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83d290c5 1# SPDX-License-Identifier: GPL-2.0+
c609719b 2#
eca3aeb3 3# (C) Copyright 2000 - 2013
c609719b 4# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
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5
6Summary:
7========
8
24ee89b9 9This directory contains the source code for U-Boot, a boot loader for
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10Embedded boards based on PowerPC, ARM, MIPS and several other
11processors, which can be installed in a boot ROM and used to
12initialize and test the hardware or to download and run application
13code.
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14
15The development of U-Boot is closely related to Linux: some parts of
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16the source code originate in the Linux source tree, we have some
17header files in common, and special provision has been made to
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18support booting of Linux images.
19
20Some attention has been paid to make this software easily
21configurable and extendable. For instance, all monitor commands are
22implemented with the same call interface, so that it's very easy to
23add new commands. Also, instead of permanently adding rarely used
24code (for instance hardware test utilities) to the monitor, you can
25load and run it dynamically.
26
27
28Status:
29=======
30
31In general, all boards for which a configuration option exists in the
24ee89b9 32Makefile have been tested to some extent and can be considered
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33"working". In fact, many of them are used in production systems.
34
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35In case of problems see the CHANGELOG file to find out who contributed
36the specific port. In addition, there are various MAINTAINERS files
37scattered throughout the U-Boot source identifying the people or
38companies responsible for various boards and subsystems.
c609719b 39
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40Note: As of August, 2010, there is no longer a CHANGELOG file in the
41actual U-Boot source tree; however, it can be created dynamically
42from the Git log using:
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43
44 make CHANGELOG
45
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46
47Where to get help:
48==================
49
24ee89b9 50In case you have questions about, problems with or contributions for
7207b366 51U-Boot, you should send a message to the U-Boot mailing list at
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52<u-boot@lists.denx.de>. There is also an archive of previous traffic
53on the mailing list - please search the archive before asking FAQ's.
54Please see http://lists.denx.de/pipermail/u-boot and
55http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
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56
57
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58Where to get source code:
59=========================
60
7207b366 61The U-Boot source code is maintained in the Git repository at
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62git://www.denx.de/git/u-boot.git ; you can browse it online at
63http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
64
65The "snapshot" links on this page allow you to download tarballs of
11ccc33f 66any version you might be interested in. Official releases are also
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67available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
68directory.
69
d4ee711d 70Pre-built (and tested) images are available from
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71ftp://ftp.denx.de/pub/u-boot/images/
72
73
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74Where we come from:
75===================
76
77- start from 8xxrom sources
24ee89b9 78- create PPCBoot project (http://sourceforge.net/projects/ppcboot)
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79- clean up code
80- make it easier to add custom boards
81- make it possible to add other [PowerPC] CPUs
82- extend functions, especially:
83 * Provide extended interface to Linux boot loader
84 * S-Record download
85 * network boot
11ccc33f 86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
24ee89b9 87- create ARMBoot project (http://sourceforge.net/projects/armboot)
c609719b 88- add other CPU families (starting with ARM)
24ee89b9 89- create U-Boot project (http://sourceforge.net/projects/u-boot)
0d28f34b 90- current project page: see http://www.denx.de/wiki/U-Boot
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91
92
93Names and Spelling:
94===================
95
96The "official" name of this project is "Das U-Boot". The spelling
97"U-Boot" shall be used in all written text (documentation, comments
98in source files etc.). Example:
99
100 This is the README file for the U-Boot project.
101
102File names etc. shall be based on the string "u-boot". Examples:
103
104 include/asm-ppc/u-boot.h
105
106 #include <asm/u-boot.h>
107
108Variable names, preprocessor constants etc. shall be either based on
109the string "u_boot" or on "U_BOOT". Example:
110
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
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113
114
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115Versioning:
116===========
117
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118Starting with the release in October 2008, the names of the releases
119were changed from numerical release numbers without deeper meaning
120into a time stamp based numbering. Regular releases are identified by
121names consisting of the calendar year and month of the release date.
122Additional fields (if present) indicate release candidates or bug fix
123releases in "stable" maintenance trees.
124
125Examples:
c0f40859 126 U-Boot v2009.11 - Release November 2009
360d883a 127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
0de21ecb 128 U-Boot v2010.09-rc1 - Release candidate 1 for September 2010 release
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129
130
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131Directory Hierarchy:
132====================
133
8d321b81 134/arch Architecture specific files
6eae68e4 135 /arc Files generic to ARC architecture
8d321b81 136 /arm Files generic to ARM architecture
8d321b81 137 /m68k Files generic to m68k architecture
8d321b81 138 /microblaze Files generic to microblaze architecture
8d321b81 139 /mips Files generic to MIPS architecture
afc1ce82 140 /nds32 Files generic to NDS32 architecture
8d321b81 141 /nios2 Files generic to Altera NIOS2 architecture
33c7731b 142 /openrisc Files generic to OpenRISC architecture
a47a12be 143 /powerpc Files generic to PowerPC architecture
3fafced7 144 /riscv Files generic to RISC-V architecture
7207b366 145 /sandbox Files generic to HW-independent "sandbox"
8d321b81 146 /sh Files generic to SH architecture
33c7731b 147 /x86 Files generic to x86 architecture
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148/api Machine/arch independent API for external apps
149/board Board dependent files
740f7e5c 150/cmd U-Boot commands functions
8d321b81 151/common Misc architecture independent functions
7207b366 152/configs Board default configuration files
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153/disk Code for disk drive partition handling
154/doc Documentation (don't expect too much)
155/drivers Commonly used device drivers
33c7731b 156/dts Contains Makefile for building internal U-Boot fdt.
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157/examples Example code for standalone applications, etc.
158/fs Filesystem code (cramfs, ext2, jffs2, etc.)
159/include Header Files
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160/lib Library routines generic to all architectures
161/Licenses Various license files
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162/net Networking code
163/post Power On Self Test
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164/scripts Various build scripts and Makefiles
165/test Various unit test files
8d321b81 166/tools Tools to build S-Record or U-Boot images, etc.
c609719b 167
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168Software Configuration:
169=======================
170
171Configuration is usually done using C preprocessor defines; the
172rationale behind that is to avoid dead code whenever possible.
173
174There are two classes of configuration variables:
175
176* Configuration _OPTIONS_:
177 These are selectable by the user and have names beginning with
178 "CONFIG_".
179
180* Configuration _SETTINGS_:
181 These depend on the hardware etc. and should not be meddled with if
182 you don't know what you're doing; they have names beginning with
6d0f6bcf 183 "CONFIG_SYS_".
c609719b 184
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185Previously, all configuration was done by hand, which involved creating
186symbolic links and editing configuration files manually. More recently,
187U-Boot has added the Kbuild infrastructure used by the Linux kernel,
188allowing you to use the "make menuconfig" command to configure your
189build.
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190
191
192Selection of Processor Architecture and Board Type:
193---------------------------------------------------
194
195For all supported boards there are ready-to-use default
ab584d67 196configurations available; just type "make <board_name>_defconfig".
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197
198Example: For a TQM823L module type:
199
200 cd u-boot
ab584d67 201 make TQM823L_defconfig
c609719b 202
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203Note: If you're looking for the default configuration file for a board
204you're sure used to be there but is now missing, check the file
205doc/README.scrapyard for a list of no longer supported boards.
c609719b 206
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207Sandbox Environment:
208--------------------
209
210U-Boot can be built natively to run on a Linux host using the 'sandbox'
211board. This allows feature development which is not board- or architecture-
212specific to be undertaken on a native platform. The sandbox is also used to
213run some of U-Boot's tests.
214
6b1978f8 215See board/sandbox/README.sandbox for more details.
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216
217
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218Board Initialisation Flow:
219--------------------------
220
221This is the intended start-up flow for boards. This should apply for both
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222SPL and U-Boot proper (i.e. they both follow the same rules).
223
224Note: "SPL" stands for "Secondary Program Loader," which is explained in
225more detail later in this file.
226
227At present, SPL mostly uses a separate code path, but the function names
228and roles of each function are the same. Some boards or architectures
229may not conform to this. At least most ARM boards which use
230CONFIG_SPL_FRAMEWORK conform to this.
231
232Execution typically starts with an architecture-specific (and possibly
233CPU-specific) start.S file, such as:
234
235 - arch/arm/cpu/armv7/start.S
236 - arch/powerpc/cpu/mpc83xx/start.S
237 - arch/mips/cpu/start.S
db910353 238
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239and so on. From there, three functions are called; the purpose and
240limitations of each of these functions are described below.
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241
242lowlevel_init():
243 - purpose: essential init to permit execution to reach board_init_f()
244 - no global_data or BSS
245 - there is no stack (ARMv7 may have one but it will soon be removed)
246 - must not set up SDRAM or use console
247 - must only do the bare minimum to allow execution to continue to
248 board_init_f()
249 - this is almost never needed
250 - return normally from this function
251
252board_init_f():
253 - purpose: set up the machine ready for running board_init_r():
254 i.e. SDRAM and serial UART
255 - global_data is available
256 - stack is in SRAM
257 - BSS is not available, so you cannot use global/static variables,
258 only stack variables and global_data
259
260 Non-SPL-specific notes:
261 - dram_init() is called to set up DRAM. If already done in SPL this
262 can do nothing
263
264 SPL-specific notes:
265 - you can override the entire board_init_f() function with your own
266 version as needed.
267 - preloader_console_init() can be called here in extremis
268 - should set up SDRAM, and anything needed to make the UART work
269 - these is no need to clear BSS, it will be done by crt0.S
270 - must return normally from this function (don't call board_init_r()
271 directly)
272
273Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
274this point the stack and global_data are relocated to below
275CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
276memory.
277
278board_init_r():
279 - purpose: main execution, common code
280 - global_data is available
281 - SDRAM is available
282 - BSS is available, all static/global variables can be used
283 - execution eventually continues to main_loop()
284
285 Non-SPL-specific notes:
286 - U-Boot is relocated to the top of memory and is now running from
287 there.
288
289 SPL-specific notes:
290 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
291 CONFIG_SPL_STACK_R_ADDR points into SDRAM
292 - preloader_console_init() can be called here - typically this is
0680f1b1 293 done by selecting CONFIG_SPL_BOARD_INIT and then supplying a
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294 spl_board_init() function containing this call
295 - loads U-Boot or (in falcon mode) Linux
296
297
298
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299Configuration Options:
300----------------------
301
302Configuration depends on the combination of board and CPU type; all
303such information is kept in a configuration file
304"include/configs/<board_name>.h".
305
306Example: For a TQM823L module, all configuration settings are in
307"include/configs/TQM823L.h".
308
309
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310Many of the options are named exactly as the corresponding Linux
311kernel configuration options. The intention is to make it easier to
312build a config tool - later.
313
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314- ARM Platform Bus Type(CCI):
315 CoreLink Cache Coherent Interconnect (CCI) is ARM BUS which
316 provides full cache coherency between two clusters of multi-core
317 CPUs and I/O coherency for devices and I/O masters
318
319 CONFIG_SYS_FSL_HAS_CCI400
320
321 Defined For SoC that has cache coherent interconnect
322 CCN-400
7f6c2cbc 323
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324 CONFIG_SYS_FSL_HAS_CCN504
325
326 Defined for SoC that has cache coherent interconnect CCN-504
327
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328The following options need to be configured:
329
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330- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
331
332- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
6ccec449 333
66412c63 334- 85xx CPU Options:
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335 CONFIG_SYS_PPC64
336
337 Specifies that the core is a 64-bit PowerPC implementation (implements
338 the "64" category of the Power ISA). This is necessary for ePAPR
339 compliance, among other possible reasons.
340
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341 CONFIG_SYS_FSL_TBCLK_DIV
342
343 Defines the core time base clock divider ratio compared to the
344 system clock. On most PQ3 devices this is 8, on newer QorIQ
345 devices it can be 16 or 32. The ratio varies from SoC to Soc.
346
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347 CONFIG_SYS_FSL_PCIE_COMPAT
348
349 Defines the string to utilize when trying to match PCIe device
350 tree nodes for the given platform.
351
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352 CONFIG_SYS_FSL_ERRATUM_A004510
353
354 Enables a workaround for erratum A004510. If set,
355 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
356 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
357
358 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
359 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
360
361 Defines one or two SoC revisions (low 8 bits of SVR)
362 for which the A004510 workaround should be applied.
363
364 The rest of SVR is either not relevant to the decision
365 of whether the erratum is present (e.g. p2040 versus
366 p2041) or is implied by the build target, which controls
367 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
368
369 See Freescale App Note 4493 for more information about
370 this erratum.
371
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372 CONFIG_A003399_NOR_WORKAROUND
373 Enables a workaround for IFC erratum A003399. It is only
b445bbb4 374 required during NOR boot.
74fa22ed 375
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376 CONFIG_A008044_WORKAROUND
377 Enables a workaround for T1040/T1042 erratum A008044. It is only
b445bbb4 378 required during NAND boot and valid for Rev 1.0 SoC revision
9f074e67 379
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380 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
381
382 This is the value to write into CCSR offset 0x18600
383 according to the A004510 workaround.
384
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385 CONFIG_SYS_FSL_DSP_DDR_ADDR
386 This value denotes start offset of DDR memory which is
387 connected exclusively to the DSP cores.
388
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389 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
390 This value denotes start offset of M2 memory
391 which is directly connected to the DSP core.
392
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393 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
394 This value denotes start offset of M3 memory which is directly
395 connected to the DSP core.
396
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397 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
398 This value denotes start offset of DSP CCSR space.
399
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400 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
401 Single Source Clock is clocking mode present in some of FSL SoC's.
402 In this mode, a single differential clock is used to supply
403 clocks to the sysclock, ddrclock and usbclock.
404
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405 CONFIG_SYS_CPC_REINIT_F
406 This CONFIG is defined when the CPC is configured as SRAM at the
a187559e 407 time of U-Boot entry and is required to be re-initialized.
fb4a2409 408
aade2004 409 CONFIG_DEEP_SLEEP
b445bbb4 410 Indicates this SoC supports deep sleep feature. If deep sleep is
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411 supported, core will start to execute uboot when wakes up.
412
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413- Generic CPU options:
414 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
415
416 Defines the endianess of the CPU. Implementation of those
417 values is arch specific.
418
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419 CONFIG_SYS_FSL_DDR
420 Freescale DDR driver in use. This type of DDR controller is
421 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
422 SoCs.
423
424 CONFIG_SYS_FSL_DDR_ADDR
425 Freescale DDR memory-mapped register base.
426
427 CONFIG_SYS_FSL_DDR_EMU
428 Specify emulator support for DDR. Some DDR features such as
429 deskew training are not available.
430
431 CONFIG_SYS_FSL_DDRC_GEN1
432 Freescale DDR1 controller.
433
434 CONFIG_SYS_FSL_DDRC_GEN2
435 Freescale DDR2 controller.
436
437 CONFIG_SYS_FSL_DDRC_GEN3
438 Freescale DDR3 controller.
439
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440 CONFIG_SYS_FSL_DDRC_GEN4
441 Freescale DDR4 controller.
442
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443 CONFIG_SYS_FSL_DDRC_ARM_GEN3
444 Freescale DDR3 controller for ARM-based SoCs.
445
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446 CONFIG_SYS_FSL_DDR1
447 Board config to use DDR1. It can be enabled for SoCs with
448 Freescale DDR1 or DDR2 controllers, depending on the board
449 implemetation.
450
451 CONFIG_SYS_FSL_DDR2
62a3b7dd 452 Board config to use DDR2. It can be enabled for SoCs with
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453 Freescale DDR2 or DDR3 controllers, depending on the board
454 implementation.
455
456 CONFIG_SYS_FSL_DDR3
457 Board config to use DDR3. It can be enabled for SoCs with
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458 Freescale DDR3 or DDR3L controllers.
459
460 CONFIG_SYS_FSL_DDR3L
461 Board config to use DDR3L. It can be enabled for SoCs with
462 DDR3L controllers.
463
464 CONFIG_SYS_FSL_DDR4
465 Board config to use DDR4. It can be enabled for SoCs with
466 DDR4 controllers.
5614e71b 467
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468 CONFIG_SYS_FSL_IFC_BE
469 Defines the IFC controller register space as Big Endian
470
471 CONFIG_SYS_FSL_IFC_LE
472 Defines the IFC controller register space as Little Endian
473
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474 CONFIG_SYS_FSL_IFC_CLK_DIV
475 Defines divider of platform clock(clock input to IFC controller).
476
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477 CONFIG_SYS_FSL_LBC_CLK_DIV
478 Defines divider of platform clock(clock input to eLBC controller).
479
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480 CONFIG_SYS_FSL_PBL_PBI
481 It enables addition of RCW (Power on reset configuration) in built image.
482 Please refer doc/README.pblimage for more details
483
484 CONFIG_SYS_FSL_PBL_RCW
485 It adds PBI(pre-boot instructions) commands in u-boot build image.
486 PBI commands can be used to configure SoC before it starts the execution.
487 Please refer doc/README.pblimage for more details
488
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489 CONFIG_SPL_FSL_PBL
490 It adds a target to create boot binary having SPL binary in PBI format
491 concatenated with u-boot binary.
492
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493 CONFIG_SYS_FSL_DDR_BE
494 Defines the DDR controller register space as Big Endian
495
496 CONFIG_SYS_FSL_DDR_LE
497 Defines the DDR controller register space as Little Endian
498
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499 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
500 Physical address from the view of DDR controllers. It is the
501 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
502 it could be different for ARM SoCs.
503
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504 CONFIG_SYS_FSL_DDR_INTLV_256B
505 DDR controller interleaving on 256-byte. This is a special
506 interleaving mode, handled by Dickens for Freescale layerscape
507 SoCs with ARM core.
508
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509 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
510 Number of controllers used as main memory.
511
512 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
513 Number of controllers used for other than main memory.
514
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515 CONFIG_SYS_FSL_HAS_DP_DDR
516 Defines the SoC has DP-DDR used for DPAA.
517
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518 CONFIG_SYS_FSL_SEC_BE
519 Defines the SEC controller register space as Big Endian
520
521 CONFIG_SYS_FSL_SEC_LE
522 Defines the SEC controller register space as Little Endian
523
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524- MIPS CPU options:
525 CONFIG_SYS_INIT_SP_OFFSET
526
527 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
528 pointer. This is needed for the temporary stack before
529 relocation.
530
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531 CONFIG_XWAY_SWAP_BYTES
532
533 Enable compilation of tools/xway-swap-bytes needed for Lantiq
534 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
535 be swapped if a flash programmer is used.
536
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537- ARM options:
538 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
539
540 Select high exception vectors of the ARM core, e.g., do not
541 clear the V bit of the c1 register of CP15.
542
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543 COUNTER_FREQUENCY
544 Generic timer clock source frequency.
545
546 COUNTER_FREQUENCY_REAL
547 Generic timer clock source frequency if the real clock is
548 different from COUNTER_FREQUENCY, and can only be determined
549 at run time.
550
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551- Tegra SoC options:
552 CONFIG_TEGRA_SUPPORT_NON_SECURE
553
554 Support executing U-Boot in non-secure (NS) mode. Certain
555 impossible actions will be skipped if the CPU is in NS mode,
556 such as ARM architectural timer initialization.
557
5da627a4 558- Linux Kernel Interface:
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559 CONFIG_CLOCKS_IN_MHZ
560
561 U-Boot stores all clock information in Hz
562 internally. For binary compatibility with older Linux
563 kernels (which expect the clocks passed in the
564 bd_info data to be in MHz) the environment variable
565 "clocks_in_mhz" can be defined so that U-Boot
566 converts clock data to MHZ before passing it to the
567 Linux kernel.
c609719b 568 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
218ca724 569 "clocks_in_mhz=1" is automatically included in the
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570 default environment.
571
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572 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
573
b445bbb4 574 When transferring memsize parameter to Linux, some versions
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575 expect it to be in bytes, others in MB.
576 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
577
fec6d9ee 578 CONFIG_OF_LIBFDT
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579
580 New kernel versions are expecting firmware settings to be
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581 passed using flattened device trees (based on open firmware
582 concepts).
583
584 CONFIG_OF_LIBFDT
585 * New libfdt-based support
586 * Adds the "fdt" command
3bb342fc 587 * The bootm command automatically updates the fdt
213bf8c8 588
f57f70aa 589 OF_TBCLK - The timebase frequency.
c2871f03 590 OF_STDOUT_PATH - The path to the console device
f57f70aa 591
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592 boards with QUICC Engines require OF_QE to set UCC MAC
593 addresses
3bb342fc 594
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595 CONFIG_OF_BOARD_SETUP
596
597 Board code has addition modification that it wants to make
598 to the flat device tree before handing it off to the kernel
f57f70aa 599
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600 CONFIG_OF_SYSTEM_SETUP
601
602 Other code has addition modification that it wants to make
603 to the flat device tree before handing it off to the kernel.
604 This causes ft_system_setup() to be called before booting
605 the kernel.
606
3887c3fb
HS
607 CONFIG_OF_IDE_FIXUP
608
609 U-Boot can detect if an IDE device is present or not.
610 If not, and this new config option is activated, U-Boot
611 removes the ATA node from the DTS before booting Linux,
612 so the Linux IDE driver does not probe the device and
613 crash. This is needed for buggy hardware (uc101) where
614 no pull down resistor is connected to the signal IDE5V_DD7.
615
7eb29398
IG
616 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
617
618 This setting is mandatory for all boards that have only one
619 machine type and must be used to specify the machine type
620 number as it appears in the ARM machine registry
621 (see http://www.arm.linux.org.uk/developer/machines/).
622 Only boards that have multiple machine types supported
623 in a single configuration file and the machine type is
624 runtime discoverable, do not have to use this setting.
625
0b2f4eca
NG
626- vxWorks boot parameters:
627
628 bootvx constructs a valid bootline using the following
9e98b7e3
BM
629 environments variables: bootdev, bootfile, ipaddr, netmask,
630 serverip, gatewayip, hostname, othbootargs.
0b2f4eca
NG
631 It loads the vxWorks image pointed bootfile.
632
0b2f4eca
NG
633 Note: If a "bootargs" environment is defined, it will overwride
634 the defaults discussed just above.
635
2c451f78
A
636- Cache Configuration:
637 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
638 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
639 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
640
93bc2193
A
641- Cache Configuration for ARM:
642 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
643 controller
644 CONFIG_SYS_PL310_BASE - Physical base address of PL310
645 controller register space
646
6705d81e 647- Serial Ports:
48d0192f 648 CONFIG_PL010_SERIAL
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WD
649
650 Define this if you want support for Amba PrimeCell PL010 UARTs.
651
48d0192f 652 CONFIG_PL011_SERIAL
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653
654 Define this if you want support for Amba PrimeCell PL011 UARTs.
655
656 CONFIG_PL011_CLOCK
657
658 If you have Amba PrimeCell PL011 UARTs, set this variable to
659 the clock speed of the UARTs.
660
661 CONFIG_PL01x_PORTS
662
663 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
664 define this to a list of base addresses for each (supported)
665 port. See e.g. include/configs/versatile.h
666
d57dee57
KM
667 CONFIG_SERIAL_HW_FLOW_CONTROL
668
669 Define this variable to enable hw flow control in serial driver.
670 Current user of this option is drivers/serial/nsl16550.c driver
6705d81e 671
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672- Console Baudrate:
673 CONFIG_BAUDRATE - in bps
674 Select one of the baudrates listed in
6d0f6bcf 675 CONFIG_SYS_BAUDRATE_TABLE, see below.
c609719b 676
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WD
677- Autoboot Command:
678 CONFIG_BOOTCOMMAND
679 Only needed when CONFIG_BOOTDELAY is enabled;
680 define a command string that is automatically executed
681 when no character is read on the console interface
682 within "Boot Delay" after reset.
683
c609719b 684 CONFIG_RAMBOOT and CONFIG_NFSBOOT
43d9616c
WD
685 The value of these goes into the environment as
686 "ramboot" and "nfsboot" respectively, and can be used
687 as a convenience, when switching between booting from
11ccc33f 688 RAM and NFS.
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689
690- Pre-Boot Commands:
691 CONFIG_PREBOOT
692
693 When this option is #defined, the existence of the
694 environment variable "preboot" will be checked
695 immediately before starting the CONFIG_BOOTDELAY
696 countdown and/or running the auto-boot command resp.
697 entering interactive mode.
698
699 This feature is especially useful when "preboot" is
700 automatically generated or modified. For an example
701 see the LWMON board specific code: here "preboot" is
702 modified when the user holds down a certain
703 combination of keys on the (special) keyboard when
704 booting the systems
705
706- Serial Download Echo Mode:
707 CONFIG_LOADS_ECHO
708 If defined to 1, all characters received during a
709 serial download (using the "loads" command) are
710 echoed back. This might be needed by some terminal
711 emulations (like "cu"), but may as well just take
712 time on others. This setting #define's the initial
713 value of the "loads_echo" environment variable.
714
602ad3b3 715- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
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716 CONFIG_KGDB_BAUDRATE
717 Select one of the baudrates listed in
6d0f6bcf 718 CONFIG_SYS_BAUDRATE_TABLE, see below.
c609719b 719
302a6487
SG
720- Removal of commands
721 If no commands are needed to boot, you can disable
722 CONFIG_CMDLINE to remove them. In this case, the command line
723 will not be available, and when U-Boot wants to execute the
724 boot command (on start-up) it will call board_run_command()
725 instead. This can reduce image size significantly for very
726 simple boot procedures.
727
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728- Regular expression support:
729 CONFIG_REGEX
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WD
730 If this variable is defined, U-Boot is linked against
731 the SLRE (Super Light Regular Expression) library,
732 which adds regex support to some commands, as for
733 example "env grep" and "setexpr".
a5ecbe62 734
45ba8077
SG
735- Device tree:
736 CONFIG_OF_CONTROL
737 If this variable is defined, U-Boot will use a device tree
738 to configure its devices, instead of relying on statically
739 compiled #defines in the board file. This option is
740 experimental and only available on a few boards. The device
741 tree is available in the global data as gd->fdt_blob.
742
2c0f79e4 743 U-Boot needs to get its device tree from somewhere. This can
82f766d1 744 be done using one of the three options below:
bbb0b128
SG
745
746 CONFIG_OF_EMBED
747 If this variable is defined, U-Boot will embed a device tree
748 binary in its image. This device tree file should be in the
749 board directory and called <soc>-<board>.dts. The binary file
750 is then picked up in board_init_f() and made available through
eb3eb602 751 the global data structure as gd->fdt_blob.
45ba8077 752
2c0f79e4
SG
753 CONFIG_OF_SEPARATE
754 If this variable is defined, U-Boot will build a device tree
755 binary. It will be called u-boot.dtb. Architecture-specific
756 code will locate it at run-time. Generally this works by:
757
758 cat u-boot.bin u-boot.dtb >image.bin
759
760 and in fact, U-Boot does this for you, creating a file called
761 u-boot-dtb.bin which is useful in the common case. You can
762 still use the individual files if you need something more
763 exotic.
764
82f766d1
AD
765 CONFIG_OF_BOARD
766 If this variable is defined, U-Boot will use the device tree
767 provided by the board at runtime instead of embedding one with
768 the image. Only boards defining board_fdt_blob_setup() support
769 this option (see include/fdtdec.h file).
770
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771- Watchdog:
772 CONFIG_WATCHDOG
773 If this variable is defined, it enables watchdog
6abe6fb6 774 support for the SoC. There must be support in the SoC
907208c4
CL
775 specific code for a watchdog. For the 8xx
776 CPUs, the SIU Watchdog feature is enabled in the SYPCR
777 register. When supported for a specific SoC is
778 available, then no further board specific code should
779 be needed to use it.
6abe6fb6
DZ
780
781 CONFIG_HW_WATCHDOG
782 When using a watchdog circuitry external to the used
783 SoC, then define this variable and provide board
784 specific code for the "hw_watchdog_reset" function.
c609719b 785
7bae0d6f
HS
786 CONFIG_AT91_HW_WDT_TIMEOUT
787 specify the timeout in seconds. default 2 seconds.
788
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789- Real-Time Clock:
790
602ad3b3 791 When CONFIG_CMD_DATE is selected, the type of the RTC
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WD
792 has to be selected, too. Define exactly one of the
793 following options:
794
c609719b 795 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
4e8b7544 796 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
c609719b 797 CONFIG_RTC_MC146818 - use MC146818 RTC
1cb8e980 798 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
c609719b 799 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
7f70e853 800 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
412921d2 801 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
3bac3513 802 CONFIG_RTC_DS164x - use Dallas DS164x RTC
9536dfcc 803 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
4c0d4c3b 804 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
2bd3cab3 805 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
71d19f30
HS
806 CONFIG_SYS_RV3029_TCR - enable trickle charger on
807 RV3029 RTC.
c609719b 808
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WD
809 Note that if the RTC uses I2C, then the I2C interface
810 must also be configured. See I2C Support, below.
811
e92739d3
PT
812- GPIO Support:
813 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
e92739d3 814
5dec49ca
CP
815 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
816 chip-ngpio pairs that tell the PCA953X driver the number of
817 pins supported by a particular chip.
818
e92739d3
PT
819 Note that if the GPIO device uses I2C, then the I2C interface
820 must also be configured. See I2C Support, below.
821
aa53233a
SG
822- I/O tracing:
823 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
824 accesses and can checksum them or write a list of them out
825 to memory. See the 'iotrace' command for details. This is
826 useful for testing device drivers since it can confirm that
827 the driver behaves the same way before and after a code
828 change. Currently this is supported on sandbox and arm. To
829 add support for your architecture, add '#include <iotrace.h>'
830 to the bottom of arch/<arch>/include/asm/io.h and test.
831
832 Example output from the 'iotrace stats' command is below.
833 Note that if the trace buffer is exhausted, the checksum will
834 still continue to operate.
835
836 iotrace is enabled
837 Start: 10000000 (buffer start address)
838 Size: 00010000 (buffer size)
839 Offset: 00000120 (current buffer offset)
840 Output: 10000120 (start + offset)
841 Count: 00000018 (number of trace records)
842 CRC32: 9526fb66 (CRC32 of all trace records)
843
c609719b
WD
844- Timestamp Support:
845
43d9616c
WD
846 When CONFIG_TIMESTAMP is selected, the timestamp
847 (date and time) of an image is printed by image
848 commands like bootm or iminfo. This option is
602ad3b3 849 automatically enabled when you select CONFIG_CMD_DATE .
c609719b 850
923c46f9
KP
851- Partition Labels (disklabels) Supported:
852 Zero or more of the following:
853 CONFIG_MAC_PARTITION Apple's MacOS partition table.
923c46f9
KP
854 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
855 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
856 bootloader. Note 2TB partition limit; see
857 disk/part_efi.c
c649e3c9 858 CONFIG_SCSI) you must configure support for at
923c46f9 859 least one non-MTD partition type as well.
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WD
860
861- IDE Reset method:
4d13cbad
WD
862 CONFIG_IDE_RESET_ROUTINE - this is defined in several
863 board configurations files but used nowhere!
c609719b 864
4d13cbad
WD
865 CONFIG_IDE_RESET - is this is defined, IDE Reset will
866 be performed by calling the function
867 ide_set_reset(int reset)
868 which has to be defined in a board specific file
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WD
869
870- ATAPI Support:
871 CONFIG_ATAPI
872
873 Set this to enable ATAPI support.
874
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WD
875- LBA48 Support
876 CONFIG_LBA48
877
878 Set this to enable support for disks larger than 137GB
4b142feb 879 Also look at CONFIG_SYS_64BIT_LBA.
c40b2956
WD
880 Whithout these , LBA48 support uses 32bit variables and will 'only'
881 support disks up to 2.1TB.
882
6d0f6bcf 883 CONFIG_SYS_64BIT_LBA:
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WD
884 When enabled, makes the IDE subsystem use 64bit sector addresses.
885 Default is 32bit.
886
c609719b 887- SCSI Support:
6d0f6bcf
JCPV
888 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
889 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
890 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
c609719b
WD
891 maximum numbers of LUNs, SCSI ID's and target
892 devices.
c609719b 893
93e14596
WD
894 The environment variable 'scsidevs' is set to the number of
895 SCSI devices found during the last scan.
447c031b 896
c609719b 897- NETWORK Support (PCI):
682011ff 898 CONFIG_E1000
ce5207e1
KM
899 Support for Intel 8254x/8257x gigabit chips.
900
901 CONFIG_E1000_SPI
902 Utility code for direct access to the SPI bus on Intel 8257x.
903 This does not do anything useful unless you set at least one
904 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
905
906 CONFIG_E1000_SPI_GENERIC
907 Allow generic access to the SPI bus on the Intel 8257x, for
908 example with the "sspi" command.
909
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WD
910 CONFIG_EEPRO100
911 Support for Intel 82557/82559/82559ER chips.
11ccc33f 912 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
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WD
913 write routine for first time initialisation.
914
915 CONFIG_TULIP
916 Support for Digital 2114x chips.
917 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
918 modem chip initialisation (KS8761/QS6611).
919
920 CONFIG_NATSEMI
921 Support for National dp83815 chips.
922
923 CONFIG_NS8382X
924 Support for National dp8382[01] gigabit chips.
925
45219c46
WD
926- NETWORK Support (other):
927
c041e9d2
JS
928 CONFIG_DRIVER_AT91EMAC
929 Support for AT91RM9200 EMAC.
930
931 CONFIG_RMII
932 Define this to use reduced MII inteface
933
934 CONFIG_DRIVER_AT91EMAC_QUIET
935 If this defined, the driver is quiet.
936 The driver doen't show link status messages.
937
efdd7319
RH
938 CONFIG_CALXEDA_XGMAC
939 Support for the Calxeda XGMAC device
940
3bb46d23 941 CONFIG_LAN91C96
45219c46
WD
942 Support for SMSC's LAN91C96 chips.
943
45219c46
WD
944 CONFIG_LAN91C96_USE_32_BIT
945 Define this to enable 32 bit addressing
946
3bb46d23 947 CONFIG_SMC91111
f39748ae
WD
948 Support for SMSC's LAN91C111 chip
949
950 CONFIG_SMC91111_BASE
951 Define this to hold the physical address
952 of the device (I/O space)
953
954 CONFIG_SMC_USE_32_BIT
955 Define this if data bus is 32 bits
956
957 CONFIG_SMC_USE_IOFUNCS
958 Define this to use i/o functions instead of macros
959 (some hardware wont work with macros)
960
dc02bada
HS
961 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
962 Define this if you have more then 3 PHYs.
963
b3dbf4a5
ML
964 CONFIG_FTGMAC100
965 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
966
967 CONFIG_FTGMAC100_EGIGA
968 Define this to use GE link update with gigabit PHY.
969 Define this if FTGMAC100 is connected to gigabit PHY.
970 If your system has 10/100 PHY only, it might not occur
971 wrong behavior. Because PHY usually return timeout or
972 useless data when polling gigabit status and gigabit
973 control registers. This behavior won't affect the
974 correctnessof 10/100 link speed update.
975
3d0075fa
YS
976 CONFIG_SH_ETHER
977 Support for Renesas on-chip Ethernet controller
978
979 CONFIG_SH_ETHER_USE_PORT
980 Define the number of ports to be used
981
982 CONFIG_SH_ETHER_PHY_ADDR
983 Define the ETH PHY's address
984
68260aab
YS
985 CONFIG_SH_ETHER_CACHE_WRITEBACK
986 If this option is set, the driver enables cache flush.
987
b2f97cf2
HS
988- PWM Support:
989 CONFIG_PWM_IMX
5052e819 990 Support for PWM module on the imx6.
b2f97cf2 991
5e124724 992- TPM Support:
90899cc0
CC
993 CONFIG_TPM
994 Support TPM devices.
995
0766ad2f
CR
996 CONFIG_TPM_TIS_INFINEON
997 Support for Infineon i2c bus TPM devices. Only one device
1b393db5
TWHT
998 per system is supported at this time.
999
1b393db5
TWHT
1000 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1001 Define the burst count bytes upper limit
1002
3aa74088
CR
1003 CONFIG_TPM_ST33ZP24
1004 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
1005
1006 CONFIG_TPM_ST33ZP24_I2C
1007 Support for STMicroelectronics ST33ZP24 I2C devices.
1008 Requires TPM_ST33ZP24 and I2C.
1009
b75fdc11
CR
1010 CONFIG_TPM_ST33ZP24_SPI
1011 Support for STMicroelectronics ST33ZP24 SPI devices.
1012 Requires TPM_ST33ZP24 and SPI.
1013
c01939c7
DE
1014 CONFIG_TPM_ATMEL_TWI
1015 Support for Atmel TWI TPM device. Requires I2C support.
1016
90899cc0 1017 CONFIG_TPM_TIS_LPC
5e124724
VB
1018 Support for generic parallel port TPM devices. Only one device
1019 per system is supported at this time.
1020
1021 CONFIG_TPM_TIS_BASE_ADDRESS
1022 Base address where the generic TPM device is mapped
1023 to. Contemporary x86 systems usually map it at
1024 0xfed40000.
1025
be6c1529
RP
1026 CONFIG_TPM
1027 Define this to enable the TPM support library which provides
1028 functional interfaces to some TPM commands.
1029 Requires support for a TPM device.
1030
1031 CONFIG_TPM_AUTH_SESSIONS
1032 Define this to enable authorized functions in the TPM library.
1033 Requires CONFIG_TPM and CONFIG_SHA1.
1034
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WD
1035- USB Support:
1036 At the moment only the UHCI host controller is
064b55cf 1037 supported (PIP405, MIP405); define
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WD
1038 CONFIG_USB_UHCI to enable it.
1039 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
30d56fae 1040 and define CONFIG_USB_STORAGE to enable the USB
c609719b
WD
1041 storage devices.
1042 Note:
1043 Supported are USB Keyboards and USB Floppy drives
1044 (TEAC FD-05PUB).
4d13cbad 1045
9ab4ce22
SG
1046 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1047 txfilltuning field in the EHCI controller on reset.
1048
6e9e0626
OT
1049 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1050 HW module registers.
1051
16c8d5e7
WD
1052- USB Device:
1053 Define the below if you wish to use the USB console.
1054 Once firmware is rebuilt from a serial console issue the
1055 command "setenv stdin usbtty; setenv stdout usbtty" and
11ccc33f 1056 attach your USB cable. The Unix command "dmesg" should print
16c8d5e7
WD
1057 it has found a new device. The environment variable usbtty
1058 can be set to gserial or cdc_acm to enable your device to
386eda02 1059 appear to a USB host as a Linux gserial device or a
16c8d5e7
WD
1060 Common Device Class Abstract Control Model serial device.
1061 If you select usbtty = gserial you should be able to enumerate
1062 a Linux host by
1063 # modprobe usbserial vendor=0xVendorID product=0xProductID
1064 else if using cdc_acm, simply setting the environment
1065 variable usbtty to be cdc_acm should suffice. The following
1066 might be defined in YourBoardName.h
386eda02 1067
16c8d5e7
WD
1068 CONFIG_USB_DEVICE
1069 Define this to build a UDC device
1070
1071 CONFIG_USB_TTY
1072 Define this to have a tty type of device available to
1073 talk to the UDC device
386eda02 1074
f9da0f89
VK
1075 CONFIG_USBD_HS
1076 Define this to enable the high speed support for usb
1077 device and usbtty. If this feature is enabled, a routine
1078 int is_usbd_high_speed(void)
1079 also needs to be defined by the driver to dynamically poll
1080 whether the enumeration has succeded at high speed or full
1081 speed.
1082
6d0f6bcf 1083 CONFIG_SYS_CONSOLE_IS_IN_ENV
16c8d5e7
WD
1084 Define this if you want stdin, stdout &/or stderr to
1085 be set to usbtty.
1086
386eda02 1087 If you have a USB-IF assigned VendorID then you may wish to
16c8d5e7 1088 define your own vendor specific values either in BoardName.h
386eda02 1089 or directly in usbd_vendor_info.h. If you don't define
16c8d5e7
WD
1090 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1091 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1092 should pretend to be a Linux device to it's target host.
1093
1094 CONFIG_USBD_MANUFACTURER
1095 Define this string as the name of your company for
1096 - CONFIG_USBD_MANUFACTURER "my company"
386eda02 1097
16c8d5e7
WD
1098 CONFIG_USBD_PRODUCT_NAME
1099 Define this string as the name of your product
1100 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1101
1102 CONFIG_USBD_VENDORID
1103 Define this as your assigned Vendor ID from the USB
1104 Implementors Forum. This *must* be a genuine Vendor ID
1105 to avoid polluting the USB namespace.
1106 - CONFIG_USBD_VENDORID 0xFFFF
386eda02 1107
16c8d5e7
WD
1108 CONFIG_USBD_PRODUCTID
1109 Define this as the unique Product ID
1110 for your device
1111 - CONFIG_USBD_PRODUCTID 0xFFFF
4d13cbad 1112
d70a560f
IG
1113- ULPI Layer Support:
1114 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1115 the generic ULPI layer. The generic layer accesses the ULPI PHY
1116 via the platform viewport, so you need both the genric layer and
1117 the viewport enabled. Currently only Chipidea/ARC based
1118 viewport is supported.
1119 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1120 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
6d365ea0
LS
1121 If your ULPI phy needs a different reference clock than the
1122 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1123 the appropriate value in Hz.
c609719b 1124
71f95118 1125- MMC Support:
8bde7f77
WD
1126 The MMC controller on the Intel PXA is supported. To
1127 enable this define CONFIG_MMC. The MMC can be
1128 accessed from the boot prompt by mapping the device
71f95118 1129 to physical memory similar to flash. Command line is
602ad3b3
JL
1130 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1131 the FAT fs. This is enabled with CONFIG_CMD_FAT.
71f95118 1132
afb35666
YS
1133 CONFIG_SH_MMCIF
1134 Support for Renesas on-chip MMCIF controller
1135
1136 CONFIG_SH_MMCIF_ADDR
1137 Define the base address of MMCIF registers
1138
1139 CONFIG_SH_MMCIF_CLK
1140 Define the clock frequency for MMCIF
1141
1fd93c6e
PA
1142 CONFIG_SUPPORT_EMMC_BOOT
1143 Enable some additional features of the eMMC boot partitions.
1144
b3ba6e94 1145- USB Device Firmware Update (DFU) class support:
bb4059a5 1146 CONFIG_DFU_OVER_USB
b3ba6e94
TR
1147 This enables the USB portion of the DFU USB class
1148
b3ba6e94
TR
1149 CONFIG_DFU_MMC
1150 This enables support for exposing (e)MMC devices via DFU.
1151
c6631764
PA
1152 CONFIG_DFU_NAND
1153 This enables support for exposing NAND devices via DFU.
1154
a9479f04
AM
1155 CONFIG_DFU_RAM
1156 This enables support for exposing RAM via DFU.
1157 Note: DFU spec refer to non-volatile memory usage, but
1158 allow usages beyond the scope of spec - here RAM usage,
1159 one that would help mostly the developer.
1160
e7e75c70
HS
1161 CONFIG_SYS_DFU_DATA_BUF_SIZE
1162 Dfu transfer uses a buffer before writing data to the
1163 raw storage device. Make the size (in bytes) of this buffer
1164 configurable. The size of this buffer is also configurable
1165 through the "dfu_bufsiz" environment variable.
1166
ea2453d5
PA
1167 CONFIG_SYS_DFU_MAX_FILE_SIZE
1168 When updating files rather than the raw storage device,
1169 we use a static buffer to copy the file into and then write
1170 the buffer once we've been given the whole file. Define
1171 this to the maximum filesize (in bytes) for the buffer.
1172 Default is 4 MiB if undefined.
1173
001a8319
HS
1174 DFU_DEFAULT_POLL_TIMEOUT
1175 Poll timeout [ms], is the timeout a device can send to the
1176 host. The host must wait for this timeout before sending
1177 a subsequent DFU_GET_STATUS request to the device.
1178
1179 DFU_MANIFEST_POLL_TIMEOUT
1180 Poll timeout [ms], which the device sends to the host when
1181 entering dfuMANIFEST state. Host waits this timeout, before
1182 sending again an USB request to the device.
1183
6705d81e 1184- Journaling Flash filesystem support:
b2482dff 1185 CONFIG_JFFS2_NAND
6705d81e
WD
1186 Define these for a default partition on a NAND device
1187
6d0f6bcf
JCPV
1188 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1189 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
6705d81e
WD
1190 Define these for a default partition on a NOR device
1191
c609719b 1192- Keyboard Support:
39f615ed
SG
1193 See Kconfig help for available keyboard drivers.
1194
1195 CONFIG_KEYBOARD
1196
1197 Define this to enable a custom keyboard support.
1198 This simply calls drv_keyboard_init() which must be
1199 defined in your board-specific files. This option is deprecated
1200 and is only used by novena. For new boards, use driver model
1201 instead.
c609719b
WD
1202
1203- Video support:
7d3053fb 1204 CONFIG_FSL_DIU_FB
04e5ae79 1205 Enable the Freescale DIU video driver. Reference boards for
7d3053fb
TT
1206 SOCs that have a DIU should define this macro to enable DIU
1207 support, and should also define these other macros:
1208
1209 CONFIG_SYS_DIU_ADDR
1210 CONFIG_VIDEO
7d3053fb
TT
1211 CONFIG_CFB_CONSOLE
1212 CONFIG_VIDEO_SW_CURSOR
1213 CONFIG_VGA_AS_SINGLE_DEVICE
1214 CONFIG_VIDEO_LOGO
1215 CONFIG_VIDEO_BMP_LOGO
1216
ba8e76bd
TT
1217 The DIU driver will look for the 'video-mode' environment
1218 variable, and if defined, enable the DIU as a console during
8eca9439 1219 boot. See the documentation file doc/README.video for a
ba8e76bd 1220 description of this variable.
7d3053fb 1221
c609719b
WD
1222- LCD Support: CONFIG_LCD
1223
1224 Define this to enable LCD support (for output to LCD
1225 display); also select one of the supported displays
1226 by defining one of these:
1227
39cf4804
SP
1228 CONFIG_ATMEL_LCD:
1229
1230 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1231
fd3103bb 1232 CONFIG_NEC_NL6448AC33:
c609719b 1233
fd3103bb 1234 NEC NL6448AC33-18. Active, color, single scan.
c609719b 1235
fd3103bb 1236 CONFIG_NEC_NL6448BC20
c609719b 1237
fd3103bb
WD
1238 NEC NL6448BC20-08. 6.5", 640x480.
1239 Active, color, single scan.
1240
1241 CONFIG_NEC_NL6448BC33_54
1242
1243 NEC NL6448BC33-54. 10.4", 640x480.
c609719b
WD
1244 Active, color, single scan.
1245
1246 CONFIG_SHARP_16x9
1247
1248 Sharp 320x240. Active, color, single scan.
1249 It isn't 16x9, and I am not sure what it is.
1250
1251 CONFIG_SHARP_LQ64D341
1252
1253 Sharp LQ64D341 display, 640x480.
1254 Active, color, single scan.
1255
1256 CONFIG_HLD1045
1257
1258 HLD1045 display, 640x480.
1259 Active, color, single scan.
1260
1261 CONFIG_OPTREX_BW
1262
1263 Optrex CBL50840-2 NF-FW 99 22 M5
1264 or
1265 Hitachi LMG6912RPFC-00T
1266 or
1267 Hitachi SP14Q002
1268
1269 320x240. Black & white.
1270
676d319e
SG
1271 CONFIG_LCD_ALIGNMENT
1272
b445bbb4 1273 Normally the LCD is page-aligned (typically 4KB). If this is
676d319e
SG
1274 defined then the LCD will be aligned to this value instead.
1275 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1276 here, since it is cheaper to change data cache settings on
1277 a per-section basis.
1278
1279
604c7d4a
HP
1280 CONFIG_LCD_ROTATION
1281
1282 Sometimes, for example if the display is mounted in portrait
1283 mode or even if it's mounted landscape but rotated by 180degree,
1284 we need to rotate our content of the display relative to the
1285 framebuffer, so that user can read the messages which are
1286 printed out.
1287 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1288 initialized with a given rotation from "vl_rot" out of
1289 "vidinfo_t" which is provided by the board specific code.
1290 The value for vl_rot is coded as following (matching to
1291 fbcon=rotate:<n> linux-kernel commandline):
1292 0 = no rotation respectively 0 degree
1293 1 = 90 degree rotation
1294 2 = 180 degree rotation
1295 3 = 270 degree rotation
1296
1297 If CONFIG_LCD_ROTATION is not defined, the console will be
1298 initialized with 0degree rotation.
1299
45d7f525
TWHT
1300 CONFIG_LCD_BMP_RLE8
1301
1302 Support drawing of RLE8-compressed bitmaps on the LCD.
1303
735987c5
TWHT
1304 CONFIG_I2C_EDID
1305
1306 Enables an 'i2c edid' command which can read EDID
1307 information over I2C from an attached LCD display.
1308
7152b1d0 1309- Splash Screen Support: CONFIG_SPLASH_SCREEN
d791b1dc 1310
8bde7f77
WD
1311 If this option is set, the environment is checked for
1312 a variable "splashimage". If found, the usual display
1313 of logo, copyright and system information on the LCD
e94d2cd9 1314 is suppressed and the BMP image at the address
8bde7f77
WD
1315 specified in "splashimage" is loaded instead. The
1316 console is redirected to the "nulldev", too. This
1317 allows for a "silent" boot where a splash screen is
1318 loaded very quickly after power-on.
d791b1dc 1319
c0880485
NK
1320 CONFIG_SPLASHIMAGE_GUARD
1321
1322 If this option is set, then U-Boot will prevent the environment
1323 variable "splashimage" from being set to a problematic address
ab5645f1 1324 (see doc/README.displaying-bmps).
c0880485
NK
1325 This option is useful for targets where, due to alignment
1326 restrictions, an improperly aligned BMP image will cause a data
1327 abort. If you think you will not have problems with unaligned
1328 accesses (for example because your toolchain prevents them)
1329 there is no need to set this option.
1330
1ca298ce
MW
1331 CONFIG_SPLASH_SCREEN_ALIGN
1332
1333 If this option is set the splash image can be freely positioned
1334 on the screen. Environment variable "splashpos" specifies the
1335 position as "x,y". If a positive number is given it is used as
1336 number of pixel from left/top. If a negative number is given it
1337 is used as number of pixel from right/bottom. You can also
1338 specify 'm' for centering the image.
1339
1340 Example:
1341 setenv splashpos m,m
1342 => image at center of screen
1343
1344 setenv splashpos 30,20
1345 => image at x = 30 and y = 20
1346
1347 setenv splashpos -10,m
1348 => vertically centered image
1349 at x = dspWidth - bmpWidth - 9
1350
98f4a3df
SR
1351- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1352
1353 If this option is set, additionally to standard BMP
1354 images, gzipped BMP images can be displayed via the
1355 splashscreen support or the bmp command.
1356
d5011762
AG
1357- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1358
1359 If this option is set, 8-bit RLE compressed BMP images
1360 can be displayed via the splashscreen support or the
1361 bmp command.
1362
c29fdfc1 1363- Compression support:
8ef70478
KC
1364 CONFIG_GZIP
1365
1366 Enabled by default to support gzip compressed images.
1367
c29fdfc1
WD
1368 CONFIG_BZIP2
1369
1370 If this option is set, support for bzip2 compressed
1371 images is included. If not, only uncompressed and gzip
1372 compressed images are supported.
1373
42d1f039 1374 NOTE: the bzip2 algorithm requires a lot of RAM, so
6d0f6bcf 1375 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
42d1f039 1376 be at least 4MB.
d791b1dc 1377
17ea1177 1378- MII/PHY support:
17ea1177
WD
1379 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1380
1381 The clock frequency of the MII bus
1382
17ea1177
WD
1383 CONFIG_PHY_RESET_DELAY
1384
1385 Some PHY like Intel LXT971A need extra delay after
1386 reset before any MII register access is possible.
1387 For such PHY, set this option to the usec delay
1388 required. (minimum 300usec for LXT971A)
1389
1390 CONFIG_PHY_CMD_DELAY (ppc4xx)
1391
1392 Some PHY like Intel LXT971A need extra delay after
1393 command issued before MII status register can be read
1394
c609719b
WD
1395- IP address:
1396 CONFIG_IPADDR
1397
1398 Define a default value for the IP address to use for
11ccc33f 1399 the default Ethernet interface, in case this is not
c609719b 1400 determined through e.g. bootp.
1ebcd654 1401 (Environment variable "ipaddr")
c609719b
WD
1402
1403- Server IP address:
1404 CONFIG_SERVERIP
1405
11ccc33f 1406 Defines a default value for the IP address of a TFTP
c609719b 1407 server to contact when using the "tftboot" command.
1ebcd654 1408 (Environment variable "serverip")
c609719b 1409
97cfe861
RG
1410 CONFIG_KEEP_SERVERADDR
1411
1412 Keeps the server's MAC address, in the env 'serveraddr'
1413 for passing to bootargs (like Linux's netconsole option)
1414
1ebcd654
WD
1415- Gateway IP address:
1416 CONFIG_GATEWAYIP
1417
1418 Defines a default value for the IP address of the
1419 default router where packets to other networks are
1420 sent to.
1421 (Environment variable "gatewayip")
1422
1423- Subnet mask:
1424 CONFIG_NETMASK
1425
1426 Defines a default value for the subnet mask (or
1427 routing prefix) which is used to determine if an IP
1428 address belongs to the local subnet or needs to be
1429 forwarded through a router.
1430 (Environment variable "netmask")
1431
53a5c424
DU
1432- Multicast TFTP Mode:
1433 CONFIG_MCAST_TFTP
1434
1435 Defines whether you want to support multicast TFTP as per
1436 rfc-2090; for example to work with atftp. Lets lots of targets
11ccc33f 1437 tftp down the same boot image concurrently. Note: the Ethernet
53a5c424
DU
1438 driver in use must provide a function: mcast() to join/leave a
1439 multicast group.
1440
c609719b
WD
1441- BOOTP Recovery Mode:
1442 CONFIG_BOOTP_RANDOM_DELAY
1443
1444 If you have many targets in a network that try to
1445 boot using BOOTP, you may want to avoid that all
1446 systems send out BOOTP requests at precisely the same
1447 moment (which would happen for instance at recovery
1448 from a power failure, when all systems will try to
1449 boot, thus flooding the BOOTP server. Defining
1450 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1451 inserted before sending out BOOTP requests. The
6c33c785 1452 following delays are inserted then:
c609719b
WD
1453
1454 1st BOOTP request: delay 0 ... 1 sec
1455 2nd BOOTP request: delay 0 ... 2 sec
1456 3rd BOOTP request: delay 0 ... 4 sec
1457 4th and following
1458 BOOTP requests: delay 0 ... 8 sec
1459
92ac8acc
TR
1460 CONFIG_BOOTP_ID_CACHE_SIZE
1461
1462 BOOTP packets are uniquely identified using a 32-bit ID. The
1463 server will copy the ID from client requests to responses and
1464 U-Boot will use this to determine if it is the destination of
1465 an incoming response. Some servers will check that addresses
1466 aren't in use before handing them out (usually using an ARP
1467 ping) and therefore take up to a few hundred milliseconds to
1468 respond. Network congestion may also influence the time it
1469 takes for a response to make it back to the client. If that
1470 time is too long, U-Boot will retransmit requests. In order
1471 to allow earlier responses to still be accepted after these
1472 retransmissions, U-Boot's BOOTP client keeps a small cache of
1473 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
1474 cache. The default is to keep IDs for up to four outstanding
1475 requests. Increasing this will allow U-Boot to accept offers
1476 from a BOOTP client in networks with unusually high latency.
1477
fe389a82 1478- DHCP Advanced Options:
1fe80d79
JL
1479 You can fine tune the DHCP functionality by defining
1480 CONFIG_BOOTP_* symbols:
1481
1fe80d79 1482 CONFIG_BOOTP_NISDOMAIN
1fe80d79 1483 CONFIG_BOOTP_BOOTFILESIZE
1fe80d79
JL
1484 CONFIG_BOOTP_SEND_HOSTNAME
1485 CONFIG_BOOTP_NTPSERVER
1486 CONFIG_BOOTP_TIMEOFFSET
1487 CONFIG_BOOTP_VENDOREX
2c00e099 1488 CONFIG_BOOTP_MAY_FAIL
fe389a82 1489
5d110f0a
WC
1490 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1491 environment variable, not the BOOTP server.
fe389a82 1492
2c00e099
JH
1493 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1494 after the configured retry count, the call will fail
1495 instead of starting over. This can be used to fail over
1496 to Link-local IP address configuration if the DHCP server
1497 is not available.
1498
fe389a82
SR
1499 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1500 to do a dynamic update of a DNS server. To do this, they
1501 need the hostname of the DHCP requester.
5d110f0a 1502 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1fe80d79
JL
1503 of the "hostname" environment variable is passed as
1504 option 12 to the DHCP server.
fe389a82 1505
d9a2f416
AV
1506 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1507
1508 A 32bit value in microseconds for a delay between
1509 receiving a "DHCP Offer" and sending the "DHCP Request".
1510 This fixes a problem with certain DHCP servers that don't
1511 respond 100% of the time to a "DHCP request". E.g. On an
1512 AT91RM9200 processor running at 180MHz, this delay needed
1513 to be *at least* 15,000 usec before a Windows Server 2003
1514 DHCP server would reply 100% of the time. I recommend at
1515 least 50,000 usec to be safe. The alternative is to hope
1516 that one of the retries will be successful but note that
1517 the DHCP timeout and retry process takes a longer than
1518 this delay.
1519
d22c338e
JH
1520 - Link-local IP address negotiation:
1521 Negotiate with other link-local clients on the local network
1522 for an address that doesn't require explicit configuration.
1523 This is especially useful if a DHCP server cannot be guaranteed
1524 to exist in all environments that the device must operate.
1525
1526 See doc/README.link-local for more information.
1527
24acb83d
PK
1528 - MAC address from environment variables
1529
1530 FDT_SEQ_MACADDR_FROM_ENV
1531
1532 Fix-up device tree with MAC addresses fetched sequentially from
1533 environment variables. This config work on assumption that
1534 non-usable ethernet node of device-tree are either not present
1535 or their status has been marked as "disabled".
1536
a3d991bd 1537 - CDP Options:
6e592385 1538 CONFIG_CDP_DEVICE_ID
a3d991bd
WD
1539
1540 The device id used in CDP trigger frames.
1541
1542 CONFIG_CDP_DEVICE_ID_PREFIX
1543
1544 A two character string which is prefixed to the MAC address
1545 of the device.
1546
1547 CONFIG_CDP_PORT_ID
1548
1549 A printf format string which contains the ascii name of
1550 the port. Normally is set to "eth%d" which sets
11ccc33f 1551 eth0 for the first Ethernet, eth1 for the second etc.
a3d991bd
WD
1552
1553 CONFIG_CDP_CAPABILITIES
1554
1555 A 32bit integer which indicates the device capabilities;
1556 0x00000010 for a normal host which does not forwards.
1557
1558 CONFIG_CDP_VERSION
1559
1560 An ascii string containing the version of the software.
1561
1562 CONFIG_CDP_PLATFORM
1563
1564 An ascii string containing the name of the platform.
1565
1566 CONFIG_CDP_TRIGGER
1567
1568 A 32bit integer sent on the trigger.
1569
1570 CONFIG_CDP_POWER_CONSUMPTION
1571
1572 A 16bit integer containing the power consumption of the
1573 device in .1 of milliwatts.
1574
1575 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1576
1577 A byte containing the id of the VLAN.
1578
79267edd 1579- Status LED: CONFIG_LED_STATUS
c609719b
WD
1580
1581 Several configurations allow to display the current
1582 status using a LED. For instance, the LED will blink
1583 fast while running U-Boot code, stop blinking as
1584 soon as a reply to a BOOTP request was received, and
1585 start blinking slow once the Linux kernel is running
1586 (supported by a status LED driver in the Linux
79267edd 1587 kernel). Defining CONFIG_LED_STATUS enables this
c609719b
WD
1588 feature in U-Boot.
1589
1df7bbba
IG
1590 Additional options:
1591
79267edd 1592 CONFIG_LED_STATUS_GPIO
1df7bbba
IG
1593 The status LED can be connected to a GPIO pin.
1594 In such cases, the gpio_led driver can be used as a
79267edd 1595 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO
1df7bbba
IG
1596 to include the gpio_led driver in the U-Boot binary.
1597
9dfdcdfe
IG
1598 CONFIG_GPIO_LED_INVERTED_TABLE
1599 Some GPIO connected LEDs may have inverted polarity in which
1600 case the GPIO high value corresponds to LED off state and
1601 GPIO low value corresponds to LED on state.
1602 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
1603 with a list of GPIO LEDs that have inverted polarity.
1604
3f4978c7
HS
1605- I2C Support: CONFIG_SYS_I2C
1606
1607 This enable the NEW i2c subsystem, and will allow you to use
1608 i2c commands at the u-boot command line (as long as you set
1609 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
1610 based realtime clock chips or other i2c devices. See
1611 common/cmd_i2c.c for a description of the command line
1612 interface.
1613
1614 ported i2c driver to the new framework:
ea818dbb
HS
1615 - drivers/i2c/soft_i2c.c:
1616 - activate first bus with CONFIG_SYS_I2C_SOFT define
1617 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
1618 for defining speed and slave address
1619 - activate second bus with I2C_SOFT_DECLARATIONS2 define
1620 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
1621 for defining speed and slave address
1622 - activate third bus with I2C_SOFT_DECLARATIONS3 define
1623 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
1624 for defining speed and slave address
1625 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
1626 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
1627 for defining speed and slave address
3f4978c7 1628
00f792e0
HS
1629 - drivers/i2c/fsl_i2c.c:
1630 - activate i2c driver with CONFIG_SYS_I2C_FSL
1631 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
1632 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
1633 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
1634 bus.
93e14596 1635 - If your board supports a second fsl i2c bus, define
00f792e0
HS
1636 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
1637 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
1638 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
1639 second bus.
1640
1f2ba722 1641 - drivers/i2c/tegra_i2c.c:
10cee516
NI
1642 - activate this driver with CONFIG_SYS_I2C_TEGRA
1643 - This driver adds 4 i2c buses with a fix speed from
1644 100000 and the slave addr 0!
1f2ba722 1645
880540de
DE
1646 - drivers/i2c/ppc4xx_i2c.c
1647 - activate this driver with CONFIG_SYS_I2C_PPC4XX
1648 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
1649 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
1650
fac96408 1651 - drivers/i2c/i2c_mxc.c
1652 - activate this driver with CONFIG_SYS_I2C_MXC
03544c66
AA
1653 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
1654 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
1655 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
1656 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
fac96408 1657 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
1658 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
1659 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
1660 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
1661 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
1662 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
03544c66
AA
1663 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
1664 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
b445bbb4 1665 If those defines are not set, default value is 100000
fac96408 1666 for speed, and 0 for slave.
1667
1086bfa9
NI
1668 - drivers/i2c/rcar_i2c.c:
1669 - activate this driver with CONFIG_SYS_I2C_RCAR
1670 - This driver adds 4 i2c buses
1671
1672 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
1673 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
1674 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
1675 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
1676 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
1677 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
1678 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
1679 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
1680 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
1681
2035d77d
NI
1682 - drivers/i2c/sh_i2c.c:
1683 - activate this driver with CONFIG_SYS_I2C_SH
1684 - This driver adds from 2 to 5 i2c buses
1685
1686 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
1687 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
1688 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
1689 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
1690 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
1691 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
1692 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
1693 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
1694 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
1695 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
b445bbb4 1696 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2035d77d 1697
6789e84e
HS
1698 - drivers/i2c/omap24xx_i2c.c
1699 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
1700 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
1701 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
1702 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
1703 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
1704 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
1705 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
1706 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
1707 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
1708 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
1709 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
1710
0bdffe71
HS
1711 - drivers/i2c/zynq_i2c.c
1712 - activate this driver with CONFIG_SYS_I2C_ZYNQ
1713 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
1714 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
1715
e717fc6d
NKC
1716 - drivers/i2c/s3c24x0_i2c.c:
1717 - activate this driver with CONFIG_SYS_I2C_S3C24X0
1718 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
1719 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
1720 with a fix speed from 100000 and the slave addr 0!
1721
b46226bd
DE
1722 - drivers/i2c/ihs_i2c.c
1723 - activate this driver with CONFIG_SYS_I2C_IHS
1724 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
1725 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
1726 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
1727 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
1728 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
1729 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
1730 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
1731 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
1732 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
1733 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
1734 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
1735 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
071be896
DE
1736 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
1737 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
1738 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
1739 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
1740 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
1741 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
1742 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
1743 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
1744 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
b46226bd 1745
3f4978c7
HS
1746 additional defines:
1747
1748 CONFIG_SYS_NUM_I2C_BUSES
945a18e6 1749 Hold the number of i2c buses you want to use.
3f4978c7
HS
1750
1751 CONFIG_SYS_I2C_DIRECT_BUS
1752 define this, if you don't use i2c muxes on your hardware.
1753 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
1754 omit this define.
1755
1756 CONFIG_SYS_I2C_MAX_HOPS
1757 define how many muxes are maximal consecutively connected
1758 on one i2c bus. If you not use i2c muxes, omit this
1759 define.
1760
1761 CONFIG_SYS_I2C_BUSES
b445bbb4 1762 hold a list of buses you want to use, only used if
3f4978c7
HS
1763 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
1764 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
1765 CONFIG_SYS_NUM_I2C_BUSES = 9:
1766
1767 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
1768 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
1769 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
1770 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
1771 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
1772 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
1773 {1, {I2C_NULL_HOP}}, \
1774 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
1775 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
1776 }
1777
1778 which defines
1779 bus 0 on adapter 0 without a mux
ea818dbb
HS
1780 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
1781 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
1782 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
1783 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
1784 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
3f4978c7 1785 bus 6 on adapter 1 without a mux
ea818dbb
HS
1786 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
1787 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
3f4978c7
HS
1788
1789 If you do not have i2c muxes on your board, omit this define.
1790
ce3b5d69 1791- Legacy I2C Support:
ea818dbb 1792 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
b37c7e5e
WD
1793 then the following macros need to be defined (examples are
1794 from include/configs/lwmon.h):
c609719b
WD
1795
1796 I2C_INIT
1797
b37c7e5e 1798 (Optional). Any commands necessary to enable the I2C
43d9616c 1799 controller or configure ports.
c609719b 1800
ba56f625 1801 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
b37c7e5e 1802
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WD
1803 I2C_ACTIVE
1804
1805 The code necessary to make the I2C data line active
1806 (driven). If the data line is open collector, this
1807 define can be null.
1808
b37c7e5e
WD
1809 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1810
c609719b
WD
1811 I2C_TRISTATE
1812
1813 The code necessary to make the I2C data line tri-stated
1814 (inactive). If the data line is open collector, this
1815 define can be null.
1816
b37c7e5e
WD
1817 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1818
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WD
1819 I2C_READ
1820
472d5460
YS
1821 Code that returns true if the I2C data line is high,
1822 false if it is low.
c609719b 1823
b37c7e5e
WD
1824 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1825
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WD
1826 I2C_SDA(bit)
1827
472d5460
YS
1828 If <bit> is true, sets the I2C data line high. If it
1829 is false, it clears it (low).
c609719b 1830
b37c7e5e 1831 eg: #define I2C_SDA(bit) \
2535d602 1832 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
ba56f625 1833 else immr->im_cpm.cp_pbdat &= ~PB_SDA
b37c7e5e 1834
c609719b
WD
1835 I2C_SCL(bit)
1836
472d5460
YS
1837 If <bit> is true, sets the I2C clock line high. If it
1838 is false, it clears it (low).
c609719b 1839
b37c7e5e 1840 eg: #define I2C_SCL(bit) \
2535d602 1841 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
ba56f625 1842 else immr->im_cpm.cp_pbdat &= ~PB_SCL
b37c7e5e 1843
c609719b
WD
1844 I2C_DELAY
1845
1846 This delay is invoked four times per clock cycle so this
1847 controls the rate of data transfer. The data rate thus
b37c7e5e 1848 is 1 / (I2C_DELAY * 4). Often defined to be something
945af8d7
WD
1849 like:
1850
b37c7e5e 1851 #define I2C_DELAY udelay(2)
c609719b 1852
793b5726
MF
1853 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1854
1855 If your arch supports the generic GPIO framework (asm/gpio.h),
1856 then you may alternatively define the two GPIOs that are to be
1857 used as SCL / SDA. Any of the previous I2C_xxx macros will
1858 have GPIO-based defaults assigned to them as appropriate.
1859
1860 You should define these to the GPIO value as given directly to
1861 the generic GPIO functions.
1862
6d0f6bcf 1863 CONFIG_SYS_I2C_INIT_BOARD
47cd00fa 1864
8bde7f77
WD
1865 When a board is reset during an i2c bus transfer
1866 chips might think that the current transfer is still
1867 in progress. On some boards it is possible to access
1868 the i2c SCLK line directly, either by using the
1869 processor pin as a GPIO or by having a second pin
1870 connected to the bus. If this option is defined a
1871 custom i2c_init_board() routine in boards/xxx/board.c
1872 is run early in the boot sequence.
47cd00fa 1873
bb99ad6d
BW
1874 CONFIG_I2C_MULTI_BUS
1875
1876 This option allows the use of multiple I2C buses, each of which
c0f40859
WD
1877 must have a controller. At any point in time, only one bus is
1878 active. To switch to a different bus, use the 'i2c dev' command.
bb99ad6d
BW
1879 Note that bus numbering is zero-based.
1880
6d0f6bcf 1881 CONFIG_SYS_I2C_NOPROBES
bb99ad6d
BW
1882
1883 This option specifies a list of I2C devices that will be skipped
c0f40859 1884 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
0f89c54b
PT
1885 is set, specify a list of bus-device pairs. Otherwise, specify
1886 a 1D array of device addresses
bb99ad6d
BW
1887
1888 e.g.
1889 #undef CONFIG_I2C_MULTI_BUS
c0f40859 1890 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
bb99ad6d
BW
1891
1892 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1893
c0f40859 1894 #define CONFIG_I2C_MULTI_BUS
945a18e6 1895 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
bb99ad6d
BW
1896
1897 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1898
6d0f6bcf 1899 CONFIG_SYS_SPD_BUS_NUM
be5e6181
TT
1900
1901 If defined, then this indicates the I2C bus number for DDR SPD.
1902 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1903
6d0f6bcf 1904 CONFIG_SYS_RTC_BUS_NUM
0dc018ec
SR
1905
1906 If defined, then this indicates the I2C bus number for the RTC.
1907 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1908
2ac6985a
AD
1909 CONFIG_SOFT_I2C_READ_REPEATED_START
1910
1911 defining this will force the i2c_read() function in
1912 the soft_i2c driver to perform an I2C repeated start
1913 between writing the address pointer and reading the
1914 data. If this define is omitted the default behaviour
1915 of doing a stop-start sequence will be used. Most I2C
1916 devices can use either method, but some require one or
1917 the other.
be5e6181 1918
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WD
1919- SPI Support: CONFIG_SPI
1920
1921 Enables SPI driver (so far only tested with
1922 SPI EEPROM, also an instance works with Crystal A/D and
1923 D/As on the SACSng board)
1924
c609719b
WD
1925 CONFIG_SOFT_SPI
1926
43d9616c
WD
1927 Enables a software (bit-bang) SPI driver rather than
1928 using hardware support. This is a general purpose
1929 driver that only requires three general I/O port pins
1930 (two outputs, one input) to function. If this is
1931 defined, the board configuration must define several
1932 SPI configuration items (port pins to use, etc). For
1933 an example, see include/configs/sacsng.h.
c609719b 1934
f659b573
HS
1935 CONFIG_SYS_SPI_MXC_WAIT
1936 Timeout for waiting until spi transfer completed.
1937 default: (CONFIG_SYS_HZ/100) /* 10 ms */
1938
0133502e 1939- FPGA Support: CONFIG_FPGA
c609719b 1940
0133502e
MF
1941 Enables FPGA subsystem.
1942
1943 CONFIG_FPGA_<vendor>
1944
1945 Enables support for specific chip vendors.
1946 (ALTERA, XILINX)
c609719b 1947
0133502e 1948 CONFIG_FPGA_<family>
c609719b 1949
0133502e
MF
1950 Enables support for FPGA family.
1951 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1952
1953 CONFIG_FPGA_COUNT
1954
1955 Specify the number of FPGA devices to support.
c609719b 1956
6d0f6bcf 1957 CONFIG_SYS_FPGA_PROG_FEEDBACK
c609719b 1958
8bde7f77 1959 Enable printing of hash marks during FPGA configuration.
c609719b 1960
6d0f6bcf 1961 CONFIG_SYS_FPGA_CHECK_BUSY
c609719b 1962
43d9616c
WD
1963 Enable checks on FPGA configuration interface busy
1964 status by the configuration function. This option
1965 will require a board or device specific function to
1966 be written.
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WD
1967
1968 CONFIG_FPGA_DELAY
1969
1970 If defined, a function that provides delays in the FPGA
1971 configuration driver.
1972
6d0f6bcf 1973 CONFIG_SYS_FPGA_CHECK_CTRLC
c609719b
WD
1974 Allow Control-C to interrupt FPGA configuration
1975
6d0f6bcf 1976 CONFIG_SYS_FPGA_CHECK_ERROR
c609719b 1977
43d9616c
WD
1978 Check for configuration errors during FPGA bitfile
1979 loading. For example, abort during Virtex II
1980 configuration if the INIT_B line goes low (which
1981 indicated a CRC error).
c609719b 1982
6d0f6bcf 1983 CONFIG_SYS_FPGA_WAIT_INIT
c609719b 1984
b445bbb4
JM
1985 Maximum time to wait for the INIT_B line to de-assert
1986 after PROB_B has been de-asserted during a Virtex II
43d9616c 1987 FPGA configuration sequence. The default time is 500
11ccc33f 1988 ms.
c609719b 1989
6d0f6bcf 1990 CONFIG_SYS_FPGA_WAIT_BUSY
c609719b 1991
b445bbb4 1992 Maximum time to wait for BUSY to de-assert during
11ccc33f 1993 Virtex II FPGA configuration. The default is 5 ms.
c609719b 1994
6d0f6bcf 1995 CONFIG_SYS_FPGA_WAIT_CONFIG
c609719b 1996
43d9616c 1997 Time to wait after FPGA configuration. The default is
11ccc33f 1998 200 ms.
c609719b
WD
1999
2000- Configuration Management:
b2b8a696
SR
2001 CONFIG_BUILD_TARGET
2002
2003 Some SoCs need special image types (e.g. U-Boot binary
2004 with a special header) as build targets. By defining
2005 CONFIG_BUILD_TARGET in the SoC / board header, this
2006 special image will be automatically built upon calling
6de80f21 2007 make / buildman.
b2b8a696 2008
c609719b
WD
2009 CONFIG_IDENT_STRING
2010
43d9616c
WD
2011 If defined, this string will be added to the U-Boot
2012 version information (U_BOOT_VERSION)
c609719b
WD
2013
2014- Vendor Parameter Protection:
2015
43d9616c
WD
2016 U-Boot considers the values of the environment
2017 variables "serial#" (Board Serial Number) and
7152b1d0 2018 "ethaddr" (Ethernet Address) to be parameters that
43d9616c
WD
2019 are set once by the board vendor / manufacturer, and
2020 protects these variables from casual modification by
2021 the user. Once set, these variables are read-only,
2022 and write or delete attempts are rejected. You can
11ccc33f 2023 change this behaviour:
c609719b
WD
2024
2025 If CONFIG_ENV_OVERWRITE is #defined in your config
2026 file, the write protection for vendor parameters is
47cd00fa 2027 completely disabled. Anybody can change or delete
c609719b
WD
2028 these parameters.
2029
92ac5208
JH
2030 Alternatively, if you define _both_ an ethaddr in the
2031 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
11ccc33f 2032 Ethernet address is installed in the environment,
c609719b
WD
2033 which can be changed exactly ONCE by the user. [The
2034 serial# is unaffected by this, i. e. it remains
2035 read-only.]
2036
2598090b
JH
2037 The same can be accomplished in a more flexible way
2038 for any variable by configuring the type of access
2039 to allow for those variables in the ".flags" variable
2040 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2041
c609719b
WD
2042- Protected RAM:
2043 CONFIG_PRAM
2044
2045 Define this variable to enable the reservation of
2046 "protected RAM", i. e. RAM which is not overwritten
2047 by U-Boot. Define CONFIG_PRAM to hold the number of
2048 kB you want to reserve for pRAM. You can overwrite
2049 this default value by defining an environment
2050 variable "pram" to the number of kB you want to
2051 reserve. Note that the board info structure will
2052 still show the full amount of RAM. If pRAM is
2053 reserved, a new environment variable "mem" will
2054 automatically be defined to hold the amount of
2055 remaining RAM in a form that can be passed as boot
2056 argument to Linux, for instance like that:
2057
fe126d8b 2058 setenv bootargs ... mem=\${mem}
c609719b
WD
2059 saveenv
2060
2061 This way you can tell Linux not to use this memory,
2062 either, which results in a memory region that will
2063 not be affected by reboots.
2064
2065 *WARNING* If your board configuration uses automatic
2066 detection of the RAM size, you must make sure that
2067 this memory test is non-destructive. So far, the
2068 following board configurations are known to be
2069 "pRAM-clean":
2070
5b8e76c3 2071 IVMS8, IVML24, SPD8xx,
1b0757ec 2072 HERMES, IP860, RPXlite, LWMON,
2eb48ff7 2073 FLAGADM
c609719b 2074
40fef049
GB
2075- Access to physical memory region (> 4GB)
2076 Some basic support is provided for operations on memory not
2077 normally accessible to U-Boot - e.g. some architectures
2078 support access to more than 4GB of memory on 32-bit
2079 machines using physical address extension or similar.
2080 Define CONFIG_PHYSMEM to access this basic support, which
2081 currently only supports clearing the memory.
2082
c609719b 2083- Error Recovery:
c609719b
WD
2084 CONFIG_NET_RETRY_COUNT
2085
43d9616c
WD
2086 This variable defines the number of retries for
2087 network operations like ARP, RARP, TFTP, or BOOTP
2088 before giving up the operation. If not defined, a
2089 default value of 5 is used.
c609719b 2090
40cb90ee
GL
2091 CONFIG_ARP_TIMEOUT
2092
2093 Timeout waiting for an ARP reply in milliseconds.
2094
48a3e999
TK
2095 CONFIG_NFS_TIMEOUT
2096
2097 Timeout in milliseconds used in NFS protocol.
2098 If you encounter "ERROR: Cannot umount" in nfs command,
2099 try longer timeout such as
2100 #define CONFIG_NFS_TIMEOUT 10000UL
2101
c609719b 2102- Command Interpreter:
6d0f6bcf 2103 CONFIG_SYS_PROMPT_HUSH_PS2
c609719b
WD
2104
2105 This defines the secondary prompt string, which is
2106 printed when the command interpreter needs more input
2107 to complete a command. Usually "> ".
2108
2109 Note:
2110
8bde7f77
WD
2111 In the current implementation, the local variables
2112 space and global environment variables space are
2113 separated. Local variables are those you define by
2114 simply typing `name=value'. To access a local
2115 variable later on, you have write `$name' or
2116 `${name}'; to execute the contents of a variable
2117 directly type `$name' at the command prompt.
c609719b 2118
43d9616c
WD
2119 Global environment variables are those you use
2120 setenv/printenv to work with. To run a command stored
2121 in such a variable, you need to use the run command,
2122 and you must not use the '$' sign to access them.
c609719b
WD
2123
2124 To store commands and special characters in a
2125 variable, please use double quotation marks
2126 surrounding the whole text of the variable, instead
2127 of the backslashes before semicolons and special
2128 symbols.
2129
b445bbb4 2130- Command Line Editing and History:
f3b267b3
MV
2131 CONFIG_CMDLINE_PS_SUPPORT
2132
2133 Enable support for changing the command prompt string
2134 at run-time. Only static string is supported so far.
2135 The string is obtained from environment variables PS1
2136 and PS2.
2137
a8c7c708 2138- Default Environment:
c609719b
WD
2139 CONFIG_EXTRA_ENV_SETTINGS
2140
43d9616c
WD
2141 Define this to contain any number of null terminated
2142 strings (variable = value pairs) that will be part of
7152b1d0 2143 the default environment compiled into the boot image.
2262cfee 2144
43d9616c
WD
2145 For example, place something like this in your
2146 board's config file:
c609719b
WD
2147
2148 #define CONFIG_EXTRA_ENV_SETTINGS \
2149 "myvar1=value1\0" \
2150 "myvar2=value2\0"
2151
43d9616c
WD
2152 Warning: This method is based on knowledge about the
2153 internal format how the environment is stored by the
2154 U-Boot code. This is NOT an official, exported
2155 interface! Although it is unlikely that this format
7152b1d0 2156 will change soon, there is no guarantee either.
c609719b
WD
2157 You better know what you are doing here.
2158
43d9616c
WD
2159 Note: overly (ab)use of the default environment is
2160 discouraged. Make sure to check other ways to preset
74de7aef 2161 the environment like the "source" command or the
43d9616c 2162 boot command first.
c609719b 2163
06fd8538
SG
2164 CONFIG_DELAY_ENVIRONMENT
2165
2166 Normally the environment is loaded when the board is
b445bbb4 2167 initialised so that it is available to U-Boot. This inhibits
06fd8538
SG
2168 that so that the environment is not available until
2169 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2170 this is instead controlled by the value of
2171 /config/load-environment.
2172
f61ec45e 2173- Serial Flash support
00fd59dd 2174 Usage requires an initial 'sf probe' to define the serial
f61ec45e
EN
2175 flash parameters, followed by read/write/erase/update
2176 commands.
2177
2178 The following defaults may be provided by the platform
2179 to handle the common case when only a single serial
2180 flash is present on the system.
2181
2182 CONFIG_SF_DEFAULT_BUS Bus identifier
2183 CONFIG_SF_DEFAULT_CS Chip-select
2184 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2185 CONFIG_SF_DEFAULT_SPEED in Hz
2186
3f85ce27 2187
ecb0ccd9
WD
2188- TFTP Fixed UDP Port:
2189 CONFIG_TFTP_PORT
2190
28cb9375 2191 If this is defined, the environment variable tftpsrcp
ecb0ccd9 2192 is used to supply the TFTP UDP source port value.
28cb9375 2193 If tftpsrcp isn't defined, the normal pseudo-random port
ecb0ccd9
WD
2194 number generator is used.
2195
28cb9375
WD
2196 Also, the environment variable tftpdstp is used to supply
2197 the TFTP UDP destination port value. If tftpdstp isn't
2198 defined, the normal port 69 is used.
2199
2200 The purpose for tftpsrcp is to allow a TFTP server to
ecb0ccd9
WD
2201 blindly start the TFTP transfer using the pre-configured
2202 target IP address and UDP port. This has the effect of
2203 "punching through" the (Windows XP) firewall, allowing
2204 the remainder of the TFTP transfer to proceed normally.
2205 A better solution is to properly configure the firewall,
2206 but sometimes that is not allowed.
2207
a8c7c708 2208- Show boot progress:
c609719b
WD
2209 CONFIG_SHOW_BOOT_PROGRESS
2210
43d9616c
WD
2211 Defining this option allows to add some board-
2212 specific code (calling a user-provided function
2213 "show_boot_progress(int)") that enables you to show
2214 the system's boot progress on some display (for
2215 example, some LED's) on your board. At the moment,
2216 the following checkpoints are implemented:
c609719b 2217
94fd1316 2218
1372cce2
MB
2219Legacy uImage format:
2220
c609719b
WD
2221 Arg Where When
2222 1 common/cmd_bootm.c before attempting to boot an image
ba56f625 2223 -1 common/cmd_bootm.c Image header has bad magic number
c609719b 2224 2 common/cmd_bootm.c Image header has correct magic number
ba56f625 2225 -2 common/cmd_bootm.c Image header has bad checksum
c609719b 2226 3 common/cmd_bootm.c Image header has correct checksum
ba56f625 2227 -3 common/cmd_bootm.c Image data has bad checksum
c609719b
WD
2228 4 common/cmd_bootm.c Image data has correct checksum
2229 -4 common/cmd_bootm.c Image is for unsupported architecture
2230 5 common/cmd_bootm.c Architecture check OK
1372cce2 2231 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
c609719b
WD
2232 6 common/cmd_bootm.c Image Type check OK
2233 -6 common/cmd_bootm.c gunzip uncompression error
2234 -7 common/cmd_bootm.c Unimplemented compression type
2235 7 common/cmd_bootm.c Uncompression OK
1372cce2 2236 8 common/cmd_bootm.c No uncompress/copy overwrite error
c609719b 2237 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1372cce2
MB
2238
2239 9 common/image.c Start initial ramdisk verification
2240 -10 common/image.c Ramdisk header has bad magic number
2241 -11 common/image.c Ramdisk header has bad checksum
2242 10 common/image.c Ramdisk header is OK
2243 -12 common/image.c Ramdisk data has bad checksum
2244 11 common/image.c Ramdisk data has correct checksum
2245 12 common/image.c Ramdisk verification complete, start loading
11ccc33f 2246 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
1372cce2
MB
2247 13 common/image.c Start multifile image verification
2248 14 common/image.c No initial ramdisk, no multifile, continue.
2249
c0f40859 2250 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
c609719b 2251
a47a12be 2252 -30 arch/powerpc/lib/board.c Fatal error, hang the system
11dadd54
WD
2253 -31 post/post.c POST test failed, detected by post_output_backlog()
2254 -32 post/post.c POST test failed, detected by post_run_single()
63e73c9a 2255
566a494f
HS
2256 34 common/cmd_doc.c before loading a Image from a DOC device
2257 -35 common/cmd_doc.c Bad usage of "doc" command
2258 35 common/cmd_doc.c correct usage of "doc" command
2259 -36 common/cmd_doc.c No boot device
2260 36 common/cmd_doc.c correct boot device
2261 -37 common/cmd_doc.c Unknown Chip ID on boot device
2262 37 common/cmd_doc.c correct chip ID found, device available
2263 -38 common/cmd_doc.c Read Error on boot device
2264 38 common/cmd_doc.c reading Image header from DOC device OK
2265 -39 common/cmd_doc.c Image header has bad magic number
2266 39 common/cmd_doc.c Image header has correct magic number
2267 -40 common/cmd_doc.c Error reading Image from DOC device
2268 40 common/cmd_doc.c Image header has correct magic number
2269 41 common/cmd_ide.c before loading a Image from a IDE device
2270 -42 common/cmd_ide.c Bad usage of "ide" command
2271 42 common/cmd_ide.c correct usage of "ide" command
2272 -43 common/cmd_ide.c No boot device
2273 43 common/cmd_ide.c boot device found
2274 -44 common/cmd_ide.c Device not available
2275 44 common/cmd_ide.c Device available
2276 -45 common/cmd_ide.c wrong partition selected
2277 45 common/cmd_ide.c partition selected
2278 -46 common/cmd_ide.c Unknown partition table
2279 46 common/cmd_ide.c valid partition table found
2280 -47 common/cmd_ide.c Invalid partition type
2281 47 common/cmd_ide.c correct partition type
2282 -48 common/cmd_ide.c Error reading Image Header on boot device
2283 48 common/cmd_ide.c reading Image Header from IDE device OK
2284 -49 common/cmd_ide.c Image header has bad magic number
2285 49 common/cmd_ide.c Image header has correct magic number
2286 -50 common/cmd_ide.c Image header has bad checksum
2287 50 common/cmd_ide.c Image header has correct checksum
2288 -51 common/cmd_ide.c Error reading Image from IDE device
2289 51 common/cmd_ide.c reading Image from IDE device OK
2290 52 common/cmd_nand.c before loading a Image from a NAND device
2291 -53 common/cmd_nand.c Bad usage of "nand" command
2292 53 common/cmd_nand.c correct usage of "nand" command
2293 -54 common/cmd_nand.c No boot device
2294 54 common/cmd_nand.c boot device found
2295 -55 common/cmd_nand.c Unknown Chip ID on boot device
2296 55 common/cmd_nand.c correct chip ID found, device available
2297 -56 common/cmd_nand.c Error reading Image Header on boot device
2298 56 common/cmd_nand.c reading Image Header from NAND device OK
2299 -57 common/cmd_nand.c Image header has bad magic number
2300 57 common/cmd_nand.c Image header has correct magic number
2301 -58 common/cmd_nand.c Error reading Image from NAND device
2302 58 common/cmd_nand.c reading Image from NAND device OK
2303
2304 -60 common/env_common.c Environment has a bad CRC, using default
2305
11ccc33f 2306 64 net/eth.c starting with Ethernet configuration.
566a494f
HS
2307 -64 net/eth.c no Ethernet found.
2308 65 net/eth.c Ethernet found.
2309
2310 -80 common/cmd_net.c usage wrong
bc0571fc
JH
2311 80 common/cmd_net.c before calling net_loop()
2312 -81 common/cmd_net.c some error in net_loop() occurred
2313 81 common/cmd_net.c net_loop() back without error
566a494f
HS
2314 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2315 82 common/cmd_net.c trying automatic boot
74de7aef
WD
2316 83 common/cmd_net.c running "source" command
2317 -83 common/cmd_net.c some error in automatic boot or "source" command
566a494f 2318 84 common/cmd_net.c end without errors
c609719b 2319
1372cce2
MB
2320FIT uImage format:
2321
2322 Arg Where When
2323 100 common/cmd_bootm.c Kernel FIT Image has correct format
2324 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2325 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2326 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2327 102 common/cmd_bootm.c Kernel unit name specified
2328 -103 common/cmd_bootm.c Can't get kernel subimage node offset
f773bea8 2329 103 common/cmd_bootm.c Found configuration node
1372cce2
MB
2330 104 common/cmd_bootm.c Got kernel subimage node offset
2331 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2332 105 common/cmd_bootm.c Kernel subimage hash verification OK
2333 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2334 106 common/cmd_bootm.c Architecture check OK
11ccc33f
MZ
2335 -106 common/cmd_bootm.c Kernel subimage has wrong type
2336 107 common/cmd_bootm.c Kernel subimage type OK
1372cce2
MB
2337 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2338 108 common/cmd_bootm.c Got kernel subimage data/size
2339 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2340 -109 common/cmd_bootm.c Can't get kernel subimage type
2341 -110 common/cmd_bootm.c Can't get kernel subimage comp
2342 -111 common/cmd_bootm.c Can't get kernel subimage os
2343 -112 common/cmd_bootm.c Can't get kernel subimage load address
2344 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2345
2346 120 common/image.c Start initial ramdisk verification
2347 -120 common/image.c Ramdisk FIT image has incorrect format
2348 121 common/image.c Ramdisk FIT image has correct format
11ccc33f 2349 122 common/image.c No ramdisk subimage unit name, using configuration
1372cce2
MB
2350 -122 common/image.c Can't get configuration for ramdisk subimage
2351 123 common/image.c Ramdisk unit name specified
2352 -124 common/image.c Can't get ramdisk subimage node offset
2353 125 common/image.c Got ramdisk subimage node offset
2354 -125 common/image.c Ramdisk subimage hash verification failed
2355 126 common/image.c Ramdisk subimage hash verification OK
2356 -126 common/image.c Ramdisk subimage for unsupported architecture
2357 127 common/image.c Architecture check OK
2358 -127 common/image.c Can't get ramdisk subimage data/size
2359 128 common/image.c Got ramdisk subimage data/size
2360 129 common/image.c Can't get ramdisk load address
2361 -129 common/image.c Got ramdisk load address
2362
11ccc33f 2363 -130 common/cmd_doc.c Incorrect FIT image format
1372cce2
MB
2364 131 common/cmd_doc.c FIT image format OK
2365
11ccc33f 2366 -140 common/cmd_ide.c Incorrect FIT image format
1372cce2
MB
2367 141 common/cmd_ide.c FIT image format OK
2368
11ccc33f 2369 -150 common/cmd_nand.c Incorrect FIT image format
1372cce2
MB
2370 151 common/cmd_nand.c FIT image format OK
2371
4cf2609b
WD
2372- Standalone program support:
2373 CONFIG_STANDALONE_LOAD_ADDR
2374
6feff899
WD
2375 This option defines a board specific value for the
2376 address where standalone program gets loaded, thus
2377 overwriting the architecture dependent default
4cf2609b
WD
2378 settings.
2379
2380- Frame Buffer Address:
2381 CONFIG_FB_ADDR
2382
2383 Define CONFIG_FB_ADDR if you want to use specific
44a53b57
WD
2384 address for frame buffer. This is typically the case
2385 when using a graphics controller has separate video
2386 memory. U-Boot will then place the frame buffer at
2387 the given address instead of dynamically reserving it
2388 in system RAM by calling lcd_setmem(), which grabs
2389 the memory for the frame buffer depending on the
2390 configured panel size.
4cf2609b
WD
2391
2392 Please see board_init_f function.
2393
cccfc2ab
DZ
2394- Automatic software updates via TFTP server
2395 CONFIG_UPDATE_TFTP
2396 CONFIG_UPDATE_TFTP_CNT_MAX
2397 CONFIG_UPDATE_TFTP_MSEC_MAX
2398
2399 These options enable and control the auto-update feature;
2400 for a more detailed description refer to doc/README.update.
2401
2402- MTD Support (mtdparts command, UBI support)
ff94bc40
HS
2403 CONFIG_MTD_UBI_WL_THRESHOLD
2404 This parameter defines the maximum difference between the highest
2405 erase counter value and the lowest erase counter value of eraseblocks
2406 of UBI devices. When this threshold is exceeded, UBI starts performing
2407 wear leveling by means of moving data from eraseblock with low erase
2408 counter to eraseblocks with high erase counter.
2409
2410 The default value should be OK for SLC NAND flashes, NOR flashes and
2411 other flashes which have eraseblock life-cycle 100000 or more.
2412 However, in case of MLC NAND flashes which typically have eraseblock
2413 life-cycle less than 10000, the threshold should be lessened (e.g.,
2414 to 128 or 256, although it does not have to be power of 2).
2415
2416 default: 4096
c654b517 2417
ff94bc40
HS
2418 CONFIG_MTD_UBI_BEB_LIMIT
2419 This option specifies the maximum bad physical eraseblocks UBI
2420 expects on the MTD device (per 1024 eraseblocks). If the
2421 underlying flash does not admit of bad eraseblocks (e.g. NOR
2422 flash), this value is ignored.
2423
2424 NAND datasheets often specify the minimum and maximum NVM
2425 (Number of Valid Blocks) for the flashes' endurance lifetime.
2426 The maximum expected bad eraseblocks per 1024 eraseblocks
2427 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
2428 which gives 20 for most NANDs (MaxNVB is basically the total
2429 count of eraseblocks on the chip).
2430
2431 To put it differently, if this value is 20, UBI will try to
2432 reserve about 1.9% of physical eraseblocks for bad blocks
2433 handling. And that will be 1.9% of eraseblocks on the entire
2434 NAND chip, not just the MTD partition UBI attaches. This means
2435 that if you have, say, a NAND flash chip admits maximum 40 bad
2436 eraseblocks, and it is split on two MTD partitions of the same
2437 size, UBI will reserve 40 eraseblocks when attaching a
2438 partition.
2439
2440 default: 20
2441
2442 CONFIG_MTD_UBI_FASTMAP
2443 Fastmap is a mechanism which allows attaching an UBI device
2444 in nearly constant time. Instead of scanning the whole MTD device it
2445 only has to locate a checkpoint (called fastmap) on the device.
2446 The on-flash fastmap contains all information needed to attach
2447 the device. Using fastmap makes only sense on large devices where
2448 attaching by scanning takes long. UBI will not automatically install
2449 a fastmap on old images, but you can set the UBI parameter
2450 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
2451 that fastmap-enabled images are still usable with UBI implementations
2452 without fastmap support. On typical flash devices the whole fastmap
2453 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
2454
2455 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
2456 Set this parameter to enable fastmap automatically on images
2457 without a fastmap.
2458 default: 0
2459
0195a7bb
HS
2460 CONFIG_MTD_UBI_FM_DEBUG
2461 Enable UBI fastmap debug
2462 default: 0
2463
6a11cf48 2464- SPL framework
04e5ae79
WD
2465 CONFIG_SPL
2466 Enable building of SPL globally.
6a11cf48 2467
95579793
TR
2468 CONFIG_SPL_LDSCRIPT
2469 LDSCRIPT for linking the SPL binary.
2470
6ebc3461
AA
2471 CONFIG_SPL_MAX_FOOTPRINT
2472 Maximum size in memory allocated to the SPL, BSS included.
2473 When defined, the linker checks that the actual memory
2474 used by SPL from _start to __bss_end does not exceed it.
8960af8b 2475 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
6ebc3461
AA
2476 must not be both defined at the same time.
2477
95579793 2478 CONFIG_SPL_MAX_SIZE
6ebc3461
AA
2479 Maximum size of the SPL image (text, data, rodata, and
2480 linker lists sections), BSS excluded.
2481 When defined, the linker checks that the actual size does
2482 not exceed it.
95579793 2483
04e5ae79
WD
2484 CONFIG_SPL_TEXT_BASE
2485 TEXT_BASE for linking the SPL binary.
6a11cf48 2486
94a45bb1
SW
2487 CONFIG_SPL_RELOC_TEXT_BASE
2488 Address to relocate to. If unspecified, this is equal to
2489 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2490
95579793
TR
2491 CONFIG_SPL_BSS_START_ADDR
2492 Link address for the BSS within the SPL binary.
2493
2494 CONFIG_SPL_BSS_MAX_SIZE
6ebc3461
AA
2495 Maximum size in memory allocated to the SPL BSS.
2496 When defined, the linker checks that the actual memory used
2497 by SPL from __bss_start to __bss_end does not exceed it.
8960af8b 2498 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
6ebc3461 2499 must not be both defined at the same time.
95579793
TR
2500
2501 CONFIG_SPL_STACK
2502 Adress of the start of the stack SPL will use
2503
8c80eb3b
AA
2504 CONFIG_SPL_PANIC_ON_RAW_IMAGE
2505 When defined, SPL will panic() if the image it has
2506 loaded does not have a signature.
2507 Defining this is useful when code which loads images
2508 in SPL cannot guarantee that absolutely all read errors
2509 will be caught.
2510 An example is the LPC32XX MLC NAND driver, which will
2511 consider that a completely unreadable NAND block is bad,
2512 and thus should be skipped silently.
2513
94a45bb1
SW
2514 CONFIG_SPL_RELOC_STACK
2515 Adress of the start of the stack SPL will use after
2516 relocation. If unspecified, this is equal to
2517 CONFIG_SPL_STACK.
2518
95579793
TR
2519 CONFIG_SYS_SPL_MALLOC_START
2520 Starting address of the malloc pool used in SPL.
9ac4fc82
FE
2521 When this option is set the full malloc is used in SPL and
2522 it is set up by spl_init() and before that, the simple malloc()
2523 can be used if CONFIG_SYS_MALLOC_F is defined.
95579793
TR
2524
2525 CONFIG_SYS_SPL_MALLOC_SIZE
2526 The size of the malloc pool used in SPL.
6a11cf48 2527
9607faf2
TR
2528 CONFIG_SPL_OS_BOOT
2529 Enable booting directly to an OS from SPL.
2530 See also: doc/README.falcon
2531
861a86f4
TR
2532 CONFIG_SPL_DISPLAY_PRINT
2533 For ARM, enable an optional function to print more information
2534 about the running system.
2535
4b919725
SW
2536 CONFIG_SPL_INIT_MINIMAL
2537 Arch init code should be built for a very small image
2538
b97300b6
PK
2539 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
2540 Partition on the MMC to load U-Boot from when the MMC is being
2541 used in raw mode
2542
2b75b0ad
PK
2543 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
2544 Sector to load kernel uImage from when MMC is being
2545 used in raw mode (for Falcon mode)
2546
2547 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
2548 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
2549 Sector and number of sectors to load kernel argument
2550 parameters from when MMC is being used in raw mode
2551 (for falcon mode)
2552
e2ccdf89
PK
2553 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
2554 Partition on the MMC to load U-Boot from when the MMC is being
2555 used in fs mode
2556
fae81c72
GG
2557 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
2558 Filename to read to load U-Boot when reading from filesystem
2559
2560 CONFIG_SPL_FS_LOAD_KERNEL_NAME
7ad2cc79 2561 Filename to read to load kernel uImage when reading
fae81c72 2562 from filesystem (for Falcon mode)
7ad2cc79 2563
fae81c72 2564 CONFIG_SPL_FS_LOAD_ARGS_NAME
7ad2cc79 2565 Filename to read to load kernel argument parameters
fae81c72 2566 when reading from filesystem (for Falcon mode)
7ad2cc79 2567
06f60ae3
SW
2568 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
2569 Set this for NAND SPL on PPC mpc83xx targets, so that
2570 start.S waits for the rest of the SPL to load before
2571 continuing (the hardware starts execution after just
2572 loading the first page rather than the full 4K).
2573
651fcf60
PK
2574 CONFIG_SPL_SKIP_RELOCATE
2575 Avoid SPL relocation
2576
6f2f01b9
SW
2577 CONFIG_SPL_NAND_BASE
2578 Include nand_base.c in the SPL. Requires
2579 CONFIG_SPL_NAND_DRIVERS.
2580
2581 CONFIG_SPL_NAND_DRIVERS
2582 SPL uses normal NAND drivers, not minimal drivers.
2583
15e207fa
JK
2584 CONFIG_SPL_NAND_IDENT
2585 SPL uses the chip ID list to identify the NAND flash.
2586 Requires CONFIG_SPL_NAND_BASE.
2587
6f2f01b9
SW
2588 CONFIG_SPL_NAND_ECC
2589 Include standard software ECC in the SPL
2590
95579793 2591 CONFIG_SPL_NAND_SIMPLE
7d4b7955
SW
2592 Support for NAND boot using simple NAND drivers that
2593 expose the cmd_ctrl() interface.
95579793 2594
6f4e7d3c
TG
2595 CONFIG_SPL_UBI
2596 Support for a lightweight UBI (fastmap) scanner and
2597 loader
2598
0c3117b1
HS
2599 CONFIG_SPL_NAND_RAW_ONLY
2600 Support to boot only raw u-boot.bin images. Use this only
2601 if you need to save space.
2602
7c8eea59
YZ
2603 CONFIG_SPL_COMMON_INIT_DDR
2604 Set for common ddr init with serial presence detect in
2605 SPL binary.
2606
95579793
TR
2607 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
2608 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
2609 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
2610 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
2611 CONFIG_SYS_NAND_ECCBYTES
2612 Defines the size and behavior of the NAND that SPL uses
7d4b7955 2613 to read U-Boot
95579793 2614
fbe76ae4
PK
2615 CONFIG_SPL_NAND_BOOT
2616 Add support NAND boot
2617
95579793 2618 CONFIG_SYS_NAND_U_BOOT_OFFS
7d4b7955
SW
2619 Location in NAND to read U-Boot from
2620
2621 CONFIG_SYS_NAND_U_BOOT_DST
2622 Location in memory to load U-Boot to
2623
2624 CONFIG_SYS_NAND_U_BOOT_SIZE
2625 Size of image to load
95579793
TR
2626
2627 CONFIG_SYS_NAND_U_BOOT_START
7d4b7955 2628 Entry point in loaded image to jump to
95579793
TR
2629
2630 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
2631 Define this if you need to first read the OOB and then the
b445bbb4 2632 data. This is used, for example, on davinci platforms.
95579793 2633
c57b953d
PM
2634 CONFIG_SPL_RAM_DEVICE
2635 Support for running image already present in ram, in SPL binary
6a11cf48 2636
74752baa 2637 CONFIG_SPL_PAD_TO
6113d3f2
BT
2638 Image offset to which the SPL should be padded before appending
2639 the SPL payload. By default, this is defined as
2640 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
2641 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
2642 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
74752baa 2643
ca2fca22
SW
2644 CONFIG_SPL_TARGET
2645 Final target image containing SPL and payload. Some SPLs
2646 use an arch-specific makefile fragment instead, for
2647 example if more than one image needs to be produced.
2648
b527b9c6 2649 CONFIG_SPL_FIT_PRINT
87ebee39
SG
2650 Printing information about a FIT image adds quite a bit of
2651 code to SPL. So this is normally disabled in SPL. Use this
2652 option to re-enable it. This will affect the output of the
2653 bootm command when booting a FIT image.
2654
3aa29de0
YZ
2655- TPL framework
2656 CONFIG_TPL
2657 Enable building of TPL globally.
2658
2659 CONFIG_TPL_PAD_TO
2660 Image offset to which the TPL should be padded before appending
2661 the TPL payload. By default, this is defined as
93e14596
WD
2662 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
2663 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
2664 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3aa29de0 2665
a8c7c708
WD
2666- Interrupt support (PPC):
2667
d4ca31c4
WD
2668 There are common interrupt_init() and timer_interrupt()
2669 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
11ccc33f 2670 for CPU specific initialization. interrupt_init_cpu()
d4ca31c4 2671 should set decrementer_count to appropriate value. If
11ccc33f 2672 CPU resets decrementer automatically after interrupt
d4ca31c4 2673 (ppc4xx) it should set decrementer_count to zero.
11ccc33f 2674 timer_interrupt() calls timer_interrupt_cpu() for CPU
d4ca31c4
WD
2675 specific handling. If board has watchdog / status_led
2676 / other_activity_monitor it works automatically from
2677 general timer_interrupt().
a8c7c708 2678
c609719b 2679
9660e442
HR
2680Board initialization settings:
2681------------------------------
2682
2683During Initialization u-boot calls a number of board specific functions
2684to allow the preparation of board specific prerequisites, e.g. pin setup
2685before drivers are initialized. To enable these callbacks the
2686following configuration macros have to be defined. Currently this is
2687architecture specific, so please check arch/your_architecture/lib/board.c
2688typically in board_init_f() and board_init_r().
2689
2690- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
2691- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
2692- CONFIG_BOARD_LATE_INIT: Call board_late_init()
2693- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
c609719b 2694
c609719b
WD
2695Configuration Settings:
2696-----------------------
2697
4d1fd7f1
YS
2698- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
2699 Optionally it can be defined to support 64-bit memory commands.
2700
6d0f6bcf 2701- CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
c609719b
WD
2702 undefine this when you're short of memory.
2703
2fb2604d
PT
2704- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2705 width of the commands listed in the 'help' command output.
2706
6d0f6bcf 2707- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
c609719b
WD
2708 prompt for user input.
2709
6d0f6bcf 2710- CONFIG_SYS_CBSIZE: Buffer size for input from the Console
c609719b 2711
6d0f6bcf 2712- CONFIG_SYS_PBSIZE: Buffer size for Console output
c609719b 2713
6d0f6bcf 2714- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
c609719b 2715
6d0f6bcf 2716- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
c609719b
WD
2717 the application (usually a Linux kernel) when it is
2718 booted
2719
6d0f6bcf 2720- CONFIG_SYS_BAUDRATE_TABLE:
c609719b
WD
2721 List of legal baudrate settings for this board.
2722
6d0f6bcf 2723- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
c609719b
WD
2724 Begin and End addresses of the area used by the
2725 simple memory test.
2726
6d0f6bcf 2727- CONFIG_SYS_MEMTEST_SCRATCH:
5f535fe1
WD
2728 Scratch address used by the alternate memory test
2729 You only need to set this if address zero isn't writeable
2730
e8149522 2731- CONFIG_SYS_MEM_RESERVE_SECURE
e61a7534 2732 Only implemented for ARMv8 for now.
e8149522
YS
2733 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
2734 is substracted from total RAM and won't be reported to OS.
2735 This memory can be used as secure memory. A variable
e61a7534 2736 gd->arch.secure_ram is used to track the location. In systems
e8149522
YS
2737 the RAM base is not zero, or RAM is divided into banks,
2738 this variable needs to be recalcuated to get the address.
2739
aabd7ddb 2740- CONFIG_SYS_MEM_TOP_HIDE:
6d0f6bcf 2741 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
14f73ca6 2742 this specified memory area will get subtracted from the top
11ccc33f 2743 (end) of RAM and won't get "touched" at all by U-Boot. By
14f73ca6
SR
2744 fixing up gd->ram_size the Linux kernel should gets passed
2745 the now "corrected" memory size and won't touch it either.
2746 This should work for arch/ppc and arch/powerpc. Only Linux
5e12e75d 2747 board ports in arch/powerpc with bootwrapper support that
14f73ca6 2748 recalculate the memory size from the SDRAM controller setup
5e12e75d 2749 will have to get fixed in Linux additionally.
14f73ca6
SR
2750
2751 This option can be used as a workaround for the 440EPx/GRx
2752 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2753 be touched.
2754
2755 WARNING: Please make sure that this value is a multiple of
2756 the Linux page size (normally 4k). If this is not the case,
2757 then the end address of the Linux memory will be located at a
2758 non page size aligned address and this could cause major
2759 problems.
2760
6d0f6bcf 2761- CONFIG_SYS_LOADS_BAUD_CHANGE:
c609719b
WD
2762 Enable temporary baudrate change while serial download
2763
6d0f6bcf 2764- CONFIG_SYS_SDRAM_BASE:
c609719b
WD
2765 Physical start address of SDRAM. _Must_ be 0 here.
2766
6d0f6bcf 2767- CONFIG_SYS_FLASH_BASE:
c609719b
WD
2768 Physical start address of Flash memory.
2769
6d0f6bcf 2770- CONFIG_SYS_MONITOR_BASE:
c609719b
WD
2771 Physical start address of boot monitor code (set by
2772 make config files to be same as the text base address
14d0a02a 2773 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
6d0f6bcf 2774 CONFIG_SYS_FLASH_BASE when booting from flash.
c609719b 2775
6d0f6bcf 2776- CONFIG_SYS_MONITOR_LEN:
8bde7f77
WD
2777 Size of memory reserved for monitor code, used to
2778 determine _at_compile_time_ (!) if the environment is
2779 embedded within the U-Boot image, or in a separate
2780 flash sector.
c609719b 2781
6d0f6bcf 2782- CONFIG_SYS_MALLOC_LEN:
c609719b
WD
2783 Size of DRAM reserved for malloc() use.
2784
d59476b6
SG
2785- CONFIG_SYS_MALLOC_F_LEN
2786 Size of the malloc() pool for use before relocation. If
2787 this is defined, then a very simple malloc() implementation
2788 will become available before relocation. The address is just
2789 below the global data, and the stack is moved down to make
2790 space.
2791
2792 This feature allocates regions with increasing addresses
2793 within the region. calloc() is supported, but realloc()
2794 is not available. free() is supported but does nothing.
b445bbb4 2795 The memory will be freed (or in fact just forgotten) when
d59476b6
SG
2796 U-Boot relocates itself.
2797
38687ae6
SG
2798- CONFIG_SYS_MALLOC_SIMPLE
2799 Provides a simple and small malloc() and calloc() for those
2800 boards which do not use the full malloc in SPL (which is
2801 enabled with CONFIG_SYS_SPL_MALLOC_START).
2802
1dfdd9ba
TR
2803- CONFIG_SYS_NONCACHED_MEMORY:
2804 Size of non-cached memory area. This area of memory will be
2805 typically located right below the malloc() area and mapped
2806 uncached in the MMU. This is useful for drivers that would
2807 otherwise require a lot of explicit cache maintenance. For
2808 some drivers it's also impossible to properly maintain the
2809 cache. For example if the regions that need to be flushed
2810 are not a multiple of the cache-line size, *and* padding
2811 cannot be allocated between the regions to align them (i.e.
2812 if the HW requires a contiguous array of regions, and the
2813 size of each region is not cache-aligned), then a flush of
2814 one region may result in overwriting data that hardware has
2815 written to another region in the same cache-line. This can
2816 happen for example in network drivers where descriptors for
2817 buffers are typically smaller than the CPU cache-line (e.g.
2818 16 bytes vs. 32 or 64 bytes).
2819
2820 Non-cached memory is only supported on 32-bit ARM at present.
2821
6d0f6bcf 2822- CONFIG_SYS_BOOTM_LEN:
15940c9a
SR
2823 Normally compressed uImages are limited to an
2824 uncompressed size of 8 MBytes. If this is not enough,
6d0f6bcf 2825 you can define CONFIG_SYS_BOOTM_LEN in your board config file
15940c9a
SR
2826 to adjust this setting to your needs.
2827
6d0f6bcf 2828- CONFIG_SYS_BOOTMAPSZ:
c609719b
WD
2829 Maximum size of memory mapped by the startup code of
2830 the Linux kernel; all data that must be processed by
7d721e34
BS
2831 the Linux kernel (bd_info, boot arguments, FDT blob if
2832 used) must be put below this limit, unless "bootm_low"
1bce2aeb 2833 environment variable is defined and non-zero. In such case
7d721e34 2834 all data for the Linux kernel must be between "bootm_low"
c0f40859 2835 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
c3624e6e
GL
2836 variable "bootm_mapsize" will override the value of
2837 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
2838 then the value in "bootm_size" will be used instead.
c609719b 2839
fca43cc8
JR
2840- CONFIG_SYS_BOOT_RAMDISK_HIGH:
2841 Enable initrd_high functionality. If defined then the
2842 initrd_high feature is enabled and the bootm ramdisk subcommand
2843 is enabled.
2844
2845- CONFIG_SYS_BOOT_GET_CMDLINE:
2846 Enables allocating and saving kernel cmdline in space between
2847 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2848
2849- CONFIG_SYS_BOOT_GET_KBD:
2850 Enables allocating and saving a kernel copy of the bd_info in
2851 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2852
6d0f6bcf 2853- CONFIG_SYS_MAX_FLASH_BANKS:
c609719b
WD
2854 Max number of Flash memory banks
2855
6d0f6bcf 2856- CONFIG_SYS_MAX_FLASH_SECT:
c609719b
WD
2857 Max number of sectors on a Flash chip
2858
6d0f6bcf 2859- CONFIG_SYS_FLASH_ERASE_TOUT:
c609719b
WD
2860 Timeout for Flash erase operations (in ms)
2861
6d0f6bcf 2862- CONFIG_SYS_FLASH_WRITE_TOUT:
c609719b
WD
2863 Timeout for Flash write operations (in ms)
2864
6d0f6bcf 2865- CONFIG_SYS_FLASH_LOCK_TOUT
8564acf9
WD
2866 Timeout for Flash set sector lock bit operation (in ms)
2867
6d0f6bcf 2868- CONFIG_SYS_FLASH_UNLOCK_TOUT
8564acf9
WD
2869 Timeout for Flash clear lock bits operation (in ms)
2870
6d0f6bcf 2871- CONFIG_SYS_FLASH_PROTECTION
8564acf9
WD
2872 If defined, hardware flash sectors protection is used
2873 instead of U-Boot software protection.
2874
6d0f6bcf 2875- CONFIG_SYS_DIRECT_FLASH_TFTP:
c609719b
WD
2876
2877 Enable TFTP transfers directly to flash memory;
2878 without this option such a download has to be
2879 performed in two steps: (1) download to RAM, and (2)
2880 copy from RAM to flash.
2881
2882 The two-step approach is usually more reliable, since
2883 you can check if the download worked before you erase
11ccc33f
MZ
2884 the flash, but in some situations (when system RAM is
2885 too limited to allow for a temporary copy of the
c609719b
WD
2886 downloaded image) this option may be very useful.
2887
6d0f6bcf 2888- CONFIG_SYS_FLASH_CFI:
43d9616c 2889 Define if the flash driver uses extra elements in the
5653fc33
WD
2890 common flash structure for storing flash geometry.
2891
00b1883a 2892- CONFIG_FLASH_CFI_DRIVER
5653fc33
WD
2893 This option also enables the building of the cfi_flash driver
2894 in the drivers directory
c609719b 2895
91809ed5
PZ
2896- CONFIG_FLASH_CFI_MTD
2897 This option enables the building of the cfi_mtd driver
2898 in the drivers directory. The driver exports CFI flash
2899 to the MTD layer.
2900
6d0f6bcf 2901- CONFIG_SYS_FLASH_USE_BUFFER_WRITE
96ef831f
GL
2902 Use buffered writes to flash.
2903
2904- CONFIG_FLASH_SPANSION_S29WS_N
2905 s29ws-n MirrorBit flash has non-standard addresses for buffered
2906 write commands.
2907
6d0f6bcf 2908- CONFIG_SYS_FLASH_QUIET_TEST
5568e613
SR
2909 If this option is defined, the common CFI flash doesn't
2910 print it's warning upon not recognized FLASH banks. This
2911 is useful, if some of the configured banks are only
2912 optionally available.
2913
9a042e9c
JVB
2914- CONFIG_FLASH_SHOW_PROGRESS
2915 If defined (must be an integer), print out countdown
2916 digits and dots. Recommended value: 45 (9..1) for 80
2917 column displays, 15 (3..1) for 40 column displays.
2918
352ef3f1
SR
2919- CONFIG_FLASH_VERIFY
2920 If defined, the content of the flash (destination) is compared
2921 against the source after the write operation. An error message
2922 will be printed when the contents are not identical.
2923 Please note that this option is useless in nearly all cases,
2924 since such flash programming errors usually are detected earlier
2925 while unprotecting/erasing/programming. Please only enable
2926 this option if you really know what you are doing.
2927
6d0f6bcf 2928- CONFIG_SYS_RX_ETH_BUFFER:
11ccc33f
MZ
2929 Defines the number of Ethernet receive buffers. On some
2930 Ethernet controllers it is recommended to set this value
53cf9435
SR
2931 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2932 buffers can be full shortly after enabling the interface
11ccc33f 2933 on high Ethernet traffic.
53cf9435
SR
2934 Defaults to 4 if not defined.
2935
ea882baf
WD
2936- CONFIG_ENV_MAX_ENTRIES
2937
071bc923
WD
2938 Maximum number of entries in the hash table that is used
2939 internally to store the environment settings. The default
2940 setting is supposed to be generous and should work in most
2941 cases. This setting can be used to tune behaviour; see
2942 lib/hashtable.c for details.
ea882baf 2943
2598090b
JH
2944- CONFIG_ENV_FLAGS_LIST_DEFAULT
2945- CONFIG_ENV_FLAGS_LIST_STATIC
1bce2aeb 2946 Enable validation of the values given to environment variables when
2598090b
JH
2947 calling env set. Variables can be restricted to only decimal,
2948 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
2949 the variables can also be restricted to IP address or MAC address.
2950
2951 The format of the list is:
2952 type_attribute = [s|d|x|b|i|m]
b445bbb4
JM
2953 access_attribute = [a|r|o|c]
2954 attributes = type_attribute[access_attribute]
2598090b
JH
2955 entry = variable_name[:attributes]
2956 list = entry[,list]
2957
2958 The type attributes are:
2959 s - String (default)
2960 d - Decimal
2961 x - Hexadecimal
2962 b - Boolean ([1yYtT|0nNfF])
2963 i - IP address
2964 m - MAC address
2965
267541f7
JH
2966 The access attributes are:
2967 a - Any (default)
2968 r - Read-only
2969 o - Write-once
2970 c - Change-default
2971
2598090b
JH
2972 - CONFIG_ENV_FLAGS_LIST_DEFAULT
2973 Define this to a list (string) to define the ".flags"
b445bbb4 2974 environment variable in the default or embedded environment.
2598090b
JH
2975
2976 - CONFIG_ENV_FLAGS_LIST_STATIC
2977 Define this to a list (string) to define validation that
2978 should be done if an entry is not found in the ".flags"
2979 environment variable. To override a setting in the static
2980 list, simply add an entry for the same variable name to the
2981 ".flags" variable.
2982
bdf1fe4e
JH
2983 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
2984 regular expression. This allows multiple variables to define the same
2985 flags without explicitly listing them for each variable.
2986
267541f7
JH
2987- CONFIG_ENV_ACCESS_IGNORE_FORCE
2988 If defined, don't allow the -f switch to env set override variable
2989 access flags.
2990
c609719b
WD
2991The following definitions that deal with the placement and management
2992of environment data (variable area); in general, we support the
2993following configurations:
2994
c3eb3fe4
MF
2995- CONFIG_BUILD_ENVCRC:
2996
2997 Builds up envcrc with the target environment so that external utils
2998 may easily extract it and embed it in final U-Boot images.
2999
c609719b 3000BE CAREFUL! The first access to the environment happens quite early
b445bbb4 3001in U-Boot initialization (when we try to get the setting of for the
11ccc33f 3002console baudrate). You *MUST* have mapped your NVRAM area then, or
c609719b
WD
3003U-Boot will hang.
3004
3005Please note that even with NVRAM we still use a copy of the
3006environment in RAM: we could work on NVRAM directly, but we want to
3007keep settings there always unmodified except somebody uses "saveenv"
3008to save the current settings.
3009
0a85a9e7
LG
3010BE CAREFUL! For some special cases, the local device can not use
3011"saveenv" command. For example, the local device will get the
fc54c7fa
LG
3012environment stored in a remote NOR flash by SRIO or PCIE link,
3013but it can not erase, write this NOR flash by SRIO or PCIE interface.
0a85a9e7 3014
b74ab737
GL
3015- CONFIG_NAND_ENV_DST
3016
3017 Defines address in RAM to which the nand_spl code should copy the
3018 environment. If redundant environment is used, it will be copied to
3019 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3020
e881cb56 3021Please note that the environment is read-only until the monitor
c609719b 3022has been relocated to RAM and a RAM copy of the environment has been
00caae6d 3023created; also, when using EEPROM you will have to use env_get_f()
c609719b
WD
3024until then to read environment variables.
3025
85ec0bcc
WD
3026The environment is protected by a CRC32 checksum. Before the monitor
3027is relocated into RAM, as a result of a bad CRC you will be working
3028with the compiled-in default environment - *silently*!!! [This is
3029necessary, because the first environment variable we need is the
3030"baudrate" setting for the console - if we have a bad CRC, we don't
3031have any device yet where we could complain.]
c609719b
WD
3032
3033Note: once the monitor has been relocated, then it will complain if
3034the default environment is used; a new CRC is computed as soon as you
85ec0bcc 3035use the "saveenv" command to store a valid environment.
c609719b 3036
6d0f6bcf 3037- CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
42d1f039 3038 Echo the inverted Ethernet link state to the fault LED.
fc3e2165 3039
6d0f6bcf 3040 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
fc3e2165
WD
3041 also needs to be defined.
3042
6d0f6bcf 3043- CONFIG_SYS_FAULT_MII_ADDR:
42d1f039 3044 MII address of the PHY to check for the Ethernet link state.
c609719b 3045
f5675aa5
RM
3046- CONFIG_NS16550_MIN_FUNCTIONS:
3047 Define this if you desire to only have use of the NS16550_init
3048 and NS16550_putc functions for the serial driver located at
3049 drivers/serial/ns16550.c. This option is useful for saving
3050 space for already greatly restricted images, including but not
3051 limited to NAND_SPL configurations.
3052
b2b92f53
SG
3053- CONFIG_DISPLAY_BOARDINFO
3054 Display information about the board that U-Boot is running on
3055 when U-Boot starts up. The board function checkboard() is called
3056 to do this.
3057
e2e3e2b1
SG
3058- CONFIG_DISPLAY_BOARDINFO_LATE
3059 Similar to the previous option, but display this information
3060 later, once stdio is running and output goes to the LCD, if
3061 present.
3062
feb85801
SS
3063- CONFIG_BOARD_SIZE_LIMIT:
3064 Maximum size of the U-Boot image. When defined, the
3065 build system checks that the actual size does not
3066 exceed it.
3067
c609719b 3068Low Level (hardware related) configuration options:
dc7c9a1a 3069---------------------------------------------------
c609719b 3070
6d0f6bcf 3071- CONFIG_SYS_CACHELINE_SIZE:
c609719b
WD
3072 Cache Line Size of the CPU.
3073
e46fedfe
TT
3074- CONFIG_SYS_CCSRBAR_DEFAULT:
3075 Default (power-on reset) physical address of CCSR on Freescale
3076 PowerPC SOCs.
3077
3078- CONFIG_SYS_CCSRBAR:
3079 Virtual address of CCSR. On a 32-bit build, this is typically
3080 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3081
e46fedfe
TT
3082- CONFIG_SYS_CCSRBAR_PHYS:
3083 Physical address of CCSR. CCSR can be relocated to a new
3084 physical address, if desired. In this case, this macro should
c0f40859 3085 be set to that address. Otherwise, it should be set to the
e46fedfe
TT
3086 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3087 is typically relocated on 36-bit builds. It is recommended
3088 that this macro be defined via the _HIGH and _LOW macros:
3089
3090 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3091 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3092
3093- CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4cf2609b
WD
3094 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3095 either 0 (32-bit build) or 0xF (36-bit build). This macro is
e46fedfe
TT
3096 used in assembly code, so it must not contain typecasts or
3097 integer size suffixes (e.g. "ULL").
3098
3099- CONFIG_SYS_CCSRBAR_PHYS_LOW:
3100 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3101 used in assembly code, so it must not contain typecasts or
3102 integer size suffixes (e.g. "ULL").
3103
3104- CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3105 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3106 forced to a value that ensures that CCSR is not relocated.
3107
7f6c2cbc 3108- Floppy Disk Support:
6d0f6bcf 3109 CONFIG_SYS_FDC_DRIVE_NUMBER
7f6c2cbc
WD
3110
3111 the default drive number (default value 0)
3112
6d0f6bcf 3113 CONFIG_SYS_ISA_IO_STRIDE
7f6c2cbc 3114
11ccc33f 3115 defines the spacing between FDC chipset registers
7f6c2cbc
WD
3116 (default value 1)
3117
6d0f6bcf 3118 CONFIG_SYS_ISA_IO_OFFSET
7f6c2cbc 3119
43d9616c
WD
3120 defines the offset of register from address. It
3121 depends on which part of the data bus is connected to
11ccc33f 3122 the FDC chipset. (default value 0)
7f6c2cbc 3123
6d0f6bcf
JCPV
3124 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3125 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
43d9616c 3126 default value.
7f6c2cbc 3127
6d0f6bcf 3128 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
43d9616c
WD
3129 fdc_hw_init() is called at the beginning of the FDC
3130 setup. fdc_hw_init() must be provided by the board
b445bbb4 3131 source code. It is used to make hardware-dependent
43d9616c 3132 initializations.
7f6c2cbc 3133
0abddf82
ML
3134- CONFIG_IDE_AHB:
3135 Most IDE controllers were designed to be connected with PCI
3136 interface. Only few of them were designed for AHB interface.
3137 When software is doing ATA command and data transfer to
3138 IDE devices through IDE-AHB controller, some additional
3139 registers accessing to these kind of IDE-AHB controller
b445bbb4 3140 is required.
0abddf82 3141
6d0f6bcf 3142- CONFIG_SYS_IMMR: Physical address of the Internal Memory.
efe2a4d5 3143 DO NOT CHANGE unless you know exactly what you're
907208c4 3144 doing! (11-4) [MPC8xx systems only]
c609719b 3145
6d0f6bcf 3146- CONFIG_SYS_INIT_RAM_ADDR:
c609719b 3147
7152b1d0 3148 Start address of memory area that can be used for
c609719b
WD
3149 initial data and stack; please note that this must be
3150 writable memory that is working WITHOUT special
3151 initialization, i. e. you CANNOT use normal RAM which
3152 will become available only after programming the
3153 memory controller and running certain initialization
3154 sequences.
3155
3156 U-Boot uses the following memory types:
907208c4 3157 - MPC8xx: IMMR (internal memory of the CPU)
c609719b 3158
6d0f6bcf 3159- CONFIG_SYS_GBL_DATA_OFFSET:
c609719b
WD
3160
3161 Offset of the initial data structure in the memory
6d0f6bcf
JCPV
3162 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3163 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
c609719b 3164 data is located at the end of the available space
553f0982 3165 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
acd51f9d 3166 GENERATED_GBL_DATA_SIZE), and the initial stack is just
6d0f6bcf
JCPV
3167 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3168 CONFIG_SYS_GBL_DATA_OFFSET) downward.
c609719b
WD
3169
3170 Note:
3171 On the MPC824X (or other systems that use the data
3172 cache for initial memory) the address chosen for
6d0f6bcf 3173 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
c609719b
WD
3174 point to an otherwise UNUSED address space between
3175 the top of RAM and the start of the PCI space.
3176
6d0f6bcf 3177- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
c609719b 3178
6d0f6bcf 3179- CONFIG_SYS_OR_TIMING_SDRAM:
c609719b
WD
3180 SDRAM timing
3181
6d0f6bcf 3182- CONFIG_SYS_MAMR_PTA:
c609719b
WD
3183 periodic timer for refresh
3184
6d0f6bcf
JCPV
3185- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3186 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3187 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3188 CONFIG_SYS_BR1_PRELIM:
c609719b
WD
3189 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3190
3191- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
6d0f6bcf
JCPV
3192 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3193 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
c609719b
WD
3194 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3195
69fd2d3b 3196- CONFIG_PCI_ENUM_ONLY
b445bbb4 3197 Only scan through and get the devices on the buses.
69fd2d3b
AS
3198 Don't do any setup work, presumably because someone or
3199 something has already done it, and we don't need to do it
3200 a second time. Useful for platforms that are pre-booted
3201 by coreboot or similar.
3202
842033e6
GJ
3203- CONFIG_PCI_INDIRECT_BRIDGE:
3204 Enable support for indirect PCI bridges.
3205
a09b9b68
KG
3206- CONFIG_SYS_SRIO:
3207 Chip has SRIO or not
3208
3209- CONFIG_SRIO1:
3210 Board has SRIO 1 port available
3211
3212- CONFIG_SRIO2:
3213 Board has SRIO 2 port available
3214
c8b28152
LG
3215- CONFIG_SRIO_PCIE_BOOT_MASTER
3216 Board can support master function for Boot from SRIO and PCIE
3217
a09b9b68
KG
3218- CONFIG_SYS_SRIOn_MEM_VIRT:
3219 Virtual Address of SRIO port 'n' memory region
3220
3221- CONFIG_SYS_SRIOn_MEM_PHYS:
3222 Physical Address of SRIO port 'n' memory region
3223
3224- CONFIG_SYS_SRIOn_MEM_SIZE:
3225 Size of SRIO port 'n' memory region
3226
66bd1846
FE
3227- CONFIG_SYS_NAND_BUSWIDTH_16BIT
3228 Defined to tell the NAND controller that the NAND chip is using
3229 a 16 bit bus.
3230 Not all NAND drivers use this symbol.
a430e916 3231 Example of drivers that use it:
a430fa06
MR
3232 - drivers/mtd/nand/raw/ndfc.c
3233 - drivers/mtd/nand/raw/mxc_nand.c
eced4626
AW
3234
3235- CONFIG_SYS_NDFC_EBC0_CFG
3236 Sets the EBC0_CFG register for the NDFC. If not defined
3237 a default value will be used.
3238
bb99ad6d 3239- CONFIG_SPD_EEPROM
218ca724
WD
3240 Get DDR timing information from an I2C EEPROM. Common
3241 with pluggable memory modules such as SODIMMs
3242
bb99ad6d
BW
3243 SPD_EEPROM_ADDRESS
3244 I2C address of the SPD EEPROM
3245
6d0f6bcf 3246- CONFIG_SYS_SPD_BUS_NUM
218ca724
WD
3247 If SPD EEPROM is on an I2C bus other than the first
3248 one, specify here. Note that the value must resolve
3249 to something your driver can deal with.
bb99ad6d 3250
1b3e3c4f
YS
3251- CONFIG_SYS_DDR_RAW_TIMING
3252 Get DDR timing information from other than SPD. Common with
3253 soldered DDR chips onboard without SPD. DDR raw timing
3254 parameters are extracted from datasheet and hard-coded into
3255 header files or board specific files.
3256
6f5e1dc5
YS
3257- CONFIG_FSL_DDR_INTERACTIVE
3258 Enable interactive DDR debugging. See doc/README.fsl-ddr.
3259
e32d59a2
YS
3260- CONFIG_FSL_DDR_SYNC_REFRESH
3261 Enable sync of refresh for multiple controllers.
3262
4516ff81
YS
3263- CONFIG_FSL_DDR_BIST
3264 Enable built-in memory test for Freescale DDR controllers.
3265
6d0f6bcf 3266- CONFIG_SYS_83XX_DDR_USES_CS0
218ca724
WD
3267 Only for 83xx systems. If specified, then DDR should
3268 be configured using CS0 and CS1 instead of CS2 and CS3.
2ad6b513 3269
c26e454d
WD
3270- CONFIG_RMII
3271 Enable RMII mode for all FECs.
3272 Note that this is a global option, we can't
3273 have one FEC in standard MII mode and another in RMII mode.
3274
5cf91d6b
WD
3275- CONFIG_CRC32_VERIFY
3276 Add a verify option to the crc32 command.
3277 The syntax is:
3278
3279 => crc32 -v <address> <count> <crc32>
3280
3281 Where address/count indicate a memory area
3282 and crc32 is the correct crc32 which the
3283 area should have.
3284
56523f12
WD
3285- CONFIG_LOOPW
3286 Add the "loopw" memory command. This only takes effect if
493f420e 3287 the memory commands are activated globally (CONFIG_CMD_MEMORY).
56523f12 3288
7b466641
SR
3289- CONFIG_MX_CYCLIC
3290 Add the "mdc" and "mwc" memory commands. These are cyclic
3291 "md/mw" commands.
3292 Examples:
3293
efe2a4d5 3294 => mdc.b 10 4 500
7b466641
SR
3295 This command will print 4 bytes (10,11,12,13) each 500 ms.
3296
efe2a4d5 3297 => mwc.l 100 12345678 10
7b466641
SR
3298 This command will write 12345678 to address 100 all 10 ms.
3299
efe2a4d5 3300 This only takes effect if the memory commands are activated
493f420e 3301 globally (CONFIG_CMD_MEMORY).
7b466641 3302
8aa1a2d1 3303- CONFIG_SKIP_LOWLEVEL_INIT
3fafced7 3304 [ARM, NDS32, MIPS, RISC-V only] If this variable is defined, then certain
844f07d8
WD
3305 low level initializations (like setting up the memory
3306 controller) are omitted and/or U-Boot does not
3307 relocate itself into RAM.
3308
3309 Normally this variable MUST NOT be defined. The only
3310 exception is when U-Boot is loaded (to RAM) by some
3311 other boot loader or by a debugger which performs
3312 these initializations itself.
8aa1a2d1 3313
b5bd0982
SG
3314- CONFIG_SKIP_LOWLEVEL_INIT_ONLY
3315 [ARM926EJ-S only] This allows just the call to lowlevel_init()
90211f77 3316 to be skipped. The normal CP15 init (such as enabling the
b5bd0982
SG
3317 instruction cache) is still performed.
3318
401bb30b 3319- CONFIG_SPL_BUILD
df81238b
ML
3320 Modifies the behaviour of start.S when compiling a loader
3321 that is executed before the actual U-Boot. E.g. when
3322 compiling a NAND SPL.
400558b5 3323
3aa29de0
YZ
3324- CONFIG_TPL_BUILD
3325 Modifies the behaviour of start.S when compiling a loader
3326 that is executed after the SPL and before the actual U-Boot.
3327 It is loaded by the SPL.
3328
5df572f0
YZ
3329- CONFIG_SYS_MPC85XX_NO_RESETVEC
3330 Only for 85xx systems. If this variable is specified, the section
3331 .resetvec is not kept and the section .bootpg is placed in the
3332 previous 4k of the .text section.
3333
4213fc29
SG
3334- CONFIG_ARCH_MAP_SYSMEM
3335 Generally U-Boot (and in particular the md command) uses
3336 effective address. It is therefore not necessary to regard
3337 U-Boot address as virtual addresses that need to be translated
3338 to physical addresses. However, sandbox requires this, since
3339 it maintains its own little RAM buffer which contains all
3340 addressable memory. This option causes some memory accesses
3341 to be mapped through map_sysmem() / unmap_sysmem().
3342
588a13f7
SG
3343- CONFIG_X86_RESET_VECTOR
3344 If defined, the x86 reset vector code is included. This is not
3345 needed when U-Boot is running from Coreboot.
b16f521a 3346
999d7d32
KM
3347- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
3348 Option to disable subpage write in NAND driver
3349 driver that uses this:
a430fa06 3350 drivers/mtd/nand/raw/davinci_nand.c
999d7d32 3351
f2717b47
TT
3352Freescale QE/FMAN Firmware Support:
3353-----------------------------------
3354
3355The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
3356loading of "firmware", which is encoded in the QE firmware binary format.
3357This firmware often needs to be loaded during U-Boot booting, so macros
3358are used to identify the storage device (NOR flash, SPI, etc) and the address
3359within that device.
3360
dcf1d774
ZQ
3361- CONFIG_SYS_FMAN_FW_ADDR
3362 The address in the storage device where the FMAN microcode is located. The
3363 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3364 is also specified.
3365
3366- CONFIG_SYS_QE_FW_ADDR
3367 The address in the storage device where the QE microcode is located. The
f2717b47
TT
3368 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3369 is also specified.
3370
3371- CONFIG_SYS_QE_FMAN_FW_LENGTH
3372 The maximum possible size of the firmware. The firmware binary format
3373 has a field that specifies the actual size of the firmware, but it
3374 might not be possible to read any part of the firmware unless some
3375 local storage is allocated to hold the entire firmware first.
3376
3377- CONFIG_SYS_QE_FMAN_FW_IN_NOR
3378 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
3379 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
3380 virtual address in NOR flash.
3381
3382- CONFIG_SYS_QE_FMAN_FW_IN_NAND
3383 Specifies that QE/FMAN firmware is located in NAND flash.
3384 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
3385
3386- CONFIG_SYS_QE_FMAN_FW_IN_MMC
3387 Specifies that QE/FMAN firmware is located on the primary SD/MMC
3388 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3389
292dc6c5
LG
3390- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
3391 Specifies that QE/FMAN firmware is located in the remote (master)
3392 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
fc54c7fa
LG
3393 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
3394 window->master inbound window->master LAW->the ucode address in
3395 master's memory space.
f2717b47 3396
b940ca64
GR
3397Freescale Layerscape Management Complex Firmware Support:
3398---------------------------------------------------------
3399The Freescale Layerscape Management Complex (MC) supports the loading of
3400"firmware".
3401This firmware often needs to be loaded during U-Boot booting, so macros
3402are used to identify the storage device (NOR flash, SPI, etc) and the address
3403within that device.
3404
3405- CONFIG_FSL_MC_ENET
3406 Enable the MC driver for Layerscape SoCs.
3407
5c055089
PK
3408Freescale Layerscape Debug Server Support:
3409-------------------------------------------
3410The Freescale Layerscape Debug Server Support supports the loading of
3411"Debug Server firmware" and triggering SP boot-rom.
3412This firmware often needs to be loaded during U-Boot booting.
3413
c0492141
YS
3414- CONFIG_SYS_MC_RSV_MEM_ALIGN
3415 Define alignment of reserved memory MC requires
5c055089 3416
f3f431a7
PK
3417Reproducible builds
3418-------------------
3419
3420In order to achieve reproducible builds, timestamps used in the U-Boot build
3421process have to be set to a fixed value.
3422
3423This is done using the SOURCE_DATE_EPOCH environment variable.
3424SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
3425option for U-Boot or an environment variable in U-Boot.
3426
3427SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
3428
c609719b
WD
3429Building the Software:
3430======================
3431
218ca724
WD
3432Building U-Boot has been tested in several native build environments
3433and in many different cross environments. Of course we cannot support
3434all possibly existing versions of cross development tools in all
3435(potentially obsolete) versions. In case of tool chain problems we
3436recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3437which is extensively used to build and test U-Boot.
c609719b 3438
218ca724
WD
3439If you are not using a native environment, it is assumed that you
3440have GNU cross compiling tools available in your path. In this case,
3441you must set the environment variable CROSS_COMPILE in your shell.
3442Note that no changes to the Makefile or any other source files are
3443necessary. For example using the ELDK on a 4xx CPU, please enter:
c609719b 3444
218ca724
WD
3445 $ CROSS_COMPILE=ppc_4xx-
3446 $ export CROSS_COMPILE
c609719b 3447
2f8d396b
PT
3448Note: If you wish to generate Windows versions of the utilities in
3449 the tools directory you can use the MinGW toolchain
3450 (http://www.mingw.org). Set your HOST tools to the MinGW
3451 toolchain and execute 'make tools'. For example:
3452
3453 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3454
3455 Binaries such as tools/mkimage.exe will be created which can
3456 be executed on computers running Windows.
3457
218ca724
WD
3458U-Boot is intended to be simple to build. After installing the
3459sources you must configure U-Boot for one specific board type. This
c609719b
WD
3460is done by typing:
3461
ab584d67 3462 make NAME_defconfig
c609719b 3463
ab584d67 3464where "NAME_defconfig" is the name of one of the existing configu-
4d675ae6 3465rations; see boards.cfg for supported names.
db01a2ea 3466
2729af9d
WD
3467Note: for some board special configuration names may exist; check if
3468 additional information is available from the board vendor; for
3469 instance, the TQM823L systems are available without (standard)
3470 or with LCD support. You can select such additional "features"
11ccc33f 3471 when choosing the configuration, i. e.
2729af9d 3472
ab584d67 3473 make TQM823L_defconfig
2729af9d
WD
3474 - will configure for a plain TQM823L, i. e. no LCD support
3475
ab584d67 3476 make TQM823L_LCD_defconfig
2729af9d
WD
3477 - will configure for a TQM823L with U-Boot console on LCD
3478
3479 etc.
3480
3481
3482Finally, type "make all", and you should get some working U-Boot
3483images ready for download to / installation on your system:
3484
3485- "u-boot.bin" is a raw binary image
3486- "u-boot" is an image in ELF binary format
3487- "u-boot.srec" is in Motorola S-Record format
3488
baf31249
MB
3489By default the build is performed locally and the objects are saved
3490in the source directory. One of the two methods can be used to change
3491this behavior and build U-Boot to some external directory:
3492
34931. Add O= to the make command line invocations:
3494
3495 make O=/tmp/build distclean
ab584d67 3496 make O=/tmp/build NAME_defconfig
baf31249
MB
3497 make O=/tmp/build all
3498
adbba996 34992. Set environment variable KBUILD_OUTPUT to point to the desired location:
baf31249 3500
adbba996 3501 export KBUILD_OUTPUT=/tmp/build
baf31249 3502 make distclean
ab584d67 3503 make NAME_defconfig
baf31249
MB
3504 make all
3505
adbba996 3506Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
baf31249
MB
3507variable.
3508
215bb1c1
DS
3509User specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by
3510setting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS.
3511For example to treat all compiler warnings as errors:
3512
3513 make KCFLAGS=-Werror
2729af9d
WD
3514
3515Please be aware that the Makefiles assume you are using GNU make, so
3516for instance on NetBSD you might need to use "gmake" instead of
3517native "make".
3518
3519
3520If the system board that you have is not listed, then you will need
3521to port U-Boot to your hardware platform. To do this, follow these
3522steps:
3523
3c1496cd 35241. Create a new directory to hold your board specific code. Add any
2729af9d 3525 files you need. In your board directory, you will need at least
3c1496cd
PS
3526 the "Makefile" and a "<board>.c".
35272. Create a new configuration file "include/configs/<board>.h" for
3528 your board.
2729af9d
WD
35293. If you're porting U-Boot to a new CPU, then also create a new
3530 directory to hold your CPU specific code. Add any files you need.
ab584d67 35314. Run "make <board>_defconfig" with your new name.
2729af9d
WD
35325. Type "make", and you should get a working "u-boot.srec" file
3533 to be installed on your target system.
35346. Debug and solve any problems that might arise.
3535 [Of course, this last step is much harder than it sounds.]
3536
3537
3538Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3539==============================================================
3540
218ca724
WD
3541If you have modified U-Boot sources (for instance added a new board
3542or support for new devices, a new CPU, etc.) you are expected to
2729af9d
WD
3543provide feedback to the other developers. The feedback normally takes
3544the form of a "patch", i. e. a context diff against a certain (latest
218ca724 3545official or latest in the git repository) version of U-Boot sources.
2729af9d 3546
218ca724
WD
3547But before you submit such a patch, please verify that your modifi-
3548cation did not break existing code. At least make sure that *ALL* of
2729af9d 3549the supported boards compile WITHOUT ANY compiler warnings. To do so,
6de80f21
SG
3550just run the buildman script (tools/buildman/buildman), which will
3551configure and build U-Boot for ALL supported system. Be warned, this
3552will take a while. Please see the buildman README, or run 'buildman -H'
3553for documentation.
baf31249
MB
3554
3555
2729af9d
WD
3556See also "U-Boot Porting Guide" below.
3557
3558
3559Monitor Commands - Overview:
3560============================
3561
3562go - start application at address 'addr'
3563run - run commands in an environment variable
3564bootm - boot application image from memory
3565bootp - boot image via network using BootP/TFTP protocol
44f074c7 3566bootz - boot zImage from memory
2729af9d
WD
3567tftpboot- boot image via network using TFTP protocol
3568 and env variables "ipaddr" and "serverip"
3569 (and eventually "gatewayip")
1fb7cd49 3570tftpput - upload a file via network using TFTP protocol
2729af9d
WD
3571rarpboot- boot image via network using RARP/TFTP protocol
3572diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3573loads - load S-Record file over serial line
3574loadb - load binary file over serial line (kermit mode)
3575md - memory display
3576mm - memory modify (auto-incrementing)
3577nm - memory modify (constant address)
3578mw - memory write (fill)
3579cp - memory copy
3580cmp - memory compare
3581crc32 - checksum calculation
0f89c54b 3582i2c - I2C sub-system
2729af9d
WD
3583sspi - SPI utility commands
3584base - print or set address offset
3585printenv- print environment variables
3586setenv - set environment variables
3587saveenv - save environment variables to persistent storage
3588protect - enable or disable FLASH write protection
3589erase - erase FLASH memory
3590flinfo - print FLASH memory information
10635afa 3591nand - NAND memory operations (see doc/README.nand)
2729af9d
WD
3592bdinfo - print Board Info structure
3593iminfo - print header information for application image
3594coninfo - print console devices and informations
3595ide - IDE sub-system
3596loop - infinite loop on address range
56523f12 3597loopw - infinite write loop on address range
2729af9d
WD
3598mtest - simple RAM test
3599icache - enable or disable instruction cache
3600dcache - enable or disable data cache
3601reset - Perform RESET of the CPU
3602echo - echo args to console
3603version - print monitor version
3604help - print online help
3605? - alias for 'help'
3606
3607
3608Monitor Commands - Detailed Description:
3609========================================
3610
3611TODO.
3612
3613For now: just type "help <command>".
3614
3615
3616Environment Variables:
3617======================
3618
3619U-Boot supports user configuration using Environment Variables which
3620can be made persistent by saving to Flash memory.
c609719b 3621
2729af9d
WD
3622Environment Variables are set using "setenv", printed using
3623"printenv", and saved to Flash using "saveenv". Using "setenv"
3624without a value can be used to delete a variable from the
3625environment. As long as you don't save the environment you are
3626working with an in-memory copy. In case the Flash area containing the
3627environment is erased by accident, a default environment is provided.
c609719b 3628
c96f86ee
WD
3629Some configuration options can be set using Environment Variables.
3630
3631List of environment variables (most likely not complete):
c609719b 3632
2729af9d 3633 baudrate - see CONFIG_BAUDRATE
c609719b 3634
2729af9d 3635 bootdelay - see CONFIG_BOOTDELAY
c609719b 3636
2729af9d 3637 bootcmd - see CONFIG_BOOTCOMMAND
4a6fd34b 3638
2729af9d 3639 bootargs - Boot arguments when booting an RTOS image
c609719b 3640
2729af9d 3641 bootfile - Name of the image to load with TFTP
c609719b 3642
7d721e34
BS
3643 bootm_low - Memory range available for image processing in the bootm
3644 command can be restricted. This variable is given as
3645 a hexadecimal number and defines lowest address allowed
3646 for use by the bootm command. See also "bootm_size"
3647 environment variable. Address defined by "bootm_low" is
3648 also the base of the initial memory mapping for the Linux
c3624e6e
GL
3649 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
3650 bootm_mapsize.
3651
c0f40859 3652 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
c3624e6e
GL
3653 This variable is given as a hexadecimal number and it
3654 defines the size of the memory region starting at base
3655 address bootm_low that is accessible by the Linux kernel
3656 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
3657 as the default value if it is defined, and bootm_size is
3658 used otherwise.
7d721e34
BS
3659
3660 bootm_size - Memory range available for image processing in the bootm
3661 command can be restricted. This variable is given as
3662 a hexadecimal number and defines the size of the region
3663 allowed for use by the bootm command. See also "bootm_low"
3664 environment variable.
3665
4bae9090
BS
3666 updatefile - Location of the software update file on a TFTP server, used
3667 by the automatic software update feature. Please refer to
3668 documentation in doc/README.update for more details.
3669
2729af9d
WD
3670 autoload - if set to "no" (any string beginning with 'n'),
3671 "bootp" will just load perform a lookup of the
3672 configuration from the BOOTP server, but not try to
3673 load any image using TFTP
c609719b 3674
2729af9d
WD
3675 autostart - if set to "yes", an image loaded using the "bootp",
3676 "rarpboot", "tftpboot" or "diskboot" commands will
3677 be automatically started (by internally calling
3678 "bootm")
38b99261 3679
2729af9d
WD
3680 If set to "no", a standalone image passed to the
3681 "bootm" command will be copied to the load address
3682 (and eventually uncompressed), but NOT be started.
3683 This can be used to load and uncompress arbitrary
3684 data.
c609719b 3685
a28afca5
DL
3686 fdt_high - if set this restricts the maximum address that the
3687 flattened device tree will be copied into upon boot.
fa34f6b2
SG
3688 For example, if you have a system with 1 GB memory
3689 at physical address 0x10000000, while Linux kernel
3690 only recognizes the first 704 MB as low memory, you
3691 may need to set fdt_high as 0x3C000000 to have the
3692 device tree blob be copied to the maximum address
3693 of the 704 MB low memory, so that Linux kernel can
3694 access it during the boot procedure.
3695
a28afca5
DL
3696 If this is set to the special value 0xFFFFFFFF then
3697 the fdt will not be copied at all on boot. For this
3698 to work it must reside in writable memory, have
3699 sufficient padding on the end of it for u-boot to
3700 add the information it needs into it, and the memory
3701 must be accessible by the kernel.
3702
eea63e05
SG
3703 fdtcontroladdr- if set this is the address of the control flattened
3704 device tree used by U-Boot when CONFIG_OF_CONTROL is
3705 defined.
3706
17ea1177
WD
3707 i2cfast - (PPC405GP|PPC405EP only)
3708 if set to 'y' configures Linux I2C driver for fast
3709 mode (400kHZ). This environment variable is used in
3710 initialization code. So, for changes to be effective
3711 it must be saved and board must be reset.
3712
2729af9d
WD
3713 initrd_high - restrict positioning of initrd images:
3714 If this variable is not set, initrd images will be
3715 copied to the highest possible address in RAM; this
3716 is usually what you want since it allows for
3717 maximum initrd size. If for some reason you want to
3718 make sure that the initrd image is loaded below the
6d0f6bcf 3719 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
2729af9d
WD
3720 variable to a value of "no" or "off" or "0".
3721 Alternatively, you can set it to a maximum upper
3722 address to use (U-Boot will still check that it
3723 does not overwrite the U-Boot stack and data).
c609719b 3724
2729af9d
WD
3725 For instance, when you have a system with 16 MB
3726 RAM, and want to reserve 4 MB from use by Linux,
3727 you can do this by adding "mem=12M" to the value of
3728 the "bootargs" variable. However, now you must make
3729 sure that the initrd image is placed in the first
3730 12 MB as well - this can be done with
c609719b 3731
2729af9d 3732 setenv initrd_high 00c00000
c609719b 3733
2729af9d
WD
3734 If you set initrd_high to 0xFFFFFFFF, this is an
3735 indication to U-Boot that all addresses are legal
3736 for the Linux kernel, including addresses in flash
3737 memory. In this case U-Boot will NOT COPY the
3738 ramdisk at all. This may be useful to reduce the
3739 boot time on your system, but requires that this
3740 feature is supported by your Linux kernel.
c609719b 3741
2729af9d 3742 ipaddr - IP address; needed for tftpboot command
c609719b 3743
2729af9d
WD
3744 loadaddr - Default load address for commands like "bootp",
3745 "rarpboot", "tftpboot", "loadb" or "diskboot"
c609719b 3746
2729af9d 3747 loads_echo - see CONFIG_LOADS_ECHO
a3d991bd 3748
2729af9d 3749 serverip - TFTP server IP address; needed for tftpboot command
a3d991bd 3750
2729af9d 3751 bootretry - see CONFIG_BOOT_RETRY_TIME
a3d991bd 3752
2729af9d 3753 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
a3d991bd 3754
2729af9d 3755 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
c609719b 3756
e2a53458 3757 ethprime - controls which interface is used first.
c609719b 3758
e2a53458
MF
3759 ethact - controls which interface is currently active.
3760 For example you can do the following
c609719b 3761
48690d80
HS
3762 => setenv ethact FEC
3763 => ping 192.168.0.1 # traffic sent on FEC
3764 => setenv ethact SCC
3765 => ping 10.0.0.1 # traffic sent on SCC
c609719b 3766
e1692577
MF
3767 ethrotate - When set to "no" U-Boot does not go through all
3768 available network interfaces.
3769 It just stays at the currently selected interface.
3770
c96f86ee 3771 netretry - When set to "no" each network operation will
2729af9d
WD
3772 either succeed or fail without retrying.
3773 When set to "once" the network operation will
3774 fail when all the available network interfaces
3775 are tried once without success.
3776 Useful on scripts which control the retry operation
3777 themselves.
c609719b 3778
b4e2f89d 3779 npe_ucode - set load address for the NPE microcode
a1cf027a 3780
b445bbb4 3781 silent_linux - If set then Linux will be told to boot silently, by
8d51aacd
SG
3782 changing the console to be empty. If "yes" it will be
3783 made silent. If "no" it will not be made silent. If
3784 unset, then it will be made silent if the U-Boot console
3785 is silent.
3786
f5fb7346 3787 tftpsrcp - If this is set, the value is used for TFTP's
ecb0ccd9
WD
3788 UDP source port.
3789
f5fb7346 3790 tftpdstp - If this is set, the value is used for TFTP's UDP
28cb9375
WD
3791 destination port instead of the Well Know Port 69.
3792
c96f86ee
WD
3793 tftpblocksize - Block size to use for TFTP transfers; if not set,
3794 we use the TFTP server's default block size
3795
3796 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3797 seconds, minimum value is 1000 = 1 second). Defines
3798 when a packet is considered to be lost so it has to
3799 be retransmitted. The default is 5000 = 5 seconds.
3800 Lowering this value may make downloads succeed
3801 faster in networks with high packet loss rates or
3802 with unreliable TFTP servers.
3803
f5fb7346
AA
3804 tftptimeoutcountmax - maximum count of TFTP timeouts (no
3805 unit, minimum value = 0). Defines how many timeouts
3806 can happen during a single file transfer before that
3807 transfer is aborted. The default is 10, and 0 means
3808 'no timeouts allowed'. Increasing this value may help
3809 downloads succeed with high packet loss rates, or with
3810 unreliable TFTP servers or client hardware.
3811
c96f86ee 3812 vlan - When set to a value < 4095 the traffic over
11ccc33f 3813 Ethernet is encapsulated/received over 802.1q
2729af9d 3814 VLAN tagged frames.
c609719b 3815
50768f5b
AM
3816 bootpretryperiod - Period during which BOOTP/DHCP sends retries.
3817 Unsigned value, in milliseconds. If not set, the period will
3818 be either the default (28000), or a value based on
3819 CONFIG_NET_RETRY_COUNT, if defined. This value has
3820 precedence over the valu based on CONFIG_NET_RETRY_COUNT.
3821
dc0b7b0e
JH
3822The following image location variables contain the location of images
3823used in booting. The "Image" column gives the role of the image and is
3824not an environment variable name. The other columns are environment
3825variable names. "File Name" gives the name of the file on a TFTP
3826server, "RAM Address" gives the location in RAM the image will be
3827loaded to, and "Flash Location" gives the image's address in NOR
3828flash or offset in NAND flash.
3829
3830*Note* - these variables don't have to be defined for all boards, some
aed9fed9 3831boards currently use other variables for these purposes, and some
dc0b7b0e
JH
3832boards use these variables for other purposes.
3833
c0f40859
WD
3834Image File Name RAM Address Flash Location
3835----- --------- ----------- --------------
3836u-boot u-boot u-boot_addr_r u-boot_addr
3837Linux kernel bootfile kernel_addr_r kernel_addr
3838device tree blob fdtfile fdt_addr_r fdt_addr
3839ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
dc0b7b0e 3840
2729af9d
WD
3841The following environment variables may be used and automatically
3842updated by the network boot commands ("bootp" and "rarpboot"),
3843depending the information provided by your boot server:
c609719b 3844
2729af9d
WD
3845 bootfile - see above
3846 dnsip - IP address of your Domain Name Server
3847 dnsip2 - IP address of your secondary Domain Name Server
3848 gatewayip - IP address of the Gateway (Router) to use
3849 hostname - Target hostname
3850 ipaddr - see above
3851 netmask - Subnet Mask
3852 rootpath - Pathname of the root filesystem on the NFS server
3853 serverip - see above
c1551ea8 3854
c1551ea8 3855
2729af9d 3856There are two special Environment Variables:
c1551ea8 3857
2729af9d
WD
3858 serial# - contains hardware identification information such
3859 as type string and/or serial number
3860 ethaddr - Ethernet address
c609719b 3861
2729af9d
WD
3862These variables can be set only once (usually during manufacturing of
3863the board). U-Boot refuses to delete or overwrite these variables
3864once they have been set once.
c609719b 3865
f07771cc 3866
2729af9d 3867Further special Environment Variables:
f07771cc 3868
2729af9d
WD
3869 ver - Contains the U-Boot version string as printed
3870 with the "version" command. This variable is
3871 readonly (see CONFIG_VERSION_VARIABLE).
f07771cc 3872
f07771cc 3873
2729af9d
WD
3874Please note that changes to some configuration parameters may take
3875only effect after the next boot (yes, that's just like Windoze :-).
f07771cc 3876
f07771cc 3877
170ab110
JH
3878Callback functions for environment variables:
3879---------------------------------------------
3880
3881For some environment variables, the behavior of u-boot needs to change
b445bbb4 3882when their values are changed. This functionality allows functions to
170ab110
JH
3883be associated with arbitrary variables. On creation, overwrite, or
3884deletion, the callback will provide the opportunity for some side
3885effect to happen or for the change to be rejected.
3886
3887The callbacks are named and associated with a function using the
3888U_BOOT_ENV_CALLBACK macro in your board or driver code.
3889
3890These callbacks are associated with variables in one of two ways. The
3891static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
3892in the board configuration to a string that defines a list of
3893associations. The list must be in the following format:
3894
3895 entry = variable_name[:callback_name]
3896 list = entry[,list]
3897
3898If the callback name is not specified, then the callback is deleted.
3899Spaces are also allowed anywhere in the list.
3900
3901Callbacks can also be associated by defining the ".callbacks" variable
3902with the same list format above. Any association in ".callbacks" will
3903override any association in the static list. You can define
3904CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
b445bbb4 3905".callbacks" environment variable in the default or embedded environment.
170ab110 3906
bdf1fe4e
JH
3907If CONFIG_REGEX is defined, the variable_name above is evaluated as a
3908regular expression. This allows multiple variables to be connected to
3909the same callback without explicitly listing them all out.
3910
1b04047a
HS
3911The signature of the callback functions is:
3912
3913 int callback(const char *name, const char *value, enum env_op op, int flags)
3914
3915* name - changed environment variable
3916* value - new value of the environment variable
3917* op - operation (create, overwrite, or delete)
3918* flags - attributes of the environment variable change, see flags H_* in
3919 include/search.h
3920
3921The return value is 0 if the variable change is accepted and 1 otherwise.
170ab110 3922
2729af9d
WD
3923Command Line Parsing:
3924=====================
f07771cc 3925
2729af9d
WD
3926There are two different command line parsers available with U-Boot:
3927the old "simple" one, and the much more powerful "hush" shell:
c609719b 3928
2729af9d
WD
3929Old, simple command line parser:
3930--------------------------------
c609719b 3931
2729af9d
WD
3932- supports environment variables (through setenv / saveenv commands)
3933- several commands on one line, separated by ';'
fe126d8b 3934- variable substitution using "... ${name} ..." syntax
2729af9d
WD
3935- special characters ('$', ';') can be escaped by prefixing with '\',
3936 for example:
fe126d8b 3937 setenv bootcmd bootm \${address}
2729af9d
WD
3938- You can also escape text by enclosing in single apostrophes, for example:
3939 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
c609719b 3940
2729af9d
WD
3941Hush shell:
3942-----------
c609719b 3943
2729af9d
WD
3944- similar to Bourne shell, with control structures like
3945 if...then...else...fi, for...do...done; while...do...done,
3946 until...do...done, ...
3947- supports environment ("global") variables (through setenv / saveenv
3948 commands) and local shell variables (through standard shell syntax
3949 "name=value"); only environment variables can be used with "run"
3950 command
3951
3952General rules:
3953--------------
c609719b 3954
2729af9d
WD
3955(1) If a command line (or an environment variable executed by a "run"
3956 command) contains several commands separated by semicolon, and
3957 one of these commands fails, then the remaining commands will be
3958 executed anyway.
c609719b 3959
2729af9d 3960(2) If you execute several variables with one call to run (i. e.
11ccc33f 3961 calling run with a list of variables as arguments), any failing
2729af9d
WD
3962 command will cause "run" to terminate, i. e. the remaining
3963 variables are not executed.
c609719b 3964
2729af9d
WD
3965Note for Redundant Ethernet Interfaces:
3966=======================================
c609719b 3967
11ccc33f 3968Some boards come with redundant Ethernet interfaces; U-Boot supports
2729af9d
WD
3969such configurations and is capable of automatic selection of a
3970"working" interface when needed. MAC assignment works as follows:
c609719b 3971
2729af9d
WD
3972Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3973MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3974"eth1addr" (=>eth1), "eth2addr", ...
c609719b 3975
2729af9d
WD
3976If the network interface stores some valid MAC address (for instance
3977in SROM), this is used as default address if there is NO correspon-
3978ding setting in the environment; if the corresponding environment
3979variable is set, this overrides the settings in the card; that means:
c609719b 3980
2729af9d
WD
3981o If the SROM has a valid MAC address, and there is no address in the
3982 environment, the SROM's address is used.
c609719b 3983
2729af9d
WD
3984o If there is no valid address in the SROM, and a definition in the
3985 environment exists, then the value from the environment variable is
3986 used.
c609719b 3987
2729af9d
WD
3988o If both the SROM and the environment contain a MAC address, and
3989 both addresses are the same, this MAC address is used.
c609719b 3990
2729af9d
WD
3991o If both the SROM and the environment contain a MAC address, and the
3992 addresses differ, the value from the environment is used and a
3993 warning is printed.
c609719b 3994
2729af9d 3995o If neither SROM nor the environment contain a MAC address, an error
bef1014b
JH
3996 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
3997 a random, locally-assigned MAC is used.
c609719b 3998
ecee9324 3999If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
c0f40859 4000will be programmed into hardware as part of the initialization process. This
ecee9324
BW
4001may be skipped by setting the appropriate 'ethmacskip' environment variable.
4002The naming convention is as follows:
4003"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
c609719b 4004
2729af9d
WD
4005Image Formats:
4006==============
c609719b 4007
3310c549
MB
4008U-Boot is capable of booting (and performing other auxiliary operations on)
4009images in two formats:
4010
4011New uImage format (FIT)
4012-----------------------
4013
4014Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4015to Flattened Device Tree). It allows the use of images with multiple
4016components (several kernels, ramdisks, etc.), with contents protected by
4017SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4018
4019
4020Old uImage format
4021-----------------
4022
4023Old image format is based on binary files which can be basically anything,
4024preceded by a special header; see the definitions in include/image.h for
4025details; basically, the header defines the following image properties:
c609719b 4026
2729af9d
WD
4027* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4028 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
f5ed9e39
PT
4029 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4030 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4031 INTEGRITY).
daab59ac 4032* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
afc1ce82 4033 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
daab59ac 4034 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC).
2729af9d
WD
4035* Compression Type (uncompressed, gzip, bzip2)
4036* Load Address
4037* Entry Point
4038* Image Name
4039* Image Timestamp
c609719b 4040
2729af9d
WD
4041The header is marked by a special Magic Number, and both the header
4042and the data portions of the image are secured against corruption by
4043CRC32 checksums.
c609719b
WD
4044
4045
2729af9d
WD
4046Linux Support:
4047==============
c609719b 4048
2729af9d
WD
4049Although U-Boot should support any OS or standalone application
4050easily, the main focus has always been on Linux during the design of
4051U-Boot.
c609719b 4052
2729af9d
WD
4053U-Boot includes many features that so far have been part of some
4054special "boot loader" code within the Linux kernel. Also, any
4055"initrd" images to be used are no longer part of one big Linux image;
4056instead, kernel and "initrd" are separate images. This implementation
4057serves several purposes:
c609719b 4058
2729af9d
WD
4059- the same features can be used for other OS or standalone
4060 applications (for instance: using compressed images to reduce the
4061 Flash memory footprint)
c609719b 4062
2729af9d
WD
4063- it becomes much easier to port new Linux kernel versions because
4064 lots of low-level, hardware dependent stuff are done by U-Boot
c609719b 4065
2729af9d
WD
4066- the same Linux kernel image can now be used with different "initrd"
4067 images; of course this also means that different kernel images can
4068 be run with the same "initrd". This makes testing easier (you don't
4069 have to build a new "zImage.initrd" Linux image when you just
4070 change a file in your "initrd"). Also, a field-upgrade of the
4071 software is easier now.
c609719b 4072
c609719b 4073
2729af9d
WD
4074Linux HOWTO:
4075============
c609719b 4076
2729af9d
WD
4077Porting Linux to U-Boot based systems:
4078---------------------------------------
c609719b 4079
2729af9d
WD
4080U-Boot cannot save you from doing all the necessary modifications to
4081configure the Linux device drivers for use with your target hardware
4082(no, we don't intend to provide a full virtual machine interface to
4083Linux :-).
c609719b 4084
a47a12be 4085But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
24ee89b9 4086
2729af9d
WD
4087Just make sure your machine specific header file (for instance
4088include/asm-ppc/tqm8xx.h) includes the same definition of the Board
1dc30693
MH
4089Information structure as we define in include/asm-<arch>/u-boot.h,
4090and make sure that your definition of IMAP_ADDR uses the same value
6d0f6bcf 4091as your U-Boot configuration in CONFIG_SYS_IMMR.
24ee89b9 4092
2eb31b13
SG
4093Note that U-Boot now has a driver model, a unified model for drivers.
4094If you are adding a new driver, plumb it into driver model. If there
4095is no uclass available, you are encouraged to create one. See
4096doc/driver-model.
4097
c609719b 4098
2729af9d
WD
4099Configuring the Linux kernel:
4100-----------------------------
c609719b 4101
2729af9d
WD
4102No specific requirements for U-Boot. Make sure you have some root
4103device (initial ramdisk, NFS) for your target system.
4104
4105
4106Building a Linux Image:
4107-----------------------
c609719b 4108
2729af9d
WD
4109With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4110not used. If you use recent kernel source, a new build target
4111"uImage" will exist which automatically builds an image usable by
4112U-Boot. Most older kernels also have support for a "pImage" target,
4113which was introduced for our predecessor project PPCBoot and uses a
4114100% compatible format.
4115
4116Example:
4117
ab584d67 4118 make TQM850L_defconfig
2729af9d
WD
4119 make oldconfig
4120 make dep
4121 make uImage
4122
4123The "uImage" build target uses a special tool (in 'tools/mkimage') to
4124encapsulate a compressed Linux kernel image with header information,
4125CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4126
4127* build a standard "vmlinux" kernel image (in ELF binary format):
4128
4129* convert the kernel into a raw binary image:
4130
4131 ${CROSS_COMPILE}-objcopy -O binary \
4132 -R .note -R .comment \
4133 -S vmlinux linux.bin
4134
4135* compress the binary image:
4136
4137 gzip -9 linux.bin
4138
4139* package compressed binary image for U-Boot:
4140
4141 mkimage -A ppc -O linux -T kernel -C gzip \
4142 -a 0 -e 0 -n "Linux Kernel Image" \
4143 -d linux.bin.gz uImage
c609719b 4144
c609719b 4145
2729af9d
WD
4146The "mkimage" tool can also be used to create ramdisk images for use
4147with U-Boot, either separated from the Linux kernel image, or
4148combined into one file. "mkimage" encapsulates the images with a 64
4149byte header containing information about target architecture,
4150operating system, image type, compression method, entry points, time
4151stamp, CRC32 checksums, etc.
4152
4153"mkimage" can be called in two ways: to verify existing images and
4154print the header information, or to build new images.
4155
4156In the first form (with "-l" option) mkimage lists the information
4157contained in the header of an existing U-Boot image; this includes
4158checksum verification:
c609719b 4159
2729af9d
WD
4160 tools/mkimage -l image
4161 -l ==> list image header information
4162
4163The second form (with "-d" option) is used to build a U-Boot image
4164from a "data file" which is used as image payload:
4165
4166 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4167 -n name -d data_file image
4168 -A ==> set architecture to 'arch'
4169 -O ==> set operating system to 'os'
4170 -T ==> set image type to 'type'
4171 -C ==> set compression type 'comp'
4172 -a ==> set load address to 'addr' (hex)
4173 -e ==> set entry point to 'ep' (hex)
4174 -n ==> set image name to 'name'
4175 -d ==> use image data from 'datafile'
4176
69459791
WD
4177Right now, all Linux kernels for PowerPC systems use the same load
4178address (0x00000000), but the entry point address depends on the
4179kernel version:
2729af9d
WD
4180
4181- 2.2.x kernels have the entry point at 0x0000000C,
4182- 2.3.x and later kernels have the entry point at 0x00000000.
4183
4184So a typical call to build a U-Boot image would read:
4185
4186 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4187 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
a47a12be 4188 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
2729af9d
WD
4189 > examples/uImage.TQM850L
4190 Image Name: 2.4.4 kernel for TQM850L
4191 Created: Wed Jul 19 02:34:59 2000
4192 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4193 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4194 Load Address: 0x00000000
4195 Entry Point: 0x00000000
4196
4197To verify the contents of the image (or check for corruption):
4198
4199 -> tools/mkimage -l examples/uImage.TQM850L
4200 Image Name: 2.4.4 kernel for TQM850L
4201 Created: Wed Jul 19 02:34:59 2000
4202 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4203 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4204 Load Address: 0x00000000
4205 Entry Point: 0x00000000
4206
4207NOTE: for embedded systems where boot time is critical you can trade
4208speed for memory and install an UNCOMPRESSED image instead: this
4209needs more space in Flash, but boots much faster since it does not
4210need to be uncompressed:
4211
a47a12be 4212 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
2729af9d
WD
4213 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4214 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
a47a12be 4215 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
2729af9d
WD
4216 > examples/uImage.TQM850L-uncompressed
4217 Image Name: 2.4.4 kernel for TQM850L
4218 Created: Wed Jul 19 02:34:59 2000
4219 Image Type: PowerPC Linux Kernel Image (uncompressed)
4220 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4221 Load Address: 0x00000000
4222 Entry Point: 0x00000000
4223
4224
4225Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4226when your kernel is intended to use an initial ramdisk:
4227
4228 -> tools/mkimage -n 'Simple Ramdisk Image' \
4229 > -A ppc -O linux -T ramdisk -C gzip \
4230 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4231 Image Name: Simple Ramdisk Image
4232 Created: Wed Jan 12 14:01:50 2000
4233 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4234 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4235 Load Address: 0x00000000
4236 Entry Point: 0x00000000
4237
a804b5ce
GMF
4238The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
4239option performs the converse operation of the mkimage's second form (the "-d"
4240option). Given an image built by mkimage, the dumpimage extracts a "data file"
4241from the image:
4242
f41f5b7c
GMF
4243 tools/dumpimage -i image -T type -p position data_file
4244 -i ==> extract from the 'image' a specific 'data_file'
4245 -T ==> set image type to 'type'
4246 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
a804b5ce 4247
2729af9d
WD
4248
4249Installing a Linux Image:
4250-------------------------
4251
4252To downloading a U-Boot image over the serial (console) interface,
4253you must convert the image to S-Record format:
4254
4255 objcopy -I binary -O srec examples/image examples/image.srec
4256
4257The 'objcopy' does not understand the information in the U-Boot
4258image header, so the resulting S-Record file will be relative to
4259address 0x00000000. To load it to a given address, you need to
4260specify the target address as 'offset' parameter with the 'loads'
4261command.
4262
4263Example: install the image to address 0x40100000 (which on the
4264TQM8xxL is in the first Flash bank):
4265
4266 => erase 40100000 401FFFFF
4267
4268 .......... done
4269 Erased 8 sectors
4270
4271 => loads 40100000
4272 ## Ready for S-Record download ...
4273 ~>examples/image.srec
4274 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4275 ...
4276 15989 15990 15991 15992
4277 [file transfer complete]
4278 [connected]
4279 ## Start Addr = 0x00000000
4280
4281
4282You can check the success of the download using the 'iminfo' command;
218ca724 4283this includes a checksum verification so you can be sure no data
2729af9d
WD
4284corruption happened:
4285
4286 => imi 40100000
4287
4288 ## Checking Image at 40100000 ...
4289 Image Name: 2.2.13 for initrd on TQM850L
4290 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4291 Data Size: 335725 Bytes = 327 kB = 0 MB
4292 Load Address: 00000000
4293 Entry Point: 0000000c
4294 Verifying Checksum ... OK
4295
4296
4297Boot Linux:
4298-----------
4299
4300The "bootm" command is used to boot an application that is stored in
4301memory (RAM or Flash). In case of a Linux kernel image, the contents
4302of the "bootargs" environment variable is passed to the kernel as
4303parameters. You can check and modify this variable using the
4304"printenv" and "setenv" commands:
4305
4306
4307 => printenv bootargs
4308 bootargs=root=/dev/ram
4309
4310 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4311
4312 => printenv bootargs
4313 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4314
4315 => bootm 40020000
4316 ## Booting Linux kernel at 40020000 ...
4317 Image Name: 2.2.13 for NFS on TQM850L
4318 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4319 Data Size: 381681 Bytes = 372 kB = 0 MB
4320 Load Address: 00000000
4321 Entry Point: 0000000c
4322 Verifying Checksum ... OK
4323 Uncompressing Kernel Image ... OK
4324 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
4325 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4326 time_init: decrementer frequency = 187500000/60
4327 Calibrating delay loop... 49.77 BogoMIPS
4328 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
4329 ...
4330
11ccc33f 4331If you want to boot a Linux kernel with initial RAM disk, you pass
2729af9d
WD
4332the memory addresses of both the kernel and the initrd image (PPBCOOT
4333format!) to the "bootm" command:
4334
4335 => imi 40100000 40200000
4336
4337 ## Checking Image at 40100000 ...
4338 Image Name: 2.2.13 for initrd on TQM850L
4339 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4340 Data Size: 335725 Bytes = 327 kB = 0 MB
4341 Load Address: 00000000
4342 Entry Point: 0000000c
4343 Verifying Checksum ... OK
4344
4345 ## Checking Image at 40200000 ...
4346 Image Name: Simple Ramdisk Image
4347 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4348 Data Size: 566530 Bytes = 553 kB = 0 MB
4349 Load Address: 00000000
4350 Entry Point: 00000000
4351 Verifying Checksum ... OK
4352
4353 => bootm 40100000 40200000
4354 ## Booting Linux kernel at 40100000 ...
4355 Image Name: 2.2.13 for initrd on TQM850L
4356 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4357 Data Size: 335725 Bytes = 327 kB = 0 MB
4358 Load Address: 00000000
4359 Entry Point: 0000000c
4360 Verifying Checksum ... OK
4361 Uncompressing Kernel Image ... OK
4362 ## Loading RAMDisk Image at 40200000 ...
4363 Image Name: Simple Ramdisk Image
4364 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4365 Data Size: 566530 Bytes = 553 kB = 0 MB
4366 Load Address: 00000000
4367 Entry Point: 00000000
4368 Verifying Checksum ... OK
4369 Loading Ramdisk ... OK
4370 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
4371 Boot arguments: root=/dev/ram
4372 time_init: decrementer frequency = 187500000/60
4373 Calibrating delay loop... 49.77 BogoMIPS
4374 ...
4375 RAMDISK: Compressed image found at block 0
4376 VFS: Mounted root (ext2 filesystem).
4377
4378 bash#
4379
0267768e
MM
4380Boot Linux and pass a flat device tree:
4381-----------
4382
4383First, U-Boot must be compiled with the appropriate defines. See the section
4384titled "Linux Kernel Interface" above for a more in depth explanation. The
4385following is an example of how to start a kernel and pass an updated
4386flat device tree:
4387
4388=> print oftaddr
4389oftaddr=0x300000
4390=> print oft
4391oft=oftrees/mpc8540ads.dtb
4392=> tftp $oftaddr $oft
4393Speed: 1000, full duplex
4394Using TSEC0 device
4395TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4396Filename 'oftrees/mpc8540ads.dtb'.
4397Load address: 0x300000
4398Loading: #
4399done
4400Bytes transferred = 4106 (100a hex)
4401=> tftp $loadaddr $bootfile
4402Speed: 1000, full duplex
4403Using TSEC0 device
4404TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4405Filename 'uImage'.
4406Load address: 0x200000
4407Loading:############
4408done
4409Bytes transferred = 1029407 (fb51f hex)
4410=> print loadaddr
4411loadaddr=200000
4412=> print oftaddr
4413oftaddr=0x300000
4414=> bootm $loadaddr - $oftaddr
4415## Booting image at 00200000 ...
a9398e01
WD
4416 Image Name: Linux-2.6.17-dirty
4417 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4418 Data Size: 1029343 Bytes = 1005.2 kB
0267768e 4419 Load Address: 00000000
a9398e01 4420 Entry Point: 00000000
0267768e
MM
4421 Verifying Checksum ... OK
4422 Uncompressing Kernel Image ... OK
4423Booting using flat device tree at 0x300000
4424Using MPC85xx ADS machine description
4425Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4426[snip]
4427
4428
2729af9d
WD
4429More About U-Boot Image Types:
4430------------------------------
4431
4432U-Boot supports the following image types:
4433
4434 "Standalone Programs" are directly runnable in the environment
4435 provided by U-Boot; it is expected that (if they behave
4436 well) you can continue to work in U-Boot after return from
4437 the Standalone Program.
4438 "OS Kernel Images" are usually images of some Embedded OS which
4439 will take over control completely. Usually these programs
4440 will install their own set of exception handlers, device
4441 drivers, set up the MMU, etc. - this means, that you cannot
4442 expect to re-enter U-Boot except by resetting the CPU.
4443 "RAMDisk Images" are more or less just data blocks, and their
4444 parameters (address, size) are passed to an OS kernel that is
4445 being started.
4446 "Multi-File Images" contain several images, typically an OS
4447 (Linux) kernel image and one or more data images like
4448 RAMDisks. This construct is useful for instance when you want
4449 to boot over the network using BOOTP etc., where the boot
4450 server provides just a single image file, but you want to get
4451 for instance an OS kernel and a RAMDisk image.
4452
4453 "Multi-File Images" start with a list of image sizes, each
4454 image size (in bytes) specified by an "uint32_t" in network
4455 byte order. This list is terminated by an "(uint32_t)0".
4456 Immediately after the terminating 0 follow the images, one by
4457 one, all aligned on "uint32_t" boundaries (size rounded up to
4458 a multiple of 4 bytes).
4459
4460 "Firmware Images" are binary images containing firmware (like
4461 U-Boot or FPGA images) which usually will be programmed to
4462 flash memory.
4463
4464 "Script files" are command sequences that will be executed by
4465 U-Boot's command interpreter; this feature is especially
4466 useful when you configure U-Boot to use a real shell (hush)
4467 as command interpreter.
4468
44f074c7
MV
4469Booting the Linux zImage:
4470-------------------------
4471
4472On some platforms, it's possible to boot Linux zImage. This is done
4473using the "bootz" command. The syntax of "bootz" command is the same
4474as the syntax of "bootm" command.
4475
8ac28563 4476Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
017e1f3f
MV
4477kernel with raw initrd images. The syntax is slightly different, the
4478address of the initrd must be augmented by it's size, in the following
4479format: "<initrd addres>:<initrd size>".
4480
2729af9d
WD
4481
4482Standalone HOWTO:
4483=================
4484
4485One of the features of U-Boot is that you can dynamically load and
4486run "standalone" applications, which can use some resources of
4487U-Boot like console I/O functions or interrupt services.
4488
4489Two simple examples are included with the sources:
4490
4491"Hello World" Demo:
4492-------------------
4493
4494'examples/hello_world.c' contains a small "Hello World" Demo
4495application; it is automatically compiled when you build U-Boot.
4496It's configured to run at address 0x00040004, so you can play with it
4497like that:
4498
4499 => loads
4500 ## Ready for S-Record download ...
4501 ~>examples/hello_world.srec
4502 1 2 3 4 5 6 7 8 9 10 11 ...
4503 [file transfer complete]
4504 [connected]
4505 ## Start Addr = 0x00040004
4506
4507 => go 40004 Hello World! This is a test.
4508 ## Starting application at 0x00040004 ...
4509 Hello World
4510 argc = 7
4511 argv[0] = "40004"
4512 argv[1] = "Hello"
4513 argv[2] = "World!"
4514 argv[3] = "This"
4515 argv[4] = "is"
4516 argv[5] = "a"
4517 argv[6] = "test."
4518 argv[7] = "<NULL>"
4519 Hit any key to exit ...
4520
4521 ## Application terminated, rc = 0x0
4522
4523Another example, which demonstrates how to register a CPM interrupt
4524handler with the U-Boot code, can be found in 'examples/timer.c'.
4525Here, a CPM timer is set up to generate an interrupt every second.
4526The interrupt service routine is trivial, just printing a '.'
4527character, but this is just a demo program. The application can be
4528controlled by the following keys:
4529
4530 ? - print current values og the CPM Timer registers
4531 b - enable interrupts and start timer
4532 e - stop timer and disable interrupts
4533 q - quit application
4534
4535 => loads
4536 ## Ready for S-Record download ...
4537 ~>examples/timer.srec
4538 1 2 3 4 5 6 7 8 9 10 11 ...
4539 [file transfer complete]
4540 [connected]
4541 ## Start Addr = 0x00040004
4542
4543 => go 40004
4544 ## Starting application at 0x00040004 ...
4545 TIMERS=0xfff00980
4546 Using timer 1
4547 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
4548
4549Hit 'b':
4550 [q, b, e, ?] Set interval 1000000 us
4551 Enabling timer
4552Hit '?':
4553 [q, b, e, ?] ........
4554 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
4555Hit '?':
4556 [q, b, e, ?] .
4557 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
4558Hit '?':
4559 [q, b, e, ?] .
4560 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
4561Hit '?':
4562 [q, b, e, ?] .
4563 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
4564Hit 'e':
4565 [q, b, e, ?] ...Stopping timer
4566Hit 'q':
4567 [q, b, e, ?] ## Application terminated, rc = 0x0
4568
4569
4570Minicom warning:
4571================
4572
4573Over time, many people have reported problems when trying to use the
4574"minicom" terminal emulation program for serial download. I (wd)
4575consider minicom to be broken, and recommend not to use it. Under
4576Unix, I recommend to use C-Kermit for general purpose use (and
4577especially for kermit binary protocol download ("loadb" command), and
e53515a2
KP
4578use "cu" for S-Record download ("loads" command). See
4579http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
4580for help with kermit.
4581
2729af9d
WD
4582
4583Nevertheless, if you absolutely want to use it try adding this
4584configuration to your "File transfer protocols" section:
4585
4586 Name Program Name U/D FullScr IO-Red. Multi
4587 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
4588 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
4589
4590
4591NetBSD Notes:
4592=============
4593
4594Starting at version 0.9.2, U-Boot supports NetBSD both as host
4595(build U-Boot) and target system (boots NetBSD/mpc8xx).
4596
4597Building requires a cross environment; it is known to work on
4598NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
4599need gmake since the Makefiles are not compatible with BSD make).
4600Note that the cross-powerpc package does not install include files;
4601attempting to build U-Boot will fail because <machine/ansi.h> is
4602missing. This file has to be installed and patched manually:
4603
4604 # cd /usr/pkg/cross/powerpc-netbsd/include
4605 # mkdir powerpc
4606 # ln -s powerpc machine
4607 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
4608 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
4609
4610Native builds *don't* work due to incompatibilities between native
4611and U-Boot include files.
4612
4613Booting assumes that (the first part of) the image booted is a
4614stage-2 loader which in turn loads and then invokes the kernel
4615proper. Loader sources will eventually appear in the NetBSD source
4616tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
2a8af187 4617meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
2729af9d
WD
4618
4619
4620Implementation Internals:
4621=========================
4622
4623The following is not intended to be a complete description of every
4624implementation detail. However, it should help to understand the
4625inner workings of U-Boot and make it easier to port it to custom
4626hardware.
4627
4628
4629Initial Stack, Global Data:
4630---------------------------
4631
4632The implementation of U-Boot is complicated by the fact that U-Boot
4633starts running out of ROM (flash memory), usually without access to
4634system RAM (because the memory controller is not initialized yet).
4635This means that we don't have writable Data or BSS segments, and BSS
4636is not initialized as zero. To be able to get a C environment working
4637at all, we have to allocate at least a minimal stack. Implementation
4638options for this are defined and restricted by the CPU used: Some CPU
4639models provide on-chip memory (like the IMMR area on MPC8xx and
4640MPC826x processors), on others (parts of) the data cache can be
4641locked as (mis-) used as memory, etc.
4642
218ca724 4643 Chris Hallinan posted a good summary of these issues to the
0668236b 4644 U-Boot mailing list:
2729af9d
WD
4645
4646 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
4647 From: "Chris Hallinan" <clh@net1plus.com>
4648 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
4649 ...
4650
4651 Correct me if I'm wrong, folks, but the way I understand it
4652 is this: Using DCACHE as initial RAM for Stack, etc, does not
4653 require any physical RAM backing up the cache. The cleverness
4654 is that the cache is being used as a temporary supply of
4655 necessary storage before the SDRAM controller is setup. It's
11ccc33f 4656 beyond the scope of this list to explain the details, but you
2729af9d
WD
4657 can see how this works by studying the cache architecture and
4658 operation in the architecture and processor-specific manuals.
4659
4660 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4661 is another option for the system designer to use as an
11ccc33f 4662 initial stack/RAM area prior to SDRAM being available. Either
2729af9d
WD
4663 option should work for you. Using CS 4 should be fine if your
4664 board designers haven't used it for something that would
4665 cause you grief during the initial boot! It is frequently not
4666 used.
4667
6d0f6bcf 4668 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
2729af9d
WD
4669 with your processor/board/system design. The default value
4670 you will find in any recent u-boot distribution in
8a316c9b 4671 walnut.h should work for you. I'd set it to a value larger
2729af9d
WD
4672 than your SDRAM module. If you have a 64MB SDRAM module, set
4673 it above 400_0000. Just make sure your board has no resources
4674 that are supposed to respond to that address! That code in
4675 start.S has been around a while and should work as is when
4676 you get the config right.
4677
4678 -Chris Hallinan
4679 DS4.COM, Inc.
4680
4681It is essential to remember this, since it has some impact on the C
4682code for the initialization procedures:
4683
4684* Initialized global data (data segment) is read-only. Do not attempt
4685 to write it.
4686
b445bbb4 4687* Do not use any uninitialized global data (or implicitly initialized
2729af9d
WD
4688 as zero data - BSS segment) at all - this is undefined, initiali-
4689 zation is performed later (when relocating to RAM).
4690
4691* Stack space is very limited. Avoid big data buffers or things like
4692 that.
4693
4694Having only the stack as writable memory limits means we cannot use
b445bbb4 4695normal global data to share information between the code. But it
2729af9d
WD
4696turned out that the implementation of U-Boot can be greatly
4697simplified by making a global data structure (gd_t) available to all
4698functions. We could pass a pointer to this data as argument to _all_
4699functions, but this would bloat the code. Instead we use a feature of
4700the GCC compiler (Global Register Variables) to share the data: we
4701place a pointer (gd) to the global data into a register which we
4702reserve for this purpose.
4703
4704When choosing a register for such a purpose we are restricted by the
4705relevant (E)ABI specifications for the current architecture, and by
4706GCC's implementation.
4707
4708For PowerPC, the following registers have specific use:
4709 R1: stack pointer
e7670f6c 4710 R2: reserved for system use
2729af9d
WD
4711 R3-R4: parameter passing and return values
4712 R5-R10: parameter passing
4713 R13: small data area pointer
4714 R30: GOT pointer
4715 R31: frame pointer
4716
e6bee808
JT
4717 (U-Boot also uses R12 as internal GOT pointer. r12
4718 is a volatile register so r12 needs to be reset when
4719 going back and forth between asm and C)
2729af9d 4720
e7670f6c 4721 ==> U-Boot will use R2 to hold a pointer to the global data
2729af9d
WD
4722
4723 Note: on PPC, we could use a static initializer (since the
4724 address of the global data structure is known at compile time),
4725 but it turned out that reserving a register results in somewhat
4726 smaller code - although the code savings are not that big (on
4727 average for all boards 752 bytes for the whole U-Boot image,
4728 624 text + 127 data).
4729
4730On ARM, the following registers are used:
4731
4732 R0: function argument word/integer result
4733 R1-R3: function argument word
12eba1b4
JH
4734 R9: platform specific
4735 R10: stack limit (used only if stack checking is enabled)
2729af9d
WD
4736 R11: argument (frame) pointer
4737 R12: temporary workspace
4738 R13: stack pointer
4739 R14: link register
4740 R15: program counter
4741
12eba1b4
JH
4742 ==> U-Boot will use R9 to hold a pointer to the global data
4743
4744 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
2729af9d 4745
0df01fd3
TC
4746On Nios II, the ABI is documented here:
4747 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4748
4749 ==> U-Boot will use gp to hold a pointer to the global data
4750
4751 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4752 to access small data sections, so gp is free.
4753
afc1ce82
ML
4754On NDS32, the following registers are used:
4755
4756 R0-R1: argument/return
4757 R2-R5: argument
4758 R15: temporary register for assembler
4759 R16: trampoline register
4760 R28: frame pointer (FP)
4761 R29: global pointer (GP)
4762 R30: link register (LP)
4763 R31: stack pointer (SP)
4764 PC: program counter (PC)
4765
4766 ==> U-Boot will use R10 to hold a pointer to the global data
4767
d87080b7
WD
4768NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4769or current versions of GCC may "optimize" the code too much.
2729af9d 4770
3fafced7
RC
4771On RISC-V, the following registers are used:
4772
4773 x0: hard-wired zero (zero)
4774 x1: return address (ra)
4775 x2: stack pointer (sp)
4776 x3: global pointer (gp)
4777 x4: thread pointer (tp)
4778 x5: link register (t0)
4779 x8: frame pointer (fp)
4780 x10-x11: arguments/return values (a0-1)
4781 x12-x17: arguments (a2-7)
4782 x28-31: temporaries (t3-6)
4783 pc: program counter (pc)
4784
4785 ==> U-Boot will use gp to hold a pointer to the global data
4786
2729af9d
WD
4787Memory Management:
4788------------------
4789
4790U-Boot runs in system state and uses physical addresses, i.e. the
4791MMU is not used either for address mapping nor for memory protection.
4792
4793The available memory is mapped to fixed addresses using the memory
4794controller. In this process, a contiguous block is formed for each
4795memory type (Flash, SDRAM, SRAM), even when it consists of several
4796physical memory banks.
4797
4798U-Boot is installed in the first 128 kB of the first Flash bank (on
4799TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4800booting and sizing and initializing DRAM, the code relocates itself
4801to the upper end of DRAM. Immediately below the U-Boot code some
6d0f6bcf 4802memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
2729af9d
WD
4803configuration setting]. Below that, a structure with global Board
4804Info data is placed, followed by the stack (growing downward).
4805
4806Additionally, some exception handler code is copied to the low 8 kB
4807of DRAM (0x00000000 ... 0x00001FFF).
4808
4809So a typical memory configuration with 16 MB of DRAM could look like
4810this:
4811
4812 0x0000 0000 Exception Vector code
4813 :
4814 0x0000 1FFF
4815 0x0000 2000 Free for Application Use
4816 :
4817 :
4818
4819 :
4820 :
4821 0x00FB FF20 Monitor Stack (Growing downward)
4822 0x00FB FFAC Board Info Data and permanent copy of global data
4823 0x00FC 0000 Malloc Arena
4824 :
4825 0x00FD FFFF
4826 0x00FE 0000 RAM Copy of Monitor Code
4827 ... eventually: LCD or video framebuffer
4828 ... eventually: pRAM (Protected RAM - unchanged by reset)
4829 0x00FF FFFF [End of RAM]
4830
4831
4832System Initialization:
4833----------------------
c609719b 4834
2729af9d 4835In the reset configuration, U-Boot starts at the reset entry point
11ccc33f 4836(on most PowerPC systems at address 0x00000100). Because of the reset
b445bbb4 4837configuration for CS0# this is a mirror of the on board Flash memory.
2729af9d
WD
4838To be able to re-map memory U-Boot then jumps to its link address.
4839To be able to implement the initialization code in C, a (small!)
4840initial stack is set up in the internal Dual Ported RAM (in case CPUs
2eb48ff7
HS
4841which provide such a feature like), or in a locked part of the data
4842cache. After that, U-Boot initializes the CPU core, the caches and
4843the SIU.
2729af9d
WD
4844
4845Next, all (potentially) available memory banks are mapped using a
4846preliminary mapping. For example, we put them on 512 MB boundaries
4847(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4848on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4849programmed for SDRAM access. Using the temporary configuration, a
4850simple memory test is run that determines the size of the SDRAM
4851banks.
4852
4853When there is more than one SDRAM bank, and the banks are of
4854different size, the largest is mapped first. For equal size, the first
4855bank (CS2#) is mapped first. The first mapping is always for address
48560x00000000, with any additional banks following immediately to create
4857contiguous memory starting from 0.
4858
4859Then, the monitor installs itself at the upper end of the SDRAM area
4860and allocates memory for use by malloc() and for the global Board
4861Info data; also, the exception vector code is copied to the low RAM
4862pages, and the final stack is set up.
4863
4864Only after this relocation will you have a "normal" C environment;
4865until that you are restricted in several ways, mostly because you are
4866running from ROM, and because the code will have to be relocated to a
4867new address in RAM.
4868
4869
4870U-Boot Porting Guide:
4871----------------------
c609719b 4872
2729af9d
WD
4873[Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4874list, October 2002]
c609719b
WD
4875
4876
6c3fef28 4877int main(int argc, char *argv[])
2729af9d
WD
4878{
4879 sighandler_t no_more_time;
c609719b 4880
6c3fef28
JVB
4881 signal(SIGALRM, no_more_time);
4882 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
c609719b 4883
2729af9d 4884 if (available_money > available_manpower) {
6c3fef28 4885 Pay consultant to port U-Boot;
c609719b
WD
4886 return 0;
4887 }
4888
2729af9d
WD
4889 Download latest U-Boot source;
4890
0668236b 4891 Subscribe to u-boot mailing list;
2729af9d 4892
6c3fef28
JVB
4893 if (clueless)
4894 email("Hi, I am new to U-Boot, how do I get started?");
2729af9d
WD
4895
4896 while (learning) {
4897 Read the README file in the top level directory;
6c3fef28
JVB
4898 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4899 Read applicable doc/*.README;
2729af9d 4900 Read the source, Luke;
6c3fef28 4901 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
2729af9d
WD
4902 }
4903
6c3fef28
JVB
4904 if (available_money > toLocalCurrency ($2500))
4905 Buy a BDI3000;
4906 else
2729af9d 4907 Add a lot of aggravation and time;
2729af9d 4908
6c3fef28
JVB
4909 if (a similar board exists) { /* hopefully... */
4910 cp -a board/<similar> board/<myboard>
4911 cp include/configs/<similar>.h include/configs/<myboard>.h
4912 } else {
4913 Create your own board support subdirectory;
4914 Create your own board include/configs/<myboard>.h file;
4915 }
4916 Edit new board/<myboard> files
4917 Edit new include/configs/<myboard>.h
4918
4919 while (!accepted) {
4920 while (!running) {
4921 do {
4922 Add / modify source code;
4923 } until (compiles);
4924 Debug;
4925 if (clueless)
4926 email("Hi, I am having problems...");
4927 }
4928 Send patch file to the U-Boot email list;
4929 if (reasonable critiques)
4930 Incorporate improvements from email list code review;
4931 else
4932 Defend code as written;
2729af9d 4933 }
2729af9d
WD
4934
4935 return 0;
4936}
4937
4938void no_more_time (int sig)
4939{
4940 hire_a_guru();
4941}
4942
c609719b 4943
2729af9d
WD
4944Coding Standards:
4945-----------------
c609719b 4946
2729af9d 4947All contributions to U-Boot should conform to the Linux kernel
659208da
BS
4948coding style; see the kernel coding style guide at
4949https://www.kernel.org/doc/html/latest/process/coding-style.html, and the
4950script "scripts/Lindent" in your Linux kernel source directory.
2c051651
DZ
4951
4952Source files originating from a different project (for example the
4953MTD subsystem) are generally exempt from these guidelines and are not
b445bbb4 4954reformatted to ease subsequent migration to newer versions of those
2c051651
DZ
4955sources.
4956
4957Please note that U-Boot is implemented in C (and to some small parts in
4958Assembler); no C++ is used, so please do not use C++ style comments (//)
4959in your code.
c609719b 4960
2729af9d
WD
4961Please also stick to the following formatting rules:
4962- remove any trailing white space
7ca9296e 4963- use TAB characters for indentation and vertical alignment, not spaces
2729af9d 4964- make sure NOT to use DOS '\r\n' line feeds
7ca9296e 4965- do not add more than 2 consecutive empty lines to source files
2729af9d 4966- do not add trailing empty lines to source files
180d3f74 4967
2729af9d
WD
4968Submissions which do not conform to the standards may be returned
4969with a request to reformat the changes.
c609719b
WD
4970
4971
2729af9d
WD
4972Submitting Patches:
4973-------------------
c609719b 4974
2729af9d
WD
4975Since the number of patches for U-Boot is growing, we need to
4976establish some rules. Submissions which do not conform to these rules
4977may be rejected, even when they contain important and valuable stuff.
c609719b 4978
0d28f34b 4979Please see http://www.denx.de/wiki/U-Boot/Patches for details.
218ca724 4980
0668236b 4981Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
1dade18e 4982see https://lists.denx.de/listinfo/u-boot
0668236b 4983
2729af9d
WD
4984When you send a patch, please include the following information with
4985it:
c609719b 4986
2729af9d
WD
4987* For bug fixes: a description of the bug and how your patch fixes
4988 this bug. Please try to include a way of demonstrating that the
4989 patch actually fixes something.
c609719b 4990
2729af9d
WD
4991* For new features: a description of the feature and your
4992 implementation.
c609719b 4993
2729af9d 4994* A CHANGELOG entry as plaintext (separate from the patch)
c609719b 4995
7207b366
RD
4996* For major contributions, add a MAINTAINERS file with your
4997 information and associated file and directory references.
c609719b 4998
27af930e
AA
4999* When you add support for a new board, don't forget to add a
5000 maintainer e-mail address to the boards.cfg file, too.
c609719b 5001
2729af9d
WD
5002* If your patch adds new configuration options, don't forget to
5003 document these in the README file.
c609719b 5004
218ca724
WD
5005* The patch itself. If you are using git (which is *strongly*
5006 recommended) you can easily generate the patch using the
7ca9296e 5007 "git format-patch". If you then use "git send-email" to send it to
218ca724
WD
5008 the U-Boot mailing list, you will avoid most of the common problems
5009 with some other mail clients.
5010
5011 If you cannot use git, use "diff -purN OLD NEW". If your version of
5012 diff does not support these options, then get the latest version of
5013 GNU diff.
c609719b 5014
218ca724
WD
5015 The current directory when running this command shall be the parent
5016 directory of the U-Boot source tree (i. e. please make sure that
5017 your patch includes sufficient directory information for the
5018 affected files).
6dff5529 5019
218ca724
WD
5020 We prefer patches as plain text. MIME attachments are discouraged,
5021 and compressed attachments must not be used.
c609719b 5022
2729af9d
WD
5023* If one logical set of modifications affects or creates several
5024 files, all these changes shall be submitted in a SINGLE patch file.
52f52c14 5025
2729af9d
WD
5026* Changesets that contain different, unrelated modifications shall be
5027 submitted as SEPARATE patches, one patch per changeset.
8bde7f77 5028
52f52c14 5029
2729af9d 5030Notes:
c609719b 5031
6de80f21 5032* Before sending the patch, run the buildman script on your patched
2729af9d
WD
5033 source tree and make sure that no errors or warnings are reported
5034 for any of the boards.
c609719b 5035
2729af9d
WD
5036* Keep your modifications to the necessary minimum: A patch
5037 containing several unrelated changes or arbitrary reformats will be
5038 returned with a request to re-formatting / split it.
c609719b 5039
2729af9d
WD
5040* If you modify existing code, make sure that your new code does not
5041 add to the memory footprint of the code ;-) Small is beautiful!
5042 When adding new features, these should compile conditionally only
5043 (using #ifdef), and the resulting code with the new feature
5044 disabled must not need more memory than the old code without your
5045 modification.
90dc6704 5046
0668236b
WD
5047* Remember that there is a size limit of 100 kB per message on the
5048 u-boot mailing list. Bigger patches will be moderated. If they are
5049 reasonable and not too big, they will be acknowledged. But patches
5050 bigger than the size limit should be avoided.