blob: d75c3fbc8596c94591bcf3aecd70e439bd8684ea [file] [log] [blame]
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:
Heiko Schocher3f4978c2012-01-16 21:12:24 +0000926 CONFIG_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
943 CONFIG_SYS_NUM_I2C_BUSES = 9:
944
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,
1367 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
1368 CONFIG_SYS_NAND_ECCBYTES
1369 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
Scott Wood7d4b7952012-09-21 18:35:27 -05001372 CONFIG_SYS_NAND_U_BOOT_DST
1373 Location in memory to load U-Boot to
1374
1375 CONFIG_SYS_NAND_U_BOOT_SIZE
1376 Size of image to load
Tom Rini95579792012-02-14 07:29:40 +00001377
1378 CONFIG_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
1381 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
1382 Define this if you need to first read the OOB and then the
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001383 data. This is used, for example, on davinci platforms.
Tom Rini95579792012-02-14 07:29:40 +00001384
Pavel Machekc57b9532012-08-30 22:42:11 +02001385 CONFIG_SPL_RAM_DEVICE
1386 Support for running image already present in ram, in SPL binary
1387
Marek Vasutb527b9c2018-05-13 00:22:52 +02001388 CONFIG_SPL_FIT_PRINT
Simon Glass87ebee32013-05-08 08:05:59 +00001389 Printing information about a FIT image adds quite a bit of
1390 code to SPL. So this is normally disabled in SPL. Use this
1391 option to re-enable it. This will affect the output of the
1392 bootm command when booting a FIT image.
1393
wdenka8c7c702003-12-06 19:49:23 +00001394- Interrupt support (PPC):
1395
wdenkd4ca31c2004-01-02 14:00:00 +00001396 There are common interrupt_init() and timer_interrupt()
1397 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001398 for CPU specific initialization. interrupt_init_cpu()
wdenkd4ca31c2004-01-02 14:00:00 +00001399 should set decrementer_count to appropriate value. If
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001400 CPU resets decrementer automatically after interrupt
wdenkd4ca31c2004-01-02 14:00:00 +00001401 (ppc4xx) it should set decrementer_count to zero.
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001402 timer_interrupt() calls timer_interrupt_cpu() for CPU
wdenkd4ca31c2004-01-02 14:00:00 +00001403 specific handling. If board has watchdog / status_led
1404 / other_activity_monitor it works automatically from
1405 general timer_interrupt().
wdenka8c7c702003-12-06 19:49:23 +00001406
wdenkc6097192002-11-03 00:24:07 +00001407
Helmut Raiger9660e442011-10-20 04:19:47 +00001408Board initialization settings:
1409------------------------------
1410
1411During Initialization u-boot calls a number of board specific functions
1412to allow the preparation of board specific prerequisites, e.g. pin setup
1413before drivers are initialized. To enable these callbacks the
1414following configuration macros have to be defined. Currently this is
1415architecture specific, so please check arch/your_architecture/lib/board.c
1416typically in board_init_f() and board_init_r().
1417
1418- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
1419- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
1420- CONFIG_BOARD_LATE_INIT: Call board_late_init()
wdenkc6097192002-11-03 00:24:07 +00001421
wdenkc6097192002-11-03 00:24:07 +00001422Configuration Settings:
1423-----------------------
1424
Simon Glass4d979bf2019-12-28 10:45:10 -07001425- MEM_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
York Sun4d1fd7f2014-02-26 17:03:19 -08001426 Optionally it can be defined to support 64-bit memory commands.
1427
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001428- CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
wdenkc6097192002-11-03 00:24:07 +00001429 undefine this when you're short of memory.
1430
Peter Tyser2fb26042009-01-27 18:03:12 -06001431- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
1432 width of the commands listed in the 'help' command output.
1433
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001434- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
wdenkc6097192002-11-03 00:24:07 +00001435 prompt for user input.
1436
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001437- CONFIG_SYS_BAUDRATE_TABLE:
wdenkc6097192002-11-03 00:24:07 +00001438 List of legal baudrate settings for this board.
1439
York Sune8149522015-12-04 11:57:07 -08001440- CONFIG_SYS_MEM_RESERVE_SECURE
York Sune61a7532016-06-24 16:46:18 -07001441 Only implemented for ARMv8 for now.
York Sune8149522015-12-04 11:57:07 -08001442 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
1443 is substracted from total RAM and won't be reported to OS.
1444 This memory can be used as secure memory. A variable
York Sune61a7532016-06-24 16:46:18 -07001445 gd->arch.secure_ram is used to track the location. In systems
York Sune8149522015-12-04 11:57:07 -08001446 the RAM base is not zero, or RAM is divided into banks,
1447 this variable needs to be recalcuated to get the address.
1448
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001449- CONFIG_SYS_SDRAM_BASE:
wdenkc6097192002-11-03 00:24:07 +00001450 Physical start address of SDRAM. _Must_ be 0 here.
1451
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001452- CONFIG_SYS_FLASH_BASE:
wdenkc6097192002-11-03 00:24:07 +00001453 Physical start address of Flash memory.
1454
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001455- CONFIG_SYS_MALLOC_LEN:
wdenkc6097192002-11-03 00:24:07 +00001456 Size of DRAM reserved for malloc() use.
1457
Simon Glassd59476b2014-07-10 22:23:28 -06001458- CONFIG_SYS_MALLOC_F_LEN
1459 Size of the malloc() pool for use before relocation. If
1460 this is defined, then a very simple malloc() implementation
1461 will become available before relocation. The address is just
1462 below the global data, and the stack is moved down to make
1463 space.
1464
1465 This feature allocates regions with increasing addresses
1466 within the region. calloc() is supported, but realloc()
1467 is not available. free() is supported but does nothing.
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001468 The memory will be freed (or in fact just forgotten) when
Simon Glassd59476b2014-07-10 22:23:28 -06001469 U-Boot relocates itself.
1470
Simon Glass38687ae2014-11-10 17:16:54 -07001471- CONFIG_SYS_MALLOC_SIMPLE
1472 Provides a simple and small malloc() and calloc() for those
1473 boards which do not use the full malloc in SPL (which is
Tom Rini10f6e4d2022-05-27 12:48:32 -04001474 enabled with CONFIG_SYS_SPL_MALLOC).
Simon Glass38687ae2014-11-10 17:16:54 -07001475
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001476- CONFIG_SYS_BOOTMAPSZ:
wdenkc6097192002-11-03 00:24:07 +00001477 Maximum size of memory mapped by the startup code of
1478 the Linux kernel; all data that must be processed by
Bartlomiej Sieka7d721e32008-04-14 15:44:16 +02001479 the Linux kernel (bd_info, boot arguments, FDT blob if
1480 used) must be put below this limit, unless "bootm_low"
Robert P. J. Day1bce2ae2013-09-16 07:15:45 -04001481 environment variable is defined and non-zero. In such case
Bartlomiej Sieka7d721e32008-04-14 15:44:16 +02001482 all data for the Linux kernel must be between "bootm_low"
Wolfgang Denkc0f40852011-10-26 10:21:21 +00001483 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
Grant Likelyc3624e62011-03-28 09:58:43 +00001484 variable "bootm_mapsize" will override the value of
1485 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
1486 then the value in "bootm_size" will be used instead.
wdenkc6097192002-11-03 00:24:07 +00001487
John Rigbyfca43cc2010-10-13 13:57:35 -06001488- CONFIG_SYS_BOOT_GET_CMDLINE:
1489 Enables allocating and saving kernel cmdline in space between
1490 "bootm_low" and "bootm_low" + BOOTMAPSZ.
1491
1492- CONFIG_SYS_BOOT_GET_KBD:
1493 Enables allocating and saving a kernel copy of the bd_info in
1494 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
1495
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001496- CONFIG_SYS_FLASH_PROTECTION
wdenk8564acf2003-07-14 22:13:32 +00001497 If defined, hardware flash sectors protection is used
1498 instead of U-Boot software protection.
1499
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001500- CONFIG_SYS_FLASH_CFI:
wdenk43d96162003-03-06 00:02:04 +00001501 Define if the flash driver uses extra elements in the
wdenk5653fc32004-02-08 22:55:38 +00001502 common flash structure for storing flash geometry.
1503
Jean-Christophe PLAGNIOL-VILLARD00b18832008-08-13 01:40:42 +02001504- CONFIG_FLASH_CFI_DRIVER
wdenk5653fc32004-02-08 22:55:38 +00001505 This option also enables the building of the cfi_flash driver
1506 in the drivers directory
wdenkc6097192002-11-03 00:24:07 +00001507
Piotr Ziecik91809ed2008-11-17 15:57:58 +01001508- CONFIG_FLASH_CFI_MTD
1509 This option enables the building of the cfi_mtd driver
1510 in the drivers directory. The driver exports CFI flash
1511 to the MTD layer.
1512
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001513- CONFIG_SYS_FLASH_USE_BUFFER_WRITE
Guennadi Liakhovetski96ef8312008-04-03 13:36:02 +02001514 Use buffered writes to flash.
1515
1516- CONFIG_FLASH_SPANSION_S29WS_N
1517 s29ws-n MirrorBit flash has non-standard addresses for buffered
1518 write commands.
1519
Jerry Van Baren9a042e92008-03-08 13:48:01 -05001520- CONFIG_FLASH_SHOW_PROGRESS
1521 If defined (must be an integer), print out countdown
1522 digits and dots. Recommended value: 45 (9..1) for 80
1523 column displays, 15 (3..1) for 40 column displays.
1524
Stefan Roese352ef3f2013-04-04 15:53:14 +02001525- CONFIG_FLASH_VERIFY
1526 If defined, the content of the flash (destination) is compared
1527 against the source after the write operation. An error message
1528 will be printed when the contents are not identical.
1529 Please note that this option is useless in nearly all cases,
1530 since such flash programming errors usually are detected earlier
1531 while unprotecting/erasing/programming. Please only enable
1532 this option if you really know what you are doing.
1533
Joe Hershberger25980902012-12-11 22:16:31 -06001534- CONFIG_ENV_FLAGS_LIST_DEFAULT
1535- CONFIG_ENV_FLAGS_LIST_STATIC
Robert P. J. Day1bce2ae2013-09-16 07:15:45 -04001536 Enable validation of the values given to environment variables when
Joe Hershberger25980902012-12-11 22:16:31 -06001537 calling env set. Variables can be restricted to only decimal,
1538 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
1539 the variables can also be restricted to IP address or MAC address.
1540
1541 The format of the list is:
1542 type_attribute = [s|d|x|b|i|m]
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001543 access_attribute = [a|r|o|c]
1544 attributes = type_attribute[access_attribute]
Joe Hershberger25980902012-12-11 22:16:31 -06001545 entry = variable_name[:attributes]
1546 list = entry[,list]
1547
1548 The type attributes are:
1549 s - String (default)
1550 d - Decimal
1551 x - Hexadecimal
1552 b - Boolean ([1yYtT|0nNfF])
1553 i - IP address
1554 m - MAC address
1555
Joe Hershberger267541f2012-12-11 22:16:34 -06001556 The access attributes are:
1557 a - Any (default)
1558 r - Read-only
1559 o - Write-once
1560 c - Change-default
1561
Joe Hershberger25980902012-12-11 22:16:31 -06001562 - CONFIG_ENV_FLAGS_LIST_DEFAULT
1563 Define this to a list (string) to define the ".flags"
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001564 environment variable in the default or embedded environment.
Joe Hershberger25980902012-12-11 22:16:31 -06001565
1566 - CONFIG_ENV_FLAGS_LIST_STATIC
1567 Define this to a list (string) to define validation that
1568 should be done if an entry is not found in the ".flags"
1569 environment variable. To override a setting in the static
1570 list, simply add an entry for the same variable name to the
1571 ".flags" variable.
1572
Joe Hershbergerbdf1fe42015-05-20 14:27:20 -05001573 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
1574 regular expression. This allows multiple variables to define the same
1575 flags without explicitly listing them for each variable.
1576
wdenkc6097192002-11-03 00:24:07 +00001577The following definitions that deal with the placement and management
1578of environment data (variable area); in general, we support the
1579following configurations:
1580
Mike Frysingerc3eb3fe2011-07-08 10:44:25 +00001581- CONFIG_BUILD_ENVCRC:
1582
1583 Builds up envcrc with the target environment so that external utils
1584 may easily extract it and embed it in final U-Boot images.
1585
wdenkc6097192002-11-03 00:24:07 +00001586BE CAREFUL! The first access to the environment happens quite early
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001587in U-Boot initialization (when we try to get the setting of for the
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001588console baudrate). You *MUST* have mapped your NVRAM area then, or
wdenkc6097192002-11-03 00:24:07 +00001589U-Boot will hang.
1590
1591Please note that even with NVRAM we still use a copy of the
1592environment in RAM: we could work on NVRAM directly, but we want to
1593keep settings there always unmodified except somebody uses "saveenv"
1594to save the current settings.
1595
Liu Gang0a85a9e2012-03-08 00:33:20 +00001596BE CAREFUL! For some special cases, the local device can not use
1597"saveenv" command. For example, the local device will get the
Liu Gangfc54c7f2012-08-09 05:10:01 +00001598environment stored in a remote NOR flash by SRIO or PCIE link,
1599but it can not erase, write this NOR flash by SRIO or PCIE interface.
Liu Gang0a85a9e2012-03-08 00:33:20 +00001600
Guennadi Liakhovetskib74ab732009-05-18 16:07:22 +02001601- CONFIG_NAND_ENV_DST
1602
1603 Defines address in RAM to which the nand_spl code should copy the
1604 environment. If redundant environment is used, it will be copied to
1605 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
1606
Bruce Adlere881cb52007-11-02 13:15:42 -07001607Please note that the environment is read-only until the monitor
wdenkc6097192002-11-03 00:24:07 +00001608has been relocated to RAM and a RAM copy of the environment has been
Simon Glass00caae62017-08-03 12:22:12 -06001609created; also, when using EEPROM you will have to use env_get_f()
wdenkc6097192002-11-03 00:24:07 +00001610until then to read environment variables.
1611
wdenk85ec0bc2003-03-31 16:34:49 +00001612The environment is protected by a CRC32 checksum. Before the monitor
1613is relocated into RAM, as a result of a bad CRC you will be working
1614with the compiled-in default environment - *silently*!!! [This is
1615necessary, because the first environment variable we need is the
1616"baudrate" setting for the console - if we have a bad CRC, we don't
1617have any device yet where we could complain.]
wdenkc6097192002-11-03 00:24:07 +00001618
1619Note: once the monitor has been relocated, then it will complain if
1620the default environment is used; a new CRC is computed as soon as you
wdenk85ec0bc2003-03-31 16:34:49 +00001621use the "saveenv" command to store a valid environment.
wdenkc6097192002-11-03 00:24:07 +00001622
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001623- CONFIG_SYS_FAULT_MII_ADDR:
wdenk42d1f032003-10-15 23:53:47 +00001624 MII address of the PHY to check for the Ethernet link state.
wdenkc6097192002-11-03 00:24:07 +00001625
Ron Madridf5675aa2009-02-18 14:30:44 -08001626- CONFIG_NS16550_MIN_FUNCTIONS:
1627 Define this if you desire to only have use of the NS16550_init
1628 and NS16550_putc functions for the serial driver located at
1629 drivers/serial/ns16550.c. This option is useful for saving
1630 space for already greatly restricted images, including but not
1631 limited to NAND_SPL configurations.
1632
Simon Glassb2b92f52012-11-30 13:01:18 +00001633- CONFIG_DISPLAY_BOARDINFO
1634 Display information about the board that U-Boot is running on
1635 when U-Boot starts up. The board function checkboard() is called
1636 to do this.
1637
Simon Glasse2e3e2b2012-11-30 13:01:19 +00001638- CONFIG_DISPLAY_BOARDINFO_LATE
1639 Similar to the previous option, but display this information
1640 later, once stdio is running and output goes to the LCD, if
1641 present.
1642
wdenkc6097192002-11-03 00:24:07 +00001643Low Level (hardware related) configuration options:
wdenkdc7c9a12003-03-26 06:55:25 +00001644---------------------------------------------------
wdenkc6097192002-11-03 00:24:07 +00001645
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001646- CONFIG_SYS_CACHELINE_SIZE:
wdenkc6097192002-11-03 00:24:07 +00001647 Cache Line Size of the CPU.
1648
Timur Tabie46fedf2011-08-04 18:03:41 -05001649- CONFIG_SYS_CCSRBAR_DEFAULT:
1650 Default (power-on reset) physical address of CCSR on Freescale
1651 PowerPC SOCs.
1652
1653- CONFIG_SYS_CCSRBAR:
1654 Virtual address of CCSR. On a 32-bit build, this is typically
1655 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
1656
Timur Tabie46fedf2011-08-04 18:03:41 -05001657- CONFIG_SYS_CCSRBAR_PHYS:
1658 Physical address of CCSR. CCSR can be relocated to a new
1659 physical address, if desired. In this case, this macro should
Wolfgang Denkc0f40852011-10-26 10:21:21 +00001660 be set to that address. Otherwise, it should be set to the
Timur Tabie46fedf2011-08-04 18:03:41 -05001661 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
1662 is typically relocated on 36-bit builds. It is recommended
1663 that this macro be defined via the _HIGH and _LOW macros:
1664
1665 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
1666 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
1667
1668- CONFIG_SYS_CCSRBAR_PHYS_HIGH:
Wolfgang Denk4cf26092011-10-07 09:58:21 +02001669 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
1670 either 0 (32-bit build) or 0xF (36-bit build). This macro is
Timur Tabie46fedf2011-08-04 18:03:41 -05001671 used in assembly code, so it must not contain typecasts or
1672 integer size suffixes (e.g. "ULL").
1673
1674- CONFIG_SYS_CCSRBAR_PHYS_LOW:
1675 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
1676 used in assembly code, so it must not contain typecasts or
1677 integer size suffixes (e.g. "ULL").
1678
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001679- CONFIG_SYS_IMMR: Physical address of the Internal Memory.
wdenkefe2a4d2004-12-16 21:44:03 +00001680 DO NOT CHANGE unless you know exactly what you're
Christophe Leroy907208c2017-07-06 10:23:22 +02001681 doing! (11-4) [MPC8xx systems only]
wdenkc6097192002-11-03 00:24:07 +00001682
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001683- CONFIG_SYS_INIT_RAM_ADDR:
wdenkc6097192002-11-03 00:24:07 +00001684
wdenk7152b1d2003-09-05 23:19:14 +00001685 Start address of memory area that can be used for
wdenkc6097192002-11-03 00:24:07 +00001686 initial data and stack; please note that this must be
1687 writable memory that is working WITHOUT special
1688 initialization, i. e. you CANNOT use normal RAM which
1689 will become available only after programming the
1690 memory controller and running certain initialization
1691 sequences.
1692
1693 U-Boot uses the following memory types:
Christophe Leroy907208c2017-07-06 10:23:22 +02001694 - MPC8xx: IMMR (internal memory of the CPU)
wdenkc6097192002-11-03 00:24:07 +00001695
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001696- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
wdenkc6097192002-11-03 00:24:07 +00001697
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001698- CONFIG_SYS_OR_TIMING_SDRAM:
wdenkc6097192002-11-03 00:24:07 +00001699 SDRAM timing
1700
Kumar Galaa09b9b62010-12-30 12:09:53 -06001701- CONFIG_SYS_SRIO:
1702 Chip has SRIO or not
1703
1704- CONFIG_SRIO1:
1705 Board has SRIO 1 port available
1706
1707- CONFIG_SRIO2:
1708 Board has SRIO 2 port available
1709
Liu Gangc8b28152013-05-07 16:30:46 +08001710- CONFIG_SRIO_PCIE_BOOT_MASTER
1711 Board can support master function for Boot from SRIO and PCIE
1712
Kumar Galaa09b9b62010-12-30 12:09:53 -06001713- CONFIG_SYS_SRIOn_MEM_VIRT:
1714 Virtual Address of SRIO port 'n' memory region
1715
Simon Glass62f9b652019-11-14 12:57:09 -07001716- CONFIG_SYS_SRIOn_MEM_PHYxS:
Kumar Galaa09b9b62010-12-30 12:09:53 -06001717 Physical Address of SRIO port 'n' memory region
1718
1719- CONFIG_SYS_SRIOn_MEM_SIZE:
1720 Size of SRIO port 'n' memory region
1721
Fabio Estevam66bd1842013-04-11 09:35:34 +00001722- CONFIG_SYS_NAND_BUSWIDTH_16BIT
1723 Defined to tell the NAND controller that the NAND chip is using
1724 a 16 bit bus.
1725 Not all NAND drivers use this symbol.
Fabio Estevama430e912013-04-11 09:35:35 +00001726 Example of drivers that use it:
Miquel Raynala430fa02018-08-16 17:30:07 +02001727 - drivers/mtd/nand/raw/ndfc.c
1728 - drivers/mtd/nand/raw/mxc_nand.c
Alex Watermaneced4622011-05-19 15:08:36 -04001729
1730- CONFIG_SYS_NDFC_EBC0_CFG
1731 Sets the EBC0_CFG register for the NDFC. If not defined
1732 a default value will be used.
1733
Ben Warrenbb99ad62006-09-07 16:50:54 -04001734- CONFIG_SPD_EEPROM
Wolfgang Denk218ca722008-03-26 10:40:12 +01001735 Get DDR timing information from an I2C EEPROM. Common
1736 with pluggable memory modules such as SODIMMs
1737
Ben Warrenbb99ad62006-09-07 16:50:54 -04001738 SPD_EEPROM_ADDRESS
1739 I2C address of the SPD EEPROM
1740
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001741- CONFIG_SYS_SPD_BUS_NUM
Wolfgang Denk218ca722008-03-26 10:40:12 +01001742 If SPD EEPROM is on an I2C bus other than the first
1743 one, specify here. Note that the value must resolve
1744 to something your driver can deal with.
Ben Warrenbb99ad62006-09-07 16:50:54 -04001745
York Sun6f5e1dc2011-09-16 13:21:35 -07001746- CONFIG_FSL_DDR_INTERACTIVE
1747 Enable interactive DDR debugging. See doc/README.fsl-ddr.
1748
York Sune32d59a2015-01-06 13:18:55 -08001749- CONFIG_FSL_DDR_SYNC_REFRESH
1750 Enable sync of refresh for multiple controllers.
1751
York Sun4516ff82015-03-19 09:30:28 -07001752- CONFIG_FSL_DDR_BIST
1753 Enable built-in memory test for Freescale DDR controllers.
1754
wdenkc26e4542004-04-18 10:13:26 +00001755- CONFIG_RMII
1756 Enable RMII mode for all FECs.
1757 Note that this is a global option, we can't
1758 have one FEC in standard MII mode and another in RMII mode.
1759
wdenk5cf91d62004-04-23 20:32:05 +00001760- CONFIG_CRC32_VERIFY
1761 Add a verify option to the crc32 command.
1762 The syntax is:
1763
1764 => crc32 -v <address> <count> <crc32>
1765
1766 Where address/count indicate a memory area
1767 and crc32 is the correct crc32 which the
1768 area should have.
1769
wdenk56523f12004-07-11 17:40:54 +00001770- CONFIG_LOOPW
1771 Add the "loopw" memory command. This only takes effect if
Simon Glass493f4202017-08-04 16:34:27 -06001772 the memory commands are activated globally (CONFIG_CMD_MEMORY).
wdenk56523f12004-07-11 17:40:54 +00001773
Joel Johnson72732312020-01-29 09:17:18 -07001774- CONFIG_CMD_MX_CYCLIC
stroese7b466642004-12-16 18:46:55 +00001775 Add the "mdc" and "mwc" memory commands. These are cyclic
1776 "md/mw" commands.
1777 Examples:
1778
wdenkefe2a4d2004-12-16 21:44:03 +00001779 => mdc.b 10 4 500
stroese7b466642004-12-16 18:46:55 +00001780 This command will print 4 bytes (10,11,12,13) each 500 ms.
1781
wdenkefe2a4d2004-12-16 21:44:03 +00001782 => mwc.l 100 12345678 10
stroese7b466642004-12-16 18:46:55 +00001783 This command will write 12345678 to address 100 all 10 ms.
1784
wdenkefe2a4d2004-12-16 21:44:03 +00001785 This only takes effect if the memory commands are activated
Simon Glass493f4202017-08-04 16:34:27 -06001786 globally (CONFIG_CMD_MEMORY).
stroese7b466642004-12-16 18:46:55 +00001787
Aneesh V401bb302011-07-13 05:11:07 +00001788- CONFIG_SPL_BUILD
Thomas Hebb32f2ca22019-11-13 18:18:03 -08001789 Set when the currently-running compilation is for an artifact
1790 that will end up in the SPL (as opposed to the TPL or U-Boot
1791 proper). Code that needs stage-specific behavior should check
1792 this.
wdenk400558b2005-04-02 23:52:25 +00001793
Ying Zhang3aa29de2013-08-16 15:16:15 +08001794- CONFIG_TPL_BUILD
Thomas Hebb32f2ca22019-11-13 18:18:03 -08001795 Set when the currently-running compilation is for an artifact
1796 that will end up in the TPL (as opposed to the SPL or U-Boot
1797 proper). Code that needs stage-specific behavior should check
1798 this.
Ying Zhang3aa29de2013-08-16 15:16:15 +08001799
Simon Glass4213fc22013-02-24 17:33:14 +00001800- CONFIG_ARCH_MAP_SYSMEM
1801 Generally U-Boot (and in particular the md command) uses
1802 effective address. It is therefore not necessary to regard
1803 U-Boot address as virtual addresses that need to be translated
1804 to physical addresses. However, sandbox requires this, since
1805 it maintains its own little RAM buffer which contains all
1806 addressable memory. This option causes some memory accesses
1807 to be mapped through map_sysmem() / unmap_sysmem().
1808
Simon Glass588a13f2013-02-14 04:18:54 +00001809- CONFIG_X86_RESET_VECTOR
1810 If defined, the x86 reset vector code is included. This is not
1811 needed when U-Boot is running from Coreboot.
Gabe Blackb16f5212012-11-27 21:08:06 +00001812
Karicheri, Muralidharan999d7d32014-04-04 13:16:50 -04001813- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
1814 Option to disable subpage write in NAND driver
1815 driver that uses this:
Miquel Raynala430fa02018-08-16 17:30:07 +02001816 drivers/mtd/nand/raw/davinci_nand.c
Karicheri, Muralidharan999d7d32014-04-04 13:16:50 -04001817
Timur Tabif2717b42011-11-22 09:21:25 -06001818Freescale QE/FMAN Firmware Support:
1819-----------------------------------
1820
1821The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
1822loading of "firmware", which is encoded in the QE firmware binary format.
1823This firmware often needs to be loaded during U-Boot booting, so macros
1824are used to identify the storage device (NOR flash, SPI, etc) and the address
1825within that device.
1826
Zhao Qiangdcf1d772014-03-21 16:21:44 +08001827- CONFIG_SYS_FMAN_FW_ADDR
1828 The address in the storage device where the FMAN microcode is located. The
Tom Rinicc1e98b2019-05-12 07:59:12 -04001829 meaning of this address depends on which CONFIG_SYS_QE_FMAN_FW_IN_xxx macro
Zhao Qiangdcf1d772014-03-21 16:21:44 +08001830 is also specified.
1831
1832- CONFIG_SYS_QE_FW_ADDR
1833 The address in the storage device where the QE microcode is located. The
Tom Rinicc1e98b2019-05-12 07:59:12 -04001834 meaning of this address depends on which CONFIG_SYS_QE_FMAN_FW_IN_xxx macro
Timur Tabif2717b42011-11-22 09:21:25 -06001835 is also specified.
1836
1837- CONFIG_SYS_QE_FMAN_FW_LENGTH
1838 The maximum possible size of the firmware. The firmware binary format
1839 has a field that specifies the actual size of the firmware, but it
1840 might not be possible to read any part of the firmware unless some
1841 local storage is allocated to hold the entire firmware first.
1842
1843- CONFIG_SYS_QE_FMAN_FW_IN_NOR
1844 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
1845 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
1846 virtual address in NOR flash.
1847
1848- CONFIG_SYS_QE_FMAN_FW_IN_NAND
1849 Specifies that QE/FMAN firmware is located in NAND flash.
1850 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
1851
1852- CONFIG_SYS_QE_FMAN_FW_IN_MMC
1853 Specifies that QE/FMAN firmware is located on the primary SD/MMC
1854 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
1855
Liu Gang292dc6c2012-03-08 00:33:18 +00001856- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
1857 Specifies that QE/FMAN firmware is located in the remote (master)
1858 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
Liu Gangfc54c7f2012-08-09 05:10:01 +00001859 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
1860 window->master inbound window->master LAW->the ucode address in
1861 master's memory space.
Timur Tabif2717b42011-11-22 09:21:25 -06001862
J. German Riverab940ca62014-06-23 15:15:55 -07001863Freescale Layerscape Management Complex Firmware Support:
1864---------------------------------------------------------
1865The Freescale Layerscape Management Complex (MC) supports the loading of
1866"firmware".
1867This firmware often needs to be loaded during U-Boot booting, so macros
1868are used to identify the storage device (NOR flash, SPI, etc) and the address
1869within that device.
1870
1871- CONFIG_FSL_MC_ENET
1872 Enable the MC driver for Layerscape SoCs.
1873
Prabhakar Kushwaha5c055082015-06-02 10:55:52 +05301874Freescale Layerscape Debug Server Support:
1875-------------------------------------------
1876The Freescale Layerscape Debug Server Support supports the loading of
1877"Debug Server firmware" and triggering SP boot-rom.
1878This firmware often needs to be loaded during U-Boot booting.
1879
York Sunc0492142015-12-07 11:08:58 -08001880- CONFIG_SYS_MC_RSV_MEM_ALIGN
1881 Define alignment of reserved memory MC requires
Prabhakar Kushwaha5c055082015-06-02 10:55:52 +05301882
Paul Kocialkowskif3f431a2015-07-26 18:48:15 +02001883Reproducible builds
1884-------------------
1885
1886In order to achieve reproducible builds, timestamps used in the U-Boot build
1887process have to be set to a fixed value.
1888
1889This is done using the SOURCE_DATE_EPOCH environment variable.
1890SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
1891option for U-Boot or an environment variable in U-Boot.
1892
1893SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
1894
wdenkc6097192002-11-03 00:24:07 +00001895Building the Software:
1896======================
1897
Wolfgang Denk218ca722008-03-26 10:40:12 +01001898Building U-Boot has been tested in several native build environments
1899and in many different cross environments. Of course we cannot support
1900all possibly existing versions of cross development tools in all
1901(potentially obsolete) versions. In case of tool chain problems we
Naoki Hayama047f6ec2020-10-08 13:17:16 +09001902recommend to use the ELDK (see https://www.denx.de/wiki/DULG/ELDK)
Wolfgang Denk218ca722008-03-26 10:40:12 +01001903which is extensively used to build and test U-Boot.
wdenkc6097192002-11-03 00:24:07 +00001904
Wolfgang Denk218ca722008-03-26 10:40:12 +01001905If you are not using a native environment, it is assumed that you
1906have GNU cross compiling tools available in your path. In this case,
1907you must set the environment variable CROSS_COMPILE in your shell.
1908Note that no changes to the Makefile or any other source files are
1909necessary. For example using the ELDK on a 4xx CPU, please enter:
wdenkc6097192002-11-03 00:24:07 +00001910
Wolfgang Denk218ca722008-03-26 10:40:12 +01001911 $ CROSS_COMPILE=ppc_4xx-
1912 $ export CROSS_COMPILE
wdenkc6097192002-11-03 00:24:07 +00001913
Wolfgang Denk218ca722008-03-26 10:40:12 +01001914U-Boot is intended to be simple to build. After installing the
1915sources you must configure U-Boot for one specific board type. This
wdenkc6097192002-11-03 00:24:07 +00001916is done by typing:
1917
Holger Freytherab584d62014-08-04 09:26:05 +02001918 make NAME_defconfig
wdenkc6097192002-11-03 00:24:07 +00001919
Holger Freytherab584d62014-08-04 09:26:05 +02001920where "NAME_defconfig" is the name of one of the existing configu-
Heinrich Schuchardtecb3a0a2020-02-24 18:36:30 +01001921rations; see configs/*_defconfig for supported names.
wdenk54387ac2003-10-08 22:45:44 +00001922
Heinrich Schuchardtecb3a0a2020-02-24 18:36:30 +01001923Note: for some boards special configuration names may exist; check if
wdenk2729af92004-05-03 20:45:30 +00001924 additional information is available from the board vendor; for
1925 instance, the TQM823L systems are available without (standard)
1926 or with LCD support. You can select such additional "features"
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001927 when choosing the configuration, i. e.
wdenkc6097192002-11-03 00:24:07 +00001928
Holger Freytherab584d62014-08-04 09:26:05 +02001929 make TQM823L_defconfig
wdenk2729af92004-05-03 20:45:30 +00001930 - will configure for a plain TQM823L, i. e. no LCD support
wdenkc6097192002-11-03 00:24:07 +00001931
Holger Freytherab584d62014-08-04 09:26:05 +02001932 make TQM823L_LCD_defconfig
wdenk2729af92004-05-03 20:45:30 +00001933 - will configure for a TQM823L with U-Boot console on LCD
wdenkc6097192002-11-03 00:24:07 +00001934
wdenk2729af92004-05-03 20:45:30 +00001935 etc.
wdenkc6097192002-11-03 00:24:07 +00001936
wdenkc6097192002-11-03 00:24:07 +00001937
wdenk2729af92004-05-03 20:45:30 +00001938Finally, type "make all", and you should get some working U-Boot
1939images ready for download to / installation on your system:
wdenkc6097192002-11-03 00:24:07 +00001940
wdenk2729af92004-05-03 20:45:30 +00001941- "u-boot.bin" is a raw binary image
1942- "u-boot" is an image in ELF binary format
1943- "u-boot.srec" is in Motorola S-Record format
wdenkc6097192002-11-03 00:24:07 +00001944
Marian Balakowiczbaf31242006-09-07 17:25:40 +02001945By default the build is performed locally and the objects are saved
1946in the source directory. One of the two methods can be used to change
1947this behavior and build U-Boot to some external directory:
1948
19491. Add O= to the make command line invocations:
1950
1951 make O=/tmp/build distclean
Holger Freytherab584d62014-08-04 09:26:05 +02001952 make O=/tmp/build NAME_defconfig
Marian Balakowiczbaf31242006-09-07 17:25:40 +02001953 make O=/tmp/build all
1954
Timo Ketolaadbba992014-11-06 14:39:05 +020019552. Set environment variable KBUILD_OUTPUT to point to the desired location:
Marian Balakowiczbaf31242006-09-07 17:25:40 +02001956
Timo Ketolaadbba992014-11-06 14:39:05 +02001957 export KBUILD_OUTPUT=/tmp/build
Marian Balakowiczbaf31242006-09-07 17:25:40 +02001958 make distclean
Holger Freytherab584d62014-08-04 09:26:05 +02001959 make NAME_defconfig
Marian Balakowiczbaf31242006-09-07 17:25:40 +02001960 make all
1961
Timo Ketolaadbba992014-11-06 14:39:05 +02001962Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
Marian Balakowiczbaf31242006-09-07 17:25:40 +02001963variable.
1964
Daniel Schwierzeck215bb1c2018-01-26 16:31:04 +01001965User specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by
1966setting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS.
1967For example to treat all compiler warnings as errors:
1968
1969 make KCFLAGS=-Werror
wdenkc6097192002-11-03 00:24:07 +00001970
wdenk2729af92004-05-03 20:45:30 +00001971Please be aware that the Makefiles assume you are using GNU make, so
1972for instance on NetBSD you might need to use "gmake" instead of
1973native "make".
wdenkc6097192002-11-03 00:24:07 +00001974
wdenkc6097192002-11-03 00:24:07 +00001975
wdenk2729af92004-05-03 20:45:30 +00001976If the system board that you have is not listed, then you will need
1977to port U-Boot to your hardware platform. To do this, follow these
1978steps:
wdenkc6097192002-11-03 00:24:07 +00001979
Phil Sutter3c1496c2015-12-25 14:41:18 +010019801. Create a new directory to hold your board specific code. Add any
wdenk2729af92004-05-03 20:45:30 +00001981 files you need. In your board directory, you will need at least
Phil Sutter3c1496c2015-12-25 14:41:18 +01001982 the "Makefile" and a "<board>.c".
19832. Create a new configuration file "include/configs/<board>.h" for
1984 your board.
wdenk2729af92004-05-03 20:45:30 +000019853. If you're porting U-Boot to a new CPU, then also create a new
1986 directory to hold your CPU specific code. Add any files you need.
Holger Freytherab584d62014-08-04 09:26:05 +020019874. Run "make <board>_defconfig" with your new name.
wdenk2729af92004-05-03 20:45:30 +000019885. Type "make", and you should get a working "u-boot.srec" file
1989 to be installed on your target system.
19906. Debug and solve any problems that might arise.
1991 [Of course, this last step is much harder than it sounds.]
wdenkc6097192002-11-03 00:24:07 +00001992
wdenkc6097192002-11-03 00:24:07 +00001993
wdenk2729af92004-05-03 20:45:30 +00001994Testing of U-Boot Modifications, Ports to New Hardware, etc.:
1995==============================================================
wdenkc6097192002-11-03 00:24:07 +00001996
Wolfgang Denk218ca722008-03-26 10:40:12 +01001997If you have modified U-Boot sources (for instance added a new board
1998or support for new devices, a new CPU, etc.) you are expected to
wdenk2729af92004-05-03 20:45:30 +00001999provide feedback to the other developers. The feedback normally takes
Thomas Hebb32f2ca22019-11-13 18:18:03 -08002000the form of a "patch", i.e. a context diff against a certain (latest
Wolfgang Denk218ca722008-03-26 10:40:12 +01002001official or latest in the git repository) version of U-Boot sources.
wdenkc6097192002-11-03 00:24:07 +00002002
Wolfgang Denk218ca722008-03-26 10:40:12 +01002003But before you submit such a patch, please verify that your modifi-
2004cation did not break existing code. At least make sure that *ALL* of
wdenk2729af92004-05-03 20:45:30 +00002005the supported boards compile WITHOUT ANY compiler warnings. To do so,
Simon Glass6de80f22016-07-27 20:33:08 -06002006just run the buildman script (tools/buildman/buildman), which will
2007configure and build U-Boot for ALL supported system. Be warned, this
2008will take a while. Please see the buildman README, or run 'buildman -H'
2009for documentation.
Marian Balakowiczbaf31242006-09-07 17:25:40 +02002010
2011
wdenk2729af92004-05-03 20:45:30 +00002012See also "U-Boot Porting Guide" below.
wdenkc6097192002-11-03 00:24:07 +00002013
wdenkc6097192002-11-03 00:24:07 +00002014
wdenk2729af92004-05-03 20:45:30 +00002015Monitor Commands - Overview:
2016============================
wdenkc6097192002-11-03 00:24:07 +00002017
wdenk2729af92004-05-03 20:45:30 +00002018go - start application at address 'addr'
2019run - run commands in an environment variable
2020bootm - boot application image from memory
2021bootp - boot image via network using BootP/TFTP protocol
Marek Vasut44f074c2012-03-14 21:52:45 +00002022bootz - boot zImage from memory
wdenk2729af92004-05-03 20:45:30 +00002023tftpboot- boot image via network using TFTP protocol
2024 and env variables "ipaddr" and "serverip"
2025 (and eventually "gatewayip")
Simon Glass1fb7cd42011-10-24 18:00:07 +00002026tftpput - upload a file via network using TFTP protocol
wdenk2729af92004-05-03 20:45:30 +00002027rarpboot- boot image via network using RARP/TFTP protocol
2028diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2029loads - load S-Record file over serial line
2030loadb - load binary file over serial line (kermit mode)
Rui Miguel Silvabfef72e2022-05-11 10:55:40 +01002031loadm - load binary blob from source address to destination address
wdenk2729af92004-05-03 20:45:30 +00002032md - memory display
2033mm - memory modify (auto-incrementing)
2034nm - memory modify (constant address)
2035mw - memory write (fill)
Simon Glassbdded202020-06-02 19:26:49 -06002036ms - memory search
wdenk2729af92004-05-03 20:45:30 +00002037cp - memory copy
2038cmp - memory compare
2039crc32 - checksum calculation
Peter Tyser0f89c542009-04-18 22:34:03 -05002040i2c - I2C sub-system
wdenk2729af92004-05-03 20:45:30 +00002041sspi - SPI utility commands
2042base - print or set address offset
2043printenv- print environment variables
Pragnesh Patel9e9a5302020-12-22 11:30:05 +05302044pwm - control pwm channels
wdenk2729af92004-05-03 20:45:30 +00002045setenv - set environment variables
2046saveenv - save environment variables to persistent storage
2047protect - enable or disable FLASH write protection
2048erase - erase FLASH memory
2049flinfo - print FLASH memory information
Karl O. Pinc10635af2012-08-03 05:57:21 +00002050nand - NAND memory operations (see doc/README.nand)
wdenk2729af92004-05-03 20:45:30 +00002051bdinfo - print Board Info structure
2052iminfo - print header information for application image
2053coninfo - print console devices and informations
2054ide - IDE sub-system
2055loop - infinite loop on address range
wdenk56523f12004-07-11 17:40:54 +00002056loopw - infinite write loop on address range
wdenk2729af92004-05-03 20:45:30 +00002057mtest - simple RAM test
2058icache - enable or disable instruction cache
2059dcache - enable or disable data cache
2060reset - Perform RESET of the CPU
2061echo - echo args to console
2062version - print monitor version
2063help - print online help
2064? - alias for 'help'
wdenkc6097192002-11-03 00:24:07 +00002065
wdenkc6097192002-11-03 00:24:07 +00002066
wdenk2729af92004-05-03 20:45:30 +00002067Monitor Commands - Detailed Description:
2068========================================
wdenkc6097192002-11-03 00:24:07 +00002069
wdenk2729af92004-05-03 20:45:30 +00002070TODO.
wdenkc6097192002-11-03 00:24:07 +00002071
wdenk2729af92004-05-03 20:45:30 +00002072For now: just type "help <command>".
wdenkc6097192002-11-03 00:24:07 +00002073
2074
wdenk2729af92004-05-03 20:45:30 +00002075Note for Redundant Ethernet Interfaces:
2076=======================================
wdenkf07771c2003-05-28 08:06:31 +00002077
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002078Some boards come with redundant Ethernet interfaces; U-Boot supports
wdenk2729af92004-05-03 20:45:30 +00002079such configurations and is capable of automatic selection of a
2080"working" interface when needed. MAC assignment works as follows:
wdenkf07771c2003-05-28 08:06:31 +00002081
wdenk2729af92004-05-03 20:45:30 +00002082Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2083MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2084"eth1addr" (=>eth1), "eth2addr", ...
wdenkf07771c2003-05-28 08:06:31 +00002085
wdenk2729af92004-05-03 20:45:30 +00002086If the network interface stores some valid MAC address (for instance
2087in SROM), this is used as default address if there is NO correspon-
2088ding setting in the environment; if the corresponding environment
2089variable is set, this overrides the settings in the card; that means:
wdenkf07771c2003-05-28 08:06:31 +00002090
wdenk2729af92004-05-03 20:45:30 +00002091o If the SROM has a valid MAC address, and there is no address in the
2092 environment, the SROM's address is used.
wdenkc6097192002-11-03 00:24:07 +00002093
wdenk2729af92004-05-03 20:45:30 +00002094o If there is no valid address in the SROM, and a definition in the
2095 environment exists, then the value from the environment variable is
2096 used.
wdenkc6097192002-11-03 00:24:07 +00002097
wdenk2729af92004-05-03 20:45:30 +00002098o If both the SROM and the environment contain a MAC address, and
2099 both addresses are the same, this MAC address is used.
wdenkc6097192002-11-03 00:24:07 +00002100
wdenk2729af92004-05-03 20:45:30 +00002101o If both the SROM and the environment contain a MAC address, and the
2102 addresses differ, the value from the environment is used and a
2103 warning is printed.
wdenkc6097192002-11-03 00:24:07 +00002104
wdenk2729af92004-05-03 20:45:30 +00002105o If neither SROM nor the environment contain a MAC address, an error
Joe Hershbergerbef10142015-05-04 14:55:13 -05002106 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
2107 a random, locally-assigned MAC is used.
wdenkc6097192002-11-03 00:24:07 +00002108
Ben Warrenecee9322010-04-26 11:11:46 -07002109If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
Wolfgang Denkc0f40852011-10-26 10:21:21 +00002110will be programmed into hardware as part of the initialization process. This
Ben Warrenecee9322010-04-26 11:11:46 -07002111may be skipped by setting the appropriate 'ethmacskip' environment variable.
2112The naming convention is as follows:
2113"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
wdenkc6097192002-11-03 00:24:07 +00002114
wdenk2729af92004-05-03 20:45:30 +00002115Image Formats:
2116==============
wdenkc6097192002-11-03 00:24:07 +00002117
Marian Balakowicz3310c542008-03-12 12:13:13 +01002118U-Boot is capable of booting (and performing other auxiliary operations on)
2119images in two formats:
2120
2121New uImage format (FIT)
2122-----------------------
2123
2124Flexible and powerful format based on Flattened Image Tree -- FIT (similar
2125to Flattened Device Tree). It allows the use of images with multiple
2126components (several kernels, ramdisks, etc.), with contents protected by
2127SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
2128
2129
2130Old uImage format
2131-----------------
2132
2133Old image format is based on binary files which can be basically anything,
2134preceded by a special header; see the definitions in include/image.h for
2135details; basically, the header defines the following image properties:
wdenkc6097192002-11-03 00:24:07 +00002136
wdenk2729af92004-05-03 20:45:30 +00002137* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2138 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
Peter Tyserf5ed9e32008-09-08 14:56:49 -05002139 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
Thomas Huth0797e732021-11-13 18:13:50 +01002140 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, INTEGRITY).
Andy Shevchenkodaab59a2017-07-05 16:25:22 +03002141* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
Tom Rini11232132022-04-06 09:21:25 -04002142 IA64, MIPS, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2143 Currently supported: ARM, Intel x86, MIPS, Nios II, PowerPC).
wdenk2729af92004-05-03 20:45:30 +00002144* Compression Type (uncompressed, gzip, bzip2)
2145* Load Address
2146* Entry Point
2147* Image Name
2148* Image Timestamp
wdenkc6097192002-11-03 00:24:07 +00002149
wdenk2729af92004-05-03 20:45:30 +00002150The header is marked by a special Magic Number, and both the header
2151and the data portions of the image are secured against corruption by
2152CRC32 checksums.
wdenkc6097192002-11-03 00:24:07 +00002153
wdenkc6097192002-11-03 00:24:07 +00002154
wdenk2729af92004-05-03 20:45:30 +00002155Linux Support:
2156==============
wdenkc6097192002-11-03 00:24:07 +00002157
wdenk2729af92004-05-03 20:45:30 +00002158Although U-Boot should support any OS or standalone application
2159easily, the main focus has always been on Linux during the design of
2160U-Boot.
wdenkc6097192002-11-03 00:24:07 +00002161
wdenk2729af92004-05-03 20:45:30 +00002162U-Boot includes many features that so far have been part of some
2163special "boot loader" code within the Linux kernel. Also, any
2164"initrd" images to be used are no longer part of one big Linux image;
2165instead, kernel and "initrd" are separate images. This implementation
2166serves several purposes:
wdenkc6097192002-11-03 00:24:07 +00002167
wdenk2729af92004-05-03 20:45:30 +00002168- the same features can be used for other OS or standalone
2169 applications (for instance: using compressed images to reduce the
2170 Flash memory footprint)
wdenkc6097192002-11-03 00:24:07 +00002171
wdenk2729af92004-05-03 20:45:30 +00002172- it becomes much easier to port new Linux kernel versions because
2173 lots of low-level, hardware dependent stuff are done by U-Boot
wdenkc6097192002-11-03 00:24:07 +00002174
wdenk2729af92004-05-03 20:45:30 +00002175- the same Linux kernel image can now be used with different "initrd"
2176 images; of course this also means that different kernel images can
2177 be run with the same "initrd". This makes testing easier (you don't
2178 have to build a new "zImage.initrd" Linux image when you just
2179 change a file in your "initrd"). Also, a field-upgrade of the
2180 software is easier now.
wdenkc6097192002-11-03 00:24:07 +00002181
wdenkc6097192002-11-03 00:24:07 +00002182
wdenk2729af92004-05-03 20:45:30 +00002183Linux HOWTO:
2184============
wdenkc6097192002-11-03 00:24:07 +00002185
wdenk2729af92004-05-03 20:45:30 +00002186Porting Linux to U-Boot based systems:
2187---------------------------------------
wdenkc6097192002-11-03 00:24:07 +00002188
wdenk2729af92004-05-03 20:45:30 +00002189U-Boot cannot save you from doing all the necessary modifications to
2190configure the Linux device drivers for use with your target hardware
2191(no, we don't intend to provide a full virtual machine interface to
2192Linux :-).
wdenkc6097192002-11-03 00:24:07 +00002193
Stefan Roesea47a12b2010-04-15 16:07:28 +02002194But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
wdenkc6097192002-11-03 00:24:07 +00002195
wdenk2729af92004-05-03 20:45:30 +00002196Just make sure your machine specific header file (for instance
2197include/asm-ppc/tqm8xx.h) includes the same definition of the Board
Markus Heidelberg1dc30692008-09-07 20:18:27 +02002198Information structure as we define in include/asm-<arch>/u-boot.h,
2199and make sure that your definition of IMAP_ADDR uses the same value
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002200as your U-Boot configuration in CONFIG_SYS_IMMR.
wdenkc6097192002-11-03 00:24:07 +00002201
Simon Glass2eb31b12014-06-11 23:29:46 -06002202Note that U-Boot now has a driver model, a unified model for drivers.
2203If you are adding a new driver, plumb it into driver model. If there
2204is no uclass available, you are encouraged to create one. See
2205doc/driver-model.
2206
wdenkc6097192002-11-03 00:24:07 +00002207
wdenk2729af92004-05-03 20:45:30 +00002208Configuring the Linux kernel:
2209-----------------------------
wdenkc6097192002-11-03 00:24:07 +00002210
wdenk2729af92004-05-03 20:45:30 +00002211No specific requirements for U-Boot. Make sure you have some root
2212device (initial ramdisk, NFS) for your target system.
wdenkc6097192002-11-03 00:24:07 +00002213
wdenkc6097192002-11-03 00:24:07 +00002214
wdenk2729af92004-05-03 20:45:30 +00002215Building a Linux Image:
2216-----------------------
wdenkc6097192002-11-03 00:24:07 +00002217
wdenk2729af92004-05-03 20:45:30 +00002218With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2219not used. If you use recent kernel source, a new build target
2220"uImage" will exist which automatically builds an image usable by
2221U-Boot. Most older kernels also have support for a "pImage" target,
2222which was introduced for our predecessor project PPCBoot and uses a
2223100% compatible format.
wdenkc6097192002-11-03 00:24:07 +00002224
wdenk2729af92004-05-03 20:45:30 +00002225Example:
wdenkc6097192002-11-03 00:24:07 +00002226
Holger Freytherab584d62014-08-04 09:26:05 +02002227 make TQM850L_defconfig
wdenk2729af92004-05-03 20:45:30 +00002228 make oldconfig
2229 make dep
2230 make uImage
wdenkc6097192002-11-03 00:24:07 +00002231
wdenk2729af92004-05-03 20:45:30 +00002232The "uImage" build target uses a special tool (in 'tools/mkimage') to
2233encapsulate a compressed Linux kernel image with header information,
2234CRC32 checksum etc. for use with U-Boot. This is what we are doing:
wdenkc6097192002-11-03 00:24:07 +00002235
wdenk2729af92004-05-03 20:45:30 +00002236* build a standard "vmlinux" kernel image (in ELF binary format):
wdenkc6097192002-11-03 00:24:07 +00002237
wdenk2729af92004-05-03 20:45:30 +00002238* convert the kernel into a raw binary image:
wdenkc6097192002-11-03 00:24:07 +00002239
wdenk2729af92004-05-03 20:45:30 +00002240 ${CROSS_COMPILE}-objcopy -O binary \
2241 -R .note -R .comment \
2242 -S vmlinux linux.bin
wdenkc6097192002-11-03 00:24:07 +00002243
wdenk2729af92004-05-03 20:45:30 +00002244* compress the binary image:
wdenkc6097192002-11-03 00:24:07 +00002245
wdenk2729af92004-05-03 20:45:30 +00002246 gzip -9 linux.bin
wdenkc6097192002-11-03 00:24:07 +00002247
wdenk2729af92004-05-03 20:45:30 +00002248* package compressed binary image for U-Boot:
wdenk24ee89b2002-11-03 17:56:27 +00002249
wdenk2729af92004-05-03 20:45:30 +00002250 mkimage -A ppc -O linux -T kernel -C gzip \
2251 -a 0 -e 0 -n "Linux Kernel Image" \
2252 -d linux.bin.gz uImage
wdenk24ee89b2002-11-03 17:56:27 +00002253
wdenk24ee89b2002-11-03 17:56:27 +00002254
wdenk2729af92004-05-03 20:45:30 +00002255The "mkimage" tool can also be used to create ramdisk images for use
2256with U-Boot, either separated from the Linux kernel image, or
2257combined into one file. "mkimage" encapsulates the images with a 64
2258byte header containing information about target architecture,
2259operating system, image type, compression method, entry points, time
2260stamp, CRC32 checksums, etc.
wdenk24ee89b2002-11-03 17:56:27 +00002261
wdenk2729af92004-05-03 20:45:30 +00002262"mkimage" can be called in two ways: to verify existing images and
2263print the header information, or to build new images.
wdenk24ee89b2002-11-03 17:56:27 +00002264
wdenk2729af92004-05-03 20:45:30 +00002265In the first form (with "-l" option) mkimage lists the information
2266contained in the header of an existing U-Boot image; this includes
2267checksum verification:
wdenk24ee89b2002-11-03 17:56:27 +00002268
wdenk2729af92004-05-03 20:45:30 +00002269 tools/mkimage -l image
2270 -l ==> list image header information
wdenk24ee89b2002-11-03 17:56:27 +00002271
wdenk2729af92004-05-03 20:45:30 +00002272The second form (with "-d" option) is used to build a U-Boot image
2273from a "data file" which is used as image payload:
wdenk24ee89b2002-11-03 17:56:27 +00002274
wdenk2729af92004-05-03 20:45:30 +00002275 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2276 -n name -d data_file image
2277 -A ==> set architecture to 'arch'
2278 -O ==> set operating system to 'os'
2279 -T ==> set image type to 'type'
2280 -C ==> set compression type 'comp'
2281 -a ==> set load address to 'addr' (hex)
2282 -e ==> set entry point to 'ep' (hex)
2283 -n ==> set image name to 'name'
2284 -d ==> use image data from 'datafile'
wdenk24ee89b2002-11-03 17:56:27 +00002285
wdenk69459792004-05-29 16:53:29 +00002286Right now, all Linux kernels for PowerPC systems use the same load
2287address (0x00000000), but the entry point address depends on the
2288kernel version:
wdenkc6097192002-11-03 00:24:07 +00002289
wdenk2729af92004-05-03 20:45:30 +00002290- 2.2.x kernels have the entry point at 0x0000000C,
2291- 2.3.x and later kernels have the entry point at 0x00000000.
wdenkc6097192002-11-03 00:24:07 +00002292
wdenk2729af92004-05-03 20:45:30 +00002293So a typical call to build a U-Boot image would read:
wdenkc6097192002-11-03 00:24:07 +00002294
wdenk2729af92004-05-03 20:45:30 +00002295 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2296 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
Stefan Roesea47a12b2010-04-15 16:07:28 +02002297 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
wdenk2729af92004-05-03 20:45:30 +00002298 > examples/uImage.TQM850L
2299 Image Name: 2.4.4 kernel for TQM850L
2300 Created: Wed Jul 19 02:34:59 2000
2301 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2302 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2303 Load Address: 0x00000000
2304 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002305
wdenk2729af92004-05-03 20:45:30 +00002306To verify the contents of the image (or check for corruption):
wdenkc6097192002-11-03 00:24:07 +00002307
wdenk2729af92004-05-03 20:45:30 +00002308 -> tools/mkimage -l examples/uImage.TQM850L
2309 Image Name: 2.4.4 kernel for TQM850L
2310 Created: Wed Jul 19 02:34:59 2000
2311 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2312 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2313 Load Address: 0x00000000
2314 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002315
wdenk2729af92004-05-03 20:45:30 +00002316NOTE: for embedded systems where boot time is critical you can trade
2317speed for memory and install an UNCOMPRESSED image instead: this
2318needs more space in Flash, but boots much faster since it does not
2319need to be uncompressed:
wdenkc6097192002-11-03 00:24:07 +00002320
Stefan Roesea47a12b2010-04-15 16:07:28 +02002321 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
wdenk2729af92004-05-03 20:45:30 +00002322 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2323 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
Stefan Roesea47a12b2010-04-15 16:07:28 +02002324 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
wdenk2729af92004-05-03 20:45:30 +00002325 > examples/uImage.TQM850L-uncompressed
2326 Image Name: 2.4.4 kernel for TQM850L
2327 Created: Wed Jul 19 02:34:59 2000
2328 Image Type: PowerPC Linux Kernel Image (uncompressed)
2329 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
2330 Load Address: 0x00000000
2331 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002332
wdenkc6097192002-11-03 00:24:07 +00002333
wdenk2729af92004-05-03 20:45:30 +00002334Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2335when your kernel is intended to use an initial ramdisk:
wdenkdb01a2e2004-04-15 23:14:49 +00002336
wdenk2729af92004-05-03 20:45:30 +00002337 -> tools/mkimage -n 'Simple Ramdisk Image' \
2338 > -A ppc -O linux -T ramdisk -C gzip \
2339 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2340 Image Name: Simple Ramdisk Image
2341 Created: Wed Jan 12 14:01:50 2000
2342 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2343 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
2344 Load Address: 0x00000000
2345 Entry Point: 0x00000000
wdenkdb01a2e2004-04-15 23:14:49 +00002346
Tyler Hickse157a112020-10-26 10:40:24 -05002347The "dumpimage" tool can be used to disassemble or list the contents of images
2348built by mkimage. See dumpimage's help output (-h) for details.
wdenkdb01a2e2004-04-15 23:14:49 +00002349
wdenk2729af92004-05-03 20:45:30 +00002350Installing a Linux Image:
2351-------------------------
wdenkdb01a2e2004-04-15 23:14:49 +00002352
wdenk2729af92004-05-03 20:45:30 +00002353To downloading a U-Boot image over the serial (console) interface,
2354you must convert the image to S-Record format:
wdenkdb01a2e2004-04-15 23:14:49 +00002355
wdenk2729af92004-05-03 20:45:30 +00002356 objcopy -I binary -O srec examples/image examples/image.srec
wdenkdb01a2e2004-04-15 23:14:49 +00002357
wdenk2729af92004-05-03 20:45:30 +00002358The 'objcopy' does not understand the information in the U-Boot
2359image header, so the resulting S-Record file will be relative to
2360address 0x00000000. To load it to a given address, you need to
2361specify the target address as 'offset' parameter with the 'loads'
2362command.
wdenkc6097192002-11-03 00:24:07 +00002363
wdenk2729af92004-05-03 20:45:30 +00002364Example: install the image to address 0x40100000 (which on the
2365TQM8xxL is in the first Flash bank):
wdenkc6097192002-11-03 00:24:07 +00002366
wdenk2729af92004-05-03 20:45:30 +00002367 => erase 40100000 401FFFFF
wdenkc6097192002-11-03 00:24:07 +00002368
wdenk2729af92004-05-03 20:45:30 +00002369 .......... done
2370 Erased 8 sectors
wdenkc6097192002-11-03 00:24:07 +00002371
wdenk2729af92004-05-03 20:45:30 +00002372 => loads 40100000
2373 ## Ready for S-Record download ...
2374 ~>examples/image.srec
2375 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2376 ...
2377 15989 15990 15991 15992
2378 [file transfer complete]
2379 [connected]
2380 ## Start Addr = 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002381
2382
wdenk2729af92004-05-03 20:45:30 +00002383You can check the success of the download using the 'iminfo' command;
Wolfgang Denk218ca722008-03-26 10:40:12 +01002384this includes a checksum verification so you can be sure no data
wdenk2729af92004-05-03 20:45:30 +00002385corruption happened:
wdenkc6097192002-11-03 00:24:07 +00002386
wdenk2729af92004-05-03 20:45:30 +00002387 => imi 40100000
wdenkc6097192002-11-03 00:24:07 +00002388
wdenk2729af92004-05-03 20:45:30 +00002389 ## Checking Image at 40100000 ...
2390 Image Name: 2.2.13 for initrd on TQM850L
2391 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2392 Data Size: 335725 Bytes = 327 kB = 0 MB
2393 Load Address: 00000000
2394 Entry Point: 0000000c
2395 Verifying Checksum ... OK
wdenkc6097192002-11-03 00:24:07 +00002396
2397
wdenk2729af92004-05-03 20:45:30 +00002398Boot Linux:
2399-----------
wdenkc6097192002-11-03 00:24:07 +00002400
wdenk2729af92004-05-03 20:45:30 +00002401The "bootm" command is used to boot an application that is stored in
2402memory (RAM or Flash). In case of a Linux kernel image, the contents
2403of the "bootargs" environment variable is passed to the kernel as
2404parameters. You can check and modify this variable using the
2405"printenv" and "setenv" commands:
wdenkc6097192002-11-03 00:24:07 +00002406
2407
wdenk2729af92004-05-03 20:45:30 +00002408 => printenv bootargs
2409 bootargs=root=/dev/ram
wdenkc6097192002-11-03 00:24:07 +00002410
wdenk2729af92004-05-03 20:45:30 +00002411 => 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 +00002412
wdenk2729af92004-05-03 20:45:30 +00002413 => printenv bootargs
2414 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 +00002415
wdenk2729af92004-05-03 20:45:30 +00002416 => bootm 40020000
2417 ## Booting Linux kernel at 40020000 ...
2418 Image Name: 2.2.13 for NFS on TQM850L
2419 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2420 Data Size: 381681 Bytes = 372 kB = 0 MB
2421 Load Address: 00000000
2422 Entry Point: 0000000c
2423 Verifying Checksum ... OK
2424 Uncompressing Kernel Image ... OK
2425 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
2426 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2427 time_init: decrementer frequency = 187500000/60
2428 Calibrating delay loop... 49.77 BogoMIPS
2429 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2430 ...
wdenkc6097192002-11-03 00:24:07 +00002431
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002432If you want to boot a Linux kernel with initial RAM disk, you pass
wdenk2729af92004-05-03 20:45:30 +00002433the memory addresses of both the kernel and the initrd image (PPBCOOT
2434format!) to the "bootm" command:
wdenkc6097192002-11-03 00:24:07 +00002435
wdenk2729af92004-05-03 20:45:30 +00002436 => imi 40100000 40200000
wdenkc6097192002-11-03 00:24:07 +00002437
wdenk2729af92004-05-03 20:45:30 +00002438 ## Checking Image at 40100000 ...
2439 Image Name: 2.2.13 for initrd on TQM850L
2440 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2441 Data Size: 335725 Bytes = 327 kB = 0 MB
2442 Load Address: 00000000
2443 Entry Point: 0000000c
2444 Verifying Checksum ... OK
wdenkc6097192002-11-03 00:24:07 +00002445
wdenk2729af92004-05-03 20:45:30 +00002446 ## Checking Image at 40200000 ...
2447 Image Name: Simple Ramdisk Image
2448 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2449 Data Size: 566530 Bytes = 553 kB = 0 MB
2450 Load Address: 00000000
2451 Entry Point: 00000000
2452 Verifying Checksum ... OK
wdenkc6097192002-11-03 00:24:07 +00002453
wdenk2729af92004-05-03 20:45:30 +00002454 => bootm 40100000 40200000
2455 ## Booting Linux kernel at 40100000 ...
2456 Image Name: 2.2.13 for initrd on TQM850L
2457 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2458 Data Size: 335725 Bytes = 327 kB = 0 MB
2459 Load Address: 00000000
2460 Entry Point: 0000000c
2461 Verifying Checksum ... OK
2462 Uncompressing Kernel Image ... OK
2463 ## Loading RAMDisk Image at 40200000 ...
2464 Image Name: Simple Ramdisk Image
2465 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2466 Data Size: 566530 Bytes = 553 kB = 0 MB
2467 Load Address: 00000000
2468 Entry Point: 00000000
2469 Verifying Checksum ... OK
2470 Loading Ramdisk ... OK
2471 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
2472 Boot arguments: root=/dev/ram
2473 time_init: decrementer frequency = 187500000/60
2474 Calibrating delay loop... 49.77 BogoMIPS
2475 ...
2476 RAMDISK: Compressed image found at block 0
2477 VFS: Mounted root (ext2 filesystem).
wdenkc6097192002-11-03 00:24:07 +00002478
wdenk2729af92004-05-03 20:45:30 +00002479 bash#
wdenkc6097192002-11-03 00:24:07 +00002480
Matthew McClintock02677682006-06-28 10:41:37 -05002481Boot Linux and pass a flat device tree:
2482-----------
2483
2484First, U-Boot must be compiled with the appropriate defines. See the section
2485titled "Linux Kernel Interface" above for a more in depth explanation. The
2486following is an example of how to start a kernel and pass an updated
2487flat device tree:
2488
2489=> print oftaddr
2490oftaddr=0x300000
2491=> print oft
2492oft=oftrees/mpc8540ads.dtb
2493=> tftp $oftaddr $oft
2494Speed: 1000, full duplex
2495Using TSEC0 device
2496TFTP from server 192.168.1.1; our IP address is 192.168.1.101
2497Filename 'oftrees/mpc8540ads.dtb'.
2498Load address: 0x300000
2499Loading: #
2500done
2501Bytes transferred = 4106 (100a hex)
2502=> tftp $loadaddr $bootfile
2503Speed: 1000, full duplex
2504Using TSEC0 device
2505TFTP from server 192.168.1.1; our IP address is 192.168.1.2
2506Filename 'uImage'.
2507Load address: 0x200000
2508Loading:############
2509done
2510Bytes transferred = 1029407 (fb51f hex)
2511=> print loadaddr
2512loadaddr=200000
2513=> print oftaddr
2514oftaddr=0x300000
2515=> bootm $loadaddr - $oftaddr
2516## Booting image at 00200000 ...
Wolfgang Denka9398e02006-11-27 15:32:42 +01002517 Image Name: Linux-2.6.17-dirty
2518 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2519 Data Size: 1029343 Bytes = 1005.2 kB
Matthew McClintock02677682006-06-28 10:41:37 -05002520 Load Address: 00000000
Wolfgang Denka9398e02006-11-27 15:32:42 +01002521 Entry Point: 00000000
Matthew McClintock02677682006-06-28 10:41:37 -05002522 Verifying Checksum ... OK
2523 Uncompressing Kernel Image ... OK
2524Booting using flat device tree at 0x300000
2525Using MPC85xx ADS machine description
2526Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
2527[snip]
2528
2529
wdenk2729af92004-05-03 20:45:30 +00002530More About U-Boot Image Types:
2531------------------------------
wdenk6069ff22003-02-28 00:49:47 +00002532
wdenk2729af92004-05-03 20:45:30 +00002533U-Boot supports the following image types:
wdenk6069ff22003-02-28 00:49:47 +00002534
wdenk2729af92004-05-03 20:45:30 +00002535 "Standalone Programs" are directly runnable in the environment
2536 provided by U-Boot; it is expected that (if they behave
2537 well) you can continue to work in U-Boot after return from
2538 the Standalone Program.
2539 "OS Kernel Images" are usually images of some Embedded OS which
2540 will take over control completely. Usually these programs
2541 will install their own set of exception handlers, device
2542 drivers, set up the MMU, etc. - this means, that you cannot
2543 expect to re-enter U-Boot except by resetting the CPU.
2544 "RAMDisk Images" are more or less just data blocks, and their
2545 parameters (address, size) are passed to an OS kernel that is
2546 being started.
2547 "Multi-File Images" contain several images, typically an OS
2548 (Linux) kernel image and one or more data images like
2549 RAMDisks. This construct is useful for instance when you want
2550 to boot over the network using BOOTP etc., where the boot
2551 server provides just a single image file, but you want to get
2552 for instance an OS kernel and a RAMDisk image.
stroesec1551ea2003-04-04 15:53:41 +00002553
wdenk2729af92004-05-03 20:45:30 +00002554 "Multi-File Images" start with a list of image sizes, each
2555 image size (in bytes) specified by an "uint32_t" in network
2556 byte order. This list is terminated by an "(uint32_t)0".
2557 Immediately after the terminating 0 follow the images, one by
2558 one, all aligned on "uint32_t" boundaries (size rounded up to
2559 a multiple of 4 bytes).
stroesec1551ea2003-04-04 15:53:41 +00002560
wdenk2729af92004-05-03 20:45:30 +00002561 "Firmware Images" are binary images containing firmware (like
2562 U-Boot or FPGA images) which usually will be programmed to
2563 flash memory.
stroesec1551ea2003-04-04 15:53:41 +00002564
wdenk2729af92004-05-03 20:45:30 +00002565 "Script files" are command sequences that will be executed by
2566 U-Boot's command interpreter; this feature is especially
2567 useful when you configure U-Boot to use a real shell (hush)
2568 as command interpreter.
wdenk6069ff22003-02-28 00:49:47 +00002569
Marek Vasut44f074c2012-03-14 21:52:45 +00002570Booting the Linux zImage:
2571-------------------------
2572
2573On some platforms, it's possible to boot Linux zImage. This is done
2574using the "bootz" command. The syntax of "bootz" command is the same
2575as the syntax of "bootm" command.
2576
Tom Rini8ac28562013-05-16 11:40:11 -04002577Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
Marek Vasut017e1f32012-03-18 11:47:58 +00002578kernel with raw initrd images. The syntax is slightly different, the
2579address of the initrd must be augmented by it's size, in the following
2580format: "<initrd addres>:<initrd size>".
2581
wdenkc6097192002-11-03 00:24:07 +00002582
wdenk2729af92004-05-03 20:45:30 +00002583Standalone HOWTO:
2584=================
wdenkc6097192002-11-03 00:24:07 +00002585
wdenk2729af92004-05-03 20:45:30 +00002586One of the features of U-Boot is that you can dynamically load and
2587run "standalone" applications, which can use some resources of
2588U-Boot like console I/O functions or interrupt services.
wdenkc6097192002-11-03 00:24:07 +00002589
wdenk2729af92004-05-03 20:45:30 +00002590Two simple examples are included with the sources:
wdenkc6097192002-11-03 00:24:07 +00002591
wdenk2729af92004-05-03 20:45:30 +00002592"Hello World" Demo:
2593-------------------
wdenkc6097192002-11-03 00:24:07 +00002594
wdenk2729af92004-05-03 20:45:30 +00002595'examples/hello_world.c' contains a small "Hello World" Demo
2596application; it is automatically compiled when you build U-Boot.
2597It's configured to run at address 0x00040004, so you can play with it
2598like that:
wdenkc6097192002-11-03 00:24:07 +00002599
wdenk2729af92004-05-03 20:45:30 +00002600 => loads
2601 ## Ready for S-Record download ...
2602 ~>examples/hello_world.srec
2603 1 2 3 4 5 6 7 8 9 10 11 ...
2604 [file transfer complete]
2605 [connected]
2606 ## Start Addr = 0x00040004
wdenkc6097192002-11-03 00:24:07 +00002607
wdenk2729af92004-05-03 20:45:30 +00002608 => go 40004 Hello World! This is a test.
2609 ## Starting application at 0x00040004 ...
2610 Hello World
2611 argc = 7
2612 argv[0] = "40004"
2613 argv[1] = "Hello"
2614 argv[2] = "World!"
2615 argv[3] = "This"
2616 argv[4] = "is"
2617 argv[5] = "a"
2618 argv[6] = "test."
2619 argv[7] = "<NULL>"
2620 Hit any key to exit ...
wdenkc6097192002-11-03 00:24:07 +00002621
wdenk2729af92004-05-03 20:45:30 +00002622 ## Application terminated, rc = 0x0
wdenkc6097192002-11-03 00:24:07 +00002623
wdenk2729af92004-05-03 20:45:30 +00002624Another example, which demonstrates how to register a CPM interrupt
2625handler with the U-Boot code, can be found in 'examples/timer.c'.
2626Here, a CPM timer is set up to generate an interrupt every second.
2627The interrupt service routine is trivial, just printing a '.'
2628character, but this is just a demo program. The application can be
2629controlled by the following keys:
wdenkc6097192002-11-03 00:24:07 +00002630
wdenk2729af92004-05-03 20:45:30 +00002631 ? - print current values og the CPM Timer registers
2632 b - enable interrupts and start timer
2633 e - stop timer and disable interrupts
2634 q - quit application
wdenkc6097192002-11-03 00:24:07 +00002635
wdenk2729af92004-05-03 20:45:30 +00002636 => loads
2637 ## Ready for S-Record download ...
2638 ~>examples/timer.srec
2639 1 2 3 4 5 6 7 8 9 10 11 ...
2640 [file transfer complete]
2641 [connected]
2642 ## Start Addr = 0x00040004
wdenkc6097192002-11-03 00:24:07 +00002643
wdenk2729af92004-05-03 20:45:30 +00002644 => go 40004
2645 ## Starting application at 0x00040004 ...
2646 TIMERS=0xfff00980
2647 Using timer 1
2648 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
wdenkc6097192002-11-03 00:24:07 +00002649
wdenk2729af92004-05-03 20:45:30 +00002650Hit 'b':
2651 [q, b, e, ?] Set interval 1000000 us
2652 Enabling timer
2653Hit '?':
2654 [q, b, e, ?] ........
2655 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
2656Hit '?':
2657 [q, b, e, ?] .
2658 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
2659Hit '?':
2660 [q, b, e, ?] .
2661 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
2662Hit '?':
2663 [q, b, e, ?] .
2664 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
2665Hit 'e':
2666 [q, b, e, ?] ...Stopping timer
2667Hit 'q':
2668 [q, b, e, ?] ## Application terminated, rc = 0x0
wdenkc6097192002-11-03 00:24:07 +00002669
2670
wdenk2729af92004-05-03 20:45:30 +00002671Minicom warning:
2672================
wdenk85ec0bc2003-03-31 16:34:49 +00002673
wdenk2729af92004-05-03 20:45:30 +00002674Over time, many people have reported problems when trying to use the
2675"minicom" terminal emulation program for serial download. I (wd)
2676consider minicom to be broken, and recommend not to use it. Under
2677Unix, I recommend to use C-Kermit for general purpose use (and
2678especially for kermit binary protocol download ("loadb" command), and
Karl O. Pince53515a2012-10-01 05:11:56 +00002679use "cu" for S-Record download ("loads" command). See
Naoki Hayama047f6ec2020-10-08 13:17:16 +09002680https://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
Karl O. Pince53515a2012-10-01 05:11:56 +00002681for help with kermit.
2682
wdenk85ec0bc2003-03-31 16:34:49 +00002683
wdenk2729af92004-05-03 20:45:30 +00002684Nevertheless, if you absolutely want to use it try adding this
2685configuration to your "File transfer protocols" section:
wdenk52f52c12003-06-19 23:04:19 +00002686
wdenk2729af92004-05-03 20:45:30 +00002687 Name Program Name U/D FullScr IO-Red. Multi
2688 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
2689 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
wdenk52f52c12003-06-19 23:04:19 +00002690
2691
wdenk2729af92004-05-03 20:45:30 +00002692NetBSD Notes:
2693=============
wdenkc6097192002-11-03 00:24:07 +00002694
wdenk2729af92004-05-03 20:45:30 +00002695Starting at version 0.9.2, U-Boot supports NetBSD both as host
2696(build U-Boot) and target system (boots NetBSD/mpc8xx).
wdenkc6097192002-11-03 00:24:07 +00002697
wdenk2729af92004-05-03 20:45:30 +00002698Building requires a cross environment; it is known to work on
2699NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
2700need gmake since the Makefiles are not compatible with BSD make).
2701Note that the cross-powerpc package does not install include files;
2702attempting to build U-Boot will fail because <machine/ansi.h> is
2703missing. This file has to be installed and patched manually:
wdenkc6097192002-11-03 00:24:07 +00002704
wdenk2729af92004-05-03 20:45:30 +00002705 # cd /usr/pkg/cross/powerpc-netbsd/include
2706 # mkdir powerpc
2707 # ln -s powerpc machine
2708 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
2709 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
wdenkc6097192002-11-03 00:24:07 +00002710
wdenk2729af92004-05-03 20:45:30 +00002711Native builds *don't* work due to incompatibilities between native
2712and U-Boot include files.
wdenkc6097192002-11-03 00:24:07 +00002713
wdenk2729af92004-05-03 20:45:30 +00002714Booting assumes that (the first part of) the image booted is a
2715stage-2 loader which in turn loads and then invokes the kernel
2716proper. Loader sources will eventually appear in the NetBSD source
2717tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
wdenk2a8af182005-04-13 10:02:42 +00002718meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
wdenkc6097192002-11-03 00:24:07 +00002719
2720
wdenk2729af92004-05-03 20:45:30 +00002721Implementation Internals:
2722=========================
wdenkc6097192002-11-03 00:24:07 +00002723
wdenk2729af92004-05-03 20:45:30 +00002724The following is not intended to be a complete description of every
2725implementation detail. However, it should help to understand the
2726inner workings of U-Boot and make it easier to port it to custom
2727hardware.
wdenkc6097192002-11-03 00:24:07 +00002728
2729
wdenk2729af92004-05-03 20:45:30 +00002730Initial Stack, Global Data:
2731---------------------------
wdenkc6097192002-11-03 00:24:07 +00002732
wdenk2729af92004-05-03 20:45:30 +00002733The implementation of U-Boot is complicated by the fact that U-Boot
2734starts running out of ROM (flash memory), usually without access to
2735system RAM (because the memory controller is not initialized yet).
2736This means that we don't have writable Data or BSS segments, and BSS
2737is not initialized as zero. To be able to get a C environment working
2738at all, we have to allocate at least a minimal stack. Implementation
2739options for this are defined and restricted by the CPU used: Some CPU
2740models provide on-chip memory (like the IMMR area on MPC8xx and
2741MPC826x processors), on others (parts of) the data cache can be
2742locked as (mis-) used as memory, etc.
wdenkc6097192002-11-03 00:24:07 +00002743
Wolfgang Denk218ca722008-03-26 10:40:12 +01002744 Chris Hallinan posted a good summary of these issues to the
Wolfgang Denk06682362008-12-30 22:56:11 +01002745 U-Boot mailing list:
wdenk43d96162003-03-06 00:02:04 +00002746
wdenk2729af92004-05-03 20:45:30 +00002747 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
2748 From: "Chris Hallinan" <clh@net1plus.com>
2749 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
2750 ...
wdenk43d96162003-03-06 00:02:04 +00002751
wdenk2729af92004-05-03 20:45:30 +00002752 Correct me if I'm wrong, folks, but the way I understand it
2753 is this: Using DCACHE as initial RAM for Stack, etc, does not
2754 require any physical RAM backing up the cache. The cleverness
2755 is that the cache is being used as a temporary supply of
2756 necessary storage before the SDRAM controller is setup. It's
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002757 beyond the scope of this list to explain the details, but you
wdenk2729af92004-05-03 20:45:30 +00002758 can see how this works by studying the cache architecture and
2759 operation in the architecture and processor-specific manuals.
wdenk43d96162003-03-06 00:02:04 +00002760
wdenk2729af92004-05-03 20:45:30 +00002761 OCM is On Chip Memory, which I believe the 405GP has 4K. It
2762 is another option for the system designer to use as an
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002763 initial stack/RAM area prior to SDRAM being available. Either
wdenk2729af92004-05-03 20:45:30 +00002764 option should work for you. Using CS 4 should be fine if your
2765 board designers haven't used it for something that would
2766 cause you grief during the initial boot! It is frequently not
2767 used.
wdenk43d96162003-03-06 00:02:04 +00002768
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002769 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
wdenk2729af92004-05-03 20:45:30 +00002770 with your processor/board/system design. The default value
2771 you will find in any recent u-boot distribution in
Stefan Roese8a316c92005-08-01 16:49:12 +02002772 walnut.h should work for you. I'd set it to a value larger
wdenk2729af92004-05-03 20:45:30 +00002773 than your SDRAM module. If you have a 64MB SDRAM module, set
2774 it above 400_0000. Just make sure your board has no resources
2775 that are supposed to respond to that address! That code in
2776 start.S has been around a while and should work as is when
2777 you get the config right.
wdenk43d96162003-03-06 00:02:04 +00002778
wdenk2729af92004-05-03 20:45:30 +00002779 -Chris Hallinan
2780 DS4.COM, Inc.
wdenk43d96162003-03-06 00:02:04 +00002781
wdenk2729af92004-05-03 20:45:30 +00002782It is essential to remember this, since it has some impact on the C
2783code for the initialization procedures:
wdenkc6097192002-11-03 00:24:07 +00002784
wdenk2729af92004-05-03 20:45:30 +00002785* Initialized global data (data segment) is read-only. Do not attempt
2786 to write it.
wdenkc6097192002-11-03 00:24:07 +00002787
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08002788* Do not use any uninitialized global data (or implicitly initialized
wdenk2729af92004-05-03 20:45:30 +00002789 as zero data - BSS segment) at all - this is undefined, initiali-
2790 zation is performed later (when relocating to RAM).
wdenkc6097192002-11-03 00:24:07 +00002791
wdenk2729af92004-05-03 20:45:30 +00002792* Stack space is very limited. Avoid big data buffers or things like
2793 that.
wdenkc6097192002-11-03 00:24:07 +00002794
wdenk2729af92004-05-03 20:45:30 +00002795Having only the stack as writable memory limits means we cannot use
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08002796normal global data to share information between the code. But it
wdenk2729af92004-05-03 20:45:30 +00002797turned out that the implementation of U-Boot can be greatly
2798simplified by making a global data structure (gd_t) available to all
2799functions. We could pass a pointer to this data as argument to _all_
2800functions, but this would bloat the code. Instead we use a feature of
2801the GCC compiler (Global Register Variables) to share the data: we
2802place a pointer (gd) to the global data into a register which we
2803reserve for this purpose.
wdenkc6097192002-11-03 00:24:07 +00002804
wdenk2729af92004-05-03 20:45:30 +00002805When choosing a register for such a purpose we are restricted by the
2806relevant (E)ABI specifications for the current architecture, and by
2807GCC's implementation.
wdenkc6097192002-11-03 00:24:07 +00002808
wdenk2729af92004-05-03 20:45:30 +00002809For PowerPC, the following registers have specific use:
2810 R1: stack pointer
Wolfgang Denke7670f62008-02-14 22:43:22 +01002811 R2: reserved for system use
wdenk2729af92004-05-03 20:45:30 +00002812 R3-R4: parameter passing and return values
2813 R5-R10: parameter passing
2814 R13: small data area pointer
2815 R30: GOT pointer
2816 R31: frame pointer
wdenkc6097192002-11-03 00:24:07 +00002817
Joakim Tjernlunde6bee802010-01-19 14:41:58 +01002818 (U-Boot also uses R12 as internal GOT pointer. r12
2819 is a volatile register so r12 needs to be reset when
2820 going back and forth between asm and C)
wdenkc6097192002-11-03 00:24:07 +00002821
Wolfgang Denke7670f62008-02-14 22:43:22 +01002822 ==> U-Boot will use R2 to hold a pointer to the global data
wdenkc6097192002-11-03 00:24:07 +00002823
wdenk2729af92004-05-03 20:45:30 +00002824 Note: on PPC, we could use a static initializer (since the
2825 address of the global data structure is known at compile time),
2826 but it turned out that reserving a register results in somewhat
2827 smaller code - although the code savings are not that big (on
2828 average for all boards 752 bytes for the whole U-Boot image,
2829 624 text + 127 data).
wdenkc6097192002-11-03 00:24:07 +00002830
wdenk2729af92004-05-03 20:45:30 +00002831On ARM, the following registers are used:
wdenkc6097192002-11-03 00:24:07 +00002832
wdenk2729af92004-05-03 20:45:30 +00002833 R0: function argument word/integer result
2834 R1-R3: function argument word
Jeroen Hofstee12eba1b2013-09-21 14:04:42 +02002835 R9: platform specific
2836 R10: stack limit (used only if stack checking is enabled)
wdenk2729af92004-05-03 20:45:30 +00002837 R11: argument (frame) pointer
2838 R12: temporary workspace
2839 R13: stack pointer
2840 R14: link register
2841 R15: program counter
wdenkc6097192002-11-03 00:24:07 +00002842
Jeroen Hofstee12eba1b2013-09-21 14:04:42 +02002843 ==> U-Boot will use R9 to hold a pointer to the global data
2844
2845 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
wdenkc6097192002-11-03 00:24:07 +00002846
Thomas Chou0df01fd2010-05-21 11:08:03 +08002847On Nios II, the ABI is documented here:
Naoki Hayama047f6ec2020-10-08 13:17:16 +09002848 https://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
Thomas Chou0df01fd2010-05-21 11:08:03 +08002849
2850 ==> U-Boot will use gp to hold a pointer to the global data
2851
2852 Note: on Nios II, we give "-G0" option to gcc and don't use gp
2853 to access small data sections, so gp is free.
2854
Rick Chen3fafced2017-12-26 13:55:59 +08002855On RISC-V, the following registers are used:
2856
2857 x0: hard-wired zero (zero)
2858 x1: return address (ra)
2859 x2: stack pointer (sp)
2860 x3: global pointer (gp)
2861 x4: thread pointer (tp)
2862 x5: link register (t0)
2863 x8: frame pointer (fp)
2864 x10-x11: arguments/return values (a0-1)
2865 x12-x17: arguments (a2-7)
2866 x28-31: temporaries (t3-6)
2867 pc: program counter (pc)
2868
2869 ==> U-Boot will use gp to hold a pointer to the global data
2870
wdenk2729af92004-05-03 20:45:30 +00002871Memory Management:
2872------------------
wdenkc6097192002-11-03 00:24:07 +00002873
wdenk2729af92004-05-03 20:45:30 +00002874U-Boot runs in system state and uses physical addresses, i.e. the
2875MMU is not used either for address mapping nor for memory protection.
wdenkc6097192002-11-03 00:24:07 +00002876
wdenk2729af92004-05-03 20:45:30 +00002877The available memory is mapped to fixed addresses using the memory
2878controller. In this process, a contiguous block is formed for each
2879memory type (Flash, SDRAM, SRAM), even when it consists of several
2880physical memory banks.
wdenkc6097192002-11-03 00:24:07 +00002881
wdenk2729af92004-05-03 20:45:30 +00002882U-Boot is installed in the first 128 kB of the first Flash bank (on
2883TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
2884booting and sizing and initializing DRAM, the code relocates itself
2885to the upper end of DRAM. Immediately below the U-Boot code some
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002886memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
wdenk2729af92004-05-03 20:45:30 +00002887configuration setting]. Below that, a structure with global Board
2888Info data is placed, followed by the stack (growing downward).
wdenkc6097192002-11-03 00:24:07 +00002889
wdenk2729af92004-05-03 20:45:30 +00002890Additionally, some exception handler code is copied to the low 8 kB
2891of DRAM (0x00000000 ... 0x00001FFF).
wdenkc6097192002-11-03 00:24:07 +00002892
wdenk2729af92004-05-03 20:45:30 +00002893So a typical memory configuration with 16 MB of DRAM could look like
2894this:
wdenkc6097192002-11-03 00:24:07 +00002895
wdenk2729af92004-05-03 20:45:30 +00002896 0x0000 0000 Exception Vector code
2897 :
2898 0x0000 1FFF
2899 0x0000 2000 Free for Application Use
2900 :
2901 :
wdenkc6097192002-11-03 00:24:07 +00002902
wdenk2729af92004-05-03 20:45:30 +00002903 :
2904 :
2905 0x00FB FF20 Monitor Stack (Growing downward)
2906 0x00FB FFAC Board Info Data and permanent copy of global data
2907 0x00FC 0000 Malloc Arena
2908 :
2909 0x00FD FFFF
2910 0x00FE 0000 RAM Copy of Monitor Code
2911 ... eventually: LCD or video framebuffer
2912 ... eventually: pRAM (Protected RAM - unchanged by reset)
2913 0x00FF FFFF [End of RAM]
wdenkc6097192002-11-03 00:24:07 +00002914
2915
wdenk2729af92004-05-03 20:45:30 +00002916System Initialization:
2917----------------------
wdenkc6097192002-11-03 00:24:07 +00002918
wdenk2729af92004-05-03 20:45:30 +00002919In the reset configuration, U-Boot starts at the reset entry point
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002920(on most PowerPC systems at address 0x00000100). Because of the reset
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08002921configuration for CS0# this is a mirror of the on board Flash memory.
wdenk2729af92004-05-03 20:45:30 +00002922To be able to re-map memory U-Boot then jumps to its link address.
2923To be able to implement the initialization code in C, a (small!)
2924initial stack is set up in the internal Dual Ported RAM (in case CPUs
Heiko Schocher2eb48ff2017-06-07 17:33:10 +02002925which provide such a feature like), or in a locked part of the data
2926cache. After that, U-Boot initializes the CPU core, the caches and
2927the SIU.
wdenkc6097192002-11-03 00:24:07 +00002928
wdenk2729af92004-05-03 20:45:30 +00002929Next, all (potentially) available memory banks are mapped using a
2930preliminary mapping. For example, we put them on 512 MB boundaries
2931(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
2932on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
2933programmed for SDRAM access. Using the temporary configuration, a
2934simple memory test is run that determines the size of the SDRAM
2935banks.
wdenkc6097192002-11-03 00:24:07 +00002936
wdenk2729af92004-05-03 20:45:30 +00002937When there is more than one SDRAM bank, and the banks are of
2938different size, the largest is mapped first. For equal size, the first
2939bank (CS2#) is mapped first. The first mapping is always for address
29400x00000000, with any additional banks following immediately to create
2941contiguous memory starting from 0.
wdenkc6097192002-11-03 00:24:07 +00002942
wdenk2729af92004-05-03 20:45:30 +00002943Then, the monitor installs itself at the upper end of the SDRAM area
2944and allocates memory for use by malloc() and for the global Board
2945Info data; also, the exception vector code is copied to the low RAM
2946pages, and the final stack is set up.
wdenkc6097192002-11-03 00:24:07 +00002947
wdenk2729af92004-05-03 20:45:30 +00002948Only after this relocation will you have a "normal" C environment;
2949until that you are restricted in several ways, mostly because you are
2950running from ROM, and because the code will have to be relocated to a
2951new address in RAM.
wdenkc6097192002-11-03 00:24:07 +00002952
2953
wdenk2729af92004-05-03 20:45:30 +00002954U-Boot Porting Guide:
2955----------------------
wdenkc6097192002-11-03 00:24:07 +00002956
wdenk2729af92004-05-03 20:45:30 +00002957[Based on messages by Jerry Van Baren in the U-Boot-Users mailing
2958list, October 2002]
wdenkc6097192002-11-03 00:24:07 +00002959
2960
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04002961int main(int argc, char *argv[])
wdenk2729af92004-05-03 20:45:30 +00002962{
2963 sighandler_t no_more_time;
wdenkc6097192002-11-03 00:24:07 +00002964
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04002965 signal(SIGALRM, no_more_time);
2966 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
wdenkc6097192002-11-03 00:24:07 +00002967
wdenk2729af92004-05-03 20:45:30 +00002968 if (available_money > available_manpower) {
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04002969 Pay consultant to port U-Boot;
wdenkc6097192002-11-03 00:24:07 +00002970 return 0;
2971 }
2972
wdenk2729af92004-05-03 20:45:30 +00002973 Download latest U-Boot source;
2974
Wolfgang Denk06682362008-12-30 22:56:11 +01002975 Subscribe to u-boot mailing list;
wdenk2729af92004-05-03 20:45:30 +00002976
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04002977 if (clueless)
2978 email("Hi, I am new to U-Boot, how do I get started?");
wdenkc6097192002-11-03 00:24:07 +00002979
wdenk2729af92004-05-03 20:45:30 +00002980 while (learning) {
2981 Read the README file in the top level directory;
Naoki Hayama047f6ec2020-10-08 13:17:16 +09002982 Read https://www.denx.de/wiki/bin/view/DULG/Manual;
Patrick Delaunay24bcaec2020-02-28 15:18:10 +01002983 Read applicable doc/README.*;
wdenk2729af92004-05-03 20:45:30 +00002984 Read the source, Luke;
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04002985 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
wdenk2729af92004-05-03 20:45:30 +00002986 }
wdenkc6097192002-11-03 00:24:07 +00002987
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04002988 if (available_money > toLocalCurrency ($2500))
2989 Buy a BDI3000;
2990 else
wdenk2729af92004-05-03 20:45:30 +00002991 Add a lot of aggravation and time;
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04002992
2993 if (a similar board exists) { /* hopefully... */
2994 cp -a board/<similar> board/<myboard>
2995 cp include/configs/<similar>.h include/configs/<myboard>.h
2996 } else {
2997 Create your own board support subdirectory;
2998 Create your own board include/configs/<myboard>.h file;
wdenk2729af92004-05-03 20:45:30 +00002999 }
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04003000 Edit new board/<myboard> files
3001 Edit new include/configs/<myboard>.h
wdenkc6097192002-11-03 00:24:07 +00003002
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04003003 while (!accepted) {
3004 while (!running) {
3005 do {
3006 Add / modify source code;
3007 } until (compiles);
3008 Debug;
3009 if (clueless)
3010 email("Hi, I am having problems...");
3011 }
3012 Send patch file to the U-Boot email list;
3013 if (reasonable critiques)
3014 Incorporate improvements from email list code review;
3015 else
3016 Defend code as written;
wdenk2729af92004-05-03 20:45:30 +00003017 }
wdenkc6097192002-11-03 00:24:07 +00003018
wdenk2729af92004-05-03 20:45:30 +00003019 return 0;
3020}
3021
3022void no_more_time (int sig)
3023{
3024 hire_a_guru();
3025}
wdenkc6097192002-11-03 00:24:07 +00003026
3027
wdenk2729af92004-05-03 20:45:30 +00003028Coding Standards:
3029-----------------
wdenkc6097192002-11-03 00:24:07 +00003030
wdenk2729af92004-05-03 20:45:30 +00003031All contributions to U-Boot should conform to the Linux kernel
Baruch Siach659208d2017-12-10 17:34:35 +02003032coding style; see the kernel coding style guide at
3033https://www.kernel.org/doc/html/latest/process/coding-style.html, and the
3034script "scripts/Lindent" in your Linux kernel source directory.
wdenk2729af92004-05-03 20:45:30 +00003035
Detlev Zundel2c051652006-09-01 15:39:02 +02003036Source files originating from a different project (for example the
3037MTD subsystem) are generally exempt from these guidelines and are not
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08003038reformatted to ease subsequent migration to newer versions of those
Detlev Zundel2c051652006-09-01 15:39:02 +02003039sources.
3040
3041Please note that U-Boot is implemented in C (and to some small parts in
3042Assembler); no C++ is used, so please do not use C++ style comments (//)
3043in your code.
wdenk2729af92004-05-03 20:45:30 +00003044
3045Please also stick to the following formatting rules:
3046- remove any trailing white space
Wolfgang Denk7ca92962011-07-27 10:59:55 +00003047- use TAB characters for indentation and vertical alignment, not spaces
wdenk2729af92004-05-03 20:45:30 +00003048- make sure NOT to use DOS '\r\n' line feeds
Wolfgang Denk7ca92962011-07-27 10:59:55 +00003049- do not add more than 2 consecutive empty lines to source files
wdenk2729af92004-05-03 20:45:30 +00003050- do not add trailing empty lines to source files
3051
3052Submissions which do not conform to the standards may be returned
3053with a request to reformat the changes.
wdenkc6097192002-11-03 00:24:07 +00003054
3055
wdenk2729af92004-05-03 20:45:30 +00003056Submitting Patches:
3057-------------------
wdenkc6097192002-11-03 00:24:07 +00003058
wdenk2729af92004-05-03 20:45:30 +00003059Since the number of patches for U-Boot is growing, we need to
3060establish some rules. Submissions which do not conform to these rules
3061may be rejected, even when they contain important and valuable stuff.
wdenkc6097192002-11-03 00:24:07 +00003062
Naoki Hayama047f6ec2020-10-08 13:17:16 +09003063Please see https://www.denx.de/wiki/U-Boot/Patches for details.
Wolfgang Denk218ca722008-03-26 10:40:12 +01003064
Wolfgang Denk06682362008-12-30 22:56:11 +01003065Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
S. Lockwood-Childs1dade182017-11-14 22:56:42 -08003066see https://lists.denx.de/listinfo/u-boot
Wolfgang Denk06682362008-12-30 22:56:11 +01003067
wdenk2729af92004-05-03 20:45:30 +00003068When you send a patch, please include the following information with
3069it:
wdenkc6097192002-11-03 00:24:07 +00003070
wdenk2729af92004-05-03 20:45:30 +00003071* For bug fixes: a description of the bug and how your patch fixes
3072 this bug. Please try to include a way of demonstrating that the
3073 patch actually fixes something.
wdenkc6097192002-11-03 00:24:07 +00003074
wdenk2729af92004-05-03 20:45:30 +00003075* For new features: a description of the feature and your
3076 implementation.
wdenkc6097192002-11-03 00:24:07 +00003077
Robert P. J. Day7207b362015-12-19 07:16:10 -05003078* For major contributions, add a MAINTAINERS file with your
3079 information and associated file and directory references.
wdenk2729af92004-05-03 20:45:30 +00003080
Albert ARIBAUD27af9302013-09-11 15:52:51 +02003081* When you add support for a new board, don't forget to add a
3082 maintainer e-mail address to the boards.cfg file, too.
wdenk2729af92004-05-03 20:45:30 +00003083
3084* If your patch adds new configuration options, don't forget to
3085 document these in the README file.
3086
Wolfgang Denk218ca722008-03-26 10:40:12 +01003087* The patch itself. If you are using git (which is *strongly*
3088 recommended) you can easily generate the patch using the
Wolfgang Denk7ca92962011-07-27 10:59:55 +00003089 "git format-patch". If you then use "git send-email" to send it to
Wolfgang Denk218ca722008-03-26 10:40:12 +01003090 the U-Boot mailing list, you will avoid most of the common problems
3091 with some other mail clients.
wdenk2729af92004-05-03 20:45:30 +00003092
Wolfgang Denk218ca722008-03-26 10:40:12 +01003093 If you cannot use git, use "diff -purN OLD NEW". If your version of
3094 diff does not support these options, then get the latest version of
3095 GNU diff.
wdenk2729af92004-05-03 20:45:30 +00003096
Wolfgang Denk218ca722008-03-26 10:40:12 +01003097 The current directory when running this command shall be the parent
3098 directory of the U-Boot source tree (i. e. please make sure that
3099 your patch includes sufficient directory information for the
3100 affected files).
3101
3102 We prefer patches as plain text. MIME attachments are discouraged,
3103 and compressed attachments must not be used.
wdenk2729af92004-05-03 20:45:30 +00003104
3105* If one logical set of modifications affects or creates several
3106 files, all these changes shall be submitted in a SINGLE patch file.
3107
3108* Changesets that contain different, unrelated modifications shall be
3109 submitted as SEPARATE patches, one patch per changeset.
3110
3111
3112Notes:
3113
Simon Glass6de80f22016-07-27 20:33:08 -06003114* Before sending the patch, run the buildman script on your patched
wdenk2729af92004-05-03 20:45:30 +00003115 source tree and make sure that no errors or warnings are reported
3116 for any of the boards.
3117
3118* Keep your modifications to the necessary minimum: A patch
3119 containing several unrelated changes or arbitrary reformats will be
3120 returned with a request to re-formatting / split it.
3121
3122* If you modify existing code, make sure that your new code does not
3123 add to the memory footprint of the code ;-) Small is beautiful!
3124 When adding new features, these should compile conditionally only
3125 (using #ifdef), and the resulting code with the new feature
3126 disabled must not need more memory than the old code without your
3127 modification.
wdenk90dc6702005-05-03 14:12:25 +00003128
Wolfgang Denk06682362008-12-30 22:56:11 +01003129* Remember that there is a size limit of 100 kB per message on the
3130 u-boot mailing list. Bigger patches will be moderated. If they are
3131 reasonable and not too big, they will be acknowledged. But patches
3132 bigger than the size limit should be avoided.