blob: 623f35907217ff17881e1b1f71438238abf3965a [file] [log] [blame]
Tom Rini10e47792018-05-06 17:58:06 -04001# SPDX-License-Identifier: GPL-2.0+
wdenkc6097192002-11-03 00:24:07 +00002#
Wolfgang Denk1234ce72013-06-21 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
wdenkce4832c2004-10-17 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. Day076ed9b2015-12-19 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. Day076ed9b2015-12-19 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. Day974ed2f2012-11-14 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. Day076ed9b2015-12-19 07:16:10 -050051U-Boot, you should send a message to the U-Boot mailing list at
Peter Tyser8804a612008-09-10 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 Hayama2bc50c22020-10-08 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 Denkb240aef2008-03-26 10:40:12 +010057Where to get source code:
58=========================
59
Robert P. J. Day076ed9b2015-12-19 07:16:10 -050060The U-Boot source code is maintained in the Git repository at
Heinrich Schuchardt28b2b852021-02-24 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 Denkb240aef2008-03-26 10:40:12 +010063
Naoki Hayama65ae68a2020-10-08 13:16:25 +090064The "Tags" links on this page allow you to download tarballs of
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +020065any version you might be interested in. Official releases are also
Naoki Hayama65ae68a2020-10-08 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 Denkb240aef2008-03-26 10:40:12 +010069
70
wdenkc6097192002-11-03 00:24:07 +000071Where we come from:
72===================
73
74- start from 8xxrom sources
Naoki Hayamae0cc1852020-10-08 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 Glassaaef3bf2019-08-01 09:47:14 -060083 * ATA disk / SCSI ... boot
Naoki Hayamae0cc1852020-10-08 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 Hayamae0cc1852020-10-08 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:
wdenkc6097192002-11-03 00:24:07 +0000107
wdenk24ee89b2002-11-03 17:56:27 +0000108 U_BOOT_VERSION u_boot_logo
109 IH_OS_U_BOOT u_boot_hush_start
110
wdenkc6097192002-11-03 00:24:07 +0000111
wdenk7474aca2002-12-17 17:55:09 +0000112Versioning:
113===========
114
Thomas Webere89e6282010-09-28 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.
wdenk7474aca2002-12-17 17:55:09 +0000121
Thomas Webere89e6282010-09-28 08:06:25 +0200122Examples:
Wolfgang Denk092ae952011-10-26 10:21:21 +0000123 U-Boot v2009.11 - Release November 2009
Thomas Webere89e6282010-09-28 08:06:25 +0200124 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
Jelle van der Waa30245ca2016-10-30 17:30:30 +0100125 U-Boot v2010.09-rc1 - Release candidate 1 for September 2010 release
wdenk7474aca2002-12-17 17:55:09 +0000126
127
wdenkc6097192002-11-03 00:24:07 +0000128Directory Hierarchy:
129====================
130
Simon Glass1a0a4ac2021-07-10 21:14:21 -0600131/arch Architecture-specific files
Masahiro Yamadaef6ebff2014-03-07 18:02:02 +0900132 /arc Files generic to ARC architecture
Peter Tysere4d1abc2010-04-12 22:28:21 -0500133 /arm Files generic to ARM architecture
Peter Tysere4d1abc2010-04-12 22:28:21 -0500134 /m68k Files generic to m68k architecture
Peter Tysere4d1abc2010-04-12 22:28:21 -0500135 /microblaze Files generic to microblaze architecture
Peter Tysere4d1abc2010-04-12 22:28:21 -0500136 /mips Files generic to MIPS architecture
Peter Tysere4d1abc2010-04-12 22:28:21 -0500137 /nios2 Files generic to Altera NIOS2 architecture
Stefan Roese88fbf932010-04-15 16:07:28 +0200138 /powerpc Files generic to PowerPC architecture
Rick Chend7e6f922017-12-26 13:55:59 +0800139 /riscv Files generic to RISC-V architecture
Robert P. J. Day076ed9b2015-12-19 07:16:10 -0500140 /sandbox Files generic to HW-independent "sandbox"
Peter Tysere4d1abc2010-04-12 22:28:21 -0500141 /sh Files generic to SH architecture
Robert P. J. Daya269c932013-09-15 18:34:15 -0400142 /x86 Files generic to x86 architecture
Naoki Hayama411f5c62020-10-08 13:16:38 +0900143 /xtensa Files generic to Xtensa architecture
Simon Glass1a0a4ac2021-07-10 21:14:21 -0600144/api Machine/arch-independent API for external apps
145/board Board-dependent files
Simon Glass91944df2021-10-14 12:47:54 -0600146/boot Support for images and booting
Xu Ziyuanfb1f9392016-08-26 19:54:49 +0800147/cmd U-Boot commands functions
Simon Glass1a0a4ac2021-07-10 21:14:21 -0600148/common Misc architecture-independent functions
Robert P. J. Day076ed9b2015-12-19 07:16:10 -0500149/configs Board default configuration files
Peter Tysere4d1abc2010-04-12 22:28:21 -0500150/disk Code for disk drive partition handling
Simon Glass1a0a4ac2021-07-10 21:14:21 -0600151/doc Documentation (a mix of ReST and READMEs)
152/drivers Device drivers
153/dts Makefile for building internal U-Boot fdt.
154/env Environment support
Peter Tysere4d1abc2010-04-12 22:28:21 -0500155/examples Example code for standalone applications, etc.
156/fs Filesystem code (cramfs, ext2, jffs2, etc.)
157/include Header Files
Robert P. J. Day076ed9b2015-12-19 07:16:10 -0500158/lib Library routines generic to all architectures
159/Licenses Various license files
Peter Tysere4d1abc2010-04-12 22:28:21 -0500160/net Networking code
161/post Power On Self Test
Robert P. J. Day076ed9b2015-12-19 07:16:10 -0500162/scripts Various build scripts and Makefiles
163/test Various unit test files
Simon Glass1a0a4ac2021-07-10 21:14:21 -0600164/tools Tools to build and sign FIT images, etc.
wdenkc6097192002-11-03 00:24:07 +0000165
wdenkc6097192002-11-03 00:24:07 +0000166Software Configuration:
167=======================
168
wdenkc6097192002-11-03 00:24:07 +0000169Selection of Processor Architecture and Board Type:
170---------------------------------------------------
171
172For all supported boards there are ready-to-use default
Holger Freyther7ba4e572014-08-04 09:26:05 +0200173configurations available; just type "make <board_name>_defconfig".
wdenkc6097192002-11-03 00:24:07 +0000174
175Example: For a TQM823L module type:
176
177 cd u-boot
Holger Freyther7ba4e572014-08-04 09:26:05 +0200178 make TQM823L_defconfig
wdenkc6097192002-11-03 00:24:07 +0000179
Robert P. J. Day076ed9b2015-12-19 07:16:10 -0500180Note: If you're looking for the default configuration file for a board
181you're sure used to be there but is now missing, check the file
182doc/README.scrapyard for a list of no longer supported boards.
wdenkc6097192002-11-03 00:24:07 +0000183
Simon Glass53552c92014-03-22 17:12:59 -0600184Sandbox Environment:
185--------------------
186
187U-Boot can be built natively to run on a Linux host using the 'sandbox'
188board. This allows feature development which is not board- or architecture-
189specific to be undertaken on a native platform. The sandbox is also used to
190run some of U-Boot's tests.
191
Naoki Hayamadd860ca2020-10-08 13:16:58 +0900192See doc/arch/sandbox.rst for more details.
Simon Glass53552c92014-03-22 17:12:59 -0600193
194
Simon Glassd8711af2015-03-03 08:03:00 -0700195Board Initialisation Flow:
196--------------------------
197
198This is the intended start-up flow for boards. This should apply for both
Robert P. J. Day076ed9b2015-12-19 07:16:10 -0500199SPL and U-Boot proper (i.e. they both follow the same rules).
200
201Note: "SPL" stands for "Secondary Program Loader," which is explained in
202more detail later in this file.
203
204At present, SPL mostly uses a separate code path, but the function names
205and roles of each function are the same. Some boards or architectures
206may not conform to this. At least most ARM boards which use
207CONFIG_SPL_FRAMEWORK conform to this.
Simon Glassd8711af2015-03-03 08:03:00 -0700208
Robert P. J. Day076ed9b2015-12-19 07:16:10 -0500209Execution typically starts with an architecture-specific (and possibly
210CPU-specific) start.S file, such as:
211
212 - arch/arm/cpu/armv7/start.S
213 - arch/powerpc/cpu/mpc83xx/start.S
214 - arch/mips/cpu/start.S
215
216and so on. From there, three functions are called; the purpose and
217limitations of each of these functions are described below.
Simon Glassd8711af2015-03-03 08:03:00 -0700218
219lowlevel_init():
220 - purpose: essential init to permit execution to reach board_init_f()
221 - no global_data or BSS
222 - there is no stack (ARMv7 may have one but it will soon be removed)
223 - must not set up SDRAM or use console
224 - must only do the bare minimum to allow execution to continue to
225 board_init_f()
226 - this is almost never needed
227 - return normally from this function
228
229board_init_f():
230 - purpose: set up the machine ready for running board_init_r():
231 i.e. SDRAM and serial UART
232 - global_data is available
233 - stack is in SRAM
234 - BSS is not available, so you cannot use global/static variables,
235 only stack variables and global_data
236
237 Non-SPL-specific notes:
238 - dram_init() is called to set up DRAM. If already done in SPL this
239 can do nothing
240
241 SPL-specific notes:
242 - you can override the entire board_init_f() function with your own
243 version as needed.
244 - preloader_console_init() can be called here in extremis
245 - should set up SDRAM, and anything needed to make the UART work
Naoki Hayamaebfd8192020-09-24 15:57:19 +0900246 - there is no need to clear BSS, it will be done by crt0.S
Andreas Dannenberg7673bed2019-08-08 12:54:49 -0500247 - for specific scenarios on certain architectures an early BSS *can*
248 be made available (via CONFIG_SPL_EARLY_BSS by moving the clearing
249 of BSS prior to entering board_init_f()) but doing so is discouraged.
250 Instead it is strongly recommended to architect any code changes
251 or additions such to not depend on the availability of BSS during
252 board_init_f() as indicated in other sections of this README to
253 maintain compatibility and consistency across the entire code base.
Simon Glassd8711af2015-03-03 08:03:00 -0700254 - must return normally from this function (don't call board_init_r()
255 directly)
256
257Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
258this point the stack and global_data are relocated to below
259CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
260memory.
261
262board_init_r():
263 - purpose: main execution, common code
264 - global_data is available
265 - SDRAM is available
266 - BSS is available, all static/global variables can be used
267 - execution eventually continues to main_loop()
268
269 Non-SPL-specific notes:
270 - U-Boot is relocated to the top of memory and is now running from
271 there.
272
273 SPL-specific notes:
274 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
Ashish Kumar11234062017-08-11 11:09:14 +0530275 CONFIG_SYS_FSL_HAS_CCI400
276
277 Defined For SoC that has cache coherent interconnect
278 CCN-400
wdenk1272e232002-11-10 22:06:23 +0000279
Ashish Kumar97393d62017-08-18 10:54:36 +0530280 CONFIG_SYS_FSL_HAS_CCN504
281
282 Defined for SoC that has cache coherent interconnect CCN-504
283
wdenkc6097192002-11-03 00:24:07 +0000284The following options need to be configured:
285
Kim Phillips203fee32007-08-10 13:28:25 -0500286- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
wdenkc6097192002-11-03 00:24:07 +0000287
Kim Phillips203fee32007-08-10 13:28:25 -0500288- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
Wolfgang Denk994ad962006-10-24 14:42:37 +0200289
Kumar Galaf4fb90f2011-02-18 05:40:54 -0600290- 85xx CPU Options:
York Sun2394a0f2012-10-08 07:44:30 +0000291 CONFIG_SYS_PPC64
292
293 Specifies that the core is a 64-bit PowerPC implementation (implements
294 the "64" category of the Power ISA). This is necessary for ePAPR
295 compliance, among other possible reasons.
296
Kumar Galaf4fb90f2011-02-18 05:40:54 -0600297 CONFIG_SYS_FSL_TBCLK_DIV
298
299 Defines the core time base clock divider ratio compared to the
300 system clock. On most PQ3 devices this is 8, on newer QorIQ
301 devices it can be 16 or 32. The ratio varies from SoC to Soc.
302
Kumar Gala179b1b22011-05-20 00:39:21 -0500303 CONFIG_SYS_FSL_PCIE_COMPAT
304
305 Defines the string to utilize when trying to match PCIe device
306 tree nodes for the given platform.
307
Scott Wood80806962012-08-14 10:14:53 +0000308 CONFIG_SYS_FSL_ERRATUM_A004510
309
310 Enables a workaround for erratum A004510. If set,
311 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
312 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
313
314 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
315 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
316
317 Defines one or two SoC revisions (low 8 bits of SVR)
318 for which the A004510 workaround should be applied.
319
320 The rest of SVR is either not relevant to the decision
321 of whether the erratum is present (e.g. p2040 versus
322 p2041) or is implied by the build target, which controls
323 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
324
325 See Freescale App Note 4493 for more information about
326 this erratum.
327
328 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
329
330 This is the value to write into CCSR offset 0x18600
331 according to the A004510 workaround.
332
Priyanka Jainc73b9032013-07-02 09:21:04 +0530333 CONFIG_SYS_FSL_DSP_DDR_ADDR
334 This value denotes start offset of DDR memory which is
335 connected exclusively to the DSP cores.
336
Priyanka Jainf81e8b22013-04-04 09:31:54 +0530337 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
338 This value denotes start offset of M2 memory
339 which is directly connected to the DSP core.
340
Priyanka Jainc73b9032013-07-02 09:21:04 +0530341 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
342 This value denotes start offset of M3 memory which is directly
343 connected to the DSP core.
344
Priyanka Jainf81e8b22013-04-04 09:31:54 +0530345 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
346 This value denotes start offset of DSP CCSR space.
347
Priyanka Jaine9dcaa82013-12-17 14:25:52 +0530348 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
349 Single Source Clock is clocking mode present in some of FSL SoC's.
350 In this mode, a single differential clock is used to supply
351 clocks to the sysclock, ddrclock and usbclock.
352
Daniel Schwierzeckd8a49ca2012-04-02 02:57:56 +0000353- Generic CPU options:
354 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
355
356 Defines the endianess of the CPU. Implementation of those
357 values is arch specific.
358
York Sunf0626592013-09-30 09:22:09 -0700359 CONFIG_SYS_FSL_DDR
360 Freescale DDR driver in use. This type of DDR controller is
Tom Rinie5404982021-05-14 21:34:26 -0400361 found in mpc83xx, mpc85xx as well as some ARM core SoCs.
York Sunf0626592013-09-30 09:22:09 -0700362
363 CONFIG_SYS_FSL_DDR_ADDR
364 Freescale DDR memory-mapped register base.
365
York Sunf0626592013-09-30 09:22:09 -0700366 CONFIG_SYS_FSL_DDRC_GEN1
367 Freescale DDR1 controller.
368
369 CONFIG_SYS_FSL_DDRC_GEN2
370 Freescale DDR2 controller.
371
372 CONFIG_SYS_FSL_DDRC_GEN3
373 Freescale DDR3 controller.
374
York Sun2896cb72014-03-27 17:54:47 -0700375 CONFIG_SYS_FSL_DDRC_GEN4
376 Freescale DDR4 controller.
377
York Sun461c9392013-09-30 14:20:51 -0700378 CONFIG_SYS_FSL_DDRC_ARM_GEN3
379 Freescale DDR3 controller for ARM-based SoCs.
380
York Sunf0626592013-09-30 09:22:09 -0700381 CONFIG_SYS_FSL_DDR1
382 Board config to use DDR1. It can be enabled for SoCs with
383 Freescale DDR1 or DDR2 controllers, depending on the board
384 implemetation.
385
386 CONFIG_SYS_FSL_DDR2
Robert P. J. Day8d56db92016-07-15 13:44:45 -0400387 Board config to use DDR2. It can be enabled for SoCs with
York Sunf0626592013-09-30 09:22:09 -0700388 Freescale DDR2 or DDR3 controllers, depending on the board
389 implementation.
390
391 CONFIG_SYS_FSL_DDR3
392 Board config to use DDR3. It can be enabled for SoCs with
York Sun2896cb72014-03-27 17:54:47 -0700393 Freescale DDR3 or DDR3L controllers.
394
395 CONFIG_SYS_FSL_DDR3L
396 Board config to use DDR3L. It can be enabled for SoCs with
397 DDR3L controllers.
398
Prabhakar Kushwaha62908c22014-01-18 12:28:30 +0530399 CONFIG_SYS_FSL_IFC_BE
400 Defines the IFC controller register space as Big Endian
401
402 CONFIG_SYS_FSL_IFC_LE
403 Defines the IFC controller register space as Little Endian
404
Prabhakar Kushwaha3c48f582017-02-02 15:01:26 +0530405 CONFIG_SYS_FSL_IFC_CLK_DIV
406 Defines divider of platform clock(clock input to IFC controller).
407
Prabhakar Kushwahabedc5622017-02-02 15:02:00 +0530408 CONFIG_SYS_FSL_LBC_CLK_DIV
409 Defines divider of platform clock(clock input to eLBC controller).
410
York Sun29647ab2014-02-10 13:59:42 -0800411 CONFIG_SYS_FSL_DDR_BE
412 Defines the DDR controller register space as Big Endian
413
414 CONFIG_SYS_FSL_DDR_LE
415 Defines the DDR controller register space as Little Endian
416
York Sun3a0916d2014-02-10 13:59:43 -0800417 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
418 Physical address from the view of DDR controllers. It is the
419 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
420 it could be different for ARM SoCs.
421
York Sunc459ae62014-02-10 13:59:44 -0800422 CONFIG_SYS_FSL_DDR_INTLV_256B
423 DDR controller interleaving on 256-byte. This is a special
424 interleaving mode, handled by Dickens for Freescale layerscape
425 SoCs with ARM core.
426
York Sun79a779b2014-08-01 15:51:00 -0700427 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
428 Number of controllers used as main memory.
429
430 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
431 Number of controllers used for other than main memory.
432
Ruchika Guptabb7143b2014-09-09 11:50:31 +0530433 CONFIG_SYS_FSL_SEC_BE
434 Defines the SEC controller register space as Big Endian
435
436 CONFIG_SYS_FSL_SEC_LE
437 Defines the SEC controller register space as Little Endian
438
Daniel Schwierzeckd52a6232011-07-27 13:22:39 +0200439- MIPS CPU options:
Daniel Schwierzeckd52a6232011-07-27 13:22:39 +0200440 CONFIG_XWAY_SWAP_BYTES
441
442 Enable compilation of tools/xway-swap-bytes needed for Lantiq
443 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
444 be swapped if a flash programmer is used.
445
Christian Riesch48c2d6d2012-02-02 00:44:39 +0000446- ARM options:
447 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
448
449 Select high exception vectors of the ARM core, e.g., do not
450 clear the V bit of the c1 register of CP15.
451
York Sun77a10972015-03-20 19:28:08 -0700452 COUNTER_FREQUENCY
453 Generic timer clock source frequency.
454
455 COUNTER_FREQUENCY_REAL
456 Generic timer clock source frequency if the real clock is
457 different from COUNTER_FREQUENCY, and can only be determined
458 at run time.
459
Stephen Warren8d1fb312015-01-19 16:25:52 -0700460- Tegra SoC options:
461 CONFIG_TEGRA_SUPPORT_NON_SECURE
462
463 Support executing U-Boot in non-secure (NS) mode. Certain
464 impossible actions will be skipped if the CPU is in NS mode,
465 such as ARM architectural timer initialization.
466
wdenk9b7f3842003-10-09 20:09:04 +0000467- Linux Kernel Interface:
wdenk9b7f3842003-10-09 20:09:04 +0000468 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
469
Jeremiah Mahler03f930c2015-01-04 18:56:50 -0800470 When transferring memsize parameter to Linux, some versions
wdenk9b7f3842003-10-09 20:09:04 +0000471 expect it to be in bytes, others in MB.
472 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
473
Gerald Van Barenfcd91bb2008-06-03 20:34:45 -0400474 CONFIG_OF_LIBFDT
Wolfgang Denk27a5b0b2005-10-13 01:45:54 +0200475
476 New kernel versions are expecting firmware settings to be
Gerald Van Barend6abef42007-03-31 12:23:51 -0400477 passed using flattened device trees (based on open firmware
478 concepts).
479
480 CONFIG_OF_LIBFDT
481 * New libfdt-based support
482 * Adds the "fdt" command
Kim Phillips9b46eb62007-08-10 14:34:14 -0500483 * The bootm command automatically updates the fdt
Gerald Van Barend6abef42007-03-31 12:23:51 -0400484
Wolfgang Denk27a5b0b2005-10-13 01:45:54 +0200485 OF_TBCLK - The timebase frequency.
486
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +0200487 boards with QUICC Engines require OF_QE to set UCC MAC
488 addresses
Kim Phillips9b46eb62007-08-10 14:34:14 -0500489
Heiko Schocherffb293a2009-09-23 07:56:08 +0200490 CONFIG_OF_IDE_FIXUP
491
492 U-Boot can detect if an IDE device is present or not.
493 If not, and this new config option is activated, U-Boot
494 removes the ATA node from the DTS before booting Linux,
495 so the Linux IDE driver does not probe the device and
496 crash. This is needed for buggy hardware (uc101) where
497 no pull down resistor is connected to the signal IDE5V_DD7.
498
Niklaus Giger0ab978d2008-11-03 22:13:47 +0100499- vxWorks boot parameters:
500
501 bootvx constructs a valid bootline using the following
Bin Mengfb694b92015-10-07 20:19:17 -0700502 environments variables: bootdev, bootfile, ipaddr, netmask,
503 serverip, gatewayip, hostname, othbootargs.
Niklaus Giger0ab978d2008-11-03 22:13:47 +0100504 It loads the vxWorks image pointed bootfile.
505
Naoki Hayama158c2262020-10-08 13:17:08 +0900506 Note: If a "bootargs" environment is defined, it will override
Niklaus Giger0ab978d2008-11-03 22:13:47 +0100507 the defaults discussed just above.
508
Aneesh V686a0752011-06-16 23:30:51 +0000509- Cache Configuration for ARM:
510 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
511 controller
512 CONFIG_SYS_PL310_BASE - Physical base address of PL310
513 controller register space
514
wdenkda04a8b2004-08-02 23:22:59 +0000515- Serial Ports:
wdenkda04a8b2004-08-02 23:22:59 +0000516 CONFIG_PL011_CLOCK
517
518 If you have Amba PrimeCell PL011 UARTs, set this variable to
519 the clock speed of the UARTs.
520
521 CONFIG_PL01x_PORTS
522
523 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
524 define this to a list of base addresses for each (supported)
525 port. See e.g. include/configs/versatile.h
526
Karicheri, Muralidharancbc08882014-04-09 15:38:46 -0400527 CONFIG_SERIAL_HW_FLOW_CONTROL
528
529 Define this variable to enable hw flow control in serial driver.
530 Current user of this option is drivers/serial/nsl16550.c driver
wdenkda04a8b2004-08-02 23:22:59 +0000531
wdenkc6097192002-11-03 00:24:07 +0000532- Serial Download Echo Mode:
533 CONFIG_LOADS_ECHO
534 If defined to 1, all characters received during a
535 serial download (using the "loads" command) are
536 echoed back. This might be needed by some terminal
537 emulations (like "cu"), but may as well just take
538 time on others. This setting #define's the initial
539 value of the "loads_echo" environment variable.
540
Simon Glassaa34ef22016-03-13 19:07:28 -0600541- Removal of commands
542 If no commands are needed to boot, you can disable
543 CONFIG_CMDLINE to remove them. In this case, the command line
544 will not be available, and when U-Boot wants to execute the
545 boot command (on start-up) it will call board_run_command()
546 instead. This can reduce image size significantly for very
547 simple boot procedures.
548
Wolfgang Denk2aceea12013-03-23 23:50:31 +0000549- Regular expression support:
550 CONFIG_REGEX
Wolfgang Denkec7fbf52013-10-04 17:43:24 +0200551 If this variable is defined, U-Boot is linked against
552 the SLRE (Super Light Regular Expression) library,
553 which adds regex support to some commands, as for
554 example "env grep" and "setexpr".
Wolfgang Denk2aceea12013-03-23 23:50:31 +0000555
wdenkc6097192002-11-03 00:24:07 +0000556- Watchdog:
Rasmus Villemoes134cc2b2021-04-14 09:18:22 +0200557 CONFIG_SYS_WATCHDOG_FREQ
558 Some platforms automatically call WATCHDOG_RESET()
559 from the timer interrupt handler every
560 CONFIG_SYS_WATCHDOG_FREQ interrupts. If not set by the
561 board configuration file, a default of CONFIG_SYS_HZ/2
562 (i.e. 500) is used. Setting CONFIG_SYS_WATCHDOG_FREQ
563 to 0 disables calling WATCHDOG_RESET() from the timer
564 interrupt.
565
wdenkc6097192002-11-03 00:24:07 +0000566- Real-Time Clock:
567
Jon Loeligerc1da5c92007-06-11 19:03:39 -0500568 When CONFIG_CMD_DATE is selected, the type of the RTC
wdenkc6097192002-11-03 00:24:07 +0000569 has to be selected, too. Define exactly one of the
570 following options:
571
wdenkc6097192002-11-03 00:24:07 +0000572 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
Fabio Estevam3f8d1782011-10-24 06:44:15 +0000573 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
wdenkc6097192002-11-03 00:24:07 +0000574 CONFIG_RTC_MC146818 - use MC146818 RTC
wdenk1fe2c702003-03-06 21:55:29 +0000575 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
wdenkc6097192002-11-03 00:24:07 +0000576 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
wdenk0893c472003-05-20 14:25:27 +0000577 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
Markus Niebel90491f22014-07-21 11:06:16 +0200578 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
wdenkef5fe752003-03-12 10:41:04 +0000579 CONFIG_RTC_DS164x - use Dallas DS164x RTC
Tor Krillb27939b2008-03-15 15:40:26 +0100580 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
wdenkaeba06f2004-06-09 17:34:58 +0000581 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
Chris Packham2d3ac512017-05-30 12:03:33 +1200582 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
Heiko Schocher1f1b7012011-03-28 09:24:22 +0200583 CONFIG_SYS_RV3029_TCR - enable trickle charger on
584 RV3029 RTC.
wdenkc6097192002-11-03 00:24:07 +0000585
wdenkb9bbd242003-06-30 16:24:52 +0000586 Note that if the RTC uses I2C, then the I2C interface
587 must also be configured. See I2C Support, below.
588
Peter Tyser9902e422008-12-17 16:36:21 -0600589- GPIO Support:
590 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
Peter Tyser9902e422008-12-17 16:36:21 -0600591
Chris Packham9b383202010-12-19 10:12:13 +0000592 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
593 chip-ngpio pairs that tell the PCA953X driver the number of
594 pins supported by a particular chip.
595
Peter Tyser9902e422008-12-17 16:36:21 -0600596 Note that if the GPIO device uses I2C, then the I2C interface
597 must also be configured. See I2C Support, below.
598
Simon Glass4dc47ca2014-06-11 23:29:41 -0600599- I/O tracing:
600 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
601 accesses and can checksum them or write a list of them out
602 to memory. See the 'iotrace' command for details. This is
603 useful for testing device drivers since it can confirm that
604 the driver behaves the same way before and after a code
605 change. Currently this is supported on sandbox and arm. To
606 add support for your architecture, add '#include <iotrace.h>'
607 to the bottom of arch/<arch>/include/asm/io.h and test.
608
609 Example output from the 'iotrace stats' command is below.
610 Note that if the trace buffer is exhausted, the checksum will
611 still continue to operate.
612
613 iotrace is enabled
614 Start: 10000000 (buffer start address)
615 Size: 00010000 (buffer size)
616 Offset: 00000120 (current buffer offset)
617 Output: 10000120 (start + offset)
618 Count: 00000018 (number of trace records)
619 CRC32: 9526fb66 (CRC32 of all trace records)
620
wdenkc6097192002-11-03 00:24:07 +0000621- Timestamp Support:
622
wdenk4a5c8a72003-03-06 00:02:04 +0000623 When CONFIG_TIMESTAMP is selected, the timestamp
624 (date and time) of an image is printed by image
625 commands like bootm or iminfo. This option is
Jon Loeligerc1da5c92007-06-11 19:03:39 -0500626 automatically enabled when you select CONFIG_CMD_DATE .
wdenkc6097192002-11-03 00:24:07 +0000627
Karl O. Pinc8b1f90a2012-08-16 06:20:15 +0000628- Partition Labels (disklabels) Supported:
629 Zero or more of the following:
630 CONFIG_MAC_PARTITION Apple's MacOS partition table.
Karl O. Pinc8b1f90a2012-08-16 06:20:15 +0000631 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
632 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
633 bootloader. Note 2TB partition limit; see
634 disk/part_efi.c
Simon Glass8706b812016-05-01 11:36:02 -0600635 CONFIG_SCSI) you must configure support for at
Karl O. Pinc8b1f90a2012-08-16 06:20:15 +0000636 least one non-MTD partition type as well.
wdenkc6097192002-11-03 00:24:07 +0000637
wdenkc6097192002-11-03 00:24:07 +0000638- NETWORK Support (PCI):
Kyle Moffett64b94dd2011-10-18 11:05:29 +0000639 CONFIG_E1000_SPI
640 Utility code for direct access to the SPI bus on Intel 8257x.
641 This does not do anything useful unless you set at least one
642 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
643
wdenkc6097192002-11-03 00:24:07 +0000644 CONFIG_NATSEMI
645 Support for National dp83815 chips.
646
647 CONFIG_NS8382X
648 Support for National dp8382[01] gigabit chips.
649
wdenkaa603362003-05-12 21:50:16 +0000650- NETWORK Support (other):
Rob Herringc9830dc2011-12-15 11:15:49 +0000651 CONFIG_CALXEDA_XGMAC
652 Support for the Calxeda XGMAC device
653
Ashok93fb8722012-10-15 06:20:47 +0000654 CONFIG_LAN91C96
wdenkaa603362003-05-12 21:50:16 +0000655 Support for SMSC's LAN91C96 chips.
656
wdenkaa603362003-05-12 21:50:16 +0000657 CONFIG_LAN91C96_USE_32_BIT
658 Define this to enable 32 bit addressing
659
Ashok93fb8722012-10-15 06:20:47 +0000660 CONFIG_SMC91111
wdenk3c711762004-06-09 13:37:52 +0000661 Support for SMSC's LAN91C111 chip
662
663 CONFIG_SMC91111_BASE
664 Define this to hold the physical address
665 of the device (I/O space)
666
667 CONFIG_SMC_USE_32_BIT
668 Define this if data bus is 32 bits
669
670 CONFIG_SMC_USE_IOFUNCS
671 Define this to use i/o functions instead of macros
672 (some hardware wont work with macros)
673
Heiko Schocher7d037f72011-11-15 10:00:04 -0500674 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
675 Define this if you have more then 3 PHYs.
676
Macpaul Lin199c6252010-12-21 16:59:46 +0800677 CONFIG_FTGMAC100
678 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
679
680 CONFIG_FTGMAC100_EGIGA
681 Define this to use GE link update with gigabit PHY.
682 Define this if FTGMAC100 is connected to gigabit PHY.
683 If your system has 10/100 PHY only, it might not occur
684 wrong behavior. Because PHY usually return timeout or
685 useless data when polling gigabit status and gigabit
686 control registers. This behavior won't affect the
687 correctnessof 10/100 link speed update.
688
Yoshihiro Shimodaed4cea02011-01-27 10:06:03 +0900689 CONFIG_SH_ETHER
690 Support for Renesas on-chip Ethernet controller
691
692 CONFIG_SH_ETHER_USE_PORT
693 Define the number of ports to be used
694
695 CONFIG_SH_ETHER_PHY_ADDR
696 Define the ETH PHY's address
697
Yoshihiro Shimoda281aa052011-01-27 10:06:08 +0900698 CONFIG_SH_ETHER_CACHE_WRITEBACK
699 If this option is set, the driver enables cache flush.
700
Vadim Bendeburydac69642011-10-17 08:36:14 +0000701- TPM Support:
Che-liang Chiouacea5702013-04-12 11:04:34 +0000702 CONFIG_TPM
703 Support TPM devices.
704
Christophe Ricard8759ff82015-10-06 22:54:41 +0200705 CONFIG_TPM_TIS_INFINEON
706 Support for Infineon i2c bus TPM devices. Only one device
Tom Wai-Hong Tame49fed52013-04-12 11:04:37 +0000707 per system is supported at this time.
708
Tom Wai-Hong Tame49fed52013-04-12 11:04:37 +0000709 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
710 Define the burst count bytes upper limit
711
Christophe Ricard88249232016-01-21 23:27:13 +0100712 CONFIG_TPM_ST33ZP24
713 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
714
715 CONFIG_TPM_ST33ZP24_I2C
716 Support for STMicroelectronics ST33ZP24 I2C devices.
717 Requires TPM_ST33ZP24 and I2C.
718
Christophe Ricard5ffadc32016-01-21 23:27:14 +0100719 CONFIG_TPM_ST33ZP24_SPI
720 Support for STMicroelectronics ST33ZP24 SPI devices.
721 Requires TPM_ST33ZP24 and SPI.
722
Dirk Eibach20489092013-06-26 15:55:15 +0200723 CONFIG_TPM_ATMEL_TWI
724 Support for Atmel TWI TPM device. Requires I2C support.
725
Che-liang Chiouacea5702013-04-12 11:04:34 +0000726 CONFIG_TPM_TIS_LPC
Vadim Bendeburydac69642011-10-17 08:36:14 +0000727 Support for generic parallel port TPM devices. Only one device
728 per system is supported at this time.
729
730 CONFIG_TPM_TIS_BASE_ADDRESS
731 Base address where the generic TPM device is mapped
732 to. Contemporary x86 systems usually map it at
733 0xfed40000.
734
Reinhard Pfau4fece432013-06-26 15:55:13 +0200735 CONFIG_TPM
736 Define this to enable the TPM support library which provides
737 functional interfaces to some TPM commands.
738 Requires support for a TPM device.
739
740 CONFIG_TPM_AUTH_SESSIONS
741 Define this to enable authorized functions in the TPM library.
742 Requires CONFIG_TPM and CONFIG_SHA1.
743
wdenkc6097192002-11-03 00:24:07 +0000744- USB Support:
745 At the moment only the UHCI host controller is
Heiko Schocher6f90e582017-06-14 05:49:40 +0200746 supported (PIP405, MIP405); define
wdenkc6097192002-11-03 00:24:07 +0000747 CONFIG_USB_UHCI to enable it.
748 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
wdenkfb30b4c2004-10-09 22:44:59 +0000749 and define CONFIG_USB_STORAGE to enable the USB
wdenkc6097192002-11-03 00:24:07 +0000750 storage devices.
751 Note:
752 Supported are USB Keyboards and USB Floppy drives
753 (TEAC FD-05PUB).
wdenk369d43d2004-03-14 14:09:05 +0000754
Oleksandr Tymoshenko7a881752014-02-01 21:51:25 -0700755 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
756 HW module registers.
757
Wolfgang Denk3f0137b2006-06-14 17:45:53 +0200758- USB Device:
759 Define the below if you wish to use the USB console.
760 Once firmware is rebuilt from a serial console issue the
761 command "setenv stdin usbtty; setenv stdout usbtty" and
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +0200762 attach your USB cable. The Unix command "dmesg" should print
Wolfgang Denk3f0137b2006-06-14 17:45:53 +0200763 it has found a new device. The environment variable usbtty
764 can be set to gserial or cdc_acm to enable your device to
Wolfgang Denke2601822006-06-14 18:14:56 +0200765 appear to a USB host as a Linux gserial device or a
Wolfgang Denk3f0137b2006-06-14 17:45:53 +0200766 Common Device Class Abstract Control Model serial device.
767 If you select usbtty = gserial you should be able to enumerate
768 a Linux host by
769 # modprobe usbserial vendor=0xVendorID product=0xProductID
770 else if using cdc_acm, simply setting the environment
771 variable usbtty to be cdc_acm should suffice. The following
772 might be defined in YourBoardName.h
Wolfgang Denke2601822006-06-14 18:14:56 +0200773
Wolfgang Denk3f0137b2006-06-14 17:45:53 +0200774 CONFIG_USB_DEVICE
775 Define this to build a UDC device
776
777 CONFIG_USB_TTY
778 Define this to have a tty type of device available to
779 talk to the UDC device
Wolfgang Denke2601822006-06-14 18:14:56 +0200780
Vipin KUMARbdb17702012-03-26 15:38:06 +0530781 CONFIG_USBD_HS
782 Define this to enable the high speed support for usb
783 device and usbtty. If this feature is enabled, a routine
784 int is_usbd_high_speed(void)
785 also needs to be defined by the driver to dynamically poll
786 whether the enumeration has succeded at high speed or full
787 speed.
788
Wolfgang Denke2601822006-06-14 18:14:56 +0200789 If you have a USB-IF assigned VendorID then you may wish to
Wolfgang Denk3f0137b2006-06-14 17:45:53 +0200790 define your own vendor specific values either in BoardName.h
Wolfgang Denke2601822006-06-14 18:14:56 +0200791 or directly in usbd_vendor_info.h. If you don't define
Wolfgang Denk3f0137b2006-06-14 17:45:53 +0200792 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
793 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
794 should pretend to be a Linux device to it's target host.
795
796 CONFIG_USBD_MANUFACTURER
797 Define this string as the name of your company for
798 - CONFIG_USBD_MANUFACTURER "my company"
Wolfgang Denke2601822006-06-14 18:14:56 +0200799
Wolfgang Denk3f0137b2006-06-14 17:45:53 +0200800 CONFIG_USBD_PRODUCT_NAME
801 Define this string as the name of your product
802 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
wdenkc6097192002-11-03 00:24:07 +0000803
Wolfgang Denk3f0137b2006-06-14 17:45:53 +0200804 CONFIG_USBD_VENDORID
805 Define this as your assigned Vendor ID from the USB
806 Implementors Forum. This *must* be a genuine Vendor ID
807 to avoid polluting the USB namespace.
808 - CONFIG_USBD_VENDORID 0xFFFF
Wolfgang Denke2601822006-06-14 18:14:56 +0200809
Wolfgang Denk3f0137b2006-06-14 17:45:53 +0200810 CONFIG_USBD_PRODUCTID
811 Define this as the unique Product ID
812 for your device
813 - CONFIG_USBD_PRODUCTID 0xFFFF
Wolfgang Denke2601822006-06-14 18:14:56 +0200814
Igor Grinbergac5f6ee2011-12-12 12:08:35 +0200815- ULPI Layer Support:
816 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
817 the generic ULPI layer. The generic layer accesses the ULPI PHY
818 via the platform viewport, so you need both the genric layer and
819 the viewport enabled. Currently only Chipidea/ARC based
820 viewport is supported.
821 To enable the ULPI layer support, define CONFIG_USB_ULPI and
822 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
Lucas Stachf31e4112012-10-01 00:44:35 +0200823 If your ULPI phy needs a different reference clock than the
824 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
825 the appropriate value in Hz.
wdenkc6097192002-11-03 00:24:07 +0000826
wdenk7a428cc2003-06-15 22:40:42 +0000827- MMC Support:
Yoshihiro Shimodadb7717b2011-07-04 22:21:22 +0000828 CONFIG_SH_MMCIF
829 Support for Renesas on-chip MMCIF controller
830
831 CONFIG_SH_MMCIF_ADDR
832 Define the base address of MMCIF registers
833
834 CONFIG_SH_MMCIF_CLK
835 Define the clock frequency for MMCIF
836
Tom Rini58a8d322013-03-14 05:32:47 +0000837- USB Device Firmware Update (DFU) class support:
Marek Vasut7f8d4362018-02-16 16:41:18 +0100838 CONFIG_DFU_OVER_USB
Tom Rini58a8d322013-03-14 05:32:47 +0000839 This enables the USB portion of the DFU USB class
840
Pantelis Antonioucf14d0d2013-03-14 05:32:52 +0000841 CONFIG_DFU_NAND
842 This enables support for exposing NAND devices via DFU.
843
Afzal Mohammede3c687a2013-09-18 01:15:24 +0530844 CONFIG_DFU_RAM
845 This enables support for exposing RAM via DFU.
846 Note: DFU spec refer to non-volatile memory usage, but
847 allow usages beyond the scope of spec - here RAM usage,
848 one that would help mostly the developer.
849
Heiko Schochera2f831e2013-06-12 06:05:51 +0200850 CONFIG_SYS_DFU_DATA_BUF_SIZE
851 Dfu transfer uses a buffer before writing data to the
852 raw storage device. Make the size (in bytes) of this buffer
853 configurable. The size of this buffer is also configurable
854 through the "dfu_bufsiz" environment variable.
855
Pantelis Antonioua6e788d2013-03-14 05:32:48 +0000856 CONFIG_SYS_DFU_MAX_FILE_SIZE
857 When updating files rather than the raw storage device,
858 we use a static buffer to copy the file into and then write
859 the buffer once we've been given the whole file. Define
860 this to the maximum filesize (in bytes) for the buffer.
861 Default is 4 MiB if undefined.
862
Heiko Schochere1ba1512014-03-18 08:09:56 +0100863 DFU_DEFAULT_POLL_TIMEOUT
864 Poll timeout [ms], is the timeout a device can send to the
865 host. The host must wait for this timeout before sending
866 a subsequent DFU_GET_STATUS request to the device.
867
868 DFU_MANIFEST_POLL_TIMEOUT
869 Poll timeout [ms], which the device sends to the host when
870 entering dfuMANIFEST state. Host waits this timeout, before
871 sending again an USB request to the device.
872
wdenkda04a8b2004-08-02 23:22:59 +0000873- Journaling Flash filesystem support:
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +0200874 CONFIG_SYS_JFFS2_FIRST_SECTOR,
875 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
wdenkda04a8b2004-08-02 23:22:59 +0000876 Define these for a default partition on a NOR device
877
wdenkc6097192002-11-03 00:24:07 +0000878- Keyboard Support:
Simon Glasseaba37e2015-11-11 10:05:47 -0700879 See Kconfig help for available keyboard drivers.
880
wdenkc6097192002-11-03 00:24:07 +0000881- LCD Support: CONFIG_LCD
882
883 Define this to enable LCD support (for output to LCD
884 display); also select one of the supported displays
885 by defining one of these:
886
wdenkc0d54ae2003-11-25 16:55:19 +0000887 CONFIG_NEC_NL6448AC33:
wdenkc6097192002-11-03 00:24:07 +0000888
wdenkc0d54ae2003-11-25 16:55:19 +0000889 NEC NL6448AC33-18. Active, color, single scan.
wdenkc6097192002-11-03 00:24:07 +0000890
wdenkc0d54ae2003-11-25 16:55:19 +0000891 CONFIG_NEC_NL6448BC20
892
893 NEC NL6448BC20-08. 6.5", 640x480.
894 Active, color, single scan.
895
896 CONFIG_NEC_NL6448BC33_54
wdenkc6097192002-11-03 00:24:07 +0000897
wdenkc0d54ae2003-11-25 16:55:19 +0000898 NEC NL6448BC33-54. 10.4", 640x480.
wdenkc6097192002-11-03 00:24:07 +0000899 Active, color, single scan.
900
901 CONFIG_SHARP_16x9
902
903 Sharp 320x240. Active, color, single scan.
904 It isn't 16x9, and I am not sure what it is.
905
906 CONFIG_SHARP_LQ64D341
907
908 Sharp LQ64D341 display, 640x480.
909 Active, color, single scan.
910
911 CONFIG_HLD1045
912
913 HLD1045 display, 640x480.
914 Active, color, single scan.
915
916 CONFIG_OPTREX_BW
917
918 Optrex CBL50840-2 NF-FW 99 22 M5
919 or
920 Hitachi LMG6912RPFC-00T
921 or
922 Hitachi SP14Q002
923
924 320x240. Black & white.
925
Simon Glass599a4df2012-10-17 13:24:54 +0000926 CONFIG_LCD_ALIGNMENT
927
Jeremiah Mahler03f930c2015-01-04 18:56:50 -0800928 Normally the LCD is page-aligned (typically 4KB). If this is
Simon Glass599a4df2012-10-17 13:24:54 +0000929 defined then the LCD will be aligned to this value instead.
930 For ARM it is sometimes useful to use MMU_SECTION_SIZE
931 here, since it is cheaper to change data cache settings on
932 a per-section basis.
933
934
Hannes Petermaiera3c8e862015-03-27 08:01:38 +0100935 CONFIG_LCD_ROTATION
936
937 Sometimes, for example if the display is mounted in portrait
938 mode or even if it's mounted landscape but rotated by 180degree,
939 we need to rotate our content of the display relative to the
940 framebuffer, so that user can read the messages which are
941 printed out.
942 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
943 initialized with a given rotation from "vl_rot" out of
944 "vidinfo_t" which is provided by the board specific code.
945 The value for vl_rot is coded as following (matching to
946 fbcon=rotate:<n> linux-kernel commandline):
947 0 = no rotation respectively 0 degree
948 1 = 90 degree rotation
949 2 = 180 degree rotation
950 3 = 270 degree rotation
951
952 If CONFIG_LCD_ROTATION is not defined, the console will be
953 initialized with 0degree rotation.
954
wdenk0e2bd9c2004-06-06 21:51:03 +0000955- MII/PHY support:
wdenk0e2bd9c2004-06-06 21:51:03 +0000956 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
957
958 The clock frequency of the MII bus
959
wdenk0e2bd9c2004-06-06 21:51:03 +0000960 CONFIG_PHY_CMD_DELAY (ppc4xx)
961
962 Some PHY like Intel LXT971A need extra delay after
963 command issued before MII status register can be read
964
wdenkc6097192002-11-03 00:24:07 +0000965- IP address:
966 CONFIG_IPADDR
967
968 Define a default value for the IP address to use for
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +0200969 the default Ethernet interface, in case this is not
wdenkc6097192002-11-03 00:24:07 +0000970 determined through e.g. bootp.
Wolfgang Denk26da2992011-10-26 10:21:22 +0000971 (Environment variable "ipaddr")
wdenkc6097192002-11-03 00:24:07 +0000972
973- Server IP address:
974 CONFIG_SERVERIP
975
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +0200976 Defines a default value for the IP address of a TFTP
wdenkc6097192002-11-03 00:24:07 +0000977 server to contact when using the "tftboot" command.
Wolfgang Denk26da2992011-10-26 10:21:22 +0000978 (Environment variable "serverip")
wdenkc6097192002-11-03 00:24:07 +0000979
Wolfgang Denk26da2992011-10-26 10:21:22 +0000980- Gateway IP address:
981 CONFIG_GATEWAYIP
982
983 Defines a default value for the IP address of the
984 default router where packets to other networks are
985 sent to.
986 (Environment variable "gatewayip")
987
988- Subnet mask:
989 CONFIG_NETMASK
990
991 Defines a default value for the subnet mask (or
992 routing prefix) which is used to determine if an IP
993 address belongs to the local subnet or needs to be
994 forwarded through a router.
995 (Environment variable "netmask")
996
wdenkc6097192002-11-03 00:24:07 +0000997- BOOTP Recovery Mode:
998 CONFIG_BOOTP_RANDOM_DELAY
999
1000 If you have many targets in a network that try to
1001 boot using BOOTP, you may want to avoid that all
1002 systems send out BOOTP requests at precisely the same
1003 moment (which would happen for instance at recovery
1004 from a power failure, when all systems will try to
1005 boot, thus flooding the BOOTP server. Defining
1006 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1007 inserted before sending out BOOTP requests. The
Wolfgang Denkb65aaf92007-08-06 23:21:05 +02001008 following delays are inserted then:
wdenkc6097192002-11-03 00:24:07 +00001009
1010 1st BOOTP request: delay 0 ... 1 sec
1011 2nd BOOTP request: delay 0 ... 2 sec
1012 3rd BOOTP request: delay 0 ... 4 sec
1013 4th and following
1014 BOOTP requests: delay 0 ... 8 sec
1015
Thierry Reding8977cda2014-08-19 10:21:24 +02001016 CONFIG_BOOTP_ID_CACHE_SIZE
1017
1018 BOOTP packets are uniquely identified using a 32-bit ID. The
1019 server will copy the ID from client requests to responses and
1020 U-Boot will use this to determine if it is the destination of
1021 an incoming response. Some servers will check that addresses
1022 aren't in use before handing them out (usually using an ARP
1023 ping) and therefore take up to a few hundred milliseconds to
1024 respond. Network congestion may also influence the time it
1025 takes for a response to make it back to the client. If that
1026 time is too long, U-Boot will retransmit requests. In order
1027 to allow earlier responses to still be accepted after these
1028 retransmissions, U-Boot's BOOTP client keeps a small cache of
1029 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
1030 cache. The default is to keep IDs for up to four outstanding
1031 requests. Increasing this will allow U-Boot to accept offers
1032 from a BOOTP client in networks with unusually high latency.
1033
stroesee0aadfb2003-08-28 14:17:32 +00001034- DHCP Advanced Options:
Joe Hershberger8ca7fa02012-05-23 07:59:19 +00001035
Joe Hershbergerb35a3a62012-05-23 08:00:12 +00001036 - Link-local IP address negotiation:
1037 Negotiate with other link-local clients on the local network
1038 for an address that doesn't require explicit configuration.
1039 This is especially useful if a DHCP server cannot be guaranteed
1040 to exist in all environments that the device must operate.
1041
1042 See doc/README.link-local for more information.
1043
Prabhakar Kushwaha2dec06f2017-11-23 16:51:32 +05301044 - MAC address from environment variables
1045
1046 FDT_SEQ_MACADDR_FROM_ENV
1047
1048 Fix-up device tree with MAC addresses fetched sequentially from
1049 environment variables. This config work on assumption that
1050 non-usable ethernet node of device-tree are either not present
1051 or their status has been marked as "disabled".
1052
wdenk145d2c12004-04-15 21:48:45 +00001053 - CDP Options:
wdenk05939202004-04-18 17:39:38 +00001054 CONFIG_CDP_DEVICE_ID
wdenk145d2c12004-04-15 21:48:45 +00001055
1056 The device id used in CDP trigger frames.
1057
1058 CONFIG_CDP_DEVICE_ID_PREFIX
1059
1060 A two character string which is prefixed to the MAC address
1061 of the device.
1062
1063 CONFIG_CDP_PORT_ID
1064
1065 A printf format string which contains the ascii name of
1066 the port. Normally is set to "eth%d" which sets
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001067 eth0 for the first Ethernet, eth1 for the second etc.
wdenk145d2c12004-04-15 21:48:45 +00001068
1069 CONFIG_CDP_CAPABILITIES
1070
1071 A 32bit integer which indicates the device capabilities;
1072 0x00000010 for a normal host which does not forwards.
1073
1074 CONFIG_CDP_VERSION
1075
1076 An ascii string containing the version of the software.
1077
1078 CONFIG_CDP_PLATFORM
1079
1080 An ascii string containing the name of the platform.
1081
1082 CONFIG_CDP_TRIGGER
1083
1084 A 32bit integer sent on the trigger.
1085
1086 CONFIG_CDP_POWER_CONSUMPTION
1087
1088 A 16bit integer containing the power consumption of the
1089 device in .1 of milliwatts.
1090
1091 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1092
1093 A byte containing the id of the VLAN.
1094
Uri Mashiach3dc6f652017-01-19 10:51:05 +02001095- Status LED: CONFIG_LED_STATUS
wdenkc6097192002-11-03 00:24:07 +00001096
1097 Several configurations allow to display the current
1098 status using a LED. For instance, the LED will blink
1099 fast while running U-Boot code, stop blinking as
1100 soon as a reply to a BOOTP request was received, and
1101 start blinking slow once the Linux kernel is running
1102 (supported by a status LED driver in the Linux
Uri Mashiach3dc6f652017-01-19 10:51:05 +02001103 kernel). Defining CONFIG_LED_STATUS enables this
wdenkc6097192002-11-03 00:24:07 +00001104 feature in U-Boot.
1105
Igor Grinberg4997a9e2013-11-08 01:03:50 +02001106 Additional options:
1107
Uri Mashiach3dc6f652017-01-19 10:51:05 +02001108 CONFIG_LED_STATUS_GPIO
Igor Grinberg4997a9e2013-11-08 01:03:50 +02001109 The status LED can be connected to a GPIO pin.
1110 In such cases, the gpio_led driver can be used as a
Uri Mashiach3dc6f652017-01-19 10:51:05 +02001111 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO
Igor Grinberg4997a9e2013-11-08 01:03:50 +02001112 to include the gpio_led driver in the U-Boot binary.
1113
Igor Grinberg203bd9f2013-11-08 01:03:52 +02001114 CONFIG_GPIO_LED_INVERTED_TABLE
1115 Some GPIO connected LEDs may have inverted polarity in which
1116 case the GPIO high value corresponds to LED off state and
1117 GPIO low value corresponds to LED on state.
1118 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
1119 with a list of GPIO LEDs that have inverted polarity.
1120
Tom Rini52b2e262021-08-18 23:12:24 -04001121- I2C Support:
Heiko Schochere0e55bc2012-01-16 21:12:24 +00001122 CONFIG_SYS_NUM_I2C_BUSES
Simon Glassb05e2b32016-10-02 18:01:05 -06001123 Hold the number of i2c buses you want to use.
Heiko Schochere0e55bc2012-01-16 21:12:24 +00001124
1125 CONFIG_SYS_I2C_DIRECT_BUS
1126 define this, if you don't use i2c muxes on your hardware.
1127 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
1128 omit this define.
1129
1130 CONFIG_SYS_I2C_MAX_HOPS
1131 define how many muxes are maximal consecutively connected
1132 on one i2c bus. If you not use i2c muxes, omit this
1133 define.
1134
1135 CONFIG_SYS_I2C_BUSES
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08001136 hold a list of buses you want to use, only used if
Heiko Schochere0e55bc2012-01-16 21:12:24 +00001137 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
1138 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
1139 CONFIG_SYS_NUM_I2C_BUSES = 9:
1140
1141 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
1142 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
1143 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
1144 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
1145 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
1146 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
1147 {1, {I2C_NULL_HOP}}, \
1148 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
1149 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
1150 }
1151
1152 which defines
1153 bus 0 on adapter 0 without a mux
Heiko Schocher479a4cf2013-01-29 08:53:15 +01001154 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
1155 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
1156 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
1157 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
1158 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
Heiko Schochere0e55bc2012-01-16 21:12:24 +00001159 bus 6 on adapter 1 without a mux
Heiko Schocher479a4cf2013-01-29 08:53:15 +01001160 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
1161 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
Heiko Schochere0e55bc2012-01-16 21:12:24 +00001162
1163 If you do not have i2c muxes on your board, omit this define.
1164
Simon Glass3efce392017-05-12 21:10:00 -06001165- Legacy I2C Support:
Heiko Schocher479a4cf2013-01-29 08:53:15 +01001166 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
wdenkb9bbd242003-06-30 16:24:52 +00001167 then the following macros need to be defined (examples are
1168 from include/configs/lwmon.h):
wdenkc6097192002-11-03 00:24:07 +00001169
1170 I2C_INIT
1171
wdenkb9bbd242003-06-30 16:24:52 +00001172 (Optional). Any commands necessary to enable the I2C
wdenk4a5c8a72003-03-06 00:02:04 +00001173 controller or configure ports.
wdenkc6097192002-11-03 00:24:07 +00001174
wdenk544e9732004-02-06 23:19:44 +00001175 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
wdenkb9bbd242003-06-30 16:24:52 +00001176
wdenkc6097192002-11-03 00:24:07 +00001177 I2C_ACTIVE
1178
1179 The code necessary to make the I2C data line active
1180 (driven). If the data line is open collector, this
1181 define can be null.
1182
wdenkb9bbd242003-06-30 16:24:52 +00001183 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1184
wdenkc6097192002-11-03 00:24:07 +00001185 I2C_TRISTATE
1186
1187 The code necessary to make the I2C data line tri-stated
1188 (inactive). If the data line is open collector, this
1189 define can be null.
1190
wdenkb9bbd242003-06-30 16:24:52 +00001191 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1192
wdenkc6097192002-11-03 00:24:07 +00001193 I2C_READ
1194
York Sun4a598092013-04-01 11:29:11 -07001195 Code that returns true if the I2C data line is high,
1196 false if it is low.
wdenkc6097192002-11-03 00:24:07 +00001197
wdenkb9bbd242003-06-30 16:24:52 +00001198 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1199
wdenkc6097192002-11-03 00:24:07 +00001200 I2C_SDA(bit)
1201
York Sun4a598092013-04-01 11:29:11 -07001202 If <bit> is true, sets the I2C data line high. If it
1203 is false, it clears it (low).
wdenkc6097192002-11-03 00:24:07 +00001204
wdenkb9bbd242003-06-30 16:24:52 +00001205 eg: #define I2C_SDA(bit) \
wdenk2bb11052003-07-17 23:16:40 +00001206 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
wdenk544e9732004-02-06 23:19:44 +00001207 else immr->im_cpm.cp_pbdat &= ~PB_SDA
wdenkb9bbd242003-06-30 16:24:52 +00001208
wdenkc6097192002-11-03 00:24:07 +00001209 I2C_SCL(bit)
1210
York Sun4a598092013-04-01 11:29:11 -07001211 If <bit> is true, sets the I2C clock line high. If it
1212 is false, it clears it (low).
wdenkc6097192002-11-03 00:24:07 +00001213
wdenkb9bbd242003-06-30 16:24:52 +00001214 eg: #define I2C_SCL(bit) \
wdenk2bb11052003-07-17 23:16:40 +00001215 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
wdenk544e9732004-02-06 23:19:44 +00001216 else immr->im_cpm.cp_pbdat &= ~PB_SCL
wdenkb9bbd242003-06-30 16:24:52 +00001217
wdenkc6097192002-11-03 00:24:07 +00001218 I2C_DELAY
1219
1220 This delay is invoked four times per clock cycle so this
1221 controls the rate of data transfer. The data rate thus
wdenkb9bbd242003-06-30 16:24:52 +00001222 is 1 / (I2C_DELAY * 4). Often defined to be something
wdenk21136db2003-07-16 21:53:01 +00001223 like:
1224
wdenkb9bbd242003-06-30 16:24:52 +00001225 #define I2C_DELAY udelay(2)
wdenkc6097192002-11-03 00:24:07 +00001226
Mike Frysingeree12d542010-07-21 13:38:02 -04001227 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1228
1229 If your arch supports the generic GPIO framework (asm/gpio.h),
1230 then you may alternatively define the two GPIOs that are to be
1231 used as SCL / SDA. Any of the previous I2C_xxx macros will
1232 have GPIO-based defaults assigned to them as appropriate.
1233
1234 You should define these to the GPIO value as given directly to
1235 the generic GPIO functions.
1236
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001237 CONFIG_SYS_I2C_INIT_BOARD
wdenkcc1e2562003-03-06 13:39:27 +00001238
wdenk57b2d802003-06-27 21:31:46 +00001239 When a board is reset during an i2c bus transfer
1240 chips might think that the current transfer is still
1241 in progress. On some boards it is possible to access
1242 the i2c SCLK line directly, either by using the
1243 processor pin as a GPIO or by having a second pin
1244 connected to the bus. If this option is defined a
1245 custom i2c_init_board() routine in boards/xxx/board.c
1246 is run early in the boot sequence.
wdenkcc1e2562003-03-06 13:39:27 +00001247
Ben Warren45657152006-09-07 16:50:54 -04001248 CONFIG_I2C_MULTI_BUS
1249
1250 This option allows the use of multiple I2C buses, each of which
Wolfgang Denk092ae952011-10-26 10:21:21 +00001251 must have a controller. At any point in time, only one bus is
1252 active. To switch to a different bus, use the 'i2c dev' command.
Ben Warren45657152006-09-07 16:50:54 -04001253 Note that bus numbering is zero-based.
1254
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001255 CONFIG_SYS_I2C_NOPROBES
Ben Warren45657152006-09-07 16:50:54 -04001256
1257 This option specifies a list of I2C devices that will be skipped
Wolfgang Denk092ae952011-10-26 10:21:21 +00001258 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
Peter Tyser469cde42009-04-18 22:34:03 -05001259 is set, specify a list of bus-device pairs. Otherwise, specify
1260 a 1D array of device addresses
Ben Warren45657152006-09-07 16:50:54 -04001261
1262 e.g.
1263 #undef CONFIG_I2C_MULTI_BUS
Wolfgang Denk092ae952011-10-26 10:21:21 +00001264 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
Ben Warren45657152006-09-07 16:50:54 -04001265
1266 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1267
Wolfgang Denk092ae952011-10-26 10:21:21 +00001268 #define CONFIG_I2C_MULTI_BUS
Simon Glassb05e2b32016-10-02 18:01:05 -06001269 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
Ben Warren45657152006-09-07 16:50:54 -04001270
1271 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1272
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001273 CONFIG_SYS_RTC_BUS_NUM
Stefan Roese096cc9b2007-02-20 10:51:26 +01001274
1275 If defined, then this indicates the I2C bus number for the RTC.
1276 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1277
Andrew Dyer58c41f92008-12-29 17:36:01 -06001278 CONFIG_SOFT_I2C_READ_REPEATED_START
1279
1280 defining this will force the i2c_read() function in
1281 the soft_i2c driver to perform an I2C repeated start
1282 between writing the address pointer and reading the
1283 data. If this define is omitted the default behaviour
1284 of doing a stop-start sequence will be used. Most I2C
1285 devices can use either method, but some require one or
1286 the other.
Timur Tabiab347542006-11-03 19:15:00 -06001287
wdenkc6097192002-11-03 00:24:07 +00001288- SPI Support: CONFIG_SPI
1289
1290 Enables SPI driver (so far only tested with
1291 SPI EEPROM, also an instance works with Crystal A/D and
1292 D/As on the SACSng board)
1293
Heiko Schocherb77c8882014-07-14 10:22:11 +02001294 CONFIG_SYS_SPI_MXC_WAIT
1295 Timeout for waiting until spi transfer completed.
1296 default: (CONFIG_SYS_HZ/100) /* 10 ms */
1297
Matthias Fuchsa4400872007-12-27 17:12:34 +01001298- FPGA Support: CONFIG_FPGA
wdenkc6097192002-11-03 00:24:07 +00001299
Matthias Fuchsa4400872007-12-27 17:12:34 +01001300 Enables FPGA subsystem.
1301
1302 CONFIG_FPGA_<vendor>
1303
1304 Enables support for specific chip vendors.
1305 (ALTERA, XILINX)
wdenkc6097192002-11-03 00:24:07 +00001306
Matthias Fuchsa4400872007-12-27 17:12:34 +01001307 CONFIG_FPGA_<family>
wdenkc6097192002-11-03 00:24:07 +00001308
Matthias Fuchsa4400872007-12-27 17:12:34 +01001309 Enables support for FPGA family.
1310 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1311
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001312 CONFIG_SYS_FPGA_CHECK_BUSY
wdenkc6097192002-11-03 00:24:07 +00001313
wdenk4a5c8a72003-03-06 00:02:04 +00001314 Enable checks on FPGA configuration interface busy
1315 status by the configuration function. This option
1316 will require a board or device specific function to
1317 be written.
wdenkc6097192002-11-03 00:24:07 +00001318
1319 CONFIG_FPGA_DELAY
1320
1321 If defined, a function that provides delays in the FPGA
1322 configuration driver.
1323
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001324 CONFIG_SYS_FPGA_CHECK_ERROR
wdenkc6097192002-11-03 00:24:07 +00001325
wdenk4a5c8a72003-03-06 00:02:04 +00001326 Check for configuration errors during FPGA bitfile
1327 loading. For example, abort during Virtex II
1328 configuration if the INIT_B line goes low (which
1329 indicated a CRC error).
wdenkc6097192002-11-03 00:24:07 +00001330
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001331 CONFIG_SYS_FPGA_WAIT_INIT
wdenkc6097192002-11-03 00:24:07 +00001332
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08001333 Maximum time to wait for the INIT_B line to de-assert
1334 after PROB_B has been de-asserted during a Virtex II
wdenk4a5c8a72003-03-06 00:02:04 +00001335 FPGA configuration sequence. The default time is 500
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001336 ms.
wdenkc6097192002-11-03 00:24:07 +00001337
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001338 CONFIG_SYS_FPGA_WAIT_BUSY
wdenkc6097192002-11-03 00:24:07 +00001339
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08001340 Maximum time to wait for BUSY to de-assert during
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001341 Virtex II FPGA configuration. The default is 5 ms.
wdenkc6097192002-11-03 00:24:07 +00001342
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001343 CONFIG_SYS_FPGA_WAIT_CONFIG
wdenkc6097192002-11-03 00:24:07 +00001344
wdenk4a5c8a72003-03-06 00:02:04 +00001345 Time to wait after FPGA configuration. The default is
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001346 200 ms.
wdenkc6097192002-11-03 00:24:07 +00001347
wdenkc6097192002-11-03 00:24:07 +00001348- Vendor Parameter Protection:
1349
wdenk4a5c8a72003-03-06 00:02:04 +00001350 U-Boot considers the values of the environment
1351 variables "serial#" (Board Serial Number) and
wdenkeb20ad32003-09-05 23:19:14 +00001352 "ethaddr" (Ethernet Address) to be parameters that
wdenk4a5c8a72003-03-06 00:02:04 +00001353 are set once by the board vendor / manufacturer, and
1354 protects these variables from casual modification by
1355 the user. Once set, these variables are read-only,
1356 and write or delete attempts are rejected. You can
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001357 change this behaviour:
wdenkc6097192002-11-03 00:24:07 +00001358
1359 If CONFIG_ENV_OVERWRITE is #defined in your config
1360 file, the write protection for vendor parameters is
wdenkcc1e2562003-03-06 13:39:27 +00001361 completely disabled. Anybody can change or delete
wdenkc6097192002-11-03 00:24:07 +00001362 these parameters.
1363
Joe Hershberger76f353e2015-05-04 14:55:14 -05001364 Alternatively, if you define _both_ an ethaddr in the
1365 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001366 Ethernet address is installed in the environment,
wdenkc6097192002-11-03 00:24:07 +00001367 which can be changed exactly ONCE by the user. [The
1368 serial# is unaffected by this, i. e. it remains
1369 read-only.]
1370
Joe Hershberger71497d02012-12-11 22:16:31 -06001371 The same can be accomplished in a more flexible way
1372 for any variable by configuring the type of access
1373 to allow for those variables in the ".flags" variable
1374 or define CONFIG_ENV_FLAGS_LIST_STATIC.
1375
wdenkc6097192002-11-03 00:24:07 +00001376- Protected RAM:
1377 CONFIG_PRAM
1378
1379 Define this variable to enable the reservation of
1380 "protected RAM", i. e. RAM which is not overwritten
1381 by U-Boot. Define CONFIG_PRAM to hold the number of
1382 kB you want to reserve for pRAM. You can overwrite
1383 this default value by defining an environment
1384 variable "pram" to the number of kB you want to
1385 reserve. Note that the board info structure will
1386 still show the full amount of RAM. If pRAM is
1387 reserved, a new environment variable "mem" will
1388 automatically be defined to hold the amount of
1389 remaining RAM in a form that can be passed as boot
1390 argument to Linux, for instance like that:
1391
Wolfgang Denk86eb3b72005-11-20 21:40:11 +01001392 setenv bootargs ... mem=\${mem}
wdenkc6097192002-11-03 00:24:07 +00001393 saveenv
1394
1395 This way you can tell Linux not to use this memory,
1396 either, which results in a memory region that will
1397 not be affected by reboots.
1398
1399 *WARNING* If your board configuration uses automatic
1400 detection of the RAM size, you must make sure that
1401 this memory test is non-destructive. So far, the
1402 following board configurations are known to be
1403 "pRAM-clean":
1404
Heiko Schocher65d94db2017-06-07 17:33:09 +02001405 IVMS8, IVML24, SPD8xx,
Wolfgang Denk90326762012-10-24 02:36:15 +00001406 HERMES, IP860, RPXlite, LWMON,
Heiko Schocher71cb3e92017-06-07 17:33:10 +02001407 FLAGADM
wdenkc6097192002-11-03 00:24:07 +00001408
1409- Error Recovery:
wdenkc6097192002-11-03 00:24:07 +00001410 Note:
1411
wdenk57b2d802003-06-27 21:31:46 +00001412 In the current implementation, the local variables
1413 space and global environment variables space are
1414 separated. Local variables are those you define by
1415 simply typing `name=value'. To access a local
1416 variable later on, you have write `$name' or
1417 `${name}'; to execute the contents of a variable
1418 directly type `$name' at the command prompt.
wdenkc6097192002-11-03 00:24:07 +00001419
wdenk4a5c8a72003-03-06 00:02:04 +00001420 Global environment variables are those you use
1421 setenv/printenv to work with. To run a command stored
1422 in such a variable, you need to use the run command,
1423 and you must not use the '$' sign to access them.
wdenkc6097192002-11-03 00:24:07 +00001424
1425 To store commands and special characters in a
1426 variable, please use double quotation marks
1427 surrounding the whole text of the variable, instead
1428 of the backslashes before semicolons and special
1429 symbols.
1430
wdenkc0aa5c52003-12-06 19:49:23 +00001431- Default Environment:
wdenkc6097192002-11-03 00:24:07 +00001432 CONFIG_EXTRA_ENV_SETTINGS
1433
wdenk4a5c8a72003-03-06 00:02:04 +00001434 Define this to contain any number of null terminated
1435 strings (variable = value pairs) that will be part of
wdenkeb20ad32003-09-05 23:19:14 +00001436 the default environment compiled into the boot image.
wdenk591dda52002-11-18 00:14:45 +00001437
wdenk4a5c8a72003-03-06 00:02:04 +00001438 For example, place something like this in your
1439 board's config file:
wdenkc6097192002-11-03 00:24:07 +00001440
1441 #define CONFIG_EXTRA_ENV_SETTINGS \
1442 "myvar1=value1\0" \
1443 "myvar2=value2\0"
1444
wdenk4a5c8a72003-03-06 00:02:04 +00001445 Warning: This method is based on knowledge about the
1446 internal format how the environment is stored by the
1447 U-Boot code. This is NOT an official, exported
1448 interface! Although it is unlikely that this format
wdenkeb20ad32003-09-05 23:19:14 +00001449 will change soon, there is no guarantee either.
wdenkc6097192002-11-03 00:24:07 +00001450 You better know what you are doing here.
1451
wdenk4a5c8a72003-03-06 00:02:04 +00001452 Note: overly (ab)use of the default environment is
1453 discouraged. Make sure to check other ways to preset
Wolfgang Denk85c25df2009-04-01 23:34:12 +02001454 the environment like the "source" command or the
wdenk4a5c8a72003-03-06 00:02:04 +00001455 boot command first.
wdenkc6097192002-11-03 00:24:07 +00001456
Simon Glass6b8d5fd2012-11-30 13:01:17 +00001457 CONFIG_DELAY_ENVIRONMENT
1458
1459 Normally the environment is loaded when the board is
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08001460 initialised so that it is available to U-Boot. This inhibits
Simon Glass6b8d5fd2012-11-30 13:01:17 +00001461 that so that the environment is not available until
1462 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
1463 this is instead controlled by the value of
1464 /config/load-environment.
1465
Wolfgang Denkd590fb12011-10-07 09:58:21 +02001466 CONFIG_STANDALONE_LOAD_ADDR
1467
Wolfgang Denk23f78482011-10-09 21:06:34 +02001468 This option defines a board specific value for the
1469 address where standalone program gets loaded, thus
1470 overwriting the architecture dependent default
Wolfgang Denkd590fb12011-10-07 09:58:21 +02001471 settings.
1472
Detlev Zundel0ecb6112009-12-01 17:16:19 +01001473- Automatic software updates via TFTP server
1474 CONFIG_UPDATE_TFTP
1475 CONFIG_UPDATE_TFTP_CNT_MAX
1476 CONFIG_UPDATE_TFTP_MSEC_MAX
1477
1478 These options enable and control the auto-update feature;
1479 for a more detailed description refer to doc/README.update.
1480
1481- MTD Support (mtdparts command, UBI support)
Heiko Schocherf5895d12014-06-24 10:10:04 +02001482 CONFIG_MTD_UBI_WL_THRESHOLD
1483 This parameter defines the maximum difference between the highest
1484 erase counter value and the lowest erase counter value of eraseblocks
1485 of UBI devices. When this threshold is exceeded, UBI starts performing
1486 wear leveling by means of moving data from eraseblock with low erase
1487 counter to eraseblocks with high erase counter.
1488
1489 The default value should be OK for SLC NAND flashes, NOR flashes and
1490 other flashes which have eraseblock life-cycle 100000 or more.
1491 However, in case of MLC NAND flashes which typically have eraseblock
1492 life-cycle less than 10000, the threshold should be lessened (e.g.,
1493 to 128 or 256, although it does not have to be power of 2).
1494
1495 default: 4096
Simon Glass6c0be912014-10-23 18:58:54 -06001496
Heiko Schocherf5895d12014-06-24 10:10:04 +02001497 CONFIG_MTD_UBI_BEB_LIMIT
1498 This option specifies the maximum bad physical eraseblocks UBI
1499 expects on the MTD device (per 1024 eraseblocks). If the
1500 underlying flash does not admit of bad eraseblocks (e.g. NOR
1501 flash), this value is ignored.
1502
1503 NAND datasheets often specify the minimum and maximum NVM
1504 (Number of Valid Blocks) for the flashes' endurance lifetime.
1505 The maximum expected bad eraseblocks per 1024 eraseblocks
1506 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
1507 which gives 20 for most NANDs (MaxNVB is basically the total
1508 count of eraseblocks on the chip).
1509
1510 To put it differently, if this value is 20, UBI will try to
1511 reserve about 1.9% of physical eraseblocks for bad blocks
1512 handling. And that will be 1.9% of eraseblocks on the entire
1513 NAND chip, not just the MTD partition UBI attaches. This means
1514 that if you have, say, a NAND flash chip admits maximum 40 bad
1515 eraseblocks, and it is split on two MTD partitions of the same
1516 size, UBI will reserve 40 eraseblocks when attaching a
1517 partition.
1518
1519 default: 20
1520
1521 CONFIG_MTD_UBI_FASTMAP
1522 Fastmap is a mechanism which allows attaching an UBI device
1523 in nearly constant time. Instead of scanning the whole MTD device it
1524 only has to locate a checkpoint (called fastmap) on the device.
1525 The on-flash fastmap contains all information needed to attach
1526 the device. Using fastmap makes only sense on large devices where
1527 attaching by scanning takes long. UBI will not automatically install
1528 a fastmap on old images, but you can set the UBI parameter
1529 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
1530 that fastmap-enabled images are still usable with UBI implementations
1531 without fastmap support. On typical flash devices the whole fastmap
1532 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
1533
1534 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
1535 Set this parameter to enable fastmap automatically on images
1536 without a fastmap.
1537 default: 0
1538
Heiko Schocher94b66de2015-10-22 06:19:21 +02001539 CONFIG_MTD_UBI_FM_DEBUG
1540 Enable UBI fastmap debug
1541 default: 0
1542
Daniel Schwierzeck39ca08e2011-07-18 07:48:07 +00001543- SPL framework
Wolfgang Denk825223d2011-09-11 21:24:09 +02001544 CONFIG_SPL
1545 Enable building of SPL globally.
Daniel Schwierzeck39ca08e2011-07-18 07:48:07 +00001546
Albert ARIBAUD \(3ADEV\)287b0942015-03-31 11:40:50 +02001547 CONFIG_SPL_PANIC_ON_RAW_IMAGE
1548 When defined, SPL will panic() if the image it has
1549 loaded does not have a signature.
1550 Defining this is useful when code which loads images
1551 in SPL cannot guarantee that absolutely all read errors
1552 will be caught.
1553 An example is the LPC32XX MLC NAND driver, which will
1554 consider that a completely unreadable NAND block is bad,
1555 and thus should be skipped silently.
1556
Tom Rinife3b0c72012-08-13 11:37:56 -07001557 CONFIG_SPL_DISPLAY_PRINT
1558 For ARM, enable an optional function to print more information
1559 about the running system.
1560
Scott Wood2b36fbb2012-12-06 13:33:17 +00001561 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
1562 Set this for NAND SPL on PPC mpc83xx targets, so that
1563 start.S waits for the rest of the SPL to load before
1564 continuing (the hardware starts execution after just
1565 loading the first page rather than the full 4K).
1566
Thomas Gleixner820d24d2016-07-12 20:28:12 +02001567 CONFIG_SPL_UBI
1568 Support for a lightweight UBI (fastmap) scanner and
1569 loader
1570
Tom Rini36853852012-02-14 07:29:40 +00001571 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
1572 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
1573 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
1574 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
1575 CONFIG_SYS_NAND_ECCBYTES
1576 Defines the size and behavior of the NAND that SPL uses
Scott Wood36c440e2012-09-21 18:35:27 -05001577 to read U-Boot
Tom Rini36853852012-02-14 07:29:40 +00001578
Scott Wood36c440e2012-09-21 18:35:27 -05001579 CONFIG_SYS_NAND_U_BOOT_DST
1580 Location in memory to load U-Boot to
1581
1582 CONFIG_SYS_NAND_U_BOOT_SIZE
1583 Size of image to load
Tom Rini36853852012-02-14 07:29:40 +00001584
1585 CONFIG_SYS_NAND_U_BOOT_START
Scott Wood36c440e2012-09-21 18:35:27 -05001586 Entry point in loaded image to jump to
Tom Rini36853852012-02-14 07:29:40 +00001587
1588 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
1589 Define this if you need to first read the OOB and then the
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08001590 data. This is used, for example, on davinci platforms.
Tom Rini36853852012-02-14 07:29:40 +00001591
Pavel Machekde997252012-08-30 22:42:11 +02001592 CONFIG_SPL_RAM_DEVICE
1593 Support for running image already present in ram, in SPL binary
1594
Marek Vasut9f2e0eb2018-05-13 00:22:52 +02001595 CONFIG_SPL_FIT_PRINT
Simon Glass82d94532013-05-08 08:05:59 +00001596 Printing information about a FIT image adds quite a bit of
1597 code to SPL. So this is normally disabled in SPL. Use this
1598 option to re-enable it. This will affect the output of the
1599 bootm command when booting a FIT image.
1600
wdenkc0aa5c52003-12-06 19:49:23 +00001601- Interrupt support (PPC):
1602
wdenk1ebf41e2004-01-02 14:00:00 +00001603 There are common interrupt_init() and timer_interrupt()
1604 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001605 for CPU specific initialization. interrupt_init_cpu()
wdenk1ebf41e2004-01-02 14:00:00 +00001606 should set decrementer_count to appropriate value. If
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001607 CPU resets decrementer automatically after interrupt
wdenk1ebf41e2004-01-02 14:00:00 +00001608 (ppc4xx) it should set decrementer_count to zero.
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001609 timer_interrupt() calls timer_interrupt_cpu() for CPU
wdenk1ebf41e2004-01-02 14:00:00 +00001610 specific handling. If board has watchdog / status_led
1611 / other_activity_monitor it works automatically from
1612 general timer_interrupt().
wdenkc0aa5c52003-12-06 19:49:23 +00001613
wdenkc6097192002-11-03 00:24:07 +00001614
Helmut Raigerd5a184b2011-10-20 04:19:47 +00001615Board initialization settings:
1616------------------------------
1617
1618During Initialization u-boot calls a number of board specific functions
1619to allow the preparation of board specific prerequisites, e.g. pin setup
1620before drivers are initialized. To enable these callbacks the
1621following configuration macros have to be defined. Currently this is
1622architecture specific, so please check arch/your_architecture/lib/board.c
1623typically in board_init_f() and board_init_r().
1624
1625- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
1626- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
1627- CONFIG_BOARD_LATE_INIT: Call board_late_init()
wdenkc6097192002-11-03 00:24:07 +00001628
wdenkc6097192002-11-03 00:24:07 +00001629Configuration Settings:
1630-----------------------
1631
Simon Glass8927bf22019-12-28 10:45:10 -07001632- MEM_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
York Sun6c480012014-02-26 17:03:19 -08001633 Optionally it can be defined to support 64-bit memory commands.
1634
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001635- CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
wdenkc6097192002-11-03 00:24:07 +00001636 undefine this when you're short of memory.
1637
Peter Tyserdfb72b82009-01-27 18:03:12 -06001638- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
1639 width of the commands listed in the 'help' command output.
1640
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001641- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
wdenkc6097192002-11-03 00:24:07 +00001642 prompt for user input.
1643
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001644- CONFIG_SYS_BAUDRATE_TABLE:
wdenkc6097192002-11-03 00:24:07 +00001645 List of legal baudrate settings for this board.
1646
York Sun5d286cd2015-12-04 11:57:07 -08001647- CONFIG_SYS_MEM_RESERVE_SECURE
York Sun1ef95cc2016-06-24 16:46:18 -07001648 Only implemented for ARMv8 for now.
York Sun5d286cd2015-12-04 11:57:07 -08001649 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
1650 is substracted from total RAM and won't be reported to OS.
1651 This memory can be used as secure memory. A variable
York Sun1ef95cc2016-06-24 16:46:18 -07001652 gd->arch.secure_ram is used to track the location. In systems
York Sun5d286cd2015-12-04 11:57:07 -08001653 the RAM base is not zero, or RAM is divided into banks,
1654 this variable needs to be recalcuated to get the address.
1655
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001656- CONFIG_SYS_LOADS_BAUD_CHANGE:
wdenkc6097192002-11-03 00:24:07 +00001657 Enable temporary baudrate change while serial download
1658
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001659- CONFIG_SYS_SDRAM_BASE:
wdenkc6097192002-11-03 00:24:07 +00001660 Physical start address of SDRAM. _Must_ be 0 here.
1661
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001662- CONFIG_SYS_FLASH_BASE:
wdenkc6097192002-11-03 00:24:07 +00001663 Physical start address of Flash memory.
1664
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001665- CONFIG_SYS_MONITOR_LEN:
wdenk57b2d802003-06-27 21:31:46 +00001666 Size of memory reserved for monitor code, used to
1667 determine _at_compile_time_ (!) if the environment is
1668 embedded within the U-Boot image, or in a separate
1669 flash sector.
wdenkc6097192002-11-03 00:24:07 +00001670
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001671- CONFIG_SYS_MALLOC_LEN:
wdenkc6097192002-11-03 00:24:07 +00001672 Size of DRAM reserved for malloc() use.
1673
Simon Glass863e4042014-07-10 22:23:28 -06001674- CONFIG_SYS_MALLOC_F_LEN
1675 Size of the malloc() pool for use before relocation. If
1676 this is defined, then a very simple malloc() implementation
1677 will become available before relocation. The address is just
1678 below the global data, and the stack is moved down to make
1679 space.
1680
1681 This feature allocates regions with increasing addresses
1682 within the region. calloc() is supported, but realloc()
1683 is not available. free() is supported but does nothing.
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08001684 The memory will be freed (or in fact just forgotten) when
Simon Glass863e4042014-07-10 22:23:28 -06001685 U-Boot relocates itself.
1686
Simon Glass9fa901b2014-11-10 17:16:54 -07001687- CONFIG_SYS_MALLOC_SIMPLE
1688 Provides a simple and small malloc() and calloc() for those
1689 boards which do not use the full malloc in SPL (which is
Tom Rini166e3222022-05-27 12:48:32 -04001690 enabled with CONFIG_SYS_SPL_MALLOC).
Simon Glass9fa901b2014-11-10 17:16:54 -07001691
Thierry Redingc97d9742014-12-09 22:25:22 -07001692- CONFIG_SYS_NONCACHED_MEMORY:
1693 Size of non-cached memory area. This area of memory will be
1694 typically located right below the malloc() area and mapped
1695 uncached in the MMU. This is useful for drivers that would
1696 otherwise require a lot of explicit cache maintenance. For
1697 some drivers it's also impossible to properly maintain the
1698 cache. For example if the regions that need to be flushed
1699 are not a multiple of the cache-line size, *and* padding
1700 cannot be allocated between the regions to align them (i.e.
1701 if the HW requires a contiguous array of regions, and the
1702 size of each region is not cache-aligned), then a flush of
1703 one region may result in overwriting data that hardware has
1704 written to another region in the same cache-line. This can
1705 happen for example in network drivers where descriptors for
1706 buffers are typically smaller than the CPU cache-line (e.g.
1707 16 bytes vs. 32 or 64 bytes).
1708
1709 Non-cached memory is only supported on 32-bit ARM at present.
1710
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001711- CONFIG_SYS_BOOTMAPSZ:
wdenkc6097192002-11-03 00:24:07 +00001712 Maximum size of memory mapped by the startup code of
1713 the Linux kernel; all data that must be processed by
Bartlomiej Siekac5648c82008-04-14 15:44:16 +02001714 the Linux kernel (bd_info, boot arguments, FDT blob if
1715 used) must be put below this limit, unless "bootm_low"
Robert P. J. Day832d36e2013-09-16 07:15:45 -04001716 environment variable is defined and non-zero. In such case
Bartlomiej Siekac5648c82008-04-14 15:44:16 +02001717 all data for the Linux kernel must be between "bootm_low"
Wolfgang Denk092ae952011-10-26 10:21:21 +00001718 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
Grant Likely26396382011-03-28 09:58:43 +00001719 variable "bootm_mapsize" will override the value of
1720 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
1721 then the value in "bootm_size" will be used instead.
wdenkc6097192002-11-03 00:24:07 +00001722
John Rigbyeea8e692010-10-13 13:57:35 -06001723- CONFIG_SYS_BOOT_GET_CMDLINE:
1724 Enables allocating and saving kernel cmdline in space between
1725 "bootm_low" and "bootm_low" + BOOTMAPSZ.
1726
1727- CONFIG_SYS_BOOT_GET_KBD:
1728 Enables allocating and saving a kernel copy of the bd_info in
1729 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
1730
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001731- CONFIG_SYS_MAX_FLASH_SECT:
wdenkc6097192002-11-03 00:24:07 +00001732 Max number of sectors on a Flash chip
1733
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001734- CONFIG_SYS_FLASH_ERASE_TOUT:
wdenkc6097192002-11-03 00:24:07 +00001735 Timeout for Flash erase operations (in ms)
1736
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001737- CONFIG_SYS_FLASH_WRITE_TOUT:
wdenkc6097192002-11-03 00:24:07 +00001738 Timeout for Flash write operations (in ms)
1739
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001740- CONFIG_SYS_FLASH_LOCK_TOUT
wdenkdccbda02003-07-14 22:13:32 +00001741 Timeout for Flash set sector lock bit operation (in ms)
1742
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001743- CONFIG_SYS_FLASH_UNLOCK_TOUT
wdenkdccbda02003-07-14 22:13:32 +00001744 Timeout for Flash clear lock bits operation (in ms)
1745
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001746- CONFIG_SYS_FLASH_PROTECTION
wdenkdccbda02003-07-14 22:13:32 +00001747 If defined, hardware flash sectors protection is used
1748 instead of U-Boot software protection.
1749
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001750- CONFIG_SYS_DIRECT_FLASH_TFTP:
wdenkc6097192002-11-03 00:24:07 +00001751
1752 Enable TFTP transfers directly to flash memory;
1753 without this option such a download has to be
1754 performed in two steps: (1) download to RAM, and (2)
1755 copy from RAM to flash.
1756
1757 The two-step approach is usually more reliable, since
1758 you can check if the download worked before you erase
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001759 the flash, but in some situations (when system RAM is
1760 too limited to allow for a temporary copy of the
wdenkc6097192002-11-03 00:24:07 +00001761 downloaded image) this option may be very useful.
1762
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001763- CONFIG_SYS_FLASH_CFI:
wdenk4a5c8a72003-03-06 00:02:04 +00001764 Define if the flash driver uses extra elements in the
wdenk2cefd152004-02-08 22:55:38 +00001765 common flash structure for storing flash geometry.
1766
Jean-Christophe PLAGNIOL-VILLARD8d94c232008-08-13 01:40:42 +02001767- CONFIG_FLASH_CFI_DRIVER
wdenk2cefd152004-02-08 22:55:38 +00001768 This option also enables the building of the cfi_flash driver
1769 in the drivers directory
wdenkc6097192002-11-03 00:24:07 +00001770
Piotr Ziecik3e939e92008-11-17 15:57:58 +01001771- CONFIG_FLASH_CFI_MTD
1772 This option enables the building of the cfi_mtd driver
1773 in the drivers directory. The driver exports CFI flash
1774 to the MTD layer.
1775
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001776- CONFIG_SYS_FLASH_USE_BUFFER_WRITE
Guennadi Liakhovetski183284f2008-04-03 13:36:02 +02001777 Use buffered writes to flash.
1778
1779- CONFIG_FLASH_SPANSION_S29WS_N
1780 s29ws-n MirrorBit flash has non-standard addresses for buffered
1781 write commands.
1782
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001783- CONFIG_SYS_FLASH_QUIET_TEST
Stefan Roesec443fe92005-11-22 13:20:42 +01001784 If this option is defined, the common CFI flash doesn't
1785 print it's warning upon not recognized FLASH banks. This
1786 is useful, if some of the configured banks are only
1787 optionally available.
1788
Jerry Van Barenaae73572008-03-08 13:48:01 -05001789- CONFIG_FLASH_SHOW_PROGRESS
1790 If defined (must be an integer), print out countdown
1791 digits and dots. Recommended value: 45 (9..1) for 80
1792 column displays, 15 (3..1) for 40 column displays.
1793
Stefan Roesed20cba52013-04-04 15:53:14 +02001794- CONFIG_FLASH_VERIFY
1795 If defined, the content of the flash (destination) is compared
1796 against the source after the write operation. An error message
1797 will be printed when the contents are not identical.
1798 Please note that this option is useless in nearly all cases,
1799 since such flash programming errors usually are detected earlier
1800 while unprotecting/erasing/programming. Please only enable
1801 this option if you really know what you are doing.
1802
Joe Hershberger71497d02012-12-11 22:16:31 -06001803- CONFIG_ENV_FLAGS_LIST_DEFAULT
1804- CONFIG_ENV_FLAGS_LIST_STATIC
Robert P. J. Day832d36e2013-09-16 07:15:45 -04001805 Enable validation of the values given to environment variables when
Joe Hershberger71497d02012-12-11 22:16:31 -06001806 calling env set. Variables can be restricted to only decimal,
1807 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
1808 the variables can also be restricted to IP address or MAC address.
1809
1810 The format of the list is:
1811 type_attribute = [s|d|x|b|i|m]
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08001812 access_attribute = [a|r|o|c]
1813 attributes = type_attribute[access_attribute]
Joe Hershberger71497d02012-12-11 22:16:31 -06001814 entry = variable_name[:attributes]
1815 list = entry[,list]
1816
1817 The type attributes are:
1818 s - String (default)
1819 d - Decimal
1820 x - Hexadecimal
1821 b - Boolean ([1yYtT|0nNfF])
1822 i - IP address
1823 m - MAC address
1824
Joe Hershberger6fe26c92012-12-11 22:16:34 -06001825 The access attributes are:
1826 a - Any (default)
1827 r - Read-only
1828 o - Write-once
1829 c - Change-default
1830
Joe Hershberger71497d02012-12-11 22:16:31 -06001831 - CONFIG_ENV_FLAGS_LIST_DEFAULT
1832 Define this to a list (string) to define the ".flags"
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08001833 environment variable in the default or embedded environment.
Joe Hershberger71497d02012-12-11 22:16:31 -06001834
1835 - CONFIG_ENV_FLAGS_LIST_STATIC
1836 Define this to a list (string) to define validation that
1837 should be done if an entry is not found in the ".flags"
1838 environment variable. To override a setting in the static
1839 list, simply add an entry for the same variable name to the
1840 ".flags" variable.
1841
Joe Hershberger6db9fd42015-05-20 14:27:20 -05001842 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
1843 regular expression. This allows multiple variables to define the same
1844 flags without explicitly listing them for each variable.
1845
wdenkc6097192002-11-03 00:24:07 +00001846The following definitions that deal with the placement and management
1847of environment data (variable area); in general, we support the
1848following configurations:
1849
Mike Frysinger63b8f122011-07-08 10:44:25 +00001850- CONFIG_BUILD_ENVCRC:
1851
1852 Builds up envcrc with the target environment so that external utils
1853 may easily extract it and embed it in final U-Boot images.
1854
wdenkc6097192002-11-03 00:24:07 +00001855BE CAREFUL! The first access to the environment happens quite early
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08001856in U-Boot initialization (when we try to get the setting of for the
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001857console baudrate). You *MUST* have mapped your NVRAM area then, or
wdenkc6097192002-11-03 00:24:07 +00001858U-Boot will hang.
1859
1860Please note that even with NVRAM we still use a copy of the
1861environment in RAM: we could work on NVRAM directly, but we want to
1862keep settings there always unmodified except somebody uses "saveenv"
1863to save the current settings.
1864
Liu Gang85bcd732012-03-08 00:33:20 +00001865BE CAREFUL! For some special cases, the local device can not use
1866"saveenv" command. For example, the local device will get the
Liu Gang357bf5a2012-08-09 05:10:01 +00001867environment stored in a remote NOR flash by SRIO or PCIE link,
1868but it can not erase, write this NOR flash by SRIO or PCIE interface.
Liu Gang85bcd732012-03-08 00:33:20 +00001869
Guennadi Liakhovetskifad24442009-05-18 16:07:22 +02001870- CONFIG_NAND_ENV_DST
1871
1872 Defines address in RAM to which the nand_spl code should copy the
1873 environment. If redundant environment is used, it will be copied to
1874 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
1875
Bruce Adleredecc942007-11-02 13:15:42 -07001876Please note that the environment is read-only until the monitor
wdenkc6097192002-11-03 00:24:07 +00001877has been relocated to RAM and a RAM copy of the environment has been
Simon Glass64b723f2017-08-03 12:22:12 -06001878created; also, when using EEPROM you will have to use env_get_f()
wdenkc6097192002-11-03 00:24:07 +00001879until then to read environment variables.
1880
wdenk8dba0502003-03-31 16:34:49 +00001881The environment is protected by a CRC32 checksum. Before the monitor
1882is relocated into RAM, as a result of a bad CRC you will be working
1883with the compiled-in default environment - *silently*!!! [This is
1884necessary, because the first environment variable we need is the
1885"baudrate" setting for the console - if we have a bad CRC, we don't
1886have any device yet where we could complain.]
wdenkc6097192002-11-03 00:24:07 +00001887
1888Note: once the monitor has been relocated, then it will complain if
1889the default environment is used; a new CRC is computed as soon as you
wdenk8dba0502003-03-31 16:34:49 +00001890use the "saveenv" command to store a valid environment.
wdenkc6097192002-11-03 00:24:07 +00001891
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001892- CONFIG_SYS_FAULT_MII_ADDR:
wdenk9c53f402003-10-15 23:53:47 +00001893 MII address of the PHY to check for the Ethernet link state.
wdenkc6097192002-11-03 00:24:07 +00001894
Ron Madriddfa028a2009-02-18 14:30:44 -08001895- CONFIG_NS16550_MIN_FUNCTIONS:
1896 Define this if you desire to only have use of the NS16550_init
1897 and NS16550_putc functions for the serial driver located at
1898 drivers/serial/ns16550.c. This option is useful for saving
1899 space for already greatly restricted images, including but not
1900 limited to NAND_SPL configurations.
1901
Simon Glass28a9e332012-11-30 13:01:18 +00001902- CONFIG_DISPLAY_BOARDINFO
1903 Display information about the board that U-Boot is running on
1904 when U-Boot starts up. The board function checkboard() is called
1905 to do this.
1906
Simon Glasse8822012012-11-30 13:01:19 +00001907- CONFIG_DISPLAY_BOARDINFO_LATE
1908 Similar to the previous option, but display this information
1909 later, once stdio is running and output goes to the LCD, if
1910 present.
1911
wdenkc6097192002-11-03 00:24:07 +00001912Low Level (hardware related) configuration options:
wdenkc8434db2003-03-26 06:55:25 +00001913---------------------------------------------------
wdenkc6097192002-11-03 00:24:07 +00001914
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001915- CONFIG_SYS_CACHELINE_SIZE:
wdenkc6097192002-11-03 00:24:07 +00001916 Cache Line Size of the CPU.
1917
Timur Tabid8f341c2011-08-04 18:03:41 -05001918- CONFIG_SYS_CCSRBAR_DEFAULT:
1919 Default (power-on reset) physical address of CCSR on Freescale
1920 PowerPC SOCs.
1921
1922- CONFIG_SYS_CCSRBAR:
1923 Virtual address of CCSR. On a 32-bit build, this is typically
1924 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
1925
Timur Tabid8f341c2011-08-04 18:03:41 -05001926- CONFIG_SYS_CCSRBAR_PHYS:
1927 Physical address of CCSR. CCSR can be relocated to a new
1928 physical address, if desired. In this case, this macro should
Wolfgang Denk092ae952011-10-26 10:21:21 +00001929 be set to that address. Otherwise, it should be set to the
Timur Tabid8f341c2011-08-04 18:03:41 -05001930 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
1931 is typically relocated on 36-bit builds. It is recommended
1932 that this macro be defined via the _HIGH and _LOW macros:
1933
1934 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
1935 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
1936
1937- CONFIG_SYS_CCSRBAR_PHYS_HIGH:
Wolfgang Denkd590fb12011-10-07 09:58:21 +02001938 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
1939 either 0 (32-bit build) or 0xF (36-bit build). This macro is
Timur Tabid8f341c2011-08-04 18:03:41 -05001940 used in assembly code, so it must not contain typecasts or
1941 integer size suffixes (e.g. "ULL").
1942
1943- CONFIG_SYS_CCSRBAR_PHYS_LOW:
1944 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
1945 used in assembly code, so it must not contain typecasts or
1946 integer size suffixes (e.g. "ULL").
1947
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001948- CONFIG_SYS_IMMR: Physical address of the Internal Memory.
wdenk07d7e6b2004-12-16 21:44:03 +00001949 DO NOT CHANGE unless you know exactly what you're
Christophe Leroy069fa832017-07-06 10:23:22 +02001950 doing! (11-4) [MPC8xx systems only]
wdenkc6097192002-11-03 00:24:07 +00001951
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001952- CONFIG_SYS_INIT_RAM_ADDR:
wdenkc6097192002-11-03 00:24:07 +00001953
wdenkeb20ad32003-09-05 23:19:14 +00001954 Start address of memory area that can be used for
wdenkc6097192002-11-03 00:24:07 +00001955 initial data and stack; please note that this must be
1956 writable memory that is working WITHOUT special
1957 initialization, i. e. you CANNOT use normal RAM which
1958 will become available only after programming the
1959 memory controller and running certain initialization
1960 sequences.
1961
1962 U-Boot uses the following memory types:
Christophe Leroy069fa832017-07-06 10:23:22 +02001963 - MPC8xx: IMMR (internal memory of the CPU)
wdenkc6097192002-11-03 00:24:07 +00001964
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001965- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
wdenkc6097192002-11-03 00:24:07 +00001966
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001967- CONFIG_SYS_OR_TIMING_SDRAM:
wdenkc6097192002-11-03 00:24:07 +00001968 SDRAM timing
1969
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001970- CONFIG_SYS_MAMR_PTA:
wdenkc6097192002-11-03 00:24:07 +00001971 periodic timer for refresh
1972
Kumar Gala8975d7a2010-12-30 12:09:53 -06001973- CONFIG_SYS_SRIO:
1974 Chip has SRIO or not
1975
1976- CONFIG_SRIO1:
1977 Board has SRIO 1 port available
1978
1979- CONFIG_SRIO2:
1980 Board has SRIO 2 port available
1981
Liu Gang27afb9c2013-05-07 16:30:46 +08001982- CONFIG_SRIO_PCIE_BOOT_MASTER
1983 Board can support master function for Boot from SRIO and PCIE
1984
Kumar Gala8975d7a2010-12-30 12:09:53 -06001985- CONFIG_SYS_SRIOn_MEM_VIRT:
1986 Virtual Address of SRIO port 'n' memory region
1987
Simon Glass970b61e2019-11-14 12:57:09 -07001988- CONFIG_SYS_SRIOn_MEM_PHYxS:
Kumar Gala8975d7a2010-12-30 12:09:53 -06001989 Physical Address of SRIO port 'n' memory region
1990
1991- CONFIG_SYS_SRIOn_MEM_SIZE:
1992 Size of SRIO port 'n' memory region
1993
Fabio Estevamf17e8782013-04-11 09:35:34 +00001994- CONFIG_SYS_NAND_BUSWIDTH_16BIT
1995 Defined to tell the NAND controller that the NAND chip is using
1996 a 16 bit bus.
1997 Not all NAND drivers use this symbol.
Fabio Estevam417052b2013-04-11 09:35:35 +00001998 Example of drivers that use it:
Miquel Raynal1f1ae152018-08-16 17:30:07 +02001999 - drivers/mtd/nand/raw/ndfc.c
2000 - drivers/mtd/nand/raw/mxc_nand.c
Alex Watermancd6aae32011-05-19 15:08:36 -04002001
2002- CONFIG_SYS_NDFC_EBC0_CFG
2003 Sets the EBC0_CFG register for the NDFC. If not defined
2004 a default value will be used.
2005
Ben Warren45657152006-09-07 16:50:54 -04002006- CONFIG_SPD_EEPROM
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002007 Get DDR timing information from an I2C EEPROM. Common
2008 with pluggable memory modules such as SODIMMs
2009
Ben Warren45657152006-09-07 16:50:54 -04002010 SPD_EEPROM_ADDRESS
2011 I2C address of the SPD EEPROM
2012
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02002013- CONFIG_SYS_SPD_BUS_NUM
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002014 If SPD EEPROM is on an I2C bus other than the first
2015 one, specify here. Note that the value must resolve
2016 to something your driver can deal with.
Ben Warren45657152006-09-07 16:50:54 -04002017
York Sunbd495cf2011-09-16 13:21:35 -07002018- CONFIG_FSL_DDR_INTERACTIVE
2019 Enable interactive DDR debugging. See doc/README.fsl-ddr.
2020
York Sun8ced0502015-01-06 13:18:55 -08002021- CONFIG_FSL_DDR_SYNC_REFRESH
2022 Enable sync of refresh for multiple controllers.
2023
York Sunb6a35f82015-03-19 09:30:28 -07002024- CONFIG_FSL_DDR_BIST
2025 Enable built-in memory test for Freescale DDR controllers.
2026
wdenk6203e402004-04-18 10:13:26 +00002027- CONFIG_RMII
2028 Enable RMII mode for all FECs.
2029 Note that this is a global option, we can't
2030 have one FEC in standard MII mode and another in RMII mode.
2031
wdenk20c98a62004-04-23 20:32:05 +00002032- CONFIG_CRC32_VERIFY
2033 Add a verify option to the crc32 command.
2034 The syntax is:
2035
2036 => crc32 -v <address> <count> <crc32>
2037
2038 Where address/count indicate a memory area
2039 and crc32 is the correct crc32 which the
2040 area should have.
2041
wdenk64519362004-07-11 17:40:54 +00002042- CONFIG_LOOPW
2043 Add the "loopw" memory command. This only takes effect if
Simon Glass92ffdee2017-08-04 16:34:27 -06002044 the memory commands are activated globally (CONFIG_CMD_MEMORY).
wdenk64519362004-07-11 17:40:54 +00002045
Joel Johnsondb5a97e2020-01-29 09:17:18 -07002046- CONFIG_CMD_MX_CYCLIC
stroesecc3af832004-12-16 18:46:55 +00002047 Add the "mdc" and "mwc" memory commands. These are cyclic
2048 "md/mw" commands.
2049 Examples:
2050
wdenk07d7e6b2004-12-16 21:44:03 +00002051 => mdc.b 10 4 500
stroesecc3af832004-12-16 18:46:55 +00002052 This command will print 4 bytes (10,11,12,13) each 500 ms.
2053
wdenk07d7e6b2004-12-16 21:44:03 +00002054 => mwc.l 100 12345678 10
stroesecc3af832004-12-16 18:46:55 +00002055 This command will write 12345678 to address 100 all 10 ms.
2056
wdenk07d7e6b2004-12-16 21:44:03 +00002057 This only takes effect if the memory commands are activated
Simon Glass92ffdee2017-08-04 16:34:27 -06002058 globally (CONFIG_CMD_MEMORY).
stroesecc3af832004-12-16 18:46:55 +00002059
Aneesh V552a3192011-07-13 05:11:07 +00002060- CONFIG_SPL_BUILD
Thomas Hebbfd37f242019-11-13 18:18:03 -08002061 Set when the currently-running compilation is for an artifact
2062 that will end up in the SPL (as opposed to the TPL or U-Boot
2063 proper). Code that needs stage-specific behavior should check
2064 this.
wdenk336b2bc2005-04-02 23:52:25 +00002065
Ying Zhang2d2e3b62013-08-16 15:16:15 +08002066- CONFIG_TPL_BUILD
Thomas Hebbfd37f242019-11-13 18:18:03 -08002067 Set when the currently-running compilation is for an artifact
2068 that will end up in the TPL (as opposed to the SPL or U-Boot
2069 proper). Code that needs stage-specific behavior should check
2070 this.
Ying Zhang2d2e3b62013-08-16 15:16:15 +08002071
Simon Glass17dabf02013-02-24 17:33:14 +00002072- CONFIG_ARCH_MAP_SYSMEM
2073 Generally U-Boot (and in particular the md command) uses
2074 effective address. It is therefore not necessary to regard
2075 U-Boot address as virtual addresses that need to be translated
2076 to physical addresses. However, sandbox requires this, since
2077 it maintains its own little RAM buffer which contains all
2078 addressable memory. This option causes some memory accesses
2079 to be mapped through map_sysmem() / unmap_sysmem().
2080
Simon Glassbfb59802013-02-14 04:18:54 +00002081- CONFIG_X86_RESET_VECTOR
2082 If defined, the x86 reset vector code is included. This is not
2083 needed when U-Boot is running from Coreboot.
Gabe Black14f82462012-11-27 21:08:06 +00002084
Karicheri, Muralidharanc1dc61b2014-04-04 13:16:50 -04002085- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
2086 Option to disable subpage write in NAND driver
2087 driver that uses this:
Miquel Raynal1f1ae152018-08-16 17:30:07 +02002088 drivers/mtd/nand/raw/davinci_nand.c
Karicheri, Muralidharanc1dc61b2014-04-04 13:16:50 -04002089
Timur Tabi275f4bb2011-11-22 09:21:25 -06002090Freescale QE/FMAN Firmware Support:
2091-----------------------------------
2092
2093The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
2094loading of "firmware", which is encoded in the QE firmware binary format.
2095This firmware often needs to be loaded during U-Boot booting, so macros
2096are used to identify the storage device (NOR flash, SPI, etc) and the address
2097within that device.
2098
Zhao Qiang83a90842014-03-21 16:21:44 +08002099- CONFIG_SYS_FMAN_FW_ADDR
2100 The address in the storage device where the FMAN microcode is located. The
Tom Rinifa911f82019-05-12 07:59:12 -04002101 meaning of this address depends on which CONFIG_SYS_QE_FMAN_FW_IN_xxx macro
Zhao Qiang83a90842014-03-21 16:21:44 +08002102 is also specified.
2103
2104- CONFIG_SYS_QE_FW_ADDR
2105 The address in the storage device where the QE microcode is located. The
Tom Rinifa911f82019-05-12 07:59:12 -04002106 meaning of this address depends on which CONFIG_SYS_QE_FMAN_FW_IN_xxx macro
Timur Tabi275f4bb2011-11-22 09:21:25 -06002107 is also specified.
2108
2109- CONFIG_SYS_QE_FMAN_FW_LENGTH
2110 The maximum possible size of the firmware. The firmware binary format
2111 has a field that specifies the actual size of the firmware, but it
2112 might not be possible to read any part of the firmware unless some
2113 local storage is allocated to hold the entire firmware first.
2114
2115- CONFIG_SYS_QE_FMAN_FW_IN_NOR
2116 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
2117 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
2118 virtual address in NOR flash.
2119
2120- CONFIG_SYS_QE_FMAN_FW_IN_NAND
2121 Specifies that QE/FMAN firmware is located in NAND flash.
2122 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
2123
2124- CONFIG_SYS_QE_FMAN_FW_IN_MMC
2125 Specifies that QE/FMAN firmware is located on the primary SD/MMC
2126 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
2127
Liu Gang1e084582012-03-08 00:33:18 +00002128- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
2129 Specifies that QE/FMAN firmware is located in the remote (master)
2130 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
Liu Gang357bf5a2012-08-09 05:10:01 +00002131 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
2132 window->master inbound window->master LAW->the ucode address in
2133 master's memory space.
Timur Tabi275f4bb2011-11-22 09:21:25 -06002134
J. German Rivera8ff14b72014-06-23 15:15:55 -07002135Freescale Layerscape Management Complex Firmware Support:
2136---------------------------------------------------------
2137The Freescale Layerscape Management Complex (MC) supports the loading of
2138"firmware".
2139This firmware often needs to be loaded during U-Boot booting, so macros
2140are used to identify the storage device (NOR flash, SPI, etc) and the address
2141within that device.
2142
2143- CONFIG_FSL_MC_ENET
2144 Enable the MC driver for Layerscape SoCs.
2145
Prabhakar Kushwaha853a9012015-06-02 10:55:52 +05302146Freescale Layerscape Debug Server Support:
2147-------------------------------------------
2148The Freescale Layerscape Debug Server Support supports the loading of
2149"Debug Server firmware" and triggering SP boot-rom.
2150This firmware often needs to be loaded during U-Boot booting.
2151
York Sun928b6812015-12-07 11:08:58 -08002152- CONFIG_SYS_MC_RSV_MEM_ALIGN
2153 Define alignment of reserved memory MC requires
Prabhakar Kushwaha853a9012015-06-02 10:55:52 +05302154
Paul Kocialkowski7b917022015-07-26 18:48:15 +02002155Reproducible builds
2156-------------------
2157
2158In order to achieve reproducible builds, timestamps used in the U-Boot build
2159process have to be set to a fixed value.
2160
2161This is done using the SOURCE_DATE_EPOCH environment variable.
2162SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
2163option for U-Boot or an environment variable in U-Boot.
2164
2165SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
2166
wdenkc6097192002-11-03 00:24:07 +00002167Building the Software:
2168======================
2169
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002170Building U-Boot has been tested in several native build environments
2171and in many different cross environments. Of course we cannot support
2172all possibly existing versions of cross development tools in all
2173(potentially obsolete) versions. In case of tool chain problems we
Naoki Hayamae0cc1852020-10-08 13:17:16 +09002174recommend to use the ELDK (see https://www.denx.de/wiki/DULG/ELDK)
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002175which is extensively used to build and test U-Boot.
wdenkc6097192002-11-03 00:24:07 +00002176
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002177If you are not using a native environment, it is assumed that you
2178have GNU cross compiling tools available in your path. In this case,
2179you must set the environment variable CROSS_COMPILE in your shell.
2180Note that no changes to the Makefile or any other source files are
2181necessary. For example using the ELDK on a 4xx CPU, please enter:
wdenkc6097192002-11-03 00:24:07 +00002182
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002183 $ CROSS_COMPILE=ppc_4xx-
2184 $ export CROSS_COMPILE
wdenkc6097192002-11-03 00:24:07 +00002185
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002186U-Boot is intended to be simple to build. After installing the
2187sources you must configure U-Boot for one specific board type. This
wdenkc6097192002-11-03 00:24:07 +00002188is done by typing:
2189
Holger Freyther7ba4e572014-08-04 09:26:05 +02002190 make NAME_defconfig
wdenkc6097192002-11-03 00:24:07 +00002191
Holger Freyther7ba4e572014-08-04 09:26:05 +02002192where "NAME_defconfig" is the name of one of the existing configu-
Heinrich Schuchardtd6e07af2020-02-24 18:36:30 +01002193rations; see configs/*_defconfig for supported names.
wdenk2f0812d2003-10-08 22:45:44 +00002194
Heinrich Schuchardtd6e07af2020-02-24 18:36:30 +01002195Note: for some boards special configuration names may exist; check if
wdenk6c59edc2004-05-03 20:45:30 +00002196 additional information is available from the board vendor; for
2197 instance, the TQM823L systems are available without (standard)
2198 or with LCD support. You can select such additional "features"
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02002199 when choosing the configuration, i. e.
wdenkc6097192002-11-03 00:24:07 +00002200
Holger Freyther7ba4e572014-08-04 09:26:05 +02002201 make TQM823L_defconfig
wdenk6c59edc2004-05-03 20:45:30 +00002202 - will configure for a plain TQM823L, i. e. no LCD support
wdenkc6097192002-11-03 00:24:07 +00002203
Holger Freyther7ba4e572014-08-04 09:26:05 +02002204 make TQM823L_LCD_defconfig
wdenk6c59edc2004-05-03 20:45:30 +00002205 - will configure for a TQM823L with U-Boot console on LCD
wdenkc6097192002-11-03 00:24:07 +00002206
wdenk6c59edc2004-05-03 20:45:30 +00002207 etc.
wdenkc6097192002-11-03 00:24:07 +00002208
wdenkc6097192002-11-03 00:24:07 +00002209
wdenk6c59edc2004-05-03 20:45:30 +00002210Finally, type "make all", and you should get some working U-Boot
2211images ready for download to / installation on your system:
wdenkc6097192002-11-03 00:24:07 +00002212
wdenk6c59edc2004-05-03 20:45:30 +00002213- "u-boot.bin" is a raw binary image
2214- "u-boot" is an image in ELF binary format
2215- "u-boot.srec" is in Motorola S-Record format
wdenkc6097192002-11-03 00:24:07 +00002216
Marian Balakowiczefe063f2006-09-07 17:25:40 +02002217By default the build is performed locally and the objects are saved
2218in the source directory. One of the two methods can be used to change
2219this behavior and build U-Boot to some external directory:
2220
22211. Add O= to the make command line invocations:
2222
2223 make O=/tmp/build distclean
Holger Freyther7ba4e572014-08-04 09:26:05 +02002224 make O=/tmp/build NAME_defconfig
Marian Balakowiczefe063f2006-09-07 17:25:40 +02002225 make O=/tmp/build all
2226
Timo Ketolac8c67602014-11-06 14:39:05 +020022272. Set environment variable KBUILD_OUTPUT to point to the desired location:
Marian Balakowiczefe063f2006-09-07 17:25:40 +02002228
Timo Ketolac8c67602014-11-06 14:39:05 +02002229 export KBUILD_OUTPUT=/tmp/build
Marian Balakowiczefe063f2006-09-07 17:25:40 +02002230 make distclean
Holger Freyther7ba4e572014-08-04 09:26:05 +02002231 make NAME_defconfig
Marian Balakowiczefe063f2006-09-07 17:25:40 +02002232 make all
2233
Timo Ketolac8c67602014-11-06 14:39:05 +02002234Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
Marian Balakowiczefe063f2006-09-07 17:25:40 +02002235variable.
2236
Daniel Schwierzeck88484422018-01-26 16:31:04 +01002237User specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by
2238setting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS.
2239For example to treat all compiler warnings as errors:
2240
2241 make KCFLAGS=-Werror
wdenkc6097192002-11-03 00:24:07 +00002242
wdenk6c59edc2004-05-03 20:45:30 +00002243Please be aware that the Makefiles assume you are using GNU make, so
2244for instance on NetBSD you might need to use "gmake" instead of
2245native "make".
wdenkc6097192002-11-03 00:24:07 +00002246
wdenkc6097192002-11-03 00:24:07 +00002247
wdenk6c59edc2004-05-03 20:45:30 +00002248If the system board that you have is not listed, then you will need
2249to port U-Boot to your hardware platform. To do this, follow these
2250steps:
wdenkc6097192002-11-03 00:24:07 +00002251
Phil Sutterc77b4882015-12-25 14:41:18 +010022521. Create a new directory to hold your board specific code. Add any
wdenk6c59edc2004-05-03 20:45:30 +00002253 files you need. In your board directory, you will need at least
Phil Sutterc77b4882015-12-25 14:41:18 +01002254 the "Makefile" and a "<board>.c".
22552. Create a new configuration file "include/configs/<board>.h" for
2256 your board.
wdenk6c59edc2004-05-03 20:45:30 +000022573. If you're porting U-Boot to a new CPU, then also create a new
2258 directory to hold your CPU specific code. Add any files you need.
Holger Freyther7ba4e572014-08-04 09:26:05 +020022594. Run "make <board>_defconfig" with your new name.
wdenk6c59edc2004-05-03 20:45:30 +000022605. Type "make", and you should get a working "u-boot.srec" file
2261 to be installed on your target system.
22626. Debug and solve any problems that might arise.
2263 [Of course, this last step is much harder than it sounds.]
wdenkc6097192002-11-03 00:24:07 +00002264
wdenkc6097192002-11-03 00:24:07 +00002265
wdenk6c59edc2004-05-03 20:45:30 +00002266Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2267==============================================================
wdenkc6097192002-11-03 00:24:07 +00002268
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002269If you have modified U-Boot sources (for instance added a new board
2270or support for new devices, a new CPU, etc.) you are expected to
wdenk6c59edc2004-05-03 20:45:30 +00002271provide feedback to the other developers. The feedback normally takes
Thomas Hebbfd37f242019-11-13 18:18:03 -08002272the form of a "patch", i.e. a context diff against a certain (latest
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002273official or latest in the git repository) version of U-Boot sources.
wdenkc6097192002-11-03 00:24:07 +00002274
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002275But before you submit such a patch, please verify that your modifi-
2276cation did not break existing code. At least make sure that *ALL* of
wdenk6c59edc2004-05-03 20:45:30 +00002277the supported boards compile WITHOUT ANY compiler warnings. To do so,
Simon Glassdc27def2016-07-27 20:33:08 -06002278just run the buildman script (tools/buildman/buildman), which will
2279configure and build U-Boot for ALL supported system. Be warned, this
2280will take a while. Please see the buildman README, or run 'buildman -H'
2281for documentation.
wdenkc6097192002-11-03 00:24:07 +00002282
Marian Balakowiczefe063f2006-09-07 17:25:40 +02002283
wdenk6c59edc2004-05-03 20:45:30 +00002284See also "U-Boot Porting Guide" below.
wdenkc6097192002-11-03 00:24:07 +00002285
wdenkc6097192002-11-03 00:24:07 +00002286
wdenk6c59edc2004-05-03 20:45:30 +00002287Monitor Commands - Overview:
2288============================
wdenkc6097192002-11-03 00:24:07 +00002289
wdenk6c59edc2004-05-03 20:45:30 +00002290go - start application at address 'addr'
2291run - run commands in an environment variable
2292bootm - boot application image from memory
2293bootp - boot image via network using BootP/TFTP protocol
Marek Vasutcf41a9b2012-03-14 21:52:45 +00002294bootz - boot zImage from memory
wdenk6c59edc2004-05-03 20:45:30 +00002295tftpboot- boot image via network using TFTP protocol
2296 and env variables "ipaddr" and "serverip"
2297 (and eventually "gatewayip")
Simon Glass6a398d22011-10-24 18:00:07 +00002298tftpput - upload a file via network using TFTP protocol
wdenk6c59edc2004-05-03 20:45:30 +00002299rarpboot- boot image via network using RARP/TFTP protocol
2300diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2301loads - load S-Record file over serial line
2302loadb - load binary file over serial line (kermit mode)
Rui Miguel Silva433f15a2022-05-11 10:55:40 +01002303loadm - load binary blob from source address to destination address
wdenk6c59edc2004-05-03 20:45:30 +00002304md - memory display
2305mm - memory modify (auto-incrementing)
2306nm - memory modify (constant address)
2307mw - memory write (fill)
Simon Glass19038de2020-06-02 19:26:49 -06002308ms - memory search
wdenk6c59edc2004-05-03 20:45:30 +00002309cp - memory copy
2310cmp - memory compare
2311crc32 - checksum calculation
Peter Tyser469cde42009-04-18 22:34:03 -05002312i2c - I2C sub-system
wdenk6c59edc2004-05-03 20:45:30 +00002313sspi - SPI utility commands
2314base - print or set address offset
2315printenv- print environment variables
Pragnesh Patel1d5955f2020-12-22 11:30:05 +05302316pwm - control pwm channels
wdenk6c59edc2004-05-03 20:45:30 +00002317setenv - set environment variables
2318saveenv - save environment variables to persistent storage
2319protect - enable or disable FLASH write protection
2320erase - erase FLASH memory
2321flinfo - print FLASH memory information
Karl O. Pinc4baf03d2012-08-03 05:57:21 +00002322nand - NAND memory operations (see doc/README.nand)
wdenk6c59edc2004-05-03 20:45:30 +00002323bdinfo - print Board Info structure
2324iminfo - print header information for application image
2325coninfo - print console devices and informations
2326ide - IDE sub-system
2327loop - infinite loop on address range
wdenk64519362004-07-11 17:40:54 +00002328loopw - infinite write loop on address range
wdenk6c59edc2004-05-03 20:45:30 +00002329mtest - simple RAM test
2330icache - enable or disable instruction cache
2331dcache - enable or disable data cache
2332reset - Perform RESET of the CPU
2333echo - echo args to console
2334version - print monitor version
2335help - print online help
2336? - alias for 'help'
wdenkc6097192002-11-03 00:24:07 +00002337
wdenkc6097192002-11-03 00:24:07 +00002338
wdenk6c59edc2004-05-03 20:45:30 +00002339Monitor Commands - Detailed Description:
2340========================================
wdenkc6097192002-11-03 00:24:07 +00002341
wdenk6c59edc2004-05-03 20:45:30 +00002342TODO.
wdenkc6097192002-11-03 00:24:07 +00002343
wdenk6c59edc2004-05-03 20:45:30 +00002344For now: just type "help <command>".
wdenkc6097192002-11-03 00:24:07 +00002345
2346
wdenk6c59edc2004-05-03 20:45:30 +00002347Note for Redundant Ethernet Interfaces:
2348=======================================
wdenkf4688a22003-05-28 08:06:31 +00002349
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02002350Some boards come with redundant Ethernet interfaces; U-Boot supports
wdenk6c59edc2004-05-03 20:45:30 +00002351such configurations and is capable of automatic selection of a
2352"working" interface when needed. MAC assignment works as follows:
wdenkf4688a22003-05-28 08:06:31 +00002353
wdenk6c59edc2004-05-03 20:45:30 +00002354Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2355MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2356"eth1addr" (=>eth1), "eth2addr", ...
wdenkf4688a22003-05-28 08:06:31 +00002357
wdenk6c59edc2004-05-03 20:45:30 +00002358If the network interface stores some valid MAC address (for instance
2359in SROM), this is used as default address if there is NO correspon-
2360ding setting in the environment; if the corresponding environment
2361variable is set, this overrides the settings in the card; that means:
wdenkf4688a22003-05-28 08:06:31 +00002362
wdenk6c59edc2004-05-03 20:45:30 +00002363o If the SROM has a valid MAC address, and there is no address in the
2364 environment, the SROM's address is used.
wdenkc6097192002-11-03 00:24:07 +00002365
wdenk6c59edc2004-05-03 20:45:30 +00002366o If there is no valid address in the SROM, and a definition in the
2367 environment exists, then the value from the environment variable is
2368 used.
wdenkc6097192002-11-03 00:24:07 +00002369
wdenk6c59edc2004-05-03 20:45:30 +00002370o If both the SROM and the environment contain a MAC address, and
2371 both addresses are the same, this MAC address is used.
wdenkc6097192002-11-03 00:24:07 +00002372
wdenk6c59edc2004-05-03 20:45:30 +00002373o If both the SROM and the environment contain a MAC address, and the
2374 addresses differ, the value from the environment is used and a
2375 warning is printed.
wdenkc6097192002-11-03 00:24:07 +00002376
wdenk6c59edc2004-05-03 20:45:30 +00002377o If neither SROM nor the environment contain a MAC address, an error
Joe Hershberger2dc2b5d2015-05-04 14:55:13 -05002378 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
2379 a random, locally-assigned MAC is used.
wdenkc6097192002-11-03 00:24:07 +00002380
Ben Warren6db991a2010-04-26 11:11:46 -07002381If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
Wolfgang Denk092ae952011-10-26 10:21:21 +00002382will be programmed into hardware as part of the initialization process. This
Ben Warren6db991a2010-04-26 11:11:46 -07002383may be skipped by setting the appropriate 'ethmacskip' environment variable.
2384The naming convention is as follows:
2385"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
wdenkc6097192002-11-03 00:24:07 +00002386
wdenk6c59edc2004-05-03 20:45:30 +00002387Image Formats:
2388==============
wdenkc6097192002-11-03 00:24:07 +00002389
Marian Balakowicz18710b82008-03-12 12:13:13 +01002390U-Boot is capable of booting (and performing other auxiliary operations on)
2391images in two formats:
2392
2393New uImage format (FIT)
2394-----------------------
2395
2396Flexible and powerful format based on Flattened Image Tree -- FIT (similar
2397to Flattened Device Tree). It allows the use of images with multiple
2398components (several kernels, ramdisks, etc.), with contents protected by
2399SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
2400
2401
2402Old uImage format
2403-----------------
2404
2405Old image format is based on binary files which can be basically anything,
2406preceded by a special header; see the definitions in include/image.h for
2407details; basically, the header defines the following image properties:
wdenkc6097192002-11-03 00:24:07 +00002408
wdenk6c59edc2004-05-03 20:45:30 +00002409* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2410 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
Peter Tyser56b8dd12008-09-08 14:56:49 -05002411 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
Thomas Huthc90d56a2021-11-13 18:13:50 +01002412 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, INTEGRITY).
Andy Shevchenko8cb5cdd2017-07-05 16:25:22 +03002413* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
Tom Rini53320122022-04-06 09:21:25 -04002414 IA64, MIPS, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2415 Currently supported: ARM, Intel x86, MIPS, Nios II, PowerPC).
wdenk6c59edc2004-05-03 20:45:30 +00002416* Compression Type (uncompressed, gzip, bzip2)
2417* Load Address
2418* Entry Point
2419* Image Name
2420* Image Timestamp
wdenkc6097192002-11-03 00:24:07 +00002421
wdenk6c59edc2004-05-03 20:45:30 +00002422The header is marked by a special Magic Number, and both the header
2423and the data portions of the image are secured against corruption by
2424CRC32 checksums.
wdenkc6097192002-11-03 00:24:07 +00002425
wdenkc6097192002-11-03 00:24:07 +00002426
wdenk6c59edc2004-05-03 20:45:30 +00002427Linux Support:
2428==============
wdenkc6097192002-11-03 00:24:07 +00002429
wdenk6c59edc2004-05-03 20:45:30 +00002430Although U-Boot should support any OS or standalone application
2431easily, the main focus has always been on Linux during the design of
2432U-Boot.
wdenkc6097192002-11-03 00:24:07 +00002433
wdenk6c59edc2004-05-03 20:45:30 +00002434U-Boot includes many features that so far have been part of some
2435special "boot loader" code within the Linux kernel. Also, any
2436"initrd" images to be used are no longer part of one big Linux image;
2437instead, kernel and "initrd" are separate images. This implementation
2438serves several purposes:
wdenkc6097192002-11-03 00:24:07 +00002439
wdenk6c59edc2004-05-03 20:45:30 +00002440- the same features can be used for other OS or standalone
2441 applications (for instance: using compressed images to reduce the
2442 Flash memory footprint)
wdenkc6097192002-11-03 00:24:07 +00002443
wdenk6c59edc2004-05-03 20:45:30 +00002444- it becomes much easier to port new Linux kernel versions because
2445 lots of low-level, hardware dependent stuff are done by U-Boot
wdenkc6097192002-11-03 00:24:07 +00002446
wdenk6c59edc2004-05-03 20:45:30 +00002447- the same Linux kernel image can now be used with different "initrd"
2448 images; of course this also means that different kernel images can
2449 be run with the same "initrd". This makes testing easier (you don't
2450 have to build a new "zImage.initrd" Linux image when you just
2451 change a file in your "initrd"). Also, a field-upgrade of the
2452 software is easier now.
wdenkc6097192002-11-03 00:24:07 +00002453
wdenkc6097192002-11-03 00:24:07 +00002454
wdenk6c59edc2004-05-03 20:45:30 +00002455Linux HOWTO:
2456============
wdenkc6097192002-11-03 00:24:07 +00002457
wdenk6c59edc2004-05-03 20:45:30 +00002458Porting Linux to U-Boot based systems:
2459---------------------------------------
wdenkc6097192002-11-03 00:24:07 +00002460
wdenk6c59edc2004-05-03 20:45:30 +00002461U-Boot cannot save you from doing all the necessary modifications to
2462configure the Linux device drivers for use with your target hardware
2463(no, we don't intend to provide a full virtual machine interface to
2464Linux :-).
wdenkc6097192002-11-03 00:24:07 +00002465
Stefan Roese88fbf932010-04-15 16:07:28 +02002466But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
wdenkc6097192002-11-03 00:24:07 +00002467
wdenk6c59edc2004-05-03 20:45:30 +00002468Just make sure your machine specific header file (for instance
2469include/asm-ppc/tqm8xx.h) includes the same definition of the Board
Markus Heidelberg47167572008-09-07 20:18:27 +02002470Information structure as we define in include/asm-<arch>/u-boot.h,
2471and make sure that your definition of IMAP_ADDR uses the same value
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02002472as your U-Boot configuration in CONFIG_SYS_IMMR.
wdenkc6097192002-11-03 00:24:07 +00002473
Simon Glassd097e592014-06-11 23:29:46 -06002474Note that U-Boot now has a driver model, a unified model for drivers.
2475If you are adding a new driver, plumb it into driver model. If there
2476is no uclass available, you are encouraged to create one. See
2477doc/driver-model.
2478
wdenkc6097192002-11-03 00:24:07 +00002479
wdenk6c59edc2004-05-03 20:45:30 +00002480Configuring the Linux kernel:
2481-----------------------------
wdenkc6097192002-11-03 00:24:07 +00002482
wdenk6c59edc2004-05-03 20:45:30 +00002483No specific requirements for U-Boot. Make sure you have some root
2484device (initial ramdisk, NFS) for your target system.
wdenkc6097192002-11-03 00:24:07 +00002485
wdenkc6097192002-11-03 00:24:07 +00002486
wdenk6c59edc2004-05-03 20:45:30 +00002487Building a Linux Image:
2488-----------------------
wdenkc6097192002-11-03 00:24:07 +00002489
wdenk6c59edc2004-05-03 20:45:30 +00002490With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2491not used. If you use recent kernel source, a new build target
2492"uImage" will exist which automatically builds an image usable by
2493U-Boot. Most older kernels also have support for a "pImage" target,
2494which was introduced for our predecessor project PPCBoot and uses a
2495100% compatible format.
wdenkc6097192002-11-03 00:24:07 +00002496
wdenk6c59edc2004-05-03 20:45:30 +00002497Example:
wdenkc6097192002-11-03 00:24:07 +00002498
Holger Freyther7ba4e572014-08-04 09:26:05 +02002499 make TQM850L_defconfig
wdenk6c59edc2004-05-03 20:45:30 +00002500 make oldconfig
2501 make dep
2502 make uImage
wdenkc6097192002-11-03 00:24:07 +00002503
wdenk6c59edc2004-05-03 20:45:30 +00002504The "uImage" build target uses a special tool (in 'tools/mkimage') to
2505encapsulate a compressed Linux kernel image with header information,
2506CRC32 checksum etc. for use with U-Boot. This is what we are doing:
wdenkc6097192002-11-03 00:24:07 +00002507
wdenk6c59edc2004-05-03 20:45:30 +00002508* build a standard "vmlinux" kernel image (in ELF binary format):
wdenkc6097192002-11-03 00:24:07 +00002509
wdenk6c59edc2004-05-03 20:45:30 +00002510* convert the kernel into a raw binary image:
wdenkc6097192002-11-03 00:24:07 +00002511
wdenk6c59edc2004-05-03 20:45:30 +00002512 ${CROSS_COMPILE}-objcopy -O binary \
2513 -R .note -R .comment \
2514 -S vmlinux linux.bin
wdenk24ee89b2002-11-03 17:56:27 +00002515
wdenk6c59edc2004-05-03 20:45:30 +00002516* compress the binary image:
wdenk24ee89b2002-11-03 17:56:27 +00002517
wdenk6c59edc2004-05-03 20:45:30 +00002518 gzip -9 linux.bin
wdenk24ee89b2002-11-03 17:56:27 +00002519
wdenk6c59edc2004-05-03 20:45:30 +00002520* package compressed binary image for U-Boot:
wdenk24ee89b2002-11-03 17:56:27 +00002521
wdenk6c59edc2004-05-03 20:45:30 +00002522 mkimage -A ppc -O linux -T kernel -C gzip \
2523 -a 0 -e 0 -n "Linux Kernel Image" \
2524 -d linux.bin.gz uImage
wdenkc6097192002-11-03 00:24:07 +00002525
wdenkc6097192002-11-03 00:24:07 +00002526
wdenk6c59edc2004-05-03 20:45:30 +00002527The "mkimage" tool can also be used to create ramdisk images for use
2528with U-Boot, either separated from the Linux kernel image, or
2529combined into one file. "mkimage" encapsulates the images with a 64
2530byte header containing information about target architecture,
2531operating system, image type, compression method, entry points, time
2532stamp, CRC32 checksums, etc.
wdenkc6097192002-11-03 00:24:07 +00002533
wdenk6c59edc2004-05-03 20:45:30 +00002534"mkimage" can be called in two ways: to verify existing images and
2535print the header information, or to build new images.
wdenk24ee89b2002-11-03 17:56:27 +00002536
wdenk6c59edc2004-05-03 20:45:30 +00002537In the first form (with "-l" option) mkimage lists the information
2538contained in the header of an existing U-Boot image; this includes
2539checksum verification:
wdenk24ee89b2002-11-03 17:56:27 +00002540
wdenk6c59edc2004-05-03 20:45:30 +00002541 tools/mkimage -l image
2542 -l ==> list image header information
wdenk24ee89b2002-11-03 17:56:27 +00002543
wdenk6c59edc2004-05-03 20:45:30 +00002544The second form (with "-d" option) is used to build a U-Boot image
2545from a "data file" which is used as image payload:
wdenk24ee89b2002-11-03 17:56:27 +00002546
wdenk6c59edc2004-05-03 20:45:30 +00002547 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2548 -n name -d data_file image
2549 -A ==> set architecture to 'arch'
2550 -O ==> set operating system to 'os'
2551 -T ==> set image type to 'type'
2552 -C ==> set compression type 'comp'
2553 -a ==> set load address to 'addr' (hex)
2554 -e ==> set entry point to 'ep' (hex)
2555 -n ==> set image name to 'name'
2556 -d ==> use image data from 'datafile'
wdenk24ee89b2002-11-03 17:56:27 +00002557
wdenkcd914452004-05-29 16:53:29 +00002558Right now, all Linux kernels for PowerPC systems use the same load
2559address (0x00000000), but the entry point address depends on the
2560kernel version:
wdenkc6097192002-11-03 00:24:07 +00002561
wdenk6c59edc2004-05-03 20:45:30 +00002562- 2.2.x kernels have the entry point at 0x0000000C,
2563- 2.3.x and later kernels have the entry point at 0x00000000.
wdenkc6097192002-11-03 00:24:07 +00002564
wdenk6c59edc2004-05-03 20:45:30 +00002565So a typical call to build a U-Boot image would read:
wdenkc6097192002-11-03 00:24:07 +00002566
wdenk6c59edc2004-05-03 20:45:30 +00002567 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2568 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
Stefan Roese88fbf932010-04-15 16:07:28 +02002569 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
wdenk6c59edc2004-05-03 20:45:30 +00002570 > examples/uImage.TQM850L
2571 Image Name: 2.4.4 kernel for TQM850L
2572 Created: Wed Jul 19 02:34:59 2000
2573 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2574 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2575 Load Address: 0x00000000
2576 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002577
wdenk6c59edc2004-05-03 20:45:30 +00002578To verify the contents of the image (or check for corruption):
wdenkc6097192002-11-03 00:24:07 +00002579
wdenk6c59edc2004-05-03 20:45:30 +00002580 -> tools/mkimage -l examples/uImage.TQM850L
2581 Image Name: 2.4.4 kernel for TQM850L
2582 Created: Wed Jul 19 02:34:59 2000
2583 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2584 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2585 Load Address: 0x00000000
2586 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002587
wdenk6c59edc2004-05-03 20:45:30 +00002588NOTE: for embedded systems where boot time is critical you can trade
2589speed for memory and install an UNCOMPRESSED image instead: this
2590needs more space in Flash, but boots much faster since it does not
2591need to be uncompressed:
wdenkc6097192002-11-03 00:24:07 +00002592
Stefan Roese88fbf932010-04-15 16:07:28 +02002593 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
wdenk6c59edc2004-05-03 20:45:30 +00002594 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2595 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
Stefan Roese88fbf932010-04-15 16:07:28 +02002596 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
wdenk6c59edc2004-05-03 20:45:30 +00002597 > examples/uImage.TQM850L-uncompressed
2598 Image Name: 2.4.4 kernel for TQM850L
2599 Created: Wed Jul 19 02:34:59 2000
2600 Image Type: PowerPC Linux Kernel Image (uncompressed)
2601 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
2602 Load Address: 0x00000000
2603 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002604
wdenkc6097192002-11-03 00:24:07 +00002605
wdenk6c59edc2004-05-03 20:45:30 +00002606Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2607when your kernel is intended to use an initial ramdisk:
wdenkc6097192002-11-03 00:24:07 +00002608
wdenk6c59edc2004-05-03 20:45:30 +00002609 -> tools/mkimage -n 'Simple Ramdisk Image' \
2610 > -A ppc -O linux -T ramdisk -C gzip \
2611 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2612 Image Name: Simple Ramdisk Image
2613 Created: Wed Jan 12 14:01:50 2000
2614 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2615 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
2616 Load Address: 0x00000000
2617 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002618
Tyler Hicks791c7472020-10-26 10:40:24 -05002619The "dumpimage" tool can be used to disassemble or list the contents of images
2620built by mkimage. See dumpimage's help output (-h) for details.
wdenkc6097192002-11-03 00:24:07 +00002621
wdenk6c59edc2004-05-03 20:45:30 +00002622Installing a Linux Image:
2623-------------------------
wdenkc6097192002-11-03 00:24:07 +00002624
wdenk6c59edc2004-05-03 20:45:30 +00002625To downloading a U-Boot image over the serial (console) interface,
2626you must convert the image to S-Record format:
wdenkc6097192002-11-03 00:24:07 +00002627
wdenk6c59edc2004-05-03 20:45:30 +00002628 objcopy -I binary -O srec examples/image examples/image.srec
wdenkc6097192002-11-03 00:24:07 +00002629
wdenk6c59edc2004-05-03 20:45:30 +00002630The 'objcopy' does not understand the information in the U-Boot
2631image header, so the resulting S-Record file will be relative to
2632address 0x00000000. To load it to a given address, you need to
2633specify the target address as 'offset' parameter with the 'loads'
2634command.
wdenkc6097192002-11-03 00:24:07 +00002635
wdenk6c59edc2004-05-03 20:45:30 +00002636Example: install the image to address 0x40100000 (which on the
2637TQM8xxL is in the first Flash bank):
wdenkc6097192002-11-03 00:24:07 +00002638
wdenk6c59edc2004-05-03 20:45:30 +00002639 => erase 40100000 401FFFFF
wdenkc6097192002-11-03 00:24:07 +00002640
wdenk6c59edc2004-05-03 20:45:30 +00002641 .......... done
2642 Erased 8 sectors
wdenkc6097192002-11-03 00:24:07 +00002643
wdenk6c59edc2004-05-03 20:45:30 +00002644 => loads 40100000
2645 ## Ready for S-Record download ...
2646 ~>examples/image.srec
2647 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2648 ...
2649 15989 15990 15991 15992
2650 [file transfer complete]
2651 [connected]
2652 ## Start Addr = 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002653
wdenkc6097192002-11-03 00:24:07 +00002654
wdenk6c59edc2004-05-03 20:45:30 +00002655You can check the success of the download using the 'iminfo' command;
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002656this includes a checksum verification so you can be sure no data
wdenk6c59edc2004-05-03 20:45:30 +00002657corruption happened:
wdenkc6097192002-11-03 00:24:07 +00002658
wdenk6c59edc2004-05-03 20:45:30 +00002659 => imi 40100000
wdenkc6097192002-11-03 00:24:07 +00002660
wdenk6c59edc2004-05-03 20:45:30 +00002661 ## Checking Image at 40100000 ...
2662 Image Name: 2.2.13 for initrd on TQM850L
2663 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2664 Data Size: 335725 Bytes = 327 kB = 0 MB
2665 Load Address: 00000000
2666 Entry Point: 0000000c
2667 Verifying Checksum ... OK
wdenkc6097192002-11-03 00:24:07 +00002668
2669
wdenk6c59edc2004-05-03 20:45:30 +00002670Boot Linux:
2671-----------
wdenkc6097192002-11-03 00:24:07 +00002672
wdenk6c59edc2004-05-03 20:45:30 +00002673The "bootm" command is used to boot an application that is stored in
2674memory (RAM or Flash). In case of a Linux kernel image, the contents
2675of the "bootargs" environment variable is passed to the kernel as
2676parameters. You can check and modify this variable using the
2677"printenv" and "setenv" commands:
wdenkc6097192002-11-03 00:24:07 +00002678
wdenkc6097192002-11-03 00:24:07 +00002679
wdenk6c59edc2004-05-03 20:45:30 +00002680 => printenv bootargs
2681 bootargs=root=/dev/ram
wdenkc6097192002-11-03 00:24:07 +00002682
wdenk6c59edc2004-05-03 20:45:30 +00002683 => 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 +00002684
wdenk6c59edc2004-05-03 20:45:30 +00002685 => printenv bootargs
2686 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 +00002687
wdenk6c59edc2004-05-03 20:45:30 +00002688 => bootm 40020000
2689 ## Booting Linux kernel at 40020000 ...
2690 Image Name: 2.2.13 for NFS on TQM850L
2691 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2692 Data Size: 381681 Bytes = 372 kB = 0 MB
2693 Load Address: 00000000
2694 Entry Point: 0000000c
2695 Verifying Checksum ... OK
2696 Uncompressing Kernel Image ... OK
2697 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
2698 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2699 time_init: decrementer frequency = 187500000/60
2700 Calibrating delay loop... 49.77 BogoMIPS
2701 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2702 ...
wdenkc6097192002-11-03 00:24:07 +00002703
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02002704If you want to boot a Linux kernel with initial RAM disk, you pass
wdenk6c59edc2004-05-03 20:45:30 +00002705the memory addresses of both the kernel and the initrd image (PPBCOOT
2706format!) to the "bootm" command:
wdenkc6097192002-11-03 00:24:07 +00002707
wdenk6c59edc2004-05-03 20:45:30 +00002708 => imi 40100000 40200000
wdenkc6097192002-11-03 00:24:07 +00002709
wdenk6c59edc2004-05-03 20:45:30 +00002710 ## Checking Image at 40100000 ...
2711 Image Name: 2.2.13 for initrd on TQM850L
2712 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2713 Data Size: 335725 Bytes = 327 kB = 0 MB
2714 Load Address: 00000000
2715 Entry Point: 0000000c
2716 Verifying Checksum ... OK
wdenkc6097192002-11-03 00:24:07 +00002717
wdenk6c59edc2004-05-03 20:45:30 +00002718 ## Checking Image at 40200000 ...
2719 Image Name: Simple Ramdisk Image
2720 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2721 Data Size: 566530 Bytes = 553 kB = 0 MB
2722 Load Address: 00000000
2723 Entry Point: 00000000
2724 Verifying Checksum ... OK
wdenkc6097192002-11-03 00:24:07 +00002725
wdenk6c59edc2004-05-03 20:45:30 +00002726 => bootm 40100000 40200000
2727 ## Booting Linux kernel at 40100000 ...
2728 Image Name: 2.2.13 for initrd on TQM850L
2729 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2730 Data Size: 335725 Bytes = 327 kB = 0 MB
2731 Load Address: 00000000
2732 Entry Point: 0000000c
2733 Verifying Checksum ... OK
2734 Uncompressing Kernel Image ... OK
2735 ## Loading RAMDisk Image at 40200000 ...
2736 Image Name: Simple Ramdisk Image
2737 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2738 Data Size: 566530 Bytes = 553 kB = 0 MB
2739 Load Address: 00000000
2740 Entry Point: 00000000
2741 Verifying Checksum ... OK
2742 Loading Ramdisk ... OK
2743 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
2744 Boot arguments: root=/dev/ram
2745 time_init: decrementer frequency = 187500000/60
2746 Calibrating delay loop... 49.77 BogoMIPS
2747 ...
2748 RAMDISK: Compressed image found at block 0
2749 VFS: Mounted root (ext2 filesystem).
wdenkc6097192002-11-03 00:24:07 +00002750
wdenk6c59edc2004-05-03 20:45:30 +00002751 bash#
wdenkc6097192002-11-03 00:24:07 +00002752
Matthew McClintockefae4ca2006-06-28 10:41:37 -05002753Boot Linux and pass a flat device tree:
2754-----------
2755
2756First, U-Boot must be compiled with the appropriate defines. See the section
2757titled "Linux Kernel Interface" above for a more in depth explanation. The
2758following is an example of how to start a kernel and pass an updated
2759flat device tree:
2760
2761=> print oftaddr
2762oftaddr=0x300000
2763=> print oft
2764oft=oftrees/mpc8540ads.dtb
2765=> tftp $oftaddr $oft
2766Speed: 1000, full duplex
2767Using TSEC0 device
2768TFTP from server 192.168.1.1; our IP address is 192.168.1.101
2769Filename 'oftrees/mpc8540ads.dtb'.
2770Load address: 0x300000
2771Loading: #
2772done
2773Bytes transferred = 4106 (100a hex)
2774=> tftp $loadaddr $bootfile
2775Speed: 1000, full duplex
2776Using TSEC0 device
2777TFTP from server 192.168.1.1; our IP address is 192.168.1.2
2778Filename 'uImage'.
2779Load address: 0x200000
2780Loading:############
2781done
2782Bytes transferred = 1029407 (fb51f hex)
2783=> print loadaddr
2784loadaddr=200000
2785=> print oftaddr
2786oftaddr=0x300000
2787=> bootm $loadaddr - $oftaddr
2788## Booting image at 00200000 ...
Wolfgang Denk018147d2006-11-27 15:32:42 +01002789 Image Name: Linux-2.6.17-dirty
2790 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2791 Data Size: 1029343 Bytes = 1005.2 kB
Matthew McClintockefae4ca2006-06-28 10:41:37 -05002792 Load Address: 00000000
Wolfgang Denk018147d2006-11-27 15:32:42 +01002793 Entry Point: 00000000
Matthew McClintockefae4ca2006-06-28 10:41:37 -05002794 Verifying Checksum ... OK
2795 Uncompressing Kernel Image ... OK
2796Booting using flat device tree at 0x300000
2797Using MPC85xx ADS machine description
2798Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
2799[snip]
2800
2801
wdenk6c59edc2004-05-03 20:45:30 +00002802More About U-Boot Image Types:
2803------------------------------
wdenkc6097192002-11-03 00:24:07 +00002804
wdenk6c59edc2004-05-03 20:45:30 +00002805U-Boot supports the following image types:
wdenkc6097192002-11-03 00:24:07 +00002806
wdenk6c59edc2004-05-03 20:45:30 +00002807 "Standalone Programs" are directly runnable in the environment
2808 provided by U-Boot; it is expected that (if they behave
2809 well) you can continue to work in U-Boot after return from
2810 the Standalone Program.
2811 "OS Kernel Images" are usually images of some Embedded OS which
2812 will take over control completely. Usually these programs
2813 will install their own set of exception handlers, device
2814 drivers, set up the MMU, etc. - this means, that you cannot
2815 expect to re-enter U-Boot except by resetting the CPU.
2816 "RAMDisk Images" are more or less just data blocks, and their
2817 parameters (address, size) are passed to an OS kernel that is
2818 being started.
2819 "Multi-File Images" contain several images, typically an OS
2820 (Linux) kernel image and one or more data images like
2821 RAMDisks. This construct is useful for instance when you want
2822 to boot over the network using BOOTP etc., where the boot
2823 server provides just a single image file, but you want to get
2824 for instance an OS kernel and a RAMDisk image.
wdenkc6097192002-11-03 00:24:07 +00002825
wdenk6c59edc2004-05-03 20:45:30 +00002826 "Multi-File Images" start with a list of image sizes, each
2827 image size (in bytes) specified by an "uint32_t" in network
2828 byte order. This list is terminated by an "(uint32_t)0".
2829 Immediately after the terminating 0 follow the images, one by
2830 one, all aligned on "uint32_t" boundaries (size rounded up to
2831 a multiple of 4 bytes).
wdenkc6097192002-11-03 00:24:07 +00002832
wdenk6c59edc2004-05-03 20:45:30 +00002833 "Firmware Images" are binary images containing firmware (like
2834 U-Boot or FPGA images) which usually will be programmed to
2835 flash memory.
wdenk4fc95692003-02-28 00:49:47 +00002836
wdenk6c59edc2004-05-03 20:45:30 +00002837 "Script files" are command sequences that will be executed by
2838 U-Boot's command interpreter; this feature is especially
2839 useful when you configure U-Boot to use a real shell (hush)
2840 as command interpreter.
wdenk4fc95692003-02-28 00:49:47 +00002841
Marek Vasutcf41a9b2012-03-14 21:52:45 +00002842Booting the Linux zImage:
2843-------------------------
2844
2845On some platforms, it's possible to boot Linux zImage. This is done
2846using the "bootz" command. The syntax of "bootz" command is the same
2847as the syntax of "bootm" command.
2848
Tom Rini45f46d12013-05-16 11:40:11 -04002849Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
Marek Vasut28850d02012-03-18 11:47:58 +00002850kernel with raw initrd images. The syntax is slightly different, the
2851address of the initrd must be augmented by it's size, in the following
2852format: "<initrd addres>:<initrd size>".
2853
stroeseb9c17c52003-04-04 15:53:41 +00002854
wdenk6c59edc2004-05-03 20:45:30 +00002855Standalone HOWTO:
2856=================
stroeseb9c17c52003-04-04 15:53:41 +00002857
wdenk6c59edc2004-05-03 20:45:30 +00002858One of the features of U-Boot is that you can dynamically load and
2859run "standalone" applications, which can use some resources of
2860U-Boot like console I/O functions or interrupt services.
stroeseb9c17c52003-04-04 15:53:41 +00002861
wdenk6c59edc2004-05-03 20:45:30 +00002862Two simple examples are included with the sources:
wdenk4fc95692003-02-28 00:49:47 +00002863
wdenk6c59edc2004-05-03 20:45:30 +00002864"Hello World" Demo:
2865-------------------
wdenkc6097192002-11-03 00:24:07 +00002866
wdenk6c59edc2004-05-03 20:45:30 +00002867'examples/hello_world.c' contains a small "Hello World" Demo
2868application; it is automatically compiled when you build U-Boot.
2869It's configured to run at address 0x00040004, so you can play with it
2870like that:
wdenkc6097192002-11-03 00:24:07 +00002871
wdenk6c59edc2004-05-03 20:45:30 +00002872 => loads
2873 ## Ready for S-Record download ...
2874 ~>examples/hello_world.srec
2875 1 2 3 4 5 6 7 8 9 10 11 ...
2876 [file transfer complete]
2877 [connected]
2878 ## Start Addr = 0x00040004
wdenkc6097192002-11-03 00:24:07 +00002879
wdenk6c59edc2004-05-03 20:45:30 +00002880 => go 40004 Hello World! This is a test.
2881 ## Starting application at 0x00040004 ...
2882 Hello World
2883 argc = 7
2884 argv[0] = "40004"
2885 argv[1] = "Hello"
2886 argv[2] = "World!"
2887 argv[3] = "This"
2888 argv[4] = "is"
2889 argv[5] = "a"
2890 argv[6] = "test."
2891 argv[7] = "<NULL>"
2892 Hit any key to exit ...
wdenkc6097192002-11-03 00:24:07 +00002893
wdenk6c59edc2004-05-03 20:45:30 +00002894 ## Application terminated, rc = 0x0
wdenkc6097192002-11-03 00:24:07 +00002895
wdenk6c59edc2004-05-03 20:45:30 +00002896Another example, which demonstrates how to register a CPM interrupt
2897handler with the U-Boot code, can be found in 'examples/timer.c'.
2898Here, a CPM timer is set up to generate an interrupt every second.
2899The interrupt service routine is trivial, just printing a '.'
2900character, but this is just a demo program. The application can be
2901controlled by the following keys:
wdenkc6097192002-11-03 00:24:07 +00002902
wdenk6c59edc2004-05-03 20:45:30 +00002903 ? - print current values og the CPM Timer registers
2904 b - enable interrupts and start timer
2905 e - stop timer and disable interrupts
2906 q - quit application
wdenkc6097192002-11-03 00:24:07 +00002907
wdenk6c59edc2004-05-03 20:45:30 +00002908 => loads
2909 ## Ready for S-Record download ...
2910 ~>examples/timer.srec
2911 1 2 3 4 5 6 7 8 9 10 11 ...
2912 [file transfer complete]
2913 [connected]
2914 ## Start Addr = 0x00040004
wdenkc6097192002-11-03 00:24:07 +00002915
wdenk6c59edc2004-05-03 20:45:30 +00002916 => go 40004
2917 ## Starting application at 0x00040004 ...
2918 TIMERS=0xfff00980
2919 Using timer 1
2920 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
wdenkc6097192002-11-03 00:24:07 +00002921
wdenk6c59edc2004-05-03 20:45:30 +00002922Hit 'b':
2923 [q, b, e, ?] Set interval 1000000 us
2924 Enabling timer
2925Hit '?':
2926 [q, b, e, ?] ........
2927 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
2928Hit '?':
2929 [q, b, e, ?] .
2930 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
2931Hit '?':
2932 [q, b, e, ?] .
2933 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
2934Hit '?':
2935 [q, b, e, ?] .
2936 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
2937Hit 'e':
2938 [q, b, e, ?] ...Stopping timer
2939Hit 'q':
2940 [q, b, e, ?] ## Application terminated, rc = 0x0
wdenkc6097192002-11-03 00:24:07 +00002941
wdenkc6097192002-11-03 00:24:07 +00002942
wdenk6c59edc2004-05-03 20:45:30 +00002943Minicom warning:
2944================
wdenkc6097192002-11-03 00:24:07 +00002945
wdenk6c59edc2004-05-03 20:45:30 +00002946Over time, many people have reported problems when trying to use the
2947"minicom" terminal emulation program for serial download. I (wd)
2948consider minicom to be broken, and recommend not to use it. Under
2949Unix, I recommend to use C-Kermit for general purpose use (and
2950especially for kermit binary protocol download ("loadb" command), and
Karl O. Pinca0189bb2012-10-01 05:11:56 +00002951use "cu" for S-Record download ("loads" command). See
Naoki Hayamae0cc1852020-10-08 13:17:16 +09002952https://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
Karl O. Pinca0189bb2012-10-01 05:11:56 +00002953for help with kermit.
2954
wdenkc6097192002-11-03 00:24:07 +00002955
wdenk6c59edc2004-05-03 20:45:30 +00002956Nevertheless, if you absolutely want to use it try adding this
2957configuration to your "File transfer protocols" section:
wdenkc6097192002-11-03 00:24:07 +00002958
wdenk6c59edc2004-05-03 20:45:30 +00002959 Name Program Name U/D FullScr IO-Red. Multi
2960 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
2961 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
wdenk8dba0502003-03-31 16:34:49 +00002962
wdenk8dba0502003-03-31 16:34:49 +00002963
wdenk6c59edc2004-05-03 20:45:30 +00002964NetBSD Notes:
2965=============
wdenkc6097192002-11-03 00:24:07 +00002966
wdenk6c59edc2004-05-03 20:45:30 +00002967Starting at version 0.9.2, U-Boot supports NetBSD both as host
2968(build U-Boot) and target system (boots NetBSD/mpc8xx).
wdenk88e72a32003-06-19 23:04:19 +00002969
wdenk6c59edc2004-05-03 20:45:30 +00002970Building requires a cross environment; it is known to work on
2971NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
2972need gmake since the Makefiles are not compatible with BSD make).
2973Note that the cross-powerpc package does not install include files;
2974attempting to build U-Boot will fail because <machine/ansi.h> is
2975missing. This file has to be installed and patched manually:
wdenk88e72a32003-06-19 23:04:19 +00002976
wdenk6c59edc2004-05-03 20:45:30 +00002977 # cd /usr/pkg/cross/powerpc-netbsd/include
2978 # mkdir powerpc
2979 # ln -s powerpc machine
2980 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
2981 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
wdenk88e72a32003-06-19 23:04:19 +00002982
wdenk6c59edc2004-05-03 20:45:30 +00002983Native builds *don't* work due to incompatibilities between native
2984and U-Boot include files.
wdenkc6097192002-11-03 00:24:07 +00002985
wdenk6c59edc2004-05-03 20:45:30 +00002986Booting assumes that (the first part of) the image booted is a
2987stage-2 loader which in turn loads and then invokes the kernel
2988proper. Loader sources will eventually appear in the NetBSD source
2989tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
wdenkd0245fc2005-04-13 10:02:42 +00002990meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
wdenkc6097192002-11-03 00:24:07 +00002991
wdenkc6097192002-11-03 00:24:07 +00002992
wdenk6c59edc2004-05-03 20:45:30 +00002993Implementation Internals:
2994=========================
wdenkc6097192002-11-03 00:24:07 +00002995
wdenk6c59edc2004-05-03 20:45:30 +00002996The following is not intended to be a complete description of every
2997implementation detail. However, it should help to understand the
2998inner workings of U-Boot and make it easier to port it to custom
2999hardware.
wdenkc6097192002-11-03 00:24:07 +00003000
wdenkc6097192002-11-03 00:24:07 +00003001
wdenk6c59edc2004-05-03 20:45:30 +00003002Initial Stack, Global Data:
3003---------------------------
wdenkc6097192002-11-03 00:24:07 +00003004
wdenk6c59edc2004-05-03 20:45:30 +00003005The implementation of U-Boot is complicated by the fact that U-Boot
3006starts running out of ROM (flash memory), usually without access to
3007system RAM (because the memory controller is not initialized yet).
3008This means that we don't have writable Data or BSS segments, and BSS
3009is not initialized as zero. To be able to get a C environment working
3010at all, we have to allocate at least a minimal stack. Implementation
3011options for this are defined and restricted by the CPU used: Some CPU
3012models provide on-chip memory (like the IMMR area on MPC8xx and
3013MPC826x processors), on others (parts of) the data cache can be
3014locked as (mis-) used as memory, etc.
wdenkc6097192002-11-03 00:24:07 +00003015
Wolfgang Denkb240aef2008-03-26 10:40:12 +01003016 Chris Hallinan posted a good summary of these issues to the
Wolfgang Denk290ae6b2008-12-30 22:56:11 +01003017 U-Boot mailing list:
wdenkc6097192002-11-03 00:24:07 +00003018
wdenk6c59edc2004-05-03 20:45:30 +00003019 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3020 From: "Chris Hallinan" <clh@net1plus.com>
3021 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3022 ...
wdenkc6097192002-11-03 00:24:07 +00003023
wdenk6c59edc2004-05-03 20:45:30 +00003024 Correct me if I'm wrong, folks, but the way I understand it
3025 is this: Using DCACHE as initial RAM for Stack, etc, does not
3026 require any physical RAM backing up the cache. The cleverness
3027 is that the cache is being used as a temporary supply of
3028 necessary storage before the SDRAM controller is setup. It's
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02003029 beyond the scope of this list to explain the details, but you
wdenk6c59edc2004-05-03 20:45:30 +00003030 can see how this works by studying the cache architecture and
3031 operation in the architecture and processor-specific manuals.
wdenkc6097192002-11-03 00:24:07 +00003032
wdenk6c59edc2004-05-03 20:45:30 +00003033 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3034 is another option for the system designer to use as an
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02003035 initial stack/RAM area prior to SDRAM being available. Either
wdenk6c59edc2004-05-03 20:45:30 +00003036 option should work for you. Using CS 4 should be fine if your
3037 board designers haven't used it for something that would
3038 cause you grief during the initial boot! It is frequently not
3039 used.
wdenkc6097192002-11-03 00:24:07 +00003040
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02003041 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
wdenk6c59edc2004-05-03 20:45:30 +00003042 with your processor/board/system design. The default value
3043 you will find in any recent u-boot distribution in
Stefan Roese3e1f1b32005-08-01 16:49:12 +02003044 walnut.h should work for you. I'd set it to a value larger
wdenk6c59edc2004-05-03 20:45:30 +00003045 than your SDRAM module. If you have a 64MB SDRAM module, set
3046 it above 400_0000. Just make sure your board has no resources
3047 that are supposed to respond to that address! That code in
3048 start.S has been around a while and should work as is when
3049 you get the config right.
wdenk4a5c8a72003-03-06 00:02:04 +00003050
wdenk6c59edc2004-05-03 20:45:30 +00003051 -Chris Hallinan
3052 DS4.COM, Inc.
wdenk4a5c8a72003-03-06 00:02:04 +00003053
wdenk6c59edc2004-05-03 20:45:30 +00003054It is essential to remember this, since it has some impact on the C
3055code for the initialization procedures:
wdenk4a5c8a72003-03-06 00:02:04 +00003056
wdenk6c59edc2004-05-03 20:45:30 +00003057* Initialized global data (data segment) is read-only. Do not attempt
3058 to write it.
wdenk4a5c8a72003-03-06 00:02:04 +00003059
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08003060* Do not use any uninitialized global data (or implicitly initialized
wdenk6c59edc2004-05-03 20:45:30 +00003061 as zero data - BSS segment) at all - this is undefined, initiali-
3062 zation is performed later (when relocating to RAM).
wdenk4a5c8a72003-03-06 00:02:04 +00003063
wdenk6c59edc2004-05-03 20:45:30 +00003064* Stack space is very limited. Avoid big data buffers or things like
3065 that.
wdenk4a5c8a72003-03-06 00:02:04 +00003066
wdenk6c59edc2004-05-03 20:45:30 +00003067Having only the stack as writable memory limits means we cannot use
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08003068normal global data to share information between the code. But it
wdenk6c59edc2004-05-03 20:45:30 +00003069turned out that the implementation of U-Boot can be greatly
3070simplified by making a global data structure (gd_t) available to all
3071functions. We could pass a pointer to this data as argument to _all_
3072functions, but this would bloat the code. Instead we use a feature of
3073the GCC compiler (Global Register Variables) to share the data: we
3074place a pointer (gd) to the global data into a register which we
3075reserve for this purpose.
wdenkc6097192002-11-03 00:24:07 +00003076
wdenk6c59edc2004-05-03 20:45:30 +00003077When choosing a register for such a purpose we are restricted by the
3078relevant (E)ABI specifications for the current architecture, and by
3079GCC's implementation.
wdenkc6097192002-11-03 00:24:07 +00003080
wdenk6c59edc2004-05-03 20:45:30 +00003081For PowerPC, the following registers have specific use:
3082 R1: stack pointer
Wolfgang Denk69c09642008-02-14 22:43:22 +01003083 R2: reserved for system use
wdenk6c59edc2004-05-03 20:45:30 +00003084 R3-R4: parameter passing and return values
3085 R5-R10: parameter passing
3086 R13: small data area pointer
3087 R30: GOT pointer
3088 R31: frame pointer
wdenkc6097192002-11-03 00:24:07 +00003089
Joakim Tjernlund693c0c12010-01-19 14:41:58 +01003090 (U-Boot also uses R12 as internal GOT pointer. r12
3091 is a volatile register so r12 needs to be reset when
3092 going back and forth between asm and C)
wdenkc6097192002-11-03 00:24:07 +00003093
Wolfgang Denk69c09642008-02-14 22:43:22 +01003094 ==> U-Boot will use R2 to hold a pointer to the global data
wdenkc6097192002-11-03 00:24:07 +00003095
wdenk6c59edc2004-05-03 20:45:30 +00003096 Note: on PPC, we could use a static initializer (since the
3097 address of the global data structure is known at compile time),
3098 but it turned out that reserving a register results in somewhat
3099 smaller code - although the code savings are not that big (on
3100 average for all boards 752 bytes for the whole U-Boot image,
3101 624 text + 127 data).
wdenkc6097192002-11-03 00:24:07 +00003102
wdenk6c59edc2004-05-03 20:45:30 +00003103On ARM, the following registers are used:
wdenkc6097192002-11-03 00:24:07 +00003104
wdenk6c59edc2004-05-03 20:45:30 +00003105 R0: function argument word/integer result
3106 R1-R3: function argument word
Jeroen Hofsteea556aca2013-09-21 14:04:42 +02003107 R9: platform specific
3108 R10: stack limit (used only if stack checking is enabled)
wdenk6c59edc2004-05-03 20:45:30 +00003109 R11: argument (frame) pointer
3110 R12: temporary workspace
3111 R13: stack pointer
3112 R14: link register
3113 R15: program counter
wdenkc6097192002-11-03 00:24:07 +00003114
Jeroen Hofsteea556aca2013-09-21 14:04:42 +02003115 ==> U-Boot will use R9 to hold a pointer to the global data
3116
3117 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
wdenkc6097192002-11-03 00:24:07 +00003118
Thomas Chou8fa38582010-05-21 11:08:03 +08003119On Nios II, the ABI is documented here:
Naoki Hayamae0cc1852020-10-08 13:17:16 +09003120 https://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
Thomas Chou8fa38582010-05-21 11:08:03 +08003121
3122 ==> U-Boot will use gp to hold a pointer to the global data
3123
3124 Note: on Nios II, we give "-G0" option to gcc and don't use gp
3125 to access small data sections, so gp is free.
3126
Rick Chend7e6f922017-12-26 13:55:59 +08003127On RISC-V, the following registers are used:
3128
3129 x0: hard-wired zero (zero)
3130 x1: return address (ra)
3131 x2: stack pointer (sp)
3132 x3: global pointer (gp)
3133 x4: thread pointer (tp)
3134 x5: link register (t0)
3135 x8: frame pointer (fp)
3136 x10-x11: arguments/return values (a0-1)
3137 x12-x17: arguments (a2-7)
3138 x28-31: temporaries (t3-6)
3139 pc: program counter (pc)
3140
3141 ==> U-Boot will use gp to hold a pointer to the global data
3142
wdenk6c59edc2004-05-03 20:45:30 +00003143Memory Management:
3144------------------
wdenkc6097192002-11-03 00:24:07 +00003145
wdenk6c59edc2004-05-03 20:45:30 +00003146U-Boot runs in system state and uses physical addresses, i.e. the
3147MMU is not used either for address mapping nor for memory protection.
wdenkc6097192002-11-03 00:24:07 +00003148
wdenk6c59edc2004-05-03 20:45:30 +00003149The available memory is mapped to fixed addresses using the memory
3150controller. In this process, a contiguous block is formed for each
3151memory type (Flash, SDRAM, SRAM), even when it consists of several
3152physical memory banks.
wdenkc6097192002-11-03 00:24:07 +00003153
wdenk6c59edc2004-05-03 20:45:30 +00003154U-Boot is installed in the first 128 kB of the first Flash bank (on
3155TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3156booting and sizing and initializing DRAM, the code relocates itself
3157to the upper end of DRAM. Immediately below the U-Boot code some
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02003158memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
wdenk6c59edc2004-05-03 20:45:30 +00003159configuration setting]. Below that, a structure with global Board
3160Info data is placed, followed by the stack (growing downward).
wdenkc6097192002-11-03 00:24:07 +00003161
wdenk6c59edc2004-05-03 20:45:30 +00003162Additionally, some exception handler code is copied to the low 8 kB
3163of DRAM (0x00000000 ... 0x00001FFF).
wdenkc6097192002-11-03 00:24:07 +00003164
wdenk6c59edc2004-05-03 20:45:30 +00003165So a typical memory configuration with 16 MB of DRAM could look like
3166this:
wdenkc6097192002-11-03 00:24:07 +00003167
wdenk6c59edc2004-05-03 20:45:30 +00003168 0x0000 0000 Exception Vector code
3169 :
3170 0x0000 1FFF
3171 0x0000 2000 Free for Application Use
3172 :
3173 :
wdenkc6097192002-11-03 00:24:07 +00003174
wdenk6c59edc2004-05-03 20:45:30 +00003175 :
3176 :
3177 0x00FB FF20 Monitor Stack (Growing downward)
3178 0x00FB FFAC Board Info Data and permanent copy of global data
3179 0x00FC 0000 Malloc Arena
3180 :
3181 0x00FD FFFF
3182 0x00FE 0000 RAM Copy of Monitor Code
3183 ... eventually: LCD or video framebuffer
3184 ... eventually: pRAM (Protected RAM - unchanged by reset)
3185 0x00FF FFFF [End of RAM]
wdenkc6097192002-11-03 00:24:07 +00003186
wdenkc6097192002-11-03 00:24:07 +00003187
wdenk6c59edc2004-05-03 20:45:30 +00003188System Initialization:
3189----------------------
wdenkc6097192002-11-03 00:24:07 +00003190
wdenk6c59edc2004-05-03 20:45:30 +00003191In the reset configuration, U-Boot starts at the reset entry point
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02003192(on most PowerPC systems at address 0x00000100). Because of the reset
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08003193configuration for CS0# this is a mirror of the on board Flash memory.
wdenk6c59edc2004-05-03 20:45:30 +00003194To be able to re-map memory U-Boot then jumps to its link address.
3195To be able to implement the initialization code in C, a (small!)
3196initial stack is set up in the internal Dual Ported RAM (in case CPUs
Heiko Schocher71cb3e92017-06-07 17:33:10 +02003197which provide such a feature like), or in a locked part of the data
3198cache. After that, U-Boot initializes the CPU core, the caches and
3199the SIU.
wdenkc6097192002-11-03 00:24:07 +00003200
wdenk6c59edc2004-05-03 20:45:30 +00003201Next, all (potentially) available memory banks are mapped using a
3202preliminary mapping. For example, we put them on 512 MB boundaries
3203(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3204on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3205programmed for SDRAM access. Using the temporary configuration, a
3206simple memory test is run that determines the size of the SDRAM
3207banks.
wdenkc6097192002-11-03 00:24:07 +00003208
wdenk6c59edc2004-05-03 20:45:30 +00003209When there is more than one SDRAM bank, and the banks are of
3210different size, the largest is mapped first. For equal size, the first
3211bank (CS2#) is mapped first. The first mapping is always for address
32120x00000000, with any additional banks following immediately to create
3213contiguous memory starting from 0.
wdenkc6097192002-11-03 00:24:07 +00003214
wdenk6c59edc2004-05-03 20:45:30 +00003215Then, the monitor installs itself at the upper end of the SDRAM area
3216and allocates memory for use by malloc() and for the global Board
3217Info data; also, the exception vector code is copied to the low RAM
3218pages, and the final stack is set up.
wdenkc6097192002-11-03 00:24:07 +00003219
wdenk6c59edc2004-05-03 20:45:30 +00003220Only after this relocation will you have a "normal" C environment;
3221until that you are restricted in several ways, mostly because you are
3222running from ROM, and because the code will have to be relocated to a
3223new address in RAM.
wdenkc6097192002-11-03 00:24:07 +00003224
wdenkc6097192002-11-03 00:24:07 +00003225
wdenk6c59edc2004-05-03 20:45:30 +00003226U-Boot Porting Guide:
3227----------------------
wdenkc6097192002-11-03 00:24:07 +00003228
wdenk6c59edc2004-05-03 20:45:30 +00003229[Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3230list, October 2002]
wdenkc6097192002-11-03 00:24:07 +00003231
wdenkc6097192002-11-03 00:24:07 +00003232
Jerry Van Barenba0687c2009-07-15 20:42:59 -04003233int main(int argc, char *argv[])
wdenk6c59edc2004-05-03 20:45:30 +00003234{
3235 sighandler_t no_more_time;
wdenkc6097192002-11-03 00:24:07 +00003236
Jerry Van Barenba0687c2009-07-15 20:42:59 -04003237 signal(SIGALRM, no_more_time);
3238 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
wdenkc6097192002-11-03 00:24:07 +00003239
wdenk6c59edc2004-05-03 20:45:30 +00003240 if (available_money > available_manpower) {
Jerry Van Barenba0687c2009-07-15 20:42:59 -04003241 Pay consultant to port U-Boot;
wdenk6c59edc2004-05-03 20:45:30 +00003242 return 0;
3243 }
wdenkc6097192002-11-03 00:24:07 +00003244
wdenk6c59edc2004-05-03 20:45:30 +00003245 Download latest U-Boot source;
wdenk34b613e2002-12-17 01:51:00 +00003246
Wolfgang Denk290ae6b2008-12-30 22:56:11 +01003247 Subscribe to u-boot mailing list;
wdenkc6097192002-11-03 00:24:07 +00003248
Jerry Van Barenba0687c2009-07-15 20:42:59 -04003249 if (clueless)
3250 email("Hi, I am new to U-Boot, how do I get started?");
wdenkc6097192002-11-03 00:24:07 +00003251
wdenk6c59edc2004-05-03 20:45:30 +00003252 while (learning) {
3253 Read the README file in the top level directory;
Naoki Hayamae0cc1852020-10-08 13:17:16 +09003254 Read https://www.denx.de/wiki/bin/view/DULG/Manual;
Patrick Delaunay9b281fa2020-02-28 15:18:10 +01003255 Read applicable doc/README.*;
wdenk6c59edc2004-05-03 20:45:30 +00003256 Read the source, Luke;
Jerry Van Barenba0687c2009-07-15 20:42:59 -04003257 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
wdenk6c59edc2004-05-03 20:45:30 +00003258 }
wdenkc6097192002-11-03 00:24:07 +00003259
Jerry Van Barenba0687c2009-07-15 20:42:59 -04003260 if (available_money > toLocalCurrency ($2500))
3261 Buy a BDI3000;
3262 else
wdenk6c59edc2004-05-03 20:45:30 +00003263 Add a lot of aggravation and time;
wdenkc6097192002-11-03 00:24:07 +00003264
Jerry Van Barenba0687c2009-07-15 20:42:59 -04003265 if (a similar board exists) { /* hopefully... */
3266 cp -a board/<similar> board/<myboard>
3267 cp include/configs/<similar>.h include/configs/<myboard>.h
3268 } else {
3269 Create your own board support subdirectory;
3270 Create your own board include/configs/<myboard>.h file;
3271 }
3272 Edit new board/<myboard> files
3273 Edit new include/configs/<myboard>.h
wdenkc6097192002-11-03 00:24:07 +00003274
Jerry Van Barenba0687c2009-07-15 20:42:59 -04003275 while (!accepted) {
3276 while (!running) {
3277 do {
3278 Add / modify source code;
3279 } until (compiles);
3280 Debug;
3281 if (clueless)
3282 email("Hi, I am having problems...");
3283 }
3284 Send patch file to the U-Boot email list;
3285 if (reasonable critiques)
3286 Incorporate improvements from email list code review;
3287 else
3288 Defend code as written;
wdenk634d2f72004-04-15 23:14:49 +00003289 }
wdenkc6097192002-11-03 00:24:07 +00003290
wdenk6c59edc2004-05-03 20:45:30 +00003291 return 0;
3292}
wdenkc6097192002-11-03 00:24:07 +00003293
wdenk6c59edc2004-05-03 20:45:30 +00003294void no_more_time (int sig)
3295{
3296 hire_a_guru();
3297}
wdenkc6097192002-11-03 00:24:07 +00003298
wdenkc6097192002-11-03 00:24:07 +00003299
wdenk6c59edc2004-05-03 20:45:30 +00003300Coding Standards:
3301-----------------
wdenkc6097192002-11-03 00:24:07 +00003302
wdenk6c59edc2004-05-03 20:45:30 +00003303All contributions to U-Boot should conform to the Linux kernel
Baruch Siachb1081252017-12-10 17:34:35 +02003304coding style; see the kernel coding style guide at
3305https://www.kernel.org/doc/html/latest/process/coding-style.html, and the
3306script "scripts/Lindent" in your Linux kernel source directory.
Detlev Zundelaa63d482006-09-01 15:39:02 +02003307
3308Source files originating from a different project (for example the
3309MTD subsystem) are generally exempt from these guidelines and are not
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08003310reformatted to ease subsequent migration to newer versions of those
Detlev Zundelaa63d482006-09-01 15:39:02 +02003311sources.
wdenkc6097192002-11-03 00:24:07 +00003312
Detlev Zundelaa63d482006-09-01 15:39:02 +02003313Please note that U-Boot is implemented in C (and to some small parts in
3314Assembler); no C++ is used, so please do not use C++ style comments (//)
3315in your code.
wdenkad276f22004-01-04 16:28:35 +00003316
wdenk6c59edc2004-05-03 20:45:30 +00003317Please also stick to the following formatting rules:
3318- remove any trailing white space
Wolfgang Denk20bd2a62011-07-27 10:59:55 +00003319- use TAB characters for indentation and vertical alignment, not spaces
wdenk6c59edc2004-05-03 20:45:30 +00003320- make sure NOT to use DOS '\r\n' line feeds
Wolfgang Denk20bd2a62011-07-27 10:59:55 +00003321- do not add more than 2 consecutive empty lines to source files
wdenk6c59edc2004-05-03 20:45:30 +00003322- do not add trailing empty lines to source files
wdenkc6097192002-11-03 00:24:07 +00003323
wdenk6c59edc2004-05-03 20:45:30 +00003324Submissions which do not conform to the standards may be returned
3325with a request to reformat the changes.
wdenkc6097192002-11-03 00:24:07 +00003326
wdenkc6097192002-11-03 00:24:07 +00003327
wdenk6c59edc2004-05-03 20:45:30 +00003328Submitting Patches:
3329-------------------
wdenkc6097192002-11-03 00:24:07 +00003330
wdenk6c59edc2004-05-03 20:45:30 +00003331Since the number of patches for U-Boot is growing, we need to
3332establish some rules. Submissions which do not conform to these rules
3333may be rejected, even when they contain important and valuable stuff.
wdenkc6097192002-11-03 00:24:07 +00003334
Naoki Hayamae0cc1852020-10-08 13:17:16 +09003335Please see https://www.denx.de/wiki/U-Boot/Patches for details.
Wolfgang Denkb240aef2008-03-26 10:40:12 +01003336
Wolfgang Denk290ae6b2008-12-30 22:56:11 +01003337Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
S. Lockwood-Childsda6d34c2017-11-14 22:56:42 -08003338see https://lists.denx.de/listinfo/u-boot
Wolfgang Denk290ae6b2008-12-30 22:56:11 +01003339
wdenk6c59edc2004-05-03 20:45:30 +00003340When you send a patch, please include the following information with
3341it:
wdenkc6097192002-11-03 00:24:07 +00003342
wdenk6c59edc2004-05-03 20:45:30 +00003343* For bug fixes: a description of the bug and how your patch fixes
3344 this bug. Please try to include a way of demonstrating that the
3345 patch actually fixes something.
wdenkc6097192002-11-03 00:24:07 +00003346
wdenk6c59edc2004-05-03 20:45:30 +00003347* For new features: a description of the feature and your
3348 implementation.
wdenkc6097192002-11-03 00:24:07 +00003349
Robert P. J. Day076ed9b2015-12-19 07:16:10 -05003350* For major contributions, add a MAINTAINERS file with your
3351 information and associated file and directory references.
wdenkc6097192002-11-03 00:24:07 +00003352
Albert ARIBAUD48e910f2013-09-11 15:52:51 +02003353* When you add support for a new board, don't forget to add a
3354 maintainer e-mail address to the boards.cfg file, too.
wdenkc6097192002-11-03 00:24:07 +00003355
wdenk6c59edc2004-05-03 20:45:30 +00003356* If your patch adds new configuration options, don't forget to
3357 document these in the README file.
wdenkc6097192002-11-03 00:24:07 +00003358
Wolfgang Denkb240aef2008-03-26 10:40:12 +01003359* The patch itself. If you are using git (which is *strongly*
3360 recommended) you can easily generate the patch using the
Wolfgang Denk20bd2a62011-07-27 10:59:55 +00003361 "git format-patch". If you then use "git send-email" to send it to
Wolfgang Denkb240aef2008-03-26 10:40:12 +01003362 the U-Boot mailing list, you will avoid most of the common problems
3363 with some other mail clients.
wdenkca9bc762003-07-15 07:45:49 +00003364
Wolfgang Denkb240aef2008-03-26 10:40:12 +01003365 If you cannot use git, use "diff -purN OLD NEW". If your version of
3366 diff does not support these options, then get the latest version of
3367 GNU diff.
wdenkc6097192002-11-03 00:24:07 +00003368
Wolfgang Denkb240aef2008-03-26 10:40:12 +01003369 The current directory when running this command shall be the parent
3370 directory of the U-Boot source tree (i. e. please make sure that
3371 your patch includes sufficient directory information for the
3372 affected files).
3373
3374 We prefer patches as plain text. MIME attachments are discouraged,
3375 and compressed attachments must not be used.
wdenk88e72a32003-06-19 23:04:19 +00003376
wdenk6c59edc2004-05-03 20:45:30 +00003377* If one logical set of modifications affects or creates several
3378 files, all these changes shall be submitted in a SINGLE patch file.
wdenk57b2d802003-06-27 21:31:46 +00003379
wdenk6c59edc2004-05-03 20:45:30 +00003380* Changesets that contain different, unrelated modifications shall be
3381 submitted as SEPARATE patches, one patch per changeset.
wdenk88e72a32003-06-19 23:04:19 +00003382
wdenkc6097192002-11-03 00:24:07 +00003383
wdenk6c59edc2004-05-03 20:45:30 +00003384Notes:
wdenkc6097192002-11-03 00:24:07 +00003385
Simon Glassdc27def2016-07-27 20:33:08 -06003386* Before sending the patch, run the buildman script on your patched
wdenk6c59edc2004-05-03 20:45:30 +00003387 source tree and make sure that no errors or warnings are reported
3388 for any of the boards.
3389
3390* Keep your modifications to the necessary minimum: A patch
3391 containing several unrelated changes or arbitrary reformats will be
3392 returned with a request to re-formatting / split it.
wdenkc6097192002-11-03 00:24:07 +00003393
wdenk6c59edc2004-05-03 20:45:30 +00003394* If you modify existing code, make sure that your new code does not
3395 add to the memory footprint of the code ;-) Small is beautiful!
3396 When adding new features, these should compile conditionally only
3397 (using #ifdef), and the resulting code with the new feature
3398 disabled must not need more memory than the old code without your
3399 modification.
wdenkcbc49a52005-05-03 14:12:25 +00003400
Wolfgang Denk290ae6b2008-12-30 22:56:11 +01003401* Remember that there is a size limit of 100 kB per message on the
3402 u-boot mailing list. Bigger patches will be moderated. If they are
3403 reasonable and not too big, they will be acknowledged. But patches
3404 bigger than the size limit should be avoided.