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Tom Rini83d290c2018-05-06 17:58:06 -04001# SPDX-License-Identifier: GPL-2.0+
wdenkc6097192002-11-03 00:24:07 +00002#
Wolfgang Denkeca3aeb2013-06-21 10:22:36 +02003# (C) Copyright 2000 - 2013
wdenkc6097192002-11-03 00:24:07 +00004# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
wdenkc6097192002-11-03 00:24:07 +00005
6Summary:
7========
8
wdenk24ee89b2002-11-03 17:56:27 +00009This directory contains the source code for U-Boot, a boot loader for
wdenke86e5a02004-10-17 21:12:06 +000010Embedded boards based on PowerPC, ARM, MIPS and several other
11processors, which can be installed in a boot ROM and used to
12initialize and test the hardware or to download and run application
13code.
wdenkc6097192002-11-03 00:24:07 +000014
15The development of U-Boot is closely related to Linux: some parts of
wdenk24ee89b2002-11-03 17:56:27 +000016the source code originate in the Linux source tree, we have some
17header files in common, and special provision has been made to
wdenkc6097192002-11-03 00:24:07 +000018support booting of Linux images.
19
20Some attention has been paid to make this software easily
21configurable and extendable. For instance, all monitor commands are
22implemented with the same call interface, so that it's very easy to
23add new commands. Also, instead of permanently adding rarely used
24code (for instance hardware test utilities) to the monitor, you can
25load and run it dynamically.
26
27
28Status:
29=======
30
31In general, all boards for which a configuration option exists in the
wdenk24ee89b2002-11-03 17:56:27 +000032Makefile have been tested to some extent and can be considered
wdenkc6097192002-11-03 00:24:07 +000033"working". In fact, many of them are used in production systems.
34
Robert P. J. Day7207b362015-12-19 07:16:10 -050035In case of problems see the CHANGELOG file to find out who contributed
36the specific port. In addition, there are various MAINTAINERS files
37scattered throughout the U-Boot source identifying the people or
38companies responsible for various boards and subsystems.
wdenkc6097192002-11-03 00:24:07 +000039
Robert P. J. Day7207b362015-12-19 07:16:10 -050040Note: As of August, 2010, there is no longer a CHANGELOG file in the
41actual U-Boot source tree; however, it can be created dynamically
42from the Git log using:
Robert P. J. Dayadb9d852012-11-14 02:03:20 +000043
44 make CHANGELOG
45
wdenkc6097192002-11-03 00:24:07 +000046
47Where to get help:
48==================
49
wdenk24ee89b2002-11-03 17:56:27 +000050In case you have questions about, problems with or contributions for
Robert P. J. Day7207b362015-12-19 07:16:10 -050051U-Boot, you should send a message to the U-Boot mailing list at
Peter Tyser0c325652008-09-10 09:18:34 -050052<u-boot@lists.denx.de>. There is also an archive of previous traffic
53on the mailing list - please search the archive before asking FAQ's.
Naoki Hayama6681bbb2020-10-08 13:16:18 +090054Please see https://lists.denx.de/pipermail/u-boot and
55https://marc.info/?l=u-boot
wdenkc6097192002-11-03 00:24:07 +000056
Wolfgang Denk218ca722008-03-26 10:40:12 +010057Where to get source code:
58=========================
59
Robert P. J. Day7207b362015-12-19 07:16:10 -050060The U-Boot source code is maintained in the Git repository at
Heinrich Schuchardta3bbd0b2021-02-24 13:19:04 +010061https://source.denx.de/u-boot/u-boot.git ; you can browse it online at
62https://source.denx.de/u-boot/u-boot
Wolfgang Denk218ca722008-03-26 10:40:12 +010063
Naoki Hayamac4bd51e2020-10-08 13:16:25 +090064The "Tags" links on this page allow you to download tarballs of
Marcel Ziswiler11ccc332008-07-09 08:17:15 +020065any version you might be interested in. Official releases are also
Naoki Hayamac4bd51e2020-10-08 13:16:25 +090066available from the DENX file server through HTTPS or FTP.
67https://ftp.denx.de/pub/u-boot/
68ftp://ftp.denx.de/pub/u-boot/
Wolfgang Denk218ca722008-03-26 10:40:12 +010069
70
wdenkc6097192002-11-03 00:24:07 +000071Where we come from:
72===================
73
74- start from 8xxrom sources
Naoki Hayama047f6ec2020-10-08 13:17:16 +090075- create PPCBoot project (https://sourceforge.net/projects/ppcboot)
wdenkc6097192002-11-03 00:24:07 +000076- clean up code
77- make it easier to add custom boards
78- make it possible to add other [PowerPC] CPUs
79- extend functions, especially:
80 * Provide extended interface to Linux boot loader
81 * S-Record download
82 * network boot
Simon Glass9e5616d2019-08-01 09:47:14 -060083 * ATA disk / SCSI ... boot
Naoki Hayama047f6ec2020-10-08 13:17:16 +090084- create ARMBoot project (https://sourceforge.net/projects/armboot)
wdenkc6097192002-11-03 00:24:07 +000085- add other CPU families (starting with ARM)
Naoki Hayama047f6ec2020-10-08 13:17:16 +090086- create U-Boot project (https://sourceforge.net/projects/u-boot)
87- current project page: see https://www.denx.de/wiki/U-Boot
wdenk24ee89b2002-11-03 17:56:27 +000088
89
90Names and Spelling:
91===================
92
93The "official" name of this project is "Das U-Boot". The spelling
94"U-Boot" shall be used in all written text (documentation, comments
95in source files etc.). Example:
96
97 This is the README file for the U-Boot project.
98
99File names etc. shall be based on the string "u-boot". Examples:
100
101 include/asm-ppc/u-boot.h
102
103 #include <asm/u-boot.h>
104
105Variable names, preprocessor constants etc. shall be either based on
106the string "u_boot" or on "U_BOOT". Example:
107
108 U_BOOT_VERSION u_boot_logo
109 IH_OS_U_BOOT u_boot_hush_start
wdenkc6097192002-11-03 00:24:07 +0000110
111
wdenk93f19cc2002-12-17 17:55:09 +0000112Versioning:
113===========
114
Thomas Weber360d8832010-09-28 08:06:25 +0200115Starting with the release in October 2008, the names of the releases
116were changed from numerical release numbers without deeper meaning
117into a time stamp based numbering. Regular releases are identified by
118names consisting of the calendar year and month of the release date.
119Additional fields (if present) indicate release candidates or bug fix
120releases in "stable" maintenance trees.
wdenk93f19cc2002-12-17 17:55:09 +0000121
Thomas Weber360d8832010-09-28 08:06:25 +0200122Examples:
Wolfgang Denkc0f40852011-10-26 10:21:21 +0000123 U-Boot v2009.11 - Release November 2009
Thomas Weber360d8832010-09-28 08:06:25 +0200124 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
Jelle van der Waa0de21ec2016-10-30 17:30:30 +0100125 U-Boot v2010.09-rc1 - Release candidate 1 for September 2010 release
wdenk93f19cc2002-12-17 17:55:09 +0000126
127
wdenkc6097192002-11-03 00:24:07 +0000128Directory Hierarchy:
129====================
130
Simon Glass6e73ed02021-07-10 21:14:21 -0600131/arch Architecture-specific files
Masahiro Yamada6eae68e2014-03-07 18:02:02 +0900132 /arc Files generic to ARC architecture
Peter Tyser8d321b82010-04-12 22:28:21 -0500133 /arm Files generic to ARM architecture
Peter Tyser8d321b82010-04-12 22:28:21 -0500134 /m68k Files generic to m68k architecture
Peter Tyser8d321b82010-04-12 22:28:21 -0500135 /microblaze Files generic to microblaze architecture
Peter Tyser8d321b82010-04-12 22:28:21 -0500136 /mips Files generic to MIPS architecture
Peter Tyser8d321b82010-04-12 22:28:21 -0500137 /nios2 Files generic to Altera NIOS2 architecture
Stefan Roesea47a12b2010-04-15 16:07:28 +0200138 /powerpc Files generic to PowerPC architecture
Rick Chen3fafced2017-12-26 13:55:59 +0800139 /riscv Files generic to RISC-V architecture
Robert P. J. Day7207b362015-12-19 07:16:10 -0500140 /sandbox Files generic to HW-independent "sandbox"
Peter Tyser8d321b82010-04-12 22:28:21 -0500141 /sh Files generic to SH architecture
Robert P. J. Day33c77312013-09-15 18:34:15 -0400142 /x86 Files generic to x86 architecture
Naoki Hayamae4eb3132020-10-08 13:16:38 +0900143 /xtensa Files generic to Xtensa architecture
Simon Glass6e73ed02021-07-10 21:14:21 -0600144/api Machine/arch-independent API for external apps
145/board Board-dependent files
Simon Glass19a91f22021-10-14 12:47:54 -0600146/boot Support for images and booting
Xu Ziyuan740f7e52016-08-26 19:54:49 +0800147/cmd U-Boot commands functions
Simon Glass6e73ed02021-07-10 21:14:21 -0600148/common Misc architecture-independent functions
Robert P. J. Day7207b362015-12-19 07:16:10 -0500149/configs Board default configuration files
Peter Tyser8d321b82010-04-12 22:28:21 -0500150/disk Code for disk drive partition handling
Simon Glass6e73ed02021-07-10 21:14:21 -0600151/doc Documentation (a mix of ReST and READMEs)
152/drivers Device drivers
153/dts Makefile for building internal U-Boot fdt.
154/env Environment support
Peter Tyser8d321b82010-04-12 22:28:21 -0500155/examples Example code for standalone applications, etc.
156/fs Filesystem code (cramfs, ext2, jffs2, etc.)
157/include Header Files
Robert P. J. Day7207b362015-12-19 07:16:10 -0500158/lib Library routines generic to all architectures
159/Licenses Various license files
Peter Tyser8d321b82010-04-12 22:28:21 -0500160/net Networking code
161/post Power On Self Test
Robert P. J. Day7207b362015-12-19 07:16:10 -0500162/scripts Various build scripts and Makefiles
163/test Various unit test files
Simon Glass6e73ed02021-07-10 21:14:21 -0600164/tools Tools to build and sign FIT images, etc.
wdenkc6097192002-11-03 00:24:07 +0000165
wdenkc6097192002-11-03 00:24:07 +0000166Software Configuration:
167=======================
168
wdenkc6097192002-11-03 00:24:07 +0000169Selection of Processor Architecture and Board Type:
170---------------------------------------------------
171
172For all supported boards there are ready-to-use default
Holger Freytherab584d62014-08-04 09:26:05 +0200173configurations available; just type "make <board_name>_defconfig".
wdenkc6097192002-11-03 00:24:07 +0000174
175Example: For a TQM823L module type:
176
177 cd u-boot
Holger Freytherab584d62014-08-04 09:26:05 +0200178 make TQM823L_defconfig
wdenkc6097192002-11-03 00:24:07 +0000179
Robert P. J. Day7207b362015-12-19 07:16:10 -0500180Note: If you're looking for the default configuration file for a board
181you're sure used to be there but is now missing, check the file
182doc/README.scrapyard for a list of no longer supported boards.
wdenkc6097192002-11-03 00:24:07 +0000183
Simon Glass75b3c3a2014-03-22 17:12:59 -0600184Sandbox Environment:
185--------------------
186
187U-Boot can be built natively to run on a Linux host using the 'sandbox'
188board. This allows feature development which is not board- or architecture-
189specific to be undertaken on a native platform. The sandbox is also used to
190run some of U-Boot's tests.
191
Naoki Hayamabbb140e2020-10-08 13:16:58 +0900192See doc/arch/sandbox.rst for more details.
Simon Glass75b3c3a2014-03-22 17:12:59 -0600193
194
Simon Glassdb910352015-03-03 08:03:00 -0700195Board Initialisation Flow:
196--------------------------
197
198This is the intended start-up flow for boards. This should apply for both
Robert P. J. Day7207b362015-12-19 07:16:10 -0500199SPL and U-Boot proper (i.e. they both follow the same rules).
Simon Glassdb910352015-03-03 08:03:00 -0700200
Robert P. J. Day7207b362015-12-19 07:16:10 -0500201Note: "SPL" stands for "Secondary Program Loader," which is explained in
202more detail later in this file.
203
204At present, SPL mostly uses a separate code path, but the function names
205and roles of each function are the same. Some boards or architectures
206may not conform to this. At least most ARM boards which use
207CONFIG_SPL_FRAMEWORK conform to this.
208
209Execution typically starts with an architecture-specific (and possibly
210CPU-specific) start.S file, such as:
211
212 - arch/arm/cpu/armv7/start.S
213 - arch/powerpc/cpu/mpc83xx/start.S
214 - arch/mips/cpu/start.S
215
216and so on. From there, three functions are called; the purpose and
217limitations of each of these functions are described below.
Simon Glassdb910352015-03-03 08:03:00 -0700218
219lowlevel_init():
220 - purpose: essential init to permit execution to reach board_init_f()
221 - no global_data or BSS
222 - there is no stack (ARMv7 may have one but it will soon be removed)
223 - must not set up SDRAM or use console
224 - must only do the bare minimum to allow execution to continue to
225 board_init_f()
226 - this is almost never needed
227 - return normally from this function
228
229board_init_f():
230 - purpose: set up the machine ready for running board_init_r():
231 i.e. SDRAM and serial UART
232 - global_data is available
233 - stack is in SRAM
234 - BSS is not available, so you cannot use global/static variables,
235 only stack variables and global_data
236
237 Non-SPL-specific notes:
238 - dram_init() is called to set up DRAM. If already done in SPL this
239 can do nothing
240
241 SPL-specific notes:
242 - you can override the entire board_init_f() function with your own
243 version as needed.
244 - preloader_console_init() can be called here in extremis
245 - should set up SDRAM, and anything needed to make the UART work
Naoki Hayama499696e2020-09-24 15:57:19 +0900246 - there is no need to clear BSS, it will be done by crt0.S
Andreas Dannenberg14254652019-08-08 12:54:49 -0500247 - for specific scenarios on certain architectures an early BSS *can*
248 be made available (via CONFIG_SPL_EARLY_BSS by moving the clearing
249 of BSS prior to entering board_init_f()) but doing so is discouraged.
250 Instead it is strongly recommended to architect any code changes
251 or additions such to not depend on the availability of BSS during
252 board_init_f() as indicated in other sections of this README to
253 maintain compatibility and consistency across the entire code base.
Simon Glassdb910352015-03-03 08:03:00 -0700254 - must return normally from this function (don't call board_init_r()
255 directly)
256
257Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
258this point the stack and global_data are relocated to below
259CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
260memory.
261
262board_init_r():
263 - purpose: main execution, common code
264 - global_data is available
265 - SDRAM is available
266 - BSS is available, all static/global variables can be used
267 - execution eventually continues to main_loop()
268
269 Non-SPL-specific notes:
270 - U-Boot is relocated to the top of memory and is now running from
271 there.
272
273 SPL-specific notes:
274 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
Ashish Kumar63b23162017-08-11 11:09:14 +0530275 CONFIG_SYS_FSL_HAS_CCI400
276
277 Defined For SoC that has cache coherent interconnect
278 CCN-400
wdenk7f6c2cb2002-11-10 22:06:23 +0000279
Ashish Kumarc055cee2017-08-18 10:54:36 +0530280 CONFIG_SYS_FSL_HAS_CCN504
281
282 Defined for SoC that has cache coherent interconnect CCN-504
283
wdenkc6097192002-11-03 00:24:07 +0000284The following options need to be configured:
285
Kim Phillips26281142007-08-10 13:28:25 -0500286- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
wdenkc6097192002-11-03 00:24:07 +0000287
Kim Phillips26281142007-08-10 13:28:25 -0500288- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
Wolfgang Denk6ccec442006-10-24 14:42:37 +0200289
Kumar Gala66412c62011-02-18 05:40:54 -0600290- 85xx CPU Options:
York Sunffd06e02012-10-08 07:44:30 +0000291 CONFIG_SYS_PPC64
292
293 Specifies that the core is a 64-bit PowerPC implementation (implements
294 the "64" category of the Power ISA). This is necessary for ePAPR
295 compliance, among other possible reasons.
296
Scott Wood33eee332012-08-14 10:14:53 +0000297 CONFIG_SYS_FSL_ERRATUM_A004510
298
299 Enables a workaround for erratum A004510. If set,
300 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
Tom Rini6cc04542022-10-28 20:27:13 -0400301 CFG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
Scott Wood33eee332012-08-14 10:14:53 +0000302
303 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
304 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
305
306 Defines one or two SoC revisions (low 8 bits of SVR)
307 for which the A004510 workaround should be applied.
308
309 The rest of SVR is either not relevant to the decision
310 of whether the erratum is present (e.g. p2040 versus
311 p2041) or is implied by the build target, which controls
312 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
313
314 See Freescale App Note 4493 for more information about
315 this erratum.
316
Tom Rini6cc04542022-10-28 20:27:13 -0400317 CFG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
Scott Wood33eee332012-08-14 10:14:53 +0000318
319 This is the value to write into CCSR offset 0x18600
320 according to the A004510 workaround.
321
Priyanka Jainb1359912013-12-17 14:25:52 +0530322 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
323 Single Source Clock is clocking mode present in some of FSL SoC's.
324 In this mode, a single differential clock is used to supply
325 clocks to the sysclock, ddrclock and usbclock.
326
Daniel Schwierzeck6cb461b2012-04-02 02:57:56 +0000327- Generic CPU options:
Daniel Schwierzeck6cb461b2012-04-02 02:57:56 +0000328
York Sun5614e712013-09-30 09:22:09 -0700329 CONFIG_SYS_FSL_DDR
330 Freescale DDR driver in use. This type of DDR controller is
Tom Rini1c588572021-05-14 21:34:26 -0400331 found in mpc83xx, mpc85xx as well as some ARM core SoCs.
York Sun5614e712013-09-30 09:22:09 -0700332
Tom Rini6cc04542022-10-28 20:27:13 -0400333 CFG_SYS_FSL_DDR_ADDR
York Sun5614e712013-09-30 09:22:09 -0700334 Freescale DDR memory-mapped register base.
335
Prabhakar Kushwaha1c407072017-02-02 15:01:26 +0530336 CONFIG_SYS_FSL_IFC_CLK_DIV
337 Defines divider of platform clock(clock input to IFC controller).
338
Prabhakar Kushwahaadd63f92017-02-02 15:02:00 +0530339 CONFIG_SYS_FSL_LBC_CLK_DIV
340 Defines divider of platform clock(clock input to eLBC controller).
341
Tom Rini6cc04542022-10-28 20:27:13 -0400342 CFG_SYS_FSL_DDR_SDRAM_BASE_PHY
York Sun6b9e3092014-02-10 13:59:43 -0800343 Physical address from the view of DDR controllers. It is the
344 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
345 it could be different for ARM SoCs.
346
Daniel Schwierzeck92bbd642011-07-27 13:22:39 +0200347- MIPS CPU options:
Daniel Schwierzeck92bbd642011-07-27 13:22:39 +0200348 CONFIG_XWAY_SWAP_BYTES
349
350 Enable compilation of tools/xway-swap-bytes needed for Lantiq
351 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
352 be swapped if a flash programmer is used.
353
Christian Rieschb67d8812012-02-02 00:44:39 +0000354- ARM options:
355 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
356
357 Select high exception vectors of the ARM core, e.g., do not
358 clear the V bit of the c1 register of CP15.
359
York Sun207774b2015-03-20 19:28:08 -0700360 COUNTER_FREQUENCY
361 Generic timer clock source frequency.
362
363 COUNTER_FREQUENCY_REAL
364 Generic timer clock source frequency if the real clock is
365 different from COUNTER_FREQUENCY, and can only be determined
366 at run time.
367
Stephen Warren73c38932015-01-19 16:25:52 -0700368- Tegra SoC options:
369 CONFIG_TEGRA_SUPPORT_NON_SECURE
370
371 Support executing U-Boot in non-secure (NS) mode. Certain
372 impossible actions will be skipped if the CPU is in NS mode,
373 such as ARM architectural timer initialization.
374
wdenk5da627a2003-10-09 20:09:04 +0000375- Linux Kernel Interface:
wdenk5da627a2003-10-09 20:09:04 +0000376 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
377
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -0800378 When transferring memsize parameter to Linux, some versions
wdenk5da627a2003-10-09 20:09:04 +0000379 expect it to be in bytes, others in MB.
380 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
381
Gerald Van Barenfec6d9e2008-06-03 20:34:45 -0400382 CONFIG_OF_LIBFDT
Wolfgang Denkf57f70a2005-10-13 01:45:54 +0200383
384 New kernel versions are expecting firmware settings to be
Gerald Van Baren213bf8c2007-03-31 12:23:51 -0400385 passed using flattened device trees (based on open firmware
386 concepts).
387
388 CONFIG_OF_LIBFDT
389 * New libfdt-based support
390 * Adds the "fdt" command
Kim Phillips3bb342f2007-08-10 14:34:14 -0500391 * The bootm command automatically updates the fdt
Gerald Van Baren213bf8c2007-03-31 12:23:51 -0400392
Wolfgang Denkf57f70a2005-10-13 01:45:54 +0200393 OF_TBCLK - The timebase frequency.
394
Marcel Ziswiler11ccc332008-07-09 08:17:15 +0200395 boards with QUICC Engines require OF_QE to set UCC MAC
396 addresses
Kim Phillips3bb342f2007-08-10 14:34:14 -0500397
Heiko Schocher3887c3f2009-09-23 07:56:08 +0200398 CONFIG_OF_IDE_FIXUP
399
400 U-Boot can detect if an IDE device is present or not.
401 If not, and this new config option is activated, U-Boot
402 removes the ATA node from the DTS before booting Linux,
403 so the Linux IDE driver does not probe the device and
404 crash. This is needed for buggy hardware (uc101) where
405 no pull down resistor is connected to the signal IDE5V_DD7.
406
Niklaus Giger0b2f4ec2008-11-03 22:13:47 +0100407- vxWorks boot parameters:
408
409 bootvx constructs a valid bootline using the following
Bin Meng9e98b7e2015-10-07 20:19:17 -0700410 environments variables: bootdev, bootfile, ipaddr, netmask,
411 serverip, gatewayip, hostname, othbootargs.
Niklaus Giger0b2f4ec2008-11-03 22:13:47 +0100412 It loads the vxWorks image pointed bootfile.
413
Naoki Hayama81a05d92020-10-08 13:17:08 +0900414 Note: If a "bootargs" environment is defined, it will override
Niklaus Giger0b2f4ec2008-11-03 22:13:47 +0100415 the defaults discussed just above.
416
Aneesh V93bc2192011-06-16 23:30:51 +0000417- Cache Configuration for ARM:
Aneesh V93bc2192011-06-16 23:30:51 +0000418 CONFIG_SYS_PL310_BASE - Physical base address of PL310
419 controller register space
420
wdenk6705d812004-08-02 23:22:59 +0000421- Serial Ports:
wdenk6705d812004-08-02 23:22:59 +0000422 CONFIG_PL011_CLOCK
423
424 If you have Amba PrimeCell PL011 UARTs, set this variable to
425 the clock speed of the UARTs.
426
427 CONFIG_PL01x_PORTS
428
429 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
430 define this to a list of base addresses for each (supported)
431 port. See e.g. include/configs/versatile.h
432
Karicheri, Muralidharand57dee52014-04-09 15:38:46 -0400433 CONFIG_SERIAL_HW_FLOW_CONTROL
434
435 Define this variable to enable hw flow control in serial driver.
436 Current user of this option is drivers/serial/nsl16550.c driver
wdenk6705d812004-08-02 23:22:59 +0000437
Simon Glass302a6482016-03-13 19:07:28 -0600438- Removal of commands
439 If no commands are needed to boot, you can disable
440 CONFIG_CMDLINE to remove them. In this case, the command line
441 will not be available, and when U-Boot wants to execute the
442 boot command (on start-up) it will call board_run_command()
443 instead. This can reduce image size significantly for very
444 simple boot procedures.
445
Wolfgang Denka5ecbe62013-03-23 23:50:31 +0000446- Regular expression support:
447 CONFIG_REGEX
Wolfgang Denk93e14592013-10-04 17:43:24 +0200448 If this variable is defined, U-Boot is linked against
449 the SLRE (Super Light Regular Expression) library,
450 which adds regex support to some commands, as for
451 example "env grep" and "setexpr".
Wolfgang Denka5ecbe62013-03-23 23:50:31 +0000452
wdenkc6097192002-11-03 00:24:07 +0000453- Watchdog:
Rasmus Villemoes933ada52021-04-14 09:18:22 +0200454 CONFIG_SYS_WATCHDOG_FREQ
455 Some platforms automatically call WATCHDOG_RESET()
456 from the timer interrupt handler every
457 CONFIG_SYS_WATCHDOG_FREQ interrupts. If not set by the
458 board configuration file, a default of CONFIG_SYS_HZ/2
459 (i.e. 500) is used. Setting CONFIG_SYS_WATCHDOG_FREQ
460 to 0 disables calling WATCHDOG_RESET() from the timer
461 interrupt.
462
wdenkc6097192002-11-03 00:24:07 +0000463- Real-Time Clock:
464
Jon Loeliger602ad3b2007-06-11 19:03:39 -0500465 When CONFIG_CMD_DATE is selected, the type of the RTC
wdenkc6097192002-11-03 00:24:07 +0000466 has to be selected, too. Define exactly one of the
467 following options:
468
wdenkc6097192002-11-03 00:24:07 +0000469 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
Fabio Estevam4e8b7542011-10-24 06:44:15 +0000470 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
wdenkc6097192002-11-03 00:24:07 +0000471 CONFIG_RTC_MC146818 - use MC146818 RTC
wdenk1cb8e982003-03-06 21:55:29 +0000472 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
wdenkc6097192002-11-03 00:24:07 +0000473 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
wdenk7f70e852003-05-20 14:25:27 +0000474 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
Markus Niebel412921d2014-07-21 11:06:16 +0200475 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
wdenk3bac3512003-03-12 10:41:04 +0000476 CONFIG_RTC_DS164x - use Dallas DS164x RTC
Tor Krill9536dfc2008-03-15 15:40:26 +0100477 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
wdenk4c0d4c32004-06-09 17:34:58 +0000478 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
Chris Packham2bd3cab2017-05-30 12:03:33 +1200479 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
Heiko Schocher71d19f32011-03-28 09:24:22 +0200480 CONFIG_SYS_RV3029_TCR - enable trickle charger on
481 RV3029 RTC.
wdenkc6097192002-11-03 00:24:07 +0000482
wdenkb37c7e52003-06-30 16:24:52 +0000483 Note that if the RTC uses I2C, then the I2C interface
484 must also be configured. See I2C Support, below.
485
Peter Tysere92739d2008-12-17 16:36:21 -0600486- GPIO Support:
487 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
Peter Tysere92739d2008-12-17 16:36:21 -0600488
Chris Packham5dec49c2010-12-19 10:12:13 +0000489 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
490 chip-ngpio pairs that tell the PCA953X driver the number of
491 pins supported by a particular chip.
492
Peter Tysere92739d2008-12-17 16:36:21 -0600493 Note that if the GPIO device uses I2C, then the I2C interface
494 must also be configured. See I2C Support, below.
495
Simon Glassaa532332014-06-11 23:29:41 -0600496- I/O tracing:
497 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
498 accesses and can checksum them or write a list of them out
499 to memory. See the 'iotrace' command for details. This is
500 useful for testing device drivers since it can confirm that
501 the driver behaves the same way before and after a code
502 change. Currently this is supported on sandbox and arm. To
503 add support for your architecture, add '#include <iotrace.h>'
504 to the bottom of arch/<arch>/include/asm/io.h and test.
505
506 Example output from the 'iotrace stats' command is below.
507 Note that if the trace buffer is exhausted, the checksum will
508 still continue to operate.
509
510 iotrace is enabled
511 Start: 10000000 (buffer start address)
512 Size: 00010000 (buffer size)
513 Offset: 00000120 (current buffer offset)
514 Output: 10000120 (start + offset)
515 Count: 00000018 (number of trace records)
516 CRC32: 9526fb66 (CRC32 of all trace records)
517
wdenkc6097192002-11-03 00:24:07 +0000518- Timestamp Support:
519
wdenk43d96162003-03-06 00:02:04 +0000520 When CONFIG_TIMESTAMP is selected, the timestamp
521 (date and time) of an image is printed by image
522 commands like bootm or iminfo. This option is
Jon Loeliger602ad3b2007-06-11 19:03:39 -0500523 automatically enabled when you select CONFIG_CMD_DATE .
wdenkc6097192002-11-03 00:24:07 +0000524
Karl O. Pinc923c46f2012-08-16 06:20:15 +0000525- Partition Labels (disklabels) Supported:
526 Zero or more of the following:
527 CONFIG_MAC_PARTITION Apple's MacOS partition table.
Karl O. Pinc923c46f2012-08-16 06:20:15 +0000528 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
529 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
530 bootloader. Note 2TB partition limit; see
531 disk/part_efi.c
Simon Glassc649e3c2016-05-01 11:36:02 -0600532 CONFIG_SCSI) you must configure support for at
Karl O. Pinc923c46f2012-08-16 06:20:15 +0000533 least one non-MTD partition type as well.
wdenkc6097192002-11-03 00:24:07 +0000534
wdenkc6097192002-11-03 00:24:07 +0000535- NETWORK Support (PCI):
Kyle Moffettce5207e2011-10-18 11:05:29 +0000536 CONFIG_E1000_SPI
537 Utility code for direct access to the SPI bus on Intel 8257x.
538 This does not do anything useful unless you set at least one
539 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
540
wdenkc6097192002-11-03 00:24:07 +0000541 CONFIG_NATSEMI
542 Support for National dp83815 chips.
543
544 CONFIG_NS8382X
545 Support for National dp8382[01] gigabit chips.
546
wdenk45219c42003-05-12 21:50:16 +0000547- NETWORK Support (other):
Rob Herringefdd7312011-12-15 11:15:49 +0000548 CONFIG_CALXEDA_XGMAC
549 Support for the Calxeda XGMAC device
550
Ashok3bb46d22012-10-15 06:20:47 +0000551 CONFIG_LAN91C96
wdenk45219c42003-05-12 21:50:16 +0000552 Support for SMSC's LAN91C96 chips.
553
wdenk45219c42003-05-12 21:50:16 +0000554 CONFIG_LAN91C96_USE_32_BIT
555 Define this to enable 32 bit addressing
556
Heiko Schocherdc02bad2011-11-15 10:00:04 -0500557 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
558 Define this if you have more then 3 PHYs.
559
Macpaul Linb3dbf4a52010-12-21 16:59:46 +0800560 CONFIG_FTGMAC100
561 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
562
563 CONFIG_FTGMAC100_EGIGA
564 Define this to use GE link update with gigabit PHY.
565 Define this if FTGMAC100 is connected to gigabit PHY.
566 If your system has 10/100 PHY only, it might not occur
567 wrong behavior. Because PHY usually return timeout or
568 useless data when polling gigabit status and gigabit
569 control registers. This behavior won't affect the
570 correctnessof 10/100 link speed update.
571
Yoshihiro Shimoda3d0075f2011-01-27 10:06:03 +0900572 CONFIG_SH_ETHER
573 Support for Renesas on-chip Ethernet controller
574
575 CONFIG_SH_ETHER_USE_PORT
576 Define the number of ports to be used
577
578 CONFIG_SH_ETHER_PHY_ADDR
579 Define the ETH PHY's address
580
Yoshihiro Shimoda68260aa2011-01-27 10:06:08 +0900581 CONFIG_SH_ETHER_CACHE_WRITEBACK
582 If this option is set, the driver enables cache flush.
583
Vadim Bendebury5e124722011-10-17 08:36:14 +0000584- TPM Support:
Che-liang Chiou90899cc2013-04-12 11:04:34 +0000585 CONFIG_TPM
586 Support TPM devices.
587
Christophe Ricard0766ad22015-10-06 22:54:41 +0200588 CONFIG_TPM_TIS_INFINEON
589 Support for Infineon i2c bus TPM devices. Only one device
Tom Wai-Hong Tam1b393db2013-04-12 11:04:37 +0000590 per system is supported at this time.
591
Tom Wai-Hong Tam1b393db2013-04-12 11:04:37 +0000592 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
593 Define the burst count bytes upper limit
594
Christophe Ricard3aa74082016-01-21 23:27:13 +0100595 CONFIG_TPM_ST33ZP24
596 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
597
598 CONFIG_TPM_ST33ZP24_I2C
599 Support for STMicroelectronics ST33ZP24 I2C devices.
600 Requires TPM_ST33ZP24 and I2C.
601
Christophe Ricardb75fdc12016-01-21 23:27:14 +0100602 CONFIG_TPM_ST33ZP24_SPI
603 Support for STMicroelectronics ST33ZP24 SPI devices.
604 Requires TPM_ST33ZP24 and SPI.
605
Dirk Eibachc01939c2013-06-26 15:55:15 +0200606 CONFIG_TPM_ATMEL_TWI
607 Support for Atmel TWI TPM device. Requires I2C support.
608
Che-liang Chiou90899cc2013-04-12 11:04:34 +0000609 CONFIG_TPM_TIS_LPC
Vadim Bendebury5e124722011-10-17 08:36:14 +0000610 Support for generic parallel port TPM devices. Only one device
611 per system is supported at this time.
612
613 CONFIG_TPM_TIS_BASE_ADDRESS
614 Base address where the generic TPM device is mapped
615 to. Contemporary x86 systems usually map it at
616 0xfed40000.
617
Reinhard Pfaube6c1522013-06-26 15:55:13 +0200618 CONFIG_TPM
619 Define this to enable the TPM support library which provides
620 functional interfaces to some TPM commands.
621 Requires support for a TPM device.
622
623 CONFIG_TPM_AUTH_SESSIONS
624 Define this to enable authorized functions in the TPM library.
625 Requires CONFIG_TPM and CONFIG_SHA1.
626
wdenkc6097192002-11-03 00:24:07 +0000627- USB Support:
628 At the moment only the UHCI host controller is
Heiko Schocher064b55c2017-06-14 05:49:40 +0200629 supported (PIP405, MIP405); define
wdenkc6097192002-11-03 00:24:07 +0000630 CONFIG_USB_UHCI to enable it.
631 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
wdenk30d56fa2004-10-09 22:44:59 +0000632 and define CONFIG_USB_STORAGE to enable the USB
wdenkc6097192002-11-03 00:24:07 +0000633 storage devices.
634 Note:
635 Supported are USB Keyboards and USB Floppy drives
636 (TEAC FD-05PUB).
wdenk4d13cba2004-03-14 14:09:05 +0000637
Oleksandr Tymoshenko6e9e0622014-02-01 21:51:25 -0700638 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
639 HW module registers.
640
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200641- USB Device:
642 Define the below if you wish to use the USB console.
643 Once firmware is rebuilt from a serial console issue the
644 command "setenv stdin usbtty; setenv stdout usbtty" and
Marcel Ziswiler11ccc332008-07-09 08:17:15 +0200645 attach your USB cable. The Unix command "dmesg" should print
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200646 it has found a new device. The environment variable usbtty
647 can be set to gserial or cdc_acm to enable your device to
Wolfgang Denk386eda02006-06-14 18:14:56 +0200648 appear to a USB host as a Linux gserial device or a
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200649 Common Device Class Abstract Control Model serial device.
650 If you select usbtty = gserial you should be able to enumerate
651 a Linux host by
652 # modprobe usbserial vendor=0xVendorID product=0xProductID
653 else if using cdc_acm, simply setting the environment
654 variable usbtty to be cdc_acm should suffice. The following
655 might be defined in YourBoardName.h
Wolfgang Denk386eda02006-06-14 18:14:56 +0200656
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200657 CONFIG_USB_DEVICE
658 Define this to build a UDC device
wdenkc6097192002-11-03 00:24:07 +0000659
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200660 CONFIG_USB_TTY
661 Define this to have a tty type of device available to
662 talk to the UDC device
Wolfgang Denk386eda02006-06-14 18:14:56 +0200663
Vipin KUMARf9da0f82012-03-26 15:38:06 +0530664 CONFIG_USBD_HS
665 Define this to enable the high speed support for usb
666 device and usbtty. If this feature is enabled, a routine
667 int is_usbd_high_speed(void)
668 also needs to be defined by the driver to dynamically poll
669 whether the enumeration has succeded at high speed or full
670 speed.
671
Wolfgang Denk386eda02006-06-14 18:14:56 +0200672 If you have a USB-IF assigned VendorID then you may wish to
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200673 define your own vendor specific values either in BoardName.h
Wolfgang Denk386eda02006-06-14 18:14:56 +0200674 or directly in usbd_vendor_info.h. If you don't define
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200675 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
676 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
677 should pretend to be a Linux device to it's target host.
678
679 CONFIG_USBD_MANUFACTURER
680 Define this string as the name of your company for
681 - CONFIG_USBD_MANUFACTURER "my company"
Wolfgang Denk386eda02006-06-14 18:14:56 +0200682
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200683 CONFIG_USBD_PRODUCT_NAME
684 Define this string as the name of your product
685 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
686
687 CONFIG_USBD_VENDORID
688 Define this as your assigned Vendor ID from the USB
689 Implementors Forum. This *must* be a genuine Vendor ID
690 to avoid polluting the USB namespace.
691 - CONFIG_USBD_VENDORID 0xFFFF
Wolfgang Denk386eda02006-06-14 18:14:56 +0200692
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200693 CONFIG_USBD_PRODUCTID
694 Define this as the unique Product ID
695 for your device
696 - CONFIG_USBD_PRODUCTID 0xFFFF
wdenkc6097192002-11-03 00:24:07 +0000697
Igor Grinbergd70a5602011-12-12 12:08:35 +0200698- ULPI Layer Support:
699 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
700 the generic ULPI layer. The generic layer accesses the ULPI PHY
701 via the platform viewport, so you need both the genric layer and
702 the viewport enabled. Currently only Chipidea/ARC based
703 viewport is supported.
704 To enable the ULPI layer support, define CONFIG_USB_ULPI and
705 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
Lucas Stach6d365ea2012-10-01 00:44:35 +0200706 If your ULPI phy needs a different reference clock than the
707 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
708 the appropriate value in Hz.
wdenkc6097192002-11-03 00:24:07 +0000709
710- MMC Support:
Yoshihiro Shimodaafb35662011-07-04 22:21:22 +0000711 CONFIG_SH_MMCIF
712 Support for Renesas on-chip MMCIF controller
713
714 CONFIG_SH_MMCIF_ADDR
715 Define the base address of MMCIF registers
716
717 CONFIG_SH_MMCIF_CLK
718 Define the clock frequency for MMCIF
719
Tom Rinib3ba6e92013-03-14 05:32:47 +0000720- USB Device Firmware Update (DFU) class support:
Marek Vasutbb4059a2018-02-16 16:41:18 +0100721 CONFIG_DFU_OVER_USB
Tom Rinib3ba6e92013-03-14 05:32:47 +0000722 This enables the USB portion of the DFU USB class
723
Pantelis Antoniouc6631762013-03-14 05:32:52 +0000724 CONFIG_DFU_NAND
725 This enables support for exposing NAND devices via DFU.
726
Afzal Mohammeda9479f02013-09-18 01:15:24 +0530727 CONFIG_DFU_RAM
728 This enables support for exposing RAM via DFU.
729 Note: DFU spec refer to non-volatile memory usage, but
730 allow usages beyond the scope of spec - here RAM usage,
731 one that would help mostly the developer.
732
Heiko Schochere7e75c72013-06-12 06:05:51 +0200733 CONFIG_SYS_DFU_DATA_BUF_SIZE
734 Dfu transfer uses a buffer before writing data to the
735 raw storage device. Make the size (in bytes) of this buffer
736 configurable. The size of this buffer is also configurable
737 through the "dfu_bufsiz" environment variable.
738
Pantelis Antoniouea2453d2013-03-14 05:32:48 +0000739 CONFIG_SYS_DFU_MAX_FILE_SIZE
740 When updating files rather than the raw storage device,
741 we use a static buffer to copy the file into and then write
742 the buffer once we've been given the whole file. Define
743 this to the maximum filesize (in bytes) for the buffer.
744 Default is 4 MiB if undefined.
745
Heiko Schocher001a8312014-03-18 08:09:56 +0100746 DFU_DEFAULT_POLL_TIMEOUT
747 Poll timeout [ms], is the timeout a device can send to the
748 host. The host must wait for this timeout before sending
749 a subsequent DFU_GET_STATUS request to the device.
750
751 DFU_MANIFEST_POLL_TIMEOUT
752 Poll timeout [ms], which the device sends to the host when
753 entering dfuMANIFEST state. Host waits this timeout, before
754 sending again an USB request to the device.
755
wdenkc6097192002-11-03 00:24:07 +0000756- Keyboard Support:
Simon Glass39f615e2015-11-11 10:05:47 -0700757 See Kconfig help for available keyboard drivers.
758
wdenk17ea1172004-06-06 21:51:03 +0000759- MII/PHY support:
wdenk17ea1172004-06-06 21:51:03 +0000760 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
761
762 The clock frequency of the MII bus
763
wdenk17ea1172004-06-06 21:51:03 +0000764 CONFIG_PHY_CMD_DELAY (ppc4xx)
765
766 Some PHY like Intel LXT971A need extra delay after
767 command issued before MII status register can be read
768
wdenkc6097192002-11-03 00:24:07 +0000769- IP address:
770 CONFIG_IPADDR
771
772 Define a default value for the IP address to use for
Marcel Ziswiler11ccc332008-07-09 08:17:15 +0200773 the default Ethernet interface, in case this is not
wdenkc6097192002-11-03 00:24:07 +0000774 determined through e.g. bootp.
Wolfgang Denk1ebcd652011-10-26 10:21:22 +0000775 (Environment variable "ipaddr")
wdenkc6097192002-11-03 00:24:07 +0000776
777- Server IP address:
778 CONFIG_SERVERIP
779
Marcel Ziswiler11ccc332008-07-09 08:17:15 +0200780 Defines a default value for the IP address of a TFTP
wdenkc6097192002-11-03 00:24:07 +0000781 server to contact when using the "tftboot" command.
Wolfgang Denk1ebcd652011-10-26 10:21:22 +0000782 (Environment variable "serverip")
wdenkc6097192002-11-03 00:24:07 +0000783
Wolfgang Denk1ebcd652011-10-26 10:21:22 +0000784- Gateway IP address:
785 CONFIG_GATEWAYIP
786
787 Defines a default value for the IP address of the
788 default router where packets to other networks are
789 sent to.
790 (Environment variable "gatewayip")
791
792- Subnet mask:
793 CONFIG_NETMASK
794
795 Defines a default value for the subnet mask (or
796 routing prefix) which is used to determine if an IP
797 address belongs to the local subnet or needs to be
798 forwarded through a router.
799 (Environment variable "netmask")
800
wdenkc6097192002-11-03 00:24:07 +0000801- BOOTP Recovery Mode:
802 CONFIG_BOOTP_RANDOM_DELAY
803
804 If you have many targets in a network that try to
805 boot using BOOTP, you may want to avoid that all
806 systems send out BOOTP requests at precisely the same
807 moment (which would happen for instance at recovery
808 from a power failure, when all systems will try to
809 boot, thus flooding the BOOTP server. Defining
810 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
811 inserted before sending out BOOTP requests. The
Wolfgang Denk6c33c782007-08-06 23:21:05 +0200812 following delays are inserted then:
wdenkc6097192002-11-03 00:24:07 +0000813
814 1st BOOTP request: delay 0 ... 1 sec
815 2nd BOOTP request: delay 0 ... 2 sec
816 3rd BOOTP request: delay 0 ... 4 sec
817 4th and following
818 BOOTP requests: delay 0 ... 8 sec
819
Thierry Reding92ac8ac2014-08-19 10:21:24 +0200820 CONFIG_BOOTP_ID_CACHE_SIZE
821
822 BOOTP packets are uniquely identified using a 32-bit ID. The
823 server will copy the ID from client requests to responses and
824 U-Boot will use this to determine if it is the destination of
825 an incoming response. Some servers will check that addresses
826 aren't in use before handing them out (usually using an ARP
827 ping) and therefore take up to a few hundred milliseconds to
828 respond. Network congestion may also influence the time it
829 takes for a response to make it back to the client. If that
830 time is too long, U-Boot will retransmit requests. In order
831 to allow earlier responses to still be accepted after these
832 retransmissions, U-Boot's BOOTP client keeps a small cache of
833 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
834 cache. The default is to keep IDs for up to four outstanding
835 requests. Increasing this will allow U-Boot to accept offers
836 from a BOOTP client in networks with unusually high latency.
837
stroesefe389a82003-08-28 14:17:32 +0000838- DHCP Advanced Options:
Joe Hershberger2c00e092012-05-23 07:59:19 +0000839
Joe Hershbergerd22c3382012-05-23 08:00:12 +0000840 - Link-local IP address negotiation:
841 Negotiate with other link-local clients on the local network
842 for an address that doesn't require explicit configuration.
843 This is especially useful if a DHCP server cannot be guaranteed
844 to exist in all environments that the device must operate.
845
846 See doc/README.link-local for more information.
847
Prabhakar Kushwaha24acb832017-11-23 16:51:32 +0530848 - MAC address from environment variables
849
850 FDT_SEQ_MACADDR_FROM_ENV
851
852 Fix-up device tree with MAC addresses fetched sequentially from
853 environment variables. This config work on assumption that
854 non-usable ethernet node of device-tree are either not present
855 or their status has been marked as "disabled".
856
wdenka3d991b2004-04-15 21:48:45 +0000857 - CDP Options:
wdenk6e592382004-04-18 17:39:38 +0000858 CONFIG_CDP_DEVICE_ID
wdenka3d991b2004-04-15 21:48:45 +0000859
860 The device id used in CDP trigger frames.
861
862 CONFIG_CDP_DEVICE_ID_PREFIX
863
864 A two character string which is prefixed to the MAC address
865 of the device.
866
867 CONFIG_CDP_PORT_ID
868
869 A printf format string which contains the ascii name of
870 the port. Normally is set to "eth%d" which sets
Marcel Ziswiler11ccc332008-07-09 08:17:15 +0200871 eth0 for the first Ethernet, eth1 for the second etc.
wdenka3d991b2004-04-15 21:48:45 +0000872
873 CONFIG_CDP_CAPABILITIES
874
875 A 32bit integer which indicates the device capabilities;
876 0x00000010 for a normal host which does not forwards.
877
878 CONFIG_CDP_VERSION
879
880 An ascii string containing the version of the software.
881
882 CONFIG_CDP_PLATFORM
883
884 An ascii string containing the name of the platform.
885
886 CONFIG_CDP_TRIGGER
887
888 A 32bit integer sent on the trigger.
889
890 CONFIG_CDP_POWER_CONSUMPTION
891
892 A 16bit integer containing the power consumption of the
893 device in .1 of milliwatts.
894
895 CONFIG_CDP_APPLIANCE_VLAN_TYPE
896
897 A byte containing the id of the VLAN.
898
Uri Mashiach79267ed2017-01-19 10:51:05 +0200899- Status LED: CONFIG_LED_STATUS
wdenkc6097192002-11-03 00:24:07 +0000900
901 Several configurations allow to display the current
902 status using a LED. For instance, the LED will blink
903 fast while running U-Boot code, stop blinking as
904 soon as a reply to a BOOTP request was received, and
905 start blinking slow once the Linux kernel is running
906 (supported by a status LED driver in the Linux
Uri Mashiach79267ed2017-01-19 10:51:05 +0200907 kernel). Defining CONFIG_LED_STATUS enables this
wdenkc6097192002-11-03 00:24:07 +0000908 feature in U-Boot.
909
Igor Grinberg1df7bbb2013-11-08 01:03:50 +0200910 Additional options:
911
Uri Mashiach79267ed2017-01-19 10:51:05 +0200912 CONFIG_LED_STATUS_GPIO
Igor Grinberg1df7bbb2013-11-08 01:03:50 +0200913 The status LED can be connected to a GPIO pin.
914 In such cases, the gpio_led driver can be used as a
Uri Mashiach79267ed2017-01-19 10:51:05 +0200915 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO
Igor Grinberg1df7bbb2013-11-08 01:03:50 +0200916 to include the gpio_led driver in the U-Boot binary.
917
Igor Grinberg9dfdcdf2013-11-08 01:03:52 +0200918 CONFIG_GPIO_LED_INVERTED_TABLE
919 Some GPIO connected LEDs may have inverted polarity in which
920 case the GPIO high value corresponds to LED off state and
921 GPIO low value corresponds to LED on state.
922 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
923 with a list of GPIO LEDs that have inverted polarity.
924
Tom Rini55dabcc2021-08-18 23:12:24 -0400925- I2C Support:
Tom Rinicdc5ed82022-11-16 13:10:29 -0500926 CFG_SYS_NUM_I2C_BUSES
Simon Glass945a18e2016-10-02 18:01:05 -0600927 Hold the number of i2c buses you want to use.
Heiko Schocher3f4978c2012-01-16 21:12:24 +0000928
929 CONFIG_SYS_I2C_DIRECT_BUS
930 define this, if you don't use i2c muxes on your hardware.
931 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
932 omit this define.
933
934 CONFIG_SYS_I2C_MAX_HOPS
935 define how many muxes are maximal consecutively connected
936 on one i2c bus. If you not use i2c muxes, omit this
937 define.
938
939 CONFIG_SYS_I2C_BUSES
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -0800940 hold a list of buses you want to use, only used if
Heiko Schocher3f4978c2012-01-16 21:12:24 +0000941 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
942 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
Tom Rinicdc5ed82022-11-16 13:10:29 -0500943 CFG_SYS_NUM_I2C_BUSES = 9:
Heiko Schocher3f4978c2012-01-16 21:12:24 +0000944
945 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
946 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
947 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
948 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
949 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
950 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
951 {1, {I2C_NULL_HOP}}, \
952 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
953 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
954 }
955
956 which defines
957 bus 0 on adapter 0 without a mux
Heiko Schocherea818db2013-01-29 08:53:15 +0100958 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
959 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
960 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
961 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
962 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
Heiko Schocher3f4978c2012-01-16 21:12:24 +0000963 bus 6 on adapter 1 without a mux
Heiko Schocherea818db2013-01-29 08:53:15 +0100964 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
965 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
Heiko Schocher3f4978c2012-01-16 21:12:24 +0000966
967 If you do not have i2c muxes on your board, omit this define.
968
Simon Glassce3b5d62017-05-12 21:10:00 -0600969- Legacy I2C Support:
Heiko Schocherea818db2013-01-29 08:53:15 +0100970 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
wdenkb37c7e52003-06-30 16:24:52 +0000971 then the following macros need to be defined (examples are
972 from include/configs/lwmon.h):
wdenkc6097192002-11-03 00:24:07 +0000973
974 I2C_INIT
975
wdenkb37c7e52003-06-30 16:24:52 +0000976 (Optional). Any commands necessary to enable the I2C
wdenk43d96162003-03-06 00:02:04 +0000977 controller or configure ports.
wdenkc6097192002-11-03 00:24:07 +0000978
wdenkba56f622004-02-06 23:19:44 +0000979 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
wdenkb37c7e52003-06-30 16:24:52 +0000980
wdenkc6097192002-11-03 00:24:07 +0000981 I2C_ACTIVE
982
983 The code necessary to make the I2C data line active
984 (driven). If the data line is open collector, this
985 define can be null.
986
wdenkb37c7e52003-06-30 16:24:52 +0000987 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
988
wdenkc6097192002-11-03 00:24:07 +0000989 I2C_TRISTATE
990
991 The code necessary to make the I2C data line tri-stated
992 (inactive). If the data line is open collector, this
993 define can be null.
994
wdenkb37c7e52003-06-30 16:24:52 +0000995 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
996
wdenkc6097192002-11-03 00:24:07 +0000997 I2C_READ
998
York Sun472d5462013-04-01 11:29:11 -0700999 Code that returns true if the I2C data line is high,
1000 false if it is low.
wdenkc6097192002-11-03 00:24:07 +00001001
wdenkb37c7e52003-06-30 16:24:52 +00001002 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1003
wdenkc6097192002-11-03 00:24:07 +00001004 I2C_SDA(bit)
1005
York Sun472d5462013-04-01 11:29:11 -07001006 If <bit> is true, sets the I2C data line high. If it
1007 is false, it clears it (low).
wdenkc6097192002-11-03 00:24:07 +00001008
wdenkb37c7e52003-06-30 16:24:52 +00001009 eg: #define I2C_SDA(bit) \
wdenk2535d602003-07-17 23:16:40 +00001010 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
wdenkba56f622004-02-06 23:19:44 +00001011 else immr->im_cpm.cp_pbdat &= ~PB_SDA
wdenkb37c7e52003-06-30 16:24:52 +00001012
wdenkc6097192002-11-03 00:24:07 +00001013 I2C_SCL(bit)
1014
York Sun472d5462013-04-01 11:29:11 -07001015 If <bit> is true, sets the I2C clock line high. If it
1016 is false, it clears it (low).
wdenkc6097192002-11-03 00:24:07 +00001017
wdenkb37c7e52003-06-30 16:24:52 +00001018 eg: #define I2C_SCL(bit) \
wdenk2535d602003-07-17 23:16:40 +00001019 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
wdenkba56f622004-02-06 23:19:44 +00001020 else immr->im_cpm.cp_pbdat &= ~PB_SCL
wdenkb37c7e52003-06-30 16:24:52 +00001021
wdenkc6097192002-11-03 00:24:07 +00001022 I2C_DELAY
1023
1024 This delay is invoked four times per clock cycle so this
1025 controls the rate of data transfer. The data rate thus
wdenkb37c7e52003-06-30 16:24:52 +00001026 is 1 / (I2C_DELAY * 4). Often defined to be something
wdenk945af8d2003-07-16 21:53:01 +00001027 like:
1028
wdenkb37c7e52003-06-30 16:24:52 +00001029 #define I2C_DELAY udelay(2)
wdenkc6097192002-11-03 00:24:07 +00001030
Mike Frysinger793b5722010-07-21 13:38:02 -04001031 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1032
1033 If your arch supports the generic GPIO framework (asm/gpio.h),
1034 then you may alternatively define the two GPIOs that are to be
1035 used as SCL / SDA. Any of the previous I2C_xxx macros will
1036 have GPIO-based defaults assigned to them as appropriate.
1037
1038 You should define these to the GPIO value as given directly to
1039 the generic GPIO functions.
1040
Ben Warrenbb99ad62006-09-07 16:50:54 -04001041 CONFIG_I2C_MULTI_BUS
1042
1043 This option allows the use of multiple I2C buses, each of which
Wolfgang Denkc0f40852011-10-26 10:21:21 +00001044 must have a controller. At any point in time, only one bus is
1045 active. To switch to a different bus, use the 'i2c dev' command.
Ben Warrenbb99ad62006-09-07 16:50:54 -04001046 Note that bus numbering is zero-based.
1047
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001048 CONFIG_SYS_I2C_NOPROBES
Ben Warrenbb99ad62006-09-07 16:50:54 -04001049
1050 This option specifies a list of I2C devices that will be skipped
Wolfgang Denkc0f40852011-10-26 10:21:21 +00001051 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
Peter Tyser0f89c542009-04-18 22:34:03 -05001052 is set, specify a list of bus-device pairs. Otherwise, specify
1053 a 1D array of device addresses
Ben Warrenbb99ad62006-09-07 16:50:54 -04001054
1055 e.g.
1056 #undef CONFIG_I2C_MULTI_BUS
Wolfgang Denkc0f40852011-10-26 10:21:21 +00001057 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
Ben Warrenbb99ad62006-09-07 16:50:54 -04001058
1059 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1060
Wolfgang Denkc0f40852011-10-26 10:21:21 +00001061 #define CONFIG_I2C_MULTI_BUS
Simon Glass945a18e2016-10-02 18:01:05 -06001062 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
Ben Warrenbb99ad62006-09-07 16:50:54 -04001063
1064 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1065
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001066 CONFIG_SYS_RTC_BUS_NUM
Stefan Roese0dc018e2007-02-20 10:51:26 +01001067
1068 If defined, then this indicates the I2C bus number for the RTC.
1069 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1070
Andrew Dyer2ac69852008-12-29 17:36:01 -06001071 CONFIG_SOFT_I2C_READ_REPEATED_START
1072
1073 defining this will force the i2c_read() function in
1074 the soft_i2c driver to perform an I2C repeated start
1075 between writing the address pointer and reading the
1076 data. If this define is omitted the default behaviour
1077 of doing a stop-start sequence will be used. Most I2C
1078 devices can use either method, but some require one or
1079 the other.
Timur Tabibe5e6182006-11-03 19:15:00 -06001080
wdenkc6097192002-11-03 00:24:07 +00001081- SPI Support: CONFIG_SPI
1082
1083 Enables SPI driver (so far only tested with
1084 SPI EEPROM, also an instance works with Crystal A/D and
1085 D/As on the SACSng board)
1086
Heiko Schocherf659b572014-07-14 10:22:11 +02001087 CONFIG_SYS_SPI_MXC_WAIT
1088 Timeout for waiting until spi transfer completed.
1089 default: (CONFIG_SYS_HZ/100) /* 10 ms */
1090
Matthias Fuchs01335022007-12-27 17:12:34 +01001091- FPGA Support: CONFIG_FPGA
1092
1093 Enables FPGA subsystem.
1094
1095 CONFIG_FPGA_<vendor>
1096
1097 Enables support for specific chip vendors.
1098 (ALTERA, XILINX)
1099
1100 CONFIG_FPGA_<family>
1101
1102 Enables support for FPGA family.
1103 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1104
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001105 CONFIG_SYS_FPGA_CHECK_BUSY
wdenkc6097192002-11-03 00:24:07 +00001106
wdenk43d96162003-03-06 00:02:04 +00001107 Enable checks on FPGA configuration interface busy
1108 status by the configuration function. This option
1109 will require a board or device specific function to
1110 be written.
wdenkc6097192002-11-03 00:24:07 +00001111
1112 CONFIG_FPGA_DELAY
1113
1114 If defined, a function that provides delays in the FPGA
1115 configuration driver.
1116
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001117 CONFIG_SYS_FPGA_CHECK_ERROR
wdenkc6097192002-11-03 00:24:07 +00001118
wdenk43d96162003-03-06 00:02:04 +00001119 Check for configuration errors during FPGA bitfile
1120 loading. For example, abort during Virtex II
1121 configuration if the INIT_B line goes low (which
1122 indicated a CRC error).
wdenkc6097192002-11-03 00:24:07 +00001123
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001124 CONFIG_SYS_FPGA_WAIT_INIT
wdenkc6097192002-11-03 00:24:07 +00001125
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001126 Maximum time to wait for the INIT_B line to de-assert
1127 after PROB_B has been de-asserted during a Virtex II
wdenk43d96162003-03-06 00:02:04 +00001128 FPGA configuration sequence. The default time is 500
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001129 ms.
wdenkc6097192002-11-03 00:24:07 +00001130
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001131 CONFIG_SYS_FPGA_WAIT_BUSY
wdenkc6097192002-11-03 00:24:07 +00001132
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001133 Maximum time to wait for BUSY to de-assert during
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001134 Virtex II FPGA configuration. The default is 5 ms.
wdenkc6097192002-11-03 00:24:07 +00001135
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001136 CONFIG_SYS_FPGA_WAIT_CONFIG
wdenkc6097192002-11-03 00:24:07 +00001137
wdenk43d96162003-03-06 00:02:04 +00001138 Time to wait after FPGA configuration. The default is
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001139 200 ms.
wdenkc6097192002-11-03 00:24:07 +00001140
wdenkc6097192002-11-03 00:24:07 +00001141- Vendor Parameter Protection:
1142
wdenk43d96162003-03-06 00:02:04 +00001143 U-Boot considers the values of the environment
1144 variables "serial#" (Board Serial Number) and
wdenk7152b1d2003-09-05 23:19:14 +00001145 "ethaddr" (Ethernet Address) to be parameters that
wdenk43d96162003-03-06 00:02:04 +00001146 are set once by the board vendor / manufacturer, and
1147 protects these variables from casual modification by
1148 the user. Once set, these variables are read-only,
1149 and write or delete attempts are rejected. You can
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001150 change this behaviour:
wdenkc6097192002-11-03 00:24:07 +00001151
1152 If CONFIG_ENV_OVERWRITE is #defined in your config
1153 file, the write protection for vendor parameters is
wdenk47cd00f2003-03-06 13:39:27 +00001154 completely disabled. Anybody can change or delete
wdenkc6097192002-11-03 00:24:07 +00001155 these parameters.
1156
Joe Hershberger92ac5202015-05-04 14:55:14 -05001157 Alternatively, if you define _both_ an ethaddr in the
1158 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001159 Ethernet address is installed in the environment,
wdenkc6097192002-11-03 00:24:07 +00001160 which can be changed exactly ONCE by the user. [The
1161 serial# is unaffected by this, i. e. it remains
1162 read-only.]
1163
Joe Hershberger25980902012-12-11 22:16:31 -06001164 The same can be accomplished in a more flexible way
1165 for any variable by configuring the type of access
1166 to allow for those variables in the ".flags" variable
1167 or define CONFIG_ENV_FLAGS_LIST_STATIC.
1168
wdenkc6097192002-11-03 00:24:07 +00001169- Protected RAM:
1170 CONFIG_PRAM
1171
1172 Define this variable to enable the reservation of
1173 "protected RAM", i. e. RAM which is not overwritten
1174 by U-Boot. Define CONFIG_PRAM to hold the number of
1175 kB you want to reserve for pRAM. You can overwrite
1176 this default value by defining an environment
1177 variable "pram" to the number of kB you want to
1178 reserve. Note that the board info structure will
1179 still show the full amount of RAM. If pRAM is
1180 reserved, a new environment variable "mem" will
1181 automatically be defined to hold the amount of
1182 remaining RAM in a form that can be passed as boot
1183 argument to Linux, for instance like that:
1184
Wolfgang Denkfe126d82005-11-20 21:40:11 +01001185 setenv bootargs ... mem=\${mem}
wdenkc6097192002-11-03 00:24:07 +00001186 saveenv
1187
1188 This way you can tell Linux not to use this memory,
1189 either, which results in a memory region that will
1190 not be affected by reboots.
1191
1192 *WARNING* If your board configuration uses automatic
1193 detection of the RAM size, you must make sure that
1194 this memory test is non-destructive. So far, the
1195 following board configurations are known to be
1196 "pRAM-clean":
1197
Heiko Schocher5b8e76c2017-06-07 17:33:09 +02001198 IVMS8, IVML24, SPD8xx,
Wolfgang Denk1b0757e2012-10-24 02:36:15 +00001199 HERMES, IP860, RPXlite, LWMON,
Heiko Schocher2eb48ff2017-06-07 17:33:10 +02001200 FLAGADM
wdenkc6097192002-11-03 00:24:07 +00001201
1202- Error Recovery:
wdenkc6097192002-11-03 00:24:07 +00001203 Note:
1204
wdenk8bde7f72003-06-27 21:31:46 +00001205 In the current implementation, the local variables
1206 space and global environment variables space are
1207 separated. Local variables are those you define by
1208 simply typing `name=value'. To access a local
1209 variable later on, you have write `$name' or
1210 `${name}'; to execute the contents of a variable
1211 directly type `$name' at the command prompt.
wdenkc6097192002-11-03 00:24:07 +00001212
wdenk43d96162003-03-06 00:02:04 +00001213 Global environment variables are those you use
1214 setenv/printenv to work with. To run a command stored
1215 in such a variable, you need to use the run command,
1216 and you must not use the '$' sign to access them.
wdenkc6097192002-11-03 00:24:07 +00001217
1218 To store commands and special characters in a
1219 variable, please use double quotation marks
1220 surrounding the whole text of the variable, instead
1221 of the backslashes before semicolons and special
1222 symbols.
1223
wdenka8c7c702003-12-06 19:49:23 +00001224- Default Environment:
wdenkc6097192002-11-03 00:24:07 +00001225 CONFIG_EXTRA_ENV_SETTINGS
1226
wdenk43d96162003-03-06 00:02:04 +00001227 Define this to contain any number of null terminated
1228 strings (variable = value pairs) that will be part of
wdenk7152b1d2003-09-05 23:19:14 +00001229 the default environment compiled into the boot image.
wdenk2262cfe2002-11-18 00:14:45 +00001230
wdenk43d96162003-03-06 00:02:04 +00001231 For example, place something like this in your
1232 board's config file:
wdenkc6097192002-11-03 00:24:07 +00001233
1234 #define CONFIG_EXTRA_ENV_SETTINGS \
1235 "myvar1=value1\0" \
1236 "myvar2=value2\0"
1237
wdenk43d96162003-03-06 00:02:04 +00001238 Warning: This method is based on knowledge about the
1239 internal format how the environment is stored by the
1240 U-Boot code. This is NOT an official, exported
1241 interface! Although it is unlikely that this format
wdenk7152b1d2003-09-05 23:19:14 +00001242 will change soon, there is no guarantee either.
wdenkc6097192002-11-03 00:24:07 +00001243 You better know what you are doing here.
1244
wdenk43d96162003-03-06 00:02:04 +00001245 Note: overly (ab)use of the default environment is
1246 discouraged. Make sure to check other ways to preset
Wolfgang Denk74de7ae2009-04-01 23:34:12 +02001247 the environment like the "source" command or the
wdenk43d96162003-03-06 00:02:04 +00001248 boot command first.
wdenkc6097192002-11-03 00:24:07 +00001249
Simon Glass06fd8532012-11-30 13:01:17 +00001250 CONFIG_DELAY_ENVIRONMENT
1251
1252 Normally the environment is loaded when the board is
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001253 initialised so that it is available to U-Boot. This inhibits
Simon Glass06fd8532012-11-30 13:01:17 +00001254 that so that the environment is not available until
1255 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
1256 this is instead controlled by the value of
1257 /config/load-environment.
1258
Wolfgang Denk4cf26092011-10-07 09:58:21 +02001259 CONFIG_STANDALONE_LOAD_ADDR
1260
Wolfgang Denk6feff892011-10-09 21:06:34 +02001261 This option defines a board specific value for the
1262 address where standalone program gets loaded, thus
1263 overwriting the architecture dependent default
Wolfgang Denk4cf26092011-10-07 09:58:21 +02001264 settings.
1265
Detlev Zundelcccfc2a2009-12-01 17:16:19 +01001266- Automatic software updates via TFTP server
1267 CONFIG_UPDATE_TFTP
1268 CONFIG_UPDATE_TFTP_CNT_MAX
1269 CONFIG_UPDATE_TFTP_MSEC_MAX
1270
1271 These options enable and control the auto-update feature;
1272 for a more detailed description refer to doc/README.update.
1273
1274- MTD Support (mtdparts command, UBI support)
Heiko Schocherff94bc42014-06-24 10:10:04 +02001275 CONFIG_MTD_UBI_WL_THRESHOLD
1276 This parameter defines the maximum difference between the highest
1277 erase counter value and the lowest erase counter value of eraseblocks
1278 of UBI devices. When this threshold is exceeded, UBI starts performing
1279 wear leveling by means of moving data from eraseblock with low erase
1280 counter to eraseblocks with high erase counter.
1281
1282 The default value should be OK for SLC NAND flashes, NOR flashes and
1283 other flashes which have eraseblock life-cycle 100000 or more.
1284 However, in case of MLC NAND flashes which typically have eraseblock
1285 life-cycle less than 10000, the threshold should be lessened (e.g.,
1286 to 128 or 256, although it does not have to be power of 2).
1287
1288 default: 4096
Simon Glassc654b512014-10-23 18:58:54 -06001289
Heiko Schocherff94bc42014-06-24 10:10:04 +02001290 CONFIG_MTD_UBI_BEB_LIMIT
1291 This option specifies the maximum bad physical eraseblocks UBI
1292 expects on the MTD device (per 1024 eraseblocks). If the
1293 underlying flash does not admit of bad eraseblocks (e.g. NOR
1294 flash), this value is ignored.
1295
1296 NAND datasheets often specify the minimum and maximum NVM
1297 (Number of Valid Blocks) for the flashes' endurance lifetime.
1298 The maximum expected bad eraseblocks per 1024 eraseblocks
1299 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
1300 which gives 20 for most NANDs (MaxNVB is basically the total
1301 count of eraseblocks on the chip).
1302
1303 To put it differently, if this value is 20, UBI will try to
1304 reserve about 1.9% of physical eraseblocks for bad blocks
1305 handling. And that will be 1.9% of eraseblocks on the entire
1306 NAND chip, not just the MTD partition UBI attaches. This means
1307 that if you have, say, a NAND flash chip admits maximum 40 bad
1308 eraseblocks, and it is split on two MTD partitions of the same
1309 size, UBI will reserve 40 eraseblocks when attaching a
1310 partition.
1311
1312 default: 20
1313
1314 CONFIG_MTD_UBI_FASTMAP
1315 Fastmap is a mechanism which allows attaching an UBI device
1316 in nearly constant time. Instead of scanning the whole MTD device it
1317 only has to locate a checkpoint (called fastmap) on the device.
1318 The on-flash fastmap contains all information needed to attach
1319 the device. Using fastmap makes only sense on large devices where
1320 attaching by scanning takes long. UBI will not automatically install
1321 a fastmap on old images, but you can set the UBI parameter
1322 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
1323 that fastmap-enabled images are still usable with UBI implementations
1324 without fastmap support. On typical flash devices the whole fastmap
1325 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
1326
1327 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
1328 Set this parameter to enable fastmap automatically on images
1329 without a fastmap.
1330 default: 0
1331
Heiko Schocher0195a7b2015-10-22 06:19:21 +02001332 CONFIG_MTD_UBI_FM_DEBUG
1333 Enable UBI fastmap debug
1334 default: 0
1335
Daniel Schwierzeck6a11cf42011-07-18 07:48:07 +00001336- SPL framework
Wolfgang Denk04e5ae72011-09-11 21:24:09 +02001337 CONFIG_SPL
1338 Enable building of SPL globally.
Daniel Schwierzeck6a11cf42011-07-18 07:48:07 +00001339
Albert ARIBAUD \(3ADEV\)8c80eb32015-03-31 11:40:50 +02001340 CONFIG_SPL_PANIC_ON_RAW_IMAGE
1341 When defined, SPL will panic() if the image it has
1342 loaded does not have a signature.
1343 Defining this is useful when code which loads images
1344 in SPL cannot guarantee that absolutely all read errors
1345 will be caught.
1346 An example is the LPC32XX MLC NAND driver, which will
1347 consider that a completely unreadable NAND block is bad,
1348 and thus should be skipped silently.
1349
Tom Rini861a86f2012-08-13 11:37:56 -07001350 CONFIG_SPL_DISPLAY_PRINT
1351 For ARM, enable an optional function to print more information
1352 about the running system.
1353
Scott Wood06f60ae2012-12-06 13:33:17 +00001354 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
1355 Set this for NAND SPL on PPC mpc83xx targets, so that
1356 start.S waits for the rest of the SPL to load before
1357 continuing (the hardware starts execution after just
1358 loading the first page rather than the full 4K).
1359
Thomas Gleixner6f4e7d32016-07-12 20:28:12 +02001360 CONFIG_SPL_UBI
1361 Support for a lightweight UBI (fastmap) scanner and
1362 loader
1363
Tom Rini95579792012-02-14 07:29:40 +00001364 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
1365 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
1366 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
Tom Rini4e590942022-11-12 17:36:51 -05001367 CFG_SYS_NAND_ECCPOS, CFG_SYS_NAND_ECCSIZE,
1368 CFG_SYS_NAND_ECCBYTES
Tom Rini95579792012-02-14 07:29:40 +00001369 Defines the size and behavior of the NAND that SPL uses
Scott Wood7d4b7952012-09-21 18:35:27 -05001370 to read U-Boot
Tom Rini95579792012-02-14 07:29:40 +00001371
Tom Rini4e590942022-11-12 17:36:51 -05001372 CFG_SYS_NAND_U_BOOT_DST
Scott Wood7d4b7952012-09-21 18:35:27 -05001373 Location in memory to load U-Boot to
1374
Tom Rini4e590942022-11-12 17:36:51 -05001375 CFG_SYS_NAND_U_BOOT_SIZE
Scott Wood7d4b7952012-09-21 18:35:27 -05001376 Size of image to load
Tom Rini95579792012-02-14 07:29:40 +00001377
Tom Rini4e590942022-11-12 17:36:51 -05001378 CFG_SYS_NAND_U_BOOT_START
Scott Wood7d4b7952012-09-21 18:35:27 -05001379 Entry point in loaded image to jump to
Tom Rini95579792012-02-14 07:29:40 +00001380
Pavel Machekc57b9532012-08-30 22:42:11 +02001381 CONFIG_SPL_RAM_DEVICE
1382 Support for running image already present in ram, in SPL binary
1383
Marek Vasutb527b9c2018-05-13 00:22:52 +02001384 CONFIG_SPL_FIT_PRINT
Simon Glass87ebee32013-05-08 08:05:59 +00001385 Printing information about a FIT image adds quite a bit of
1386 code to SPL. So this is normally disabled in SPL. Use this
1387 option to re-enable it. This will affect the output of the
1388 bootm command when booting a FIT image.
1389
wdenka8c7c702003-12-06 19:49:23 +00001390- Interrupt support (PPC):
1391
wdenkd4ca31c2004-01-02 14:00:00 +00001392 There are common interrupt_init() and timer_interrupt()
1393 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001394 for CPU specific initialization. interrupt_init_cpu()
wdenkd4ca31c2004-01-02 14:00:00 +00001395 should set decrementer_count to appropriate value. If
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001396 CPU resets decrementer automatically after interrupt
wdenkd4ca31c2004-01-02 14:00:00 +00001397 (ppc4xx) it should set decrementer_count to zero.
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001398 timer_interrupt() calls timer_interrupt_cpu() for CPU
wdenkd4ca31c2004-01-02 14:00:00 +00001399 specific handling. If board has watchdog / status_led
1400 / other_activity_monitor it works automatically from
1401 general timer_interrupt().
wdenka8c7c702003-12-06 19:49:23 +00001402
wdenkc6097192002-11-03 00:24:07 +00001403
Helmut Raiger9660e442011-10-20 04:19:47 +00001404Board initialization settings:
1405------------------------------
1406
1407During Initialization u-boot calls a number of board specific functions
1408to allow the preparation of board specific prerequisites, e.g. pin setup
1409before drivers are initialized. To enable these callbacks the
1410following configuration macros have to be defined. Currently this is
1411architecture specific, so please check arch/your_architecture/lib/board.c
1412typically in board_init_f() and board_init_r().
1413
1414- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
1415- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
1416- CONFIG_BOARD_LATE_INIT: Call board_late_init()
wdenkc6097192002-11-03 00:24:07 +00001417
wdenkc6097192002-11-03 00:24:07 +00001418Configuration Settings:
1419-----------------------
1420
Simon Glass4d979bf2019-12-28 10:45:10 -07001421- MEM_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
York Sun4d1fd7f2014-02-26 17:03:19 -08001422 Optionally it can be defined to support 64-bit memory commands.
1423
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001424- CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
wdenkc6097192002-11-03 00:24:07 +00001425 undefine this when you're short of memory.
1426
Peter Tyser2fb26042009-01-27 18:03:12 -06001427- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
1428 width of the commands listed in the 'help' command output.
1429
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001430- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
wdenkc6097192002-11-03 00:24:07 +00001431 prompt for user input.
1432
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001433- CONFIG_SYS_BAUDRATE_TABLE:
wdenkc6097192002-11-03 00:24:07 +00001434 List of legal baudrate settings for this board.
1435
York Sune8149522015-12-04 11:57:07 -08001436- CONFIG_SYS_MEM_RESERVE_SECURE
York Sune61a7532016-06-24 16:46:18 -07001437 Only implemented for ARMv8 for now.
York Sune8149522015-12-04 11:57:07 -08001438 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
1439 is substracted from total RAM and won't be reported to OS.
1440 This memory can be used as secure memory. A variable
York Sune61a7532016-06-24 16:46:18 -07001441 gd->arch.secure_ram is used to track the location. In systems
York Sune8149522015-12-04 11:57:07 -08001442 the RAM base is not zero, or RAM is divided into banks,
1443 this variable needs to be recalcuated to get the address.
1444
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001445- CONFIG_SYS_SDRAM_BASE:
wdenkc6097192002-11-03 00:24:07 +00001446 Physical start address of SDRAM. _Must_ be 0 here.
1447
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001448- CONFIG_SYS_FLASH_BASE:
wdenkc6097192002-11-03 00:24:07 +00001449 Physical start address of Flash memory.
1450
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001451- CONFIG_SYS_MALLOC_LEN:
wdenkc6097192002-11-03 00:24:07 +00001452 Size of DRAM reserved for malloc() use.
1453
Simon Glassd59476b2014-07-10 22:23:28 -06001454- CONFIG_SYS_MALLOC_F_LEN
1455 Size of the malloc() pool for use before relocation. If
1456 this is defined, then a very simple malloc() implementation
1457 will become available before relocation. The address is just
1458 below the global data, and the stack is moved down to make
1459 space.
1460
1461 This feature allocates regions with increasing addresses
1462 within the region. calloc() is supported, but realloc()
1463 is not available. free() is supported but does nothing.
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001464 The memory will be freed (or in fact just forgotten) when
Simon Glassd59476b2014-07-10 22:23:28 -06001465 U-Boot relocates itself.
1466
Simon Glass38687ae2014-11-10 17:16:54 -07001467- CONFIG_SYS_MALLOC_SIMPLE
1468 Provides a simple and small malloc() and calloc() for those
1469 boards which do not use the full malloc in SPL (which is
Tom Rini10f6e4d2022-05-27 12:48:32 -04001470 enabled with CONFIG_SYS_SPL_MALLOC).
Simon Glass38687ae2014-11-10 17:16:54 -07001471
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001472- CONFIG_SYS_BOOTMAPSZ:
wdenkc6097192002-11-03 00:24:07 +00001473 Maximum size of memory mapped by the startup code of
1474 the Linux kernel; all data that must be processed by
Bartlomiej Sieka7d721e32008-04-14 15:44:16 +02001475 the Linux kernel (bd_info, boot arguments, FDT blob if
1476 used) must be put below this limit, unless "bootm_low"
Robert P. J. Day1bce2ae2013-09-16 07:15:45 -04001477 environment variable is defined and non-zero. In such case
Bartlomiej Sieka7d721e32008-04-14 15:44:16 +02001478 all data for the Linux kernel must be between "bootm_low"
Wolfgang Denkc0f40852011-10-26 10:21:21 +00001479 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
Grant Likelyc3624e62011-03-28 09:58:43 +00001480 variable "bootm_mapsize" will override the value of
1481 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
1482 then the value in "bootm_size" will be used instead.
wdenkc6097192002-11-03 00:24:07 +00001483
John Rigbyfca43cc2010-10-13 13:57:35 -06001484- CONFIG_SYS_BOOT_GET_CMDLINE:
1485 Enables allocating and saving kernel cmdline in space between
1486 "bootm_low" and "bootm_low" + BOOTMAPSZ.
1487
1488- CONFIG_SYS_BOOT_GET_KBD:
1489 Enables allocating and saving a kernel copy of the bd_info in
1490 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
1491
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001492- CONFIG_SYS_FLASH_PROTECTION
wdenk8564acf2003-07-14 22:13:32 +00001493 If defined, hardware flash sectors protection is used
1494 instead of U-Boot software protection.
1495
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001496- CONFIG_SYS_FLASH_CFI:
wdenk43d96162003-03-06 00:02:04 +00001497 Define if the flash driver uses extra elements in the
wdenk5653fc32004-02-08 22:55:38 +00001498 common flash structure for storing flash geometry.
1499
Jean-Christophe PLAGNIOL-VILLARD00b18832008-08-13 01:40:42 +02001500- CONFIG_FLASH_CFI_DRIVER
wdenk5653fc32004-02-08 22:55:38 +00001501 This option also enables the building of the cfi_flash driver
1502 in the drivers directory
wdenkc6097192002-11-03 00:24:07 +00001503
Piotr Ziecik91809ed2008-11-17 15:57:58 +01001504- CONFIG_FLASH_CFI_MTD
1505 This option enables the building of the cfi_mtd driver
1506 in the drivers directory. The driver exports CFI flash
1507 to the MTD layer.
1508
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001509- CONFIG_SYS_FLASH_USE_BUFFER_WRITE
Guennadi Liakhovetski96ef8312008-04-03 13:36:02 +02001510 Use buffered writes to flash.
1511
1512- CONFIG_FLASH_SPANSION_S29WS_N
1513 s29ws-n MirrorBit flash has non-standard addresses for buffered
1514 write commands.
1515
Jerry Van Baren9a042e92008-03-08 13:48:01 -05001516- CONFIG_FLASH_SHOW_PROGRESS
1517 If defined (must be an integer), print out countdown
1518 digits and dots. Recommended value: 45 (9..1) for 80
1519 column displays, 15 (3..1) for 40 column displays.
1520
Stefan Roese352ef3f2013-04-04 15:53:14 +02001521- CONFIG_FLASH_VERIFY
1522 If defined, the content of the flash (destination) is compared
1523 against the source after the write operation. An error message
1524 will be printed when the contents are not identical.
1525 Please note that this option is useless in nearly all cases,
1526 since such flash programming errors usually are detected earlier
1527 while unprotecting/erasing/programming. Please only enable
1528 this option if you really know what you are doing.
1529
Joe Hershberger25980902012-12-11 22:16:31 -06001530- CONFIG_ENV_FLAGS_LIST_DEFAULT
1531- CONFIG_ENV_FLAGS_LIST_STATIC
Robert P. J. Day1bce2ae2013-09-16 07:15:45 -04001532 Enable validation of the values given to environment variables when
Joe Hershberger25980902012-12-11 22:16:31 -06001533 calling env set. Variables can be restricted to only decimal,
1534 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
1535 the variables can also be restricted to IP address or MAC address.
1536
1537 The format of the list is:
1538 type_attribute = [s|d|x|b|i|m]
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001539 access_attribute = [a|r|o|c]
1540 attributes = type_attribute[access_attribute]
Joe Hershberger25980902012-12-11 22:16:31 -06001541 entry = variable_name[:attributes]
1542 list = entry[,list]
1543
1544 The type attributes are:
1545 s - String (default)
1546 d - Decimal
1547 x - Hexadecimal
1548 b - Boolean ([1yYtT|0nNfF])
1549 i - IP address
1550 m - MAC address
1551
Joe Hershberger267541f2012-12-11 22:16:34 -06001552 The access attributes are:
1553 a - Any (default)
1554 r - Read-only
1555 o - Write-once
1556 c - Change-default
1557
Joe Hershberger25980902012-12-11 22:16:31 -06001558 - CONFIG_ENV_FLAGS_LIST_DEFAULT
1559 Define this to a list (string) to define the ".flags"
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001560 environment variable in the default or embedded environment.
Joe Hershberger25980902012-12-11 22:16:31 -06001561
1562 - CONFIG_ENV_FLAGS_LIST_STATIC
1563 Define this to a list (string) to define validation that
1564 should be done if an entry is not found in the ".flags"
1565 environment variable. To override a setting in the static
1566 list, simply add an entry for the same variable name to the
1567 ".flags" variable.
1568
Joe Hershbergerbdf1fe42015-05-20 14:27:20 -05001569 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
1570 regular expression. This allows multiple variables to define the same
1571 flags without explicitly listing them for each variable.
1572
wdenkc6097192002-11-03 00:24:07 +00001573The following definitions that deal with the placement and management
1574of environment data (variable area); in general, we support the
1575following configurations:
1576
Mike Frysingerc3eb3fe2011-07-08 10:44:25 +00001577- CONFIG_BUILD_ENVCRC:
1578
1579 Builds up envcrc with the target environment so that external utils
1580 may easily extract it and embed it in final U-Boot images.
1581
wdenkc6097192002-11-03 00:24:07 +00001582BE CAREFUL! The first access to the environment happens quite early
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001583in U-Boot initialization (when we try to get the setting of for the
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001584console baudrate). You *MUST* have mapped your NVRAM area then, or
wdenkc6097192002-11-03 00:24:07 +00001585U-Boot will hang.
1586
1587Please note that even with NVRAM we still use a copy of the
1588environment in RAM: we could work on NVRAM directly, but we want to
1589keep settings there always unmodified except somebody uses "saveenv"
1590to save the current settings.
1591
Liu Gang0a85a9e2012-03-08 00:33:20 +00001592BE CAREFUL! For some special cases, the local device can not use
1593"saveenv" command. For example, the local device will get the
Liu Gangfc54c7f2012-08-09 05:10:01 +00001594environment stored in a remote NOR flash by SRIO or PCIE link,
1595but it can not erase, write this NOR flash by SRIO or PCIE interface.
Liu Gang0a85a9e2012-03-08 00:33:20 +00001596
Guennadi Liakhovetskib74ab732009-05-18 16:07:22 +02001597- CONFIG_NAND_ENV_DST
1598
1599 Defines address in RAM to which the nand_spl code should copy the
1600 environment. If redundant environment is used, it will be copied to
1601 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
1602
Bruce Adlere881cb52007-11-02 13:15:42 -07001603Please note that the environment is read-only until the monitor
wdenkc6097192002-11-03 00:24:07 +00001604has been relocated to RAM and a RAM copy of the environment has been
Simon Glass00caae62017-08-03 12:22:12 -06001605created; also, when using EEPROM you will have to use env_get_f()
wdenkc6097192002-11-03 00:24:07 +00001606until then to read environment variables.
1607
wdenk85ec0bc2003-03-31 16:34:49 +00001608The environment is protected by a CRC32 checksum. Before the monitor
1609is relocated into RAM, as a result of a bad CRC you will be working
1610with the compiled-in default environment - *silently*!!! [This is
1611necessary, because the first environment variable we need is the
1612"baudrate" setting for the console - if we have a bad CRC, we don't
1613have any device yet where we could complain.]
wdenkc6097192002-11-03 00:24:07 +00001614
1615Note: once the monitor has been relocated, then it will complain if
1616the default environment is used; a new CRC is computed as soon as you
wdenk85ec0bc2003-03-31 16:34:49 +00001617use the "saveenv" command to store a valid environment.
wdenkc6097192002-11-03 00:24:07 +00001618
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001619- CONFIG_SYS_FAULT_MII_ADDR:
wdenk42d1f032003-10-15 23:53:47 +00001620 MII address of the PHY to check for the Ethernet link state.
wdenkc6097192002-11-03 00:24:07 +00001621
Simon Glassb2b92f52012-11-30 13:01:18 +00001622- CONFIG_DISPLAY_BOARDINFO
1623 Display information about the board that U-Boot is running on
1624 when U-Boot starts up. The board function checkboard() is called
1625 to do this.
1626
Simon Glasse2e3e2b2012-11-30 13:01:19 +00001627- CONFIG_DISPLAY_BOARDINFO_LATE
1628 Similar to the previous option, but display this information
1629 later, once stdio is running and output goes to the LCD, if
1630 present.
1631
wdenkc6097192002-11-03 00:24:07 +00001632Low Level (hardware related) configuration options:
wdenkdc7c9a12003-03-26 06:55:25 +00001633---------------------------------------------------
wdenkc6097192002-11-03 00:24:07 +00001634
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001635- CONFIG_SYS_CACHELINE_SIZE:
wdenkc6097192002-11-03 00:24:07 +00001636 Cache Line Size of the CPU.
1637
Timur Tabie46fedf2011-08-04 18:03:41 -05001638- CONFIG_SYS_CCSRBAR_DEFAULT:
1639 Default (power-on reset) physical address of CCSR on Freescale
1640 PowerPC SOCs.
1641
1642- CONFIG_SYS_CCSRBAR:
1643 Virtual address of CCSR. On a 32-bit build, this is typically
1644 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
1645
Timur Tabie46fedf2011-08-04 18:03:41 -05001646- CONFIG_SYS_CCSRBAR_PHYS:
1647 Physical address of CCSR. CCSR can be relocated to a new
1648 physical address, if desired. In this case, this macro should
Wolfgang Denkc0f40852011-10-26 10:21:21 +00001649 be set to that address. Otherwise, it should be set to the
Timur Tabie46fedf2011-08-04 18:03:41 -05001650 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
1651 is typically relocated on 36-bit builds. It is recommended
1652 that this macro be defined via the _HIGH and _LOW macros:
1653
1654 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
1655 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
1656
1657- CONFIG_SYS_CCSRBAR_PHYS_HIGH:
Wolfgang Denk4cf26092011-10-07 09:58:21 +02001658 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
1659 either 0 (32-bit build) or 0xF (36-bit build). This macro is
Timur Tabie46fedf2011-08-04 18:03:41 -05001660 used in assembly code, so it must not contain typecasts or
1661 integer size suffixes (e.g. "ULL").
1662
1663- CONFIG_SYS_CCSRBAR_PHYS_LOW:
1664 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
1665 used in assembly code, so it must not contain typecasts or
1666 integer size suffixes (e.g. "ULL").
1667
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001668- CONFIG_SYS_IMMR: Physical address of the Internal Memory.
wdenkefe2a4d2004-12-16 21:44:03 +00001669 DO NOT CHANGE unless you know exactly what you're
Christophe Leroy907208c2017-07-06 10:23:22 +02001670 doing! (11-4) [MPC8xx systems only]
wdenkc6097192002-11-03 00:24:07 +00001671
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001672- CONFIG_SYS_INIT_RAM_ADDR:
wdenkc6097192002-11-03 00:24:07 +00001673
wdenk7152b1d2003-09-05 23:19:14 +00001674 Start address of memory area that can be used for
wdenkc6097192002-11-03 00:24:07 +00001675 initial data and stack; please note that this must be
1676 writable memory that is working WITHOUT special
1677 initialization, i. e. you CANNOT use normal RAM which
1678 will become available only after programming the
1679 memory controller and running certain initialization
1680 sequences.
1681
1682 U-Boot uses the following memory types:
Christophe Leroy907208c2017-07-06 10:23:22 +02001683 - MPC8xx: IMMR (internal memory of the CPU)
wdenkc6097192002-11-03 00:24:07 +00001684
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001685- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
wdenkc6097192002-11-03 00:24:07 +00001686
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001687- CONFIG_SYS_OR_TIMING_SDRAM:
wdenkc6097192002-11-03 00:24:07 +00001688 SDRAM timing
1689
Kumar Galaa09b9b62010-12-30 12:09:53 -06001690- CONFIG_SYS_SRIO:
1691 Chip has SRIO or not
1692
1693- CONFIG_SRIO1:
1694 Board has SRIO 1 port available
1695
1696- CONFIG_SRIO2:
1697 Board has SRIO 2 port available
1698
Liu Gangc8b28152013-05-07 16:30:46 +08001699- CONFIG_SRIO_PCIE_BOOT_MASTER
1700 Board can support master function for Boot from SRIO and PCIE
1701
Kumar Galaa09b9b62010-12-30 12:09:53 -06001702- CONFIG_SYS_SRIOn_MEM_VIRT:
1703 Virtual Address of SRIO port 'n' memory region
1704
Simon Glass62f9b652019-11-14 12:57:09 -07001705- CONFIG_SYS_SRIOn_MEM_PHYxS:
Kumar Galaa09b9b62010-12-30 12:09:53 -06001706 Physical Address of SRIO port 'n' memory region
1707
1708- CONFIG_SYS_SRIOn_MEM_SIZE:
1709 Size of SRIO port 'n' memory region
1710
Fabio Estevam66bd1842013-04-11 09:35:34 +00001711- CONFIG_SYS_NAND_BUSWIDTH_16BIT
1712 Defined to tell the NAND controller that the NAND chip is using
1713 a 16 bit bus.
1714 Not all NAND drivers use this symbol.
Fabio Estevama430e912013-04-11 09:35:35 +00001715 Example of drivers that use it:
Miquel Raynala430fa02018-08-16 17:30:07 +02001716 - drivers/mtd/nand/raw/ndfc.c
1717 - drivers/mtd/nand/raw/mxc_nand.c
Alex Watermaneced4622011-05-19 15:08:36 -04001718
1719- CONFIG_SYS_NDFC_EBC0_CFG
1720 Sets the EBC0_CFG register for the NDFC. If not defined
1721 a default value will be used.
1722
Ben Warrenbb99ad62006-09-07 16:50:54 -04001723- CONFIG_SPD_EEPROM
Wolfgang Denk218ca722008-03-26 10:40:12 +01001724 Get DDR timing information from an I2C EEPROM. Common
1725 with pluggable memory modules such as SODIMMs
1726
Ben Warrenbb99ad62006-09-07 16:50:54 -04001727 SPD_EEPROM_ADDRESS
1728 I2C address of the SPD EEPROM
1729
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001730- CONFIG_SYS_SPD_BUS_NUM
Wolfgang Denk218ca722008-03-26 10:40:12 +01001731 If SPD EEPROM is on an I2C bus other than the first
1732 one, specify here. Note that the value must resolve
1733 to something your driver can deal with.
Ben Warrenbb99ad62006-09-07 16:50:54 -04001734
York Sun6f5e1dc2011-09-16 13:21:35 -07001735- CONFIG_FSL_DDR_INTERACTIVE
1736 Enable interactive DDR debugging. See doc/README.fsl-ddr.
1737
York Sune32d59a2015-01-06 13:18:55 -08001738- CONFIG_FSL_DDR_SYNC_REFRESH
1739 Enable sync of refresh for multiple controllers.
1740
York Sun4516ff82015-03-19 09:30:28 -07001741- CONFIG_FSL_DDR_BIST
1742 Enable built-in memory test for Freescale DDR controllers.
1743
wdenkc26e4542004-04-18 10:13:26 +00001744- CONFIG_RMII
1745 Enable RMII mode for all FECs.
1746 Note that this is a global option, we can't
1747 have one FEC in standard MII mode and another in RMII mode.
1748
wdenk5cf91d62004-04-23 20:32:05 +00001749- CONFIG_CRC32_VERIFY
1750 Add a verify option to the crc32 command.
1751 The syntax is:
1752
1753 => crc32 -v <address> <count> <crc32>
1754
1755 Where address/count indicate a memory area
1756 and crc32 is the correct crc32 which the
1757 area should have.
1758
wdenk56523f12004-07-11 17:40:54 +00001759- CONFIG_LOOPW
1760 Add the "loopw" memory command. This only takes effect if
Simon Glass493f4202017-08-04 16:34:27 -06001761 the memory commands are activated globally (CONFIG_CMD_MEMORY).
wdenk56523f12004-07-11 17:40:54 +00001762
Joel Johnson72732312020-01-29 09:17:18 -07001763- CONFIG_CMD_MX_CYCLIC
stroese7b466642004-12-16 18:46:55 +00001764 Add the "mdc" and "mwc" memory commands. These are cyclic
1765 "md/mw" commands.
1766 Examples:
1767
wdenkefe2a4d2004-12-16 21:44:03 +00001768 => mdc.b 10 4 500
stroese7b466642004-12-16 18:46:55 +00001769 This command will print 4 bytes (10,11,12,13) each 500 ms.
1770
wdenkefe2a4d2004-12-16 21:44:03 +00001771 => mwc.l 100 12345678 10
stroese7b466642004-12-16 18:46:55 +00001772 This command will write 12345678 to address 100 all 10 ms.
1773
wdenkefe2a4d2004-12-16 21:44:03 +00001774 This only takes effect if the memory commands are activated
Simon Glass493f4202017-08-04 16:34:27 -06001775 globally (CONFIG_CMD_MEMORY).
stroese7b466642004-12-16 18:46:55 +00001776
Aneesh V401bb302011-07-13 05:11:07 +00001777- CONFIG_SPL_BUILD
Thomas Hebb32f2ca22019-11-13 18:18:03 -08001778 Set when the currently-running compilation is for an artifact
1779 that will end up in the SPL (as opposed to the TPL or U-Boot
1780 proper). Code that needs stage-specific behavior should check
1781 this.
wdenk400558b2005-04-02 23:52:25 +00001782
Ying Zhang3aa29de2013-08-16 15:16:15 +08001783- CONFIG_TPL_BUILD
Thomas Hebb32f2ca22019-11-13 18:18:03 -08001784 Set when the currently-running compilation is for an artifact
1785 that will end up in the TPL (as opposed to the SPL or U-Boot
1786 proper). Code that needs stage-specific behavior should check
1787 this.
Ying Zhang3aa29de2013-08-16 15:16:15 +08001788
Simon Glass4213fc22013-02-24 17:33:14 +00001789- CONFIG_ARCH_MAP_SYSMEM
1790 Generally U-Boot (and in particular the md command) uses
1791 effective address. It is therefore not necessary to regard
1792 U-Boot address as virtual addresses that need to be translated
1793 to physical addresses. However, sandbox requires this, since
1794 it maintains its own little RAM buffer which contains all
1795 addressable memory. This option causes some memory accesses
1796 to be mapped through map_sysmem() / unmap_sysmem().
1797
Simon Glass588a13f2013-02-14 04:18:54 +00001798- CONFIG_X86_RESET_VECTOR
1799 If defined, the x86 reset vector code is included. This is not
1800 needed when U-Boot is running from Coreboot.
Gabe Blackb16f5212012-11-27 21:08:06 +00001801
Timur Tabif2717b42011-11-22 09:21:25 -06001802Freescale QE/FMAN Firmware Support:
1803-----------------------------------
1804
1805The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
1806loading of "firmware", which is encoded in the QE firmware binary format.
1807This firmware often needs to be loaded during U-Boot booting, so macros
1808are used to identify the storage device (NOR flash, SPI, etc) and the address
1809within that device.
1810
Zhao Qiangdcf1d772014-03-21 16:21:44 +08001811- CONFIG_SYS_FMAN_FW_ADDR
1812 The address in the storage device where the FMAN microcode is located. The
Tom Rinicc1e98b2019-05-12 07:59:12 -04001813 meaning of this address depends on which CONFIG_SYS_QE_FMAN_FW_IN_xxx macro
Zhao Qiangdcf1d772014-03-21 16:21:44 +08001814 is also specified.
1815
1816- CONFIG_SYS_QE_FW_ADDR
1817 The address in the storage device where the QE microcode is located. The
Tom Rinicc1e98b2019-05-12 07:59:12 -04001818 meaning of this address depends on which CONFIG_SYS_QE_FMAN_FW_IN_xxx macro
Timur Tabif2717b42011-11-22 09:21:25 -06001819 is also specified.
1820
1821- CONFIG_SYS_QE_FMAN_FW_LENGTH
1822 The maximum possible size of the firmware. The firmware binary format
1823 has a field that specifies the actual size of the firmware, but it
1824 might not be possible to read any part of the firmware unless some
1825 local storage is allocated to hold the entire firmware first.
1826
1827- CONFIG_SYS_QE_FMAN_FW_IN_NOR
1828 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
1829 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
1830 virtual address in NOR flash.
1831
1832- CONFIG_SYS_QE_FMAN_FW_IN_NAND
1833 Specifies that QE/FMAN firmware is located in NAND flash.
1834 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
1835
1836- CONFIG_SYS_QE_FMAN_FW_IN_MMC
1837 Specifies that QE/FMAN firmware is located on the primary SD/MMC
1838 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
1839
Liu Gang292dc6c2012-03-08 00:33:18 +00001840- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
1841 Specifies that QE/FMAN firmware is located in the remote (master)
1842 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
Liu Gangfc54c7f2012-08-09 05:10:01 +00001843 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
1844 window->master inbound window->master LAW->the ucode address in
1845 master's memory space.
Timur Tabif2717b42011-11-22 09:21:25 -06001846
J. German Riverab940ca62014-06-23 15:15:55 -07001847Freescale Layerscape Management Complex Firmware Support:
1848---------------------------------------------------------
1849The Freescale Layerscape Management Complex (MC) supports the loading of
1850"firmware".
1851This firmware often needs to be loaded during U-Boot booting, so macros
1852are used to identify the storage device (NOR flash, SPI, etc) and the address
1853within that device.
1854
1855- CONFIG_FSL_MC_ENET
1856 Enable the MC driver for Layerscape SoCs.
1857
Prabhakar Kushwaha5c055082015-06-02 10:55:52 +05301858Freescale Layerscape Debug Server Support:
1859-------------------------------------------
1860The Freescale Layerscape Debug Server Support supports the loading of
1861"Debug Server firmware" and triggering SP boot-rom.
1862This firmware often needs to be loaded during U-Boot booting.
1863
York Sunc0492142015-12-07 11:08:58 -08001864- CONFIG_SYS_MC_RSV_MEM_ALIGN
1865 Define alignment of reserved memory MC requires
Prabhakar Kushwaha5c055082015-06-02 10:55:52 +05301866
Paul Kocialkowskif3f431a2015-07-26 18:48:15 +02001867Reproducible builds
1868-------------------
1869
1870In order to achieve reproducible builds, timestamps used in the U-Boot build
1871process have to be set to a fixed value.
1872
1873This is done using the SOURCE_DATE_EPOCH environment variable.
1874SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
1875option for U-Boot or an environment variable in U-Boot.
1876
1877SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
1878
wdenkc6097192002-11-03 00:24:07 +00001879Building the Software:
1880======================
1881
Wolfgang Denk218ca722008-03-26 10:40:12 +01001882Building U-Boot has been tested in several native build environments
1883and in many different cross environments. Of course we cannot support
1884all possibly existing versions of cross development tools in all
1885(potentially obsolete) versions. In case of tool chain problems we
Naoki Hayama047f6ec2020-10-08 13:17:16 +09001886recommend to use the ELDK (see https://www.denx.de/wiki/DULG/ELDK)
Wolfgang Denk218ca722008-03-26 10:40:12 +01001887which is extensively used to build and test U-Boot.
wdenkc6097192002-11-03 00:24:07 +00001888
Wolfgang Denk218ca722008-03-26 10:40:12 +01001889If you are not using a native environment, it is assumed that you
1890have GNU cross compiling tools available in your path. In this case,
1891you must set the environment variable CROSS_COMPILE in your shell.
1892Note that no changes to the Makefile or any other source files are
1893necessary. For example using the ELDK on a 4xx CPU, please enter:
wdenkc6097192002-11-03 00:24:07 +00001894
Wolfgang Denk218ca722008-03-26 10:40:12 +01001895 $ CROSS_COMPILE=ppc_4xx-
1896 $ export CROSS_COMPILE
wdenkc6097192002-11-03 00:24:07 +00001897
Wolfgang Denk218ca722008-03-26 10:40:12 +01001898U-Boot is intended to be simple to build. After installing the
1899sources you must configure U-Boot for one specific board type. This
wdenkc6097192002-11-03 00:24:07 +00001900is done by typing:
1901
Holger Freytherab584d62014-08-04 09:26:05 +02001902 make NAME_defconfig
wdenkc6097192002-11-03 00:24:07 +00001903
Holger Freytherab584d62014-08-04 09:26:05 +02001904where "NAME_defconfig" is the name of one of the existing configu-
Heinrich Schuchardtecb3a0a2020-02-24 18:36:30 +01001905rations; see configs/*_defconfig for supported names.
wdenk54387ac2003-10-08 22:45:44 +00001906
Heinrich Schuchardtecb3a0a2020-02-24 18:36:30 +01001907Note: for some boards special configuration names may exist; check if
wdenk2729af92004-05-03 20:45:30 +00001908 additional information is available from the board vendor; for
1909 instance, the TQM823L systems are available without (standard)
1910 or with LCD support. You can select such additional "features"
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001911 when choosing the configuration, i. e.
wdenkc6097192002-11-03 00:24:07 +00001912
Holger Freytherab584d62014-08-04 09:26:05 +02001913 make TQM823L_defconfig
wdenk2729af92004-05-03 20:45:30 +00001914 - will configure for a plain TQM823L, i. e. no LCD support
wdenkc6097192002-11-03 00:24:07 +00001915
Holger Freytherab584d62014-08-04 09:26:05 +02001916 make TQM823L_LCD_defconfig
wdenk2729af92004-05-03 20:45:30 +00001917 - will configure for a TQM823L with U-Boot console on LCD
wdenkc6097192002-11-03 00:24:07 +00001918
wdenk2729af92004-05-03 20:45:30 +00001919 etc.
wdenkc6097192002-11-03 00:24:07 +00001920
wdenkc6097192002-11-03 00:24:07 +00001921
wdenk2729af92004-05-03 20:45:30 +00001922Finally, type "make all", and you should get some working U-Boot
1923images ready for download to / installation on your system:
wdenkc6097192002-11-03 00:24:07 +00001924
wdenk2729af92004-05-03 20:45:30 +00001925- "u-boot.bin" is a raw binary image
1926- "u-boot" is an image in ELF binary format
1927- "u-boot.srec" is in Motorola S-Record format
wdenkc6097192002-11-03 00:24:07 +00001928
Marian Balakowiczbaf31242006-09-07 17:25:40 +02001929By default the build is performed locally and the objects are saved
1930in the source directory. One of the two methods can be used to change
1931this behavior and build U-Boot to some external directory:
1932
19331. Add O= to the make command line invocations:
1934
1935 make O=/tmp/build distclean
Holger Freytherab584d62014-08-04 09:26:05 +02001936 make O=/tmp/build NAME_defconfig
Marian Balakowiczbaf31242006-09-07 17:25:40 +02001937 make O=/tmp/build all
1938
Timo Ketolaadbba992014-11-06 14:39:05 +020019392. Set environment variable KBUILD_OUTPUT to point to the desired location:
Marian Balakowiczbaf31242006-09-07 17:25:40 +02001940
Timo Ketolaadbba992014-11-06 14:39:05 +02001941 export KBUILD_OUTPUT=/tmp/build
Marian Balakowiczbaf31242006-09-07 17:25:40 +02001942 make distclean
Holger Freytherab584d62014-08-04 09:26:05 +02001943 make NAME_defconfig
Marian Balakowiczbaf31242006-09-07 17:25:40 +02001944 make all
1945
Timo Ketolaadbba992014-11-06 14:39:05 +02001946Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
Marian Balakowiczbaf31242006-09-07 17:25:40 +02001947variable.
1948
Daniel Schwierzeck215bb1c2018-01-26 16:31:04 +01001949User specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by
1950setting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS.
1951For example to treat all compiler warnings as errors:
1952
1953 make KCFLAGS=-Werror
wdenkc6097192002-11-03 00:24:07 +00001954
wdenk2729af92004-05-03 20:45:30 +00001955Please be aware that the Makefiles assume you are using GNU make, so
1956for instance on NetBSD you might need to use "gmake" instead of
1957native "make".
wdenkc6097192002-11-03 00:24:07 +00001958
wdenkc6097192002-11-03 00:24:07 +00001959
wdenk2729af92004-05-03 20:45:30 +00001960If the system board that you have is not listed, then you will need
1961to port U-Boot to your hardware platform. To do this, follow these
1962steps:
wdenkc6097192002-11-03 00:24:07 +00001963
Phil Sutter3c1496c2015-12-25 14:41:18 +010019641. Create a new directory to hold your board specific code. Add any
wdenk2729af92004-05-03 20:45:30 +00001965 files you need. In your board directory, you will need at least
Phil Sutter3c1496c2015-12-25 14:41:18 +01001966 the "Makefile" and a "<board>.c".
19672. Create a new configuration file "include/configs/<board>.h" for
1968 your board.
wdenk2729af92004-05-03 20:45:30 +000019693. If you're porting U-Boot to a new CPU, then also create a new
1970 directory to hold your CPU specific code. Add any files you need.
Holger Freytherab584d62014-08-04 09:26:05 +020019714. Run "make <board>_defconfig" with your new name.
wdenk2729af92004-05-03 20:45:30 +000019725. Type "make", and you should get a working "u-boot.srec" file
1973 to be installed on your target system.
19746. Debug and solve any problems that might arise.
1975 [Of course, this last step is much harder than it sounds.]
wdenkc6097192002-11-03 00:24:07 +00001976
wdenkc6097192002-11-03 00:24:07 +00001977
wdenk2729af92004-05-03 20:45:30 +00001978Testing of U-Boot Modifications, Ports to New Hardware, etc.:
1979==============================================================
wdenkc6097192002-11-03 00:24:07 +00001980
Wolfgang Denk218ca722008-03-26 10:40:12 +01001981If you have modified U-Boot sources (for instance added a new board
1982or support for new devices, a new CPU, etc.) you are expected to
wdenk2729af92004-05-03 20:45:30 +00001983provide feedback to the other developers. The feedback normally takes
Thomas Hebb32f2ca22019-11-13 18:18:03 -08001984the form of a "patch", i.e. a context diff against a certain (latest
Wolfgang Denk218ca722008-03-26 10:40:12 +01001985official or latest in the git repository) version of U-Boot sources.
wdenkc6097192002-11-03 00:24:07 +00001986
Wolfgang Denk218ca722008-03-26 10:40:12 +01001987But before you submit such a patch, please verify that your modifi-
1988cation did not break existing code. At least make sure that *ALL* of
wdenk2729af92004-05-03 20:45:30 +00001989the supported boards compile WITHOUT ANY compiler warnings. To do so,
Simon Glass6de80f22016-07-27 20:33:08 -06001990just run the buildman script (tools/buildman/buildman), which will
1991configure and build U-Boot for ALL supported system. Be warned, this
1992will take a while. Please see the buildman README, or run 'buildman -H'
1993for documentation.
Marian Balakowiczbaf31242006-09-07 17:25:40 +02001994
1995
wdenk2729af92004-05-03 20:45:30 +00001996See also "U-Boot Porting Guide" below.
wdenkc6097192002-11-03 00:24:07 +00001997
wdenkc6097192002-11-03 00:24:07 +00001998
wdenk2729af92004-05-03 20:45:30 +00001999Monitor Commands - Overview:
2000============================
wdenkc6097192002-11-03 00:24:07 +00002001
wdenk2729af92004-05-03 20:45:30 +00002002go - start application at address 'addr'
2003run - run commands in an environment variable
2004bootm - boot application image from memory
2005bootp - boot image via network using BootP/TFTP protocol
Marek Vasut44f074c2012-03-14 21:52:45 +00002006bootz - boot zImage from memory
wdenk2729af92004-05-03 20:45:30 +00002007tftpboot- boot image via network using TFTP protocol
2008 and env variables "ipaddr" and "serverip"
2009 (and eventually "gatewayip")
Simon Glass1fb7cd42011-10-24 18:00:07 +00002010tftpput - upload a file via network using TFTP protocol
wdenk2729af92004-05-03 20:45:30 +00002011rarpboot- boot image via network using RARP/TFTP protocol
2012diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2013loads - load S-Record file over serial line
2014loadb - load binary file over serial line (kermit mode)
Rui Miguel Silvabfef72e2022-05-11 10:55:40 +01002015loadm - load binary blob from source address to destination address
wdenk2729af92004-05-03 20:45:30 +00002016md - memory display
2017mm - memory modify (auto-incrementing)
2018nm - memory modify (constant address)
2019mw - memory write (fill)
Simon Glassbdded202020-06-02 19:26:49 -06002020ms - memory search
wdenk2729af92004-05-03 20:45:30 +00002021cp - memory copy
2022cmp - memory compare
2023crc32 - checksum calculation
Peter Tyser0f89c542009-04-18 22:34:03 -05002024i2c - I2C sub-system
wdenk2729af92004-05-03 20:45:30 +00002025sspi - SPI utility commands
2026base - print or set address offset
2027printenv- print environment variables
Pragnesh Patel9e9a5302020-12-22 11:30:05 +05302028pwm - control pwm channels
wdenk2729af92004-05-03 20:45:30 +00002029setenv - set environment variables
2030saveenv - save environment variables to persistent storage
2031protect - enable or disable FLASH write protection
2032erase - erase FLASH memory
2033flinfo - print FLASH memory information
Karl O. Pinc10635af2012-08-03 05:57:21 +00002034nand - NAND memory operations (see doc/README.nand)
wdenk2729af92004-05-03 20:45:30 +00002035bdinfo - print Board Info structure
2036iminfo - print header information for application image
2037coninfo - print console devices and informations
2038ide - IDE sub-system
2039loop - infinite loop on address range
wdenk56523f12004-07-11 17:40:54 +00002040loopw - infinite write loop on address range
wdenk2729af92004-05-03 20:45:30 +00002041mtest - simple RAM test
2042icache - enable or disable instruction cache
2043dcache - enable or disable data cache
2044reset - Perform RESET of the CPU
2045echo - echo args to console
2046version - print monitor version
2047help - print online help
2048? - alias for 'help'
wdenkc6097192002-11-03 00:24:07 +00002049
wdenkc6097192002-11-03 00:24:07 +00002050
wdenk2729af92004-05-03 20:45:30 +00002051Monitor Commands - Detailed Description:
2052========================================
wdenkc6097192002-11-03 00:24:07 +00002053
wdenk2729af92004-05-03 20:45:30 +00002054TODO.
wdenkc6097192002-11-03 00:24:07 +00002055
wdenk2729af92004-05-03 20:45:30 +00002056For now: just type "help <command>".
wdenkc6097192002-11-03 00:24:07 +00002057
2058
wdenk2729af92004-05-03 20:45:30 +00002059Note for Redundant Ethernet Interfaces:
2060=======================================
wdenkf07771c2003-05-28 08:06:31 +00002061
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002062Some boards come with redundant Ethernet interfaces; U-Boot supports
wdenk2729af92004-05-03 20:45:30 +00002063such configurations and is capable of automatic selection of a
2064"working" interface when needed. MAC assignment works as follows:
wdenkf07771c2003-05-28 08:06:31 +00002065
wdenk2729af92004-05-03 20:45:30 +00002066Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2067MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2068"eth1addr" (=>eth1), "eth2addr", ...
wdenkf07771c2003-05-28 08:06:31 +00002069
wdenk2729af92004-05-03 20:45:30 +00002070If the network interface stores some valid MAC address (for instance
2071in SROM), this is used as default address if there is NO correspon-
2072ding setting in the environment; if the corresponding environment
2073variable is set, this overrides the settings in the card; that means:
wdenkf07771c2003-05-28 08:06:31 +00002074
wdenk2729af92004-05-03 20:45:30 +00002075o If the SROM has a valid MAC address, and there is no address in the
2076 environment, the SROM's address is used.
wdenkc6097192002-11-03 00:24:07 +00002077
wdenk2729af92004-05-03 20:45:30 +00002078o If there is no valid address in the SROM, and a definition in the
2079 environment exists, then the value from the environment variable is
2080 used.
wdenkc6097192002-11-03 00:24:07 +00002081
wdenk2729af92004-05-03 20:45:30 +00002082o If both the SROM and the environment contain a MAC address, and
2083 both addresses are the same, this MAC address is used.
wdenkc6097192002-11-03 00:24:07 +00002084
wdenk2729af92004-05-03 20:45:30 +00002085o If both the SROM and the environment contain a MAC address, and the
2086 addresses differ, the value from the environment is used and a
2087 warning is printed.
wdenkc6097192002-11-03 00:24:07 +00002088
wdenk2729af92004-05-03 20:45:30 +00002089o If neither SROM nor the environment contain a MAC address, an error
Joe Hershbergerbef10142015-05-04 14:55:13 -05002090 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
2091 a random, locally-assigned MAC is used.
wdenkc6097192002-11-03 00:24:07 +00002092
Ben Warrenecee9322010-04-26 11:11:46 -07002093If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
Wolfgang Denkc0f40852011-10-26 10:21:21 +00002094will be programmed into hardware as part of the initialization process. This
Ben Warrenecee9322010-04-26 11:11:46 -07002095may be skipped by setting the appropriate 'ethmacskip' environment variable.
2096The naming convention is as follows:
2097"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
wdenkc6097192002-11-03 00:24:07 +00002098
wdenk2729af92004-05-03 20:45:30 +00002099Image Formats:
2100==============
wdenkc6097192002-11-03 00:24:07 +00002101
Marian Balakowicz3310c542008-03-12 12:13:13 +01002102U-Boot is capable of booting (and performing other auxiliary operations on)
2103images in two formats:
2104
2105New uImage format (FIT)
2106-----------------------
2107
2108Flexible and powerful format based on Flattened Image Tree -- FIT (similar
2109to Flattened Device Tree). It allows the use of images with multiple
2110components (several kernels, ramdisks, etc.), with contents protected by
2111SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
2112
2113
2114Old uImage format
2115-----------------
2116
2117Old image format is based on binary files which can be basically anything,
2118preceded by a special header; see the definitions in include/image.h for
2119details; basically, the header defines the following image properties:
wdenkc6097192002-11-03 00:24:07 +00002120
wdenk2729af92004-05-03 20:45:30 +00002121* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2122 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
Peter Tyserf5ed9e32008-09-08 14:56:49 -05002123 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
Thomas Huth0797e732021-11-13 18:13:50 +01002124 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, INTEGRITY).
Andy Shevchenkodaab59a2017-07-05 16:25:22 +03002125* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
Tom Rini11232132022-04-06 09:21:25 -04002126 IA64, MIPS, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2127 Currently supported: ARM, Intel x86, MIPS, Nios II, PowerPC).
wdenk2729af92004-05-03 20:45:30 +00002128* Compression Type (uncompressed, gzip, bzip2)
2129* Load Address
2130* Entry Point
2131* Image Name
2132* Image Timestamp
wdenkc6097192002-11-03 00:24:07 +00002133
wdenk2729af92004-05-03 20:45:30 +00002134The header is marked by a special Magic Number, and both the header
2135and the data portions of the image are secured against corruption by
2136CRC32 checksums.
wdenkc6097192002-11-03 00:24:07 +00002137
wdenkc6097192002-11-03 00:24:07 +00002138
wdenk2729af92004-05-03 20:45:30 +00002139Linux Support:
2140==============
wdenkc6097192002-11-03 00:24:07 +00002141
wdenk2729af92004-05-03 20:45:30 +00002142Although U-Boot should support any OS or standalone application
2143easily, the main focus has always been on Linux during the design of
2144U-Boot.
wdenkc6097192002-11-03 00:24:07 +00002145
wdenk2729af92004-05-03 20:45:30 +00002146U-Boot includes many features that so far have been part of some
2147special "boot loader" code within the Linux kernel. Also, any
2148"initrd" images to be used are no longer part of one big Linux image;
2149instead, kernel and "initrd" are separate images. This implementation
2150serves several purposes:
wdenkc6097192002-11-03 00:24:07 +00002151
wdenk2729af92004-05-03 20:45:30 +00002152- the same features can be used for other OS or standalone
2153 applications (for instance: using compressed images to reduce the
2154 Flash memory footprint)
wdenkc6097192002-11-03 00:24:07 +00002155
wdenk2729af92004-05-03 20:45:30 +00002156- it becomes much easier to port new Linux kernel versions because
2157 lots of low-level, hardware dependent stuff are done by U-Boot
wdenkc6097192002-11-03 00:24:07 +00002158
wdenk2729af92004-05-03 20:45:30 +00002159- the same Linux kernel image can now be used with different "initrd"
2160 images; of course this also means that different kernel images can
2161 be run with the same "initrd". This makes testing easier (you don't
2162 have to build a new "zImage.initrd" Linux image when you just
2163 change a file in your "initrd"). Also, a field-upgrade of the
2164 software is easier now.
wdenkc6097192002-11-03 00:24:07 +00002165
wdenkc6097192002-11-03 00:24:07 +00002166
wdenk2729af92004-05-03 20:45:30 +00002167Linux HOWTO:
2168============
wdenkc6097192002-11-03 00:24:07 +00002169
wdenk2729af92004-05-03 20:45:30 +00002170Porting Linux to U-Boot based systems:
2171---------------------------------------
wdenkc6097192002-11-03 00:24:07 +00002172
wdenk2729af92004-05-03 20:45:30 +00002173U-Boot cannot save you from doing all the necessary modifications to
2174configure the Linux device drivers for use with your target hardware
2175(no, we don't intend to provide a full virtual machine interface to
2176Linux :-).
wdenkc6097192002-11-03 00:24:07 +00002177
Stefan Roesea47a12b2010-04-15 16:07:28 +02002178But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
wdenkc6097192002-11-03 00:24:07 +00002179
wdenk2729af92004-05-03 20:45:30 +00002180Just make sure your machine specific header file (for instance
2181include/asm-ppc/tqm8xx.h) includes the same definition of the Board
Markus Heidelberg1dc30692008-09-07 20:18:27 +02002182Information structure as we define in include/asm-<arch>/u-boot.h,
2183and make sure that your definition of IMAP_ADDR uses the same value
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002184as your U-Boot configuration in CONFIG_SYS_IMMR.
wdenkc6097192002-11-03 00:24:07 +00002185
Simon Glass2eb31b12014-06-11 23:29:46 -06002186Note that U-Boot now has a driver model, a unified model for drivers.
2187If you are adding a new driver, plumb it into driver model. If there
2188is no uclass available, you are encouraged to create one. See
2189doc/driver-model.
2190
wdenkc6097192002-11-03 00:24:07 +00002191
wdenk2729af92004-05-03 20:45:30 +00002192Configuring the Linux kernel:
2193-----------------------------
wdenkc6097192002-11-03 00:24:07 +00002194
wdenk2729af92004-05-03 20:45:30 +00002195No specific requirements for U-Boot. Make sure you have some root
2196device (initial ramdisk, NFS) for your target system.
wdenkc6097192002-11-03 00:24:07 +00002197
wdenkc6097192002-11-03 00:24:07 +00002198
wdenk2729af92004-05-03 20:45:30 +00002199Building a Linux Image:
2200-----------------------
wdenkc6097192002-11-03 00:24:07 +00002201
wdenk2729af92004-05-03 20:45:30 +00002202With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2203not used. If you use recent kernel source, a new build target
2204"uImage" will exist which automatically builds an image usable by
2205U-Boot. Most older kernels also have support for a "pImage" target,
2206which was introduced for our predecessor project PPCBoot and uses a
2207100% compatible format.
wdenkc6097192002-11-03 00:24:07 +00002208
wdenk2729af92004-05-03 20:45:30 +00002209Example:
wdenkc6097192002-11-03 00:24:07 +00002210
Holger Freytherab584d62014-08-04 09:26:05 +02002211 make TQM850L_defconfig
wdenk2729af92004-05-03 20:45:30 +00002212 make oldconfig
2213 make dep
2214 make uImage
wdenkc6097192002-11-03 00:24:07 +00002215
wdenk2729af92004-05-03 20:45:30 +00002216The "uImage" build target uses a special tool (in 'tools/mkimage') to
2217encapsulate a compressed Linux kernel image with header information,
2218CRC32 checksum etc. for use with U-Boot. This is what we are doing:
wdenkc6097192002-11-03 00:24:07 +00002219
wdenk2729af92004-05-03 20:45:30 +00002220* build a standard "vmlinux" kernel image (in ELF binary format):
wdenkc6097192002-11-03 00:24:07 +00002221
wdenk2729af92004-05-03 20:45:30 +00002222* convert the kernel into a raw binary image:
wdenkc6097192002-11-03 00:24:07 +00002223
wdenk2729af92004-05-03 20:45:30 +00002224 ${CROSS_COMPILE}-objcopy -O binary \
2225 -R .note -R .comment \
2226 -S vmlinux linux.bin
wdenkc6097192002-11-03 00:24:07 +00002227
wdenk2729af92004-05-03 20:45:30 +00002228* compress the binary image:
wdenkc6097192002-11-03 00:24:07 +00002229
wdenk2729af92004-05-03 20:45:30 +00002230 gzip -9 linux.bin
wdenkc6097192002-11-03 00:24:07 +00002231
wdenk2729af92004-05-03 20:45:30 +00002232* package compressed binary image for U-Boot:
wdenk24ee89b2002-11-03 17:56:27 +00002233
wdenk2729af92004-05-03 20:45:30 +00002234 mkimage -A ppc -O linux -T kernel -C gzip \
2235 -a 0 -e 0 -n "Linux Kernel Image" \
2236 -d linux.bin.gz uImage
wdenk24ee89b2002-11-03 17:56:27 +00002237
wdenk24ee89b2002-11-03 17:56:27 +00002238
wdenk2729af92004-05-03 20:45:30 +00002239The "mkimage" tool can also be used to create ramdisk images for use
2240with U-Boot, either separated from the Linux kernel image, or
2241combined into one file. "mkimage" encapsulates the images with a 64
2242byte header containing information about target architecture,
2243operating system, image type, compression method, entry points, time
2244stamp, CRC32 checksums, etc.
wdenk24ee89b2002-11-03 17:56:27 +00002245
wdenk2729af92004-05-03 20:45:30 +00002246"mkimage" can be called in two ways: to verify existing images and
2247print the header information, or to build new images.
wdenk24ee89b2002-11-03 17:56:27 +00002248
wdenk2729af92004-05-03 20:45:30 +00002249In the first form (with "-l" option) mkimage lists the information
2250contained in the header of an existing U-Boot image; this includes
2251checksum verification:
wdenk24ee89b2002-11-03 17:56:27 +00002252
wdenk2729af92004-05-03 20:45:30 +00002253 tools/mkimage -l image
2254 -l ==> list image header information
wdenk24ee89b2002-11-03 17:56:27 +00002255
wdenk2729af92004-05-03 20:45:30 +00002256The second form (with "-d" option) is used to build a U-Boot image
2257from a "data file" which is used as image payload:
wdenk24ee89b2002-11-03 17:56:27 +00002258
wdenk2729af92004-05-03 20:45:30 +00002259 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2260 -n name -d data_file image
2261 -A ==> set architecture to 'arch'
2262 -O ==> set operating system to 'os'
2263 -T ==> set image type to 'type'
2264 -C ==> set compression type 'comp'
2265 -a ==> set load address to 'addr' (hex)
2266 -e ==> set entry point to 'ep' (hex)
2267 -n ==> set image name to 'name'
2268 -d ==> use image data from 'datafile'
wdenk24ee89b2002-11-03 17:56:27 +00002269
wdenk69459792004-05-29 16:53:29 +00002270Right now, all Linux kernels for PowerPC systems use the same load
2271address (0x00000000), but the entry point address depends on the
2272kernel version:
wdenkc6097192002-11-03 00:24:07 +00002273
wdenk2729af92004-05-03 20:45:30 +00002274- 2.2.x kernels have the entry point at 0x0000000C,
2275- 2.3.x and later kernels have the entry point at 0x00000000.
wdenkc6097192002-11-03 00:24:07 +00002276
wdenk2729af92004-05-03 20:45:30 +00002277So a typical call to build a U-Boot image would read:
wdenkc6097192002-11-03 00:24:07 +00002278
wdenk2729af92004-05-03 20:45:30 +00002279 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2280 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
Stefan Roesea47a12b2010-04-15 16:07:28 +02002281 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
wdenk2729af92004-05-03 20:45:30 +00002282 > examples/uImage.TQM850L
2283 Image Name: 2.4.4 kernel for TQM850L
2284 Created: Wed Jul 19 02:34:59 2000
2285 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2286 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2287 Load Address: 0x00000000
2288 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002289
wdenk2729af92004-05-03 20:45:30 +00002290To verify the contents of the image (or check for corruption):
wdenkc6097192002-11-03 00:24:07 +00002291
wdenk2729af92004-05-03 20:45:30 +00002292 -> tools/mkimage -l examples/uImage.TQM850L
2293 Image Name: 2.4.4 kernel for TQM850L
2294 Created: Wed Jul 19 02:34:59 2000
2295 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2296 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2297 Load Address: 0x00000000
2298 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002299
wdenk2729af92004-05-03 20:45:30 +00002300NOTE: for embedded systems where boot time is critical you can trade
2301speed for memory and install an UNCOMPRESSED image instead: this
2302needs more space in Flash, but boots much faster since it does not
2303need to be uncompressed:
wdenkc6097192002-11-03 00:24:07 +00002304
Stefan Roesea47a12b2010-04-15 16:07:28 +02002305 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
wdenk2729af92004-05-03 20:45:30 +00002306 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2307 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
Stefan Roesea47a12b2010-04-15 16:07:28 +02002308 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
wdenk2729af92004-05-03 20:45:30 +00002309 > examples/uImage.TQM850L-uncompressed
2310 Image Name: 2.4.4 kernel for TQM850L
2311 Created: Wed Jul 19 02:34:59 2000
2312 Image Type: PowerPC Linux Kernel Image (uncompressed)
2313 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
2314 Load Address: 0x00000000
2315 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002316
wdenkc6097192002-11-03 00:24:07 +00002317
wdenk2729af92004-05-03 20:45:30 +00002318Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2319when your kernel is intended to use an initial ramdisk:
wdenkdb01a2e2004-04-15 23:14:49 +00002320
wdenk2729af92004-05-03 20:45:30 +00002321 -> tools/mkimage -n 'Simple Ramdisk Image' \
2322 > -A ppc -O linux -T ramdisk -C gzip \
2323 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2324 Image Name: Simple Ramdisk Image
2325 Created: Wed Jan 12 14:01:50 2000
2326 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2327 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
2328 Load Address: 0x00000000
2329 Entry Point: 0x00000000
wdenkdb01a2e2004-04-15 23:14:49 +00002330
Tyler Hickse157a112020-10-26 10:40:24 -05002331The "dumpimage" tool can be used to disassemble or list the contents of images
2332built by mkimage. See dumpimage's help output (-h) for details.
wdenkdb01a2e2004-04-15 23:14:49 +00002333
wdenk2729af92004-05-03 20:45:30 +00002334Installing a Linux Image:
2335-------------------------
wdenkdb01a2e2004-04-15 23:14:49 +00002336
wdenk2729af92004-05-03 20:45:30 +00002337To downloading a U-Boot image over the serial (console) interface,
2338you must convert the image to S-Record format:
wdenkdb01a2e2004-04-15 23:14:49 +00002339
wdenk2729af92004-05-03 20:45:30 +00002340 objcopy -I binary -O srec examples/image examples/image.srec
wdenkdb01a2e2004-04-15 23:14:49 +00002341
wdenk2729af92004-05-03 20:45:30 +00002342The 'objcopy' does not understand the information in the U-Boot
2343image header, so the resulting S-Record file will be relative to
2344address 0x00000000. To load it to a given address, you need to
2345specify the target address as 'offset' parameter with the 'loads'
2346command.
wdenkc6097192002-11-03 00:24:07 +00002347
wdenk2729af92004-05-03 20:45:30 +00002348Example: install the image to address 0x40100000 (which on the
2349TQM8xxL is in the first Flash bank):
wdenkc6097192002-11-03 00:24:07 +00002350
wdenk2729af92004-05-03 20:45:30 +00002351 => erase 40100000 401FFFFF
wdenkc6097192002-11-03 00:24:07 +00002352
wdenk2729af92004-05-03 20:45:30 +00002353 .......... done
2354 Erased 8 sectors
wdenkc6097192002-11-03 00:24:07 +00002355
wdenk2729af92004-05-03 20:45:30 +00002356 => loads 40100000
2357 ## Ready for S-Record download ...
2358 ~>examples/image.srec
2359 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2360 ...
2361 15989 15990 15991 15992
2362 [file transfer complete]
2363 [connected]
2364 ## Start Addr = 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002365
2366
wdenk2729af92004-05-03 20:45:30 +00002367You can check the success of the download using the 'iminfo' command;
Wolfgang Denk218ca722008-03-26 10:40:12 +01002368this includes a checksum verification so you can be sure no data
wdenk2729af92004-05-03 20:45:30 +00002369corruption happened:
wdenkc6097192002-11-03 00:24:07 +00002370
wdenk2729af92004-05-03 20:45:30 +00002371 => imi 40100000
wdenkc6097192002-11-03 00:24:07 +00002372
wdenk2729af92004-05-03 20:45:30 +00002373 ## Checking Image at 40100000 ...
2374 Image Name: 2.2.13 for initrd on TQM850L
2375 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2376 Data Size: 335725 Bytes = 327 kB = 0 MB
2377 Load Address: 00000000
2378 Entry Point: 0000000c
2379 Verifying Checksum ... OK
wdenkc6097192002-11-03 00:24:07 +00002380
2381
wdenk2729af92004-05-03 20:45:30 +00002382Boot Linux:
2383-----------
wdenkc6097192002-11-03 00:24:07 +00002384
wdenk2729af92004-05-03 20:45:30 +00002385The "bootm" command is used to boot an application that is stored in
2386memory (RAM or Flash). In case of a Linux kernel image, the contents
2387of the "bootargs" environment variable is passed to the kernel as
2388parameters. You can check and modify this variable using the
2389"printenv" and "setenv" commands:
wdenkc6097192002-11-03 00:24:07 +00002390
2391
wdenk2729af92004-05-03 20:45:30 +00002392 => printenv bootargs
2393 bootargs=root=/dev/ram
wdenkc6097192002-11-03 00:24:07 +00002394
wdenk2729af92004-05-03 20:45:30 +00002395 => 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 +00002396
wdenk2729af92004-05-03 20:45:30 +00002397 => printenv bootargs
2398 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 +00002399
wdenk2729af92004-05-03 20:45:30 +00002400 => bootm 40020000
2401 ## Booting Linux kernel at 40020000 ...
2402 Image Name: 2.2.13 for NFS on TQM850L
2403 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2404 Data Size: 381681 Bytes = 372 kB = 0 MB
2405 Load Address: 00000000
2406 Entry Point: 0000000c
2407 Verifying Checksum ... OK
2408 Uncompressing Kernel Image ... OK
2409 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
2410 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2411 time_init: decrementer frequency = 187500000/60
2412 Calibrating delay loop... 49.77 BogoMIPS
2413 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2414 ...
wdenkc6097192002-11-03 00:24:07 +00002415
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002416If you want to boot a Linux kernel with initial RAM disk, you pass
wdenk2729af92004-05-03 20:45:30 +00002417the memory addresses of both the kernel and the initrd image (PPBCOOT
2418format!) to the "bootm" command:
wdenkc6097192002-11-03 00:24:07 +00002419
wdenk2729af92004-05-03 20:45:30 +00002420 => imi 40100000 40200000
wdenkc6097192002-11-03 00:24:07 +00002421
wdenk2729af92004-05-03 20:45:30 +00002422 ## Checking Image at 40100000 ...
2423 Image Name: 2.2.13 for initrd on TQM850L
2424 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2425 Data Size: 335725 Bytes = 327 kB = 0 MB
2426 Load Address: 00000000
2427 Entry Point: 0000000c
2428 Verifying Checksum ... OK
wdenkc6097192002-11-03 00:24:07 +00002429
wdenk2729af92004-05-03 20:45:30 +00002430 ## Checking Image at 40200000 ...
2431 Image Name: Simple Ramdisk Image
2432 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2433 Data Size: 566530 Bytes = 553 kB = 0 MB
2434 Load Address: 00000000
2435 Entry Point: 00000000
2436 Verifying Checksum ... OK
wdenkc6097192002-11-03 00:24:07 +00002437
wdenk2729af92004-05-03 20:45:30 +00002438 => bootm 40100000 40200000
2439 ## Booting Linux kernel at 40100000 ...
2440 Image Name: 2.2.13 for initrd on TQM850L
2441 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2442 Data Size: 335725 Bytes = 327 kB = 0 MB
2443 Load Address: 00000000
2444 Entry Point: 0000000c
2445 Verifying Checksum ... OK
2446 Uncompressing Kernel Image ... OK
2447 ## Loading RAMDisk Image at 40200000 ...
2448 Image Name: Simple Ramdisk Image
2449 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2450 Data Size: 566530 Bytes = 553 kB = 0 MB
2451 Load Address: 00000000
2452 Entry Point: 00000000
2453 Verifying Checksum ... OK
2454 Loading Ramdisk ... OK
2455 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
2456 Boot arguments: root=/dev/ram
2457 time_init: decrementer frequency = 187500000/60
2458 Calibrating delay loop... 49.77 BogoMIPS
2459 ...
2460 RAMDISK: Compressed image found at block 0
2461 VFS: Mounted root (ext2 filesystem).
wdenkc6097192002-11-03 00:24:07 +00002462
wdenk2729af92004-05-03 20:45:30 +00002463 bash#
wdenkc6097192002-11-03 00:24:07 +00002464
Matthew McClintock02677682006-06-28 10:41:37 -05002465Boot Linux and pass a flat device tree:
2466-----------
2467
2468First, U-Boot must be compiled with the appropriate defines. See the section
2469titled "Linux Kernel Interface" above for a more in depth explanation. The
2470following is an example of how to start a kernel and pass an updated
2471flat device tree:
2472
2473=> print oftaddr
2474oftaddr=0x300000
2475=> print oft
2476oft=oftrees/mpc8540ads.dtb
2477=> tftp $oftaddr $oft
2478Speed: 1000, full duplex
2479Using TSEC0 device
2480TFTP from server 192.168.1.1; our IP address is 192.168.1.101
2481Filename 'oftrees/mpc8540ads.dtb'.
2482Load address: 0x300000
2483Loading: #
2484done
2485Bytes transferred = 4106 (100a hex)
2486=> tftp $loadaddr $bootfile
2487Speed: 1000, full duplex
2488Using TSEC0 device
2489TFTP from server 192.168.1.1; our IP address is 192.168.1.2
2490Filename 'uImage'.
2491Load address: 0x200000
2492Loading:############
2493done
2494Bytes transferred = 1029407 (fb51f hex)
2495=> print loadaddr
2496loadaddr=200000
2497=> print oftaddr
2498oftaddr=0x300000
2499=> bootm $loadaddr - $oftaddr
2500## Booting image at 00200000 ...
Wolfgang Denka9398e02006-11-27 15:32:42 +01002501 Image Name: Linux-2.6.17-dirty
2502 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2503 Data Size: 1029343 Bytes = 1005.2 kB
Matthew McClintock02677682006-06-28 10:41:37 -05002504 Load Address: 00000000
Wolfgang Denka9398e02006-11-27 15:32:42 +01002505 Entry Point: 00000000
Matthew McClintock02677682006-06-28 10:41:37 -05002506 Verifying Checksum ... OK
2507 Uncompressing Kernel Image ... OK
2508Booting using flat device tree at 0x300000
2509Using MPC85xx ADS machine description
2510Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
2511[snip]
2512
2513
wdenk2729af92004-05-03 20:45:30 +00002514More About U-Boot Image Types:
2515------------------------------
wdenk6069ff22003-02-28 00:49:47 +00002516
wdenk2729af92004-05-03 20:45:30 +00002517U-Boot supports the following image types:
wdenk6069ff22003-02-28 00:49:47 +00002518
wdenk2729af92004-05-03 20:45:30 +00002519 "Standalone Programs" are directly runnable in the environment
2520 provided by U-Boot; it is expected that (if they behave
2521 well) you can continue to work in U-Boot after return from
2522 the Standalone Program.
2523 "OS Kernel Images" are usually images of some Embedded OS which
2524 will take over control completely. Usually these programs
2525 will install their own set of exception handlers, device
2526 drivers, set up the MMU, etc. - this means, that you cannot
2527 expect to re-enter U-Boot except by resetting the CPU.
2528 "RAMDisk Images" are more or less just data blocks, and their
2529 parameters (address, size) are passed to an OS kernel that is
2530 being started.
2531 "Multi-File Images" contain several images, typically an OS
2532 (Linux) kernel image and one or more data images like
2533 RAMDisks. This construct is useful for instance when you want
2534 to boot over the network using BOOTP etc., where the boot
2535 server provides just a single image file, but you want to get
2536 for instance an OS kernel and a RAMDisk image.
stroesec1551ea2003-04-04 15:53:41 +00002537
wdenk2729af92004-05-03 20:45:30 +00002538 "Multi-File Images" start with a list of image sizes, each
2539 image size (in bytes) specified by an "uint32_t" in network
2540 byte order. This list is terminated by an "(uint32_t)0".
2541 Immediately after the terminating 0 follow the images, one by
2542 one, all aligned on "uint32_t" boundaries (size rounded up to
2543 a multiple of 4 bytes).
stroesec1551ea2003-04-04 15:53:41 +00002544
wdenk2729af92004-05-03 20:45:30 +00002545 "Firmware Images" are binary images containing firmware (like
2546 U-Boot or FPGA images) which usually will be programmed to
2547 flash memory.
stroesec1551ea2003-04-04 15:53:41 +00002548
wdenk2729af92004-05-03 20:45:30 +00002549 "Script files" are command sequences that will be executed by
2550 U-Boot's command interpreter; this feature is especially
2551 useful when you configure U-Boot to use a real shell (hush)
2552 as command interpreter.
wdenk6069ff22003-02-28 00:49:47 +00002553
Marek Vasut44f074c2012-03-14 21:52:45 +00002554Booting the Linux zImage:
2555-------------------------
2556
2557On some platforms, it's possible to boot Linux zImage. This is done
2558using the "bootz" command. The syntax of "bootz" command is the same
2559as the syntax of "bootm" command.
2560
Tom Rini8ac28562013-05-16 11:40:11 -04002561Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
Marek Vasut017e1f32012-03-18 11:47:58 +00002562kernel with raw initrd images. The syntax is slightly different, the
2563address of the initrd must be augmented by it's size, in the following
2564format: "<initrd addres>:<initrd size>".
2565
wdenkc6097192002-11-03 00:24:07 +00002566
wdenk2729af92004-05-03 20:45:30 +00002567Standalone HOWTO:
2568=================
wdenkc6097192002-11-03 00:24:07 +00002569
wdenk2729af92004-05-03 20:45:30 +00002570One of the features of U-Boot is that you can dynamically load and
2571run "standalone" applications, which can use some resources of
2572U-Boot like console I/O functions or interrupt services.
wdenkc6097192002-11-03 00:24:07 +00002573
wdenk2729af92004-05-03 20:45:30 +00002574Two simple examples are included with the sources:
wdenkc6097192002-11-03 00:24:07 +00002575
wdenk2729af92004-05-03 20:45:30 +00002576"Hello World" Demo:
2577-------------------
wdenkc6097192002-11-03 00:24:07 +00002578
wdenk2729af92004-05-03 20:45:30 +00002579'examples/hello_world.c' contains a small "Hello World" Demo
2580application; it is automatically compiled when you build U-Boot.
2581It's configured to run at address 0x00040004, so you can play with it
2582like that:
wdenkc6097192002-11-03 00:24:07 +00002583
wdenk2729af92004-05-03 20:45:30 +00002584 => loads
2585 ## Ready for S-Record download ...
2586 ~>examples/hello_world.srec
2587 1 2 3 4 5 6 7 8 9 10 11 ...
2588 [file transfer complete]
2589 [connected]
2590 ## Start Addr = 0x00040004
wdenkc6097192002-11-03 00:24:07 +00002591
wdenk2729af92004-05-03 20:45:30 +00002592 => go 40004 Hello World! This is a test.
2593 ## Starting application at 0x00040004 ...
2594 Hello World
2595 argc = 7
2596 argv[0] = "40004"
2597 argv[1] = "Hello"
2598 argv[2] = "World!"
2599 argv[3] = "This"
2600 argv[4] = "is"
2601 argv[5] = "a"
2602 argv[6] = "test."
2603 argv[7] = "<NULL>"
2604 Hit any key to exit ...
wdenkc6097192002-11-03 00:24:07 +00002605
wdenk2729af92004-05-03 20:45:30 +00002606 ## Application terminated, rc = 0x0
wdenkc6097192002-11-03 00:24:07 +00002607
wdenk2729af92004-05-03 20:45:30 +00002608Another example, which demonstrates how to register a CPM interrupt
2609handler with the U-Boot code, can be found in 'examples/timer.c'.
2610Here, a CPM timer is set up to generate an interrupt every second.
2611The interrupt service routine is trivial, just printing a '.'
2612character, but this is just a demo program. The application can be
2613controlled by the following keys:
wdenkc6097192002-11-03 00:24:07 +00002614
wdenk2729af92004-05-03 20:45:30 +00002615 ? - print current values og the CPM Timer registers
2616 b - enable interrupts and start timer
2617 e - stop timer and disable interrupts
2618 q - quit application
wdenkc6097192002-11-03 00:24:07 +00002619
wdenk2729af92004-05-03 20:45:30 +00002620 => loads
2621 ## Ready for S-Record download ...
2622 ~>examples/timer.srec
2623 1 2 3 4 5 6 7 8 9 10 11 ...
2624 [file transfer complete]
2625 [connected]
2626 ## Start Addr = 0x00040004
wdenkc6097192002-11-03 00:24:07 +00002627
wdenk2729af92004-05-03 20:45:30 +00002628 => go 40004
2629 ## Starting application at 0x00040004 ...
2630 TIMERS=0xfff00980
2631 Using timer 1
2632 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
wdenkc6097192002-11-03 00:24:07 +00002633
wdenk2729af92004-05-03 20:45:30 +00002634Hit 'b':
2635 [q, b, e, ?] Set interval 1000000 us
2636 Enabling timer
2637Hit '?':
2638 [q, b, e, ?] ........
2639 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
2640Hit '?':
2641 [q, b, e, ?] .
2642 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
2643Hit '?':
2644 [q, b, e, ?] .
2645 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
2646Hit '?':
2647 [q, b, e, ?] .
2648 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
2649Hit 'e':
2650 [q, b, e, ?] ...Stopping timer
2651Hit 'q':
2652 [q, b, e, ?] ## Application terminated, rc = 0x0
wdenkc6097192002-11-03 00:24:07 +00002653
2654
wdenk2729af92004-05-03 20:45:30 +00002655Minicom warning:
2656================
wdenk85ec0bc2003-03-31 16:34:49 +00002657
wdenk2729af92004-05-03 20:45:30 +00002658Over time, many people have reported problems when trying to use the
2659"minicom" terminal emulation program for serial download. I (wd)
2660consider minicom to be broken, and recommend not to use it. Under
2661Unix, I recommend to use C-Kermit for general purpose use (and
2662especially for kermit binary protocol download ("loadb" command), and
Karl O. Pince53515a2012-10-01 05:11:56 +00002663use "cu" for S-Record download ("loads" command). See
Naoki Hayama047f6ec2020-10-08 13:17:16 +09002664https://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
Karl O. Pince53515a2012-10-01 05:11:56 +00002665for help with kermit.
2666
wdenk85ec0bc2003-03-31 16:34:49 +00002667
wdenk2729af92004-05-03 20:45:30 +00002668Nevertheless, if you absolutely want to use it try adding this
2669configuration to your "File transfer protocols" section:
wdenk52f52c12003-06-19 23:04:19 +00002670
wdenk2729af92004-05-03 20:45:30 +00002671 Name Program Name U/D FullScr IO-Red. Multi
2672 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
2673 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
wdenk52f52c12003-06-19 23:04:19 +00002674
2675
wdenk2729af92004-05-03 20:45:30 +00002676NetBSD Notes:
2677=============
wdenkc6097192002-11-03 00:24:07 +00002678
wdenk2729af92004-05-03 20:45:30 +00002679Starting at version 0.9.2, U-Boot supports NetBSD both as host
2680(build U-Boot) and target system (boots NetBSD/mpc8xx).
wdenkc6097192002-11-03 00:24:07 +00002681
wdenk2729af92004-05-03 20:45:30 +00002682Building requires a cross environment; it is known to work on
2683NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
2684need gmake since the Makefiles are not compatible with BSD make).
2685Note that the cross-powerpc package does not install include files;
2686attempting to build U-Boot will fail because <machine/ansi.h> is
2687missing. This file has to be installed and patched manually:
wdenkc6097192002-11-03 00:24:07 +00002688
wdenk2729af92004-05-03 20:45:30 +00002689 # cd /usr/pkg/cross/powerpc-netbsd/include
2690 # mkdir powerpc
2691 # ln -s powerpc machine
2692 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
2693 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
wdenkc6097192002-11-03 00:24:07 +00002694
wdenk2729af92004-05-03 20:45:30 +00002695Native builds *don't* work due to incompatibilities between native
2696and U-Boot include files.
wdenkc6097192002-11-03 00:24:07 +00002697
wdenk2729af92004-05-03 20:45:30 +00002698Booting assumes that (the first part of) the image booted is a
2699stage-2 loader which in turn loads and then invokes the kernel
2700proper. Loader sources will eventually appear in the NetBSD source
2701tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
wdenk2a8af182005-04-13 10:02:42 +00002702meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
wdenkc6097192002-11-03 00:24:07 +00002703
2704
wdenk2729af92004-05-03 20:45:30 +00002705Implementation Internals:
2706=========================
wdenkc6097192002-11-03 00:24:07 +00002707
wdenk2729af92004-05-03 20:45:30 +00002708The following is not intended to be a complete description of every
2709implementation detail. However, it should help to understand the
2710inner workings of U-Boot and make it easier to port it to custom
2711hardware.
wdenkc6097192002-11-03 00:24:07 +00002712
2713
wdenk2729af92004-05-03 20:45:30 +00002714Initial Stack, Global Data:
2715---------------------------
wdenkc6097192002-11-03 00:24:07 +00002716
wdenk2729af92004-05-03 20:45:30 +00002717The implementation of U-Boot is complicated by the fact that U-Boot
2718starts running out of ROM (flash memory), usually without access to
2719system RAM (because the memory controller is not initialized yet).
2720This means that we don't have writable Data or BSS segments, and BSS
2721is not initialized as zero. To be able to get a C environment working
2722at all, we have to allocate at least a minimal stack. Implementation
2723options for this are defined and restricted by the CPU used: Some CPU
2724models provide on-chip memory (like the IMMR area on MPC8xx and
2725MPC826x processors), on others (parts of) the data cache can be
2726locked as (mis-) used as memory, etc.
wdenkc6097192002-11-03 00:24:07 +00002727
Wolfgang Denk218ca722008-03-26 10:40:12 +01002728 Chris Hallinan posted a good summary of these issues to the
Wolfgang Denk06682362008-12-30 22:56:11 +01002729 U-Boot mailing list:
wdenk43d96162003-03-06 00:02:04 +00002730
wdenk2729af92004-05-03 20:45:30 +00002731 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
2732 From: "Chris Hallinan" <clh@net1plus.com>
2733 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
2734 ...
wdenk43d96162003-03-06 00:02:04 +00002735
wdenk2729af92004-05-03 20:45:30 +00002736 Correct me if I'm wrong, folks, but the way I understand it
2737 is this: Using DCACHE as initial RAM for Stack, etc, does not
2738 require any physical RAM backing up the cache. The cleverness
2739 is that the cache is being used as a temporary supply of
2740 necessary storage before the SDRAM controller is setup. It's
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002741 beyond the scope of this list to explain the details, but you
wdenk2729af92004-05-03 20:45:30 +00002742 can see how this works by studying the cache architecture and
2743 operation in the architecture and processor-specific manuals.
wdenk43d96162003-03-06 00:02:04 +00002744
wdenk2729af92004-05-03 20:45:30 +00002745 OCM is On Chip Memory, which I believe the 405GP has 4K. It
2746 is another option for the system designer to use as an
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002747 initial stack/RAM area prior to SDRAM being available. Either
wdenk2729af92004-05-03 20:45:30 +00002748 option should work for you. Using CS 4 should be fine if your
2749 board designers haven't used it for something that would
2750 cause you grief during the initial boot! It is frequently not
2751 used.
wdenk43d96162003-03-06 00:02:04 +00002752
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002753 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
wdenk2729af92004-05-03 20:45:30 +00002754 with your processor/board/system design. The default value
2755 you will find in any recent u-boot distribution in
Stefan Roese8a316c92005-08-01 16:49:12 +02002756 walnut.h should work for you. I'd set it to a value larger
wdenk2729af92004-05-03 20:45:30 +00002757 than your SDRAM module. If you have a 64MB SDRAM module, set
2758 it above 400_0000. Just make sure your board has no resources
2759 that are supposed to respond to that address! That code in
2760 start.S has been around a while and should work as is when
2761 you get the config right.
wdenk43d96162003-03-06 00:02:04 +00002762
wdenk2729af92004-05-03 20:45:30 +00002763 -Chris Hallinan
2764 DS4.COM, Inc.
wdenk43d96162003-03-06 00:02:04 +00002765
wdenk2729af92004-05-03 20:45:30 +00002766It is essential to remember this, since it has some impact on the C
2767code for the initialization procedures:
wdenkc6097192002-11-03 00:24:07 +00002768
wdenk2729af92004-05-03 20:45:30 +00002769* Initialized global data (data segment) is read-only. Do not attempt
2770 to write it.
wdenkc6097192002-11-03 00:24:07 +00002771
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08002772* Do not use any uninitialized global data (or implicitly initialized
wdenk2729af92004-05-03 20:45:30 +00002773 as zero data - BSS segment) at all - this is undefined, initiali-
2774 zation is performed later (when relocating to RAM).
wdenkc6097192002-11-03 00:24:07 +00002775
wdenk2729af92004-05-03 20:45:30 +00002776* Stack space is very limited. Avoid big data buffers or things like
2777 that.
wdenkc6097192002-11-03 00:24:07 +00002778
wdenk2729af92004-05-03 20:45:30 +00002779Having only the stack as writable memory limits means we cannot use
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08002780normal global data to share information between the code. But it
wdenk2729af92004-05-03 20:45:30 +00002781turned out that the implementation of U-Boot can be greatly
2782simplified by making a global data structure (gd_t) available to all
2783functions. We could pass a pointer to this data as argument to _all_
2784functions, but this would bloat the code. Instead we use a feature of
2785the GCC compiler (Global Register Variables) to share the data: we
2786place a pointer (gd) to the global data into a register which we
2787reserve for this purpose.
wdenkc6097192002-11-03 00:24:07 +00002788
wdenk2729af92004-05-03 20:45:30 +00002789When choosing a register for such a purpose we are restricted by the
2790relevant (E)ABI specifications for the current architecture, and by
2791GCC's implementation.
wdenkc6097192002-11-03 00:24:07 +00002792
wdenk2729af92004-05-03 20:45:30 +00002793For PowerPC, the following registers have specific use:
2794 R1: stack pointer
Wolfgang Denke7670f62008-02-14 22:43:22 +01002795 R2: reserved for system use
wdenk2729af92004-05-03 20:45:30 +00002796 R3-R4: parameter passing and return values
2797 R5-R10: parameter passing
2798 R13: small data area pointer
2799 R30: GOT pointer
2800 R31: frame pointer
wdenkc6097192002-11-03 00:24:07 +00002801
Joakim Tjernlunde6bee802010-01-19 14:41:58 +01002802 (U-Boot also uses R12 as internal GOT pointer. r12
2803 is a volatile register so r12 needs to be reset when
2804 going back and forth between asm and C)
wdenkc6097192002-11-03 00:24:07 +00002805
Wolfgang Denke7670f62008-02-14 22:43:22 +01002806 ==> U-Boot will use R2 to hold a pointer to the global data
wdenkc6097192002-11-03 00:24:07 +00002807
wdenk2729af92004-05-03 20:45:30 +00002808 Note: on PPC, we could use a static initializer (since the
2809 address of the global data structure is known at compile time),
2810 but it turned out that reserving a register results in somewhat
2811 smaller code - although the code savings are not that big (on
2812 average for all boards 752 bytes for the whole U-Boot image,
2813 624 text + 127 data).
wdenkc6097192002-11-03 00:24:07 +00002814
wdenk2729af92004-05-03 20:45:30 +00002815On ARM, the following registers are used:
wdenkc6097192002-11-03 00:24:07 +00002816
wdenk2729af92004-05-03 20:45:30 +00002817 R0: function argument word/integer result
2818 R1-R3: function argument word
Jeroen Hofstee12eba1b2013-09-21 14:04:42 +02002819 R9: platform specific
2820 R10: stack limit (used only if stack checking is enabled)
wdenk2729af92004-05-03 20:45:30 +00002821 R11: argument (frame) pointer
2822 R12: temporary workspace
2823 R13: stack pointer
2824 R14: link register
2825 R15: program counter
wdenkc6097192002-11-03 00:24:07 +00002826
Jeroen Hofstee12eba1b2013-09-21 14:04:42 +02002827 ==> U-Boot will use R9 to hold a pointer to the global data
2828
2829 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
wdenkc6097192002-11-03 00:24:07 +00002830
Thomas Chou0df01fd2010-05-21 11:08:03 +08002831On Nios II, the ABI is documented here:
Naoki Hayama047f6ec2020-10-08 13:17:16 +09002832 https://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
Thomas Chou0df01fd2010-05-21 11:08:03 +08002833
2834 ==> U-Boot will use gp to hold a pointer to the global data
2835
2836 Note: on Nios II, we give "-G0" option to gcc and don't use gp
2837 to access small data sections, so gp is free.
2838
Rick Chen3fafced2017-12-26 13:55:59 +08002839On RISC-V, the following registers are used:
2840
2841 x0: hard-wired zero (zero)
2842 x1: return address (ra)
2843 x2: stack pointer (sp)
2844 x3: global pointer (gp)
2845 x4: thread pointer (tp)
2846 x5: link register (t0)
2847 x8: frame pointer (fp)
2848 x10-x11: arguments/return values (a0-1)
2849 x12-x17: arguments (a2-7)
2850 x28-31: temporaries (t3-6)
2851 pc: program counter (pc)
2852
2853 ==> U-Boot will use gp to hold a pointer to the global data
2854
wdenk2729af92004-05-03 20:45:30 +00002855Memory Management:
2856------------------
wdenkc6097192002-11-03 00:24:07 +00002857
wdenk2729af92004-05-03 20:45:30 +00002858U-Boot runs in system state and uses physical addresses, i.e. the
2859MMU is not used either for address mapping nor for memory protection.
wdenkc6097192002-11-03 00:24:07 +00002860
wdenk2729af92004-05-03 20:45:30 +00002861The available memory is mapped to fixed addresses using the memory
2862controller. In this process, a contiguous block is formed for each
2863memory type (Flash, SDRAM, SRAM), even when it consists of several
2864physical memory banks.
wdenkc6097192002-11-03 00:24:07 +00002865
wdenk2729af92004-05-03 20:45:30 +00002866U-Boot is installed in the first 128 kB of the first Flash bank (on
2867TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
2868booting and sizing and initializing DRAM, the code relocates itself
2869to the upper end of DRAM. Immediately below the U-Boot code some
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002870memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
wdenk2729af92004-05-03 20:45:30 +00002871configuration setting]. Below that, a structure with global Board
2872Info data is placed, followed by the stack (growing downward).
wdenkc6097192002-11-03 00:24:07 +00002873
wdenk2729af92004-05-03 20:45:30 +00002874Additionally, some exception handler code is copied to the low 8 kB
2875of DRAM (0x00000000 ... 0x00001FFF).
wdenkc6097192002-11-03 00:24:07 +00002876
wdenk2729af92004-05-03 20:45:30 +00002877So a typical memory configuration with 16 MB of DRAM could look like
2878this:
wdenkc6097192002-11-03 00:24:07 +00002879
wdenk2729af92004-05-03 20:45:30 +00002880 0x0000 0000 Exception Vector code
2881 :
2882 0x0000 1FFF
2883 0x0000 2000 Free for Application Use
2884 :
2885 :
wdenkc6097192002-11-03 00:24:07 +00002886
wdenk2729af92004-05-03 20:45:30 +00002887 :
2888 :
2889 0x00FB FF20 Monitor Stack (Growing downward)
2890 0x00FB FFAC Board Info Data and permanent copy of global data
2891 0x00FC 0000 Malloc Arena
2892 :
2893 0x00FD FFFF
2894 0x00FE 0000 RAM Copy of Monitor Code
2895 ... eventually: LCD or video framebuffer
2896 ... eventually: pRAM (Protected RAM - unchanged by reset)
2897 0x00FF FFFF [End of RAM]
wdenkc6097192002-11-03 00:24:07 +00002898
2899
wdenk2729af92004-05-03 20:45:30 +00002900System Initialization:
2901----------------------
wdenkc6097192002-11-03 00:24:07 +00002902
wdenk2729af92004-05-03 20:45:30 +00002903In the reset configuration, U-Boot starts at the reset entry point
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002904(on most PowerPC systems at address 0x00000100). Because of the reset
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08002905configuration for CS0# this is a mirror of the on board Flash memory.
wdenk2729af92004-05-03 20:45:30 +00002906To be able to re-map memory U-Boot then jumps to its link address.
2907To be able to implement the initialization code in C, a (small!)
2908initial stack is set up in the internal Dual Ported RAM (in case CPUs
Heiko Schocher2eb48ff2017-06-07 17:33:10 +02002909which provide such a feature like), or in a locked part of the data
2910cache. After that, U-Boot initializes the CPU core, the caches and
2911the SIU.
wdenkc6097192002-11-03 00:24:07 +00002912
wdenk2729af92004-05-03 20:45:30 +00002913Next, all (potentially) available memory banks are mapped using a
2914preliminary mapping. For example, we put them on 512 MB boundaries
2915(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
2916on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
2917programmed for SDRAM access. Using the temporary configuration, a
2918simple memory test is run that determines the size of the SDRAM
2919banks.
wdenkc6097192002-11-03 00:24:07 +00002920
wdenk2729af92004-05-03 20:45:30 +00002921When there is more than one SDRAM bank, and the banks are of
2922different size, the largest is mapped first. For equal size, the first
2923bank (CS2#) is mapped first. The first mapping is always for address
29240x00000000, with any additional banks following immediately to create
2925contiguous memory starting from 0.
wdenkc6097192002-11-03 00:24:07 +00002926
wdenk2729af92004-05-03 20:45:30 +00002927Then, the monitor installs itself at the upper end of the SDRAM area
2928and allocates memory for use by malloc() and for the global Board
2929Info data; also, the exception vector code is copied to the low RAM
2930pages, and the final stack is set up.
wdenkc6097192002-11-03 00:24:07 +00002931
wdenk2729af92004-05-03 20:45:30 +00002932Only after this relocation will you have a "normal" C environment;
2933until that you are restricted in several ways, mostly because you are
2934running from ROM, and because the code will have to be relocated to a
2935new address in RAM.
wdenkc6097192002-11-03 00:24:07 +00002936
2937
wdenk2729af92004-05-03 20:45:30 +00002938U-Boot Porting Guide:
2939----------------------
wdenkc6097192002-11-03 00:24:07 +00002940
wdenk2729af92004-05-03 20:45:30 +00002941[Based on messages by Jerry Van Baren in the U-Boot-Users mailing
2942list, October 2002]
wdenkc6097192002-11-03 00:24:07 +00002943
2944
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04002945int main(int argc, char *argv[])
wdenk2729af92004-05-03 20:45:30 +00002946{
2947 sighandler_t no_more_time;
wdenkc6097192002-11-03 00:24:07 +00002948
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04002949 signal(SIGALRM, no_more_time);
2950 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
wdenkc6097192002-11-03 00:24:07 +00002951
wdenk2729af92004-05-03 20:45:30 +00002952 if (available_money > available_manpower) {
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04002953 Pay consultant to port U-Boot;
wdenkc6097192002-11-03 00:24:07 +00002954 return 0;
2955 }
2956
wdenk2729af92004-05-03 20:45:30 +00002957 Download latest U-Boot source;
2958
Wolfgang Denk06682362008-12-30 22:56:11 +01002959 Subscribe to u-boot mailing list;
wdenk2729af92004-05-03 20:45:30 +00002960
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04002961 if (clueless)
2962 email("Hi, I am new to U-Boot, how do I get started?");
wdenkc6097192002-11-03 00:24:07 +00002963
wdenk2729af92004-05-03 20:45:30 +00002964 while (learning) {
2965 Read the README file in the top level directory;
Naoki Hayama047f6ec2020-10-08 13:17:16 +09002966 Read https://www.denx.de/wiki/bin/view/DULG/Manual;
Patrick Delaunay24bcaec2020-02-28 15:18:10 +01002967 Read applicable doc/README.*;
wdenk2729af92004-05-03 20:45:30 +00002968 Read the source, Luke;
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04002969 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
wdenk2729af92004-05-03 20:45:30 +00002970 }
wdenkc6097192002-11-03 00:24:07 +00002971
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04002972 if (available_money > toLocalCurrency ($2500))
2973 Buy a BDI3000;
2974 else
wdenk2729af92004-05-03 20:45:30 +00002975 Add a lot of aggravation and time;
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04002976
2977 if (a similar board exists) { /* hopefully... */
2978 cp -a board/<similar> board/<myboard>
2979 cp include/configs/<similar>.h include/configs/<myboard>.h
2980 } else {
2981 Create your own board support subdirectory;
2982 Create your own board include/configs/<myboard>.h file;
wdenk2729af92004-05-03 20:45:30 +00002983 }
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04002984 Edit new board/<myboard> files
2985 Edit new include/configs/<myboard>.h
wdenkc6097192002-11-03 00:24:07 +00002986
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04002987 while (!accepted) {
2988 while (!running) {
2989 do {
2990 Add / modify source code;
2991 } until (compiles);
2992 Debug;
2993 if (clueless)
2994 email("Hi, I am having problems...");
2995 }
2996 Send patch file to the U-Boot email list;
2997 if (reasonable critiques)
2998 Incorporate improvements from email list code review;
2999 else
3000 Defend code as written;
wdenk2729af92004-05-03 20:45:30 +00003001 }
wdenkc6097192002-11-03 00:24:07 +00003002
wdenk2729af92004-05-03 20:45:30 +00003003 return 0;
3004}
3005
3006void no_more_time (int sig)
3007{
3008 hire_a_guru();
3009}
wdenkc6097192002-11-03 00:24:07 +00003010
3011
wdenk2729af92004-05-03 20:45:30 +00003012Coding Standards:
3013-----------------
wdenkc6097192002-11-03 00:24:07 +00003014
wdenk2729af92004-05-03 20:45:30 +00003015All contributions to U-Boot should conform to the Linux kernel
Baruch Siach659208d2017-12-10 17:34:35 +02003016coding style; see the kernel coding style guide at
3017https://www.kernel.org/doc/html/latest/process/coding-style.html, and the
3018script "scripts/Lindent" in your Linux kernel source directory.
wdenk2729af92004-05-03 20:45:30 +00003019
Detlev Zundel2c051652006-09-01 15:39:02 +02003020Source files originating from a different project (for example the
3021MTD subsystem) are generally exempt from these guidelines and are not
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08003022reformatted to ease subsequent migration to newer versions of those
Detlev Zundel2c051652006-09-01 15:39:02 +02003023sources.
3024
3025Please note that U-Boot is implemented in C (and to some small parts in
3026Assembler); no C++ is used, so please do not use C++ style comments (//)
3027in your code.
wdenk2729af92004-05-03 20:45:30 +00003028
3029Please also stick to the following formatting rules:
3030- remove any trailing white space
Wolfgang Denk7ca92962011-07-27 10:59:55 +00003031- use TAB characters for indentation and vertical alignment, not spaces
wdenk2729af92004-05-03 20:45:30 +00003032- make sure NOT to use DOS '\r\n' line feeds
Wolfgang Denk7ca92962011-07-27 10:59:55 +00003033- do not add more than 2 consecutive empty lines to source files
wdenk2729af92004-05-03 20:45:30 +00003034- do not add trailing empty lines to source files
3035
3036Submissions which do not conform to the standards may be returned
3037with a request to reformat the changes.
wdenkc6097192002-11-03 00:24:07 +00003038
3039
wdenk2729af92004-05-03 20:45:30 +00003040Submitting Patches:
3041-------------------
wdenkc6097192002-11-03 00:24:07 +00003042
wdenk2729af92004-05-03 20:45:30 +00003043Since the number of patches for U-Boot is growing, we need to
3044establish some rules. Submissions which do not conform to these rules
3045may be rejected, even when they contain important and valuable stuff.
wdenkc6097192002-11-03 00:24:07 +00003046
Naoki Hayama047f6ec2020-10-08 13:17:16 +09003047Please see https://www.denx.de/wiki/U-Boot/Patches for details.
Wolfgang Denk218ca722008-03-26 10:40:12 +01003048
Wolfgang Denk06682362008-12-30 22:56:11 +01003049Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
S. Lockwood-Childs1dade182017-11-14 22:56:42 -08003050see https://lists.denx.de/listinfo/u-boot
Wolfgang Denk06682362008-12-30 22:56:11 +01003051
wdenk2729af92004-05-03 20:45:30 +00003052When you send a patch, please include the following information with
3053it:
wdenkc6097192002-11-03 00:24:07 +00003054
wdenk2729af92004-05-03 20:45:30 +00003055* For bug fixes: a description of the bug and how your patch fixes
3056 this bug. Please try to include a way of demonstrating that the
3057 patch actually fixes something.
wdenkc6097192002-11-03 00:24:07 +00003058
wdenk2729af92004-05-03 20:45:30 +00003059* For new features: a description of the feature and your
3060 implementation.
wdenkc6097192002-11-03 00:24:07 +00003061
Robert P. J. Day7207b362015-12-19 07:16:10 -05003062* For major contributions, add a MAINTAINERS file with your
3063 information and associated file and directory references.
wdenk2729af92004-05-03 20:45:30 +00003064
Albert ARIBAUD27af9302013-09-11 15:52:51 +02003065* When you add support for a new board, don't forget to add a
3066 maintainer e-mail address to the boards.cfg file, too.
wdenk2729af92004-05-03 20:45:30 +00003067
3068* If your patch adds new configuration options, don't forget to
3069 document these in the README file.
3070
Wolfgang Denk218ca722008-03-26 10:40:12 +01003071* The patch itself. If you are using git (which is *strongly*
3072 recommended) you can easily generate the patch using the
Wolfgang Denk7ca92962011-07-27 10:59:55 +00003073 "git format-patch". If you then use "git send-email" to send it to
Wolfgang Denk218ca722008-03-26 10:40:12 +01003074 the U-Boot mailing list, you will avoid most of the common problems
3075 with some other mail clients.
wdenk2729af92004-05-03 20:45:30 +00003076
Wolfgang Denk218ca722008-03-26 10:40:12 +01003077 If you cannot use git, use "diff -purN OLD NEW". If your version of
3078 diff does not support these options, then get the latest version of
3079 GNU diff.
wdenk2729af92004-05-03 20:45:30 +00003080
Wolfgang Denk218ca722008-03-26 10:40:12 +01003081 The current directory when running this command shall be the parent
3082 directory of the U-Boot source tree (i. e. please make sure that
3083 your patch includes sufficient directory information for the
3084 affected files).
3085
3086 We prefer patches as plain text. MIME attachments are discouraged,
3087 and compressed attachments must not be used.
wdenk2729af92004-05-03 20:45:30 +00003088
3089* If one logical set of modifications affects or creates several
3090 files, all these changes shall be submitted in a SINGLE patch file.
3091
3092* Changesets that contain different, unrelated modifications shall be
3093 submitted as SEPARATE patches, one patch per changeset.
3094
3095
3096Notes:
3097
Simon Glass6de80f22016-07-27 20:33:08 -06003098* Before sending the patch, run the buildman script on your patched
wdenk2729af92004-05-03 20:45:30 +00003099 source tree and make sure that no errors or warnings are reported
3100 for any of the boards.
3101
3102* Keep your modifications to the necessary minimum: A patch
3103 containing several unrelated changes or arbitrary reformats will be
3104 returned with a request to re-formatting / split it.
3105
3106* If you modify existing code, make sure that your new code does not
3107 add to the memory footprint of the code ;-) Small is beautiful!
3108 When adding new features, these should compile conditionally only
3109 (using #ifdef), and the resulting code with the new feature
3110 disabled must not need more memory than the old code without your
3111 modification.
wdenk90dc6702005-05-03 14:12:25 +00003112
Wolfgang Denk06682362008-12-30 22:56:11 +01003113* Remember that there is a size limit of 100 kB per message on the
3114 u-boot mailing list. Bigger patches will be moderated. If they are
3115 reasonable and not too big, they will be acknowledged. But patches
3116 bigger than the size limit should be avoided.