
2840necessary. For example using the ELDK on a 4xx CPU, please enter:
wdenkc6097192002-11-03 00:24:07 +00002841
Wolfgang Denk218ca722008-03-26 10:40:12 +01002842 $ CROSS_COMPILE=ppc_4xx-
2843 $ export CROSS_COMPILE
wdenkc6097192002-11-03 00:24:07 +00002844
Wolfgang Denk218ca722008-03-26 10:40:12 +01002845U-Boot is intended to be simple to build. After installing the
2846sources you must configure U-Boot for one specific board type. This
wdenkc6097192002-11-03 00:24:07 +00002847is done by typing:
2848
Holger Freytherab584d62014-08-04 09:26:05 +02002849 make NAME_defconfig
wdenkc6097192002-11-03 00:24:07 +00002850
Holger Freytherab584d62014-08-04 09:26:05 +02002851where "NAME_defconfig" is the name of one of the existing configu-
Heinrich Schuchardtecb3a0a2020-02-24 18:36:30 +01002852rations; see configs/*_defconfig for supported names.
wdenk54387ac2003-10-08 22:45:44 +00002853
Heinrich Schuchardtecb3a0a2020-02-24 18:36:30 +01002854Note: for some boards special configuration names may exist; check if
wdenk2729af92004-05-03 20:45:30 +00002855 additional information is available from the board vendor; for
2856 instance, the TQM823L systems are available without (standard)
2857 or with LCD support. You can select such additional "features"
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002858 when choosing the configuration, i. e.
wdenkc6097192002-11-03 00:24:07 +00002859
Holger Freytherab584d62014-08-04 09:26:05 +02002860 make TQM823L_defconfig
wdenk2729af92004-05-03 20:45:30 +00002861 - will configure for a plain TQM823L, i. e. no LCD support
wdenkc6097192002-11-03 00:24:07 +00002862
Holger Freytherab584d62014-08-04 09:26:05 +02002863 make TQM823L_LCD_defconfig
wdenk2729af92004-05-03 20:45:30 +00002864 - will configure for a TQM823L with U-Boot console on LCD
wdenkc6097192002-11-03 00:24:07 +00002865
wdenk2729af92004-05-03 20:45:30 +00002866 etc.
wdenkc6097192002-11-03 00:24:07 +00002867
wdenkc6097192002-11-03 00:24:07 +00002868
wdenk2729af92004-05-03 20:45:30 +00002869Finally, type "make all", and you should get some working U-Boot
2870images ready for download to / installation on your system:
wdenkc6097192002-11-03 00:24:07 +00002871
wdenk2729af92004-05-03 20:45:30 +00002872- "u-boot.bin" is a raw binary image
2873- "u-boot" is an image in ELF binary format
2874- "u-boot.srec" is in Motorola S-Record format
wdenkc6097192002-11-03 00:24:07 +00002875
Marian Balakowiczbaf31242006-09-07 17:25:40 +02002876By default the build is performed locally and the objects are saved
2877in the source directory. One of the two methods can be used to change
2878this behavior and build U-Boot to some external directory:
2879
28801. Add O= to the make command line invocations:
2881
2882 make O=/tmp/build distclean
Holger Freytherab584d62014-08-04 09:26:05 +02002883 make O=/tmp/build NAME_defconfig
Marian Balakowiczbaf31242006-09-07 17:25:40 +02002884 make O=/tmp/build all
2885
Timo Ketolaadbba992014-11-06 14:39:05 +020028862. Set environment variable KBUILD_OUTPUT to point to the desired location:
Marian Balakowiczbaf31242006-09-07 17:25:40 +02002887
Timo Ketolaadbba992014-11-06 14:39:05 +02002888 export KBUILD_OUTPUT=/tmp/build
Marian Balakowiczbaf31242006-09-07 17:25:40 +02002889 make distclean
Holger Freytherab584d62014-08-04 09:26:05 +02002890 make NAME_defconfig
Marian Balakowiczbaf31242006-09-07 17:25:40 +02002891 make all
2892
Timo Ketolaadbba992014-11-06 14:39:05 +02002893Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
Marian Balakowiczbaf31242006-09-07 17:25:40 +02002894variable.
2895
Daniel Schwierzeck215bb1c2018-01-26 16:31:04 +01002896User specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by
2897setting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS.
2898For example to treat all compiler warnings as errors:
2899
2900 make KCFLAGS=-Werror
wdenkc6097192002-11-03 00:24:07 +00002901
wdenk2729af92004-05-03 20:45:30 +00002902Please be aware that the Makefiles assume you are using GNU make, so
2903for instance on NetBSD you might need to use "gmake" instead of
2904native "make".
wdenkc6097192002-11-03 00:24:07 +00002905
wdenkc6097192002-11-03 00:24:07 +00002906
wdenk2729af92004-05-03 20:45:30 +00002907If the system board that you have is not listed, then you will need
2908to port U-Boot to your hardware platform. To do this, follow these
2909steps:
wdenkc6097192002-11-03 00:24:07 +00002910
Phil Sutter3c1496c2015-12-25 14:41:18 +010029111. Create a new directory to hold your board specific code. Add any
wdenk2729af92004-05-03 20:45:30 +00002912 files you need. In your board directory, you will need at least
Phil Sutter3c1496c2015-12-25 14:41:18 +01002913 the "Makefile" and a "<board>.c".
29142. Create a new configuration file "include/configs/<board>.h" for
2915 your board.
wdenk2729af92004-05-03 20:45:30 +000029163. If you're porting U-Boot to a new CPU, then also create a new
2917 directory to hold your CPU specific code. Add any files you need.
Holger Freytherab584d62014-08-04 09:26:05 +020029184. Run "make <board>_defconfig" with your new name.
wdenk2729af92004-05-03 20:45:30 +000029195. Type "make", and you should get a working "u-boot.srec" file
2920 to be installed on your target system.
29216. Debug and solve any problems that might arise.
2922 [Of course, this last step is much harder than it sounds.]
wdenkc6097192002-11-03 00:24:07 +00002923
wdenkc6097192002-11-03 00:24:07 +00002924
wdenk2729af92004-05-03 20:45:30 +00002925Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2926==============================================================
wdenkc6097192002-11-03 00:24:07 +00002927
Wolfgang Denk218ca722008-03-26 10:40:12 +01002928If you have modified U-Boot sources (for instance added a new board
2929or support for new devices, a new CPU, etc.) you are expected to
wdenk2729af92004-05-03 20:45:30 +00002930provide feedback to the other developers. The feedback normally takes
Thomas Hebb32f2ca22019-11-13 18:18:03 -08002931the form of a "patch", i.e. a context diff against a certain (latest
Wolfgang Denk218ca722008-03-26 10:40:12 +01002932official or latest in the git repository) version of U-Boot sources.
wdenkc6097192002-11-03 00:24:07 +00002933
Wolfgang Denk218ca722008-03-26 10:40:12 +01002934But before you submit such a patch, please verify that your modifi-
2935cation did not break existing code. At least make sure that *ALL* of
wdenk2729af92004-05-03 20:45:30 +00002936the supported boards compile WITHOUT ANY compiler warnings. To do so,
Simon Glass6de80f22016-07-27 20:33:08 -06002937just run the buildman script (tools/buildman/buildman), which will
2938configure and build U-Boot for ALL supported system. Be warned, this
2939will take a while. Please see the buildman README, or run 'buildman -H'
2940for documentation.
Marian Balakowiczbaf31242006-09-07 17:25:40 +02002941
2942
wdenk2729af92004-05-03 20:45:30 +00002943See also "U-Boot Porting Guide" below.
wdenkc6097192002-11-03 00:24:07 +00002944
wdenkc6097192002-11-03 00:24:07 +00002945
wdenk2729af92004-05-03 20:45:30 +00002946Monitor Commands - Overview:
2947============================
wdenkc6097192002-11-03 00:24:07 +00002948
wdenk2729af92004-05-03 20:45:30 +00002949go - start application at address 'addr'
2950run - run commands in an environment variable
2951bootm - boot application image from memory
2952bootp - boot image via network using BootP/TFTP protocol
Marek Vasut44f074c2012-03-14 21:52:45 +00002953bootz - boot zImage from memory
wdenk2729af92004-05-03 20:45:30 +00002954tftpboot- boot image via network using TFTP protocol
2955 and env variables "ipaddr" and "serverip"
2956 (and eventually "gatewayip")
Simon Glass1fb7cd42011-10-24 18:00:07 +00002957tftpput - upload a file via network using TFTP protocol
wdenk2729af92004-05-03 20:45:30 +00002958rarpboot- boot image via network using RARP/TFTP protocol
2959diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2960loads - load S-Record file over serial line
2961loadb - load binary file over serial line (kermit mode)
2962md - memory display
2963mm - memory modify (auto-incrementing)
2964nm - memory modify (constant address)
2965mw - memory write (fill)
Simon Glassbdded202020-06-02 19:26:49 -06002966ms - memory search
wdenk2729af92004-05-03 20:45:30 +00002967cp - memory copy
2968cmp - memory compare
2969crc32 - checksum calculation
Peter Tyser0f89c542009-04-18 22:34:03 -05002970i2c - I2C sub-system
wdenk2729af92004-05-03 20:45:30 +00002971sspi - SPI utility commands
2972base - print or set address offset
2973printenv- print environment variables
Pragnesh Patel9e9a5302020-12-22 11:30:05 +05302974pwm - control pwm channels
wdenk2729af92004-05-03 20:45:30 +00002975setenv - set environment variables
2976saveenv - save environment variables to persistent storage
2977protect - enable or disable FLASH write protection
2978erase - erase FLASH memory
2979flinfo - print FLASH memory information
Karl O. Pinc10635af2012-08-03 05:57:21 +00002980nand - NAND memory operations (see doc/README.nand)
wdenk2729af92004-05-03 20:45:30 +00002981bdinfo - print Board Info structure
2982iminfo - print header information for application image
2983coninfo - print console devices and informations
2984ide - IDE sub-system
2985loop - infinite loop on address range
wdenk56523f12004-07-11 17:40:54 +00002986loopw - infinite write loop on address range
wdenk2729af92004-05-03 20:45:30 +00002987mtest - simple RAM test
2988icache - enable or disable instruction cache
2989dcache - enable or disable data cache
2990reset - Perform RESET of the CPU
2991echo - echo args to console
2992version - print monitor version
2993help - print online help
2994? - alias for 'help'
wdenkc6097192002-11-03 00:24:07 +00002995
wdenkc6097192002-11-03 00:24:07 +00002996
wdenk2729af92004-05-03 20:45:30 +00002997Monitor Commands - Detailed Description:
2998========================================
wdenkc6097192002-11-03 00:24:07 +00002999
wdenk2729af92004-05-03 20:45:30 +00003000TODO.
wdenkc6097192002-11-03 00:24:07 +00003001
wdenk2729af92004-05-03 20:45:30 +00003002For now: just type "help <command>".
wdenkc6097192002-11-03 00:24:07 +00003003
3004
wdenk2729af92004-05-03 20:45:30 +00003005Environment Variables:
3006======================
wdenkc6097192002-11-03 00:24:07 +00003007
wdenk2729af92004-05-03 20:45:30 +00003008U-Boot supports user configuration using Environment Variables which
3009can be made persistent by saving to Flash memory.
wdenkc6097192002-11-03 00:24:07 +00003010
wdenk2729af92004-05-03 20:45:30 +00003011Environment Variables are set using "setenv", printed using
3012"printenv", and saved to Flash using "saveenv". Using "setenv"
3013without a value can be used to delete a variable from the
3014environment. As long as you don't save the environment you are
3015working with an in-memory copy. In case the Flash area containing the
3016environment is erased by accident, a default environment is provided.
wdenkc6097192002-11-03 00:24:07 +00003017
Wolfgang Denkc96f86e2010-01-17 23:55:53 +01003018Some configuration options can be set using Environment Variables.
3019
3020List of environment variables (most likely not complete):
wdenkc6097192002-11-03 00:24:07 +00003021
wdenk2729af92004-05-03 20:45:30 +00003022 baudrate - see CONFIG_BAUDRATE
wdenkc6097192002-11-03 00:24:07 +00003023
wdenk2729af92004-05-03 20:45:30 +00003024 bootdelay - see CONFIG_BOOTDELAY
wdenkc6097192002-11-03 00:24:07 +00003025
wdenk2729af92004-05-03 20:45:30 +00003026 bootcmd - see CONFIG_BOOTCOMMAND
wdenkc6097192002-11-03 00:24:07 +00003027
wdenk2729af92004-05-03 20:45:30 +00003028 bootargs - Boot arguments when booting an RTOS image
wdenkc6097192002-11-03 00:24:07 +00003029
wdenk2729af92004-05-03 20:45:30 +00003030 bootfile - Name of the image to load with TFTP
wdenkc6097192002-11-03 00:24:07 +00003031
Bartlomiej Sieka7d721e32008-04-14 15:44:16 +02003032 bootm_low - Memory range available for image processing in the bootm
3033 command can be restricted. This variable is given as
3034 a hexadecimal number and defines lowest address allowed
3035 for use by the bootm command. See also "bootm_size"
3036 environment variable. Address defined by "bootm_low" is
3037 also the base of the initial memory mapping for the Linux
Grant Likelyc3624e62011-03-28 09:58:43 +00003038 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
3039 bootm_mapsize.
3040
Wolfgang Denkc0f40852011-10-26 10:21:21 +00003041 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
Grant Likelyc3624e62011-03-28 09:58:43 +00003042 This variable is given as a hexadecimal number and it
3043 defines the size of the memory region starting at base
3044 address bootm_low that is accessible by the Linux kernel
3045 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
3046 as the default value if it is defined, and bootm_size is
3047 used otherwise.
Bartlomiej Sieka7d721e32008-04-14 15:44:16 +02003048
3049 bootm_size - Memory range available for image processing in the bootm
3050 command can be restricted. This variable is given as
3051 a hexadecimal number and defines the size of the region
3052 allowed for use by the bootm command. See also "bootm_low"
3053 environment variable.
3054
Simon Glass88fa4be2019-07-20 20:51:17 -06003055 bootstopkeysha256, bootdelaykey, bootstopkey - See README.autoboot
3056
Bartlomiej Sieka4bae9092008-10-01 15:26:31 +02003057 updatefile - Location of the software update file on a TFTP server, used
3058 by the automatic software update feature. Please refer to
3059 documentation in doc/README.update for more details.
3060
wdenk2729af92004-05-03 20:45:30 +00003061 autoload - if set to "no" (any string beginning with 'n'),
3062 "bootp" will just load perform a lookup of the
3063 configuration from the BOOTP server, but not try to
3064 load any image using TFTP
wdenkc6097192002-11-03 00:24:07 +00003065
wdenk2729af92004-05-03 20:45:30 +00003066 autostart - if set to "yes", an image loaded using the "bootp",
3067 "rarpboot", "tftpboot" or "diskboot" commands will
3068 be automatically started (by internally calling
3069 "bootm")
wdenkc6097192002-11-03 00:24:07 +00003070
wdenk2729af92004-05-03 20:45:30 +00003071 If set to "no", a standalone image passed to the
3072 "bootm" command will be copied to the load address
3073 (and eventually uncompressed), but NOT be started.
3074 This can be used to load and uncompress arbitrary
3075 data.
wdenkc6097192002-11-03 00:24:07 +00003076
David A. Longa28afca2011-07-09 16:40:19 -04003077 fdt_high - if set this restricts the maximum address that the
3078 flattened device tree will be copied into upon boot.
Shawn Guofa34f6b2012-01-09 21:54:08 +00003079 For example, if you have a system with 1 GB memory
3080 at physical address 0x10000000, while Linux kernel
3081 only recognizes the first 704 MB as low memory, you
3082 may need to set fdt_high as 0x3C000000 to have the
3083 device tree blob be copied to the maximum address
3084 of the 704 MB low memory, so that Linux kernel can
3085 access it during the boot procedure.
3086
David A. Longa28afca2011-07-09 16:40:19 -04003087 If this is set to the special value 0xFFFFFFFF then
3088 the fdt will not be copied at all on boot. For this
3089 to work it must reside in writable memory, have
3090 sufficient padding on the end of it for u-boot to
3091 add the information it needs into it, and the memory
3092 must be accessible by the kernel.
3093
Simon Glasseea63e02011-10-24 19:15:34 +00003094 fdtcontroladdr- if set this is the address of the control flattened
3095 device tree used by U-Boot when CONFIG_OF_CONTROL is
3096 defined.
3097
wdenk17ea1172004-06-06 21:51:03 +00003098 i2cfast - (PPC405GP|PPC405EP only)
3099 if set to 'y' configures Linux I2C driver for fast
3100 mode (400kHZ). This environment variable is used in
3101 initialization code. So, for changes to be effective
3102 it must be saved and board must be reset.
3103
wdenk2729af92004-05-03 20:45:30 +00003104 initrd_high - restrict positioning of initrd images:
3105 If this variable is not set, initrd images will be
3106 copied to the highest possible address in RAM; this
3107 is usually what you want since it allows for
3108 maximum initrd size. If for some reason you want to
3109 make sure that the initrd image is loaded below the
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02003110 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
wdenk2729af92004-05-03 20:45:30 +00003111 variable to a value of "no" or "off" or "0".
3112 Alternatively, you can set it to a maximum upper
3113 address to use (U-Boot will still check that it
3114 does not overwrite the U-Boot stack and data).
wdenkc6097192002-11-03 00:24:07 +00003115
wdenk2729af92004-05-03 20:45:30 +00003116 For instance, when you have a system with 16 MB
3117 RAM, and want to reserve 4 MB from use by Linux,
3118 you can do this by adding "mem=12M" to the value of
3119 the "bootargs" variable. However, now you must make
3120 sure that the initrd image is placed in the first
3121 12 MB as well - this can be done with
wdenkc6097192002-11-03 00:24:07 +00003122
wdenk2729af92004-05-03 20:45:30 +00003123 setenv initrd_high 00c00000
wdenkc6097192002-11-03 00:24:07 +00003124
wdenk2729af92004-05-03 20:45:30 +00003125 If you set initrd_high to 0xFFFFFFFF, this is an
3126 indication to U-Boot that all addresses are legal
3127 for the Linux kernel, including addresses in flash
3128 memory. In this case U-Boot will NOT COPY the
3129 ramdisk at all. This may be useful to reduce the
3130 boot time on your system, but requires that this
3131 feature is supported by your Linux kernel.
wdenk4a6fd342003-04-12 23:38:12 +00003132
wdenk2729af92004-05-03 20:45:30 +00003133 ipaddr - IP address; needed for tftpboot command
wdenkc6097192002-11-03 00:24:07 +00003134
wdenk2729af92004-05-03 20:45:30 +00003135 loadaddr - Default load address for commands like "bootp",
3136 "rarpboot", "tftpboot", "loadb" or "diskboot"
wdenkc6097192002-11-03 00:24:07 +00003137
wdenk2729af92004-05-03 20:45:30 +00003138 loads_echo - see CONFIG_LOADS_ECHO
wdenkc6097192002-11-03 00:24:07 +00003139
wdenk2729af92004-05-03 20:45:30 +00003140 serverip - TFTP server IP address; needed for tftpboot command
wdenk38b99262003-05-23 23:18:21 +00003141
wdenk2729af92004-05-03 20:45:30 +00003142 bootretry - see CONFIG_BOOT_RETRY_TIME
wdenkc6097192002-11-03 00:24:07 +00003143
wdenk2729af92004-05-03 20:45:30 +00003144 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
wdenkc6097192002-11-03 00:24:07 +00003145
wdenk2729af92004-05-03 20:45:30 +00003146 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
wdenkc6097192002-11-03 00:24:07 +00003147
Mike Frysingere2a53452011-10-02 10:01:27 +00003148 ethprime - controls which interface is used first.
wdenkc6097192002-11-03 00:24:07 +00003149
Mike Frysingere2a53452011-10-02 10:01:27 +00003150 ethact - controls which interface is currently active.
3151 For example you can do the following
wdenkc6097192002-11-03 00:24:07 +00003152
Heiko Schocher48690d82010-07-20 17:45:02 +02003153 => setenv ethact FEC
3154 => ping 192.168.0.1 # traffic sent on FEC
3155 => setenv ethact SCC
3156 => ping 10.0.0.1 # traffic sent on SCC
wdenkc6097192002-11-03 00:24:07 +00003157
Matthias Fuchse1692572008-01-17 07:45:05 +01003158 ethrotate - When set to "no" U-Boot does not go through all
3159 available network interfaces.
3160 It just stays at the currently selected interface.
3161
Wolfgang Denkc96f86e2010-01-17 23:55:53 +01003162 netretry - When set to "no" each network operation will
wdenk2729af92004-05-03 20:45:30 +00003163 either succeed or fail without retrying.
3164 When set to "once" the network operation will
3165 fail when all the available network interfaces
3166 are tried once without success.
3167 Useful on scripts which control the retry operation
3168 themselves.
wdenkc6097192002-11-03 00:24:07 +00003169
Jean-Christophe PLAGNIOL-VILLARDb4e2f892009-01-31 09:53:39 +01003170 npe_ucode - set load address for the NPE microcode
Jean-Christophe PLAGNIOL-VILLARDa1cf0272008-01-07 08:41:34 +01003171
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08003172 silent_linux - If set then Linux will be told to boot silently, by
Simon Glass8d51aac2013-07-16 20:10:00 -07003173 changing the console to be empty. If "yes" it will be
3174 made silent. If "no" it will not be made silent. If
3175 unset, then it will be made silent if the U-Boot console
3176 is silent.
3177
Albert ARIBAUD \(3ADEV\)f5fb7342015-10-12 00:02:57 +02003178 tftpsrcp - If this is set, the value is used for TFTP's
Wolfgang Denkecb0ccd2005-09-24 22:37:32 +02003179 UDP source port.
3180
Albert ARIBAUD \(3ADEV\)f5fb7342015-10-12 00:02:57 +02003181 tftpdstp - If this is set, the value is used for TFTP's UDP
Wolfgang Denk28cb9372005-09-24 23:25:46 +02003182 destination port instead of the Well Know Port 69.
3183
Wolfgang Denkc96f86e2010-01-17 23:55:53 +01003184 tftpblocksize - Block size to use for TFTP transfers; if not set,
3185 we use the TFTP server's default block size
3186
3187 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3188 seconds, minimum value is 1000 = 1 second). Defines
3189 when a packet is considered to be lost so it has to
3190 be retransmitted. The default is 5000 = 5 seconds.
3191 Lowering this value may make downloads succeed
3192 faster in networks with high packet loss rates or
3193 with unreliable TFTP servers.
3194
Albert ARIBAUD \(3ADEV\)f5fb7342015-10-12 00:02:57 +02003195 tftptimeoutcountmax - maximum count of TFTP timeouts (no
3196 unit, minimum value = 0). Defines how many timeouts
3197 can happen during a single file transfer before that
3198 transfer is aborted. The default is 10, and 0 means
3199 'no timeouts allowed'. Increasing this value may help
3200 downloads succeed with high packet loss rates, or with
3201 unreliable TFTP servers or client hardware.
3202
Ramon Friedcc6b87e2020-07-18 23:31:46 +03003203 tftpwindowsize - if this is set, the value is used for TFTP's
3204 window size as described by RFC 7440.
3205 This means the count of blocks we can receive before
3206 sending ack to server.
3207
Wolfgang Denkc96f86e2010-01-17 23:55:53 +01003208 vlan - When set to a value < 4095 the traffic over
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02003209 Ethernet is encapsulated/received over 802.1q
wdenk2729af92004-05-03 20:45:30 +00003210 VLAN tagged frames.
wdenka3d991b2004-04-15 21:48:45 +00003211
Alexandre Messier50768f52016-02-01 17:08:57 -05003212 bootpretryperiod - Period during which BOOTP/DHCP sends retries.
3213 Unsigned value, in milliseconds. If not set, the period will
3214 be either the default (28000), or a value based on
3215 CONFIG_NET_RETRY_COUNT, if defined. This value has
3216 precedence over the valu based on CONFIG_NET_RETRY_COUNT.
3217
Simon Glassbdded202020-06-02 19:26:49 -06003218 memmatches - Number of matches found by the last 'ms' command, in hex
3219
3220 memaddr - Address of the last match found by the 'ms' command, in hex,
3221 or 0 if none
3222
3223 mempos - Index position of the last match found by the 'ms' command,
3224 in units of the size (.b, .w, .l) of the search
3225
Simon Glass126f47c2020-09-05 14:50:48 -06003226 zbootbase - (x86 only) Base address of the bzImage 'setup' block
3227
3228 zbootaddr - (x86 only) Address of the loaded bzImage, typically
3229 BZIMAGE_LOAD_ADDR which is 0x100000
Simon Glassbdded202020-06-02 19:26:49 -06003230
Jason Hobbsdc0b7b02011-08-31 05:37:28 +00003231The following image location variables contain the location of images
3232used in booting. The "Image" column gives the role of the image and is
3233not an environment variable name. The other columns are environment
3234variable names. "File Name" gives the name of the file on a TFTP
3235server, "RAM Address" gives the location in RAM the image will be
3236loaded to, and "Flash Location" gives the image's address in NOR
3237flash or offset in NAND flash.
3238
3239*Note* - these variables don't have to be defined for all boards, some
Fabio Estevamaed9fed2015-04-25 18:53:10 -03003240boards currently use other variables for these purposes, and some
Jason Hobbsdc0b7b02011-08-31 05:37:28 +00003241boards use these variables for other purposes.
3242
Wolfgang Denkc0f40852011-10-26 10:21:21 +00003243Image File Name RAM Address Flash Location
3244----- --------- ----------- --------------
3245u-boot u-boot u-boot_addr_r u-boot_addr
3246Linux kernel bootfile kernel_addr_r kernel_addr
3247device tree blob fdtfile fdt_addr_r fdt_addr
3248ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
Jason Hobbsdc0b7b02011-08-31 05:37:28 +00003249
wdenk2729af92004-05-03 20:45:30 +00003250The following environment variables may be used and automatically
3251updated by the network boot commands ("bootp" and "rarpboot"),
3252depending the information provided by your boot server:
wdenka3d991b2004-04-15 21:48:45 +00003253
wdenk2729af92004-05-03 20:45:30 +00003254 bootfile - see above
3255 dnsip - IP address of your Domain Name Server
3256 dnsip2 - IP address of your secondary Domain Name Server
3257 gatewayip - IP address of the Gateway (Router) to use
3258 hostname - Target hostname
3259 ipaddr - see above
3260 netmask - Subnet Mask
3261 rootpath - Pathname of the root filesystem on the NFS server
3262 serverip - see above
wdenka3d991b2004-04-15 21:48:45 +00003263
wdenka3d991b2004-04-15 21:48:45 +00003264
wdenk2729af92004-05-03 20:45:30 +00003265There are two special Environment Variables:
wdenkc6097192002-11-03 00:24:07 +00003266
wdenk2729af92004-05-03 20:45:30 +00003267 serial# - contains hardware identification information such
3268 as type string and/or serial number
3269 ethaddr - Ethernet address
wdenkc6097192002-11-03 00:24:07 +00003270
wdenk2729af92004-05-03 20:45:30 +00003271These variables can be set only once (usually during manufacturing of
3272the board). U-Boot refuses to delete or overwrite these variables
3273once they have been set once.
wdenkc6097192002-11-03 00:24:07 +00003274
3275
wdenk2729af92004-05-03 20:45:30 +00003276Further special Environment Variables:
wdenkc6097192002-11-03 00:24:07 +00003277
wdenk2729af92004-05-03 20:45:30 +00003278 ver - Contains the U-Boot version string as printed
3279 with the "version" command. This variable is
3280 readonly (see CONFIG_VERSION_VARIABLE).
wdenkc6097192002-11-03 00:24:07 +00003281
wdenkc6097192002-11-03 00:24:07 +00003282
wdenk2729af92004-05-03 20:45:30 +00003283Please note that changes to some configuration parameters may take
3284only effect after the next boot (yes, that's just like Windoze :-).
wdenkc6097192002-11-03 00:24:07 +00003285
stroesec1551ea2003-04-04 15:53:41 +00003286
Joe Hershberger170ab112012-12-11 22:16:24 -06003287Callback functions for environment variables:
3288---------------------------------------------
3289
3290For some environment variables, the behavior of u-boot needs to change
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08003291when their values are changed. This functionality allows functions to
Joe Hershberger170ab112012-12-11 22:16:24 -06003292be associated with arbitrary variables. On creation, overwrite, or
3293deletion, the callback will provide the opportunity for some side
3294effect to happen or for the change to be rejected.
3295
3296The callbacks are named and associated with a function using the
3297U_BOOT_ENV_CALLBACK macro in your board or driver code.
3298
3299These callbacks are associated with variables in one of two ways. The
3300static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
3301in the board configuration to a string that defines a list of
3302associations. The list must be in the following format:
3303
3304 entry = variable_name[:callback_name]
3305 list = entry[,list]
3306
3307If the callback name is not specified, then the callback is deleted.
3308Spaces are also allowed anywhere in the list.
3309
3310Callbacks can also be associated by defining the ".callbacks" variable
3311with the same list format above. Any association in ".callbacks" will
3312override any association in the static list. You can define
3313CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08003314".callbacks" environment variable in the default or embedded environment.
Joe Hershberger170ab112012-12-11 22:16:24 -06003315
Joe Hershbergerbdf1fe42015-05-20 14:27:20 -05003316If CONFIG_REGEX is defined, the variable_name above is evaluated as a
3317regular expression. This allows multiple variables to be connected to
3318the same callback without explicitly listing them all out.
3319
Heinrich Schuchardt1b040472018-07-29 11:08:14 +02003320The signature of the callback functions is:
3321
3322 int callback(const char *name, const char *value, enum env_op op, int flags)
3323
3324* name - changed environment variable
3325* value - new value of the environment variable
3326* op - operation (create, overwrite, or delete)
3327* flags - attributes of the environment variable change, see flags H_* in
3328 include/search.h
3329
3330The return value is 0 if the variable change is accepted and 1 otherwise.
Joe Hershberger170ab112012-12-11 22:16:24 -06003331
wdenkf07771c2003-05-28 08:06:31 +00003332
wdenk2729af92004-05-03 20:45:30 +00003333Note for Redundant Ethernet Interfaces:
3334=======================================
wdenkf07771c2003-05-28 08:06:31 +00003335
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02003336Some boards come with redundant Ethernet interfaces; U-Boot supports
wdenk2729af92004-05-03 20:45:30 +00003337such configurations and is capable of automatic selection of a
3338"working" interface when needed. MAC assignment works as follows:
wdenkf07771c2003-05-28 08:06:31 +00003339
wdenk2729af92004-05-03 20:45:30 +00003340Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3341MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3342"eth1addr" (=>eth1), "eth2addr", ...
wdenkf07771c2003-05-28 08:06:31 +00003343
wdenk2729af92004-05-03 20:45:30 +00003344If the network interface stores some valid MAC address (for instance
3345in SROM), this is used as default address if there is NO correspon-
3346ding setting in the environment; if the corresponding environment
3347variable is set, this overrides the settings in the card; that means:
wdenkf07771c2003-05-28 08:06:31 +00003348
wdenk2729af92004-05-03 20:45:30 +00003349o If the SROM has a valid MAC address, and there is no address in the
3350 environment, the SROM's address is used.
wdenkc6097192002-11-03 00:24:07 +00003351
wdenk2729af92004-05-03 20:45:30 +00003352o If there is no valid address in the SROM, and a definition in the
3353 environment exists, then the value from the environment variable is
3354 used.
wdenkc6097192002-11-03 00:24:07 +00003355
wdenk2729af92004-05-03 20:45:30 +00003356o If both the SROM and the environment contain a MAC address, and
3357 both addresses are the same, this MAC address is used.
wdenkc6097192002-11-03 00:24:07 +00003358
wdenk2729af92004-05-03 20:45:30 +00003359o If both the SROM and the environment contain a MAC address, and the
3360 addresses differ, the value from the environment is used and a
3361 warning is printed.
wdenkc6097192002-11-03 00:24:07 +00003362
wdenk2729af92004-05-03 20:45:30 +00003363o If neither SROM nor the environment contain a MAC address, an error
Joe Hershbergerbef10142015-05-04 14:55:13 -05003364 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
3365 a random, locally-assigned MAC is used.
wdenkc6097192002-11-03 00:24:07 +00003366
Ben Warrenecee9322010-04-26 11:11:46 -07003367If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
Wolfgang Denkc0f40852011-10-26 10:21:21 +00003368will be programmed into hardware as part of the initialization process. This
Ben Warrenecee9322010-04-26 11:11:46 -07003369may be skipped by setting the appropriate 'ethmacskip' environment variable.
3370The naming convention is as follows:
3371"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
wdenkc6097192002-11-03 00:24:07 +00003372
wdenk2729af92004-05-03 20:45:30 +00003373Image Formats:
3374==============
wdenkc6097192002-11-03 00:24:07 +00003375
Marian Balakowicz3310c542008-03-12 12:13:13 +01003376U-Boot is capable of booting (and performing other auxiliary operations on)
3377images in two formats:
3378
3379New uImage format (FIT)
3380-----------------------
3381
3382Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3383to Flattened Device Tree). It allows the use of images with multiple
3384components (several kernels, ramdisks, etc.), with contents protected by
3385SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3386
3387
3388Old uImage format
3389-----------------
3390
3391Old image format is based on binary files which can be basically anything,
3392preceded by a special header; see the definitions in include/image.h for
3393details; basically, the header defines the following image properties:
wdenkc6097192002-11-03 00:24:07 +00003394
wdenk2729af92004-05-03 20:45:30 +00003395* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3396 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
Peter Tyserf5ed9e32008-09-08 14:56:49 -05003397 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3398 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3399 INTEGRITY).
Andy Shevchenkodaab59a2017-07-05 16:25:22 +03003400* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
Macpaul Linafc1ce82011-10-19 20:41:11 +00003401 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
Andy Shevchenkodaab59a2017-07-05 16:25:22 +03003402 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC).
wdenk2729af92004-05-03 20:45:30 +00003403* Compression Type (uncompressed, gzip, bzip2)
3404* Load Address
3405* Entry Point
3406* Image Name
3407* Image Timestamp
wdenkc6097192002-11-03 00:24:07 +00003408
wdenk2729af92004-05-03 20:45:30 +00003409The header is marked by a special Magic Number, and both the header
3410and the data portions of the image are secured against corruption by
3411CRC32 checksums.
wdenkc6097192002-11-03 00:24:07 +00003412
wdenkc6097192002-11-03 00:24:07 +00003413
wdenk2729af92004-05-03 20:45:30 +00003414Linux Support:
3415==============
wdenkc6097192002-11-03 00:24:07 +00003416
wdenk2729af92004-05-03 20:45:30 +00003417Although U-Boot should support any OS or standalone application
3418easily, the main focus has always been on Linux during the design of
3419U-Boot.
wdenkc6097192002-11-03 00:24:07 +00003420
wdenk2729af92004-05-03 20:45:30 +00003421U-Boot includes many features that so far have been part of some
3422special "boot loader" code within the Linux kernel. Also, any
3423"initrd" images to be used are no longer part of one big Linux image;
3424instead, kernel and "initrd" are separate images. This implementation
3425serves several purposes:
wdenkc6097192002-11-03 00:24:07 +00003426
wdenk2729af92004-05-03 20:45:30 +00003427- the same features can be used for other OS or standalone
3428 applications (for instance: using compressed images to reduce the
3429 Flash memory footprint)
wdenkc6097192002-11-03 00:24:07 +00003430
wdenk2729af92004-05-03 20:45:30 +00003431- it becomes much easier to port new Linux kernel versions because
3432 lots of low-level, hardware dependent stuff are done by U-Boot
wdenkc6097192002-11-03 00:24:07 +00003433
wdenk2729af92004-05-03 20:45:30 +00003434- the same Linux kernel image can now be used with different "initrd"
3435 images; of course this also means that different kernel images can
3436 be run with the same "initrd". This makes testing easier (you don't
3437 have to build a new "zImage.initrd" Linux image when you just
3438 change a file in your "initrd"). Also, a field-upgrade of the
3439 software is easier now.
wdenkc6097192002-11-03 00:24:07 +00003440
wdenkc6097192002-11-03 00:24:07 +00003441
wdenk2729af92004-05-03 20:45:30 +00003442Linux HOWTO:
3443============
wdenkc6097192002-11-03 00:24:07 +00003444
wdenk2729af92004-05-03 20:45:30 +00003445Porting Linux to U-Boot based systems:
3446---------------------------------------
wdenkc6097192002-11-03 00:24:07 +00003447
wdenk2729af92004-05-03 20:45:30 +00003448U-Boot cannot save you from doing all the necessary modifications to
3449configure the Linux device drivers for use with your target hardware
3450(no, we don't intend to provide a full virtual machine interface to
3451Linux :-).
wdenkc6097192002-11-03 00:24:07 +00003452
Stefan Roesea47a12b2010-04-15 16:07:28 +02003453But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
wdenkc6097192002-11-03 00:24:07 +00003454
wdenk2729af92004-05-03 20:45:30 +00003455Just make sure your machine specific header file (for instance
3456include/asm-ppc/tqm8xx.h) includes the same definition of the Board
Markus Heidelberg1dc30692008-09-07 20:18:27 +02003457Information structure as we define in include/asm-<arch>/u-boot.h,
3458and make sure that your definition of IMAP_ADDR uses the same value
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02003459as your U-Boot configuration in CONFIG_SYS_IMMR.
wdenkc6097192002-11-03 00:24:07 +00003460
Simon Glass2eb31b12014-06-11 23:29:46 -06003461Note that U-Boot now has a driver model, a unified model for drivers.
3462If you are adding a new driver, plumb it into driver model. If there
3463is no uclass available, you are encouraged to create one. See
3464doc/driver-model.
3465
wdenkc6097192002-11-03 00:24:07 +00003466
wdenk2729af92004-05-03 20:45:30 +00003467Configuring the Linux kernel:
3468-----------------------------
wdenkc6097192002-11-03 00:24:07 +00003469
wdenk2729af92004-05-03 20:45:30 +00003470No specific requirements for U-Boot. Make sure you have some root
3471device (initial ramdisk, NFS) for your target system.
wdenkc6097192002-11-03 00:24:07 +00003472
wdenkc6097192002-11-03 00:24:07 +00003473
wdenk2729af92004-05-03 20:45:30 +00003474Building a Linux Image:
3475-----------------------
wdenkc6097192002-11-03 00:24:07 +00003476
wdenk2729af92004-05-03 20:45:30 +00003477With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3478not used. If you use recent kernel source, a new build target
3479"uImage" will exist which automatically builds an image usable by
3480U-Boot. Most older kernels also have support for a "pImage" target,
3481which was introduced for our predecessor project PPCBoot and uses a
3482100% compatible format.
wdenkc6097192002-11-03 00:24:07 +00003483
wdenk2729af92004-05-03 20:45:30 +00003484Example:
wdenkc6097192002-11-03 00:24:07 +00003485
Holger Freytherab584d62014-08-04 09:26:05 +02003486 make TQM850L_defconfig
wdenk2729af92004-05-03 20:45:30 +00003487 make oldconfig
3488 make dep
3489 make uImage
wdenkc6097192002-11-03 00:24:07 +00003490
wdenk2729af92004-05-03 20:45:30 +00003491The "uImage" build target uses a special tool (in 'tools/mkimage') to
3492encapsulate a compressed Linux kernel image with header information,
3493CRC32 checksum etc. for use with U-Boot. This is what we are doing:
wdenkc6097192002-11-03 00:24:07 +00003494
wdenk2729af92004-05-03 20:45:30 +00003495* build a standard "vmlinux" kernel image (in ELF binary format):
wdenkc6097192002-11-03 00:24:07 +00003496
wdenk2729af92004-05-03 20:45:30 +00003497* convert the kernel into a raw binary image:
wdenkc6097192002-11-03 00:24:07 +00003498
wdenk2729af92004-05-03 20:45:30 +00003499 ${CROSS_COMPILE}-objcopy -O binary \
3500 -R .note -R .comment \
3501 -S vmlinux linux.bin
wdenkc6097192002-11-03 00:24:07 +00003502
wdenk2729af92004-05-03 20:45:30 +00003503* compress the binary image:
wdenkc6097192002-11-03 00:24:07 +00003504
wdenk2729af92004-05-03 20:45:30 +00003505 gzip -9 linux.bin
wdenkc6097192002-11-03 00:24:07 +00003506
wdenk2729af92004-05-03 20:45:30 +00003507* package compressed binary image for U-Boot:
wdenk24ee89b2002-11-03 17:56:27 +00003508
wdenk2729af92004-05-03 20:45:30 +00003509 mkimage -A ppc -O linux -T kernel -C gzip \
3510 -a 0 -e 0 -n "Linux Kernel Image" \
3511 -d linux.bin.gz uImage
wdenk24ee89b2002-11-03 17:56:27 +00003512
wdenk24ee89b2002-11-03 17:56:27 +00003513
wdenk2729af92004-05-03 20:45:30 +00003514The "mkimage" tool can also be used to create ramdisk images for use
3515with U-Boot, either separated from the Linux kernel image, or
3516combined into one file. "mkimage" encapsulates the images with a 64
3517byte header containing information about target architecture,
3518operating system, image type, compression method, entry points, time
3519stamp, CRC32 checksums, etc.
wdenk24ee89b2002-11-03 17:56:27 +00003520
wdenk2729af92004-05-03 20:45:30 +00003521"mkimage" can be called in two ways: to verify existing images and
3522print the header information, or to build new images.
wdenk24ee89b2002-11-03 17:56:27 +00003523
wdenk2729af92004-05-03 20:45:30 +00003524In the first form (with "-l" option) mkimage lists the information
3525contained in the header of an existing U-Boot image; this includes
3526checksum verification:
wdenk24ee89b2002-11-03 17:56:27 +00003527
wdenk2729af92004-05-03 20:45:30 +00003528 tools/mkimage -l image
3529 -l ==> list image header information
wdenk24ee89b2002-11-03 17:56:27 +00003530
wdenk2729af92004-05-03 20:45:30 +00003531The second form (with "-d" option) is used to build a U-Boot image
3532from a "data file" which is used as image payload:
wdenk24ee89b2002-11-03 17:56:27 +00003533
wdenk2729af92004-05-03 20:45:30 +00003534 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3535 -n name -d data_file image
3536 -A ==> set architecture to 'arch'
3537 -O ==> set operating system to 'os'
3538 -T ==> set image type to 'type'
3539 -C ==> set compression type 'comp'
3540 -a ==> set load address to 'addr' (hex)
3541 -e ==> set entry point to 'ep' (hex)
3542 -n ==> set image name to 'name'
3543 -d ==> use image data from 'datafile'
wdenk24ee89b2002-11-03 17:56:27 +00003544
wdenk69459792004-05-29 16:53:29 +00003545Right now, all Linux kernels for PowerPC systems use the same load
3546address (0x00000000), but the entry point address depends on the
3547kernel version:
wdenkc6097192002-11-03 00:24:07 +00003548
wdenk2729af92004-05-03 20:45:30 +00003549- 2.2.x kernels have the entry point at 0x0000000C,
3550- 2.3.x and later kernels have the entry point at 0x00000000.
wdenkc6097192002-11-03 00:24:07 +00003551
wdenk2729af92004-05-03 20:45:30 +00003552So a typical call to build a U-Boot image would read:
wdenkc6097192002-11-03 00:24:07 +00003553
wdenk2729af92004-05-03 20:45:30 +00003554 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3555 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
Stefan Roesea47a12b2010-04-15 16:07:28 +02003556 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
wdenk2729af92004-05-03 20:45:30 +00003557 > examples/uImage.TQM850L
3558 Image Name: 2.4.4 kernel for TQM850L
3559 Created: Wed Jul 19 02:34:59 2000
3560 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3561 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3562 Load Address: 0x00000000
3563 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00003564
wdenk2729af92004-05-03 20:45:30 +00003565To verify the contents of the image (or check for corruption):
wdenkc6097192002-11-03 00:24:07 +00003566
wdenk2729af92004-05-03 20:45:30 +00003567 -> tools/mkimage -l examples/uImage.TQM850L
3568 Image Name: 2.4.4 kernel for TQM850L
3569 Created: Wed Jul 19 02:34:59 2000
3570 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3571 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3572 Load Address: 0x00000000
3573 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00003574
wdenk2729af92004-05-03 20:45:30 +00003575NOTE: for embedded systems where boot time is critical you can trade
3576speed for memory and install an UNCOMPRESSED image instead: this
3577needs more space in Flash, but boots much faster since it does not
3578need to be uncompressed:
wdenkc6097192002-11-03 00:24:07 +00003579
Stefan Roesea47a12b2010-04-15 16:07:28 +02003580 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
wdenk2729af92004-05-03 20:45:30 +00003581 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3582 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
Stefan Roesea47a12b2010-04-15 16:07:28 +02003583 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
wdenk2729af92004-05-03 20:45:30 +00003584 > examples/uImage.TQM850L-uncompressed
3585 Image Name: 2.4.4 kernel for TQM850L
3586 Created: Wed Jul 19 02:34:59 2000
3587 Image Type: PowerPC Linux Kernel Image (uncompressed)
3588 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3589 Load Address: 0x00000000
3590 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00003591
wdenkc6097192002-11-03 00:24:07 +00003592
wdenk2729af92004-05-03 20:45:30 +00003593Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3594when your kernel is intended to use an initial ramdisk:
wdenkdb01a2e2004-04-15 23:14:49 +00003595
wdenk2729af92004-05-03 20:45:30 +00003596 -> tools/mkimage -n 'Simple Ramdisk Image' \
3597 > -A ppc -O linux -T ramdisk -C gzip \
3598 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3599 Image Name: Simple Ramdisk Image
3600 Created: Wed Jan 12 14:01:50 2000
3601 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3602 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3603 Load Address: 0x00000000
3604 Entry Point: 0x00000000
wdenkdb01a2e2004-04-15 23:14:49 +00003605
Tyler Hickse157a112020-10-26 10:40:24 -05003606The "dumpimage" tool can be used to disassemble or list the contents of images
3607built by mkimage. See dumpimage's help output (-h) for details.
wdenkdb01a2e2004-04-15 23:14:49 +00003608
wdenk2729af92004-05-03 20:45:30 +00003609Installing a Linux Image:
3610-------------------------
wdenkdb01a2e2004-04-15 23:14:49 +00003611
wdenk2729af92004-05-03 20:45:30 +00003612To downloading a U-Boot image over the serial (console) interface,
3613you must convert the image to S-Record format:
wdenkdb01a2e2004-04-15 23:14:49 +00003614
wdenk2729af92004-05-03 20:45:30 +00003615 objcopy -I binary -O srec examples/image examples/image.srec
wdenkdb01a2e2004-04-15 23:14:49 +00003616
wdenk2729af92004-05-03 20:45:30 +00003617The 'objcopy' does not understand the information in the U-Boot
3618image header, so the resulting S-Record file will be relative to
3619address 0x00000000. To load it to a given address, you need to
3620specify the target address as 'offset' parameter with the 'loads'
3621command.
wdenkc6097192002-11-03 00:24:07 +00003622
wdenk2729af92004-05-03 20:45:30 +00003623Example: install the image to address 0x40100000 (which on the
3624TQM8xxL is in the first Flash bank):
wdenkc6097192002-11-03 00:24:07 +00003625
wdenk2729af92004-05-03 20:45:30 +00003626 => erase 40100000 401FFFFF
wdenkc6097192002-11-03 00:24:07 +00003627
wdenk2729af92004-05-03 20:45:30 +00003628 .......... done
3629 Erased 8 sectors
wdenkc6097192002-11-03 00:24:07 +00003630
wdenk2729af92004-05-03 20:45:30 +00003631 => loads 40100000
3632 ## Ready for S-Record download ...
3633 ~>examples/image.srec
3634 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3635 ...
3636 15989 15990 15991 15992
3637 [file transfer complete]
3638 [connected]
3639 ## Start Addr = 0x00000000
wdenkc6097192002-11-03 00:24:07 +00003640
3641
wdenk2729af92004-05-03 20:45:30 +00003642You can check the success of the download using the 'iminfo' command;
Wolfgang Denk218ca722008-03-26 10:40:12 +01003643this includes a checksum verification so you can be sure no data
wdenk2729af92004-05-03 20:45:30 +00003644corruption happened:
wdenkc6097192002-11-03 00:24:07 +00003645
wdenk2729af92004-05-03 20:45:30 +00003646 => imi 40100000
wdenkc6097192002-11-03 00:24:07 +00003647
wdenk2729af92004-05-03 20:45:30 +00003648 ## Checking Image at 40100000 ...
3649 Image Name: 2.2.13 for initrd on TQM850L
3650 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3651 Data Size: 335725 Bytes = 327 kB = 0 MB
3652 Load Address: 00000000
3653 Entry Point: 0000000c
3654 Verifying Checksum ... OK
wdenkc6097192002-11-03 00:24:07 +00003655
3656
wdenk2729af92004-05-03 20:45:30 +00003657Boot Linux:
3658-----------
wdenkc6097192002-11-03 00:24:07 +00003659
wdenk2729af92004-05-03 20:45:30 +00003660The "bootm" command is used to boot an application that is stored in
3661memory (RAM or Flash). In case of a Linux kernel image, the contents
3662of the "bootargs" environment variable is passed to the kernel as
3663parameters. You can check and modify this variable using the
3664"printenv" and "setenv" commands:
wdenkc6097192002-11-03 00:24:07 +00003665
3666
wdenk2729af92004-05-03 20:45:30 +00003667 => printenv bootargs
3668 bootargs=root=/dev/ram
wdenkc6097192002-11-03 00:24:07 +00003669
wdenk2729af92004-05-03 20:45:30 +00003670 => 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 +00003671
wdenk2729af92004-05-03 20:45:30 +00003672 => printenv bootargs
3673 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 +00003674
wdenk2729af92004-05-03 20:45:30 +00003675 => bootm 40020000
3676 ## Booting Linux kernel at 40020000 ...
3677 Image Name: 2.2.13 for NFS on TQM850L
3678 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3679 Data Size: 381681 Bytes = 372 kB = 0 MB
3680 Load Address: 00000000
3681 Entry Point: 0000000c
3682 Verifying Checksum ... OK
3683 Uncompressing Kernel Image ... OK
3684 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
3685 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3686 time_init: decrementer frequency = 187500000/60
3687 Calibrating delay loop... 49.77 BogoMIPS
3688 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3689 ...
wdenkc6097192002-11-03 00:24:07 +00003690
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02003691If you want to boot a Linux kernel with initial RAM disk, you pass
wdenk2729af92004-05-03 20:45:30 +00003692the memory addresses of both the kernel and the initrd image (PPBCOOT
3693format!) to the "bootm" command:
wdenkc6097192002-11-03 00:24:07 +00003694
wdenk2729af92004-05-03 20:45:30 +00003695 => imi 40100000 40200000
wdenkc6097192002-11-03 00:24:07 +00003696
wdenk2729af92004-05-03 20:45:30 +00003697 ## Checking Image at 40100000 ...
3698 Image Name: 2.2.13 for initrd on TQM850L
3699 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3700 Data Size: 335725 Bytes = 327 kB = 0 MB
3701 Load Address: 00000000
3702 Entry Point: 0000000c
3703 Verifying Checksum ... OK
wdenkc6097192002-11-03 00:24:07 +00003704
wdenk2729af92004-05-03 20:45:30 +00003705 ## Checking Image at 40200000 ...
3706 Image Name: Simple Ramdisk Image
3707 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3708 Data Size: 566530 Bytes = 553 kB = 0 MB
3709 Load Address: 00000000
3710 Entry Point: 00000000
3711 Verifying Checksum ... OK
wdenkc6097192002-11-03 00:24:07 +00003712
wdenk2729af92004-05-03 20:45:30 +00003713 => bootm 40100000 40200000
3714 ## Booting Linux kernel at 40100000 ...
3715 Image Name: 2.2.13 for initrd on TQM850L
3716 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3717 Data Size: 335725 Bytes = 327 kB = 0 MB
3718 Load Address: 00000000
3719 Entry Point: 0000000c
3720 Verifying Checksum ... OK
3721 Uncompressing Kernel Image ... OK
3722 ## Loading RAMDisk Image at 40200000 ...
3723 Image Name: Simple Ramdisk Image
3724 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3725 Data Size: 566530 Bytes = 553 kB = 0 MB
3726 Load Address: 00000000
3727 Entry Point: 00000000
3728 Verifying Checksum ... OK
3729 Loading Ramdisk ... OK
3730 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
3731 Boot arguments: root=/dev/ram
3732 time_init: decrementer frequency = 187500000/60
3733 Calibrating delay loop... 49.77 BogoMIPS
3734 ...
3735 RAMDISK: Compressed image found at block 0
3736 VFS: Mounted root (ext2 filesystem).
wdenkc6097192002-11-03 00:24:07 +00003737
wdenk2729af92004-05-03 20:45:30 +00003738 bash#
wdenkc6097192002-11-03 00:24:07 +00003739
Matthew McClintock02677682006-06-28 10:41:37 -05003740Boot Linux and pass a flat device tree:
3741-----------
3742
3743First, U-Boot must be compiled with the appropriate defines. See the section
3744titled "Linux Kernel Interface" above for a more in depth explanation. The
3745following is an example of how to start a kernel and pass an updated
3746flat device tree:
3747
3748=> print oftaddr
3749oftaddr=0x300000
3750=> print oft
3751oft=oftrees/mpc8540ads.dtb
3752=> tftp $oftaddr $oft
3753Speed: 1000, full duplex
3754Using TSEC0 device
3755TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3756Filename 'oftrees/mpc8540ads.dtb'.
3757Load address: 0x300000
3758Loading: #
3759done
3760Bytes transferred = 4106 (100a hex)
3761=> tftp $loadaddr $bootfile
3762Speed: 1000, full duplex
3763Using TSEC0 device
3764TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3765Filename 'uImage'.
3766Load address: 0x200000
3767Loading:############
3768done
3769Bytes transferred = 1029407 (fb51f hex)
3770=> print loadaddr
3771loadaddr=200000
3772=> print oftaddr
3773oftaddr=0x300000
3774=> bootm $loadaddr - $oftaddr
3775## Booting image at 00200000 ...
Wolfgang Denka9398e02006-11-27 15:32:42 +01003776 Image Name: Linux-2.6.17-dirty
3777 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3778 Data Size: 1029343 Bytes = 1005.2 kB
Matthew McClintock02677682006-06-28 10:41:37 -05003779 Load Address: 00000000
Wolfgang Denka9398e02006-11-27 15:32:42 +01003780 Entry Point: 00000000
Matthew McClintock02677682006-06-28 10:41:37 -05003781 Verifying Checksum ... OK
3782 Uncompressing Kernel Image ... OK
3783Booting using flat device tree at 0x300000
3784Using MPC85xx ADS machine description
3785Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3786[snip]
3787
3788
wdenk2729af92004-05-03 20:45:30 +00003789More About U-Boot Image Types:
3790------------------------------
wdenk6069ff22003-02-28 00:49:47 +00003791
wdenk2729af92004-05-03 20:45:30 +00003792U-Boot supports the following image types:
wdenk6069ff22003-02-28 00:49:47 +00003793
wdenk2729af92004-05-03 20:45:30 +00003794 "Standalone Programs" are directly runnable in the environment
3795 provided by U-Boot; it is expected that (if they behave
3796 well) you can continue to work in U-Boot after return from
3797 the Standalone Program.
3798 "OS Kernel Images" are usually images of some Embedded OS which
3799 will take over control completely. Usually these programs
3800 will install their own set of exception handlers, device
3801 drivers, set up the MMU, etc. - this means, that you cannot
3802 expect to re-enter U-Boot except by resetting the CPU.
3803 "RAMDisk Images" are more or less just data blocks, and their
3804 parameters (address, size) are passed to an OS kernel that is
3805 being started.
3806 "Multi-File Images" contain several images, typically an OS
3807 (Linux) kernel image and one or more data images like
3808 RAMDisks. This construct is useful for instance when you want
3809 to boot over the network using BOOTP etc., where the boot
3810 server provides just a single image file, but you want to get
3811 for instance an OS kernel and a RAMDisk image.
stroesec1551ea2003-04-04 15:53:41 +00003812
wdenk2729af92004-05-03 20:45:30 +00003813 "Multi-File Images" start with a list of image sizes, each
3814 image size (in bytes) specified by an "uint32_t" in network
3815 byte order. This list is terminated by an "(uint32_t)0".
3816 Immediately after the terminating 0 follow the images, one by
3817 one, all aligned on "uint32_t" boundaries (size rounded up to
3818 a multiple of 4 bytes).
stroesec1551ea2003-04-04 15:53:41 +00003819
wdenk2729af92004-05-03 20:45:30 +00003820 "Firmware Images" are binary images containing firmware (like
3821 U-Boot or FPGA images) which usually will be programmed to
3822 flash memory.
stroesec1551ea2003-04-04 15:53:41 +00003823
wdenk2729af92004-05-03 20:45:30 +00003824 "Script files" are command sequences that will be executed by
3825 U-Boot's command interpreter; this feature is especially
3826 useful when you configure U-Boot to use a real shell (hush)
3827 as command interpreter.
wdenk6069ff22003-02-28 00:49:47 +00003828
Marek Vasut44f074c2012-03-14 21:52:45 +00003829Booting the Linux zImage:
3830-------------------------
3831
3832On some platforms, it's possible to boot Linux zImage. This is done
3833using the "bootz" command. The syntax of "bootz" command is the same
3834as the syntax of "bootm" command.
3835
Tom Rini8ac28562013-05-16 11:40:11 -04003836Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
Marek Vasut017e1f32012-03-18 11:47:58 +00003837kernel with raw initrd images. The syntax is slightly different, the
3838address of the initrd must be augmented by it's size, in the following
3839format: "<initrd addres>:<initrd size>".
3840
wdenkc6097192002-11-03 00:24:07 +00003841
wdenk2729af92004-05-03 20:45:30 +00003842Standalone HOWTO:
3843=================
wdenkc6097192002-11-03 00:24:07 +00003844
wdenk2729af92004-05-03 20:45:30 +00003845One of the features of U-Boot is that you can dynamically load and
3846run "standalone" applications, which can use some resources of
3847U-Boot like console I/O functions or interrupt services.
wdenkc6097192002-11-03 00:24:07 +00003848
wdenk2729af92004-05-03 20:45:30 +00003849Two simple examples are included with the sources:
wdenkc6097192002-11-03 00:24:07 +00003850
wdenk2729af92004-05-03 20:45:30 +00003851"Hello World" Demo:
3852-------------------
wdenkc6097192002-11-03 00:24:07 +00003853
wdenk2729af92004-05-03 20:45:30 +00003854'examples/hello_world.c' contains a small "Hello World" Demo
3855application; it is automatically compiled when you build U-Boot.
3856It's configured to run at address 0x00040004, so you can play with it
3857like that:
wdenkc6097192002-11-03 00:24:07 +00003858
wdenk2729af92004-05-03 20:45:30 +00003859 => loads
3860 ## Ready for S-Record download ...
3861 ~>examples/hello_world.srec
3862 1 2 3 4 5 6 7 8 9 10 11 ...
3863 [file transfer complete]
3864 [connected]
3865 ## Start Addr = 0x00040004
wdenkc6097192002-11-03 00:24:07 +00003866
wdenk2729af92004-05-03 20:45:30 +00003867 => go 40004 Hello World! This is a test.
3868 ## Starting application at 0x00040004 ...
3869 Hello World
3870 argc = 7
3871 argv[0] = "40004"
3872 argv[1] = "Hello"
3873 argv[2] = "World!"
3874 argv[3] = "This"
3875 argv[4] = "is"
3876 argv[5] = "a"
3877 argv[6] = "test."
3878 argv[7] = "<NULL>"
3879 Hit any key to exit ...
wdenkc6097192002-11-03 00:24:07 +00003880
wdenk2729af92004-05-03 20:45:30 +00003881 ## Application terminated, rc = 0x0
wdenkc6097192002-11-03 00:24:07 +00003882
wdenk2729af92004-05-03 20:45:30 +00003883Another example, which demonstrates how to register a CPM interrupt
3884handler with the U-Boot code, can be found in 'examples/timer.c'.
3885Here, a CPM timer is set up to generate an interrupt every second.
3886The interrupt service routine is trivial, just printing a '.'
3887character, but this is just a demo program. The application can be
3888controlled by the following keys:
wdenkc6097192002-11-03 00:24:07 +00003889
wdenk2729af92004-05-03 20:45:30 +00003890 ? - print current values og the CPM Timer registers
3891 b - enable interrupts and start timer
3892 e - stop timer and disable interrupts
3893 q - quit application
wdenkc6097192002-11-03 00:24:07 +00003894
wdenk2729af92004-05-03 20:45:30 +00003895 => loads
3896 ## Ready for S-Record download ...
3897 ~>examples/timer.srec
3898 1 2 3 4 5 6 7 8 9 10 11 ...
3899 [file transfer complete]
3900 [connected]
3901 ## Start Addr = 0x00040004
wdenkc6097192002-11-03 00:24:07 +00003902
wdenk2729af92004-05-03 20:45:30 +00003903 => go 40004
3904 ## Starting application at 0x00040004 ...
3905 TIMERS=0xfff00980
3906 Using timer 1
3907 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
wdenkc6097192002-11-03 00:24:07 +00003908
wdenk2729af92004-05-03 20:45:30 +00003909Hit 'b':
3910 [q, b, e, ?] Set interval 1000000 us
3911 Enabling timer
3912Hit '?':
3913 [q, b, e, ?] ........
3914 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3915Hit '?':
3916 [q, b, e, ?] .
3917 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3918Hit '?':
3919 [q, b, e, ?] .
3920 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3921Hit '?':
3922 [q, b, e, ?] .
3923 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3924Hit 'e':
3925 [q, b, e, ?] ...Stopping timer
3926Hit 'q':
3927 [q, b, e, ?] ## Application terminated, rc = 0x0
wdenkc6097192002-11-03 00:24:07 +00003928
3929
wdenk2729af92004-05-03 20:45:30 +00003930Minicom warning:
3931================
wdenk85ec0bc2003-03-31 16:34:49 +00003932
wdenk2729af92004-05-03 20:45:30 +00003933Over time, many people have reported problems when trying to use the
3934"minicom" terminal emulation program for serial download. I (wd)
3935consider minicom to be broken, and recommend not to use it. Under
3936Unix, I recommend to use C-Kermit for general purpose use (and
3937especially for kermit binary protocol download ("loadb" command), and
Karl O. Pince53515a2012-10-01 05:11:56 +00003938use "cu" for S-Record download ("loads" command). See
Naoki Hayama047f6ec2020-10-08 13:17:16 +09003939https://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
Karl O. Pince53515a2012-10-01 05:11:56 +00003940for help with kermit.
3941
wdenk85ec0bc2003-03-31 16:34:49 +00003942
wdenk2729af92004-05-03 20:45:30 +00003943Nevertheless, if you absolutely want to use it try adding this
3944configuration to your "File transfer protocols" section:
wdenk52f52c12003-06-19 23:04:19 +00003945
wdenk2729af92004-05-03 20:45:30 +00003946 Name Program Name U/D FullScr IO-Red. Multi
3947 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3948 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
wdenk52f52c12003-06-19 23:04:19 +00003949
3950
wdenk2729af92004-05-03 20:45:30 +00003951NetBSD Notes:
3952=============
wdenkc6097192002-11-03 00:24:07 +00003953
wdenk2729af92004-05-03 20:45:30 +00003954Starting at version 0.9.2, U-Boot supports NetBSD both as host
3955(build U-Boot) and target system (boots NetBSD/mpc8xx).
wdenkc6097192002-11-03 00:24:07 +00003956
wdenk2729af92004-05-03 20:45:30 +00003957Building requires a cross environment; it is known to work on
3958NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3959need gmake since the Makefiles are not compatible with BSD make).
3960Note that the cross-powerpc package does not install include files;
3961attempting to build U-Boot will fail because <machine/ansi.h> is
3962missing. This file has to be installed and patched manually:
wdenkc6097192002-11-03 00:24:07 +00003963
wdenk2729af92004-05-03 20:45:30 +00003964 # cd /usr/pkg/cross/powerpc-netbsd/include
3965 # mkdir powerpc
3966 # ln -s powerpc machine
3967 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3968 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
wdenkc6097192002-11-03 00:24:07 +00003969
wdenk2729af92004-05-03 20:45:30 +00003970Native builds *don't* work due to incompatibilities between native
3971and U-Boot include files.
wdenkc6097192002-11-03 00:24:07 +00003972
wdenk2729af92004-05-03 20:45:30 +00003973Booting assumes that (the first part of) the image booted is a
3974stage-2 loader which in turn loads and then invokes the kernel
3975proper. Loader sources will eventually appear in the NetBSD source
3976tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
wdenk2a8af182005-04-13 10:02:42 +00003977meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
wdenkc6097192002-11-03 00:24:07 +00003978
3979
wdenk2729af92004-05-03 20:45:30 +00003980Implementation Internals:
3981=========================
wdenkc6097192002-11-03 00:24:07 +00003982
wdenk2729af92004-05-03 20:45:30 +00003983The following is not intended to be a complete description of every
3984implementation detail. However, it should help to understand the
3985inner workings of U-Boot and make it easier to port it to custom
3986hardware.
wdenkc6097192002-11-03 00:24:07 +00003987
3988
wdenk2729af92004-05-03 20:45:30 +00003989Initial Stack, Global Data:
3990---------------------------
wdenkc6097192002-11-03 00:24:07 +00003991
wdenk2729af92004-05-03 20:45:30 +00003992The implementation of U-Boot is complicated by the fact that U-Boot
3993starts running out of ROM (flash memory), usually without access to
3994system RAM (because the memory controller is not initialized yet).
3995This means that we don't have writable Data or BSS segments, and BSS
3996is not initialized as zero. To be able to get a C environment working
3997at all, we have to allocate at least a minimal stack. Implementation
3998options for this are defined and restricted by the CPU used: Some CPU
3999models provide on-chip memory (like the IMMR area on MPC8xx and
4000MPC826x processors), on others (parts of) the data cache can be
4001locked as (mis-) used as memory, etc.
wdenkc6097192002-11-03 00:24:07 +00004002
Wolfgang Denk218ca722008-03-26 10:40:12 +01004003 Chris Hallinan posted a good summary of these issues to the
Wolfgang Denk06682362008-12-30 22:56:11 +01004004 U-Boot mailing list:
wdenk43d96162003-03-06 00:02:04 +00004005
wdenk2729af92004-05-03 20:45:30 +00004006 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
4007 From: "Chris Hallinan" <clh@net1plus.com>
4008 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
4009 ...
wdenk43d96162003-03-06 00:02:04 +00004010
wdenk2729af92004-05-03 20:45:30 +00004011 Correct me if I'm wrong, folks, but the way I understand it
4012 is this: Using DCACHE as initial RAM for Stack, etc, does not
4013 require any physical RAM backing up the cache. The cleverness
4014 is that the cache is being used as a temporary supply of
4015 necessary storage before the SDRAM controller is setup. It's
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02004016 beyond the scope of this list to explain the details, but you
wdenk2729af92004-05-03 20:45:30 +00004017 can see how this works by studying the cache architecture and
4018 operation in the architecture and processor-specific manuals.
wdenk43d96162003-03-06 00:02:04 +00004019
wdenk2729af92004-05-03 20:45:30 +00004020 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4021 is another option for the system designer to use as an
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02004022 initial stack/RAM area prior to SDRAM being available. Either
wdenk2729af92004-05-03 20:45:30 +00004023 option should work for you. Using CS 4 should be fine if your
4024 board designers haven't used it for something that would
4025 cause you grief during the initial boot! It is frequently not
4026 used.
wdenk43d96162003-03-06 00:02:04 +00004027
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02004028 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
wdenk2729af92004-05-03 20:45:30 +00004029 with your processor/board/system design. The default value
4030 you will find in any recent u-boot distribution in
Stefan Roese8a316c92005-08-01 16:49:12 +02004031 walnut.h should work for you. I'd set it to a value larger
wdenk2729af92004-05-03 20:45:30 +00004032 than your SDRAM module. If you have a 64MB SDRAM module, set
4033 it above 400_0000. Just make sure your board has no resources
4034 that are supposed to respond to that address! That code in
4035 start.S has been around a while and should work as is when
4036 you get the config right.
wdenk43d96162003-03-06 00:02:04 +00004037
wdenk2729af92004-05-03 20:45:30 +00004038 -Chris Hallinan
4039 DS4.COM, Inc.
wdenk43d96162003-03-06 00:02:04 +00004040
wdenk2729af92004-05-03 20:45:30 +00004041It is essential to remember this, since it has some impact on the C
4042code for the initialization procedures:
wdenkc6097192002-11-03 00:24:07 +00004043
wdenk2729af92004-05-03 20:45:30 +00004044* Initialized global data (data segment) is read-only. Do not attempt
4045 to write it.
wdenkc6097192002-11-03 00:24:07 +00004046
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08004047* Do not use any uninitialized global data (or implicitly initialized
wdenk2729af92004-05-03 20:45:30 +00004048 as zero data - BSS segment) at all - this is undefined, initiali-
4049 zation is performed later (when relocating to RAM).
wdenkc6097192002-11-03 00:24:07 +00004050
wdenk2729af92004-05-03 20:45:30 +00004051* Stack space is very limited. Avoid big data buffers or things like
4052 that.
wdenkc6097192002-11-03 00:24:07 +00004053
wdenk2729af92004-05-03 20:45:30 +00004054Having only the stack as writable memory limits means we cannot use
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08004055normal global data to share information between the code. But it
wdenk2729af92004-05-03 20:45:30 +00004056turned out that the implementation of U-Boot can be greatly
4057simplified by making a global data structure (gd_t) available to all
4058functions. We could pass a pointer to this data as argument to _all_
4059functions, but this would bloat the code. Instead we use a feature of
4060the GCC compiler (Global Register Variables) to share the data: we
4061place a pointer (gd) to the global data into a register which we
4062reserve for this purpose.
wdenkc6097192002-11-03 00:24:07 +00004063
wdenk2729af92004-05-03 20:45:30 +00004064When choosing a register for such a purpose we are restricted by the
4065relevant (E)ABI specifications for the current architecture, and by
4066GCC's implementation.
wdenkc6097192002-11-03 00:24:07 +00004067
wdenk2729af92004-05-03 20:45:30 +00004068For PowerPC, the following registers have specific use:
4069 R1: stack pointer
Wolfgang Denke7670f62008-02-14 22:43:22 +01004070 R2: reserved for system use
wdenk2729af92004-05-03 20:45:30 +00004071 R3-R4: parameter passing and return values
4072 R5-R10: parameter passing
4073 R13: small data area pointer
4074 R30: GOT pointer
4075 R31: frame pointer
wdenkc6097192002-11-03 00:24:07 +00004076
Joakim Tjernlunde6bee802010-01-19 14:41:58 +01004077 (U-Boot also uses R12 as internal GOT pointer. r12
4078 is a volatile register so r12 needs to be reset when
4079 going back and forth between asm and C)
wdenkc6097192002-11-03 00:24:07 +00004080
Wolfgang Denke7670f62008-02-14 22:43:22 +01004081 ==> U-Boot will use R2 to hold a pointer to the global data
wdenkc6097192002-11-03 00:24:07 +00004082
wdenk2729af92004-05-03 20:45:30 +00004083 Note: on PPC, we could use a static initializer (since the
4084 address of the global data structure is known at compile time),
4085 but it turned out that reserving a register results in somewhat
4086 smaller code - although the code savings are not that big (on
4087 average for all boards 752 bytes for the whole U-Boot image,
4088 624 text + 127 data).
wdenkc6097192002-11-03 00:24:07 +00004089
wdenk2729af92004-05-03 20:45:30 +00004090On ARM, the following registers are used:
wdenkc6097192002-11-03 00:24:07 +00004091
wdenk2729af92004-05-03 20:45:30 +00004092 R0: function argument word/integer result
4093 R1-R3: function argument word
Jeroen Hofstee12eba1b2013-09-21 14:04:42 +02004094 R9: platform specific
4095 R10: stack limit (used only if stack checking is enabled)
wdenk2729af92004-05-03 20:45:30 +00004096 R11: argument (frame) pointer
4097 R12: temporary workspace
4098 R13: stack pointer
4099 R14: link register
4100 R15: program counter
wdenkc6097192002-11-03 00:24:07 +00004101
Jeroen Hofstee12eba1b2013-09-21 14:04:42 +02004102 ==> U-Boot will use R9 to hold a pointer to the global data
4103
4104 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
wdenkc6097192002-11-03 00:24:07 +00004105
Thomas Chou0df01fd2010-05-21 11:08:03 +08004106On Nios II, the ABI is documented here:
Naoki Hayama047f6ec2020-10-08 13:17:16 +09004107 https://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
Thomas Chou0df01fd2010-05-21 11:08:03 +08004108
4109 ==> U-Boot will use gp to hold a pointer to the global data
4110
4111 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4112 to access small data sections, so gp is free.
4113
Macpaul Linafc1ce82011-10-19 20:41:11 +00004114On NDS32, the following registers are used:
4115
4116 R0-R1: argument/return
4117 R2-R5: argument
4118 R15: temporary register for assembler
4119 R16: trampoline register
4120 R28: frame pointer (FP)
4121 R29: global pointer (GP)
4122 R30: link register (LP)
4123 R31: stack pointer (SP)
4124 PC: program counter (PC)
4125
4126 ==> U-Boot will use R10 to hold a pointer to the global data
4127
Wolfgang Denkd87080b2006-03-31 18:32:53 +02004128NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4129or current versions of GCC may "optimize" the code too much.
wdenkc6097192002-11-03 00:24:07 +00004130
Rick Chen3fafced2017-12-26 13:55:59 +08004131On RISC-V, the following registers are used:
4132
4133 x0: hard-wired zero (zero)
4134 x1: return address (ra)
4135 x2: stack pointer (sp)
4136 x3: global pointer (gp)
4137 x4: thread pointer (tp)
4138 x5: link register (t0)
4139 x8: frame pointer (fp)
4140 x10-x11: arguments/return values (a0-1)
4141 x12-x17: arguments (a2-7)
4142 x28-31: temporaries (t3-6)
4143 pc: program counter (pc)
4144
4145 ==> U-Boot will use gp to hold a pointer to the global data
4146
wdenk2729af92004-05-03 20:45:30 +00004147Memory Management:
4148------------------
wdenkc6097192002-11-03 00:24:07 +00004149
wdenk2729af92004-05-03 20:45:30 +00004150U-Boot runs in system state and uses physical addresses, i.e. the
4151MMU is not used either for address mapping nor for memory protection.
wdenkc6097192002-11-03 00:24:07 +00004152
wdenk2729af92004-05-03 20:45:30 +00004153The available memory is mapped to fixed addresses using the memory
4154controller. In this process, a contiguous block is formed for each
4155memory type (Flash, SDRAM, SRAM), even when it consists of several
4156physical memory banks.
wdenkc6097192002-11-03 00:24:07 +00004157
wdenk2729af92004-05-03 20:45:30 +00004158U-Boot is installed in the first 128 kB of the first Flash bank (on
4159TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4160booting and sizing and initializing DRAM, the code relocates itself
4161to the upper end of DRAM. Immediately below the U-Boot code some
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02004162memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
wdenk2729af92004-05-03 20:45:30 +00004163configuration setting]. Below that, a structure with global Board
4164Info data is placed, followed by the stack (growing downward).
wdenkc6097192002-11-03 00:24:07 +00004165
wdenk2729af92004-05-03 20:45:30 +00004166Additionally, some exception handler code is copied to the low 8 kB
4167of DRAM (0x00000000 ... 0x00001FFF).
wdenkc6097192002-11-03 00:24:07 +00004168
wdenk2729af92004-05-03 20:45:30 +00004169So a typical memory configuration with 16 MB of DRAM could look like
4170this:
wdenkc6097192002-11-03 00:24:07 +00004171
wdenk2729af92004-05-03 20:45:30 +00004172 0x0000 0000 Exception Vector code
4173 :
4174 0x0000 1FFF
4175 0x0000 2000 Free for Application Use
4176 :
4177 :
wdenkc6097192002-11-03 00:24:07 +00004178
wdenk2729af92004-05-03 20:45:30 +00004179 :
4180 :
4181 0x00FB FF20 Monitor Stack (Growing downward)
4182 0x00FB FFAC Board Info Data and permanent copy of global data
4183 0x00FC 0000 Malloc Arena
4184 :
4185 0x00FD FFFF
4186 0x00FE 0000 RAM Copy of Monitor Code
4187 ... eventually: LCD or video framebuffer
4188 ... eventually: pRAM (Protected RAM - unchanged by reset)
4189 0x00FF FFFF [End of RAM]
wdenkc6097192002-11-03 00:24:07 +00004190
4191
wdenk2729af92004-05-03 20:45:30 +00004192System Initialization:
4193----------------------
wdenkc6097192002-11-03 00:24:07 +00004194
wdenk2729af92004-05-03 20:45:30 +00004195In the reset configuration, U-Boot starts at the reset entry point
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02004196(on most PowerPC systems at address 0x00000100). Because of the reset
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08004197configuration for CS0# this is a mirror of the on board Flash memory.
wdenk2729af92004-05-03 20:45:30 +00004198To be able to re-map memory U-Boot then jumps to its link address.
4199To be able to implement the initialization code in C, a (small!)
4200initial stack is set up in the internal Dual Ported RAM (in case CPUs
Heiko Schocher2eb48ff2017-06-07 17:33:10 +02004201which provide such a feature like), or in a locked part of the data
4202cache. After that, U-Boot initializes the CPU core, the caches and
4203the SIU.
wdenkc6097192002-11-03 00:24:07 +00004204
wdenk2729af92004-05-03 20:45:30 +00004205Next, all (potentially) available memory banks are mapped using a
4206preliminary mapping. For example, we put them on 512 MB boundaries
4207(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4208on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4209programmed for SDRAM access. Using the temporary configuration, a
4210simple memory test is run that determines the size of the SDRAM
4211banks.
wdenkc6097192002-11-03 00:24:07 +00004212
wdenk2729af92004-05-03 20:45:30 +00004213When there is more than one SDRAM bank, and the banks are of
4214different size, the largest is mapped first. For equal size, the first
4215bank (CS2#) is mapped first. The first mapping is always for address
42160x00000000, with any additional banks following immediately to create
4217contiguous memory starting from 0.
wdenkc6097192002-11-03 00:24:07 +00004218
wdenk2729af92004-05-03 20:45:30 +00004219Then, the monitor installs itself at the upper end of the SDRAM area
4220and allocates memory for use by malloc() and for the global Board
4221Info data; also, the exception vector code is copied to the low RAM
4222pages, and the final stack is set up.
wdenkc6097192002-11-03 00:24:07 +00004223
wdenk2729af92004-05-03 20:45:30 +00004224Only after this relocation will you have a "normal" C environment;
4225until that you are restricted in several ways, mostly because you are
4226running from ROM, and because the code will have to be relocated to a
4227new address in RAM.
wdenkc6097192002-11-03 00:24:07 +00004228
4229
wdenk2729af92004-05-03 20:45:30 +00004230U-Boot Porting Guide:
4231----------------------
wdenkc6097192002-11-03 00:24:07 +00004232
wdenk2729af92004-05-03 20:45:30 +00004233[Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4234list, October 2002]
wdenkc6097192002-11-03 00:24:07 +00004235
4236
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04004237int main(int argc, char *argv[])
wdenk2729af92004-05-03 20:45:30 +00004238{
4239 sighandler_t no_more_time;
wdenkc6097192002-11-03 00:24:07 +00004240
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04004241 signal(SIGALRM, no_more_time);
4242 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
wdenkc6097192002-11-03 00:24:07 +00004243
wdenk2729af92004-05-03 20:45:30 +00004244 if (available_money > available_manpower) {
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04004245 Pay consultant to port U-Boot;
wdenkc6097192002-11-03 00:24:07 +00004246 return 0;
4247 }
4248
wdenk2729af92004-05-03 20:45:30 +00004249 Download latest U-Boot source;
4250
Wolfgang Denk06682362008-12-30 22:56:11 +01004251 Subscribe to u-boot mailing list;
wdenk2729af92004-05-03 20:45:30 +00004252
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04004253 if (clueless)
4254 email("Hi, I am new to U-Boot, how do I get started?");
wdenkc6097192002-11-03 00:24:07 +00004255
wdenk2729af92004-05-03 20:45:30 +00004256 while (learning) {
4257 Read the README file in the top level directory;
Naoki Hayama047f6ec2020-10-08 13:17:16 +09004258 Read https://www.denx.de/wiki/bin/view/DULG/Manual;
Patrick Delaunay24bcaec2020-02-28 15:18:10 +01004259 Read applicable doc/README.*;
wdenk2729af92004-05-03 20:45:30 +00004260 Read the source, Luke;
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04004261 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
wdenk2729af92004-05-03 20:45:30 +00004262 }
wdenkc6097192002-11-03 00:24:07 +00004263
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04004264 if (available_money > toLocalCurrency ($2500))
4265 Buy a BDI3000;
4266 else
wdenk2729af92004-05-03 20:45:30 +00004267 Add a lot of aggravation and time;
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04004268
4269 if (a similar board exists) { /* hopefully... */
4270 cp -a board/<similar> board/<myboard>
4271 cp include/configs/<similar>.h include/configs/<myboard>.h
4272 } else {
4273 Create your own board support subdirectory;
4274 Create your own board include/configs/<myboard>.h file;
wdenk2729af92004-05-03 20:45:30 +00004275 }
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04004276 Edit new board/<myboard> files
4277 Edit new include/configs/<myboard>.h
wdenkc6097192002-11-03 00:24:07 +00004278
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04004279 while (!accepted) {
4280 while (!running) {
4281 do {
4282 Add / modify source code;
4283 } until (compiles);
4284 Debug;
4285 if (clueless)
4286 email("Hi, I am having problems...");
4287 }
4288 Send patch file to the U-Boot email list;
4289 if (reasonable critiques)
4290 Incorporate improvements from email list code review;
4291 else
4292 Defend code as written;
wdenk2729af92004-05-03 20:45:30 +00004293 }
wdenkc6097192002-11-03 00:24:07 +00004294
wdenk2729af92004-05-03 20:45:30 +00004295 return 0;
4296}
4297
4298void no_more_time (int sig)
4299{
4300 hire_a_guru();
4301}
wdenkc6097192002-11-03 00:24:07 +00004302
4303
wdenk2729af92004-05-03 20:45:30 +00004304Coding Standards:
4305-----------------
wdenkc6097192002-11-03 00:24:07 +00004306
wdenk2729af92004-05-03 20:45:30 +00004307All contributions to U-Boot should conform to the Linux kernel
Baruch Siach659208d2017-12-10 17:34:35 +02004308coding style; see the kernel coding style guide at
4309https://www.kernel.org/doc/html/latest/process/coding-style.html, and the
4310script "scripts/Lindent" in your Linux kernel source directory.
wdenk2729af92004-05-03 20:45:30 +00004311
Detlev Zundel2c051652006-09-01 15:39:02 +02004312Source files originating from a different project (for example the
4313MTD subsystem) are generally exempt from these guidelines and are not
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08004314reformatted to ease subsequent migration to newer versions of those
Detlev Zundel2c051652006-09-01 15:39:02 +02004315sources.
4316
4317Please note that U-Boot is implemented in C (and to some small parts in
4318Assembler); no C++ is used, so please do not use C++ style comments (//)
4319in your code.
wdenk2729af92004-05-03 20:45:30 +00004320
4321Please also stick to the following formatting rules:
4322- remove any trailing white space
Wolfgang Denk7ca92962011-07-27 10:59:55 +00004323- use TAB characters for indentation and vertical alignment, not spaces
wdenk2729af92004-05-03 20:45:30 +00004324- make sure NOT to use DOS '\r\n' line feeds
Wolfgang Denk7ca92962011-07-27 10:59:55 +00004325- do not add more than 2 consecutive empty lines to source files
wdenk2729af92004-05-03 20:45:30 +00004326- do not add trailing empty lines to source files
4327
4328Submissions which do not conform to the standards may be returned
4329with a request to reformat the changes.
wdenkc6097192002-11-03 00:24:07 +00004330
4331
wdenk2729af92004-05-03 20:45:30 +00004332Submitting Patches:
4333-------------------
wdenkc6097192002-11-03 00:24:07 +00004334
wdenk2729af92004-05-03 20:45:30 +00004335Since the number of patches for U-Boot is growing, we need to
4336establish some rules. Submissions which do not conform to these rules
4337may be rejected, even when they contain important and valuable stuff.
wdenkc6097192002-11-03 00:24:07 +00004338
Naoki Hayama047f6ec2020-10-08 13:17:16 +09004339Please see https://www.denx.de/wiki/U-Boot/Patches for details.
Wolfgang Denk218ca722008-03-26 10:40:12 +01004340
Wolfgang Denk06682362008-12-30 22:56:11 +01004341Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
S. Lockwood-Childs1dade182017-11-14 22:56:42 -08004342see https://lists.denx.de/listinfo/u-boot
Wolfgang Denk06682362008-12-30 22:56:11 +01004343
wdenk2729af92004-05-03 20:45:30 +00004344When you send a patch, please include the following information with
4345it:
wdenkc6097192002-11-03 00:24:07 +00004346
wdenk2729af92004-05-03 20:45:30 +00004347* For bug fixes: a description of the bug and how your patch fixes
4348 this bug. Please try to include a way of demonstrating that the
4349 patch actually fixes something.
wdenkc6097192002-11-03 00:24:07 +00004350
wdenk2729af92004-05-03 20:45:30 +00004351* For new features: a description of the feature and your
4352 implementation.
wdenkc6097192002-11-03 00:24:07 +00004353
Robert P. J. Day7207b362015-12-19 07:16:10 -05004354* For major contributions, add a MAINTAINERS file with your
4355 information and associated file and directory references.
wdenk2729af92004-05-03 20:45:30 +00004356
Albert ARIBAUD27af9302013-09-11 15:52:51 +02004357* When you add support for a new board, don't forget to add a
4358 maintainer e-mail address to the boards.cfg file, too.
wdenk2729af92004-05-03 20:45:30 +00004359
4360* If your patch adds new configuration options, don't forget to
4361 document these in the README file.
4362
Wolfgang Denk218ca722008-03-26 10:40:12 +01004363* The patch itself. If you are using git (which is *strongly*
4364 recommended) you can easily generate the patch using the
Wolfgang Denk7ca92962011-07-27 10:59:55 +00004365 "git format-patch". If you then use "git send-email" to send it to
Wolfgang Denk218ca722008-03-26 10:40:12 +01004366 the U-Boot mailing list, you will avoid most of the common problems
4367 with some other mail clients.
wdenk2729af92004-05-03 20:45:30 +00004368
Wolfgang Denk218ca722008-03-26 10:40:12 +01004369 If you cannot use git, use "diff -purN OLD NEW". If your version of
4370 diff does not support these options, then get the latest version of
4371 GNU diff.
wdenk2729af92004-05-03 20:45:30 +00004372
Wolfgang Denk218ca722008-03-26 10:40:12 +01004373 The current directory when running this command shall be the parent
4374 directory of the U-Boot source tree (i. e. please make sure that
4375 your patch includes sufficient directory information for the
4376 affected files).
4377
4378 We prefer patches as plain text. MIME attachments are discouraged,
4379 and compressed attachments must not be used.
wdenk2729af92004-05-03 20:45:30 +00004380
4381* If one logical set of modifications affects or creates several
4382 files, all these changes shall be submitted in a SINGLE patch file.
4383
4384* Changesets that contain different, unrelated modifications shall be
4385 submitted as SEPARATE patches, one patch per changeset.
4386
4387
4388Notes:
4389
Simon Glass6de80f22016-07-27 20:33:08 -06004390* Before sending the patch, run the buildman script on your patched
wdenk2729af92004-05-03 20:45:30 +00004391 source tree and make sure that no errors or warnings are reported
4392 for any of the boards.
4393
4394* Keep your modifications to the necessary minimum: A patch
4395 containing several unrelated changes or arbitrary reformats will be
4396 returned with a request to re-formatting / split it.
4397
4398* If you modify existing code, make sure that your new code does not
4399 add to the memory footprint of the code ;-) Small is beautiful!
4400 When adding new features, these should compile conditionally only
4401 (using #ifdef), and the resulting code with the new feature
4402 disabled must not need more memory than the old code without your
4403 modification.
wdenk90dc6702005-05-03 14:12:25 +00004404
Wolfgang Denk06682362008-12-30 22:56:11 +01004405* Remember that there is a size limit of 100 kB per message on the
4406 u-boot mailing list. Bigger patches will be moderated. If they are
4407 reasonable and not too big, they will be acknowledged. But patches
4408 bigger than the size limit should be avoided.