blob: 120963317608b9c116cae9df534b9370b55439e4 [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
Scott Wood80806962012-08-14 10:14:53 +0000297 CONFIG_SYS_FSL_ERRATUM_A004510
298
299 Enables a workaround for erratum A004510. If set,
300 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
Tom Rini376b88a2022-10-28 20:27:13 -0400301 CFG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
Scott Wood80806962012-08-14 10:14:53 +0000302
303 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
304 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
305
306 Defines one or two SoC revisions (low 8 bits of SVR)
307 for which the A004510 workaround should be applied.
308
309 The rest of SVR is either not relevant to the decision
310 of whether the erratum is present (e.g. p2040 versus
311 p2041) or is implied by the build target, which controls
312 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
313
314 See Freescale App Note 4493 for more information about
315 this erratum.
316
Tom Rini376b88a2022-10-28 20:27:13 -0400317 CFG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
Scott Wood80806962012-08-14 10:14:53 +0000318
319 This is the value to write into CCSR offset 0x18600
320 according to the A004510 workaround.
321
Priyanka Jaine9dcaa82013-12-17 14:25:52 +0530322 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
323 Single Source Clock is clocking mode present in some of FSL SoC's.
324 In this mode, a single differential clock is used to supply
325 clocks to the sysclock, ddrclock and usbclock.
326
Daniel Schwierzeckd8a49ca2012-04-02 02:57:56 +0000327- Generic CPU options:
Daniel Schwierzeckd8a49ca2012-04-02 02:57:56 +0000328
York Sunf0626592013-09-30 09:22:09 -0700329 CONFIG_SYS_FSL_DDR
330 Freescale DDR driver in use. This type of DDR controller is
Tom Rinie5404982021-05-14 21:34:26 -0400331 found in mpc83xx, mpc85xx as well as some ARM core SoCs.
York Sunf0626592013-09-30 09:22:09 -0700332
Tom Rini376b88a2022-10-28 20:27:13 -0400333 CFG_SYS_FSL_DDR_ADDR
York Sunf0626592013-09-30 09:22:09 -0700334 Freescale DDR memory-mapped register base.
335
Prabhakar Kushwaha3c48f582017-02-02 15:01:26 +0530336 CONFIG_SYS_FSL_IFC_CLK_DIV
337 Defines divider of platform clock(clock input to IFC controller).
338
Prabhakar Kushwahabedc5622017-02-02 15:02:00 +0530339 CONFIG_SYS_FSL_LBC_CLK_DIV
340 Defines divider of platform clock(clock input to eLBC controller).
341
Tom Rini376b88a2022-10-28 20:27:13 -0400342 CFG_SYS_FSL_DDR_SDRAM_BASE_PHY
York Sun3a0916d2014-02-10 13:59:43 -0800343 Physical address from the view of DDR controllers. It is the
Tom Rini6a5dccc2022-11-16 13:10:41 -0500344 same as CFG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
York Sun3a0916d2014-02-10 13:59:43 -0800345 it could be different for ARM SoCs.
346
Daniel Schwierzeckd52a6232011-07-27 13:22:39 +0200347- MIPS CPU options:
Daniel Schwierzeckd52a6232011-07-27 13:22:39 +0200348 CONFIG_XWAY_SWAP_BYTES
349
350 Enable compilation of tools/xway-swap-bytes needed for Lantiq
351 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
352 be swapped if a flash programmer is used.
353
Christian Riesch48c2d6d2012-02-02 00:44:39 +0000354- ARM options:
Tom Rini6a5dccc2022-11-16 13:10:41 -0500355 CFG_SYS_EXCEPTION_VECTORS_HIGH
Christian Riesch48c2d6d2012-02-02 00:44:39 +0000356
357 Select high exception vectors of the ARM core, e.g., do not
358 clear the V bit of the c1 register of CP15.
359
York Sun77a10972015-03-20 19:28:08 -0700360 COUNTER_FREQUENCY
361 Generic timer clock source frequency.
362
363 COUNTER_FREQUENCY_REAL
364 Generic timer clock source frequency if the real clock is
365 different from COUNTER_FREQUENCY, and can only be determined
366 at run time.
367
Stephen Warren8d1fb312015-01-19 16:25:52 -0700368- Tegra SoC options:
369 CONFIG_TEGRA_SUPPORT_NON_SECURE
370
371 Support executing U-Boot in non-secure (NS) mode. Certain
372 impossible actions will be skipped if the CPU is in NS mode,
373 such as ARM architectural timer initialization.
374
wdenk9b7f3842003-10-09 20:09:04 +0000375- Linux Kernel Interface:
wdenk9b7f3842003-10-09 20:09:04 +0000376 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
377
Jeremiah Mahler03f930c2015-01-04 18:56:50 -0800378 When transferring memsize parameter to Linux, some versions
wdenk9b7f3842003-10-09 20:09:04 +0000379 expect it to be in bytes, others in MB.
380 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
381
Gerald Van Barenfcd91bb2008-06-03 20:34:45 -0400382 CONFIG_OF_LIBFDT
Wolfgang Denk27a5b0b2005-10-13 01:45:54 +0200383
384 New kernel versions are expecting firmware settings to be
Gerald Van Barend6abef42007-03-31 12:23:51 -0400385 passed using flattened device trees (based on open firmware
386 concepts).
387
388 CONFIG_OF_LIBFDT
389 * New libfdt-based support
390 * Adds the "fdt" command
Kim Phillips9b46eb62007-08-10 14:34:14 -0500391 * The bootm command automatically updates the fdt
Gerald Van Barend6abef42007-03-31 12:23:51 -0400392
Wolfgang Denk27a5b0b2005-10-13 01:45:54 +0200393 OF_TBCLK - The timebase frequency.
394
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +0200395 boards with QUICC Engines require OF_QE to set UCC MAC
396 addresses
Kim Phillips9b46eb62007-08-10 14:34:14 -0500397
Heiko Schocherffb293a2009-09-23 07:56:08 +0200398 CONFIG_OF_IDE_FIXUP
399
400 U-Boot can detect if an IDE device is present or not.
401 If not, and this new config option is activated, U-Boot
402 removes the ATA node from the DTS before booting Linux,
403 so the Linux IDE driver does not probe the device and
404 crash. This is needed for buggy hardware (uc101) where
405 no pull down resistor is connected to the signal IDE5V_DD7.
406
Niklaus Giger0ab978d2008-11-03 22:13:47 +0100407- vxWorks boot parameters:
408
409 bootvx constructs a valid bootline using the following
Bin Mengfb694b92015-10-07 20:19:17 -0700410 environments variables: bootdev, bootfile, ipaddr, netmask,
411 serverip, gatewayip, hostname, othbootargs.
Niklaus Giger0ab978d2008-11-03 22:13:47 +0100412 It loads the vxWorks image pointed bootfile.
413
Naoki Hayama158c2262020-10-08 13:17:08 +0900414 Note: If a "bootargs" environment is defined, it will override
Niklaus Giger0ab978d2008-11-03 22:13:47 +0100415 the defaults discussed just above.
416
Aneesh V686a0752011-06-16 23:30:51 +0000417- Cache Configuration for ARM:
Tom Rini6a5dccc2022-11-16 13:10:41 -0500418 CFG_SYS_PL310_BASE - Physical base address of PL310
Aneesh V686a0752011-06-16 23:30:51 +0000419 controller register space
420
wdenkda04a8b2004-08-02 23:22:59 +0000421- Serial Ports:
wdenkda04a8b2004-08-02 23:22:59 +0000422 CONFIG_PL011_CLOCK
423
424 If you have Amba PrimeCell PL011 UARTs, set this variable to
425 the clock speed of the UARTs.
426
427 CONFIG_PL01x_PORTS
428
429 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
430 define this to a list of base addresses for each (supported)
431 port. See e.g. include/configs/versatile.h
432
Karicheri, Muralidharancbc08882014-04-09 15:38:46 -0400433 CONFIG_SERIAL_HW_FLOW_CONTROL
434
435 Define this variable to enable hw flow control in serial driver.
436 Current user of this option is drivers/serial/nsl16550.c driver
wdenkda04a8b2004-08-02 23:22:59 +0000437
Simon Glassaa34ef22016-03-13 19:07:28 -0600438- Removal of commands
439 If no commands are needed to boot, you can disable
440 CONFIG_CMDLINE to remove them. In this case, the command line
441 will not be available, and when U-Boot wants to execute the
442 boot command (on start-up) it will call board_run_command()
443 instead. This can reduce image size significantly for very
444 simple boot procedures.
445
Wolfgang Denk2aceea12013-03-23 23:50:31 +0000446- Regular expression support:
447 CONFIG_REGEX
Wolfgang Denkec7fbf52013-10-04 17:43:24 +0200448 If this variable is defined, U-Boot is linked against
449 the SLRE (Super Light Regular Expression) library,
450 which adds regex support to some commands, as for
451 example "env grep" and "setexpr".
Wolfgang Denk2aceea12013-03-23 23:50:31 +0000452
wdenkc6097192002-11-03 00:24:07 +0000453- Watchdog:
Rasmus Villemoes134cc2b2021-04-14 09:18:22 +0200454 CONFIG_SYS_WATCHDOG_FREQ
455 Some platforms automatically call WATCHDOG_RESET()
456 from the timer interrupt handler every
457 CONFIG_SYS_WATCHDOG_FREQ interrupts. If not set by the
458 board configuration file, a default of CONFIG_SYS_HZ/2
459 (i.e. 500) is used. Setting CONFIG_SYS_WATCHDOG_FREQ
460 to 0 disables calling WATCHDOG_RESET() from the timer
461 interrupt.
462
Peter Tyser9902e422008-12-17 16:36:21 -0600463- GPIO Support:
Tom Rini6a5dccc2022-11-16 13:10:41 -0500464 The CFG_SYS_I2C_PCA953X_WIDTH option specifies a list of
Chris Packham9b383202010-12-19 10:12:13 +0000465 chip-ngpio pairs that tell the PCA953X driver the number of
466 pins supported by a particular chip.
467
Peter Tyser9902e422008-12-17 16:36:21 -0600468 Note that if the GPIO device uses I2C, then the I2C interface
469 must also be configured. See I2C Support, below.
470
Simon Glass4dc47ca2014-06-11 23:29:41 -0600471- I/O tracing:
472 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
473 accesses and can checksum them or write a list of them out
474 to memory. See the 'iotrace' command for details. This is
475 useful for testing device drivers since it can confirm that
476 the driver behaves the same way before and after a code
477 change. Currently this is supported on sandbox and arm. To
478 add support for your architecture, add '#include <iotrace.h>'
479 to the bottom of arch/<arch>/include/asm/io.h and test.
480
481 Example output from the 'iotrace stats' command is below.
482 Note that if the trace buffer is exhausted, the checksum will
483 still continue to operate.
484
485 iotrace is enabled
486 Start: 10000000 (buffer start address)
487 Size: 00010000 (buffer size)
488 Offset: 00000120 (current buffer offset)
489 Output: 10000120 (start + offset)
490 Count: 00000018 (number of trace records)
491 CRC32: 9526fb66 (CRC32 of all trace records)
492
wdenkc6097192002-11-03 00:24:07 +0000493- Timestamp Support:
494
wdenk4a5c8a72003-03-06 00:02:04 +0000495 When CONFIG_TIMESTAMP is selected, the timestamp
496 (date and time) of an image is printed by image
497 commands like bootm or iminfo. This option is
Jon Loeligerc1da5c92007-06-11 19:03:39 -0500498 automatically enabled when you select CONFIG_CMD_DATE .
wdenkc6097192002-11-03 00:24:07 +0000499
Karl O. Pinc8b1f90a2012-08-16 06:20:15 +0000500- Partition Labels (disklabels) Supported:
501 Zero or more of the following:
502 CONFIG_MAC_PARTITION Apple's MacOS partition table.
Karl O. Pinc8b1f90a2012-08-16 06:20:15 +0000503 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
504 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
505 bootloader. Note 2TB partition limit; see
506 disk/part_efi.c
Simon Glass8706b812016-05-01 11:36:02 -0600507 CONFIG_SCSI) you must configure support for at
Karl O. Pinc8b1f90a2012-08-16 06:20:15 +0000508 least one non-MTD partition type as well.
wdenkc6097192002-11-03 00:24:07 +0000509
wdenkc6097192002-11-03 00:24:07 +0000510- NETWORK Support (PCI):
Kyle Moffett64b94dd2011-10-18 11:05:29 +0000511 CONFIG_E1000_SPI
512 Utility code for direct access to the SPI bus on Intel 8257x.
513 This does not do anything useful unless you set at least one
514 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
515
wdenkc6097192002-11-03 00:24:07 +0000516 CONFIG_NATSEMI
517 Support for National dp83815 chips.
518
519 CONFIG_NS8382X
520 Support for National dp8382[01] gigabit chips.
521
wdenkaa603362003-05-12 21:50:16 +0000522- NETWORK Support (other):
Rob Herringc9830dc2011-12-15 11:15:49 +0000523 CONFIG_CALXEDA_XGMAC
524 Support for the Calxeda XGMAC device
525
Ashok93fb8722012-10-15 06:20:47 +0000526 CONFIG_LAN91C96
wdenkaa603362003-05-12 21:50:16 +0000527 Support for SMSC's LAN91C96 chips.
528
wdenkaa603362003-05-12 21:50:16 +0000529 CONFIG_LAN91C96_USE_32_BIT
530 Define this to enable 32 bit addressing
531
Heiko Schocher7d037f72011-11-15 10:00:04 -0500532 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
533 Define this if you have more then 3 PHYs.
534
Macpaul Lin199c6252010-12-21 16:59:46 +0800535 CONFIG_FTGMAC100
536 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
537
538 CONFIG_FTGMAC100_EGIGA
539 Define this to use GE link update with gigabit PHY.
540 Define this if FTGMAC100 is connected to gigabit PHY.
541 If your system has 10/100 PHY only, it might not occur
542 wrong behavior. Because PHY usually return timeout or
543 useless data when polling gigabit status and gigabit
544 control registers. This behavior won't affect the
545 correctnessof 10/100 link speed update.
546
Yoshihiro Shimodaed4cea02011-01-27 10:06:03 +0900547 CONFIG_SH_ETHER
548 Support for Renesas on-chip Ethernet controller
549
550 CONFIG_SH_ETHER_USE_PORT
551 Define the number of ports to be used
552
553 CONFIG_SH_ETHER_PHY_ADDR
554 Define the ETH PHY's address
555
Yoshihiro Shimoda281aa052011-01-27 10:06:08 +0900556 CONFIG_SH_ETHER_CACHE_WRITEBACK
557 If this option is set, the driver enables cache flush.
558
Vadim Bendeburydac69642011-10-17 08:36:14 +0000559- TPM Support:
Che-liang Chiouacea5702013-04-12 11:04:34 +0000560 CONFIG_TPM
561 Support TPM devices.
562
Christophe Ricard8759ff82015-10-06 22:54:41 +0200563 CONFIG_TPM_TIS_INFINEON
564 Support for Infineon i2c bus TPM devices. Only one device
Tom Wai-Hong Tame49fed52013-04-12 11:04:37 +0000565 per system is supported at this time.
566
Tom Wai-Hong Tame49fed52013-04-12 11:04:37 +0000567 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
568 Define the burst count bytes upper limit
569
Christophe Ricard88249232016-01-21 23:27:13 +0100570 CONFIG_TPM_ST33ZP24
571 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
572
573 CONFIG_TPM_ST33ZP24_I2C
574 Support for STMicroelectronics ST33ZP24 I2C devices.
575 Requires TPM_ST33ZP24 and I2C.
576
Christophe Ricard5ffadc32016-01-21 23:27:14 +0100577 CONFIG_TPM_ST33ZP24_SPI
578 Support for STMicroelectronics ST33ZP24 SPI devices.
579 Requires TPM_ST33ZP24 and SPI.
580
Dirk Eibach20489092013-06-26 15:55:15 +0200581 CONFIG_TPM_ATMEL_TWI
582 Support for Atmel TWI TPM device. Requires I2C support.
583
Che-liang Chiouacea5702013-04-12 11:04:34 +0000584 CONFIG_TPM_TIS_LPC
Vadim Bendeburydac69642011-10-17 08:36:14 +0000585 Support for generic parallel port TPM devices. Only one device
586 per system is supported at this time.
587
588 CONFIG_TPM_TIS_BASE_ADDRESS
589 Base address where the generic TPM device is mapped
590 to. Contemporary x86 systems usually map it at
591 0xfed40000.
592
Reinhard Pfau4fece432013-06-26 15:55:13 +0200593 CONFIG_TPM
594 Define this to enable the TPM support library which provides
595 functional interfaces to some TPM commands.
596 Requires support for a TPM device.
597
598 CONFIG_TPM_AUTH_SESSIONS
599 Define this to enable authorized functions in the TPM library.
600 Requires CONFIG_TPM and CONFIG_SHA1.
601
wdenkc6097192002-11-03 00:24:07 +0000602- USB Support:
603 At the moment only the UHCI host controller is
Heiko Schocher6f90e582017-06-14 05:49:40 +0200604 supported (PIP405, MIP405); define
wdenkc6097192002-11-03 00:24:07 +0000605 CONFIG_USB_UHCI to enable it.
606 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
wdenkfb30b4c2004-10-09 22:44:59 +0000607 and define CONFIG_USB_STORAGE to enable the USB
wdenkc6097192002-11-03 00:24:07 +0000608 storage devices.
609 Note:
610 Supported are USB Keyboards and USB Floppy drives
611 (TEAC FD-05PUB).
wdenk369d43d2004-03-14 14:09:05 +0000612
Oleksandr Tymoshenko7a881752014-02-01 21:51:25 -0700613 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
614 HW module registers.
615
Wolfgang Denk3f0137b2006-06-14 17:45:53 +0200616- USB Device:
617 Define the below if you wish to use the USB console.
618 Once firmware is rebuilt from a serial console issue the
619 command "setenv stdin usbtty; setenv stdout usbtty" and
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +0200620 attach your USB cable. The Unix command "dmesg" should print
Wolfgang Denk3f0137b2006-06-14 17:45:53 +0200621 it has found a new device. The environment variable usbtty
622 can be set to gserial or cdc_acm to enable your device to
Wolfgang Denke2601822006-06-14 18:14:56 +0200623 appear to a USB host as a Linux gserial device or a
Wolfgang Denk3f0137b2006-06-14 17:45:53 +0200624 Common Device Class Abstract Control Model serial device.
625 If you select usbtty = gserial you should be able to enumerate
626 a Linux host by
627 # modprobe usbserial vendor=0xVendorID product=0xProductID
628 else if using cdc_acm, simply setting the environment
629 variable usbtty to be cdc_acm should suffice. The following
630 might be defined in YourBoardName.h
Wolfgang Denke2601822006-06-14 18:14:56 +0200631
Vipin KUMARbdb17702012-03-26 15:38:06 +0530632 CONFIG_USBD_HS
633 Define this to enable the high speed support for usb
634 device and usbtty. If this feature is enabled, a routine
635 int is_usbd_high_speed(void)
636 also needs to be defined by the driver to dynamically poll
637 whether the enumeration has succeded at high speed or full
638 speed.
639
Wolfgang Denke2601822006-06-14 18:14:56 +0200640 If you have a USB-IF assigned VendorID then you may wish to
Wolfgang Denk3f0137b2006-06-14 17:45:53 +0200641 define your own vendor specific values either in BoardName.h
Wolfgang Denke2601822006-06-14 18:14:56 +0200642 or directly in usbd_vendor_info.h. If you don't define
Wolfgang Denk3f0137b2006-06-14 17:45:53 +0200643 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
644 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
645 should pretend to be a Linux device to it's target host.
646
647 CONFIG_USBD_MANUFACTURER
648 Define this string as the name of your company for
649 - CONFIG_USBD_MANUFACTURER "my company"
Wolfgang Denke2601822006-06-14 18:14:56 +0200650
Wolfgang Denk3f0137b2006-06-14 17:45:53 +0200651 CONFIG_USBD_PRODUCT_NAME
652 Define this string as the name of your product
653 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
wdenkc6097192002-11-03 00:24:07 +0000654
Wolfgang Denk3f0137b2006-06-14 17:45:53 +0200655 CONFIG_USBD_VENDORID
656 Define this as your assigned Vendor ID from the USB
657 Implementors Forum. This *must* be a genuine Vendor ID
658 to avoid polluting the USB namespace.
659 - CONFIG_USBD_VENDORID 0xFFFF
Wolfgang Denke2601822006-06-14 18:14:56 +0200660
Wolfgang Denk3f0137b2006-06-14 17:45:53 +0200661 CONFIG_USBD_PRODUCTID
662 Define this as the unique Product ID
663 for your device
664 - CONFIG_USBD_PRODUCTID 0xFFFF
Wolfgang Denke2601822006-06-14 18:14:56 +0200665
Igor Grinbergac5f6ee2011-12-12 12:08:35 +0200666- ULPI Layer Support:
667 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
668 the generic ULPI layer. The generic layer accesses the ULPI PHY
669 via the platform viewport, so you need both the genric layer and
670 the viewport enabled. Currently only Chipidea/ARC based
671 viewport is supported.
672 To enable the ULPI layer support, define CONFIG_USB_ULPI and
673 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
Lucas Stachf31e4112012-10-01 00:44:35 +0200674 If your ULPI phy needs a different reference clock than the
675 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
676 the appropriate value in Hz.
wdenkc6097192002-11-03 00:24:07 +0000677
wdenk7a428cc2003-06-15 22:40:42 +0000678- MMC Support:
Yoshihiro Shimodadb7717b2011-07-04 22:21:22 +0000679 CONFIG_SH_MMCIF
680 Support for Renesas on-chip MMCIF controller
681
682 CONFIG_SH_MMCIF_ADDR
683 Define the base address of MMCIF registers
684
685 CONFIG_SH_MMCIF_CLK
686 Define the clock frequency for MMCIF
687
Tom Rini58a8d322013-03-14 05:32:47 +0000688- USB Device Firmware Update (DFU) class support:
Marek Vasut7f8d4362018-02-16 16:41:18 +0100689 CONFIG_DFU_OVER_USB
Tom Rini58a8d322013-03-14 05:32:47 +0000690 This enables the USB portion of the DFU USB class
691
Pantelis Antonioucf14d0d2013-03-14 05:32:52 +0000692 CONFIG_DFU_NAND
693 This enables support for exposing NAND devices via DFU.
694
Afzal Mohammede3c687a2013-09-18 01:15:24 +0530695 CONFIG_DFU_RAM
696 This enables support for exposing RAM via DFU.
697 Note: DFU spec refer to non-volatile memory usage, but
698 allow usages beyond the scope of spec - here RAM usage,
699 one that would help mostly the developer.
700
Heiko Schochera2f831e2013-06-12 06:05:51 +0200701 CONFIG_SYS_DFU_DATA_BUF_SIZE
702 Dfu transfer uses a buffer before writing data to the
703 raw storage device. Make the size (in bytes) of this buffer
704 configurable. The size of this buffer is also configurable
705 through the "dfu_bufsiz" environment variable.
706
Pantelis Antonioua6e788d2013-03-14 05:32:48 +0000707 CONFIG_SYS_DFU_MAX_FILE_SIZE
708 When updating files rather than the raw storage device,
709 we use a static buffer to copy the file into and then write
710 the buffer once we've been given the whole file. Define
711 this to the maximum filesize (in bytes) for the buffer.
712 Default is 4 MiB if undefined.
713
Heiko Schochere1ba1512014-03-18 08:09:56 +0100714 DFU_DEFAULT_POLL_TIMEOUT
715 Poll timeout [ms], is the timeout a device can send to the
716 host. The host must wait for this timeout before sending
717 a subsequent DFU_GET_STATUS request to the device.
718
719 DFU_MANIFEST_POLL_TIMEOUT
720 Poll timeout [ms], which the device sends to the host when
721 entering dfuMANIFEST state. Host waits this timeout, before
722 sending again an USB request to the device.
723
wdenkc6097192002-11-03 00:24:07 +0000724- Keyboard Support:
Simon Glasseaba37e2015-11-11 10:05:47 -0700725 See Kconfig help for available keyboard drivers.
726
wdenk0e2bd9c2004-06-06 21:51:03 +0000727- MII/PHY support:
wdenk0e2bd9c2004-06-06 21:51:03 +0000728 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
729
730 The clock frequency of the MII bus
731
wdenk0e2bd9c2004-06-06 21:51:03 +0000732 CONFIG_PHY_CMD_DELAY (ppc4xx)
733
734 Some PHY like Intel LXT971A need extra delay after
735 command issued before MII status register can be read
736
wdenkc6097192002-11-03 00:24:07 +0000737- BOOTP Recovery Mode:
738 CONFIG_BOOTP_RANDOM_DELAY
739
740 If you have many targets in a network that try to
741 boot using BOOTP, you may want to avoid that all
742 systems send out BOOTP requests at precisely the same
743 moment (which would happen for instance at recovery
744 from a power failure, when all systems will try to
745 boot, thus flooding the BOOTP server. Defining
746 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
747 inserted before sending out BOOTP requests. The
Wolfgang Denkb65aaf92007-08-06 23:21:05 +0200748 following delays are inserted then:
wdenkc6097192002-11-03 00:24:07 +0000749
750 1st BOOTP request: delay 0 ... 1 sec
751 2nd BOOTP request: delay 0 ... 2 sec
752 3rd BOOTP request: delay 0 ... 4 sec
753 4th and following
754 BOOTP requests: delay 0 ... 8 sec
755
Thierry Reding8977cda2014-08-19 10:21:24 +0200756 CONFIG_BOOTP_ID_CACHE_SIZE
757
758 BOOTP packets are uniquely identified using a 32-bit ID. The
759 server will copy the ID from client requests to responses and
760 U-Boot will use this to determine if it is the destination of
761 an incoming response. Some servers will check that addresses
762 aren't in use before handing them out (usually using an ARP
763 ping) and therefore take up to a few hundred milliseconds to
764 respond. Network congestion may also influence the time it
765 takes for a response to make it back to the client. If that
766 time is too long, U-Boot will retransmit requests. In order
767 to allow earlier responses to still be accepted after these
768 retransmissions, U-Boot's BOOTP client keeps a small cache of
769 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
770 cache. The default is to keep IDs for up to four outstanding
771 requests. Increasing this will allow U-Boot to accept offers
772 from a BOOTP client in networks with unusually high latency.
773
stroesee0aadfb2003-08-28 14:17:32 +0000774- DHCP Advanced Options:
Joe Hershberger8ca7fa02012-05-23 07:59:19 +0000775
Joe Hershbergerb35a3a62012-05-23 08:00:12 +0000776 - Link-local IP address negotiation:
777 Negotiate with other link-local clients on the local network
778 for an address that doesn't require explicit configuration.
779 This is especially useful if a DHCP server cannot be guaranteed
780 to exist in all environments that the device must operate.
781
782 See doc/README.link-local for more information.
783
Prabhakar Kushwaha2dec06f2017-11-23 16:51:32 +0530784 - MAC address from environment variables
785
786 FDT_SEQ_MACADDR_FROM_ENV
787
788 Fix-up device tree with MAC addresses fetched sequentially from
789 environment variables. This config work on assumption that
790 non-usable ethernet node of device-tree are either not present
791 or their status has been marked as "disabled".
792
wdenk145d2c12004-04-15 21:48:45 +0000793 - CDP Options:
wdenk05939202004-04-18 17:39:38 +0000794 CONFIG_CDP_DEVICE_ID
wdenk145d2c12004-04-15 21:48:45 +0000795
796 The device id used in CDP trigger frames.
797
798 CONFIG_CDP_DEVICE_ID_PREFIX
799
800 A two character string which is prefixed to the MAC address
801 of the device.
802
803 CONFIG_CDP_PORT_ID
804
805 A printf format string which contains the ascii name of
806 the port. Normally is set to "eth%d" which sets
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +0200807 eth0 for the first Ethernet, eth1 for the second etc.
wdenk145d2c12004-04-15 21:48:45 +0000808
809 CONFIG_CDP_CAPABILITIES
810
811 A 32bit integer which indicates the device capabilities;
812 0x00000010 for a normal host which does not forwards.
813
814 CONFIG_CDP_VERSION
815
816 An ascii string containing the version of the software.
817
818 CONFIG_CDP_PLATFORM
819
820 An ascii string containing the name of the platform.
821
822 CONFIG_CDP_TRIGGER
823
824 A 32bit integer sent on the trigger.
825
826 CONFIG_CDP_POWER_CONSUMPTION
827
828 A 16bit integer containing the power consumption of the
829 device in .1 of milliwatts.
830
831 CONFIG_CDP_APPLIANCE_VLAN_TYPE
832
833 A byte containing the id of the VLAN.
834
Uri Mashiach3dc6f652017-01-19 10:51:05 +0200835- Status LED: CONFIG_LED_STATUS
wdenkc6097192002-11-03 00:24:07 +0000836
837 Several configurations allow to display the current
838 status using a LED. For instance, the LED will blink
839 fast while running U-Boot code, stop blinking as
840 soon as a reply to a BOOTP request was received, and
841 start blinking slow once the Linux kernel is running
842 (supported by a status LED driver in the Linux
Uri Mashiach3dc6f652017-01-19 10:51:05 +0200843 kernel). Defining CONFIG_LED_STATUS enables this
wdenkc6097192002-11-03 00:24:07 +0000844 feature in U-Boot.
845
Igor Grinberg4997a9e2013-11-08 01:03:50 +0200846 Additional options:
847
Uri Mashiach3dc6f652017-01-19 10:51:05 +0200848 CONFIG_LED_STATUS_GPIO
Igor Grinberg4997a9e2013-11-08 01:03:50 +0200849 The status LED can be connected to a GPIO pin.
850 In such cases, the gpio_led driver can be used as a
Uri Mashiach3dc6f652017-01-19 10:51:05 +0200851 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO
Igor Grinberg4997a9e2013-11-08 01:03:50 +0200852 to include the gpio_led driver in the U-Boot binary.
853
Igor Grinberg203bd9f2013-11-08 01:03:52 +0200854 CONFIG_GPIO_LED_INVERTED_TABLE
855 Some GPIO connected LEDs may have inverted polarity in which
856 case the GPIO high value corresponds to LED off state and
857 GPIO low value corresponds to LED on state.
858 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
859 with a list of GPIO LEDs that have inverted polarity.
860
Tom Rini52b2e262021-08-18 23:12:24 -0400861- I2C Support:
Tom Rini0a2bac72022-11-16 13:10:29 -0500862 CFG_SYS_NUM_I2C_BUSES
Simon Glassb05e2b32016-10-02 18:01:05 -0600863 Hold the number of i2c buses you want to use.
Heiko Schochere0e55bc2012-01-16 21:12:24 +0000864
865 CONFIG_SYS_I2C_DIRECT_BUS
866 define this, if you don't use i2c muxes on your hardware.
Tom Rini6a5dccc2022-11-16 13:10:41 -0500867 if CFG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
Heiko Schochere0e55bc2012-01-16 21:12:24 +0000868 omit this define.
869
Tom Rini6a5dccc2022-11-16 13:10:41 -0500870 CFG_SYS_I2C_MAX_HOPS
Heiko Schochere0e55bc2012-01-16 21:12:24 +0000871 define how many muxes are maximal consecutively connected
872 on one i2c bus. If you not use i2c muxes, omit this
873 define.
874
Tom Rini6a5dccc2022-11-16 13:10:41 -0500875 CFG_SYS_I2C_BUSES
Jeremiah Mahler03f930c2015-01-04 18:56:50 -0800876 hold a list of buses you want to use, only used if
Heiko Schochere0e55bc2012-01-16 21:12:24 +0000877 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
Tom Rini6a5dccc2022-11-16 13:10:41 -0500878 a board with CFG_SYS_I2C_MAX_HOPS = 1 and
Tom Rini0a2bac72022-11-16 13:10:29 -0500879 CFG_SYS_NUM_I2C_BUSES = 9:
Heiko Schochere0e55bc2012-01-16 21:12:24 +0000880
Tom Rini6a5dccc2022-11-16 13:10:41 -0500881 CFG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
Heiko Schochere0e55bc2012-01-16 21:12:24 +0000882 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
883 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
884 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
885 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
886 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
887 {1, {I2C_NULL_HOP}}, \
888 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
889 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
890 }
891
892 which defines
893 bus 0 on adapter 0 without a mux
Heiko Schocher479a4cf2013-01-29 08:53:15 +0100894 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
895 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
896 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
897 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
898 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
Heiko Schochere0e55bc2012-01-16 21:12:24 +0000899 bus 6 on adapter 1 without a mux
Heiko Schocher479a4cf2013-01-29 08:53:15 +0100900 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
901 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
Heiko Schochere0e55bc2012-01-16 21:12:24 +0000902
903 If you do not have i2c muxes on your board, omit this define.
904
Simon Glass3efce392017-05-12 21:10:00 -0600905- Legacy I2C Support:
Heiko Schocher479a4cf2013-01-29 08:53:15 +0100906 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
wdenkb9bbd242003-06-30 16:24:52 +0000907 then the following macros need to be defined (examples are
908 from include/configs/lwmon.h):
wdenkc6097192002-11-03 00:24:07 +0000909
910 I2C_INIT
911
wdenkb9bbd242003-06-30 16:24:52 +0000912 (Optional). Any commands necessary to enable the I2C
wdenk4a5c8a72003-03-06 00:02:04 +0000913 controller or configure ports.
wdenkc6097192002-11-03 00:24:07 +0000914
wdenk544e9732004-02-06 23:19:44 +0000915 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
wdenkb9bbd242003-06-30 16:24:52 +0000916
wdenkc6097192002-11-03 00:24:07 +0000917 I2C_ACTIVE
918
919 The code necessary to make the I2C data line active
920 (driven). If the data line is open collector, this
921 define can be null.
922
wdenkb9bbd242003-06-30 16:24:52 +0000923 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
924
wdenkc6097192002-11-03 00:24:07 +0000925 I2C_TRISTATE
926
927 The code necessary to make the I2C data line tri-stated
928 (inactive). If the data line is open collector, this
929 define can be null.
930
wdenkb9bbd242003-06-30 16:24:52 +0000931 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
932
wdenkc6097192002-11-03 00:24:07 +0000933 I2C_READ
934
York Sun4a598092013-04-01 11:29:11 -0700935 Code that returns true if the I2C data line is high,
936 false if it is low.
wdenkc6097192002-11-03 00:24:07 +0000937
wdenkb9bbd242003-06-30 16:24:52 +0000938 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
939
wdenkc6097192002-11-03 00:24:07 +0000940 I2C_SDA(bit)
941
York Sun4a598092013-04-01 11:29:11 -0700942 If <bit> is true, sets the I2C data line high. If it
943 is false, it clears it (low).
wdenkc6097192002-11-03 00:24:07 +0000944
wdenkb9bbd242003-06-30 16:24:52 +0000945 eg: #define I2C_SDA(bit) \
wdenk2bb11052003-07-17 23:16:40 +0000946 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
wdenk544e9732004-02-06 23:19:44 +0000947 else immr->im_cpm.cp_pbdat &= ~PB_SDA
wdenkb9bbd242003-06-30 16:24:52 +0000948
wdenkc6097192002-11-03 00:24:07 +0000949 I2C_SCL(bit)
950
York Sun4a598092013-04-01 11:29:11 -0700951 If <bit> is true, sets the I2C clock line high. If it
952 is false, it clears it (low).
wdenkc6097192002-11-03 00:24:07 +0000953
wdenkb9bbd242003-06-30 16:24:52 +0000954 eg: #define I2C_SCL(bit) \
wdenk2bb11052003-07-17 23:16:40 +0000955 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
wdenk544e9732004-02-06 23:19:44 +0000956 else immr->im_cpm.cp_pbdat &= ~PB_SCL
wdenkb9bbd242003-06-30 16:24:52 +0000957
wdenkc6097192002-11-03 00:24:07 +0000958 I2C_DELAY
959
960 This delay is invoked four times per clock cycle so this
961 controls the rate of data transfer. The data rate thus
wdenkb9bbd242003-06-30 16:24:52 +0000962 is 1 / (I2C_DELAY * 4). Often defined to be something
wdenk21136db2003-07-16 21:53:01 +0000963 like:
964
wdenkb9bbd242003-06-30 16:24:52 +0000965 #define I2C_DELAY udelay(2)
wdenkc6097192002-11-03 00:24:07 +0000966
Mike Frysingeree12d542010-07-21 13:38:02 -0400967 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
968
969 If your arch supports the generic GPIO framework (asm/gpio.h),
970 then you may alternatively define the two GPIOs that are to be
971 used as SCL / SDA. Any of the previous I2C_xxx macros will
972 have GPIO-based defaults assigned to them as appropriate.
973
974 You should define these to the GPIO value as given directly to
975 the generic GPIO functions.
976
Ben Warren45657152006-09-07 16:50:54 -0400977 CONFIG_I2C_MULTI_BUS
978
979 This option allows the use of multiple I2C buses, each of which
Wolfgang Denk092ae952011-10-26 10:21:21 +0000980 must have a controller. At any point in time, only one bus is
981 active. To switch to a different bus, use the 'i2c dev' command.
Ben Warren45657152006-09-07 16:50:54 -0400982 Note that bus numbering is zero-based.
983
Tom Rini6a5dccc2022-11-16 13:10:41 -0500984 CFG_SYS_I2C_NOPROBES
Ben Warren45657152006-09-07 16:50:54 -0400985
986 This option specifies a list of I2C devices that will be skipped
Tom Rini6da96a12022-12-02 16:42:30 -0500987 when the 'i2c probe' command is issued.
Ben Warren45657152006-09-07 16:50:54 -0400988
989 e.g.
Tom Rini6a5dccc2022-11-16 13:10:41 -0500990 #define CFG_SYS_I2C_NOPROBES {0x50,0x68}
Ben Warren45657152006-09-07 16:50:54 -0400991
992 will skip addresses 0x50 and 0x68 on a board with one I2C bus
993
Tom Rini6a5dccc2022-11-16 13:10:41 -0500994 CFG_SYS_RTC_BUS_NUM
Stefan Roese096cc9b2007-02-20 10:51:26 +0100995
996 If defined, then this indicates the I2C bus number for the RTC.
997 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
998
Andrew Dyer58c41f92008-12-29 17:36:01 -0600999 CONFIG_SOFT_I2C_READ_REPEATED_START
1000
1001 defining this will force the i2c_read() function in
1002 the soft_i2c driver to perform an I2C repeated start
1003 between writing the address pointer and reading the
1004 data. If this define is omitted the default behaviour
1005 of doing a stop-start sequence will be used. Most I2C
1006 devices can use either method, but some require one or
1007 the other.
Timur Tabiab347542006-11-03 19:15:00 -06001008
wdenkc6097192002-11-03 00:24:07 +00001009- SPI Support: CONFIG_SPI
1010
1011 Enables SPI driver (so far only tested with
1012 SPI EEPROM, also an instance works with Crystal A/D and
1013 D/As on the SACSng board)
1014
Heiko Schocherb77c8882014-07-14 10:22:11 +02001015 CONFIG_SYS_SPI_MXC_WAIT
1016 Timeout for waiting until spi transfer completed.
1017 default: (CONFIG_SYS_HZ/100) /* 10 ms */
1018
Matthias Fuchsa4400872007-12-27 17:12:34 +01001019- FPGA Support: CONFIG_FPGA
wdenkc6097192002-11-03 00:24:07 +00001020
Matthias Fuchsa4400872007-12-27 17:12:34 +01001021 Enables FPGA subsystem.
1022
1023 CONFIG_FPGA_<vendor>
1024
1025 Enables support for specific chip vendors.
1026 (ALTERA, XILINX)
wdenkc6097192002-11-03 00:24:07 +00001027
Matthias Fuchsa4400872007-12-27 17:12:34 +01001028 CONFIG_FPGA_<family>
wdenkc6097192002-11-03 00:24:07 +00001029
Matthias Fuchsa4400872007-12-27 17:12:34 +01001030 Enables support for FPGA family.
1031 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1032
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001033 CONFIG_SYS_FPGA_CHECK_BUSY
wdenkc6097192002-11-03 00:24:07 +00001034
wdenk4a5c8a72003-03-06 00:02:04 +00001035 Enable checks on FPGA configuration interface busy
1036 status by the configuration function. This option
1037 will require a board or device specific function to
1038 be written.
wdenkc6097192002-11-03 00:24:07 +00001039
1040 CONFIG_FPGA_DELAY
1041
1042 If defined, a function that provides delays in the FPGA
1043 configuration driver.
1044
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001045 CONFIG_SYS_FPGA_CHECK_ERROR
wdenkc6097192002-11-03 00:24:07 +00001046
wdenk4a5c8a72003-03-06 00:02:04 +00001047 Check for configuration errors during FPGA bitfile
1048 loading. For example, abort during Virtex II
1049 configuration if the INIT_B line goes low (which
1050 indicated a CRC error).
wdenkc6097192002-11-03 00:24:07 +00001051
Tom Rini6a5dccc2022-11-16 13:10:41 -05001052 CFG_SYS_FPGA_WAIT_INIT
wdenkc6097192002-11-03 00:24:07 +00001053
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08001054 Maximum time to wait for the INIT_B line to de-assert
1055 after PROB_B has been de-asserted during a Virtex II
wdenk4a5c8a72003-03-06 00:02:04 +00001056 FPGA configuration sequence. The default time is 500
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001057 ms.
wdenkc6097192002-11-03 00:24:07 +00001058
Tom Rini6a5dccc2022-11-16 13:10:41 -05001059 CFG_SYS_FPGA_WAIT_BUSY
wdenkc6097192002-11-03 00:24:07 +00001060
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08001061 Maximum time to wait for BUSY to de-assert during
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001062 Virtex II FPGA configuration. The default is 5 ms.
wdenkc6097192002-11-03 00:24:07 +00001063
Tom Rini6a5dccc2022-11-16 13:10:41 -05001064 CFG_SYS_FPGA_WAIT_CONFIG
wdenkc6097192002-11-03 00:24:07 +00001065
wdenk4a5c8a72003-03-06 00:02:04 +00001066 Time to wait after FPGA configuration. The default is
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001067 200 ms.
wdenkc6097192002-11-03 00:24:07 +00001068
wdenkc6097192002-11-03 00:24:07 +00001069- Vendor Parameter Protection:
1070
wdenk4a5c8a72003-03-06 00:02:04 +00001071 U-Boot considers the values of the environment
1072 variables "serial#" (Board Serial Number) and
wdenkeb20ad32003-09-05 23:19:14 +00001073 "ethaddr" (Ethernet Address) to be parameters that
wdenk4a5c8a72003-03-06 00:02:04 +00001074 are set once by the board vendor / manufacturer, and
1075 protects these variables from casual modification by
1076 the user. Once set, these variables are read-only,
1077 and write or delete attempts are rejected. You can
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001078 change this behaviour:
wdenkc6097192002-11-03 00:24:07 +00001079
1080 If CONFIG_ENV_OVERWRITE is #defined in your config
1081 file, the write protection for vendor parameters is
wdenkcc1e2562003-03-06 13:39:27 +00001082 completely disabled. Anybody can change or delete
wdenkc6097192002-11-03 00:24:07 +00001083 these parameters.
1084
Joe Hershberger76f353e2015-05-04 14:55:14 -05001085 Alternatively, if you define _both_ an ethaddr in the
1086 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001087 Ethernet address is installed in the environment,
wdenkc6097192002-11-03 00:24:07 +00001088 which can be changed exactly ONCE by the user. [The
1089 serial# is unaffected by this, i. e. it remains
1090 read-only.]
1091
Joe Hershberger71497d02012-12-11 22:16:31 -06001092 The same can be accomplished in a more flexible way
1093 for any variable by configuring the type of access
1094 to allow for those variables in the ".flags" variable
1095 or define CONFIG_ENV_FLAGS_LIST_STATIC.
1096
wdenkc6097192002-11-03 00:24:07 +00001097- Protected RAM:
1098 CONFIG_PRAM
1099
1100 Define this variable to enable the reservation of
1101 "protected RAM", i. e. RAM which is not overwritten
1102 by U-Boot. Define CONFIG_PRAM to hold the number of
1103 kB you want to reserve for pRAM. You can overwrite
1104 this default value by defining an environment
1105 variable "pram" to the number of kB you want to
1106 reserve. Note that the board info structure will
1107 still show the full amount of RAM. If pRAM is
1108 reserved, a new environment variable "mem" will
1109 automatically be defined to hold the amount of
1110 remaining RAM in a form that can be passed as boot
1111 argument to Linux, for instance like that:
1112
Wolfgang Denk86eb3b72005-11-20 21:40:11 +01001113 setenv bootargs ... mem=\${mem}
wdenkc6097192002-11-03 00:24:07 +00001114 saveenv
1115
1116 This way you can tell Linux not to use this memory,
1117 either, which results in a memory region that will
1118 not be affected by reboots.
1119
1120 *WARNING* If your board configuration uses automatic
1121 detection of the RAM size, you must make sure that
1122 this memory test is non-destructive. So far, the
1123 following board configurations are known to be
1124 "pRAM-clean":
1125
Heiko Schocher65d94db2017-06-07 17:33:09 +02001126 IVMS8, IVML24, SPD8xx,
Wolfgang Denk90326762012-10-24 02:36:15 +00001127 HERMES, IP860, RPXlite, LWMON,
Heiko Schocher71cb3e92017-06-07 17:33:10 +02001128 FLAGADM
wdenkc6097192002-11-03 00:24:07 +00001129
1130- Error Recovery:
wdenkc6097192002-11-03 00:24:07 +00001131 Note:
1132
wdenk57b2d802003-06-27 21:31:46 +00001133 In the current implementation, the local variables
1134 space and global environment variables space are
1135 separated. Local variables are those you define by
1136 simply typing `name=value'. To access a local
1137 variable later on, you have write `$name' or
1138 `${name}'; to execute the contents of a variable
1139 directly type `$name' at the command prompt.
wdenkc6097192002-11-03 00:24:07 +00001140
wdenk4a5c8a72003-03-06 00:02:04 +00001141 Global environment variables are those you use
1142 setenv/printenv to work with. To run a command stored
1143 in such a variable, you need to use the run command,
1144 and you must not use the '$' sign to access them.
wdenkc6097192002-11-03 00:24:07 +00001145
1146 To store commands and special characters in a
1147 variable, please use double quotation marks
1148 surrounding the whole text of the variable, instead
1149 of the backslashes before semicolons and special
1150 symbols.
1151
wdenkc0aa5c52003-12-06 19:49:23 +00001152- Default Environment:
wdenkc6097192002-11-03 00:24:07 +00001153 CONFIG_EXTRA_ENV_SETTINGS
1154
wdenk4a5c8a72003-03-06 00:02:04 +00001155 Define this to contain any number of null terminated
1156 strings (variable = value pairs) that will be part of
wdenkeb20ad32003-09-05 23:19:14 +00001157 the default environment compiled into the boot image.
wdenk591dda52002-11-18 00:14:45 +00001158
wdenk4a5c8a72003-03-06 00:02:04 +00001159 For example, place something like this in your
1160 board's config file:
wdenkc6097192002-11-03 00:24:07 +00001161
1162 #define CONFIG_EXTRA_ENV_SETTINGS \
1163 "myvar1=value1\0" \
1164 "myvar2=value2\0"
1165
wdenk4a5c8a72003-03-06 00:02:04 +00001166 Warning: This method is based on knowledge about the
1167 internal format how the environment is stored by the
1168 U-Boot code. This is NOT an official, exported
1169 interface! Although it is unlikely that this format
wdenkeb20ad32003-09-05 23:19:14 +00001170 will change soon, there is no guarantee either.
wdenkc6097192002-11-03 00:24:07 +00001171 You better know what you are doing here.
1172
wdenk4a5c8a72003-03-06 00:02:04 +00001173 Note: overly (ab)use of the default environment is
1174 discouraged. Make sure to check other ways to preset
Wolfgang Denk85c25df2009-04-01 23:34:12 +02001175 the environment like the "source" command or the
wdenk4a5c8a72003-03-06 00:02:04 +00001176 boot command first.
wdenkc6097192002-11-03 00:24:07 +00001177
Simon Glass6b8d5fd2012-11-30 13:01:17 +00001178 CONFIG_DELAY_ENVIRONMENT
1179
1180 Normally the environment is loaded when the board is
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08001181 initialised so that it is available to U-Boot. This inhibits
Simon Glass6b8d5fd2012-11-30 13:01:17 +00001182 that so that the environment is not available until
1183 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
1184 this is instead controlled by the value of
1185 /config/load-environment.
1186
Wolfgang Denkd590fb12011-10-07 09:58:21 +02001187 CONFIG_STANDALONE_LOAD_ADDR
1188
Wolfgang Denk23f78482011-10-09 21:06:34 +02001189 This option defines a board specific value for the
1190 address where standalone program gets loaded, thus
1191 overwriting the architecture dependent default
Wolfgang Denkd590fb12011-10-07 09:58:21 +02001192 settings.
1193
Detlev Zundel0ecb6112009-12-01 17:16:19 +01001194- Automatic software updates via TFTP server
1195 CONFIG_UPDATE_TFTP
1196 CONFIG_UPDATE_TFTP_CNT_MAX
1197 CONFIG_UPDATE_TFTP_MSEC_MAX
1198
1199 These options enable and control the auto-update feature;
1200 for a more detailed description refer to doc/README.update.
1201
1202- MTD Support (mtdparts command, UBI support)
Heiko Schocherf5895d12014-06-24 10:10:04 +02001203 CONFIG_MTD_UBI_WL_THRESHOLD
1204 This parameter defines the maximum difference between the highest
1205 erase counter value and the lowest erase counter value of eraseblocks
1206 of UBI devices. When this threshold is exceeded, UBI starts performing
1207 wear leveling by means of moving data from eraseblock with low erase
1208 counter to eraseblocks with high erase counter.
1209
1210 The default value should be OK for SLC NAND flashes, NOR flashes and
1211 other flashes which have eraseblock life-cycle 100000 or more.
1212 However, in case of MLC NAND flashes which typically have eraseblock
1213 life-cycle less than 10000, the threshold should be lessened (e.g.,
1214 to 128 or 256, although it does not have to be power of 2).
1215
1216 default: 4096
Simon Glass6c0be912014-10-23 18:58:54 -06001217
Heiko Schocherf5895d12014-06-24 10:10:04 +02001218 CONFIG_MTD_UBI_BEB_LIMIT
1219 This option specifies the maximum bad physical eraseblocks UBI
1220 expects on the MTD device (per 1024 eraseblocks). If the
1221 underlying flash does not admit of bad eraseblocks (e.g. NOR
1222 flash), this value is ignored.
1223
1224 NAND datasheets often specify the minimum and maximum NVM
1225 (Number of Valid Blocks) for the flashes' endurance lifetime.
1226 The maximum expected bad eraseblocks per 1024 eraseblocks
1227 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
1228 which gives 20 for most NANDs (MaxNVB is basically the total
1229 count of eraseblocks on the chip).
1230
1231 To put it differently, if this value is 20, UBI will try to
1232 reserve about 1.9% of physical eraseblocks for bad blocks
1233 handling. And that will be 1.9% of eraseblocks on the entire
1234 NAND chip, not just the MTD partition UBI attaches. This means
1235 that if you have, say, a NAND flash chip admits maximum 40 bad
1236 eraseblocks, and it is split on two MTD partitions of the same
1237 size, UBI will reserve 40 eraseblocks when attaching a
1238 partition.
1239
1240 default: 20
1241
1242 CONFIG_MTD_UBI_FASTMAP
1243 Fastmap is a mechanism which allows attaching an UBI device
1244 in nearly constant time. Instead of scanning the whole MTD device it
1245 only has to locate a checkpoint (called fastmap) on the device.
1246 The on-flash fastmap contains all information needed to attach
1247 the device. Using fastmap makes only sense on large devices where
1248 attaching by scanning takes long. UBI will not automatically install
1249 a fastmap on old images, but you can set the UBI parameter
1250 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
1251 that fastmap-enabled images are still usable with UBI implementations
1252 without fastmap support. On typical flash devices the whole fastmap
1253 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
1254
1255 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
1256 Set this parameter to enable fastmap automatically on images
1257 without a fastmap.
1258 default: 0
1259
Heiko Schocher94b66de2015-10-22 06:19:21 +02001260 CONFIG_MTD_UBI_FM_DEBUG
1261 Enable UBI fastmap debug
1262 default: 0
1263
Daniel Schwierzeck39ca08e2011-07-18 07:48:07 +00001264- SPL framework
Wolfgang Denk825223d2011-09-11 21:24:09 +02001265 CONFIG_SPL
1266 Enable building of SPL globally.
Daniel Schwierzeck39ca08e2011-07-18 07:48:07 +00001267
Albert ARIBAUD \(3ADEV\)287b0942015-03-31 11:40:50 +02001268 CONFIG_SPL_PANIC_ON_RAW_IMAGE
1269 When defined, SPL will panic() if the image it has
1270 loaded does not have a signature.
1271 Defining this is useful when code which loads images
1272 in SPL cannot guarantee that absolutely all read errors
1273 will be caught.
1274 An example is the LPC32XX MLC NAND driver, which will
1275 consider that a completely unreadable NAND block is bad,
1276 and thus should be skipped silently.
1277
Tom Rinife3b0c72012-08-13 11:37:56 -07001278 CONFIG_SPL_DISPLAY_PRINT
1279 For ARM, enable an optional function to print more information
1280 about the running system.
1281
Scott Wood2b36fbb2012-12-06 13:33:17 +00001282 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
1283 Set this for NAND SPL on PPC mpc83xx targets, so that
1284 start.S waits for the rest of the SPL to load before
1285 continuing (the hardware starts execution after just
1286 loading the first page rather than the full 4K).
1287
Thomas Gleixner820d24d2016-07-12 20:28:12 +02001288 CONFIG_SPL_UBI
1289 Support for a lightweight UBI (fastmap) scanner and
1290 loader
1291
Tom Rini36853852012-02-14 07:29:40 +00001292 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
1293 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
1294 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
Tom Rinib4213492022-11-12 17:36:51 -05001295 CFG_SYS_NAND_ECCPOS, CFG_SYS_NAND_ECCSIZE,
1296 CFG_SYS_NAND_ECCBYTES
Tom Rini36853852012-02-14 07:29:40 +00001297 Defines the size and behavior of the NAND that SPL uses
Scott Wood36c440e2012-09-21 18:35:27 -05001298 to read U-Boot
Tom Rini36853852012-02-14 07:29:40 +00001299
Tom Rinib4213492022-11-12 17:36:51 -05001300 CFG_SYS_NAND_U_BOOT_DST
Scott Wood36c440e2012-09-21 18:35:27 -05001301 Location in memory to load U-Boot to
1302
Tom Rinib4213492022-11-12 17:36:51 -05001303 CFG_SYS_NAND_U_BOOT_SIZE
Scott Wood36c440e2012-09-21 18:35:27 -05001304 Size of image to load
Tom Rini36853852012-02-14 07:29:40 +00001305
Tom Rinib4213492022-11-12 17:36:51 -05001306 CFG_SYS_NAND_U_BOOT_START
Scott Wood36c440e2012-09-21 18:35:27 -05001307 Entry point in loaded image to jump to
Tom Rini36853852012-02-14 07:29:40 +00001308
Pavel Machekde997252012-08-30 22:42:11 +02001309 CONFIG_SPL_RAM_DEVICE
1310 Support for running image already present in ram, in SPL binary
1311
Marek Vasut9f2e0eb2018-05-13 00:22:52 +02001312 CONFIG_SPL_FIT_PRINT
Simon Glass82d94532013-05-08 08:05:59 +00001313 Printing information about a FIT image adds quite a bit of
1314 code to SPL. So this is normally disabled in SPL. Use this
1315 option to re-enable it. This will affect the output of the
1316 bootm command when booting a FIT image.
1317
wdenkc0aa5c52003-12-06 19:49:23 +00001318- Interrupt support (PPC):
1319
wdenk1ebf41e2004-01-02 14:00:00 +00001320 There are common interrupt_init() and timer_interrupt()
1321 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001322 for CPU specific initialization. interrupt_init_cpu()
wdenk1ebf41e2004-01-02 14:00:00 +00001323 should set decrementer_count to appropriate value. If
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001324 CPU resets decrementer automatically after interrupt
wdenk1ebf41e2004-01-02 14:00:00 +00001325 (ppc4xx) it should set decrementer_count to zero.
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001326 timer_interrupt() calls timer_interrupt_cpu() for CPU
wdenk1ebf41e2004-01-02 14:00:00 +00001327 specific handling. If board has watchdog / status_led
1328 / other_activity_monitor it works automatically from
1329 general timer_interrupt().
wdenkc0aa5c52003-12-06 19:49:23 +00001330
wdenkc6097192002-11-03 00:24:07 +00001331
Helmut Raigerd5a184b2011-10-20 04:19:47 +00001332Board initialization settings:
1333------------------------------
1334
1335During Initialization u-boot calls a number of board specific functions
1336to allow the preparation of board specific prerequisites, e.g. pin setup
1337before drivers are initialized. To enable these callbacks the
1338following configuration macros have to be defined. Currently this is
1339architecture specific, so please check arch/your_architecture/lib/board.c
1340typically in board_init_f() and board_init_r().
1341
1342- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
1343- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
1344- CONFIG_BOARD_LATE_INIT: Call board_late_init()
wdenkc6097192002-11-03 00:24:07 +00001345
wdenkc6097192002-11-03 00:24:07 +00001346Configuration Settings:
1347-----------------------
1348
Simon Glass8927bf22019-12-28 10:45:10 -07001349- MEM_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
York Sun6c480012014-02-26 17:03:19 -08001350 Optionally it can be defined to support 64-bit memory commands.
1351
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001352- CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
wdenkc6097192002-11-03 00:24:07 +00001353 undefine this when you're short of memory.
1354
Peter Tyserdfb72b82009-01-27 18:03:12 -06001355- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
1356 width of the commands listed in the 'help' command output.
1357
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001358- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
wdenkc6097192002-11-03 00:24:07 +00001359 prompt for user input.
1360
Tom Rini6a5dccc2022-11-16 13:10:41 -05001361- CFG_SYS_BAUDRATE_TABLE:
wdenkc6097192002-11-03 00:24:07 +00001362 List of legal baudrate settings for this board.
1363
Tom Rini6a5dccc2022-11-16 13:10:41 -05001364- CFG_SYS_MEM_RESERVE_SECURE
York Sun1ef95cc2016-06-24 16:46:18 -07001365 Only implemented for ARMv8 for now.
Tom Rini6a5dccc2022-11-16 13:10:41 -05001366 If defined, the size of CFG_SYS_MEM_RESERVE_SECURE memory
York Sun5d286cd2015-12-04 11:57:07 -08001367 is substracted from total RAM and won't be reported to OS.
1368 This memory can be used as secure memory. A variable
York Sun1ef95cc2016-06-24 16:46:18 -07001369 gd->arch.secure_ram is used to track the location. In systems
York Sun5d286cd2015-12-04 11:57:07 -08001370 the RAM base is not zero, or RAM is divided into banks,
1371 this variable needs to be recalcuated to get the address.
1372
Tom Rinibb4dd962022-11-16 13:10:37 -05001373- CFG_SYS_SDRAM_BASE:
wdenkc6097192002-11-03 00:24:07 +00001374 Physical start address of SDRAM. _Must_ be 0 here.
1375
Tom Rini6a5dccc2022-11-16 13:10:41 -05001376- CFG_SYS_FLASH_BASE:
wdenkc6097192002-11-03 00:24:07 +00001377 Physical start address of Flash memory.
1378
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001379- CONFIG_SYS_MALLOC_LEN:
wdenkc6097192002-11-03 00:24:07 +00001380 Size of DRAM reserved for malloc() use.
1381
Simon Glass863e4042014-07-10 22:23:28 -06001382- CONFIG_SYS_MALLOC_F_LEN
1383 Size of the malloc() pool for use before relocation. If
1384 this is defined, then a very simple malloc() implementation
1385 will become available before relocation. The address is just
1386 below the global data, and the stack is moved down to make
1387 space.
1388
1389 This feature allocates regions with increasing addresses
1390 within the region. calloc() is supported, but realloc()
1391 is not available. free() is supported but does nothing.
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08001392 The memory will be freed (or in fact just forgotten) when
Simon Glass863e4042014-07-10 22:23:28 -06001393 U-Boot relocates itself.
1394
Simon Glass9fa901b2014-11-10 17:16:54 -07001395- CONFIG_SYS_MALLOC_SIMPLE
1396 Provides a simple and small malloc() and calloc() for those
1397 boards which do not use the full malloc in SPL (which is
Tom Rini166e3222022-05-27 12:48:32 -04001398 enabled with CONFIG_SYS_SPL_MALLOC).
Simon Glass9fa901b2014-11-10 17:16:54 -07001399
Tom Rini6a5dccc2022-11-16 13:10:41 -05001400- CFG_SYS_BOOTMAPSZ:
wdenkc6097192002-11-03 00:24:07 +00001401 Maximum size of memory mapped by the startup code of
1402 the Linux kernel; all data that must be processed by
Bartlomiej Siekac5648c82008-04-14 15:44:16 +02001403 the Linux kernel (bd_info, boot arguments, FDT blob if
1404 used) must be put below this limit, unless "bootm_low"
Robert P. J. Day832d36e2013-09-16 07:15:45 -04001405 environment variable is defined and non-zero. In such case
Bartlomiej Siekac5648c82008-04-14 15:44:16 +02001406 all data for the Linux kernel must be between "bootm_low"
Tom Rini6a5dccc2022-11-16 13:10:41 -05001407 and "bootm_low" + CFG_SYS_BOOTMAPSZ. The environment
Grant Likely26396382011-03-28 09:58:43 +00001408 variable "bootm_mapsize" will override the value of
Tom Rini6a5dccc2022-11-16 13:10:41 -05001409 CFG_SYS_BOOTMAPSZ. If CFG_SYS_BOOTMAPSZ is undefined,
Grant Likely26396382011-03-28 09:58:43 +00001410 then the value in "bootm_size" will be used instead.
wdenkc6097192002-11-03 00:24:07 +00001411
John Rigbyeea8e692010-10-13 13:57:35 -06001412- CONFIG_SYS_BOOT_GET_CMDLINE:
1413 Enables allocating and saving kernel cmdline in space between
1414 "bootm_low" and "bootm_low" + BOOTMAPSZ.
1415
1416- CONFIG_SYS_BOOT_GET_KBD:
1417 Enables allocating and saving a kernel copy of the bd_info in
1418 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
1419
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001420- CONFIG_SYS_FLASH_PROTECTION
wdenkdccbda02003-07-14 22:13:32 +00001421 If defined, hardware flash sectors protection is used
1422 instead of U-Boot software protection.
1423
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001424- CONFIG_SYS_FLASH_CFI:
wdenk4a5c8a72003-03-06 00:02:04 +00001425 Define if the flash driver uses extra elements in the
wdenk2cefd152004-02-08 22:55:38 +00001426 common flash structure for storing flash geometry.
1427
Jean-Christophe PLAGNIOL-VILLARD8d94c232008-08-13 01:40:42 +02001428- CONFIG_FLASH_CFI_DRIVER
wdenk2cefd152004-02-08 22:55:38 +00001429 This option also enables the building of the cfi_flash driver
1430 in the drivers directory
wdenkc6097192002-11-03 00:24:07 +00001431
Piotr Ziecik3e939e92008-11-17 15:57:58 +01001432- CONFIG_FLASH_CFI_MTD
1433 This option enables the building of the cfi_mtd driver
1434 in the drivers directory. The driver exports CFI flash
1435 to the MTD layer.
1436
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001437- CONFIG_SYS_FLASH_USE_BUFFER_WRITE
Guennadi Liakhovetski183284f2008-04-03 13:36:02 +02001438 Use buffered writes to flash.
1439
Joe Hershberger71497d02012-12-11 22:16:31 -06001440- CONFIG_ENV_FLAGS_LIST_DEFAULT
1441- CONFIG_ENV_FLAGS_LIST_STATIC
Robert P. J. Day832d36e2013-09-16 07:15:45 -04001442 Enable validation of the values given to environment variables when
Joe Hershberger71497d02012-12-11 22:16:31 -06001443 calling env set. Variables can be restricted to only decimal,
1444 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
1445 the variables can also be restricted to IP address or MAC address.
1446
1447 The format of the list is:
1448 type_attribute = [s|d|x|b|i|m]
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08001449 access_attribute = [a|r|o|c]
1450 attributes = type_attribute[access_attribute]
Joe Hershberger71497d02012-12-11 22:16:31 -06001451 entry = variable_name[:attributes]
1452 list = entry[,list]
1453
1454 The type attributes are:
1455 s - String (default)
1456 d - Decimal
1457 x - Hexadecimal
1458 b - Boolean ([1yYtT|0nNfF])
1459 i - IP address
1460 m - MAC address
1461
Joe Hershberger6fe26c92012-12-11 22:16:34 -06001462 The access attributes are:
1463 a - Any (default)
1464 r - Read-only
1465 o - Write-once
1466 c - Change-default
1467
Joe Hershberger71497d02012-12-11 22:16:31 -06001468 - CONFIG_ENV_FLAGS_LIST_DEFAULT
1469 Define this to a list (string) to define the ".flags"
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08001470 environment variable in the default or embedded environment.
Joe Hershberger71497d02012-12-11 22:16:31 -06001471
1472 - CONFIG_ENV_FLAGS_LIST_STATIC
1473 Define this to a list (string) to define validation that
1474 should be done if an entry is not found in the ".flags"
1475 environment variable. To override a setting in the static
1476 list, simply add an entry for the same variable name to the
1477 ".flags" variable.
1478
Joe Hershberger6db9fd42015-05-20 14:27:20 -05001479 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
1480 regular expression. This allows multiple variables to define the same
1481 flags without explicitly listing them for each variable.
1482
wdenkc6097192002-11-03 00:24:07 +00001483The following definitions that deal with the placement and management
1484of environment data (variable area); in general, we support the
1485following configurations:
1486
wdenkc6097192002-11-03 00:24:07 +00001487BE CAREFUL! The first access to the environment happens quite early
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08001488in U-Boot initialization (when we try to get the setting of for the
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001489console baudrate). You *MUST* have mapped your NVRAM area then, or
wdenkc6097192002-11-03 00:24:07 +00001490U-Boot will hang.
1491
1492Please note that even with NVRAM we still use a copy of the
1493environment in RAM: we could work on NVRAM directly, but we want to
1494keep settings there always unmodified except somebody uses "saveenv"
1495to save the current settings.
1496
Liu Gang85bcd732012-03-08 00:33:20 +00001497BE CAREFUL! For some special cases, the local device can not use
1498"saveenv" command. For example, the local device will get the
Liu Gang357bf5a2012-08-09 05:10:01 +00001499environment stored in a remote NOR flash by SRIO or PCIE link,
1500but it can not erase, write this NOR flash by SRIO or PCIE interface.
Liu Gang85bcd732012-03-08 00:33:20 +00001501
Guennadi Liakhovetskifad24442009-05-18 16:07:22 +02001502- CONFIG_NAND_ENV_DST
1503
1504 Defines address in RAM to which the nand_spl code should copy the
1505 environment. If redundant environment is used, it will be copied to
1506 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
1507
Bruce Adleredecc942007-11-02 13:15:42 -07001508Please note that the environment is read-only until the monitor
wdenkc6097192002-11-03 00:24:07 +00001509has been relocated to RAM and a RAM copy of the environment has been
Simon Glass64b723f2017-08-03 12:22:12 -06001510created; also, when using EEPROM you will have to use env_get_f()
wdenkc6097192002-11-03 00:24:07 +00001511until then to read environment variables.
1512
wdenk8dba0502003-03-31 16:34:49 +00001513The environment is protected by a CRC32 checksum. Before the monitor
1514is relocated into RAM, as a result of a bad CRC you will be working
1515with the compiled-in default environment - *silently*!!! [This is
1516necessary, because the first environment variable we need is the
1517"baudrate" setting for the console - if we have a bad CRC, we don't
1518have any device yet where we could complain.]
wdenkc6097192002-11-03 00:24:07 +00001519
1520Note: once the monitor has been relocated, then it will complain if
1521the default environment is used; a new CRC is computed as soon as you
wdenk8dba0502003-03-31 16:34:49 +00001522use the "saveenv" command to store a valid environment.
wdenkc6097192002-11-03 00:24:07 +00001523
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001524- CONFIG_SYS_FAULT_MII_ADDR:
wdenk9c53f402003-10-15 23:53:47 +00001525 MII address of the PHY to check for the Ethernet link state.
wdenkc6097192002-11-03 00:24:07 +00001526
Simon Glass28a9e332012-11-30 13:01:18 +00001527- CONFIG_DISPLAY_BOARDINFO
1528 Display information about the board that U-Boot is running on
1529 when U-Boot starts up. The board function checkboard() is called
1530 to do this.
1531
Simon Glasse8822012012-11-30 13:01:19 +00001532- CONFIG_DISPLAY_BOARDINFO_LATE
1533 Similar to the previous option, but display this information
1534 later, once stdio is running and output goes to the LCD, if
1535 present.
1536
wdenkc6097192002-11-03 00:24:07 +00001537Low Level (hardware related) configuration options:
wdenkc8434db2003-03-26 06:55:25 +00001538---------------------------------------------------
wdenkc6097192002-11-03 00:24:07 +00001539
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001540- CONFIG_SYS_CACHELINE_SIZE:
wdenkc6097192002-11-03 00:24:07 +00001541 Cache Line Size of the CPU.
1542
Timur Tabid8f341c2011-08-04 18:03:41 -05001543- CONFIG_SYS_CCSRBAR_DEFAULT:
1544 Default (power-on reset) physical address of CCSR on Freescale
1545 PowerPC SOCs.
1546
Tom Rini6a5dccc2022-11-16 13:10:41 -05001547- CFG_SYS_CCSRBAR:
Timur Tabid8f341c2011-08-04 18:03:41 -05001548 Virtual address of CCSR. On a 32-bit build, this is typically
1549 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
1550
Tom Rini6a5dccc2022-11-16 13:10:41 -05001551- CFG_SYS_CCSRBAR_PHYS:
Timur Tabid8f341c2011-08-04 18:03:41 -05001552 Physical address of CCSR. CCSR can be relocated to a new
1553 physical address, if desired. In this case, this macro should
Wolfgang Denk092ae952011-10-26 10:21:21 +00001554 be set to that address. Otherwise, it should be set to the
Timur Tabid8f341c2011-08-04 18:03:41 -05001555 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
1556 is typically relocated on 36-bit builds. It is recommended
1557 that this macro be defined via the _HIGH and _LOW macros:
1558
Tom Rini6a5dccc2022-11-16 13:10:41 -05001559 #define CFG_SYS_CCSRBAR_PHYS ((CFG_SYS_CCSRBAR_PHYS_HIGH
1560 * 1ull) << 32 | CFG_SYS_CCSRBAR_PHYS_LOW)
Timur Tabid8f341c2011-08-04 18:03:41 -05001561
Tom Rini6a5dccc2022-11-16 13:10:41 -05001562- CFG_SYS_CCSRBAR_PHYS_HIGH:
1563 Bits 33-36 of CFG_SYS_CCSRBAR_PHYS. This value is typically
Wolfgang Denkd590fb12011-10-07 09:58:21 +02001564 either 0 (32-bit build) or 0xF (36-bit build). This macro is
Timur Tabid8f341c2011-08-04 18:03:41 -05001565 used in assembly code, so it must not contain typecasts or
1566 integer size suffixes (e.g. "ULL").
1567
Tom Rini6a5dccc2022-11-16 13:10:41 -05001568- CFG_SYS_CCSRBAR_PHYS_LOW:
1569 Lower 32-bits of CFG_SYS_CCSRBAR_PHYS. This macro is
Timur Tabid8f341c2011-08-04 18:03:41 -05001570 used in assembly code, so it must not contain typecasts or
1571 integer size suffixes (e.g. "ULL").
1572
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001573- CONFIG_SYS_IMMR: Physical address of the Internal Memory.
wdenk07d7e6b2004-12-16 21:44:03 +00001574 DO NOT CHANGE unless you know exactly what you're
Christophe Leroy069fa832017-07-06 10:23:22 +02001575 doing! (11-4) [MPC8xx systems only]
wdenkc6097192002-11-03 00:24:07 +00001576
Tom Rini6a5dccc2022-11-16 13:10:41 -05001577- CFG_SYS_INIT_RAM_ADDR:
wdenkc6097192002-11-03 00:24:07 +00001578
wdenkeb20ad32003-09-05 23:19:14 +00001579 Start address of memory area that can be used for
wdenkc6097192002-11-03 00:24:07 +00001580 initial data and stack; please note that this must be
1581 writable memory that is working WITHOUT special
1582 initialization, i. e. you CANNOT use normal RAM which
1583 will become available only after programming the
1584 memory controller and running certain initialization
1585 sequences.
1586
1587 U-Boot uses the following memory types:
Christophe Leroy069fa832017-07-06 10:23:22 +02001588 - MPC8xx: IMMR (internal memory of the CPU)
wdenkc6097192002-11-03 00:24:07 +00001589
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001590- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
wdenkc6097192002-11-03 00:24:07 +00001591
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001592- CONFIG_SYS_OR_TIMING_SDRAM:
wdenkc6097192002-11-03 00:24:07 +00001593 SDRAM timing
1594
Kumar Gala8975d7a2010-12-30 12:09:53 -06001595- CONFIG_SYS_SRIOn_MEM_VIRT:
1596 Virtual Address of SRIO port 'n' memory region
1597
Simon Glass970b61e2019-11-14 12:57:09 -07001598- CONFIG_SYS_SRIOn_MEM_PHYxS:
Kumar Gala8975d7a2010-12-30 12:09:53 -06001599 Physical Address of SRIO port 'n' memory region
1600
1601- CONFIG_SYS_SRIOn_MEM_SIZE:
1602 Size of SRIO port 'n' memory region
1603
Fabio Estevamf17e8782013-04-11 09:35:34 +00001604- CONFIG_SYS_NAND_BUSWIDTH_16BIT
1605 Defined to tell the NAND controller that the NAND chip is using
1606 a 16 bit bus.
1607 Not all NAND drivers use this symbol.
Fabio Estevam417052b2013-04-11 09:35:35 +00001608 Example of drivers that use it:
Miquel Raynal1f1ae152018-08-16 17:30:07 +02001609 - drivers/mtd/nand/raw/ndfc.c
1610 - drivers/mtd/nand/raw/mxc_nand.c
Alex Watermancd6aae32011-05-19 15:08:36 -04001611
1612- CONFIG_SYS_NDFC_EBC0_CFG
1613 Sets the EBC0_CFG register for the NDFC. If not defined
1614 a default value will be used.
1615
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001616- CONFIG_SYS_SPD_BUS_NUM
Wolfgang Denkb240aef2008-03-26 10:40:12 +01001617 If SPD EEPROM is on an I2C bus other than the first
1618 one, specify here. Note that the value must resolve
1619 to something your driver can deal with.
Ben Warren45657152006-09-07 16:50:54 -04001620
York Sunbd495cf2011-09-16 13:21:35 -07001621- CONFIG_FSL_DDR_INTERACTIVE
1622 Enable interactive DDR debugging. See doc/README.fsl-ddr.
1623
York Sun8ced0502015-01-06 13:18:55 -08001624- CONFIG_FSL_DDR_SYNC_REFRESH
1625 Enable sync of refresh for multiple controllers.
1626
York Sunb6a35f82015-03-19 09:30:28 -07001627- CONFIG_FSL_DDR_BIST
1628 Enable built-in memory test for Freescale DDR controllers.
1629
wdenk6203e402004-04-18 10:13:26 +00001630- CONFIG_RMII
1631 Enable RMII mode for all FECs.
1632 Note that this is a global option, we can't
1633 have one FEC in standard MII mode and another in RMII mode.
1634
wdenk20c98a62004-04-23 20:32:05 +00001635- CONFIG_CRC32_VERIFY
1636 Add a verify option to the crc32 command.
1637 The syntax is:
1638
1639 => crc32 -v <address> <count> <crc32>
1640
1641 Where address/count indicate a memory area
1642 and crc32 is the correct crc32 which the
1643 area should have.
1644
wdenk64519362004-07-11 17:40:54 +00001645- CONFIG_LOOPW
1646 Add the "loopw" memory command. This only takes effect if
Simon Glass92ffdee2017-08-04 16:34:27 -06001647 the memory commands are activated globally (CONFIG_CMD_MEMORY).
wdenk64519362004-07-11 17:40:54 +00001648
Joel Johnsondb5a97e2020-01-29 09:17:18 -07001649- CONFIG_CMD_MX_CYCLIC
stroesecc3af832004-12-16 18:46:55 +00001650 Add the "mdc" and "mwc" memory commands. These are cyclic
1651 "md/mw" commands.
1652 Examples:
1653
wdenk07d7e6b2004-12-16 21:44:03 +00001654 => mdc.b 10 4 500
stroesecc3af832004-12-16 18:46:55 +00001655 This command will print 4 bytes (10,11,12,13) each 500 ms.
1656
wdenk07d7e6b2004-12-16 21:44:03 +00001657 => mwc.l 100 12345678 10
stroesecc3af832004-12-16 18:46:55 +00001658 This command will write 12345678 to address 100 all 10 ms.
1659
wdenk07d7e6b2004-12-16 21:44:03 +00001660 This only takes effect if the memory commands are activated
Simon Glass92ffdee2017-08-04 16:34:27 -06001661 globally (CONFIG_CMD_MEMORY).
stroesecc3af832004-12-16 18:46:55 +00001662
Aneesh V552a3192011-07-13 05:11:07 +00001663- CONFIG_SPL_BUILD
Thomas Hebbfd37f242019-11-13 18:18:03 -08001664 Set when the currently-running compilation is for an artifact
1665 that will end up in the SPL (as opposed to the TPL or U-Boot
1666 proper). Code that needs stage-specific behavior should check
1667 this.
wdenk336b2bc2005-04-02 23:52:25 +00001668
Ying Zhang2d2e3b62013-08-16 15:16:15 +08001669- CONFIG_TPL_BUILD
Thomas Hebbfd37f242019-11-13 18:18:03 -08001670 Set when the currently-running compilation is for an artifact
1671 that will end up in the TPL (as opposed to the SPL or U-Boot
1672 proper). Code that needs stage-specific behavior should check
1673 this.
Ying Zhang2d2e3b62013-08-16 15:16:15 +08001674
Simon Glass17dabf02013-02-24 17:33:14 +00001675- CONFIG_ARCH_MAP_SYSMEM
1676 Generally U-Boot (and in particular the md command) uses
1677 effective address. It is therefore not necessary to regard
1678 U-Boot address as virtual addresses that need to be translated
1679 to physical addresses. However, sandbox requires this, since
1680 it maintains its own little RAM buffer which contains all
1681 addressable memory. This option causes some memory accesses
1682 to be mapped through map_sysmem() / unmap_sysmem().
1683
Simon Glassbfb59802013-02-14 04:18:54 +00001684- CONFIG_X86_RESET_VECTOR
1685 If defined, the x86 reset vector code is included. This is not
1686 needed when U-Boot is running from Coreboot.
Gabe Black14f82462012-11-27 21:08:06 +00001687
Timur Tabi275f4bb2011-11-22 09:21:25 -06001688Freescale QE/FMAN Firmware Support:
1689-----------------------------------
1690
1691The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
1692loading of "firmware", which is encoded in the QE firmware binary format.
1693This firmware often needs to be loaded during U-Boot booting, so macros
1694are used to identify the storage device (NOR flash, SPI, etc) and the address
1695within that device.
1696
Zhao Qiang83a90842014-03-21 16:21:44 +08001697- CONFIG_SYS_FMAN_FW_ADDR
1698 The address in the storage device where the FMAN microcode is located. The
Tom Rinifa911f82019-05-12 07:59:12 -04001699 meaning of this address depends on which CONFIG_SYS_QE_FMAN_FW_IN_xxx macro
Zhao Qiang83a90842014-03-21 16:21:44 +08001700 is also specified.
1701
1702- CONFIG_SYS_QE_FW_ADDR
1703 The address in the storage device where the QE microcode is located. The
Tom Rinifa911f82019-05-12 07:59:12 -04001704 meaning of this address depends on which CONFIG_SYS_QE_FMAN_FW_IN_xxx macro
Timur Tabi275f4bb2011-11-22 09:21:25 -06001705 is also specified.
1706
1707- CONFIG_SYS_QE_FMAN_FW_LENGTH
1708 The maximum possible size of the firmware. The firmware binary format
1709 has a field that specifies the actual size of the firmware, but it
1710 might not be possible to read any part of the firmware unless some
1711 local storage is allocated to hold the entire firmware first.
1712
1713- CONFIG_SYS_QE_FMAN_FW_IN_NOR
1714 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
1715 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
1716 virtual address in NOR flash.
1717
1718- CONFIG_SYS_QE_FMAN_FW_IN_NAND
1719 Specifies that QE/FMAN firmware is located in NAND flash.
1720 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
1721
1722- CONFIG_SYS_QE_FMAN_FW_IN_MMC
1723 Specifies that QE/FMAN firmware is located on the primary SD/MMC
1724 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
1725
Liu Gang1e084582012-03-08 00:33:18 +00001726- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
1727 Specifies that QE/FMAN firmware is located in the remote (master)
1728 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
Liu Gang357bf5a2012-08-09 05:10:01 +00001729 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
1730 window->master inbound window->master LAW->the ucode address in
1731 master's memory space.
Timur Tabi275f4bb2011-11-22 09:21:25 -06001732
J. German Rivera8ff14b72014-06-23 15:15:55 -07001733Freescale Layerscape Management Complex Firmware Support:
1734---------------------------------------------------------
1735The Freescale Layerscape Management Complex (MC) supports the loading of
1736"firmware".
1737This firmware often needs to be loaded during U-Boot booting, so macros
1738are used to identify the storage device (NOR flash, SPI, etc) and the address
1739within that device.
1740
1741- CONFIG_FSL_MC_ENET
1742 Enable the MC driver for Layerscape SoCs.
1743
Prabhakar Kushwaha853a9012015-06-02 10:55:52 +05301744Freescale Layerscape Debug Server Support:
1745-------------------------------------------
1746The Freescale Layerscape Debug Server Support supports the loading of
1747"Debug Server firmware" and triggering SP boot-rom.
1748This firmware often needs to be loaded during U-Boot booting.
1749
York Sun928b6812015-12-07 11:08:58 -08001750- CONFIG_SYS_MC_RSV_MEM_ALIGN
1751 Define alignment of reserved memory MC requires
Prabhakar Kushwaha853a9012015-06-02 10:55:52 +05301752
Paul Kocialkowski7b917022015-07-26 18:48:15 +02001753Reproducible builds
1754-------------------
1755
1756In order to achieve reproducible builds, timestamps used in the U-Boot build
1757process have to be set to a fixed value.
1758
1759This is done using the SOURCE_DATE_EPOCH environment variable.
1760SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
1761option for U-Boot or an environment variable in U-Boot.
1762
1763SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
1764
wdenkc6097192002-11-03 00:24:07 +00001765Building the Software:
1766======================
1767
Wolfgang Denkb240aef2008-03-26 10:40:12 +01001768Building U-Boot has been tested in several native build environments
1769and in many different cross environments. Of course we cannot support
1770all possibly existing versions of cross development tools in all
1771(potentially obsolete) versions. In case of tool chain problems we
Naoki Hayamae0cc1852020-10-08 13:17:16 +09001772recommend to use the ELDK (see https://www.denx.de/wiki/DULG/ELDK)
Wolfgang Denkb240aef2008-03-26 10:40:12 +01001773which is extensively used to build and test U-Boot.
wdenkc6097192002-11-03 00:24:07 +00001774
Wolfgang Denkb240aef2008-03-26 10:40:12 +01001775If you are not using a native environment, it is assumed that you
1776have GNU cross compiling tools available in your path. In this case,
1777you must set the environment variable CROSS_COMPILE in your shell.
1778Note that no changes to the Makefile or any other source files are
1779necessary. For example using the ELDK on a 4xx CPU, please enter:
wdenkc6097192002-11-03 00:24:07 +00001780
Wolfgang Denkb240aef2008-03-26 10:40:12 +01001781 $ CROSS_COMPILE=ppc_4xx-
1782 $ export CROSS_COMPILE
wdenkc6097192002-11-03 00:24:07 +00001783
Wolfgang Denkb240aef2008-03-26 10:40:12 +01001784U-Boot is intended to be simple to build. After installing the
1785sources you must configure U-Boot for one specific board type. This
wdenkc6097192002-11-03 00:24:07 +00001786is done by typing:
1787
Holger Freyther7ba4e572014-08-04 09:26:05 +02001788 make NAME_defconfig
wdenkc6097192002-11-03 00:24:07 +00001789
Holger Freyther7ba4e572014-08-04 09:26:05 +02001790where "NAME_defconfig" is the name of one of the existing configu-
Heinrich Schuchardtd6e07af2020-02-24 18:36:30 +01001791rations; see configs/*_defconfig for supported names.
wdenk2f0812d2003-10-08 22:45:44 +00001792
Heinrich Schuchardtd6e07af2020-02-24 18:36:30 +01001793Note: for some boards special configuration names may exist; check if
wdenk6c59edc2004-05-03 20:45:30 +00001794 additional information is available from the board vendor; for
1795 instance, the TQM823L systems are available without (standard)
1796 or with LCD support. You can select such additional "features"
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001797 when choosing the configuration, i. e.
wdenkc6097192002-11-03 00:24:07 +00001798
Holger Freyther7ba4e572014-08-04 09:26:05 +02001799 make TQM823L_defconfig
wdenk6c59edc2004-05-03 20:45:30 +00001800 - will configure for a plain TQM823L, i. e. no LCD support
wdenkc6097192002-11-03 00:24:07 +00001801
Holger Freyther7ba4e572014-08-04 09:26:05 +02001802 make TQM823L_LCD_defconfig
wdenk6c59edc2004-05-03 20:45:30 +00001803 - will configure for a TQM823L with U-Boot console on LCD
wdenkc6097192002-11-03 00:24:07 +00001804
wdenk6c59edc2004-05-03 20:45:30 +00001805 etc.
wdenkc6097192002-11-03 00:24:07 +00001806
wdenkc6097192002-11-03 00:24:07 +00001807
wdenk6c59edc2004-05-03 20:45:30 +00001808Finally, type "make all", and you should get some working U-Boot
1809images ready for download to / installation on your system:
wdenkc6097192002-11-03 00:24:07 +00001810
wdenk6c59edc2004-05-03 20:45:30 +00001811- "u-boot.bin" is a raw binary image
1812- "u-boot" is an image in ELF binary format
1813- "u-boot.srec" is in Motorola S-Record format
wdenkc6097192002-11-03 00:24:07 +00001814
Marian Balakowiczefe063f2006-09-07 17:25:40 +02001815By default the build is performed locally and the objects are saved
1816in the source directory. One of the two methods can be used to change
1817this behavior and build U-Boot to some external directory:
1818
18191. Add O= to the make command line invocations:
1820
1821 make O=/tmp/build distclean
Holger Freyther7ba4e572014-08-04 09:26:05 +02001822 make O=/tmp/build NAME_defconfig
Marian Balakowiczefe063f2006-09-07 17:25:40 +02001823 make O=/tmp/build all
1824
Timo Ketolac8c67602014-11-06 14:39:05 +020018252. Set environment variable KBUILD_OUTPUT to point to the desired location:
Marian Balakowiczefe063f2006-09-07 17:25:40 +02001826
Timo Ketolac8c67602014-11-06 14:39:05 +02001827 export KBUILD_OUTPUT=/tmp/build
Marian Balakowiczefe063f2006-09-07 17:25:40 +02001828 make distclean
Holger Freyther7ba4e572014-08-04 09:26:05 +02001829 make NAME_defconfig
Marian Balakowiczefe063f2006-09-07 17:25:40 +02001830 make all
1831
Timo Ketolac8c67602014-11-06 14:39:05 +02001832Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
Marian Balakowiczefe063f2006-09-07 17:25:40 +02001833variable.
1834
Daniel Schwierzeck88484422018-01-26 16:31:04 +01001835User specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by
1836setting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS.
1837For example to treat all compiler warnings as errors:
1838
1839 make KCFLAGS=-Werror
wdenkc6097192002-11-03 00:24:07 +00001840
wdenk6c59edc2004-05-03 20:45:30 +00001841Please be aware that the Makefiles assume you are using GNU make, so
1842for instance on NetBSD you might need to use "gmake" instead of
1843native "make".
wdenkc6097192002-11-03 00:24:07 +00001844
wdenkc6097192002-11-03 00:24:07 +00001845
wdenk6c59edc2004-05-03 20:45:30 +00001846If the system board that you have is not listed, then you will need
1847to port U-Boot to your hardware platform. To do this, follow these
1848steps:
wdenkc6097192002-11-03 00:24:07 +00001849
Phil Sutterc77b4882015-12-25 14:41:18 +010018501. Create a new directory to hold your board specific code. Add any
wdenk6c59edc2004-05-03 20:45:30 +00001851 files you need. In your board directory, you will need at least
Phil Sutterc77b4882015-12-25 14:41:18 +01001852 the "Makefile" and a "<board>.c".
18532. Create a new configuration file "include/configs/<board>.h" for
1854 your board.
wdenk6c59edc2004-05-03 20:45:30 +000018553. If you're porting U-Boot to a new CPU, then also create a new
1856 directory to hold your CPU specific code. Add any files you need.
Holger Freyther7ba4e572014-08-04 09:26:05 +020018574. Run "make <board>_defconfig" with your new name.
wdenk6c59edc2004-05-03 20:45:30 +000018585. Type "make", and you should get a working "u-boot.srec" file
1859 to be installed on your target system.
18606. Debug and solve any problems that might arise.
1861 [Of course, this last step is much harder than it sounds.]
wdenkc6097192002-11-03 00:24:07 +00001862
wdenkc6097192002-11-03 00:24:07 +00001863
wdenk6c59edc2004-05-03 20:45:30 +00001864Testing of U-Boot Modifications, Ports to New Hardware, etc.:
1865==============================================================
wdenkc6097192002-11-03 00:24:07 +00001866
Wolfgang Denkb240aef2008-03-26 10:40:12 +01001867If you have modified U-Boot sources (for instance added a new board
1868or support for new devices, a new CPU, etc.) you are expected to
wdenk6c59edc2004-05-03 20:45:30 +00001869provide feedback to the other developers. The feedback normally takes
Thomas Hebbfd37f242019-11-13 18:18:03 -08001870the form of a "patch", i.e. a context diff against a certain (latest
Wolfgang Denkb240aef2008-03-26 10:40:12 +01001871official or latest in the git repository) version of U-Boot sources.
wdenkc6097192002-11-03 00:24:07 +00001872
Wolfgang Denkb240aef2008-03-26 10:40:12 +01001873But before you submit such a patch, please verify that your modifi-
1874cation did not break existing code. At least make sure that *ALL* of
wdenk6c59edc2004-05-03 20:45:30 +00001875the supported boards compile WITHOUT ANY compiler warnings. To do so,
Simon Glassdc27def2016-07-27 20:33:08 -06001876just run the buildman script (tools/buildman/buildman), which will
1877configure and build U-Boot for ALL supported system. Be warned, this
1878will take a while. Please see the buildman README, or run 'buildman -H'
1879for documentation.
wdenkc6097192002-11-03 00:24:07 +00001880
Marian Balakowiczefe063f2006-09-07 17:25:40 +02001881
wdenk6c59edc2004-05-03 20:45:30 +00001882See also "U-Boot Porting Guide" below.
wdenkc6097192002-11-03 00:24:07 +00001883
wdenkc6097192002-11-03 00:24:07 +00001884
wdenk6c59edc2004-05-03 20:45:30 +00001885Monitor Commands - Overview:
1886============================
wdenkc6097192002-11-03 00:24:07 +00001887
wdenk6c59edc2004-05-03 20:45:30 +00001888go - start application at address 'addr'
1889run - run commands in an environment variable
1890bootm - boot application image from memory
1891bootp - boot image via network using BootP/TFTP protocol
Marek Vasutcf41a9b2012-03-14 21:52:45 +00001892bootz - boot zImage from memory
wdenk6c59edc2004-05-03 20:45:30 +00001893tftpboot- boot image via network using TFTP protocol
1894 and env variables "ipaddr" and "serverip"
1895 (and eventually "gatewayip")
Simon Glass6a398d22011-10-24 18:00:07 +00001896tftpput - upload a file via network using TFTP protocol
wdenk6c59edc2004-05-03 20:45:30 +00001897rarpboot- boot image via network using RARP/TFTP protocol
1898diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
1899loads - load S-Record file over serial line
1900loadb - load binary file over serial line (kermit mode)
Rui Miguel Silva433f15a2022-05-11 10:55:40 +01001901loadm - load binary blob from source address to destination address
wdenk6c59edc2004-05-03 20:45:30 +00001902md - memory display
1903mm - memory modify (auto-incrementing)
1904nm - memory modify (constant address)
1905mw - memory write (fill)
Simon Glass19038de2020-06-02 19:26:49 -06001906ms - memory search
wdenk6c59edc2004-05-03 20:45:30 +00001907cp - memory copy
1908cmp - memory compare
1909crc32 - checksum calculation
Peter Tyser469cde42009-04-18 22:34:03 -05001910i2c - I2C sub-system
wdenk6c59edc2004-05-03 20:45:30 +00001911sspi - SPI utility commands
1912base - print or set address offset
1913printenv- print environment variables
Pragnesh Patel1d5955f2020-12-22 11:30:05 +05301914pwm - control pwm channels
wdenk6c59edc2004-05-03 20:45:30 +00001915setenv - set environment variables
1916saveenv - save environment variables to persistent storage
1917protect - enable or disable FLASH write protection
1918erase - erase FLASH memory
1919flinfo - print FLASH memory information
Karl O. Pinc4baf03d2012-08-03 05:57:21 +00001920nand - NAND memory operations (see doc/README.nand)
wdenk6c59edc2004-05-03 20:45:30 +00001921bdinfo - print Board Info structure
1922iminfo - print header information for application image
1923coninfo - print console devices and informations
1924ide - IDE sub-system
1925loop - infinite loop on address range
wdenk64519362004-07-11 17:40:54 +00001926loopw - infinite write loop on address range
wdenk6c59edc2004-05-03 20:45:30 +00001927mtest - simple RAM test
1928icache - enable or disable instruction cache
1929dcache - enable or disable data cache
1930reset - Perform RESET of the CPU
1931echo - echo args to console
1932version - print monitor version
1933help - print online help
1934? - alias for 'help'
wdenkc6097192002-11-03 00:24:07 +00001935
wdenkc6097192002-11-03 00:24:07 +00001936
wdenk6c59edc2004-05-03 20:45:30 +00001937Monitor Commands - Detailed Description:
1938========================================
wdenkc6097192002-11-03 00:24:07 +00001939
wdenk6c59edc2004-05-03 20:45:30 +00001940TODO.
wdenkc6097192002-11-03 00:24:07 +00001941
wdenk6c59edc2004-05-03 20:45:30 +00001942For now: just type "help <command>".
wdenkc6097192002-11-03 00:24:07 +00001943
1944
wdenk6c59edc2004-05-03 20:45:30 +00001945Note for Redundant Ethernet Interfaces:
1946=======================================
wdenkf4688a22003-05-28 08:06:31 +00001947
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001948Some boards come with redundant Ethernet interfaces; U-Boot supports
wdenk6c59edc2004-05-03 20:45:30 +00001949such configurations and is capable of automatic selection of a
1950"working" interface when needed. MAC assignment works as follows:
wdenkf4688a22003-05-28 08:06:31 +00001951
wdenk6c59edc2004-05-03 20:45:30 +00001952Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
1953MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
1954"eth1addr" (=>eth1), "eth2addr", ...
wdenkf4688a22003-05-28 08:06:31 +00001955
wdenk6c59edc2004-05-03 20:45:30 +00001956If the network interface stores some valid MAC address (for instance
1957in SROM), this is used as default address if there is NO correspon-
1958ding setting in the environment; if the corresponding environment
1959variable is set, this overrides the settings in the card; that means:
wdenkf4688a22003-05-28 08:06:31 +00001960
wdenk6c59edc2004-05-03 20:45:30 +00001961o If the SROM has a valid MAC address, and there is no address in the
1962 environment, the SROM's address is used.
wdenkc6097192002-11-03 00:24:07 +00001963
wdenk6c59edc2004-05-03 20:45:30 +00001964o If there is no valid address in the SROM, and a definition in the
1965 environment exists, then the value from the environment variable is
1966 used.
wdenkc6097192002-11-03 00:24:07 +00001967
wdenk6c59edc2004-05-03 20:45:30 +00001968o If both the SROM and the environment contain a MAC address, and
1969 both addresses are the same, this MAC address is used.
wdenkc6097192002-11-03 00:24:07 +00001970
wdenk6c59edc2004-05-03 20:45:30 +00001971o If both the SROM and the environment contain a MAC address, and the
1972 addresses differ, the value from the environment is used and a
1973 warning is printed.
wdenkc6097192002-11-03 00:24:07 +00001974
wdenk6c59edc2004-05-03 20:45:30 +00001975o If neither SROM nor the environment contain a MAC address, an error
Joe Hershberger2dc2b5d2015-05-04 14:55:13 -05001976 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
1977 a random, locally-assigned MAC is used.
wdenkc6097192002-11-03 00:24:07 +00001978
Ben Warren6db991a2010-04-26 11:11:46 -07001979If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
Wolfgang Denk092ae952011-10-26 10:21:21 +00001980will be programmed into hardware as part of the initialization process. This
Ben Warren6db991a2010-04-26 11:11:46 -07001981may be skipped by setting the appropriate 'ethmacskip' environment variable.
1982The naming convention is as follows:
1983"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
wdenkc6097192002-11-03 00:24:07 +00001984
wdenk6c59edc2004-05-03 20:45:30 +00001985Image Formats:
1986==============
wdenkc6097192002-11-03 00:24:07 +00001987
Marian Balakowicz18710b82008-03-12 12:13:13 +01001988U-Boot is capable of booting (and performing other auxiliary operations on)
1989images in two formats:
1990
1991New uImage format (FIT)
1992-----------------------
1993
1994Flexible and powerful format based on Flattened Image Tree -- FIT (similar
1995to Flattened Device Tree). It allows the use of images with multiple
1996components (several kernels, ramdisks, etc.), with contents protected by
1997SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
1998
1999
2000Old uImage format
2001-----------------
2002
2003Old image format is based on binary files which can be basically anything,
2004preceded by a special header; see the definitions in include/image.h for
2005details; basically, the header defines the following image properties:
wdenkc6097192002-11-03 00:24:07 +00002006
wdenk6c59edc2004-05-03 20:45:30 +00002007* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2008 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
Peter Tyser56b8dd12008-09-08 14:56:49 -05002009 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
Thomas Huthc90d56a2021-11-13 18:13:50 +01002010 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, INTEGRITY).
Andy Shevchenko8cb5cdd2017-07-05 16:25:22 +03002011* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
Tom Rini53320122022-04-06 09:21:25 -04002012 IA64, MIPS, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2013 Currently supported: ARM, Intel x86, MIPS, Nios II, PowerPC).
wdenk6c59edc2004-05-03 20:45:30 +00002014* Compression Type (uncompressed, gzip, bzip2)
2015* Load Address
2016* Entry Point
2017* Image Name
2018* Image Timestamp
wdenkc6097192002-11-03 00:24:07 +00002019
wdenk6c59edc2004-05-03 20:45:30 +00002020The header is marked by a special Magic Number, and both the header
2021and the data portions of the image are secured against corruption by
2022CRC32 checksums.
wdenkc6097192002-11-03 00:24:07 +00002023
wdenkc6097192002-11-03 00:24:07 +00002024
wdenk6c59edc2004-05-03 20:45:30 +00002025Linux Support:
2026==============
wdenkc6097192002-11-03 00:24:07 +00002027
wdenk6c59edc2004-05-03 20:45:30 +00002028Although U-Boot should support any OS or standalone application
2029easily, the main focus has always been on Linux during the design of
2030U-Boot.
wdenkc6097192002-11-03 00:24:07 +00002031
wdenk6c59edc2004-05-03 20:45:30 +00002032U-Boot includes many features that so far have been part of some
2033special "boot loader" code within the Linux kernel. Also, any
2034"initrd" images to be used are no longer part of one big Linux image;
2035instead, kernel and "initrd" are separate images. This implementation
2036serves several purposes:
wdenkc6097192002-11-03 00:24:07 +00002037
wdenk6c59edc2004-05-03 20:45:30 +00002038- the same features can be used for other OS or standalone
2039 applications (for instance: using compressed images to reduce the
2040 Flash memory footprint)
wdenkc6097192002-11-03 00:24:07 +00002041
wdenk6c59edc2004-05-03 20:45:30 +00002042- it becomes much easier to port new Linux kernel versions because
2043 lots of low-level, hardware dependent stuff are done by U-Boot
wdenkc6097192002-11-03 00:24:07 +00002044
wdenk6c59edc2004-05-03 20:45:30 +00002045- the same Linux kernel image can now be used with different "initrd"
2046 images; of course this also means that different kernel images can
2047 be run with the same "initrd". This makes testing easier (you don't
2048 have to build a new "zImage.initrd" Linux image when you just
2049 change a file in your "initrd"). Also, a field-upgrade of the
2050 software is easier now.
wdenkc6097192002-11-03 00:24:07 +00002051
wdenkc6097192002-11-03 00:24:07 +00002052
wdenk6c59edc2004-05-03 20:45:30 +00002053Linux HOWTO:
2054============
wdenkc6097192002-11-03 00:24:07 +00002055
wdenk6c59edc2004-05-03 20:45:30 +00002056Porting Linux to U-Boot based systems:
2057---------------------------------------
wdenkc6097192002-11-03 00:24:07 +00002058
wdenk6c59edc2004-05-03 20:45:30 +00002059U-Boot cannot save you from doing all the necessary modifications to
2060configure the Linux device drivers for use with your target hardware
2061(no, we don't intend to provide a full virtual machine interface to
2062Linux :-).
wdenkc6097192002-11-03 00:24:07 +00002063
Stefan Roese88fbf932010-04-15 16:07:28 +02002064But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
wdenkc6097192002-11-03 00:24:07 +00002065
wdenk6c59edc2004-05-03 20:45:30 +00002066Just make sure your machine specific header file (for instance
2067include/asm-ppc/tqm8xx.h) includes the same definition of the Board
Markus Heidelberg47167572008-09-07 20:18:27 +02002068Information structure as we define in include/asm-<arch>/u-boot.h,
2069and make sure that your definition of IMAP_ADDR uses the same value
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02002070as your U-Boot configuration in CONFIG_SYS_IMMR.
wdenkc6097192002-11-03 00:24:07 +00002071
Simon Glassd097e592014-06-11 23:29:46 -06002072Note that U-Boot now has a driver model, a unified model for drivers.
2073If you are adding a new driver, plumb it into driver model. If there
2074is no uclass available, you are encouraged to create one. See
2075doc/driver-model.
2076
wdenkc6097192002-11-03 00:24:07 +00002077
wdenk6c59edc2004-05-03 20:45:30 +00002078Configuring the Linux kernel:
2079-----------------------------
wdenkc6097192002-11-03 00:24:07 +00002080
wdenk6c59edc2004-05-03 20:45:30 +00002081No specific requirements for U-Boot. Make sure you have some root
2082device (initial ramdisk, NFS) for your target system.
wdenkc6097192002-11-03 00:24:07 +00002083
wdenkc6097192002-11-03 00:24:07 +00002084
wdenk6c59edc2004-05-03 20:45:30 +00002085Building a Linux Image:
2086-----------------------
wdenkc6097192002-11-03 00:24:07 +00002087
wdenk6c59edc2004-05-03 20:45:30 +00002088With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2089not used. If you use recent kernel source, a new build target
2090"uImage" will exist which automatically builds an image usable by
2091U-Boot. Most older kernels also have support for a "pImage" target,
2092which was introduced for our predecessor project PPCBoot and uses a
2093100% compatible format.
wdenkc6097192002-11-03 00:24:07 +00002094
wdenk6c59edc2004-05-03 20:45:30 +00002095Example:
wdenkc6097192002-11-03 00:24:07 +00002096
Holger Freyther7ba4e572014-08-04 09:26:05 +02002097 make TQM850L_defconfig
wdenk6c59edc2004-05-03 20:45:30 +00002098 make oldconfig
2099 make dep
2100 make uImage
wdenkc6097192002-11-03 00:24:07 +00002101
wdenk6c59edc2004-05-03 20:45:30 +00002102The "uImage" build target uses a special tool (in 'tools/mkimage') to
2103encapsulate a compressed Linux kernel image with header information,
2104CRC32 checksum etc. for use with U-Boot. This is what we are doing:
wdenkc6097192002-11-03 00:24:07 +00002105
wdenk6c59edc2004-05-03 20:45:30 +00002106* build a standard "vmlinux" kernel image (in ELF binary format):
wdenkc6097192002-11-03 00:24:07 +00002107
wdenk6c59edc2004-05-03 20:45:30 +00002108* convert the kernel into a raw binary image:
wdenkc6097192002-11-03 00:24:07 +00002109
wdenk6c59edc2004-05-03 20:45:30 +00002110 ${CROSS_COMPILE}-objcopy -O binary \
2111 -R .note -R .comment \
2112 -S vmlinux linux.bin
wdenk24ee89b2002-11-03 17:56:27 +00002113
wdenk6c59edc2004-05-03 20:45:30 +00002114* compress the binary image:
wdenk24ee89b2002-11-03 17:56:27 +00002115
wdenk6c59edc2004-05-03 20:45:30 +00002116 gzip -9 linux.bin
wdenk24ee89b2002-11-03 17:56:27 +00002117
wdenk6c59edc2004-05-03 20:45:30 +00002118* package compressed binary image for U-Boot:
wdenk24ee89b2002-11-03 17:56:27 +00002119
wdenk6c59edc2004-05-03 20:45:30 +00002120 mkimage -A ppc -O linux -T kernel -C gzip \
2121 -a 0 -e 0 -n "Linux Kernel Image" \
2122 -d linux.bin.gz uImage
wdenkc6097192002-11-03 00:24:07 +00002123
wdenkc6097192002-11-03 00:24:07 +00002124
wdenk6c59edc2004-05-03 20:45:30 +00002125The "mkimage" tool can also be used to create ramdisk images for use
2126with U-Boot, either separated from the Linux kernel image, or
2127combined into one file. "mkimage" encapsulates the images with a 64
2128byte header containing information about target architecture,
2129operating system, image type, compression method, entry points, time
2130stamp, CRC32 checksums, etc.
wdenkc6097192002-11-03 00:24:07 +00002131
wdenk6c59edc2004-05-03 20:45:30 +00002132"mkimage" can be called in two ways: to verify existing images and
2133print the header information, or to build new images.
wdenk24ee89b2002-11-03 17:56:27 +00002134
wdenk6c59edc2004-05-03 20:45:30 +00002135In the first form (with "-l" option) mkimage lists the information
2136contained in the header of an existing U-Boot image; this includes
2137checksum verification:
wdenk24ee89b2002-11-03 17:56:27 +00002138
wdenk6c59edc2004-05-03 20:45:30 +00002139 tools/mkimage -l image
2140 -l ==> list image header information
wdenk24ee89b2002-11-03 17:56:27 +00002141
wdenk6c59edc2004-05-03 20:45:30 +00002142The second form (with "-d" option) is used to build a U-Boot image
2143from a "data file" which is used as image payload:
wdenk24ee89b2002-11-03 17:56:27 +00002144
wdenk6c59edc2004-05-03 20:45:30 +00002145 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2146 -n name -d data_file image
2147 -A ==> set architecture to 'arch'
2148 -O ==> set operating system to 'os'
2149 -T ==> set image type to 'type'
2150 -C ==> set compression type 'comp'
2151 -a ==> set load address to 'addr' (hex)
2152 -e ==> set entry point to 'ep' (hex)
2153 -n ==> set image name to 'name'
2154 -d ==> use image data from 'datafile'
wdenk24ee89b2002-11-03 17:56:27 +00002155
wdenkcd914452004-05-29 16:53:29 +00002156Right now, all Linux kernels for PowerPC systems use the same load
2157address (0x00000000), but the entry point address depends on the
2158kernel version:
wdenkc6097192002-11-03 00:24:07 +00002159
wdenk6c59edc2004-05-03 20:45:30 +00002160- 2.2.x kernels have the entry point at 0x0000000C,
2161- 2.3.x and later kernels have the entry point at 0x00000000.
wdenkc6097192002-11-03 00:24:07 +00002162
wdenk6c59edc2004-05-03 20:45:30 +00002163So a typical call to build a U-Boot image would read:
wdenkc6097192002-11-03 00:24:07 +00002164
wdenk6c59edc2004-05-03 20:45:30 +00002165 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2166 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
Stefan Roese88fbf932010-04-15 16:07:28 +02002167 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
wdenk6c59edc2004-05-03 20:45:30 +00002168 > examples/uImage.TQM850L
2169 Image Name: 2.4.4 kernel for TQM850L
2170 Created: Wed Jul 19 02:34:59 2000
2171 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2172 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2173 Load Address: 0x00000000
2174 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002175
wdenk6c59edc2004-05-03 20:45:30 +00002176To verify the contents of the image (or check for corruption):
wdenkc6097192002-11-03 00:24:07 +00002177
wdenk6c59edc2004-05-03 20:45:30 +00002178 -> tools/mkimage -l examples/uImage.TQM850L
2179 Image Name: 2.4.4 kernel for TQM850L
2180 Created: Wed Jul 19 02:34:59 2000
2181 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2182 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2183 Load Address: 0x00000000
2184 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002185
wdenk6c59edc2004-05-03 20:45:30 +00002186NOTE: for embedded systems where boot time is critical you can trade
2187speed for memory and install an UNCOMPRESSED image instead: this
2188needs more space in Flash, but boots much faster since it does not
2189need to be uncompressed:
wdenkc6097192002-11-03 00:24:07 +00002190
Stefan Roese88fbf932010-04-15 16:07:28 +02002191 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
wdenk6c59edc2004-05-03 20:45:30 +00002192 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2193 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
Stefan Roese88fbf932010-04-15 16:07:28 +02002194 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
wdenk6c59edc2004-05-03 20:45:30 +00002195 > examples/uImage.TQM850L-uncompressed
2196 Image Name: 2.4.4 kernel for TQM850L
2197 Created: Wed Jul 19 02:34:59 2000
2198 Image Type: PowerPC Linux Kernel Image (uncompressed)
2199 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
2200 Load Address: 0x00000000
2201 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002202
wdenkc6097192002-11-03 00:24:07 +00002203
wdenk6c59edc2004-05-03 20:45:30 +00002204Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2205when your kernel is intended to use an initial ramdisk:
wdenkc6097192002-11-03 00:24:07 +00002206
wdenk6c59edc2004-05-03 20:45:30 +00002207 -> tools/mkimage -n 'Simple Ramdisk Image' \
2208 > -A ppc -O linux -T ramdisk -C gzip \
2209 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2210 Image Name: Simple Ramdisk Image
2211 Created: Wed Jan 12 14:01:50 2000
2212 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2213 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
2214 Load Address: 0x00000000
2215 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002216
Tyler Hicks791c7472020-10-26 10:40:24 -05002217The "dumpimage" tool can be used to disassemble or list the contents of images
2218built by mkimage. See dumpimage's help output (-h) for details.
wdenkc6097192002-11-03 00:24:07 +00002219
wdenk6c59edc2004-05-03 20:45:30 +00002220Installing a Linux Image:
2221-------------------------
wdenkc6097192002-11-03 00:24:07 +00002222
wdenk6c59edc2004-05-03 20:45:30 +00002223To downloading a U-Boot image over the serial (console) interface,
2224you must convert the image to S-Record format:
wdenkc6097192002-11-03 00:24:07 +00002225
wdenk6c59edc2004-05-03 20:45:30 +00002226 objcopy -I binary -O srec examples/image examples/image.srec
wdenkc6097192002-11-03 00:24:07 +00002227
wdenk6c59edc2004-05-03 20:45:30 +00002228The 'objcopy' does not understand the information in the U-Boot
2229image header, so the resulting S-Record file will be relative to
2230address 0x00000000. To load it to a given address, you need to
2231specify the target address as 'offset' parameter with the 'loads'
2232command.
wdenkc6097192002-11-03 00:24:07 +00002233
wdenk6c59edc2004-05-03 20:45:30 +00002234Example: install the image to address 0x40100000 (which on the
2235TQM8xxL is in the first Flash bank):
wdenkc6097192002-11-03 00:24:07 +00002236
wdenk6c59edc2004-05-03 20:45:30 +00002237 => erase 40100000 401FFFFF
wdenkc6097192002-11-03 00:24:07 +00002238
wdenk6c59edc2004-05-03 20:45:30 +00002239 .......... done
2240 Erased 8 sectors
wdenkc6097192002-11-03 00:24:07 +00002241
wdenk6c59edc2004-05-03 20:45:30 +00002242 => loads 40100000
2243 ## Ready for S-Record download ...
2244 ~>examples/image.srec
2245 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2246 ...
2247 15989 15990 15991 15992
2248 [file transfer complete]
2249 [connected]
2250 ## Start Addr = 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002251
wdenkc6097192002-11-03 00:24:07 +00002252
wdenk6c59edc2004-05-03 20:45:30 +00002253You can check the success of the download using the 'iminfo' command;
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002254this includes a checksum verification so you can be sure no data
wdenk6c59edc2004-05-03 20:45:30 +00002255corruption happened:
wdenkc6097192002-11-03 00:24:07 +00002256
wdenk6c59edc2004-05-03 20:45:30 +00002257 => imi 40100000
wdenkc6097192002-11-03 00:24:07 +00002258
wdenk6c59edc2004-05-03 20:45:30 +00002259 ## Checking Image at 40100000 ...
2260 Image Name: 2.2.13 for initrd on TQM850L
2261 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2262 Data Size: 335725 Bytes = 327 kB = 0 MB
2263 Load Address: 00000000
2264 Entry Point: 0000000c
2265 Verifying Checksum ... OK
wdenkc6097192002-11-03 00:24:07 +00002266
2267
wdenk6c59edc2004-05-03 20:45:30 +00002268Boot Linux:
2269-----------
wdenkc6097192002-11-03 00:24:07 +00002270
wdenk6c59edc2004-05-03 20:45:30 +00002271The "bootm" command is used to boot an application that is stored in
2272memory (RAM or Flash). In case of a Linux kernel image, the contents
2273of the "bootargs" environment variable is passed to the kernel as
2274parameters. You can check and modify this variable using the
2275"printenv" and "setenv" commands:
wdenkc6097192002-11-03 00:24:07 +00002276
wdenkc6097192002-11-03 00:24:07 +00002277
wdenk6c59edc2004-05-03 20:45:30 +00002278 => printenv bootargs
2279 bootargs=root=/dev/ram
wdenkc6097192002-11-03 00:24:07 +00002280
wdenk6c59edc2004-05-03 20:45:30 +00002281 => 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 +00002282
wdenk6c59edc2004-05-03 20:45:30 +00002283 => printenv bootargs
2284 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 +00002285
wdenk6c59edc2004-05-03 20:45:30 +00002286 => bootm 40020000
2287 ## Booting Linux kernel at 40020000 ...
2288 Image Name: 2.2.13 for NFS on TQM850L
2289 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2290 Data Size: 381681 Bytes = 372 kB = 0 MB
2291 Load Address: 00000000
2292 Entry Point: 0000000c
2293 Verifying Checksum ... OK
2294 Uncompressing Kernel Image ... OK
2295 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
2296 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2297 time_init: decrementer frequency = 187500000/60
2298 Calibrating delay loop... 49.77 BogoMIPS
2299 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2300 ...
wdenkc6097192002-11-03 00:24:07 +00002301
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02002302If you want to boot a Linux kernel with initial RAM disk, you pass
wdenk6c59edc2004-05-03 20:45:30 +00002303the memory addresses of both the kernel and the initrd image (PPBCOOT
2304format!) to the "bootm" command:
wdenkc6097192002-11-03 00:24:07 +00002305
wdenk6c59edc2004-05-03 20:45:30 +00002306 => imi 40100000 40200000
wdenkc6097192002-11-03 00:24:07 +00002307
wdenk6c59edc2004-05-03 20:45:30 +00002308 ## Checking Image at 40100000 ...
2309 Image Name: 2.2.13 for initrd on TQM850L
2310 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2311 Data Size: 335725 Bytes = 327 kB = 0 MB
2312 Load Address: 00000000
2313 Entry Point: 0000000c
2314 Verifying Checksum ... OK
wdenkc6097192002-11-03 00:24:07 +00002315
wdenk6c59edc2004-05-03 20:45:30 +00002316 ## Checking Image at 40200000 ...
2317 Image Name: Simple Ramdisk Image
2318 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2319 Data Size: 566530 Bytes = 553 kB = 0 MB
2320 Load Address: 00000000
2321 Entry Point: 00000000
2322 Verifying Checksum ... OK
wdenkc6097192002-11-03 00:24:07 +00002323
wdenk6c59edc2004-05-03 20:45:30 +00002324 => bootm 40100000 40200000
2325 ## Booting Linux kernel at 40100000 ...
2326 Image Name: 2.2.13 for initrd on TQM850L
2327 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2328 Data Size: 335725 Bytes = 327 kB = 0 MB
2329 Load Address: 00000000
2330 Entry Point: 0000000c
2331 Verifying Checksum ... OK
2332 Uncompressing Kernel Image ... OK
2333 ## Loading RAMDisk Image at 40200000 ...
2334 Image Name: Simple Ramdisk Image
2335 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2336 Data Size: 566530 Bytes = 553 kB = 0 MB
2337 Load Address: 00000000
2338 Entry Point: 00000000
2339 Verifying Checksum ... OK
2340 Loading Ramdisk ... OK
2341 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
2342 Boot arguments: root=/dev/ram
2343 time_init: decrementer frequency = 187500000/60
2344 Calibrating delay loop... 49.77 BogoMIPS
2345 ...
2346 RAMDISK: Compressed image found at block 0
2347 VFS: Mounted root (ext2 filesystem).
wdenkc6097192002-11-03 00:24:07 +00002348
wdenk6c59edc2004-05-03 20:45:30 +00002349 bash#
wdenkc6097192002-11-03 00:24:07 +00002350
Matthew McClintockefae4ca2006-06-28 10:41:37 -05002351Boot Linux and pass a flat device tree:
2352-----------
2353
2354First, U-Boot must be compiled with the appropriate defines. See the section
2355titled "Linux Kernel Interface" above for a more in depth explanation. The
2356following is an example of how to start a kernel and pass an updated
2357flat device tree:
2358
2359=> print oftaddr
2360oftaddr=0x300000
2361=> print oft
2362oft=oftrees/mpc8540ads.dtb
2363=> tftp $oftaddr $oft
2364Speed: 1000, full duplex
2365Using TSEC0 device
2366TFTP from server 192.168.1.1; our IP address is 192.168.1.101
2367Filename 'oftrees/mpc8540ads.dtb'.
2368Load address: 0x300000
2369Loading: #
2370done
2371Bytes transferred = 4106 (100a hex)
2372=> tftp $loadaddr $bootfile
2373Speed: 1000, full duplex
2374Using TSEC0 device
2375TFTP from server 192.168.1.1; our IP address is 192.168.1.2
2376Filename 'uImage'.
2377Load address: 0x200000
2378Loading:############
2379done
2380Bytes transferred = 1029407 (fb51f hex)
2381=> print loadaddr
2382loadaddr=200000
2383=> print oftaddr
2384oftaddr=0x300000
2385=> bootm $loadaddr - $oftaddr
2386## Booting image at 00200000 ...
Wolfgang Denk018147d2006-11-27 15:32:42 +01002387 Image Name: Linux-2.6.17-dirty
2388 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2389 Data Size: 1029343 Bytes = 1005.2 kB
Matthew McClintockefae4ca2006-06-28 10:41:37 -05002390 Load Address: 00000000
Wolfgang Denk018147d2006-11-27 15:32:42 +01002391 Entry Point: 00000000
Matthew McClintockefae4ca2006-06-28 10:41:37 -05002392 Verifying Checksum ... OK
2393 Uncompressing Kernel Image ... OK
2394Booting using flat device tree at 0x300000
2395Using MPC85xx ADS machine description
2396Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
2397[snip]
2398
2399
wdenk6c59edc2004-05-03 20:45:30 +00002400More About U-Boot Image Types:
2401------------------------------
wdenkc6097192002-11-03 00:24:07 +00002402
wdenk6c59edc2004-05-03 20:45:30 +00002403U-Boot supports the following image types:
wdenkc6097192002-11-03 00:24:07 +00002404
wdenk6c59edc2004-05-03 20:45:30 +00002405 "Standalone Programs" are directly runnable in the environment
2406 provided by U-Boot; it is expected that (if they behave
2407 well) you can continue to work in U-Boot after return from
2408 the Standalone Program.
2409 "OS Kernel Images" are usually images of some Embedded OS which
2410 will take over control completely. Usually these programs
2411 will install their own set of exception handlers, device
2412 drivers, set up the MMU, etc. - this means, that you cannot
2413 expect to re-enter U-Boot except by resetting the CPU.
2414 "RAMDisk Images" are more or less just data blocks, and their
2415 parameters (address, size) are passed to an OS kernel that is
2416 being started.
2417 "Multi-File Images" contain several images, typically an OS
2418 (Linux) kernel image and one or more data images like
2419 RAMDisks. This construct is useful for instance when you want
2420 to boot over the network using BOOTP etc., where the boot
2421 server provides just a single image file, but you want to get
2422 for instance an OS kernel and a RAMDisk image.
wdenkc6097192002-11-03 00:24:07 +00002423
wdenk6c59edc2004-05-03 20:45:30 +00002424 "Multi-File Images" start with a list of image sizes, each
2425 image size (in bytes) specified by an "uint32_t" in network
2426 byte order. This list is terminated by an "(uint32_t)0".
2427 Immediately after the terminating 0 follow the images, one by
2428 one, all aligned on "uint32_t" boundaries (size rounded up to
2429 a multiple of 4 bytes).
wdenkc6097192002-11-03 00:24:07 +00002430
wdenk6c59edc2004-05-03 20:45:30 +00002431 "Firmware Images" are binary images containing firmware (like
2432 U-Boot or FPGA images) which usually will be programmed to
2433 flash memory.
wdenk4fc95692003-02-28 00:49:47 +00002434
wdenk6c59edc2004-05-03 20:45:30 +00002435 "Script files" are command sequences that will be executed by
2436 U-Boot's command interpreter; this feature is especially
2437 useful when you configure U-Boot to use a real shell (hush)
2438 as command interpreter.
wdenk4fc95692003-02-28 00:49:47 +00002439
Marek Vasutcf41a9b2012-03-14 21:52:45 +00002440Booting the Linux zImage:
2441-------------------------
2442
2443On some platforms, it's possible to boot Linux zImage. This is done
2444using the "bootz" command. The syntax of "bootz" command is the same
2445as the syntax of "bootm" command.
2446
Tom Rini45f46d12013-05-16 11:40:11 -04002447Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
Marek Vasut28850d02012-03-18 11:47:58 +00002448kernel with raw initrd images. The syntax is slightly different, the
2449address of the initrd must be augmented by it's size, in the following
2450format: "<initrd addres>:<initrd size>".
2451
stroeseb9c17c52003-04-04 15:53:41 +00002452
wdenk6c59edc2004-05-03 20:45:30 +00002453Standalone HOWTO:
2454=================
stroeseb9c17c52003-04-04 15:53:41 +00002455
wdenk6c59edc2004-05-03 20:45:30 +00002456One of the features of U-Boot is that you can dynamically load and
2457run "standalone" applications, which can use some resources of
2458U-Boot like console I/O functions or interrupt services.
stroeseb9c17c52003-04-04 15:53:41 +00002459
wdenk6c59edc2004-05-03 20:45:30 +00002460Two simple examples are included with the sources:
wdenk4fc95692003-02-28 00:49:47 +00002461
wdenk6c59edc2004-05-03 20:45:30 +00002462"Hello World" Demo:
2463-------------------
wdenkc6097192002-11-03 00:24:07 +00002464
wdenk6c59edc2004-05-03 20:45:30 +00002465'examples/hello_world.c' contains a small "Hello World" Demo
2466application; it is automatically compiled when you build U-Boot.
2467It's configured to run at address 0x00040004, so you can play with it
2468like that:
wdenkc6097192002-11-03 00:24:07 +00002469
wdenk6c59edc2004-05-03 20:45:30 +00002470 => loads
2471 ## Ready for S-Record download ...
2472 ~>examples/hello_world.srec
2473 1 2 3 4 5 6 7 8 9 10 11 ...
2474 [file transfer complete]
2475 [connected]
2476 ## Start Addr = 0x00040004
wdenkc6097192002-11-03 00:24:07 +00002477
wdenk6c59edc2004-05-03 20:45:30 +00002478 => go 40004 Hello World! This is a test.
2479 ## Starting application at 0x00040004 ...
2480 Hello World
2481 argc = 7
2482 argv[0] = "40004"
2483 argv[1] = "Hello"
2484 argv[2] = "World!"
2485 argv[3] = "This"
2486 argv[4] = "is"
2487 argv[5] = "a"
2488 argv[6] = "test."
2489 argv[7] = "<NULL>"
2490 Hit any key to exit ...
wdenkc6097192002-11-03 00:24:07 +00002491
wdenk6c59edc2004-05-03 20:45:30 +00002492 ## Application terminated, rc = 0x0
wdenkc6097192002-11-03 00:24:07 +00002493
wdenk6c59edc2004-05-03 20:45:30 +00002494Another example, which demonstrates how to register a CPM interrupt
2495handler with the U-Boot code, can be found in 'examples/timer.c'.
2496Here, a CPM timer is set up to generate an interrupt every second.
2497The interrupt service routine is trivial, just printing a '.'
2498character, but this is just a demo program. The application can be
2499controlled by the following keys:
wdenkc6097192002-11-03 00:24:07 +00002500
wdenk6c59edc2004-05-03 20:45:30 +00002501 ? - print current values og the CPM Timer registers
2502 b - enable interrupts and start timer
2503 e - stop timer and disable interrupts
2504 q - quit application
wdenkc6097192002-11-03 00:24:07 +00002505
wdenk6c59edc2004-05-03 20:45:30 +00002506 => loads
2507 ## Ready for S-Record download ...
2508 ~>examples/timer.srec
2509 1 2 3 4 5 6 7 8 9 10 11 ...
2510 [file transfer complete]
2511 [connected]
2512 ## Start Addr = 0x00040004
wdenkc6097192002-11-03 00:24:07 +00002513
wdenk6c59edc2004-05-03 20:45:30 +00002514 => go 40004
2515 ## Starting application at 0x00040004 ...
2516 TIMERS=0xfff00980
2517 Using timer 1
2518 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
wdenkc6097192002-11-03 00:24:07 +00002519
wdenk6c59edc2004-05-03 20:45:30 +00002520Hit 'b':
2521 [q, b, e, ?] Set interval 1000000 us
2522 Enabling timer
2523Hit '?':
2524 [q, b, e, ?] ........
2525 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
2526Hit '?':
2527 [q, b, e, ?] .
2528 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
2529Hit '?':
2530 [q, b, e, ?] .
2531 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
2532Hit '?':
2533 [q, b, e, ?] .
2534 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
2535Hit 'e':
2536 [q, b, e, ?] ...Stopping timer
2537Hit 'q':
2538 [q, b, e, ?] ## Application terminated, rc = 0x0
wdenkc6097192002-11-03 00:24:07 +00002539
wdenkc6097192002-11-03 00:24:07 +00002540
wdenk6c59edc2004-05-03 20:45:30 +00002541Minicom warning:
2542================
wdenkc6097192002-11-03 00:24:07 +00002543
wdenk6c59edc2004-05-03 20:45:30 +00002544Over time, many people have reported problems when trying to use the
2545"minicom" terminal emulation program for serial download. I (wd)
2546consider minicom to be broken, and recommend not to use it. Under
2547Unix, I recommend to use C-Kermit for general purpose use (and
2548especially for kermit binary protocol download ("loadb" command), and
Karl O. Pinca0189bb2012-10-01 05:11:56 +00002549use "cu" for S-Record download ("loads" command). See
Naoki Hayamae0cc1852020-10-08 13:17:16 +09002550https://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
Karl O. Pinca0189bb2012-10-01 05:11:56 +00002551for help with kermit.
2552
wdenkc6097192002-11-03 00:24:07 +00002553
wdenk6c59edc2004-05-03 20:45:30 +00002554Nevertheless, if you absolutely want to use it try adding this
2555configuration to your "File transfer protocols" section:
wdenkc6097192002-11-03 00:24:07 +00002556
wdenk6c59edc2004-05-03 20:45:30 +00002557 Name Program Name U/D FullScr IO-Red. Multi
2558 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
2559 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
wdenk8dba0502003-03-31 16:34:49 +00002560
wdenk8dba0502003-03-31 16:34:49 +00002561
wdenk6c59edc2004-05-03 20:45:30 +00002562NetBSD Notes:
2563=============
wdenkc6097192002-11-03 00:24:07 +00002564
wdenk6c59edc2004-05-03 20:45:30 +00002565Starting at version 0.9.2, U-Boot supports NetBSD both as host
2566(build U-Boot) and target system (boots NetBSD/mpc8xx).
wdenk88e72a32003-06-19 23:04:19 +00002567
wdenk6c59edc2004-05-03 20:45:30 +00002568Building requires a cross environment; it is known to work on
2569NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
2570need gmake since the Makefiles are not compatible with BSD make).
2571Note that the cross-powerpc package does not install include files;
2572attempting to build U-Boot will fail because <machine/ansi.h> is
2573missing. This file has to be installed and patched manually:
wdenk88e72a32003-06-19 23:04:19 +00002574
wdenk6c59edc2004-05-03 20:45:30 +00002575 # cd /usr/pkg/cross/powerpc-netbsd/include
2576 # mkdir powerpc
2577 # ln -s powerpc machine
2578 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
2579 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
wdenk88e72a32003-06-19 23:04:19 +00002580
wdenk6c59edc2004-05-03 20:45:30 +00002581Native builds *don't* work due to incompatibilities between native
2582and U-Boot include files.
wdenkc6097192002-11-03 00:24:07 +00002583
wdenk6c59edc2004-05-03 20:45:30 +00002584Booting assumes that (the first part of) the image booted is a
2585stage-2 loader which in turn loads and then invokes the kernel
2586proper. Loader sources will eventually appear in the NetBSD source
2587tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
wdenkd0245fc2005-04-13 10:02:42 +00002588meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
wdenkc6097192002-11-03 00:24:07 +00002589
wdenkc6097192002-11-03 00:24:07 +00002590
wdenk6c59edc2004-05-03 20:45:30 +00002591Implementation Internals:
2592=========================
wdenkc6097192002-11-03 00:24:07 +00002593
wdenk6c59edc2004-05-03 20:45:30 +00002594The following is not intended to be a complete description of every
2595implementation detail. However, it should help to understand the
2596inner workings of U-Boot and make it easier to port it to custom
2597hardware.
wdenkc6097192002-11-03 00:24:07 +00002598
wdenkc6097192002-11-03 00:24:07 +00002599
wdenk6c59edc2004-05-03 20:45:30 +00002600Initial Stack, Global Data:
2601---------------------------
wdenkc6097192002-11-03 00:24:07 +00002602
wdenk6c59edc2004-05-03 20:45:30 +00002603The implementation of U-Boot is complicated by the fact that U-Boot
2604starts running out of ROM (flash memory), usually without access to
2605system RAM (because the memory controller is not initialized yet).
2606This means that we don't have writable Data or BSS segments, and BSS
2607is not initialized as zero. To be able to get a C environment working
2608at all, we have to allocate at least a minimal stack. Implementation
2609options for this are defined and restricted by the CPU used: Some CPU
2610models provide on-chip memory (like the IMMR area on MPC8xx and
2611MPC826x processors), on others (parts of) the data cache can be
2612locked as (mis-) used as memory, etc.
wdenkc6097192002-11-03 00:24:07 +00002613
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002614 Chris Hallinan posted a good summary of these issues to the
Wolfgang Denk290ae6b2008-12-30 22:56:11 +01002615 U-Boot mailing list:
wdenkc6097192002-11-03 00:24:07 +00002616
wdenk6c59edc2004-05-03 20:45:30 +00002617 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
2618 From: "Chris Hallinan" <clh@net1plus.com>
2619 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
2620 ...
wdenkc6097192002-11-03 00:24:07 +00002621
wdenk6c59edc2004-05-03 20:45:30 +00002622 Correct me if I'm wrong, folks, but the way I understand it
2623 is this: Using DCACHE as initial RAM for Stack, etc, does not
2624 require any physical RAM backing up the cache. The cleverness
2625 is that the cache is being used as a temporary supply of
2626 necessary storage before the SDRAM controller is setup. It's
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02002627 beyond the scope of this list to explain the details, but you
wdenk6c59edc2004-05-03 20:45:30 +00002628 can see how this works by studying the cache architecture and
2629 operation in the architecture and processor-specific manuals.
wdenkc6097192002-11-03 00:24:07 +00002630
wdenk6c59edc2004-05-03 20:45:30 +00002631 OCM is On Chip Memory, which I believe the 405GP has 4K. It
2632 is another option for the system designer to use as an
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02002633 initial stack/RAM area prior to SDRAM being available. Either
wdenk6c59edc2004-05-03 20:45:30 +00002634 option should work for you. Using CS 4 should be fine if your
2635 board designers haven't used it for something that would
2636 cause you grief during the initial boot! It is frequently not
2637 used.
wdenkc6097192002-11-03 00:24:07 +00002638
Tom Rini6a5dccc2022-11-16 13:10:41 -05002639 CFG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
wdenk6c59edc2004-05-03 20:45:30 +00002640 with your processor/board/system design. The default value
2641 you will find in any recent u-boot distribution in
Stefan Roese3e1f1b32005-08-01 16:49:12 +02002642 walnut.h should work for you. I'd set it to a value larger
wdenk6c59edc2004-05-03 20:45:30 +00002643 than your SDRAM module. If you have a 64MB SDRAM module, set
2644 it above 400_0000. Just make sure your board has no resources
2645 that are supposed to respond to that address! That code in
2646 start.S has been around a while and should work as is when
2647 you get the config right.
wdenk4a5c8a72003-03-06 00:02:04 +00002648
wdenk6c59edc2004-05-03 20:45:30 +00002649 -Chris Hallinan
2650 DS4.COM, Inc.
wdenk4a5c8a72003-03-06 00:02:04 +00002651
wdenk6c59edc2004-05-03 20:45:30 +00002652It is essential to remember this, since it has some impact on the C
2653code for the initialization procedures:
wdenk4a5c8a72003-03-06 00:02:04 +00002654
wdenk6c59edc2004-05-03 20:45:30 +00002655* Initialized global data (data segment) is read-only. Do not attempt
2656 to write it.
wdenk4a5c8a72003-03-06 00:02:04 +00002657
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08002658* Do not use any uninitialized global data (or implicitly initialized
wdenk6c59edc2004-05-03 20:45:30 +00002659 as zero data - BSS segment) at all - this is undefined, initiali-
2660 zation is performed later (when relocating to RAM).
wdenk4a5c8a72003-03-06 00:02:04 +00002661
wdenk6c59edc2004-05-03 20:45:30 +00002662* Stack space is very limited. Avoid big data buffers or things like
2663 that.
wdenk4a5c8a72003-03-06 00:02:04 +00002664
wdenk6c59edc2004-05-03 20:45:30 +00002665Having only the stack as writable memory limits means we cannot use
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08002666normal global data to share information between the code. But it
wdenk6c59edc2004-05-03 20:45:30 +00002667turned out that the implementation of U-Boot can be greatly
2668simplified by making a global data structure (gd_t) available to all
2669functions. We could pass a pointer to this data as argument to _all_
2670functions, but this would bloat the code. Instead we use a feature of
2671the GCC compiler (Global Register Variables) to share the data: we
2672place a pointer (gd) to the global data into a register which we
2673reserve for this purpose.
wdenkc6097192002-11-03 00:24:07 +00002674
wdenk6c59edc2004-05-03 20:45:30 +00002675When choosing a register for such a purpose we are restricted by the
2676relevant (E)ABI specifications for the current architecture, and by
2677GCC's implementation.
wdenkc6097192002-11-03 00:24:07 +00002678
wdenk6c59edc2004-05-03 20:45:30 +00002679For PowerPC, the following registers have specific use:
2680 R1: stack pointer
Wolfgang Denk69c09642008-02-14 22:43:22 +01002681 R2: reserved for system use
wdenk6c59edc2004-05-03 20:45:30 +00002682 R3-R4: parameter passing and return values
2683 R5-R10: parameter passing
2684 R13: small data area pointer
2685 R30: GOT pointer
2686 R31: frame pointer
wdenkc6097192002-11-03 00:24:07 +00002687
Joakim Tjernlund693c0c12010-01-19 14:41:58 +01002688 (U-Boot also uses R12 as internal GOT pointer. r12
2689 is a volatile register so r12 needs to be reset when
2690 going back and forth between asm and C)
wdenkc6097192002-11-03 00:24:07 +00002691
Wolfgang Denk69c09642008-02-14 22:43:22 +01002692 ==> U-Boot will use R2 to hold a pointer to the global data
wdenkc6097192002-11-03 00:24:07 +00002693
wdenk6c59edc2004-05-03 20:45:30 +00002694 Note: on PPC, we could use a static initializer (since the
2695 address of the global data structure is known at compile time),
2696 but it turned out that reserving a register results in somewhat
2697 smaller code - although the code savings are not that big (on
2698 average for all boards 752 bytes for the whole U-Boot image,
2699 624 text + 127 data).
wdenkc6097192002-11-03 00:24:07 +00002700
wdenk6c59edc2004-05-03 20:45:30 +00002701On ARM, the following registers are used:
wdenkc6097192002-11-03 00:24:07 +00002702
wdenk6c59edc2004-05-03 20:45:30 +00002703 R0: function argument word/integer result
2704 R1-R3: function argument word
Jeroen Hofsteea556aca2013-09-21 14:04:42 +02002705 R9: platform specific
2706 R10: stack limit (used only if stack checking is enabled)
wdenk6c59edc2004-05-03 20:45:30 +00002707 R11: argument (frame) pointer
2708 R12: temporary workspace
2709 R13: stack pointer
2710 R14: link register
2711 R15: program counter
wdenkc6097192002-11-03 00:24:07 +00002712
Jeroen Hofsteea556aca2013-09-21 14:04:42 +02002713 ==> U-Boot will use R9 to hold a pointer to the global data
2714
2715 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
wdenkc6097192002-11-03 00:24:07 +00002716
Thomas Chou8fa38582010-05-21 11:08:03 +08002717On Nios II, the ABI is documented here:
Naoki Hayamae0cc1852020-10-08 13:17:16 +09002718 https://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
Thomas Chou8fa38582010-05-21 11:08:03 +08002719
2720 ==> U-Boot will use gp to hold a pointer to the global data
2721
2722 Note: on Nios II, we give "-G0" option to gcc and don't use gp
2723 to access small data sections, so gp is free.
2724
Rick Chend7e6f922017-12-26 13:55:59 +08002725On RISC-V, the following registers are used:
2726
2727 x0: hard-wired zero (zero)
2728 x1: return address (ra)
2729 x2: stack pointer (sp)
2730 x3: global pointer (gp)
2731 x4: thread pointer (tp)
2732 x5: link register (t0)
2733 x8: frame pointer (fp)
2734 x10-x11: arguments/return values (a0-1)
2735 x12-x17: arguments (a2-7)
2736 x28-31: temporaries (t3-6)
2737 pc: program counter (pc)
2738
2739 ==> U-Boot will use gp to hold a pointer to the global data
2740
wdenk6c59edc2004-05-03 20:45:30 +00002741Memory Management:
2742------------------
wdenkc6097192002-11-03 00:24:07 +00002743
wdenk6c59edc2004-05-03 20:45:30 +00002744U-Boot runs in system state and uses physical addresses, i.e. the
2745MMU is not used either for address mapping nor for memory protection.
wdenkc6097192002-11-03 00:24:07 +00002746
wdenk6c59edc2004-05-03 20:45:30 +00002747The available memory is mapped to fixed addresses using the memory
2748controller. In this process, a contiguous block is formed for each
2749memory type (Flash, SDRAM, SRAM), even when it consists of several
2750physical memory banks.
wdenkc6097192002-11-03 00:24:07 +00002751
wdenk6c59edc2004-05-03 20:45:30 +00002752U-Boot is installed in the first 128 kB of the first Flash bank (on
2753TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
2754booting and sizing and initializing DRAM, the code relocates itself
2755to the upper end of DRAM. Immediately below the U-Boot code some
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02002756memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
wdenk6c59edc2004-05-03 20:45:30 +00002757configuration setting]. Below that, a structure with global Board
2758Info data is placed, followed by the stack (growing downward).
wdenkc6097192002-11-03 00:24:07 +00002759
wdenk6c59edc2004-05-03 20:45:30 +00002760Additionally, some exception handler code is copied to the low 8 kB
2761of DRAM (0x00000000 ... 0x00001FFF).
wdenkc6097192002-11-03 00:24:07 +00002762
wdenk6c59edc2004-05-03 20:45:30 +00002763So a typical memory configuration with 16 MB of DRAM could look like
2764this:
wdenkc6097192002-11-03 00:24:07 +00002765
wdenk6c59edc2004-05-03 20:45:30 +00002766 0x0000 0000 Exception Vector code
2767 :
2768 0x0000 1FFF
2769 0x0000 2000 Free for Application Use
2770 :
2771 :
wdenkc6097192002-11-03 00:24:07 +00002772
wdenk6c59edc2004-05-03 20:45:30 +00002773 :
2774 :
2775 0x00FB FF20 Monitor Stack (Growing downward)
2776 0x00FB FFAC Board Info Data and permanent copy of global data
2777 0x00FC 0000 Malloc Arena
2778 :
2779 0x00FD FFFF
2780 0x00FE 0000 RAM Copy of Monitor Code
2781 ... eventually: LCD or video framebuffer
2782 ... eventually: pRAM (Protected RAM - unchanged by reset)
2783 0x00FF FFFF [End of RAM]
wdenkc6097192002-11-03 00:24:07 +00002784
wdenkc6097192002-11-03 00:24:07 +00002785
wdenk6c59edc2004-05-03 20:45:30 +00002786System Initialization:
2787----------------------
wdenkc6097192002-11-03 00:24:07 +00002788
wdenk6c59edc2004-05-03 20:45:30 +00002789In the reset configuration, U-Boot starts at the reset entry point
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02002790(on most PowerPC systems at address 0x00000100). Because of the reset
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08002791configuration for CS0# this is a mirror of the on board Flash memory.
wdenk6c59edc2004-05-03 20:45:30 +00002792To be able to re-map memory U-Boot then jumps to its link address.
2793To be able to implement the initialization code in C, a (small!)
2794initial stack is set up in the internal Dual Ported RAM (in case CPUs
Heiko Schocher71cb3e92017-06-07 17:33:10 +02002795which provide such a feature like), or in a locked part of the data
2796cache. After that, U-Boot initializes the CPU core, the caches and
2797the SIU.
wdenkc6097192002-11-03 00:24:07 +00002798
wdenk6c59edc2004-05-03 20:45:30 +00002799Next, all (potentially) available memory banks are mapped using a
2800preliminary mapping. For example, we put them on 512 MB boundaries
2801(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
2802on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
2803programmed for SDRAM access. Using the temporary configuration, a
2804simple memory test is run that determines the size of the SDRAM
2805banks.
wdenkc6097192002-11-03 00:24:07 +00002806
wdenk6c59edc2004-05-03 20:45:30 +00002807When there is more than one SDRAM bank, and the banks are of
2808different size, the largest is mapped first. For equal size, the first
2809bank (CS2#) is mapped first. The first mapping is always for address
28100x00000000, with any additional banks following immediately to create
2811contiguous memory starting from 0.
wdenkc6097192002-11-03 00:24:07 +00002812
wdenk6c59edc2004-05-03 20:45:30 +00002813Then, the monitor installs itself at the upper end of the SDRAM area
2814and allocates memory for use by malloc() and for the global Board
2815Info data; also, the exception vector code is copied to the low RAM
2816pages, and the final stack is set up.
wdenkc6097192002-11-03 00:24:07 +00002817
wdenk6c59edc2004-05-03 20:45:30 +00002818Only after this relocation will you have a "normal" C environment;
2819until that you are restricted in several ways, mostly because you are
2820running from ROM, and because the code will have to be relocated to a
2821new address in RAM.
wdenkc6097192002-11-03 00:24:07 +00002822
wdenkc6097192002-11-03 00:24:07 +00002823
wdenk6c59edc2004-05-03 20:45:30 +00002824U-Boot Porting Guide:
2825----------------------
wdenkc6097192002-11-03 00:24:07 +00002826
wdenk6c59edc2004-05-03 20:45:30 +00002827[Based on messages by Jerry Van Baren in the U-Boot-Users mailing
2828list, October 2002]
wdenkc6097192002-11-03 00:24:07 +00002829
wdenkc6097192002-11-03 00:24:07 +00002830
Jerry Van Barenba0687c2009-07-15 20:42:59 -04002831int main(int argc, char *argv[])
wdenk6c59edc2004-05-03 20:45:30 +00002832{
2833 sighandler_t no_more_time;
wdenkc6097192002-11-03 00:24:07 +00002834
Jerry Van Barenba0687c2009-07-15 20:42:59 -04002835 signal(SIGALRM, no_more_time);
2836 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
wdenkc6097192002-11-03 00:24:07 +00002837
wdenk6c59edc2004-05-03 20:45:30 +00002838 if (available_money > available_manpower) {
Jerry Van Barenba0687c2009-07-15 20:42:59 -04002839 Pay consultant to port U-Boot;
wdenk6c59edc2004-05-03 20:45:30 +00002840 return 0;
2841 }
wdenkc6097192002-11-03 00:24:07 +00002842
wdenk6c59edc2004-05-03 20:45:30 +00002843 Download latest U-Boot source;
wdenk34b613e2002-12-17 01:51:00 +00002844
Wolfgang Denk290ae6b2008-12-30 22:56:11 +01002845 Subscribe to u-boot mailing list;
wdenkc6097192002-11-03 00:24:07 +00002846
Jerry Van Barenba0687c2009-07-15 20:42:59 -04002847 if (clueless)
2848 email("Hi, I am new to U-Boot, how do I get started?");
wdenkc6097192002-11-03 00:24:07 +00002849
wdenk6c59edc2004-05-03 20:45:30 +00002850 while (learning) {
2851 Read the README file in the top level directory;
Naoki Hayamae0cc1852020-10-08 13:17:16 +09002852 Read https://www.denx.de/wiki/bin/view/DULG/Manual;
Patrick Delaunay9b281fa2020-02-28 15:18:10 +01002853 Read applicable doc/README.*;
wdenk6c59edc2004-05-03 20:45:30 +00002854 Read the source, Luke;
Jerry Van Barenba0687c2009-07-15 20:42:59 -04002855 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
wdenk6c59edc2004-05-03 20:45:30 +00002856 }
wdenkc6097192002-11-03 00:24:07 +00002857
Jerry Van Barenba0687c2009-07-15 20:42:59 -04002858 if (available_money > toLocalCurrency ($2500))
2859 Buy a BDI3000;
2860 else
wdenk6c59edc2004-05-03 20:45:30 +00002861 Add a lot of aggravation and time;
wdenkc6097192002-11-03 00:24:07 +00002862
Jerry Van Barenba0687c2009-07-15 20:42:59 -04002863 if (a similar board exists) { /* hopefully... */
2864 cp -a board/<similar> board/<myboard>
2865 cp include/configs/<similar>.h include/configs/<myboard>.h
2866 } else {
2867 Create your own board support subdirectory;
2868 Create your own board include/configs/<myboard>.h file;
2869 }
2870 Edit new board/<myboard> files
2871 Edit new include/configs/<myboard>.h
wdenkc6097192002-11-03 00:24:07 +00002872
Jerry Van Barenba0687c2009-07-15 20:42:59 -04002873 while (!accepted) {
2874 while (!running) {
2875 do {
2876 Add / modify source code;
2877 } until (compiles);
2878 Debug;
2879 if (clueless)
2880 email("Hi, I am having problems...");
2881 }
2882 Send patch file to the U-Boot email list;
2883 if (reasonable critiques)
2884 Incorporate improvements from email list code review;
2885 else
2886 Defend code as written;
wdenk634d2f72004-04-15 23:14:49 +00002887 }
wdenkc6097192002-11-03 00:24:07 +00002888
wdenk6c59edc2004-05-03 20:45:30 +00002889 return 0;
2890}
wdenkc6097192002-11-03 00:24:07 +00002891
wdenk6c59edc2004-05-03 20:45:30 +00002892void no_more_time (int sig)
2893{
2894 hire_a_guru();
2895}
wdenkc6097192002-11-03 00:24:07 +00002896
wdenkc6097192002-11-03 00:24:07 +00002897
wdenk6c59edc2004-05-03 20:45:30 +00002898Coding Standards:
2899-----------------
wdenkc6097192002-11-03 00:24:07 +00002900
wdenk6c59edc2004-05-03 20:45:30 +00002901All contributions to U-Boot should conform to the Linux kernel
Baruch Siachb1081252017-12-10 17:34:35 +02002902coding style; see the kernel coding style guide at
2903https://www.kernel.org/doc/html/latest/process/coding-style.html, and the
2904script "scripts/Lindent" in your Linux kernel source directory.
Detlev Zundelaa63d482006-09-01 15:39:02 +02002905
2906Source files originating from a different project (for example the
2907MTD subsystem) are generally exempt from these guidelines and are not
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08002908reformatted to ease subsequent migration to newer versions of those
Detlev Zundelaa63d482006-09-01 15:39:02 +02002909sources.
wdenkc6097192002-11-03 00:24:07 +00002910
Detlev Zundelaa63d482006-09-01 15:39:02 +02002911Please note that U-Boot is implemented in C (and to some small parts in
2912Assembler); no C++ is used, so please do not use C++ style comments (//)
2913in your code.
wdenkad276f22004-01-04 16:28:35 +00002914
wdenk6c59edc2004-05-03 20:45:30 +00002915Please also stick to the following formatting rules:
2916- remove any trailing white space
Wolfgang Denk20bd2a62011-07-27 10:59:55 +00002917- use TAB characters for indentation and vertical alignment, not spaces
wdenk6c59edc2004-05-03 20:45:30 +00002918- make sure NOT to use DOS '\r\n' line feeds
Wolfgang Denk20bd2a62011-07-27 10:59:55 +00002919- do not add more than 2 consecutive empty lines to source files
wdenk6c59edc2004-05-03 20:45:30 +00002920- do not add trailing empty lines to source files
wdenkc6097192002-11-03 00:24:07 +00002921
wdenk6c59edc2004-05-03 20:45:30 +00002922Submissions which do not conform to the standards may be returned
2923with a request to reformat the changes.
wdenkc6097192002-11-03 00:24:07 +00002924
wdenkc6097192002-11-03 00:24:07 +00002925
wdenk6c59edc2004-05-03 20:45:30 +00002926Submitting Patches:
2927-------------------
wdenkc6097192002-11-03 00:24:07 +00002928
wdenk6c59edc2004-05-03 20:45:30 +00002929Since the number of patches for U-Boot is growing, we need to
2930establish some rules. Submissions which do not conform to these rules
2931may be rejected, even when they contain important and valuable stuff.
wdenkc6097192002-11-03 00:24:07 +00002932
Naoki Hayamae0cc1852020-10-08 13:17:16 +09002933Please see https://www.denx.de/wiki/U-Boot/Patches for details.
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002934
Wolfgang Denk290ae6b2008-12-30 22:56:11 +01002935Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
S. Lockwood-Childsda6d34c2017-11-14 22:56:42 -08002936see https://lists.denx.de/listinfo/u-boot
Wolfgang Denk290ae6b2008-12-30 22:56:11 +01002937
wdenk6c59edc2004-05-03 20:45:30 +00002938When you send a patch, please include the following information with
2939it:
wdenkc6097192002-11-03 00:24:07 +00002940
wdenk6c59edc2004-05-03 20:45:30 +00002941* For bug fixes: a description of the bug and how your patch fixes
2942 this bug. Please try to include a way of demonstrating that the
2943 patch actually fixes something.
wdenkc6097192002-11-03 00:24:07 +00002944
wdenk6c59edc2004-05-03 20:45:30 +00002945* For new features: a description of the feature and your
2946 implementation.
wdenkc6097192002-11-03 00:24:07 +00002947
Robert P. J. Day076ed9b2015-12-19 07:16:10 -05002948* For major contributions, add a MAINTAINERS file with your
2949 information and associated file and directory references.
wdenkc6097192002-11-03 00:24:07 +00002950
Albert ARIBAUD48e910f2013-09-11 15:52:51 +02002951* When you add support for a new board, don't forget to add a
2952 maintainer e-mail address to the boards.cfg file, too.
wdenkc6097192002-11-03 00:24:07 +00002953
wdenk6c59edc2004-05-03 20:45:30 +00002954* If your patch adds new configuration options, don't forget to
2955 document these in the README file.
wdenkc6097192002-11-03 00:24:07 +00002956
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002957* The patch itself. If you are using git (which is *strongly*
2958 recommended) you can easily generate the patch using the
Wolfgang Denk20bd2a62011-07-27 10:59:55 +00002959 "git format-patch". If you then use "git send-email" to send it to
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002960 the U-Boot mailing list, you will avoid most of the common problems
2961 with some other mail clients.
wdenkca9bc762003-07-15 07:45:49 +00002962
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002963 If you cannot use git, use "diff -purN OLD NEW". If your version of
2964 diff does not support these options, then get the latest version of
2965 GNU diff.
wdenkc6097192002-11-03 00:24:07 +00002966
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002967 The current directory when running this command shall be the parent
2968 directory of the U-Boot source tree (i. e. please make sure that
2969 your patch includes sufficient directory information for the
2970 affected files).
2971
2972 We prefer patches as plain text. MIME attachments are discouraged,
2973 and compressed attachments must not be used.
wdenk88e72a32003-06-19 23:04:19 +00002974
wdenk6c59edc2004-05-03 20:45:30 +00002975* If one logical set of modifications affects or creates several
2976 files, all these changes shall be submitted in a SINGLE patch file.
wdenk57b2d802003-06-27 21:31:46 +00002977
wdenk6c59edc2004-05-03 20:45:30 +00002978* Changesets that contain different, unrelated modifications shall be
2979 submitted as SEPARATE patches, one patch per changeset.
wdenk88e72a32003-06-19 23:04:19 +00002980
wdenkc6097192002-11-03 00:24:07 +00002981
wdenk6c59edc2004-05-03 20:45:30 +00002982Notes:
wdenkc6097192002-11-03 00:24:07 +00002983
Simon Glassdc27def2016-07-27 20:33:08 -06002984* Before sending the patch, run the buildman script on your patched
wdenk6c59edc2004-05-03 20:45:30 +00002985 source tree and make sure that no errors or warnings are reported
2986 for any of the boards.
2987
2988* Keep your modifications to the necessary minimum: A patch
2989 containing several unrelated changes or arbitrary reformats will be
2990 returned with a request to re-formatting / split it.
wdenkc6097192002-11-03 00:24:07 +00002991
wdenk6c59edc2004-05-03 20:45:30 +00002992* If you modify existing code, make sure that your new code does not
2993 add to the memory footprint of the code ;-) Small is beautiful!
2994 When adding new features, these should compile conditionally only
2995 (using #ifdef), and the resulting code with the new feature
2996 disabled must not need more memory than the old code without your
2997 modification.
wdenkcbc49a52005-05-03 14:12:25 +00002998
Wolfgang Denk290ae6b2008-12-30 22:56:11 +01002999* Remember that there is a size limit of 100 kB per message on the
3000 u-boot mailing list. Bigger patches will be moderated. If they are
3001 reasonable and not too big, they will be acknowledged. But patches
3002 bigger than the size limit should be avoided.