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c609719b 1#
eca3aeb3 2# (C) Copyright 2000 - 2013
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3# Wolfgang Denk, DENX Software Engineering, [email protected].
4#
eca3aeb3 5# SPDX-License-Identifier: GPL-2.0+
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6#
7
8Summary:
9========
10
24ee89b9 11This directory contains the source code for U-Boot, a boot loader for
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12Embedded boards based on PowerPC, ARM, MIPS and several other
13processors, which can be installed in a boot ROM and used to
14initialize and test the hardware or to download and run application
15code.
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16
17The development of U-Boot is closely related to Linux: some parts of
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18the source code originate in the Linux source tree, we have some
19header files in common, and special provision has been made to
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20support booting of Linux images.
21
22Some attention has been paid to make this software easily
23configurable and extendable. For instance, all monitor commands are
24implemented with the same call interface, so that it's very easy to
25add new commands. Also, instead of permanently adding rarely used
26code (for instance hardware test utilities) to the monitor, you can
27load and run it dynamically.
28
29
30Status:
31=======
32
33In general, all boards for which a configuration option exists in the
24ee89b9 34Makefile have been tested to some extent and can be considered
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35"working". In fact, many of them are used in production systems.
36
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37In case of problems see the CHANGELOG file to find out who contributed
38the specific port. In addition, there are various MAINTAINERS files
39scattered throughout the U-Boot source identifying the people or
40companies responsible for various boards and subsystems.
c609719b 41
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42Note: As of August, 2010, there is no longer a CHANGELOG file in the
43actual U-Boot source tree; however, it can be created dynamically
44from the Git log using:
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45
46 make CHANGELOG
47
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48
49Where to get help:
50==================
51
24ee89b9 52In case you have questions about, problems with or contributions for
7207b366 53U-Boot, you should send a message to the U-Boot mailing list at
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54<[email protected]>. There is also an archive of previous traffic
55on the mailing list - please search the archive before asking FAQ's.
56Please see http://lists.denx.de/pipermail/u-boot and
57http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
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58
59
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60Where to get source code:
61=========================
62
7207b366 63The U-Boot source code is maintained in the Git repository at
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64git://www.denx.de/git/u-boot.git ; you can browse it online at
65http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
66
67The "snapshot" links on this page allow you to download tarballs of
11ccc33f 68any version you might be interested in. Official releases are also
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69available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70directory.
71
d4ee711d 72Pre-built (and tested) images are available from
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73ftp://ftp.denx.de/pub/u-boot/images/
74
75
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76Where we come from:
77===================
78
79- start from 8xxrom sources
24ee89b9 80- create PPCBoot project (http://sourceforge.net/projects/ppcboot)
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81- clean up code
82- make it easier to add custom boards
83- make it possible to add other [PowerPC] CPUs
84- extend functions, especially:
85 * Provide extended interface to Linux boot loader
86 * S-Record download
87 * network boot
11ccc33f 88 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
24ee89b9 89- create ARMBoot project (http://sourceforge.net/projects/armboot)
c609719b 90- add other CPU families (starting with ARM)
24ee89b9 91- create U-Boot project (http://sourceforge.net/projects/u-boot)
0d28f34b 92- current project page: see http://www.denx.de/wiki/U-Boot
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93
94
95Names and Spelling:
96===================
97
98The "official" name of this project is "Das U-Boot". The spelling
99"U-Boot" shall be used in all written text (documentation, comments
100in source files etc.). Example:
101
102 This is the README file for the U-Boot project.
103
104File names etc. shall be based on the string "u-boot". Examples:
105
106 include/asm-ppc/u-boot.h
107
108 #include <asm/u-boot.h>
109
110Variable names, preprocessor constants etc. shall be either based on
111the string "u_boot" or on "U_BOOT". Example:
112
113 U_BOOT_VERSION u_boot_logo
114 IH_OS_U_BOOT u_boot_hush_start
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115
116
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117Versioning:
118===========
119
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120Starting with the release in October 2008, the names of the releases
121were changed from numerical release numbers without deeper meaning
122into a time stamp based numbering. Regular releases are identified by
123names consisting of the calendar year and month of the release date.
124Additional fields (if present) indicate release candidates or bug fix
125releases in "stable" maintenance trees.
126
127Examples:
c0f40859 128 U-Boot v2009.11 - Release November 2009
360d883a 129 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
0de21ecb 130 U-Boot v2010.09-rc1 - Release candidate 1 for September 2010 release
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131
132
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133Directory Hierarchy:
134====================
135
8d321b81 136/arch Architecture specific files
6eae68e4 137 /arc Files generic to ARC architecture
8d321b81 138 /arm Files generic to ARM architecture
8d321b81 139 /m68k Files generic to m68k architecture
8d321b81 140 /microblaze Files generic to microblaze architecture
8d321b81 141 /mips Files generic to MIPS architecture
afc1ce82 142 /nds32 Files generic to NDS32 architecture
8d321b81 143 /nios2 Files generic to Altera NIOS2 architecture
33c7731b 144 /openrisc Files generic to OpenRISC architecture
a47a12be 145 /powerpc Files generic to PowerPC architecture
3fafced7 146 /riscv Files generic to RISC-V architecture
7207b366 147 /sandbox Files generic to HW-independent "sandbox"
8d321b81 148 /sh Files generic to SH architecture
33c7731b 149 /x86 Files generic to x86 architecture
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150/api Machine/arch independent API for external apps
151/board Board dependent files
740f7e5c 152/cmd U-Boot commands functions
8d321b81 153/common Misc architecture independent functions
7207b366 154/configs Board default configuration files
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155/disk Code for disk drive partition handling
156/doc Documentation (don't expect too much)
157/drivers Commonly used device drivers
33c7731b 158/dts Contains Makefile for building internal U-Boot fdt.
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159/examples Example code for standalone applications, etc.
160/fs Filesystem code (cramfs, ext2, jffs2, etc.)
161/include Header Files
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162/lib Library routines generic to all architectures
163/Licenses Various license files
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164/net Networking code
165/post Power On Self Test
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166/scripts Various build scripts and Makefiles
167/test Various unit test files
8d321b81 168/tools Tools to build S-Record or U-Boot images, etc.
c609719b 169
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170Software Configuration:
171=======================
172
173Configuration is usually done using C preprocessor defines; the
174rationale behind that is to avoid dead code whenever possible.
175
176There are two classes of configuration variables:
177
178* Configuration _OPTIONS_:
179 These are selectable by the user and have names beginning with
180 "CONFIG_".
181
182* Configuration _SETTINGS_:
183 These depend on the hardware etc. and should not be meddled with if
184 you don't know what you're doing; they have names beginning with
6d0f6bcf 185 "CONFIG_SYS_".
c609719b 186
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187Previously, all configuration was done by hand, which involved creating
188symbolic links and editing configuration files manually. More recently,
189U-Boot has added the Kbuild infrastructure used by the Linux kernel,
190allowing you to use the "make menuconfig" command to configure your
191build.
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192
193
194Selection of Processor Architecture and Board Type:
195---------------------------------------------------
196
197For all supported boards there are ready-to-use default
ab584d67 198configurations available; just type "make <board_name>_defconfig".
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199
200Example: For a TQM823L module type:
201
202 cd u-boot
ab584d67 203 make TQM823L_defconfig
c609719b 204
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205Note: If you're looking for the default configuration file for a board
206you're sure used to be there but is now missing, check the file
207doc/README.scrapyard for a list of no longer supported boards.
c609719b 208
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209Sandbox Environment:
210--------------------
211
212U-Boot can be built natively to run on a Linux host using the 'sandbox'
213board. This allows feature development which is not board- or architecture-
214specific to be undertaken on a native platform. The sandbox is also used to
215run some of U-Boot's tests.
216
6b1978f8 217See board/sandbox/README.sandbox for more details.
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218
219
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220Board Initialisation Flow:
221--------------------------
222
223This is the intended start-up flow for boards. This should apply for both
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224SPL and U-Boot proper (i.e. they both follow the same rules).
225
226Note: "SPL" stands for "Secondary Program Loader," which is explained in
227more detail later in this file.
228
229At present, SPL mostly uses a separate code path, but the function names
230and roles of each function are the same. Some boards or architectures
231may not conform to this. At least most ARM boards which use
232CONFIG_SPL_FRAMEWORK conform to this.
233
234Execution typically starts with an architecture-specific (and possibly
235CPU-specific) start.S file, such as:
236
237 - arch/arm/cpu/armv7/start.S
238 - arch/powerpc/cpu/mpc83xx/start.S
239 - arch/mips/cpu/start.S
db910353 240
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241and so on. From there, three functions are called; the purpose and
242limitations of each of these functions are described below.
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243
244lowlevel_init():
245 - purpose: essential init to permit execution to reach board_init_f()
246 - no global_data or BSS
247 - there is no stack (ARMv7 may have one but it will soon be removed)
248 - must not set up SDRAM or use console
249 - must only do the bare minimum to allow execution to continue to
250 board_init_f()
251 - this is almost never needed
252 - return normally from this function
253
254board_init_f():
255 - purpose: set up the machine ready for running board_init_r():
256 i.e. SDRAM and serial UART
257 - global_data is available
258 - stack is in SRAM
259 - BSS is not available, so you cannot use global/static variables,
260 only stack variables and global_data
261
262 Non-SPL-specific notes:
263 - dram_init() is called to set up DRAM. If already done in SPL this
264 can do nothing
265
266 SPL-specific notes:
267 - you can override the entire board_init_f() function with your own
268 version as needed.
269 - preloader_console_init() can be called here in extremis
270 - should set up SDRAM, and anything needed to make the UART work
271 - these is no need to clear BSS, it will be done by crt0.S
272 - must return normally from this function (don't call board_init_r()
273 directly)
274
275Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
276this point the stack and global_data are relocated to below
277CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
278memory.
279
280board_init_r():
281 - purpose: main execution, common code
282 - global_data is available
283 - SDRAM is available
284 - BSS is available, all static/global variables can be used
285 - execution eventually continues to main_loop()
286
287 Non-SPL-specific notes:
288 - U-Boot is relocated to the top of memory and is now running from
289 there.
290
291 SPL-specific notes:
292 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
293 CONFIG_SPL_STACK_R_ADDR points into SDRAM
294 - preloader_console_init() can be called here - typically this is
0680f1b1 295 done by selecting CONFIG_SPL_BOARD_INIT and then supplying a
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296 spl_board_init() function containing this call
297 - loads U-Boot or (in falcon mode) Linux
298
299
300
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301Configuration Options:
302----------------------
303
304Configuration depends on the combination of board and CPU type; all
305such information is kept in a configuration file
306"include/configs/<board_name>.h".
307
308Example: For a TQM823L module, all configuration settings are in
309"include/configs/TQM823L.h".
310
311
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312Many of the options are named exactly as the corresponding Linux
313kernel configuration options. The intention is to make it easier to
314build a config tool - later.
315
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316- ARM Platform Bus Type(CCI):
317 CoreLink Cache Coherent Interconnect (CCI) is ARM BUS which
318 provides full cache coherency between two clusters of multi-core
319 CPUs and I/O coherency for devices and I/O masters
320
321 CONFIG_SYS_FSL_HAS_CCI400
322
323 Defined For SoC that has cache coherent interconnect
324 CCN-400
7f6c2cbc 325
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326 CONFIG_SYS_FSL_HAS_CCN504
327
328 Defined for SoC that has cache coherent interconnect CCN-504
329
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330The following options need to be configured:
331
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332- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
333
334- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
6ccec449 335
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336- Marvell Family Member
337 CONFIG_SYS_MVFS - define it if you want to enable
338 multiple fs option at one time
339 for marvell soc family
340
66412c63 341- 85xx CPU Options:
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342 CONFIG_SYS_PPC64
343
344 Specifies that the core is a 64-bit PowerPC implementation (implements
345 the "64" category of the Power ISA). This is necessary for ePAPR
346 compliance, among other possible reasons.
347
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348 CONFIG_SYS_FSL_TBCLK_DIV
349
350 Defines the core time base clock divider ratio compared to the
351 system clock. On most PQ3 devices this is 8, on newer QorIQ
352 devices it can be 16 or 32. The ratio varies from SoC to Soc.
353
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354 CONFIG_SYS_FSL_PCIE_COMPAT
355
356 Defines the string to utilize when trying to match PCIe device
357 tree nodes for the given platform.
358
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359 CONFIG_SYS_FSL_ERRATUM_A004510
360
361 Enables a workaround for erratum A004510. If set,
362 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
363 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
364
365 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
366 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
367
368 Defines one or two SoC revisions (low 8 bits of SVR)
369 for which the A004510 workaround should be applied.
370
371 The rest of SVR is either not relevant to the decision
372 of whether the erratum is present (e.g. p2040 versus
373 p2041) or is implied by the build target, which controls
374 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
375
376 See Freescale App Note 4493 for more information about
377 this erratum.
378
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379 CONFIG_A003399_NOR_WORKAROUND
380 Enables a workaround for IFC erratum A003399. It is only
b445bbb4 381 required during NOR boot.
74fa22ed 382
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383 CONFIG_A008044_WORKAROUND
384 Enables a workaround for T1040/T1042 erratum A008044. It is only
b445bbb4 385 required during NAND boot and valid for Rev 1.0 SoC revision
9f074e67 386
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387 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
388
389 This is the value to write into CCSR offset 0x18600
390 according to the A004510 workaround.
391
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392 CONFIG_SYS_FSL_DSP_DDR_ADDR
393 This value denotes start offset of DDR memory which is
394 connected exclusively to the DSP cores.
395
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396 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
397 This value denotes start offset of M2 memory
398 which is directly connected to the DSP core.
399
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400 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
401 This value denotes start offset of M3 memory which is directly
402 connected to the DSP core.
403
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404 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
405 This value denotes start offset of DSP CCSR space.
406
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407 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
408 Single Source Clock is clocking mode present in some of FSL SoC's.
409 In this mode, a single differential clock is used to supply
410 clocks to the sysclock, ddrclock and usbclock.
411
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412 CONFIG_SYS_CPC_REINIT_F
413 This CONFIG is defined when the CPC is configured as SRAM at the
a187559e 414 time of U-Boot entry and is required to be re-initialized.
fb4a2409 415
aade2004 416 CONFIG_DEEP_SLEEP
b445bbb4 417 Indicates this SoC supports deep sleep feature. If deep sleep is
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418 supported, core will start to execute uboot when wakes up.
419
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420- Generic CPU options:
421 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
422
423 Defines the endianess of the CPU. Implementation of those
424 values is arch specific.
425
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426 CONFIG_SYS_FSL_DDR
427 Freescale DDR driver in use. This type of DDR controller is
428 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
429 SoCs.
430
431 CONFIG_SYS_FSL_DDR_ADDR
432 Freescale DDR memory-mapped register base.
433
434 CONFIG_SYS_FSL_DDR_EMU
435 Specify emulator support for DDR. Some DDR features such as
436 deskew training are not available.
437
438 CONFIG_SYS_FSL_DDRC_GEN1
439 Freescale DDR1 controller.
440
441 CONFIG_SYS_FSL_DDRC_GEN2
442 Freescale DDR2 controller.
443
444 CONFIG_SYS_FSL_DDRC_GEN3
445 Freescale DDR3 controller.
446
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447 CONFIG_SYS_FSL_DDRC_GEN4
448 Freescale DDR4 controller.
449
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450 CONFIG_SYS_FSL_DDRC_ARM_GEN3
451 Freescale DDR3 controller for ARM-based SoCs.
452
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453 CONFIG_SYS_FSL_DDR1
454 Board config to use DDR1. It can be enabled for SoCs with
455 Freescale DDR1 or DDR2 controllers, depending on the board
456 implemetation.
457
458 CONFIG_SYS_FSL_DDR2
62a3b7dd 459 Board config to use DDR2. It can be enabled for SoCs with
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460 Freescale DDR2 or DDR3 controllers, depending on the board
461 implementation.
462
463 CONFIG_SYS_FSL_DDR3
464 Board config to use DDR3. It can be enabled for SoCs with
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465 Freescale DDR3 or DDR3L controllers.
466
467 CONFIG_SYS_FSL_DDR3L
468 Board config to use DDR3L. It can be enabled for SoCs with
469 DDR3L controllers.
470
471 CONFIG_SYS_FSL_DDR4
472 Board config to use DDR4. It can be enabled for SoCs with
473 DDR4 controllers.
5614e71b 474
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475 CONFIG_SYS_FSL_IFC_BE
476 Defines the IFC controller register space as Big Endian
477
478 CONFIG_SYS_FSL_IFC_LE
479 Defines the IFC controller register space as Little Endian
480
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481 CONFIG_SYS_FSL_IFC_CLK_DIV
482 Defines divider of platform clock(clock input to IFC controller).
483
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484 CONFIG_SYS_FSL_LBC_CLK_DIV
485 Defines divider of platform clock(clock input to eLBC controller).
486
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487 CONFIG_SYS_FSL_PBL_PBI
488 It enables addition of RCW (Power on reset configuration) in built image.
489 Please refer doc/README.pblimage for more details
490
491 CONFIG_SYS_FSL_PBL_RCW
492 It adds PBI(pre-boot instructions) commands in u-boot build image.
493 PBI commands can be used to configure SoC before it starts the execution.
494 Please refer doc/README.pblimage for more details
495
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496 CONFIG_SPL_FSL_PBL
497 It adds a target to create boot binary having SPL binary in PBI format
498 concatenated with u-boot binary.
499
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500 CONFIG_SYS_FSL_DDR_BE
501 Defines the DDR controller register space as Big Endian
502
503 CONFIG_SYS_FSL_DDR_LE
504 Defines the DDR controller register space as Little Endian
505
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506 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
507 Physical address from the view of DDR controllers. It is the
508 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
509 it could be different for ARM SoCs.
510
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511 CONFIG_SYS_FSL_DDR_INTLV_256B
512 DDR controller interleaving on 256-byte. This is a special
513 interleaving mode, handled by Dickens for Freescale layerscape
514 SoCs with ARM core.
515
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516 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
517 Number of controllers used as main memory.
518
519 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
520 Number of controllers used for other than main memory.
521
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522 CONFIG_SYS_FSL_HAS_DP_DDR
523 Defines the SoC has DP-DDR used for DPAA.
524
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525 CONFIG_SYS_FSL_SEC_BE
526 Defines the SEC controller register space as Big Endian
527
528 CONFIG_SYS_FSL_SEC_LE
529 Defines the SEC controller register space as Little Endian
530
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531- MIPS CPU options:
532 CONFIG_SYS_INIT_SP_OFFSET
533
534 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
535 pointer. This is needed for the temporary stack before
536 relocation.
537
538 CONFIG_SYS_MIPS_CACHE_MODE
539
540 Cache operation mode for the MIPS CPU.
541 See also arch/mips/include/asm/mipsregs.h.
542 Possible values are:
543 CONF_CM_CACHABLE_NO_WA
544 CONF_CM_CACHABLE_WA
545 CONF_CM_UNCACHED
546 CONF_CM_CACHABLE_NONCOHERENT
547 CONF_CM_CACHABLE_CE
548 CONF_CM_CACHABLE_COW
549 CONF_CM_CACHABLE_CUW
550 CONF_CM_CACHABLE_ACCELERATED
551
552 CONFIG_SYS_XWAY_EBU_BOOTCFG
553
554 Special option for Lantiq XWAY SoCs for booting from NOR flash.
555 See also arch/mips/cpu/mips32/start.S.
556
557 CONFIG_XWAY_SWAP_BYTES
558
559 Enable compilation of tools/xway-swap-bytes needed for Lantiq
560 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
561 be swapped if a flash programmer is used.
562
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563- ARM options:
564 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
565
566 Select high exception vectors of the ARM core, e.g., do not
567 clear the V bit of the c1 register of CP15.
568
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569 COUNTER_FREQUENCY
570 Generic timer clock source frequency.
571
572 COUNTER_FREQUENCY_REAL
573 Generic timer clock source frequency if the real clock is
574 different from COUNTER_FREQUENCY, and can only be determined
575 at run time.
576
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577- Tegra SoC options:
578 CONFIG_TEGRA_SUPPORT_NON_SECURE
579
580 Support executing U-Boot in non-secure (NS) mode. Certain
581 impossible actions will be skipped if the CPU is in NS mode,
582 such as ARM architectural timer initialization.
583
5da627a4 584- Linux Kernel Interface:
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585 CONFIG_CLOCKS_IN_MHZ
586
587 U-Boot stores all clock information in Hz
588 internally. For binary compatibility with older Linux
589 kernels (which expect the clocks passed in the
590 bd_info data to be in MHz) the environment variable
591 "clocks_in_mhz" can be defined so that U-Boot
592 converts clock data to MHZ before passing it to the
593 Linux kernel.
c609719b 594 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
218ca724 595 "clocks_in_mhz=1" is automatically included in the
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596 default environment.
597
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598 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
599
b445bbb4 600 When transferring memsize parameter to Linux, some versions
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601 expect it to be in bytes, others in MB.
602 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
603
fec6d9ee 604 CONFIG_OF_LIBFDT
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605
606 New kernel versions are expecting firmware settings to be
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607 passed using flattened device trees (based on open firmware
608 concepts).
609
610 CONFIG_OF_LIBFDT
611 * New libfdt-based support
612 * Adds the "fdt" command
3bb342fc 613 * The bootm command automatically updates the fdt
213bf8c8 614
f57f70aa 615 OF_TBCLK - The timebase frequency.
c2871f03 616 OF_STDOUT_PATH - The path to the console device
f57f70aa 617
11ccc33f
MZ
618 boards with QUICC Engines require OF_QE to set UCC MAC
619 addresses
3bb342fc 620
4e253137
KG
621 CONFIG_OF_BOARD_SETUP
622
623 Board code has addition modification that it wants to make
624 to the flat device tree before handing it off to the kernel
f57f70aa 625
c654b517
SG
626 CONFIG_OF_SYSTEM_SETUP
627
628 Other code has addition modification that it wants to make
629 to the flat device tree before handing it off to the kernel.
630 This causes ft_system_setup() to be called before booting
631 the kernel.
632
3887c3fb
HS
633 CONFIG_OF_IDE_FIXUP
634
635 U-Boot can detect if an IDE device is present or not.
636 If not, and this new config option is activated, U-Boot
637 removes the ATA node from the DTS before booting Linux,
638 so the Linux IDE driver does not probe the device and
639 crash. This is needed for buggy hardware (uc101) where
640 no pull down resistor is connected to the signal IDE5V_DD7.
641
7eb29398
IG
642 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
643
644 This setting is mandatory for all boards that have only one
645 machine type and must be used to specify the machine type
646 number as it appears in the ARM machine registry
647 (see http://www.arm.linux.org.uk/developer/machines/).
648 Only boards that have multiple machine types supported
649 in a single configuration file and the machine type is
650 runtime discoverable, do not have to use this setting.
651
0b2f4eca
NG
652- vxWorks boot parameters:
653
654 bootvx constructs a valid bootline using the following
9e98b7e3
BM
655 environments variables: bootdev, bootfile, ipaddr, netmask,
656 serverip, gatewayip, hostname, othbootargs.
0b2f4eca
NG
657 It loads the vxWorks image pointed bootfile.
658
0b2f4eca
NG
659 Note: If a "bootargs" environment is defined, it will overwride
660 the defaults discussed just above.
661
2c451f78
A
662- Cache Configuration:
663 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
664 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
665 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
666
93bc2193
A
667- Cache Configuration for ARM:
668 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
669 controller
670 CONFIG_SYS_PL310_BASE - Physical base address of PL310
671 controller register space
672
6705d81e 673- Serial Ports:
48d0192f 674 CONFIG_PL010_SERIAL
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WD
675
676 Define this if you want support for Amba PrimeCell PL010 UARTs.
677
48d0192f 678 CONFIG_PL011_SERIAL
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679
680 Define this if you want support for Amba PrimeCell PL011 UARTs.
681
682 CONFIG_PL011_CLOCK
683
684 If you have Amba PrimeCell PL011 UARTs, set this variable to
685 the clock speed of the UARTs.
686
687 CONFIG_PL01x_PORTS
688
689 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
690 define this to a list of base addresses for each (supported)
691 port. See e.g. include/configs/versatile.h
692
d57dee57
KM
693 CONFIG_SERIAL_HW_FLOW_CONTROL
694
695 Define this variable to enable hw flow control in serial driver.
696 Current user of this option is drivers/serial/nsl16550.c driver
6705d81e 697
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698- Console Baudrate:
699 CONFIG_BAUDRATE - in bps
700 Select one of the baudrates listed in
6d0f6bcf 701 CONFIG_SYS_BAUDRATE_TABLE, see below.
c609719b 702
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WD
703- Autoboot Command:
704 CONFIG_BOOTCOMMAND
705 Only needed when CONFIG_BOOTDELAY is enabled;
706 define a command string that is automatically executed
707 when no character is read on the console interface
708 within "Boot Delay" after reset.
709
c609719b 710 CONFIG_RAMBOOT and CONFIG_NFSBOOT
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WD
711 The value of these goes into the environment as
712 "ramboot" and "nfsboot" respectively, and can be used
713 as a convenience, when switching between booting from
11ccc33f 714 RAM and NFS.
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715
716- Pre-Boot Commands:
717 CONFIG_PREBOOT
718
719 When this option is #defined, the existence of the
720 environment variable "preboot" will be checked
721 immediately before starting the CONFIG_BOOTDELAY
722 countdown and/or running the auto-boot command resp.
723 entering interactive mode.
724
725 This feature is especially useful when "preboot" is
726 automatically generated or modified. For an example
727 see the LWMON board specific code: here "preboot" is
728 modified when the user holds down a certain
729 combination of keys on the (special) keyboard when
730 booting the systems
731
732- Serial Download Echo Mode:
733 CONFIG_LOADS_ECHO
734 If defined to 1, all characters received during a
735 serial download (using the "loads" command) are
736 echoed back. This might be needed by some terminal
737 emulations (like "cu"), but may as well just take
738 time on others. This setting #define's the initial
739 value of the "loads_echo" environment variable.
740
602ad3b3 741- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
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742 CONFIG_KGDB_BAUDRATE
743 Select one of the baudrates listed in
6d0f6bcf 744 CONFIG_SYS_BAUDRATE_TABLE, see below.
c609719b 745
302a6487
SG
746- Removal of commands
747 If no commands are needed to boot, you can disable
748 CONFIG_CMDLINE to remove them. In this case, the command line
749 will not be available, and when U-Boot wants to execute the
750 boot command (on start-up) it will call board_run_command()
751 instead. This can reduce image size significantly for very
752 simple boot procedures.
753
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WD
754- Regular expression support:
755 CONFIG_REGEX
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756 If this variable is defined, U-Boot is linked against
757 the SLRE (Super Light Regular Expression) library,
758 which adds regex support to some commands, as for
759 example "env grep" and "setexpr".
a5ecbe62 760
45ba8077
SG
761- Device tree:
762 CONFIG_OF_CONTROL
763 If this variable is defined, U-Boot will use a device tree
764 to configure its devices, instead of relying on statically
765 compiled #defines in the board file. This option is
766 experimental and only available on a few boards. The device
767 tree is available in the global data as gd->fdt_blob.
768
2c0f79e4 769 U-Boot needs to get its device tree from somewhere. This can
82f766d1 770 be done using one of the three options below:
bbb0b128
SG
771
772 CONFIG_OF_EMBED
773 If this variable is defined, U-Boot will embed a device tree
774 binary in its image. This device tree file should be in the
775 board directory and called <soc>-<board>.dts. The binary file
776 is then picked up in board_init_f() and made available through
eb3eb602 777 the global data structure as gd->fdt_blob.
45ba8077 778
2c0f79e4
SG
779 CONFIG_OF_SEPARATE
780 If this variable is defined, U-Boot will build a device tree
781 binary. It will be called u-boot.dtb. Architecture-specific
782 code will locate it at run-time. Generally this works by:
783
784 cat u-boot.bin u-boot.dtb >image.bin
785
786 and in fact, U-Boot does this for you, creating a file called
787 u-boot-dtb.bin which is useful in the common case. You can
788 still use the individual files if you need something more
789 exotic.
790
82f766d1
AD
791 CONFIG_OF_BOARD
792 If this variable is defined, U-Boot will use the device tree
793 provided by the board at runtime instead of embedding one with
794 the image. Only boards defining board_fdt_blob_setup() support
795 this option (see include/fdtdec.h file).
796
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797- Watchdog:
798 CONFIG_WATCHDOG
799 If this variable is defined, it enables watchdog
6abe6fb6 800 support for the SoC. There must be support in the SoC
907208c4
CL
801 specific code for a watchdog. For the 8xx
802 CPUs, the SIU Watchdog feature is enabled in the SYPCR
803 register. When supported for a specific SoC is
804 available, then no further board specific code should
805 be needed to use it.
6abe6fb6
DZ
806
807 CONFIG_HW_WATCHDOG
808 When using a watchdog circuitry external to the used
809 SoC, then define this variable and provide board
810 specific code for the "hw_watchdog_reset" function.
c609719b 811
7bae0d6f
HS
812 CONFIG_AT91_HW_WDT_TIMEOUT
813 specify the timeout in seconds. default 2 seconds.
814
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815- Real-Time Clock:
816
602ad3b3 817 When CONFIG_CMD_DATE is selected, the type of the RTC
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WD
818 has to be selected, too. Define exactly one of the
819 following options:
820
c609719b 821 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
4e8b7544 822 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
c609719b 823 CONFIG_RTC_MC146818 - use MC146818 RTC
1cb8e980 824 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
c609719b 825 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
7f70e853 826 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
412921d2 827 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
3bac3513 828 CONFIG_RTC_DS164x - use Dallas DS164x RTC
9536dfcc 829 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
4c0d4c3b 830 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
2bd3cab3 831 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
71d19f30
HS
832 CONFIG_SYS_RV3029_TCR - enable trickle charger on
833 RV3029 RTC.
c609719b 834
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WD
835 Note that if the RTC uses I2C, then the I2C interface
836 must also be configured. See I2C Support, below.
837
e92739d3
PT
838- GPIO Support:
839 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
e92739d3 840
5dec49ca
CP
841 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
842 chip-ngpio pairs that tell the PCA953X driver the number of
843 pins supported by a particular chip.
844
e92739d3
PT
845 Note that if the GPIO device uses I2C, then the I2C interface
846 must also be configured. See I2C Support, below.
847
aa53233a
SG
848- I/O tracing:
849 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
850 accesses and can checksum them or write a list of them out
851 to memory. See the 'iotrace' command for details. This is
852 useful for testing device drivers since it can confirm that
853 the driver behaves the same way before and after a code
854 change. Currently this is supported on sandbox and arm. To
855 add support for your architecture, add '#include <iotrace.h>'
856 to the bottom of arch/<arch>/include/asm/io.h and test.
857
858 Example output from the 'iotrace stats' command is below.
859 Note that if the trace buffer is exhausted, the checksum will
860 still continue to operate.
861
862 iotrace is enabled
863 Start: 10000000 (buffer start address)
864 Size: 00010000 (buffer size)
865 Offset: 00000120 (current buffer offset)
866 Output: 10000120 (start + offset)
867 Count: 00000018 (number of trace records)
868 CRC32: 9526fb66 (CRC32 of all trace records)
869
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WD
870- Timestamp Support:
871
43d9616c
WD
872 When CONFIG_TIMESTAMP is selected, the timestamp
873 (date and time) of an image is printed by image
874 commands like bootm or iminfo. This option is
602ad3b3 875 automatically enabled when you select CONFIG_CMD_DATE .
c609719b 876
923c46f9
KP
877- Partition Labels (disklabels) Supported:
878 Zero or more of the following:
879 CONFIG_MAC_PARTITION Apple's MacOS partition table.
923c46f9
KP
880 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
881 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
882 bootloader. Note 2TB partition limit; see
883 disk/part_efi.c
884 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
c609719b 885
fc843a02 886 If IDE or SCSI support is enabled (CONFIG_IDE or
c649e3c9 887 CONFIG_SCSI) you must configure support for at
923c46f9 888 least one non-MTD partition type as well.
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WD
889
890- IDE Reset method:
4d13cbad
WD
891 CONFIG_IDE_RESET_ROUTINE - this is defined in several
892 board configurations files but used nowhere!
c609719b 893
4d13cbad
WD
894 CONFIG_IDE_RESET - is this is defined, IDE Reset will
895 be performed by calling the function
896 ide_set_reset(int reset)
897 which has to be defined in a board specific file
c609719b
WD
898
899- ATAPI Support:
900 CONFIG_ATAPI
901
902 Set this to enable ATAPI support.
903
c40b2956
WD
904- LBA48 Support
905 CONFIG_LBA48
906
907 Set this to enable support for disks larger than 137GB
4b142feb 908 Also look at CONFIG_SYS_64BIT_LBA.
c40b2956
WD
909 Whithout these , LBA48 support uses 32bit variables and will 'only'
910 support disks up to 2.1TB.
911
6d0f6bcf 912 CONFIG_SYS_64BIT_LBA:
c40b2956
WD
913 When enabled, makes the IDE subsystem use 64bit sector addresses.
914 Default is 32bit.
915
c609719b 916- SCSI Support:
6d0f6bcf
JCPV
917 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
918 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
919 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
c609719b
WD
920 maximum numbers of LUNs, SCSI ID's and target
921 devices.
c609719b 922
93e14596
WD
923 The environment variable 'scsidevs' is set to the number of
924 SCSI devices found during the last scan.
447c031b 925
c609719b 926- NETWORK Support (PCI):
682011ff 927 CONFIG_E1000
ce5207e1
KM
928 Support for Intel 8254x/8257x gigabit chips.
929
930 CONFIG_E1000_SPI
931 Utility code for direct access to the SPI bus on Intel 8257x.
932 This does not do anything useful unless you set at least one
933 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
934
935 CONFIG_E1000_SPI_GENERIC
936 Allow generic access to the SPI bus on the Intel 8257x, for
937 example with the "sspi" command.
938
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WD
939 CONFIG_EEPRO100
940 Support for Intel 82557/82559/82559ER chips.
11ccc33f 941 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
c609719b
WD
942 write routine for first time initialisation.
943
944 CONFIG_TULIP
945 Support for Digital 2114x chips.
946 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
947 modem chip initialisation (KS8761/QS6611).
948
949 CONFIG_NATSEMI
950 Support for National dp83815 chips.
951
952 CONFIG_NS8382X
953 Support for National dp8382[01] gigabit chips.
954
45219c46
WD
955- NETWORK Support (other):
956
c041e9d2
JS
957 CONFIG_DRIVER_AT91EMAC
958 Support for AT91RM9200 EMAC.
959
960 CONFIG_RMII
961 Define this to use reduced MII inteface
962
963 CONFIG_DRIVER_AT91EMAC_QUIET
964 If this defined, the driver is quiet.
965 The driver doen't show link status messages.
966
efdd7319
RH
967 CONFIG_CALXEDA_XGMAC
968 Support for the Calxeda XGMAC device
969
3bb46d23 970 CONFIG_LAN91C96
45219c46
WD
971 Support for SMSC's LAN91C96 chips.
972
45219c46
WD
973 CONFIG_LAN91C96_USE_32_BIT
974 Define this to enable 32 bit addressing
975
3bb46d23 976 CONFIG_SMC91111
f39748ae
WD
977 Support for SMSC's LAN91C111 chip
978
979 CONFIG_SMC91111_BASE
980 Define this to hold the physical address
981 of the device (I/O space)
982
983 CONFIG_SMC_USE_32_BIT
984 Define this if data bus is 32 bits
985
986 CONFIG_SMC_USE_IOFUNCS
987 Define this to use i/o functions instead of macros
988 (some hardware wont work with macros)
989
dc02bada
HS
990 CONFIG_DRIVER_TI_EMAC
991 Support for davinci emac
992
993 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
994 Define this if you have more then 3 PHYs.
995
b3dbf4a5
ML
996 CONFIG_FTGMAC100
997 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
998
999 CONFIG_FTGMAC100_EGIGA
1000 Define this to use GE link update with gigabit PHY.
1001 Define this if FTGMAC100 is connected to gigabit PHY.
1002 If your system has 10/100 PHY only, it might not occur
1003 wrong behavior. Because PHY usually return timeout or
1004 useless data when polling gigabit status and gigabit
1005 control registers. This behavior won't affect the
1006 correctnessof 10/100 link speed update.
1007
3d0075fa
YS
1008 CONFIG_SH_ETHER
1009 Support for Renesas on-chip Ethernet controller
1010
1011 CONFIG_SH_ETHER_USE_PORT
1012 Define the number of ports to be used
1013
1014 CONFIG_SH_ETHER_PHY_ADDR
1015 Define the ETH PHY's address
1016
68260aab
YS
1017 CONFIG_SH_ETHER_CACHE_WRITEBACK
1018 If this option is set, the driver enables cache flush.
1019
b2f97cf2
HS
1020- PWM Support:
1021 CONFIG_PWM_IMX
5052e819 1022 Support for PWM module on the imx6.
b2f97cf2 1023
5e124724 1024- TPM Support:
90899cc0
CC
1025 CONFIG_TPM
1026 Support TPM devices.
1027
0766ad2f
CR
1028 CONFIG_TPM_TIS_INFINEON
1029 Support for Infineon i2c bus TPM devices. Only one device
1b393db5
TWHT
1030 per system is supported at this time.
1031
1b393db5
TWHT
1032 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1033 Define the burst count bytes upper limit
1034
3aa74088
CR
1035 CONFIG_TPM_ST33ZP24
1036 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
1037
1038 CONFIG_TPM_ST33ZP24_I2C
1039 Support for STMicroelectronics ST33ZP24 I2C devices.
1040 Requires TPM_ST33ZP24 and I2C.
1041
b75fdc11
CR
1042 CONFIG_TPM_ST33ZP24_SPI
1043 Support for STMicroelectronics ST33ZP24 SPI devices.
1044 Requires TPM_ST33ZP24 and SPI.
1045
c01939c7
DE
1046 CONFIG_TPM_ATMEL_TWI
1047 Support for Atmel TWI TPM device. Requires I2C support.
1048
90899cc0 1049 CONFIG_TPM_TIS_LPC
5e124724
VB
1050 Support for generic parallel port TPM devices. Only one device
1051 per system is supported at this time.
1052
1053 CONFIG_TPM_TIS_BASE_ADDRESS
1054 Base address where the generic TPM device is mapped
1055 to. Contemporary x86 systems usually map it at
1056 0xfed40000.
1057
be6c1529
RP
1058 CONFIG_TPM
1059 Define this to enable the TPM support library which provides
1060 functional interfaces to some TPM commands.
1061 Requires support for a TPM device.
1062
1063 CONFIG_TPM_AUTH_SESSIONS
1064 Define this to enable authorized functions in the TPM library.
1065 Requires CONFIG_TPM and CONFIG_SHA1.
1066
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WD
1067- USB Support:
1068 At the moment only the UHCI host controller is
064b55cf 1069 supported (PIP405, MIP405); define
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WD
1070 CONFIG_USB_UHCI to enable it.
1071 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
30d56fae 1072 and define CONFIG_USB_STORAGE to enable the USB
c609719b
WD
1073 storage devices.
1074 Note:
1075 Supported are USB Keyboards and USB Floppy drives
1076 (TEAC FD-05PUB).
4d13cbad 1077
9ab4ce22
SG
1078 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1079 txfilltuning field in the EHCI controller on reset.
1080
6e9e0626
OT
1081 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1082 HW module registers.
1083
16c8d5e7
WD
1084- USB Device:
1085 Define the below if you wish to use the USB console.
1086 Once firmware is rebuilt from a serial console issue the
1087 command "setenv stdin usbtty; setenv stdout usbtty" and
11ccc33f 1088 attach your USB cable. The Unix command "dmesg" should print
16c8d5e7
WD
1089 it has found a new device. The environment variable usbtty
1090 can be set to gserial or cdc_acm to enable your device to
386eda02 1091 appear to a USB host as a Linux gserial device or a
16c8d5e7
WD
1092 Common Device Class Abstract Control Model serial device.
1093 If you select usbtty = gserial you should be able to enumerate
1094 a Linux host by
1095 # modprobe usbserial vendor=0xVendorID product=0xProductID
1096 else if using cdc_acm, simply setting the environment
1097 variable usbtty to be cdc_acm should suffice. The following
1098 might be defined in YourBoardName.h
386eda02 1099
16c8d5e7
WD
1100 CONFIG_USB_DEVICE
1101 Define this to build a UDC device
1102
1103 CONFIG_USB_TTY
1104 Define this to have a tty type of device available to
1105 talk to the UDC device
386eda02 1106
f9da0f89
VK
1107 CONFIG_USBD_HS
1108 Define this to enable the high speed support for usb
1109 device and usbtty. If this feature is enabled, a routine
1110 int is_usbd_high_speed(void)
1111 also needs to be defined by the driver to dynamically poll
1112 whether the enumeration has succeded at high speed or full
1113 speed.
1114
6d0f6bcf 1115 CONFIG_SYS_CONSOLE_IS_IN_ENV
16c8d5e7
WD
1116 Define this if you want stdin, stdout &/or stderr to
1117 be set to usbtty.
1118
386eda02 1119 If you have a USB-IF assigned VendorID then you may wish to
16c8d5e7 1120 define your own vendor specific values either in BoardName.h
386eda02 1121 or directly in usbd_vendor_info.h. If you don't define
16c8d5e7
WD
1122 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1123 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1124 should pretend to be a Linux device to it's target host.
1125
1126 CONFIG_USBD_MANUFACTURER
1127 Define this string as the name of your company for
1128 - CONFIG_USBD_MANUFACTURER "my company"
386eda02 1129
16c8d5e7
WD
1130 CONFIG_USBD_PRODUCT_NAME
1131 Define this string as the name of your product
1132 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1133
1134 CONFIG_USBD_VENDORID
1135 Define this as your assigned Vendor ID from the USB
1136 Implementors Forum. This *must* be a genuine Vendor ID
1137 to avoid polluting the USB namespace.
1138 - CONFIG_USBD_VENDORID 0xFFFF
386eda02 1139
16c8d5e7
WD
1140 CONFIG_USBD_PRODUCTID
1141 Define this as the unique Product ID
1142 for your device
1143 - CONFIG_USBD_PRODUCTID 0xFFFF
4d13cbad 1144
d70a560f
IG
1145- ULPI Layer Support:
1146 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1147 the generic ULPI layer. The generic layer accesses the ULPI PHY
1148 via the platform viewport, so you need both the genric layer and
1149 the viewport enabled. Currently only Chipidea/ARC based
1150 viewport is supported.
1151 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1152 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
6d365ea0
LS
1153 If your ULPI phy needs a different reference clock than the
1154 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1155 the appropriate value in Hz.
c609719b 1156
71f95118 1157- MMC Support:
8bde7f77
WD
1158 The MMC controller on the Intel PXA is supported. To
1159 enable this define CONFIG_MMC. The MMC can be
1160 accessed from the boot prompt by mapping the device
71f95118 1161 to physical memory similar to flash. Command line is
602ad3b3
JL
1162 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1163 the FAT fs. This is enabled with CONFIG_CMD_FAT.
71f95118 1164
afb35666
YS
1165 CONFIG_SH_MMCIF
1166 Support for Renesas on-chip MMCIF controller
1167
1168 CONFIG_SH_MMCIF_ADDR
1169 Define the base address of MMCIF registers
1170
1171 CONFIG_SH_MMCIF_CLK
1172 Define the clock frequency for MMCIF
1173
1fd93c6e
PA
1174 CONFIG_SUPPORT_EMMC_BOOT
1175 Enable some additional features of the eMMC boot partitions.
1176
1177 CONFIG_SUPPORT_EMMC_RPMB
1178 Enable the commands for reading, writing and programming the
1179 key for the Replay Protection Memory Block partition in eMMC.
1180
b3ba6e94 1181- USB Device Firmware Update (DFU) class support:
bb4059a5 1182 CONFIG_DFU_OVER_USB
b3ba6e94
TR
1183 This enables the USB portion of the DFU USB class
1184
b3ba6e94
TR
1185 CONFIG_DFU_MMC
1186 This enables support for exposing (e)MMC devices via DFU.
1187
c6631764
PA
1188 CONFIG_DFU_NAND
1189 This enables support for exposing NAND devices via DFU.
1190
a9479f04
AM
1191 CONFIG_DFU_RAM
1192 This enables support for exposing RAM via DFU.
1193 Note: DFU spec refer to non-volatile memory usage, but
1194 allow usages beyond the scope of spec - here RAM usage,
1195 one that would help mostly the developer.
1196
e7e75c70
HS
1197 CONFIG_SYS_DFU_DATA_BUF_SIZE
1198 Dfu transfer uses a buffer before writing data to the
1199 raw storage device. Make the size (in bytes) of this buffer
1200 configurable. The size of this buffer is also configurable
1201 through the "dfu_bufsiz" environment variable.
1202
ea2453d5
PA
1203 CONFIG_SYS_DFU_MAX_FILE_SIZE
1204 When updating files rather than the raw storage device,
1205 we use a static buffer to copy the file into and then write
1206 the buffer once we've been given the whole file. Define
1207 this to the maximum filesize (in bytes) for the buffer.
1208 Default is 4 MiB if undefined.
1209
001a8319
HS
1210 DFU_DEFAULT_POLL_TIMEOUT
1211 Poll timeout [ms], is the timeout a device can send to the
1212 host. The host must wait for this timeout before sending
1213 a subsequent DFU_GET_STATUS request to the device.
1214
1215 DFU_MANIFEST_POLL_TIMEOUT
1216 Poll timeout [ms], which the device sends to the host when
1217 entering dfuMANIFEST state. Host waits this timeout, before
1218 sending again an USB request to the device.
1219
6705d81e 1220- Journaling Flash filesystem support:
b2482dff 1221 CONFIG_JFFS2_NAND
6705d81e
WD
1222 Define these for a default partition on a NAND device
1223
6d0f6bcf
JCPV
1224 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1225 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
6705d81e
WD
1226 Define these for a default partition on a NOR device
1227
c609719b 1228- Keyboard Support:
39f615ed
SG
1229 See Kconfig help for available keyboard drivers.
1230
1231 CONFIG_KEYBOARD
1232
1233 Define this to enable a custom keyboard support.
1234 This simply calls drv_keyboard_init() which must be
1235 defined in your board-specific files. This option is deprecated
1236 and is only used by novena. For new boards, use driver model
1237 instead.
c609719b
WD
1238
1239- Video support:
7d3053fb 1240 CONFIG_FSL_DIU_FB
04e5ae79 1241 Enable the Freescale DIU video driver. Reference boards for
7d3053fb
TT
1242 SOCs that have a DIU should define this macro to enable DIU
1243 support, and should also define these other macros:
1244
1245 CONFIG_SYS_DIU_ADDR
1246 CONFIG_VIDEO
7d3053fb
TT
1247 CONFIG_CFB_CONSOLE
1248 CONFIG_VIDEO_SW_CURSOR
1249 CONFIG_VGA_AS_SINGLE_DEVICE
1250 CONFIG_VIDEO_LOGO
1251 CONFIG_VIDEO_BMP_LOGO
1252
ba8e76bd
TT
1253 The DIU driver will look for the 'video-mode' environment
1254 variable, and if defined, enable the DIU as a console during
8eca9439 1255 boot. See the documentation file doc/README.video for a
ba8e76bd 1256 description of this variable.
7d3053fb 1257
c609719b
WD
1258- LCD Support: CONFIG_LCD
1259
1260 Define this to enable LCD support (for output to LCD
1261 display); also select one of the supported displays
1262 by defining one of these:
1263
39cf4804
SP
1264 CONFIG_ATMEL_LCD:
1265
1266 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1267
fd3103bb 1268 CONFIG_NEC_NL6448AC33:
c609719b 1269
fd3103bb 1270 NEC NL6448AC33-18. Active, color, single scan.
c609719b 1271
fd3103bb 1272 CONFIG_NEC_NL6448BC20
c609719b 1273
fd3103bb
WD
1274 NEC NL6448BC20-08. 6.5", 640x480.
1275 Active, color, single scan.
1276
1277 CONFIG_NEC_NL6448BC33_54
1278
1279 NEC NL6448BC33-54. 10.4", 640x480.
c609719b
WD
1280 Active, color, single scan.
1281
1282 CONFIG_SHARP_16x9
1283
1284 Sharp 320x240. Active, color, single scan.
1285 It isn't 16x9, and I am not sure what it is.
1286
1287 CONFIG_SHARP_LQ64D341
1288
1289 Sharp LQ64D341 display, 640x480.
1290 Active, color, single scan.
1291
1292 CONFIG_HLD1045
1293
1294 HLD1045 display, 640x480.
1295 Active, color, single scan.
1296
1297 CONFIG_OPTREX_BW
1298
1299 Optrex CBL50840-2 NF-FW 99 22 M5
1300 or
1301 Hitachi LMG6912RPFC-00T
1302 or
1303 Hitachi SP14Q002
1304
1305 320x240. Black & white.
1306
676d319e
SG
1307 CONFIG_LCD_ALIGNMENT
1308
b445bbb4 1309 Normally the LCD is page-aligned (typically 4KB). If this is
676d319e
SG
1310 defined then the LCD will be aligned to this value instead.
1311 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1312 here, since it is cheaper to change data cache settings on
1313 a per-section basis.
1314
1315
604c7d4a
HP
1316 CONFIG_LCD_ROTATION
1317
1318 Sometimes, for example if the display is mounted in portrait
1319 mode or even if it's mounted landscape but rotated by 180degree,
1320 we need to rotate our content of the display relative to the
1321 framebuffer, so that user can read the messages which are
1322 printed out.
1323 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1324 initialized with a given rotation from "vl_rot" out of
1325 "vidinfo_t" which is provided by the board specific code.
1326 The value for vl_rot is coded as following (matching to
1327 fbcon=rotate:<n> linux-kernel commandline):
1328 0 = no rotation respectively 0 degree
1329 1 = 90 degree rotation
1330 2 = 180 degree rotation
1331 3 = 270 degree rotation
1332
1333 If CONFIG_LCD_ROTATION is not defined, the console will be
1334 initialized with 0degree rotation.
1335
45d7f525
TWHT
1336 CONFIG_LCD_BMP_RLE8
1337
1338 Support drawing of RLE8-compressed bitmaps on the LCD.
1339
735987c5
TWHT
1340 CONFIG_I2C_EDID
1341
1342 Enables an 'i2c edid' command which can read EDID
1343 information over I2C from an attached LCD display.
1344
7152b1d0 1345- Splash Screen Support: CONFIG_SPLASH_SCREEN
d791b1dc 1346
8bde7f77
WD
1347 If this option is set, the environment is checked for
1348 a variable "splashimage". If found, the usual display
1349 of logo, copyright and system information on the LCD
e94d2cd9 1350 is suppressed and the BMP image at the address
8bde7f77
WD
1351 specified in "splashimage" is loaded instead. The
1352 console is redirected to the "nulldev", too. This
1353 allows for a "silent" boot where a splash screen is
1354 loaded very quickly after power-on.
d791b1dc 1355
c0880485
NK
1356 CONFIG_SPLASHIMAGE_GUARD
1357
1358 If this option is set, then U-Boot will prevent the environment
1359 variable "splashimage" from being set to a problematic address
ab5645f1 1360 (see doc/README.displaying-bmps).
c0880485
NK
1361 This option is useful for targets where, due to alignment
1362 restrictions, an improperly aligned BMP image will cause a data
1363 abort. If you think you will not have problems with unaligned
1364 accesses (for example because your toolchain prevents them)
1365 there is no need to set this option.
1366
1ca298ce
MW
1367 CONFIG_SPLASH_SCREEN_ALIGN
1368
1369 If this option is set the splash image can be freely positioned
1370 on the screen. Environment variable "splashpos" specifies the
1371 position as "x,y". If a positive number is given it is used as
1372 number of pixel from left/top. If a negative number is given it
1373 is used as number of pixel from right/bottom. You can also
1374 specify 'm' for centering the image.
1375
1376 Example:
1377 setenv splashpos m,m
1378 => image at center of screen
1379
1380 setenv splashpos 30,20
1381 => image at x = 30 and y = 20
1382
1383 setenv splashpos -10,m
1384 => vertically centered image
1385 at x = dspWidth - bmpWidth - 9
1386
98f4a3df
SR
1387- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1388
1389 If this option is set, additionally to standard BMP
1390 images, gzipped BMP images can be displayed via the
1391 splashscreen support or the bmp command.
1392
d5011762
AG
1393- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1394
1395 If this option is set, 8-bit RLE compressed BMP images
1396 can be displayed via the splashscreen support or the
1397 bmp command.
1398
c29fdfc1 1399- Compression support:
8ef70478
KC
1400 CONFIG_GZIP
1401
1402 Enabled by default to support gzip compressed images.
1403
c29fdfc1
WD
1404 CONFIG_BZIP2
1405
1406 If this option is set, support for bzip2 compressed
1407 images is included. If not, only uncompressed and gzip
1408 compressed images are supported.
1409
42d1f039 1410 NOTE: the bzip2 algorithm requires a lot of RAM, so
6d0f6bcf 1411 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
42d1f039 1412 be at least 4MB.
d791b1dc 1413
17ea1177 1414- MII/PHY support:
17ea1177
WD
1415 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1416
1417 The clock frequency of the MII bus
1418
17ea1177
WD
1419 CONFIG_PHY_RESET_DELAY
1420
1421 Some PHY like Intel LXT971A need extra delay after
1422 reset before any MII register access is possible.
1423 For such PHY, set this option to the usec delay
1424 required. (minimum 300usec for LXT971A)
1425
1426 CONFIG_PHY_CMD_DELAY (ppc4xx)
1427
1428 Some PHY like Intel LXT971A need extra delay after
1429 command issued before MII status register can be read
1430
c609719b
WD
1431- IP address:
1432 CONFIG_IPADDR
1433
1434 Define a default value for the IP address to use for
11ccc33f 1435 the default Ethernet interface, in case this is not
c609719b 1436 determined through e.g. bootp.
1ebcd654 1437 (Environment variable "ipaddr")
c609719b
WD
1438
1439- Server IP address:
1440 CONFIG_SERVERIP
1441
11ccc33f 1442 Defines a default value for the IP address of a TFTP
c609719b 1443 server to contact when using the "tftboot" command.
1ebcd654 1444 (Environment variable "serverip")
c609719b 1445
97cfe861
RG
1446 CONFIG_KEEP_SERVERADDR
1447
1448 Keeps the server's MAC address, in the env 'serveraddr'
1449 for passing to bootargs (like Linux's netconsole option)
1450
1ebcd654
WD
1451- Gateway IP address:
1452 CONFIG_GATEWAYIP
1453
1454 Defines a default value for the IP address of the
1455 default router where packets to other networks are
1456 sent to.
1457 (Environment variable "gatewayip")
1458
1459- Subnet mask:
1460 CONFIG_NETMASK
1461
1462 Defines a default value for the subnet mask (or
1463 routing prefix) which is used to determine if an IP
1464 address belongs to the local subnet or needs to be
1465 forwarded through a router.
1466 (Environment variable "netmask")
1467
53a5c424
DU
1468- Multicast TFTP Mode:
1469 CONFIG_MCAST_TFTP
1470
1471 Defines whether you want to support multicast TFTP as per
1472 rfc-2090; for example to work with atftp. Lets lots of targets
11ccc33f 1473 tftp down the same boot image concurrently. Note: the Ethernet
53a5c424
DU
1474 driver in use must provide a function: mcast() to join/leave a
1475 multicast group.
1476
c609719b
WD
1477- BOOTP Recovery Mode:
1478 CONFIG_BOOTP_RANDOM_DELAY
1479
1480 If you have many targets in a network that try to
1481 boot using BOOTP, you may want to avoid that all
1482 systems send out BOOTP requests at precisely the same
1483 moment (which would happen for instance at recovery
1484 from a power failure, when all systems will try to
1485 boot, thus flooding the BOOTP server. Defining
1486 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1487 inserted before sending out BOOTP requests. The
6c33c785 1488 following delays are inserted then:
c609719b
WD
1489
1490 1st BOOTP request: delay 0 ... 1 sec
1491 2nd BOOTP request: delay 0 ... 2 sec
1492 3rd BOOTP request: delay 0 ... 4 sec
1493 4th and following
1494 BOOTP requests: delay 0 ... 8 sec
1495
92ac8acc
TR
1496 CONFIG_BOOTP_ID_CACHE_SIZE
1497
1498 BOOTP packets are uniquely identified using a 32-bit ID. The
1499 server will copy the ID from client requests to responses and
1500 U-Boot will use this to determine if it is the destination of
1501 an incoming response. Some servers will check that addresses
1502 aren't in use before handing them out (usually using an ARP
1503 ping) and therefore take up to a few hundred milliseconds to
1504 respond. Network congestion may also influence the time it
1505 takes for a response to make it back to the client. If that
1506 time is too long, U-Boot will retransmit requests. In order
1507 to allow earlier responses to still be accepted after these
1508 retransmissions, U-Boot's BOOTP client keeps a small cache of
1509 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
1510 cache. The default is to keep IDs for up to four outstanding
1511 requests. Increasing this will allow U-Boot to accept offers
1512 from a BOOTP client in networks with unusually high latency.
1513
fe389a82 1514- DHCP Advanced Options:
1fe80d79
JL
1515 You can fine tune the DHCP functionality by defining
1516 CONFIG_BOOTP_* symbols:
1517
1fe80d79 1518 CONFIG_BOOTP_NISDOMAIN
1fe80d79 1519 CONFIG_BOOTP_BOOTFILESIZE
1fe80d79
JL
1520 CONFIG_BOOTP_SEND_HOSTNAME
1521 CONFIG_BOOTP_NTPSERVER
1522 CONFIG_BOOTP_TIMEOFFSET
1523 CONFIG_BOOTP_VENDOREX
2c00e099 1524 CONFIG_BOOTP_MAY_FAIL
fe389a82 1525
5d110f0a
WC
1526 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1527 environment variable, not the BOOTP server.
fe389a82 1528
2c00e099
JH
1529 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1530 after the configured retry count, the call will fail
1531 instead of starting over. This can be used to fail over
1532 to Link-local IP address configuration if the DHCP server
1533 is not available.
1534
fe389a82
SR
1535 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1536 to do a dynamic update of a DNS server. To do this, they
1537 need the hostname of the DHCP requester.
5d110f0a 1538 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1fe80d79
JL
1539 of the "hostname" environment variable is passed as
1540 option 12 to the DHCP server.
fe389a82 1541
d9a2f416
AV
1542 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1543
1544 A 32bit value in microseconds for a delay between
1545 receiving a "DHCP Offer" and sending the "DHCP Request".
1546 This fixes a problem with certain DHCP servers that don't
1547 respond 100% of the time to a "DHCP request". E.g. On an
1548 AT91RM9200 processor running at 180MHz, this delay needed
1549 to be *at least* 15,000 usec before a Windows Server 2003
1550 DHCP server would reply 100% of the time. I recommend at
1551 least 50,000 usec to be safe. The alternative is to hope
1552 that one of the retries will be successful but note that
1553 the DHCP timeout and retry process takes a longer than
1554 this delay.
1555
d22c338e
JH
1556 - Link-local IP address negotiation:
1557 Negotiate with other link-local clients on the local network
1558 for an address that doesn't require explicit configuration.
1559 This is especially useful if a DHCP server cannot be guaranteed
1560 to exist in all environments that the device must operate.
1561
1562 See doc/README.link-local for more information.
1563
24acb83d
PK
1564 - MAC address from environment variables
1565
1566 FDT_SEQ_MACADDR_FROM_ENV
1567
1568 Fix-up device tree with MAC addresses fetched sequentially from
1569 environment variables. This config work on assumption that
1570 non-usable ethernet node of device-tree are either not present
1571 or their status has been marked as "disabled".
1572
a3d991bd 1573 - CDP Options:
6e592385 1574 CONFIG_CDP_DEVICE_ID
a3d991bd
WD
1575
1576 The device id used in CDP trigger frames.
1577
1578 CONFIG_CDP_DEVICE_ID_PREFIX
1579
1580 A two character string which is prefixed to the MAC address
1581 of the device.
1582
1583 CONFIG_CDP_PORT_ID
1584
1585 A printf format string which contains the ascii name of
1586 the port. Normally is set to "eth%d" which sets
11ccc33f 1587 eth0 for the first Ethernet, eth1 for the second etc.
a3d991bd
WD
1588
1589 CONFIG_CDP_CAPABILITIES
1590
1591 A 32bit integer which indicates the device capabilities;
1592 0x00000010 for a normal host which does not forwards.
1593
1594 CONFIG_CDP_VERSION
1595
1596 An ascii string containing the version of the software.
1597
1598 CONFIG_CDP_PLATFORM
1599
1600 An ascii string containing the name of the platform.
1601
1602 CONFIG_CDP_TRIGGER
1603
1604 A 32bit integer sent on the trigger.
1605
1606 CONFIG_CDP_POWER_CONSUMPTION
1607
1608 A 16bit integer containing the power consumption of the
1609 device in .1 of milliwatts.
1610
1611 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1612
1613 A byte containing the id of the VLAN.
1614
79267edd 1615- Status LED: CONFIG_LED_STATUS
c609719b
WD
1616
1617 Several configurations allow to display the current
1618 status using a LED. For instance, the LED will blink
1619 fast while running U-Boot code, stop blinking as
1620 soon as a reply to a BOOTP request was received, and
1621 start blinking slow once the Linux kernel is running
1622 (supported by a status LED driver in the Linux
79267edd 1623 kernel). Defining CONFIG_LED_STATUS enables this
c609719b
WD
1624 feature in U-Boot.
1625
1df7bbba
IG
1626 Additional options:
1627
79267edd 1628 CONFIG_LED_STATUS_GPIO
1df7bbba
IG
1629 The status LED can be connected to a GPIO pin.
1630 In such cases, the gpio_led driver can be used as a
79267edd 1631 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO
1df7bbba
IG
1632 to include the gpio_led driver in the U-Boot binary.
1633
9dfdcdfe
IG
1634 CONFIG_GPIO_LED_INVERTED_TABLE
1635 Some GPIO connected LEDs may have inverted polarity in which
1636 case the GPIO high value corresponds to LED off state and
1637 GPIO low value corresponds to LED on state.
1638 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
1639 with a list of GPIO LEDs that have inverted polarity.
1640
3f4978c7
HS
1641- I2C Support: CONFIG_SYS_I2C
1642
1643 This enable the NEW i2c subsystem, and will allow you to use
1644 i2c commands at the u-boot command line (as long as you set
1645 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
1646 based realtime clock chips or other i2c devices. See
1647 common/cmd_i2c.c for a description of the command line
1648 interface.
1649
1650 ported i2c driver to the new framework:
ea818dbb
HS
1651 - drivers/i2c/soft_i2c.c:
1652 - activate first bus with CONFIG_SYS_I2C_SOFT define
1653 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
1654 for defining speed and slave address
1655 - activate second bus with I2C_SOFT_DECLARATIONS2 define
1656 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
1657 for defining speed and slave address
1658 - activate third bus with I2C_SOFT_DECLARATIONS3 define
1659 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
1660 for defining speed and slave address
1661 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
1662 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
1663 for defining speed and slave address
3f4978c7 1664
00f792e0
HS
1665 - drivers/i2c/fsl_i2c.c:
1666 - activate i2c driver with CONFIG_SYS_I2C_FSL
1667 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
1668 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
1669 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
1670 bus.
93e14596 1671 - If your board supports a second fsl i2c bus, define
00f792e0
HS
1672 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
1673 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
1674 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
1675 second bus.
1676
1f2ba722 1677 - drivers/i2c/tegra_i2c.c:
10cee516
NI
1678 - activate this driver with CONFIG_SYS_I2C_TEGRA
1679 - This driver adds 4 i2c buses with a fix speed from
1680 100000 and the slave addr 0!
1f2ba722 1681
880540de
DE
1682 - drivers/i2c/ppc4xx_i2c.c
1683 - activate this driver with CONFIG_SYS_I2C_PPC4XX
1684 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
1685 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
1686
fac96408 1687 - drivers/i2c/i2c_mxc.c
1688 - activate this driver with CONFIG_SYS_I2C_MXC
03544c66
AA
1689 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
1690 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
1691 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
1692 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
fac96408 1693 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
1694 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
1695 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
1696 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
1697 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
1698 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
03544c66
AA
1699 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
1700 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
b445bbb4 1701 If those defines are not set, default value is 100000
fac96408 1702 for speed, and 0 for slave.
1703
1086bfa9
NI
1704 - drivers/i2c/rcar_i2c.c:
1705 - activate this driver with CONFIG_SYS_I2C_RCAR
1706 - This driver adds 4 i2c buses
1707
1708 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
1709 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
1710 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
1711 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
1712 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
1713 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
1714 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
1715 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
1716 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
1717
2035d77d
NI
1718 - drivers/i2c/sh_i2c.c:
1719 - activate this driver with CONFIG_SYS_I2C_SH
1720 - This driver adds from 2 to 5 i2c buses
1721
1722 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
1723 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
1724 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
1725 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
1726 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
1727 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
1728 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
1729 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
1730 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
1731 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
b445bbb4 1732 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2035d77d 1733
6789e84e
HS
1734 - drivers/i2c/omap24xx_i2c.c
1735 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
1736 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
1737 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
1738 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
1739 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
1740 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
1741 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
1742 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
1743 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
1744 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
1745 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
1746
0bdffe71
HS
1747 - drivers/i2c/zynq_i2c.c
1748 - activate this driver with CONFIG_SYS_I2C_ZYNQ
1749 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
1750 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
1751
e717fc6d
NKC
1752 - drivers/i2c/s3c24x0_i2c.c:
1753 - activate this driver with CONFIG_SYS_I2C_S3C24X0
1754 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
1755 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
1756 with a fix speed from 100000 and the slave addr 0!
1757
b46226bd
DE
1758 - drivers/i2c/ihs_i2c.c
1759 - activate this driver with CONFIG_SYS_I2C_IHS
1760 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
1761 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
1762 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
1763 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
1764 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
1765 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
1766 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
1767 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
1768 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
1769 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
1770 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
1771 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
071be896
DE
1772 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
1773 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
1774 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
1775 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
1776 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
1777 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
1778 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
1779 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
1780 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
b46226bd 1781
3f4978c7
HS
1782 additional defines:
1783
1784 CONFIG_SYS_NUM_I2C_BUSES
945a18e6 1785 Hold the number of i2c buses you want to use.
3f4978c7
HS
1786
1787 CONFIG_SYS_I2C_DIRECT_BUS
1788 define this, if you don't use i2c muxes on your hardware.
1789 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
1790 omit this define.
1791
1792 CONFIG_SYS_I2C_MAX_HOPS
1793 define how many muxes are maximal consecutively connected
1794 on one i2c bus. If you not use i2c muxes, omit this
1795 define.
1796
1797 CONFIG_SYS_I2C_BUSES
b445bbb4 1798 hold a list of buses you want to use, only used if
3f4978c7
HS
1799 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
1800 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
1801 CONFIG_SYS_NUM_I2C_BUSES = 9:
1802
1803 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
1804 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
1805 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
1806 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
1807 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
1808 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
1809 {1, {I2C_NULL_HOP}}, \
1810 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
1811 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
1812 }
1813
1814 which defines
1815 bus 0 on adapter 0 without a mux
ea818dbb
HS
1816 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
1817 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
1818 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
1819 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
1820 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
3f4978c7 1821 bus 6 on adapter 1 without a mux
ea818dbb
HS
1822 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
1823 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
3f4978c7
HS
1824
1825 If you do not have i2c muxes on your board, omit this define.
1826
ce3b5d69 1827- Legacy I2C Support:
ea818dbb 1828 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
b37c7e5e
WD
1829 then the following macros need to be defined (examples are
1830 from include/configs/lwmon.h):
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WD
1831
1832 I2C_INIT
1833
b37c7e5e 1834 (Optional). Any commands necessary to enable the I2C
43d9616c 1835 controller or configure ports.
c609719b 1836
ba56f625 1837 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
b37c7e5e 1838
c609719b
WD
1839 I2C_ACTIVE
1840
1841 The code necessary to make the I2C data line active
1842 (driven). If the data line is open collector, this
1843 define can be null.
1844
b37c7e5e
WD
1845 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1846
c609719b
WD
1847 I2C_TRISTATE
1848
1849 The code necessary to make the I2C data line tri-stated
1850 (inactive). If the data line is open collector, this
1851 define can be null.
1852
b37c7e5e
WD
1853 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1854
c609719b
WD
1855 I2C_READ
1856
472d5460
YS
1857 Code that returns true if the I2C data line is high,
1858 false if it is low.
c609719b 1859
b37c7e5e
WD
1860 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1861
c609719b
WD
1862 I2C_SDA(bit)
1863
472d5460
YS
1864 If <bit> is true, sets the I2C data line high. If it
1865 is false, it clears it (low).
c609719b 1866
b37c7e5e 1867 eg: #define I2C_SDA(bit) \
2535d602 1868 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
ba56f625 1869 else immr->im_cpm.cp_pbdat &= ~PB_SDA
b37c7e5e 1870
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WD
1871 I2C_SCL(bit)
1872
472d5460
YS
1873 If <bit> is true, sets the I2C clock line high. If it
1874 is false, it clears it (low).
c609719b 1875
b37c7e5e 1876 eg: #define I2C_SCL(bit) \
2535d602 1877 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
ba56f625 1878 else immr->im_cpm.cp_pbdat &= ~PB_SCL
b37c7e5e 1879
c609719b
WD
1880 I2C_DELAY
1881
1882 This delay is invoked four times per clock cycle so this
1883 controls the rate of data transfer. The data rate thus
b37c7e5e 1884 is 1 / (I2C_DELAY * 4). Often defined to be something
945af8d7
WD
1885 like:
1886
b37c7e5e 1887 #define I2C_DELAY udelay(2)
c609719b 1888
793b5726
MF
1889 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1890
1891 If your arch supports the generic GPIO framework (asm/gpio.h),
1892 then you may alternatively define the two GPIOs that are to be
1893 used as SCL / SDA. Any of the previous I2C_xxx macros will
1894 have GPIO-based defaults assigned to them as appropriate.
1895
1896 You should define these to the GPIO value as given directly to
1897 the generic GPIO functions.
1898
6d0f6bcf 1899 CONFIG_SYS_I2C_INIT_BOARD
47cd00fa 1900
8bde7f77
WD
1901 When a board is reset during an i2c bus transfer
1902 chips might think that the current transfer is still
1903 in progress. On some boards it is possible to access
1904 the i2c SCLK line directly, either by using the
1905 processor pin as a GPIO or by having a second pin
1906 connected to the bus. If this option is defined a
1907 custom i2c_init_board() routine in boards/xxx/board.c
1908 is run early in the boot sequence.
47cd00fa 1909
bb99ad6d
BW
1910 CONFIG_I2C_MULTI_BUS
1911
1912 This option allows the use of multiple I2C buses, each of which
c0f40859
WD
1913 must have a controller. At any point in time, only one bus is
1914 active. To switch to a different bus, use the 'i2c dev' command.
bb99ad6d
BW
1915 Note that bus numbering is zero-based.
1916
6d0f6bcf 1917 CONFIG_SYS_I2C_NOPROBES
bb99ad6d
BW
1918
1919 This option specifies a list of I2C devices that will be skipped
c0f40859 1920 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
0f89c54b
PT
1921 is set, specify a list of bus-device pairs. Otherwise, specify
1922 a 1D array of device addresses
bb99ad6d
BW
1923
1924 e.g.
1925 #undef CONFIG_I2C_MULTI_BUS
c0f40859 1926 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
bb99ad6d
BW
1927
1928 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1929
c0f40859 1930 #define CONFIG_I2C_MULTI_BUS
945a18e6 1931 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
bb99ad6d
BW
1932
1933 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1934
6d0f6bcf 1935 CONFIG_SYS_SPD_BUS_NUM
be5e6181
TT
1936
1937 If defined, then this indicates the I2C bus number for DDR SPD.
1938 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1939
6d0f6bcf 1940 CONFIG_SYS_RTC_BUS_NUM
0dc018ec
SR
1941
1942 If defined, then this indicates the I2C bus number for the RTC.
1943 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1944
2ac6985a
AD
1945 CONFIG_SOFT_I2C_READ_REPEATED_START
1946
1947 defining this will force the i2c_read() function in
1948 the soft_i2c driver to perform an I2C repeated start
1949 between writing the address pointer and reading the
1950 data. If this define is omitted the default behaviour
1951 of doing a stop-start sequence will be used. Most I2C
1952 devices can use either method, but some require one or
1953 the other.
be5e6181 1954
c609719b
WD
1955- SPI Support: CONFIG_SPI
1956
1957 Enables SPI driver (so far only tested with
1958 SPI EEPROM, also an instance works with Crystal A/D and
1959 D/As on the SACSng board)
1960
c609719b
WD
1961 CONFIG_SOFT_SPI
1962
43d9616c
WD
1963 Enables a software (bit-bang) SPI driver rather than
1964 using hardware support. This is a general purpose
1965 driver that only requires three general I/O port pins
1966 (two outputs, one input) to function. If this is
1967 defined, the board configuration must define several
1968 SPI configuration items (port pins to use, etc). For
1969 an example, see include/configs/sacsng.h.
c609719b 1970
04a9e118
BW
1971 CONFIG_HARD_SPI
1972
1973 Enables a hardware SPI driver for general-purpose reads
1974 and writes. As with CONFIG_SOFT_SPI, the board configuration
1975 must define a list of chip-select function pointers.
c0f40859 1976 Currently supported on some MPC8xxx processors. For an
04a9e118
BW
1977 example, see include/configs/mpc8349emds.h.
1978
f659b573
HS
1979 CONFIG_SYS_SPI_MXC_WAIT
1980 Timeout for waiting until spi transfer completed.
1981 default: (CONFIG_SYS_HZ/100) /* 10 ms */
1982
0133502e 1983- FPGA Support: CONFIG_FPGA
c609719b 1984
0133502e
MF
1985 Enables FPGA subsystem.
1986
1987 CONFIG_FPGA_<vendor>
1988
1989 Enables support for specific chip vendors.
1990 (ALTERA, XILINX)
c609719b 1991
0133502e 1992 CONFIG_FPGA_<family>
c609719b 1993
0133502e
MF
1994 Enables support for FPGA family.
1995 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1996
1997 CONFIG_FPGA_COUNT
1998
1999 Specify the number of FPGA devices to support.
c609719b 2000
6d0f6bcf 2001 CONFIG_SYS_FPGA_PROG_FEEDBACK
c609719b 2002
8bde7f77 2003 Enable printing of hash marks during FPGA configuration.
c609719b 2004
6d0f6bcf 2005 CONFIG_SYS_FPGA_CHECK_BUSY
c609719b 2006
43d9616c
WD
2007 Enable checks on FPGA configuration interface busy
2008 status by the configuration function. This option
2009 will require a board or device specific function to
2010 be written.
c609719b
WD
2011
2012 CONFIG_FPGA_DELAY
2013
2014 If defined, a function that provides delays in the FPGA
2015 configuration driver.
2016
6d0f6bcf 2017 CONFIG_SYS_FPGA_CHECK_CTRLC
c609719b
WD
2018 Allow Control-C to interrupt FPGA configuration
2019
6d0f6bcf 2020 CONFIG_SYS_FPGA_CHECK_ERROR
c609719b 2021
43d9616c
WD
2022 Check for configuration errors during FPGA bitfile
2023 loading. For example, abort during Virtex II
2024 configuration if the INIT_B line goes low (which
2025 indicated a CRC error).
c609719b 2026
6d0f6bcf 2027 CONFIG_SYS_FPGA_WAIT_INIT
c609719b 2028
b445bbb4
JM
2029 Maximum time to wait for the INIT_B line to de-assert
2030 after PROB_B has been de-asserted during a Virtex II
43d9616c 2031 FPGA configuration sequence. The default time is 500
11ccc33f 2032 ms.
c609719b 2033
6d0f6bcf 2034 CONFIG_SYS_FPGA_WAIT_BUSY
c609719b 2035
b445bbb4 2036 Maximum time to wait for BUSY to de-assert during
11ccc33f 2037 Virtex II FPGA configuration. The default is 5 ms.
c609719b 2038
6d0f6bcf 2039 CONFIG_SYS_FPGA_WAIT_CONFIG
c609719b 2040
43d9616c 2041 Time to wait after FPGA configuration. The default is
11ccc33f 2042 200 ms.
c609719b
WD
2043
2044- Configuration Management:
b2b8a696
SR
2045 CONFIG_BUILD_TARGET
2046
2047 Some SoCs need special image types (e.g. U-Boot binary
2048 with a special header) as build targets. By defining
2049 CONFIG_BUILD_TARGET in the SoC / board header, this
2050 special image will be automatically built upon calling
6de80f21 2051 make / buildman.
b2b8a696 2052
c609719b
WD
2053 CONFIG_IDENT_STRING
2054
43d9616c
WD
2055 If defined, this string will be added to the U-Boot
2056 version information (U_BOOT_VERSION)
c609719b
WD
2057
2058- Vendor Parameter Protection:
2059
43d9616c
WD
2060 U-Boot considers the values of the environment
2061 variables "serial#" (Board Serial Number) and
7152b1d0 2062 "ethaddr" (Ethernet Address) to be parameters that
43d9616c
WD
2063 are set once by the board vendor / manufacturer, and
2064 protects these variables from casual modification by
2065 the user. Once set, these variables are read-only,
2066 and write or delete attempts are rejected. You can
11ccc33f 2067 change this behaviour:
c609719b
WD
2068
2069 If CONFIG_ENV_OVERWRITE is #defined in your config
2070 file, the write protection for vendor parameters is
47cd00fa 2071 completely disabled. Anybody can change or delete
c609719b
WD
2072 these parameters.
2073
92ac5208
JH
2074 Alternatively, if you define _both_ an ethaddr in the
2075 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
11ccc33f 2076 Ethernet address is installed in the environment,
c609719b
WD
2077 which can be changed exactly ONCE by the user. [The
2078 serial# is unaffected by this, i. e. it remains
2079 read-only.]
2080
2598090b
JH
2081 The same can be accomplished in a more flexible way
2082 for any variable by configuring the type of access
2083 to allow for those variables in the ".flags" variable
2084 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2085
c609719b
WD
2086- Protected RAM:
2087 CONFIG_PRAM
2088
2089 Define this variable to enable the reservation of
2090 "protected RAM", i. e. RAM which is not overwritten
2091 by U-Boot. Define CONFIG_PRAM to hold the number of
2092 kB you want to reserve for pRAM. You can overwrite
2093 this default value by defining an environment
2094 variable "pram" to the number of kB you want to
2095 reserve. Note that the board info structure will
2096 still show the full amount of RAM. If pRAM is
2097 reserved, a new environment variable "mem" will
2098 automatically be defined to hold the amount of
2099 remaining RAM in a form that can be passed as boot
2100 argument to Linux, for instance like that:
2101
fe126d8b 2102 setenv bootargs ... mem=\${mem}
c609719b
WD
2103 saveenv
2104
2105 This way you can tell Linux not to use this memory,
2106 either, which results in a memory region that will
2107 not be affected by reboots.
2108
2109 *WARNING* If your board configuration uses automatic
2110 detection of the RAM size, you must make sure that
2111 this memory test is non-destructive. So far, the
2112 following board configurations are known to be
2113 "pRAM-clean":
2114
5b8e76c3 2115 IVMS8, IVML24, SPD8xx,
1b0757ec 2116 HERMES, IP860, RPXlite, LWMON,
2eb48ff7 2117 FLAGADM
c609719b 2118
40fef049
GB
2119- Access to physical memory region (> 4GB)
2120 Some basic support is provided for operations on memory not
2121 normally accessible to U-Boot - e.g. some architectures
2122 support access to more than 4GB of memory on 32-bit
2123 machines using physical address extension or similar.
2124 Define CONFIG_PHYSMEM to access this basic support, which
2125 currently only supports clearing the memory.
2126
c609719b 2127- Error Recovery:
c609719b
WD
2128 CONFIG_NET_RETRY_COUNT
2129
43d9616c
WD
2130 This variable defines the number of retries for
2131 network operations like ARP, RARP, TFTP, or BOOTP
2132 before giving up the operation. If not defined, a
2133 default value of 5 is used.
c609719b 2134
40cb90ee
GL
2135 CONFIG_ARP_TIMEOUT
2136
2137 Timeout waiting for an ARP reply in milliseconds.
2138
48a3e999
TK
2139 CONFIG_NFS_TIMEOUT
2140
2141 Timeout in milliseconds used in NFS protocol.
2142 If you encounter "ERROR: Cannot umount" in nfs command,
2143 try longer timeout such as
2144 #define CONFIG_NFS_TIMEOUT 10000UL
2145
c609719b 2146- Command Interpreter:
6d0f6bcf 2147 CONFIG_SYS_PROMPT_HUSH_PS2
c609719b
WD
2148
2149 This defines the secondary prompt string, which is
2150 printed when the command interpreter needs more input
2151 to complete a command. Usually "> ".
2152
2153 Note:
2154
8bde7f77
WD
2155 In the current implementation, the local variables
2156 space and global environment variables space are
2157 separated. Local variables are those you define by
2158 simply typing `name=value'. To access a local
2159 variable later on, you have write `$name' or
2160 `${name}'; to execute the contents of a variable
2161 directly type `$name' at the command prompt.
c609719b 2162
43d9616c
WD
2163 Global environment variables are those you use
2164 setenv/printenv to work with. To run a command stored
2165 in such a variable, you need to use the run command,
2166 and you must not use the '$' sign to access them.
c609719b
WD
2167
2168 To store commands and special characters in a
2169 variable, please use double quotation marks
2170 surrounding the whole text of the variable, instead
2171 of the backslashes before semicolons and special
2172 symbols.
2173
b445bbb4 2174- Command Line Editing and History:
f3b267b3
MV
2175 CONFIG_CMDLINE_PS_SUPPORT
2176
2177 Enable support for changing the command prompt string
2178 at run-time. Only static string is supported so far.
2179 The string is obtained from environment variables PS1
2180 and PS2.
2181
a8c7c708 2182- Default Environment:
c609719b
WD
2183 CONFIG_EXTRA_ENV_SETTINGS
2184
43d9616c
WD
2185 Define this to contain any number of null terminated
2186 strings (variable = value pairs) that will be part of
7152b1d0 2187 the default environment compiled into the boot image.
2262cfee 2188
43d9616c
WD
2189 For example, place something like this in your
2190 board's config file:
c609719b
WD
2191
2192 #define CONFIG_EXTRA_ENV_SETTINGS \
2193 "myvar1=value1\0" \
2194 "myvar2=value2\0"
2195
43d9616c
WD
2196 Warning: This method is based on knowledge about the
2197 internal format how the environment is stored by the
2198 U-Boot code. This is NOT an official, exported
2199 interface! Although it is unlikely that this format
7152b1d0 2200 will change soon, there is no guarantee either.
c609719b
WD
2201 You better know what you are doing here.
2202
43d9616c
WD
2203 Note: overly (ab)use of the default environment is
2204 discouraged. Make sure to check other ways to preset
74de7aef 2205 the environment like the "source" command or the
43d9616c 2206 boot command first.
c609719b 2207
06fd8538
SG
2208 CONFIG_DELAY_ENVIRONMENT
2209
2210 Normally the environment is loaded when the board is
b445bbb4 2211 initialised so that it is available to U-Boot. This inhibits
06fd8538
SG
2212 that so that the environment is not available until
2213 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2214 this is instead controlled by the value of
2215 /config/load-environment.
2216
f61ec45e 2217- Serial Flash support
00fd59dd 2218 Usage requires an initial 'sf probe' to define the serial
f61ec45e
EN
2219 flash parameters, followed by read/write/erase/update
2220 commands.
2221
2222 The following defaults may be provided by the platform
2223 to handle the common case when only a single serial
2224 flash is present on the system.
2225
2226 CONFIG_SF_DEFAULT_BUS Bus identifier
2227 CONFIG_SF_DEFAULT_CS Chip-select
2228 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2229 CONFIG_SF_DEFAULT_SPEED in Hz
2230
3f85ce27 2231
ecb0ccd9
WD
2232- TFTP Fixed UDP Port:
2233 CONFIG_TFTP_PORT
2234
28cb9375 2235 If this is defined, the environment variable tftpsrcp
ecb0ccd9 2236 is used to supply the TFTP UDP source port value.
28cb9375 2237 If tftpsrcp isn't defined, the normal pseudo-random port
ecb0ccd9
WD
2238 number generator is used.
2239
28cb9375
WD
2240 Also, the environment variable tftpdstp is used to supply
2241 the TFTP UDP destination port value. If tftpdstp isn't
2242 defined, the normal port 69 is used.
2243
2244 The purpose for tftpsrcp is to allow a TFTP server to
ecb0ccd9
WD
2245 blindly start the TFTP transfer using the pre-configured
2246 target IP address and UDP port. This has the effect of
2247 "punching through" the (Windows XP) firewall, allowing
2248 the remainder of the TFTP transfer to proceed normally.
2249 A better solution is to properly configure the firewall,
2250 but sometimes that is not allowed.
2251
a8c7c708 2252- Show boot progress:
c609719b
WD
2253 CONFIG_SHOW_BOOT_PROGRESS
2254
43d9616c
WD
2255 Defining this option allows to add some board-
2256 specific code (calling a user-provided function
2257 "show_boot_progress(int)") that enables you to show
2258 the system's boot progress on some display (for
2259 example, some LED's) on your board. At the moment,
2260 the following checkpoints are implemented:
c609719b 2261
94fd1316 2262
1372cce2
MB
2263Legacy uImage format:
2264
c609719b
WD
2265 Arg Where When
2266 1 common/cmd_bootm.c before attempting to boot an image
ba56f625 2267 -1 common/cmd_bootm.c Image header has bad magic number
c609719b 2268 2 common/cmd_bootm.c Image header has correct magic number
ba56f625 2269 -2 common/cmd_bootm.c Image header has bad checksum
c609719b 2270 3 common/cmd_bootm.c Image header has correct checksum
ba56f625 2271 -3 common/cmd_bootm.c Image data has bad checksum
c609719b
WD
2272 4 common/cmd_bootm.c Image data has correct checksum
2273 -4 common/cmd_bootm.c Image is for unsupported architecture
2274 5 common/cmd_bootm.c Architecture check OK
1372cce2 2275 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
c609719b
WD
2276 6 common/cmd_bootm.c Image Type check OK
2277 -6 common/cmd_bootm.c gunzip uncompression error
2278 -7 common/cmd_bootm.c Unimplemented compression type
2279 7 common/cmd_bootm.c Uncompression OK
1372cce2 2280 8 common/cmd_bootm.c No uncompress/copy overwrite error
c609719b 2281 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1372cce2
MB
2282
2283 9 common/image.c Start initial ramdisk verification
2284 -10 common/image.c Ramdisk header has bad magic number
2285 -11 common/image.c Ramdisk header has bad checksum
2286 10 common/image.c Ramdisk header is OK
2287 -12 common/image.c Ramdisk data has bad checksum
2288 11 common/image.c Ramdisk data has correct checksum
2289 12 common/image.c Ramdisk verification complete, start loading
11ccc33f 2290 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
1372cce2
MB
2291 13 common/image.c Start multifile image verification
2292 14 common/image.c No initial ramdisk, no multifile, continue.
2293
c0f40859 2294 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
c609719b 2295
a47a12be 2296 -30 arch/powerpc/lib/board.c Fatal error, hang the system
11dadd54
WD
2297 -31 post/post.c POST test failed, detected by post_output_backlog()
2298 -32 post/post.c POST test failed, detected by post_run_single()
63e73c9a 2299
566a494f
HS
2300 34 common/cmd_doc.c before loading a Image from a DOC device
2301 -35 common/cmd_doc.c Bad usage of "doc" command
2302 35 common/cmd_doc.c correct usage of "doc" command
2303 -36 common/cmd_doc.c No boot device
2304 36 common/cmd_doc.c correct boot device
2305 -37 common/cmd_doc.c Unknown Chip ID on boot device
2306 37 common/cmd_doc.c correct chip ID found, device available
2307 -38 common/cmd_doc.c Read Error on boot device
2308 38 common/cmd_doc.c reading Image header from DOC device OK
2309 -39 common/cmd_doc.c Image header has bad magic number
2310 39 common/cmd_doc.c Image header has correct magic number
2311 -40 common/cmd_doc.c Error reading Image from DOC device
2312 40 common/cmd_doc.c Image header has correct magic number
2313 41 common/cmd_ide.c before loading a Image from a IDE device
2314 -42 common/cmd_ide.c Bad usage of "ide" command
2315 42 common/cmd_ide.c correct usage of "ide" command
2316 -43 common/cmd_ide.c No boot device
2317 43 common/cmd_ide.c boot device found
2318 -44 common/cmd_ide.c Device not available
2319 44 common/cmd_ide.c Device available
2320 -45 common/cmd_ide.c wrong partition selected
2321 45 common/cmd_ide.c partition selected
2322 -46 common/cmd_ide.c Unknown partition table
2323 46 common/cmd_ide.c valid partition table found
2324 -47 common/cmd_ide.c Invalid partition type
2325 47 common/cmd_ide.c correct partition type
2326 -48 common/cmd_ide.c Error reading Image Header on boot device
2327 48 common/cmd_ide.c reading Image Header from IDE device OK
2328 -49 common/cmd_ide.c Image header has bad magic number
2329 49 common/cmd_ide.c Image header has correct magic number
2330 -50 common/cmd_ide.c Image header has bad checksum
2331 50 common/cmd_ide.c Image header has correct checksum
2332 -51 common/cmd_ide.c Error reading Image from IDE device
2333 51 common/cmd_ide.c reading Image from IDE device OK
2334 52 common/cmd_nand.c before loading a Image from a NAND device
2335 -53 common/cmd_nand.c Bad usage of "nand" command
2336 53 common/cmd_nand.c correct usage of "nand" command
2337 -54 common/cmd_nand.c No boot device
2338 54 common/cmd_nand.c boot device found
2339 -55 common/cmd_nand.c Unknown Chip ID on boot device
2340 55 common/cmd_nand.c correct chip ID found, device available
2341 -56 common/cmd_nand.c Error reading Image Header on boot device
2342 56 common/cmd_nand.c reading Image Header from NAND device OK
2343 -57 common/cmd_nand.c Image header has bad magic number
2344 57 common/cmd_nand.c Image header has correct magic number
2345 -58 common/cmd_nand.c Error reading Image from NAND device
2346 58 common/cmd_nand.c reading Image from NAND device OK
2347
2348 -60 common/env_common.c Environment has a bad CRC, using default
2349
11ccc33f 2350 64 net/eth.c starting with Ethernet configuration.
566a494f
HS
2351 -64 net/eth.c no Ethernet found.
2352 65 net/eth.c Ethernet found.
2353
2354 -80 common/cmd_net.c usage wrong
bc0571fc
JH
2355 80 common/cmd_net.c before calling net_loop()
2356 -81 common/cmd_net.c some error in net_loop() occurred
2357 81 common/cmd_net.c net_loop() back without error
566a494f
HS
2358 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2359 82 common/cmd_net.c trying automatic boot
74de7aef
WD
2360 83 common/cmd_net.c running "source" command
2361 -83 common/cmd_net.c some error in automatic boot or "source" command
566a494f 2362 84 common/cmd_net.c end without errors
c609719b 2363
1372cce2
MB
2364FIT uImage format:
2365
2366 Arg Where When
2367 100 common/cmd_bootm.c Kernel FIT Image has correct format
2368 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2369 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2370 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2371 102 common/cmd_bootm.c Kernel unit name specified
2372 -103 common/cmd_bootm.c Can't get kernel subimage node offset
f773bea8 2373 103 common/cmd_bootm.c Found configuration node
1372cce2
MB
2374 104 common/cmd_bootm.c Got kernel subimage node offset
2375 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2376 105 common/cmd_bootm.c Kernel subimage hash verification OK
2377 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2378 106 common/cmd_bootm.c Architecture check OK
11ccc33f
MZ
2379 -106 common/cmd_bootm.c Kernel subimage has wrong type
2380 107 common/cmd_bootm.c Kernel subimage type OK
1372cce2
MB
2381 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2382 108 common/cmd_bootm.c Got kernel subimage data/size
2383 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2384 -109 common/cmd_bootm.c Can't get kernel subimage type
2385 -110 common/cmd_bootm.c Can't get kernel subimage comp
2386 -111 common/cmd_bootm.c Can't get kernel subimage os
2387 -112 common/cmd_bootm.c Can't get kernel subimage load address
2388 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2389
2390 120 common/image.c Start initial ramdisk verification
2391 -120 common/image.c Ramdisk FIT image has incorrect format
2392 121 common/image.c Ramdisk FIT image has correct format
11ccc33f 2393 122 common/image.c No ramdisk subimage unit name, using configuration
1372cce2
MB
2394 -122 common/image.c Can't get configuration for ramdisk subimage
2395 123 common/image.c Ramdisk unit name specified
2396 -124 common/image.c Can't get ramdisk subimage node offset
2397 125 common/image.c Got ramdisk subimage node offset
2398 -125 common/image.c Ramdisk subimage hash verification failed
2399 126 common/image.c Ramdisk subimage hash verification OK
2400 -126 common/image.c Ramdisk subimage for unsupported architecture
2401 127 common/image.c Architecture check OK
2402 -127 common/image.c Can't get ramdisk subimage data/size
2403 128 common/image.c Got ramdisk subimage data/size
2404 129 common/image.c Can't get ramdisk load address
2405 -129 common/image.c Got ramdisk load address
2406
11ccc33f 2407 -130 common/cmd_doc.c Incorrect FIT image format
1372cce2
MB
2408 131 common/cmd_doc.c FIT image format OK
2409
11ccc33f 2410 -140 common/cmd_ide.c Incorrect FIT image format
1372cce2
MB
2411 141 common/cmd_ide.c FIT image format OK
2412
11ccc33f 2413 -150 common/cmd_nand.c Incorrect FIT image format
1372cce2
MB
2414 151 common/cmd_nand.c FIT image format OK
2415
21d29f7f
HS
2416- legacy image format:
2417 CONFIG_IMAGE_FORMAT_LEGACY
2418 enables the legacy image format support in U-Boot.
2419
2420 Default:
2421 enabled if CONFIG_FIT_SIGNATURE is not defined.
2422
2423 CONFIG_DISABLE_IMAGE_LEGACY
2424 disable the legacy image format
2425
2426 This define is introduced, as the legacy image format is
2427 enabled per default for backward compatibility.
2428
4cf2609b
WD
2429- Standalone program support:
2430 CONFIG_STANDALONE_LOAD_ADDR
2431
6feff899
WD
2432 This option defines a board specific value for the
2433 address where standalone program gets loaded, thus
2434 overwriting the architecture dependent default
4cf2609b
WD
2435 settings.
2436
2437- Frame Buffer Address:
2438 CONFIG_FB_ADDR
2439
2440 Define CONFIG_FB_ADDR if you want to use specific
44a53b57
WD
2441 address for frame buffer. This is typically the case
2442 when using a graphics controller has separate video
2443 memory. U-Boot will then place the frame buffer at
2444 the given address instead of dynamically reserving it
2445 in system RAM by calling lcd_setmem(), which grabs
2446 the memory for the frame buffer depending on the
2447 configured panel size.
4cf2609b
WD
2448
2449 Please see board_init_f function.
2450
cccfc2ab
DZ
2451- Automatic software updates via TFTP server
2452 CONFIG_UPDATE_TFTP
2453 CONFIG_UPDATE_TFTP_CNT_MAX
2454 CONFIG_UPDATE_TFTP_MSEC_MAX
2455
2456 These options enable and control the auto-update feature;
2457 for a more detailed description refer to doc/README.update.
2458
2459- MTD Support (mtdparts command, UBI support)
2460 CONFIG_MTD_DEVICE
2461
2462 Adds the MTD device infrastructure from the Linux kernel.
2463 Needed for mtdparts command support.
2464
2465 CONFIG_MTD_PARTITIONS
2466
2467 Adds the MTD partitioning infrastructure from the Linux
2468 kernel. Needed for UBI support.
2469
70c219cd 2470- UBI support
ff94bc40
HS
2471 CONFIG_MTD_UBI_WL_THRESHOLD
2472 This parameter defines the maximum difference between the highest
2473 erase counter value and the lowest erase counter value of eraseblocks
2474 of UBI devices. When this threshold is exceeded, UBI starts performing
2475 wear leveling by means of moving data from eraseblock with low erase
2476 counter to eraseblocks with high erase counter.
2477
2478 The default value should be OK for SLC NAND flashes, NOR flashes and
2479 other flashes which have eraseblock life-cycle 100000 or more.
2480 However, in case of MLC NAND flashes which typically have eraseblock
2481 life-cycle less than 10000, the threshold should be lessened (e.g.,
2482 to 128 or 256, although it does not have to be power of 2).
2483
2484 default: 4096
c654b517 2485
ff94bc40
HS
2486 CONFIG_MTD_UBI_BEB_LIMIT
2487 This option specifies the maximum bad physical eraseblocks UBI
2488 expects on the MTD device (per 1024 eraseblocks). If the
2489 underlying flash does not admit of bad eraseblocks (e.g. NOR
2490 flash), this value is ignored.
2491
2492 NAND datasheets often specify the minimum and maximum NVM
2493 (Number of Valid Blocks) for the flashes' endurance lifetime.
2494 The maximum expected bad eraseblocks per 1024 eraseblocks
2495 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
2496 which gives 20 for most NANDs (MaxNVB is basically the total
2497 count of eraseblocks on the chip).
2498
2499 To put it differently, if this value is 20, UBI will try to
2500 reserve about 1.9% of physical eraseblocks for bad blocks
2501 handling. And that will be 1.9% of eraseblocks on the entire
2502 NAND chip, not just the MTD partition UBI attaches. This means
2503 that if you have, say, a NAND flash chip admits maximum 40 bad
2504 eraseblocks, and it is split on two MTD partitions of the same
2505 size, UBI will reserve 40 eraseblocks when attaching a
2506 partition.
2507
2508 default: 20
2509
2510 CONFIG_MTD_UBI_FASTMAP
2511 Fastmap is a mechanism which allows attaching an UBI device
2512 in nearly constant time. Instead of scanning the whole MTD device it
2513 only has to locate a checkpoint (called fastmap) on the device.
2514 The on-flash fastmap contains all information needed to attach
2515 the device. Using fastmap makes only sense on large devices where
2516 attaching by scanning takes long. UBI will not automatically install
2517 a fastmap on old images, but you can set the UBI parameter
2518 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
2519 that fastmap-enabled images are still usable with UBI implementations
2520 without fastmap support. On typical flash devices the whole fastmap
2521 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
2522
2523 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
2524 Set this parameter to enable fastmap automatically on images
2525 without a fastmap.
2526 default: 0
2527
0195a7bb
HS
2528 CONFIG_MTD_UBI_FM_DEBUG
2529 Enable UBI fastmap debug
2530 default: 0
2531
6a11cf48 2532- SPL framework
04e5ae79
WD
2533 CONFIG_SPL
2534 Enable building of SPL globally.
6a11cf48 2535
95579793
TR
2536 CONFIG_SPL_LDSCRIPT
2537 LDSCRIPT for linking the SPL binary.
2538
6ebc3461
AA
2539 CONFIG_SPL_MAX_FOOTPRINT
2540 Maximum size in memory allocated to the SPL, BSS included.
2541 When defined, the linker checks that the actual memory
2542 used by SPL from _start to __bss_end does not exceed it.
8960af8b 2543 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
6ebc3461
AA
2544 must not be both defined at the same time.
2545
95579793 2546 CONFIG_SPL_MAX_SIZE
6ebc3461
AA
2547 Maximum size of the SPL image (text, data, rodata, and
2548 linker lists sections), BSS excluded.
2549 When defined, the linker checks that the actual size does
2550 not exceed it.
95579793 2551
04e5ae79
WD
2552 CONFIG_SPL_TEXT_BASE
2553 TEXT_BASE for linking the SPL binary.
6a11cf48 2554
94a45bb1
SW
2555 CONFIG_SPL_RELOC_TEXT_BASE
2556 Address to relocate to. If unspecified, this is equal to
2557 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2558
95579793
TR
2559 CONFIG_SPL_BSS_START_ADDR
2560 Link address for the BSS within the SPL binary.
2561
2562 CONFIG_SPL_BSS_MAX_SIZE
6ebc3461
AA
2563 Maximum size in memory allocated to the SPL BSS.
2564 When defined, the linker checks that the actual memory used
2565 by SPL from __bss_start to __bss_end does not exceed it.
8960af8b 2566 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
6ebc3461 2567 must not be both defined at the same time.
95579793
TR
2568
2569 CONFIG_SPL_STACK
2570 Adress of the start of the stack SPL will use
2571
8c80eb3b
AA
2572 CONFIG_SPL_PANIC_ON_RAW_IMAGE
2573 When defined, SPL will panic() if the image it has
2574 loaded does not have a signature.
2575 Defining this is useful when code which loads images
2576 in SPL cannot guarantee that absolutely all read errors
2577 will be caught.
2578 An example is the LPC32XX MLC NAND driver, which will
2579 consider that a completely unreadable NAND block is bad,
2580 and thus should be skipped silently.
2581
94a45bb1
SW
2582 CONFIG_SPL_RELOC_STACK
2583 Adress of the start of the stack SPL will use after
2584 relocation. If unspecified, this is equal to
2585 CONFIG_SPL_STACK.
2586
95579793
TR
2587 CONFIG_SYS_SPL_MALLOC_START
2588 Starting address of the malloc pool used in SPL.
9ac4fc82
FE
2589 When this option is set the full malloc is used in SPL and
2590 it is set up by spl_init() and before that, the simple malloc()
2591 can be used if CONFIG_SYS_MALLOC_F is defined.
95579793
TR
2592
2593 CONFIG_SYS_SPL_MALLOC_SIZE
2594 The size of the malloc pool used in SPL.
6a11cf48 2595
9607faf2
TR
2596 CONFIG_SPL_OS_BOOT
2597 Enable booting directly to an OS from SPL.
2598 See also: doc/README.falcon
2599
861a86f4
TR
2600 CONFIG_SPL_DISPLAY_PRINT
2601 For ARM, enable an optional function to print more information
2602 about the running system.
2603
4b919725
SW
2604 CONFIG_SPL_INIT_MINIMAL
2605 Arch init code should be built for a very small image
2606
b97300b6
PK
2607 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
2608 Partition on the MMC to load U-Boot from when the MMC is being
2609 used in raw mode
2610
2b75b0ad
PK
2611 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
2612 Sector to load kernel uImage from when MMC is being
2613 used in raw mode (for Falcon mode)
2614
2615 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
2616 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
2617 Sector and number of sectors to load kernel argument
2618 parameters from when MMC is being used in raw mode
2619 (for falcon mode)
2620
e2ccdf89
PK
2621 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
2622 Partition on the MMC to load U-Boot from when the MMC is being
2623 used in fs mode
2624
fae81c72
GG
2625 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
2626 Filename to read to load U-Boot when reading from filesystem
2627
2628 CONFIG_SPL_FS_LOAD_KERNEL_NAME
7ad2cc79 2629 Filename to read to load kernel uImage when reading
fae81c72 2630 from filesystem (for Falcon mode)
7ad2cc79 2631
fae81c72 2632 CONFIG_SPL_FS_LOAD_ARGS_NAME
7ad2cc79 2633 Filename to read to load kernel argument parameters
fae81c72 2634 when reading from filesystem (for Falcon mode)
7ad2cc79 2635
06f60ae3
SW
2636 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
2637 Set this for NAND SPL on PPC mpc83xx targets, so that
2638 start.S waits for the rest of the SPL to load before
2639 continuing (the hardware starts execution after just
2640 loading the first page rather than the full 4K).
2641
651fcf60
PK
2642 CONFIG_SPL_SKIP_RELOCATE
2643 Avoid SPL relocation
2644
6f2f01b9
SW
2645 CONFIG_SPL_NAND_BASE
2646 Include nand_base.c in the SPL. Requires
2647 CONFIG_SPL_NAND_DRIVERS.
2648
2649 CONFIG_SPL_NAND_DRIVERS
2650 SPL uses normal NAND drivers, not minimal drivers.
2651
2652 CONFIG_SPL_NAND_ECC
2653 Include standard software ECC in the SPL
2654
95579793 2655 CONFIG_SPL_NAND_SIMPLE
7d4b7955
SW
2656 Support for NAND boot using simple NAND drivers that
2657 expose the cmd_ctrl() interface.
95579793 2658
6f4e7d3c
TG
2659 CONFIG_SPL_UBI
2660 Support for a lightweight UBI (fastmap) scanner and
2661 loader
2662
0c3117b1
HS
2663 CONFIG_SPL_NAND_RAW_ONLY
2664 Support to boot only raw u-boot.bin images. Use this only
2665 if you need to save space.
2666
7c8eea59
YZ
2667 CONFIG_SPL_COMMON_INIT_DDR
2668 Set for common ddr init with serial presence detect in
2669 SPL binary.
2670
95579793
TR
2671 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
2672 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
2673 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
2674 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
2675 CONFIG_SYS_NAND_ECCBYTES
2676 Defines the size and behavior of the NAND that SPL uses
7d4b7955 2677 to read U-Boot
95579793 2678
fbe76ae4
PK
2679 CONFIG_SPL_NAND_BOOT
2680 Add support NAND boot
2681
95579793 2682 CONFIG_SYS_NAND_U_BOOT_OFFS
7d4b7955
SW
2683 Location in NAND to read U-Boot from
2684
2685 CONFIG_SYS_NAND_U_BOOT_DST
2686 Location in memory to load U-Boot to
2687
2688 CONFIG_SYS_NAND_U_BOOT_SIZE
2689 Size of image to load
95579793
TR
2690
2691 CONFIG_SYS_NAND_U_BOOT_START
7d4b7955 2692 Entry point in loaded image to jump to
95579793
TR
2693
2694 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
2695 Define this if you need to first read the OOB and then the
b445bbb4 2696 data. This is used, for example, on davinci platforms.
95579793 2697
c57b953d
PM
2698 CONFIG_SPL_RAM_DEVICE
2699 Support for running image already present in ram, in SPL binary
6a11cf48 2700
74752baa 2701 CONFIG_SPL_PAD_TO
6113d3f2
BT
2702 Image offset to which the SPL should be padded before appending
2703 the SPL payload. By default, this is defined as
2704 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
2705 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
2706 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
74752baa 2707
ca2fca22
SW
2708 CONFIG_SPL_TARGET
2709 Final target image containing SPL and payload. Some SPLs
2710 use an arch-specific makefile fragment instead, for
2711 example if more than one image needs to be produced.
2712
87ebee39
SG
2713 CONFIG_FIT_SPL_PRINT
2714 Printing information about a FIT image adds quite a bit of
2715 code to SPL. So this is normally disabled in SPL. Use this
2716 option to re-enable it. This will affect the output of the
2717 bootm command when booting a FIT image.
2718
3aa29de0
YZ
2719- TPL framework
2720 CONFIG_TPL
2721 Enable building of TPL globally.
2722
2723 CONFIG_TPL_PAD_TO
2724 Image offset to which the TPL should be padded before appending
2725 the TPL payload. By default, this is defined as
93e14596
WD
2726 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
2727 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
2728 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3aa29de0 2729
a8c7c708
WD
2730- Interrupt support (PPC):
2731
d4ca31c4
WD
2732 There are common interrupt_init() and timer_interrupt()
2733 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
11ccc33f 2734 for CPU specific initialization. interrupt_init_cpu()
d4ca31c4 2735 should set decrementer_count to appropriate value. If
11ccc33f 2736 CPU resets decrementer automatically after interrupt
d4ca31c4 2737 (ppc4xx) it should set decrementer_count to zero.
11ccc33f 2738 timer_interrupt() calls timer_interrupt_cpu() for CPU
d4ca31c4
WD
2739 specific handling. If board has watchdog / status_led
2740 / other_activity_monitor it works automatically from
2741 general timer_interrupt().
a8c7c708 2742
c609719b 2743
9660e442
HR
2744Board initialization settings:
2745------------------------------
2746
2747During Initialization u-boot calls a number of board specific functions
2748to allow the preparation of board specific prerequisites, e.g. pin setup
2749before drivers are initialized. To enable these callbacks the
2750following configuration macros have to be defined. Currently this is
2751architecture specific, so please check arch/your_architecture/lib/board.c
2752typically in board_init_f() and board_init_r().
2753
2754- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
2755- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
2756- CONFIG_BOARD_LATE_INIT: Call board_late_init()
2757- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
c609719b 2758
c609719b
WD
2759Configuration Settings:
2760-----------------------
2761
4d1fd7f1
YS
2762- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
2763 Optionally it can be defined to support 64-bit memory commands.
2764
6d0f6bcf 2765- CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
c609719b
WD
2766 undefine this when you're short of memory.
2767
2fb2604d
PT
2768- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2769 width of the commands listed in the 'help' command output.
2770
6d0f6bcf 2771- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
c609719b
WD
2772 prompt for user input.
2773
6d0f6bcf 2774- CONFIG_SYS_CBSIZE: Buffer size for input from the Console
c609719b 2775
6d0f6bcf 2776- CONFIG_SYS_PBSIZE: Buffer size for Console output
c609719b 2777
6d0f6bcf 2778- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
c609719b 2779
6d0f6bcf 2780- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
c609719b
WD
2781 the application (usually a Linux kernel) when it is
2782 booted
2783
6d0f6bcf 2784- CONFIG_SYS_BAUDRATE_TABLE:
c609719b
WD
2785 List of legal baudrate settings for this board.
2786
6d0f6bcf 2787- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
c609719b
WD
2788 Begin and End addresses of the area used by the
2789 simple memory test.
2790
6d0f6bcf 2791- CONFIG_SYS_MEMTEST_SCRATCH:
5f535fe1
WD
2792 Scratch address used by the alternate memory test
2793 You only need to set this if address zero isn't writeable
2794
e8149522 2795- CONFIG_SYS_MEM_RESERVE_SECURE
e61a7534 2796 Only implemented for ARMv8 for now.
e8149522
YS
2797 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
2798 is substracted from total RAM and won't be reported to OS.
2799 This memory can be used as secure memory. A variable
e61a7534 2800 gd->arch.secure_ram is used to track the location. In systems
e8149522
YS
2801 the RAM base is not zero, or RAM is divided into banks,
2802 this variable needs to be recalcuated to get the address.
2803
aabd7ddb 2804- CONFIG_SYS_MEM_TOP_HIDE:
6d0f6bcf 2805 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
14f73ca6 2806 this specified memory area will get subtracted from the top
11ccc33f 2807 (end) of RAM and won't get "touched" at all by U-Boot. By
14f73ca6
SR
2808 fixing up gd->ram_size the Linux kernel should gets passed
2809 the now "corrected" memory size and won't touch it either.
2810 This should work for arch/ppc and arch/powerpc. Only Linux
5e12e75d 2811 board ports in arch/powerpc with bootwrapper support that
14f73ca6 2812 recalculate the memory size from the SDRAM controller setup
5e12e75d 2813 will have to get fixed in Linux additionally.
14f73ca6
SR
2814
2815 This option can be used as a workaround for the 440EPx/GRx
2816 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2817 be touched.
2818
2819 WARNING: Please make sure that this value is a multiple of
2820 the Linux page size (normally 4k). If this is not the case,
2821 then the end address of the Linux memory will be located at a
2822 non page size aligned address and this could cause major
2823 problems.
2824
6d0f6bcf 2825- CONFIG_SYS_LOADS_BAUD_CHANGE:
c609719b
WD
2826 Enable temporary baudrate change while serial download
2827
6d0f6bcf 2828- CONFIG_SYS_SDRAM_BASE:
c609719b
WD
2829 Physical start address of SDRAM. _Must_ be 0 here.
2830
6d0f6bcf 2831- CONFIG_SYS_FLASH_BASE:
c609719b
WD
2832 Physical start address of Flash memory.
2833
6d0f6bcf 2834- CONFIG_SYS_MONITOR_BASE:
c609719b
WD
2835 Physical start address of boot monitor code (set by
2836 make config files to be same as the text base address
14d0a02a 2837 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
6d0f6bcf 2838 CONFIG_SYS_FLASH_BASE when booting from flash.
c609719b 2839
6d0f6bcf 2840- CONFIG_SYS_MONITOR_LEN:
8bde7f77
WD
2841 Size of memory reserved for monitor code, used to
2842 determine _at_compile_time_ (!) if the environment is
2843 embedded within the U-Boot image, or in a separate
2844 flash sector.
c609719b 2845
6d0f6bcf 2846- CONFIG_SYS_MALLOC_LEN:
c609719b
WD
2847 Size of DRAM reserved for malloc() use.
2848
d59476b6
SG
2849- CONFIG_SYS_MALLOC_F_LEN
2850 Size of the malloc() pool for use before relocation. If
2851 this is defined, then a very simple malloc() implementation
2852 will become available before relocation. The address is just
2853 below the global data, and the stack is moved down to make
2854 space.
2855
2856 This feature allocates regions with increasing addresses
2857 within the region. calloc() is supported, but realloc()
2858 is not available. free() is supported but does nothing.
b445bbb4 2859 The memory will be freed (or in fact just forgotten) when
d59476b6
SG
2860 U-Boot relocates itself.
2861
38687ae6
SG
2862- CONFIG_SYS_MALLOC_SIMPLE
2863 Provides a simple and small malloc() and calloc() for those
2864 boards which do not use the full malloc in SPL (which is
2865 enabled with CONFIG_SYS_SPL_MALLOC_START).
2866
1dfdd9ba
TR
2867- CONFIG_SYS_NONCACHED_MEMORY:
2868 Size of non-cached memory area. This area of memory will be
2869 typically located right below the malloc() area and mapped
2870 uncached in the MMU. This is useful for drivers that would
2871 otherwise require a lot of explicit cache maintenance. For
2872 some drivers it's also impossible to properly maintain the
2873 cache. For example if the regions that need to be flushed
2874 are not a multiple of the cache-line size, *and* padding
2875 cannot be allocated between the regions to align them (i.e.
2876 if the HW requires a contiguous array of regions, and the
2877 size of each region is not cache-aligned), then a flush of
2878 one region may result in overwriting data that hardware has
2879 written to another region in the same cache-line. This can
2880 happen for example in network drivers where descriptors for
2881 buffers are typically smaller than the CPU cache-line (e.g.
2882 16 bytes vs. 32 or 64 bytes).
2883
2884 Non-cached memory is only supported on 32-bit ARM at present.
2885
6d0f6bcf 2886- CONFIG_SYS_BOOTM_LEN:
15940c9a
SR
2887 Normally compressed uImages are limited to an
2888 uncompressed size of 8 MBytes. If this is not enough,
6d0f6bcf 2889 you can define CONFIG_SYS_BOOTM_LEN in your board config file
15940c9a
SR
2890 to adjust this setting to your needs.
2891
6d0f6bcf 2892- CONFIG_SYS_BOOTMAPSZ:
c609719b
WD
2893 Maximum size of memory mapped by the startup code of
2894 the Linux kernel; all data that must be processed by
7d721e34
BS
2895 the Linux kernel (bd_info, boot arguments, FDT blob if
2896 used) must be put below this limit, unless "bootm_low"
1bce2aeb 2897 environment variable is defined and non-zero. In such case
7d721e34 2898 all data for the Linux kernel must be between "bootm_low"
c0f40859 2899 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
c3624e6e
GL
2900 variable "bootm_mapsize" will override the value of
2901 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
2902 then the value in "bootm_size" will be used instead.
c609719b 2903
fca43cc8
JR
2904- CONFIG_SYS_BOOT_RAMDISK_HIGH:
2905 Enable initrd_high functionality. If defined then the
2906 initrd_high feature is enabled and the bootm ramdisk subcommand
2907 is enabled.
2908
2909- CONFIG_SYS_BOOT_GET_CMDLINE:
2910 Enables allocating and saving kernel cmdline in space between
2911 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2912
2913- CONFIG_SYS_BOOT_GET_KBD:
2914 Enables allocating and saving a kernel copy of the bd_info in
2915 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2916
6d0f6bcf 2917- CONFIG_SYS_MAX_FLASH_BANKS:
c609719b
WD
2918 Max number of Flash memory banks
2919
6d0f6bcf 2920- CONFIG_SYS_MAX_FLASH_SECT:
c609719b
WD
2921 Max number of sectors on a Flash chip
2922
6d0f6bcf 2923- CONFIG_SYS_FLASH_ERASE_TOUT:
c609719b
WD
2924 Timeout for Flash erase operations (in ms)
2925
6d0f6bcf 2926- CONFIG_SYS_FLASH_WRITE_TOUT:
c609719b
WD
2927 Timeout for Flash write operations (in ms)
2928
6d0f6bcf 2929- CONFIG_SYS_FLASH_LOCK_TOUT
8564acf9
WD
2930 Timeout for Flash set sector lock bit operation (in ms)
2931
6d0f6bcf 2932- CONFIG_SYS_FLASH_UNLOCK_TOUT
8564acf9
WD
2933 Timeout for Flash clear lock bits operation (in ms)
2934
6d0f6bcf 2935- CONFIG_SYS_FLASH_PROTECTION
8564acf9
WD
2936 If defined, hardware flash sectors protection is used
2937 instead of U-Boot software protection.
2938
6d0f6bcf 2939- CONFIG_SYS_DIRECT_FLASH_TFTP:
c609719b
WD
2940
2941 Enable TFTP transfers directly to flash memory;
2942 without this option such a download has to be
2943 performed in two steps: (1) download to RAM, and (2)
2944 copy from RAM to flash.
2945
2946 The two-step approach is usually more reliable, since
2947 you can check if the download worked before you erase
11ccc33f
MZ
2948 the flash, but in some situations (when system RAM is
2949 too limited to allow for a temporary copy of the
c609719b
WD
2950 downloaded image) this option may be very useful.
2951
6d0f6bcf 2952- CONFIG_SYS_FLASH_CFI:
43d9616c 2953 Define if the flash driver uses extra elements in the
5653fc33
WD
2954 common flash structure for storing flash geometry.
2955
00b1883a 2956- CONFIG_FLASH_CFI_DRIVER
5653fc33
WD
2957 This option also enables the building of the cfi_flash driver
2958 in the drivers directory
c609719b 2959
91809ed5
PZ
2960- CONFIG_FLASH_CFI_MTD
2961 This option enables the building of the cfi_mtd driver
2962 in the drivers directory. The driver exports CFI flash
2963 to the MTD layer.
2964
6d0f6bcf 2965- CONFIG_SYS_FLASH_USE_BUFFER_WRITE
96ef831f
GL
2966 Use buffered writes to flash.
2967
2968- CONFIG_FLASH_SPANSION_S29WS_N
2969 s29ws-n MirrorBit flash has non-standard addresses for buffered
2970 write commands.
2971
6d0f6bcf 2972- CONFIG_SYS_FLASH_QUIET_TEST
5568e613
SR
2973 If this option is defined, the common CFI flash doesn't
2974 print it's warning upon not recognized FLASH banks. This
2975 is useful, if some of the configured banks are only
2976 optionally available.
2977
9a042e9c
JVB
2978- CONFIG_FLASH_SHOW_PROGRESS
2979 If defined (must be an integer), print out countdown
2980 digits and dots. Recommended value: 45 (9..1) for 80
2981 column displays, 15 (3..1) for 40 column displays.
2982
352ef3f1
SR
2983- CONFIG_FLASH_VERIFY
2984 If defined, the content of the flash (destination) is compared
2985 against the source after the write operation. An error message
2986 will be printed when the contents are not identical.
2987 Please note that this option is useless in nearly all cases,
2988 since such flash programming errors usually are detected earlier
2989 while unprotecting/erasing/programming. Please only enable
2990 this option if you really know what you are doing.
2991
6d0f6bcf 2992- CONFIG_SYS_RX_ETH_BUFFER:
11ccc33f
MZ
2993 Defines the number of Ethernet receive buffers. On some
2994 Ethernet controllers it is recommended to set this value
53cf9435
SR
2995 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2996 buffers can be full shortly after enabling the interface
11ccc33f 2997 on high Ethernet traffic.
53cf9435
SR
2998 Defaults to 4 if not defined.
2999
ea882baf
WD
3000- CONFIG_ENV_MAX_ENTRIES
3001
071bc923
WD
3002 Maximum number of entries in the hash table that is used
3003 internally to store the environment settings. The default
3004 setting is supposed to be generous and should work in most
3005 cases. This setting can be used to tune behaviour; see
3006 lib/hashtable.c for details.
ea882baf 3007
2598090b
JH
3008- CONFIG_ENV_FLAGS_LIST_DEFAULT
3009- CONFIG_ENV_FLAGS_LIST_STATIC
1bce2aeb 3010 Enable validation of the values given to environment variables when
2598090b
JH
3011 calling env set. Variables can be restricted to only decimal,
3012 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3013 the variables can also be restricted to IP address or MAC address.
3014
3015 The format of the list is:
3016 type_attribute = [s|d|x|b|i|m]
b445bbb4
JM
3017 access_attribute = [a|r|o|c]
3018 attributes = type_attribute[access_attribute]
2598090b
JH
3019 entry = variable_name[:attributes]
3020 list = entry[,list]
3021
3022 The type attributes are:
3023 s - String (default)
3024 d - Decimal
3025 x - Hexadecimal
3026 b - Boolean ([1yYtT|0nNfF])
3027 i - IP address
3028 m - MAC address
3029
267541f7
JH
3030 The access attributes are:
3031 a - Any (default)
3032 r - Read-only
3033 o - Write-once
3034 c - Change-default
3035
2598090b
JH
3036 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3037 Define this to a list (string) to define the ".flags"
b445bbb4 3038 environment variable in the default or embedded environment.
2598090b
JH
3039
3040 - CONFIG_ENV_FLAGS_LIST_STATIC
3041 Define this to a list (string) to define validation that
3042 should be done if an entry is not found in the ".flags"
3043 environment variable. To override a setting in the static
3044 list, simply add an entry for the same variable name to the
3045 ".flags" variable.
3046
bdf1fe4e
JH
3047 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
3048 regular expression. This allows multiple variables to define the same
3049 flags without explicitly listing them for each variable.
3050
267541f7
JH
3051- CONFIG_ENV_ACCESS_IGNORE_FORCE
3052 If defined, don't allow the -f switch to env set override variable
3053 access flags.
3054
0d296cc2
GB
3055- CONFIG_USE_STDINT
3056 If stdint.h is available with your toolchain you can define this
3057 option to enable it. You can provide option 'USE_STDINT=1' when
3058 building U-Boot to enable this.
3059
c609719b
WD
3060The following definitions that deal with the placement and management
3061of environment data (variable area); in general, we support the
3062following configurations:
3063
c3eb3fe4
MF
3064- CONFIG_BUILD_ENVCRC:
3065
3066 Builds up envcrc with the target environment so that external utils
3067 may easily extract it and embed it in final U-Boot images.
3068
c609719b 3069BE CAREFUL! The first access to the environment happens quite early
b445bbb4 3070in U-Boot initialization (when we try to get the setting of for the
11ccc33f 3071console baudrate). You *MUST* have mapped your NVRAM area then, or
c609719b
WD
3072U-Boot will hang.
3073
3074Please note that even with NVRAM we still use a copy of the
3075environment in RAM: we could work on NVRAM directly, but we want to
3076keep settings there always unmodified except somebody uses "saveenv"
3077to save the current settings.
3078
0a85a9e7
LG
3079BE CAREFUL! For some special cases, the local device can not use
3080"saveenv" command. For example, the local device will get the
fc54c7fa
LG
3081environment stored in a remote NOR flash by SRIO or PCIE link,
3082but it can not erase, write this NOR flash by SRIO or PCIE interface.
0a85a9e7 3083
b74ab737
GL
3084- CONFIG_NAND_ENV_DST
3085
3086 Defines address in RAM to which the nand_spl code should copy the
3087 environment. If redundant environment is used, it will be copied to
3088 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3089
e881cb56 3090Please note that the environment is read-only until the monitor
c609719b 3091has been relocated to RAM and a RAM copy of the environment has been
00caae6d 3092created; also, when using EEPROM you will have to use env_get_f()
c609719b
WD
3093until then to read environment variables.
3094
85ec0bcc
WD
3095The environment is protected by a CRC32 checksum. Before the monitor
3096is relocated into RAM, as a result of a bad CRC you will be working
3097with the compiled-in default environment - *silently*!!! [This is
3098necessary, because the first environment variable we need is the
3099"baudrate" setting for the console - if we have a bad CRC, we don't
3100have any device yet where we could complain.]
c609719b
WD
3101
3102Note: once the monitor has been relocated, then it will complain if
3103the default environment is used; a new CRC is computed as soon as you
85ec0bcc 3104use the "saveenv" command to store a valid environment.
c609719b 3105
6d0f6bcf 3106- CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
42d1f039 3107 Echo the inverted Ethernet link state to the fault LED.
fc3e2165 3108
6d0f6bcf 3109 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
fc3e2165
WD
3110 also needs to be defined.
3111
6d0f6bcf 3112- CONFIG_SYS_FAULT_MII_ADDR:
42d1f039 3113 MII address of the PHY to check for the Ethernet link state.
c609719b 3114
f5675aa5
RM
3115- CONFIG_NS16550_MIN_FUNCTIONS:
3116 Define this if you desire to only have use of the NS16550_init
3117 and NS16550_putc functions for the serial driver located at
3118 drivers/serial/ns16550.c. This option is useful for saving
3119 space for already greatly restricted images, including but not
3120 limited to NAND_SPL configurations.
3121
b2b92f53
SG
3122- CONFIG_DISPLAY_BOARDINFO
3123 Display information about the board that U-Boot is running on
3124 when U-Boot starts up. The board function checkboard() is called
3125 to do this.
3126
e2e3e2b1
SG
3127- CONFIG_DISPLAY_BOARDINFO_LATE
3128 Similar to the previous option, but display this information
3129 later, once stdio is running and output goes to the LCD, if
3130 present.
3131
feb85801
SS
3132- CONFIG_BOARD_SIZE_LIMIT:
3133 Maximum size of the U-Boot image. When defined, the
3134 build system checks that the actual size does not
3135 exceed it.
3136
c609719b 3137Low Level (hardware related) configuration options:
dc7c9a1a 3138---------------------------------------------------
c609719b 3139
6d0f6bcf 3140- CONFIG_SYS_CACHELINE_SIZE:
c609719b
WD
3141 Cache Line Size of the CPU.
3142
e46fedfe
TT
3143- CONFIG_SYS_CCSRBAR_DEFAULT:
3144 Default (power-on reset) physical address of CCSR on Freescale
3145 PowerPC SOCs.
3146
3147- CONFIG_SYS_CCSRBAR:
3148 Virtual address of CCSR. On a 32-bit build, this is typically
3149 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3150
e46fedfe
TT
3151- CONFIG_SYS_CCSRBAR_PHYS:
3152 Physical address of CCSR. CCSR can be relocated to a new
3153 physical address, if desired. In this case, this macro should
c0f40859 3154 be set to that address. Otherwise, it should be set to the
e46fedfe
TT
3155 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3156 is typically relocated on 36-bit builds. It is recommended
3157 that this macro be defined via the _HIGH and _LOW macros:
3158
3159 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3160 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3161
3162- CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4cf2609b
WD
3163 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3164 either 0 (32-bit build) or 0xF (36-bit build). This macro is
e46fedfe
TT
3165 used in assembly code, so it must not contain typecasts or
3166 integer size suffixes (e.g. "ULL").
3167
3168- CONFIG_SYS_CCSRBAR_PHYS_LOW:
3169 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3170 used in assembly code, so it must not contain typecasts or
3171 integer size suffixes (e.g. "ULL").
3172
3173- CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3174 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3175 forced to a value that ensures that CCSR is not relocated.
3176
7f6c2cbc 3177- Floppy Disk Support:
6d0f6bcf 3178 CONFIG_SYS_FDC_DRIVE_NUMBER
7f6c2cbc
WD
3179
3180 the default drive number (default value 0)
3181
6d0f6bcf 3182 CONFIG_SYS_ISA_IO_STRIDE
7f6c2cbc 3183
11ccc33f 3184 defines the spacing between FDC chipset registers
7f6c2cbc
WD
3185 (default value 1)
3186
6d0f6bcf 3187 CONFIG_SYS_ISA_IO_OFFSET
7f6c2cbc 3188
43d9616c
WD
3189 defines the offset of register from address. It
3190 depends on which part of the data bus is connected to
11ccc33f 3191 the FDC chipset. (default value 0)
7f6c2cbc 3192
6d0f6bcf
JCPV
3193 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3194 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
43d9616c 3195 default value.
7f6c2cbc 3196
6d0f6bcf 3197 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
43d9616c
WD
3198 fdc_hw_init() is called at the beginning of the FDC
3199 setup. fdc_hw_init() must be provided by the board
b445bbb4 3200 source code. It is used to make hardware-dependent
43d9616c 3201 initializations.
7f6c2cbc 3202
0abddf82
ML
3203- CONFIG_IDE_AHB:
3204 Most IDE controllers were designed to be connected with PCI
3205 interface. Only few of them were designed for AHB interface.
3206 When software is doing ATA command and data transfer to
3207 IDE devices through IDE-AHB controller, some additional
3208 registers accessing to these kind of IDE-AHB controller
b445bbb4 3209 is required.
0abddf82 3210
6d0f6bcf 3211- CONFIG_SYS_IMMR: Physical address of the Internal Memory.
efe2a4d5 3212 DO NOT CHANGE unless you know exactly what you're
907208c4 3213 doing! (11-4) [MPC8xx systems only]
c609719b 3214
6d0f6bcf 3215- CONFIG_SYS_INIT_RAM_ADDR:
c609719b 3216
7152b1d0 3217 Start address of memory area that can be used for
c609719b
WD
3218 initial data and stack; please note that this must be
3219 writable memory that is working WITHOUT special
3220 initialization, i. e. you CANNOT use normal RAM which
3221 will become available only after programming the
3222 memory controller and running certain initialization
3223 sequences.
3224
3225 U-Boot uses the following memory types:
907208c4 3226 - MPC8xx: IMMR (internal memory of the CPU)
c609719b 3227
6d0f6bcf 3228- CONFIG_SYS_GBL_DATA_OFFSET:
c609719b
WD
3229
3230 Offset of the initial data structure in the memory
6d0f6bcf
JCPV
3231 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3232 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
c609719b 3233 data is located at the end of the available space
553f0982 3234 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
acd51f9d 3235 GENERATED_GBL_DATA_SIZE), and the initial stack is just
6d0f6bcf
JCPV
3236 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3237 CONFIG_SYS_GBL_DATA_OFFSET) downward.
c609719b
WD
3238
3239 Note:
3240 On the MPC824X (or other systems that use the data
3241 cache for initial memory) the address chosen for
6d0f6bcf 3242 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
c609719b
WD
3243 point to an otherwise UNUSED address space between
3244 the top of RAM and the start of the PCI space.
3245
6d0f6bcf 3246- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
c609719b 3247
6d0f6bcf 3248- CONFIG_SYS_OR_TIMING_SDRAM:
c609719b
WD
3249 SDRAM timing
3250
6d0f6bcf 3251- CONFIG_SYS_MAMR_PTA:
c609719b
WD
3252 periodic timer for refresh
3253
6d0f6bcf
JCPV
3254- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3255 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3256 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3257 CONFIG_SYS_BR1_PRELIM:
c609719b
WD
3258 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3259
3260- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
6d0f6bcf
JCPV
3261 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3262 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
c609719b
WD
3263 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3264
69fd2d3b 3265- CONFIG_PCI_ENUM_ONLY
b445bbb4 3266 Only scan through and get the devices on the buses.
69fd2d3b
AS
3267 Don't do any setup work, presumably because someone or
3268 something has already done it, and we don't need to do it
3269 a second time. Useful for platforms that are pre-booted
3270 by coreboot or similar.
3271
842033e6
GJ
3272- CONFIG_PCI_INDIRECT_BRIDGE:
3273 Enable support for indirect PCI bridges.
3274
a09b9b68
KG
3275- CONFIG_SYS_SRIO:
3276 Chip has SRIO or not
3277
3278- CONFIG_SRIO1:
3279 Board has SRIO 1 port available
3280
3281- CONFIG_SRIO2:
3282 Board has SRIO 2 port available
3283
c8b28152
LG
3284- CONFIG_SRIO_PCIE_BOOT_MASTER
3285 Board can support master function for Boot from SRIO and PCIE
3286
a09b9b68
KG
3287- CONFIG_SYS_SRIOn_MEM_VIRT:
3288 Virtual Address of SRIO port 'n' memory region
3289
3290- CONFIG_SYS_SRIOn_MEM_PHYS:
3291 Physical Address of SRIO port 'n' memory region
3292
3293- CONFIG_SYS_SRIOn_MEM_SIZE:
3294 Size of SRIO port 'n' memory region
3295
66bd1846
FE
3296- CONFIG_SYS_NAND_BUSWIDTH_16BIT
3297 Defined to tell the NAND controller that the NAND chip is using
3298 a 16 bit bus.
3299 Not all NAND drivers use this symbol.
a430e916 3300 Example of drivers that use it:
66bd1846 3301 - drivers/mtd/nand/ndfc.c
a430e916 3302 - drivers/mtd/nand/mxc_nand.c
eced4626
AW
3303
3304- CONFIG_SYS_NDFC_EBC0_CFG
3305 Sets the EBC0_CFG register for the NDFC. If not defined
3306 a default value will be used.
3307
bb99ad6d 3308- CONFIG_SPD_EEPROM
218ca724
WD
3309 Get DDR timing information from an I2C EEPROM. Common
3310 with pluggable memory modules such as SODIMMs
3311
bb99ad6d
BW
3312 SPD_EEPROM_ADDRESS
3313 I2C address of the SPD EEPROM
3314
6d0f6bcf 3315- CONFIG_SYS_SPD_BUS_NUM
218ca724
WD
3316 If SPD EEPROM is on an I2C bus other than the first
3317 one, specify here. Note that the value must resolve
3318 to something your driver can deal with.
bb99ad6d 3319
1b3e3c4f
YS
3320- CONFIG_SYS_DDR_RAW_TIMING
3321 Get DDR timing information from other than SPD. Common with
3322 soldered DDR chips onboard without SPD. DDR raw timing
3323 parameters are extracted from datasheet and hard-coded into
3324 header files or board specific files.
3325
6f5e1dc5
YS
3326- CONFIG_FSL_DDR_INTERACTIVE
3327 Enable interactive DDR debugging. See doc/README.fsl-ddr.
3328
e32d59a2
YS
3329- CONFIG_FSL_DDR_SYNC_REFRESH
3330 Enable sync of refresh for multiple controllers.
3331
4516ff81
YS
3332- CONFIG_FSL_DDR_BIST
3333 Enable built-in memory test for Freescale DDR controllers.
3334
6d0f6bcf 3335- CONFIG_SYS_83XX_DDR_USES_CS0
218ca724
WD
3336 Only for 83xx systems. If specified, then DDR should
3337 be configured using CS0 and CS1 instead of CS2 and CS3.
2ad6b513 3338
c26e454d
WD
3339- CONFIG_RMII
3340 Enable RMII mode for all FECs.
3341 Note that this is a global option, we can't
3342 have one FEC in standard MII mode and another in RMII mode.
3343
5cf91d6b
WD
3344- CONFIG_CRC32_VERIFY
3345 Add a verify option to the crc32 command.
3346 The syntax is:
3347
3348 => crc32 -v <address> <count> <crc32>
3349
3350 Where address/count indicate a memory area
3351 and crc32 is the correct crc32 which the
3352 area should have.
3353
56523f12
WD
3354- CONFIG_LOOPW
3355 Add the "loopw" memory command. This only takes effect if
493f420e 3356 the memory commands are activated globally (CONFIG_CMD_MEMORY).
56523f12 3357
7b466641
SR
3358- CONFIG_MX_CYCLIC
3359 Add the "mdc" and "mwc" memory commands. These are cyclic
3360 "md/mw" commands.
3361 Examples:
3362
efe2a4d5 3363 => mdc.b 10 4 500
7b466641
SR
3364 This command will print 4 bytes (10,11,12,13) each 500 ms.
3365
efe2a4d5 3366 => mwc.l 100 12345678 10
7b466641
SR
3367 This command will write 12345678 to address 100 all 10 ms.
3368
efe2a4d5 3369 This only takes effect if the memory commands are activated
493f420e 3370 globally (CONFIG_CMD_MEMORY).
7b466641 3371
8aa1a2d1 3372- CONFIG_SKIP_LOWLEVEL_INIT
3fafced7 3373 [ARM, NDS32, MIPS, RISC-V only] If this variable is defined, then certain
844f07d8
WD
3374 low level initializations (like setting up the memory
3375 controller) are omitted and/or U-Boot does not
3376 relocate itself into RAM.
3377
3378 Normally this variable MUST NOT be defined. The only
3379 exception is when U-Boot is loaded (to RAM) by some
3380 other boot loader or by a debugger which performs
3381 these initializations itself.
8aa1a2d1 3382
b5bd0982
SG
3383- CONFIG_SKIP_LOWLEVEL_INIT_ONLY
3384 [ARM926EJ-S only] This allows just the call to lowlevel_init()
90211f77 3385 to be skipped. The normal CP15 init (such as enabling the
b5bd0982
SG
3386 instruction cache) is still performed.
3387
401bb30b 3388- CONFIG_SPL_BUILD
df81238b
ML
3389 Modifies the behaviour of start.S when compiling a loader
3390 that is executed before the actual U-Boot. E.g. when
3391 compiling a NAND SPL.
400558b5 3392
3aa29de0
YZ
3393- CONFIG_TPL_BUILD
3394 Modifies the behaviour of start.S when compiling a loader
3395 that is executed after the SPL and before the actual U-Boot.
3396 It is loaded by the SPL.
3397
5df572f0
YZ
3398- CONFIG_SYS_MPC85XX_NO_RESETVEC
3399 Only for 85xx systems. If this variable is specified, the section
3400 .resetvec is not kept and the section .bootpg is placed in the
3401 previous 4k of the .text section.
3402
4213fc29
SG
3403- CONFIG_ARCH_MAP_SYSMEM
3404 Generally U-Boot (and in particular the md command) uses
3405 effective address. It is therefore not necessary to regard
3406 U-Boot address as virtual addresses that need to be translated
3407 to physical addresses. However, sandbox requires this, since
3408 it maintains its own little RAM buffer which contains all
3409 addressable memory. This option causes some memory accesses
3410 to be mapped through map_sysmem() / unmap_sysmem().
3411
588a13f7
SG
3412- CONFIG_X86_RESET_VECTOR
3413 If defined, the x86 reset vector code is included. This is not
3414 needed when U-Boot is running from Coreboot.
b16f521a 3415
999d7d32
KM
3416- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
3417 Option to disable subpage write in NAND driver
3418 driver that uses this:
3419 drivers/mtd/nand/davinci_nand.c
3420
f2717b47
TT
3421Freescale QE/FMAN Firmware Support:
3422-----------------------------------
3423
3424The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
3425loading of "firmware", which is encoded in the QE firmware binary format.
3426This firmware often needs to be loaded during U-Boot booting, so macros
3427are used to identify the storage device (NOR flash, SPI, etc) and the address
3428within that device.
3429
dcf1d774
ZQ
3430- CONFIG_SYS_FMAN_FW_ADDR
3431 The address in the storage device where the FMAN microcode is located. The
3432 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3433 is also specified.
3434
3435- CONFIG_SYS_QE_FW_ADDR
3436 The address in the storage device where the QE microcode is located. The
f2717b47
TT
3437 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3438 is also specified.
3439
3440- CONFIG_SYS_QE_FMAN_FW_LENGTH
3441 The maximum possible size of the firmware. The firmware binary format
3442 has a field that specifies the actual size of the firmware, but it
3443 might not be possible to read any part of the firmware unless some
3444 local storage is allocated to hold the entire firmware first.
3445
3446- CONFIG_SYS_QE_FMAN_FW_IN_NOR
3447 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
3448 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
3449 virtual address in NOR flash.
3450
3451- CONFIG_SYS_QE_FMAN_FW_IN_NAND
3452 Specifies that QE/FMAN firmware is located in NAND flash.
3453 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
3454
3455- CONFIG_SYS_QE_FMAN_FW_IN_MMC
3456 Specifies that QE/FMAN firmware is located on the primary SD/MMC
3457 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3458
292dc6c5
LG
3459- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
3460 Specifies that QE/FMAN firmware is located in the remote (master)
3461 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
fc54c7fa
LG
3462 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
3463 window->master inbound window->master LAW->the ucode address in
3464 master's memory space.
f2717b47 3465
b940ca64
GR
3466Freescale Layerscape Management Complex Firmware Support:
3467---------------------------------------------------------
3468The Freescale Layerscape Management Complex (MC) supports the loading of
3469"firmware".
3470This firmware often needs to be loaded during U-Boot booting, so macros
3471are used to identify the storage device (NOR flash, SPI, etc) and the address
3472within that device.
3473
3474- CONFIG_FSL_MC_ENET
3475 Enable the MC driver for Layerscape SoCs.
3476
5c055089
PK
3477Freescale Layerscape Debug Server Support:
3478-------------------------------------------
3479The Freescale Layerscape Debug Server Support supports the loading of
3480"Debug Server firmware" and triggering SP boot-rom.
3481This firmware often needs to be loaded during U-Boot booting.
3482
c0492141
YS
3483- CONFIG_SYS_MC_RSV_MEM_ALIGN
3484 Define alignment of reserved memory MC requires
5c055089 3485
f3f431a7
PK
3486Reproducible builds
3487-------------------
3488
3489In order to achieve reproducible builds, timestamps used in the U-Boot build
3490process have to be set to a fixed value.
3491
3492This is done using the SOURCE_DATE_EPOCH environment variable.
3493SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
3494option for U-Boot or an environment variable in U-Boot.
3495
3496SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
3497
c609719b
WD
3498Building the Software:
3499======================
3500
218ca724
WD
3501Building U-Boot has been tested in several native build environments
3502and in many different cross environments. Of course we cannot support
3503all possibly existing versions of cross development tools in all
3504(potentially obsolete) versions. In case of tool chain problems we
3505recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3506which is extensively used to build and test U-Boot.
c609719b 3507
218ca724
WD
3508If you are not using a native environment, it is assumed that you
3509have GNU cross compiling tools available in your path. In this case,
3510you must set the environment variable CROSS_COMPILE in your shell.
3511Note that no changes to the Makefile or any other source files are
3512necessary. For example using the ELDK on a 4xx CPU, please enter:
c609719b 3513
218ca724
WD
3514 $ CROSS_COMPILE=ppc_4xx-
3515 $ export CROSS_COMPILE
c609719b 3516
2f8d396b
PT
3517Note: If you wish to generate Windows versions of the utilities in
3518 the tools directory you can use the MinGW toolchain
3519 (http://www.mingw.org). Set your HOST tools to the MinGW
3520 toolchain and execute 'make tools'. For example:
3521
3522 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3523
3524 Binaries such as tools/mkimage.exe will be created which can
3525 be executed on computers running Windows.
3526
218ca724
WD
3527U-Boot is intended to be simple to build. After installing the
3528sources you must configure U-Boot for one specific board type. This
c609719b
WD
3529is done by typing:
3530
ab584d67 3531 make NAME_defconfig
c609719b 3532
ab584d67 3533where "NAME_defconfig" is the name of one of the existing configu-
4d675ae6 3534rations; see boards.cfg for supported names.
db01a2ea 3535
2729af9d
WD
3536Note: for some board special configuration names may exist; check if
3537 additional information is available from the board vendor; for
3538 instance, the TQM823L systems are available without (standard)
3539 or with LCD support. You can select such additional "features"
11ccc33f 3540 when choosing the configuration, i. e.
2729af9d 3541
ab584d67 3542 make TQM823L_defconfig
2729af9d
WD
3543 - will configure for a plain TQM823L, i. e. no LCD support
3544
ab584d67 3545 make TQM823L_LCD_defconfig
2729af9d
WD
3546 - will configure for a TQM823L with U-Boot console on LCD
3547
3548 etc.
3549
3550
3551Finally, type "make all", and you should get some working U-Boot
3552images ready for download to / installation on your system:
3553
3554- "u-boot.bin" is a raw binary image
3555- "u-boot" is an image in ELF binary format
3556- "u-boot.srec" is in Motorola S-Record format
3557
baf31249
MB
3558By default the build is performed locally and the objects are saved
3559in the source directory. One of the two methods can be used to change
3560this behavior and build U-Boot to some external directory:
3561
35621. Add O= to the make command line invocations:
3563
3564 make O=/tmp/build distclean
ab584d67 3565 make O=/tmp/build NAME_defconfig
baf31249
MB
3566 make O=/tmp/build all
3567
adbba996 35682. Set environment variable KBUILD_OUTPUT to point to the desired location:
baf31249 3569
adbba996 3570 export KBUILD_OUTPUT=/tmp/build
baf31249 3571 make distclean
ab584d67 3572 make NAME_defconfig
baf31249
MB
3573 make all
3574
adbba996 3575Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
baf31249
MB
3576variable.
3577
215bb1c1
DS
3578User specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by
3579setting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS.
3580For example to treat all compiler warnings as errors:
3581
3582 make KCFLAGS=-Werror
2729af9d
WD
3583
3584Please be aware that the Makefiles assume you are using GNU make, so
3585for instance on NetBSD you might need to use "gmake" instead of
3586native "make".
3587
3588
3589If the system board that you have is not listed, then you will need
3590to port U-Boot to your hardware platform. To do this, follow these
3591steps:
3592
3c1496cd 35931. Create a new directory to hold your board specific code. Add any
2729af9d 3594 files you need. In your board directory, you will need at least
3c1496cd
PS
3595 the "Makefile" and a "<board>.c".
35962. Create a new configuration file "include/configs/<board>.h" for
3597 your board.
2729af9d
WD
35983. If you're porting U-Boot to a new CPU, then also create a new
3599 directory to hold your CPU specific code. Add any files you need.
ab584d67 36004. Run "make <board>_defconfig" with your new name.
2729af9d
WD
36015. Type "make", and you should get a working "u-boot.srec" file
3602 to be installed on your target system.
36036. Debug and solve any problems that might arise.
3604 [Of course, this last step is much harder than it sounds.]
3605
3606
3607Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3608==============================================================
3609
218ca724
WD
3610If you have modified U-Boot sources (for instance added a new board
3611or support for new devices, a new CPU, etc.) you are expected to
2729af9d
WD
3612provide feedback to the other developers. The feedback normally takes
3613the form of a "patch", i. e. a context diff against a certain (latest
218ca724 3614official or latest in the git repository) version of U-Boot sources.
2729af9d 3615
218ca724
WD
3616But before you submit such a patch, please verify that your modifi-
3617cation did not break existing code. At least make sure that *ALL* of
2729af9d 3618the supported boards compile WITHOUT ANY compiler warnings. To do so,
6de80f21
SG
3619just run the buildman script (tools/buildman/buildman), which will
3620configure and build U-Boot for ALL supported system. Be warned, this
3621will take a while. Please see the buildman README, or run 'buildman -H'
3622for documentation.
baf31249
MB
3623
3624
2729af9d
WD
3625See also "U-Boot Porting Guide" below.
3626
3627
3628Monitor Commands - Overview:
3629============================
3630
3631go - start application at address 'addr'
3632run - run commands in an environment variable
3633bootm - boot application image from memory
3634bootp - boot image via network using BootP/TFTP protocol
44f074c7 3635bootz - boot zImage from memory
2729af9d
WD
3636tftpboot- boot image via network using TFTP protocol
3637 and env variables "ipaddr" and "serverip"
3638 (and eventually "gatewayip")
1fb7cd49 3639tftpput - upload a file via network using TFTP protocol
2729af9d
WD
3640rarpboot- boot image via network using RARP/TFTP protocol
3641diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3642loads - load S-Record file over serial line
3643loadb - load binary file over serial line (kermit mode)
3644md - memory display
3645mm - memory modify (auto-incrementing)
3646nm - memory modify (constant address)
3647mw - memory write (fill)
3648cp - memory copy
3649cmp - memory compare
3650crc32 - checksum calculation
0f89c54b 3651i2c - I2C sub-system
2729af9d
WD
3652sspi - SPI utility commands
3653base - print or set address offset
3654printenv- print environment variables
3655setenv - set environment variables
3656saveenv - save environment variables to persistent storage
3657protect - enable or disable FLASH write protection
3658erase - erase FLASH memory
3659flinfo - print FLASH memory information
10635afa 3660nand - NAND memory operations (see doc/README.nand)
2729af9d
WD
3661bdinfo - print Board Info structure
3662iminfo - print header information for application image
3663coninfo - print console devices and informations
3664ide - IDE sub-system
3665loop - infinite loop on address range
56523f12 3666loopw - infinite write loop on address range
2729af9d
WD
3667mtest - simple RAM test
3668icache - enable or disable instruction cache
3669dcache - enable or disable data cache
3670reset - Perform RESET of the CPU
3671echo - echo args to console
3672version - print monitor version
3673help - print online help
3674? - alias for 'help'
3675
3676
3677Monitor Commands - Detailed Description:
3678========================================
3679
3680TODO.
3681
3682For now: just type "help <command>".
3683
3684
3685Environment Variables:
3686======================
3687
3688U-Boot supports user configuration using Environment Variables which
3689can be made persistent by saving to Flash memory.
c609719b 3690
2729af9d
WD
3691Environment Variables are set using "setenv", printed using
3692"printenv", and saved to Flash using "saveenv". Using "setenv"
3693without a value can be used to delete a variable from the
3694environment. As long as you don't save the environment you are
3695working with an in-memory copy. In case the Flash area containing the
3696environment is erased by accident, a default environment is provided.
c609719b 3697
c96f86ee
WD
3698Some configuration options can be set using Environment Variables.
3699
3700List of environment variables (most likely not complete):
c609719b 3701
2729af9d 3702 baudrate - see CONFIG_BAUDRATE
c609719b 3703
2729af9d 3704 bootdelay - see CONFIG_BOOTDELAY
c609719b 3705
2729af9d 3706 bootcmd - see CONFIG_BOOTCOMMAND
4a6fd34b 3707
2729af9d 3708 bootargs - Boot arguments when booting an RTOS image
c609719b 3709
2729af9d 3710 bootfile - Name of the image to load with TFTP
c609719b 3711
7d721e34
BS
3712 bootm_low - Memory range available for image processing in the bootm
3713 command can be restricted. This variable is given as
3714 a hexadecimal number and defines lowest address allowed
3715 for use by the bootm command. See also "bootm_size"
3716 environment variable. Address defined by "bootm_low" is
3717 also the base of the initial memory mapping for the Linux
c3624e6e
GL
3718 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
3719 bootm_mapsize.
3720
c0f40859 3721 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
c3624e6e
GL
3722 This variable is given as a hexadecimal number and it
3723 defines the size of the memory region starting at base
3724 address bootm_low that is accessible by the Linux kernel
3725 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
3726 as the default value if it is defined, and bootm_size is
3727 used otherwise.
7d721e34
BS
3728
3729 bootm_size - Memory range available for image processing in the bootm
3730 command can be restricted. This variable is given as
3731 a hexadecimal number and defines the size of the region
3732 allowed for use by the bootm command. See also "bootm_low"
3733 environment variable.
3734
4bae9090
BS
3735 updatefile - Location of the software update file on a TFTP server, used
3736 by the automatic software update feature. Please refer to
3737 documentation in doc/README.update for more details.
3738
2729af9d
WD
3739 autoload - if set to "no" (any string beginning with 'n'),
3740 "bootp" will just load perform a lookup of the
3741 configuration from the BOOTP server, but not try to
3742 load any image using TFTP
c609719b 3743
2729af9d
WD
3744 autostart - if set to "yes", an image loaded using the "bootp",
3745 "rarpboot", "tftpboot" or "diskboot" commands will
3746 be automatically started (by internally calling
3747 "bootm")
38b99261 3748
2729af9d
WD
3749 If set to "no", a standalone image passed to the
3750 "bootm" command will be copied to the load address
3751 (and eventually uncompressed), but NOT be started.
3752 This can be used to load and uncompress arbitrary
3753 data.
c609719b 3754
a28afca5
DL
3755 fdt_high - if set this restricts the maximum address that the
3756 flattened device tree will be copied into upon boot.
fa34f6b2
SG
3757 For example, if you have a system with 1 GB memory
3758 at physical address 0x10000000, while Linux kernel
3759 only recognizes the first 704 MB as low memory, you
3760 may need to set fdt_high as 0x3C000000 to have the
3761 device tree blob be copied to the maximum address
3762 of the 704 MB low memory, so that Linux kernel can
3763 access it during the boot procedure.
3764
a28afca5
DL
3765 If this is set to the special value 0xFFFFFFFF then
3766 the fdt will not be copied at all on boot. For this
3767 to work it must reside in writable memory, have
3768 sufficient padding on the end of it for u-boot to
3769 add the information it needs into it, and the memory
3770 must be accessible by the kernel.
3771
eea63e05
SG
3772 fdtcontroladdr- if set this is the address of the control flattened
3773 device tree used by U-Boot when CONFIG_OF_CONTROL is
3774 defined.
3775
17ea1177
WD
3776 i2cfast - (PPC405GP|PPC405EP only)
3777 if set to 'y' configures Linux I2C driver for fast
3778 mode (400kHZ). This environment variable is used in
3779 initialization code. So, for changes to be effective
3780 it must be saved and board must be reset.
3781
2729af9d
WD
3782 initrd_high - restrict positioning of initrd images:
3783 If this variable is not set, initrd images will be
3784 copied to the highest possible address in RAM; this
3785 is usually what you want since it allows for
3786 maximum initrd size. If for some reason you want to
3787 make sure that the initrd image is loaded below the
6d0f6bcf 3788 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
2729af9d
WD
3789 variable to a value of "no" or "off" or "0".
3790 Alternatively, you can set it to a maximum upper
3791 address to use (U-Boot will still check that it
3792 does not overwrite the U-Boot stack and data).
c609719b 3793
2729af9d
WD
3794 For instance, when you have a system with 16 MB
3795 RAM, and want to reserve 4 MB from use by Linux,
3796 you can do this by adding "mem=12M" to the value of
3797 the "bootargs" variable. However, now you must make
3798 sure that the initrd image is placed in the first
3799 12 MB as well - this can be done with
c609719b 3800
2729af9d 3801 setenv initrd_high 00c00000
c609719b 3802
2729af9d
WD
3803 If you set initrd_high to 0xFFFFFFFF, this is an
3804 indication to U-Boot that all addresses are legal
3805 for the Linux kernel, including addresses in flash
3806 memory. In this case U-Boot will NOT COPY the
3807 ramdisk at all. This may be useful to reduce the
3808 boot time on your system, but requires that this
3809 feature is supported by your Linux kernel.
c609719b 3810
2729af9d 3811 ipaddr - IP address; needed for tftpboot command
c609719b 3812
2729af9d
WD
3813 loadaddr - Default load address for commands like "bootp",
3814 "rarpboot", "tftpboot", "loadb" or "diskboot"
c609719b 3815
2729af9d 3816 loads_echo - see CONFIG_LOADS_ECHO
a3d991bd 3817
2729af9d 3818 serverip - TFTP server IP address; needed for tftpboot command
a3d991bd 3819
2729af9d 3820 bootretry - see CONFIG_BOOT_RETRY_TIME
a3d991bd 3821
2729af9d 3822 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
a3d991bd 3823
2729af9d 3824 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
c609719b 3825
e2a53458 3826 ethprime - controls which interface is used first.
c609719b 3827
e2a53458
MF
3828 ethact - controls which interface is currently active.
3829 For example you can do the following
c609719b 3830
48690d80
HS
3831 => setenv ethact FEC
3832 => ping 192.168.0.1 # traffic sent on FEC
3833 => setenv ethact SCC
3834 => ping 10.0.0.1 # traffic sent on SCC
c609719b 3835
e1692577
MF
3836 ethrotate - When set to "no" U-Boot does not go through all
3837 available network interfaces.
3838 It just stays at the currently selected interface.
3839
c96f86ee 3840 netretry - When set to "no" each network operation will
2729af9d
WD
3841 either succeed or fail without retrying.
3842 When set to "once" the network operation will
3843 fail when all the available network interfaces
3844 are tried once without success.
3845 Useful on scripts which control the retry operation
3846 themselves.
c609719b 3847
b4e2f89d 3848 npe_ucode - set load address for the NPE microcode
a1cf027a 3849
b445bbb4 3850 silent_linux - If set then Linux will be told to boot silently, by
8d51aacd
SG
3851 changing the console to be empty. If "yes" it will be
3852 made silent. If "no" it will not be made silent. If
3853 unset, then it will be made silent if the U-Boot console
3854 is silent.
3855
f5fb7346 3856 tftpsrcp - If this is set, the value is used for TFTP's
ecb0ccd9
WD
3857 UDP source port.
3858
f5fb7346 3859 tftpdstp - If this is set, the value is used for TFTP's UDP
28cb9375
WD
3860 destination port instead of the Well Know Port 69.
3861
c96f86ee
WD
3862 tftpblocksize - Block size to use for TFTP transfers; if not set,
3863 we use the TFTP server's default block size
3864
3865 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3866 seconds, minimum value is 1000 = 1 second). Defines
3867 when a packet is considered to be lost so it has to
3868 be retransmitted. The default is 5000 = 5 seconds.
3869 Lowering this value may make downloads succeed
3870 faster in networks with high packet loss rates or
3871 with unreliable TFTP servers.
3872
f5fb7346
AA
3873 tftptimeoutcountmax - maximum count of TFTP timeouts (no
3874 unit, minimum value = 0). Defines how many timeouts
3875 can happen during a single file transfer before that
3876 transfer is aborted. The default is 10, and 0 means
3877 'no timeouts allowed'. Increasing this value may help
3878 downloads succeed with high packet loss rates, or with
3879 unreliable TFTP servers or client hardware.
3880
c96f86ee 3881 vlan - When set to a value < 4095 the traffic over
11ccc33f 3882 Ethernet is encapsulated/received over 802.1q
2729af9d 3883 VLAN tagged frames.
c609719b 3884
50768f5b
AM
3885 bootpretryperiod - Period during which BOOTP/DHCP sends retries.
3886 Unsigned value, in milliseconds. If not set, the period will
3887 be either the default (28000), or a value based on
3888 CONFIG_NET_RETRY_COUNT, if defined. This value has
3889 precedence over the valu based on CONFIG_NET_RETRY_COUNT.
3890
dc0b7b0e
JH
3891The following image location variables contain the location of images
3892used in booting. The "Image" column gives the role of the image and is
3893not an environment variable name. The other columns are environment
3894variable names. "File Name" gives the name of the file on a TFTP
3895server, "RAM Address" gives the location in RAM the image will be
3896loaded to, and "Flash Location" gives the image's address in NOR
3897flash or offset in NAND flash.
3898
3899*Note* - these variables don't have to be defined for all boards, some
aed9fed9 3900boards currently use other variables for these purposes, and some
dc0b7b0e
JH
3901boards use these variables for other purposes.
3902
c0f40859
WD
3903Image File Name RAM Address Flash Location
3904----- --------- ----------- --------------
3905u-boot u-boot u-boot_addr_r u-boot_addr
3906Linux kernel bootfile kernel_addr_r kernel_addr
3907device tree blob fdtfile fdt_addr_r fdt_addr
3908ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
dc0b7b0e 3909
2729af9d
WD
3910The following environment variables may be used and automatically
3911updated by the network boot commands ("bootp" and "rarpboot"),
3912depending the information provided by your boot server:
c609719b 3913
2729af9d
WD
3914 bootfile - see above
3915 dnsip - IP address of your Domain Name Server
3916 dnsip2 - IP address of your secondary Domain Name Server
3917 gatewayip - IP address of the Gateway (Router) to use
3918 hostname - Target hostname
3919 ipaddr - see above
3920 netmask - Subnet Mask
3921 rootpath - Pathname of the root filesystem on the NFS server
3922 serverip - see above
c1551ea8 3923
c1551ea8 3924
2729af9d 3925There are two special Environment Variables:
c1551ea8 3926
2729af9d
WD
3927 serial# - contains hardware identification information such
3928 as type string and/or serial number
3929 ethaddr - Ethernet address
c609719b 3930
2729af9d
WD
3931These variables can be set only once (usually during manufacturing of
3932the board). U-Boot refuses to delete or overwrite these variables
3933once they have been set once.
c609719b 3934
f07771cc 3935
2729af9d 3936Further special Environment Variables:
f07771cc 3937
2729af9d
WD
3938 ver - Contains the U-Boot version string as printed
3939 with the "version" command. This variable is
3940 readonly (see CONFIG_VERSION_VARIABLE).
f07771cc 3941
f07771cc 3942
2729af9d
WD
3943Please note that changes to some configuration parameters may take
3944only effect after the next boot (yes, that's just like Windoze :-).
f07771cc 3945
f07771cc 3946
170ab110
JH
3947Callback functions for environment variables:
3948---------------------------------------------
3949
3950For some environment variables, the behavior of u-boot needs to change
b445bbb4 3951when their values are changed. This functionality allows functions to
170ab110
JH
3952be associated with arbitrary variables. On creation, overwrite, or
3953deletion, the callback will provide the opportunity for some side
3954effect to happen or for the change to be rejected.
3955
3956The callbacks are named and associated with a function using the
3957U_BOOT_ENV_CALLBACK macro in your board or driver code.
3958
3959These callbacks are associated with variables in one of two ways. The
3960static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
3961in the board configuration to a string that defines a list of
3962associations. The list must be in the following format:
3963
3964 entry = variable_name[:callback_name]
3965 list = entry[,list]
3966
3967If the callback name is not specified, then the callback is deleted.
3968Spaces are also allowed anywhere in the list.
3969
3970Callbacks can also be associated by defining the ".callbacks" variable
3971with the same list format above. Any association in ".callbacks" will
3972override any association in the static list. You can define
3973CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
b445bbb4 3974".callbacks" environment variable in the default or embedded environment.
170ab110 3975
bdf1fe4e
JH
3976If CONFIG_REGEX is defined, the variable_name above is evaluated as a
3977regular expression. This allows multiple variables to be connected to
3978the same callback without explicitly listing them all out.
3979
170ab110 3980
2729af9d
WD
3981Command Line Parsing:
3982=====================
f07771cc 3983
2729af9d
WD
3984There are two different command line parsers available with U-Boot:
3985the old "simple" one, and the much more powerful "hush" shell:
c609719b 3986
2729af9d
WD
3987Old, simple command line parser:
3988--------------------------------
c609719b 3989
2729af9d
WD
3990- supports environment variables (through setenv / saveenv commands)
3991- several commands on one line, separated by ';'
fe126d8b 3992- variable substitution using "... ${name} ..." syntax
2729af9d
WD
3993- special characters ('$', ';') can be escaped by prefixing with '\',
3994 for example:
fe126d8b 3995 setenv bootcmd bootm \${address}
2729af9d
WD
3996- You can also escape text by enclosing in single apostrophes, for example:
3997 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
c609719b 3998
2729af9d
WD
3999Hush shell:
4000-----------
c609719b 4001
2729af9d
WD
4002- similar to Bourne shell, with control structures like
4003 if...then...else...fi, for...do...done; while...do...done,
4004 until...do...done, ...
4005- supports environment ("global") variables (through setenv / saveenv
4006 commands) and local shell variables (through standard shell syntax
4007 "name=value"); only environment variables can be used with "run"
4008 command
4009
4010General rules:
4011--------------
c609719b 4012
2729af9d
WD
4013(1) If a command line (or an environment variable executed by a "run"
4014 command) contains several commands separated by semicolon, and
4015 one of these commands fails, then the remaining commands will be
4016 executed anyway.
c609719b 4017
2729af9d 4018(2) If you execute several variables with one call to run (i. e.
11ccc33f 4019 calling run with a list of variables as arguments), any failing
2729af9d
WD
4020 command will cause "run" to terminate, i. e. the remaining
4021 variables are not executed.
c609719b 4022
2729af9d
WD
4023Note for Redundant Ethernet Interfaces:
4024=======================================
c609719b 4025
11ccc33f 4026Some boards come with redundant Ethernet interfaces; U-Boot supports
2729af9d
WD
4027such configurations and is capable of automatic selection of a
4028"working" interface when needed. MAC assignment works as follows:
c609719b 4029
2729af9d
WD
4030Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4031MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4032"eth1addr" (=>eth1), "eth2addr", ...
c609719b 4033
2729af9d
WD
4034If the network interface stores some valid MAC address (for instance
4035in SROM), this is used as default address if there is NO correspon-
4036ding setting in the environment; if the corresponding environment
4037variable is set, this overrides the settings in the card; that means:
c609719b 4038
2729af9d
WD
4039o If the SROM has a valid MAC address, and there is no address in the
4040 environment, the SROM's address is used.
c609719b 4041
2729af9d
WD
4042o If there is no valid address in the SROM, and a definition in the
4043 environment exists, then the value from the environment variable is
4044 used.
c609719b 4045
2729af9d
WD
4046o If both the SROM and the environment contain a MAC address, and
4047 both addresses are the same, this MAC address is used.
c609719b 4048
2729af9d
WD
4049o If both the SROM and the environment contain a MAC address, and the
4050 addresses differ, the value from the environment is used and a
4051 warning is printed.
c609719b 4052
2729af9d 4053o If neither SROM nor the environment contain a MAC address, an error
bef1014b
JH
4054 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
4055 a random, locally-assigned MAC is used.
c609719b 4056
ecee9324 4057If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
c0f40859 4058will be programmed into hardware as part of the initialization process. This
ecee9324
BW
4059may be skipped by setting the appropriate 'ethmacskip' environment variable.
4060The naming convention is as follows:
4061"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
c609719b 4062
2729af9d
WD
4063Image Formats:
4064==============
c609719b 4065
3310c549
MB
4066U-Boot is capable of booting (and performing other auxiliary operations on)
4067images in two formats:
4068
4069New uImage format (FIT)
4070-----------------------
4071
4072Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4073to Flattened Device Tree). It allows the use of images with multiple
4074components (several kernels, ramdisks, etc.), with contents protected by
4075SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4076
4077
4078Old uImage format
4079-----------------
4080
4081Old image format is based on binary files which can be basically anything,
4082preceded by a special header; see the definitions in include/image.h for
4083details; basically, the header defines the following image properties:
c609719b 4084
2729af9d
WD
4085* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4086 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
f5ed9e39
PT
4087 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4088 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4089 INTEGRITY).
daab59ac 4090* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
afc1ce82 4091 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
daab59ac 4092 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC).
2729af9d
WD
4093* Compression Type (uncompressed, gzip, bzip2)
4094* Load Address
4095* Entry Point
4096* Image Name
4097* Image Timestamp
c609719b 4098
2729af9d
WD
4099The header is marked by a special Magic Number, and both the header
4100and the data portions of the image are secured against corruption by
4101CRC32 checksums.
c609719b
WD
4102
4103
2729af9d
WD
4104Linux Support:
4105==============
c609719b 4106
2729af9d
WD
4107Although U-Boot should support any OS or standalone application
4108easily, the main focus has always been on Linux during the design of
4109U-Boot.
c609719b 4110
2729af9d
WD
4111U-Boot includes many features that so far have been part of some
4112special "boot loader" code within the Linux kernel. Also, any
4113"initrd" images to be used are no longer part of one big Linux image;
4114instead, kernel and "initrd" are separate images. This implementation
4115serves several purposes:
c609719b 4116
2729af9d
WD
4117- the same features can be used for other OS or standalone
4118 applications (for instance: using compressed images to reduce the
4119 Flash memory footprint)
c609719b 4120
2729af9d
WD
4121- it becomes much easier to port new Linux kernel versions because
4122 lots of low-level, hardware dependent stuff are done by U-Boot
c609719b 4123
2729af9d
WD
4124- the same Linux kernel image can now be used with different "initrd"
4125 images; of course this also means that different kernel images can
4126 be run with the same "initrd". This makes testing easier (you don't
4127 have to build a new "zImage.initrd" Linux image when you just
4128 change a file in your "initrd"). Also, a field-upgrade of the
4129 software is easier now.
c609719b 4130
c609719b 4131
2729af9d
WD
4132Linux HOWTO:
4133============
c609719b 4134
2729af9d
WD
4135Porting Linux to U-Boot based systems:
4136---------------------------------------
c609719b 4137
2729af9d
WD
4138U-Boot cannot save you from doing all the necessary modifications to
4139configure the Linux device drivers for use with your target hardware
4140(no, we don't intend to provide a full virtual machine interface to
4141Linux :-).
c609719b 4142
a47a12be 4143But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
24ee89b9 4144
2729af9d
WD
4145Just make sure your machine specific header file (for instance
4146include/asm-ppc/tqm8xx.h) includes the same definition of the Board
1dc30693
MH
4147Information structure as we define in include/asm-<arch>/u-boot.h,
4148and make sure that your definition of IMAP_ADDR uses the same value
6d0f6bcf 4149as your U-Boot configuration in CONFIG_SYS_IMMR.
24ee89b9 4150
2eb31b13
SG
4151Note that U-Boot now has a driver model, a unified model for drivers.
4152If you are adding a new driver, plumb it into driver model. If there
4153is no uclass available, you are encouraged to create one. See
4154doc/driver-model.
4155
c609719b 4156
2729af9d
WD
4157Configuring the Linux kernel:
4158-----------------------------
c609719b 4159
2729af9d
WD
4160No specific requirements for U-Boot. Make sure you have some root
4161device (initial ramdisk, NFS) for your target system.
4162
4163
4164Building a Linux Image:
4165-----------------------
c609719b 4166
2729af9d
WD
4167With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4168not used. If you use recent kernel source, a new build target
4169"uImage" will exist which automatically builds an image usable by
4170U-Boot. Most older kernels also have support for a "pImage" target,
4171which was introduced for our predecessor project PPCBoot and uses a
4172100% compatible format.
4173
4174Example:
4175
ab584d67 4176 make TQM850L_defconfig
2729af9d
WD
4177 make oldconfig
4178 make dep
4179 make uImage
4180
4181The "uImage" build target uses a special tool (in 'tools/mkimage') to
4182encapsulate a compressed Linux kernel image with header information,
4183CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4184
4185* build a standard "vmlinux" kernel image (in ELF binary format):
4186
4187* convert the kernel into a raw binary image:
4188
4189 ${CROSS_COMPILE}-objcopy -O binary \
4190 -R .note -R .comment \
4191 -S vmlinux linux.bin
4192
4193* compress the binary image:
4194
4195 gzip -9 linux.bin
4196
4197* package compressed binary image for U-Boot:
4198
4199 mkimage -A ppc -O linux -T kernel -C gzip \
4200 -a 0 -e 0 -n "Linux Kernel Image" \
4201 -d linux.bin.gz uImage
c609719b 4202
c609719b 4203
2729af9d
WD
4204The "mkimage" tool can also be used to create ramdisk images for use
4205with U-Boot, either separated from the Linux kernel image, or
4206combined into one file. "mkimage" encapsulates the images with a 64
4207byte header containing information about target architecture,
4208operating system, image type, compression method, entry points, time
4209stamp, CRC32 checksums, etc.
4210
4211"mkimage" can be called in two ways: to verify existing images and
4212print the header information, or to build new images.
4213
4214In the first form (with "-l" option) mkimage lists the information
4215contained in the header of an existing U-Boot image; this includes
4216checksum verification:
c609719b 4217
2729af9d
WD
4218 tools/mkimage -l image
4219 -l ==> list image header information
4220
4221The second form (with "-d" option) is used to build a U-Boot image
4222from a "data file" which is used as image payload:
4223
4224 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4225 -n name -d data_file image
4226 -A ==> set architecture to 'arch'
4227 -O ==> set operating system to 'os'
4228 -T ==> set image type to 'type'
4229 -C ==> set compression type 'comp'
4230 -a ==> set load address to 'addr' (hex)
4231 -e ==> set entry point to 'ep' (hex)
4232 -n ==> set image name to 'name'
4233 -d ==> use image data from 'datafile'
4234
69459791
WD
4235Right now, all Linux kernels for PowerPC systems use the same load
4236address (0x00000000), but the entry point address depends on the
4237kernel version:
2729af9d
WD
4238
4239- 2.2.x kernels have the entry point at 0x0000000C,
4240- 2.3.x and later kernels have the entry point at 0x00000000.
4241
4242So a typical call to build a U-Boot image would read:
4243
4244 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4245 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
a47a12be 4246 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
2729af9d
WD
4247 > examples/uImage.TQM850L
4248 Image Name: 2.4.4 kernel for TQM850L
4249 Created: Wed Jul 19 02:34:59 2000
4250 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4251 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4252 Load Address: 0x00000000
4253 Entry Point: 0x00000000
4254
4255To verify the contents of the image (or check for corruption):
4256
4257 -> tools/mkimage -l examples/uImage.TQM850L
4258 Image Name: 2.4.4 kernel for TQM850L
4259 Created: Wed Jul 19 02:34:59 2000
4260 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4261 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4262 Load Address: 0x00000000
4263 Entry Point: 0x00000000
4264
4265NOTE: for embedded systems where boot time is critical you can trade
4266speed for memory and install an UNCOMPRESSED image instead: this
4267needs more space in Flash, but boots much faster since it does not
4268need to be uncompressed:
4269
a47a12be 4270 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
2729af9d
WD
4271 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4272 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
a47a12be 4273 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
2729af9d
WD
4274 > examples/uImage.TQM850L-uncompressed
4275 Image Name: 2.4.4 kernel for TQM850L
4276 Created: Wed Jul 19 02:34:59 2000
4277 Image Type: PowerPC Linux Kernel Image (uncompressed)
4278 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4279 Load Address: 0x00000000
4280 Entry Point: 0x00000000
4281
4282
4283Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4284when your kernel is intended to use an initial ramdisk:
4285
4286 -> tools/mkimage -n 'Simple Ramdisk Image' \
4287 > -A ppc -O linux -T ramdisk -C gzip \
4288 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4289 Image Name: Simple Ramdisk Image
4290 Created: Wed Jan 12 14:01:50 2000
4291 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4292 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4293 Load Address: 0x00000000
4294 Entry Point: 0x00000000
4295
a804b5ce
GMF
4296The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
4297option performs the converse operation of the mkimage's second form (the "-d"
4298option). Given an image built by mkimage, the dumpimage extracts a "data file"
4299from the image:
4300
f41f5b7c
GMF
4301 tools/dumpimage -i image -T type -p position data_file
4302 -i ==> extract from the 'image' a specific 'data_file'
4303 -T ==> set image type to 'type'
4304 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
a804b5ce 4305
2729af9d
WD
4306
4307Installing a Linux Image:
4308-------------------------
4309
4310To downloading a U-Boot image over the serial (console) interface,
4311you must convert the image to S-Record format:
4312
4313 objcopy -I binary -O srec examples/image examples/image.srec
4314
4315The 'objcopy' does not understand the information in the U-Boot
4316image header, so the resulting S-Record file will be relative to
4317address 0x00000000. To load it to a given address, you need to
4318specify the target address as 'offset' parameter with the 'loads'
4319command.
4320
4321Example: install the image to address 0x40100000 (which on the
4322TQM8xxL is in the first Flash bank):
4323
4324 => erase 40100000 401FFFFF
4325
4326 .......... done
4327 Erased 8 sectors
4328
4329 => loads 40100000
4330 ## Ready for S-Record download ...
4331 ~>examples/image.srec
4332 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4333 ...
4334 15989 15990 15991 15992
4335 [file transfer complete]
4336 [connected]
4337 ## Start Addr = 0x00000000
4338
4339
4340You can check the success of the download using the 'iminfo' command;
218ca724 4341this includes a checksum verification so you can be sure no data
2729af9d
WD
4342corruption happened:
4343
4344 => imi 40100000
4345
4346 ## Checking Image at 40100000 ...
4347 Image Name: 2.2.13 for initrd on TQM850L
4348 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4349 Data Size: 335725 Bytes = 327 kB = 0 MB
4350 Load Address: 00000000
4351 Entry Point: 0000000c
4352 Verifying Checksum ... OK
4353
4354
4355Boot Linux:
4356-----------
4357
4358The "bootm" command is used to boot an application that is stored in
4359memory (RAM or Flash). In case of a Linux kernel image, the contents
4360of the "bootargs" environment variable is passed to the kernel as
4361parameters. You can check and modify this variable using the
4362"printenv" and "setenv" commands:
4363
4364
4365 => printenv bootargs
4366 bootargs=root=/dev/ram
4367
4368 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4369
4370 => printenv bootargs
4371 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4372
4373 => bootm 40020000
4374 ## Booting Linux kernel at 40020000 ...
4375 Image Name: 2.2.13 for NFS on TQM850L
4376 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4377 Data Size: 381681 Bytes = 372 kB = 0 MB
4378 Load Address: 00000000
4379 Entry Point: 0000000c
4380 Verifying Checksum ... OK
4381 Uncompressing Kernel Image ... OK
4382 Linux version 2.2.13 ([email protected]) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
4383 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4384 time_init: decrementer frequency = 187500000/60
4385 Calibrating delay loop... 49.77 BogoMIPS
4386 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
4387 ...
4388
11ccc33f 4389If you want to boot a Linux kernel with initial RAM disk, you pass
2729af9d
WD
4390the memory addresses of both the kernel and the initrd image (PPBCOOT
4391format!) to the "bootm" command:
4392
4393 => imi 40100000 40200000
4394
4395 ## Checking Image at 40100000 ...
4396 Image Name: 2.2.13 for initrd on TQM850L
4397 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4398 Data Size: 335725 Bytes = 327 kB = 0 MB
4399 Load Address: 00000000
4400 Entry Point: 0000000c
4401 Verifying Checksum ... OK
4402
4403 ## Checking Image at 40200000 ...
4404 Image Name: Simple Ramdisk Image
4405 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4406 Data Size: 566530 Bytes = 553 kB = 0 MB
4407 Load Address: 00000000
4408 Entry Point: 00000000
4409 Verifying Checksum ... OK
4410
4411 => bootm 40100000 40200000
4412 ## Booting Linux kernel at 40100000 ...
4413 Image Name: 2.2.13 for initrd on TQM850L
4414 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4415 Data Size: 335725 Bytes = 327 kB = 0 MB
4416 Load Address: 00000000
4417 Entry Point: 0000000c
4418 Verifying Checksum ... OK
4419 Uncompressing Kernel Image ... OK
4420 ## Loading RAMDisk Image at 40200000 ...
4421 Image Name: Simple Ramdisk Image
4422 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4423 Data Size: 566530 Bytes = 553 kB = 0 MB
4424 Load Address: 00000000
4425 Entry Point: 00000000
4426 Verifying Checksum ... OK
4427 Loading Ramdisk ... OK
4428 Linux version 2.2.13 ([email protected]) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
4429 Boot arguments: root=/dev/ram
4430 time_init: decrementer frequency = 187500000/60
4431 Calibrating delay loop... 49.77 BogoMIPS
4432 ...
4433 RAMDISK: Compressed image found at block 0
4434 VFS: Mounted root (ext2 filesystem).
4435
4436 bash#
4437
0267768e
MM
4438Boot Linux and pass a flat device tree:
4439-----------
4440
4441First, U-Boot must be compiled with the appropriate defines. See the section
4442titled "Linux Kernel Interface" above for a more in depth explanation. The
4443following is an example of how to start a kernel and pass an updated
4444flat device tree:
4445
4446=> print oftaddr
4447oftaddr=0x300000
4448=> print oft
4449oft=oftrees/mpc8540ads.dtb
4450=> tftp $oftaddr $oft
4451Speed: 1000, full duplex
4452Using TSEC0 device
4453TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4454Filename 'oftrees/mpc8540ads.dtb'.
4455Load address: 0x300000
4456Loading: #
4457done
4458Bytes transferred = 4106 (100a hex)
4459=> tftp $loadaddr $bootfile
4460Speed: 1000, full duplex
4461Using TSEC0 device
4462TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4463Filename 'uImage'.
4464Load address: 0x200000
4465Loading:############
4466done
4467Bytes transferred = 1029407 (fb51f hex)
4468=> print loadaddr
4469loadaddr=200000
4470=> print oftaddr
4471oftaddr=0x300000
4472=> bootm $loadaddr - $oftaddr
4473## Booting image at 00200000 ...
a9398e01
WD
4474 Image Name: Linux-2.6.17-dirty
4475 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4476 Data Size: 1029343 Bytes = 1005.2 kB
0267768e 4477 Load Address: 00000000
a9398e01 4478 Entry Point: 00000000
0267768e
MM
4479 Verifying Checksum ... OK
4480 Uncompressing Kernel Image ... OK
4481Booting using flat device tree at 0x300000
4482Using MPC85xx ADS machine description
4483Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4484[snip]
4485
4486
2729af9d
WD
4487More About U-Boot Image Types:
4488------------------------------
4489
4490U-Boot supports the following image types:
4491
4492 "Standalone Programs" are directly runnable in the environment
4493 provided by U-Boot; it is expected that (if they behave
4494 well) you can continue to work in U-Boot after return from
4495 the Standalone Program.
4496 "OS Kernel Images" are usually images of some Embedded OS which
4497 will take over control completely. Usually these programs
4498 will install their own set of exception handlers, device
4499 drivers, set up the MMU, etc. - this means, that you cannot
4500 expect to re-enter U-Boot except by resetting the CPU.
4501 "RAMDisk Images" are more or less just data blocks, and their
4502 parameters (address, size) are passed to an OS kernel that is
4503 being started.
4504 "Multi-File Images" contain several images, typically an OS
4505 (Linux) kernel image and one or more data images like
4506 RAMDisks. This construct is useful for instance when you want
4507 to boot over the network using BOOTP etc., where the boot
4508 server provides just a single image file, but you want to get
4509 for instance an OS kernel and a RAMDisk image.
4510
4511 "Multi-File Images" start with a list of image sizes, each
4512 image size (in bytes) specified by an "uint32_t" in network
4513 byte order. This list is terminated by an "(uint32_t)0".
4514 Immediately after the terminating 0 follow the images, one by
4515 one, all aligned on "uint32_t" boundaries (size rounded up to
4516 a multiple of 4 bytes).
4517
4518 "Firmware Images" are binary images containing firmware (like
4519 U-Boot or FPGA images) which usually will be programmed to
4520 flash memory.
4521
4522 "Script files" are command sequences that will be executed by
4523 U-Boot's command interpreter; this feature is especially
4524 useful when you configure U-Boot to use a real shell (hush)
4525 as command interpreter.
4526
44f074c7
MV
4527Booting the Linux zImage:
4528-------------------------
4529
4530On some platforms, it's possible to boot Linux zImage. This is done
4531using the "bootz" command. The syntax of "bootz" command is the same
4532as the syntax of "bootm" command.
4533
8ac28563 4534Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
017e1f3f
MV
4535kernel with raw initrd images. The syntax is slightly different, the
4536address of the initrd must be augmented by it's size, in the following
4537format: "<initrd addres>:<initrd size>".
4538
2729af9d
WD
4539
4540Standalone HOWTO:
4541=================
4542
4543One of the features of U-Boot is that you can dynamically load and
4544run "standalone" applications, which can use some resources of
4545U-Boot like console I/O functions or interrupt services.
4546
4547Two simple examples are included with the sources:
4548
4549"Hello World" Demo:
4550-------------------
4551
4552'examples/hello_world.c' contains a small "Hello World" Demo
4553application; it is automatically compiled when you build U-Boot.
4554It's configured to run at address 0x00040004, so you can play with it
4555like that:
4556
4557 => loads
4558 ## Ready for S-Record download ...
4559 ~>examples/hello_world.srec
4560 1 2 3 4 5 6 7 8 9 10 11 ...
4561 [file transfer complete]
4562 [connected]
4563 ## Start Addr = 0x00040004
4564
4565 => go 40004 Hello World! This is a test.
4566 ## Starting application at 0x00040004 ...
4567 Hello World
4568 argc = 7
4569 argv[0] = "40004"
4570 argv[1] = "Hello"
4571 argv[2] = "World!"
4572 argv[3] = "This"
4573 argv[4] = "is"
4574 argv[5] = "a"
4575 argv[6] = "test."
4576 argv[7] = "<NULL>"
4577 Hit any key to exit ...
4578
4579 ## Application terminated, rc = 0x0
4580
4581Another example, which demonstrates how to register a CPM interrupt
4582handler with the U-Boot code, can be found in 'examples/timer.c'.
4583Here, a CPM timer is set up to generate an interrupt every second.
4584The interrupt service routine is trivial, just printing a '.'
4585character, but this is just a demo program. The application can be
4586controlled by the following keys:
4587
4588 ? - print current values og the CPM Timer registers
4589 b - enable interrupts and start timer
4590 e - stop timer and disable interrupts
4591 q - quit application
4592
4593 => loads
4594 ## Ready for S-Record download ...
4595 ~>examples/timer.srec
4596 1 2 3 4 5 6 7 8 9 10 11 ...
4597 [file transfer complete]
4598 [connected]
4599 ## Start Addr = 0x00040004
4600
4601 => go 40004
4602 ## Starting application at 0x00040004 ...
4603 TIMERS=0xfff00980
4604 Using timer 1
4605 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
4606
4607Hit 'b':
4608 [q, b, e, ?] Set interval 1000000 us
4609 Enabling timer
4610Hit '?':
4611 [q, b, e, ?] ........
4612 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
4613Hit '?':
4614 [q, b, e, ?] .
4615 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
4616Hit '?':
4617 [q, b, e, ?] .
4618 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
4619Hit '?':
4620 [q, b, e, ?] .
4621 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
4622Hit 'e':
4623 [q, b, e, ?] ...Stopping timer
4624Hit 'q':
4625 [q, b, e, ?] ## Application terminated, rc = 0x0
4626
4627
4628Minicom warning:
4629================
4630
4631Over time, many people have reported problems when trying to use the
4632"minicom" terminal emulation program for serial download. I (wd)
4633consider minicom to be broken, and recommend not to use it. Under
4634Unix, I recommend to use C-Kermit for general purpose use (and
4635especially for kermit binary protocol download ("loadb" command), and
e53515a2
KP
4636use "cu" for S-Record download ("loads" command). See
4637http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
4638for help with kermit.
4639
2729af9d
WD
4640
4641Nevertheless, if you absolutely want to use it try adding this
4642configuration to your "File transfer protocols" section:
4643
4644 Name Program Name U/D FullScr IO-Red. Multi
4645 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
4646 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
4647
4648
4649NetBSD Notes:
4650=============
4651
4652Starting at version 0.9.2, U-Boot supports NetBSD both as host
4653(build U-Boot) and target system (boots NetBSD/mpc8xx).
4654
4655Building requires a cross environment; it is known to work on
4656NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
4657need gmake since the Makefiles are not compatible with BSD make).
4658Note that the cross-powerpc package does not install include files;
4659attempting to build U-Boot will fail because <machine/ansi.h> is
4660missing. This file has to be installed and patched manually:
4661
4662 # cd /usr/pkg/cross/powerpc-netbsd/include
4663 # mkdir powerpc
4664 # ln -s powerpc machine
4665 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
4666 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
4667
4668Native builds *don't* work due to incompatibilities between native
4669and U-Boot include files.
4670
4671Booting assumes that (the first part of) the image booted is a
4672stage-2 loader which in turn loads and then invokes the kernel
4673proper. Loader sources will eventually appear in the NetBSD source
4674tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
2a8af187 4675meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
2729af9d
WD
4676
4677
4678Implementation Internals:
4679=========================
4680
4681The following is not intended to be a complete description of every
4682implementation detail. However, it should help to understand the
4683inner workings of U-Boot and make it easier to port it to custom
4684hardware.
4685
4686
4687Initial Stack, Global Data:
4688---------------------------
4689
4690The implementation of U-Boot is complicated by the fact that U-Boot
4691starts running out of ROM (flash memory), usually without access to
4692system RAM (because the memory controller is not initialized yet).
4693This means that we don't have writable Data or BSS segments, and BSS
4694is not initialized as zero. To be able to get a C environment working
4695at all, we have to allocate at least a minimal stack. Implementation
4696options for this are defined and restricted by the CPU used: Some CPU
4697models provide on-chip memory (like the IMMR area on MPC8xx and
4698MPC826x processors), on others (parts of) the data cache can be
4699locked as (mis-) used as memory, etc.
4700
218ca724 4701 Chris Hallinan posted a good summary of these issues to the
0668236b 4702 U-Boot mailing list:
2729af9d
WD
4703
4704 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
4705 From: "Chris Hallinan" <[email protected]>
4706 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
4707 ...
4708
4709 Correct me if I'm wrong, folks, but the way I understand it
4710 is this: Using DCACHE as initial RAM for Stack, etc, does not
4711 require any physical RAM backing up the cache. The cleverness
4712 is that the cache is being used as a temporary supply of
4713 necessary storage before the SDRAM controller is setup. It's
11ccc33f 4714 beyond the scope of this list to explain the details, but you
2729af9d
WD
4715 can see how this works by studying the cache architecture and
4716 operation in the architecture and processor-specific manuals.
4717
4718 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4719 is another option for the system designer to use as an
11ccc33f 4720 initial stack/RAM area prior to SDRAM being available. Either
2729af9d
WD
4721 option should work for you. Using CS 4 should be fine if your
4722 board designers haven't used it for something that would
4723 cause you grief during the initial boot! It is frequently not
4724 used.
4725
6d0f6bcf 4726 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
2729af9d
WD
4727 with your processor/board/system design. The default value
4728 you will find in any recent u-boot distribution in
8a316c9b 4729 walnut.h should work for you. I'd set it to a value larger
2729af9d
WD
4730 than your SDRAM module. If you have a 64MB SDRAM module, set
4731 it above 400_0000. Just make sure your board has no resources
4732 that are supposed to respond to that address! That code in
4733 start.S has been around a while and should work as is when
4734 you get the config right.
4735
4736 -Chris Hallinan
4737 DS4.COM, Inc.
4738
4739It is essential to remember this, since it has some impact on the C
4740code for the initialization procedures:
4741
4742* Initialized global data (data segment) is read-only. Do not attempt
4743 to write it.
4744
b445bbb4 4745* Do not use any uninitialized global data (or implicitly initialized
2729af9d
WD
4746 as zero data - BSS segment) at all - this is undefined, initiali-
4747 zation is performed later (when relocating to RAM).
4748
4749* Stack space is very limited. Avoid big data buffers or things like
4750 that.
4751
4752Having only the stack as writable memory limits means we cannot use
b445bbb4 4753normal global data to share information between the code. But it
2729af9d
WD
4754turned out that the implementation of U-Boot can be greatly
4755simplified by making a global data structure (gd_t) available to all
4756functions. We could pass a pointer to this data as argument to _all_
4757functions, but this would bloat the code. Instead we use a feature of
4758the GCC compiler (Global Register Variables) to share the data: we
4759place a pointer (gd) to the global data into a register which we
4760reserve for this purpose.
4761
4762When choosing a register for such a purpose we are restricted by the
4763relevant (E)ABI specifications for the current architecture, and by
4764GCC's implementation.
4765
4766For PowerPC, the following registers have specific use:
4767 R1: stack pointer
e7670f6c 4768 R2: reserved for system use
2729af9d
WD
4769 R3-R4: parameter passing and return values
4770 R5-R10: parameter passing
4771 R13: small data area pointer
4772 R30: GOT pointer
4773 R31: frame pointer
4774
e6bee808
JT
4775 (U-Boot also uses R12 as internal GOT pointer. r12
4776 is a volatile register so r12 needs to be reset when
4777 going back and forth between asm and C)
2729af9d 4778
e7670f6c 4779 ==> U-Boot will use R2 to hold a pointer to the global data
2729af9d
WD
4780
4781 Note: on PPC, we could use a static initializer (since the
4782 address of the global data structure is known at compile time),
4783 but it turned out that reserving a register results in somewhat
4784 smaller code - although the code savings are not that big (on
4785 average for all boards 752 bytes for the whole U-Boot image,
4786 624 text + 127 data).
4787
4788On ARM, the following registers are used:
4789
4790 R0: function argument word/integer result
4791 R1-R3: function argument word
12eba1b4
JH
4792 R9: platform specific
4793 R10: stack limit (used only if stack checking is enabled)
2729af9d
WD
4794 R11: argument (frame) pointer
4795 R12: temporary workspace
4796 R13: stack pointer
4797 R14: link register
4798 R15: program counter
4799
12eba1b4
JH
4800 ==> U-Boot will use R9 to hold a pointer to the global data
4801
4802 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
2729af9d 4803
0df01fd3
TC
4804On Nios II, the ABI is documented here:
4805 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4806
4807 ==> U-Boot will use gp to hold a pointer to the global data
4808
4809 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4810 to access small data sections, so gp is free.
4811
afc1ce82
ML
4812On NDS32, the following registers are used:
4813
4814 R0-R1: argument/return
4815 R2-R5: argument
4816 R15: temporary register for assembler
4817 R16: trampoline register
4818 R28: frame pointer (FP)
4819 R29: global pointer (GP)
4820 R30: link register (LP)
4821 R31: stack pointer (SP)
4822 PC: program counter (PC)
4823
4824 ==> U-Boot will use R10 to hold a pointer to the global data
4825
d87080b7
WD
4826NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4827or current versions of GCC may "optimize" the code too much.
2729af9d 4828
3fafced7
RC
4829On RISC-V, the following registers are used:
4830
4831 x0: hard-wired zero (zero)
4832 x1: return address (ra)
4833 x2: stack pointer (sp)
4834 x3: global pointer (gp)
4835 x4: thread pointer (tp)
4836 x5: link register (t0)
4837 x8: frame pointer (fp)
4838 x10-x11: arguments/return values (a0-1)
4839 x12-x17: arguments (a2-7)
4840 x28-31: temporaries (t3-6)
4841 pc: program counter (pc)
4842
4843 ==> U-Boot will use gp to hold a pointer to the global data
4844
2729af9d
WD
4845Memory Management:
4846------------------
4847
4848U-Boot runs in system state and uses physical addresses, i.e. the
4849MMU is not used either for address mapping nor for memory protection.
4850
4851The available memory is mapped to fixed addresses using the memory
4852controller. In this process, a contiguous block is formed for each
4853memory type (Flash, SDRAM, SRAM), even when it consists of several
4854physical memory banks.
4855
4856U-Boot is installed in the first 128 kB of the first Flash bank (on
4857TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4858booting and sizing and initializing DRAM, the code relocates itself
4859to the upper end of DRAM. Immediately below the U-Boot code some
6d0f6bcf 4860memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
2729af9d
WD
4861configuration setting]. Below that, a structure with global Board
4862Info data is placed, followed by the stack (growing downward).
4863
4864Additionally, some exception handler code is copied to the low 8 kB
4865of DRAM (0x00000000 ... 0x00001FFF).
4866
4867So a typical memory configuration with 16 MB of DRAM could look like
4868this:
4869
4870 0x0000 0000 Exception Vector code
4871 :
4872 0x0000 1FFF
4873 0x0000 2000 Free for Application Use
4874 :
4875 :
4876
4877 :
4878 :
4879 0x00FB FF20 Monitor Stack (Growing downward)
4880 0x00FB FFAC Board Info Data and permanent copy of global data
4881 0x00FC 0000 Malloc Arena
4882 :
4883 0x00FD FFFF
4884 0x00FE 0000 RAM Copy of Monitor Code
4885 ... eventually: LCD or video framebuffer
4886 ... eventually: pRAM (Protected RAM - unchanged by reset)
4887 0x00FF FFFF [End of RAM]
4888
4889
4890System Initialization:
4891----------------------
c609719b 4892
2729af9d 4893In the reset configuration, U-Boot starts at the reset entry point
11ccc33f 4894(on most PowerPC systems at address 0x00000100). Because of the reset
b445bbb4 4895configuration for CS0# this is a mirror of the on board Flash memory.
2729af9d
WD
4896To be able to re-map memory U-Boot then jumps to its link address.
4897To be able to implement the initialization code in C, a (small!)
4898initial stack is set up in the internal Dual Ported RAM (in case CPUs
2eb48ff7
HS
4899which provide such a feature like), or in a locked part of the data
4900cache. After that, U-Boot initializes the CPU core, the caches and
4901the SIU.
2729af9d
WD
4902
4903Next, all (potentially) available memory banks are mapped using a
4904preliminary mapping. For example, we put them on 512 MB boundaries
4905(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4906on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4907programmed for SDRAM access. Using the temporary configuration, a
4908simple memory test is run that determines the size of the SDRAM
4909banks.
4910
4911When there is more than one SDRAM bank, and the banks are of
4912different size, the largest is mapped first. For equal size, the first
4913bank (CS2#) is mapped first. The first mapping is always for address
49140x00000000, with any additional banks following immediately to create
4915contiguous memory starting from 0.
4916
4917Then, the monitor installs itself at the upper end of the SDRAM area
4918and allocates memory for use by malloc() and for the global Board
4919Info data; also, the exception vector code is copied to the low RAM
4920pages, and the final stack is set up.
4921
4922Only after this relocation will you have a "normal" C environment;
4923until that you are restricted in several ways, mostly because you are
4924running from ROM, and because the code will have to be relocated to a
4925new address in RAM.
4926
4927
4928U-Boot Porting Guide:
4929----------------------
c609719b 4930
2729af9d
WD
4931[Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4932list, October 2002]
c609719b
WD
4933
4934
6c3fef28 4935int main(int argc, char *argv[])
2729af9d
WD
4936{
4937 sighandler_t no_more_time;
c609719b 4938
6c3fef28
JVB
4939 signal(SIGALRM, no_more_time);
4940 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
c609719b 4941
2729af9d 4942 if (available_money > available_manpower) {
6c3fef28 4943 Pay consultant to port U-Boot;
c609719b
WD
4944 return 0;
4945 }
4946
2729af9d
WD
4947 Download latest U-Boot source;
4948
0668236b 4949 Subscribe to u-boot mailing list;
2729af9d 4950
6c3fef28
JVB
4951 if (clueless)
4952 email("Hi, I am new to U-Boot, how do I get started?");
2729af9d
WD
4953
4954 while (learning) {
4955 Read the README file in the top level directory;
6c3fef28
JVB
4956 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4957 Read applicable doc/*.README;
2729af9d 4958 Read the source, Luke;
6c3fef28 4959 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
2729af9d
WD
4960 }
4961
6c3fef28
JVB
4962 if (available_money > toLocalCurrency ($2500))
4963 Buy a BDI3000;
4964 else
2729af9d 4965 Add a lot of aggravation and time;
2729af9d 4966
6c3fef28
JVB
4967 if (a similar board exists) { /* hopefully... */
4968 cp -a board/<similar> board/<myboard>
4969 cp include/configs/<similar>.h include/configs/<myboard>.h
4970 } else {
4971 Create your own board support subdirectory;
4972 Create your own board include/configs/<myboard>.h file;
4973 }
4974 Edit new board/<myboard> files
4975 Edit new include/configs/<myboard>.h
4976
4977 while (!accepted) {
4978 while (!running) {
4979 do {
4980 Add / modify source code;
4981 } until (compiles);
4982 Debug;
4983 if (clueless)
4984 email("Hi, I am having problems...");
4985 }
4986 Send patch file to the U-Boot email list;
4987 if (reasonable critiques)
4988 Incorporate improvements from email list code review;
4989 else
4990 Defend code as written;
2729af9d 4991 }
2729af9d
WD
4992
4993 return 0;
4994}
4995
4996void no_more_time (int sig)
4997{
4998 hire_a_guru();
4999}
5000
c609719b 5001
2729af9d
WD
5002Coding Standards:
5003-----------------
c609719b 5004
2729af9d 5005All contributions to U-Boot should conform to the Linux kernel
659208da
BS
5006coding style; see the kernel coding style guide at
5007https://www.kernel.org/doc/html/latest/process/coding-style.html, and the
5008script "scripts/Lindent" in your Linux kernel source directory.
2c051651
DZ
5009
5010Source files originating from a different project (for example the
5011MTD subsystem) are generally exempt from these guidelines and are not
b445bbb4 5012reformatted to ease subsequent migration to newer versions of those
2c051651
DZ
5013sources.
5014
5015Please note that U-Boot is implemented in C (and to some small parts in
5016Assembler); no C++ is used, so please do not use C++ style comments (//)
5017in your code.
c609719b 5018
2729af9d
WD
5019Please also stick to the following formatting rules:
5020- remove any trailing white space
7ca9296e 5021- use TAB characters for indentation and vertical alignment, not spaces
2729af9d 5022- make sure NOT to use DOS '\r\n' line feeds
7ca9296e 5023- do not add more than 2 consecutive empty lines to source files
2729af9d 5024- do not add trailing empty lines to source files
180d3f74 5025
2729af9d
WD
5026Submissions which do not conform to the standards may be returned
5027with a request to reformat the changes.
c609719b
WD
5028
5029
2729af9d
WD
5030Submitting Patches:
5031-------------------
c609719b 5032
2729af9d
WD
5033Since the number of patches for U-Boot is growing, we need to
5034establish some rules. Submissions which do not conform to these rules
5035may be rejected, even when they contain important and valuable stuff.
c609719b 5036
0d28f34b 5037Please see http://www.denx.de/wiki/U-Boot/Patches for details.
218ca724 5038
0668236b 5039Patches shall be sent to the u-boot mailing list <[email protected]>;
1dade18e 5040see https://lists.denx.de/listinfo/u-boot
0668236b 5041
2729af9d
WD
5042When you send a patch, please include the following information with
5043it:
c609719b 5044
2729af9d
WD
5045* For bug fixes: a description of the bug and how your patch fixes
5046 this bug. Please try to include a way of demonstrating that the
5047 patch actually fixes something.
c609719b 5048
2729af9d
WD
5049* For new features: a description of the feature and your
5050 implementation.
c609719b 5051
2729af9d 5052* A CHANGELOG entry as plaintext (separate from the patch)
c609719b 5053
7207b366
RD
5054* For major contributions, add a MAINTAINERS file with your
5055 information and associated file and directory references.
c609719b 5056
27af930e
AA
5057* When you add support for a new board, don't forget to add a
5058 maintainer e-mail address to the boards.cfg file, too.
c609719b 5059
2729af9d
WD
5060* If your patch adds new configuration options, don't forget to
5061 document these in the README file.
c609719b 5062
218ca724
WD
5063* The patch itself. If you are using git (which is *strongly*
5064 recommended) you can easily generate the patch using the
7ca9296e 5065 "git format-patch". If you then use "git send-email" to send it to
218ca724
WD
5066 the U-Boot mailing list, you will avoid most of the common problems
5067 with some other mail clients.
5068
5069 If you cannot use git, use "diff -purN OLD NEW". If your version of
5070 diff does not support these options, then get the latest version of
5071 GNU diff.
c609719b 5072
218ca724
WD
5073 The current directory when running this command shall be the parent
5074 directory of the U-Boot source tree (i. e. please make sure that
5075 your patch includes sufficient directory information for the
5076 affected files).
6dff5529 5077
218ca724
WD
5078 We prefer patches as plain text. MIME attachments are discouraged,
5079 and compressed attachments must not be used.
c609719b 5080
2729af9d
WD
5081* If one logical set of modifications affects or creates several
5082 files, all these changes shall be submitted in a SINGLE patch file.
52f52c14 5083
2729af9d
WD
5084* Changesets that contain different, unrelated modifications shall be
5085 submitted as SEPARATE patches, one patch per changeset.
8bde7f77 5086
52f52c14 5087
2729af9d 5088Notes:
c609719b 5089
6de80f21 5090* Before sending the patch, run the buildman script on your patched
2729af9d
WD
5091 source tree and make sure that no errors or warnings are reported
5092 for any of the boards.
c609719b 5093
2729af9d
WD
5094* Keep your modifications to the necessary minimum: A patch
5095 containing several unrelated changes or arbitrary reformats will be
5096 returned with a request to re-formatting / split it.
c609719b 5097
2729af9d
WD
5098* If you modify existing code, make sure that your new code does not
5099 add to the memory footprint of the code ;-) Small is beautiful!
5100 When adding new features, these should compile conditionally only
5101 (using #ifdef), and the resulting code with the new feature
5102 disabled must not need more memory than the old code without your
5103 modification.
90dc6704 5104
0668236b
WD
5105* Remember that there is a size limit of 100 kB per message on the
5106 u-boot mailing list. Bigger patches will be moderated. If they are
5107 reasonable and not too big, they will be acknowledged. But patches
5108 bigger than the size limit should be avoided.
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