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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
169Configuration is usually done using C preprocessor defines; the
170rationale behind that is to avoid dead code whenever possible.
171
172There are two classes of configuration variables:
173
174* Configuration _OPTIONS_:
175 These are selectable by the user and have names beginning with
176 "CONFIG_".
177
178* Configuration _SETTINGS_:
179 These depend on the hardware etc. and should not be meddled with if
180 you don't know what you're doing; they have names beginning with
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +0200181 "CONFIG_SYS_".
wdenkc6097192002-11-03 00:24:07 +0000182
Robert P. J. Day076ed9b2015-12-19 07:16:10 -0500183Previously, all configuration was done by hand, which involved creating
184symbolic links and editing configuration files manually. More recently,
185U-Boot has added the Kbuild infrastructure used by the Linux kernel,
186allowing you to use the "make menuconfig" command to configure your
187build.
wdenkc6097192002-11-03 00:24:07 +0000188
189
190Selection of Processor Architecture and Board Type:
191---------------------------------------------------
192
193For all supported boards there are ready-to-use default
Holger Freyther7ba4e572014-08-04 09:26:05 +0200194configurations available; just type "make <board_name>_defconfig".
wdenkc6097192002-11-03 00:24:07 +0000195
196Example: For a TQM823L module type:
197
198 cd u-boot
Holger Freyther7ba4e572014-08-04 09:26:05 +0200199 make TQM823L_defconfig
wdenkc6097192002-11-03 00:24:07 +0000200
Robert P. J. Day076ed9b2015-12-19 07:16:10 -0500201Note: If you're looking for the default configuration file for a board
202you're sure used to be there but is now missing, check the file
203doc/README.scrapyard for a list of no longer supported boards.
wdenkc6097192002-11-03 00:24:07 +0000204
Simon Glass53552c92014-03-22 17:12:59 -0600205Sandbox Environment:
206--------------------
207
208U-Boot can be built natively to run on a Linux host using the 'sandbox'
209board. This allows feature development which is not board- or architecture-
210specific to be undertaken on a native platform. The sandbox is also used to
211run some of U-Boot's tests.
212
Naoki Hayamadd860ca2020-10-08 13:16:58 +0900213See doc/arch/sandbox.rst for more details.
Simon Glass53552c92014-03-22 17:12:59 -0600214
215
Simon Glassd8711af2015-03-03 08:03:00 -0700216Board Initialisation Flow:
217--------------------------
218
219This is the intended start-up flow for boards. This should apply for both
Robert P. J. Day076ed9b2015-12-19 07:16:10 -0500220SPL and U-Boot proper (i.e. they both follow the same rules).
221
222Note: "SPL" stands for "Secondary Program Loader," which is explained in
223more detail later in this file.
224
225At present, SPL mostly uses a separate code path, but the function names
226and roles of each function are the same. Some boards or architectures
227may not conform to this. At least most ARM boards which use
228CONFIG_SPL_FRAMEWORK conform to this.
Simon Glassd8711af2015-03-03 08:03:00 -0700229
Robert P. J. Day076ed9b2015-12-19 07:16:10 -0500230Execution typically starts with an architecture-specific (and possibly
231CPU-specific) start.S file, such as:
232
233 - arch/arm/cpu/armv7/start.S
234 - arch/powerpc/cpu/mpc83xx/start.S
235 - arch/mips/cpu/start.S
236
237and so on. From there, three functions are called; the purpose and
238limitations of each of these functions are described below.
Simon Glassd8711af2015-03-03 08:03:00 -0700239
240lowlevel_init():
241 - purpose: essential init to permit execution to reach board_init_f()
242 - no global_data or BSS
243 - there is no stack (ARMv7 may have one but it will soon be removed)
244 - must not set up SDRAM or use console
245 - must only do the bare minimum to allow execution to continue to
246 board_init_f()
247 - this is almost never needed
248 - return normally from this function
249
250board_init_f():
251 - purpose: set up the machine ready for running board_init_r():
252 i.e. SDRAM and serial UART
253 - global_data is available
254 - stack is in SRAM
255 - BSS is not available, so you cannot use global/static variables,
256 only stack variables and global_data
257
258 Non-SPL-specific notes:
259 - dram_init() is called to set up DRAM. If already done in SPL this
260 can do nothing
261
262 SPL-specific notes:
263 - you can override the entire board_init_f() function with your own
264 version as needed.
265 - preloader_console_init() can be called here in extremis
266 - should set up SDRAM, and anything needed to make the UART work
Naoki Hayamaebfd8192020-09-24 15:57:19 +0900267 - there is no need to clear BSS, it will be done by crt0.S
Andreas Dannenberg7673bed2019-08-08 12:54:49 -0500268 - for specific scenarios on certain architectures an early BSS *can*
269 be made available (via CONFIG_SPL_EARLY_BSS by moving the clearing
270 of BSS prior to entering board_init_f()) but doing so is discouraged.
271 Instead it is strongly recommended to architect any code changes
272 or additions such to not depend on the availability of BSS during
273 board_init_f() as indicated in other sections of this README to
274 maintain compatibility and consistency across the entire code base.
Simon Glassd8711af2015-03-03 08:03:00 -0700275 - must return normally from this function (don't call board_init_r()
276 directly)
277
278Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
279this point the stack and global_data are relocated to below
280CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
281memory.
282
283board_init_r():
284 - purpose: main execution, common code
285 - global_data is available
286 - SDRAM is available
287 - BSS is available, all static/global variables can be used
288 - execution eventually continues to main_loop()
289
290 Non-SPL-specific notes:
291 - U-Boot is relocated to the top of memory and is now running from
292 there.
293
294 SPL-specific notes:
295 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
Ashish Kumar11234062017-08-11 11:09:14 +0530296 CONFIG_SYS_FSL_HAS_CCI400
297
298 Defined For SoC that has cache coherent interconnect
299 CCN-400
wdenk1272e232002-11-10 22:06:23 +0000300
Ashish Kumar97393d62017-08-18 10:54:36 +0530301 CONFIG_SYS_FSL_HAS_CCN504
302
303 Defined for SoC that has cache coherent interconnect CCN-504
304
wdenkc6097192002-11-03 00:24:07 +0000305The following options need to be configured:
306
Kim Phillips203fee32007-08-10 13:28:25 -0500307- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
wdenkc6097192002-11-03 00:24:07 +0000308
Kim Phillips203fee32007-08-10 13:28:25 -0500309- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
Wolfgang Denk994ad962006-10-24 14:42:37 +0200310
Kumar Galaf4fb90f2011-02-18 05:40:54 -0600311- 85xx CPU Options:
York Sun2394a0f2012-10-08 07:44:30 +0000312 CONFIG_SYS_PPC64
313
314 Specifies that the core is a 64-bit PowerPC implementation (implements
315 the "64" category of the Power ISA). This is necessary for ePAPR
316 compliance, among other possible reasons.
317
Kumar Galaf4fb90f2011-02-18 05:40:54 -0600318 CONFIG_SYS_FSL_TBCLK_DIV
319
320 Defines the core time base clock divider ratio compared to the
321 system clock. On most PQ3 devices this is 8, on newer QorIQ
322 devices it can be 16 or 32. The ratio varies from SoC to Soc.
323
Kumar Gala179b1b22011-05-20 00:39:21 -0500324 CONFIG_SYS_FSL_PCIE_COMPAT
325
326 Defines the string to utilize when trying to match PCIe device
327 tree nodes for the given platform.
328
Scott Wood80806962012-08-14 10:14:53 +0000329 CONFIG_SYS_FSL_ERRATUM_A004510
330
331 Enables a workaround for erratum A004510. If set,
332 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
333 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
334
335 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
336 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
337
338 Defines one or two SoC revisions (low 8 bits of SVR)
339 for which the A004510 workaround should be applied.
340
341 The rest of SVR is either not relevant to the decision
342 of whether the erratum is present (e.g. p2040 versus
343 p2041) or is implied by the build target, which controls
344 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
345
346 See Freescale App Note 4493 for more information about
347 this erratum.
348
349 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
350
351 This is the value to write into CCSR offset 0x18600
352 according to the A004510 workaround.
353
Priyanka Jainc73b9032013-07-02 09:21:04 +0530354 CONFIG_SYS_FSL_DSP_DDR_ADDR
355 This value denotes start offset of DDR memory which is
356 connected exclusively to the DSP cores.
357
Priyanka Jainf81e8b22013-04-04 09:31:54 +0530358 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
359 This value denotes start offset of M2 memory
360 which is directly connected to the DSP core.
361
Priyanka Jainc73b9032013-07-02 09:21:04 +0530362 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
363 This value denotes start offset of M3 memory which is directly
364 connected to the DSP core.
365
Priyanka Jainf81e8b22013-04-04 09:31:54 +0530366 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
367 This value denotes start offset of DSP CCSR space.
368
Priyanka Jaine9dcaa82013-12-17 14:25:52 +0530369 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
370 Single Source Clock is clocking mode present in some of FSL SoC's.
371 In this mode, a single differential clock is used to supply
372 clocks to the sysclock, ddrclock and usbclock.
373
Aneesh Bansal8bcbc272014-03-18 23:40:26 +0530374 CONFIG_SYS_CPC_REINIT_F
375 This CONFIG is defined when the CPC is configured as SRAM at the
Bin Meng75574052016-02-05 19:30:11 -0800376 time of U-Boot entry and is required to be re-initialized.
Aneesh Bansal8bcbc272014-03-18 23:40:26 +0530377
Daniel Schwierzeckd8a49ca2012-04-02 02:57:56 +0000378- Generic CPU options:
379 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
380
381 Defines the endianess of the CPU. Implementation of those
382 values is arch specific.
383
York Sunf0626592013-09-30 09:22:09 -0700384 CONFIG_SYS_FSL_DDR
385 Freescale DDR driver in use. This type of DDR controller is
Tom Rinie5404982021-05-14 21:34:26 -0400386 found in mpc83xx, mpc85xx as well as some ARM core SoCs.
York Sunf0626592013-09-30 09:22:09 -0700387
388 CONFIG_SYS_FSL_DDR_ADDR
389 Freescale DDR memory-mapped register base.
390
391 CONFIG_SYS_FSL_DDR_EMU
392 Specify emulator support for DDR. Some DDR features such as
393 deskew training are not available.
394
395 CONFIG_SYS_FSL_DDRC_GEN1
396 Freescale DDR1 controller.
397
398 CONFIG_SYS_FSL_DDRC_GEN2
399 Freescale DDR2 controller.
400
401 CONFIG_SYS_FSL_DDRC_GEN3
402 Freescale DDR3 controller.
403
York Sun2896cb72014-03-27 17:54:47 -0700404 CONFIG_SYS_FSL_DDRC_GEN4
405 Freescale DDR4 controller.
406
York Sun461c9392013-09-30 14:20:51 -0700407 CONFIG_SYS_FSL_DDRC_ARM_GEN3
408 Freescale DDR3 controller for ARM-based SoCs.
409
York Sunf0626592013-09-30 09:22:09 -0700410 CONFIG_SYS_FSL_DDR1
411 Board config to use DDR1. It can be enabled for SoCs with
412 Freescale DDR1 or DDR2 controllers, depending on the board
413 implemetation.
414
415 CONFIG_SYS_FSL_DDR2
Robert P. J. Day8d56db92016-07-15 13:44:45 -0400416 Board config to use DDR2. It can be enabled for SoCs with
York Sunf0626592013-09-30 09:22:09 -0700417 Freescale DDR2 or DDR3 controllers, depending on the board
418 implementation.
419
420 CONFIG_SYS_FSL_DDR3
421 Board config to use DDR3. It can be enabled for SoCs with
York Sun2896cb72014-03-27 17:54:47 -0700422 Freescale DDR3 or DDR3L controllers.
423
424 CONFIG_SYS_FSL_DDR3L
425 Board config to use DDR3L. It can be enabled for SoCs with
426 DDR3L controllers.
427
Prabhakar Kushwaha62908c22014-01-18 12:28:30 +0530428 CONFIG_SYS_FSL_IFC_BE
429 Defines the IFC controller register space as Big Endian
430
431 CONFIG_SYS_FSL_IFC_LE
432 Defines the IFC controller register space as Little Endian
433
Prabhakar Kushwaha3c48f582017-02-02 15:01:26 +0530434 CONFIG_SYS_FSL_IFC_CLK_DIV
435 Defines divider of platform clock(clock input to IFC controller).
436
Prabhakar Kushwahabedc5622017-02-02 15:02:00 +0530437 CONFIG_SYS_FSL_LBC_CLK_DIV
438 Defines divider of platform clock(clock input to eLBC controller).
439
York Sun29647ab2014-02-10 13:59:42 -0800440 CONFIG_SYS_FSL_DDR_BE
441 Defines the DDR controller register space as Big Endian
442
443 CONFIG_SYS_FSL_DDR_LE
444 Defines the DDR controller register space as Little Endian
445
York Sun3a0916d2014-02-10 13:59:43 -0800446 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
447 Physical address from the view of DDR controllers. It is the
448 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
449 it could be different for ARM SoCs.
450
York Sunc459ae62014-02-10 13:59:44 -0800451 CONFIG_SYS_FSL_DDR_INTLV_256B
452 DDR controller interleaving on 256-byte. This is a special
453 interleaving mode, handled by Dickens for Freescale layerscape
454 SoCs with ARM core.
455
York Sun79a779b2014-08-01 15:51:00 -0700456 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
457 Number of controllers used as main memory.
458
459 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
460 Number of controllers used for other than main memory.
461
Ruchika Guptabb7143b2014-09-09 11:50:31 +0530462 CONFIG_SYS_FSL_SEC_BE
463 Defines the SEC controller register space as Big Endian
464
465 CONFIG_SYS_FSL_SEC_LE
466 Defines the SEC controller register space as Little Endian
467
Daniel Schwierzeckd52a6232011-07-27 13:22:39 +0200468- MIPS CPU options:
Daniel Schwierzeckd52a6232011-07-27 13:22:39 +0200469 CONFIG_XWAY_SWAP_BYTES
470
471 Enable compilation of tools/xway-swap-bytes needed for Lantiq
472 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
473 be swapped if a flash programmer is used.
474
Christian Riesch48c2d6d2012-02-02 00:44:39 +0000475- ARM options:
476 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
477
478 Select high exception vectors of the ARM core, e.g., do not
479 clear the V bit of the c1 register of CP15.
480
York Sun77a10972015-03-20 19:28:08 -0700481 COUNTER_FREQUENCY
482 Generic timer clock source frequency.
483
484 COUNTER_FREQUENCY_REAL
485 Generic timer clock source frequency if the real clock is
486 different from COUNTER_FREQUENCY, and can only be determined
487 at run time.
488
Stephen Warren8d1fb312015-01-19 16:25:52 -0700489- Tegra SoC options:
490 CONFIG_TEGRA_SUPPORT_NON_SECURE
491
492 Support executing U-Boot in non-secure (NS) mode. Certain
493 impossible actions will be skipped if the CPU is in NS mode,
494 such as ARM architectural timer initialization.
495
wdenk9b7f3842003-10-09 20:09:04 +0000496- Linux Kernel Interface:
wdenk9b7f3842003-10-09 20:09:04 +0000497 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
498
Jeremiah Mahler03f930c2015-01-04 18:56:50 -0800499 When transferring memsize parameter to Linux, some versions
wdenk9b7f3842003-10-09 20:09:04 +0000500 expect it to be in bytes, others in MB.
501 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
502
Gerald Van Barenfcd91bb2008-06-03 20:34:45 -0400503 CONFIG_OF_LIBFDT
Wolfgang Denk27a5b0b2005-10-13 01:45:54 +0200504
505 New kernel versions are expecting firmware settings to be
Gerald Van Barend6abef42007-03-31 12:23:51 -0400506 passed using flattened device trees (based on open firmware
507 concepts).
508
509 CONFIG_OF_LIBFDT
510 * New libfdt-based support
511 * Adds the "fdt" command
Kim Phillips9b46eb62007-08-10 14:34:14 -0500512 * The bootm command automatically updates the fdt
Gerald Van Barend6abef42007-03-31 12:23:51 -0400513
Wolfgang Denk27a5b0b2005-10-13 01:45:54 +0200514 OF_TBCLK - The timebase frequency.
515
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +0200516 boards with QUICC Engines require OF_QE to set UCC MAC
517 addresses
Kim Phillips9b46eb62007-08-10 14:34:14 -0500518
Heiko Schocherffb293a2009-09-23 07:56:08 +0200519 CONFIG_OF_IDE_FIXUP
520
521 U-Boot can detect if an IDE device is present or not.
522 If not, and this new config option is activated, U-Boot
523 removes the ATA node from the DTS before booting Linux,
524 so the Linux IDE driver does not probe the device and
525 crash. This is needed for buggy hardware (uc101) where
526 no pull down resistor is connected to the signal IDE5V_DD7.
527
Niklaus Giger0ab978d2008-11-03 22:13:47 +0100528- vxWorks boot parameters:
529
530 bootvx constructs a valid bootline using the following
Bin Mengfb694b92015-10-07 20:19:17 -0700531 environments variables: bootdev, bootfile, ipaddr, netmask,
532 serverip, gatewayip, hostname, othbootargs.
Niklaus Giger0ab978d2008-11-03 22:13:47 +0100533 It loads the vxWorks image pointed bootfile.
534
Naoki Hayama158c2262020-10-08 13:17:08 +0900535 Note: If a "bootargs" environment is defined, it will override
Niklaus Giger0ab978d2008-11-03 22:13:47 +0100536 the defaults discussed just above.
537
Aneesh V686a0752011-06-16 23:30:51 +0000538- Cache Configuration for ARM:
539 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
540 controller
541 CONFIG_SYS_PL310_BASE - Physical base address of PL310
542 controller register space
543
wdenkda04a8b2004-08-02 23:22:59 +0000544- Serial Ports:
wdenkda04a8b2004-08-02 23:22:59 +0000545 CONFIG_PL011_CLOCK
546
547 If you have Amba PrimeCell PL011 UARTs, set this variable to
548 the clock speed of the UARTs.
549
550 CONFIG_PL01x_PORTS
551
552 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
553 define this to a list of base addresses for each (supported)
554 port. See e.g. include/configs/versatile.h
555
Karicheri, Muralidharancbc08882014-04-09 15:38:46 -0400556 CONFIG_SERIAL_HW_FLOW_CONTROL
557
558 Define this variable to enable hw flow control in serial driver.
559 Current user of this option is drivers/serial/nsl16550.c driver
wdenkda04a8b2004-08-02 23:22:59 +0000560
wdenkc6097192002-11-03 00:24:07 +0000561- Serial Download Echo Mode:
562 CONFIG_LOADS_ECHO
563 If defined to 1, all characters received during a
564 serial download (using the "loads" command) are
565 echoed back. This might be needed by some terminal
566 emulations (like "cu"), but may as well just take
567 time on others. This setting #define's the initial
568 value of the "loads_echo" environment variable.
569
Simon Glassaa34ef22016-03-13 19:07:28 -0600570- Removal of commands
571 If no commands are needed to boot, you can disable
572 CONFIG_CMDLINE to remove them. In this case, the command line
573 will not be available, and when U-Boot wants to execute the
574 boot command (on start-up) it will call board_run_command()
575 instead. This can reduce image size significantly for very
576 simple boot procedures.
577
Wolfgang Denk2aceea12013-03-23 23:50:31 +0000578- Regular expression support:
579 CONFIG_REGEX
Wolfgang Denkec7fbf52013-10-04 17:43:24 +0200580 If this variable is defined, U-Boot is linked against
581 the SLRE (Super Light Regular Expression) library,
582 which adds regex support to some commands, as for
583 example "env grep" and "setexpr".
Wolfgang Denk2aceea12013-03-23 23:50:31 +0000584
wdenkc6097192002-11-03 00:24:07 +0000585- Watchdog:
Rasmus Villemoes134cc2b2021-04-14 09:18:22 +0200586 CONFIG_SYS_WATCHDOG_FREQ
587 Some platforms automatically call WATCHDOG_RESET()
588 from the timer interrupt handler every
589 CONFIG_SYS_WATCHDOG_FREQ interrupts. If not set by the
590 board configuration file, a default of CONFIG_SYS_HZ/2
591 (i.e. 500) is used. Setting CONFIG_SYS_WATCHDOG_FREQ
592 to 0 disables calling WATCHDOG_RESET() from the timer
593 interrupt.
594
wdenkc6097192002-11-03 00:24:07 +0000595- Real-Time Clock:
596
Jon Loeligerc1da5c92007-06-11 19:03:39 -0500597 When CONFIG_CMD_DATE is selected, the type of the RTC
wdenkc6097192002-11-03 00:24:07 +0000598 has to be selected, too. Define exactly one of the
599 following options:
600
wdenkc6097192002-11-03 00:24:07 +0000601 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
Fabio Estevam3f8d1782011-10-24 06:44:15 +0000602 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
wdenkc6097192002-11-03 00:24:07 +0000603 CONFIG_RTC_MC146818 - use MC146818 RTC
wdenk1fe2c702003-03-06 21:55:29 +0000604 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
wdenkc6097192002-11-03 00:24:07 +0000605 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
wdenk0893c472003-05-20 14:25:27 +0000606 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
Markus Niebel90491f22014-07-21 11:06:16 +0200607 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
wdenkef5fe752003-03-12 10:41:04 +0000608 CONFIG_RTC_DS164x - use Dallas DS164x RTC
Tor Krillb27939b2008-03-15 15:40:26 +0100609 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
wdenkaeba06f2004-06-09 17:34:58 +0000610 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
Chris Packham2d3ac512017-05-30 12:03:33 +1200611 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
Heiko Schocher1f1b7012011-03-28 09:24:22 +0200612 CONFIG_SYS_RV3029_TCR - enable trickle charger on
613 RV3029 RTC.
wdenkc6097192002-11-03 00:24:07 +0000614
wdenkb9bbd242003-06-30 16:24:52 +0000615 Note that if the RTC uses I2C, then the I2C interface
616 must also be configured. See I2C Support, below.
617
Peter Tyser9902e422008-12-17 16:36:21 -0600618- GPIO Support:
619 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
Peter Tyser9902e422008-12-17 16:36:21 -0600620
Chris Packham9b383202010-12-19 10:12:13 +0000621 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
622 chip-ngpio pairs that tell the PCA953X driver the number of
623 pins supported by a particular chip.
624
Peter Tyser9902e422008-12-17 16:36:21 -0600625 Note that if the GPIO device uses I2C, then the I2C interface
626 must also be configured. See I2C Support, below.
627
Simon Glass4dc47ca2014-06-11 23:29:41 -0600628- I/O tracing:
629 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
630 accesses and can checksum them or write a list of them out
631 to memory. See the 'iotrace' command for details. This is
632 useful for testing device drivers since it can confirm that
633 the driver behaves the same way before and after a code
634 change. Currently this is supported on sandbox and arm. To
635 add support for your architecture, add '#include <iotrace.h>'
636 to the bottom of arch/<arch>/include/asm/io.h and test.
637
638 Example output from the 'iotrace stats' command is below.
639 Note that if the trace buffer is exhausted, the checksum will
640 still continue to operate.
641
642 iotrace is enabled
643 Start: 10000000 (buffer start address)
644 Size: 00010000 (buffer size)
645 Offset: 00000120 (current buffer offset)
646 Output: 10000120 (start + offset)
647 Count: 00000018 (number of trace records)
648 CRC32: 9526fb66 (CRC32 of all trace records)
649
wdenkc6097192002-11-03 00:24:07 +0000650- Timestamp Support:
651
wdenk4a5c8a72003-03-06 00:02:04 +0000652 When CONFIG_TIMESTAMP is selected, the timestamp
653 (date and time) of an image is printed by image
654 commands like bootm or iminfo. This option is
Jon Loeligerc1da5c92007-06-11 19:03:39 -0500655 automatically enabled when you select CONFIG_CMD_DATE .
wdenkc6097192002-11-03 00:24:07 +0000656
Karl O. Pinc8b1f90a2012-08-16 06:20:15 +0000657- Partition Labels (disklabels) Supported:
658 Zero or more of the following:
659 CONFIG_MAC_PARTITION Apple's MacOS partition table.
Karl O. Pinc8b1f90a2012-08-16 06:20:15 +0000660 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
661 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
662 bootloader. Note 2TB partition limit; see
663 disk/part_efi.c
Simon Glass8706b812016-05-01 11:36:02 -0600664 CONFIG_SCSI) you must configure support for at
Karl O. Pinc8b1f90a2012-08-16 06:20:15 +0000665 least one non-MTD partition type as well.
wdenkc6097192002-11-03 00:24:07 +0000666
wdenkf602aa02004-03-13 23:29:43 +0000667- LBA48 Support
668 CONFIG_LBA48
669
670 Set this to enable support for disks larger than 137GB
Heiko Schocher0f602e12009-12-03 11:21:21 +0100671 Also look at CONFIG_SYS_64BIT_LBA.
wdenkf602aa02004-03-13 23:29:43 +0000672 Whithout these , LBA48 support uses 32bit variables and will 'only'
673 support disks up to 2.1TB.
674
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +0200675 CONFIG_SYS_64BIT_LBA:
wdenkf602aa02004-03-13 23:29:43 +0000676 When enabled, makes the IDE subsystem use 64bit sector addresses.
677 Default is 32bit.
678
wdenkc6097192002-11-03 00:24:07 +0000679- NETWORK Support (PCI):
Kyle Moffett64b94dd2011-10-18 11:05:29 +0000680 CONFIG_E1000_SPI
681 Utility code for direct access to the SPI bus on Intel 8257x.
682 This does not do anything useful unless you set at least one
683 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
684
wdenkc6097192002-11-03 00:24:07 +0000685 CONFIG_NATSEMI
686 Support for National dp83815 chips.
687
688 CONFIG_NS8382X
689 Support for National dp8382[01] gigabit chips.
690
wdenkaa603362003-05-12 21:50:16 +0000691- NETWORK Support (other):
Rob Herringc9830dc2011-12-15 11:15:49 +0000692 CONFIG_CALXEDA_XGMAC
693 Support for the Calxeda XGMAC device
694
Ashok93fb8722012-10-15 06:20:47 +0000695 CONFIG_LAN91C96
wdenkaa603362003-05-12 21:50:16 +0000696 Support for SMSC's LAN91C96 chips.
697
wdenkaa603362003-05-12 21:50:16 +0000698 CONFIG_LAN91C96_USE_32_BIT
699 Define this to enable 32 bit addressing
700
Ashok93fb8722012-10-15 06:20:47 +0000701 CONFIG_SMC91111
wdenk3c711762004-06-09 13:37:52 +0000702 Support for SMSC's LAN91C111 chip
703
704 CONFIG_SMC91111_BASE
705 Define this to hold the physical address
706 of the device (I/O space)
707
708 CONFIG_SMC_USE_32_BIT
709 Define this if data bus is 32 bits
710
711 CONFIG_SMC_USE_IOFUNCS
712 Define this to use i/o functions instead of macros
713 (some hardware wont work with macros)
714
Heiko Schocher7d037f72011-11-15 10:00:04 -0500715 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
716 Define this if you have more then 3 PHYs.
717
Macpaul Lin199c6252010-12-21 16:59:46 +0800718 CONFIG_FTGMAC100
719 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
720
721 CONFIG_FTGMAC100_EGIGA
722 Define this to use GE link update with gigabit PHY.
723 Define this if FTGMAC100 is connected to gigabit PHY.
724 If your system has 10/100 PHY only, it might not occur
725 wrong behavior. Because PHY usually return timeout or
726 useless data when polling gigabit status and gigabit
727 control registers. This behavior won't affect the
728 correctnessof 10/100 link speed update.
729
Yoshihiro Shimodaed4cea02011-01-27 10:06:03 +0900730 CONFIG_SH_ETHER
731 Support for Renesas on-chip Ethernet controller
732
733 CONFIG_SH_ETHER_USE_PORT
734 Define the number of ports to be used
735
736 CONFIG_SH_ETHER_PHY_ADDR
737 Define the ETH PHY's address
738
Yoshihiro Shimoda281aa052011-01-27 10:06:08 +0900739 CONFIG_SH_ETHER_CACHE_WRITEBACK
740 If this option is set, the driver enables cache flush.
741
Vadim Bendeburydac69642011-10-17 08:36:14 +0000742- TPM Support:
Che-liang Chiouacea5702013-04-12 11:04:34 +0000743 CONFIG_TPM
744 Support TPM devices.
745
Christophe Ricard8759ff82015-10-06 22:54:41 +0200746 CONFIG_TPM_TIS_INFINEON
747 Support for Infineon i2c bus TPM devices. Only one device
Tom Wai-Hong Tame49fed52013-04-12 11:04:37 +0000748 per system is supported at this time.
749
Tom Wai-Hong Tame49fed52013-04-12 11:04:37 +0000750 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
751 Define the burst count bytes upper limit
752
Christophe Ricard88249232016-01-21 23:27:13 +0100753 CONFIG_TPM_ST33ZP24
754 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
755
756 CONFIG_TPM_ST33ZP24_I2C
757 Support for STMicroelectronics ST33ZP24 I2C devices.
758 Requires TPM_ST33ZP24 and I2C.
759
Christophe Ricard5ffadc32016-01-21 23:27:14 +0100760 CONFIG_TPM_ST33ZP24_SPI
761 Support for STMicroelectronics ST33ZP24 SPI devices.
762 Requires TPM_ST33ZP24 and SPI.
763
Dirk Eibach20489092013-06-26 15:55:15 +0200764 CONFIG_TPM_ATMEL_TWI
765 Support for Atmel TWI TPM device. Requires I2C support.
766
Che-liang Chiouacea5702013-04-12 11:04:34 +0000767 CONFIG_TPM_TIS_LPC
Vadim Bendeburydac69642011-10-17 08:36:14 +0000768 Support for generic parallel port TPM devices. Only one device
769 per system is supported at this time.
770
771 CONFIG_TPM_TIS_BASE_ADDRESS
772 Base address where the generic TPM device is mapped
773 to. Contemporary x86 systems usually map it at
774 0xfed40000.
775
Reinhard Pfau4fece432013-06-26 15:55:13 +0200776 CONFIG_TPM
777 Define this to enable the TPM support library which provides
778 functional interfaces to some TPM commands.
779 Requires support for a TPM device.
780
781 CONFIG_TPM_AUTH_SESSIONS
782 Define this to enable authorized functions in the TPM library.
783 Requires CONFIG_TPM and CONFIG_SHA1.
784
wdenkc6097192002-11-03 00:24:07 +0000785- USB Support:
786 At the moment only the UHCI host controller is
Heiko Schocher6f90e582017-06-14 05:49:40 +0200787 supported (PIP405, MIP405); define
wdenkc6097192002-11-03 00:24:07 +0000788 CONFIG_USB_UHCI to enable it.
789 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
wdenkfb30b4c2004-10-09 22:44:59 +0000790 and define CONFIG_USB_STORAGE to enable the USB
wdenkc6097192002-11-03 00:24:07 +0000791 storage devices.
792 Note:
793 Supported are USB Keyboards and USB Floppy drives
794 (TEAC FD-05PUB).
wdenk369d43d2004-03-14 14:09:05 +0000795
Oleksandr Tymoshenko7a881752014-02-01 21:51:25 -0700796 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
797 HW module registers.
798
Wolfgang Denk3f0137b2006-06-14 17:45:53 +0200799- USB Device:
800 Define the below if you wish to use the USB console.
801 Once firmware is rebuilt from a serial console issue the
802 command "setenv stdin usbtty; setenv stdout usbtty" and
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +0200803 attach your USB cable. The Unix command "dmesg" should print
Wolfgang Denk3f0137b2006-06-14 17:45:53 +0200804 it has found a new device. The environment variable usbtty
805 can be set to gserial or cdc_acm to enable your device to
Wolfgang Denke2601822006-06-14 18:14:56 +0200806 appear to a USB host as a Linux gserial device or a
Wolfgang Denk3f0137b2006-06-14 17:45:53 +0200807 Common Device Class Abstract Control Model serial device.
808 If you select usbtty = gserial you should be able to enumerate
809 a Linux host by
810 # modprobe usbserial vendor=0xVendorID product=0xProductID
811 else if using cdc_acm, simply setting the environment
812 variable usbtty to be cdc_acm should suffice. The following
813 might be defined in YourBoardName.h
Wolfgang Denke2601822006-06-14 18:14:56 +0200814
Wolfgang Denk3f0137b2006-06-14 17:45:53 +0200815 CONFIG_USB_DEVICE
816 Define this to build a UDC device
817
818 CONFIG_USB_TTY
819 Define this to have a tty type of device available to
820 talk to the UDC device
Wolfgang Denke2601822006-06-14 18:14:56 +0200821
Vipin KUMARbdb17702012-03-26 15:38:06 +0530822 CONFIG_USBD_HS
823 Define this to enable the high speed support for usb
824 device and usbtty. If this feature is enabled, a routine
825 int is_usbd_high_speed(void)
826 also needs to be defined by the driver to dynamically poll
827 whether the enumeration has succeded at high speed or full
828 speed.
829
Wolfgang Denke2601822006-06-14 18:14:56 +0200830 If you have a USB-IF assigned VendorID then you may wish to
Wolfgang Denk3f0137b2006-06-14 17:45:53 +0200831 define your own vendor specific values either in BoardName.h
Wolfgang Denke2601822006-06-14 18:14:56 +0200832 or directly in usbd_vendor_info.h. If you don't define
Wolfgang Denk3f0137b2006-06-14 17:45:53 +0200833 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
834 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
835 should pretend to be a Linux device to it's target host.
836
837 CONFIG_USBD_MANUFACTURER
838 Define this string as the name of your company for
839 - CONFIG_USBD_MANUFACTURER "my company"
Wolfgang Denke2601822006-06-14 18:14:56 +0200840
Wolfgang Denk3f0137b2006-06-14 17:45:53 +0200841 CONFIG_USBD_PRODUCT_NAME
842 Define this string as the name of your product
843 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
wdenkc6097192002-11-03 00:24:07 +0000844
Wolfgang Denk3f0137b2006-06-14 17:45:53 +0200845 CONFIG_USBD_VENDORID
846 Define this as your assigned Vendor ID from the USB
847 Implementors Forum. This *must* be a genuine Vendor ID
848 to avoid polluting the USB namespace.
849 - CONFIG_USBD_VENDORID 0xFFFF
Wolfgang Denke2601822006-06-14 18:14:56 +0200850
Wolfgang Denk3f0137b2006-06-14 17:45:53 +0200851 CONFIG_USBD_PRODUCTID
852 Define this as the unique Product ID
853 for your device
854 - CONFIG_USBD_PRODUCTID 0xFFFF
Wolfgang Denke2601822006-06-14 18:14:56 +0200855
Igor Grinbergac5f6ee2011-12-12 12:08:35 +0200856- ULPI Layer Support:
857 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
858 the generic ULPI layer. The generic layer accesses the ULPI PHY
859 via the platform viewport, so you need both the genric layer and
860 the viewport enabled. Currently only Chipidea/ARC based
861 viewport is supported.
862 To enable the ULPI layer support, define CONFIG_USB_ULPI and
863 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
Lucas Stachf31e4112012-10-01 00:44:35 +0200864 If your ULPI phy needs a different reference clock than the
865 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
866 the appropriate value in Hz.
wdenkc6097192002-11-03 00:24:07 +0000867
wdenk7a428cc2003-06-15 22:40:42 +0000868- MMC Support:
wdenk57b2d802003-06-27 21:31:46 +0000869 The MMC controller on the Intel PXA is supported. To
870 enable this define CONFIG_MMC. The MMC can be
871 accessed from the boot prompt by mapping the device
wdenk7a428cc2003-06-15 22:40:42 +0000872 to physical memory similar to flash. Command line is
Jon Loeligerc1da5c92007-06-11 19:03:39 -0500873 enabled with CONFIG_CMD_MMC. The MMC driver also works with
874 the FAT fs. This is enabled with CONFIG_CMD_FAT.
wdenk7a428cc2003-06-15 22:40:42 +0000875
Yoshihiro Shimodadb7717b2011-07-04 22:21:22 +0000876 CONFIG_SH_MMCIF
877 Support for Renesas on-chip MMCIF controller
878
879 CONFIG_SH_MMCIF_ADDR
880 Define the base address of MMCIF registers
881
882 CONFIG_SH_MMCIF_CLK
883 Define the clock frequency for MMCIF
884
Tom Rini58a8d322013-03-14 05:32:47 +0000885- USB Device Firmware Update (DFU) class support:
Marek Vasut7f8d4362018-02-16 16:41:18 +0100886 CONFIG_DFU_OVER_USB
Tom Rini58a8d322013-03-14 05:32:47 +0000887 This enables the USB portion of the DFU USB class
888
Pantelis Antonioucf14d0d2013-03-14 05:32:52 +0000889 CONFIG_DFU_NAND
890 This enables support for exposing NAND devices via DFU.
891
Afzal Mohammede3c687a2013-09-18 01:15:24 +0530892 CONFIG_DFU_RAM
893 This enables support for exposing RAM via DFU.
894 Note: DFU spec refer to non-volatile memory usage, but
895 allow usages beyond the scope of spec - here RAM usage,
896 one that would help mostly the developer.
897
Heiko Schochera2f831e2013-06-12 06:05:51 +0200898 CONFIG_SYS_DFU_DATA_BUF_SIZE
899 Dfu transfer uses a buffer before writing data to the
900 raw storage device. Make the size (in bytes) of this buffer
901 configurable. The size of this buffer is also configurable
902 through the "dfu_bufsiz" environment variable.
903
Pantelis Antonioua6e788d2013-03-14 05:32:48 +0000904 CONFIG_SYS_DFU_MAX_FILE_SIZE
905 When updating files rather than the raw storage device,
906 we use a static buffer to copy the file into and then write
907 the buffer once we've been given the whole file. Define
908 this to the maximum filesize (in bytes) for the buffer.
909 Default is 4 MiB if undefined.
910
Heiko Schochere1ba1512014-03-18 08:09:56 +0100911 DFU_DEFAULT_POLL_TIMEOUT
912 Poll timeout [ms], is the timeout a device can send to the
913 host. The host must wait for this timeout before sending
914 a subsequent DFU_GET_STATUS request to the device.
915
916 DFU_MANIFEST_POLL_TIMEOUT
917 Poll timeout [ms], which the device sends to the host when
918 entering dfuMANIFEST state. Host waits this timeout, before
919 sending again an USB request to the device.
920
wdenkda04a8b2004-08-02 23:22:59 +0000921- Journaling Flash filesystem support:
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +0200922 CONFIG_SYS_JFFS2_FIRST_SECTOR,
923 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
wdenkda04a8b2004-08-02 23:22:59 +0000924 Define these for a default partition on a NOR device
925
wdenkc6097192002-11-03 00:24:07 +0000926- Keyboard Support:
Simon Glasseaba37e2015-11-11 10:05:47 -0700927 See Kconfig help for available keyboard drivers.
928
wdenkc6097192002-11-03 00:24:07 +0000929- LCD Support: CONFIG_LCD
930
931 Define this to enable LCD support (for output to LCD
932 display); also select one of the supported displays
933 by defining one of these:
934
wdenkc0d54ae2003-11-25 16:55:19 +0000935 CONFIG_NEC_NL6448AC33:
wdenkc6097192002-11-03 00:24:07 +0000936
wdenkc0d54ae2003-11-25 16:55:19 +0000937 NEC NL6448AC33-18. Active, color, single scan.
wdenkc6097192002-11-03 00:24:07 +0000938
wdenkc0d54ae2003-11-25 16:55:19 +0000939 CONFIG_NEC_NL6448BC20
940
941 NEC NL6448BC20-08. 6.5", 640x480.
942 Active, color, single scan.
943
944 CONFIG_NEC_NL6448BC33_54
wdenkc6097192002-11-03 00:24:07 +0000945
wdenkc0d54ae2003-11-25 16:55:19 +0000946 NEC NL6448BC33-54. 10.4", 640x480.
wdenkc6097192002-11-03 00:24:07 +0000947 Active, color, single scan.
948
949 CONFIG_SHARP_16x9
950
951 Sharp 320x240. Active, color, single scan.
952 It isn't 16x9, and I am not sure what it is.
953
954 CONFIG_SHARP_LQ64D341
955
956 Sharp LQ64D341 display, 640x480.
957 Active, color, single scan.
958
959 CONFIG_HLD1045
960
961 HLD1045 display, 640x480.
962 Active, color, single scan.
963
964 CONFIG_OPTREX_BW
965
966 Optrex CBL50840-2 NF-FW 99 22 M5
967 or
968 Hitachi LMG6912RPFC-00T
969 or
970 Hitachi SP14Q002
971
972 320x240. Black & white.
973
Simon Glass599a4df2012-10-17 13:24:54 +0000974 CONFIG_LCD_ALIGNMENT
975
Jeremiah Mahler03f930c2015-01-04 18:56:50 -0800976 Normally the LCD is page-aligned (typically 4KB). If this is
Simon Glass599a4df2012-10-17 13:24:54 +0000977 defined then the LCD will be aligned to this value instead.
978 For ARM it is sometimes useful to use MMU_SECTION_SIZE
979 here, since it is cheaper to change data cache settings on
980 a per-section basis.
981
982
Hannes Petermaiera3c8e862015-03-27 08:01:38 +0100983 CONFIG_LCD_ROTATION
984
985 Sometimes, for example if the display is mounted in portrait
986 mode or even if it's mounted landscape but rotated by 180degree,
987 we need to rotate our content of the display relative to the
988 framebuffer, so that user can read the messages which are
989 printed out.
990 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
991 initialized with a given rotation from "vl_rot" out of
992 "vidinfo_t" which is provided by the board specific code.
993 The value for vl_rot is coded as following (matching to
994 fbcon=rotate:<n> linux-kernel commandline):
995 0 = no rotation respectively 0 degree
996 1 = 90 degree rotation
997 2 = 180 degree rotation
998 3 = 270 degree rotation
999
1000 If CONFIG_LCD_ROTATION is not defined, the console will be
1001 initialized with 0degree rotation.
1002
wdenk0e2bd9c2004-06-06 21:51:03 +00001003- MII/PHY support:
wdenk0e2bd9c2004-06-06 21:51:03 +00001004 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1005
1006 The clock frequency of the MII bus
1007
wdenk0e2bd9c2004-06-06 21:51:03 +00001008 CONFIG_PHY_CMD_DELAY (ppc4xx)
1009
1010 Some PHY like Intel LXT971A need extra delay after
1011 command issued before MII status register can be read
1012
wdenkc6097192002-11-03 00:24:07 +00001013- IP address:
1014 CONFIG_IPADDR
1015
1016 Define a default value for the IP address to use for
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001017 the default Ethernet interface, in case this is not
wdenkc6097192002-11-03 00:24:07 +00001018 determined through e.g. bootp.
Wolfgang Denk26da2992011-10-26 10:21:22 +00001019 (Environment variable "ipaddr")
wdenkc6097192002-11-03 00:24:07 +00001020
1021- Server IP address:
1022 CONFIG_SERVERIP
1023
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001024 Defines a default value for the IP address of a TFTP
wdenkc6097192002-11-03 00:24:07 +00001025 server to contact when using the "tftboot" command.
Wolfgang Denk26da2992011-10-26 10:21:22 +00001026 (Environment variable "serverip")
wdenkc6097192002-11-03 00:24:07 +00001027
Wolfgang Denk26da2992011-10-26 10:21:22 +00001028- Gateway IP address:
1029 CONFIG_GATEWAYIP
1030
1031 Defines a default value for the IP address of the
1032 default router where packets to other networks are
1033 sent to.
1034 (Environment variable "gatewayip")
1035
1036- Subnet mask:
1037 CONFIG_NETMASK
1038
1039 Defines a default value for the subnet mask (or
1040 routing prefix) which is used to determine if an IP
1041 address belongs to the local subnet or needs to be
1042 forwarded through a router.
1043 (Environment variable "netmask")
1044
wdenkc6097192002-11-03 00:24:07 +00001045- BOOTP Recovery Mode:
1046 CONFIG_BOOTP_RANDOM_DELAY
1047
1048 If you have many targets in a network that try to
1049 boot using BOOTP, you may want to avoid that all
1050 systems send out BOOTP requests at precisely the same
1051 moment (which would happen for instance at recovery
1052 from a power failure, when all systems will try to
1053 boot, thus flooding the BOOTP server. Defining
1054 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1055 inserted before sending out BOOTP requests. The
Wolfgang Denkb65aaf92007-08-06 23:21:05 +02001056 following delays are inserted then:
wdenkc6097192002-11-03 00:24:07 +00001057
1058 1st BOOTP request: delay 0 ... 1 sec
1059 2nd BOOTP request: delay 0 ... 2 sec
1060 3rd BOOTP request: delay 0 ... 4 sec
1061 4th and following
1062 BOOTP requests: delay 0 ... 8 sec
1063
Thierry Reding8977cda2014-08-19 10:21:24 +02001064 CONFIG_BOOTP_ID_CACHE_SIZE
1065
1066 BOOTP packets are uniquely identified using a 32-bit ID. The
1067 server will copy the ID from client requests to responses and
1068 U-Boot will use this to determine if it is the destination of
1069 an incoming response. Some servers will check that addresses
1070 aren't in use before handing them out (usually using an ARP
1071 ping) and therefore take up to a few hundred milliseconds to
1072 respond. Network congestion may also influence the time it
1073 takes for a response to make it back to the client. If that
1074 time is too long, U-Boot will retransmit requests. In order
1075 to allow earlier responses to still be accepted after these
1076 retransmissions, U-Boot's BOOTP client keeps a small cache of
1077 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
1078 cache. The default is to keep IDs for up to four outstanding
1079 requests. Increasing this will allow U-Boot to accept offers
1080 from a BOOTP client in networks with unusually high latency.
1081
stroesee0aadfb2003-08-28 14:17:32 +00001082- DHCP Advanced Options:
Joe Hershberger8ca7fa02012-05-23 07:59:19 +00001083
Joe Hershbergerb35a3a62012-05-23 08:00:12 +00001084 - Link-local IP address negotiation:
1085 Negotiate with other link-local clients on the local network
1086 for an address that doesn't require explicit configuration.
1087 This is especially useful if a DHCP server cannot be guaranteed
1088 to exist in all environments that the device must operate.
1089
1090 See doc/README.link-local for more information.
1091
Prabhakar Kushwaha2dec06f2017-11-23 16:51:32 +05301092 - MAC address from environment variables
1093
1094 FDT_SEQ_MACADDR_FROM_ENV
1095
1096 Fix-up device tree with MAC addresses fetched sequentially from
1097 environment variables. This config work on assumption that
1098 non-usable ethernet node of device-tree are either not present
1099 or their status has been marked as "disabled".
1100
wdenk145d2c12004-04-15 21:48:45 +00001101 - CDP Options:
wdenk05939202004-04-18 17:39:38 +00001102 CONFIG_CDP_DEVICE_ID
wdenk145d2c12004-04-15 21:48:45 +00001103
1104 The device id used in CDP trigger frames.
1105
1106 CONFIG_CDP_DEVICE_ID_PREFIX
1107
1108 A two character string which is prefixed to the MAC address
1109 of the device.
1110
1111 CONFIG_CDP_PORT_ID
1112
1113 A printf format string which contains the ascii name of
1114 the port. Normally is set to "eth%d" which sets
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001115 eth0 for the first Ethernet, eth1 for the second etc.
wdenk145d2c12004-04-15 21:48:45 +00001116
1117 CONFIG_CDP_CAPABILITIES
1118
1119 A 32bit integer which indicates the device capabilities;
1120 0x00000010 for a normal host which does not forwards.
1121
1122 CONFIG_CDP_VERSION
1123
1124 An ascii string containing the version of the software.
1125
1126 CONFIG_CDP_PLATFORM
1127
1128 An ascii string containing the name of the platform.
1129
1130 CONFIG_CDP_TRIGGER
1131
1132 A 32bit integer sent on the trigger.
1133
1134 CONFIG_CDP_POWER_CONSUMPTION
1135
1136 A 16bit integer containing the power consumption of the
1137 device in .1 of milliwatts.
1138
1139 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1140
1141 A byte containing the id of the VLAN.
1142
Uri Mashiach3dc6f652017-01-19 10:51:05 +02001143- Status LED: CONFIG_LED_STATUS
wdenkc6097192002-11-03 00:24:07 +00001144
1145 Several configurations allow to display the current
1146 status using a LED. For instance, the LED will blink
1147 fast while running U-Boot code, stop blinking as
1148 soon as a reply to a BOOTP request was received, and
1149 start blinking slow once the Linux kernel is running
1150 (supported by a status LED driver in the Linux
Uri Mashiach3dc6f652017-01-19 10:51:05 +02001151 kernel). Defining CONFIG_LED_STATUS enables this
wdenkc6097192002-11-03 00:24:07 +00001152 feature in U-Boot.
1153
Igor Grinberg4997a9e2013-11-08 01:03:50 +02001154 Additional options:
1155
Uri Mashiach3dc6f652017-01-19 10:51:05 +02001156 CONFIG_LED_STATUS_GPIO
Igor Grinberg4997a9e2013-11-08 01:03:50 +02001157 The status LED can be connected to a GPIO pin.
1158 In such cases, the gpio_led driver can be used as a
Uri Mashiach3dc6f652017-01-19 10:51:05 +02001159 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO
Igor Grinberg4997a9e2013-11-08 01:03:50 +02001160 to include the gpio_led driver in the U-Boot binary.
1161
Igor Grinberg203bd9f2013-11-08 01:03:52 +02001162 CONFIG_GPIO_LED_INVERTED_TABLE
1163 Some GPIO connected LEDs may have inverted polarity in which
1164 case the GPIO high value corresponds to LED off state and
1165 GPIO low value corresponds to LED on state.
1166 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
1167 with a list of GPIO LEDs that have inverted polarity.
1168
Tom Rini52b2e262021-08-18 23:12:24 -04001169- I2C Support:
Heiko Schochere0e55bc2012-01-16 21:12:24 +00001170 CONFIG_SYS_NUM_I2C_BUSES
Simon Glassb05e2b32016-10-02 18:01:05 -06001171 Hold the number of i2c buses you want to use.
Heiko Schochere0e55bc2012-01-16 21:12:24 +00001172
1173 CONFIG_SYS_I2C_DIRECT_BUS
1174 define this, if you don't use i2c muxes on your hardware.
1175 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
1176 omit this define.
1177
1178 CONFIG_SYS_I2C_MAX_HOPS
1179 define how many muxes are maximal consecutively connected
1180 on one i2c bus. If you not use i2c muxes, omit this
1181 define.
1182
1183 CONFIG_SYS_I2C_BUSES
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08001184 hold a list of buses you want to use, only used if
Heiko Schochere0e55bc2012-01-16 21:12:24 +00001185 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
1186 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
1187 CONFIG_SYS_NUM_I2C_BUSES = 9:
1188
1189 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
1190 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
1191 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
1192 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
1193 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
1194 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
1195 {1, {I2C_NULL_HOP}}, \
1196 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
1197 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
1198 }
1199
1200 which defines
1201 bus 0 on adapter 0 without a mux
Heiko Schocher479a4cf2013-01-29 08:53:15 +01001202 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
1203 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
1204 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
1205 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
1206 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
Heiko Schochere0e55bc2012-01-16 21:12:24 +00001207 bus 6 on adapter 1 without a mux
Heiko Schocher479a4cf2013-01-29 08:53:15 +01001208 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
1209 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
Heiko Schochere0e55bc2012-01-16 21:12:24 +00001210
1211 If you do not have i2c muxes on your board, omit this define.
1212
Simon Glass3efce392017-05-12 21:10:00 -06001213- Legacy I2C Support:
Heiko Schocher479a4cf2013-01-29 08:53:15 +01001214 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
wdenkb9bbd242003-06-30 16:24:52 +00001215 then the following macros need to be defined (examples are
1216 from include/configs/lwmon.h):
wdenkc6097192002-11-03 00:24:07 +00001217
1218 I2C_INIT
1219
wdenkb9bbd242003-06-30 16:24:52 +00001220 (Optional). Any commands necessary to enable the I2C
wdenk4a5c8a72003-03-06 00:02:04 +00001221 controller or configure ports.
wdenkc6097192002-11-03 00:24:07 +00001222
wdenk544e9732004-02-06 23:19:44 +00001223 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
wdenkb9bbd242003-06-30 16:24:52 +00001224
wdenkc6097192002-11-03 00:24:07 +00001225 I2C_ACTIVE
1226
1227 The code necessary to make the I2C data line active
1228 (driven). If the data line is open collector, this
1229 define can be null.
1230
wdenkb9bbd242003-06-30 16:24:52 +00001231 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1232
wdenkc6097192002-11-03 00:24:07 +00001233 I2C_TRISTATE
1234
1235 The code necessary to make the I2C data line tri-stated
1236 (inactive). If the data line is open collector, this
1237 define can be null.
1238
wdenkb9bbd242003-06-30 16:24:52 +00001239 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1240
wdenkc6097192002-11-03 00:24:07 +00001241 I2C_READ
1242
York Sun4a598092013-04-01 11:29:11 -07001243 Code that returns true if the I2C data line is high,
1244 false if it is low.
wdenkc6097192002-11-03 00:24:07 +00001245
wdenkb9bbd242003-06-30 16:24:52 +00001246 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1247
wdenkc6097192002-11-03 00:24:07 +00001248 I2C_SDA(bit)
1249
York Sun4a598092013-04-01 11:29:11 -07001250 If <bit> is true, sets the I2C data line high. If it
1251 is false, it clears it (low).
wdenkc6097192002-11-03 00:24:07 +00001252
wdenkb9bbd242003-06-30 16:24:52 +00001253 eg: #define I2C_SDA(bit) \
wdenk2bb11052003-07-17 23:16:40 +00001254 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
wdenk544e9732004-02-06 23:19:44 +00001255 else immr->im_cpm.cp_pbdat &= ~PB_SDA
wdenkb9bbd242003-06-30 16:24:52 +00001256
wdenkc6097192002-11-03 00:24:07 +00001257 I2C_SCL(bit)
1258
York Sun4a598092013-04-01 11:29:11 -07001259 If <bit> is true, sets the I2C clock line high. If it
1260 is false, it clears it (low).
wdenkc6097192002-11-03 00:24:07 +00001261
wdenkb9bbd242003-06-30 16:24:52 +00001262 eg: #define I2C_SCL(bit) \
wdenk2bb11052003-07-17 23:16:40 +00001263 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
wdenk544e9732004-02-06 23:19:44 +00001264 else immr->im_cpm.cp_pbdat &= ~PB_SCL
wdenkb9bbd242003-06-30 16:24:52 +00001265
wdenkc6097192002-11-03 00:24:07 +00001266 I2C_DELAY
1267
1268 This delay is invoked four times per clock cycle so this
1269 controls the rate of data transfer. The data rate thus
wdenkb9bbd242003-06-30 16:24:52 +00001270 is 1 / (I2C_DELAY * 4). Often defined to be something
wdenk21136db2003-07-16 21:53:01 +00001271 like:
1272
wdenkb9bbd242003-06-30 16:24:52 +00001273 #define I2C_DELAY udelay(2)
wdenkc6097192002-11-03 00:24:07 +00001274
Mike Frysingeree12d542010-07-21 13:38:02 -04001275 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1276
1277 If your arch supports the generic GPIO framework (asm/gpio.h),
1278 then you may alternatively define the two GPIOs that are to be
1279 used as SCL / SDA. Any of the previous I2C_xxx macros will
1280 have GPIO-based defaults assigned to them as appropriate.
1281
1282 You should define these to the GPIO value as given directly to
1283 the generic GPIO functions.
1284
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001285 CONFIG_SYS_I2C_INIT_BOARD
wdenkcc1e2562003-03-06 13:39:27 +00001286
wdenk57b2d802003-06-27 21:31:46 +00001287 When a board is reset during an i2c bus transfer
1288 chips might think that the current transfer is still
1289 in progress. On some boards it is possible to access
1290 the i2c SCLK line directly, either by using the
1291 processor pin as a GPIO or by having a second pin
1292 connected to the bus. If this option is defined a
1293 custom i2c_init_board() routine in boards/xxx/board.c
1294 is run early in the boot sequence.
wdenkcc1e2562003-03-06 13:39:27 +00001295
Ben Warren45657152006-09-07 16:50:54 -04001296 CONFIG_I2C_MULTI_BUS
1297
1298 This option allows the use of multiple I2C buses, each of which
Wolfgang Denk092ae952011-10-26 10:21:21 +00001299 must have a controller. At any point in time, only one bus is
1300 active. To switch to a different bus, use the 'i2c dev' command.
Ben Warren45657152006-09-07 16:50:54 -04001301 Note that bus numbering is zero-based.
1302
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001303 CONFIG_SYS_I2C_NOPROBES
Ben Warren45657152006-09-07 16:50:54 -04001304
1305 This option specifies a list of I2C devices that will be skipped
Wolfgang Denk092ae952011-10-26 10:21:21 +00001306 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
Peter Tyser469cde42009-04-18 22:34:03 -05001307 is set, specify a list of bus-device pairs. Otherwise, specify
1308 a 1D array of device addresses
Ben Warren45657152006-09-07 16:50:54 -04001309
1310 e.g.
1311 #undef CONFIG_I2C_MULTI_BUS
Wolfgang Denk092ae952011-10-26 10:21:21 +00001312 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
Ben Warren45657152006-09-07 16:50:54 -04001313
1314 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1315
Wolfgang Denk092ae952011-10-26 10:21:21 +00001316 #define CONFIG_I2C_MULTI_BUS
Simon Glassb05e2b32016-10-02 18:01:05 -06001317 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
Ben Warren45657152006-09-07 16:50:54 -04001318
1319 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1320
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001321 CONFIG_SYS_SPD_BUS_NUM
Timur Tabiab347542006-11-03 19:15:00 -06001322
1323 If defined, then this indicates the I2C bus number for DDR SPD.
1324 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1325
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001326 CONFIG_SYS_RTC_BUS_NUM
Stefan Roese096cc9b2007-02-20 10:51:26 +01001327
1328 If defined, then this indicates the I2C bus number for the RTC.
1329 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1330
Andrew Dyer58c41f92008-12-29 17:36:01 -06001331 CONFIG_SOFT_I2C_READ_REPEATED_START
1332
1333 defining this will force the i2c_read() function in
1334 the soft_i2c driver to perform an I2C repeated start
1335 between writing the address pointer and reading the
1336 data. If this define is omitted the default behaviour
1337 of doing a stop-start sequence will be used. Most I2C
1338 devices can use either method, but some require one or
1339 the other.
Timur Tabiab347542006-11-03 19:15:00 -06001340
wdenkc6097192002-11-03 00:24:07 +00001341- SPI Support: CONFIG_SPI
1342
1343 Enables SPI driver (so far only tested with
1344 SPI EEPROM, also an instance works with Crystal A/D and
1345 D/As on the SACSng board)
1346
Heiko Schocherb77c8882014-07-14 10:22:11 +02001347 CONFIG_SYS_SPI_MXC_WAIT
1348 Timeout for waiting until spi transfer completed.
1349 default: (CONFIG_SYS_HZ/100) /* 10 ms */
1350
Matthias Fuchsa4400872007-12-27 17:12:34 +01001351- FPGA Support: CONFIG_FPGA
wdenkc6097192002-11-03 00:24:07 +00001352
Matthias Fuchsa4400872007-12-27 17:12:34 +01001353 Enables FPGA subsystem.
1354
1355 CONFIG_FPGA_<vendor>
1356
1357 Enables support for specific chip vendors.
1358 (ALTERA, XILINX)
wdenkc6097192002-11-03 00:24:07 +00001359
Matthias Fuchsa4400872007-12-27 17:12:34 +01001360 CONFIG_FPGA_<family>
wdenkc6097192002-11-03 00:24:07 +00001361
Matthias Fuchsa4400872007-12-27 17:12:34 +01001362 Enables support for FPGA family.
1363 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1364
1365 CONFIG_FPGA_COUNT
1366
1367 Specify the number of FPGA devices to support.
wdenkc6097192002-11-03 00:24:07 +00001368
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001369 CONFIG_SYS_FPGA_PROG_FEEDBACK
wdenkc6097192002-11-03 00:24:07 +00001370
wdenk57b2d802003-06-27 21:31:46 +00001371 Enable printing of hash marks during FPGA configuration.
wdenkc6097192002-11-03 00:24:07 +00001372
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001373 CONFIG_SYS_FPGA_CHECK_BUSY
wdenkc6097192002-11-03 00:24:07 +00001374
wdenk4a5c8a72003-03-06 00:02:04 +00001375 Enable checks on FPGA configuration interface busy
1376 status by the configuration function. This option
1377 will require a board or device specific function to
1378 be written.
wdenkc6097192002-11-03 00:24:07 +00001379
1380 CONFIG_FPGA_DELAY
1381
1382 If defined, a function that provides delays in the FPGA
1383 configuration driver.
1384
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001385 CONFIG_SYS_FPGA_CHECK_CTRLC
wdenkc6097192002-11-03 00:24:07 +00001386 Allow Control-C to interrupt FPGA configuration
1387
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001388 CONFIG_SYS_FPGA_CHECK_ERROR
wdenkc6097192002-11-03 00:24:07 +00001389
wdenk4a5c8a72003-03-06 00:02:04 +00001390 Check for configuration errors during FPGA bitfile
1391 loading. For example, abort during Virtex II
1392 configuration if the INIT_B line goes low (which
1393 indicated a CRC error).
wdenkc6097192002-11-03 00:24:07 +00001394
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001395 CONFIG_SYS_FPGA_WAIT_INIT
wdenkc6097192002-11-03 00:24:07 +00001396
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08001397 Maximum time to wait for the INIT_B line to de-assert
1398 after PROB_B has been de-asserted during a Virtex II
wdenk4a5c8a72003-03-06 00:02:04 +00001399 FPGA configuration sequence. The default time is 500
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001400 ms.
wdenkc6097192002-11-03 00:24:07 +00001401
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001402 CONFIG_SYS_FPGA_WAIT_BUSY
wdenkc6097192002-11-03 00:24:07 +00001403
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08001404 Maximum time to wait for BUSY to de-assert during
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001405 Virtex II FPGA configuration. The default is 5 ms.
wdenkc6097192002-11-03 00:24:07 +00001406
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001407 CONFIG_SYS_FPGA_WAIT_CONFIG
wdenkc6097192002-11-03 00:24:07 +00001408
wdenk4a5c8a72003-03-06 00:02:04 +00001409 Time to wait after FPGA configuration. The default is
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001410 200 ms.
wdenkc6097192002-11-03 00:24:07 +00001411
wdenkc6097192002-11-03 00:24:07 +00001412- Vendor Parameter Protection:
1413
wdenk4a5c8a72003-03-06 00:02:04 +00001414 U-Boot considers the values of the environment
1415 variables "serial#" (Board Serial Number) and
wdenkeb20ad32003-09-05 23:19:14 +00001416 "ethaddr" (Ethernet Address) to be parameters that
wdenk4a5c8a72003-03-06 00:02:04 +00001417 are set once by the board vendor / manufacturer, and
1418 protects these variables from casual modification by
1419 the user. Once set, these variables are read-only,
1420 and write or delete attempts are rejected. You can
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001421 change this behaviour:
wdenkc6097192002-11-03 00:24:07 +00001422
1423 If CONFIG_ENV_OVERWRITE is #defined in your config
1424 file, the write protection for vendor parameters is
wdenkcc1e2562003-03-06 13:39:27 +00001425 completely disabled. Anybody can change or delete
wdenkc6097192002-11-03 00:24:07 +00001426 these parameters.
1427
Joe Hershberger76f353e2015-05-04 14:55:14 -05001428 Alternatively, if you define _both_ an ethaddr in the
1429 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001430 Ethernet address is installed in the environment,
wdenkc6097192002-11-03 00:24:07 +00001431 which can be changed exactly ONCE by the user. [The
1432 serial# is unaffected by this, i. e. it remains
1433 read-only.]
1434
Joe Hershberger71497d02012-12-11 22:16:31 -06001435 The same can be accomplished in a more flexible way
1436 for any variable by configuring the type of access
1437 to allow for those variables in the ".flags" variable
1438 or define CONFIG_ENV_FLAGS_LIST_STATIC.
1439
wdenkc6097192002-11-03 00:24:07 +00001440- Protected RAM:
1441 CONFIG_PRAM
1442
1443 Define this variable to enable the reservation of
1444 "protected RAM", i. e. RAM which is not overwritten
1445 by U-Boot. Define CONFIG_PRAM to hold the number of
1446 kB you want to reserve for pRAM. You can overwrite
1447 this default value by defining an environment
1448 variable "pram" to the number of kB you want to
1449 reserve. Note that the board info structure will
1450 still show the full amount of RAM. If pRAM is
1451 reserved, a new environment variable "mem" will
1452 automatically be defined to hold the amount of
1453 remaining RAM in a form that can be passed as boot
1454 argument to Linux, for instance like that:
1455
Wolfgang Denk86eb3b72005-11-20 21:40:11 +01001456 setenv bootargs ... mem=\${mem}
wdenkc6097192002-11-03 00:24:07 +00001457 saveenv
1458
1459 This way you can tell Linux not to use this memory,
1460 either, which results in a memory region that will
1461 not be affected by reboots.
1462
1463 *WARNING* If your board configuration uses automatic
1464 detection of the RAM size, you must make sure that
1465 this memory test is non-destructive. So far, the
1466 following board configurations are known to be
1467 "pRAM-clean":
1468
Heiko Schocher65d94db2017-06-07 17:33:09 +02001469 IVMS8, IVML24, SPD8xx,
Wolfgang Denk90326762012-10-24 02:36:15 +00001470 HERMES, IP860, RPXlite, LWMON,
Heiko Schocher71cb3e92017-06-07 17:33:10 +02001471 FLAGADM
wdenkc6097192002-11-03 00:24:07 +00001472
1473- Error Recovery:
wdenkc6097192002-11-03 00:24:07 +00001474 Note:
1475
wdenk57b2d802003-06-27 21:31:46 +00001476 In the current implementation, the local variables
1477 space and global environment variables space are
1478 separated. Local variables are those you define by
1479 simply typing `name=value'. To access a local
1480 variable later on, you have write `$name' or
1481 `${name}'; to execute the contents of a variable
1482 directly type `$name' at the command prompt.
wdenkc6097192002-11-03 00:24:07 +00001483
wdenk4a5c8a72003-03-06 00:02:04 +00001484 Global environment variables are those you use
1485 setenv/printenv to work with. To run a command stored
1486 in such a variable, you need to use the run command,
1487 and you must not use the '$' sign to access them.
wdenkc6097192002-11-03 00:24:07 +00001488
1489 To store commands and special characters in a
1490 variable, please use double quotation marks
1491 surrounding the whole text of the variable, instead
1492 of the backslashes before semicolons and special
1493 symbols.
1494
wdenkc0aa5c52003-12-06 19:49:23 +00001495- Default Environment:
wdenkc6097192002-11-03 00:24:07 +00001496 CONFIG_EXTRA_ENV_SETTINGS
1497
wdenk4a5c8a72003-03-06 00:02:04 +00001498 Define this to contain any number of null terminated
1499 strings (variable = value pairs) that will be part of
wdenkeb20ad32003-09-05 23:19:14 +00001500 the default environment compiled into the boot image.
wdenk591dda52002-11-18 00:14:45 +00001501
wdenk4a5c8a72003-03-06 00:02:04 +00001502 For example, place something like this in your
1503 board's config file:
wdenkc6097192002-11-03 00:24:07 +00001504
1505 #define CONFIG_EXTRA_ENV_SETTINGS \
1506 "myvar1=value1\0" \
1507 "myvar2=value2\0"
1508
wdenk4a5c8a72003-03-06 00:02:04 +00001509 Warning: This method is based on knowledge about the
1510 internal format how the environment is stored by the
1511 U-Boot code. This is NOT an official, exported
1512 interface! Although it is unlikely that this format
wdenkeb20ad32003-09-05 23:19:14 +00001513 will change soon, there is no guarantee either.
wdenkc6097192002-11-03 00:24:07 +00001514 You better know what you are doing here.
1515
wdenk4a5c8a72003-03-06 00:02:04 +00001516 Note: overly (ab)use of the default environment is
1517 discouraged. Make sure to check other ways to preset
Wolfgang Denk85c25df2009-04-01 23:34:12 +02001518 the environment like the "source" command or the
wdenk4a5c8a72003-03-06 00:02:04 +00001519 boot command first.
wdenkc6097192002-11-03 00:24:07 +00001520
Simon Glass6b8d5fd2012-11-30 13:01:17 +00001521 CONFIG_DELAY_ENVIRONMENT
1522
1523 Normally the environment is loaded when the board is
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08001524 initialised so that it is available to U-Boot. This inhibits
Simon Glass6b8d5fd2012-11-30 13:01:17 +00001525 that so that the environment is not available until
1526 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
1527 this is instead controlled by the value of
1528 /config/load-environment.
1529
Wolfgang Denkd590fb12011-10-07 09:58:21 +02001530 CONFIG_STANDALONE_LOAD_ADDR
1531
Wolfgang Denk23f78482011-10-09 21:06:34 +02001532 This option defines a board specific value for the
1533 address where standalone program gets loaded, thus
1534 overwriting the architecture dependent default
Wolfgang Denkd590fb12011-10-07 09:58:21 +02001535 settings.
1536
1537- Frame Buffer Address:
1538 CONFIG_FB_ADDR
1539
1540 Define CONFIG_FB_ADDR if you want to use specific
Wolfgang Denka71eb8e2013-01-03 00:43:59 +00001541 address for frame buffer. This is typically the case
1542 when using a graphics controller has separate video
1543 memory. U-Boot will then place the frame buffer at
1544 the given address instead of dynamically reserving it
1545 in system RAM by calling lcd_setmem(), which grabs
1546 the memory for the frame buffer depending on the
1547 configured panel size.
Wolfgang Denkd590fb12011-10-07 09:58:21 +02001548
1549 Please see board_init_f function.
1550
Detlev Zundel0ecb6112009-12-01 17:16:19 +01001551- Automatic software updates via TFTP server
1552 CONFIG_UPDATE_TFTP
1553 CONFIG_UPDATE_TFTP_CNT_MAX
1554 CONFIG_UPDATE_TFTP_MSEC_MAX
1555
1556 These options enable and control the auto-update feature;
1557 for a more detailed description refer to doc/README.update.
1558
1559- MTD Support (mtdparts command, UBI support)
Heiko Schocherf5895d12014-06-24 10:10:04 +02001560 CONFIG_MTD_UBI_WL_THRESHOLD
1561 This parameter defines the maximum difference between the highest
1562 erase counter value and the lowest erase counter value of eraseblocks
1563 of UBI devices. When this threshold is exceeded, UBI starts performing
1564 wear leveling by means of moving data from eraseblock with low erase
1565 counter to eraseblocks with high erase counter.
1566
1567 The default value should be OK for SLC NAND flashes, NOR flashes and
1568 other flashes which have eraseblock life-cycle 100000 or more.
1569 However, in case of MLC NAND flashes which typically have eraseblock
1570 life-cycle less than 10000, the threshold should be lessened (e.g.,
1571 to 128 or 256, although it does not have to be power of 2).
1572
1573 default: 4096
Simon Glass6c0be912014-10-23 18:58:54 -06001574
Heiko Schocherf5895d12014-06-24 10:10:04 +02001575 CONFIG_MTD_UBI_BEB_LIMIT
1576 This option specifies the maximum bad physical eraseblocks UBI
1577 expects on the MTD device (per 1024 eraseblocks). If the
1578 underlying flash does not admit of bad eraseblocks (e.g. NOR
1579 flash), this value is ignored.
1580
1581 NAND datasheets often specify the minimum and maximum NVM
1582 (Number of Valid Blocks) for the flashes' endurance lifetime.
1583 The maximum expected bad eraseblocks per 1024 eraseblocks
1584 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
1585 which gives 20 for most NANDs (MaxNVB is basically the total
1586 count of eraseblocks on the chip).
1587
1588 To put it differently, if this value is 20, UBI will try to
1589 reserve about 1.9% of physical eraseblocks for bad blocks
1590 handling. And that will be 1.9% of eraseblocks on the entire
1591 NAND chip, not just the MTD partition UBI attaches. This means
1592 that if you have, say, a NAND flash chip admits maximum 40 bad
1593 eraseblocks, and it is split on two MTD partitions of the same
1594 size, UBI will reserve 40 eraseblocks when attaching a
1595 partition.
1596
1597 default: 20
1598
1599 CONFIG_MTD_UBI_FASTMAP
1600 Fastmap is a mechanism which allows attaching an UBI device
1601 in nearly constant time. Instead of scanning the whole MTD device it
1602 only has to locate a checkpoint (called fastmap) on the device.
1603 The on-flash fastmap contains all information needed to attach
1604 the device. Using fastmap makes only sense on large devices where
1605 attaching by scanning takes long. UBI will not automatically install
1606 a fastmap on old images, but you can set the UBI parameter
1607 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
1608 that fastmap-enabled images are still usable with UBI implementations
1609 without fastmap support. On typical flash devices the whole fastmap
1610 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
1611
1612 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
1613 Set this parameter to enable fastmap automatically on images
1614 without a fastmap.
1615 default: 0
1616
Heiko Schocher94b66de2015-10-22 06:19:21 +02001617 CONFIG_MTD_UBI_FM_DEBUG
1618 Enable UBI fastmap debug
1619 default: 0
1620
Daniel Schwierzeck39ca08e2011-07-18 07:48:07 +00001621- SPL framework
Wolfgang Denk825223d2011-09-11 21:24:09 +02001622 CONFIG_SPL
1623 Enable building of SPL globally.
Daniel Schwierzeck39ca08e2011-07-18 07:48:07 +00001624
Albert ARIBAUD \(3ADEV\)287b0942015-03-31 11:40:50 +02001625 CONFIG_SPL_PANIC_ON_RAW_IMAGE
1626 When defined, SPL will panic() if the image it has
1627 loaded does not have a signature.
1628 Defining this is useful when code which loads images
1629 in SPL cannot guarantee that absolutely all read errors
1630 will be caught.
1631 An example is the LPC32XX MLC NAND driver, which will
1632 consider that a completely unreadable NAND block is bad,
1633 and thus should be skipped silently.
1634
Tom Rinife3b0c72012-08-13 11:37:56 -07001635 CONFIG_SPL_DISPLAY_PRINT
1636 For ARM, enable an optional function to print more information
1637 about the running system.
1638
Scott Wood2b36fbb2012-12-06 13:33:17 +00001639 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
1640 Set this for NAND SPL on PPC mpc83xx targets, so that
1641 start.S waits for the rest of the SPL to load before
1642 continuing (the hardware starts execution after just
1643 loading the first page rather than the full 4K).
1644
Thomas Gleixner820d24d2016-07-12 20:28:12 +02001645 CONFIG_SPL_UBI
1646 Support for a lightweight UBI (fastmap) scanner and
1647 loader
1648
Tom Rini36853852012-02-14 07:29:40 +00001649 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
1650 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
1651 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
1652 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
1653 CONFIG_SYS_NAND_ECCBYTES
1654 Defines the size and behavior of the NAND that SPL uses
Scott Wood36c440e2012-09-21 18:35:27 -05001655 to read U-Boot
Tom Rini36853852012-02-14 07:29:40 +00001656
Scott Wood36c440e2012-09-21 18:35:27 -05001657 CONFIG_SYS_NAND_U_BOOT_DST
1658 Location in memory to load U-Boot to
1659
1660 CONFIG_SYS_NAND_U_BOOT_SIZE
1661 Size of image to load
Tom Rini36853852012-02-14 07:29:40 +00001662
1663 CONFIG_SYS_NAND_U_BOOT_START
Scott Wood36c440e2012-09-21 18:35:27 -05001664 Entry point in loaded image to jump to
Tom Rini36853852012-02-14 07:29:40 +00001665
1666 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
1667 Define this if you need to first read the OOB and then the
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08001668 data. This is used, for example, on davinci platforms.
Tom Rini36853852012-02-14 07:29:40 +00001669
Pavel Machekde997252012-08-30 22:42:11 +02001670 CONFIG_SPL_RAM_DEVICE
1671 Support for running image already present in ram, in SPL binary
1672
Marek Vasut9f2e0eb2018-05-13 00:22:52 +02001673 CONFIG_SPL_FIT_PRINT
Simon Glass82d94532013-05-08 08:05:59 +00001674 Printing information about a FIT image adds quite a bit of
1675 code to SPL. So this is normally disabled in SPL. Use this
1676 option to re-enable it. This will affect the output of the
1677 bootm command when booting a FIT image.
1678
wdenkc0aa5c52003-12-06 19:49:23 +00001679- Interrupt support (PPC):
1680
wdenk1ebf41e2004-01-02 14:00:00 +00001681 There are common interrupt_init() and timer_interrupt()
1682 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001683 for CPU specific initialization. interrupt_init_cpu()
wdenk1ebf41e2004-01-02 14:00:00 +00001684 should set decrementer_count to appropriate value. If
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001685 CPU resets decrementer automatically after interrupt
wdenk1ebf41e2004-01-02 14:00:00 +00001686 (ppc4xx) it should set decrementer_count to zero.
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001687 timer_interrupt() calls timer_interrupt_cpu() for CPU
wdenk1ebf41e2004-01-02 14:00:00 +00001688 specific handling. If board has watchdog / status_led
1689 / other_activity_monitor it works automatically from
1690 general timer_interrupt().
wdenkc0aa5c52003-12-06 19:49:23 +00001691
wdenkc6097192002-11-03 00:24:07 +00001692
Helmut Raigerd5a184b2011-10-20 04:19:47 +00001693Board initialization settings:
1694------------------------------
1695
1696During Initialization u-boot calls a number of board specific functions
1697to allow the preparation of board specific prerequisites, e.g. pin setup
1698before drivers are initialized. To enable these callbacks the
1699following configuration macros have to be defined. Currently this is
1700architecture specific, so please check arch/your_architecture/lib/board.c
1701typically in board_init_f() and board_init_r().
1702
1703- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
1704- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
1705- CONFIG_BOARD_LATE_INIT: Call board_late_init()
wdenkc6097192002-11-03 00:24:07 +00001706
wdenkc6097192002-11-03 00:24:07 +00001707Configuration Settings:
1708-----------------------
1709
Simon Glass8927bf22019-12-28 10:45:10 -07001710- MEM_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
York Sun6c480012014-02-26 17:03:19 -08001711 Optionally it can be defined to support 64-bit memory commands.
1712
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001713- CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
wdenkc6097192002-11-03 00:24:07 +00001714 undefine this when you're short of memory.
1715
Peter Tyserdfb72b82009-01-27 18:03:12 -06001716- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
1717 width of the commands listed in the 'help' command output.
1718
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001719- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
wdenkc6097192002-11-03 00:24:07 +00001720 prompt for user input.
1721
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001722- CONFIG_SYS_BAUDRATE_TABLE:
wdenkc6097192002-11-03 00:24:07 +00001723 List of legal baudrate settings for this board.
1724
York Sun5d286cd2015-12-04 11:57:07 -08001725- CONFIG_SYS_MEM_RESERVE_SECURE
York Sun1ef95cc2016-06-24 16:46:18 -07001726 Only implemented for ARMv8 for now.
York Sun5d286cd2015-12-04 11:57:07 -08001727 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
1728 is substracted from total RAM and won't be reported to OS.
1729 This memory can be used as secure memory. A variable
York Sun1ef95cc2016-06-24 16:46:18 -07001730 gd->arch.secure_ram is used to track the location. In systems
York Sun5d286cd2015-12-04 11:57:07 -08001731 the RAM base is not zero, or RAM is divided into banks,
1732 this variable needs to be recalcuated to get the address.
1733
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001734- CONFIG_SYS_LOADS_BAUD_CHANGE:
wdenkc6097192002-11-03 00:24:07 +00001735 Enable temporary baudrate change while serial download
1736
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001737- CONFIG_SYS_SDRAM_BASE:
wdenkc6097192002-11-03 00:24:07 +00001738 Physical start address of SDRAM. _Must_ be 0 here.
1739
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001740- CONFIG_SYS_FLASH_BASE:
wdenkc6097192002-11-03 00:24:07 +00001741 Physical start address of Flash memory.
1742
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001743- CONFIG_SYS_MONITOR_LEN:
wdenk57b2d802003-06-27 21:31:46 +00001744 Size of memory reserved for monitor code, used to
1745 determine _at_compile_time_ (!) if the environment is
1746 embedded within the U-Boot image, or in a separate
1747 flash sector.
wdenkc6097192002-11-03 00:24:07 +00001748
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001749- CONFIG_SYS_MALLOC_LEN:
wdenkc6097192002-11-03 00:24:07 +00001750 Size of DRAM reserved for malloc() use.
1751
Simon Glass863e4042014-07-10 22:23:28 -06001752- CONFIG_SYS_MALLOC_F_LEN
1753 Size of the malloc() pool for use before relocation. If
1754 this is defined, then a very simple malloc() implementation
1755 will become available before relocation. The address is just
1756 below the global data, and the stack is moved down to make
1757 space.
1758
1759 This feature allocates regions with increasing addresses
1760 within the region. calloc() is supported, but realloc()
1761 is not available. free() is supported but does nothing.
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08001762 The memory will be freed (or in fact just forgotten) when
Simon Glass863e4042014-07-10 22:23:28 -06001763 U-Boot relocates itself.
1764
Simon Glass9fa901b2014-11-10 17:16:54 -07001765- CONFIG_SYS_MALLOC_SIMPLE
1766 Provides a simple and small malloc() and calloc() for those
1767 boards which do not use the full malloc in SPL (which is
Tom Rini166e3222022-05-27 12:48:32 -04001768 enabled with CONFIG_SYS_SPL_MALLOC).
Simon Glass9fa901b2014-11-10 17:16:54 -07001769
Thierry Redingc97d9742014-12-09 22:25:22 -07001770- CONFIG_SYS_NONCACHED_MEMORY:
1771 Size of non-cached memory area. This area of memory will be
1772 typically located right below the malloc() area and mapped
1773 uncached in the MMU. This is useful for drivers that would
1774 otherwise require a lot of explicit cache maintenance. For
1775 some drivers it's also impossible to properly maintain the
1776 cache. For example if the regions that need to be flushed
1777 are not a multiple of the cache-line size, *and* padding
1778 cannot be allocated between the regions to align them (i.e.
1779 if the HW requires a contiguous array of regions, and the
1780 size of each region is not cache-aligned), then a flush of
1781 one region may result in overwriting data that hardware has
1782 written to another region in the same cache-line. This can
1783 happen for example in network drivers where descriptors for
1784 buffers are typically smaller than the CPU cache-line (e.g.
1785 16 bytes vs. 32 or 64 bytes).
1786
1787 Non-cached memory is only supported on 32-bit ARM at present.
1788
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001789- CONFIG_SYS_BOOTM_LEN:
Stefan Roese5d5ce292006-03-13 11:16:36 +01001790 Normally compressed uImages are limited to an
1791 uncompressed size of 8 MBytes. If this is not enough,
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001792 you can define CONFIG_SYS_BOOTM_LEN in your board config file
Stefan Roese5d5ce292006-03-13 11:16:36 +01001793 to adjust this setting to your needs.
1794
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001795- CONFIG_SYS_BOOTMAPSZ:
wdenkc6097192002-11-03 00:24:07 +00001796 Maximum size of memory mapped by the startup code of
1797 the Linux kernel; all data that must be processed by
Bartlomiej Siekac5648c82008-04-14 15:44:16 +02001798 the Linux kernel (bd_info, boot arguments, FDT blob if
1799 used) must be put below this limit, unless "bootm_low"
Robert P. J. Day832d36e2013-09-16 07:15:45 -04001800 environment variable is defined and non-zero. In such case
Bartlomiej Siekac5648c82008-04-14 15:44:16 +02001801 all data for the Linux kernel must be between "bootm_low"
Wolfgang Denk092ae952011-10-26 10:21:21 +00001802 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
Grant Likely26396382011-03-28 09:58:43 +00001803 variable "bootm_mapsize" will override the value of
1804 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
1805 then the value in "bootm_size" will be used instead.
wdenkc6097192002-11-03 00:24:07 +00001806
John Rigbyeea8e692010-10-13 13:57:35 -06001807- CONFIG_SYS_BOOT_RAMDISK_HIGH:
1808 Enable initrd_high functionality. If defined then the
1809 initrd_high feature is enabled and the bootm ramdisk subcommand
1810 is enabled.
1811
1812- CONFIG_SYS_BOOT_GET_CMDLINE:
1813 Enables allocating and saving kernel cmdline in space between
1814 "bootm_low" and "bootm_low" + BOOTMAPSZ.
1815
1816- CONFIG_SYS_BOOT_GET_KBD:
1817 Enables allocating and saving a kernel copy of the bd_info in
1818 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
1819
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001820- CONFIG_SYS_MAX_FLASH_SECT:
wdenkc6097192002-11-03 00:24:07 +00001821 Max number of sectors on a Flash chip
1822
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001823- CONFIG_SYS_FLASH_ERASE_TOUT:
wdenkc6097192002-11-03 00:24:07 +00001824 Timeout for Flash erase operations (in ms)
1825
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001826- CONFIG_SYS_FLASH_WRITE_TOUT:
wdenkc6097192002-11-03 00:24:07 +00001827 Timeout for Flash write operations (in ms)
1828
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001829- CONFIG_SYS_FLASH_LOCK_TOUT
wdenkdccbda02003-07-14 22:13:32 +00001830 Timeout for Flash set sector lock bit operation (in ms)
1831
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001832- CONFIG_SYS_FLASH_UNLOCK_TOUT
wdenkdccbda02003-07-14 22:13:32 +00001833 Timeout for Flash clear lock bits operation (in ms)
1834
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001835- CONFIG_SYS_FLASH_PROTECTION
wdenkdccbda02003-07-14 22:13:32 +00001836 If defined, hardware flash sectors protection is used
1837 instead of U-Boot software protection.
1838
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001839- CONFIG_SYS_DIRECT_FLASH_TFTP:
wdenkc6097192002-11-03 00:24:07 +00001840
1841 Enable TFTP transfers directly to flash memory;
1842 without this option such a download has to be
1843 performed in two steps: (1) download to RAM, and (2)
1844 copy from RAM to flash.
1845
1846 The two-step approach is usually more reliable, since
1847 you can check if the download worked before you erase
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001848 the flash, but in some situations (when system RAM is
1849 too limited to allow for a temporary copy of the
wdenkc6097192002-11-03 00:24:07 +00001850 downloaded image) this option may be very useful.
1851
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001852- CONFIG_SYS_FLASH_CFI:
wdenk4a5c8a72003-03-06 00:02:04 +00001853 Define if the flash driver uses extra elements in the
wdenk2cefd152004-02-08 22:55:38 +00001854 common flash structure for storing flash geometry.
1855
Jean-Christophe PLAGNIOL-VILLARD8d94c232008-08-13 01:40:42 +02001856- CONFIG_FLASH_CFI_DRIVER
wdenk2cefd152004-02-08 22:55:38 +00001857 This option also enables the building of the cfi_flash driver
1858 in the drivers directory
wdenkc6097192002-11-03 00:24:07 +00001859
Piotr Ziecik3e939e92008-11-17 15:57:58 +01001860- CONFIG_FLASH_CFI_MTD
1861 This option enables the building of the cfi_mtd driver
1862 in the drivers directory. The driver exports CFI flash
1863 to the MTD layer.
1864
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001865- CONFIG_SYS_FLASH_USE_BUFFER_WRITE
Guennadi Liakhovetski183284f2008-04-03 13:36:02 +02001866 Use buffered writes to flash.
1867
1868- CONFIG_FLASH_SPANSION_S29WS_N
1869 s29ws-n MirrorBit flash has non-standard addresses for buffered
1870 write commands.
1871
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001872- CONFIG_SYS_FLASH_QUIET_TEST
Stefan Roesec443fe92005-11-22 13:20:42 +01001873 If this option is defined, the common CFI flash doesn't
1874 print it's warning upon not recognized FLASH banks. This
1875 is useful, if some of the configured banks are only
1876 optionally available.
1877
Jerry Van Barenaae73572008-03-08 13:48:01 -05001878- CONFIG_FLASH_SHOW_PROGRESS
1879 If defined (must be an integer), print out countdown
1880 digits and dots. Recommended value: 45 (9..1) for 80
1881 column displays, 15 (3..1) for 40 column displays.
1882
Stefan Roesed20cba52013-04-04 15:53:14 +02001883- CONFIG_FLASH_VERIFY
1884 If defined, the content of the flash (destination) is compared
1885 against the source after the write operation. An error message
1886 will be printed when the contents are not identical.
1887 Please note that this option is useless in nearly all cases,
1888 since such flash programming errors usually are detected earlier
1889 while unprotecting/erasing/programming. Please only enable
1890 this option if you really know what you are doing.
1891
Wolfgang Denk460a9ff2010-06-20 23:33:59 +02001892- CONFIG_ENV_MAX_ENTRIES
1893
Wolfgang Denk1136f692010-10-27 22:48:30 +02001894 Maximum number of entries in the hash table that is used
1895 internally to store the environment settings. The default
1896 setting is supposed to be generous and should work in most
1897 cases. This setting can be used to tune behaviour; see
1898 lib/hashtable.c for details.
Wolfgang Denk460a9ff2010-06-20 23:33:59 +02001899
Joe Hershberger71497d02012-12-11 22:16:31 -06001900- CONFIG_ENV_FLAGS_LIST_DEFAULT
1901- CONFIG_ENV_FLAGS_LIST_STATIC
Robert P. J. Day832d36e2013-09-16 07:15:45 -04001902 Enable validation of the values given to environment variables when
Joe Hershberger71497d02012-12-11 22:16:31 -06001903 calling env set. Variables can be restricted to only decimal,
1904 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
1905 the variables can also be restricted to IP address or MAC address.
1906
1907 The format of the list is:
1908 type_attribute = [s|d|x|b|i|m]
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08001909 access_attribute = [a|r|o|c]
1910 attributes = type_attribute[access_attribute]
Joe Hershberger71497d02012-12-11 22:16:31 -06001911 entry = variable_name[:attributes]
1912 list = entry[,list]
1913
1914 The type attributes are:
1915 s - String (default)
1916 d - Decimal
1917 x - Hexadecimal
1918 b - Boolean ([1yYtT|0nNfF])
1919 i - IP address
1920 m - MAC address
1921
Joe Hershberger6fe26c92012-12-11 22:16:34 -06001922 The access attributes are:
1923 a - Any (default)
1924 r - Read-only
1925 o - Write-once
1926 c - Change-default
1927
Joe Hershberger71497d02012-12-11 22:16:31 -06001928 - CONFIG_ENV_FLAGS_LIST_DEFAULT
1929 Define this to a list (string) to define the ".flags"
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08001930 environment variable in the default or embedded environment.
Joe Hershberger71497d02012-12-11 22:16:31 -06001931
1932 - CONFIG_ENV_FLAGS_LIST_STATIC
1933 Define this to a list (string) to define validation that
1934 should be done if an entry is not found in the ".flags"
1935 environment variable. To override a setting in the static
1936 list, simply add an entry for the same variable name to the
1937 ".flags" variable.
1938
Joe Hershberger6db9fd42015-05-20 14:27:20 -05001939 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
1940 regular expression. This allows multiple variables to define the same
1941 flags without explicitly listing them for each variable.
1942
wdenkc6097192002-11-03 00:24:07 +00001943The following definitions that deal with the placement and management
1944of environment data (variable area); in general, we support the
1945following configurations:
1946
Mike Frysinger63b8f122011-07-08 10:44:25 +00001947- CONFIG_BUILD_ENVCRC:
1948
1949 Builds up envcrc with the target environment so that external utils
1950 may easily extract it and embed it in final U-Boot images.
1951
wdenkc6097192002-11-03 00:24:07 +00001952BE CAREFUL! The first access to the environment happens quite early
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08001953in U-Boot initialization (when we try to get the setting of for the
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02001954console baudrate). You *MUST* have mapped your NVRAM area then, or
wdenkc6097192002-11-03 00:24:07 +00001955U-Boot will hang.
1956
1957Please note that even with NVRAM we still use a copy of the
1958environment in RAM: we could work on NVRAM directly, but we want to
1959keep settings there always unmodified except somebody uses "saveenv"
1960to save the current settings.
1961
Liu Gang85bcd732012-03-08 00:33:20 +00001962BE CAREFUL! For some special cases, the local device can not use
1963"saveenv" command. For example, the local device will get the
Liu Gang357bf5a2012-08-09 05:10:01 +00001964environment stored in a remote NOR flash by SRIO or PCIE link,
1965but it can not erase, write this NOR flash by SRIO or PCIE interface.
Liu Gang85bcd732012-03-08 00:33:20 +00001966
Guennadi Liakhovetskifad24442009-05-18 16:07:22 +02001967- CONFIG_NAND_ENV_DST
1968
1969 Defines address in RAM to which the nand_spl code should copy the
1970 environment. If redundant environment is used, it will be copied to
1971 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
1972
Bruce Adleredecc942007-11-02 13:15:42 -07001973Please note that the environment is read-only until the monitor
wdenkc6097192002-11-03 00:24:07 +00001974has been relocated to RAM and a RAM copy of the environment has been
Simon Glass64b723f2017-08-03 12:22:12 -06001975created; also, when using EEPROM you will have to use env_get_f()
wdenkc6097192002-11-03 00:24:07 +00001976until then to read environment variables.
1977
wdenk8dba0502003-03-31 16:34:49 +00001978The environment is protected by a CRC32 checksum. Before the monitor
1979is relocated into RAM, as a result of a bad CRC you will be working
1980with the compiled-in default environment - *silently*!!! [This is
1981necessary, because the first environment variable we need is the
1982"baudrate" setting for the console - if we have a bad CRC, we don't
1983have any device yet where we could complain.]
wdenkc6097192002-11-03 00:24:07 +00001984
1985Note: once the monitor has been relocated, then it will complain if
1986the default environment is used; a new CRC is computed as soon as you
wdenk8dba0502003-03-31 16:34:49 +00001987use the "saveenv" command to store a valid environment.
wdenkc6097192002-11-03 00:24:07 +00001988
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02001989- CONFIG_SYS_FAULT_MII_ADDR:
wdenk9c53f402003-10-15 23:53:47 +00001990 MII address of the PHY to check for the Ethernet link state.
wdenkc6097192002-11-03 00:24:07 +00001991
Ron Madriddfa028a2009-02-18 14:30:44 -08001992- CONFIG_NS16550_MIN_FUNCTIONS:
1993 Define this if you desire to only have use of the NS16550_init
1994 and NS16550_putc functions for the serial driver located at
1995 drivers/serial/ns16550.c. This option is useful for saving
1996 space for already greatly restricted images, including but not
1997 limited to NAND_SPL configurations.
1998
Simon Glass28a9e332012-11-30 13:01:18 +00001999- CONFIG_DISPLAY_BOARDINFO
2000 Display information about the board that U-Boot is running on
2001 when U-Boot starts up. The board function checkboard() is called
2002 to do this.
2003
Simon Glasse8822012012-11-30 13:01:19 +00002004- CONFIG_DISPLAY_BOARDINFO_LATE
2005 Similar to the previous option, but display this information
2006 later, once stdio is running and output goes to the LCD, if
2007 present.
2008
wdenkc6097192002-11-03 00:24:07 +00002009Low Level (hardware related) configuration options:
wdenkc8434db2003-03-26 06:55:25 +00002010---------------------------------------------------
wdenkc6097192002-11-03 00:24:07 +00002011
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02002012- CONFIG_SYS_CACHELINE_SIZE:
wdenkc6097192002-11-03 00:24:07 +00002013 Cache Line Size of the CPU.
2014
Timur Tabid8f341c2011-08-04 18:03:41 -05002015- CONFIG_SYS_CCSRBAR_DEFAULT:
2016 Default (power-on reset) physical address of CCSR on Freescale
2017 PowerPC SOCs.
2018
2019- CONFIG_SYS_CCSRBAR:
2020 Virtual address of CCSR. On a 32-bit build, this is typically
2021 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
2022
Timur Tabid8f341c2011-08-04 18:03:41 -05002023- CONFIG_SYS_CCSRBAR_PHYS:
2024 Physical address of CCSR. CCSR can be relocated to a new
2025 physical address, if desired. In this case, this macro should
Wolfgang Denk092ae952011-10-26 10:21:21 +00002026 be set to that address. Otherwise, it should be set to the
Timur Tabid8f341c2011-08-04 18:03:41 -05002027 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
2028 is typically relocated on 36-bit builds. It is recommended
2029 that this macro be defined via the _HIGH and _LOW macros:
2030
2031 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
2032 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
2033
2034- CONFIG_SYS_CCSRBAR_PHYS_HIGH:
Wolfgang Denkd590fb12011-10-07 09:58:21 +02002035 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
2036 either 0 (32-bit build) or 0xF (36-bit build). This macro is
Timur Tabid8f341c2011-08-04 18:03:41 -05002037 used in assembly code, so it must not contain typecasts or
2038 integer size suffixes (e.g. "ULL").
2039
2040- CONFIG_SYS_CCSRBAR_PHYS_LOW:
2041 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
2042 used in assembly code, so it must not contain typecasts or
2043 integer size suffixes (e.g. "ULL").
2044
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02002045- CONFIG_SYS_IMMR: Physical address of the Internal Memory.
wdenk07d7e6b2004-12-16 21:44:03 +00002046 DO NOT CHANGE unless you know exactly what you're
Christophe Leroy069fa832017-07-06 10:23:22 +02002047 doing! (11-4) [MPC8xx systems only]
wdenkc6097192002-11-03 00:24:07 +00002048
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02002049- CONFIG_SYS_INIT_RAM_ADDR:
wdenkc6097192002-11-03 00:24:07 +00002050
wdenkeb20ad32003-09-05 23:19:14 +00002051 Start address of memory area that can be used for
wdenkc6097192002-11-03 00:24:07 +00002052 initial data and stack; please note that this must be
2053 writable memory that is working WITHOUT special
2054 initialization, i. e. you CANNOT use normal RAM which
2055 will become available only after programming the
2056 memory controller and running certain initialization
2057 sequences.
2058
2059 U-Boot uses the following memory types:
Christophe Leroy069fa832017-07-06 10:23:22 +02002060 - MPC8xx: IMMR (internal memory of the CPU)
wdenkc6097192002-11-03 00:24:07 +00002061
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02002062- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
wdenkc6097192002-11-03 00:24:07 +00002063
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02002064- CONFIG_SYS_OR_TIMING_SDRAM:
wdenkc6097192002-11-03 00:24:07 +00002065 SDRAM timing
2066
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02002067- CONFIG_SYS_MAMR_PTA:
wdenkc6097192002-11-03 00:24:07 +00002068 periodic timer for refresh
2069
Kumar Gala8975d7a2010-12-30 12:09:53 -06002070- CONFIG_SYS_SRIO:
2071 Chip has SRIO or not
2072
2073- CONFIG_SRIO1:
2074 Board has SRIO 1 port available
2075
2076- CONFIG_SRIO2:
2077 Board has SRIO 2 port available
2078
Liu Gang27afb9c2013-05-07 16:30:46 +08002079- CONFIG_SRIO_PCIE_BOOT_MASTER
2080 Board can support master function for Boot from SRIO and PCIE
2081
Kumar Gala8975d7a2010-12-30 12:09:53 -06002082- CONFIG_SYS_SRIOn_MEM_VIRT:
2083 Virtual Address of SRIO port 'n' memory region
2084
Simon Glass970b61e2019-11-14 12:57:09 -07002085- CONFIG_SYS_SRIOn_MEM_PHYxS:
Kumar Gala8975d7a2010-12-30 12:09:53 -06002086 Physical Address of SRIO port 'n' memory region
2087
2088- CONFIG_SYS_SRIOn_MEM_SIZE:
2089 Size of SRIO port 'n' memory region
2090
Fabio Estevamf17e8782013-04-11 09:35:34 +00002091- CONFIG_SYS_NAND_BUSWIDTH_16BIT
2092 Defined to tell the NAND controller that the NAND chip is using
2093 a 16 bit bus.
2094 Not all NAND drivers use this symbol.
Fabio Estevam417052b2013-04-11 09:35:35 +00002095 Example of drivers that use it:
Miquel Raynal1f1ae152018-08-16 17:30:07 +02002096 - drivers/mtd/nand/raw/ndfc.c
2097 - drivers/mtd/nand/raw/mxc_nand.c
Alex Watermancd6aae32011-05-19 15:08:36 -04002098
2099- CONFIG_SYS_NDFC_EBC0_CFG
2100 Sets the EBC0_CFG register for the NDFC. If not defined
2101 a default value will be used.
2102
Ben Warren45657152006-09-07 16:50:54 -04002103- CONFIG_SPD_EEPROM
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002104 Get DDR timing information from an I2C EEPROM. Common
2105 with pluggable memory modules such as SODIMMs
2106
Ben Warren45657152006-09-07 16:50:54 -04002107 SPD_EEPROM_ADDRESS
2108 I2C address of the SPD EEPROM
2109
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02002110- CONFIG_SYS_SPD_BUS_NUM
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002111 If SPD EEPROM is on an I2C bus other than the first
2112 one, specify here. Note that the value must resolve
2113 to something your driver can deal with.
Ben Warren45657152006-09-07 16:50:54 -04002114
York Sune73cc042011-06-07 09:42:16 +08002115- CONFIG_SYS_DDR_RAW_TIMING
2116 Get DDR timing information from other than SPD. Common with
2117 soldered DDR chips onboard without SPD. DDR raw timing
2118 parameters are extracted from datasheet and hard-coded into
2119 header files or board specific files.
2120
York Sunbd495cf2011-09-16 13:21:35 -07002121- CONFIG_FSL_DDR_INTERACTIVE
2122 Enable interactive DDR debugging. See doc/README.fsl-ddr.
2123
York Sun8ced0502015-01-06 13:18:55 -08002124- CONFIG_FSL_DDR_SYNC_REFRESH
2125 Enable sync of refresh for multiple controllers.
2126
York Sunb6a35f82015-03-19 09:30:28 -07002127- CONFIG_FSL_DDR_BIST
2128 Enable built-in memory test for Freescale DDR controllers.
2129
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02002130- CONFIG_SYS_83XX_DDR_USES_CS0
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002131 Only for 83xx systems. If specified, then DDR should
2132 be configured using CS0 and CS1 instead of CS2 and CS3.
Timur Tabi054838e2006-10-31 18:44:42 -06002133
wdenk6203e402004-04-18 10:13:26 +00002134- CONFIG_RMII
2135 Enable RMII mode for all FECs.
2136 Note that this is a global option, we can't
2137 have one FEC in standard MII mode and another in RMII mode.
2138
wdenk20c98a62004-04-23 20:32:05 +00002139- CONFIG_CRC32_VERIFY
2140 Add a verify option to the crc32 command.
2141 The syntax is:
2142
2143 => crc32 -v <address> <count> <crc32>
2144
2145 Where address/count indicate a memory area
2146 and crc32 is the correct crc32 which the
2147 area should have.
2148
wdenk64519362004-07-11 17:40:54 +00002149- CONFIG_LOOPW
2150 Add the "loopw" memory command. This only takes effect if
Simon Glass92ffdee2017-08-04 16:34:27 -06002151 the memory commands are activated globally (CONFIG_CMD_MEMORY).
wdenk64519362004-07-11 17:40:54 +00002152
Joel Johnsondb5a97e2020-01-29 09:17:18 -07002153- CONFIG_CMD_MX_CYCLIC
stroesecc3af832004-12-16 18:46:55 +00002154 Add the "mdc" and "mwc" memory commands. These are cyclic
2155 "md/mw" commands.
2156 Examples:
2157
wdenk07d7e6b2004-12-16 21:44:03 +00002158 => mdc.b 10 4 500
stroesecc3af832004-12-16 18:46:55 +00002159 This command will print 4 bytes (10,11,12,13) each 500 ms.
2160
wdenk07d7e6b2004-12-16 21:44:03 +00002161 => mwc.l 100 12345678 10
stroesecc3af832004-12-16 18:46:55 +00002162 This command will write 12345678 to address 100 all 10 ms.
2163
wdenk07d7e6b2004-12-16 21:44:03 +00002164 This only takes effect if the memory commands are activated
Simon Glass92ffdee2017-08-04 16:34:27 -06002165 globally (CONFIG_CMD_MEMORY).
stroesecc3af832004-12-16 18:46:55 +00002166
Aneesh V552a3192011-07-13 05:11:07 +00002167- CONFIG_SPL_BUILD
Thomas Hebbfd37f242019-11-13 18:18:03 -08002168 Set when the currently-running compilation is for an artifact
2169 that will end up in the SPL (as opposed to the TPL or U-Boot
2170 proper). Code that needs stage-specific behavior should check
2171 this.
wdenk336b2bc2005-04-02 23:52:25 +00002172
Ying Zhang2d2e3b62013-08-16 15:16:15 +08002173- CONFIG_TPL_BUILD
Thomas Hebbfd37f242019-11-13 18:18:03 -08002174 Set when the currently-running compilation is for an artifact
2175 that will end up in the TPL (as opposed to the SPL or U-Boot
2176 proper). Code that needs stage-specific behavior should check
2177 this.
Ying Zhang2d2e3b62013-08-16 15:16:15 +08002178
Ying Zhang0d4f5442013-05-20 14:07:23 +08002179- CONFIG_SYS_MPC85XX_NO_RESETVEC
2180 Only for 85xx systems. If this variable is specified, the section
2181 .resetvec is not kept and the section .bootpg is placed in the
2182 previous 4k of the .text section.
2183
Simon Glass17dabf02013-02-24 17:33:14 +00002184- CONFIG_ARCH_MAP_SYSMEM
2185 Generally U-Boot (and in particular the md command) uses
2186 effective address. It is therefore not necessary to regard
2187 U-Boot address as virtual addresses that need to be translated
2188 to physical addresses. However, sandbox requires this, since
2189 it maintains its own little RAM buffer which contains all
2190 addressable memory. This option causes some memory accesses
2191 to be mapped through map_sysmem() / unmap_sysmem().
2192
Simon Glassbfb59802013-02-14 04:18:54 +00002193- CONFIG_X86_RESET_VECTOR
2194 If defined, the x86 reset vector code is included. This is not
2195 needed when U-Boot is running from Coreboot.
Gabe Black14f82462012-11-27 21:08:06 +00002196
Karicheri, Muralidharanc1dc61b2014-04-04 13:16:50 -04002197- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
2198 Option to disable subpage write in NAND driver
2199 driver that uses this:
Miquel Raynal1f1ae152018-08-16 17:30:07 +02002200 drivers/mtd/nand/raw/davinci_nand.c
Karicheri, Muralidharanc1dc61b2014-04-04 13:16:50 -04002201
Timur Tabi275f4bb2011-11-22 09:21:25 -06002202Freescale QE/FMAN Firmware Support:
2203-----------------------------------
2204
2205The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
2206loading of "firmware", which is encoded in the QE firmware binary format.
2207This firmware often needs to be loaded during U-Boot booting, so macros
2208are used to identify the storage device (NOR flash, SPI, etc) and the address
2209within that device.
2210
Zhao Qiang83a90842014-03-21 16:21:44 +08002211- CONFIG_SYS_FMAN_FW_ADDR
2212 The address in the storage device where the FMAN microcode is located. The
Tom Rinifa911f82019-05-12 07:59:12 -04002213 meaning of this address depends on which CONFIG_SYS_QE_FMAN_FW_IN_xxx macro
Zhao Qiang83a90842014-03-21 16:21:44 +08002214 is also specified.
2215
2216- CONFIG_SYS_QE_FW_ADDR
2217 The address in the storage device where the QE microcode is located. The
Tom Rinifa911f82019-05-12 07:59:12 -04002218 meaning of this address depends on which CONFIG_SYS_QE_FMAN_FW_IN_xxx macro
Timur Tabi275f4bb2011-11-22 09:21:25 -06002219 is also specified.
2220
2221- CONFIG_SYS_QE_FMAN_FW_LENGTH
2222 The maximum possible size of the firmware. The firmware binary format
2223 has a field that specifies the actual size of the firmware, but it
2224 might not be possible to read any part of the firmware unless some
2225 local storage is allocated to hold the entire firmware first.
2226
2227- CONFIG_SYS_QE_FMAN_FW_IN_NOR
2228 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
2229 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
2230 virtual address in NOR flash.
2231
2232- CONFIG_SYS_QE_FMAN_FW_IN_NAND
2233 Specifies that QE/FMAN firmware is located in NAND flash.
2234 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
2235
2236- CONFIG_SYS_QE_FMAN_FW_IN_MMC
2237 Specifies that QE/FMAN firmware is located on the primary SD/MMC
2238 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
2239
Liu Gang1e084582012-03-08 00:33:18 +00002240- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
2241 Specifies that QE/FMAN firmware is located in the remote (master)
2242 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
Liu Gang357bf5a2012-08-09 05:10:01 +00002243 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
2244 window->master inbound window->master LAW->the ucode address in
2245 master's memory space.
Timur Tabi275f4bb2011-11-22 09:21:25 -06002246
J. German Rivera8ff14b72014-06-23 15:15:55 -07002247Freescale Layerscape Management Complex Firmware Support:
2248---------------------------------------------------------
2249The Freescale Layerscape Management Complex (MC) supports the loading of
2250"firmware".
2251This firmware often needs to be loaded during U-Boot booting, so macros
2252are used to identify the storage device (NOR flash, SPI, etc) and the address
2253within that device.
2254
2255- CONFIG_FSL_MC_ENET
2256 Enable the MC driver for Layerscape SoCs.
2257
Prabhakar Kushwaha853a9012015-06-02 10:55:52 +05302258Freescale Layerscape Debug Server Support:
2259-------------------------------------------
2260The Freescale Layerscape Debug Server Support supports the loading of
2261"Debug Server firmware" and triggering SP boot-rom.
2262This firmware often needs to be loaded during U-Boot booting.
2263
York Sun928b6812015-12-07 11:08:58 -08002264- CONFIG_SYS_MC_RSV_MEM_ALIGN
2265 Define alignment of reserved memory MC requires
Prabhakar Kushwaha853a9012015-06-02 10:55:52 +05302266
Paul Kocialkowski7b917022015-07-26 18:48:15 +02002267Reproducible builds
2268-------------------
2269
2270In order to achieve reproducible builds, timestamps used in the U-Boot build
2271process have to be set to a fixed value.
2272
2273This is done using the SOURCE_DATE_EPOCH environment variable.
2274SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
2275option for U-Boot or an environment variable in U-Boot.
2276
2277SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
2278
wdenkc6097192002-11-03 00:24:07 +00002279Building the Software:
2280======================
2281
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002282Building U-Boot has been tested in several native build environments
2283and in many different cross environments. Of course we cannot support
2284all possibly existing versions of cross development tools in all
2285(potentially obsolete) versions. In case of tool chain problems we
Naoki Hayamae0cc1852020-10-08 13:17:16 +09002286recommend to use the ELDK (see https://www.denx.de/wiki/DULG/ELDK)
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002287which is extensively used to build and test U-Boot.
wdenkc6097192002-11-03 00:24:07 +00002288
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002289If you are not using a native environment, it is assumed that you
2290have GNU cross compiling tools available in your path. In this case,
2291you must set the environment variable CROSS_COMPILE in your shell.
2292Note that no changes to the Makefile or any other source files are
2293necessary. For example using the ELDK on a 4xx CPU, please enter:
wdenkc6097192002-11-03 00:24:07 +00002294
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002295 $ CROSS_COMPILE=ppc_4xx-
2296 $ export CROSS_COMPILE
wdenkc6097192002-11-03 00:24:07 +00002297
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002298U-Boot is intended to be simple to build. After installing the
2299sources you must configure U-Boot for one specific board type. This
wdenkc6097192002-11-03 00:24:07 +00002300is done by typing:
2301
Holger Freyther7ba4e572014-08-04 09:26:05 +02002302 make NAME_defconfig
wdenkc6097192002-11-03 00:24:07 +00002303
Holger Freyther7ba4e572014-08-04 09:26:05 +02002304where "NAME_defconfig" is the name of one of the existing configu-
Heinrich Schuchardtd6e07af2020-02-24 18:36:30 +01002305rations; see configs/*_defconfig for supported names.
wdenk2f0812d2003-10-08 22:45:44 +00002306
Heinrich Schuchardtd6e07af2020-02-24 18:36:30 +01002307Note: for some boards special configuration names may exist; check if
wdenk6c59edc2004-05-03 20:45:30 +00002308 additional information is available from the board vendor; for
2309 instance, the TQM823L systems are available without (standard)
2310 or with LCD support. You can select such additional "features"
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02002311 when choosing the configuration, i. e.
wdenkc6097192002-11-03 00:24:07 +00002312
Holger Freyther7ba4e572014-08-04 09:26:05 +02002313 make TQM823L_defconfig
wdenk6c59edc2004-05-03 20:45:30 +00002314 - will configure for a plain TQM823L, i. e. no LCD support
wdenkc6097192002-11-03 00:24:07 +00002315
Holger Freyther7ba4e572014-08-04 09:26:05 +02002316 make TQM823L_LCD_defconfig
wdenk6c59edc2004-05-03 20:45:30 +00002317 - will configure for a TQM823L with U-Boot console on LCD
wdenkc6097192002-11-03 00:24:07 +00002318
wdenk6c59edc2004-05-03 20:45:30 +00002319 etc.
wdenkc6097192002-11-03 00:24:07 +00002320
wdenkc6097192002-11-03 00:24:07 +00002321
wdenk6c59edc2004-05-03 20:45:30 +00002322Finally, type "make all", and you should get some working U-Boot
2323images ready for download to / installation on your system:
wdenkc6097192002-11-03 00:24:07 +00002324
wdenk6c59edc2004-05-03 20:45:30 +00002325- "u-boot.bin" is a raw binary image
2326- "u-boot" is an image in ELF binary format
2327- "u-boot.srec" is in Motorola S-Record format
wdenkc6097192002-11-03 00:24:07 +00002328
Marian Balakowiczefe063f2006-09-07 17:25:40 +02002329By default the build is performed locally and the objects are saved
2330in the source directory. One of the two methods can be used to change
2331this behavior and build U-Boot to some external directory:
2332
23331. Add O= to the make command line invocations:
2334
2335 make O=/tmp/build distclean
Holger Freyther7ba4e572014-08-04 09:26:05 +02002336 make O=/tmp/build NAME_defconfig
Marian Balakowiczefe063f2006-09-07 17:25:40 +02002337 make O=/tmp/build all
2338
Timo Ketolac8c67602014-11-06 14:39:05 +020023392. Set environment variable KBUILD_OUTPUT to point to the desired location:
Marian Balakowiczefe063f2006-09-07 17:25:40 +02002340
Timo Ketolac8c67602014-11-06 14:39:05 +02002341 export KBUILD_OUTPUT=/tmp/build
Marian Balakowiczefe063f2006-09-07 17:25:40 +02002342 make distclean
Holger Freyther7ba4e572014-08-04 09:26:05 +02002343 make NAME_defconfig
Marian Balakowiczefe063f2006-09-07 17:25:40 +02002344 make all
2345
Timo Ketolac8c67602014-11-06 14:39:05 +02002346Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
Marian Balakowiczefe063f2006-09-07 17:25:40 +02002347variable.
2348
Daniel Schwierzeck88484422018-01-26 16:31:04 +01002349User specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by
2350setting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS.
2351For example to treat all compiler warnings as errors:
2352
2353 make KCFLAGS=-Werror
wdenkc6097192002-11-03 00:24:07 +00002354
wdenk6c59edc2004-05-03 20:45:30 +00002355Please be aware that the Makefiles assume you are using GNU make, so
2356for instance on NetBSD you might need to use "gmake" instead of
2357native "make".
wdenkc6097192002-11-03 00:24:07 +00002358
wdenkc6097192002-11-03 00:24:07 +00002359
wdenk6c59edc2004-05-03 20:45:30 +00002360If the system board that you have is not listed, then you will need
2361to port U-Boot to your hardware platform. To do this, follow these
2362steps:
wdenkc6097192002-11-03 00:24:07 +00002363
Phil Sutterc77b4882015-12-25 14:41:18 +010023641. Create a new directory to hold your board specific code. Add any
wdenk6c59edc2004-05-03 20:45:30 +00002365 files you need. In your board directory, you will need at least
Phil Sutterc77b4882015-12-25 14:41:18 +01002366 the "Makefile" and a "<board>.c".
23672. Create a new configuration file "include/configs/<board>.h" for
2368 your board.
wdenk6c59edc2004-05-03 20:45:30 +000023693. If you're porting U-Boot to a new CPU, then also create a new
2370 directory to hold your CPU specific code. Add any files you need.
Holger Freyther7ba4e572014-08-04 09:26:05 +020023714. Run "make <board>_defconfig" with your new name.
wdenk6c59edc2004-05-03 20:45:30 +000023725. Type "make", and you should get a working "u-boot.srec" file
2373 to be installed on your target system.
23746. Debug and solve any problems that might arise.
2375 [Of course, this last step is much harder than it sounds.]
wdenkc6097192002-11-03 00:24:07 +00002376
wdenkc6097192002-11-03 00:24:07 +00002377
wdenk6c59edc2004-05-03 20:45:30 +00002378Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2379==============================================================
wdenkc6097192002-11-03 00:24:07 +00002380
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002381If you have modified U-Boot sources (for instance added a new board
2382or support for new devices, a new CPU, etc.) you are expected to
wdenk6c59edc2004-05-03 20:45:30 +00002383provide feedback to the other developers. The feedback normally takes
Thomas Hebbfd37f242019-11-13 18:18:03 -08002384the form of a "patch", i.e. a context diff against a certain (latest
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002385official or latest in the git repository) version of U-Boot sources.
wdenkc6097192002-11-03 00:24:07 +00002386
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002387But before you submit such a patch, please verify that your modifi-
2388cation did not break existing code. At least make sure that *ALL* of
wdenk6c59edc2004-05-03 20:45:30 +00002389the supported boards compile WITHOUT ANY compiler warnings. To do so,
Simon Glassdc27def2016-07-27 20:33:08 -06002390just run the buildman script (tools/buildman/buildman), which will
2391configure and build U-Boot for ALL supported system. Be warned, this
2392will take a while. Please see the buildman README, or run 'buildman -H'
2393for documentation.
wdenkc6097192002-11-03 00:24:07 +00002394
Marian Balakowiczefe063f2006-09-07 17:25:40 +02002395
wdenk6c59edc2004-05-03 20:45:30 +00002396See also "U-Boot Porting Guide" below.
wdenkc6097192002-11-03 00:24:07 +00002397
wdenkc6097192002-11-03 00:24:07 +00002398
wdenk6c59edc2004-05-03 20:45:30 +00002399Monitor Commands - Overview:
2400============================
wdenkc6097192002-11-03 00:24:07 +00002401
wdenk6c59edc2004-05-03 20:45:30 +00002402go - start application at address 'addr'
2403run - run commands in an environment variable
2404bootm - boot application image from memory
2405bootp - boot image via network using BootP/TFTP protocol
Marek Vasutcf41a9b2012-03-14 21:52:45 +00002406bootz - boot zImage from memory
wdenk6c59edc2004-05-03 20:45:30 +00002407tftpboot- boot image via network using TFTP protocol
2408 and env variables "ipaddr" and "serverip"
2409 (and eventually "gatewayip")
Simon Glass6a398d22011-10-24 18:00:07 +00002410tftpput - upload a file via network using TFTP protocol
wdenk6c59edc2004-05-03 20:45:30 +00002411rarpboot- boot image via network using RARP/TFTP protocol
2412diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2413loads - load S-Record file over serial line
2414loadb - load binary file over serial line (kermit mode)
Rui Miguel Silva433f15a2022-05-11 10:55:40 +01002415loadm - load binary blob from source address to destination address
wdenk6c59edc2004-05-03 20:45:30 +00002416md - memory display
2417mm - memory modify (auto-incrementing)
2418nm - memory modify (constant address)
2419mw - memory write (fill)
Simon Glass19038de2020-06-02 19:26:49 -06002420ms - memory search
wdenk6c59edc2004-05-03 20:45:30 +00002421cp - memory copy
2422cmp - memory compare
2423crc32 - checksum calculation
Peter Tyser469cde42009-04-18 22:34:03 -05002424i2c - I2C sub-system
wdenk6c59edc2004-05-03 20:45:30 +00002425sspi - SPI utility commands
2426base - print or set address offset
2427printenv- print environment variables
Pragnesh Patel1d5955f2020-12-22 11:30:05 +05302428pwm - control pwm channels
wdenk6c59edc2004-05-03 20:45:30 +00002429setenv - set environment variables
2430saveenv - save environment variables to persistent storage
2431protect - enable or disable FLASH write protection
2432erase - erase FLASH memory
2433flinfo - print FLASH memory information
Karl O. Pinc4baf03d2012-08-03 05:57:21 +00002434nand - NAND memory operations (see doc/README.nand)
wdenk6c59edc2004-05-03 20:45:30 +00002435bdinfo - print Board Info structure
2436iminfo - print header information for application image
2437coninfo - print console devices and informations
2438ide - IDE sub-system
2439loop - infinite loop on address range
wdenk64519362004-07-11 17:40:54 +00002440loopw - infinite write loop on address range
wdenk6c59edc2004-05-03 20:45:30 +00002441mtest - simple RAM test
2442icache - enable or disable instruction cache
2443dcache - enable or disable data cache
2444reset - Perform RESET of the CPU
2445echo - echo args to console
2446version - print monitor version
2447help - print online help
2448? - alias for 'help'
wdenkc6097192002-11-03 00:24:07 +00002449
wdenkc6097192002-11-03 00:24:07 +00002450
wdenk6c59edc2004-05-03 20:45:30 +00002451Monitor Commands - Detailed Description:
2452========================================
wdenkc6097192002-11-03 00:24:07 +00002453
wdenk6c59edc2004-05-03 20:45:30 +00002454TODO.
wdenkc6097192002-11-03 00:24:07 +00002455
wdenk6c59edc2004-05-03 20:45:30 +00002456For now: just type "help <command>".
wdenkc6097192002-11-03 00:24:07 +00002457
2458
wdenk6c59edc2004-05-03 20:45:30 +00002459Note for Redundant Ethernet Interfaces:
2460=======================================
wdenkf4688a22003-05-28 08:06:31 +00002461
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02002462Some boards come with redundant Ethernet interfaces; U-Boot supports
wdenk6c59edc2004-05-03 20:45:30 +00002463such configurations and is capable of automatic selection of a
2464"working" interface when needed. MAC assignment works as follows:
wdenkf4688a22003-05-28 08:06:31 +00002465
wdenk6c59edc2004-05-03 20:45:30 +00002466Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2467MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2468"eth1addr" (=>eth1), "eth2addr", ...
wdenkf4688a22003-05-28 08:06:31 +00002469
wdenk6c59edc2004-05-03 20:45:30 +00002470If the network interface stores some valid MAC address (for instance
2471in SROM), this is used as default address if there is NO correspon-
2472ding setting in the environment; if the corresponding environment
2473variable is set, this overrides the settings in the card; that means:
wdenkf4688a22003-05-28 08:06:31 +00002474
wdenk6c59edc2004-05-03 20:45:30 +00002475o If the SROM has a valid MAC address, and there is no address in the
2476 environment, the SROM's address is used.
wdenkc6097192002-11-03 00:24:07 +00002477
wdenk6c59edc2004-05-03 20:45:30 +00002478o If there is no valid address in the SROM, and a definition in the
2479 environment exists, then the value from the environment variable is
2480 used.
wdenkc6097192002-11-03 00:24:07 +00002481
wdenk6c59edc2004-05-03 20:45:30 +00002482o If both the SROM and the environment contain a MAC address, and
2483 both addresses are the same, this MAC address is used.
wdenkc6097192002-11-03 00:24:07 +00002484
wdenk6c59edc2004-05-03 20:45:30 +00002485o If both the SROM and the environment contain a MAC address, and the
2486 addresses differ, the value from the environment is used and a
2487 warning is printed.
wdenkc6097192002-11-03 00:24:07 +00002488
wdenk6c59edc2004-05-03 20:45:30 +00002489o If neither SROM nor the environment contain a MAC address, an error
Joe Hershberger2dc2b5d2015-05-04 14:55:13 -05002490 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
2491 a random, locally-assigned MAC is used.
wdenkc6097192002-11-03 00:24:07 +00002492
Ben Warren6db991a2010-04-26 11:11:46 -07002493If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
Wolfgang Denk092ae952011-10-26 10:21:21 +00002494will be programmed into hardware as part of the initialization process. This
Ben Warren6db991a2010-04-26 11:11:46 -07002495may be skipped by setting the appropriate 'ethmacskip' environment variable.
2496The naming convention is as follows:
2497"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
wdenkc6097192002-11-03 00:24:07 +00002498
wdenk6c59edc2004-05-03 20:45:30 +00002499Image Formats:
2500==============
wdenkc6097192002-11-03 00:24:07 +00002501
Marian Balakowicz18710b82008-03-12 12:13:13 +01002502U-Boot is capable of booting (and performing other auxiliary operations on)
2503images in two formats:
2504
2505New uImage format (FIT)
2506-----------------------
2507
2508Flexible and powerful format based on Flattened Image Tree -- FIT (similar
2509to Flattened Device Tree). It allows the use of images with multiple
2510components (several kernels, ramdisks, etc.), with contents protected by
2511SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
2512
2513
2514Old uImage format
2515-----------------
2516
2517Old image format is based on binary files which can be basically anything,
2518preceded by a special header; see the definitions in include/image.h for
2519details; basically, the header defines the following image properties:
wdenkc6097192002-11-03 00:24:07 +00002520
wdenk6c59edc2004-05-03 20:45:30 +00002521* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2522 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
Peter Tyser56b8dd12008-09-08 14:56:49 -05002523 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
Thomas Huthc90d56a2021-11-13 18:13:50 +01002524 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, INTEGRITY).
Andy Shevchenko8cb5cdd2017-07-05 16:25:22 +03002525* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
Tom Rini53320122022-04-06 09:21:25 -04002526 IA64, MIPS, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2527 Currently supported: ARM, Intel x86, MIPS, Nios II, PowerPC).
wdenk6c59edc2004-05-03 20:45:30 +00002528* Compression Type (uncompressed, gzip, bzip2)
2529* Load Address
2530* Entry Point
2531* Image Name
2532* Image Timestamp
wdenkc6097192002-11-03 00:24:07 +00002533
wdenk6c59edc2004-05-03 20:45:30 +00002534The header is marked by a special Magic Number, and both the header
2535and the data portions of the image are secured against corruption by
2536CRC32 checksums.
wdenkc6097192002-11-03 00:24:07 +00002537
wdenkc6097192002-11-03 00:24:07 +00002538
wdenk6c59edc2004-05-03 20:45:30 +00002539Linux Support:
2540==============
wdenkc6097192002-11-03 00:24:07 +00002541
wdenk6c59edc2004-05-03 20:45:30 +00002542Although U-Boot should support any OS or standalone application
2543easily, the main focus has always been on Linux during the design of
2544U-Boot.
wdenkc6097192002-11-03 00:24:07 +00002545
wdenk6c59edc2004-05-03 20:45:30 +00002546U-Boot includes many features that so far have been part of some
2547special "boot loader" code within the Linux kernel. Also, any
2548"initrd" images to be used are no longer part of one big Linux image;
2549instead, kernel and "initrd" are separate images. This implementation
2550serves several purposes:
wdenkc6097192002-11-03 00:24:07 +00002551
wdenk6c59edc2004-05-03 20:45:30 +00002552- the same features can be used for other OS or standalone
2553 applications (for instance: using compressed images to reduce the
2554 Flash memory footprint)
wdenkc6097192002-11-03 00:24:07 +00002555
wdenk6c59edc2004-05-03 20:45:30 +00002556- it becomes much easier to port new Linux kernel versions because
2557 lots of low-level, hardware dependent stuff are done by U-Boot
wdenkc6097192002-11-03 00:24:07 +00002558
wdenk6c59edc2004-05-03 20:45:30 +00002559- the same Linux kernel image can now be used with different "initrd"
2560 images; of course this also means that different kernel images can
2561 be run with the same "initrd". This makes testing easier (you don't
2562 have to build a new "zImage.initrd" Linux image when you just
2563 change a file in your "initrd"). Also, a field-upgrade of the
2564 software is easier now.
wdenkc6097192002-11-03 00:24:07 +00002565
wdenkc6097192002-11-03 00:24:07 +00002566
wdenk6c59edc2004-05-03 20:45:30 +00002567Linux HOWTO:
2568============
wdenkc6097192002-11-03 00:24:07 +00002569
wdenk6c59edc2004-05-03 20:45:30 +00002570Porting Linux to U-Boot based systems:
2571---------------------------------------
wdenkc6097192002-11-03 00:24:07 +00002572
wdenk6c59edc2004-05-03 20:45:30 +00002573U-Boot cannot save you from doing all the necessary modifications to
2574configure the Linux device drivers for use with your target hardware
2575(no, we don't intend to provide a full virtual machine interface to
2576Linux :-).
wdenkc6097192002-11-03 00:24:07 +00002577
Stefan Roese88fbf932010-04-15 16:07:28 +02002578But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
wdenkc6097192002-11-03 00:24:07 +00002579
wdenk6c59edc2004-05-03 20:45:30 +00002580Just make sure your machine specific header file (for instance
2581include/asm-ppc/tqm8xx.h) includes the same definition of the Board
Markus Heidelberg47167572008-09-07 20:18:27 +02002582Information structure as we define in include/asm-<arch>/u-boot.h,
2583and make sure that your definition of IMAP_ADDR uses the same value
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02002584as your U-Boot configuration in CONFIG_SYS_IMMR.
wdenkc6097192002-11-03 00:24:07 +00002585
Simon Glassd097e592014-06-11 23:29:46 -06002586Note that U-Boot now has a driver model, a unified model for drivers.
2587If you are adding a new driver, plumb it into driver model. If there
2588is no uclass available, you are encouraged to create one. See
2589doc/driver-model.
2590
wdenkc6097192002-11-03 00:24:07 +00002591
wdenk6c59edc2004-05-03 20:45:30 +00002592Configuring the Linux kernel:
2593-----------------------------
wdenkc6097192002-11-03 00:24:07 +00002594
wdenk6c59edc2004-05-03 20:45:30 +00002595No specific requirements for U-Boot. Make sure you have some root
2596device (initial ramdisk, NFS) for your target system.
wdenkc6097192002-11-03 00:24:07 +00002597
wdenkc6097192002-11-03 00:24:07 +00002598
wdenk6c59edc2004-05-03 20:45:30 +00002599Building a Linux Image:
2600-----------------------
wdenkc6097192002-11-03 00:24:07 +00002601
wdenk6c59edc2004-05-03 20:45:30 +00002602With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2603not used. If you use recent kernel source, a new build target
2604"uImage" will exist which automatically builds an image usable by
2605U-Boot. Most older kernels also have support for a "pImage" target,
2606which was introduced for our predecessor project PPCBoot and uses a
2607100% compatible format.
wdenkc6097192002-11-03 00:24:07 +00002608
wdenk6c59edc2004-05-03 20:45:30 +00002609Example:
wdenkc6097192002-11-03 00:24:07 +00002610
Holger Freyther7ba4e572014-08-04 09:26:05 +02002611 make TQM850L_defconfig
wdenk6c59edc2004-05-03 20:45:30 +00002612 make oldconfig
2613 make dep
2614 make uImage
wdenkc6097192002-11-03 00:24:07 +00002615
wdenk6c59edc2004-05-03 20:45:30 +00002616The "uImage" build target uses a special tool (in 'tools/mkimage') to
2617encapsulate a compressed Linux kernel image with header information,
2618CRC32 checksum etc. for use with U-Boot. This is what we are doing:
wdenkc6097192002-11-03 00:24:07 +00002619
wdenk6c59edc2004-05-03 20:45:30 +00002620* build a standard "vmlinux" kernel image (in ELF binary format):
wdenkc6097192002-11-03 00:24:07 +00002621
wdenk6c59edc2004-05-03 20:45:30 +00002622* convert the kernel into a raw binary image:
wdenkc6097192002-11-03 00:24:07 +00002623
wdenk6c59edc2004-05-03 20:45:30 +00002624 ${CROSS_COMPILE}-objcopy -O binary \
2625 -R .note -R .comment \
2626 -S vmlinux linux.bin
wdenk24ee89b2002-11-03 17:56:27 +00002627
wdenk6c59edc2004-05-03 20:45:30 +00002628* compress the binary image:
wdenk24ee89b2002-11-03 17:56:27 +00002629
wdenk6c59edc2004-05-03 20:45:30 +00002630 gzip -9 linux.bin
wdenk24ee89b2002-11-03 17:56:27 +00002631
wdenk6c59edc2004-05-03 20:45:30 +00002632* package compressed binary image for U-Boot:
wdenk24ee89b2002-11-03 17:56:27 +00002633
wdenk6c59edc2004-05-03 20:45:30 +00002634 mkimage -A ppc -O linux -T kernel -C gzip \
2635 -a 0 -e 0 -n "Linux Kernel Image" \
2636 -d linux.bin.gz uImage
wdenkc6097192002-11-03 00:24:07 +00002637
wdenkc6097192002-11-03 00:24:07 +00002638
wdenk6c59edc2004-05-03 20:45:30 +00002639The "mkimage" tool can also be used to create ramdisk images for use
2640with U-Boot, either separated from the Linux kernel image, or
2641combined into one file. "mkimage" encapsulates the images with a 64
2642byte header containing information about target architecture,
2643operating system, image type, compression method, entry points, time
2644stamp, CRC32 checksums, etc.
wdenkc6097192002-11-03 00:24:07 +00002645
wdenk6c59edc2004-05-03 20:45:30 +00002646"mkimage" can be called in two ways: to verify existing images and
2647print the header information, or to build new images.
wdenk24ee89b2002-11-03 17:56:27 +00002648
wdenk6c59edc2004-05-03 20:45:30 +00002649In the first form (with "-l" option) mkimage lists the information
2650contained in the header of an existing U-Boot image; this includes
2651checksum verification:
wdenk24ee89b2002-11-03 17:56:27 +00002652
wdenk6c59edc2004-05-03 20:45:30 +00002653 tools/mkimage -l image
2654 -l ==> list image header information
wdenk24ee89b2002-11-03 17:56:27 +00002655
wdenk6c59edc2004-05-03 20:45:30 +00002656The second form (with "-d" option) is used to build a U-Boot image
2657from a "data file" which is used as image payload:
wdenk24ee89b2002-11-03 17:56:27 +00002658
wdenk6c59edc2004-05-03 20:45:30 +00002659 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2660 -n name -d data_file image
2661 -A ==> set architecture to 'arch'
2662 -O ==> set operating system to 'os'
2663 -T ==> set image type to 'type'
2664 -C ==> set compression type 'comp'
2665 -a ==> set load address to 'addr' (hex)
2666 -e ==> set entry point to 'ep' (hex)
2667 -n ==> set image name to 'name'
2668 -d ==> use image data from 'datafile'
wdenk24ee89b2002-11-03 17:56:27 +00002669
wdenkcd914452004-05-29 16:53:29 +00002670Right now, all Linux kernels for PowerPC systems use the same load
2671address (0x00000000), but the entry point address depends on the
2672kernel version:
wdenkc6097192002-11-03 00:24:07 +00002673
wdenk6c59edc2004-05-03 20:45:30 +00002674- 2.2.x kernels have the entry point at 0x0000000C,
2675- 2.3.x and later kernels have the entry point at 0x00000000.
wdenkc6097192002-11-03 00:24:07 +00002676
wdenk6c59edc2004-05-03 20:45:30 +00002677So a typical call to build a U-Boot image would read:
wdenkc6097192002-11-03 00:24:07 +00002678
wdenk6c59edc2004-05-03 20:45:30 +00002679 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2680 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
Stefan Roese88fbf932010-04-15 16:07:28 +02002681 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
wdenk6c59edc2004-05-03 20:45:30 +00002682 > examples/uImage.TQM850L
2683 Image Name: 2.4.4 kernel for TQM850L
2684 Created: Wed Jul 19 02:34:59 2000
2685 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2686 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2687 Load Address: 0x00000000
2688 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002689
wdenk6c59edc2004-05-03 20:45:30 +00002690To verify the contents of the image (or check for corruption):
wdenkc6097192002-11-03 00:24:07 +00002691
wdenk6c59edc2004-05-03 20:45:30 +00002692 -> tools/mkimage -l examples/uImage.TQM850L
2693 Image Name: 2.4.4 kernel for TQM850L
2694 Created: Wed Jul 19 02:34:59 2000
2695 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2696 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2697 Load Address: 0x00000000
2698 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002699
wdenk6c59edc2004-05-03 20:45:30 +00002700NOTE: for embedded systems where boot time is critical you can trade
2701speed for memory and install an UNCOMPRESSED image instead: this
2702needs more space in Flash, but boots much faster since it does not
2703need to be uncompressed:
wdenkc6097192002-11-03 00:24:07 +00002704
Stefan Roese88fbf932010-04-15 16:07:28 +02002705 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
wdenk6c59edc2004-05-03 20:45:30 +00002706 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2707 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
Stefan Roese88fbf932010-04-15 16:07:28 +02002708 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
wdenk6c59edc2004-05-03 20:45:30 +00002709 > examples/uImage.TQM850L-uncompressed
2710 Image Name: 2.4.4 kernel for TQM850L
2711 Created: Wed Jul 19 02:34:59 2000
2712 Image Type: PowerPC Linux Kernel Image (uncompressed)
2713 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
2714 Load Address: 0x00000000
2715 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002716
wdenkc6097192002-11-03 00:24:07 +00002717
wdenk6c59edc2004-05-03 20:45:30 +00002718Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2719when your kernel is intended to use an initial ramdisk:
wdenkc6097192002-11-03 00:24:07 +00002720
wdenk6c59edc2004-05-03 20:45:30 +00002721 -> tools/mkimage -n 'Simple Ramdisk Image' \
2722 > -A ppc -O linux -T ramdisk -C gzip \
2723 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2724 Image Name: Simple Ramdisk Image
2725 Created: Wed Jan 12 14:01:50 2000
2726 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2727 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
2728 Load Address: 0x00000000
2729 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002730
Tyler Hicks791c7472020-10-26 10:40:24 -05002731The "dumpimage" tool can be used to disassemble or list the contents of images
2732built by mkimage. See dumpimage's help output (-h) for details.
wdenkc6097192002-11-03 00:24:07 +00002733
wdenk6c59edc2004-05-03 20:45:30 +00002734Installing a Linux Image:
2735-------------------------
wdenkc6097192002-11-03 00:24:07 +00002736
wdenk6c59edc2004-05-03 20:45:30 +00002737To downloading a U-Boot image over the serial (console) interface,
2738you must convert the image to S-Record format:
wdenkc6097192002-11-03 00:24:07 +00002739
wdenk6c59edc2004-05-03 20:45:30 +00002740 objcopy -I binary -O srec examples/image examples/image.srec
wdenkc6097192002-11-03 00:24:07 +00002741
wdenk6c59edc2004-05-03 20:45:30 +00002742The 'objcopy' does not understand the information in the U-Boot
2743image header, so the resulting S-Record file will be relative to
2744address 0x00000000. To load it to a given address, you need to
2745specify the target address as 'offset' parameter with the 'loads'
2746command.
wdenkc6097192002-11-03 00:24:07 +00002747
wdenk6c59edc2004-05-03 20:45:30 +00002748Example: install the image to address 0x40100000 (which on the
2749TQM8xxL is in the first Flash bank):
wdenkc6097192002-11-03 00:24:07 +00002750
wdenk6c59edc2004-05-03 20:45:30 +00002751 => erase 40100000 401FFFFF
wdenkc6097192002-11-03 00:24:07 +00002752
wdenk6c59edc2004-05-03 20:45:30 +00002753 .......... done
2754 Erased 8 sectors
wdenkc6097192002-11-03 00:24:07 +00002755
wdenk6c59edc2004-05-03 20:45:30 +00002756 => loads 40100000
2757 ## Ready for S-Record download ...
2758 ~>examples/image.srec
2759 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2760 ...
2761 15989 15990 15991 15992
2762 [file transfer complete]
2763 [connected]
2764 ## Start Addr = 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002765
wdenkc6097192002-11-03 00:24:07 +00002766
wdenk6c59edc2004-05-03 20:45:30 +00002767You can check the success of the download using the 'iminfo' command;
Wolfgang Denkb240aef2008-03-26 10:40:12 +01002768this includes a checksum verification so you can be sure no data
wdenk6c59edc2004-05-03 20:45:30 +00002769corruption happened:
wdenkc6097192002-11-03 00:24:07 +00002770
wdenk6c59edc2004-05-03 20:45:30 +00002771 => imi 40100000
wdenkc6097192002-11-03 00:24:07 +00002772
wdenk6c59edc2004-05-03 20:45:30 +00002773 ## Checking Image at 40100000 ...
2774 Image Name: 2.2.13 for initrd on TQM850L
2775 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2776 Data Size: 335725 Bytes = 327 kB = 0 MB
2777 Load Address: 00000000
2778 Entry Point: 0000000c
2779 Verifying Checksum ... OK
wdenkc6097192002-11-03 00:24:07 +00002780
2781
wdenk6c59edc2004-05-03 20:45:30 +00002782Boot Linux:
2783-----------
wdenkc6097192002-11-03 00:24:07 +00002784
wdenk6c59edc2004-05-03 20:45:30 +00002785The "bootm" command is used to boot an application that is stored in
2786memory (RAM or Flash). In case of a Linux kernel image, the contents
2787of the "bootargs" environment variable is passed to the kernel as
2788parameters. You can check and modify this variable using the
2789"printenv" and "setenv" commands:
wdenkc6097192002-11-03 00:24:07 +00002790
wdenkc6097192002-11-03 00:24:07 +00002791
wdenk6c59edc2004-05-03 20:45:30 +00002792 => printenv bootargs
2793 bootargs=root=/dev/ram
wdenkc6097192002-11-03 00:24:07 +00002794
wdenk6c59edc2004-05-03 20:45:30 +00002795 => 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 +00002796
wdenk6c59edc2004-05-03 20:45:30 +00002797 => printenv bootargs
2798 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 +00002799
wdenk6c59edc2004-05-03 20:45:30 +00002800 => bootm 40020000
2801 ## Booting Linux kernel at 40020000 ...
2802 Image Name: 2.2.13 for NFS on TQM850L
2803 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2804 Data Size: 381681 Bytes = 372 kB = 0 MB
2805 Load Address: 00000000
2806 Entry Point: 0000000c
2807 Verifying Checksum ... OK
2808 Uncompressing Kernel Image ... OK
2809 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
2810 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2811 time_init: decrementer frequency = 187500000/60
2812 Calibrating delay loop... 49.77 BogoMIPS
2813 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2814 ...
wdenkc6097192002-11-03 00:24:07 +00002815
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02002816If you want to boot a Linux kernel with initial RAM disk, you pass
wdenk6c59edc2004-05-03 20:45:30 +00002817the memory addresses of both the kernel and the initrd image (PPBCOOT
2818format!) to the "bootm" command:
wdenkc6097192002-11-03 00:24:07 +00002819
wdenk6c59edc2004-05-03 20:45:30 +00002820 => imi 40100000 40200000
wdenkc6097192002-11-03 00:24:07 +00002821
wdenk6c59edc2004-05-03 20:45:30 +00002822 ## Checking Image at 40100000 ...
2823 Image Name: 2.2.13 for initrd on TQM850L
2824 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2825 Data Size: 335725 Bytes = 327 kB = 0 MB
2826 Load Address: 00000000
2827 Entry Point: 0000000c
2828 Verifying Checksum ... OK
wdenkc6097192002-11-03 00:24:07 +00002829
wdenk6c59edc2004-05-03 20:45:30 +00002830 ## Checking Image at 40200000 ...
2831 Image Name: Simple Ramdisk Image
2832 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2833 Data Size: 566530 Bytes = 553 kB = 0 MB
2834 Load Address: 00000000
2835 Entry Point: 00000000
2836 Verifying Checksum ... OK
wdenkc6097192002-11-03 00:24:07 +00002837
wdenk6c59edc2004-05-03 20:45:30 +00002838 => bootm 40100000 40200000
2839 ## Booting Linux kernel at 40100000 ...
2840 Image Name: 2.2.13 for initrd on TQM850L
2841 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2842 Data Size: 335725 Bytes = 327 kB = 0 MB
2843 Load Address: 00000000
2844 Entry Point: 0000000c
2845 Verifying Checksum ... OK
2846 Uncompressing Kernel Image ... OK
2847 ## Loading RAMDisk Image at 40200000 ...
2848 Image Name: Simple Ramdisk Image
2849 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2850 Data Size: 566530 Bytes = 553 kB = 0 MB
2851 Load Address: 00000000
2852 Entry Point: 00000000
2853 Verifying Checksum ... OK
2854 Loading Ramdisk ... OK
2855 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
2856 Boot arguments: root=/dev/ram
2857 time_init: decrementer frequency = 187500000/60
2858 Calibrating delay loop... 49.77 BogoMIPS
2859 ...
2860 RAMDISK: Compressed image found at block 0
2861 VFS: Mounted root (ext2 filesystem).
wdenkc6097192002-11-03 00:24:07 +00002862
wdenk6c59edc2004-05-03 20:45:30 +00002863 bash#
wdenkc6097192002-11-03 00:24:07 +00002864
Matthew McClintockefae4ca2006-06-28 10:41:37 -05002865Boot Linux and pass a flat device tree:
2866-----------
2867
2868First, U-Boot must be compiled with the appropriate defines. See the section
2869titled "Linux Kernel Interface" above for a more in depth explanation. The
2870following is an example of how to start a kernel and pass an updated
2871flat device tree:
2872
2873=> print oftaddr
2874oftaddr=0x300000
2875=> print oft
2876oft=oftrees/mpc8540ads.dtb
2877=> tftp $oftaddr $oft
2878Speed: 1000, full duplex
2879Using TSEC0 device
2880TFTP from server 192.168.1.1; our IP address is 192.168.1.101
2881Filename 'oftrees/mpc8540ads.dtb'.
2882Load address: 0x300000
2883Loading: #
2884done
2885Bytes transferred = 4106 (100a hex)
2886=> tftp $loadaddr $bootfile
2887Speed: 1000, full duplex
2888Using TSEC0 device
2889TFTP from server 192.168.1.1; our IP address is 192.168.1.2
2890Filename 'uImage'.
2891Load address: 0x200000
2892Loading:############
2893done
2894Bytes transferred = 1029407 (fb51f hex)
2895=> print loadaddr
2896loadaddr=200000
2897=> print oftaddr
2898oftaddr=0x300000
2899=> bootm $loadaddr - $oftaddr
2900## Booting image at 00200000 ...
Wolfgang Denk018147d2006-11-27 15:32:42 +01002901 Image Name: Linux-2.6.17-dirty
2902 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2903 Data Size: 1029343 Bytes = 1005.2 kB
Matthew McClintockefae4ca2006-06-28 10:41:37 -05002904 Load Address: 00000000
Wolfgang Denk018147d2006-11-27 15:32:42 +01002905 Entry Point: 00000000
Matthew McClintockefae4ca2006-06-28 10:41:37 -05002906 Verifying Checksum ... OK
2907 Uncompressing Kernel Image ... OK
2908Booting using flat device tree at 0x300000
2909Using MPC85xx ADS machine description
2910Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
2911[snip]
2912
2913
wdenk6c59edc2004-05-03 20:45:30 +00002914More About U-Boot Image Types:
2915------------------------------
wdenkc6097192002-11-03 00:24:07 +00002916
wdenk6c59edc2004-05-03 20:45:30 +00002917U-Boot supports the following image types:
wdenkc6097192002-11-03 00:24:07 +00002918
wdenk6c59edc2004-05-03 20:45:30 +00002919 "Standalone Programs" are directly runnable in the environment
2920 provided by U-Boot; it is expected that (if they behave
2921 well) you can continue to work in U-Boot after return from
2922 the Standalone Program.
2923 "OS Kernel Images" are usually images of some Embedded OS which
2924 will take over control completely. Usually these programs
2925 will install their own set of exception handlers, device
2926 drivers, set up the MMU, etc. - this means, that you cannot
2927 expect to re-enter U-Boot except by resetting the CPU.
2928 "RAMDisk Images" are more or less just data blocks, and their
2929 parameters (address, size) are passed to an OS kernel that is
2930 being started.
2931 "Multi-File Images" contain several images, typically an OS
2932 (Linux) kernel image and one or more data images like
2933 RAMDisks. This construct is useful for instance when you want
2934 to boot over the network using BOOTP etc., where the boot
2935 server provides just a single image file, but you want to get
2936 for instance an OS kernel and a RAMDisk image.
wdenkc6097192002-11-03 00:24:07 +00002937
wdenk6c59edc2004-05-03 20:45:30 +00002938 "Multi-File Images" start with a list of image sizes, each
2939 image size (in bytes) specified by an "uint32_t" in network
2940 byte order. This list is terminated by an "(uint32_t)0".
2941 Immediately after the terminating 0 follow the images, one by
2942 one, all aligned on "uint32_t" boundaries (size rounded up to
2943 a multiple of 4 bytes).
wdenkc6097192002-11-03 00:24:07 +00002944
wdenk6c59edc2004-05-03 20:45:30 +00002945 "Firmware Images" are binary images containing firmware (like
2946 U-Boot or FPGA images) which usually will be programmed to
2947 flash memory.
wdenk4fc95692003-02-28 00:49:47 +00002948
wdenk6c59edc2004-05-03 20:45:30 +00002949 "Script files" are command sequences that will be executed by
2950 U-Boot's command interpreter; this feature is especially
2951 useful when you configure U-Boot to use a real shell (hush)
2952 as command interpreter.
wdenk4fc95692003-02-28 00:49:47 +00002953
Marek Vasutcf41a9b2012-03-14 21:52:45 +00002954Booting the Linux zImage:
2955-------------------------
2956
2957On some platforms, it's possible to boot Linux zImage. This is done
2958using the "bootz" command. The syntax of "bootz" command is the same
2959as the syntax of "bootm" command.
2960
Tom Rini45f46d12013-05-16 11:40:11 -04002961Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
Marek Vasut28850d02012-03-18 11:47:58 +00002962kernel with raw initrd images. The syntax is slightly different, the
2963address of the initrd must be augmented by it's size, in the following
2964format: "<initrd addres>:<initrd size>".
2965
stroeseb9c17c52003-04-04 15:53:41 +00002966
wdenk6c59edc2004-05-03 20:45:30 +00002967Standalone HOWTO:
2968=================
stroeseb9c17c52003-04-04 15:53:41 +00002969
wdenk6c59edc2004-05-03 20:45:30 +00002970One of the features of U-Boot is that you can dynamically load and
2971run "standalone" applications, which can use some resources of
2972U-Boot like console I/O functions or interrupt services.
stroeseb9c17c52003-04-04 15:53:41 +00002973
wdenk6c59edc2004-05-03 20:45:30 +00002974Two simple examples are included with the sources:
wdenk4fc95692003-02-28 00:49:47 +00002975
wdenk6c59edc2004-05-03 20:45:30 +00002976"Hello World" Demo:
2977-------------------
wdenkc6097192002-11-03 00:24:07 +00002978
wdenk6c59edc2004-05-03 20:45:30 +00002979'examples/hello_world.c' contains a small "Hello World" Demo
2980application; it is automatically compiled when you build U-Boot.
2981It's configured to run at address 0x00040004, so you can play with it
2982like that:
wdenkc6097192002-11-03 00:24:07 +00002983
wdenk6c59edc2004-05-03 20:45:30 +00002984 => loads
2985 ## Ready for S-Record download ...
2986 ~>examples/hello_world.srec
2987 1 2 3 4 5 6 7 8 9 10 11 ...
2988 [file transfer complete]
2989 [connected]
2990 ## Start Addr = 0x00040004
wdenkc6097192002-11-03 00:24:07 +00002991
wdenk6c59edc2004-05-03 20:45:30 +00002992 => go 40004 Hello World! This is a test.
2993 ## Starting application at 0x00040004 ...
2994 Hello World
2995 argc = 7
2996 argv[0] = "40004"
2997 argv[1] = "Hello"
2998 argv[2] = "World!"
2999 argv[3] = "This"
3000 argv[4] = "is"
3001 argv[5] = "a"
3002 argv[6] = "test."
3003 argv[7] = "<NULL>"
3004 Hit any key to exit ...
wdenkc6097192002-11-03 00:24:07 +00003005
wdenk6c59edc2004-05-03 20:45:30 +00003006 ## Application terminated, rc = 0x0
wdenkc6097192002-11-03 00:24:07 +00003007
wdenk6c59edc2004-05-03 20:45:30 +00003008Another example, which demonstrates how to register a CPM interrupt
3009handler with the U-Boot code, can be found in 'examples/timer.c'.
3010Here, a CPM timer is set up to generate an interrupt every second.
3011The interrupt service routine is trivial, just printing a '.'
3012character, but this is just a demo program. The application can be
3013controlled by the following keys:
wdenkc6097192002-11-03 00:24:07 +00003014
wdenk6c59edc2004-05-03 20:45:30 +00003015 ? - print current values og the CPM Timer registers
3016 b - enable interrupts and start timer
3017 e - stop timer and disable interrupts
3018 q - quit application
wdenkc6097192002-11-03 00:24:07 +00003019
wdenk6c59edc2004-05-03 20:45:30 +00003020 => loads
3021 ## Ready for S-Record download ...
3022 ~>examples/timer.srec
3023 1 2 3 4 5 6 7 8 9 10 11 ...
3024 [file transfer complete]
3025 [connected]
3026 ## Start Addr = 0x00040004
wdenkc6097192002-11-03 00:24:07 +00003027
wdenk6c59edc2004-05-03 20:45:30 +00003028 => go 40004
3029 ## Starting application at 0x00040004 ...
3030 TIMERS=0xfff00980
3031 Using timer 1
3032 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
wdenkc6097192002-11-03 00:24:07 +00003033
wdenk6c59edc2004-05-03 20:45:30 +00003034Hit 'b':
3035 [q, b, e, ?] Set interval 1000000 us
3036 Enabling timer
3037Hit '?':
3038 [q, b, e, ?] ........
3039 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3040Hit '?':
3041 [q, b, e, ?] .
3042 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3043Hit '?':
3044 [q, b, e, ?] .
3045 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3046Hit '?':
3047 [q, b, e, ?] .
3048 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3049Hit 'e':
3050 [q, b, e, ?] ...Stopping timer
3051Hit 'q':
3052 [q, b, e, ?] ## Application terminated, rc = 0x0
wdenkc6097192002-11-03 00:24:07 +00003053
wdenkc6097192002-11-03 00:24:07 +00003054
wdenk6c59edc2004-05-03 20:45:30 +00003055Minicom warning:
3056================
wdenkc6097192002-11-03 00:24:07 +00003057
wdenk6c59edc2004-05-03 20:45:30 +00003058Over time, many people have reported problems when trying to use the
3059"minicom" terminal emulation program for serial download. I (wd)
3060consider minicom to be broken, and recommend not to use it. Under
3061Unix, I recommend to use C-Kermit for general purpose use (and
3062especially for kermit binary protocol download ("loadb" command), and
Karl O. Pinca0189bb2012-10-01 05:11:56 +00003063use "cu" for S-Record download ("loads" command). See
Naoki Hayamae0cc1852020-10-08 13:17:16 +09003064https://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
Karl O. Pinca0189bb2012-10-01 05:11:56 +00003065for help with kermit.
3066
wdenkc6097192002-11-03 00:24:07 +00003067
wdenk6c59edc2004-05-03 20:45:30 +00003068Nevertheless, if you absolutely want to use it try adding this
3069configuration to your "File transfer protocols" section:
wdenkc6097192002-11-03 00:24:07 +00003070
wdenk6c59edc2004-05-03 20:45:30 +00003071 Name Program Name U/D FullScr IO-Red. Multi
3072 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3073 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
wdenk8dba0502003-03-31 16:34:49 +00003074
wdenk8dba0502003-03-31 16:34:49 +00003075
wdenk6c59edc2004-05-03 20:45:30 +00003076NetBSD Notes:
3077=============
wdenkc6097192002-11-03 00:24:07 +00003078
wdenk6c59edc2004-05-03 20:45:30 +00003079Starting at version 0.9.2, U-Boot supports NetBSD both as host
3080(build U-Boot) and target system (boots NetBSD/mpc8xx).
wdenk88e72a32003-06-19 23:04:19 +00003081
wdenk6c59edc2004-05-03 20:45:30 +00003082Building requires a cross environment; it is known to work on
3083NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3084need gmake since the Makefiles are not compatible with BSD make).
3085Note that the cross-powerpc package does not install include files;
3086attempting to build U-Boot will fail because <machine/ansi.h> is
3087missing. This file has to be installed and patched manually:
wdenk88e72a32003-06-19 23:04:19 +00003088
wdenk6c59edc2004-05-03 20:45:30 +00003089 # cd /usr/pkg/cross/powerpc-netbsd/include
3090 # mkdir powerpc
3091 # ln -s powerpc machine
3092 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3093 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
wdenk88e72a32003-06-19 23:04:19 +00003094
wdenk6c59edc2004-05-03 20:45:30 +00003095Native builds *don't* work due to incompatibilities between native
3096and U-Boot include files.
wdenkc6097192002-11-03 00:24:07 +00003097
wdenk6c59edc2004-05-03 20:45:30 +00003098Booting assumes that (the first part of) the image booted is a
3099stage-2 loader which in turn loads and then invokes the kernel
3100proper. Loader sources will eventually appear in the NetBSD source
3101tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
wdenkd0245fc2005-04-13 10:02:42 +00003102meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
wdenkc6097192002-11-03 00:24:07 +00003103
wdenkc6097192002-11-03 00:24:07 +00003104
wdenk6c59edc2004-05-03 20:45:30 +00003105Implementation Internals:
3106=========================
wdenkc6097192002-11-03 00:24:07 +00003107
wdenk6c59edc2004-05-03 20:45:30 +00003108The following is not intended to be a complete description of every
3109implementation detail. However, it should help to understand the
3110inner workings of U-Boot and make it easier to port it to custom
3111hardware.
wdenkc6097192002-11-03 00:24:07 +00003112
wdenkc6097192002-11-03 00:24:07 +00003113
wdenk6c59edc2004-05-03 20:45:30 +00003114Initial Stack, Global Data:
3115---------------------------
wdenkc6097192002-11-03 00:24:07 +00003116
wdenk6c59edc2004-05-03 20:45:30 +00003117The implementation of U-Boot is complicated by the fact that U-Boot
3118starts running out of ROM (flash memory), usually without access to
3119system RAM (because the memory controller is not initialized yet).
3120This means that we don't have writable Data or BSS segments, and BSS
3121is not initialized as zero. To be able to get a C environment working
3122at all, we have to allocate at least a minimal stack. Implementation
3123options for this are defined and restricted by the CPU used: Some CPU
3124models provide on-chip memory (like the IMMR area on MPC8xx and
3125MPC826x processors), on others (parts of) the data cache can be
3126locked as (mis-) used as memory, etc.
wdenkc6097192002-11-03 00:24:07 +00003127
Wolfgang Denkb240aef2008-03-26 10:40:12 +01003128 Chris Hallinan posted a good summary of these issues to the
Wolfgang Denk290ae6b2008-12-30 22:56:11 +01003129 U-Boot mailing list:
wdenkc6097192002-11-03 00:24:07 +00003130
wdenk6c59edc2004-05-03 20:45:30 +00003131 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3132 From: "Chris Hallinan" <clh@net1plus.com>
3133 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3134 ...
wdenkc6097192002-11-03 00:24:07 +00003135
wdenk6c59edc2004-05-03 20:45:30 +00003136 Correct me if I'm wrong, folks, but the way I understand it
3137 is this: Using DCACHE as initial RAM for Stack, etc, does not
3138 require any physical RAM backing up the cache. The cleverness
3139 is that the cache is being used as a temporary supply of
3140 necessary storage before the SDRAM controller is setup. It's
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02003141 beyond the scope of this list to explain the details, but you
wdenk6c59edc2004-05-03 20:45:30 +00003142 can see how this works by studying the cache architecture and
3143 operation in the architecture and processor-specific manuals.
wdenkc6097192002-11-03 00:24:07 +00003144
wdenk6c59edc2004-05-03 20:45:30 +00003145 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3146 is another option for the system designer to use as an
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02003147 initial stack/RAM area prior to SDRAM being available. Either
wdenk6c59edc2004-05-03 20:45:30 +00003148 option should work for you. Using CS 4 should be fine if your
3149 board designers haven't used it for something that would
3150 cause you grief during the initial boot! It is frequently not
3151 used.
wdenkc6097192002-11-03 00:24:07 +00003152
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02003153 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
wdenk6c59edc2004-05-03 20:45:30 +00003154 with your processor/board/system design. The default value
3155 you will find in any recent u-boot distribution in
Stefan Roese3e1f1b32005-08-01 16:49:12 +02003156 walnut.h should work for you. I'd set it to a value larger
wdenk6c59edc2004-05-03 20:45:30 +00003157 than your SDRAM module. If you have a 64MB SDRAM module, set
3158 it above 400_0000. Just make sure your board has no resources
3159 that are supposed to respond to that address! That code in
3160 start.S has been around a while and should work as is when
3161 you get the config right.
wdenk4a5c8a72003-03-06 00:02:04 +00003162
wdenk6c59edc2004-05-03 20:45:30 +00003163 -Chris Hallinan
3164 DS4.COM, Inc.
wdenk4a5c8a72003-03-06 00:02:04 +00003165
wdenk6c59edc2004-05-03 20:45:30 +00003166It is essential to remember this, since it has some impact on the C
3167code for the initialization procedures:
wdenk4a5c8a72003-03-06 00:02:04 +00003168
wdenk6c59edc2004-05-03 20:45:30 +00003169* Initialized global data (data segment) is read-only. Do not attempt
3170 to write it.
wdenk4a5c8a72003-03-06 00:02:04 +00003171
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08003172* Do not use any uninitialized global data (or implicitly initialized
wdenk6c59edc2004-05-03 20:45:30 +00003173 as zero data - BSS segment) at all - this is undefined, initiali-
3174 zation is performed later (when relocating to RAM).
wdenk4a5c8a72003-03-06 00:02:04 +00003175
wdenk6c59edc2004-05-03 20:45:30 +00003176* Stack space is very limited. Avoid big data buffers or things like
3177 that.
wdenk4a5c8a72003-03-06 00:02:04 +00003178
wdenk6c59edc2004-05-03 20:45:30 +00003179Having only the stack as writable memory limits means we cannot use
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08003180normal global data to share information between the code. But it
wdenk6c59edc2004-05-03 20:45:30 +00003181turned out that the implementation of U-Boot can be greatly
3182simplified by making a global data structure (gd_t) available to all
3183functions. We could pass a pointer to this data as argument to _all_
3184functions, but this would bloat the code. Instead we use a feature of
3185the GCC compiler (Global Register Variables) to share the data: we
3186place a pointer (gd) to the global data into a register which we
3187reserve for this purpose.
wdenkc6097192002-11-03 00:24:07 +00003188
wdenk6c59edc2004-05-03 20:45:30 +00003189When choosing a register for such a purpose we are restricted by the
3190relevant (E)ABI specifications for the current architecture, and by
3191GCC's implementation.
wdenkc6097192002-11-03 00:24:07 +00003192
wdenk6c59edc2004-05-03 20:45:30 +00003193For PowerPC, the following registers have specific use:
3194 R1: stack pointer
Wolfgang Denk69c09642008-02-14 22:43:22 +01003195 R2: reserved for system use
wdenk6c59edc2004-05-03 20:45:30 +00003196 R3-R4: parameter passing and return values
3197 R5-R10: parameter passing
3198 R13: small data area pointer
3199 R30: GOT pointer
3200 R31: frame pointer
wdenkc6097192002-11-03 00:24:07 +00003201
Joakim Tjernlund693c0c12010-01-19 14:41:58 +01003202 (U-Boot also uses R12 as internal GOT pointer. r12
3203 is a volatile register so r12 needs to be reset when
3204 going back and forth between asm and C)
wdenkc6097192002-11-03 00:24:07 +00003205
Wolfgang Denk69c09642008-02-14 22:43:22 +01003206 ==> U-Boot will use R2 to hold a pointer to the global data
wdenkc6097192002-11-03 00:24:07 +00003207
wdenk6c59edc2004-05-03 20:45:30 +00003208 Note: on PPC, we could use a static initializer (since the
3209 address of the global data structure is known at compile time),
3210 but it turned out that reserving a register results in somewhat
3211 smaller code - although the code savings are not that big (on
3212 average for all boards 752 bytes for the whole U-Boot image,
3213 624 text + 127 data).
wdenkc6097192002-11-03 00:24:07 +00003214
wdenk6c59edc2004-05-03 20:45:30 +00003215On ARM, the following registers are used:
wdenkc6097192002-11-03 00:24:07 +00003216
wdenk6c59edc2004-05-03 20:45:30 +00003217 R0: function argument word/integer result
3218 R1-R3: function argument word
Jeroen Hofsteea556aca2013-09-21 14:04:42 +02003219 R9: platform specific
3220 R10: stack limit (used only if stack checking is enabled)
wdenk6c59edc2004-05-03 20:45:30 +00003221 R11: argument (frame) pointer
3222 R12: temporary workspace
3223 R13: stack pointer
3224 R14: link register
3225 R15: program counter
wdenkc6097192002-11-03 00:24:07 +00003226
Jeroen Hofsteea556aca2013-09-21 14:04:42 +02003227 ==> U-Boot will use R9 to hold a pointer to the global data
3228
3229 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
wdenkc6097192002-11-03 00:24:07 +00003230
Thomas Chou8fa38582010-05-21 11:08:03 +08003231On Nios II, the ABI is documented here:
Naoki Hayamae0cc1852020-10-08 13:17:16 +09003232 https://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
Thomas Chou8fa38582010-05-21 11:08:03 +08003233
3234 ==> U-Boot will use gp to hold a pointer to the global data
3235
3236 Note: on Nios II, we give "-G0" option to gcc and don't use gp
3237 to access small data sections, so gp is free.
3238
Rick Chend7e6f922017-12-26 13:55:59 +08003239On RISC-V, the following registers are used:
3240
3241 x0: hard-wired zero (zero)
3242 x1: return address (ra)
3243 x2: stack pointer (sp)
3244 x3: global pointer (gp)
3245 x4: thread pointer (tp)
3246 x5: link register (t0)
3247 x8: frame pointer (fp)
3248 x10-x11: arguments/return values (a0-1)
3249 x12-x17: arguments (a2-7)
3250 x28-31: temporaries (t3-6)
3251 pc: program counter (pc)
3252
3253 ==> U-Boot will use gp to hold a pointer to the global data
3254
wdenk6c59edc2004-05-03 20:45:30 +00003255Memory Management:
3256------------------
wdenkc6097192002-11-03 00:24:07 +00003257
wdenk6c59edc2004-05-03 20:45:30 +00003258U-Boot runs in system state and uses physical addresses, i.e. the
3259MMU is not used either for address mapping nor for memory protection.
wdenkc6097192002-11-03 00:24:07 +00003260
wdenk6c59edc2004-05-03 20:45:30 +00003261The available memory is mapped to fixed addresses using the memory
3262controller. In this process, a contiguous block is formed for each
3263memory type (Flash, SDRAM, SRAM), even when it consists of several
3264physical memory banks.
wdenkc6097192002-11-03 00:24:07 +00003265
wdenk6c59edc2004-05-03 20:45:30 +00003266U-Boot is installed in the first 128 kB of the first Flash bank (on
3267TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3268booting and sizing and initializing DRAM, the code relocates itself
3269to the upper end of DRAM. Immediately below the U-Boot code some
Jean-Christophe PLAGNIOL-VILLARD03836942008-10-16 15:01:15 +02003270memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
wdenk6c59edc2004-05-03 20:45:30 +00003271configuration setting]. Below that, a structure with global Board
3272Info data is placed, followed by the stack (growing downward).
wdenkc6097192002-11-03 00:24:07 +00003273
wdenk6c59edc2004-05-03 20:45:30 +00003274Additionally, some exception handler code is copied to the low 8 kB
3275of DRAM (0x00000000 ... 0x00001FFF).
wdenkc6097192002-11-03 00:24:07 +00003276
wdenk6c59edc2004-05-03 20:45:30 +00003277So a typical memory configuration with 16 MB of DRAM could look like
3278this:
wdenkc6097192002-11-03 00:24:07 +00003279
wdenk6c59edc2004-05-03 20:45:30 +00003280 0x0000 0000 Exception Vector code
3281 :
3282 0x0000 1FFF
3283 0x0000 2000 Free for Application Use
3284 :
3285 :
wdenkc6097192002-11-03 00:24:07 +00003286
wdenk6c59edc2004-05-03 20:45:30 +00003287 :
3288 :
3289 0x00FB FF20 Monitor Stack (Growing downward)
3290 0x00FB FFAC Board Info Data and permanent copy of global data
3291 0x00FC 0000 Malloc Arena
3292 :
3293 0x00FD FFFF
3294 0x00FE 0000 RAM Copy of Monitor Code
3295 ... eventually: LCD or video framebuffer
3296 ... eventually: pRAM (Protected RAM - unchanged by reset)
3297 0x00FF FFFF [End of RAM]
wdenkc6097192002-11-03 00:24:07 +00003298
wdenkc6097192002-11-03 00:24:07 +00003299
wdenk6c59edc2004-05-03 20:45:30 +00003300System Initialization:
3301----------------------
wdenkc6097192002-11-03 00:24:07 +00003302
wdenk6c59edc2004-05-03 20:45:30 +00003303In the reset configuration, U-Boot starts at the reset entry point
Marcel Ziswilerabd8dcb2008-07-09 08:17:15 +02003304(on most PowerPC systems at address 0x00000100). Because of the reset
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08003305configuration for CS0# this is a mirror of the on board Flash memory.
wdenk6c59edc2004-05-03 20:45:30 +00003306To be able to re-map memory U-Boot then jumps to its link address.
3307To be able to implement the initialization code in C, a (small!)
3308initial stack is set up in the internal Dual Ported RAM (in case CPUs
Heiko Schocher71cb3e92017-06-07 17:33:10 +02003309which provide such a feature like), or in a locked part of the data
3310cache. After that, U-Boot initializes the CPU core, the caches and
3311the SIU.
wdenkc6097192002-11-03 00:24:07 +00003312
wdenk6c59edc2004-05-03 20:45:30 +00003313Next, all (potentially) available memory banks are mapped using a
3314preliminary mapping. For example, we put them on 512 MB boundaries
3315(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3316on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3317programmed for SDRAM access. Using the temporary configuration, a
3318simple memory test is run that determines the size of the SDRAM
3319banks.
wdenkc6097192002-11-03 00:24:07 +00003320
wdenk6c59edc2004-05-03 20:45:30 +00003321When there is more than one SDRAM bank, and the banks are of
3322different size, the largest is mapped first. For equal size, the first
3323bank (CS2#) is mapped first. The first mapping is always for address
33240x00000000, with any additional banks following immediately to create
3325contiguous memory starting from 0.
wdenkc6097192002-11-03 00:24:07 +00003326
wdenk6c59edc2004-05-03 20:45:30 +00003327Then, the monitor installs itself at the upper end of the SDRAM area
3328and allocates memory for use by malloc() and for the global Board
3329Info data; also, the exception vector code is copied to the low RAM
3330pages, and the final stack is set up.
wdenkc6097192002-11-03 00:24:07 +00003331
wdenk6c59edc2004-05-03 20:45:30 +00003332Only after this relocation will you have a "normal" C environment;
3333until that you are restricted in several ways, mostly because you are
3334running from ROM, and because the code will have to be relocated to a
3335new address in RAM.
wdenkc6097192002-11-03 00:24:07 +00003336
wdenkc6097192002-11-03 00:24:07 +00003337
wdenk6c59edc2004-05-03 20:45:30 +00003338U-Boot Porting Guide:
3339----------------------
wdenkc6097192002-11-03 00:24:07 +00003340
wdenk6c59edc2004-05-03 20:45:30 +00003341[Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3342list, October 2002]
wdenkc6097192002-11-03 00:24:07 +00003343
wdenkc6097192002-11-03 00:24:07 +00003344
Jerry Van Barenba0687c2009-07-15 20:42:59 -04003345int main(int argc, char *argv[])
wdenk6c59edc2004-05-03 20:45:30 +00003346{
3347 sighandler_t no_more_time;
wdenkc6097192002-11-03 00:24:07 +00003348
Jerry Van Barenba0687c2009-07-15 20:42:59 -04003349 signal(SIGALRM, no_more_time);
3350 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
wdenkc6097192002-11-03 00:24:07 +00003351
wdenk6c59edc2004-05-03 20:45:30 +00003352 if (available_money > available_manpower) {
Jerry Van Barenba0687c2009-07-15 20:42:59 -04003353 Pay consultant to port U-Boot;
wdenk6c59edc2004-05-03 20:45:30 +00003354 return 0;
3355 }
wdenkc6097192002-11-03 00:24:07 +00003356
wdenk6c59edc2004-05-03 20:45:30 +00003357 Download latest U-Boot source;
wdenk34b613e2002-12-17 01:51:00 +00003358
Wolfgang Denk290ae6b2008-12-30 22:56:11 +01003359 Subscribe to u-boot mailing list;
wdenkc6097192002-11-03 00:24:07 +00003360
Jerry Van Barenba0687c2009-07-15 20:42:59 -04003361 if (clueless)
3362 email("Hi, I am new to U-Boot, how do I get started?");
wdenkc6097192002-11-03 00:24:07 +00003363
wdenk6c59edc2004-05-03 20:45:30 +00003364 while (learning) {
3365 Read the README file in the top level directory;
Naoki Hayamae0cc1852020-10-08 13:17:16 +09003366 Read https://www.denx.de/wiki/bin/view/DULG/Manual;
Patrick Delaunay9b281fa2020-02-28 15:18:10 +01003367 Read applicable doc/README.*;
wdenk6c59edc2004-05-03 20:45:30 +00003368 Read the source, Luke;
Jerry Van Barenba0687c2009-07-15 20:42:59 -04003369 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
wdenk6c59edc2004-05-03 20:45:30 +00003370 }
wdenkc6097192002-11-03 00:24:07 +00003371
Jerry Van Barenba0687c2009-07-15 20:42:59 -04003372 if (available_money > toLocalCurrency ($2500))
3373 Buy a BDI3000;
3374 else
wdenk6c59edc2004-05-03 20:45:30 +00003375 Add a lot of aggravation and time;
wdenkc6097192002-11-03 00:24:07 +00003376
Jerry Van Barenba0687c2009-07-15 20:42:59 -04003377 if (a similar board exists) { /* hopefully... */
3378 cp -a board/<similar> board/<myboard>
3379 cp include/configs/<similar>.h include/configs/<myboard>.h
3380 } else {
3381 Create your own board support subdirectory;
3382 Create your own board include/configs/<myboard>.h file;
3383 }
3384 Edit new board/<myboard> files
3385 Edit new include/configs/<myboard>.h
wdenkc6097192002-11-03 00:24:07 +00003386
Jerry Van Barenba0687c2009-07-15 20:42:59 -04003387 while (!accepted) {
3388 while (!running) {
3389 do {
3390 Add / modify source code;
3391 } until (compiles);
3392 Debug;
3393 if (clueless)
3394 email("Hi, I am having problems...");
3395 }
3396 Send patch file to the U-Boot email list;
3397 if (reasonable critiques)
3398 Incorporate improvements from email list code review;
3399 else
3400 Defend code as written;
wdenk634d2f72004-04-15 23:14:49 +00003401 }
wdenkc6097192002-11-03 00:24:07 +00003402
wdenk6c59edc2004-05-03 20:45:30 +00003403 return 0;
3404}
wdenkc6097192002-11-03 00:24:07 +00003405
wdenk6c59edc2004-05-03 20:45:30 +00003406void no_more_time (int sig)
3407{
3408 hire_a_guru();
3409}
wdenkc6097192002-11-03 00:24:07 +00003410
wdenkc6097192002-11-03 00:24:07 +00003411
wdenk6c59edc2004-05-03 20:45:30 +00003412Coding Standards:
3413-----------------
wdenkc6097192002-11-03 00:24:07 +00003414
wdenk6c59edc2004-05-03 20:45:30 +00003415All contributions to U-Boot should conform to the Linux kernel
Baruch Siachb1081252017-12-10 17:34:35 +02003416coding style; see the kernel coding style guide at
3417https://www.kernel.org/doc/html/latest/process/coding-style.html, and the
3418script "scripts/Lindent" in your Linux kernel source directory.
Detlev Zundelaa63d482006-09-01 15:39:02 +02003419
3420Source files originating from a different project (for example the
3421MTD subsystem) are generally exempt from these guidelines and are not
Jeremiah Mahler03f930c2015-01-04 18:56:50 -08003422reformatted to ease subsequent migration to newer versions of those
Detlev Zundelaa63d482006-09-01 15:39:02 +02003423sources.
wdenkc6097192002-11-03 00:24:07 +00003424
Detlev Zundelaa63d482006-09-01 15:39:02 +02003425Please note that U-Boot is implemented in C (and to some small parts in
3426Assembler); no C++ is used, so please do not use C++ style comments (//)
3427in your code.
wdenkad276f22004-01-04 16:28:35 +00003428
wdenk6c59edc2004-05-03 20:45:30 +00003429Please also stick to the following formatting rules:
3430- remove any trailing white space
Wolfgang Denk20bd2a62011-07-27 10:59:55 +00003431- use TAB characters for indentation and vertical alignment, not spaces
wdenk6c59edc2004-05-03 20:45:30 +00003432- make sure NOT to use DOS '\r\n' line feeds
Wolfgang Denk20bd2a62011-07-27 10:59:55 +00003433- do not add more than 2 consecutive empty lines to source files
wdenk6c59edc2004-05-03 20:45:30 +00003434- do not add trailing empty lines to source files
wdenkc6097192002-11-03 00:24:07 +00003435
wdenk6c59edc2004-05-03 20:45:30 +00003436Submissions which do not conform to the standards may be returned
3437with a request to reformat the changes.
wdenkc6097192002-11-03 00:24:07 +00003438
wdenkc6097192002-11-03 00:24:07 +00003439
wdenk6c59edc2004-05-03 20:45:30 +00003440Submitting Patches:
3441-------------------
wdenkc6097192002-11-03 00:24:07 +00003442
wdenk6c59edc2004-05-03 20:45:30 +00003443Since the number of patches for U-Boot is growing, we need to
3444establish some rules. Submissions which do not conform to these rules
3445may be rejected, even when they contain important and valuable stuff.
wdenkc6097192002-11-03 00:24:07 +00003446
Naoki Hayamae0cc1852020-10-08 13:17:16 +09003447Please see https://www.denx.de/wiki/U-Boot/Patches for details.
Wolfgang Denkb240aef2008-03-26 10:40:12 +01003448
Wolfgang Denk290ae6b2008-12-30 22:56:11 +01003449Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
S. Lockwood-Childsda6d34c2017-11-14 22:56:42 -08003450see https://lists.denx.de/listinfo/u-boot
Wolfgang Denk290ae6b2008-12-30 22:56:11 +01003451
wdenk6c59edc2004-05-03 20:45:30 +00003452When you send a patch, please include the following information with
3453it:
wdenkc6097192002-11-03 00:24:07 +00003454
wdenk6c59edc2004-05-03 20:45:30 +00003455* For bug fixes: a description of the bug and how your patch fixes
3456 this bug. Please try to include a way of demonstrating that the
3457 patch actually fixes something.
wdenkc6097192002-11-03 00:24:07 +00003458
wdenk6c59edc2004-05-03 20:45:30 +00003459* For new features: a description of the feature and your
3460 implementation.
wdenkc6097192002-11-03 00:24:07 +00003461
Robert P. J. Day076ed9b2015-12-19 07:16:10 -05003462* For major contributions, add a MAINTAINERS file with your
3463 information and associated file and directory references.
wdenkc6097192002-11-03 00:24:07 +00003464
Albert ARIBAUD48e910f2013-09-11 15:52:51 +02003465* When you add support for a new board, don't forget to add a
3466 maintainer e-mail address to the boards.cfg file, too.
wdenkc6097192002-11-03 00:24:07 +00003467
wdenk6c59edc2004-05-03 20:45:30 +00003468* If your patch adds new configuration options, don't forget to
3469 document these in the README file.
wdenkc6097192002-11-03 00:24:07 +00003470
Wolfgang Denkb240aef2008-03-26 10:40:12 +01003471* The patch itself. If you are using git (which is *strongly*
3472 recommended) you can easily generate the patch using the
Wolfgang Denk20bd2a62011-07-27 10:59:55 +00003473 "git format-patch". If you then use "git send-email" to send it to
Wolfgang Denkb240aef2008-03-26 10:40:12 +01003474 the U-Boot mailing list, you will avoid most of the common problems
3475 with some other mail clients.
wdenkca9bc762003-07-15 07:45:49 +00003476
Wolfgang Denkb240aef2008-03-26 10:40:12 +01003477 If you cannot use git, use "diff -purN OLD NEW". If your version of
3478 diff does not support these options, then get the latest version of
3479 GNU diff.
wdenkc6097192002-11-03 00:24:07 +00003480
Wolfgang Denkb240aef2008-03-26 10:40:12 +01003481 The current directory when running this command shall be the parent
3482 directory of the U-Boot source tree (i. e. please make sure that
3483 your patch includes sufficient directory information for the
3484 affected files).
3485
3486 We prefer patches as plain text. MIME attachments are discouraged,
3487 and compressed attachments must not be used.
wdenk88e72a32003-06-19 23:04:19 +00003488
wdenk6c59edc2004-05-03 20:45:30 +00003489* If one logical set of modifications affects or creates several
3490 files, all these changes shall be submitted in a SINGLE patch file.
wdenk57b2d802003-06-27 21:31:46 +00003491
wdenk6c59edc2004-05-03 20:45:30 +00003492* Changesets that contain different, unrelated modifications shall be
3493 submitted as SEPARATE patches, one patch per changeset.
wdenk88e72a32003-06-19 23:04:19 +00003494
wdenkc6097192002-11-03 00:24:07 +00003495
wdenk6c59edc2004-05-03 20:45:30 +00003496Notes:
wdenkc6097192002-11-03 00:24:07 +00003497
Simon Glassdc27def2016-07-27 20:33:08 -06003498* Before sending the patch, run the buildman script on your patched
wdenk6c59edc2004-05-03 20:45:30 +00003499 source tree and make sure that no errors or warnings are reported
3500 for any of the boards.
3501
3502* Keep your modifications to the necessary minimum: A patch
3503 containing several unrelated changes or arbitrary reformats will be
3504 returned with a request to re-formatting / split it.
wdenkc6097192002-11-03 00:24:07 +00003505
wdenk6c59edc2004-05-03 20:45:30 +00003506* If you modify existing code, make sure that your new code does not
3507 add to the memory footprint of the code ;-) Small is beautiful!
3508 When adding new features, these should compile conditionally only
3509 (using #ifdef), and the resulting code with the new feature
3510 disabled must not need more memory than the old code without your
3511 modification.
wdenkcbc49a52005-05-03 14:12:25 +00003512
Wolfgang Denk290ae6b2008-12-30 22:56:11 +01003513* Remember that there is a size limit of 100 kB per message on the
3514 u-boot mailing list. Bigger patches will be moderated. If they are
3515 reasonable and not too big, they will be acknowledged. But patches
3516 bigger than the size limit should be avoided.