blob: 9800359e5dfe2748796be515b04a88517ac1efc4 [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
169Configuration is usually done using C preprocessor defines; the
170rationale behind that is to avoid dead code whenever possible.
171
172There are two classes of configuration variables:
173
174* Configuration _OPTIONS_:
175 These are selectable by the user and have names beginning with
176 "CONFIG_".
177
178* Configuration _SETTINGS_:
179 These depend on the hardware etc. and should not be meddled with if
180 you don't know what you're doing; they have names beginning with
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200181 "CONFIG_SYS_".
wdenkc6097192002-11-03 00:24:07 +0000182
Robert P. J. Day7207b362015-12-19 07:16:10 -0500183Previously, all configuration was done by hand, which involved creating
184symbolic links and editing configuration files manually. More recently,
185U-Boot has added the Kbuild infrastructure used by the Linux kernel,
186allowing you to use the "make menuconfig" command to configure your
187build.
wdenkc6097192002-11-03 00:24:07 +0000188
189
190Selection of Processor Architecture and Board Type:
191---------------------------------------------------
192
193For all supported boards there are ready-to-use default
Holger Freytherab584d62014-08-04 09:26:05 +0200194configurations available; just type "make <board_name>_defconfig".
wdenkc6097192002-11-03 00:24:07 +0000195
196Example: For a TQM823L module type:
197
198 cd u-boot
Holger Freytherab584d62014-08-04 09:26:05 +0200199 make TQM823L_defconfig
wdenkc6097192002-11-03 00:24:07 +0000200
Robert P. J. Day7207b362015-12-19 07:16:10 -0500201Note: If you're looking for the default configuration file for a board
202you're sure used to be there but is now missing, check the file
203doc/README.scrapyard for a list of no longer supported boards.
wdenkc6097192002-11-03 00:24:07 +0000204
Simon Glass75b3c3a2014-03-22 17:12:59 -0600205Sandbox Environment:
206--------------------
207
208U-Boot can be built natively to run on a Linux host using the 'sandbox'
209board. This allows feature development which is not board- or architecture-
210specific to be undertaken on a native platform. The sandbox is also used to
211run some of U-Boot's tests.
212
Naoki Hayamabbb140e2020-10-08 13:16:58 +0900213See doc/arch/sandbox.rst for more details.
Simon Glass75b3c3a2014-03-22 17:12:59 -0600214
215
Simon Glassdb910352015-03-03 08:03:00 -0700216Board Initialisation Flow:
217--------------------------
218
219This is the intended start-up flow for boards. This should apply for both
Robert P. J. Day7207b362015-12-19 07:16:10 -0500220SPL and U-Boot proper (i.e. they both follow the same rules).
Simon Glassdb910352015-03-03 08:03:00 -0700221
Robert P. J. Day7207b362015-12-19 07:16:10 -0500222Note: "SPL" stands for "Secondary Program Loader," which is explained in
223more detail later in this file.
224
225At present, SPL mostly uses a separate code path, but the function names
226and roles of each function are the same. Some boards or architectures
227may not conform to this. At least most ARM boards which use
228CONFIG_SPL_FRAMEWORK conform to this.
229
230Execution typically starts with an architecture-specific (and possibly
231CPU-specific) start.S file, such as:
232
233 - arch/arm/cpu/armv7/start.S
234 - arch/powerpc/cpu/mpc83xx/start.S
235 - arch/mips/cpu/start.S
236
237and so on. From there, three functions are called; the purpose and
238limitations of each of these functions are described below.
Simon Glassdb910352015-03-03 08:03:00 -0700239
240lowlevel_init():
241 - purpose: essential init to permit execution to reach board_init_f()
242 - no global_data or BSS
243 - there is no stack (ARMv7 may have one but it will soon be removed)
244 - must not set up SDRAM or use console
245 - must only do the bare minimum to allow execution to continue to
246 board_init_f()
247 - this is almost never needed
248 - return normally from this function
249
250board_init_f():
251 - purpose: set up the machine ready for running board_init_r():
252 i.e. SDRAM and serial UART
253 - global_data is available
254 - stack is in SRAM
255 - BSS is not available, so you cannot use global/static variables,
256 only stack variables and global_data
257
258 Non-SPL-specific notes:
259 - dram_init() is called to set up DRAM. If already done in SPL this
260 can do nothing
261
262 SPL-specific notes:
263 - you can override the entire board_init_f() function with your own
264 version as needed.
265 - preloader_console_init() can be called here in extremis
266 - should set up SDRAM, and anything needed to make the UART work
Naoki Hayama499696e2020-09-24 15:57:19 +0900267 - there is no need to clear BSS, it will be done by crt0.S
Andreas Dannenberg14254652019-08-08 12:54:49 -0500268 - for specific scenarios on certain architectures an early BSS *can*
269 be made available (via CONFIG_SPL_EARLY_BSS by moving the clearing
270 of BSS prior to entering board_init_f()) but doing so is discouraged.
271 Instead it is strongly recommended to architect any code changes
272 or additions such to not depend on the availability of BSS during
273 board_init_f() as indicated in other sections of this README to
274 maintain compatibility and consistency across the entire code base.
Simon Glassdb910352015-03-03 08:03:00 -0700275 - must return normally from this function (don't call board_init_r()
276 directly)
277
278Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
279this point the stack and global_data are relocated to below
280CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
281memory.
282
283board_init_r():
284 - purpose: main execution, common code
285 - global_data is available
286 - SDRAM is available
287 - BSS is available, all static/global variables can be used
288 - execution eventually continues to main_loop()
289
290 Non-SPL-specific notes:
291 - U-Boot is relocated to the top of memory and is now running from
292 there.
293
294 SPL-specific notes:
295 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
Ashish Kumar63b23162017-08-11 11:09:14 +0530296 CONFIG_SYS_FSL_HAS_CCI400
297
298 Defined For SoC that has cache coherent interconnect
299 CCN-400
wdenk7f6c2cb2002-11-10 22:06:23 +0000300
Ashish Kumarc055cee2017-08-18 10:54:36 +0530301 CONFIG_SYS_FSL_HAS_CCN504
302
303 Defined for SoC that has cache coherent interconnect CCN-504
304
wdenkc6097192002-11-03 00:24:07 +0000305The following options need to be configured:
306
Kim Phillips26281142007-08-10 13:28:25 -0500307- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
wdenkc6097192002-11-03 00:24:07 +0000308
Kim Phillips26281142007-08-10 13:28:25 -0500309- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
Wolfgang Denk6ccec442006-10-24 14:42:37 +0200310
Kumar Gala66412c62011-02-18 05:40:54 -0600311- 85xx CPU Options:
York Sunffd06e02012-10-08 07:44:30 +0000312 CONFIG_SYS_PPC64
313
314 Specifies that the core is a 64-bit PowerPC implementation (implements
315 the "64" category of the Power ISA). This is necessary for ePAPR
316 compliance, among other possible reasons.
317
Kumar Gala66412c62011-02-18 05:40:54 -0600318 CONFIG_SYS_FSL_TBCLK_DIV
319
320 Defines the core time base clock divider ratio compared to the
321 system clock. On most PQ3 devices this is 8, on newer QorIQ
322 devices it can be 16 or 32. The ratio varies from SoC to Soc.
323
Kumar Gala8f290842011-05-20 00:39:21 -0500324 CONFIG_SYS_FSL_PCIE_COMPAT
325
326 Defines the string to utilize when trying to match PCIe device
327 tree nodes for the given platform.
328
Scott Wood33eee332012-08-14 10:14:53 +0000329 CONFIG_SYS_FSL_ERRATUM_A004510
330
331 Enables a workaround for erratum A004510. If set,
332 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
333 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
334
335 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
336 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
337
338 Defines one or two SoC revisions (low 8 bits of SVR)
339 for which the A004510 workaround should be applied.
340
341 The rest of SVR is either not relevant to the decision
342 of whether the erratum is present (e.g. p2040 versus
343 p2041) or is implied by the build target, which controls
344 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
345
346 See Freescale App Note 4493 for more information about
347 this erratum.
348
349 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
350
351 This is the value to write into CCSR offset 0x18600
352 according to the A004510 workaround.
353
Priyanka Jain64501c62013-07-02 09:21:04 +0530354 CONFIG_SYS_FSL_DSP_DDR_ADDR
355 This value denotes start offset of DDR memory which is
356 connected exclusively to the DSP cores.
357
Priyanka Jain765b0bd2013-04-04 09:31:54 +0530358 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
359 This value denotes start offset of M2 memory
360 which is directly connected to the DSP core.
361
Priyanka Jain64501c62013-07-02 09:21:04 +0530362 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
363 This value denotes start offset of M3 memory which is directly
364 connected to the DSP core.
365
Priyanka Jain765b0bd2013-04-04 09:31:54 +0530366 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
367 This value denotes start offset of DSP CCSR space.
368
Priyanka Jainb1359912013-12-17 14:25:52 +0530369 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
370 Single Source Clock is clocking mode present in some of FSL SoC's.
371 In this mode, a single differential clock is used to supply
372 clocks to the sysclock, ddrclock and usbclock.
373
Aneesh Bansalfb4a2402014-03-18 23:40:26 +0530374 CONFIG_SYS_CPC_REINIT_F
375 This CONFIG is defined when the CPC is configured as SRAM at the
Bin Menga1875592016-02-05 19:30:11 -0800376 time of U-Boot entry and is required to be re-initialized.
Aneesh Bansalfb4a2402014-03-18 23:40:26 +0530377
Daniel Schwierzeck6cb461b2012-04-02 02:57:56 +0000378- Generic CPU options:
379 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
380
381 Defines the endianess of the CPU. Implementation of those
382 values is arch specific.
383
York Sun5614e712013-09-30 09:22:09 -0700384 CONFIG_SYS_FSL_DDR
385 Freescale DDR driver in use. This type of DDR controller is
Tom Rini1c588572021-05-14 21:34:26 -0400386 found in mpc83xx, mpc85xx as well as some ARM core SoCs.
York Sun5614e712013-09-30 09:22:09 -0700387
388 CONFIG_SYS_FSL_DDR_ADDR
389 Freescale DDR memory-mapped register base.
390
391 CONFIG_SYS_FSL_DDR_EMU
392 Specify emulator support for DDR. Some DDR features such as
393 deskew training are not available.
394
395 CONFIG_SYS_FSL_DDRC_GEN1
396 Freescale DDR1 controller.
397
398 CONFIG_SYS_FSL_DDRC_GEN2
399 Freescale DDR2 controller.
400
401 CONFIG_SYS_FSL_DDRC_GEN3
402 Freescale DDR3 controller.
403
York Sun34e026f2014-03-27 17:54:47 -0700404 CONFIG_SYS_FSL_DDRC_GEN4
405 Freescale DDR4 controller.
406
York Sun9ac4ffb2013-09-30 14:20:51 -0700407 CONFIG_SYS_FSL_DDRC_ARM_GEN3
408 Freescale DDR3 controller for ARM-based SoCs.
409
York Sun5614e712013-09-30 09:22:09 -0700410 CONFIG_SYS_FSL_DDR1
411 Board config to use DDR1. It can be enabled for SoCs with
412 Freescale DDR1 or DDR2 controllers, depending on the board
413 implemetation.
414
415 CONFIG_SYS_FSL_DDR2
Robert P. J. Day62a3b7d2016-07-15 13:44:45 -0400416 Board config to use DDR2. It can be enabled for SoCs with
York Sun5614e712013-09-30 09:22:09 -0700417 Freescale DDR2 or DDR3 controllers, depending on the board
418 implementation.
419
420 CONFIG_SYS_FSL_DDR3
421 Board config to use DDR3. It can be enabled for SoCs with
York Sun34e026f2014-03-27 17:54:47 -0700422 Freescale DDR3 or DDR3L controllers.
423
424 CONFIG_SYS_FSL_DDR3L
425 Board config to use DDR3L. It can be enabled for SoCs with
426 DDR3L controllers.
427
Prabhakar Kushwaha1b4175d2014-01-18 12:28:30 +0530428 CONFIG_SYS_FSL_IFC_BE
429 Defines the IFC controller register space as Big Endian
430
431 CONFIG_SYS_FSL_IFC_LE
432 Defines the IFC controller register space as Little Endian
433
Prabhakar Kushwaha1c407072017-02-02 15:01:26 +0530434 CONFIG_SYS_FSL_IFC_CLK_DIV
435 Defines divider of platform clock(clock input to IFC controller).
436
Prabhakar Kushwahaadd63f92017-02-02 15:02:00 +0530437 CONFIG_SYS_FSL_LBC_CLK_DIV
438 Defines divider of platform clock(clock input to eLBC controller).
439
York Sun4e5b1bd2014-02-10 13:59:42 -0800440 CONFIG_SYS_FSL_DDR_BE
441 Defines the DDR controller register space as Big Endian
442
443 CONFIG_SYS_FSL_DDR_LE
444 Defines the DDR controller register space as Little Endian
445
York Sun6b9e3092014-02-10 13:59:43 -0800446 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
447 Physical address from the view of DDR controllers. It is the
448 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
449 it could be different for ARM SoCs.
450
York Sun6b1e1252014-02-10 13:59:44 -0800451 CONFIG_SYS_FSL_DDR_INTLV_256B
452 DDR controller interleaving on 256-byte. This is a special
453 interleaving mode, handled by Dickens for Freescale layerscape
454 SoCs with ARM core.
455
York Sun1d71efb2014-08-01 15:51:00 -0700456 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
457 Number of controllers used as main memory.
458
459 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
460 Number of controllers used for other than main memory.
461
Ruchika Gupta028dbb82014-09-09 11:50:31 +0530462 CONFIG_SYS_FSL_SEC_BE
463 Defines the SEC controller register space as Big Endian
464
465 CONFIG_SYS_FSL_SEC_LE
466 Defines the SEC controller register space as Little Endian
467
Daniel Schwierzeck92bbd642011-07-27 13:22:39 +0200468- MIPS CPU options:
Daniel Schwierzeck92bbd642011-07-27 13:22:39 +0200469 CONFIG_XWAY_SWAP_BYTES
470
471 Enable compilation of tools/xway-swap-bytes needed for Lantiq
472 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
473 be swapped if a flash programmer is used.
474
Christian Rieschb67d8812012-02-02 00:44:39 +0000475- ARM options:
476 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
477
478 Select high exception vectors of the ARM core, e.g., do not
479 clear the V bit of the c1 register of CP15.
480
York Sun207774b2015-03-20 19:28:08 -0700481 COUNTER_FREQUENCY
482 Generic timer clock source frequency.
483
484 COUNTER_FREQUENCY_REAL
485 Generic timer clock source frequency if the real clock is
486 different from COUNTER_FREQUENCY, and can only be determined
487 at run time.
488
Stephen Warren73c38932015-01-19 16:25:52 -0700489- Tegra SoC options:
490 CONFIG_TEGRA_SUPPORT_NON_SECURE
491
492 Support executing U-Boot in non-secure (NS) mode. Certain
493 impossible actions will be skipped if the CPU is in NS mode,
494 such as ARM architectural timer initialization.
495
wdenk5da627a2003-10-09 20:09:04 +0000496- Linux Kernel Interface:
wdenk5da627a2003-10-09 20:09:04 +0000497 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
498
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -0800499 When transferring memsize parameter to Linux, some versions
wdenk5da627a2003-10-09 20:09:04 +0000500 expect it to be in bytes, others in MB.
501 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
502
Gerald Van Barenfec6d9e2008-06-03 20:34:45 -0400503 CONFIG_OF_LIBFDT
Wolfgang Denkf57f70a2005-10-13 01:45:54 +0200504
505 New kernel versions are expecting firmware settings to be
Gerald Van Baren213bf8c2007-03-31 12:23:51 -0400506 passed using flattened device trees (based on open firmware
507 concepts).
508
509 CONFIG_OF_LIBFDT
510 * New libfdt-based support
511 * Adds the "fdt" command
Kim Phillips3bb342f2007-08-10 14:34:14 -0500512 * The bootm command automatically updates the fdt
Gerald Van Baren213bf8c2007-03-31 12:23:51 -0400513
Wolfgang Denkf57f70a2005-10-13 01:45:54 +0200514 OF_TBCLK - The timebase frequency.
515
Marcel Ziswiler11ccc332008-07-09 08:17:15 +0200516 boards with QUICC Engines require OF_QE to set UCC MAC
517 addresses
Kim Phillips3bb342f2007-08-10 14:34:14 -0500518
Heiko Schocher3887c3f2009-09-23 07:56:08 +0200519 CONFIG_OF_IDE_FIXUP
520
521 U-Boot can detect if an IDE device is present or not.
522 If not, and this new config option is activated, U-Boot
523 removes the ATA node from the DTS before booting Linux,
524 so the Linux IDE driver does not probe the device and
525 crash. This is needed for buggy hardware (uc101) where
526 no pull down resistor is connected to the signal IDE5V_DD7.
527
Niklaus Giger0b2f4ec2008-11-03 22:13:47 +0100528- vxWorks boot parameters:
529
530 bootvx constructs a valid bootline using the following
Bin Meng9e98b7e2015-10-07 20:19:17 -0700531 environments variables: bootdev, bootfile, ipaddr, netmask,
532 serverip, gatewayip, hostname, othbootargs.
Niklaus Giger0b2f4ec2008-11-03 22:13:47 +0100533 It loads the vxWorks image pointed bootfile.
534
Naoki Hayama81a05d92020-10-08 13:17:08 +0900535 Note: If a "bootargs" environment is defined, it will override
Niklaus Giger0b2f4ec2008-11-03 22:13:47 +0100536 the defaults discussed just above.
537
Aneesh V93bc2192011-06-16 23:30:51 +0000538- Cache Configuration for ARM:
539 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
540 controller
541 CONFIG_SYS_PL310_BASE - Physical base address of PL310
542 controller register space
543
wdenk6705d812004-08-02 23:22:59 +0000544- Serial Ports:
wdenk6705d812004-08-02 23:22:59 +0000545 CONFIG_PL011_CLOCK
546
547 If you have Amba PrimeCell PL011 UARTs, set this variable to
548 the clock speed of the UARTs.
549
550 CONFIG_PL01x_PORTS
551
552 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
553 define this to a list of base addresses for each (supported)
554 port. See e.g. include/configs/versatile.h
555
Karicheri, Muralidharand57dee52014-04-09 15:38:46 -0400556 CONFIG_SERIAL_HW_FLOW_CONTROL
557
558 Define this variable to enable hw flow control in serial driver.
559 Current user of this option is drivers/serial/nsl16550.c driver
wdenk6705d812004-08-02 23:22:59 +0000560
wdenkc6097192002-11-03 00:24:07 +0000561- Serial Download Echo Mode:
562 CONFIG_LOADS_ECHO
563 If defined to 1, all characters received during a
564 serial download (using the "loads" command) are
565 echoed back. This might be needed by some terminal
566 emulations (like "cu"), but may as well just take
567 time on others. This setting #define's the initial
568 value of the "loads_echo" environment variable.
569
Simon Glass302a6482016-03-13 19:07:28 -0600570- Removal of commands
571 If no commands are needed to boot, you can disable
572 CONFIG_CMDLINE to remove them. In this case, the command line
573 will not be available, and when U-Boot wants to execute the
574 boot command (on start-up) it will call board_run_command()
575 instead. This can reduce image size significantly for very
576 simple boot procedures.
577
Wolfgang Denka5ecbe62013-03-23 23:50:31 +0000578- Regular expression support:
579 CONFIG_REGEX
Wolfgang Denk93e14592013-10-04 17:43:24 +0200580 If this variable is defined, U-Boot is linked against
581 the SLRE (Super Light Regular Expression) library,
582 which adds regex support to some commands, as for
583 example "env grep" and "setexpr".
Wolfgang Denka5ecbe62013-03-23 23:50:31 +0000584
wdenkc6097192002-11-03 00:24:07 +0000585- Watchdog:
Rasmus Villemoes933ada52021-04-14 09:18:22 +0200586 CONFIG_SYS_WATCHDOG_FREQ
587 Some platforms automatically call WATCHDOG_RESET()
588 from the timer interrupt handler every
589 CONFIG_SYS_WATCHDOG_FREQ interrupts. If not set by the
590 board configuration file, a default of CONFIG_SYS_HZ/2
591 (i.e. 500) is used. Setting CONFIG_SYS_WATCHDOG_FREQ
592 to 0 disables calling WATCHDOG_RESET() from the timer
593 interrupt.
594
wdenkc6097192002-11-03 00:24:07 +0000595- Real-Time Clock:
596
Jon Loeliger602ad3b2007-06-11 19:03:39 -0500597 When CONFIG_CMD_DATE is selected, the type of the RTC
wdenkc6097192002-11-03 00:24:07 +0000598 has to be selected, too. Define exactly one of the
599 following options:
600
wdenkc6097192002-11-03 00:24:07 +0000601 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
Fabio Estevam4e8b7542011-10-24 06:44:15 +0000602 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
wdenkc6097192002-11-03 00:24:07 +0000603 CONFIG_RTC_MC146818 - use MC146818 RTC
wdenk1cb8e982003-03-06 21:55:29 +0000604 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
wdenkc6097192002-11-03 00:24:07 +0000605 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
wdenk7f70e852003-05-20 14:25:27 +0000606 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
Markus Niebel412921d2014-07-21 11:06:16 +0200607 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
wdenk3bac3512003-03-12 10:41:04 +0000608 CONFIG_RTC_DS164x - use Dallas DS164x RTC
Tor Krill9536dfc2008-03-15 15:40:26 +0100609 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
wdenk4c0d4c32004-06-09 17:34:58 +0000610 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
Chris Packham2bd3cab2017-05-30 12:03:33 +1200611 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
Heiko Schocher71d19f32011-03-28 09:24:22 +0200612 CONFIG_SYS_RV3029_TCR - enable trickle charger on
613 RV3029 RTC.
wdenkc6097192002-11-03 00:24:07 +0000614
wdenkb37c7e52003-06-30 16:24:52 +0000615 Note that if the RTC uses I2C, then the I2C interface
616 must also be configured. See I2C Support, below.
617
Peter Tysere92739d2008-12-17 16:36:21 -0600618- GPIO Support:
619 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
Peter Tysere92739d2008-12-17 16:36:21 -0600620
Chris Packham5dec49c2010-12-19 10:12:13 +0000621 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
622 chip-ngpio pairs that tell the PCA953X driver the number of
623 pins supported by a particular chip.
624
Peter Tysere92739d2008-12-17 16:36:21 -0600625 Note that if the GPIO device uses I2C, then the I2C interface
626 must also be configured. See I2C Support, below.
627
Simon Glassaa532332014-06-11 23:29:41 -0600628- I/O tracing:
629 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
630 accesses and can checksum them or write a list of them out
631 to memory. See the 'iotrace' command for details. This is
632 useful for testing device drivers since it can confirm that
633 the driver behaves the same way before and after a code
634 change. Currently this is supported on sandbox and arm. To
635 add support for your architecture, add '#include <iotrace.h>'
636 to the bottom of arch/<arch>/include/asm/io.h and test.
637
638 Example output from the 'iotrace stats' command is below.
639 Note that if the trace buffer is exhausted, the checksum will
640 still continue to operate.
641
642 iotrace is enabled
643 Start: 10000000 (buffer start address)
644 Size: 00010000 (buffer size)
645 Offset: 00000120 (current buffer offset)
646 Output: 10000120 (start + offset)
647 Count: 00000018 (number of trace records)
648 CRC32: 9526fb66 (CRC32 of all trace records)
649
wdenkc6097192002-11-03 00:24:07 +0000650- Timestamp Support:
651
wdenk43d96162003-03-06 00:02:04 +0000652 When CONFIG_TIMESTAMP is selected, the timestamp
653 (date and time) of an image is printed by image
654 commands like bootm or iminfo. This option is
Jon Loeliger602ad3b2007-06-11 19:03:39 -0500655 automatically enabled when you select CONFIG_CMD_DATE .
wdenkc6097192002-11-03 00:24:07 +0000656
Karl O. Pinc923c46f2012-08-16 06:20:15 +0000657- Partition Labels (disklabels) Supported:
658 Zero or more of the following:
659 CONFIG_MAC_PARTITION Apple's MacOS partition table.
Karl O. Pinc923c46f2012-08-16 06:20:15 +0000660 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
661 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
662 bootloader. Note 2TB partition limit; see
663 disk/part_efi.c
Simon Glassc649e3c2016-05-01 11:36:02 -0600664 CONFIG_SCSI) you must configure support for at
Karl O. Pinc923c46f2012-08-16 06:20:15 +0000665 least one non-MTD partition type as well.
wdenkc6097192002-11-03 00:24:07 +0000666
wdenkc40b2952004-03-13 23:29:43 +0000667- LBA48 Support
668 CONFIG_LBA48
669
670 Set this to enable support for disks larger than 137GB
Heiko Schocher4b142fe2009-12-03 11:21:21 +0100671 Also look at CONFIG_SYS_64BIT_LBA.
wdenkc40b2952004-03-13 23:29:43 +0000672 Whithout these , LBA48 support uses 32bit variables and will 'only'
673 support disks up to 2.1TB.
674
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200675 CONFIG_SYS_64BIT_LBA:
wdenkc40b2952004-03-13 23:29:43 +0000676 When enabled, makes the IDE subsystem use 64bit sector addresses.
677 Default is 32bit.
678
wdenkc6097192002-11-03 00:24:07 +0000679- NETWORK Support (PCI):
Kyle Moffettce5207e2011-10-18 11:05:29 +0000680 CONFIG_E1000_SPI
681 Utility code for direct access to the SPI bus on Intel 8257x.
682 This does not do anything useful unless you set at least one
683 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
684
wdenkc6097192002-11-03 00:24:07 +0000685 CONFIG_NATSEMI
686 Support for National dp83815 chips.
687
688 CONFIG_NS8382X
689 Support for National dp8382[01] gigabit chips.
690
wdenk45219c42003-05-12 21:50:16 +0000691- NETWORK Support (other):
Rob Herringefdd7312011-12-15 11:15:49 +0000692 CONFIG_CALXEDA_XGMAC
693 Support for the Calxeda XGMAC device
694
Ashok3bb46d22012-10-15 06:20:47 +0000695 CONFIG_LAN91C96
wdenk45219c42003-05-12 21:50:16 +0000696 Support for SMSC's LAN91C96 chips.
697
wdenk45219c42003-05-12 21:50:16 +0000698 CONFIG_LAN91C96_USE_32_BIT
699 Define this to enable 32 bit addressing
700
Ashok3bb46d22012-10-15 06:20:47 +0000701 CONFIG_SMC91111
wdenkf39748a2004-06-09 13:37:52 +0000702 Support for SMSC's LAN91C111 chip
703
704 CONFIG_SMC91111_BASE
705 Define this to hold the physical address
706 of the device (I/O space)
707
708 CONFIG_SMC_USE_32_BIT
709 Define this if data bus is 32 bits
710
711 CONFIG_SMC_USE_IOFUNCS
712 Define this to use i/o functions instead of macros
713 (some hardware wont work with macros)
714
Heiko Schocherdc02bad2011-11-15 10:00:04 -0500715 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
716 Define this if you have more then 3 PHYs.
717
Macpaul Linb3dbf4a52010-12-21 16:59:46 +0800718 CONFIG_FTGMAC100
719 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
720
721 CONFIG_FTGMAC100_EGIGA
722 Define this to use GE link update with gigabit PHY.
723 Define this if FTGMAC100 is connected to gigabit PHY.
724 If your system has 10/100 PHY only, it might not occur
725 wrong behavior. Because PHY usually return timeout or
726 useless data when polling gigabit status and gigabit
727 control registers. This behavior won't affect the
728 correctnessof 10/100 link speed update.
729
Yoshihiro Shimoda3d0075f2011-01-27 10:06:03 +0900730 CONFIG_SH_ETHER
731 Support for Renesas on-chip Ethernet controller
732
733 CONFIG_SH_ETHER_USE_PORT
734 Define the number of ports to be used
735
736 CONFIG_SH_ETHER_PHY_ADDR
737 Define the ETH PHY's address
738
Yoshihiro Shimoda68260aa2011-01-27 10:06:08 +0900739 CONFIG_SH_ETHER_CACHE_WRITEBACK
740 If this option is set, the driver enables cache flush.
741
Vadim Bendebury5e124722011-10-17 08:36:14 +0000742- TPM Support:
Che-liang Chiou90899cc2013-04-12 11:04:34 +0000743 CONFIG_TPM
744 Support TPM devices.
745
Christophe Ricard0766ad22015-10-06 22:54:41 +0200746 CONFIG_TPM_TIS_INFINEON
747 Support for Infineon i2c bus TPM devices. Only one device
Tom Wai-Hong Tam1b393db2013-04-12 11:04:37 +0000748 per system is supported at this time.
749
Tom Wai-Hong Tam1b393db2013-04-12 11:04:37 +0000750 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
751 Define the burst count bytes upper limit
752
Christophe Ricard3aa74082016-01-21 23:27:13 +0100753 CONFIG_TPM_ST33ZP24
754 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
755
756 CONFIG_TPM_ST33ZP24_I2C
757 Support for STMicroelectronics ST33ZP24 I2C devices.
758 Requires TPM_ST33ZP24 and I2C.
759
Christophe Ricardb75fdc12016-01-21 23:27:14 +0100760 CONFIG_TPM_ST33ZP24_SPI
761 Support for STMicroelectronics ST33ZP24 SPI devices.
762 Requires TPM_ST33ZP24 and SPI.
763
Dirk Eibachc01939c2013-06-26 15:55:15 +0200764 CONFIG_TPM_ATMEL_TWI
765 Support for Atmel TWI TPM device. Requires I2C support.
766
Che-liang Chiou90899cc2013-04-12 11:04:34 +0000767 CONFIG_TPM_TIS_LPC
Vadim Bendebury5e124722011-10-17 08:36:14 +0000768 Support for generic parallel port TPM devices. Only one device
769 per system is supported at this time.
770
771 CONFIG_TPM_TIS_BASE_ADDRESS
772 Base address where the generic TPM device is mapped
773 to. Contemporary x86 systems usually map it at
774 0xfed40000.
775
Reinhard Pfaube6c1522013-06-26 15:55:13 +0200776 CONFIG_TPM
777 Define this to enable the TPM support library which provides
778 functional interfaces to some TPM commands.
779 Requires support for a TPM device.
780
781 CONFIG_TPM_AUTH_SESSIONS
782 Define this to enable authorized functions in the TPM library.
783 Requires CONFIG_TPM and CONFIG_SHA1.
784
wdenkc6097192002-11-03 00:24:07 +0000785- USB Support:
786 At the moment only the UHCI host controller is
Heiko Schocher064b55c2017-06-14 05:49:40 +0200787 supported (PIP405, MIP405); define
wdenkc6097192002-11-03 00:24:07 +0000788 CONFIG_USB_UHCI to enable it.
789 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
wdenk30d56fa2004-10-09 22:44:59 +0000790 and define CONFIG_USB_STORAGE to enable the USB
wdenkc6097192002-11-03 00:24:07 +0000791 storage devices.
792 Note:
793 Supported are USB Keyboards and USB Floppy drives
794 (TEAC FD-05PUB).
wdenk4d13cba2004-03-14 14:09:05 +0000795
Simon Glass9ab4ce22012-02-27 10:52:47 +0000796 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
797 txfilltuning field in the EHCI controller on reset.
798
Oleksandr Tymoshenko6e9e0622014-02-01 21:51:25 -0700799 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
800 HW module registers.
801
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200802- USB Device:
803 Define the below if you wish to use the USB console.
804 Once firmware is rebuilt from a serial console issue the
805 command "setenv stdin usbtty; setenv stdout usbtty" and
Marcel Ziswiler11ccc332008-07-09 08:17:15 +0200806 attach your USB cable. The Unix command "dmesg" should print
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200807 it has found a new device. The environment variable usbtty
808 can be set to gserial or cdc_acm to enable your device to
Wolfgang Denk386eda02006-06-14 18:14:56 +0200809 appear to a USB host as a Linux gserial device or a
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200810 Common Device Class Abstract Control Model serial device.
811 If you select usbtty = gserial you should be able to enumerate
812 a Linux host by
813 # modprobe usbserial vendor=0xVendorID product=0xProductID
814 else if using cdc_acm, simply setting the environment
815 variable usbtty to be cdc_acm should suffice. The following
816 might be defined in YourBoardName.h
Wolfgang Denk386eda02006-06-14 18:14:56 +0200817
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200818 CONFIG_USB_DEVICE
819 Define this to build a UDC device
wdenkc6097192002-11-03 00:24:07 +0000820
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200821 CONFIG_USB_TTY
822 Define this to have a tty type of device available to
823 talk to the UDC device
Wolfgang Denk386eda02006-06-14 18:14:56 +0200824
Vipin KUMARf9da0f82012-03-26 15:38:06 +0530825 CONFIG_USBD_HS
826 Define this to enable the high speed support for usb
827 device and usbtty. If this feature is enabled, a routine
828 int is_usbd_high_speed(void)
829 also needs to be defined by the driver to dynamically poll
830 whether the enumeration has succeded at high speed or full
831 speed.
832
Wolfgang Denk386eda02006-06-14 18:14:56 +0200833 If you have a USB-IF assigned VendorID then you may wish to
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200834 define your own vendor specific values either in BoardName.h
Wolfgang Denk386eda02006-06-14 18:14:56 +0200835 or directly in usbd_vendor_info.h. If you don't define
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200836 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
837 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
838 should pretend to be a Linux device to it's target host.
839
840 CONFIG_USBD_MANUFACTURER
841 Define this string as the name of your company for
842 - CONFIG_USBD_MANUFACTURER "my company"
Wolfgang Denk386eda02006-06-14 18:14:56 +0200843
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200844 CONFIG_USBD_PRODUCT_NAME
845 Define this string as the name of your product
846 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
847
848 CONFIG_USBD_VENDORID
849 Define this as your assigned Vendor ID from the USB
850 Implementors Forum. This *must* be a genuine Vendor ID
851 to avoid polluting the USB namespace.
852 - CONFIG_USBD_VENDORID 0xFFFF
Wolfgang Denk386eda02006-06-14 18:14:56 +0200853
Wolfgang Denk16c8d5e2006-06-14 17:45:53 +0200854 CONFIG_USBD_PRODUCTID
855 Define this as the unique Product ID
856 for your device
857 - CONFIG_USBD_PRODUCTID 0xFFFF
wdenkc6097192002-11-03 00:24:07 +0000858
Igor Grinbergd70a5602011-12-12 12:08:35 +0200859- ULPI Layer Support:
860 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
861 the generic ULPI layer. The generic layer accesses the ULPI PHY
862 via the platform viewport, so you need both the genric layer and
863 the viewport enabled. Currently only Chipidea/ARC based
864 viewport is supported.
865 To enable the ULPI layer support, define CONFIG_USB_ULPI and
866 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
Lucas Stach6d365ea2012-10-01 00:44:35 +0200867 If your ULPI phy needs a different reference clock than the
868 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
869 the appropriate value in Hz.
wdenkc6097192002-11-03 00:24:07 +0000870
871- MMC Support:
872 The MMC controller on the Intel PXA is supported. To
873 enable this define CONFIG_MMC. The MMC can be
874 accessed from the boot prompt by mapping the device
875 to physical memory similar to flash. Command line is
Jon Loeliger602ad3b2007-06-11 19:03:39 -0500876 enabled with CONFIG_CMD_MMC. The MMC driver also works with
877 the FAT fs. This is enabled with CONFIG_CMD_FAT.
wdenkc6097192002-11-03 00:24:07 +0000878
Yoshihiro Shimodaafb35662011-07-04 22:21:22 +0000879 CONFIG_SH_MMCIF
880 Support for Renesas on-chip MMCIF controller
881
882 CONFIG_SH_MMCIF_ADDR
883 Define the base address of MMCIF registers
884
885 CONFIG_SH_MMCIF_CLK
886 Define the clock frequency for MMCIF
887
Tom Rinib3ba6e92013-03-14 05:32:47 +0000888- USB Device Firmware Update (DFU) class support:
Marek Vasutbb4059a2018-02-16 16:41:18 +0100889 CONFIG_DFU_OVER_USB
Tom Rinib3ba6e92013-03-14 05:32:47 +0000890 This enables the USB portion of the DFU USB class
891
Pantelis Antoniouc6631762013-03-14 05:32:52 +0000892 CONFIG_DFU_NAND
893 This enables support for exposing NAND devices via DFU.
894
Afzal Mohammeda9479f02013-09-18 01:15:24 +0530895 CONFIG_DFU_RAM
896 This enables support for exposing RAM via DFU.
897 Note: DFU spec refer to non-volatile memory usage, but
898 allow usages beyond the scope of spec - here RAM usage,
899 one that would help mostly the developer.
900
Heiko Schochere7e75c72013-06-12 06:05:51 +0200901 CONFIG_SYS_DFU_DATA_BUF_SIZE
902 Dfu transfer uses a buffer before writing data to the
903 raw storage device. Make the size (in bytes) of this buffer
904 configurable. The size of this buffer is also configurable
905 through the "dfu_bufsiz" environment variable.
906
Pantelis Antoniouea2453d2013-03-14 05:32:48 +0000907 CONFIG_SYS_DFU_MAX_FILE_SIZE
908 When updating files rather than the raw storage device,
909 we use a static buffer to copy the file into and then write
910 the buffer once we've been given the whole file. Define
911 this to the maximum filesize (in bytes) for the buffer.
912 Default is 4 MiB if undefined.
913
Heiko Schocher001a8312014-03-18 08:09:56 +0100914 DFU_DEFAULT_POLL_TIMEOUT
915 Poll timeout [ms], is the timeout a device can send to the
916 host. The host must wait for this timeout before sending
917 a subsequent DFU_GET_STATUS request to the device.
918
919 DFU_MANIFEST_POLL_TIMEOUT
920 Poll timeout [ms], which the device sends to the host when
921 entering dfuMANIFEST state. Host waits this timeout, before
922 sending again an USB request to the device.
923
wdenk6705d812004-08-02 23:22:59 +0000924- Journaling Flash filesystem support:
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200925 CONFIG_SYS_JFFS2_FIRST_SECTOR,
926 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
wdenk6705d812004-08-02 23:22:59 +0000927 Define these for a default partition on a NOR device
928
wdenkc6097192002-11-03 00:24:07 +0000929- Keyboard Support:
Simon Glass39f615e2015-11-11 10:05:47 -0700930 See Kconfig help for available keyboard drivers.
931
wdenkc6097192002-11-03 00:24:07 +0000932- LCD Support: CONFIG_LCD
933
934 Define this to enable LCD support (for output to LCD
935 display); also select one of the supported displays
936 by defining one of these:
937
wdenkfd3103b2003-11-25 16:55:19 +0000938 CONFIG_NEC_NL6448AC33:
wdenkc6097192002-11-03 00:24:07 +0000939
wdenkfd3103b2003-11-25 16:55:19 +0000940 NEC NL6448AC33-18. Active, color, single scan.
wdenkc6097192002-11-03 00:24:07 +0000941
wdenkfd3103b2003-11-25 16:55:19 +0000942 CONFIG_NEC_NL6448BC20
wdenkc6097192002-11-03 00:24:07 +0000943
wdenkfd3103b2003-11-25 16:55:19 +0000944 NEC NL6448BC20-08. 6.5", 640x480.
945 Active, color, single scan.
946
947 CONFIG_NEC_NL6448BC33_54
948
949 NEC NL6448BC33-54. 10.4", 640x480.
wdenkc6097192002-11-03 00:24:07 +0000950 Active, color, single scan.
951
952 CONFIG_SHARP_16x9
953
954 Sharp 320x240. Active, color, single scan.
955 It isn't 16x9, and I am not sure what it is.
956
957 CONFIG_SHARP_LQ64D341
958
959 Sharp LQ64D341 display, 640x480.
960 Active, color, single scan.
961
962 CONFIG_HLD1045
963
964 HLD1045 display, 640x480.
965 Active, color, single scan.
966
967 CONFIG_OPTREX_BW
968
969 Optrex CBL50840-2 NF-FW 99 22 M5
970 or
971 Hitachi LMG6912RPFC-00T
972 or
973 Hitachi SP14Q002
974
975 320x240. Black & white.
976
Simon Glass676d3192012-10-17 13:24:54 +0000977 CONFIG_LCD_ALIGNMENT
978
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -0800979 Normally the LCD is page-aligned (typically 4KB). If this is
Simon Glass676d3192012-10-17 13:24:54 +0000980 defined then the LCD will be aligned to this value instead.
981 For ARM it is sometimes useful to use MMU_SECTION_SIZE
982 here, since it is cheaper to change data cache settings on
983 a per-section basis.
984
985
Hannes Petermaier604c7d42015-03-27 08:01:38 +0100986 CONFIG_LCD_ROTATION
987
988 Sometimes, for example if the display is mounted in portrait
989 mode or even if it's mounted landscape but rotated by 180degree,
990 we need to rotate our content of the display relative to the
991 framebuffer, so that user can read the messages which are
992 printed out.
993 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
994 initialized with a given rotation from "vl_rot" out of
995 "vidinfo_t" which is provided by the board specific code.
996 The value for vl_rot is coded as following (matching to
997 fbcon=rotate:<n> linux-kernel commandline):
998 0 = no rotation respectively 0 degree
999 1 = 90 degree rotation
1000 2 = 180 degree rotation
1001 3 = 270 degree rotation
1002
1003 If CONFIG_LCD_ROTATION is not defined, the console will be
1004 initialized with 0degree rotation.
1005
wdenk17ea1172004-06-06 21:51:03 +00001006- MII/PHY support:
wdenk17ea1172004-06-06 21:51:03 +00001007 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1008
1009 The clock frequency of the MII bus
1010
wdenk17ea1172004-06-06 21:51:03 +00001011 CONFIG_PHY_CMD_DELAY (ppc4xx)
1012
1013 Some PHY like Intel LXT971A need extra delay after
1014 command issued before MII status register can be read
1015
wdenkc6097192002-11-03 00:24:07 +00001016- IP address:
1017 CONFIG_IPADDR
1018
1019 Define a default value for the IP address to use for
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001020 the default Ethernet interface, in case this is not
wdenkc6097192002-11-03 00:24:07 +00001021 determined through e.g. bootp.
Wolfgang Denk1ebcd652011-10-26 10:21:22 +00001022 (Environment variable "ipaddr")
wdenkc6097192002-11-03 00:24:07 +00001023
1024- Server IP address:
1025 CONFIG_SERVERIP
1026
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001027 Defines a default value for the IP address of a TFTP
wdenkc6097192002-11-03 00:24:07 +00001028 server to contact when using the "tftboot" command.
Wolfgang Denk1ebcd652011-10-26 10:21:22 +00001029 (Environment variable "serverip")
wdenkc6097192002-11-03 00:24:07 +00001030
Wolfgang Denk1ebcd652011-10-26 10:21:22 +00001031- Gateway IP address:
1032 CONFIG_GATEWAYIP
1033
1034 Defines a default value for the IP address of the
1035 default router where packets to other networks are
1036 sent to.
1037 (Environment variable "gatewayip")
1038
1039- Subnet mask:
1040 CONFIG_NETMASK
1041
1042 Defines a default value for the subnet mask (or
1043 routing prefix) which is used to determine if an IP
1044 address belongs to the local subnet or needs to be
1045 forwarded through a router.
1046 (Environment variable "netmask")
1047
wdenkc6097192002-11-03 00:24:07 +00001048- BOOTP Recovery Mode:
1049 CONFIG_BOOTP_RANDOM_DELAY
1050
1051 If you have many targets in a network that try to
1052 boot using BOOTP, you may want to avoid that all
1053 systems send out BOOTP requests at precisely the same
1054 moment (which would happen for instance at recovery
1055 from a power failure, when all systems will try to
1056 boot, thus flooding the BOOTP server. Defining
1057 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1058 inserted before sending out BOOTP requests. The
Wolfgang Denk6c33c782007-08-06 23:21:05 +02001059 following delays are inserted then:
wdenkc6097192002-11-03 00:24:07 +00001060
1061 1st BOOTP request: delay 0 ... 1 sec
1062 2nd BOOTP request: delay 0 ... 2 sec
1063 3rd BOOTP request: delay 0 ... 4 sec
1064 4th and following
1065 BOOTP requests: delay 0 ... 8 sec
1066
Thierry Reding92ac8ac2014-08-19 10:21:24 +02001067 CONFIG_BOOTP_ID_CACHE_SIZE
1068
1069 BOOTP packets are uniquely identified using a 32-bit ID. The
1070 server will copy the ID from client requests to responses and
1071 U-Boot will use this to determine if it is the destination of
1072 an incoming response. Some servers will check that addresses
1073 aren't in use before handing them out (usually using an ARP
1074 ping) and therefore take up to a few hundred milliseconds to
1075 respond. Network congestion may also influence the time it
1076 takes for a response to make it back to the client. If that
1077 time is too long, U-Boot will retransmit requests. In order
1078 to allow earlier responses to still be accepted after these
1079 retransmissions, U-Boot's BOOTP client keeps a small cache of
1080 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
1081 cache. The default is to keep IDs for up to four outstanding
1082 requests. Increasing this will allow U-Boot to accept offers
1083 from a BOOTP client in networks with unusually high latency.
1084
stroesefe389a82003-08-28 14:17:32 +00001085- DHCP Advanced Options:
Joe Hershberger2c00e092012-05-23 07:59:19 +00001086
Joe Hershbergerd22c3382012-05-23 08:00:12 +00001087 - Link-local IP address negotiation:
1088 Negotiate with other link-local clients on the local network
1089 for an address that doesn't require explicit configuration.
1090 This is especially useful if a DHCP server cannot be guaranteed
1091 to exist in all environments that the device must operate.
1092
1093 See doc/README.link-local for more information.
1094
Prabhakar Kushwaha24acb832017-11-23 16:51:32 +05301095 - MAC address from environment variables
1096
1097 FDT_SEQ_MACADDR_FROM_ENV
1098
1099 Fix-up device tree with MAC addresses fetched sequentially from
1100 environment variables. This config work on assumption that
1101 non-usable ethernet node of device-tree are either not present
1102 or their status has been marked as "disabled".
1103
wdenka3d991b2004-04-15 21:48:45 +00001104 - CDP Options:
wdenk6e592382004-04-18 17:39:38 +00001105 CONFIG_CDP_DEVICE_ID
wdenka3d991b2004-04-15 21:48:45 +00001106
1107 The device id used in CDP trigger frames.
1108
1109 CONFIG_CDP_DEVICE_ID_PREFIX
1110
1111 A two character string which is prefixed to the MAC address
1112 of the device.
1113
1114 CONFIG_CDP_PORT_ID
1115
1116 A printf format string which contains the ascii name of
1117 the port. Normally is set to "eth%d" which sets
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001118 eth0 for the first Ethernet, eth1 for the second etc.
wdenka3d991b2004-04-15 21:48:45 +00001119
1120 CONFIG_CDP_CAPABILITIES
1121
1122 A 32bit integer which indicates the device capabilities;
1123 0x00000010 for a normal host which does not forwards.
1124
1125 CONFIG_CDP_VERSION
1126
1127 An ascii string containing the version of the software.
1128
1129 CONFIG_CDP_PLATFORM
1130
1131 An ascii string containing the name of the platform.
1132
1133 CONFIG_CDP_TRIGGER
1134
1135 A 32bit integer sent on the trigger.
1136
1137 CONFIG_CDP_POWER_CONSUMPTION
1138
1139 A 16bit integer containing the power consumption of the
1140 device in .1 of milliwatts.
1141
1142 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1143
1144 A byte containing the id of the VLAN.
1145
Uri Mashiach79267ed2017-01-19 10:51:05 +02001146- Status LED: CONFIG_LED_STATUS
wdenkc6097192002-11-03 00:24:07 +00001147
1148 Several configurations allow to display the current
1149 status using a LED. For instance, the LED will blink
1150 fast while running U-Boot code, stop blinking as
1151 soon as a reply to a BOOTP request was received, and
1152 start blinking slow once the Linux kernel is running
1153 (supported by a status LED driver in the Linux
Uri Mashiach79267ed2017-01-19 10:51:05 +02001154 kernel). Defining CONFIG_LED_STATUS enables this
wdenkc6097192002-11-03 00:24:07 +00001155 feature in U-Boot.
1156
Igor Grinberg1df7bbb2013-11-08 01:03:50 +02001157 Additional options:
1158
Uri Mashiach79267ed2017-01-19 10:51:05 +02001159 CONFIG_LED_STATUS_GPIO
Igor Grinberg1df7bbb2013-11-08 01:03:50 +02001160 The status LED can be connected to a GPIO pin.
1161 In such cases, the gpio_led driver can be used as a
Uri Mashiach79267ed2017-01-19 10:51:05 +02001162 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO
Igor Grinberg1df7bbb2013-11-08 01:03:50 +02001163 to include the gpio_led driver in the U-Boot binary.
1164
Igor Grinberg9dfdcdf2013-11-08 01:03:52 +02001165 CONFIG_GPIO_LED_INVERTED_TABLE
1166 Some GPIO connected LEDs may have inverted polarity in which
1167 case the GPIO high value corresponds to LED off state and
1168 GPIO low value corresponds to LED on state.
1169 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
1170 with a list of GPIO LEDs that have inverted polarity.
1171
Tom Rini55dabcc2021-08-18 23:12:24 -04001172- I2C Support:
Heiko Schocher3f4978c2012-01-16 21:12:24 +00001173 CONFIG_SYS_NUM_I2C_BUSES
Simon Glass945a18e2016-10-02 18:01:05 -06001174 Hold the number of i2c buses you want to use.
Heiko Schocher3f4978c2012-01-16 21:12:24 +00001175
1176 CONFIG_SYS_I2C_DIRECT_BUS
1177 define this, if you don't use i2c muxes on your hardware.
1178 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
1179 omit this define.
1180
1181 CONFIG_SYS_I2C_MAX_HOPS
1182 define how many muxes are maximal consecutively connected
1183 on one i2c bus. If you not use i2c muxes, omit this
1184 define.
1185
1186 CONFIG_SYS_I2C_BUSES
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001187 hold a list of buses you want to use, only used if
Heiko Schocher3f4978c2012-01-16 21:12:24 +00001188 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
1189 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
1190 CONFIG_SYS_NUM_I2C_BUSES = 9:
1191
1192 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
1193 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
1194 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
1195 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
1196 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
1197 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
1198 {1, {I2C_NULL_HOP}}, \
1199 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
1200 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
1201 }
1202
1203 which defines
1204 bus 0 on adapter 0 without a mux
Heiko Schocherea818db2013-01-29 08:53:15 +01001205 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
1206 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
1207 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
1208 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
1209 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
Heiko Schocher3f4978c2012-01-16 21:12:24 +00001210 bus 6 on adapter 1 without a mux
Heiko Schocherea818db2013-01-29 08:53:15 +01001211 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
1212 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
Heiko Schocher3f4978c2012-01-16 21:12:24 +00001213
1214 If you do not have i2c muxes on your board, omit this define.
1215
Simon Glassce3b5d62017-05-12 21:10:00 -06001216- Legacy I2C Support:
Heiko Schocherea818db2013-01-29 08:53:15 +01001217 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
wdenkb37c7e52003-06-30 16:24:52 +00001218 then the following macros need to be defined (examples are
1219 from include/configs/lwmon.h):
wdenkc6097192002-11-03 00:24:07 +00001220
1221 I2C_INIT
1222
wdenkb37c7e52003-06-30 16:24:52 +00001223 (Optional). Any commands necessary to enable the I2C
wdenk43d96162003-03-06 00:02:04 +00001224 controller or configure ports.
wdenkc6097192002-11-03 00:24:07 +00001225
wdenkba56f622004-02-06 23:19:44 +00001226 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
wdenkb37c7e52003-06-30 16:24:52 +00001227
wdenkc6097192002-11-03 00:24:07 +00001228 I2C_ACTIVE
1229
1230 The code necessary to make the I2C data line active
1231 (driven). If the data line is open collector, this
1232 define can be null.
1233
wdenkb37c7e52003-06-30 16:24:52 +00001234 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1235
wdenkc6097192002-11-03 00:24:07 +00001236 I2C_TRISTATE
1237
1238 The code necessary to make the I2C data line tri-stated
1239 (inactive). If the data line is open collector, this
1240 define can be null.
1241
wdenkb37c7e52003-06-30 16:24:52 +00001242 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1243
wdenkc6097192002-11-03 00:24:07 +00001244 I2C_READ
1245
York Sun472d5462013-04-01 11:29:11 -07001246 Code that returns true if the I2C data line is high,
1247 false if it is low.
wdenkc6097192002-11-03 00:24:07 +00001248
wdenkb37c7e52003-06-30 16:24:52 +00001249 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1250
wdenkc6097192002-11-03 00:24:07 +00001251 I2C_SDA(bit)
1252
York Sun472d5462013-04-01 11:29:11 -07001253 If <bit> is true, sets the I2C data line high. If it
1254 is false, it clears it (low).
wdenkc6097192002-11-03 00:24:07 +00001255
wdenkb37c7e52003-06-30 16:24:52 +00001256 eg: #define I2C_SDA(bit) \
wdenk2535d602003-07-17 23:16:40 +00001257 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
wdenkba56f622004-02-06 23:19:44 +00001258 else immr->im_cpm.cp_pbdat &= ~PB_SDA
wdenkb37c7e52003-06-30 16:24:52 +00001259
wdenkc6097192002-11-03 00:24:07 +00001260 I2C_SCL(bit)
1261
York Sun472d5462013-04-01 11:29:11 -07001262 If <bit> is true, sets the I2C clock line high. If it
1263 is false, it clears it (low).
wdenkc6097192002-11-03 00:24:07 +00001264
wdenkb37c7e52003-06-30 16:24:52 +00001265 eg: #define I2C_SCL(bit) \
wdenk2535d602003-07-17 23:16:40 +00001266 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
wdenkba56f622004-02-06 23:19:44 +00001267 else immr->im_cpm.cp_pbdat &= ~PB_SCL
wdenkb37c7e52003-06-30 16:24:52 +00001268
wdenkc6097192002-11-03 00:24:07 +00001269 I2C_DELAY
1270
1271 This delay is invoked four times per clock cycle so this
1272 controls the rate of data transfer. The data rate thus
wdenkb37c7e52003-06-30 16:24:52 +00001273 is 1 / (I2C_DELAY * 4). Often defined to be something
wdenk945af8d2003-07-16 21:53:01 +00001274 like:
1275
wdenkb37c7e52003-06-30 16:24:52 +00001276 #define I2C_DELAY udelay(2)
wdenkc6097192002-11-03 00:24:07 +00001277
Mike Frysinger793b5722010-07-21 13:38:02 -04001278 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1279
1280 If your arch supports the generic GPIO framework (asm/gpio.h),
1281 then you may alternatively define the two GPIOs that are to be
1282 used as SCL / SDA. Any of the previous I2C_xxx macros will
1283 have GPIO-based defaults assigned to them as appropriate.
1284
1285 You should define these to the GPIO value as given directly to
1286 the generic GPIO functions.
1287
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001288 CONFIG_SYS_I2C_INIT_BOARD
wdenk47cd00f2003-03-06 13:39:27 +00001289
wdenk8bde7f72003-06-27 21:31:46 +00001290 When a board is reset during an i2c bus transfer
1291 chips might think that the current transfer is still
1292 in progress. On some boards it is possible to access
1293 the i2c SCLK line directly, either by using the
1294 processor pin as a GPIO or by having a second pin
1295 connected to the bus. If this option is defined a
1296 custom i2c_init_board() routine in boards/xxx/board.c
1297 is run early in the boot sequence.
wdenk47cd00f2003-03-06 13:39:27 +00001298
Ben Warrenbb99ad62006-09-07 16:50:54 -04001299 CONFIG_I2C_MULTI_BUS
1300
1301 This option allows the use of multiple I2C buses, each of which
Wolfgang Denkc0f40852011-10-26 10:21:21 +00001302 must have a controller. At any point in time, only one bus is
1303 active. To switch to a different bus, use the 'i2c dev' command.
Ben Warrenbb99ad62006-09-07 16:50:54 -04001304 Note that bus numbering is zero-based.
1305
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001306 CONFIG_SYS_I2C_NOPROBES
Ben Warrenbb99ad62006-09-07 16:50:54 -04001307
1308 This option specifies a list of I2C devices that will be skipped
Wolfgang Denkc0f40852011-10-26 10:21:21 +00001309 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
Peter Tyser0f89c542009-04-18 22:34:03 -05001310 is set, specify a list of bus-device pairs. Otherwise, specify
1311 a 1D array of device addresses
Ben Warrenbb99ad62006-09-07 16:50:54 -04001312
1313 e.g.
1314 #undef CONFIG_I2C_MULTI_BUS
Wolfgang Denkc0f40852011-10-26 10:21:21 +00001315 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
Ben Warrenbb99ad62006-09-07 16:50:54 -04001316
1317 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1318
Wolfgang Denkc0f40852011-10-26 10:21:21 +00001319 #define CONFIG_I2C_MULTI_BUS
Simon Glass945a18e2016-10-02 18:01:05 -06001320 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
Ben Warrenbb99ad62006-09-07 16:50:54 -04001321
1322 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1323
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001324 CONFIG_SYS_SPD_BUS_NUM
Timur Tabibe5e6182006-11-03 19:15:00 -06001325
1326 If defined, then this indicates the I2C bus number for DDR SPD.
1327 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1328
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001329 CONFIG_SYS_RTC_BUS_NUM
Stefan Roese0dc018e2007-02-20 10:51:26 +01001330
1331 If defined, then this indicates the I2C bus number for the RTC.
1332 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1333
Andrew Dyer2ac69852008-12-29 17:36:01 -06001334 CONFIG_SOFT_I2C_READ_REPEATED_START
1335
1336 defining this will force the i2c_read() function in
1337 the soft_i2c driver to perform an I2C repeated start
1338 between writing the address pointer and reading the
1339 data. If this define is omitted the default behaviour
1340 of doing a stop-start sequence will be used. Most I2C
1341 devices can use either method, but some require one or
1342 the other.
Timur Tabibe5e6182006-11-03 19:15:00 -06001343
wdenkc6097192002-11-03 00:24:07 +00001344- SPI Support: CONFIG_SPI
1345
1346 Enables SPI driver (so far only tested with
1347 SPI EEPROM, also an instance works with Crystal A/D and
1348 D/As on the SACSng board)
1349
Heiko Schocherf659b572014-07-14 10:22:11 +02001350 CONFIG_SYS_SPI_MXC_WAIT
1351 Timeout for waiting until spi transfer completed.
1352 default: (CONFIG_SYS_HZ/100) /* 10 ms */
1353
Matthias Fuchs01335022007-12-27 17:12:34 +01001354- FPGA Support: CONFIG_FPGA
1355
1356 Enables FPGA subsystem.
1357
1358 CONFIG_FPGA_<vendor>
1359
1360 Enables support for specific chip vendors.
1361 (ALTERA, XILINX)
1362
1363 CONFIG_FPGA_<family>
1364
1365 Enables support for FPGA family.
1366 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1367
1368 CONFIG_FPGA_COUNT
wdenkc6097192002-11-03 00:24:07 +00001369
wdenk43d96162003-03-06 00:02:04 +00001370 Specify the number of FPGA devices to support.
wdenkc6097192002-11-03 00:24:07 +00001371
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001372 CONFIG_SYS_FPGA_PROG_FEEDBACK
wdenkc6097192002-11-03 00:24:07 +00001373
wdenk8bde7f72003-06-27 21:31:46 +00001374 Enable printing of hash marks during FPGA configuration.
wdenkc6097192002-11-03 00:24:07 +00001375
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001376 CONFIG_SYS_FPGA_CHECK_BUSY
wdenkc6097192002-11-03 00:24:07 +00001377
wdenk43d96162003-03-06 00:02:04 +00001378 Enable checks on FPGA configuration interface busy
1379 status by the configuration function. This option
1380 will require a board or device specific function to
1381 be written.
wdenkc6097192002-11-03 00:24:07 +00001382
1383 CONFIG_FPGA_DELAY
1384
1385 If defined, a function that provides delays in the FPGA
1386 configuration driver.
1387
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001388 CONFIG_SYS_FPGA_CHECK_CTRLC
wdenkc6097192002-11-03 00:24:07 +00001389 Allow Control-C to interrupt FPGA configuration
1390
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001391 CONFIG_SYS_FPGA_CHECK_ERROR
wdenkc6097192002-11-03 00:24:07 +00001392
wdenk43d96162003-03-06 00:02:04 +00001393 Check for configuration errors during FPGA bitfile
1394 loading. For example, abort during Virtex II
1395 configuration if the INIT_B line goes low (which
1396 indicated a CRC error).
wdenkc6097192002-11-03 00:24:07 +00001397
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001398 CONFIG_SYS_FPGA_WAIT_INIT
wdenkc6097192002-11-03 00:24:07 +00001399
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001400 Maximum time to wait for the INIT_B line to de-assert
1401 after PROB_B has been de-asserted during a Virtex II
wdenk43d96162003-03-06 00:02:04 +00001402 FPGA configuration sequence. The default time is 500
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001403 ms.
wdenkc6097192002-11-03 00:24:07 +00001404
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001405 CONFIG_SYS_FPGA_WAIT_BUSY
wdenkc6097192002-11-03 00:24:07 +00001406
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001407 Maximum time to wait for BUSY to de-assert during
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001408 Virtex II FPGA configuration. The default is 5 ms.
wdenkc6097192002-11-03 00:24:07 +00001409
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001410 CONFIG_SYS_FPGA_WAIT_CONFIG
wdenkc6097192002-11-03 00:24:07 +00001411
wdenk43d96162003-03-06 00:02:04 +00001412 Time to wait after FPGA configuration. The default is
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001413 200 ms.
wdenkc6097192002-11-03 00:24:07 +00001414
wdenkc6097192002-11-03 00:24:07 +00001415- Vendor Parameter Protection:
1416
wdenk43d96162003-03-06 00:02:04 +00001417 U-Boot considers the values of the environment
1418 variables "serial#" (Board Serial Number) and
wdenk7152b1d2003-09-05 23:19:14 +00001419 "ethaddr" (Ethernet Address) to be parameters that
wdenk43d96162003-03-06 00:02:04 +00001420 are set once by the board vendor / manufacturer, and
1421 protects these variables from casual modification by
1422 the user. Once set, these variables are read-only,
1423 and write or delete attempts are rejected. You can
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001424 change this behaviour:
wdenkc6097192002-11-03 00:24:07 +00001425
1426 If CONFIG_ENV_OVERWRITE is #defined in your config
1427 file, the write protection for vendor parameters is
wdenk47cd00f2003-03-06 13:39:27 +00001428 completely disabled. Anybody can change or delete
wdenkc6097192002-11-03 00:24:07 +00001429 these parameters.
1430
Joe Hershberger92ac5202015-05-04 14:55:14 -05001431 Alternatively, if you define _both_ an ethaddr in the
1432 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001433 Ethernet address is installed in the environment,
wdenkc6097192002-11-03 00:24:07 +00001434 which can be changed exactly ONCE by the user. [The
1435 serial# is unaffected by this, i. e. it remains
1436 read-only.]
1437
Joe Hershberger25980902012-12-11 22:16:31 -06001438 The same can be accomplished in a more flexible way
1439 for any variable by configuring the type of access
1440 to allow for those variables in the ".flags" variable
1441 or define CONFIG_ENV_FLAGS_LIST_STATIC.
1442
wdenkc6097192002-11-03 00:24:07 +00001443- Protected RAM:
1444 CONFIG_PRAM
1445
1446 Define this variable to enable the reservation of
1447 "protected RAM", i. e. RAM which is not overwritten
1448 by U-Boot. Define CONFIG_PRAM to hold the number of
1449 kB you want to reserve for pRAM. You can overwrite
1450 this default value by defining an environment
1451 variable "pram" to the number of kB you want to
1452 reserve. Note that the board info structure will
1453 still show the full amount of RAM. If pRAM is
1454 reserved, a new environment variable "mem" will
1455 automatically be defined to hold the amount of
1456 remaining RAM in a form that can be passed as boot
1457 argument to Linux, for instance like that:
1458
Wolfgang Denkfe126d82005-11-20 21:40:11 +01001459 setenv bootargs ... mem=\${mem}
wdenkc6097192002-11-03 00:24:07 +00001460 saveenv
1461
1462 This way you can tell Linux not to use this memory,
1463 either, which results in a memory region that will
1464 not be affected by reboots.
1465
1466 *WARNING* If your board configuration uses automatic
1467 detection of the RAM size, you must make sure that
1468 this memory test is non-destructive. So far, the
1469 following board configurations are known to be
1470 "pRAM-clean":
1471
Heiko Schocher5b8e76c2017-06-07 17:33:09 +02001472 IVMS8, IVML24, SPD8xx,
Wolfgang Denk1b0757e2012-10-24 02:36:15 +00001473 HERMES, IP860, RPXlite, LWMON,
Heiko Schocher2eb48ff2017-06-07 17:33:10 +02001474 FLAGADM
wdenkc6097192002-11-03 00:24:07 +00001475
1476- Error Recovery:
wdenkc6097192002-11-03 00:24:07 +00001477 Note:
1478
wdenk8bde7f72003-06-27 21:31:46 +00001479 In the current implementation, the local variables
1480 space and global environment variables space are
1481 separated. Local variables are those you define by
1482 simply typing `name=value'. To access a local
1483 variable later on, you have write `$name' or
1484 `${name}'; to execute the contents of a variable
1485 directly type `$name' at the command prompt.
wdenkc6097192002-11-03 00:24:07 +00001486
wdenk43d96162003-03-06 00:02:04 +00001487 Global environment variables are those you use
1488 setenv/printenv to work with. To run a command stored
1489 in such a variable, you need to use the run command,
1490 and you must not use the '$' sign to access them.
wdenkc6097192002-11-03 00:24:07 +00001491
1492 To store commands and special characters in a
1493 variable, please use double quotation marks
1494 surrounding the whole text of the variable, instead
1495 of the backslashes before semicolons and special
1496 symbols.
1497
wdenka8c7c702003-12-06 19:49:23 +00001498- Default Environment:
wdenkc6097192002-11-03 00:24:07 +00001499 CONFIG_EXTRA_ENV_SETTINGS
1500
wdenk43d96162003-03-06 00:02:04 +00001501 Define this to contain any number of null terminated
1502 strings (variable = value pairs) that will be part of
wdenk7152b1d2003-09-05 23:19:14 +00001503 the default environment compiled into the boot image.
wdenk2262cfe2002-11-18 00:14:45 +00001504
wdenk43d96162003-03-06 00:02:04 +00001505 For example, place something like this in your
1506 board's config file:
wdenkc6097192002-11-03 00:24:07 +00001507
1508 #define CONFIG_EXTRA_ENV_SETTINGS \
1509 "myvar1=value1\0" \
1510 "myvar2=value2\0"
1511
wdenk43d96162003-03-06 00:02:04 +00001512 Warning: This method is based on knowledge about the
1513 internal format how the environment is stored by the
1514 U-Boot code. This is NOT an official, exported
1515 interface! Although it is unlikely that this format
wdenk7152b1d2003-09-05 23:19:14 +00001516 will change soon, there is no guarantee either.
wdenkc6097192002-11-03 00:24:07 +00001517 You better know what you are doing here.
1518
wdenk43d96162003-03-06 00:02:04 +00001519 Note: overly (ab)use of the default environment is
1520 discouraged. Make sure to check other ways to preset
Wolfgang Denk74de7ae2009-04-01 23:34:12 +02001521 the environment like the "source" command or the
wdenk43d96162003-03-06 00:02:04 +00001522 boot command first.
wdenkc6097192002-11-03 00:24:07 +00001523
Simon Glass06fd8532012-11-30 13:01:17 +00001524 CONFIG_DELAY_ENVIRONMENT
1525
1526 Normally the environment is loaded when the board is
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001527 initialised so that it is available to U-Boot. This inhibits
Simon Glass06fd8532012-11-30 13:01:17 +00001528 that so that the environment is not available until
1529 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
1530 this is instead controlled by the value of
1531 /config/load-environment.
1532
Wolfgang Denk4cf26092011-10-07 09:58:21 +02001533 CONFIG_STANDALONE_LOAD_ADDR
1534
Wolfgang Denk6feff892011-10-09 21:06:34 +02001535 This option defines a board specific value for the
1536 address where standalone program gets loaded, thus
1537 overwriting the architecture dependent default
Wolfgang Denk4cf26092011-10-07 09:58:21 +02001538 settings.
1539
1540- Frame Buffer Address:
1541 CONFIG_FB_ADDR
1542
1543 Define CONFIG_FB_ADDR if you want to use specific
Wolfgang Denk44a53b52013-01-03 00:43:59 +00001544 address for frame buffer. This is typically the case
1545 when using a graphics controller has separate video
1546 memory. U-Boot will then place the frame buffer at
1547 the given address instead of dynamically reserving it
1548 in system RAM by calling lcd_setmem(), which grabs
1549 the memory for the frame buffer depending on the
1550 configured panel size.
Wolfgang Denk4cf26092011-10-07 09:58:21 +02001551
1552 Please see board_init_f function.
1553
Detlev Zundelcccfc2a2009-12-01 17:16:19 +01001554- Automatic software updates via TFTP server
1555 CONFIG_UPDATE_TFTP
1556 CONFIG_UPDATE_TFTP_CNT_MAX
1557 CONFIG_UPDATE_TFTP_MSEC_MAX
1558
1559 These options enable and control the auto-update feature;
1560 for a more detailed description refer to doc/README.update.
1561
1562- MTD Support (mtdparts command, UBI support)
Heiko Schocherff94bc42014-06-24 10:10:04 +02001563 CONFIG_MTD_UBI_WL_THRESHOLD
1564 This parameter defines the maximum difference between the highest
1565 erase counter value and the lowest erase counter value of eraseblocks
1566 of UBI devices. When this threshold is exceeded, UBI starts performing
1567 wear leveling by means of moving data from eraseblock with low erase
1568 counter to eraseblocks with high erase counter.
1569
1570 The default value should be OK for SLC NAND flashes, NOR flashes and
1571 other flashes which have eraseblock life-cycle 100000 or more.
1572 However, in case of MLC NAND flashes which typically have eraseblock
1573 life-cycle less than 10000, the threshold should be lessened (e.g.,
1574 to 128 or 256, although it does not have to be power of 2).
1575
1576 default: 4096
Simon Glassc654b512014-10-23 18:58:54 -06001577
Heiko Schocherff94bc42014-06-24 10:10:04 +02001578 CONFIG_MTD_UBI_BEB_LIMIT
1579 This option specifies the maximum bad physical eraseblocks UBI
1580 expects on the MTD device (per 1024 eraseblocks). If the
1581 underlying flash does not admit of bad eraseblocks (e.g. NOR
1582 flash), this value is ignored.
1583
1584 NAND datasheets often specify the minimum and maximum NVM
1585 (Number of Valid Blocks) for the flashes' endurance lifetime.
1586 The maximum expected bad eraseblocks per 1024 eraseblocks
1587 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
1588 which gives 20 for most NANDs (MaxNVB is basically the total
1589 count of eraseblocks on the chip).
1590
1591 To put it differently, if this value is 20, UBI will try to
1592 reserve about 1.9% of physical eraseblocks for bad blocks
1593 handling. And that will be 1.9% of eraseblocks on the entire
1594 NAND chip, not just the MTD partition UBI attaches. This means
1595 that if you have, say, a NAND flash chip admits maximum 40 bad
1596 eraseblocks, and it is split on two MTD partitions of the same
1597 size, UBI will reserve 40 eraseblocks when attaching a
1598 partition.
1599
1600 default: 20
1601
1602 CONFIG_MTD_UBI_FASTMAP
1603 Fastmap is a mechanism which allows attaching an UBI device
1604 in nearly constant time. Instead of scanning the whole MTD device it
1605 only has to locate a checkpoint (called fastmap) on the device.
1606 The on-flash fastmap contains all information needed to attach
1607 the device. Using fastmap makes only sense on large devices where
1608 attaching by scanning takes long. UBI will not automatically install
1609 a fastmap on old images, but you can set the UBI parameter
1610 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
1611 that fastmap-enabled images are still usable with UBI implementations
1612 without fastmap support. On typical flash devices the whole fastmap
1613 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
1614
1615 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
1616 Set this parameter to enable fastmap automatically on images
1617 without a fastmap.
1618 default: 0
1619
Heiko Schocher0195a7b2015-10-22 06:19:21 +02001620 CONFIG_MTD_UBI_FM_DEBUG
1621 Enable UBI fastmap debug
1622 default: 0
1623
Daniel Schwierzeck6a11cf42011-07-18 07:48:07 +00001624- SPL framework
Wolfgang Denk04e5ae72011-09-11 21:24:09 +02001625 CONFIG_SPL
1626 Enable building of SPL globally.
Daniel Schwierzeck6a11cf42011-07-18 07:48:07 +00001627
Albert ARIBAUD \(3ADEV\)8c80eb32015-03-31 11:40:50 +02001628 CONFIG_SPL_PANIC_ON_RAW_IMAGE
1629 When defined, SPL will panic() if the image it has
1630 loaded does not have a signature.
1631 Defining this is useful when code which loads images
1632 in SPL cannot guarantee that absolutely all read errors
1633 will be caught.
1634 An example is the LPC32XX MLC NAND driver, which will
1635 consider that a completely unreadable NAND block is bad,
1636 and thus should be skipped silently.
1637
Tom Rini861a86f2012-08-13 11:37:56 -07001638 CONFIG_SPL_DISPLAY_PRINT
1639 For ARM, enable an optional function to print more information
1640 about the running system.
1641
Scott Wood06f60ae2012-12-06 13:33:17 +00001642 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
1643 Set this for NAND SPL on PPC mpc83xx targets, so that
1644 start.S waits for the rest of the SPL to load before
1645 continuing (the hardware starts execution after just
1646 loading the first page rather than the full 4K).
1647
Thomas Gleixner6f4e7d32016-07-12 20:28:12 +02001648 CONFIG_SPL_UBI
1649 Support for a lightweight UBI (fastmap) scanner and
1650 loader
1651
Tom Rini95579792012-02-14 07:29:40 +00001652 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
1653 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
1654 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
1655 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
1656 CONFIG_SYS_NAND_ECCBYTES
1657 Defines the size and behavior of the NAND that SPL uses
Scott Wood7d4b7952012-09-21 18:35:27 -05001658 to read U-Boot
Tom Rini95579792012-02-14 07:29:40 +00001659
Scott Wood7d4b7952012-09-21 18:35:27 -05001660 CONFIG_SYS_NAND_U_BOOT_DST
1661 Location in memory to load U-Boot to
1662
1663 CONFIG_SYS_NAND_U_BOOT_SIZE
1664 Size of image to load
Tom Rini95579792012-02-14 07:29:40 +00001665
1666 CONFIG_SYS_NAND_U_BOOT_START
Scott Wood7d4b7952012-09-21 18:35:27 -05001667 Entry point in loaded image to jump to
Tom Rini95579792012-02-14 07:29:40 +00001668
1669 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
1670 Define this if you need to first read the OOB and then the
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001671 data. This is used, for example, on davinci platforms.
Tom Rini95579792012-02-14 07:29:40 +00001672
Pavel Machekc57b9532012-08-30 22:42:11 +02001673 CONFIG_SPL_RAM_DEVICE
1674 Support for running image already present in ram, in SPL binary
1675
Marek Vasutb527b9c2018-05-13 00:22:52 +02001676 CONFIG_SPL_FIT_PRINT
Simon Glass87ebee32013-05-08 08:05:59 +00001677 Printing information about a FIT image adds quite a bit of
1678 code to SPL. So this is normally disabled in SPL. Use this
1679 option to re-enable it. This will affect the output of the
1680 bootm command when booting a FIT image.
1681
wdenka8c7c702003-12-06 19:49:23 +00001682- Interrupt support (PPC):
1683
wdenkd4ca31c2004-01-02 14:00:00 +00001684 There are common interrupt_init() and timer_interrupt()
1685 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001686 for CPU specific initialization. interrupt_init_cpu()
wdenkd4ca31c2004-01-02 14:00:00 +00001687 should set decrementer_count to appropriate value. If
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001688 CPU resets decrementer automatically after interrupt
wdenkd4ca31c2004-01-02 14:00:00 +00001689 (ppc4xx) it should set decrementer_count to zero.
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001690 timer_interrupt() calls timer_interrupt_cpu() for CPU
wdenkd4ca31c2004-01-02 14:00:00 +00001691 specific handling. If board has watchdog / status_led
1692 / other_activity_monitor it works automatically from
1693 general timer_interrupt().
wdenka8c7c702003-12-06 19:49:23 +00001694
wdenkc6097192002-11-03 00:24:07 +00001695
Helmut Raiger9660e442011-10-20 04:19:47 +00001696Board initialization settings:
1697------------------------------
1698
1699During Initialization u-boot calls a number of board specific functions
1700to allow the preparation of board specific prerequisites, e.g. pin setup
1701before drivers are initialized. To enable these callbacks the
1702following configuration macros have to be defined. Currently this is
1703architecture specific, so please check arch/your_architecture/lib/board.c
1704typically in board_init_f() and board_init_r().
1705
1706- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
1707- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
1708- CONFIG_BOARD_LATE_INIT: Call board_late_init()
wdenkc6097192002-11-03 00:24:07 +00001709
wdenkc6097192002-11-03 00:24:07 +00001710Configuration Settings:
1711-----------------------
1712
Simon Glass4d979bf2019-12-28 10:45:10 -07001713- MEM_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
York Sun4d1fd7f2014-02-26 17:03:19 -08001714 Optionally it can be defined to support 64-bit memory commands.
1715
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001716- CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
wdenkc6097192002-11-03 00:24:07 +00001717 undefine this when you're short of memory.
1718
Peter Tyser2fb26042009-01-27 18:03:12 -06001719- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
1720 width of the commands listed in the 'help' command output.
1721
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001722- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
wdenkc6097192002-11-03 00:24:07 +00001723 prompt for user input.
1724
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001725- CONFIG_SYS_BAUDRATE_TABLE:
wdenkc6097192002-11-03 00:24:07 +00001726 List of legal baudrate settings for this board.
1727
York Sune8149522015-12-04 11:57:07 -08001728- CONFIG_SYS_MEM_RESERVE_SECURE
York Sune61a7532016-06-24 16:46:18 -07001729 Only implemented for ARMv8 for now.
York Sune8149522015-12-04 11:57:07 -08001730 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
1731 is substracted from total RAM and won't be reported to OS.
1732 This memory can be used as secure memory. A variable
York Sune61a7532016-06-24 16:46:18 -07001733 gd->arch.secure_ram is used to track the location. In systems
York Sune8149522015-12-04 11:57:07 -08001734 the RAM base is not zero, or RAM is divided into banks,
1735 this variable needs to be recalcuated to get the address.
1736
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001737- CONFIG_SYS_LOADS_BAUD_CHANGE:
wdenkc6097192002-11-03 00:24:07 +00001738 Enable temporary baudrate change while serial download
1739
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001740- CONFIG_SYS_SDRAM_BASE:
wdenkc6097192002-11-03 00:24:07 +00001741 Physical start address of SDRAM. _Must_ be 0 here.
1742
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001743- CONFIG_SYS_FLASH_BASE:
wdenkc6097192002-11-03 00:24:07 +00001744 Physical start address of Flash memory.
1745
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001746- CONFIG_SYS_MONITOR_LEN:
wdenk8bde7f72003-06-27 21:31:46 +00001747 Size of memory reserved for monitor code, used to
1748 determine _at_compile_time_ (!) if the environment is
1749 embedded within the U-Boot image, or in a separate
1750 flash sector.
wdenkc6097192002-11-03 00:24:07 +00001751
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001752- CONFIG_SYS_MALLOC_LEN:
wdenkc6097192002-11-03 00:24:07 +00001753 Size of DRAM reserved for malloc() use.
1754
Simon Glassd59476b2014-07-10 22:23:28 -06001755- CONFIG_SYS_MALLOC_F_LEN
1756 Size of the malloc() pool for use before relocation. If
1757 this is defined, then a very simple malloc() implementation
1758 will become available before relocation. The address is just
1759 below the global data, and the stack is moved down to make
1760 space.
1761
1762 This feature allocates regions with increasing addresses
1763 within the region. calloc() is supported, but realloc()
1764 is not available. free() is supported but does nothing.
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001765 The memory will be freed (or in fact just forgotten) when
Simon Glassd59476b2014-07-10 22:23:28 -06001766 U-Boot relocates itself.
1767
Simon Glass38687ae2014-11-10 17:16:54 -07001768- CONFIG_SYS_MALLOC_SIMPLE
1769 Provides a simple and small malloc() and calloc() for those
1770 boards which do not use the full malloc in SPL (which is
Tom Rini10f6e4d2022-05-27 12:48:32 -04001771 enabled with CONFIG_SYS_SPL_MALLOC).
Simon Glass38687ae2014-11-10 17:16:54 -07001772
Thierry Reding1dfdd9b2014-12-09 22:25:22 -07001773- CONFIG_SYS_NONCACHED_MEMORY:
1774 Size of non-cached memory area. This area of memory will be
1775 typically located right below the malloc() area and mapped
1776 uncached in the MMU. This is useful for drivers that would
1777 otherwise require a lot of explicit cache maintenance. For
1778 some drivers it's also impossible to properly maintain the
1779 cache. For example if the regions that need to be flushed
1780 are not a multiple of the cache-line size, *and* padding
1781 cannot be allocated between the regions to align them (i.e.
1782 if the HW requires a contiguous array of regions, and the
1783 size of each region is not cache-aligned), then a flush of
1784 one region may result in overwriting data that hardware has
1785 written to another region in the same cache-line. This can
1786 happen for example in network drivers where descriptors for
1787 buffers are typically smaller than the CPU cache-line (e.g.
1788 16 bytes vs. 32 or 64 bytes).
1789
1790 Non-cached memory is only supported on 32-bit ARM at present.
1791
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001792- CONFIG_SYS_BOOTM_LEN:
Stefan Roese15940c92006-03-13 11:16:36 +01001793 Normally compressed uImages are limited to an
1794 uncompressed size of 8 MBytes. If this is not enough,
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001795 you can define CONFIG_SYS_BOOTM_LEN in your board config file
Stefan Roese15940c92006-03-13 11:16:36 +01001796 to adjust this setting to your needs.
1797
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001798- CONFIG_SYS_BOOTMAPSZ:
wdenkc6097192002-11-03 00:24:07 +00001799 Maximum size of memory mapped by the startup code of
1800 the Linux kernel; all data that must be processed by
Bartlomiej Sieka7d721e32008-04-14 15:44:16 +02001801 the Linux kernel (bd_info, boot arguments, FDT blob if
1802 used) must be put below this limit, unless "bootm_low"
Robert P. J. Day1bce2ae2013-09-16 07:15:45 -04001803 environment variable is defined and non-zero. In such case
Bartlomiej Sieka7d721e32008-04-14 15:44:16 +02001804 all data for the Linux kernel must be between "bootm_low"
Wolfgang Denkc0f40852011-10-26 10:21:21 +00001805 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
Grant Likelyc3624e62011-03-28 09:58:43 +00001806 variable "bootm_mapsize" will override the value of
1807 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
1808 then the value in "bootm_size" will be used instead.
wdenkc6097192002-11-03 00:24:07 +00001809
John Rigbyfca43cc2010-10-13 13:57:35 -06001810- CONFIG_SYS_BOOT_RAMDISK_HIGH:
1811 Enable initrd_high functionality. If defined then the
1812 initrd_high feature is enabled and the bootm ramdisk subcommand
1813 is enabled.
1814
1815- CONFIG_SYS_BOOT_GET_CMDLINE:
1816 Enables allocating and saving kernel cmdline in space between
1817 "bootm_low" and "bootm_low" + BOOTMAPSZ.
1818
1819- CONFIG_SYS_BOOT_GET_KBD:
1820 Enables allocating and saving a kernel copy of the bd_info in
1821 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
1822
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001823- CONFIG_SYS_MAX_FLASH_SECT:
wdenkc6097192002-11-03 00:24:07 +00001824 Max number of sectors on a Flash chip
1825
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001826- CONFIG_SYS_FLASH_ERASE_TOUT:
wdenkc6097192002-11-03 00:24:07 +00001827 Timeout for Flash erase operations (in ms)
1828
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001829- CONFIG_SYS_FLASH_WRITE_TOUT:
wdenkc6097192002-11-03 00:24:07 +00001830 Timeout for Flash write operations (in ms)
1831
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001832- CONFIG_SYS_FLASH_LOCK_TOUT
wdenk8564acf2003-07-14 22:13:32 +00001833 Timeout for Flash set sector lock bit operation (in ms)
1834
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001835- CONFIG_SYS_FLASH_UNLOCK_TOUT
wdenk8564acf2003-07-14 22:13:32 +00001836 Timeout for Flash clear lock bits operation (in ms)
1837
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001838- CONFIG_SYS_FLASH_PROTECTION
wdenk8564acf2003-07-14 22:13:32 +00001839 If defined, hardware flash sectors protection is used
1840 instead of U-Boot software protection.
1841
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001842- CONFIG_SYS_DIRECT_FLASH_TFTP:
wdenkc6097192002-11-03 00:24:07 +00001843
1844 Enable TFTP transfers directly to flash memory;
1845 without this option such a download has to be
1846 performed in two steps: (1) download to RAM, and (2)
1847 copy from RAM to flash.
1848
1849 The two-step approach is usually more reliable, since
1850 you can check if the download worked before you erase
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001851 the flash, but in some situations (when system RAM is
1852 too limited to allow for a temporary copy of the
wdenkc6097192002-11-03 00:24:07 +00001853 downloaded image) this option may be very useful.
1854
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001855- CONFIG_SYS_FLASH_CFI:
wdenk43d96162003-03-06 00:02:04 +00001856 Define if the flash driver uses extra elements in the
wdenk5653fc32004-02-08 22:55:38 +00001857 common flash structure for storing flash geometry.
1858
Jean-Christophe PLAGNIOL-VILLARD00b18832008-08-13 01:40:42 +02001859- CONFIG_FLASH_CFI_DRIVER
wdenk5653fc32004-02-08 22:55:38 +00001860 This option also enables the building of the cfi_flash driver
1861 in the drivers directory
wdenkc6097192002-11-03 00:24:07 +00001862
Piotr Ziecik91809ed2008-11-17 15:57:58 +01001863- CONFIG_FLASH_CFI_MTD
1864 This option enables the building of the cfi_mtd driver
1865 in the drivers directory. The driver exports CFI flash
1866 to the MTD layer.
1867
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001868- CONFIG_SYS_FLASH_USE_BUFFER_WRITE
Guennadi Liakhovetski96ef8312008-04-03 13:36:02 +02001869 Use buffered writes to flash.
1870
1871- CONFIG_FLASH_SPANSION_S29WS_N
1872 s29ws-n MirrorBit flash has non-standard addresses for buffered
1873 write commands.
1874
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001875- CONFIG_SYS_FLASH_QUIET_TEST
Stefan Roese5568e612005-11-22 13:20:42 +01001876 If this option is defined, the common CFI flash doesn't
1877 print it's warning upon not recognized FLASH banks. This
1878 is useful, if some of the configured banks are only
1879 optionally available.
1880
Jerry Van Baren9a042e92008-03-08 13:48:01 -05001881- CONFIG_FLASH_SHOW_PROGRESS
1882 If defined (must be an integer), print out countdown
1883 digits and dots. Recommended value: 45 (9..1) for 80
1884 column displays, 15 (3..1) for 40 column displays.
1885
Stefan Roese352ef3f2013-04-04 15:53:14 +02001886- CONFIG_FLASH_VERIFY
1887 If defined, the content of the flash (destination) is compared
1888 against the source after the write operation. An error message
1889 will be printed when the contents are not identical.
1890 Please note that this option is useless in nearly all cases,
1891 since such flash programming errors usually are detected earlier
1892 while unprotecting/erasing/programming. Please only enable
1893 this option if you really know what you are doing.
1894
Wolfgang Denkea882ba2010-06-20 23:33:59 +02001895- CONFIG_ENV_MAX_ENTRIES
1896
Wolfgang Denk071bc922010-10-27 22:48:30 +02001897 Maximum number of entries in the hash table that is used
1898 internally to store the environment settings. The default
1899 setting is supposed to be generous and should work in most
1900 cases. This setting can be used to tune behaviour; see
1901 lib/hashtable.c for details.
Wolfgang Denkea882ba2010-06-20 23:33:59 +02001902
Joe Hershberger25980902012-12-11 22:16:31 -06001903- CONFIG_ENV_FLAGS_LIST_DEFAULT
1904- CONFIG_ENV_FLAGS_LIST_STATIC
Robert P. J. Day1bce2ae2013-09-16 07:15:45 -04001905 Enable validation of the values given to environment variables when
Joe Hershberger25980902012-12-11 22:16:31 -06001906 calling env set. Variables can be restricted to only decimal,
1907 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
1908 the variables can also be restricted to IP address or MAC address.
1909
1910 The format of the list is:
1911 type_attribute = [s|d|x|b|i|m]
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001912 access_attribute = [a|r|o|c]
1913 attributes = type_attribute[access_attribute]
Joe Hershberger25980902012-12-11 22:16:31 -06001914 entry = variable_name[:attributes]
1915 list = entry[,list]
1916
1917 The type attributes are:
1918 s - String (default)
1919 d - Decimal
1920 x - Hexadecimal
1921 b - Boolean ([1yYtT|0nNfF])
1922 i - IP address
1923 m - MAC address
1924
Joe Hershberger267541f2012-12-11 22:16:34 -06001925 The access attributes are:
1926 a - Any (default)
1927 r - Read-only
1928 o - Write-once
1929 c - Change-default
1930
Joe Hershberger25980902012-12-11 22:16:31 -06001931 - CONFIG_ENV_FLAGS_LIST_DEFAULT
1932 Define this to a list (string) to define the ".flags"
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001933 environment variable in the default or embedded environment.
Joe Hershberger25980902012-12-11 22:16:31 -06001934
1935 - CONFIG_ENV_FLAGS_LIST_STATIC
1936 Define this to a list (string) to define validation that
1937 should be done if an entry is not found in the ".flags"
1938 environment variable. To override a setting in the static
1939 list, simply add an entry for the same variable name to the
1940 ".flags" variable.
1941
Joe Hershbergerbdf1fe42015-05-20 14:27:20 -05001942 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
1943 regular expression. This allows multiple variables to define the same
1944 flags without explicitly listing them for each variable.
1945
wdenkc6097192002-11-03 00:24:07 +00001946The following definitions that deal with the placement and management
1947of environment data (variable area); in general, we support the
1948following configurations:
1949
Mike Frysingerc3eb3fe2011-07-08 10:44:25 +00001950- CONFIG_BUILD_ENVCRC:
1951
1952 Builds up envcrc with the target environment so that external utils
1953 may easily extract it and embed it in final U-Boot images.
1954
wdenkc6097192002-11-03 00:24:07 +00001955BE CAREFUL! The first access to the environment happens quite early
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08001956in U-Boot initialization (when we try to get the setting of for the
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02001957console baudrate). You *MUST* have mapped your NVRAM area then, or
wdenkc6097192002-11-03 00:24:07 +00001958U-Boot will hang.
1959
1960Please note that even with NVRAM we still use a copy of the
1961environment in RAM: we could work on NVRAM directly, but we want to
1962keep settings there always unmodified except somebody uses "saveenv"
1963to save the current settings.
1964
Liu Gang0a85a9e2012-03-08 00:33:20 +00001965BE CAREFUL! For some special cases, the local device can not use
1966"saveenv" command. For example, the local device will get the
Liu Gangfc54c7f2012-08-09 05:10:01 +00001967environment stored in a remote NOR flash by SRIO or PCIE link,
1968but it can not erase, write this NOR flash by SRIO or PCIE interface.
Liu Gang0a85a9e2012-03-08 00:33:20 +00001969
Guennadi Liakhovetskib74ab732009-05-18 16:07:22 +02001970- CONFIG_NAND_ENV_DST
1971
1972 Defines address in RAM to which the nand_spl code should copy the
1973 environment. If redundant environment is used, it will be copied to
1974 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
1975
Bruce Adlere881cb52007-11-02 13:15:42 -07001976Please note that the environment is read-only until the monitor
wdenkc6097192002-11-03 00:24:07 +00001977has been relocated to RAM and a RAM copy of the environment has been
Simon Glass00caae62017-08-03 12:22:12 -06001978created; also, when using EEPROM you will have to use env_get_f()
wdenkc6097192002-11-03 00:24:07 +00001979until then to read environment variables.
1980
wdenk85ec0bc2003-03-31 16:34:49 +00001981The environment is protected by a CRC32 checksum. Before the monitor
1982is relocated into RAM, as a result of a bad CRC you will be working
1983with the compiled-in default environment - *silently*!!! [This is
1984necessary, because the first environment variable we need is the
1985"baudrate" setting for the console - if we have a bad CRC, we don't
1986have any device yet where we could complain.]
wdenkc6097192002-11-03 00:24:07 +00001987
1988Note: once the monitor has been relocated, then it will complain if
1989the default environment is used; a new CRC is computed as soon as you
wdenk85ec0bc2003-03-31 16:34:49 +00001990use the "saveenv" command to store a valid environment.
wdenkc6097192002-11-03 00:24:07 +00001991
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02001992- CONFIG_SYS_FAULT_MII_ADDR:
wdenk42d1f032003-10-15 23:53:47 +00001993 MII address of the PHY to check for the Ethernet link state.
wdenkc6097192002-11-03 00:24:07 +00001994
Ron Madridf5675aa2009-02-18 14:30:44 -08001995- CONFIG_NS16550_MIN_FUNCTIONS:
1996 Define this if you desire to only have use of the NS16550_init
1997 and NS16550_putc functions for the serial driver located at
1998 drivers/serial/ns16550.c. This option is useful for saving
1999 space for already greatly restricted images, including but not
2000 limited to NAND_SPL configurations.
2001
Simon Glassb2b92f52012-11-30 13:01:18 +00002002- CONFIG_DISPLAY_BOARDINFO
2003 Display information about the board that U-Boot is running on
2004 when U-Boot starts up. The board function checkboard() is called
2005 to do this.
2006
Simon Glasse2e3e2b2012-11-30 13:01:19 +00002007- CONFIG_DISPLAY_BOARDINFO_LATE
2008 Similar to the previous option, but display this information
2009 later, once stdio is running and output goes to the LCD, if
2010 present.
2011
wdenkc6097192002-11-03 00:24:07 +00002012Low Level (hardware related) configuration options:
wdenkdc7c9a12003-03-26 06:55:25 +00002013---------------------------------------------------
wdenkc6097192002-11-03 00:24:07 +00002014
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002015- CONFIG_SYS_CACHELINE_SIZE:
wdenkc6097192002-11-03 00:24:07 +00002016 Cache Line Size of the CPU.
2017
Timur Tabie46fedf2011-08-04 18:03:41 -05002018- CONFIG_SYS_CCSRBAR_DEFAULT:
2019 Default (power-on reset) physical address of CCSR on Freescale
2020 PowerPC SOCs.
2021
2022- CONFIG_SYS_CCSRBAR:
2023 Virtual address of CCSR. On a 32-bit build, this is typically
2024 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
2025
Timur Tabie46fedf2011-08-04 18:03:41 -05002026- CONFIG_SYS_CCSRBAR_PHYS:
2027 Physical address of CCSR. CCSR can be relocated to a new
2028 physical address, if desired. In this case, this macro should
Wolfgang Denkc0f40852011-10-26 10:21:21 +00002029 be set to that address. Otherwise, it should be set to the
Timur Tabie46fedf2011-08-04 18:03:41 -05002030 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
2031 is typically relocated on 36-bit builds. It is recommended
2032 that this macro be defined via the _HIGH and _LOW macros:
2033
2034 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
2035 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
2036
2037- CONFIG_SYS_CCSRBAR_PHYS_HIGH:
Wolfgang Denk4cf26092011-10-07 09:58:21 +02002038 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
2039 either 0 (32-bit build) or 0xF (36-bit build). This macro is
Timur Tabie46fedf2011-08-04 18:03:41 -05002040 used in assembly code, so it must not contain typecasts or
2041 integer size suffixes (e.g. "ULL").
2042
2043- CONFIG_SYS_CCSRBAR_PHYS_LOW:
2044 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
2045 used in assembly code, so it must not contain typecasts or
2046 integer size suffixes (e.g. "ULL").
2047
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002048- CONFIG_SYS_IMMR: Physical address of the Internal Memory.
wdenkefe2a4d2004-12-16 21:44:03 +00002049 DO NOT CHANGE unless you know exactly what you're
Christophe Leroy907208c2017-07-06 10:23:22 +02002050 doing! (11-4) [MPC8xx systems only]
wdenkc6097192002-11-03 00:24:07 +00002051
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002052- CONFIG_SYS_INIT_RAM_ADDR:
wdenkc6097192002-11-03 00:24:07 +00002053
wdenk7152b1d2003-09-05 23:19:14 +00002054 Start address of memory area that can be used for
wdenkc6097192002-11-03 00:24:07 +00002055 initial data and stack; please note that this must be
2056 writable memory that is working WITHOUT special
2057 initialization, i. e. you CANNOT use normal RAM which
2058 will become available only after programming the
2059 memory controller and running certain initialization
2060 sequences.
2061
2062 U-Boot uses the following memory types:
Christophe Leroy907208c2017-07-06 10:23:22 +02002063 - MPC8xx: IMMR (internal memory of the CPU)
wdenkc6097192002-11-03 00:24:07 +00002064
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002065- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
wdenkc6097192002-11-03 00:24:07 +00002066
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002067- CONFIG_SYS_OR_TIMING_SDRAM:
wdenkc6097192002-11-03 00:24:07 +00002068 SDRAM timing
2069
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002070- CONFIG_SYS_MAMR_PTA:
wdenkc6097192002-11-03 00:24:07 +00002071 periodic timer for refresh
2072
Kumar Galaa09b9b62010-12-30 12:09:53 -06002073- CONFIG_SYS_SRIO:
2074 Chip has SRIO or not
2075
2076- CONFIG_SRIO1:
2077 Board has SRIO 1 port available
2078
2079- CONFIG_SRIO2:
2080 Board has SRIO 2 port available
2081
Liu Gangc8b28152013-05-07 16:30:46 +08002082- CONFIG_SRIO_PCIE_BOOT_MASTER
2083 Board can support master function for Boot from SRIO and PCIE
2084
Kumar Galaa09b9b62010-12-30 12:09:53 -06002085- CONFIG_SYS_SRIOn_MEM_VIRT:
2086 Virtual Address of SRIO port 'n' memory region
2087
Simon Glass62f9b652019-11-14 12:57:09 -07002088- CONFIG_SYS_SRIOn_MEM_PHYxS:
Kumar Galaa09b9b62010-12-30 12:09:53 -06002089 Physical Address of SRIO port 'n' memory region
2090
2091- CONFIG_SYS_SRIOn_MEM_SIZE:
2092 Size of SRIO port 'n' memory region
2093
Fabio Estevam66bd1842013-04-11 09:35:34 +00002094- CONFIG_SYS_NAND_BUSWIDTH_16BIT
2095 Defined to tell the NAND controller that the NAND chip is using
2096 a 16 bit bus.
2097 Not all NAND drivers use this symbol.
Fabio Estevama430e912013-04-11 09:35:35 +00002098 Example of drivers that use it:
Miquel Raynala430fa02018-08-16 17:30:07 +02002099 - drivers/mtd/nand/raw/ndfc.c
2100 - drivers/mtd/nand/raw/mxc_nand.c
Alex Watermaneced4622011-05-19 15:08:36 -04002101
2102- CONFIG_SYS_NDFC_EBC0_CFG
2103 Sets the EBC0_CFG register for the NDFC. If not defined
2104 a default value will be used.
2105
Ben Warrenbb99ad62006-09-07 16:50:54 -04002106- CONFIG_SPD_EEPROM
Wolfgang Denk218ca722008-03-26 10:40:12 +01002107 Get DDR timing information from an I2C EEPROM. Common
2108 with pluggable memory modules such as SODIMMs
2109
Ben Warrenbb99ad62006-09-07 16:50:54 -04002110 SPD_EEPROM_ADDRESS
2111 I2C address of the SPD EEPROM
2112
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002113- CONFIG_SYS_SPD_BUS_NUM
Wolfgang Denk218ca722008-03-26 10:40:12 +01002114 If SPD EEPROM is on an I2C bus other than the first
2115 one, specify here. Note that the value must resolve
2116 to something your driver can deal with.
Ben Warrenbb99ad62006-09-07 16:50:54 -04002117
York Sun1b3e3c42011-06-07 09:42:16 +08002118- CONFIG_SYS_DDR_RAW_TIMING
2119 Get DDR timing information from other than SPD. Common with
2120 soldered DDR chips onboard without SPD. DDR raw timing
2121 parameters are extracted from datasheet and hard-coded into
2122 header files or board specific files.
2123
York Sun6f5e1dc2011-09-16 13:21:35 -07002124- CONFIG_FSL_DDR_INTERACTIVE
2125 Enable interactive DDR debugging. See doc/README.fsl-ddr.
2126
York Sune32d59a2015-01-06 13:18:55 -08002127- CONFIG_FSL_DDR_SYNC_REFRESH
2128 Enable sync of refresh for multiple controllers.
2129
York Sun4516ff82015-03-19 09:30:28 -07002130- CONFIG_FSL_DDR_BIST
2131 Enable built-in memory test for Freescale DDR controllers.
2132
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002133- CONFIG_SYS_83XX_DDR_USES_CS0
Wolfgang Denk218ca722008-03-26 10:40:12 +01002134 Only for 83xx systems. If specified, then DDR should
2135 be configured using CS0 and CS1 instead of CS2 and CS3.
Timur Tabi2ad6b512006-10-31 18:44:42 -06002136
wdenkc26e4542004-04-18 10:13:26 +00002137- CONFIG_RMII
2138 Enable RMII mode for all FECs.
2139 Note that this is a global option, we can't
2140 have one FEC in standard MII mode and another in RMII mode.
2141
wdenk5cf91d62004-04-23 20:32:05 +00002142- CONFIG_CRC32_VERIFY
2143 Add a verify option to the crc32 command.
2144 The syntax is:
2145
2146 => crc32 -v <address> <count> <crc32>
2147
2148 Where address/count indicate a memory area
2149 and crc32 is the correct crc32 which the
2150 area should have.
2151
wdenk56523f12004-07-11 17:40:54 +00002152- CONFIG_LOOPW
2153 Add the "loopw" memory command. This only takes effect if
Simon Glass493f4202017-08-04 16:34:27 -06002154 the memory commands are activated globally (CONFIG_CMD_MEMORY).
wdenk56523f12004-07-11 17:40:54 +00002155
Joel Johnson72732312020-01-29 09:17:18 -07002156- CONFIG_CMD_MX_CYCLIC
stroese7b466642004-12-16 18:46:55 +00002157 Add the "mdc" and "mwc" memory commands. These are cyclic
2158 "md/mw" commands.
2159 Examples:
2160
wdenkefe2a4d2004-12-16 21:44:03 +00002161 => mdc.b 10 4 500
stroese7b466642004-12-16 18:46:55 +00002162 This command will print 4 bytes (10,11,12,13) each 500 ms.
2163
wdenkefe2a4d2004-12-16 21:44:03 +00002164 => mwc.l 100 12345678 10
stroese7b466642004-12-16 18:46:55 +00002165 This command will write 12345678 to address 100 all 10 ms.
2166
wdenkefe2a4d2004-12-16 21:44:03 +00002167 This only takes effect if the memory commands are activated
Simon Glass493f4202017-08-04 16:34:27 -06002168 globally (CONFIG_CMD_MEMORY).
stroese7b466642004-12-16 18:46:55 +00002169
Aneesh V401bb302011-07-13 05:11:07 +00002170- CONFIG_SPL_BUILD
Thomas Hebb32f2ca22019-11-13 18:18:03 -08002171 Set when the currently-running compilation is for an artifact
2172 that will end up in the SPL (as opposed to the TPL or U-Boot
2173 proper). Code that needs stage-specific behavior should check
2174 this.
wdenk400558b2005-04-02 23:52:25 +00002175
Ying Zhang3aa29de2013-08-16 15:16:15 +08002176- CONFIG_TPL_BUILD
Thomas Hebb32f2ca22019-11-13 18:18:03 -08002177 Set when the currently-running compilation is for an artifact
2178 that will end up in the TPL (as opposed to the SPL or U-Boot
2179 proper). Code that needs stage-specific behavior should check
2180 this.
Ying Zhang3aa29de2013-08-16 15:16:15 +08002181
Ying Zhang5df572f2013-05-20 14:07:23 +08002182- CONFIG_SYS_MPC85XX_NO_RESETVEC
2183 Only for 85xx systems. If this variable is specified, the section
2184 .resetvec is not kept and the section .bootpg is placed in the
2185 previous 4k of the .text section.
2186
Simon Glass4213fc22013-02-24 17:33:14 +00002187- CONFIG_ARCH_MAP_SYSMEM
2188 Generally U-Boot (and in particular the md command) uses
2189 effective address. It is therefore not necessary to regard
2190 U-Boot address as virtual addresses that need to be translated
2191 to physical addresses. However, sandbox requires this, since
2192 it maintains its own little RAM buffer which contains all
2193 addressable memory. This option causes some memory accesses
2194 to be mapped through map_sysmem() / unmap_sysmem().
2195
Simon Glass588a13f2013-02-14 04:18:54 +00002196- CONFIG_X86_RESET_VECTOR
2197 If defined, the x86 reset vector code is included. This is not
2198 needed when U-Boot is running from Coreboot.
Gabe Blackb16f5212012-11-27 21:08:06 +00002199
Karicheri, Muralidharan999d7d32014-04-04 13:16:50 -04002200- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
2201 Option to disable subpage write in NAND driver
2202 driver that uses this:
Miquel Raynala430fa02018-08-16 17:30:07 +02002203 drivers/mtd/nand/raw/davinci_nand.c
Karicheri, Muralidharan999d7d32014-04-04 13:16:50 -04002204
Timur Tabif2717b42011-11-22 09:21:25 -06002205Freescale QE/FMAN Firmware Support:
2206-----------------------------------
2207
2208The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
2209loading of "firmware", which is encoded in the QE firmware binary format.
2210This firmware often needs to be loaded during U-Boot booting, so macros
2211are used to identify the storage device (NOR flash, SPI, etc) and the address
2212within that device.
2213
Zhao Qiangdcf1d772014-03-21 16:21:44 +08002214- CONFIG_SYS_FMAN_FW_ADDR
2215 The address in the storage device where the FMAN microcode is located. The
Tom Rinicc1e98b2019-05-12 07:59:12 -04002216 meaning of this address depends on which CONFIG_SYS_QE_FMAN_FW_IN_xxx macro
Zhao Qiangdcf1d772014-03-21 16:21:44 +08002217 is also specified.
2218
2219- CONFIG_SYS_QE_FW_ADDR
2220 The address in the storage device where the QE microcode is located. The
Tom Rinicc1e98b2019-05-12 07:59:12 -04002221 meaning of this address depends on which CONFIG_SYS_QE_FMAN_FW_IN_xxx macro
Timur Tabif2717b42011-11-22 09:21:25 -06002222 is also specified.
2223
2224- CONFIG_SYS_QE_FMAN_FW_LENGTH
2225 The maximum possible size of the firmware. The firmware binary format
2226 has a field that specifies the actual size of the firmware, but it
2227 might not be possible to read any part of the firmware unless some
2228 local storage is allocated to hold the entire firmware first.
2229
2230- CONFIG_SYS_QE_FMAN_FW_IN_NOR
2231 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
2232 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
2233 virtual address in NOR flash.
2234
2235- CONFIG_SYS_QE_FMAN_FW_IN_NAND
2236 Specifies that QE/FMAN firmware is located in NAND flash.
2237 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
2238
2239- CONFIG_SYS_QE_FMAN_FW_IN_MMC
2240 Specifies that QE/FMAN firmware is located on the primary SD/MMC
2241 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
2242
Liu Gang292dc6c2012-03-08 00:33:18 +00002243- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
2244 Specifies that QE/FMAN firmware is located in the remote (master)
2245 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
Liu Gangfc54c7f2012-08-09 05:10:01 +00002246 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
2247 window->master inbound window->master LAW->the ucode address in
2248 master's memory space.
Timur Tabif2717b42011-11-22 09:21:25 -06002249
J. German Riverab940ca62014-06-23 15:15:55 -07002250Freescale Layerscape Management Complex Firmware Support:
2251---------------------------------------------------------
2252The Freescale Layerscape Management Complex (MC) supports the loading of
2253"firmware".
2254This firmware often needs to be loaded during U-Boot booting, so macros
2255are used to identify the storage device (NOR flash, SPI, etc) and the address
2256within that device.
2257
2258- CONFIG_FSL_MC_ENET
2259 Enable the MC driver for Layerscape SoCs.
2260
Prabhakar Kushwaha5c055082015-06-02 10:55:52 +05302261Freescale Layerscape Debug Server Support:
2262-------------------------------------------
2263The Freescale Layerscape Debug Server Support supports the loading of
2264"Debug Server firmware" and triggering SP boot-rom.
2265This firmware often needs to be loaded during U-Boot booting.
2266
York Sunc0492142015-12-07 11:08:58 -08002267- CONFIG_SYS_MC_RSV_MEM_ALIGN
2268 Define alignment of reserved memory MC requires
Prabhakar Kushwaha5c055082015-06-02 10:55:52 +05302269
Paul Kocialkowskif3f431a2015-07-26 18:48:15 +02002270Reproducible builds
2271-------------------
2272
2273In order to achieve reproducible builds, timestamps used in the U-Boot build
2274process have to be set to a fixed value.
2275
2276This is done using the SOURCE_DATE_EPOCH environment variable.
2277SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
2278option for U-Boot or an environment variable in U-Boot.
2279
2280SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
2281
wdenkc6097192002-11-03 00:24:07 +00002282Building the Software:
2283======================
2284
Wolfgang Denk218ca722008-03-26 10:40:12 +01002285Building U-Boot has been tested in several native build environments
2286and in many different cross environments. Of course we cannot support
2287all possibly existing versions of cross development tools in all
2288(potentially obsolete) versions. In case of tool chain problems we
Naoki Hayama047f6ec2020-10-08 13:17:16 +09002289recommend to use the ELDK (see https://www.denx.de/wiki/DULG/ELDK)
Wolfgang Denk218ca722008-03-26 10:40:12 +01002290which is extensively used to build and test U-Boot.
wdenkc6097192002-11-03 00:24:07 +00002291
Wolfgang Denk218ca722008-03-26 10:40:12 +01002292If you are not using a native environment, it is assumed that you
2293have GNU cross compiling tools available in your path. In this case,
2294you must set the environment variable CROSS_COMPILE in your shell.
2295Note that no changes to the Makefile or any other source files are
2296necessary. For example using the ELDK on a 4xx CPU, please enter:
wdenkc6097192002-11-03 00:24:07 +00002297
Wolfgang Denk218ca722008-03-26 10:40:12 +01002298 $ CROSS_COMPILE=ppc_4xx-
2299 $ export CROSS_COMPILE
wdenkc6097192002-11-03 00:24:07 +00002300
Wolfgang Denk218ca722008-03-26 10:40:12 +01002301U-Boot is intended to be simple to build. After installing the
2302sources you must configure U-Boot for one specific board type. This
wdenkc6097192002-11-03 00:24:07 +00002303is done by typing:
2304
Holger Freytherab584d62014-08-04 09:26:05 +02002305 make NAME_defconfig
wdenkc6097192002-11-03 00:24:07 +00002306
Holger Freytherab584d62014-08-04 09:26:05 +02002307where "NAME_defconfig" is the name of one of the existing configu-
Heinrich Schuchardtecb3a0a2020-02-24 18:36:30 +01002308rations; see configs/*_defconfig for supported names.
wdenk54387ac2003-10-08 22:45:44 +00002309
Heinrich Schuchardtecb3a0a2020-02-24 18:36:30 +01002310Note: for some boards special configuration names may exist; check if
wdenk2729af92004-05-03 20:45:30 +00002311 additional information is available from the board vendor; for
2312 instance, the TQM823L systems are available without (standard)
2313 or with LCD support. You can select such additional "features"
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002314 when choosing the configuration, i. e.
wdenkc6097192002-11-03 00:24:07 +00002315
Holger Freytherab584d62014-08-04 09:26:05 +02002316 make TQM823L_defconfig
wdenk2729af92004-05-03 20:45:30 +00002317 - will configure for a plain TQM823L, i. e. no LCD support
wdenkc6097192002-11-03 00:24:07 +00002318
Holger Freytherab584d62014-08-04 09:26:05 +02002319 make TQM823L_LCD_defconfig
wdenk2729af92004-05-03 20:45:30 +00002320 - will configure for a TQM823L with U-Boot console on LCD
wdenkc6097192002-11-03 00:24:07 +00002321
wdenk2729af92004-05-03 20:45:30 +00002322 etc.
wdenkc6097192002-11-03 00:24:07 +00002323
wdenkc6097192002-11-03 00:24:07 +00002324
wdenk2729af92004-05-03 20:45:30 +00002325Finally, type "make all", and you should get some working U-Boot
2326images ready for download to / installation on your system:
wdenkc6097192002-11-03 00:24:07 +00002327
wdenk2729af92004-05-03 20:45:30 +00002328- "u-boot.bin" is a raw binary image
2329- "u-boot" is an image in ELF binary format
2330- "u-boot.srec" is in Motorola S-Record format
wdenkc6097192002-11-03 00:24:07 +00002331
Marian Balakowiczbaf31242006-09-07 17:25:40 +02002332By default the build is performed locally and the objects are saved
2333in the source directory. One of the two methods can be used to change
2334this behavior and build U-Boot to some external directory:
2335
23361. Add O= to the make command line invocations:
2337
2338 make O=/tmp/build distclean
Holger Freytherab584d62014-08-04 09:26:05 +02002339 make O=/tmp/build NAME_defconfig
Marian Balakowiczbaf31242006-09-07 17:25:40 +02002340 make O=/tmp/build all
2341
Timo Ketolaadbba992014-11-06 14:39:05 +020023422. Set environment variable KBUILD_OUTPUT to point to the desired location:
Marian Balakowiczbaf31242006-09-07 17:25:40 +02002343
Timo Ketolaadbba992014-11-06 14:39:05 +02002344 export KBUILD_OUTPUT=/tmp/build
Marian Balakowiczbaf31242006-09-07 17:25:40 +02002345 make distclean
Holger Freytherab584d62014-08-04 09:26:05 +02002346 make NAME_defconfig
Marian Balakowiczbaf31242006-09-07 17:25:40 +02002347 make all
2348
Timo Ketolaadbba992014-11-06 14:39:05 +02002349Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
Marian Balakowiczbaf31242006-09-07 17:25:40 +02002350variable.
2351
Daniel Schwierzeck215bb1c2018-01-26 16:31:04 +01002352User specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by
2353setting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS.
2354For example to treat all compiler warnings as errors:
2355
2356 make KCFLAGS=-Werror
wdenkc6097192002-11-03 00:24:07 +00002357
wdenk2729af92004-05-03 20:45:30 +00002358Please be aware that the Makefiles assume you are using GNU make, so
2359for instance on NetBSD you might need to use "gmake" instead of
2360native "make".
wdenkc6097192002-11-03 00:24:07 +00002361
wdenkc6097192002-11-03 00:24:07 +00002362
wdenk2729af92004-05-03 20:45:30 +00002363If the system board that you have is not listed, then you will need
2364to port U-Boot to your hardware platform. To do this, follow these
2365steps:
wdenkc6097192002-11-03 00:24:07 +00002366
Phil Sutter3c1496c2015-12-25 14:41:18 +010023671. Create a new directory to hold your board specific code. Add any
wdenk2729af92004-05-03 20:45:30 +00002368 files you need. In your board directory, you will need at least
Phil Sutter3c1496c2015-12-25 14:41:18 +01002369 the "Makefile" and a "<board>.c".
23702. Create a new configuration file "include/configs/<board>.h" for
2371 your board.
wdenk2729af92004-05-03 20:45:30 +000023723. If you're porting U-Boot to a new CPU, then also create a new
2373 directory to hold your CPU specific code. Add any files you need.
Holger Freytherab584d62014-08-04 09:26:05 +020023744. Run "make <board>_defconfig" with your new name.
wdenk2729af92004-05-03 20:45:30 +000023755. Type "make", and you should get a working "u-boot.srec" file
2376 to be installed on your target system.
23776. Debug and solve any problems that might arise.
2378 [Of course, this last step is much harder than it sounds.]
wdenkc6097192002-11-03 00:24:07 +00002379
wdenkc6097192002-11-03 00:24:07 +00002380
wdenk2729af92004-05-03 20:45:30 +00002381Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2382==============================================================
wdenkc6097192002-11-03 00:24:07 +00002383
Wolfgang Denk218ca722008-03-26 10:40:12 +01002384If you have modified U-Boot sources (for instance added a new board
2385or support for new devices, a new CPU, etc.) you are expected to
wdenk2729af92004-05-03 20:45:30 +00002386provide feedback to the other developers. The feedback normally takes
Thomas Hebb32f2ca22019-11-13 18:18:03 -08002387the form of a "patch", i.e. a context diff against a certain (latest
Wolfgang Denk218ca722008-03-26 10:40:12 +01002388official or latest in the git repository) version of U-Boot sources.
wdenkc6097192002-11-03 00:24:07 +00002389
Wolfgang Denk218ca722008-03-26 10:40:12 +01002390But before you submit such a patch, please verify that your modifi-
2391cation did not break existing code. At least make sure that *ALL* of
wdenk2729af92004-05-03 20:45:30 +00002392the supported boards compile WITHOUT ANY compiler warnings. To do so,
Simon Glass6de80f22016-07-27 20:33:08 -06002393just run the buildman script (tools/buildman/buildman), which will
2394configure and build U-Boot for ALL supported system. Be warned, this
2395will take a while. Please see the buildman README, or run 'buildman -H'
2396for documentation.
Marian Balakowiczbaf31242006-09-07 17:25:40 +02002397
2398
wdenk2729af92004-05-03 20:45:30 +00002399See also "U-Boot Porting Guide" below.
wdenkc6097192002-11-03 00:24:07 +00002400
wdenkc6097192002-11-03 00:24:07 +00002401
wdenk2729af92004-05-03 20:45:30 +00002402Monitor Commands - Overview:
2403============================
wdenkc6097192002-11-03 00:24:07 +00002404
wdenk2729af92004-05-03 20:45:30 +00002405go - start application at address 'addr'
2406run - run commands in an environment variable
2407bootm - boot application image from memory
2408bootp - boot image via network using BootP/TFTP protocol
Marek Vasut44f074c2012-03-14 21:52:45 +00002409bootz - boot zImage from memory
wdenk2729af92004-05-03 20:45:30 +00002410tftpboot- boot image via network using TFTP protocol
2411 and env variables "ipaddr" and "serverip"
2412 (and eventually "gatewayip")
Simon Glass1fb7cd42011-10-24 18:00:07 +00002413tftpput - upload a file via network using TFTP protocol
wdenk2729af92004-05-03 20:45:30 +00002414rarpboot- boot image via network using RARP/TFTP protocol
2415diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2416loads - load S-Record file over serial line
2417loadb - load binary file over serial line (kermit mode)
2418md - memory display
2419mm - memory modify (auto-incrementing)
2420nm - memory modify (constant address)
2421mw - memory write (fill)
Simon Glassbdded202020-06-02 19:26:49 -06002422ms - memory search
wdenk2729af92004-05-03 20:45:30 +00002423cp - memory copy
2424cmp - memory compare
2425crc32 - checksum calculation
Peter Tyser0f89c542009-04-18 22:34:03 -05002426i2c - I2C sub-system
wdenk2729af92004-05-03 20:45:30 +00002427sspi - SPI utility commands
2428base - print or set address offset
2429printenv- print environment variables
Pragnesh Patel9e9a5302020-12-22 11:30:05 +05302430pwm - control pwm channels
wdenk2729af92004-05-03 20:45:30 +00002431setenv - set environment variables
2432saveenv - save environment variables to persistent storage
2433protect - enable or disable FLASH write protection
2434erase - erase FLASH memory
2435flinfo - print FLASH memory information
Karl O. Pinc10635af2012-08-03 05:57:21 +00002436nand - NAND memory operations (see doc/README.nand)
wdenk2729af92004-05-03 20:45:30 +00002437bdinfo - print Board Info structure
2438iminfo - print header information for application image
2439coninfo - print console devices and informations
2440ide - IDE sub-system
2441loop - infinite loop on address range
wdenk56523f12004-07-11 17:40:54 +00002442loopw - infinite write loop on address range
wdenk2729af92004-05-03 20:45:30 +00002443mtest - simple RAM test
2444icache - enable or disable instruction cache
2445dcache - enable or disable data cache
2446reset - Perform RESET of the CPU
2447echo - echo args to console
2448version - print monitor version
2449help - print online help
2450? - alias for 'help'
wdenkc6097192002-11-03 00:24:07 +00002451
wdenkc6097192002-11-03 00:24:07 +00002452
wdenk2729af92004-05-03 20:45:30 +00002453Monitor Commands - Detailed Description:
2454========================================
wdenkc6097192002-11-03 00:24:07 +00002455
wdenk2729af92004-05-03 20:45:30 +00002456TODO.
wdenkc6097192002-11-03 00:24:07 +00002457
wdenk2729af92004-05-03 20:45:30 +00002458For now: just type "help <command>".
wdenkc6097192002-11-03 00:24:07 +00002459
2460
wdenk2729af92004-05-03 20:45:30 +00002461Note for Redundant Ethernet Interfaces:
2462=======================================
wdenkf07771c2003-05-28 08:06:31 +00002463
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002464Some boards come with redundant Ethernet interfaces; U-Boot supports
wdenk2729af92004-05-03 20:45:30 +00002465such configurations and is capable of automatic selection of a
2466"working" interface when needed. MAC assignment works as follows:
wdenkf07771c2003-05-28 08:06:31 +00002467
wdenk2729af92004-05-03 20:45:30 +00002468Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2469MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2470"eth1addr" (=>eth1), "eth2addr", ...
wdenkf07771c2003-05-28 08:06:31 +00002471
wdenk2729af92004-05-03 20:45:30 +00002472If the network interface stores some valid MAC address (for instance
2473in SROM), this is used as default address if there is NO correspon-
2474ding setting in the environment; if the corresponding environment
2475variable is set, this overrides the settings in the card; that means:
wdenkf07771c2003-05-28 08:06:31 +00002476
wdenk2729af92004-05-03 20:45:30 +00002477o If the SROM has a valid MAC address, and there is no address in the
2478 environment, the SROM's address is used.
wdenkc6097192002-11-03 00:24:07 +00002479
wdenk2729af92004-05-03 20:45:30 +00002480o If there is no valid address in the SROM, and a definition in the
2481 environment exists, then the value from the environment variable is
2482 used.
wdenkc6097192002-11-03 00:24:07 +00002483
wdenk2729af92004-05-03 20:45:30 +00002484o If both the SROM and the environment contain a MAC address, and
2485 both addresses are the same, this MAC address is used.
wdenkc6097192002-11-03 00:24:07 +00002486
wdenk2729af92004-05-03 20:45:30 +00002487o If both the SROM and the environment contain a MAC address, and the
2488 addresses differ, the value from the environment is used and a
2489 warning is printed.
wdenkc6097192002-11-03 00:24:07 +00002490
wdenk2729af92004-05-03 20:45:30 +00002491o If neither SROM nor the environment contain a MAC address, an error
Joe Hershbergerbef10142015-05-04 14:55:13 -05002492 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
2493 a random, locally-assigned MAC is used.
wdenkc6097192002-11-03 00:24:07 +00002494
Ben Warrenecee9322010-04-26 11:11:46 -07002495If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
Wolfgang Denkc0f40852011-10-26 10:21:21 +00002496will be programmed into hardware as part of the initialization process. This
Ben Warrenecee9322010-04-26 11:11:46 -07002497may be skipped by setting the appropriate 'ethmacskip' environment variable.
2498The naming convention is as follows:
2499"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
wdenkc6097192002-11-03 00:24:07 +00002500
wdenk2729af92004-05-03 20:45:30 +00002501Image Formats:
2502==============
wdenkc6097192002-11-03 00:24:07 +00002503
Marian Balakowicz3310c542008-03-12 12:13:13 +01002504U-Boot is capable of booting (and performing other auxiliary operations on)
2505images in two formats:
2506
2507New uImage format (FIT)
2508-----------------------
2509
2510Flexible and powerful format based on Flattened Image Tree -- FIT (similar
2511to Flattened Device Tree). It allows the use of images with multiple
2512components (several kernels, ramdisks, etc.), with contents protected by
2513SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
2514
2515
2516Old uImage format
2517-----------------
2518
2519Old image format is based on binary files which can be basically anything,
2520preceded by a special header; see the definitions in include/image.h for
2521details; basically, the header defines the following image properties:
wdenkc6097192002-11-03 00:24:07 +00002522
wdenk2729af92004-05-03 20:45:30 +00002523* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2524 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
Peter Tyserf5ed9e32008-09-08 14:56:49 -05002525 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
Thomas Huth0797e732021-11-13 18:13:50 +01002526 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, INTEGRITY).
Andy Shevchenkodaab59a2017-07-05 16:25:22 +03002527* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
Tom Rini11232132022-04-06 09:21:25 -04002528 IA64, MIPS, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2529 Currently supported: ARM, Intel x86, MIPS, Nios II, PowerPC).
wdenk2729af92004-05-03 20:45:30 +00002530* Compression Type (uncompressed, gzip, bzip2)
2531* Load Address
2532* Entry Point
2533* Image Name
2534* Image Timestamp
wdenkc6097192002-11-03 00:24:07 +00002535
wdenk2729af92004-05-03 20:45:30 +00002536The header is marked by a special Magic Number, and both the header
2537and the data portions of the image are secured against corruption by
2538CRC32 checksums.
wdenkc6097192002-11-03 00:24:07 +00002539
wdenkc6097192002-11-03 00:24:07 +00002540
wdenk2729af92004-05-03 20:45:30 +00002541Linux Support:
2542==============
wdenkc6097192002-11-03 00:24:07 +00002543
wdenk2729af92004-05-03 20:45:30 +00002544Although U-Boot should support any OS or standalone application
2545easily, the main focus has always been on Linux during the design of
2546U-Boot.
wdenkc6097192002-11-03 00:24:07 +00002547
wdenk2729af92004-05-03 20:45:30 +00002548U-Boot includes many features that so far have been part of some
2549special "boot loader" code within the Linux kernel. Also, any
2550"initrd" images to be used are no longer part of one big Linux image;
2551instead, kernel and "initrd" are separate images. This implementation
2552serves several purposes:
wdenkc6097192002-11-03 00:24:07 +00002553
wdenk2729af92004-05-03 20:45:30 +00002554- the same features can be used for other OS or standalone
2555 applications (for instance: using compressed images to reduce the
2556 Flash memory footprint)
wdenkc6097192002-11-03 00:24:07 +00002557
wdenk2729af92004-05-03 20:45:30 +00002558- it becomes much easier to port new Linux kernel versions because
2559 lots of low-level, hardware dependent stuff are done by U-Boot
wdenkc6097192002-11-03 00:24:07 +00002560
wdenk2729af92004-05-03 20:45:30 +00002561- the same Linux kernel image can now be used with different "initrd"
2562 images; of course this also means that different kernel images can
2563 be run with the same "initrd". This makes testing easier (you don't
2564 have to build a new "zImage.initrd" Linux image when you just
2565 change a file in your "initrd"). Also, a field-upgrade of the
2566 software is easier now.
wdenkc6097192002-11-03 00:24:07 +00002567
wdenkc6097192002-11-03 00:24:07 +00002568
wdenk2729af92004-05-03 20:45:30 +00002569Linux HOWTO:
2570============
wdenkc6097192002-11-03 00:24:07 +00002571
wdenk2729af92004-05-03 20:45:30 +00002572Porting Linux to U-Boot based systems:
2573---------------------------------------
wdenkc6097192002-11-03 00:24:07 +00002574
wdenk2729af92004-05-03 20:45:30 +00002575U-Boot cannot save you from doing all the necessary modifications to
2576configure the Linux device drivers for use with your target hardware
2577(no, we don't intend to provide a full virtual machine interface to
2578Linux :-).
wdenkc6097192002-11-03 00:24:07 +00002579
Stefan Roesea47a12b2010-04-15 16:07:28 +02002580But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
wdenkc6097192002-11-03 00:24:07 +00002581
wdenk2729af92004-05-03 20:45:30 +00002582Just make sure your machine specific header file (for instance
2583include/asm-ppc/tqm8xx.h) includes the same definition of the Board
Markus Heidelberg1dc30692008-09-07 20:18:27 +02002584Information structure as we define in include/asm-<arch>/u-boot.h,
2585and make sure that your definition of IMAP_ADDR uses the same value
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02002586as your U-Boot configuration in CONFIG_SYS_IMMR.
wdenkc6097192002-11-03 00:24:07 +00002587
Simon Glass2eb31b12014-06-11 23:29:46 -06002588Note that U-Boot now has a driver model, a unified model for drivers.
2589If you are adding a new driver, plumb it into driver model. If there
2590is no uclass available, you are encouraged to create one. See
2591doc/driver-model.
2592
wdenkc6097192002-11-03 00:24:07 +00002593
wdenk2729af92004-05-03 20:45:30 +00002594Configuring the Linux kernel:
2595-----------------------------
wdenkc6097192002-11-03 00:24:07 +00002596
wdenk2729af92004-05-03 20:45:30 +00002597No specific requirements for U-Boot. Make sure you have some root
2598device (initial ramdisk, NFS) for your target system.
wdenkc6097192002-11-03 00:24:07 +00002599
wdenkc6097192002-11-03 00:24:07 +00002600
wdenk2729af92004-05-03 20:45:30 +00002601Building a Linux Image:
2602-----------------------
wdenkc6097192002-11-03 00:24:07 +00002603
wdenk2729af92004-05-03 20:45:30 +00002604With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2605not used. If you use recent kernel source, a new build target
2606"uImage" will exist which automatically builds an image usable by
2607U-Boot. Most older kernels also have support for a "pImage" target,
2608which was introduced for our predecessor project PPCBoot and uses a
2609100% compatible format.
wdenkc6097192002-11-03 00:24:07 +00002610
wdenk2729af92004-05-03 20:45:30 +00002611Example:
wdenkc6097192002-11-03 00:24:07 +00002612
Holger Freytherab584d62014-08-04 09:26:05 +02002613 make TQM850L_defconfig
wdenk2729af92004-05-03 20:45:30 +00002614 make oldconfig
2615 make dep
2616 make uImage
wdenkc6097192002-11-03 00:24:07 +00002617
wdenk2729af92004-05-03 20:45:30 +00002618The "uImage" build target uses a special tool (in 'tools/mkimage') to
2619encapsulate a compressed Linux kernel image with header information,
2620CRC32 checksum etc. for use with U-Boot. This is what we are doing:
wdenkc6097192002-11-03 00:24:07 +00002621
wdenk2729af92004-05-03 20:45:30 +00002622* build a standard "vmlinux" kernel image (in ELF binary format):
wdenkc6097192002-11-03 00:24:07 +00002623
wdenk2729af92004-05-03 20:45:30 +00002624* convert the kernel into a raw binary image:
wdenkc6097192002-11-03 00:24:07 +00002625
wdenk2729af92004-05-03 20:45:30 +00002626 ${CROSS_COMPILE}-objcopy -O binary \
2627 -R .note -R .comment \
2628 -S vmlinux linux.bin
wdenkc6097192002-11-03 00:24:07 +00002629
wdenk2729af92004-05-03 20:45:30 +00002630* compress the binary image:
wdenkc6097192002-11-03 00:24:07 +00002631
wdenk2729af92004-05-03 20:45:30 +00002632 gzip -9 linux.bin
wdenkc6097192002-11-03 00:24:07 +00002633
wdenk2729af92004-05-03 20:45:30 +00002634* package compressed binary image for U-Boot:
wdenk24ee89b2002-11-03 17:56:27 +00002635
wdenk2729af92004-05-03 20:45:30 +00002636 mkimage -A ppc -O linux -T kernel -C gzip \
2637 -a 0 -e 0 -n "Linux Kernel Image" \
2638 -d linux.bin.gz uImage
wdenk24ee89b2002-11-03 17:56:27 +00002639
wdenk24ee89b2002-11-03 17:56:27 +00002640
wdenk2729af92004-05-03 20:45:30 +00002641The "mkimage" tool can also be used to create ramdisk images for use
2642with U-Boot, either separated from the Linux kernel image, or
2643combined into one file. "mkimage" encapsulates the images with a 64
2644byte header containing information about target architecture,
2645operating system, image type, compression method, entry points, time
2646stamp, CRC32 checksums, etc.
wdenk24ee89b2002-11-03 17:56:27 +00002647
wdenk2729af92004-05-03 20:45:30 +00002648"mkimage" can be called in two ways: to verify existing images and
2649print the header information, or to build new images.
wdenk24ee89b2002-11-03 17:56:27 +00002650
wdenk2729af92004-05-03 20:45:30 +00002651In the first form (with "-l" option) mkimage lists the information
2652contained in the header of an existing U-Boot image; this includes
2653checksum verification:
wdenk24ee89b2002-11-03 17:56:27 +00002654
wdenk2729af92004-05-03 20:45:30 +00002655 tools/mkimage -l image
2656 -l ==> list image header information
wdenk24ee89b2002-11-03 17:56:27 +00002657
wdenk2729af92004-05-03 20:45:30 +00002658The second form (with "-d" option) is used to build a U-Boot image
2659from a "data file" which is used as image payload:
wdenk24ee89b2002-11-03 17:56:27 +00002660
wdenk2729af92004-05-03 20:45:30 +00002661 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2662 -n name -d data_file image
2663 -A ==> set architecture to 'arch'
2664 -O ==> set operating system to 'os'
2665 -T ==> set image type to 'type'
2666 -C ==> set compression type 'comp'
2667 -a ==> set load address to 'addr' (hex)
2668 -e ==> set entry point to 'ep' (hex)
2669 -n ==> set image name to 'name'
2670 -d ==> use image data from 'datafile'
wdenk24ee89b2002-11-03 17:56:27 +00002671
wdenk69459792004-05-29 16:53:29 +00002672Right now, all Linux kernels for PowerPC systems use the same load
2673address (0x00000000), but the entry point address depends on the
2674kernel version:
wdenkc6097192002-11-03 00:24:07 +00002675
wdenk2729af92004-05-03 20:45:30 +00002676- 2.2.x kernels have the entry point at 0x0000000C,
2677- 2.3.x and later kernels have the entry point at 0x00000000.
wdenkc6097192002-11-03 00:24:07 +00002678
wdenk2729af92004-05-03 20:45:30 +00002679So a typical call to build a U-Boot image would read:
wdenkc6097192002-11-03 00:24:07 +00002680
wdenk2729af92004-05-03 20:45:30 +00002681 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2682 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
Stefan Roesea47a12b2010-04-15 16:07:28 +02002683 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
wdenk2729af92004-05-03 20:45:30 +00002684 > examples/uImage.TQM850L
2685 Image Name: 2.4.4 kernel for TQM850L
2686 Created: Wed Jul 19 02:34:59 2000
2687 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2688 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2689 Load Address: 0x00000000
2690 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002691
wdenk2729af92004-05-03 20:45:30 +00002692To verify the contents of the image (or check for corruption):
wdenkc6097192002-11-03 00:24:07 +00002693
wdenk2729af92004-05-03 20:45:30 +00002694 -> tools/mkimage -l examples/uImage.TQM850L
2695 Image Name: 2.4.4 kernel for TQM850L
2696 Created: Wed Jul 19 02:34:59 2000
2697 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2698 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2699 Load Address: 0x00000000
2700 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002701
wdenk2729af92004-05-03 20:45:30 +00002702NOTE: for embedded systems where boot time is critical you can trade
2703speed for memory and install an UNCOMPRESSED image instead: this
2704needs more space in Flash, but boots much faster since it does not
2705need to be uncompressed:
wdenkc6097192002-11-03 00:24:07 +00002706
Stefan Roesea47a12b2010-04-15 16:07:28 +02002707 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
wdenk2729af92004-05-03 20:45:30 +00002708 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2709 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
Stefan Roesea47a12b2010-04-15 16:07:28 +02002710 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
wdenk2729af92004-05-03 20:45:30 +00002711 > examples/uImage.TQM850L-uncompressed
2712 Image Name: 2.4.4 kernel for TQM850L
2713 Created: Wed Jul 19 02:34:59 2000
2714 Image Type: PowerPC Linux Kernel Image (uncompressed)
2715 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
2716 Load Address: 0x00000000
2717 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002718
wdenkc6097192002-11-03 00:24:07 +00002719
wdenk2729af92004-05-03 20:45:30 +00002720Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2721when your kernel is intended to use an initial ramdisk:
wdenkdb01a2e2004-04-15 23:14:49 +00002722
wdenk2729af92004-05-03 20:45:30 +00002723 -> tools/mkimage -n 'Simple Ramdisk Image' \
2724 > -A ppc -O linux -T ramdisk -C gzip \
2725 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2726 Image Name: Simple Ramdisk Image
2727 Created: Wed Jan 12 14:01:50 2000
2728 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2729 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
2730 Load Address: 0x00000000
2731 Entry Point: 0x00000000
wdenkdb01a2e2004-04-15 23:14:49 +00002732
Tyler Hickse157a112020-10-26 10:40:24 -05002733The "dumpimage" tool can be used to disassemble or list the contents of images
2734built by mkimage. See dumpimage's help output (-h) for details.
wdenkdb01a2e2004-04-15 23:14:49 +00002735
wdenk2729af92004-05-03 20:45:30 +00002736Installing a Linux Image:
2737-------------------------
wdenkdb01a2e2004-04-15 23:14:49 +00002738
wdenk2729af92004-05-03 20:45:30 +00002739To downloading a U-Boot image over the serial (console) interface,
2740you must convert the image to S-Record format:
wdenkdb01a2e2004-04-15 23:14:49 +00002741
wdenk2729af92004-05-03 20:45:30 +00002742 objcopy -I binary -O srec examples/image examples/image.srec
wdenkdb01a2e2004-04-15 23:14:49 +00002743
wdenk2729af92004-05-03 20:45:30 +00002744The 'objcopy' does not understand the information in the U-Boot
2745image header, so the resulting S-Record file will be relative to
2746address 0x00000000. To load it to a given address, you need to
2747specify the target address as 'offset' parameter with the 'loads'
2748command.
wdenkc6097192002-11-03 00:24:07 +00002749
wdenk2729af92004-05-03 20:45:30 +00002750Example: install the image to address 0x40100000 (which on the
2751TQM8xxL is in the first Flash bank):
wdenkc6097192002-11-03 00:24:07 +00002752
wdenk2729af92004-05-03 20:45:30 +00002753 => erase 40100000 401FFFFF
wdenkc6097192002-11-03 00:24:07 +00002754
wdenk2729af92004-05-03 20:45:30 +00002755 .......... done
2756 Erased 8 sectors
wdenkc6097192002-11-03 00:24:07 +00002757
wdenk2729af92004-05-03 20:45:30 +00002758 => loads 40100000
2759 ## Ready for S-Record download ...
2760 ~>examples/image.srec
2761 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2762 ...
2763 15989 15990 15991 15992
2764 [file transfer complete]
2765 [connected]
2766 ## Start Addr = 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002767
2768
wdenk2729af92004-05-03 20:45:30 +00002769You can check the success of the download using the 'iminfo' command;
Wolfgang Denk218ca722008-03-26 10:40:12 +01002770this includes a checksum verification so you can be sure no data
wdenk2729af92004-05-03 20:45:30 +00002771corruption happened:
wdenkc6097192002-11-03 00:24:07 +00002772
wdenk2729af92004-05-03 20:45:30 +00002773 => imi 40100000
wdenkc6097192002-11-03 00:24:07 +00002774
wdenk2729af92004-05-03 20:45:30 +00002775 ## Checking Image at 40100000 ...
2776 Image Name: 2.2.13 for initrd on TQM850L
2777 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2778 Data Size: 335725 Bytes = 327 kB = 0 MB
2779 Load Address: 00000000
2780 Entry Point: 0000000c
2781 Verifying Checksum ... OK
wdenkc6097192002-11-03 00:24:07 +00002782
2783
wdenk2729af92004-05-03 20:45:30 +00002784Boot Linux:
2785-----------
wdenkc6097192002-11-03 00:24:07 +00002786
wdenk2729af92004-05-03 20:45:30 +00002787The "bootm" command is used to boot an application that is stored in
2788memory (RAM or Flash). In case of a Linux kernel image, the contents
2789of the "bootargs" environment variable is passed to the kernel as
2790parameters. You can check and modify this variable using the
2791"printenv" and "setenv" commands:
wdenkc6097192002-11-03 00:24:07 +00002792
2793
wdenk2729af92004-05-03 20:45:30 +00002794 => printenv bootargs
2795 bootargs=root=/dev/ram
wdenkc6097192002-11-03 00:24:07 +00002796
wdenk2729af92004-05-03 20:45:30 +00002797 => 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 +00002798
wdenk2729af92004-05-03 20:45:30 +00002799 => printenv bootargs
2800 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 +00002801
wdenk2729af92004-05-03 20:45:30 +00002802 => bootm 40020000
2803 ## Booting Linux kernel at 40020000 ...
2804 Image Name: 2.2.13 for NFS on TQM850L
2805 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2806 Data Size: 381681 Bytes = 372 kB = 0 MB
2807 Load Address: 00000000
2808 Entry Point: 0000000c
2809 Verifying Checksum ... OK
2810 Uncompressing Kernel Image ... OK
2811 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
2812 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2813 time_init: decrementer frequency = 187500000/60
2814 Calibrating delay loop... 49.77 BogoMIPS
2815 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2816 ...
wdenkc6097192002-11-03 00:24:07 +00002817
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02002818If you want to boot a Linux kernel with initial RAM disk, you pass
wdenk2729af92004-05-03 20:45:30 +00002819the memory addresses of both the kernel and the initrd image (PPBCOOT
2820format!) to the "bootm" command:
wdenkc6097192002-11-03 00:24:07 +00002821
wdenk2729af92004-05-03 20:45:30 +00002822 => imi 40100000 40200000
wdenkc6097192002-11-03 00:24:07 +00002823
wdenk2729af92004-05-03 20:45:30 +00002824 ## Checking Image at 40100000 ...
2825 Image Name: 2.2.13 for initrd on TQM850L
2826 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2827 Data Size: 335725 Bytes = 327 kB = 0 MB
2828 Load Address: 00000000
2829 Entry Point: 0000000c
2830 Verifying Checksum ... OK
wdenkc6097192002-11-03 00:24:07 +00002831
wdenk2729af92004-05-03 20:45:30 +00002832 ## Checking Image at 40200000 ...
2833 Image Name: Simple Ramdisk Image
2834 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2835 Data Size: 566530 Bytes = 553 kB = 0 MB
2836 Load Address: 00000000
2837 Entry Point: 00000000
2838 Verifying Checksum ... OK
wdenkc6097192002-11-03 00:24:07 +00002839
wdenk2729af92004-05-03 20:45:30 +00002840 => bootm 40100000 40200000
2841 ## Booting Linux kernel at 40100000 ...
2842 Image Name: 2.2.13 for initrd on TQM850L
2843 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2844 Data Size: 335725 Bytes = 327 kB = 0 MB
2845 Load Address: 00000000
2846 Entry Point: 0000000c
2847 Verifying Checksum ... OK
2848 Uncompressing Kernel Image ... OK
2849 ## Loading RAMDisk Image at 40200000 ...
2850 Image Name: Simple Ramdisk Image
2851 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2852 Data Size: 566530 Bytes = 553 kB = 0 MB
2853 Load Address: 00000000
2854 Entry Point: 00000000
2855 Verifying Checksum ... OK
2856 Loading Ramdisk ... OK
2857 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
2858 Boot arguments: root=/dev/ram
2859 time_init: decrementer frequency = 187500000/60
2860 Calibrating delay loop... 49.77 BogoMIPS
2861 ...
2862 RAMDISK: Compressed image found at block 0
2863 VFS: Mounted root (ext2 filesystem).
wdenkc6097192002-11-03 00:24:07 +00002864
wdenk2729af92004-05-03 20:45:30 +00002865 bash#
wdenkc6097192002-11-03 00:24:07 +00002866
Matthew McClintock02677682006-06-28 10:41:37 -05002867Boot Linux and pass a flat device tree:
2868-----------
2869
2870First, U-Boot must be compiled with the appropriate defines. See the section
2871titled "Linux Kernel Interface" above for a more in depth explanation. The
2872following is an example of how to start a kernel and pass an updated
2873flat device tree:
2874
2875=> print oftaddr
2876oftaddr=0x300000
2877=> print oft
2878oft=oftrees/mpc8540ads.dtb
2879=> tftp $oftaddr $oft
2880Speed: 1000, full duplex
2881Using TSEC0 device
2882TFTP from server 192.168.1.1; our IP address is 192.168.1.101
2883Filename 'oftrees/mpc8540ads.dtb'.
2884Load address: 0x300000
2885Loading: #
2886done
2887Bytes transferred = 4106 (100a hex)
2888=> tftp $loadaddr $bootfile
2889Speed: 1000, full duplex
2890Using TSEC0 device
2891TFTP from server 192.168.1.1; our IP address is 192.168.1.2
2892Filename 'uImage'.
2893Load address: 0x200000
2894Loading:############
2895done
2896Bytes transferred = 1029407 (fb51f hex)
2897=> print loadaddr
2898loadaddr=200000
2899=> print oftaddr
2900oftaddr=0x300000
2901=> bootm $loadaddr - $oftaddr
2902## Booting image at 00200000 ...
Wolfgang Denka9398e02006-11-27 15:32:42 +01002903 Image Name: Linux-2.6.17-dirty
2904 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2905 Data Size: 1029343 Bytes = 1005.2 kB
Matthew McClintock02677682006-06-28 10:41:37 -05002906 Load Address: 00000000
Wolfgang Denka9398e02006-11-27 15:32:42 +01002907 Entry Point: 00000000
Matthew McClintock02677682006-06-28 10:41:37 -05002908 Verifying Checksum ... OK
2909 Uncompressing Kernel Image ... OK
2910Booting using flat device tree at 0x300000
2911Using MPC85xx ADS machine description
2912Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
2913[snip]
2914
2915
wdenk2729af92004-05-03 20:45:30 +00002916More About U-Boot Image Types:
2917------------------------------
wdenk6069ff22003-02-28 00:49:47 +00002918
wdenk2729af92004-05-03 20:45:30 +00002919U-Boot supports the following image types:
wdenk6069ff22003-02-28 00:49:47 +00002920
wdenk2729af92004-05-03 20:45:30 +00002921 "Standalone Programs" are directly runnable in the environment
2922 provided by U-Boot; it is expected that (if they behave
2923 well) you can continue to work in U-Boot after return from
2924 the Standalone Program.
2925 "OS Kernel Images" are usually images of some Embedded OS which
2926 will take over control completely. Usually these programs
2927 will install their own set of exception handlers, device
2928 drivers, set up the MMU, etc. - this means, that you cannot
2929 expect to re-enter U-Boot except by resetting the CPU.
2930 "RAMDisk Images" are more or less just data blocks, and their
2931 parameters (address, size) are passed to an OS kernel that is
2932 being started.
2933 "Multi-File Images" contain several images, typically an OS
2934 (Linux) kernel image and one or more data images like
2935 RAMDisks. This construct is useful for instance when you want
2936 to boot over the network using BOOTP etc., where the boot
2937 server provides just a single image file, but you want to get
2938 for instance an OS kernel and a RAMDisk image.
stroesec1551ea2003-04-04 15:53:41 +00002939
wdenk2729af92004-05-03 20:45:30 +00002940 "Multi-File Images" start with a list of image sizes, each
2941 image size (in bytes) specified by an "uint32_t" in network
2942 byte order. This list is terminated by an "(uint32_t)0".
2943 Immediately after the terminating 0 follow the images, one by
2944 one, all aligned on "uint32_t" boundaries (size rounded up to
2945 a multiple of 4 bytes).
stroesec1551ea2003-04-04 15:53:41 +00002946
wdenk2729af92004-05-03 20:45:30 +00002947 "Firmware Images" are binary images containing firmware (like
2948 U-Boot or FPGA images) which usually will be programmed to
2949 flash memory.
stroesec1551ea2003-04-04 15:53:41 +00002950
wdenk2729af92004-05-03 20:45:30 +00002951 "Script files" are command sequences that will be executed by
2952 U-Boot's command interpreter; this feature is especially
2953 useful when you configure U-Boot to use a real shell (hush)
2954 as command interpreter.
wdenk6069ff22003-02-28 00:49:47 +00002955
Marek Vasut44f074c2012-03-14 21:52:45 +00002956Booting the Linux zImage:
2957-------------------------
2958
2959On some platforms, it's possible to boot Linux zImage. This is done
2960using the "bootz" command. The syntax of "bootz" command is the same
2961as the syntax of "bootm" command.
2962
Tom Rini8ac28562013-05-16 11:40:11 -04002963Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
Marek Vasut017e1f32012-03-18 11:47:58 +00002964kernel with raw initrd images. The syntax is slightly different, the
2965address of the initrd must be augmented by it's size, in the following
2966format: "<initrd addres>:<initrd size>".
2967
wdenkc6097192002-11-03 00:24:07 +00002968
wdenk2729af92004-05-03 20:45:30 +00002969Standalone HOWTO:
2970=================
wdenkc6097192002-11-03 00:24:07 +00002971
wdenk2729af92004-05-03 20:45:30 +00002972One of the features of U-Boot is that you can dynamically load and
2973run "standalone" applications, which can use some resources of
2974U-Boot like console I/O functions or interrupt services.
wdenkc6097192002-11-03 00:24:07 +00002975
wdenk2729af92004-05-03 20:45:30 +00002976Two simple examples are included with the sources:
wdenkc6097192002-11-03 00:24:07 +00002977
wdenk2729af92004-05-03 20:45:30 +00002978"Hello World" Demo:
2979-------------------
wdenkc6097192002-11-03 00:24:07 +00002980
wdenk2729af92004-05-03 20:45:30 +00002981'examples/hello_world.c' contains a small "Hello World" Demo
2982application; it is automatically compiled when you build U-Boot.
2983It's configured to run at address 0x00040004, so you can play with it
2984like that:
wdenkc6097192002-11-03 00:24:07 +00002985
wdenk2729af92004-05-03 20:45:30 +00002986 => loads
2987 ## Ready for S-Record download ...
2988 ~>examples/hello_world.srec
2989 1 2 3 4 5 6 7 8 9 10 11 ...
2990 [file transfer complete]
2991 [connected]
2992 ## Start Addr = 0x00040004
wdenkc6097192002-11-03 00:24:07 +00002993
wdenk2729af92004-05-03 20:45:30 +00002994 => go 40004 Hello World! This is a test.
2995 ## Starting application at 0x00040004 ...
2996 Hello World
2997 argc = 7
2998 argv[0] = "40004"
2999 argv[1] = "Hello"
3000 argv[2] = "World!"
3001 argv[3] = "This"
3002 argv[4] = "is"
3003 argv[5] = "a"
3004 argv[6] = "test."
3005 argv[7] = "<NULL>"
3006 Hit any key to exit ...
wdenkc6097192002-11-03 00:24:07 +00003007
wdenk2729af92004-05-03 20:45:30 +00003008 ## Application terminated, rc = 0x0
wdenkc6097192002-11-03 00:24:07 +00003009
wdenk2729af92004-05-03 20:45:30 +00003010Another example, which demonstrates how to register a CPM interrupt
3011handler with the U-Boot code, can be found in 'examples/timer.c'.
3012Here, a CPM timer is set up to generate an interrupt every second.
3013The interrupt service routine is trivial, just printing a '.'
3014character, but this is just a demo program. The application can be
3015controlled by the following keys:
wdenkc6097192002-11-03 00:24:07 +00003016
wdenk2729af92004-05-03 20:45:30 +00003017 ? - print current values og the CPM Timer registers
3018 b - enable interrupts and start timer
3019 e - stop timer and disable interrupts
3020 q - quit application
wdenkc6097192002-11-03 00:24:07 +00003021
wdenk2729af92004-05-03 20:45:30 +00003022 => loads
3023 ## Ready for S-Record download ...
3024 ~>examples/timer.srec
3025 1 2 3 4 5 6 7 8 9 10 11 ...
3026 [file transfer complete]
3027 [connected]
3028 ## Start Addr = 0x00040004
wdenkc6097192002-11-03 00:24:07 +00003029
wdenk2729af92004-05-03 20:45:30 +00003030 => go 40004
3031 ## Starting application at 0x00040004 ...
3032 TIMERS=0xfff00980
3033 Using timer 1
3034 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
wdenkc6097192002-11-03 00:24:07 +00003035
wdenk2729af92004-05-03 20:45:30 +00003036Hit 'b':
3037 [q, b, e, ?] Set interval 1000000 us
3038 Enabling timer
3039Hit '?':
3040 [q, b, e, ?] ........
3041 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3042Hit '?':
3043 [q, b, e, ?] .
3044 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3045Hit '?':
3046 [q, b, e, ?] .
3047 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3048Hit '?':
3049 [q, b, e, ?] .
3050 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3051Hit 'e':
3052 [q, b, e, ?] ...Stopping timer
3053Hit 'q':
3054 [q, b, e, ?] ## Application terminated, rc = 0x0
wdenkc6097192002-11-03 00:24:07 +00003055
3056
wdenk2729af92004-05-03 20:45:30 +00003057Minicom warning:
3058================
wdenk85ec0bc2003-03-31 16:34:49 +00003059
wdenk2729af92004-05-03 20:45:30 +00003060Over time, many people have reported problems when trying to use the
3061"minicom" terminal emulation program for serial download. I (wd)
3062consider minicom to be broken, and recommend not to use it. Under
3063Unix, I recommend to use C-Kermit for general purpose use (and
3064especially for kermit binary protocol download ("loadb" command), and
Karl O. Pince53515a2012-10-01 05:11:56 +00003065use "cu" for S-Record download ("loads" command). See
Naoki Hayama047f6ec2020-10-08 13:17:16 +09003066https://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
Karl O. Pince53515a2012-10-01 05:11:56 +00003067for help with kermit.
3068
wdenk85ec0bc2003-03-31 16:34:49 +00003069
wdenk2729af92004-05-03 20:45:30 +00003070Nevertheless, if you absolutely want to use it try adding this
3071configuration to your "File transfer protocols" section:
wdenk52f52c12003-06-19 23:04:19 +00003072
wdenk2729af92004-05-03 20:45:30 +00003073 Name Program Name U/D FullScr IO-Red. Multi
3074 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3075 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
wdenk52f52c12003-06-19 23:04:19 +00003076
3077
wdenk2729af92004-05-03 20:45:30 +00003078NetBSD Notes:
3079=============
wdenkc6097192002-11-03 00:24:07 +00003080
wdenk2729af92004-05-03 20:45:30 +00003081Starting at version 0.9.2, U-Boot supports NetBSD both as host
3082(build U-Boot) and target system (boots NetBSD/mpc8xx).
wdenkc6097192002-11-03 00:24:07 +00003083
wdenk2729af92004-05-03 20:45:30 +00003084Building requires a cross environment; it is known to work on
3085NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3086need gmake since the Makefiles are not compatible with BSD make).
3087Note that the cross-powerpc package does not install include files;
3088attempting to build U-Boot will fail because <machine/ansi.h> is
3089missing. This file has to be installed and patched manually:
wdenkc6097192002-11-03 00:24:07 +00003090
wdenk2729af92004-05-03 20:45:30 +00003091 # cd /usr/pkg/cross/powerpc-netbsd/include
3092 # mkdir powerpc
3093 # ln -s powerpc machine
3094 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3095 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
wdenkc6097192002-11-03 00:24:07 +00003096
wdenk2729af92004-05-03 20:45:30 +00003097Native builds *don't* work due to incompatibilities between native
3098and U-Boot include files.
wdenkc6097192002-11-03 00:24:07 +00003099
wdenk2729af92004-05-03 20:45:30 +00003100Booting assumes that (the first part of) the image booted is a
3101stage-2 loader which in turn loads and then invokes the kernel
3102proper. Loader sources will eventually appear in the NetBSD source
3103tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
wdenk2a8af182005-04-13 10:02:42 +00003104meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
wdenkc6097192002-11-03 00:24:07 +00003105
3106
wdenk2729af92004-05-03 20:45:30 +00003107Implementation Internals:
3108=========================
wdenkc6097192002-11-03 00:24:07 +00003109
wdenk2729af92004-05-03 20:45:30 +00003110The following is not intended to be a complete description of every
3111implementation detail. However, it should help to understand the
3112inner workings of U-Boot and make it easier to port it to custom
3113hardware.
wdenkc6097192002-11-03 00:24:07 +00003114
3115
wdenk2729af92004-05-03 20:45:30 +00003116Initial Stack, Global Data:
3117---------------------------
wdenkc6097192002-11-03 00:24:07 +00003118
wdenk2729af92004-05-03 20:45:30 +00003119The implementation of U-Boot is complicated by the fact that U-Boot
3120starts running out of ROM (flash memory), usually without access to
3121system RAM (because the memory controller is not initialized yet).
3122This means that we don't have writable Data or BSS segments, and BSS
3123is not initialized as zero. To be able to get a C environment working
3124at all, we have to allocate at least a minimal stack. Implementation
3125options for this are defined and restricted by the CPU used: Some CPU
3126models provide on-chip memory (like the IMMR area on MPC8xx and
3127MPC826x processors), on others (parts of) the data cache can be
3128locked as (mis-) used as memory, etc.
wdenkc6097192002-11-03 00:24:07 +00003129
Wolfgang Denk218ca722008-03-26 10:40:12 +01003130 Chris Hallinan posted a good summary of these issues to the
Wolfgang Denk06682362008-12-30 22:56:11 +01003131 U-Boot mailing list:
wdenk43d96162003-03-06 00:02:04 +00003132
wdenk2729af92004-05-03 20:45:30 +00003133 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3134 From: "Chris Hallinan" <clh@net1plus.com>
3135 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3136 ...
wdenk43d96162003-03-06 00:02:04 +00003137
wdenk2729af92004-05-03 20:45:30 +00003138 Correct me if I'm wrong, folks, but the way I understand it
3139 is this: Using DCACHE as initial RAM for Stack, etc, does not
3140 require any physical RAM backing up the cache. The cleverness
3141 is that the cache is being used as a temporary supply of
3142 necessary storage before the SDRAM controller is setup. It's
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02003143 beyond the scope of this list to explain the details, but you
wdenk2729af92004-05-03 20:45:30 +00003144 can see how this works by studying the cache architecture and
3145 operation in the architecture and processor-specific manuals.
wdenk43d96162003-03-06 00:02:04 +00003146
wdenk2729af92004-05-03 20:45:30 +00003147 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3148 is another option for the system designer to use as an
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02003149 initial stack/RAM area prior to SDRAM being available. Either
wdenk2729af92004-05-03 20:45:30 +00003150 option should work for you. Using CS 4 should be fine if your
3151 board designers haven't used it for something that would
3152 cause you grief during the initial boot! It is frequently not
3153 used.
wdenk43d96162003-03-06 00:02:04 +00003154
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02003155 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
wdenk2729af92004-05-03 20:45:30 +00003156 with your processor/board/system design. The default value
3157 you will find in any recent u-boot distribution in
Stefan Roese8a316c92005-08-01 16:49:12 +02003158 walnut.h should work for you. I'd set it to a value larger
wdenk2729af92004-05-03 20:45:30 +00003159 than your SDRAM module. If you have a 64MB SDRAM module, set
3160 it above 400_0000. Just make sure your board has no resources
3161 that are supposed to respond to that address! That code in
3162 start.S has been around a while and should work as is when
3163 you get the config right.
wdenk43d96162003-03-06 00:02:04 +00003164
wdenk2729af92004-05-03 20:45:30 +00003165 -Chris Hallinan
3166 DS4.COM, Inc.
wdenk43d96162003-03-06 00:02:04 +00003167
wdenk2729af92004-05-03 20:45:30 +00003168It is essential to remember this, since it has some impact on the C
3169code for the initialization procedures:
wdenkc6097192002-11-03 00:24:07 +00003170
wdenk2729af92004-05-03 20:45:30 +00003171* Initialized global data (data segment) is read-only. Do not attempt
3172 to write it.
wdenkc6097192002-11-03 00:24:07 +00003173
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08003174* Do not use any uninitialized global data (or implicitly initialized
wdenk2729af92004-05-03 20:45:30 +00003175 as zero data - BSS segment) at all - this is undefined, initiali-
3176 zation is performed later (when relocating to RAM).
wdenkc6097192002-11-03 00:24:07 +00003177
wdenk2729af92004-05-03 20:45:30 +00003178* Stack space is very limited. Avoid big data buffers or things like
3179 that.
wdenkc6097192002-11-03 00:24:07 +00003180
wdenk2729af92004-05-03 20:45:30 +00003181Having only the stack as writable memory limits means we cannot use
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08003182normal global data to share information between the code. But it
wdenk2729af92004-05-03 20:45:30 +00003183turned out that the implementation of U-Boot can be greatly
3184simplified by making a global data structure (gd_t) available to all
3185functions. We could pass a pointer to this data as argument to _all_
3186functions, but this would bloat the code. Instead we use a feature of
3187the GCC compiler (Global Register Variables) to share the data: we
3188place a pointer (gd) to the global data into a register which we
3189reserve for this purpose.
wdenkc6097192002-11-03 00:24:07 +00003190
wdenk2729af92004-05-03 20:45:30 +00003191When choosing a register for such a purpose we are restricted by the
3192relevant (E)ABI specifications for the current architecture, and by
3193GCC's implementation.
wdenkc6097192002-11-03 00:24:07 +00003194
wdenk2729af92004-05-03 20:45:30 +00003195For PowerPC, the following registers have specific use:
3196 R1: stack pointer
Wolfgang Denke7670f62008-02-14 22:43:22 +01003197 R2: reserved for system use
wdenk2729af92004-05-03 20:45:30 +00003198 R3-R4: parameter passing and return values
3199 R5-R10: parameter passing
3200 R13: small data area pointer
3201 R30: GOT pointer
3202 R31: frame pointer
wdenkc6097192002-11-03 00:24:07 +00003203
Joakim Tjernlunde6bee802010-01-19 14:41:58 +01003204 (U-Boot also uses R12 as internal GOT pointer. r12
3205 is a volatile register so r12 needs to be reset when
3206 going back and forth between asm and C)
wdenkc6097192002-11-03 00:24:07 +00003207
Wolfgang Denke7670f62008-02-14 22:43:22 +01003208 ==> U-Boot will use R2 to hold a pointer to the global data
wdenkc6097192002-11-03 00:24:07 +00003209
wdenk2729af92004-05-03 20:45:30 +00003210 Note: on PPC, we could use a static initializer (since the
3211 address of the global data structure is known at compile time),
3212 but it turned out that reserving a register results in somewhat
3213 smaller code - although the code savings are not that big (on
3214 average for all boards 752 bytes for the whole U-Boot image,
3215 624 text + 127 data).
wdenkc6097192002-11-03 00:24:07 +00003216
wdenk2729af92004-05-03 20:45:30 +00003217On ARM, the following registers are used:
wdenkc6097192002-11-03 00:24:07 +00003218
wdenk2729af92004-05-03 20:45:30 +00003219 R0: function argument word/integer result
3220 R1-R3: function argument word
Jeroen Hofstee12eba1b2013-09-21 14:04:42 +02003221 R9: platform specific
3222 R10: stack limit (used only if stack checking is enabled)
wdenk2729af92004-05-03 20:45:30 +00003223 R11: argument (frame) pointer
3224 R12: temporary workspace
3225 R13: stack pointer
3226 R14: link register
3227 R15: program counter
wdenkc6097192002-11-03 00:24:07 +00003228
Jeroen Hofstee12eba1b2013-09-21 14:04:42 +02003229 ==> U-Boot will use R9 to hold a pointer to the global data
3230
3231 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
wdenkc6097192002-11-03 00:24:07 +00003232
Thomas Chou0df01fd32010-05-21 11:08:03 +08003233On Nios II, the ABI is documented here:
Naoki Hayama047f6ec2020-10-08 13:17:16 +09003234 https://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
Thomas Chou0df01fd32010-05-21 11:08:03 +08003235
3236 ==> U-Boot will use gp to hold a pointer to the global data
3237
3238 Note: on Nios II, we give "-G0" option to gcc and don't use gp
3239 to access small data sections, so gp is free.
3240
Rick Chen3fafced2017-12-26 13:55:59 +08003241On RISC-V, the following registers are used:
3242
3243 x0: hard-wired zero (zero)
3244 x1: return address (ra)
3245 x2: stack pointer (sp)
3246 x3: global pointer (gp)
3247 x4: thread pointer (tp)
3248 x5: link register (t0)
3249 x8: frame pointer (fp)
3250 x10-x11: arguments/return values (a0-1)
3251 x12-x17: arguments (a2-7)
3252 x28-31: temporaries (t3-6)
3253 pc: program counter (pc)
3254
3255 ==> U-Boot will use gp to hold a pointer to the global data
3256
wdenk2729af92004-05-03 20:45:30 +00003257Memory Management:
3258------------------
wdenkc6097192002-11-03 00:24:07 +00003259
wdenk2729af92004-05-03 20:45:30 +00003260U-Boot runs in system state and uses physical addresses, i.e. the
3261MMU is not used either for address mapping nor for memory protection.
wdenkc6097192002-11-03 00:24:07 +00003262
wdenk2729af92004-05-03 20:45:30 +00003263The available memory is mapped to fixed addresses using the memory
3264controller. In this process, a contiguous block is formed for each
3265memory type (Flash, SDRAM, SRAM), even when it consists of several
3266physical memory banks.
wdenkc6097192002-11-03 00:24:07 +00003267
wdenk2729af92004-05-03 20:45:30 +00003268U-Boot is installed in the first 128 kB of the first Flash bank (on
3269TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3270booting and sizing and initializing DRAM, the code relocates itself
3271to the upper end of DRAM. Immediately below the U-Boot code some
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +02003272memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
wdenk2729af92004-05-03 20:45:30 +00003273configuration setting]. Below that, a structure with global Board
3274Info data is placed, followed by the stack (growing downward).
wdenkc6097192002-11-03 00:24:07 +00003275
wdenk2729af92004-05-03 20:45:30 +00003276Additionally, some exception handler code is copied to the low 8 kB
3277of DRAM (0x00000000 ... 0x00001FFF).
wdenkc6097192002-11-03 00:24:07 +00003278
wdenk2729af92004-05-03 20:45:30 +00003279So a typical memory configuration with 16 MB of DRAM could look like
3280this:
wdenkc6097192002-11-03 00:24:07 +00003281
wdenk2729af92004-05-03 20:45:30 +00003282 0x0000 0000 Exception Vector code
3283 :
3284 0x0000 1FFF
3285 0x0000 2000 Free for Application Use
3286 :
3287 :
wdenkc6097192002-11-03 00:24:07 +00003288
wdenk2729af92004-05-03 20:45:30 +00003289 :
3290 :
3291 0x00FB FF20 Monitor Stack (Growing downward)
3292 0x00FB FFAC Board Info Data and permanent copy of global data
3293 0x00FC 0000 Malloc Arena
3294 :
3295 0x00FD FFFF
3296 0x00FE 0000 RAM Copy of Monitor Code
3297 ... eventually: LCD or video framebuffer
3298 ... eventually: pRAM (Protected RAM - unchanged by reset)
3299 0x00FF FFFF [End of RAM]
wdenkc6097192002-11-03 00:24:07 +00003300
3301
wdenk2729af92004-05-03 20:45:30 +00003302System Initialization:
3303----------------------
wdenkc6097192002-11-03 00:24:07 +00003304
wdenk2729af92004-05-03 20:45:30 +00003305In the reset configuration, U-Boot starts at the reset entry point
Marcel Ziswiler11ccc332008-07-09 08:17:15 +02003306(on most PowerPC systems at address 0x00000100). Because of the reset
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08003307configuration for CS0# this is a mirror of the on board Flash memory.
wdenk2729af92004-05-03 20:45:30 +00003308To be able to re-map memory U-Boot then jumps to its link address.
3309To be able to implement the initialization code in C, a (small!)
3310initial stack is set up in the internal Dual Ported RAM (in case CPUs
Heiko Schocher2eb48ff2017-06-07 17:33:10 +02003311which provide such a feature like), or in a locked part of the data
3312cache. After that, U-Boot initializes the CPU core, the caches and
3313the SIU.
wdenkc6097192002-11-03 00:24:07 +00003314
wdenk2729af92004-05-03 20:45:30 +00003315Next, all (potentially) available memory banks are mapped using a
3316preliminary mapping. For example, we put them on 512 MB boundaries
3317(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3318on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3319programmed for SDRAM access. Using the temporary configuration, a
3320simple memory test is run that determines the size of the SDRAM
3321banks.
wdenkc6097192002-11-03 00:24:07 +00003322
wdenk2729af92004-05-03 20:45:30 +00003323When there is more than one SDRAM bank, and the banks are of
3324different size, the largest is mapped first. For equal size, the first
3325bank (CS2#) is mapped first. The first mapping is always for address
33260x00000000, with any additional banks following immediately to create
3327contiguous memory starting from 0.
wdenkc6097192002-11-03 00:24:07 +00003328
wdenk2729af92004-05-03 20:45:30 +00003329Then, the monitor installs itself at the upper end of the SDRAM area
3330and allocates memory for use by malloc() and for the global Board
3331Info data; also, the exception vector code is copied to the low RAM
3332pages, and the final stack is set up.
wdenkc6097192002-11-03 00:24:07 +00003333
wdenk2729af92004-05-03 20:45:30 +00003334Only after this relocation will you have a "normal" C environment;
3335until that you are restricted in several ways, mostly because you are
3336running from ROM, and because the code will have to be relocated to a
3337new address in RAM.
wdenkc6097192002-11-03 00:24:07 +00003338
3339
wdenk2729af92004-05-03 20:45:30 +00003340U-Boot Porting Guide:
3341----------------------
wdenkc6097192002-11-03 00:24:07 +00003342
wdenk2729af92004-05-03 20:45:30 +00003343[Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3344list, October 2002]
wdenkc6097192002-11-03 00:24:07 +00003345
3346
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04003347int main(int argc, char *argv[])
wdenk2729af92004-05-03 20:45:30 +00003348{
3349 sighandler_t no_more_time;
wdenkc6097192002-11-03 00:24:07 +00003350
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04003351 signal(SIGALRM, no_more_time);
3352 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
wdenkc6097192002-11-03 00:24:07 +00003353
wdenk2729af92004-05-03 20:45:30 +00003354 if (available_money > available_manpower) {
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04003355 Pay consultant to port U-Boot;
wdenkc6097192002-11-03 00:24:07 +00003356 return 0;
3357 }
3358
wdenk2729af92004-05-03 20:45:30 +00003359 Download latest U-Boot source;
3360
Wolfgang Denk06682362008-12-30 22:56:11 +01003361 Subscribe to u-boot mailing list;
wdenk2729af92004-05-03 20:45:30 +00003362
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04003363 if (clueless)
3364 email("Hi, I am new to U-Boot, how do I get started?");
wdenkc6097192002-11-03 00:24:07 +00003365
wdenk2729af92004-05-03 20:45:30 +00003366 while (learning) {
3367 Read the README file in the top level directory;
Naoki Hayama047f6ec2020-10-08 13:17:16 +09003368 Read https://www.denx.de/wiki/bin/view/DULG/Manual;
Patrick Delaunay24bcaec2020-02-28 15:18:10 +01003369 Read applicable doc/README.*;
wdenk2729af92004-05-03 20:45:30 +00003370 Read the source, Luke;
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04003371 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
wdenk2729af92004-05-03 20:45:30 +00003372 }
wdenkc6097192002-11-03 00:24:07 +00003373
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04003374 if (available_money > toLocalCurrency ($2500))
3375 Buy a BDI3000;
3376 else
wdenk2729af92004-05-03 20:45:30 +00003377 Add a lot of aggravation and time;
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04003378
3379 if (a similar board exists) { /* hopefully... */
3380 cp -a board/<similar> board/<myboard>
3381 cp include/configs/<similar>.h include/configs/<myboard>.h
3382 } else {
3383 Create your own board support subdirectory;
3384 Create your own board include/configs/<myboard>.h file;
wdenk2729af92004-05-03 20:45:30 +00003385 }
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04003386 Edit new board/<myboard> files
3387 Edit new include/configs/<myboard>.h
wdenkc6097192002-11-03 00:24:07 +00003388
Jerry Van Baren6c3fef22009-07-15 20:42:59 -04003389 while (!accepted) {
3390 while (!running) {
3391 do {
3392 Add / modify source code;
3393 } until (compiles);
3394 Debug;
3395 if (clueless)
3396 email("Hi, I am having problems...");
3397 }
3398 Send patch file to the U-Boot email list;
3399 if (reasonable critiques)
3400 Incorporate improvements from email list code review;
3401 else
3402 Defend code as written;
wdenk2729af92004-05-03 20:45:30 +00003403 }
wdenkc6097192002-11-03 00:24:07 +00003404
wdenk2729af92004-05-03 20:45:30 +00003405 return 0;
3406}
3407
3408void no_more_time (int sig)
3409{
3410 hire_a_guru();
3411}
wdenkc6097192002-11-03 00:24:07 +00003412
3413
wdenk2729af92004-05-03 20:45:30 +00003414Coding Standards:
3415-----------------
wdenkc6097192002-11-03 00:24:07 +00003416
wdenk2729af92004-05-03 20:45:30 +00003417All contributions to U-Boot should conform to the Linux kernel
Baruch Siach659208d2017-12-10 17:34:35 +02003418coding style; see the kernel coding style guide at
3419https://www.kernel.org/doc/html/latest/process/coding-style.html, and the
3420script "scripts/Lindent" in your Linux kernel source directory.
wdenk2729af92004-05-03 20:45:30 +00003421
Detlev Zundel2c051652006-09-01 15:39:02 +02003422Source files originating from a different project (for example the
3423MTD subsystem) are generally exempt from these guidelines and are not
Jeremiah Mahlerb445bbb2015-01-04 18:56:50 -08003424reformatted to ease subsequent migration to newer versions of those
Detlev Zundel2c051652006-09-01 15:39:02 +02003425sources.
3426
3427Please note that U-Boot is implemented in C (and to some small parts in
3428Assembler); no C++ is used, so please do not use C++ style comments (//)
3429in your code.
wdenk2729af92004-05-03 20:45:30 +00003430
3431Please also stick to the following formatting rules:
3432- remove any trailing white space
Wolfgang Denk7ca92962011-07-27 10:59:55 +00003433- use TAB characters for indentation and vertical alignment, not spaces
wdenk2729af92004-05-03 20:45:30 +00003434- make sure NOT to use DOS '\r\n' line feeds
Wolfgang Denk7ca92962011-07-27 10:59:55 +00003435- do not add more than 2 consecutive empty lines to source files
wdenk2729af92004-05-03 20:45:30 +00003436- do not add trailing empty lines to source files
3437
3438Submissions which do not conform to the standards may be returned
3439with a request to reformat the changes.
wdenkc6097192002-11-03 00:24:07 +00003440
3441
wdenk2729af92004-05-03 20:45:30 +00003442Submitting Patches:
3443-------------------
wdenkc6097192002-11-03 00:24:07 +00003444
wdenk2729af92004-05-03 20:45:30 +00003445Since the number of patches for U-Boot is growing, we need to
3446establish some rules. Submissions which do not conform to these rules
3447may be rejected, even when they contain important and valuable stuff.
wdenkc6097192002-11-03 00:24:07 +00003448
Naoki Hayama047f6ec2020-10-08 13:17:16 +09003449Please see https://www.denx.de/wiki/U-Boot/Patches for details.
Wolfgang Denk218ca722008-03-26 10:40:12 +01003450
Wolfgang Denk06682362008-12-30 22:56:11 +01003451Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
S. Lockwood-Childs1dade182017-11-14 22:56:42 -08003452see https://lists.denx.de/listinfo/u-boot
Wolfgang Denk06682362008-12-30 22:56:11 +01003453
wdenk2729af92004-05-03 20:45:30 +00003454When you send a patch, please include the following information with
3455it:
wdenkc6097192002-11-03 00:24:07 +00003456
wdenk2729af92004-05-03 20:45:30 +00003457* For bug fixes: a description of the bug and how your patch fixes
3458 this bug. Please try to include a way of demonstrating that the
3459 patch actually fixes something.
wdenkc6097192002-11-03 00:24:07 +00003460
wdenk2729af92004-05-03 20:45:30 +00003461* For new features: a description of the feature and your
3462 implementation.
wdenkc6097192002-11-03 00:24:07 +00003463
Robert P. J. Day7207b362015-12-19 07:16:10 -05003464* For major contributions, add a MAINTAINERS file with your
3465 information and associated file and directory references.
wdenk2729af92004-05-03 20:45:30 +00003466
Albert ARIBAUD27af9302013-09-11 15:52:51 +02003467* When you add support for a new board, don't forget to add a
3468 maintainer e-mail address to the boards.cfg file, too.
wdenk2729af92004-05-03 20:45:30 +00003469
3470* If your patch adds new configuration options, don't forget to
3471 document these in the README file.
3472
Wolfgang Denk218ca722008-03-26 10:40:12 +01003473* The patch itself. If you are using git (which is *strongly*
3474 recommended) you can easily generate the patch using the
Wolfgang Denk7ca92962011-07-27 10:59:55 +00003475 "git format-patch". If you then use "git send-email" to send it to
Wolfgang Denk218ca722008-03-26 10:40:12 +01003476 the U-Boot mailing list, you will avoid most of the common problems
3477 with some other mail clients.
wdenk2729af92004-05-03 20:45:30 +00003478
Wolfgang Denk218ca722008-03-26 10:40:12 +01003479 If you cannot use git, use "diff -purN OLD NEW". If your version of
3480 diff does not support these options, then get the latest version of
3481 GNU diff.
wdenk2729af92004-05-03 20:45:30 +00003482
Wolfgang Denk218ca722008-03-26 10:40:12 +01003483 The current directory when running this command shall be the parent
3484 directory of the U-Boot source tree (i. e. please make sure that
3485 your patch includes sufficient directory information for the
3486 affected files).
3487
3488 We prefer patches as plain text. MIME attachments are discouraged,
3489 and compressed attachments must not be used.
wdenk2729af92004-05-03 20:45:30 +00003490
3491* If one logical set of modifications affects or creates several
3492 files, all these changes shall be submitted in a SINGLE patch file.
3493
3494* Changesets that contain different, unrelated modifications shall be
3495 submitted as SEPARATE patches, one patch per changeset.
3496
3497
3498Notes:
3499
Simon Glass6de80f22016-07-27 20:33:08 -06003500* Before sending the patch, run the buildman script on your patched
wdenk2729af92004-05-03 20:45:30 +00003501 source tree and make sure that no errors or warnings are reported
3502 for any of the boards.
3503
3504* Keep your modifications to the necessary minimum: A patch
3505 containing several unrelated changes or arbitrary reformats will be
3506 returned with a request to re-formatting / split it.
3507
3508* If you modify existing code, make sure that your new code does not
3509 add to the memory footprint of the code ;-) Small is beautiful!
3510 When adding new features, these should compile conditionally only
3511 (using #ifdef), and the resulting code with the new feature
3512 disabled must not need more memory than the old code without your
3513 modification.
wdenk90dc6702005-05-03 14:12:25 +00003514
Wolfgang Denk06682362008-12-30 22:56:11 +01003515* Remember that there is a size limit of 100 kB per message on the
3516 u-boot mailing list. Bigger patches will be moderated. If they are
3517 reasonable and not too big, they will be acknowledged. But patches
3518 bigger than the size limit should be avoided.