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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
Simon Glass19a91f22021-10-14 12:47:54 -0600147/boot Support for images and booting
Xu Ziyuan740f7e52016-08-26 19:54:49 +0800148/cmd U-Boot commands functions
Simon Glass6e73ed02021-07-10 21:14:21 -0600149/common Misc architecture-independent functions
Robert P. J. Day7207b362015-12-19 07:16:10 -0500150/configs Board default configuration files
Peter Tyser8d321b82010-04-12 22:28:21 -0500151/disk Code for disk drive partition handling
Simon Glass6e73ed02021-07-10 21:14:21 -0600152/doc Documentation (a mix of ReST and READMEs)
153/drivers Device drivers
154/dts Makefile for building internal U-Boot fdt.
155/env Environment support
Peter Tyser8d321b82010-04-12 22:28:21 -0500156/examples Example code for standalone applications, etc.
157/fs Filesystem code (cramfs, ext2, jffs2, etc.)
158/include Header Files
Robert P. J. Day7207b362015-12-19 07:16:10 -0500159/lib Library routines generic to all architectures
160/Licenses Various license files
Peter Tyser8d321b82010-04-12 22:28:21 -0500161/net Networking code
162/post Power On Self Test
Robert P. J. Day7207b362015-12-19 07:16:10 -0500163/scripts Various build scripts and Makefiles
164/test Various unit test files
Simon Glass6e73ed02021-07-10 21:14:21 -0600165/tools Tools to build and sign FIT images, etc.
wdenkc6097192002-11-03 00:24:07 +0000166
wdenkc6097192002-11-03 00:24:07 +0000167Software Configuration:
168=======================
169
170Configuration is usually done using C preprocessor defines; the
171rationale behind that is to avoid dead code whenever possible.
172
173There are two classes of configuration variables:
174
175* Configuration _OPTIONS_:
176 These are selectable by the user and have names beginning with
177 "CONFIG_".
178
179* Configuration _SETTINGS_:
180 These depend on the hardware etc. and should not be meddled with if
181 you don't know what you're doing; they have names beginning with
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200182 "CONFIG_SYS_".
wdenkc6097192002-11-03 00:24:07 +0000183
Robert P. J. Day7207b362015-12-19 07:16:10 -0500184Previously, all configuration was done by hand, which involved creating
185symbolic links and editing configuration files manually. More recently,
186U-Boot has added the Kbuild infrastructure used by the Linux kernel,
187allowing you to use the "make menuconfig" command to configure your
188build.
wdenkc6097192002-11-03 00:24:07 +0000189
190
191Selection of Processor Architecture and Board Type:
192---------------------------------------------------
193
194For all supported boards there are ready-to-use default
Holger Freytherab584d62014-08-04 09:26:05 +0200195configurations available; just type "make <board_name>_defconfig".
wdenkc6097192002-11-03 00:24:07 +0000196
197Example: For a TQM823L module type:
198
199 cd u-boot
Holger Freytherab584d62014-08-04 09:26:05 +0200200 make TQM823L_defconfig
wdenkc6097192002-11-03 00:24:07 +0000201
Robert P. J. Day7207b362015-12-19 07:16:10 -0500202Note: If you're looking for the default configuration file for a board
203you're sure used to be there but is now missing, check the file
204doc/README.scrapyard for a list of no longer supported boards.
wdenkc6097192002-11-03 00:24:07 +0000205
Simon Glass75b3c3a2014-03-22 17:12:59 -0600206Sandbox Environment:
207--------------------
208
209U-Boot can be built natively to run on a Linux host using the 'sandbox'
210board. This allows feature development which is not board- or architecture-
211specific to be undertaken on a native platform. The sandbox is also used to
212run some of U-Boot's tests.
213
Naoki Hayamabbb140e2020-10-08 13:16:58 +0900214See doc/arch/sandbox.rst for more details.
Simon Glass75b3c3a2014-03-22 17:12:59 -0600215
216
Simon Glassdb910352015-03-03 08:03:00 -0700217Board Initialisation Flow:
218--------------------------
219
220This is the intended start-up flow for boards. This should apply for both
Robert P. J. Day7207b362015-12-19 07:16:10 -0500221SPL and U-Boot proper (i.e. they both follow the same rules).
Simon Glassdb910352015-03-03 08:03:00 -0700222
Robert P. J. Day7207b362015-12-19 07:16:10 -0500223Note: "SPL" stands for "Secondary Program Loader," which is explained in
224more detail later in this file.
225
226At present, SPL mostly uses a separate code path, but the function names
227and roles of each function are the same. Some boards or architectures
228may not conform to this. At least most ARM boards which use
229CONFIG_SPL_FRAMEWORK conform to this.
230
231Execution typically starts with an architecture-specific (and possibly
232CPU-specific) start.S file, such as:
233
234 - arch/arm/cpu/armv7/start.S
235 - arch/powerpc/cpu/mpc83xx/start.S
236 - arch/mips/cpu/start.S
237
238and so on. From there, three functions are called; the purpose and
239limitations of each of these functions are described below.
Simon Glassdb910352015-03-03 08:03:00 -0700240
241lowlevel_init():
242 - purpose: essential init to permit execution to reach board_init_f()
243 - no global_data or BSS
244 - there is no stack (ARMv7 may have one but it will soon be removed)
245 - must not set up SDRAM or use console
246 - must only do the bare minimum to allow execution to continue to
247 board_init_f()
248 - this is almost never needed
249 - return normally from this function
250
251board_init_f():
252 - purpose: set up the machine ready for running board_init_r():
253 i.e. SDRAM and serial UART
254 - global_data is available
255 - stack is in SRAM
256 - BSS is not available, so you cannot use global/static variables,
257 only stack variables and global_data
258
259 Non-SPL-specific notes:
260 - dram_init() is called to set up DRAM. If already done in SPL this
261 can do nothing
262
263 SPL-specific notes:
264 - you can override the entire board_init_f() function with your own
265 version as needed.
266 - preloader_console_init() can be called here in extremis
267 - should set up SDRAM, and anything needed to make the UART work
Naoki Hayama499696e2020-09-24 15:57:19 +0900268 - there is no need to clear BSS, it will be done by crt0.S
Andreas Dannenberg14254652019-08-08 12:54:49 -0500269 - for specific scenarios on certain architectures an early BSS *can*
270 be made available (via CONFIG_SPL_EARLY_BSS by moving the clearing
271 of BSS prior to entering board_init_f()) but doing so is discouraged.
272 Instead it is strongly recommended to architect any code changes
273 or additions such to not depend on the availability of BSS during
274 board_init_f() as indicated in other sections of this README to
275 maintain compatibility and consistency across the entire code base.
Simon Glassdb910352015-03-03 08:03:00 -0700276 - must return normally from this function (don't call board_init_r()
277 directly)
278
279Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
280this point the stack and global_data are relocated to below
281CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
282memory.
283
284board_init_r():
285 - purpose: main execution, common code
286 - global_data is available
287 - SDRAM is available
288 - BSS is available, all static/global variables can be used
289 - execution eventually continues to main_loop()
290
291 Non-SPL-specific notes:
292 - U-Boot is relocated to the top of memory and is now running from
293 there.
294
295 SPL-specific notes:
296 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
297 CONFIG_SPL_STACK_R_ADDR points into SDRAM
298 - preloader_console_init() can be called here - typically this is
Ley Foon Tan0680f1b2017-05-03 17:13:32 +0800299 done by selecting CONFIG_SPL_BOARD_INIT and then supplying a
Simon Glassdb910352015-03-03 08:03:00 -0700300 spl_board_init() function containing this call
301 - loads U-Boot or (in falcon mode) Linux
302
303
wdenkc6097192002-11-03 00:24:07 +0000304Configuration Options:
305----------------------
306
307Configuration depends on the combination of board and CPU type; all
308such information is kept in a configuration file
309"include/configs/<board_name>.h".
310
311Example: For a TQM823L module, all configuration settings are in
312"include/configs/TQM823L.h".
313
314
wdenk7f6c2cb2002-11-10 22:06:23 +0000315Many of the options are named exactly as the corresponding Linux
316kernel configuration options. The intention is to make it easier to
317build a config tool - later.
318
Ashish Kumar63b23162017-08-11 11:09:14 +0530319- ARM Platform Bus Type(CCI):
320 CoreLink Cache Coherent Interconnect (CCI) is ARM BUS which
321 provides full cache coherency between two clusters of multi-core
322 CPUs and I/O coherency for devices and I/O masters
323
324 CONFIG_SYS_FSL_HAS_CCI400
325
326 Defined For SoC that has cache coherent interconnect
327 CCN-400
wdenk7f6c2cb2002-11-10 22:06:23 +0000328
Ashish Kumarc055cee2017-08-18 10:54:36 +0530329 CONFIG_SYS_FSL_HAS_CCN504
330
331 Defined for SoC that has cache coherent interconnect CCN-504
332
wdenkc6097192002-11-03 00:24:07 +0000333The following options need to be configured:
334
Kim Phillips26281142007-08-10 13:28:25 -0500335- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
wdenkc6097192002-11-03 00:24:07 +0000336
Kim Phillips26281142007-08-10 13:28:25 -0500337- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
Wolfgang Denk6ccec442006-10-24 14:42:37 +0200338
Kumar Gala66412c62011-02-18 05:40:54 -0600339- 85xx CPU Options:
York Sunffd06e02012-10-08 07:44:30 +0000340 CONFIG_SYS_PPC64
341
342 Specifies that the core is a 64-bit PowerPC implementation (implements
343 the "64" category of the Power ISA). This is necessary for ePAPR
344 compliance, among other possible reasons.
345
Kumar Gala66412c62011-02-18 05:40:54 -0600346 CONFIG_SYS_FSL_TBCLK_DIV
347
348 Defines the core time base clock divider ratio compared to the
349 system clock. On most PQ3 devices this is 8, on newer QorIQ
350 devices it can be 16 or 32. The ratio varies from SoC to Soc.
351
Kumar Gala8f290842011-05-20 00:39:21 -0500352 CONFIG_SYS_FSL_PCIE_COMPAT
353
354 Defines the string to utilize when trying to match PCIe device
355 tree nodes for the given platform.
356
Scott Wood33eee332012-08-14 10:14:53 +0000357 CONFIG_SYS_FSL_ERRATUM_A004510
358
359 Enables a workaround for erratum A004510. If set,
360 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
361 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
362
363 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
364 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
365
366 Defines one or two SoC revisions (low 8 bits of SVR)
367 for which the A004510 workaround should be applied.
368
369 The rest of SVR is either not relevant to the decision
370 of whether the erratum is present (e.g. p2040 versus
371 p2041) or is implied by the build target, which controls
372 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
373
374 See Freescale App Note 4493 for more information about
375 this erratum.
376
377 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
378
379 This is the value to write into CCSR offset 0x18600
380 according to the A004510 workaround.
381
Priyanka Jain64501c62013-07-02 09:21:04 +0530382 CONFIG_SYS_FSL_DSP_DDR_ADDR
383 This value denotes start offset of DDR memory which is
384 connected exclusively to the DSP cores.
385
Priyanka Jain765b0bd2013-04-04 09:31:54 +0530386 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
387 This value denotes start offset of M2 memory
388 which is directly connected to the DSP core.
389
Priyanka Jain64501c62013-07-02 09:21:04 +0530390 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
391 This value denotes start offset of M3 memory which is directly
392 connected to the DSP core.
393
Priyanka Jain765b0bd2013-04-04 09:31:54 +0530394 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
395 This value denotes start offset of DSP CCSR space.
396
Priyanka Jainb1359912013-12-17 14:25:52 +0530397 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
398 Single Source Clock is clocking mode present in some of FSL SoC's.
399 In this mode, a single differential clock is used to supply
400 clocks to the sysclock, ddrclock and usbclock.
401
Aneesh Bansalfb4a2402014-03-18 23:40:26 +0530402 CONFIG_SYS_CPC_REINIT_F
403 This CONFIG is defined when the CPC is configured as SRAM at the
Bin Menga1875592016-02-05 19:30:11 -0800404 time of U-Boot entry and is required to be re-initialized.
Aneesh Bansalfb4a2402014-03-18 23:40:26 +0530405
Daniel Schwierzeck6cb461b2012-04-02 02:57:56 +0000406- Generic CPU options:
407 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
408
409 Defines the endianess of the CPU. Implementation of those
410 values is arch specific.
411
York Sun5614e712013-09-30 09:22:09 -0700412 CONFIG_SYS_FSL_DDR
413 Freescale DDR driver in use. This type of DDR controller is
Tom Rini1c588572021-05-14 21:34:26 -0400414 found in mpc83xx, mpc85xx as well as some ARM core SoCs.
York Sun5614e712013-09-30 09:22:09 -0700415
416 CONFIG_SYS_FSL_DDR_ADDR
417 Freescale DDR memory-mapped register base.
418
419 CONFIG_SYS_FSL_DDR_EMU
420 Specify emulator support for DDR. Some DDR features such as
421 deskew training are not available.
422
423 CONFIG_SYS_FSL_DDRC_GEN1
424 Freescale DDR1 controller.
425
426 CONFIG_SYS_FSL_DDRC_GEN2
427 Freescale DDR2 controller.
428
429 CONFIG_SYS_FSL_DDRC_GEN3
430 Freescale DDR3 controller.
431
York Sun34e026f2014-03-27 17:54:47 -0700432 CONFIG_SYS_FSL_DDRC_GEN4
433 Freescale DDR4 controller.
434
York Sun9ac4ffb2013-09-30 14:20:51 -0700435 CONFIG_SYS_FSL_DDRC_ARM_GEN3
436 Freescale DDR3 controller for ARM-based SoCs.
437
York Sun5614e712013-09-30 09:22:09 -0700438 CONFIG_SYS_FSL_DDR1
439 Board config to use DDR1. It can be enabled for SoCs with
440 Freescale DDR1 or DDR2 controllers, depending on the board
441 implemetation.
442
443 CONFIG_SYS_FSL_DDR2
Robert P. J. Day62a3b7d2016-07-15 13:44:45 -0400444 Board config to use DDR2. It can be enabled for SoCs with
York Sun5614e712013-09-30 09:22:09 -0700445 Freescale DDR2 or DDR3 controllers, depending on the board
446 implementation.
447
448 CONFIG_SYS_FSL_DDR3
449 Board config to use DDR3. It can be enabled for SoCs with
York Sun34e026f2014-03-27 17:54:47 -0700450 Freescale DDR3 or DDR3L controllers.
451
452 CONFIG_SYS_FSL_DDR3L
453 Board config to use DDR3L. It can be enabled for SoCs with
454 DDR3L controllers.
455
Prabhakar Kushwaha1b4175d2014-01-18 12:28:30 +0530456 CONFIG_SYS_FSL_IFC_BE
457 Defines the IFC controller register space as Big Endian
458
459 CONFIG_SYS_FSL_IFC_LE
460 Defines the IFC controller register space as Little Endian
461
Prabhakar Kushwaha1c407072017-02-02 15:01:26 +0530462 CONFIG_SYS_FSL_IFC_CLK_DIV
463 Defines divider of platform clock(clock input to IFC controller).
464
Prabhakar Kushwahaadd63f92017-02-02 15:02:00 +0530465 CONFIG_SYS_FSL_LBC_CLK_DIV
466 Defines divider of platform clock(clock input to eLBC controller).
467
York Sun4e5b1bd2014-02-10 13:59:42 -0800468 CONFIG_SYS_FSL_DDR_BE
469 Defines the DDR controller register space as Big Endian
470
471 CONFIG_SYS_FSL_DDR_LE
472 Defines the DDR controller register space as Little Endian
473
York Sun6b9e3092014-02-10 13:59:43 -0800474 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
475 Physical address from the view of DDR controllers. It is the
476 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
477 it could be different for ARM SoCs.
478
York Sun6b1e1252014-02-10 13:59:44 -0800479 CONFIG_SYS_FSL_DDR_INTLV_256B
480 DDR controller interleaving on 256-byte. This is a special
481 interleaving mode, handled by Dickens for Freescale layerscape
482 SoCs with ARM core.
483
York Sun1d71efb2014-08-01 15:51:00 -0700484 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
485 Number of controllers used as main memory.
486
487 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
488 Number of controllers used for other than main memory.
489
Ruchika Gupta028dbb82014-09-09 11:50:31 +0530490 CONFIG_SYS_FSL_SEC_BE
491 Defines the SEC controller register space as Big Endian
492
493 CONFIG_SYS_FSL_SEC_LE
494 Defines the SEC controller register space as Little Endian
495
Daniel Schwierzeck92bbd642011-07-27 13:22:39 +0200496- MIPS CPU options:
497 CONFIG_SYS_INIT_SP_OFFSET
498
499 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
500 pointer. This is needed for the temporary stack before
501 relocation.
502
Daniel Schwierzeck92bbd642011-07-27 13:22:39 +0200503 CONFIG_XWAY_SWAP_BYTES
504
505 Enable compilation of tools/xway-swap-bytes needed for Lantiq
506 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
507 be swapped if a flash programmer is used.
508
Christian Rieschb67d8812012-02-02 00:44:39 +0000509- ARM options:
510 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
511
512 Select high exception vectors of the ARM core, e.g., do not
513 clear the V bit of the c1 register of CP15.
514
York Sun207774b2015-03-20 19:28:08 -0700515 COUNTER_FREQUENCY
516 Generic timer clock source frequency.
517
518 COUNTER_FREQUENCY_REAL
519 Generic timer clock source frequency if the real clock is
520 different from COUNTER_FREQUENCY, and can only be determined
521 at run time.
522
Stephen Warren73c38932015-01-19 16:25:52 -0700523- Tegra SoC options:
524 CONFIG_TEGRA_SUPPORT_NON_SECURE
525
526 Support executing U-Boot in non-secure (NS) mode. Certain
527 impossible actions will be skipped if the CPU is in NS mode,
528 such as ARM architectural timer initialization.
529
wdenk5da627a2003-10-09 20:09:04 +0000530- Linux Kernel Interface:
wdenk5da627a2003-10-09 20:09:04 +0000531 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
532
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -0800533 When transferring memsize parameter to Linux, some versions
wdenk5da627a2003-10-09 20:09:04 +0000534 expect it to be in bytes, others in MB.
535 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
536
Gerald Van Barenfec6d9e2008-06-03 20:34:45 -0400537 CONFIG_OF_LIBFDT
Wolfgang Denkf57f70a2005-10-13 01:45:54 +0200538
539 New kernel versions are expecting firmware settings to be
Gerald Van Baren213bf8c2007-03-31 12:23:51 -0400540 passed using flattened device trees (based on open firmware
541 concepts).
542
543 CONFIG_OF_LIBFDT
544 * New libfdt-based support
545 * Adds the "fdt" command
Kim Phillips3bb342f2007-08-10 14:34:14 -0500546 * The bootm command automatically updates the fdt
Gerald Van Baren213bf8c2007-03-31 12:23:51 -0400547
Wolfgang Denkf57f70a2005-10-13 01:45:54 +0200548 OF_TBCLK - The timebase frequency.
549
Marcel Ziswiler11ccc332008-07-09 08:17:15 +0200550 boards with QUICC Engines require OF_QE to set UCC MAC
551 addresses
Kim Phillips3bb342f2007-08-10 14:34:14 -0500552
Heiko Schocher3887c3f2009-09-23 07:56:08 +0200553 CONFIG_OF_IDE_FIXUP
554
555 U-Boot can detect if an IDE device is present or not.
556 If not, and this new config option is activated, U-Boot
557 removes the ATA node from the DTS before booting Linux,
558 so the Linux IDE driver does not probe the device and
559 crash. This is needed for buggy hardware (uc101) where
560 no pull down resistor is connected to the signal IDE5V_DD7.
561
Niklaus Giger0b2f4ec2008-11-03 22:13:47 +0100562- vxWorks boot parameters:
563
564 bootvx constructs a valid bootline using the following
Bin Meng9e98b7e2015-10-07 20:19:17 -0700565 environments variables: bootdev, bootfile, ipaddr, netmask,
566 serverip, gatewayip, hostname, othbootargs.
Niklaus Giger0b2f4ec2008-11-03 22:13:47 +0100567 It loads the vxWorks image pointed bootfile.
568
Naoki Hayama81a05d92020-10-08 13:17:08 +0900569 Note: If a "bootargs" environment is defined, it will override
Niklaus Giger0b2f4ec2008-11-03 22:13:47 +0100570 the defaults discussed just above.
571
Aneesh V93bc2192011-06-16 23:30:51 +0000572- Cache Configuration for ARM:
573 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
574 controller
575 CONFIG_SYS_PL310_BASE - Physical base address of PL310
576 controller register space
577
wdenk6705d812004-08-02 23:22:59 +0000578- Serial Ports:
wdenk6705d812004-08-02 23:22:59 +0000579 CONFIG_PL011_CLOCK
580
581 If you have Amba PrimeCell PL011 UARTs, set this variable to
582 the clock speed of the UARTs.
583
584 CONFIG_PL01x_PORTS
585
586 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
587 define this to a list of base addresses for each (supported)
588 port. See e.g. include/configs/versatile.h
589
Karicheri, Muralidharand57dee52014-04-09 15:38:46 -0400590 CONFIG_SERIAL_HW_FLOW_CONTROL
591
592 Define this variable to enable hw flow control in serial driver.
593 Current user of this option is drivers/serial/nsl16550.c driver
wdenk6705d812004-08-02 23:22:59 +0000594
wdenkc6097192002-11-03 00:24:07 +0000595- Serial Download Echo Mode:
596 CONFIG_LOADS_ECHO
597 If defined to 1, all characters received during a
598 serial download (using the "loads" command) are
599 echoed back. This might be needed by some terminal
600 emulations (like "cu"), but may as well just take
601 time on others. This setting #define's the initial
602 value of the "loads_echo" environment variable.
603
Simon Glass302a6482016-03-13 19:07:28 -0600604- Removal of commands
605 If no commands are needed to boot, you can disable
606 CONFIG_CMDLINE to remove them. In this case, the command line
607 will not be available, and when U-Boot wants to execute the
608 boot command (on start-up) it will call board_run_command()
609 instead. This can reduce image size significantly for very
610 simple boot procedures.
611
Wolfgang Denka5ecbe62013-03-23 23:50:31 +0000612- Regular expression support:
613 CONFIG_REGEX
Wolfgang Denk93e14592013-10-04 17:43:24 +0200614 If this variable is defined, U-Boot is linked against
615 the SLRE (Super Light Regular Expression) library,
616 which adds regex support to some commands, as for
617 example "env grep" and "setexpr".
Wolfgang Denka5ecbe62013-03-23 23:50:31 +0000618
wdenkc6097192002-11-03 00:24:07 +0000619- Watchdog:
Rasmus Villemoes933ada52021-04-14 09:18:22 +0200620 CONFIG_SYS_WATCHDOG_FREQ
621 Some platforms automatically call WATCHDOG_RESET()
622 from the timer interrupt handler every
623 CONFIG_SYS_WATCHDOG_FREQ interrupts. If not set by the
624 board configuration file, a default of CONFIG_SYS_HZ/2
625 (i.e. 500) is used. Setting CONFIG_SYS_WATCHDOG_FREQ
626 to 0 disables calling WATCHDOG_RESET() from the timer
627 interrupt.
628
wdenkc6097192002-11-03 00:24:07 +0000629- Real-Time Clock:
630
Jon Loeliger602ad3b2007-06-11 19:03:39 -0500631 When CONFIG_CMD_DATE is selected, the type of the RTC
wdenkc6097192002-11-03 00:24:07 +0000632 has to be selected, too. Define exactly one of the
633 following options:
634
wdenkc6097192002-11-03 00:24:07 +0000635 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
Fabio Estevam4e8b7542011-10-24 06:44:15 +0000636 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
wdenkc6097192002-11-03 00:24:07 +0000637 CONFIG_RTC_MC146818 - use MC146818 RTC
wdenk1cb8e982003-03-06 21:55:29 +0000638 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
wdenkc6097192002-11-03 00:24:07 +0000639 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
wdenk7f70e852003-05-20 14:25:27 +0000640 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
Markus Niebel412921d2014-07-21 11:06:16 +0200641 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
wdenk3bac3512003-03-12 10:41:04 +0000642 CONFIG_RTC_DS164x - use Dallas DS164x RTC
Tor Krill9536dfc2008-03-15 15:40:26 +0100643 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
wdenk4c0d4c32004-06-09 17:34:58 +0000644 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
Chris Packham2bd3cab2017-05-30 12:03:33 +1200645 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
Heiko Schocher71d19f32011-03-28 09:24:22 +0200646 CONFIG_SYS_RV3029_TCR - enable trickle charger on
647 RV3029 RTC.
wdenkc6097192002-11-03 00:24:07 +0000648
wdenkb37c7e52003-06-30 16:24:52 +0000649 Note that if the RTC uses I2C, then the I2C interface
650 must also be configured. See I2C Support, below.
651
Peter Tysere92739d2008-12-17 16:36:21 -0600652- GPIO Support:
653 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
Peter Tysere92739d2008-12-17 16:36:21 -0600654
Chris Packham5dec49c2010-12-19 10:12:13 +0000655 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
656 chip-ngpio pairs that tell the PCA953X driver the number of
657 pins supported by a particular chip.
658
Peter Tysere92739d2008-12-17 16:36:21 -0600659 Note that if the GPIO device uses I2C, then the I2C interface
660 must also be configured. See I2C Support, below.
661
Simon Glassaa532332014-06-11 23:29:41 -0600662- I/O tracing:
663 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
664 accesses and can checksum them or write a list of them out
665 to memory. See the 'iotrace' command for details. This is
666 useful for testing device drivers since it can confirm that
667 the driver behaves the same way before and after a code
668 change. Currently this is supported on sandbox and arm. To
669 add support for your architecture, add '#include <iotrace.h>'
670 to the bottom of arch/<arch>/include/asm/io.h and test.
671
672 Example output from the 'iotrace stats' command is below.
673 Note that if the trace buffer is exhausted, the checksum will
674 still continue to operate.
675
676 iotrace is enabled
677 Start: 10000000 (buffer start address)
678 Size: 00010000 (buffer size)
679 Offset: 00000120 (current buffer offset)
680 Output: 10000120 (start + offset)
681 Count: 00000018 (number of trace records)
682 CRC32: 9526fb66 (CRC32 of all trace records)
683
wdenkc6097192002-11-03 00:24:07 +0000684- Timestamp Support:
685
wdenk43d96162003-03-06 00:02:04 +0000686 When CONFIG_TIMESTAMP is selected, the timestamp
687 (date and time) of an image is printed by image
688 commands like bootm or iminfo. This option is
Jon Loeliger602ad3b2007-06-11 19:03:39 -0500689 automatically enabled when you select CONFIG_CMD_DATE .
wdenkc6097192002-11-03 00:24:07 +0000690
Karl O. Pinc923c46f2012-08-16 06:20:15 +0000691- Partition Labels (disklabels) Supported:
692 Zero or more of the following:
693 CONFIG_MAC_PARTITION Apple's MacOS partition table.
Karl O. Pinc923c46f2012-08-16 06:20:15 +0000694 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
695 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
696 bootloader. Note 2TB partition limit; see
697 disk/part_efi.c
Simon Glassc649e3c2016-05-01 11:36:02 -0600698 CONFIG_SCSI) you must configure support for at
Karl O. Pinc923c46f2012-08-16 06:20:15 +0000699 least one non-MTD partition type as well.
wdenkc6097192002-11-03 00:24:07 +0000700
wdenkc40b2952004-03-13 23:29:43 +0000701- LBA48 Support
702 CONFIG_LBA48
703
704 Set this to enable support for disks larger than 137GB
Heiko Schocher4b142fe2009-12-03 11:21:21 +0100705 Also look at CONFIG_SYS_64BIT_LBA.
wdenkc40b2952004-03-13 23:29:43 +0000706 Whithout these , LBA48 support uses 32bit variables and will 'only'
707 support disks up to 2.1TB.
708
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200709 CONFIG_SYS_64BIT_LBA:
wdenkc40b2952004-03-13 23:29:43 +0000710 When enabled, makes the IDE subsystem use 64bit sector addresses.
711 Default is 32bit.
712
wdenkc6097192002-11-03 00:24:07 +0000713- NETWORK Support (PCI):
Kyle Moffettce5207e2011-10-18 11:05:29 +0000714 CONFIG_E1000_SPI
715 Utility code for direct access to the SPI bus on Intel 8257x.
716 This does not do anything useful unless you set at least one
717 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
718
wdenkc6097192002-11-03 00:24:07 +0000719 CONFIG_NATSEMI
720 Support for National dp83815 chips.
721
722 CONFIG_NS8382X
723 Support for National dp8382[01] gigabit chips.
724
wdenk45219c42003-05-12 21:50:16 +0000725- NETWORK Support (other):
Rob Herringefdd7312011-12-15 11:15:49 +0000726 CONFIG_CALXEDA_XGMAC
727 Support for the Calxeda XGMAC device
728
Ashok3bb46d22012-10-15 06:20:47 +0000729 CONFIG_LAN91C96
wdenk45219c42003-05-12 21:50:16 +0000730 Support for SMSC's LAN91C96 chips.
731
wdenk45219c42003-05-12 21:50:16 +0000732 CONFIG_LAN91C96_USE_32_BIT
733 Define this to enable 32 bit addressing
734
Ashok3bb46d22012-10-15 06:20:47 +0000735 CONFIG_SMC91111
wdenkf39748a2004-06-09 13:37:52 +0000736 Support for SMSC's LAN91C111 chip
737
738 CONFIG_SMC91111_BASE
739 Define this to hold the physical address
740 of the device (I/O space)
741
742 CONFIG_SMC_USE_32_BIT
743 Define this if data bus is 32 bits
744
745 CONFIG_SMC_USE_IOFUNCS
746 Define this to use i/o functions instead of macros
747 (some hardware wont work with macros)
748
Heiko Schocherdc02bad2011-11-15 10:00:04 -0500749 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
750 Define this if you have more then 3 PHYs.
751
Macpaul Linb3dbf4a52010-12-21 16:59:46 +0800752 CONFIG_FTGMAC100
753 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
754
755 CONFIG_FTGMAC100_EGIGA
756 Define this to use GE link update with gigabit PHY.
757 Define this if FTGMAC100 is connected to gigabit PHY.
758 If your system has 10/100 PHY only, it might not occur
759 wrong behavior. Because PHY usually return timeout or
760 useless data when polling gigabit status and gigabit
761 control registers. This behavior won't affect the
762 correctnessof 10/100 link speed update.
763
Yoshihiro Shimoda3d0075f2011-01-27 10:06:03 +0900764 CONFIG_SH_ETHER
765 Support for Renesas on-chip Ethernet controller
766
767 CONFIG_SH_ETHER_USE_PORT
768 Define the number of ports to be used
769
770 CONFIG_SH_ETHER_PHY_ADDR
771 Define the ETH PHY's address
772
Yoshihiro Shimoda68260aa2011-01-27 10:06:08 +0900773 CONFIG_SH_ETHER_CACHE_WRITEBACK
774 If this option is set, the driver enables cache flush.
775
Vadim Bendebury5e124722011-10-17 08:36:14 +0000776- TPM Support:
Che-liang Chiou90899cc2013-04-12 11:04:34 +0000777 CONFIG_TPM
778 Support TPM devices.
779
Christophe Ricard0766ad22015-10-06 22:54:41 +0200780 CONFIG_TPM_TIS_INFINEON
781 Support for Infineon i2c bus TPM devices. Only one device
Tom Wai-Hong Tam1b393db2013-04-12 11:04:37 +0000782 per system is supported at this time.
783
Tom Wai-Hong Tam1b393db2013-04-12 11:04:37 +0000784 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
785 Define the burst count bytes upper limit
786
Christophe Ricard3aa74082016-01-21 23:27:13 +0100787 CONFIG_TPM_ST33ZP24
788 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
789
790 CONFIG_TPM_ST33ZP24_I2C
791 Support for STMicroelectronics ST33ZP24 I2C devices.
792 Requires TPM_ST33ZP24 and I2C.
793
Christophe Ricardb75fdc12016-01-21 23:27:14 +0100794 CONFIG_TPM_ST33ZP24_SPI
795 Support for STMicroelectronics ST33ZP24 SPI devices.
796 Requires TPM_ST33ZP24 and SPI.
797
Dirk Eibachc01939c2013-06-26 15:55:15 +0200798 CONFIG_TPM_ATMEL_TWI
799 Support for Atmel TWI TPM device. Requires I2C support.
800
Che-liang Chiou90899cc2013-04-12 11:04:34 +0000801 CONFIG_TPM_TIS_LPC
Vadim Bendebury5e124722011-10-17 08:36:14 +0000802 Support for generic parallel port TPM devices. Only one device
803 per system is supported at this time.
804
805 CONFIG_TPM_TIS_BASE_ADDRESS
806 Base address where the generic TPM device is mapped
807 to. Contemporary x86 systems usually map it at
808 0xfed40000.
809
Reinhard Pfaube6c1522013-06-26 15:55:13 +0200810 CONFIG_TPM
811 Define this to enable the TPM support library which provides
812 functional interfaces to some TPM commands.
813 Requires support for a TPM device.
814
815 CONFIG_TPM_AUTH_SESSIONS
816 Define this to enable authorized functions in the TPM library.
817 Requires CONFIG_TPM and CONFIG_SHA1.
818
wdenkc6097192002-11-03 00:24:07 +0000819- USB Support:
820 At the moment only the UHCI host controller is
Heiko Schocher064b55c2017-06-14 05:49:40 +0200821 supported (PIP405, MIP405); define
wdenkc6097192002-11-03 00:24:07 +0000822 CONFIG_USB_UHCI to enable it.
823 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
wdenk30d56fa2004-10-09 22:44:59 +0000824 and define CONFIG_USB_STORAGE to enable the USB
wdenkc6097192002-11-03 00:24:07 +0000825 storage devices.
826 Note:
827 Supported are USB Keyboards and USB Floppy drives
828 (TEAC FD-05PUB).
wdenk4d13cba2004-03-14 14:09:05 +0000829
Simon Glass9ab4ce22012-02-27 10:52:47 +0000830 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
831 txfilltuning field in the EHCI controller on reset.
832
Oleksandr Tymoshenko6e9e0622014-02-01 21:51:25 -0700833 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
834 HW module registers.
835
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200836- USB Device:
837 Define the below if you wish to use the USB console.
838 Once firmware is rebuilt from a serial console issue the
839 command "setenv stdin usbtty; setenv stdout usbtty" and
Marcel Ziswiler11ccc332008-07-09 08:17:15 +0200840 attach your USB cable. The Unix command "dmesg" should print
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200841 it has found a new device. The environment variable usbtty
842 can be set to gserial or cdc_acm to enable your device to
Wolfgang Denk386eda02006-06-14 18:14:56 +0200843 appear to a USB host as a Linux gserial device or a
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200844 Common Device Class Abstract Control Model serial device.
845 If you select usbtty = gserial you should be able to enumerate
846 a Linux host by
847 # modprobe usbserial vendor=0xVendorID product=0xProductID
848 else if using cdc_acm, simply setting the environment
849 variable usbtty to be cdc_acm should suffice. The following
850 might be defined in YourBoardName.h
Wolfgang Denk386eda02006-06-14 18:14:56 +0200851
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200852 CONFIG_USB_DEVICE
853 Define this to build a UDC device
wdenkc6097192002-11-03 00:24:07 +0000854
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200855 CONFIG_USB_TTY
856 Define this to have a tty type of device available to
857 talk to the UDC device
Wolfgang Denk386eda02006-06-14 18:14:56 +0200858
Vipin KUMARf9da0f82012-03-26 15:38:06 +0530859 CONFIG_USBD_HS
860 Define this to enable the high speed support for usb
861 device and usbtty. If this feature is enabled, a routine
862 int is_usbd_high_speed(void)
863 also needs to be defined by the driver to dynamically poll
864 whether the enumeration has succeded at high speed or full
865 speed.
866
Wolfgang Denk386eda02006-06-14 18:14:56 +0200867 If you have a USB-IF assigned VendorID then you may wish to
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200868 define your own vendor specific values either in BoardName.h
Wolfgang Denk386eda02006-06-14 18:14:56 +0200869 or directly in usbd_vendor_info.h. If you don't define
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200870 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
871 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
872 should pretend to be a Linux device to it's target host.
873
874 CONFIG_USBD_MANUFACTURER
875 Define this string as the name of your company for
876 - CONFIG_USBD_MANUFACTURER "my company"
Wolfgang Denk386eda02006-06-14 18:14:56 +0200877
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200878 CONFIG_USBD_PRODUCT_NAME
879 Define this string as the name of your product
880 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
881
882 CONFIG_USBD_VENDORID
883 Define this as your assigned Vendor ID from the USB
884 Implementors Forum. This *must* be a genuine Vendor ID
885 to avoid polluting the USB namespace.
886 - CONFIG_USBD_VENDORID 0xFFFF
Wolfgang Denk386eda02006-06-14 18:14:56 +0200887
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200888 CONFIG_USBD_PRODUCTID
889 Define this as the unique Product ID
890 for your device
891 - CONFIG_USBD_PRODUCTID 0xFFFF
wdenkc6097192002-11-03 00:24:07 +0000892
Igor Grinbergd70a5602011-12-12 12:08:35 +0200893- ULPI Layer Support:
894 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
895 the generic ULPI layer. The generic layer accesses the ULPI PHY
896 via the platform viewport, so you need both the genric layer and
897 the viewport enabled. Currently only Chipidea/ARC based
898 viewport is supported.
899 To enable the ULPI layer support, define CONFIG_USB_ULPI and
900 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
Lucas Stach6d365ea2012-10-01 00:44:35 +0200901 If your ULPI phy needs a different reference clock than the
902 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
903 the appropriate value in Hz.
wdenkc6097192002-11-03 00:24:07 +0000904
905- MMC Support:
906 The MMC controller on the Intel PXA is supported. To
907 enable this define CONFIG_MMC. The MMC can be
908 accessed from the boot prompt by mapping the device
909 to physical memory similar to flash. Command line is
Jon Loeliger602ad3b2007-06-11 19:03:39 -0500910 enabled with CONFIG_CMD_MMC. The MMC driver also works with
911 the FAT fs. This is enabled with CONFIG_CMD_FAT.
wdenkc6097192002-11-03 00:24:07 +0000912
Yoshihiro Shimodaafb35662011-07-04 22:21:22 +0000913 CONFIG_SH_MMCIF
914 Support for Renesas on-chip MMCIF controller
915
916 CONFIG_SH_MMCIF_ADDR
917 Define the base address of MMCIF registers
918
919 CONFIG_SH_MMCIF_CLK
920 Define the clock frequency for MMCIF
921
Tom Rinib3ba6e92013-03-14 05:32:47 +0000922- USB Device Firmware Update (DFU) class support:
Marek Vasutbb4059a2018-02-16 16:41:18 +0100923 CONFIG_DFU_OVER_USB
Tom Rinib3ba6e92013-03-14 05:32:47 +0000924 This enables the USB portion of the DFU USB class
925
Pantelis Antoniouc6631762013-03-14 05:32:52 +0000926 CONFIG_DFU_NAND
927 This enables support for exposing NAND devices via DFU.
928
Afzal Mohammeda9479f02013-09-18 01:15:24 +0530929 CONFIG_DFU_RAM
930 This enables support for exposing RAM via DFU.
931 Note: DFU spec refer to non-volatile memory usage, but
932 allow usages beyond the scope of spec - here RAM usage,
933 one that would help mostly the developer.
934
Heiko Schochere7e75c72013-06-12 06:05:51 +0200935 CONFIG_SYS_DFU_DATA_BUF_SIZE
936 Dfu transfer uses a buffer before writing data to the
937 raw storage device. Make the size (in bytes) of this buffer
938 configurable. The size of this buffer is also configurable
939 through the "dfu_bufsiz" environment variable.
940
Pantelis Antoniouea2453d2013-03-14 05:32:48 +0000941 CONFIG_SYS_DFU_MAX_FILE_SIZE
942 When updating files rather than the raw storage device,
943 we use a static buffer to copy the file into and then write
944 the buffer once we've been given the whole file. Define
945 this to the maximum filesize (in bytes) for the buffer.
946 Default is 4 MiB if undefined.
947
Heiko Schocher001a8312014-03-18 08:09:56 +0100948 DFU_DEFAULT_POLL_TIMEOUT
949 Poll timeout [ms], is the timeout a device can send to the
950 host. The host must wait for this timeout before sending
951 a subsequent DFU_GET_STATUS request to the device.
952
953 DFU_MANIFEST_POLL_TIMEOUT
954 Poll timeout [ms], which the device sends to the host when
955 entering dfuMANIFEST state. Host waits this timeout, before
956 sending again an USB request to the device.
957
wdenk6705d812004-08-02 23:22:59 +0000958- Journaling Flash filesystem support:
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200959 CONFIG_SYS_JFFS2_FIRST_SECTOR,
960 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
wdenk6705d812004-08-02 23:22:59 +0000961 Define these for a default partition on a NOR device
962
wdenkc6097192002-11-03 00:24:07 +0000963- Keyboard Support:
Simon Glass39f615e2015-11-11 10:05:47 -0700964 See Kconfig help for available keyboard drivers.
965
wdenkc6097192002-11-03 00:24:07 +0000966- LCD Support: CONFIG_LCD
967
968 Define this to enable LCD support (for output to LCD
969 display); also select one of the supported displays
970 by defining one of these:
971
wdenkfd3103b2003-11-25 16:55:19 +0000972 CONFIG_NEC_NL6448AC33:
wdenkc6097192002-11-03 00:24:07 +0000973
wdenkfd3103b2003-11-25 16:55:19 +0000974 NEC NL6448AC33-18. Active, color, single scan.
wdenkc6097192002-11-03 00:24:07 +0000975
wdenkfd3103b2003-11-25 16:55:19 +0000976 CONFIG_NEC_NL6448BC20
wdenkc6097192002-11-03 00:24:07 +0000977
wdenkfd3103b2003-11-25 16:55:19 +0000978 NEC NL6448BC20-08. 6.5", 640x480.
979 Active, color, single scan.
980
981 CONFIG_NEC_NL6448BC33_54
982
983 NEC NL6448BC33-54. 10.4", 640x480.
wdenkc6097192002-11-03 00:24:07 +0000984 Active, color, single scan.
985
986 CONFIG_SHARP_16x9
987
988 Sharp 320x240. Active, color, single scan.
989 It isn't 16x9, and I am not sure what it is.
990
991 CONFIG_SHARP_LQ64D341
992
993 Sharp LQ64D341 display, 640x480.
994 Active, color, single scan.
995
996 CONFIG_HLD1045
997
998 HLD1045 display, 640x480.
999 Active, color, single scan.
1000
1001 CONFIG_OPTREX_BW
1002
1003 Optrex CBL50840-2 NF-FW 99 22 M5
1004 or
1005 Hitachi LMG6912RPFC-00T
1006 or
1007 Hitachi SP14Q002
1008
1009 320x240. Black & white.
1010
Simon Glass676d3192012-10-17 13:24:54 +00001011 CONFIG_LCD_ALIGNMENT
1012
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001013 Normally the LCD is page-aligned (typically 4KB). If this is
Simon Glass676d3192012-10-17 13:24:54 +00001014 defined then the LCD will be aligned to this value instead.
1015 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1016 here, since it is cheaper to change data cache settings on
1017 a per-section basis.
1018
1019
Hannes Petermaier604c7d42015-03-27 08:01:38 +01001020 CONFIG_LCD_ROTATION
1021
1022 Sometimes, for example if the display is mounted in portrait
1023 mode or even if it's mounted landscape but rotated by 180degree,
1024 we need to rotate our content of the display relative to the
1025 framebuffer, so that user can read the messages which are
1026 printed out.
1027 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1028 initialized with a given rotation from "vl_rot" out of
1029 "vidinfo_t" which is provided by the board specific code.
1030 The value for vl_rot is coded as following (matching to
1031 fbcon=rotate:<n> linux-kernel commandline):
1032 0 = no rotation respectively 0 degree
1033 1 = 90 degree rotation
1034 2 = 180 degree rotation
1035 3 = 270 degree rotation
1036
1037 If CONFIG_LCD_ROTATION is not defined, the console will be
1038 initialized with 0degree rotation.
1039
wdenk17ea1172004-06-06 21:51:03 +00001040- MII/PHY support:
wdenk17ea1172004-06-06 21:51:03 +00001041 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1042
1043 The clock frequency of the MII bus
1044
wdenk17ea1172004-06-06 21:51:03 +00001045 CONFIG_PHY_CMD_DELAY (ppc4xx)
1046
1047 Some PHY like Intel LXT971A need extra delay after
1048 command issued before MII status register can be read
1049
wdenkc6097192002-11-03 00:24:07 +00001050- IP address:
1051 CONFIG_IPADDR
1052
1053 Define a default value for the IP address to use for
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001054 the default Ethernet interface, in case this is not
wdenkc6097192002-11-03 00:24:07 +00001055 determined through e.g. bootp.
Wolfgang Denk1ebcd652011-10-26 10:21:22 +00001056 (Environment variable "ipaddr")
wdenkc6097192002-11-03 00:24:07 +00001057
1058- Server IP address:
1059 CONFIG_SERVERIP
1060
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001061 Defines a default value for the IP address of a TFTP
wdenkc6097192002-11-03 00:24:07 +00001062 server to contact when using the "tftboot" command.
Wolfgang Denk1ebcd652011-10-26 10:21:22 +00001063 (Environment variable "serverip")
wdenkc6097192002-11-03 00:24:07 +00001064
Wolfgang Denk1ebcd652011-10-26 10:21:22 +00001065- Gateway IP address:
1066 CONFIG_GATEWAYIP
1067
1068 Defines a default value for the IP address of the
1069 default router where packets to other networks are
1070 sent to.
1071 (Environment variable "gatewayip")
1072
1073- Subnet mask:
1074 CONFIG_NETMASK
1075
1076 Defines a default value for the subnet mask (or
1077 routing prefix) which is used to determine if an IP
1078 address belongs to the local subnet or needs to be
1079 forwarded through a router.
1080 (Environment variable "netmask")
1081
wdenkc6097192002-11-03 00:24:07 +00001082- BOOTP Recovery Mode:
1083 CONFIG_BOOTP_RANDOM_DELAY
1084
1085 If you have many targets in a network that try to
1086 boot using BOOTP, you may want to avoid that all
1087 systems send out BOOTP requests at precisely the same
1088 moment (which would happen for instance at recovery
1089 from a power failure, when all systems will try to
1090 boot, thus flooding the BOOTP server. Defining
1091 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1092 inserted before sending out BOOTP requests. The
Wolfgang Denk6c33c782007-08-06 23:21:05 +02001093 following delays are inserted then:
wdenkc6097192002-11-03 00:24:07 +00001094
1095 1st BOOTP request: delay 0 ... 1 sec
1096 2nd BOOTP request: delay 0 ... 2 sec
1097 3rd BOOTP request: delay 0 ... 4 sec
1098 4th and following
1099 BOOTP requests: delay 0 ... 8 sec
1100
Thierry Reding92ac8ac2014-08-19 10:21:24 +02001101 CONFIG_BOOTP_ID_CACHE_SIZE
1102
1103 BOOTP packets are uniquely identified using a 32-bit ID. The
1104 server will copy the ID from client requests to responses and
1105 U-Boot will use this to determine if it is the destination of
1106 an incoming response. Some servers will check that addresses
1107 aren't in use before handing them out (usually using an ARP
1108 ping) and therefore take up to a few hundred milliseconds to
1109 respond. Network congestion may also influence the time it
1110 takes for a response to make it back to the client. If that
1111 time is too long, U-Boot will retransmit requests. In order
1112 to allow earlier responses to still be accepted after these
1113 retransmissions, U-Boot's BOOTP client keeps a small cache of
1114 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
1115 cache. The default is to keep IDs for up to four outstanding
1116 requests. Increasing this will allow U-Boot to accept offers
1117 from a BOOTP client in networks with unusually high latency.
1118
stroesefe389a82003-08-28 14:17:32 +00001119- DHCP Advanced Options:
Joe Hershberger2c00e092012-05-23 07:59:19 +00001120
Joe Hershbergerd22c3382012-05-23 08:00:12 +00001121 - Link-local IP address negotiation:
1122 Negotiate with other link-local clients on the local network
1123 for an address that doesn't require explicit configuration.
1124 This is especially useful if a DHCP server cannot be guaranteed
1125 to exist in all environments that the device must operate.
1126
1127 See doc/README.link-local for more information.
1128
Prabhakar Kushwaha24acb832017-11-23 16:51:32 +05301129 - MAC address from environment variables
1130
1131 FDT_SEQ_MACADDR_FROM_ENV
1132
1133 Fix-up device tree with MAC addresses fetched sequentially from
1134 environment variables. This config work on assumption that
1135 non-usable ethernet node of device-tree are either not present
1136 or their status has been marked as "disabled".
1137
wdenka3d991b2004-04-15 21:48:45 +00001138 - CDP Options:
wdenk6e592382004-04-18 17:39:38 +00001139 CONFIG_CDP_DEVICE_ID
wdenka3d991b2004-04-15 21:48:45 +00001140
1141 The device id used in CDP trigger frames.
1142
1143 CONFIG_CDP_DEVICE_ID_PREFIX
1144
1145 A two character string which is prefixed to the MAC address
1146 of the device.
1147
1148 CONFIG_CDP_PORT_ID
1149
1150 A printf format string which contains the ascii name of
1151 the port. Normally is set to "eth%d" which sets
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001152 eth0 for the first Ethernet, eth1 for the second etc.
wdenka3d991b2004-04-15 21:48:45 +00001153
1154 CONFIG_CDP_CAPABILITIES
1155
1156 A 32bit integer which indicates the device capabilities;
1157 0x00000010 for a normal host which does not forwards.
1158
1159 CONFIG_CDP_VERSION
1160
1161 An ascii string containing the version of the software.
1162
1163 CONFIG_CDP_PLATFORM
1164
1165 An ascii string containing the name of the platform.
1166
1167 CONFIG_CDP_TRIGGER
1168
1169 A 32bit integer sent on the trigger.
1170
1171 CONFIG_CDP_POWER_CONSUMPTION
1172
1173 A 16bit integer containing the power consumption of the
1174 device in .1 of milliwatts.
1175
1176 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1177
1178 A byte containing the id of the VLAN.
1179
Uri Mashiach79267ed2017-01-19 10:51:05 +02001180- Status LED: CONFIG_LED_STATUS
wdenkc6097192002-11-03 00:24:07 +00001181
1182 Several configurations allow to display the current
1183 status using a LED. For instance, the LED will blink
1184 fast while running U-Boot code, stop blinking as
1185 soon as a reply to a BOOTP request was received, and
1186 start blinking slow once the Linux kernel is running
1187 (supported by a status LED driver in the Linux
Uri Mashiach79267ed2017-01-19 10:51:05 +02001188 kernel). Defining CONFIG_LED_STATUS enables this
wdenkc6097192002-11-03 00:24:07 +00001189 feature in U-Boot.
1190
Igor Grinberg1df7bbb2013-11-08 01:03:50 +02001191 Additional options:
1192
Uri Mashiach79267ed2017-01-19 10:51:05 +02001193 CONFIG_LED_STATUS_GPIO
Igor Grinberg1df7bbb2013-11-08 01:03:50 +02001194 The status LED can be connected to a GPIO pin.
1195 In such cases, the gpio_led driver can be used as a
Uri Mashiach79267ed2017-01-19 10:51:05 +02001196 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO
Igor Grinberg1df7bbb2013-11-08 01:03:50 +02001197 to include the gpio_led driver in the U-Boot binary.
1198
Igor Grinberg9dfdcdf2013-11-08 01:03:52 +02001199 CONFIG_GPIO_LED_INVERTED_TABLE
1200 Some GPIO connected LEDs may have inverted polarity in which
1201 case the GPIO high value corresponds to LED off state and
1202 GPIO low value corresponds to LED on state.
1203 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
1204 with a list of GPIO LEDs that have inverted polarity.
1205
Tom Rini55dabcc2021-08-18 23:12:24 -04001206- I2C Support:
Heiko Schocher3f4978c2012-01-16 21:12:24 +00001207 CONFIG_SYS_NUM_I2C_BUSES
Simon Glass945a18e2016-10-02 18:01:05 -06001208 Hold the number of i2c buses you want to use.
Heiko Schocher3f4978c2012-01-16 21:12:24 +00001209
1210 CONFIG_SYS_I2C_DIRECT_BUS
1211 define this, if you don't use i2c muxes on your hardware.
1212 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
1213 omit this define.
1214
1215 CONFIG_SYS_I2C_MAX_HOPS
1216 define how many muxes are maximal consecutively connected
1217 on one i2c bus. If you not use i2c muxes, omit this
1218 define.
1219
1220 CONFIG_SYS_I2C_BUSES
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001221 hold a list of buses you want to use, only used if
Heiko Schocher3f4978c2012-01-16 21:12:24 +00001222 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
1223 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
1224 CONFIG_SYS_NUM_I2C_BUSES = 9:
1225
1226 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
1227 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
1228 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
1229 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
1230 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
1231 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
1232 {1, {I2C_NULL_HOP}}, \
1233 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
1234 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
1235 }
1236
1237 which defines
1238 bus 0 on adapter 0 without a mux
Heiko Schocherea818db2013-01-29 08:53:15 +01001239 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
1240 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
1241 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
1242 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
1243 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
Heiko Schocher3f4978c2012-01-16 21:12:24 +00001244 bus 6 on adapter 1 without a mux
Heiko Schocherea818db2013-01-29 08:53:15 +01001245 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
1246 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
Heiko Schocher3f4978c2012-01-16 21:12:24 +00001247
1248 If you do not have i2c muxes on your board, omit this define.
1249
Simon Glassce3b5d62017-05-12 21:10:00 -06001250- Legacy I2C Support:
Heiko Schocherea818db2013-01-29 08:53:15 +01001251 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
wdenkb37c7e52003-06-30 16:24:52 +00001252 then the following macros need to be defined (examples are
1253 from include/configs/lwmon.h):
wdenkc6097192002-11-03 00:24:07 +00001254
1255 I2C_INIT
1256
wdenkb37c7e52003-06-30 16:24:52 +00001257 (Optional). Any commands necessary to enable the I2C
wdenk43d96162003-03-06 00:02:04 +00001258 controller or configure ports.
wdenkc6097192002-11-03 00:24:07 +00001259
wdenkba56f622004-02-06 23:19:44 +00001260 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
wdenkb37c7e52003-06-30 16:24:52 +00001261
wdenkc6097192002-11-03 00:24:07 +00001262 I2C_ACTIVE
1263
1264 The code necessary to make the I2C data line active
1265 (driven). If the data line is open collector, this
1266 define can be null.
1267
wdenkb37c7e52003-06-30 16:24:52 +00001268 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1269
wdenkc6097192002-11-03 00:24:07 +00001270 I2C_TRISTATE
1271
1272 The code necessary to make the I2C data line tri-stated
1273 (inactive). If the data line is open collector, this
1274 define can be null.
1275
wdenkb37c7e52003-06-30 16:24:52 +00001276 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1277
wdenkc6097192002-11-03 00:24:07 +00001278 I2C_READ
1279
York Sun472d5462013-04-01 11:29:11 -07001280 Code that returns true if the I2C data line is high,
1281 false if it is low.
wdenkc6097192002-11-03 00:24:07 +00001282
wdenkb37c7e52003-06-30 16:24:52 +00001283 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1284
wdenkc6097192002-11-03 00:24:07 +00001285 I2C_SDA(bit)
1286
York Sun472d5462013-04-01 11:29:11 -07001287 If <bit> is true, sets the I2C data line high. If it
1288 is false, it clears it (low).
wdenkc6097192002-11-03 00:24:07 +00001289
wdenkb37c7e52003-06-30 16:24:52 +00001290 eg: #define I2C_SDA(bit) \
wdenk2535d602003-07-17 23:16:40 +00001291 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
wdenkba56f622004-02-06 23:19:44 +00001292 else immr->im_cpm.cp_pbdat &= ~PB_SDA
wdenkb37c7e52003-06-30 16:24:52 +00001293
wdenkc6097192002-11-03 00:24:07 +00001294 I2C_SCL(bit)
1295
York Sun472d5462013-04-01 11:29:11 -07001296 If <bit> is true, sets the I2C clock line high. If it
1297 is false, it clears it (low).
wdenkc6097192002-11-03 00:24:07 +00001298
wdenkb37c7e52003-06-30 16:24:52 +00001299 eg: #define I2C_SCL(bit) \
wdenk2535d602003-07-17 23:16:40 +00001300 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
wdenkba56f622004-02-06 23:19:44 +00001301 else immr->im_cpm.cp_pbdat &= ~PB_SCL
wdenkb37c7e52003-06-30 16:24:52 +00001302
wdenkc6097192002-11-03 00:24:07 +00001303 I2C_DELAY
1304
1305 This delay is invoked four times per clock cycle so this
1306 controls the rate of data transfer. The data rate thus
wdenkb37c7e52003-06-30 16:24:52 +00001307 is 1 / (I2C_DELAY * 4). Often defined to be something
wdenk945af8d2003-07-16 21:53:01 +00001308 like:
1309
wdenkb37c7e52003-06-30 16:24:52 +00001310 #define I2C_DELAY udelay(2)
wdenkc6097192002-11-03 00:24:07 +00001311
Mike Frysinger793b5722010-07-21 13:38:02 -04001312 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1313
1314 If your arch supports the generic GPIO framework (asm/gpio.h),
1315 then you may alternatively define the two GPIOs that are to be
1316 used as SCL / SDA. Any of the previous I2C_xxx macros will
1317 have GPIO-based defaults assigned to them as appropriate.
1318
1319 You should define these to the GPIO value as given directly to
1320 the generic GPIO functions.
1321
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001322 CONFIG_SYS_I2C_INIT_BOARD
wdenk47cd00f2003-03-06 13:39:27 +00001323
wdenk8bde7f72003-06-27 21:31:46 +00001324 When a board is reset during an i2c bus transfer
1325 chips might think that the current transfer is still
1326 in progress. On some boards it is possible to access
1327 the i2c SCLK line directly, either by using the
1328 processor pin as a GPIO or by having a second pin
1329 connected to the bus. If this option is defined a
1330 custom i2c_init_board() routine in boards/xxx/board.c
1331 is run early in the boot sequence.
wdenk47cd00f2003-03-06 13:39:27 +00001332
Ben Warrenbb99ad62006-09-07 16:50:54 -04001333 CONFIG_I2C_MULTI_BUS
1334
1335 This option allows the use of multiple I2C buses, each of which
Wolfgang Denkc0f40852011-10-26 10:21:21 +00001336 must have a controller. At any point in time, only one bus is
1337 active. To switch to a different bus, use the 'i2c dev' command.
Ben Warrenbb99ad62006-09-07 16:50:54 -04001338 Note that bus numbering is zero-based.
1339
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001340 CONFIG_SYS_I2C_NOPROBES
Ben Warrenbb99ad62006-09-07 16:50:54 -04001341
1342 This option specifies a list of I2C devices that will be skipped
Wolfgang Denkc0f40852011-10-26 10:21:21 +00001343 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
Peter Tyser0f89c542009-04-18 22:34:03 -05001344 is set, specify a list of bus-device pairs. Otherwise, specify
1345 a 1D array of device addresses
Ben Warrenbb99ad62006-09-07 16:50:54 -04001346
1347 e.g.
1348 #undef CONFIG_I2C_MULTI_BUS
Wolfgang Denkc0f40852011-10-26 10:21:21 +00001349 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
Ben Warrenbb99ad62006-09-07 16:50:54 -04001350
1351 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1352
Wolfgang Denkc0f40852011-10-26 10:21:21 +00001353 #define CONFIG_I2C_MULTI_BUS
Simon Glass945a18e2016-10-02 18:01:05 -06001354 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
Ben Warrenbb99ad62006-09-07 16:50:54 -04001355
1356 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1357
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001358 CONFIG_SYS_SPD_BUS_NUM
Timur Tabibe5e6182006-11-03 19:15:00 -06001359
1360 If defined, then this indicates the I2C bus number for DDR SPD.
1361 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1362
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001363 CONFIG_SYS_RTC_BUS_NUM
Stefan Roese0dc018e2007-02-20 10:51:26 +01001364
1365 If defined, then this indicates the I2C bus number for the RTC.
1366 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1367
Andrew Dyer2ac69852008-12-29 17:36:01 -06001368 CONFIG_SOFT_I2C_READ_REPEATED_START
1369
1370 defining this will force the i2c_read() function in
1371 the soft_i2c driver to perform an I2C repeated start
1372 between writing the address pointer and reading the
1373 data. If this define is omitted the default behaviour
1374 of doing a stop-start sequence will be used. Most I2C
1375 devices can use either method, but some require one or
1376 the other.
Timur Tabibe5e6182006-11-03 19:15:00 -06001377
wdenkc6097192002-11-03 00:24:07 +00001378- SPI Support: CONFIG_SPI
1379
1380 Enables SPI driver (so far only tested with
1381 SPI EEPROM, also an instance works with Crystal A/D and
1382 D/As on the SACSng board)
1383
Heiko Schocherf659b572014-07-14 10:22:11 +02001384 CONFIG_SYS_SPI_MXC_WAIT
1385 Timeout for waiting until spi transfer completed.
1386 default: (CONFIG_SYS_HZ/100) /* 10 ms */
1387
Matthias Fuchs01335022007-12-27 17:12:34 +01001388- FPGA Support: CONFIG_FPGA
1389
1390 Enables FPGA subsystem.
1391
1392 CONFIG_FPGA_<vendor>
1393
1394 Enables support for specific chip vendors.
1395 (ALTERA, XILINX)
1396
1397 CONFIG_FPGA_<family>
1398
1399 Enables support for FPGA family.
1400 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1401
1402 CONFIG_FPGA_COUNT
wdenkc6097192002-11-03 00:24:07 +00001403
wdenk43d96162003-03-06 00:02:04 +00001404 Specify the number of FPGA devices to support.
wdenkc6097192002-11-03 00:24:07 +00001405
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001406 CONFIG_SYS_FPGA_PROG_FEEDBACK
wdenkc6097192002-11-03 00:24:07 +00001407
wdenk8bde7f72003-06-27 21:31:46 +00001408 Enable printing of hash marks during FPGA configuration.
wdenkc6097192002-11-03 00:24:07 +00001409
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001410 CONFIG_SYS_FPGA_CHECK_BUSY
wdenkc6097192002-11-03 00:24:07 +00001411
wdenk43d96162003-03-06 00:02:04 +00001412 Enable checks on FPGA configuration interface busy
1413 status by the configuration function. This option
1414 will require a board or device specific function to
1415 be written.
wdenkc6097192002-11-03 00:24:07 +00001416
1417 CONFIG_FPGA_DELAY
1418
1419 If defined, a function that provides delays in the FPGA
1420 configuration driver.
1421
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001422 CONFIG_SYS_FPGA_CHECK_CTRLC
wdenkc6097192002-11-03 00:24:07 +00001423 Allow Control-C to interrupt FPGA configuration
1424
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001425 CONFIG_SYS_FPGA_CHECK_ERROR
wdenkc6097192002-11-03 00:24:07 +00001426
wdenk43d96162003-03-06 00:02:04 +00001427 Check for configuration errors during FPGA bitfile
1428 loading. For example, abort during Virtex II
1429 configuration if the INIT_B line goes low (which
1430 indicated a CRC error).
wdenkc6097192002-11-03 00:24:07 +00001431
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001432 CONFIG_SYS_FPGA_WAIT_INIT
wdenkc6097192002-11-03 00:24:07 +00001433
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001434 Maximum time to wait for the INIT_B line to de-assert
1435 after PROB_B has been de-asserted during a Virtex II
wdenk43d96162003-03-06 00:02:04 +00001436 FPGA configuration sequence. The default time is 500
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001437 ms.
wdenkc6097192002-11-03 00:24:07 +00001438
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001439 CONFIG_SYS_FPGA_WAIT_BUSY
wdenkc6097192002-11-03 00:24:07 +00001440
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001441 Maximum time to wait for BUSY to de-assert during
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001442 Virtex II FPGA configuration. The default is 5 ms.
wdenkc6097192002-11-03 00:24:07 +00001443
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001444 CONFIG_SYS_FPGA_WAIT_CONFIG
wdenkc6097192002-11-03 00:24:07 +00001445
wdenk43d96162003-03-06 00:02:04 +00001446 Time to wait after FPGA configuration. The default is
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001447 200 ms.
wdenkc6097192002-11-03 00:24:07 +00001448
wdenkc6097192002-11-03 00:24:07 +00001449- Vendor Parameter Protection:
1450
wdenk43d96162003-03-06 00:02:04 +00001451 U-Boot considers the values of the environment
1452 variables "serial#" (Board Serial Number) and
wdenk7152b1d2003-09-05 23:19:14 +00001453 "ethaddr" (Ethernet Address) to be parameters that
wdenk43d96162003-03-06 00:02:04 +00001454 are set once by the board vendor / manufacturer, and
1455 protects these variables from casual modification by
1456 the user. Once set, these variables are read-only,
1457 and write or delete attempts are rejected. You can
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001458 change this behaviour:
wdenkc6097192002-11-03 00:24:07 +00001459
1460 If CONFIG_ENV_OVERWRITE is #defined in your config
1461 file, the write protection for vendor parameters is
wdenk47cd00f2003-03-06 13:39:27 +00001462 completely disabled. Anybody can change or delete
wdenkc6097192002-11-03 00:24:07 +00001463 these parameters.
1464
Joe Hershberger92ac5202015-05-04 14:55:14 -05001465 Alternatively, if you define _both_ an ethaddr in the
1466 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001467 Ethernet address is installed in the environment,
wdenkc6097192002-11-03 00:24:07 +00001468 which can be changed exactly ONCE by the user. [The
1469 serial# is unaffected by this, i. e. it remains
1470 read-only.]
1471
Joe Hershberger25980902012-12-11 22:16:31 -06001472 The same can be accomplished in a more flexible way
1473 for any variable by configuring the type of access
1474 to allow for those variables in the ".flags" variable
1475 or define CONFIG_ENV_FLAGS_LIST_STATIC.
1476
wdenkc6097192002-11-03 00:24:07 +00001477- Protected RAM:
1478 CONFIG_PRAM
1479
1480 Define this variable to enable the reservation of
1481 "protected RAM", i. e. RAM which is not overwritten
1482 by U-Boot. Define CONFIG_PRAM to hold the number of
1483 kB you want to reserve for pRAM. You can overwrite
1484 this default value by defining an environment
1485 variable "pram" to the number of kB you want to
1486 reserve. Note that the board info structure will
1487 still show the full amount of RAM. If pRAM is
1488 reserved, a new environment variable "mem" will
1489 automatically be defined to hold the amount of
1490 remaining RAM in a form that can be passed as boot
1491 argument to Linux, for instance like that:
1492
Wolfgang Denkfe126d82005-11-20 21:40:11 +01001493 setenv bootargs ... mem=\${mem}
wdenkc6097192002-11-03 00:24:07 +00001494 saveenv
1495
1496 This way you can tell Linux not to use this memory,
1497 either, which results in a memory region that will
1498 not be affected by reboots.
1499
1500 *WARNING* If your board configuration uses automatic
1501 detection of the RAM size, you must make sure that
1502 this memory test is non-destructive. So far, the
1503 following board configurations are known to be
1504 "pRAM-clean":
1505
Heiko Schocher5b8e76c2017-06-07 17:33:09 +02001506 IVMS8, IVML24, SPD8xx,
Wolfgang Denk1b0757e2012-10-24 02:36:15 +00001507 HERMES, IP860, RPXlite, LWMON,
Heiko Schocher2eb48ff2017-06-07 17:33:10 +02001508 FLAGADM
wdenkc6097192002-11-03 00:24:07 +00001509
1510- Error Recovery:
wdenkc6097192002-11-03 00:24:07 +00001511 Note:
1512
wdenk8bde7f72003-06-27 21:31:46 +00001513 In the current implementation, the local variables
1514 space and global environment variables space are
1515 separated. Local variables are those you define by
1516 simply typing `name=value'. To access a local
1517 variable later on, you have write `$name' or
1518 `${name}'; to execute the contents of a variable
1519 directly type `$name' at the command prompt.
wdenkc6097192002-11-03 00:24:07 +00001520
wdenk43d96162003-03-06 00:02:04 +00001521 Global environment variables are those you use
1522 setenv/printenv to work with. To run a command stored
1523 in such a variable, you need to use the run command,
1524 and you must not use the '$' sign to access them.
wdenkc6097192002-11-03 00:24:07 +00001525
1526 To store commands and special characters in a
1527 variable, please use double quotation marks
1528 surrounding the whole text of the variable, instead
1529 of the backslashes before semicolons and special
1530 symbols.
1531
wdenka8c7c702003-12-06 19:49:23 +00001532- Default Environment:
wdenkc6097192002-11-03 00:24:07 +00001533 CONFIG_EXTRA_ENV_SETTINGS
1534
wdenk43d96162003-03-06 00:02:04 +00001535 Define this to contain any number of null terminated
1536 strings (variable = value pairs) that will be part of
wdenk7152b1d2003-09-05 23:19:14 +00001537 the default environment compiled into the boot image.
wdenk2262cfe2002-11-18 00:14:45 +00001538
wdenk43d96162003-03-06 00:02:04 +00001539 For example, place something like this in your
1540 board's config file:
wdenkc6097192002-11-03 00:24:07 +00001541
1542 #define CONFIG_EXTRA_ENV_SETTINGS \
1543 "myvar1=value1\0" \
1544 "myvar2=value2\0"
1545
wdenk43d96162003-03-06 00:02:04 +00001546 Warning: This method is based on knowledge about the
1547 internal format how the environment is stored by the
1548 U-Boot code. This is NOT an official, exported
1549 interface! Although it is unlikely that this format
wdenk7152b1d2003-09-05 23:19:14 +00001550 will change soon, there is no guarantee either.
wdenkc6097192002-11-03 00:24:07 +00001551 You better know what you are doing here.
1552
wdenk43d96162003-03-06 00:02:04 +00001553 Note: overly (ab)use of the default environment is
1554 discouraged. Make sure to check other ways to preset
Wolfgang Denk74de7ae2009-04-01 23:34:12 +02001555 the environment like the "source" command or the
wdenk43d96162003-03-06 00:02:04 +00001556 boot command first.
wdenkc6097192002-11-03 00:24:07 +00001557
Simon Glass06fd8532012-11-30 13:01:17 +00001558 CONFIG_DELAY_ENVIRONMENT
1559
1560 Normally the environment is loaded when the board is
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001561 initialised so that it is available to U-Boot. This inhibits
Simon Glass06fd8532012-11-30 13:01:17 +00001562 that so that the environment is not available until
1563 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
1564 this is instead controlled by the value of
1565 /config/load-environment.
1566
Wolfgang Denk4cf26092011-10-07 09:58:21 +02001567 CONFIG_STANDALONE_LOAD_ADDR
1568
Wolfgang Denk6feff892011-10-09 21:06:34 +02001569 This option defines a board specific value for the
1570 address where standalone program gets loaded, thus
1571 overwriting the architecture dependent default
Wolfgang Denk4cf26092011-10-07 09:58:21 +02001572 settings.
1573
1574- Frame Buffer Address:
1575 CONFIG_FB_ADDR
1576
1577 Define CONFIG_FB_ADDR if you want to use specific
Wolfgang Denk44a53b52013-01-03 00:43:59 +00001578 address for frame buffer. This is typically the case
1579 when using a graphics controller has separate video
1580 memory. U-Boot will then place the frame buffer at
1581 the given address instead of dynamically reserving it
1582 in system RAM by calling lcd_setmem(), which grabs
1583 the memory for the frame buffer depending on the
1584 configured panel size.
Wolfgang Denk4cf26092011-10-07 09:58:21 +02001585
1586 Please see board_init_f function.
1587
Detlev Zundelcccfc2a2009-12-01 17:16:19 +01001588- Automatic software updates via TFTP server
1589 CONFIG_UPDATE_TFTP
1590 CONFIG_UPDATE_TFTP_CNT_MAX
1591 CONFIG_UPDATE_TFTP_MSEC_MAX
1592
1593 These options enable and control the auto-update feature;
1594 for a more detailed description refer to doc/README.update.
1595
1596- MTD Support (mtdparts command, UBI support)
Heiko Schocherff94bc42014-06-24 10:10:04 +02001597 CONFIG_MTD_UBI_WL_THRESHOLD
1598 This parameter defines the maximum difference between the highest
1599 erase counter value and the lowest erase counter value of eraseblocks
1600 of UBI devices. When this threshold is exceeded, UBI starts performing
1601 wear leveling by means of moving data from eraseblock with low erase
1602 counter to eraseblocks with high erase counter.
1603
1604 The default value should be OK for SLC NAND flashes, NOR flashes and
1605 other flashes which have eraseblock life-cycle 100000 or more.
1606 However, in case of MLC NAND flashes which typically have eraseblock
1607 life-cycle less than 10000, the threshold should be lessened (e.g.,
1608 to 128 or 256, although it does not have to be power of 2).
1609
1610 default: 4096
Simon Glassc654b512014-10-23 18:58:54 -06001611
Heiko Schocherff94bc42014-06-24 10:10:04 +02001612 CONFIG_MTD_UBI_BEB_LIMIT
1613 This option specifies the maximum bad physical eraseblocks UBI
1614 expects on the MTD device (per 1024 eraseblocks). If the
1615 underlying flash does not admit of bad eraseblocks (e.g. NOR
1616 flash), this value is ignored.
1617
1618 NAND datasheets often specify the minimum and maximum NVM
1619 (Number of Valid Blocks) for the flashes' endurance lifetime.
1620 The maximum expected bad eraseblocks per 1024 eraseblocks
1621 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
1622 which gives 20 for most NANDs (MaxNVB is basically the total
1623 count of eraseblocks on the chip).
1624
1625 To put it differently, if this value is 20, UBI will try to
1626 reserve about 1.9% of physical eraseblocks for bad blocks
1627 handling. And that will be 1.9% of eraseblocks on the entire
1628 NAND chip, not just the MTD partition UBI attaches. This means
1629 that if you have, say, a NAND flash chip admits maximum 40 bad
1630 eraseblocks, and it is split on two MTD partitions of the same
1631 size, UBI will reserve 40 eraseblocks when attaching a
1632 partition.
1633
1634 default: 20
1635
1636 CONFIG_MTD_UBI_FASTMAP
1637 Fastmap is a mechanism which allows attaching an UBI device
1638 in nearly constant time. Instead of scanning the whole MTD device it
1639 only has to locate a checkpoint (called fastmap) on the device.
1640 The on-flash fastmap contains all information needed to attach
1641 the device. Using fastmap makes only sense on large devices where
1642 attaching by scanning takes long. UBI will not automatically install
1643 a fastmap on old images, but you can set the UBI parameter
1644 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
1645 that fastmap-enabled images are still usable with UBI implementations
1646 without fastmap support. On typical flash devices the whole fastmap
1647 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
1648
1649 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
1650 Set this parameter to enable fastmap automatically on images
1651 without a fastmap.
1652 default: 0
1653
Heiko Schocher0195a7b2015-10-22 06:19:21 +02001654 CONFIG_MTD_UBI_FM_DEBUG
1655 Enable UBI fastmap debug
1656 default: 0
1657
Daniel Schwierzeck6a11cf42011-07-18 07:48:07 +00001658- SPL framework
Wolfgang Denk04e5ae72011-09-11 21:24:09 +02001659 CONFIG_SPL
1660 Enable building of SPL globally.
Daniel Schwierzeck6a11cf42011-07-18 07:48:07 +00001661
Albert ARIBAUD6ebc3462013-04-12 05:14:30 +00001662 CONFIG_SPL_MAX_FOOTPRINT
1663 Maximum size in memory allocated to the SPL, BSS included.
1664 When defined, the linker checks that the actual memory
1665 used by SPL from _start to __bss_end does not exceed it.
Albert ARIBAUD8960af82013-04-14 04:48:38 +00001666 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
Albert ARIBAUD6ebc3462013-04-12 05:14:30 +00001667 must not be both defined at the same time.
1668
Tom Rini95579792012-02-14 07:29:40 +00001669 CONFIG_SPL_MAX_SIZE
Albert ARIBAUD6ebc3462013-04-12 05:14:30 +00001670 Maximum size of the SPL image (text, data, rodata, and
1671 linker lists sections), BSS excluded.
1672 When defined, the linker checks that the actual size does
1673 not exceed it.
Tom Rini95579792012-02-14 07:29:40 +00001674
Scott Wood94a45bb2012-09-20 19:05:12 -05001675 CONFIG_SPL_RELOC_TEXT_BASE
1676 Address to relocate to. If unspecified, this is equal to
1677 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
1678
Tom Rini95579792012-02-14 07:29:40 +00001679 CONFIG_SPL_BSS_START_ADDR
1680 Link address for the BSS within the SPL binary.
1681
1682 CONFIG_SPL_BSS_MAX_SIZE
Albert ARIBAUD6ebc3462013-04-12 05:14:30 +00001683 Maximum size in memory allocated to the SPL BSS.
1684 When defined, the linker checks that the actual memory used
1685 by SPL from __bss_start to __bss_end does not exceed it.
Albert ARIBAUD8960af82013-04-14 04:48:38 +00001686 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
Albert ARIBAUD6ebc3462013-04-12 05:14:30 +00001687 must not be both defined at the same time.
Tom Rini95579792012-02-14 07:29:40 +00001688
1689 CONFIG_SPL_STACK
1690 Adress of the start of the stack SPL will use
1691
Albert ARIBAUD \(3ADEV\)8c80eb32015-03-31 11:40:50 +02001692 CONFIG_SPL_PANIC_ON_RAW_IMAGE
1693 When defined, SPL will panic() if the image it has
1694 loaded does not have a signature.
1695 Defining this is useful when code which loads images
1696 in SPL cannot guarantee that absolutely all read errors
1697 will be caught.
1698 An example is the LPC32XX MLC NAND driver, which will
1699 consider that a completely unreadable NAND block is bad,
1700 and thus should be skipped silently.
1701
Scott Wood94a45bb2012-09-20 19:05:12 -05001702 CONFIG_SPL_RELOC_STACK
1703 Adress of the start of the stack SPL will use after
1704 relocation. If unspecified, this is equal to
1705 CONFIG_SPL_STACK.
1706
Tom Rini95579792012-02-14 07:29:40 +00001707 CONFIG_SYS_SPL_MALLOC_START
1708 Starting address of the malloc pool used in SPL.
Fabio Estevam9ac4fc82015-11-12 12:30:19 -02001709 When this option is set the full malloc is used in SPL and
1710 it is set up by spl_init() and before that, the simple malloc()
1711 can be used if CONFIG_SYS_MALLOC_F is defined.
Tom Rini95579792012-02-14 07:29:40 +00001712
1713 CONFIG_SYS_SPL_MALLOC_SIZE
1714 The size of the malloc pool used in SPL.
Daniel Schwierzeck6a11cf42011-07-18 07:48:07 +00001715
Tom Rini861a86f2012-08-13 11:37:56 -07001716 CONFIG_SPL_DISPLAY_PRINT
1717 For ARM, enable an optional function to print more information
1718 about the running system.
1719
Scott Wood4b919722012-09-20 16:35:21 -05001720 CONFIG_SPL_INIT_MINIMAL
1721 Arch init code should be built for a very small image
1722
Peter Korsgaard2b75b0a2013-05-13 08:36:29 +00001723 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
1724 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
1725 Sector and number of sectors to load kernel argument
1726 parameters from when MMC is being used in raw mode
1727 (for falcon mode)
1728
Guillaume GARDETfae81c72014-10-15 17:53:13 +02001729 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
1730 Filename to read to load U-Boot when reading from filesystem
1731
1732 CONFIG_SPL_FS_LOAD_KERNEL_NAME
Peter Korsgaard7ad2cc72013-05-13 08:36:27 +00001733 Filename to read to load kernel uImage when reading
Guillaume GARDETfae81c72014-10-15 17:53:13 +02001734 from filesystem (for Falcon mode)
Peter Korsgaard7ad2cc72013-05-13 08:36:27 +00001735
Guillaume GARDETfae81c72014-10-15 17:53:13 +02001736 CONFIG_SPL_FS_LOAD_ARGS_NAME
Peter Korsgaard7ad2cc72013-05-13 08:36:27 +00001737 Filename to read to load kernel argument parameters
Guillaume GARDETfae81c72014-10-15 17:53:13 +02001738 when reading from filesystem (for Falcon mode)
Peter Korsgaard7ad2cc72013-05-13 08:36:27 +00001739
Scott Wood06f60ae2012-12-06 13:33:17 +00001740 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
1741 Set this for NAND SPL on PPC mpc83xx targets, so that
1742 start.S waits for the rest of the SPL to load before
1743 continuing (the hardware starts execution after just
1744 loading the first page rather than the full 4K).
1745
Prabhakar Kushwaha651fcf62014-04-08 19:12:31 +05301746 CONFIG_SPL_SKIP_RELOCATE
1747 Avoid SPL relocation
1748
Thomas Gleixner6f4e7d32016-07-12 20:28:12 +02001749 CONFIG_SPL_UBI
1750 Support for a lightweight UBI (fastmap) scanner and
1751 loader
1752
Heiko Schocher0c3117b2014-10-31 08:31:00 +01001753 CONFIG_SPL_NAND_RAW_ONLY
1754 Support to boot only raw u-boot.bin images. Use this only
1755 if you need to save space.
1756
Ying Zhang7c8eea52013-08-16 15:16:12 +08001757 CONFIG_SPL_COMMON_INIT_DDR
1758 Set for common ddr init with serial presence detect in
1759 SPL binary.
1760
Tom Rini95579792012-02-14 07:29:40 +00001761 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
1762 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
1763 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
1764 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
1765 CONFIG_SYS_NAND_ECCBYTES
1766 Defines the size and behavior of the NAND that SPL uses
Scott Wood7d4b7952012-09-21 18:35:27 -05001767 to read U-Boot
Tom Rini95579792012-02-14 07:29:40 +00001768
Scott Wood7d4b7952012-09-21 18:35:27 -05001769 CONFIG_SYS_NAND_U_BOOT_DST
1770 Location in memory to load U-Boot to
1771
1772 CONFIG_SYS_NAND_U_BOOT_SIZE
1773 Size of image to load
Tom Rini95579792012-02-14 07:29:40 +00001774
1775 CONFIG_SYS_NAND_U_BOOT_START
Scott Wood7d4b7952012-09-21 18:35:27 -05001776 Entry point in loaded image to jump to
Tom Rini95579792012-02-14 07:29:40 +00001777
1778 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
1779 Define this if you need to first read the OOB and then the
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001780 data. This is used, for example, on davinci platforms.
Tom Rini95579792012-02-14 07:29:40 +00001781
Pavel Machekc57b9532012-08-30 22:42:11 +02001782 CONFIG_SPL_RAM_DEVICE
1783 Support for running image already present in ram, in SPL binary
1784
Scott Wood74752ba2012-12-06 13:33:16 +00001785 CONFIG_SPL_PAD_TO
Benoît Thébaudeau6113d3f2013-04-11 09:35:49 +00001786 Image offset to which the SPL should be padded before appending
1787 the SPL payload. By default, this is defined as
1788 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
1789 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
1790 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
Scott Wood74752ba2012-12-06 13:33:16 +00001791
Scott Woodca2fca22012-09-21 16:27:32 -05001792 CONFIG_SPL_TARGET
1793 Final target image containing SPL and payload. Some SPLs
1794 use an arch-specific makefile fragment instead, for
1795 example if more than one image needs to be produced.
1796
Marek Vasutb527b9c2018-05-13 00:22:52 +02001797 CONFIG_SPL_FIT_PRINT
Simon Glass87ebee32013-05-08 08:05:59 +00001798 Printing information about a FIT image adds quite a bit of
1799 code to SPL. So this is normally disabled in SPL. Use this
1800 option to re-enable it. This will affect the output of the
1801 bootm command when booting a FIT image.
1802
Ying Zhang3aa29de2013-08-16 15:16:15 +08001803- TPL framework
1804 CONFIG_TPL
1805 Enable building of TPL globally.
1806
1807 CONFIG_TPL_PAD_TO
1808 Image offset to which the TPL should be padded before appending
1809 the TPL payload. By default, this is defined as
Wolfgang Denk93e14592013-10-04 17:43:24 +02001810 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
1811 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
1812 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
Ying Zhang3aa29de2013-08-16 15:16:15 +08001813
wdenka8c7c702003-12-06 19:49:23 +00001814- Interrupt support (PPC):
1815
wdenkd4ca31c2004-01-02 14:00:00 +00001816 There are common interrupt_init() and timer_interrupt()
1817 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001818 for CPU specific initialization. interrupt_init_cpu()
wdenkd4ca31c2004-01-02 14:00:00 +00001819 should set decrementer_count to appropriate value. If
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001820 CPU resets decrementer automatically after interrupt
wdenkd4ca31c2004-01-02 14:00:00 +00001821 (ppc4xx) it should set decrementer_count to zero.
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001822 timer_interrupt() calls timer_interrupt_cpu() for CPU
wdenkd4ca31c2004-01-02 14:00:00 +00001823 specific handling. If board has watchdog / status_led
1824 / other_activity_monitor it works automatically from
1825 general timer_interrupt().
wdenka8c7c702003-12-06 19:49:23 +00001826
wdenkc6097192002-11-03 00:24:07 +00001827
Helmut Raiger9660e442011-10-20 04:19:47 +00001828Board initialization settings:
1829------------------------------
1830
1831During Initialization u-boot calls a number of board specific functions
1832to allow the preparation of board specific prerequisites, e.g. pin setup
1833before drivers are initialized. To enable these callbacks the
1834following configuration macros have to be defined. Currently this is
1835architecture specific, so please check arch/your_architecture/lib/board.c
1836typically in board_init_f() and board_init_r().
1837
1838- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
1839- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
1840- CONFIG_BOARD_LATE_INIT: Call board_late_init()
wdenkc6097192002-11-03 00:24:07 +00001841
wdenkc6097192002-11-03 00:24:07 +00001842Configuration Settings:
1843-----------------------
1844
Simon Glass4d979bf2019-12-28 10:45:10 -07001845- MEM_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
York Sun4d1fd7f2014-02-26 17:03:19 -08001846 Optionally it can be defined to support 64-bit memory commands.
1847
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001848- CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
wdenkc6097192002-11-03 00:24:07 +00001849 undefine this when you're short of memory.
1850
Peter Tyser2fb26042009-01-27 18:03:12 -06001851- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
1852 width of the commands listed in the 'help' command output.
1853
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001854- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
wdenkc6097192002-11-03 00:24:07 +00001855 prompt for user input.
1856
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001857- CONFIG_SYS_CBSIZE: Buffer size for input from the Console
wdenkc6097192002-11-03 00:24:07 +00001858
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001859- CONFIG_SYS_PBSIZE: Buffer size for Console output
wdenkc6097192002-11-03 00:24:07 +00001860
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001861- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
wdenkc6097192002-11-03 00:24:07 +00001862
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001863- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
wdenkc6097192002-11-03 00:24:07 +00001864 the application (usually a Linux kernel) when it is
1865 booted
1866
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001867- CONFIG_SYS_BAUDRATE_TABLE:
wdenkc6097192002-11-03 00:24:07 +00001868 List of legal baudrate settings for this board.
1869
York Sune8149522015-12-04 11:57:07 -08001870- CONFIG_SYS_MEM_RESERVE_SECURE
York Sune61a7532016-06-24 16:46:18 -07001871 Only implemented for ARMv8 for now.
York Sune8149522015-12-04 11:57:07 -08001872 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
1873 is substracted from total RAM and won't be reported to OS.
1874 This memory can be used as secure memory. A variable
York Sune61a7532016-06-24 16:46:18 -07001875 gd->arch.secure_ram is used to track the location. In systems
York Sune8149522015-12-04 11:57:07 -08001876 the RAM base is not zero, or RAM is divided into banks,
1877 this variable needs to be recalcuated to get the address.
1878
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001879- CONFIG_SYS_LOADS_BAUD_CHANGE:
wdenkc6097192002-11-03 00:24:07 +00001880 Enable temporary baudrate change while serial download
1881
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001882- CONFIG_SYS_SDRAM_BASE:
wdenkc6097192002-11-03 00:24:07 +00001883 Physical start address of SDRAM. _Must_ be 0 here.
1884
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001885- CONFIG_SYS_FLASH_BASE:
wdenkc6097192002-11-03 00:24:07 +00001886 Physical start address of Flash memory.
1887
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001888- CONFIG_SYS_MONITOR_LEN:
wdenk8bde7f72003-06-27 21:31:46 +00001889 Size of memory reserved for monitor code, used to
1890 determine _at_compile_time_ (!) if the environment is
1891 embedded within the U-Boot image, or in a separate
1892 flash sector.
wdenkc6097192002-11-03 00:24:07 +00001893
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001894- CONFIG_SYS_MALLOC_LEN:
wdenkc6097192002-11-03 00:24:07 +00001895 Size of DRAM reserved for malloc() use.
1896
Simon Glassd59476b2014-07-10 22:23:28 -06001897- CONFIG_SYS_MALLOC_F_LEN
1898 Size of the malloc() pool for use before relocation. If
1899 this is defined, then a very simple malloc() implementation
1900 will become available before relocation. The address is just
1901 below the global data, and the stack is moved down to make
1902 space.
1903
1904 This feature allocates regions with increasing addresses
1905 within the region. calloc() is supported, but realloc()
1906 is not available. free() is supported but does nothing.
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001907 The memory will be freed (or in fact just forgotten) when
Simon Glassd59476b2014-07-10 22:23:28 -06001908 U-Boot relocates itself.
1909
Simon Glass38687ae2014-11-10 17:16:54 -07001910- CONFIG_SYS_MALLOC_SIMPLE
1911 Provides a simple and small malloc() and calloc() for those
1912 boards which do not use the full malloc in SPL (which is
1913 enabled with CONFIG_SYS_SPL_MALLOC_START).
1914
Thierry Reding1dfdd9b2014-12-09 22:25:22 -07001915- CONFIG_SYS_NONCACHED_MEMORY:
1916 Size of non-cached memory area. This area of memory will be
1917 typically located right below the malloc() area and mapped
1918 uncached in the MMU. This is useful for drivers that would
1919 otherwise require a lot of explicit cache maintenance. For
1920 some drivers it's also impossible to properly maintain the
1921 cache. For example if the regions that need to be flushed
1922 are not a multiple of the cache-line size, *and* padding
1923 cannot be allocated between the regions to align them (i.e.
1924 if the HW requires a contiguous array of regions, and the
1925 size of each region is not cache-aligned), then a flush of
1926 one region may result in overwriting data that hardware has
1927 written to another region in the same cache-line. This can
1928 happen for example in network drivers where descriptors for
1929 buffers are typically smaller than the CPU cache-line (e.g.
1930 16 bytes vs. 32 or 64 bytes).
1931
1932 Non-cached memory is only supported on 32-bit ARM at present.
1933
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001934- CONFIG_SYS_BOOTM_LEN:
Stefan Roese15940c92006-03-13 11:16:36 +01001935 Normally compressed uImages are limited to an
1936 uncompressed size of 8 MBytes. If this is not enough,
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001937 you can define CONFIG_SYS_BOOTM_LEN in your board config file
Stefan Roese15940c92006-03-13 11:16:36 +01001938 to adjust this setting to your needs.
1939
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001940- CONFIG_SYS_BOOTMAPSZ:
wdenkc6097192002-11-03 00:24:07 +00001941 Maximum size of memory mapped by the startup code of
1942 the Linux kernel; all data that must be processed by
Bartlomiej Sieka7d721e32008-04-14 15:44:16 +02001943 the Linux kernel (bd_info, boot arguments, FDT blob if
1944 used) must be put below this limit, unless "bootm_low"
Robert P. J. Day1bce2ae2013-09-16 07:15:45 -04001945 environment variable is defined and non-zero. In such case
Bartlomiej Sieka7d721e32008-04-14 15:44:16 +02001946 all data for the Linux kernel must be between "bootm_low"
Wolfgang Denkc0f40852011-10-26 10:21:21 +00001947 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
Grant Likelyc3624e62011-03-28 09:58:43 +00001948 variable "bootm_mapsize" will override the value of
1949 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
1950 then the value in "bootm_size" will be used instead.
wdenkc6097192002-11-03 00:24:07 +00001951
John Rigbyfca43cc2010-10-13 13:57:35 -06001952- CONFIG_SYS_BOOT_RAMDISK_HIGH:
1953 Enable initrd_high functionality. If defined then the
1954 initrd_high feature is enabled and the bootm ramdisk subcommand
1955 is enabled.
1956
1957- CONFIG_SYS_BOOT_GET_CMDLINE:
1958 Enables allocating and saving kernel cmdline in space between
1959 "bootm_low" and "bootm_low" + BOOTMAPSZ.
1960
1961- CONFIG_SYS_BOOT_GET_KBD:
1962 Enables allocating and saving a kernel copy of the bd_info in
1963 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
1964
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001965- CONFIG_SYS_MAX_FLASH_SECT:
wdenkc6097192002-11-03 00:24:07 +00001966 Max number of sectors on a Flash chip
1967
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001968- CONFIG_SYS_FLASH_ERASE_TOUT:
wdenkc6097192002-11-03 00:24:07 +00001969 Timeout for Flash erase operations (in ms)
1970
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001971- CONFIG_SYS_FLASH_WRITE_TOUT:
wdenkc6097192002-11-03 00:24:07 +00001972 Timeout for Flash write operations (in ms)
1973
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001974- CONFIG_SYS_FLASH_LOCK_TOUT
wdenk8564acf2003-07-14 22:13:32 +00001975 Timeout for Flash set sector lock bit operation (in ms)
1976
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001977- CONFIG_SYS_FLASH_UNLOCK_TOUT
wdenk8564acf2003-07-14 22:13:32 +00001978 Timeout for Flash clear lock bits operation (in ms)
1979
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001980- CONFIG_SYS_FLASH_PROTECTION
wdenk8564acf2003-07-14 22:13:32 +00001981 If defined, hardware flash sectors protection is used
1982 instead of U-Boot software protection.
1983
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001984- CONFIG_SYS_DIRECT_FLASH_TFTP:
wdenkc6097192002-11-03 00:24:07 +00001985
1986 Enable TFTP transfers directly to flash memory;
1987 without this option such a download has to be
1988 performed in two steps: (1) download to RAM, and (2)
1989 copy from RAM to flash.
1990
1991 The two-step approach is usually more reliable, since
1992 you can check if the download worked before you erase
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001993 the flash, but in some situations (when system RAM is
1994 too limited to allow for a temporary copy of the
wdenkc6097192002-11-03 00:24:07 +00001995 downloaded image) this option may be very useful.
1996
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001997- CONFIG_SYS_FLASH_CFI:
wdenk43d96162003-03-06 00:02:04 +00001998 Define if the flash driver uses extra elements in the
wdenk5653fc32004-02-08 22:55:38 +00001999 common flash structure for storing flash geometry.
2000
Jean-Christophe PLAGNIOL-VILLARD00b18832008-08-13 01:40:42 +02002001- CONFIG_FLASH_CFI_DRIVER
wdenk5653fc32004-02-08 22:55:38 +00002002 This option also enables the building of the cfi_flash driver
2003 in the drivers directory
wdenkc6097192002-11-03 00:24:07 +00002004
Piotr Ziecik91809ed2008-11-17 15:57:58 +01002005- CONFIG_FLASH_CFI_MTD
2006 This option enables the building of the cfi_mtd driver
2007 in the drivers directory. The driver exports CFI flash
2008 to the MTD layer.
2009
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002010- CONFIG_SYS_FLASH_USE_BUFFER_WRITE
Guennadi Liakhovetski96ef8312008-04-03 13:36:02 +02002011 Use buffered writes to flash.
2012
2013- CONFIG_FLASH_SPANSION_S29WS_N
2014 s29ws-n MirrorBit flash has non-standard addresses for buffered
2015 write commands.
2016
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002017- CONFIG_SYS_FLASH_QUIET_TEST
Stefan Roese5568e612005-11-22 13:20:42 +01002018 If this option is defined, the common CFI flash doesn't
2019 print it's warning upon not recognized FLASH banks. This
2020 is useful, if some of the configured banks are only
2021 optionally available.
2022
Jerry Van Baren9a042e92008-03-08 13:48:01 -05002023- CONFIG_FLASH_SHOW_PROGRESS
2024 If defined (must be an integer), print out countdown
2025 digits and dots. Recommended value: 45 (9..1) for 80
2026 column displays, 15 (3..1) for 40 column displays.
2027
Stefan Roese352ef3f2013-04-04 15:53:14 +02002028- CONFIG_FLASH_VERIFY
2029 If defined, the content of the flash (destination) is compared
2030 against the source after the write operation. An error message
2031 will be printed when the contents are not identical.
2032 Please note that this option is useless in nearly all cases,
2033 since such flash programming errors usually are detected earlier
2034 while unprotecting/erasing/programming. Please only enable
2035 this option if you really know what you are doing.
2036
Wolfgang Denkea882ba2010-06-20 23:33:59 +02002037- CONFIG_ENV_MAX_ENTRIES
2038
Wolfgang Denk071bc922010-10-27 22:48:30 +02002039 Maximum number of entries in the hash table that is used
2040 internally to store the environment settings. The default
2041 setting is supposed to be generous and should work in most
2042 cases. This setting can be used to tune behaviour; see
2043 lib/hashtable.c for details.
Wolfgang Denkea882ba2010-06-20 23:33:59 +02002044
Joe Hershberger25980902012-12-11 22:16:31 -06002045- CONFIG_ENV_FLAGS_LIST_DEFAULT
2046- CONFIG_ENV_FLAGS_LIST_STATIC
Robert P. J. Day1bce2ae2013-09-16 07:15:45 -04002047 Enable validation of the values given to environment variables when
Joe Hershberger25980902012-12-11 22:16:31 -06002048 calling env set. Variables can be restricted to only decimal,
2049 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
2050 the variables can also be restricted to IP address or MAC address.
2051
2052 The format of the list is:
2053 type_attribute = [s|d|x|b|i|m]
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08002054 access_attribute = [a|r|o|c]
2055 attributes = type_attribute[access_attribute]
Joe Hershberger25980902012-12-11 22:16:31 -06002056 entry = variable_name[:attributes]
2057 list = entry[,list]
2058
2059 The type attributes are:
2060 s - String (default)
2061 d - Decimal
2062 x - Hexadecimal
2063 b - Boolean ([1yYtT|0nNfF])
2064 i - IP address
2065 m - MAC address
2066
Joe Hershberger267541f2012-12-11 22:16:34 -06002067 The access attributes are:
2068 a - Any (default)
2069 r - Read-only
2070 o - Write-once
2071 c - Change-default
2072
Joe Hershberger25980902012-12-11 22:16:31 -06002073 - CONFIG_ENV_FLAGS_LIST_DEFAULT
2074 Define this to a list (string) to define the ".flags"
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08002075 environment variable in the default or embedded environment.
Joe Hershberger25980902012-12-11 22:16:31 -06002076
2077 - CONFIG_ENV_FLAGS_LIST_STATIC
2078 Define this to a list (string) to define validation that
2079 should be done if an entry is not found in the ".flags"
2080 environment variable. To override a setting in the static
2081 list, simply add an entry for the same variable name to the
2082 ".flags" variable.
2083
Joe Hershbergerbdf1fe42015-05-20 14:27:20 -05002084 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
2085 regular expression. This allows multiple variables to define the same
2086 flags without explicitly listing them for each variable.
2087
wdenkc6097192002-11-03 00:24:07 +00002088The following definitions that deal with the placement and management
2089of environment data (variable area); in general, we support the
2090following configurations:
2091
Mike Frysingerc3eb3fe2011-07-08 10:44:25 +00002092- CONFIG_BUILD_ENVCRC:
2093
2094 Builds up envcrc with the target environment so that external utils
2095 may easily extract it and embed it in final U-Boot images.
2096
wdenkc6097192002-11-03 00:24:07 +00002097BE CAREFUL! The first access to the environment happens quite early
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08002098in U-Boot initialization (when we try to get the setting of for the
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002099console baudrate). You *MUST* have mapped your NVRAM area then, or
wdenkc6097192002-11-03 00:24:07 +00002100U-Boot will hang.
2101
2102Please note that even with NVRAM we still use a copy of the
2103environment in RAM: we could work on NVRAM directly, but we want to
2104keep settings there always unmodified except somebody uses "saveenv"
2105to save the current settings.
2106
Liu Gang0a85a9e2012-03-08 00:33:20 +00002107BE CAREFUL! For some special cases, the local device can not use
2108"saveenv" command. For example, the local device will get the
Liu Gangfc54c7f2012-08-09 05:10:01 +00002109environment stored in a remote NOR flash by SRIO or PCIE link,
2110but it can not erase, write this NOR flash by SRIO or PCIE interface.
Liu Gang0a85a9e2012-03-08 00:33:20 +00002111
Guennadi Liakhovetskib74ab732009-05-18 16:07:22 +02002112- CONFIG_NAND_ENV_DST
2113
2114 Defines address in RAM to which the nand_spl code should copy the
2115 environment. If redundant environment is used, it will be copied to
2116 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2117
Bruce Adlere881cb52007-11-02 13:15:42 -07002118Please note that the environment is read-only until the monitor
wdenkc6097192002-11-03 00:24:07 +00002119has been relocated to RAM and a RAM copy of the environment has been
Simon Glass00caae62017-08-03 12:22:12 -06002120created; also, when using EEPROM you will have to use env_get_f()
wdenkc6097192002-11-03 00:24:07 +00002121until then to read environment variables.
2122
wdenk85ec0bc2003-03-31 16:34:49 +00002123The environment is protected by a CRC32 checksum. Before the monitor
2124is relocated into RAM, as a result of a bad CRC you will be working
2125with the compiled-in default environment - *silently*!!! [This is
2126necessary, because the first environment variable we need is the
2127"baudrate" setting for the console - if we have a bad CRC, we don't
2128have any device yet where we could complain.]
wdenkc6097192002-11-03 00:24:07 +00002129
2130Note: once the monitor has been relocated, then it will complain if
2131the default environment is used; a new CRC is computed as soon as you
wdenk85ec0bc2003-03-31 16:34:49 +00002132use the "saveenv" command to store a valid environment.
wdenkc6097192002-11-03 00:24:07 +00002133
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002134- CONFIG_SYS_FAULT_MII_ADDR:
wdenk42d1f032003-10-15 23:53:47 +00002135 MII address of the PHY to check for the Ethernet link state.
wdenkc6097192002-11-03 00:24:07 +00002136
Ron Madridf5675aa2009-02-18 14:30:44 -08002137- CONFIG_NS16550_MIN_FUNCTIONS:
2138 Define this if you desire to only have use of the NS16550_init
2139 and NS16550_putc functions for the serial driver located at
2140 drivers/serial/ns16550.c. This option is useful for saving
2141 space for already greatly restricted images, including but not
2142 limited to NAND_SPL configurations.
2143
Simon Glassb2b92f52012-11-30 13:01:18 +00002144- CONFIG_DISPLAY_BOARDINFO
2145 Display information about the board that U-Boot is running on
2146 when U-Boot starts up. The board function checkboard() is called
2147 to do this.
2148
Simon Glasse2e3e2b2012-11-30 13:01:19 +00002149- CONFIG_DISPLAY_BOARDINFO_LATE
2150 Similar to the previous option, but display this information
2151 later, once stdio is running and output goes to the LCD, if
2152 present.
2153
wdenkc6097192002-11-03 00:24:07 +00002154Low Level (hardware related) configuration options:
wdenkdc7c9a12003-03-26 06:55:25 +00002155---------------------------------------------------
wdenkc6097192002-11-03 00:24:07 +00002156
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002157- CONFIG_SYS_CACHELINE_SIZE:
wdenkc6097192002-11-03 00:24:07 +00002158 Cache Line Size of the CPU.
2159
Timur Tabie46fedf2011-08-04 18:03:41 -05002160- CONFIG_SYS_CCSRBAR_DEFAULT:
2161 Default (power-on reset) physical address of CCSR on Freescale
2162 PowerPC SOCs.
2163
2164- CONFIG_SYS_CCSRBAR:
2165 Virtual address of CCSR. On a 32-bit build, this is typically
2166 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
2167
Timur Tabie46fedf2011-08-04 18:03:41 -05002168- CONFIG_SYS_CCSRBAR_PHYS:
2169 Physical address of CCSR. CCSR can be relocated to a new
2170 physical address, if desired. In this case, this macro should
Wolfgang Denkc0f40852011-10-26 10:21:21 +00002171 be set to that address. Otherwise, it should be set to the
Timur Tabie46fedf2011-08-04 18:03:41 -05002172 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
2173 is typically relocated on 36-bit builds. It is recommended
2174 that this macro be defined via the _HIGH and _LOW macros:
2175
2176 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
2177 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
2178
2179- CONFIG_SYS_CCSRBAR_PHYS_HIGH:
Wolfgang Denk4cf26092011-10-07 09:58:21 +02002180 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
2181 either 0 (32-bit build) or 0xF (36-bit build). This macro is
Timur Tabie46fedf2011-08-04 18:03:41 -05002182 used in assembly code, so it must not contain typecasts or
2183 integer size suffixes (e.g. "ULL").
2184
2185- CONFIG_SYS_CCSRBAR_PHYS_LOW:
2186 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
2187 used in assembly code, so it must not contain typecasts or
2188 integer size suffixes (e.g. "ULL").
2189
2190- CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
2191 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
2192 forced to a value that ensures that CCSR is not relocated.
2193
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002194- CONFIG_SYS_IMMR: Physical address of the Internal Memory.
wdenkefe2a4d2004-12-16 21:44:03 +00002195 DO NOT CHANGE unless you know exactly what you're
Christophe Leroy907208c2017-07-06 10:23:22 +02002196 doing! (11-4) [MPC8xx systems only]
wdenkc6097192002-11-03 00:24:07 +00002197
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002198- CONFIG_SYS_INIT_RAM_ADDR:
wdenkc6097192002-11-03 00:24:07 +00002199
wdenk7152b1d2003-09-05 23:19:14 +00002200 Start address of memory area that can be used for
wdenkc6097192002-11-03 00:24:07 +00002201 initial data and stack; please note that this must be
2202 writable memory that is working WITHOUT special
2203 initialization, i. e. you CANNOT use normal RAM which
2204 will become available only after programming the
2205 memory controller and running certain initialization
2206 sequences.
2207
2208 U-Boot uses the following memory types:
Christophe Leroy907208c2017-07-06 10:23:22 +02002209 - MPC8xx: IMMR (internal memory of the CPU)
wdenkc6097192002-11-03 00:24:07 +00002210
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002211- CONFIG_SYS_GBL_DATA_OFFSET:
wdenkc6097192002-11-03 00:24:07 +00002212
2213 Offset of the initial data structure in the memory
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002214 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2215 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
wdenkc6097192002-11-03 00:24:07 +00002216 data is located at the end of the available space
Wolfgang Denk553f0982010-10-26 13:32:32 +02002217 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
Simon Glassacd51f92016-10-02 18:01:06 -06002218 GENERATED_GBL_DATA_SIZE), and the initial stack is just
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002219 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2220 CONFIG_SYS_GBL_DATA_OFFSET) downward.
wdenkc6097192002-11-03 00:24:07 +00002221
2222 Note:
2223 On the MPC824X (or other systems that use the data
2224 cache for initial memory) the address chosen for
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002225 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
wdenkc6097192002-11-03 00:24:07 +00002226 point to an otherwise UNUSED address space between
2227 the top of RAM and the start of the PCI space.
2228
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002229- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
wdenkc6097192002-11-03 00:24:07 +00002230
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002231- CONFIG_SYS_OR_TIMING_SDRAM:
wdenkc6097192002-11-03 00:24:07 +00002232 SDRAM timing
2233
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002234- CONFIG_SYS_MAMR_PTA:
wdenkc6097192002-11-03 00:24:07 +00002235 periodic timer for refresh
2236
Kumar Galaa09b9b62010-12-30 12:09:53 -06002237- CONFIG_SYS_SRIO:
2238 Chip has SRIO or not
2239
2240- CONFIG_SRIO1:
2241 Board has SRIO 1 port available
2242
2243- CONFIG_SRIO2:
2244 Board has SRIO 2 port available
2245
Liu Gangc8b28152013-05-07 16:30:46 +08002246- CONFIG_SRIO_PCIE_BOOT_MASTER
2247 Board can support master function for Boot from SRIO and PCIE
2248
Kumar Galaa09b9b62010-12-30 12:09:53 -06002249- CONFIG_SYS_SRIOn_MEM_VIRT:
2250 Virtual Address of SRIO port 'n' memory region
2251
Simon Glass62f9b652019-11-14 12:57:09 -07002252- CONFIG_SYS_SRIOn_MEM_PHYxS:
Kumar Galaa09b9b62010-12-30 12:09:53 -06002253 Physical Address of SRIO port 'n' memory region
2254
2255- CONFIG_SYS_SRIOn_MEM_SIZE:
2256 Size of SRIO port 'n' memory region
2257
Fabio Estevam66bd1842013-04-11 09:35:34 +00002258- CONFIG_SYS_NAND_BUSWIDTH_16BIT
2259 Defined to tell the NAND controller that the NAND chip is using
2260 a 16 bit bus.
2261 Not all NAND drivers use this symbol.
Fabio Estevama430e912013-04-11 09:35:35 +00002262 Example of drivers that use it:
Miquel Raynala430fa02018-08-16 17:30:07 +02002263 - drivers/mtd/nand/raw/ndfc.c
2264 - drivers/mtd/nand/raw/mxc_nand.c
Alex Watermaneced4622011-05-19 15:08:36 -04002265
2266- CONFIG_SYS_NDFC_EBC0_CFG
2267 Sets the EBC0_CFG register for the NDFC. If not defined
2268 a default value will be used.
2269
Ben Warrenbb99ad62006-09-07 16:50:54 -04002270- CONFIG_SPD_EEPROM
Wolfgang Denk218ca722008-03-26 10:40:12 +01002271 Get DDR timing information from an I2C EEPROM. Common
2272 with pluggable memory modules such as SODIMMs
2273
Ben Warrenbb99ad62006-09-07 16:50:54 -04002274 SPD_EEPROM_ADDRESS
2275 I2C address of the SPD EEPROM
2276
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002277- CONFIG_SYS_SPD_BUS_NUM
Wolfgang Denk218ca722008-03-26 10:40:12 +01002278 If SPD EEPROM is on an I2C bus other than the first
2279 one, specify here. Note that the value must resolve
2280 to something your driver can deal with.
Ben Warrenbb99ad62006-09-07 16:50:54 -04002281
York Sun1b3e3c42011-06-07 09:42:16 +08002282- CONFIG_SYS_DDR_RAW_TIMING
2283 Get DDR timing information from other than SPD. Common with
2284 soldered DDR chips onboard without SPD. DDR raw timing
2285 parameters are extracted from datasheet and hard-coded into
2286 header files or board specific files.
2287
York Sun6f5e1dc2011-09-16 13:21:35 -07002288- CONFIG_FSL_DDR_INTERACTIVE
2289 Enable interactive DDR debugging. See doc/README.fsl-ddr.
2290
York Sune32d59a2015-01-06 13:18:55 -08002291- CONFIG_FSL_DDR_SYNC_REFRESH
2292 Enable sync of refresh for multiple controllers.
2293
York Sun4516ff82015-03-19 09:30:28 -07002294- CONFIG_FSL_DDR_BIST
2295 Enable built-in memory test for Freescale DDR controllers.
2296
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002297- CONFIG_SYS_83XX_DDR_USES_CS0
Wolfgang Denk218ca722008-03-26 10:40:12 +01002298 Only for 83xx systems. If specified, then DDR should
2299 be configured using CS0 and CS1 instead of CS2 and CS3.
Timur Tabi2ad6b512006-10-31 18:44:42 -06002300
wdenkc26e4542004-04-18 10:13:26 +00002301- CONFIG_RMII
2302 Enable RMII mode for all FECs.
2303 Note that this is a global option, we can't
2304 have one FEC in standard MII mode and another in RMII mode.
2305
wdenk5cf91d62004-04-23 20:32:05 +00002306- CONFIG_CRC32_VERIFY
2307 Add a verify option to the crc32 command.
2308 The syntax is:
2309
2310 => crc32 -v <address> <count> <crc32>
2311
2312 Where address/count indicate a memory area
2313 and crc32 is the correct crc32 which the
2314 area should have.
2315
wdenk56523f12004-07-11 17:40:54 +00002316- CONFIG_LOOPW
2317 Add the "loopw" memory command. This only takes effect if
Simon Glass493f4202017-08-04 16:34:27 -06002318 the memory commands are activated globally (CONFIG_CMD_MEMORY).
wdenk56523f12004-07-11 17:40:54 +00002319
Joel Johnson72732312020-01-29 09:17:18 -07002320- CONFIG_CMD_MX_CYCLIC
stroese7b466642004-12-16 18:46:55 +00002321 Add the "mdc" and "mwc" memory commands. These are cyclic
2322 "md/mw" commands.
2323 Examples:
2324
wdenkefe2a4d2004-12-16 21:44:03 +00002325 => mdc.b 10 4 500
stroese7b466642004-12-16 18:46:55 +00002326 This command will print 4 bytes (10,11,12,13) each 500 ms.
2327
wdenkefe2a4d2004-12-16 21:44:03 +00002328 => mwc.l 100 12345678 10
stroese7b466642004-12-16 18:46:55 +00002329 This command will write 12345678 to address 100 all 10 ms.
2330
wdenkefe2a4d2004-12-16 21:44:03 +00002331 This only takes effect if the memory commands are activated
Simon Glass493f4202017-08-04 16:34:27 -06002332 globally (CONFIG_CMD_MEMORY).
stroese7b466642004-12-16 18:46:55 +00002333
Aneesh V401bb302011-07-13 05:11:07 +00002334- CONFIG_SPL_BUILD
Thomas Hebb32f2ca22019-11-13 18:18:03 -08002335 Set when the currently-running compilation is for an artifact
2336 that will end up in the SPL (as opposed to the TPL or U-Boot
2337 proper). Code that needs stage-specific behavior should check
2338 this.
wdenk400558b2005-04-02 23:52:25 +00002339
Ying Zhang3aa29de2013-08-16 15:16:15 +08002340- CONFIG_TPL_BUILD
Thomas Hebb32f2ca22019-11-13 18:18:03 -08002341 Set when the currently-running compilation is for an artifact
2342 that will end up in the TPL (as opposed to the SPL or U-Boot
2343 proper). Code that needs stage-specific behavior should check
2344 this.
Ying Zhang3aa29de2013-08-16 15:16:15 +08002345
Ying Zhang5df572f2013-05-20 14:07:23 +08002346- CONFIG_SYS_MPC85XX_NO_RESETVEC
2347 Only for 85xx systems. If this variable is specified, the section
2348 .resetvec is not kept and the section .bootpg is placed in the
2349 previous 4k of the .text section.
2350
Simon Glass4213fc22013-02-24 17:33:14 +00002351- CONFIG_ARCH_MAP_SYSMEM
2352 Generally U-Boot (and in particular the md command) uses
2353 effective address. It is therefore not necessary to regard
2354 U-Boot address as virtual addresses that need to be translated
2355 to physical addresses. However, sandbox requires this, since
2356 it maintains its own little RAM buffer which contains all
2357 addressable memory. This option causes some memory accesses
2358 to be mapped through map_sysmem() / unmap_sysmem().
2359
Simon Glass588a13f2013-02-14 04:18:54 +00002360- CONFIG_X86_RESET_VECTOR
2361 If defined, the x86 reset vector code is included. This is not
2362 needed when U-Boot is running from Coreboot.
Gabe Blackb16f5212012-11-27 21:08:06 +00002363
Karicheri, Muralidharan999d7d32014-04-04 13:16:50 -04002364- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
2365 Option to disable subpage write in NAND driver
2366 driver that uses this:
Miquel Raynala430fa02018-08-16 17:30:07 +02002367 drivers/mtd/nand/raw/davinci_nand.c
Karicheri, Muralidharan999d7d32014-04-04 13:16:50 -04002368
Timur Tabif2717b42011-11-22 09:21:25 -06002369Freescale QE/FMAN Firmware Support:
2370-----------------------------------
2371
2372The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
2373loading of "firmware", which is encoded in the QE firmware binary format.
2374This firmware often needs to be loaded during U-Boot booting, so macros
2375are used to identify the storage device (NOR flash, SPI, etc) and the address
2376within that device.
2377
Zhao Qiangdcf1d772014-03-21 16:21:44 +08002378- CONFIG_SYS_FMAN_FW_ADDR
2379 The address in the storage device where the FMAN microcode is located. The
Tom Rinicc1e98b2019-05-12 07:59:12 -04002380 meaning of this address depends on which CONFIG_SYS_QE_FMAN_FW_IN_xxx macro
Zhao Qiangdcf1d772014-03-21 16:21:44 +08002381 is also specified.
2382
2383- CONFIG_SYS_QE_FW_ADDR
2384 The address in the storage device where the QE microcode is located. The
Tom Rinicc1e98b2019-05-12 07:59:12 -04002385 meaning of this address depends on which CONFIG_SYS_QE_FMAN_FW_IN_xxx macro
Timur Tabif2717b42011-11-22 09:21:25 -06002386 is also specified.
2387
2388- CONFIG_SYS_QE_FMAN_FW_LENGTH
2389 The maximum possible size of the firmware. The firmware binary format
2390 has a field that specifies the actual size of the firmware, but it
2391 might not be possible to read any part of the firmware unless some
2392 local storage is allocated to hold the entire firmware first.
2393
2394- CONFIG_SYS_QE_FMAN_FW_IN_NOR
2395 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
2396 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
2397 virtual address in NOR flash.
2398
2399- CONFIG_SYS_QE_FMAN_FW_IN_NAND
2400 Specifies that QE/FMAN firmware is located in NAND flash.
2401 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
2402
2403- CONFIG_SYS_QE_FMAN_FW_IN_MMC
2404 Specifies that QE/FMAN firmware is located on the primary SD/MMC
2405 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
2406
Liu Gang292dc6c2012-03-08 00:33:18 +00002407- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
2408 Specifies that QE/FMAN firmware is located in the remote (master)
2409 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
Liu Gangfc54c7f2012-08-09 05:10:01 +00002410 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
2411 window->master inbound window->master LAW->the ucode address in
2412 master's memory space.
Timur Tabif2717b42011-11-22 09:21:25 -06002413
J. German Riverab940ca62014-06-23 15:15:55 -07002414Freescale Layerscape Management Complex Firmware Support:
2415---------------------------------------------------------
2416The Freescale Layerscape Management Complex (MC) supports the loading of
2417"firmware".
2418This firmware often needs to be loaded during U-Boot booting, so macros
2419are used to identify the storage device (NOR flash, SPI, etc) and the address
2420within that device.
2421
2422- CONFIG_FSL_MC_ENET
2423 Enable the MC driver for Layerscape SoCs.
2424
Prabhakar Kushwaha5c055082015-06-02 10:55:52 +05302425Freescale Layerscape Debug Server Support:
2426-------------------------------------------
2427The Freescale Layerscape Debug Server Support supports the loading of
2428"Debug Server firmware" and triggering SP boot-rom.
2429This firmware often needs to be loaded during U-Boot booting.
2430
York Sunc0492142015-12-07 11:08:58 -08002431- CONFIG_SYS_MC_RSV_MEM_ALIGN
2432 Define alignment of reserved memory MC requires
Prabhakar Kushwaha5c055082015-06-02 10:55:52 +05302433
Paul Kocialkowskif3f431a2015-07-26 18:48:15 +02002434Reproducible builds
2435-------------------
2436
2437In order to achieve reproducible builds, timestamps used in the U-Boot build
2438process have to be set to a fixed value.
2439
2440This is done using the SOURCE_DATE_EPOCH environment variable.
2441SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
2442option for U-Boot or an environment variable in U-Boot.
2443
2444SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
2445
wdenkc6097192002-11-03 00:24:07 +00002446Building the Software:
2447======================
2448
Wolfgang Denk218ca722008-03-26 10:40:12 +01002449Building U-Boot has been tested in several native build environments
2450and in many different cross environments. Of course we cannot support
2451all possibly existing versions of cross development tools in all
2452(potentially obsolete) versions. In case of tool chain problems we
Naoki Hayama047f6ec2020-10-08 13:17:16 +09002453recommend to use the ELDK (see https://www.denx.de/wiki/DULG/ELDK)
Wolfgang Denk218ca722008-03-26 10:40:12 +01002454which is extensively used to build and test U-Boot.
wdenkc6097192002-11-03 00:24:07 +00002455
Wolfgang Denk218ca722008-03-26 10:40:12 +01002456If you are not using a native environment, it is assumed that you
2457have GNU cross compiling tools available in your path. In this case,
2458you must set the environment variable CROSS_COMPILE in your shell.
2459Note that no changes to the Makefile or any other source files are
2460necessary. For example using the ELDK on a 4xx CPU, please enter:
wdenkc6097192002-11-03 00:24:07 +00002461
Wolfgang Denk218ca722008-03-26 10:40:12 +01002462 $ CROSS_COMPILE=ppc_4xx-
2463 $ export CROSS_COMPILE
wdenkc6097192002-11-03 00:24:07 +00002464
Wolfgang Denk218ca722008-03-26 10:40:12 +01002465U-Boot is intended to be simple to build. After installing the
2466sources you must configure U-Boot for one specific board type. This
wdenkc6097192002-11-03 00:24:07 +00002467is done by typing:
2468
Holger Freytherab584d62014-08-04 09:26:05 +02002469 make NAME_defconfig
wdenkc6097192002-11-03 00:24:07 +00002470
Holger Freytherab584d62014-08-04 09:26:05 +02002471where "NAME_defconfig" is the name of one of the existing configu-
Heinrich Schuchardtecb3a0a2020-02-24 18:36:30 +01002472rations; see configs/*_defconfig for supported names.
wdenk54387ac2003-10-08 22:45:44 +00002473
Heinrich Schuchardtecb3a0a2020-02-24 18:36:30 +01002474Note: for some boards special configuration names may exist; check if
wdenk2729af92004-05-03 20:45:30 +00002475 additional information is available from the board vendor; for
2476 instance, the TQM823L systems are available without (standard)
2477 or with LCD support. You can select such additional "features"
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002478 when choosing the configuration, i. e.
wdenkc6097192002-11-03 00:24:07 +00002479
Holger Freytherab584d62014-08-04 09:26:05 +02002480 make TQM823L_defconfig
wdenk2729af92004-05-03 20:45:30 +00002481 - will configure for a plain TQM823L, i. e. no LCD support
wdenkc6097192002-11-03 00:24:07 +00002482
Holger Freytherab584d62014-08-04 09:26:05 +02002483 make TQM823L_LCD_defconfig
wdenk2729af92004-05-03 20:45:30 +00002484 - will configure for a TQM823L with U-Boot console on LCD
wdenkc6097192002-11-03 00:24:07 +00002485
wdenk2729af92004-05-03 20:45:30 +00002486 etc.
wdenkc6097192002-11-03 00:24:07 +00002487
wdenkc6097192002-11-03 00:24:07 +00002488
wdenk2729af92004-05-03 20:45:30 +00002489Finally, type "make all", and you should get some working U-Boot
2490images ready for download to / installation on your system:
wdenkc6097192002-11-03 00:24:07 +00002491
wdenk2729af92004-05-03 20:45:30 +00002492- "u-boot.bin" is a raw binary image
2493- "u-boot" is an image in ELF binary format
2494- "u-boot.srec" is in Motorola S-Record format
wdenkc6097192002-11-03 00:24:07 +00002495
Marian Balakowiczbaf31242006-09-07 17:25:40 +02002496By default the build is performed locally and the objects are saved
2497in the source directory. One of the two methods can be used to change
2498this behavior and build U-Boot to some external directory:
2499
25001. Add O= to the make command line invocations:
2501
2502 make O=/tmp/build distclean
Holger Freytherab584d62014-08-04 09:26:05 +02002503 make O=/tmp/build NAME_defconfig
Marian Balakowiczbaf31242006-09-07 17:25:40 +02002504 make O=/tmp/build all
2505
Timo Ketolaadbba992014-11-06 14:39:05 +020025062. Set environment variable KBUILD_OUTPUT to point to the desired location:
Marian Balakowiczbaf31242006-09-07 17:25:40 +02002507
Timo Ketolaadbba992014-11-06 14:39:05 +02002508 export KBUILD_OUTPUT=/tmp/build
Marian Balakowiczbaf31242006-09-07 17:25:40 +02002509 make distclean
Holger Freytherab584d62014-08-04 09:26:05 +02002510 make NAME_defconfig
Marian Balakowiczbaf31242006-09-07 17:25:40 +02002511 make all
2512
Timo Ketolaadbba992014-11-06 14:39:05 +02002513Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
Marian Balakowiczbaf31242006-09-07 17:25:40 +02002514variable.
2515
Daniel Schwierzeck215bb1c2018-01-26 16:31:04 +01002516User specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by
2517setting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS.
2518For example to treat all compiler warnings as errors:
2519
2520 make KCFLAGS=-Werror
wdenkc6097192002-11-03 00:24:07 +00002521
wdenk2729af92004-05-03 20:45:30 +00002522Please be aware that the Makefiles assume you are using GNU make, so
2523for instance on NetBSD you might need to use "gmake" instead of
2524native "make".
wdenkc6097192002-11-03 00:24:07 +00002525
wdenkc6097192002-11-03 00:24:07 +00002526
wdenk2729af92004-05-03 20:45:30 +00002527If the system board that you have is not listed, then you will need
2528to port U-Boot to your hardware platform. To do this, follow these
2529steps:
wdenkc6097192002-11-03 00:24:07 +00002530
Phil Sutter3c1496c2015-12-25 14:41:18 +010025311. Create a new directory to hold your board specific code. Add any
wdenk2729af92004-05-03 20:45:30 +00002532 files you need. In your board directory, you will need at least
Phil Sutter3c1496c2015-12-25 14:41:18 +01002533 the "Makefile" and a "<board>.c".
25342. Create a new configuration file "include/configs/<board>.h" for
2535 your board.
wdenk2729af92004-05-03 20:45:30 +000025363. If you're porting U-Boot to a new CPU, then also create a new
2537 directory to hold your CPU specific code. Add any files you need.
Holger Freytherab584d62014-08-04 09:26:05 +020025384. Run "make <board>_defconfig" with your new name.
wdenk2729af92004-05-03 20:45:30 +000025395. Type "make", and you should get a working "u-boot.srec" file
2540 to be installed on your target system.
25416. Debug and solve any problems that might arise.
2542 [Of course, this last step is much harder than it sounds.]
wdenkc6097192002-11-03 00:24:07 +00002543
wdenkc6097192002-11-03 00:24:07 +00002544
wdenk2729af92004-05-03 20:45:30 +00002545Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2546==============================================================
wdenkc6097192002-11-03 00:24:07 +00002547
Wolfgang Denk218ca722008-03-26 10:40:12 +01002548If you have modified U-Boot sources (for instance added a new board
2549or support for new devices, a new CPU, etc.) you are expected to
wdenk2729af92004-05-03 20:45:30 +00002550provide feedback to the other developers. The feedback normally takes
Thomas Hebb32f2ca22019-11-13 18:18:03 -08002551the form of a "patch", i.e. a context diff against a certain (latest
Wolfgang Denk218ca722008-03-26 10:40:12 +01002552official or latest in the git repository) version of U-Boot sources.
wdenkc6097192002-11-03 00:24:07 +00002553
Wolfgang Denk218ca722008-03-26 10:40:12 +01002554But before you submit such a patch, please verify that your modifi-
2555cation did not break existing code. At least make sure that *ALL* of
wdenk2729af92004-05-03 20:45:30 +00002556the supported boards compile WITHOUT ANY compiler warnings. To do so,
Simon Glass6de80f22016-07-27 20:33:08 -06002557just run the buildman script (tools/buildman/buildman), which will
2558configure and build U-Boot for ALL supported system. Be warned, this
2559will take a while. Please see the buildman README, or run 'buildman -H'
2560for documentation.
Marian Balakowiczbaf31242006-09-07 17:25:40 +02002561
2562
wdenk2729af92004-05-03 20:45:30 +00002563See also "U-Boot Porting Guide" below.
wdenkc6097192002-11-03 00:24:07 +00002564
wdenkc6097192002-11-03 00:24:07 +00002565
wdenk2729af92004-05-03 20:45:30 +00002566Monitor Commands - Overview:
2567============================
wdenkc6097192002-11-03 00:24:07 +00002568
wdenk2729af92004-05-03 20:45:30 +00002569go - start application at address 'addr'
2570run - run commands in an environment variable
2571bootm - boot application image from memory
2572bootp - boot image via network using BootP/TFTP protocol
Marek Vasut44f074c2012-03-14 21:52:45 +00002573bootz - boot zImage from memory
wdenk2729af92004-05-03 20:45:30 +00002574tftpboot- boot image via network using TFTP protocol
2575 and env variables "ipaddr" and "serverip"
2576 (and eventually "gatewayip")
Simon Glass1fb7cd42011-10-24 18:00:07 +00002577tftpput - upload a file via network using TFTP protocol
wdenk2729af92004-05-03 20:45:30 +00002578rarpboot- boot image via network using RARP/TFTP protocol
2579diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2580loads - load S-Record file over serial line
2581loadb - load binary file over serial line (kermit mode)
2582md - memory display
2583mm - memory modify (auto-incrementing)
2584nm - memory modify (constant address)
2585mw - memory write (fill)
Simon Glassbdded202020-06-02 19:26:49 -06002586ms - memory search
wdenk2729af92004-05-03 20:45:30 +00002587cp - memory copy
2588cmp - memory compare
2589crc32 - checksum calculation
Peter Tyser0f89c542009-04-18 22:34:03 -05002590i2c - I2C sub-system
wdenk2729af92004-05-03 20:45:30 +00002591sspi - SPI utility commands
2592base - print or set address offset
2593printenv- print environment variables
Pragnesh Patel9e9a5302020-12-22 11:30:05 +05302594pwm - control pwm channels
wdenk2729af92004-05-03 20:45:30 +00002595setenv - set environment variables
2596saveenv - save environment variables to persistent storage
2597protect - enable or disable FLASH write protection
2598erase - erase FLASH memory
2599flinfo - print FLASH memory information
Karl O. Pinc10635af2012-08-03 05:57:21 +00002600nand - NAND memory operations (see doc/README.nand)
wdenk2729af92004-05-03 20:45:30 +00002601bdinfo - print Board Info structure
2602iminfo - print header information for application image
2603coninfo - print console devices and informations
2604ide - IDE sub-system
2605loop - infinite loop on address range
wdenk56523f12004-07-11 17:40:54 +00002606loopw - infinite write loop on address range
wdenk2729af92004-05-03 20:45:30 +00002607mtest - simple RAM test
2608icache - enable or disable instruction cache
2609dcache - enable or disable data cache
2610reset - Perform RESET of the CPU
2611echo - echo args to console
2612version - print monitor version
2613help - print online help
2614? - alias for 'help'
wdenkc6097192002-11-03 00:24:07 +00002615
wdenkc6097192002-11-03 00:24:07 +00002616
wdenk2729af92004-05-03 20:45:30 +00002617Monitor Commands - Detailed Description:
2618========================================
wdenkc6097192002-11-03 00:24:07 +00002619
wdenk2729af92004-05-03 20:45:30 +00002620TODO.
wdenkc6097192002-11-03 00:24:07 +00002621
wdenk2729af92004-05-03 20:45:30 +00002622For now: just type "help <command>".
wdenkc6097192002-11-03 00:24:07 +00002623
2624
wdenk2729af92004-05-03 20:45:30 +00002625Note for Redundant Ethernet Interfaces:
2626=======================================
wdenkf07771c2003-05-28 08:06:31 +00002627
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002628Some boards come with redundant Ethernet interfaces; U-Boot supports
wdenk2729af92004-05-03 20:45:30 +00002629such configurations and is capable of automatic selection of a
2630"working" interface when needed. MAC assignment works as follows:
wdenkf07771c2003-05-28 08:06:31 +00002631
wdenk2729af92004-05-03 20:45:30 +00002632Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2633MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2634"eth1addr" (=>eth1), "eth2addr", ...
wdenkf07771c2003-05-28 08:06:31 +00002635
wdenk2729af92004-05-03 20:45:30 +00002636If the network interface stores some valid MAC address (for instance
2637in SROM), this is used as default address if there is NO correspon-
2638ding setting in the environment; if the corresponding environment
2639variable is set, this overrides the settings in the card; that means:
wdenkf07771c2003-05-28 08:06:31 +00002640
wdenk2729af92004-05-03 20:45:30 +00002641o If the SROM has a valid MAC address, and there is no address in the
2642 environment, the SROM's address is used.
wdenkc6097192002-11-03 00:24:07 +00002643
wdenk2729af92004-05-03 20:45:30 +00002644o If there is no valid address in the SROM, and a definition in the
2645 environment exists, then the value from the environment variable is
2646 used.
wdenkc6097192002-11-03 00:24:07 +00002647
wdenk2729af92004-05-03 20:45:30 +00002648o If both the SROM and the environment contain a MAC address, and
2649 both addresses are the same, this MAC address is used.
wdenkc6097192002-11-03 00:24:07 +00002650
wdenk2729af92004-05-03 20:45:30 +00002651o If both the SROM and the environment contain a MAC address, and the
2652 addresses differ, the value from the environment is used and a
2653 warning is printed.
wdenkc6097192002-11-03 00:24:07 +00002654
wdenk2729af92004-05-03 20:45:30 +00002655o If neither SROM nor the environment contain a MAC address, an error
Joe Hershbergerbef10142015-05-04 14:55:13 -05002656 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
2657 a random, locally-assigned MAC is used.
wdenkc6097192002-11-03 00:24:07 +00002658
Ben Warrenecee9322010-04-26 11:11:46 -07002659If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
Wolfgang Denkc0f40852011-10-26 10:21:21 +00002660will be programmed into hardware as part of the initialization process. This
Ben Warrenecee9322010-04-26 11:11:46 -07002661may be skipped by setting the appropriate 'ethmacskip' environment variable.
2662The naming convention is as follows:
2663"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
wdenkc6097192002-11-03 00:24:07 +00002664
wdenk2729af92004-05-03 20:45:30 +00002665Image Formats:
2666==============
wdenkc6097192002-11-03 00:24:07 +00002667
Marian Balakowicz3310c542008-03-12 12:13:13 +01002668U-Boot is capable of booting (and performing other auxiliary operations on)
2669images in two formats:
2670
2671New uImage format (FIT)
2672-----------------------
2673
2674Flexible and powerful format based on Flattened Image Tree -- FIT (similar
2675to Flattened Device Tree). It allows the use of images with multiple
2676components (several kernels, ramdisks, etc.), with contents protected by
2677SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
2678
2679
2680Old uImage format
2681-----------------
2682
2683Old image format is based on binary files which can be basically anything,
2684preceded by a special header; see the definitions in include/image.h for
2685details; basically, the header defines the following image properties:
wdenkc6097192002-11-03 00:24:07 +00002686
wdenk2729af92004-05-03 20:45:30 +00002687* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2688 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
Peter Tyserf5ed9e32008-09-08 14:56:49 -05002689 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
Thomas Huth0797e732021-11-13 18:13:50 +01002690 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, INTEGRITY).
Andy Shevchenkodaab59a2017-07-05 16:25:22 +03002691* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
Macpaul Linafc1ce82011-10-19 20:41:11 +00002692 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
Andy Shevchenkodaab59a2017-07-05 16:25:22 +03002693 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC).
wdenk2729af92004-05-03 20:45:30 +00002694* Compression Type (uncompressed, gzip, bzip2)
2695* Load Address
2696* Entry Point
2697* Image Name
2698* Image Timestamp
wdenkc6097192002-11-03 00:24:07 +00002699
wdenk2729af92004-05-03 20:45:30 +00002700The header is marked by a special Magic Number, and both the header
2701and the data portions of the image are secured against corruption by
2702CRC32 checksums.
wdenkc6097192002-11-03 00:24:07 +00002703
wdenkc6097192002-11-03 00:24:07 +00002704
wdenk2729af92004-05-03 20:45:30 +00002705Linux Support:
2706==============
wdenkc6097192002-11-03 00:24:07 +00002707
wdenk2729af92004-05-03 20:45:30 +00002708Although U-Boot should support any OS or standalone application
2709easily, the main focus has always been on Linux during the design of
2710U-Boot.
wdenkc6097192002-11-03 00:24:07 +00002711
wdenk2729af92004-05-03 20:45:30 +00002712U-Boot includes many features that so far have been part of some
2713special "boot loader" code within the Linux kernel. Also, any
2714"initrd" images to be used are no longer part of one big Linux image;
2715instead, kernel and "initrd" are separate images. This implementation
2716serves several purposes:
wdenkc6097192002-11-03 00:24:07 +00002717
wdenk2729af92004-05-03 20:45:30 +00002718- the same features can be used for other OS or standalone
2719 applications (for instance: using compressed images to reduce the
2720 Flash memory footprint)
wdenkc6097192002-11-03 00:24:07 +00002721
wdenk2729af92004-05-03 20:45:30 +00002722- it becomes much easier to port new Linux kernel versions because
2723 lots of low-level, hardware dependent stuff are done by U-Boot
wdenkc6097192002-11-03 00:24:07 +00002724
wdenk2729af92004-05-03 20:45:30 +00002725- the same Linux kernel image can now be used with different "initrd"
2726 images; of course this also means that different kernel images can
2727 be run with the same "initrd". This makes testing easier (you don't
2728 have to build a new "zImage.initrd" Linux image when you just
2729 change a file in your "initrd"). Also, a field-upgrade of the
2730 software is easier now.
wdenkc6097192002-11-03 00:24:07 +00002731
wdenkc6097192002-11-03 00:24:07 +00002732
wdenk2729af92004-05-03 20:45:30 +00002733Linux HOWTO:
2734============
wdenkc6097192002-11-03 00:24:07 +00002735
wdenk2729af92004-05-03 20:45:30 +00002736Porting Linux to U-Boot based systems:
2737---------------------------------------
wdenkc6097192002-11-03 00:24:07 +00002738
wdenk2729af92004-05-03 20:45:30 +00002739U-Boot cannot save you from doing all the necessary modifications to
2740configure the Linux device drivers for use with your target hardware
2741(no, we don't intend to provide a full virtual machine interface to
2742Linux :-).
wdenkc6097192002-11-03 00:24:07 +00002743
Stefan Roesea47a12b2010-04-15 16:07:28 +02002744But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
wdenkc6097192002-11-03 00:24:07 +00002745
wdenk2729af92004-05-03 20:45:30 +00002746Just make sure your machine specific header file (for instance
2747include/asm-ppc/tqm8xx.h) includes the same definition of the Board
Markus Heidelberg1dc30692008-09-07 20:18:27 +02002748Information structure as we define in include/asm-<arch>/u-boot.h,
2749and make sure that your definition of IMAP_ADDR uses the same value
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002750as your U-Boot configuration in CONFIG_SYS_IMMR.
wdenkc6097192002-11-03 00:24:07 +00002751
Simon Glass2eb31b12014-06-11 23:29:46 -06002752Note that U-Boot now has a driver model, a unified model for drivers.
2753If you are adding a new driver, plumb it into driver model. If there
2754is no uclass available, you are encouraged to create one. See
2755doc/driver-model.
2756
wdenkc6097192002-11-03 00:24:07 +00002757
wdenk2729af92004-05-03 20:45:30 +00002758Configuring the Linux kernel:
2759-----------------------------
wdenkc6097192002-11-03 00:24:07 +00002760
wdenk2729af92004-05-03 20:45:30 +00002761No specific requirements for U-Boot. Make sure you have some root
2762device (initial ramdisk, NFS) for your target system.
wdenkc6097192002-11-03 00:24:07 +00002763
wdenkc6097192002-11-03 00:24:07 +00002764
wdenk2729af92004-05-03 20:45:30 +00002765Building a Linux Image:
2766-----------------------
wdenkc6097192002-11-03 00:24:07 +00002767
wdenk2729af92004-05-03 20:45:30 +00002768With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2769not used. If you use recent kernel source, a new build target
2770"uImage" will exist which automatically builds an image usable by
2771U-Boot. Most older kernels also have support for a "pImage" target,
2772which was introduced for our predecessor project PPCBoot and uses a
2773100% compatible format.
wdenkc6097192002-11-03 00:24:07 +00002774
wdenk2729af92004-05-03 20:45:30 +00002775Example:
wdenkc6097192002-11-03 00:24:07 +00002776
Holger Freytherab584d62014-08-04 09:26:05 +02002777 make TQM850L_defconfig
wdenk2729af92004-05-03 20:45:30 +00002778 make oldconfig
2779 make dep
2780 make uImage
wdenkc6097192002-11-03 00:24:07 +00002781
wdenk2729af92004-05-03 20:45:30 +00002782The "uImage" build target uses a special tool (in 'tools/mkimage') to
2783encapsulate a compressed Linux kernel image with header information,
2784CRC32 checksum etc. for use with U-Boot. This is what we are doing:
wdenkc6097192002-11-03 00:24:07 +00002785
wdenk2729af92004-05-03 20:45:30 +00002786* build a standard "vmlinux" kernel image (in ELF binary format):
wdenkc6097192002-11-03 00:24:07 +00002787
wdenk2729af92004-05-03 20:45:30 +00002788* convert the kernel into a raw binary image:
wdenkc6097192002-11-03 00:24:07 +00002789
wdenk2729af92004-05-03 20:45:30 +00002790 ${CROSS_COMPILE}-objcopy -O binary \
2791 -R .note -R .comment \
2792 -S vmlinux linux.bin
wdenkc6097192002-11-03 00:24:07 +00002793
wdenk2729af92004-05-03 20:45:30 +00002794* compress the binary image:
wdenkc6097192002-11-03 00:24:07 +00002795
wdenk2729af92004-05-03 20:45:30 +00002796 gzip -9 linux.bin
wdenkc6097192002-11-03 00:24:07 +00002797
wdenk2729af92004-05-03 20:45:30 +00002798* package compressed binary image for U-Boot:
wdenk24ee89b2002-11-03 17:56:27 +00002799
wdenk2729af92004-05-03 20:45:30 +00002800 mkimage -A ppc -O linux -T kernel -C gzip \
2801 -a 0 -e 0 -n "Linux Kernel Image" \
2802 -d linux.bin.gz uImage
wdenk24ee89b2002-11-03 17:56:27 +00002803
wdenk24ee89b2002-11-03 17:56:27 +00002804
wdenk2729af92004-05-03 20:45:30 +00002805The "mkimage" tool can also be used to create ramdisk images for use
2806with U-Boot, either separated from the Linux kernel image, or
2807combined into one file. "mkimage" encapsulates the images with a 64
2808byte header containing information about target architecture,
2809operating system, image type, compression method, entry points, time
2810stamp, CRC32 checksums, etc.
wdenk24ee89b2002-11-03 17:56:27 +00002811
wdenk2729af92004-05-03 20:45:30 +00002812"mkimage" can be called in two ways: to verify existing images and
2813print the header information, or to build new images.
wdenk24ee89b2002-11-03 17:56:27 +00002814
wdenk2729af92004-05-03 20:45:30 +00002815In the first form (with "-l" option) mkimage lists the information
2816contained in the header of an existing U-Boot image; this includes
2817checksum verification:
wdenk24ee89b2002-11-03 17:56:27 +00002818
wdenk2729af92004-05-03 20:45:30 +00002819 tools/mkimage -l image
2820 -l ==> list image header information
wdenk24ee89b2002-11-03 17:56:27 +00002821
wdenk2729af92004-05-03 20:45:30 +00002822The second form (with "-d" option) is used to build a U-Boot image
2823from a "data file" which is used as image payload:
wdenk24ee89b2002-11-03 17:56:27 +00002824
wdenk2729af92004-05-03 20:45:30 +00002825 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2826 -n name -d data_file image
2827 -A ==> set architecture to 'arch'
2828 -O ==> set operating system to 'os'
2829 -T ==> set image type to 'type'
2830 -C ==> set compression type 'comp'
2831 -a ==> set load address to 'addr' (hex)
2832 -e ==> set entry point to 'ep' (hex)
2833 -n ==> set image name to 'name'
2834 -d ==> use image data from 'datafile'
wdenk24ee89b2002-11-03 17:56:27 +00002835
wdenk69459792004-05-29 16:53:29 +00002836Right now, all Linux kernels for PowerPC systems use the same load
2837address (0x00000000), but the entry point address depends on the
2838kernel version:
wdenkc6097192002-11-03 00:24:07 +00002839
wdenk2729af92004-05-03 20:45:30 +00002840- 2.2.x kernels have the entry point at 0x0000000C,
2841- 2.3.x and later kernels have the entry point at 0x00000000.
wdenkc6097192002-11-03 00:24:07 +00002842
wdenk2729af92004-05-03 20:45:30 +00002843So a typical call to build a U-Boot image would read:
wdenkc6097192002-11-03 00:24:07 +00002844
wdenk2729af92004-05-03 20:45:30 +00002845 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2846 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
Stefan Roesea47a12b2010-04-15 16:07:28 +02002847 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
wdenk2729af92004-05-03 20:45:30 +00002848 > examples/uImage.TQM850L
2849 Image Name: 2.4.4 kernel for TQM850L
2850 Created: Wed Jul 19 02:34:59 2000
2851 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2852 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2853 Load Address: 0x00000000
2854 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002855
wdenk2729af92004-05-03 20:45:30 +00002856To verify the contents of the image (or check for corruption):
wdenkc6097192002-11-03 00:24:07 +00002857
wdenk2729af92004-05-03 20:45:30 +00002858 -> tools/mkimage -l examples/uImage.TQM850L
2859 Image Name: 2.4.4 kernel for TQM850L
2860 Created: Wed Jul 19 02:34:59 2000
2861 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2862 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2863 Load Address: 0x00000000
2864 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002865
wdenk2729af92004-05-03 20:45:30 +00002866NOTE: for embedded systems where boot time is critical you can trade
2867speed for memory and install an UNCOMPRESSED image instead: this
2868needs more space in Flash, but boots much faster since it does not
2869need to be uncompressed:
wdenkc6097192002-11-03 00:24:07 +00002870
Stefan Roesea47a12b2010-04-15 16:07:28 +02002871 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
wdenk2729af92004-05-03 20:45:30 +00002872 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2873 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
Stefan Roesea47a12b2010-04-15 16:07:28 +02002874 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
wdenk2729af92004-05-03 20:45:30 +00002875 > examples/uImage.TQM850L-uncompressed
2876 Image Name: 2.4.4 kernel for TQM850L
2877 Created: Wed Jul 19 02:34:59 2000
2878 Image Type: PowerPC Linux Kernel Image (uncompressed)
2879 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
2880 Load Address: 0x00000000
2881 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002882
wdenkc6097192002-11-03 00:24:07 +00002883
wdenk2729af92004-05-03 20:45:30 +00002884Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2885when your kernel is intended to use an initial ramdisk:
wdenkdb01a2e2004-04-15 23:14:49 +00002886
wdenk2729af92004-05-03 20:45:30 +00002887 -> tools/mkimage -n 'Simple Ramdisk Image' \
2888 > -A ppc -O linux -T ramdisk -C gzip \
2889 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2890 Image Name: Simple Ramdisk Image
2891 Created: Wed Jan 12 14:01:50 2000
2892 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2893 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
2894 Load Address: 0x00000000
2895 Entry Point: 0x00000000
wdenkdb01a2e2004-04-15 23:14:49 +00002896
Tyler Hickse157a112020-10-26 10:40:24 -05002897The "dumpimage" tool can be used to disassemble or list the contents of images
2898built by mkimage. See dumpimage's help output (-h) for details.
wdenkdb01a2e2004-04-15 23:14:49 +00002899
wdenk2729af92004-05-03 20:45:30 +00002900Installing a Linux Image:
2901-------------------------
wdenkdb01a2e2004-04-15 23:14:49 +00002902
wdenk2729af92004-05-03 20:45:30 +00002903To downloading a U-Boot image over the serial (console) interface,
2904you must convert the image to S-Record format:
wdenkdb01a2e2004-04-15 23:14:49 +00002905
wdenk2729af92004-05-03 20:45:30 +00002906 objcopy -I binary -O srec examples/image examples/image.srec
wdenkdb01a2e2004-04-15 23:14:49 +00002907
wdenk2729af92004-05-03 20:45:30 +00002908The 'objcopy' does not understand the information in the U-Boot
2909image header, so the resulting S-Record file will be relative to
2910address 0x00000000. To load it to a given address, you need to
2911specify the target address as 'offset' parameter with the 'loads'
2912command.
wdenkc6097192002-11-03 00:24:07 +00002913
wdenk2729af92004-05-03 20:45:30 +00002914Example: install the image to address 0x40100000 (which on the
2915TQM8xxL is in the first Flash bank):
wdenkc6097192002-11-03 00:24:07 +00002916
wdenk2729af92004-05-03 20:45:30 +00002917 => erase 40100000 401FFFFF
wdenkc6097192002-11-03 00:24:07 +00002918
wdenk2729af92004-05-03 20:45:30 +00002919 .......... done
2920 Erased 8 sectors
wdenkc6097192002-11-03 00:24:07 +00002921
wdenk2729af92004-05-03 20:45:30 +00002922 => loads 40100000
2923 ## Ready for S-Record download ...
2924 ~>examples/image.srec
2925 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2926 ...
2927 15989 15990 15991 15992
2928 [file transfer complete]
2929 [connected]
2930 ## Start Addr = 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002931
2932
wdenk2729af92004-05-03 20:45:30 +00002933You can check the success of the download using the 'iminfo' command;
Wolfgang Denk218ca722008-03-26 10:40:12 +01002934this includes a checksum verification so you can be sure no data
wdenk2729af92004-05-03 20:45:30 +00002935corruption happened:
wdenkc6097192002-11-03 00:24:07 +00002936
wdenk2729af92004-05-03 20:45:30 +00002937 => imi 40100000
wdenkc6097192002-11-03 00:24:07 +00002938
wdenk2729af92004-05-03 20:45:30 +00002939 ## Checking Image at 40100000 ...
2940 Image Name: 2.2.13 for initrd on TQM850L
2941 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2942 Data Size: 335725 Bytes = 327 kB = 0 MB
2943 Load Address: 00000000
2944 Entry Point: 0000000c
2945 Verifying Checksum ... OK
wdenkc6097192002-11-03 00:24:07 +00002946
2947
wdenk2729af92004-05-03 20:45:30 +00002948Boot Linux:
2949-----------
wdenkc6097192002-11-03 00:24:07 +00002950
wdenk2729af92004-05-03 20:45:30 +00002951The "bootm" command is used to boot an application that is stored in
2952memory (RAM or Flash). In case of a Linux kernel image, the contents
2953of the "bootargs" environment variable is passed to the kernel as
2954parameters. You can check and modify this variable using the
2955"printenv" and "setenv" commands:
wdenkc6097192002-11-03 00:24:07 +00002956
2957
wdenk2729af92004-05-03 20:45:30 +00002958 => printenv bootargs
2959 bootargs=root=/dev/ram
wdenkc6097192002-11-03 00:24:07 +00002960
wdenk2729af92004-05-03 20:45:30 +00002961 => 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 +00002962
wdenk2729af92004-05-03 20:45:30 +00002963 => printenv bootargs
2964 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 +00002965
wdenk2729af92004-05-03 20:45:30 +00002966 => bootm 40020000
2967 ## Booting Linux kernel at 40020000 ...
2968 Image Name: 2.2.13 for NFS on TQM850L
2969 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2970 Data Size: 381681 Bytes = 372 kB = 0 MB
2971 Load Address: 00000000
2972 Entry Point: 0000000c
2973 Verifying Checksum ... OK
2974 Uncompressing Kernel Image ... OK
2975 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
2976 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2977 time_init: decrementer frequency = 187500000/60
2978 Calibrating delay loop... 49.77 BogoMIPS
2979 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2980 ...
wdenkc6097192002-11-03 00:24:07 +00002981
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002982If you want to boot a Linux kernel with initial RAM disk, you pass
wdenk2729af92004-05-03 20:45:30 +00002983the memory addresses of both the kernel and the initrd image (PPBCOOT
2984format!) to the "bootm" command:
wdenkc6097192002-11-03 00:24:07 +00002985
wdenk2729af92004-05-03 20:45:30 +00002986 => imi 40100000 40200000
wdenkc6097192002-11-03 00:24:07 +00002987
wdenk2729af92004-05-03 20:45:30 +00002988 ## Checking Image at 40100000 ...
2989 Image Name: 2.2.13 for initrd on TQM850L
2990 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2991 Data Size: 335725 Bytes = 327 kB = 0 MB
2992 Load Address: 00000000
2993 Entry Point: 0000000c
2994 Verifying Checksum ... OK
wdenkc6097192002-11-03 00:24:07 +00002995
wdenk2729af92004-05-03 20:45:30 +00002996 ## Checking Image at 40200000 ...
2997 Image Name: Simple Ramdisk Image
2998 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2999 Data Size: 566530 Bytes = 553 kB = 0 MB
3000 Load Address: 00000000
3001 Entry Point: 00000000
3002 Verifying Checksum ... OK
wdenkc6097192002-11-03 00:24:07 +00003003
wdenk2729af92004-05-03 20:45:30 +00003004 => bootm 40100000 40200000
3005 ## Booting Linux kernel at 40100000 ...
3006 Image Name: 2.2.13 for initrd on TQM850L
3007 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3008 Data Size: 335725 Bytes = 327 kB = 0 MB
3009 Load Address: 00000000
3010 Entry Point: 0000000c
3011 Verifying Checksum ... OK
3012 Uncompressing Kernel Image ... OK
3013 ## Loading RAMDisk Image at 40200000 ...
3014 Image Name: Simple Ramdisk Image
3015 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3016 Data Size: 566530 Bytes = 553 kB = 0 MB
3017 Load Address: 00000000
3018 Entry Point: 00000000
3019 Verifying Checksum ... OK
3020 Loading Ramdisk ... OK
3021 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
3022 Boot arguments: root=/dev/ram
3023 time_init: decrementer frequency = 187500000/60
3024 Calibrating delay loop... 49.77 BogoMIPS
3025 ...
3026 RAMDISK: Compressed image found at block 0
3027 VFS: Mounted root (ext2 filesystem).
wdenkc6097192002-11-03 00:24:07 +00003028
wdenk2729af92004-05-03 20:45:30 +00003029 bash#
wdenkc6097192002-11-03 00:24:07 +00003030
Matthew McClintock02677682006-06-28 10:41:37 -05003031Boot Linux and pass a flat device tree:
3032-----------
3033
3034First, U-Boot must be compiled with the appropriate defines. See the section
3035titled "Linux Kernel Interface" above for a more in depth explanation. The
3036following is an example of how to start a kernel and pass an updated
3037flat device tree:
3038
3039=> print oftaddr
3040oftaddr=0x300000
3041=> print oft
3042oft=oftrees/mpc8540ads.dtb
3043=> tftp $oftaddr $oft
3044Speed: 1000, full duplex
3045Using TSEC0 device
3046TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3047Filename 'oftrees/mpc8540ads.dtb'.
3048Load address: 0x300000
3049Loading: #
3050done
3051Bytes transferred = 4106 (100a hex)
3052=> tftp $loadaddr $bootfile
3053Speed: 1000, full duplex
3054Using TSEC0 device
3055TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3056Filename 'uImage'.
3057Load address: 0x200000
3058Loading:############
3059done
3060Bytes transferred = 1029407 (fb51f hex)
3061=> print loadaddr
3062loadaddr=200000
3063=> print oftaddr
3064oftaddr=0x300000
3065=> bootm $loadaddr - $oftaddr
3066## Booting image at 00200000 ...
Wolfgang Denka9398e02006-11-27 15:32:42 +01003067 Image Name: Linux-2.6.17-dirty
3068 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3069 Data Size: 1029343 Bytes = 1005.2 kB
Matthew McClintock02677682006-06-28 10:41:37 -05003070 Load Address: 00000000
Wolfgang Denka9398e02006-11-27 15:32:42 +01003071 Entry Point: 00000000
Matthew McClintock02677682006-06-28 10:41:37 -05003072 Verifying Checksum ... OK
3073 Uncompressing Kernel Image ... OK
3074Booting using flat device tree at 0x300000
3075Using MPC85xx ADS machine description
3076Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3077[snip]
3078
3079
wdenk2729af92004-05-03 20:45:30 +00003080More About U-Boot Image Types:
3081------------------------------
wdenk6069ff22003-02-28 00:49:47 +00003082
wdenk2729af92004-05-03 20:45:30 +00003083U-Boot supports the following image types:
wdenk6069ff22003-02-28 00:49:47 +00003084
wdenk2729af92004-05-03 20:45:30 +00003085 "Standalone Programs" are directly runnable in the environment
3086 provided by U-Boot; it is expected that (if they behave
3087 well) you can continue to work in U-Boot after return from
3088 the Standalone Program.
3089 "OS Kernel Images" are usually images of some Embedded OS which
3090 will take over control completely. Usually these programs
3091 will install their own set of exception handlers, device
3092 drivers, set up the MMU, etc. - this means, that you cannot
3093 expect to re-enter U-Boot except by resetting the CPU.
3094 "RAMDisk Images" are more or less just data blocks, and their
3095 parameters (address, size) are passed to an OS kernel that is
3096 being started.
3097 "Multi-File Images" contain several images, typically an OS
3098 (Linux) kernel image and one or more data images like
3099 RAMDisks. This construct is useful for instance when you want
3100 to boot over the network using BOOTP etc., where the boot
3101 server provides just a single image file, but you want to get
3102 for instance an OS kernel and a RAMDisk image.
stroesec1551ea2003-04-04 15:53:41 +00003103
wdenk2729af92004-05-03 20:45:30 +00003104 "Multi-File Images" start with a list of image sizes, each
3105 image size (in bytes) specified by an "uint32_t" in network
3106 byte order. This list is terminated by an "(uint32_t)0".
3107 Immediately after the terminating 0 follow the images, one by
3108 one, all aligned on "uint32_t" boundaries (size rounded up to
3109 a multiple of 4 bytes).
stroesec1551ea2003-04-04 15:53:41 +00003110
wdenk2729af92004-05-03 20:45:30 +00003111 "Firmware Images" are binary images containing firmware (like
3112 U-Boot or FPGA images) which usually will be programmed to
3113 flash memory.
stroesec1551ea2003-04-04 15:53:41 +00003114
wdenk2729af92004-05-03 20:45:30 +00003115 "Script files" are command sequences that will be executed by
3116 U-Boot's command interpreter; this feature is especially
3117 useful when you configure U-Boot to use a real shell (hush)
3118 as command interpreter.
wdenk6069ff22003-02-28 00:49:47 +00003119
Marek Vasut44f074c2012-03-14 21:52:45 +00003120Booting the Linux zImage:
3121-------------------------
3122
3123On some platforms, it's possible to boot Linux zImage. This is done
3124using the "bootz" command. The syntax of "bootz" command is the same
3125as the syntax of "bootm" command.
3126
Tom Rini8ac28562013-05-16 11:40:11 -04003127Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
Marek Vasut017e1f32012-03-18 11:47:58 +00003128kernel with raw initrd images. The syntax is slightly different, the
3129address of the initrd must be augmented by it's size, in the following
3130format: "<initrd addres>:<initrd size>".
3131
wdenkc6097192002-11-03 00:24:07 +00003132
wdenk2729af92004-05-03 20:45:30 +00003133Standalone HOWTO:
3134=================
wdenkc6097192002-11-03 00:24:07 +00003135
wdenk2729af92004-05-03 20:45:30 +00003136One of the features of U-Boot is that you can dynamically load and
3137run "standalone" applications, which can use some resources of
3138U-Boot like console I/O functions or interrupt services.
wdenkc6097192002-11-03 00:24:07 +00003139
wdenk2729af92004-05-03 20:45:30 +00003140Two simple examples are included with the sources:
wdenkc6097192002-11-03 00:24:07 +00003141
wdenk2729af92004-05-03 20:45:30 +00003142"Hello World" Demo:
3143-------------------
wdenkc6097192002-11-03 00:24:07 +00003144
wdenk2729af92004-05-03 20:45:30 +00003145'examples/hello_world.c' contains a small "Hello World" Demo
3146application; it is automatically compiled when you build U-Boot.
3147It's configured to run at address 0x00040004, so you can play with it
3148like that:
wdenkc6097192002-11-03 00:24:07 +00003149
wdenk2729af92004-05-03 20:45:30 +00003150 => loads
3151 ## Ready for S-Record download ...
3152 ~>examples/hello_world.srec
3153 1 2 3 4 5 6 7 8 9 10 11 ...
3154 [file transfer complete]
3155 [connected]
3156 ## Start Addr = 0x00040004
wdenkc6097192002-11-03 00:24:07 +00003157
wdenk2729af92004-05-03 20:45:30 +00003158 => go 40004 Hello World! This is a test.
3159 ## Starting application at 0x00040004 ...
3160 Hello World
3161 argc = 7
3162 argv[0] = "40004"
3163 argv[1] = "Hello"
3164 argv[2] = "World!"
3165 argv[3] = "This"
3166 argv[4] = "is"
3167 argv[5] = "a"
3168 argv[6] = "test."
3169 argv[7] = "<NULL>"
3170 Hit any key to exit ...
wdenkc6097192002-11-03 00:24:07 +00003171
wdenk2729af92004-05-03 20:45:30 +00003172 ## Application terminated, rc = 0x0
wdenkc6097192002-11-03 00:24:07 +00003173
wdenk2729af92004-05-03 20:45:30 +00003174Another example, which demonstrates how to register a CPM interrupt
3175handler with the U-Boot code, can be found in 'examples/timer.c'.
3176Here, a CPM timer is set up to generate an interrupt every second.
3177The interrupt service routine is trivial, just printing a '.'
3178character, but this is just a demo program. The application can be
3179controlled by the following keys:
wdenkc6097192002-11-03 00:24:07 +00003180
wdenk2729af92004-05-03 20:45:30 +00003181 ? - print current values og the CPM Timer registers
3182 b - enable interrupts and start timer
3183 e - stop timer and disable interrupts
3184 q - quit application
wdenkc6097192002-11-03 00:24:07 +00003185
wdenk2729af92004-05-03 20:45:30 +00003186 => loads
3187 ## Ready for S-Record download ...
3188 ~>examples/timer.srec
3189 1 2 3 4 5 6 7 8 9 10 11 ...
3190 [file transfer complete]
3191 [connected]
3192 ## Start Addr = 0x00040004
wdenkc6097192002-11-03 00:24:07 +00003193
wdenk2729af92004-05-03 20:45:30 +00003194 => go 40004
3195 ## Starting application at 0x00040004 ...
3196 TIMERS=0xfff00980
3197 Using timer 1
3198 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
wdenkc6097192002-11-03 00:24:07 +00003199
wdenk2729af92004-05-03 20:45:30 +00003200Hit 'b':
3201 [q, b, e, ?] Set interval 1000000 us
3202 Enabling timer
3203Hit '?':
3204 [q, b, e, ?] ........
3205 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3206Hit '?':
3207 [q, b, e, ?] .
3208 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3209Hit '?':
3210 [q, b, e, ?] .
3211 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3212Hit '?':
3213 [q, b, e, ?] .
3214 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3215Hit 'e':
3216 [q, b, e, ?] ...Stopping timer
3217Hit 'q':
3218 [q, b, e, ?] ## Application terminated, rc = 0x0
wdenkc6097192002-11-03 00:24:07 +00003219
3220
wdenk2729af92004-05-03 20:45:30 +00003221Minicom warning:
3222================
wdenk85ec0bc2003-03-31 16:34:49 +00003223
wdenk2729af92004-05-03 20:45:30 +00003224Over time, many people have reported problems when trying to use the
3225"minicom" terminal emulation program for serial download. I (wd)
3226consider minicom to be broken, and recommend not to use it. Under
3227Unix, I recommend to use C-Kermit for general purpose use (and
3228especially for kermit binary protocol download ("loadb" command), and
Karl O. Pince53515a2012-10-01 05:11:56 +00003229use "cu" for S-Record download ("loads" command). See
Naoki Hayama047f6ec2020-10-08 13:17:16 +09003230https://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
Karl O. Pince53515a2012-10-01 05:11:56 +00003231for help with kermit.
3232
wdenk85ec0bc2003-03-31 16:34:49 +00003233
wdenk2729af92004-05-03 20:45:30 +00003234Nevertheless, if you absolutely want to use it try adding this
3235configuration to your "File transfer protocols" section:
wdenk52f52c12003-06-19 23:04:19 +00003236
wdenk2729af92004-05-03 20:45:30 +00003237 Name Program Name U/D FullScr IO-Red. Multi
3238 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3239 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
wdenk52f52c12003-06-19 23:04:19 +00003240
3241
wdenk2729af92004-05-03 20:45:30 +00003242NetBSD Notes:
3243=============
wdenkc6097192002-11-03 00:24:07 +00003244
wdenk2729af92004-05-03 20:45:30 +00003245Starting at version 0.9.2, U-Boot supports NetBSD both as host
3246(build U-Boot) and target system (boots NetBSD/mpc8xx).
wdenkc6097192002-11-03 00:24:07 +00003247
wdenk2729af92004-05-03 20:45:30 +00003248Building requires a cross environment; it is known to work on
3249NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3250need gmake since the Makefiles are not compatible with BSD make).
3251Note that the cross-powerpc package does not install include files;
3252attempting to build U-Boot will fail because <machine/ansi.h> is
3253missing. This file has to be installed and patched manually:
wdenkc6097192002-11-03 00:24:07 +00003254
wdenk2729af92004-05-03 20:45:30 +00003255 # cd /usr/pkg/cross/powerpc-netbsd/include
3256 # mkdir powerpc
3257 # ln -s powerpc machine
3258 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3259 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
wdenkc6097192002-11-03 00:24:07 +00003260
wdenk2729af92004-05-03 20:45:30 +00003261Native builds *don't* work due to incompatibilities between native
3262and U-Boot include files.
wdenkc6097192002-11-03 00:24:07 +00003263
wdenk2729af92004-05-03 20:45:30 +00003264Booting assumes that (the first part of) the image booted is a
3265stage-2 loader which in turn loads and then invokes the kernel
3266proper. Loader sources will eventually appear in the NetBSD source
3267tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
wdenk2a8af182005-04-13 10:02:42 +00003268meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
wdenkc6097192002-11-03 00:24:07 +00003269
3270
wdenk2729af92004-05-03 20:45:30 +00003271Implementation Internals:
3272=========================
wdenkc6097192002-11-03 00:24:07 +00003273
wdenk2729af92004-05-03 20:45:30 +00003274The following is not intended to be a complete description of every
3275implementation detail. However, it should help to understand the
3276inner workings of U-Boot and make it easier to port it to custom
3277hardware.
wdenkc6097192002-11-03 00:24:07 +00003278
3279
wdenk2729af92004-05-03 20:45:30 +00003280Initial Stack, Global Data:
3281---------------------------
wdenkc6097192002-11-03 00:24:07 +00003282
wdenk2729af92004-05-03 20:45:30 +00003283The implementation of U-Boot is complicated by the fact that U-Boot
3284starts running out of ROM (flash memory), usually without access to
3285system RAM (because the memory controller is not initialized yet).
3286This means that we don't have writable Data or BSS segments, and BSS
3287is not initialized as zero. To be able to get a C environment working
3288at all, we have to allocate at least a minimal stack. Implementation
3289options for this are defined and restricted by the CPU used: Some CPU
3290models provide on-chip memory (like the IMMR area on MPC8xx and
3291MPC826x processors), on others (parts of) the data cache can be
3292locked as (mis-) used as memory, etc.
wdenkc6097192002-11-03 00:24:07 +00003293
Wolfgang Denk218ca722008-03-26 10:40:12 +01003294 Chris Hallinan posted a good summary of these issues to the
Wolfgang Denk06682362008-12-30 22:56:11 +01003295 U-Boot mailing list:
wdenk43d96162003-03-06 00:02:04 +00003296
wdenk2729af92004-05-03 20:45:30 +00003297 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3298 From: "Chris Hallinan" <clh@net1plus.com>
3299 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3300 ...
wdenk43d96162003-03-06 00:02:04 +00003301
wdenk2729af92004-05-03 20:45:30 +00003302 Correct me if I'm wrong, folks, but the way I understand it
3303 is this: Using DCACHE as initial RAM for Stack, etc, does not
3304 require any physical RAM backing up the cache. The cleverness
3305 is that the cache is being used as a temporary supply of
3306 necessary storage before the SDRAM controller is setup. It's
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02003307 beyond the scope of this list to explain the details, but you
wdenk2729af92004-05-03 20:45:30 +00003308 can see how this works by studying the cache architecture and
3309 operation in the architecture and processor-specific manuals.
wdenk43d96162003-03-06 00:02:04 +00003310
wdenk2729af92004-05-03 20:45:30 +00003311 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3312 is another option for the system designer to use as an
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02003313 initial stack/RAM area prior to SDRAM being available. Either
wdenk2729af92004-05-03 20:45:30 +00003314 option should work for you. Using CS 4 should be fine if your
3315 board designers haven't used it for something that would
3316 cause you grief during the initial boot! It is frequently not
3317 used.
wdenk43d96162003-03-06 00:02:04 +00003318
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02003319 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
wdenk2729af92004-05-03 20:45:30 +00003320 with your processor/board/system design. The default value
3321 you will find in any recent u-boot distribution in
Stefan Roese8a316c92005-08-01 16:49:12 +02003322 walnut.h should work for you. I'd set it to a value larger
wdenk2729af92004-05-03 20:45:30 +00003323 than your SDRAM module. If you have a 64MB SDRAM module, set
3324 it above 400_0000. Just make sure your board has no resources
3325 that are supposed to respond to that address! That code in
3326 start.S has been around a while and should work as is when
3327 you get the config right.
wdenk43d96162003-03-06 00:02:04 +00003328
wdenk2729af92004-05-03 20:45:30 +00003329 -Chris Hallinan
3330 DS4.COM, Inc.
wdenk43d96162003-03-06 00:02:04 +00003331
wdenk2729af92004-05-03 20:45:30 +00003332It is essential to remember this, since it has some impact on the C
3333code for the initialization procedures:
wdenkc6097192002-11-03 00:24:07 +00003334
wdenk2729af92004-05-03 20:45:30 +00003335* Initialized global data (data segment) is read-only. Do not attempt
3336 to write it.
wdenkc6097192002-11-03 00:24:07 +00003337
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08003338* Do not use any uninitialized global data (or implicitly initialized
wdenk2729af92004-05-03 20:45:30 +00003339 as zero data - BSS segment) at all - this is undefined, initiali-
3340 zation is performed later (when relocating to RAM).
wdenkc6097192002-11-03 00:24:07 +00003341
wdenk2729af92004-05-03 20:45:30 +00003342* Stack space is very limited. Avoid big data buffers or things like
3343 that.
wdenkc6097192002-11-03 00:24:07 +00003344
wdenk2729af92004-05-03 20:45:30 +00003345Having only the stack as writable memory limits means we cannot use
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08003346normal global data to share information between the code. But it
wdenk2729af92004-05-03 20:45:30 +00003347turned out that the implementation of U-Boot can be greatly
3348simplified by making a global data structure (gd_t) available to all
3349functions. We could pass a pointer to this data as argument to _all_
3350functions, but this would bloat the code. Instead we use a feature of
3351the GCC compiler (Global Register Variables) to share the data: we
3352place a pointer (gd) to the global data into a register which we
3353reserve for this purpose.
wdenkc6097192002-11-03 00:24:07 +00003354
wdenk2729af92004-05-03 20:45:30 +00003355When choosing a register for such a purpose we are restricted by the
3356relevant (E)ABI specifications for the current architecture, and by
3357GCC's implementation.
wdenkc6097192002-11-03 00:24:07 +00003358
wdenk2729af92004-05-03 20:45:30 +00003359For PowerPC, the following registers have specific use:
3360 R1: stack pointer
Wolfgang Denke7670f62008-02-14 22:43:22 +01003361 R2: reserved for system use
wdenk2729af92004-05-03 20:45:30 +00003362 R3-R4: parameter passing and return values
3363 R5-R10: parameter passing
3364 R13: small data area pointer
3365 R30: GOT pointer
3366 R31: frame pointer
wdenkc6097192002-11-03 00:24:07 +00003367
Joakim Tjernlunde6bee802010-01-19 14:41:58 +01003368 (U-Boot also uses R12 as internal GOT pointer. r12
3369 is a volatile register so r12 needs to be reset when
3370 going back and forth between asm and C)
wdenkc6097192002-11-03 00:24:07 +00003371
Wolfgang Denke7670f62008-02-14 22:43:22 +01003372 ==> U-Boot will use R2 to hold a pointer to the global data
wdenkc6097192002-11-03 00:24:07 +00003373
wdenk2729af92004-05-03 20:45:30 +00003374 Note: on PPC, we could use a static initializer (since the
3375 address of the global data structure is known at compile time),
3376 but it turned out that reserving a register results in somewhat
3377 smaller code - although the code savings are not that big (on
3378 average for all boards 752 bytes for the whole U-Boot image,
3379 624 text + 127 data).
wdenkc6097192002-11-03 00:24:07 +00003380
wdenk2729af92004-05-03 20:45:30 +00003381On ARM, the following registers are used:
wdenkc6097192002-11-03 00:24:07 +00003382
wdenk2729af92004-05-03 20:45:30 +00003383 R0: function argument word/integer result
3384 R1-R3: function argument word
Jeroen Hofstee12eba1b2013-09-21 14:04:42 +02003385 R9: platform specific
3386 R10: stack limit (used only if stack checking is enabled)
wdenk2729af92004-05-03 20:45:30 +00003387 R11: argument (frame) pointer
3388 R12: temporary workspace
3389 R13: stack pointer
3390 R14: link register
3391 R15: program counter
wdenkc6097192002-11-03 00:24:07 +00003392
Jeroen Hofstee12eba1b2013-09-21 14:04:42 +02003393 ==> U-Boot will use R9 to hold a pointer to the global data
3394
3395 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
wdenkc6097192002-11-03 00:24:07 +00003396
Thomas Chou0df01fd2010-05-21 11:08:03 +08003397On Nios II, the ABI is documented here:
Naoki Hayama047f6ec2020-10-08 13:17:16 +09003398 https://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
Thomas Chou0df01fd2010-05-21 11:08:03 +08003399
3400 ==> U-Boot will use gp to hold a pointer to the global data
3401
3402 Note: on Nios II, we give "-G0" option to gcc and don't use gp
3403 to access small data sections, so gp is free.
3404
Macpaul Linafc1ce82011-10-19 20:41:11 +00003405On NDS32, the following registers are used:
3406
3407 R0-R1: argument/return
3408 R2-R5: argument
3409 R15: temporary register for assembler
3410 R16: trampoline register
3411 R28: frame pointer (FP)
3412 R29: global pointer (GP)
3413 R30: link register (LP)
3414 R31: stack pointer (SP)
3415 PC: program counter (PC)
3416
3417 ==> U-Boot will use R10 to hold a pointer to the global data
3418
Wolfgang Denkd87080b2006-03-31 18:32:53 +02003419NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3420or current versions of GCC may "optimize" the code too much.
wdenkc6097192002-11-03 00:24:07 +00003421
Rick Chen3fafced2017-12-26 13:55:59 +08003422On RISC-V, the following registers are used:
3423
3424 x0: hard-wired zero (zero)
3425 x1: return address (ra)
3426 x2: stack pointer (sp)
3427 x3: global pointer (gp)
3428 x4: thread pointer (tp)
3429 x5: link register (t0)
3430 x8: frame pointer (fp)
3431 x10-x11: arguments/return values (a0-1)
3432 x12-x17: arguments (a2-7)
3433 x28-31: temporaries (t3-6)
3434 pc: program counter (pc)
3435
3436 ==> U-Boot will use gp to hold a pointer to the global data
3437
wdenk2729af92004-05-03 20:45:30 +00003438Memory Management:
3439------------------
wdenkc6097192002-11-03 00:24:07 +00003440
wdenk2729af92004-05-03 20:45:30 +00003441U-Boot runs in system state and uses physical addresses, i.e. the
3442MMU is not used either for address mapping nor for memory protection.
wdenkc6097192002-11-03 00:24:07 +00003443
wdenk2729af92004-05-03 20:45:30 +00003444The available memory is mapped to fixed addresses using the memory
3445controller. In this process, a contiguous block is formed for each
3446memory type (Flash, SDRAM, SRAM), even when it consists of several
3447physical memory banks.
wdenkc6097192002-11-03 00:24:07 +00003448
wdenk2729af92004-05-03 20:45:30 +00003449U-Boot is installed in the first 128 kB of the first Flash bank (on
3450TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3451booting and sizing and initializing DRAM, the code relocates itself
3452to the upper end of DRAM. Immediately below the U-Boot code some
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02003453memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
wdenk2729af92004-05-03 20:45:30 +00003454configuration setting]. Below that, a structure with global Board
3455Info data is placed, followed by the stack (growing downward).
wdenkc6097192002-11-03 00:24:07 +00003456
wdenk2729af92004-05-03 20:45:30 +00003457Additionally, some exception handler code is copied to the low 8 kB
3458of DRAM (0x00000000 ... 0x00001FFF).
wdenkc6097192002-11-03 00:24:07 +00003459
wdenk2729af92004-05-03 20:45:30 +00003460So a typical memory configuration with 16 MB of DRAM could look like
3461this:
wdenkc6097192002-11-03 00:24:07 +00003462
wdenk2729af92004-05-03 20:45:30 +00003463 0x0000 0000 Exception Vector code
3464 :
3465 0x0000 1FFF
3466 0x0000 2000 Free for Application Use
3467 :
3468 :
wdenkc6097192002-11-03 00:24:07 +00003469
wdenk2729af92004-05-03 20:45:30 +00003470 :
3471 :
3472 0x00FB FF20 Monitor Stack (Growing downward)
3473 0x00FB FFAC Board Info Data and permanent copy of global data
3474 0x00FC 0000 Malloc Arena
3475 :
3476 0x00FD FFFF
3477 0x00FE 0000 RAM Copy of Monitor Code
3478 ... eventually: LCD or video framebuffer
3479 ... eventually: pRAM (Protected RAM - unchanged by reset)
3480 0x00FF FFFF [End of RAM]
wdenkc6097192002-11-03 00:24:07 +00003481
3482
wdenk2729af92004-05-03 20:45:30 +00003483System Initialization:
3484----------------------
wdenkc6097192002-11-03 00:24:07 +00003485
wdenk2729af92004-05-03 20:45:30 +00003486In the reset configuration, U-Boot starts at the reset entry point
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02003487(on most PowerPC systems at address 0x00000100). Because of the reset
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08003488configuration for CS0# this is a mirror of the on board Flash memory.
wdenk2729af92004-05-03 20:45:30 +00003489To be able to re-map memory U-Boot then jumps to its link address.
3490To be able to implement the initialization code in C, a (small!)
3491initial stack is set up in the internal Dual Ported RAM (in case CPUs
Heiko Schocher2eb48ff2017-06-07 17:33:10 +02003492which provide such a feature like), or in a locked part of the data
3493cache. After that, U-Boot initializes the CPU core, the caches and
3494the SIU.
wdenkc6097192002-11-03 00:24:07 +00003495
wdenk2729af92004-05-03 20:45:30 +00003496Next, all (potentially) available memory banks are mapped using a
3497preliminary mapping. For example, we put them on 512 MB boundaries
3498(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3499on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3500programmed for SDRAM access. Using the temporary configuration, a
3501simple memory test is run that determines the size of the SDRAM
3502banks.
wdenkc6097192002-11-03 00:24:07 +00003503
wdenk2729af92004-05-03 20:45:30 +00003504When there is more than one SDRAM bank, and the banks are of
3505different size, the largest is mapped first. For equal size, the first
3506bank (CS2#) is mapped first. The first mapping is always for address
35070x00000000, with any additional banks following immediately to create
3508contiguous memory starting from 0.
wdenkc6097192002-11-03 00:24:07 +00003509
wdenk2729af92004-05-03 20:45:30 +00003510Then, the monitor installs itself at the upper end of the SDRAM area
3511and allocates memory for use by malloc() and for the global Board
3512Info data; also, the exception vector code is copied to the low RAM
3513pages, and the final stack is set up.
wdenkc6097192002-11-03 00:24:07 +00003514
wdenk2729af92004-05-03 20:45:30 +00003515Only after this relocation will you have a "normal" C environment;
3516until that you are restricted in several ways, mostly because you are
3517running from ROM, and because the code will have to be relocated to a
3518new address in RAM.
wdenkc6097192002-11-03 00:24:07 +00003519
3520
wdenk2729af92004-05-03 20:45:30 +00003521U-Boot Porting Guide:
3522----------------------
wdenkc6097192002-11-03 00:24:07 +00003523
wdenk2729af92004-05-03 20:45:30 +00003524[Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3525list, October 2002]
wdenkc6097192002-11-03 00:24:07 +00003526
3527
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04003528int main(int argc, char *argv[])
wdenk2729af92004-05-03 20:45:30 +00003529{
3530 sighandler_t no_more_time;
wdenkc6097192002-11-03 00:24:07 +00003531
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04003532 signal(SIGALRM, no_more_time);
3533 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
wdenkc6097192002-11-03 00:24:07 +00003534
wdenk2729af92004-05-03 20:45:30 +00003535 if (available_money > available_manpower) {
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04003536 Pay consultant to port U-Boot;
wdenkc6097192002-11-03 00:24:07 +00003537 return 0;
3538 }
3539
wdenk2729af92004-05-03 20:45:30 +00003540 Download latest U-Boot source;
3541
Wolfgang Denk06682362008-12-30 22:56:11 +01003542 Subscribe to u-boot mailing list;
wdenk2729af92004-05-03 20:45:30 +00003543
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04003544 if (clueless)
3545 email("Hi, I am new to U-Boot, how do I get started?");
wdenkc6097192002-11-03 00:24:07 +00003546
wdenk2729af92004-05-03 20:45:30 +00003547 while (learning) {
3548 Read the README file in the top level directory;
Naoki Hayama047f6ec2020-10-08 13:17:16 +09003549 Read https://www.denx.de/wiki/bin/view/DULG/Manual;
Patrick Delaunay24bcaec2020-02-28 15:18:10 +01003550 Read applicable doc/README.*;
wdenk2729af92004-05-03 20:45:30 +00003551 Read the source, Luke;
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04003552 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
wdenk2729af92004-05-03 20:45:30 +00003553 }
wdenkc6097192002-11-03 00:24:07 +00003554
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04003555 if (available_money > toLocalCurrency ($2500))
3556 Buy a BDI3000;
3557 else
wdenk2729af92004-05-03 20:45:30 +00003558 Add a lot of aggravation and time;
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04003559
3560 if (a similar board exists) { /* hopefully... */
3561 cp -a board/<similar> board/<myboard>
3562 cp include/configs/<similar>.h include/configs/<myboard>.h
3563 } else {
3564 Create your own board support subdirectory;
3565 Create your own board include/configs/<myboard>.h file;
wdenk2729af92004-05-03 20:45:30 +00003566 }
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04003567 Edit new board/<myboard> files
3568 Edit new include/configs/<myboard>.h
wdenkc6097192002-11-03 00:24:07 +00003569
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04003570 while (!accepted) {
3571 while (!running) {
3572 do {
3573 Add / modify source code;
3574 } until (compiles);
3575 Debug;
3576 if (clueless)
3577 email("Hi, I am having problems...");
3578 }
3579 Send patch file to the U-Boot email list;
3580 if (reasonable critiques)
3581 Incorporate improvements from email list code review;
3582 else
3583 Defend code as written;
wdenk2729af92004-05-03 20:45:30 +00003584 }
wdenkc6097192002-11-03 00:24:07 +00003585
wdenk2729af92004-05-03 20:45:30 +00003586 return 0;
3587}
3588
3589void no_more_time (int sig)
3590{
3591 hire_a_guru();
3592}
wdenkc6097192002-11-03 00:24:07 +00003593
3594
wdenk2729af92004-05-03 20:45:30 +00003595Coding Standards:
3596-----------------
wdenkc6097192002-11-03 00:24:07 +00003597
wdenk2729af92004-05-03 20:45:30 +00003598All contributions to U-Boot should conform to the Linux kernel
Baruch Siach659208d2017-12-10 17:34:35 +02003599coding style; see the kernel coding style guide at
3600https://www.kernel.org/doc/html/latest/process/coding-style.html, and the
3601script "scripts/Lindent" in your Linux kernel source directory.
wdenk2729af92004-05-03 20:45:30 +00003602
Detlev Zundel2c051652006-09-01 15:39:02 +02003603Source files originating from a different project (for example the
3604MTD subsystem) are generally exempt from these guidelines and are not
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08003605reformatted to ease subsequent migration to newer versions of those
Detlev Zundel2c051652006-09-01 15:39:02 +02003606sources.
3607
3608Please note that U-Boot is implemented in C (and to some small parts in
3609Assembler); no C++ is used, so please do not use C++ style comments (//)
3610in your code.
wdenk2729af92004-05-03 20:45:30 +00003611
3612Please also stick to the following formatting rules:
3613- remove any trailing white space
Wolfgang Denk7ca92962011-07-27 10:59:55 +00003614- use TAB characters for indentation and vertical alignment, not spaces
wdenk2729af92004-05-03 20:45:30 +00003615- make sure NOT to use DOS '\r\n' line feeds
Wolfgang Denk7ca92962011-07-27 10:59:55 +00003616- do not add more than 2 consecutive empty lines to source files
wdenk2729af92004-05-03 20:45:30 +00003617- do not add trailing empty lines to source files
3618
3619Submissions which do not conform to the standards may be returned
3620with a request to reformat the changes.
wdenkc6097192002-11-03 00:24:07 +00003621
3622
wdenk2729af92004-05-03 20:45:30 +00003623Submitting Patches:
3624-------------------
wdenkc6097192002-11-03 00:24:07 +00003625
wdenk2729af92004-05-03 20:45:30 +00003626Since the number of patches for U-Boot is growing, we need to
3627establish some rules. Submissions which do not conform to these rules
3628may be rejected, even when they contain important and valuable stuff.
wdenkc6097192002-11-03 00:24:07 +00003629
Naoki Hayama047f6ec2020-10-08 13:17:16 +09003630Please see https://www.denx.de/wiki/U-Boot/Patches for details.
Wolfgang Denk218ca722008-03-26 10:40:12 +01003631
Wolfgang Denk06682362008-12-30 22:56:11 +01003632Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
S. Lockwood-Childs1dade182017-11-14 22:56:42 -08003633see https://lists.denx.de/listinfo/u-boot
Wolfgang Denk06682362008-12-30 22:56:11 +01003634
wdenk2729af92004-05-03 20:45:30 +00003635When you send a patch, please include the following information with
3636it:
wdenkc6097192002-11-03 00:24:07 +00003637
wdenk2729af92004-05-03 20:45:30 +00003638* For bug fixes: a description of the bug and how your patch fixes
3639 this bug. Please try to include a way of demonstrating that the
3640 patch actually fixes something.
wdenkc6097192002-11-03 00:24:07 +00003641
wdenk2729af92004-05-03 20:45:30 +00003642* For new features: a description of the feature and your
3643 implementation.
wdenkc6097192002-11-03 00:24:07 +00003644
Robert P. J. Day7207b362015-12-19 07:16:10 -05003645* For major contributions, add a MAINTAINERS file with your
3646 information and associated file and directory references.
wdenk2729af92004-05-03 20:45:30 +00003647
Albert ARIBAUD27af9302013-09-11 15:52:51 +02003648* When you add support for a new board, don't forget to add a
3649 maintainer e-mail address to the boards.cfg file, too.
wdenk2729af92004-05-03 20:45:30 +00003650
3651* If your patch adds new configuration options, don't forget to
3652 document these in the README file.
3653
Wolfgang Denk218ca722008-03-26 10:40:12 +01003654* The patch itself. If you are using git (which is *strongly*
3655 recommended) you can easily generate the patch using the
Wolfgang Denk7ca92962011-07-27 10:59:55 +00003656 "git format-patch". If you then use "git send-email" to send it to
Wolfgang Denk218ca722008-03-26 10:40:12 +01003657 the U-Boot mailing list, you will avoid most of the common problems
3658 with some other mail clients.
wdenk2729af92004-05-03 20:45:30 +00003659
Wolfgang Denk218ca722008-03-26 10:40:12 +01003660 If you cannot use git, use "diff -purN OLD NEW". If your version of
3661 diff does not support these options, then get the latest version of
3662 GNU diff.
wdenk2729af92004-05-03 20:45:30 +00003663
Wolfgang Denk218ca722008-03-26 10:40:12 +01003664 The current directory when running this command shall be the parent
3665 directory of the U-Boot source tree (i. e. please make sure that
3666 your patch includes sufficient directory information for the
3667 affected files).
3668
3669 We prefer patches as plain text. MIME attachments are discouraged,
3670 and compressed attachments must not be used.
wdenk2729af92004-05-03 20:45:30 +00003671
3672* If one logical set of modifications affects or creates several
3673 files, all these changes shall be submitted in a SINGLE patch file.
3674
3675* Changesets that contain different, unrelated modifications shall be
3676 submitted as SEPARATE patches, one patch per changeset.
3677
3678
3679Notes:
3680
Simon Glass6de80f22016-07-27 20:33:08 -06003681* Before sending the patch, run the buildman script on your patched
wdenk2729af92004-05-03 20:45:30 +00003682 source tree and make sure that no errors or warnings are reported
3683 for any of the boards.
3684
3685* Keep your modifications to the necessary minimum: A patch
3686 containing several unrelated changes or arbitrary reformats will be
3687 returned with a request to re-formatting / split it.
3688
3689* If you modify existing code, make sure that your new code does not
3690 add to the memory footprint of the code ;-) Small is beautiful!
3691 When adding new features, these should compile conditionally only
3692 (using #ifdef), and the resulting code with the new feature
3693 disabled must not need more memory than the old code without your
3694 modification.
wdenk90dc6702005-05-03 14:12:25 +00003695
Wolfgang Denk06682362008-12-30 22:56:11 +01003696* Remember that there is a size limit of 100 kB per message on the
3697 u-boot mailing list. Bigger patches will be moderated. If they are
3698 reasonable and not too big, they will be acknowledged. But patches
3699 bigger than the size limit should be avoided.