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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, [email protected].
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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<[email protected]>. 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
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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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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
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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
c6631764
PA
1149 CONFIG_DFU_NAND
1150 This enables support for exposing NAND devices via DFU.
1151
a9479f04
AM
1152 CONFIG_DFU_RAM
1153 This enables support for exposing RAM via DFU.
1154 Note: DFU spec refer to non-volatile memory usage, but
1155 allow usages beyond the scope of spec - here RAM usage,
1156 one that would help mostly the developer.
1157
e7e75c70
HS
1158 CONFIG_SYS_DFU_DATA_BUF_SIZE
1159 Dfu transfer uses a buffer before writing data to the
1160 raw storage device. Make the size (in bytes) of this buffer
1161 configurable. The size of this buffer is also configurable
1162 through the "dfu_bufsiz" environment variable.
1163
ea2453d5
PA
1164 CONFIG_SYS_DFU_MAX_FILE_SIZE
1165 When updating files rather than the raw storage device,
1166 we use a static buffer to copy the file into and then write
1167 the buffer once we've been given the whole file. Define
1168 this to the maximum filesize (in bytes) for the buffer.
1169 Default is 4 MiB if undefined.
1170
001a8319
HS
1171 DFU_DEFAULT_POLL_TIMEOUT
1172 Poll timeout [ms], is the timeout a device can send to the
1173 host. The host must wait for this timeout before sending
1174 a subsequent DFU_GET_STATUS request to the device.
1175
1176 DFU_MANIFEST_POLL_TIMEOUT
1177 Poll timeout [ms], which the device sends to the host when
1178 entering dfuMANIFEST state. Host waits this timeout, before
1179 sending again an USB request to the device.
1180
6705d81e 1181- Journaling Flash filesystem support:
b2482dff 1182 CONFIG_JFFS2_NAND
6705d81e
WD
1183 Define these for a default partition on a NAND device
1184
6d0f6bcf
JCPV
1185 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1186 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
6705d81e
WD
1187 Define these for a default partition on a NOR device
1188
c609719b 1189- Keyboard Support:
39f615ed
SG
1190 See Kconfig help for available keyboard drivers.
1191
1192 CONFIG_KEYBOARD
1193
1194 Define this to enable a custom keyboard support.
1195 This simply calls drv_keyboard_init() which must be
1196 defined in your board-specific files. This option is deprecated
1197 and is only used by novena. For new boards, use driver model
1198 instead.
c609719b
WD
1199
1200- Video support:
7d3053fb 1201 CONFIG_FSL_DIU_FB
04e5ae79 1202 Enable the Freescale DIU video driver. Reference boards for
7d3053fb
TT
1203 SOCs that have a DIU should define this macro to enable DIU
1204 support, and should also define these other macros:
1205
1206 CONFIG_SYS_DIU_ADDR
1207 CONFIG_VIDEO
7d3053fb
TT
1208 CONFIG_CFB_CONSOLE
1209 CONFIG_VIDEO_SW_CURSOR
1210 CONFIG_VGA_AS_SINGLE_DEVICE
1211 CONFIG_VIDEO_LOGO
1212 CONFIG_VIDEO_BMP_LOGO
1213
ba8e76bd
TT
1214 The DIU driver will look for the 'video-mode' environment
1215 variable, and if defined, enable the DIU as a console during
8eca9439 1216 boot. See the documentation file doc/README.video for a
ba8e76bd 1217 description of this variable.
7d3053fb 1218
c609719b
WD
1219- LCD Support: CONFIG_LCD
1220
1221 Define this to enable LCD support (for output to LCD
1222 display); also select one of the supported displays
1223 by defining one of these:
1224
39cf4804
SP
1225 CONFIG_ATMEL_LCD:
1226
1227 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1228
fd3103bb 1229 CONFIG_NEC_NL6448AC33:
c609719b 1230
fd3103bb 1231 NEC NL6448AC33-18. Active, color, single scan.
c609719b 1232
fd3103bb 1233 CONFIG_NEC_NL6448BC20
c609719b 1234
fd3103bb
WD
1235 NEC NL6448BC20-08. 6.5", 640x480.
1236 Active, color, single scan.
1237
1238 CONFIG_NEC_NL6448BC33_54
1239
1240 NEC NL6448BC33-54. 10.4", 640x480.
c609719b
WD
1241 Active, color, single scan.
1242
1243 CONFIG_SHARP_16x9
1244
1245 Sharp 320x240. Active, color, single scan.
1246 It isn't 16x9, and I am not sure what it is.
1247
1248 CONFIG_SHARP_LQ64D341
1249
1250 Sharp LQ64D341 display, 640x480.
1251 Active, color, single scan.
1252
1253 CONFIG_HLD1045
1254
1255 HLD1045 display, 640x480.
1256 Active, color, single scan.
1257
1258 CONFIG_OPTREX_BW
1259
1260 Optrex CBL50840-2 NF-FW 99 22 M5
1261 or
1262 Hitachi LMG6912RPFC-00T
1263 or
1264 Hitachi SP14Q002
1265
1266 320x240. Black & white.
1267
676d319e
SG
1268 CONFIG_LCD_ALIGNMENT
1269
b445bbb4 1270 Normally the LCD is page-aligned (typically 4KB). If this is
676d319e
SG
1271 defined then the LCD will be aligned to this value instead.
1272 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1273 here, since it is cheaper to change data cache settings on
1274 a per-section basis.
1275
1276
604c7d4a
HP
1277 CONFIG_LCD_ROTATION
1278
1279 Sometimes, for example if the display is mounted in portrait
1280 mode or even if it's mounted landscape but rotated by 180degree,
1281 we need to rotate our content of the display relative to the
1282 framebuffer, so that user can read the messages which are
1283 printed out.
1284 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1285 initialized with a given rotation from "vl_rot" out of
1286 "vidinfo_t" which is provided by the board specific code.
1287 The value for vl_rot is coded as following (matching to
1288 fbcon=rotate:<n> linux-kernel commandline):
1289 0 = no rotation respectively 0 degree
1290 1 = 90 degree rotation
1291 2 = 180 degree rotation
1292 3 = 270 degree rotation
1293
1294 If CONFIG_LCD_ROTATION is not defined, the console will be
1295 initialized with 0degree rotation.
1296
45d7f525
TWHT
1297 CONFIG_LCD_BMP_RLE8
1298
1299 Support drawing of RLE8-compressed bitmaps on the LCD.
1300
735987c5
TWHT
1301 CONFIG_I2C_EDID
1302
1303 Enables an 'i2c edid' command which can read EDID
1304 information over I2C from an attached LCD display.
1305
7152b1d0 1306- Splash Screen Support: CONFIG_SPLASH_SCREEN
d791b1dc 1307
8bde7f77
WD
1308 If this option is set, the environment is checked for
1309 a variable "splashimage". If found, the usual display
1310 of logo, copyright and system information on the LCD
e94d2cd9 1311 is suppressed and the BMP image at the address
8bde7f77
WD
1312 specified in "splashimage" is loaded instead. The
1313 console is redirected to the "nulldev", too. This
1314 allows for a "silent" boot where a splash screen is
1315 loaded very quickly after power-on.
d791b1dc 1316
c0880485
NK
1317 CONFIG_SPLASHIMAGE_GUARD
1318
1319 If this option is set, then U-Boot will prevent the environment
1320 variable "splashimage" from being set to a problematic address
ab5645f1 1321 (see doc/README.displaying-bmps).
c0880485
NK
1322 This option is useful for targets where, due to alignment
1323 restrictions, an improperly aligned BMP image will cause a data
1324 abort. If you think you will not have problems with unaligned
1325 accesses (for example because your toolchain prevents them)
1326 there is no need to set this option.
1327
1ca298ce
MW
1328 CONFIG_SPLASH_SCREEN_ALIGN
1329
1330 If this option is set the splash image can be freely positioned
1331 on the screen. Environment variable "splashpos" specifies the
1332 position as "x,y". If a positive number is given it is used as
1333 number of pixel from left/top. If a negative number is given it
1334 is used as number of pixel from right/bottom. You can also
1335 specify 'm' for centering the image.
1336
1337 Example:
1338 setenv splashpos m,m
1339 => image at center of screen
1340
1341 setenv splashpos 30,20
1342 => image at x = 30 and y = 20
1343
1344 setenv splashpos -10,m
1345 => vertically centered image
1346 at x = dspWidth - bmpWidth - 9
1347
98f4a3df
SR
1348- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1349
1350 If this option is set, additionally to standard BMP
1351 images, gzipped BMP images can be displayed via the
1352 splashscreen support or the bmp command.
1353
d5011762
AG
1354- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1355
1356 If this option is set, 8-bit RLE compressed BMP images
1357 can be displayed via the splashscreen support or the
1358 bmp command.
1359
c29fdfc1 1360- Compression support:
8ef70478
KC
1361 CONFIG_GZIP
1362
1363 Enabled by default to support gzip compressed images.
1364
c29fdfc1
WD
1365 CONFIG_BZIP2
1366
1367 If this option is set, support for bzip2 compressed
1368 images is included. If not, only uncompressed and gzip
1369 compressed images are supported.
1370
42d1f039 1371 NOTE: the bzip2 algorithm requires a lot of RAM, so
6d0f6bcf 1372 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
42d1f039 1373 be at least 4MB.
d791b1dc 1374
17ea1177 1375- MII/PHY support:
17ea1177
WD
1376 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1377
1378 The clock frequency of the MII bus
1379
17ea1177
WD
1380 CONFIG_PHY_RESET_DELAY
1381
1382 Some PHY like Intel LXT971A need extra delay after
1383 reset before any MII register access is possible.
1384 For such PHY, set this option to the usec delay
1385 required. (minimum 300usec for LXT971A)
1386
1387 CONFIG_PHY_CMD_DELAY (ppc4xx)
1388
1389 Some PHY like Intel LXT971A need extra delay after
1390 command issued before MII status register can be read
1391
c609719b
WD
1392- IP address:
1393 CONFIG_IPADDR
1394
1395 Define a default value for the IP address to use for
11ccc33f 1396 the default Ethernet interface, in case this is not
c609719b 1397 determined through e.g. bootp.
1ebcd654 1398 (Environment variable "ipaddr")
c609719b
WD
1399
1400- Server IP address:
1401 CONFIG_SERVERIP
1402
11ccc33f 1403 Defines a default value for the IP address of a TFTP
c609719b 1404 server to contact when using the "tftboot" command.
1ebcd654 1405 (Environment variable "serverip")
c609719b 1406
97cfe861
RG
1407 CONFIG_KEEP_SERVERADDR
1408
1409 Keeps the server's MAC address, in the env 'serveraddr'
1410 for passing to bootargs (like Linux's netconsole option)
1411
1ebcd654
WD
1412- Gateway IP address:
1413 CONFIG_GATEWAYIP
1414
1415 Defines a default value for the IP address of the
1416 default router where packets to other networks are
1417 sent to.
1418 (Environment variable "gatewayip")
1419
1420- Subnet mask:
1421 CONFIG_NETMASK
1422
1423 Defines a default value for the subnet mask (or
1424 routing prefix) which is used to determine if an IP
1425 address belongs to the local subnet or needs to be
1426 forwarded through a router.
1427 (Environment variable "netmask")
1428
c609719b
WD
1429- BOOTP Recovery Mode:
1430 CONFIG_BOOTP_RANDOM_DELAY
1431
1432 If you have many targets in a network that try to
1433 boot using BOOTP, you may want to avoid that all
1434 systems send out BOOTP requests at precisely the same
1435 moment (which would happen for instance at recovery
1436 from a power failure, when all systems will try to
1437 boot, thus flooding the BOOTP server. Defining
1438 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1439 inserted before sending out BOOTP requests. The
6c33c785 1440 following delays are inserted then:
c609719b
WD
1441
1442 1st BOOTP request: delay 0 ... 1 sec
1443 2nd BOOTP request: delay 0 ... 2 sec
1444 3rd BOOTP request: delay 0 ... 4 sec
1445 4th and following
1446 BOOTP requests: delay 0 ... 8 sec
1447
92ac8acc
TR
1448 CONFIG_BOOTP_ID_CACHE_SIZE
1449
1450 BOOTP packets are uniquely identified using a 32-bit ID. The
1451 server will copy the ID from client requests to responses and
1452 U-Boot will use this to determine if it is the destination of
1453 an incoming response. Some servers will check that addresses
1454 aren't in use before handing them out (usually using an ARP
1455 ping) and therefore take up to a few hundred milliseconds to
1456 respond. Network congestion may also influence the time it
1457 takes for a response to make it back to the client. If that
1458 time is too long, U-Boot will retransmit requests. In order
1459 to allow earlier responses to still be accepted after these
1460 retransmissions, U-Boot's BOOTP client keeps a small cache of
1461 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
1462 cache. The default is to keep IDs for up to four outstanding
1463 requests. Increasing this will allow U-Boot to accept offers
1464 from a BOOTP client in networks with unusually high latency.
1465
fe389a82 1466- DHCP Advanced Options:
1fe80d79
JL
1467 You can fine tune the DHCP functionality by defining
1468 CONFIG_BOOTP_* symbols:
1469
1fe80d79 1470 CONFIG_BOOTP_NISDOMAIN
1fe80d79 1471 CONFIG_BOOTP_BOOTFILESIZE
1fe80d79
JL
1472 CONFIG_BOOTP_SEND_HOSTNAME
1473 CONFIG_BOOTP_NTPSERVER
1474 CONFIG_BOOTP_TIMEOFFSET
1475 CONFIG_BOOTP_VENDOREX
2c00e099 1476 CONFIG_BOOTP_MAY_FAIL
fe389a82 1477
5d110f0a
WC
1478 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1479 environment variable, not the BOOTP server.
fe389a82 1480
2c00e099
JH
1481 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1482 after the configured retry count, the call will fail
1483 instead of starting over. This can be used to fail over
1484 to Link-local IP address configuration if the DHCP server
1485 is not available.
1486
fe389a82
SR
1487 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1488 to do a dynamic update of a DNS server. To do this, they
1489 need the hostname of the DHCP requester.
5d110f0a 1490 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1fe80d79
JL
1491 of the "hostname" environment variable is passed as
1492 option 12 to the DHCP server.
fe389a82 1493
d9a2f416
AV
1494 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1495
1496 A 32bit value in microseconds for a delay between
1497 receiving a "DHCP Offer" and sending the "DHCP Request".
1498 This fixes a problem with certain DHCP servers that don't
1499 respond 100% of the time to a "DHCP request". E.g. On an
1500 AT91RM9200 processor running at 180MHz, this delay needed
1501 to be *at least* 15,000 usec before a Windows Server 2003
1502 DHCP server would reply 100% of the time. I recommend at
1503 least 50,000 usec to be safe. The alternative is to hope
1504 that one of the retries will be successful but note that
1505 the DHCP timeout and retry process takes a longer than
1506 this delay.
1507
d22c338e
JH
1508 - Link-local IP address negotiation:
1509 Negotiate with other link-local clients on the local network
1510 for an address that doesn't require explicit configuration.
1511 This is especially useful if a DHCP server cannot be guaranteed
1512 to exist in all environments that the device must operate.
1513
1514 See doc/README.link-local for more information.
1515
24acb83d
PK
1516 - MAC address from environment variables
1517
1518 FDT_SEQ_MACADDR_FROM_ENV
1519
1520 Fix-up device tree with MAC addresses fetched sequentially from
1521 environment variables. This config work on assumption that
1522 non-usable ethernet node of device-tree are either not present
1523 or their status has been marked as "disabled".
1524
a3d991bd 1525 - CDP Options:
6e592385 1526 CONFIG_CDP_DEVICE_ID
a3d991bd
WD
1527
1528 The device id used in CDP trigger frames.
1529
1530 CONFIG_CDP_DEVICE_ID_PREFIX
1531
1532 A two character string which is prefixed to the MAC address
1533 of the device.
1534
1535 CONFIG_CDP_PORT_ID
1536
1537 A printf format string which contains the ascii name of
1538 the port. Normally is set to "eth%d" which sets
11ccc33f 1539 eth0 for the first Ethernet, eth1 for the second etc.
a3d991bd
WD
1540
1541 CONFIG_CDP_CAPABILITIES
1542
1543 A 32bit integer which indicates the device capabilities;
1544 0x00000010 for a normal host which does not forwards.
1545
1546 CONFIG_CDP_VERSION
1547
1548 An ascii string containing the version of the software.
1549
1550 CONFIG_CDP_PLATFORM
1551
1552 An ascii string containing the name of the platform.
1553
1554 CONFIG_CDP_TRIGGER
1555
1556 A 32bit integer sent on the trigger.
1557
1558 CONFIG_CDP_POWER_CONSUMPTION
1559
1560 A 16bit integer containing the power consumption of the
1561 device in .1 of milliwatts.
1562
1563 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1564
1565 A byte containing the id of the VLAN.
1566
79267edd 1567- Status LED: CONFIG_LED_STATUS
c609719b
WD
1568
1569 Several configurations allow to display the current
1570 status using a LED. For instance, the LED will blink
1571 fast while running U-Boot code, stop blinking as
1572 soon as a reply to a BOOTP request was received, and
1573 start blinking slow once the Linux kernel is running
1574 (supported by a status LED driver in the Linux
79267edd 1575 kernel). Defining CONFIG_LED_STATUS enables this
c609719b
WD
1576 feature in U-Boot.
1577
1df7bbba
IG
1578 Additional options:
1579
79267edd 1580 CONFIG_LED_STATUS_GPIO
1df7bbba
IG
1581 The status LED can be connected to a GPIO pin.
1582 In such cases, the gpio_led driver can be used as a
79267edd 1583 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO
1df7bbba
IG
1584 to include the gpio_led driver in the U-Boot binary.
1585
9dfdcdfe
IG
1586 CONFIG_GPIO_LED_INVERTED_TABLE
1587 Some GPIO connected LEDs may have inverted polarity in which
1588 case the GPIO high value corresponds to LED off state and
1589 GPIO low value corresponds to LED on state.
1590 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
1591 with a list of GPIO LEDs that have inverted polarity.
1592
3f4978c7
HS
1593- I2C Support: CONFIG_SYS_I2C
1594
1595 This enable the NEW i2c subsystem, and will allow you to use
1596 i2c commands at the u-boot command line (as long as you set
1597 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
1598 based realtime clock chips or other i2c devices. See
1599 common/cmd_i2c.c for a description of the command line
1600 interface.
1601
1602 ported i2c driver to the new framework:
ea818dbb
HS
1603 - drivers/i2c/soft_i2c.c:
1604 - activate first bus with CONFIG_SYS_I2C_SOFT define
1605 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
1606 for defining speed and slave address
1607 - activate second bus with I2C_SOFT_DECLARATIONS2 define
1608 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
1609 for defining speed and slave address
1610 - activate third bus with I2C_SOFT_DECLARATIONS3 define
1611 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
1612 for defining speed and slave address
1613 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
1614 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
1615 for defining speed and slave address
3f4978c7 1616
00f792e0
HS
1617 - drivers/i2c/fsl_i2c.c:
1618 - activate i2c driver with CONFIG_SYS_I2C_FSL
1619 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
1620 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
1621 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
1622 bus.
93e14596 1623 - If your board supports a second fsl i2c bus, define
00f792e0
HS
1624 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
1625 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
1626 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
1627 second bus.
1628
1f2ba722 1629 - drivers/i2c/tegra_i2c.c:
10cee516
NI
1630 - activate this driver with CONFIG_SYS_I2C_TEGRA
1631 - This driver adds 4 i2c buses with a fix speed from
1632 100000 and the slave addr 0!
1f2ba722 1633
880540de
DE
1634 - drivers/i2c/ppc4xx_i2c.c
1635 - activate this driver with CONFIG_SYS_I2C_PPC4XX
1636 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
1637 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
1638
fac96408 1639 - drivers/i2c/i2c_mxc.c
1640 - activate this driver with CONFIG_SYS_I2C_MXC
03544c66
AA
1641 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
1642 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
1643 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
1644 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
fac96408 1645 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
1646 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
1647 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
1648 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
1649 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
1650 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
03544c66
AA
1651 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
1652 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
b445bbb4 1653 If those defines are not set, default value is 100000
fac96408 1654 for speed, and 0 for slave.
1655
1086bfa9
NI
1656 - drivers/i2c/rcar_i2c.c:
1657 - activate this driver with CONFIG_SYS_I2C_RCAR
1658 - This driver adds 4 i2c buses
1659
1660 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
1661 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
1662 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
1663 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
1664 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
1665 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
1666 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
1667 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
1668 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
1669
2035d77d
NI
1670 - drivers/i2c/sh_i2c.c:
1671 - activate this driver with CONFIG_SYS_I2C_SH
1672 - This driver adds from 2 to 5 i2c buses
1673
1674 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
1675 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
1676 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
1677 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
1678 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
1679 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
1680 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
1681 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
1682 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
1683 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
b445bbb4 1684 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2035d77d 1685
6789e84e
HS
1686 - drivers/i2c/omap24xx_i2c.c
1687 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
1688 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
1689 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
1690 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
1691 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
1692 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
1693 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
1694 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
1695 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
1696 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
1697 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
1698
e717fc6d
NKC
1699 - drivers/i2c/s3c24x0_i2c.c:
1700 - activate this driver with CONFIG_SYS_I2C_S3C24X0
1701 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
1702 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
1703 with a fix speed from 100000 and the slave addr 0!
1704
b46226bd
DE
1705 - drivers/i2c/ihs_i2c.c
1706 - activate this driver with CONFIG_SYS_I2C_IHS
1707 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
1708 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
1709 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
1710 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
1711 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
1712 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
1713 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
1714 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
1715 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
1716 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
1717 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
1718 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
071be896
DE
1719 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
1720 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
1721 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
1722 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
1723 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
1724 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
1725 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
1726 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
1727 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
b46226bd 1728
3f4978c7
HS
1729 additional defines:
1730
1731 CONFIG_SYS_NUM_I2C_BUSES
945a18e6 1732 Hold the number of i2c buses you want to use.
3f4978c7
HS
1733
1734 CONFIG_SYS_I2C_DIRECT_BUS
1735 define this, if you don't use i2c muxes on your hardware.
1736 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
1737 omit this define.
1738
1739 CONFIG_SYS_I2C_MAX_HOPS
1740 define how many muxes are maximal consecutively connected
1741 on one i2c bus. If you not use i2c muxes, omit this
1742 define.
1743
1744 CONFIG_SYS_I2C_BUSES
b445bbb4 1745 hold a list of buses you want to use, only used if
3f4978c7
HS
1746 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
1747 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
1748 CONFIG_SYS_NUM_I2C_BUSES = 9:
1749
1750 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
1751 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
1752 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
1753 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
1754 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
1755 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
1756 {1, {I2C_NULL_HOP}}, \
1757 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
1758 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
1759 }
1760
1761 which defines
1762 bus 0 on adapter 0 without a mux
ea818dbb
HS
1763 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
1764 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
1765 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
1766 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
1767 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
3f4978c7 1768 bus 6 on adapter 1 without a mux
ea818dbb
HS
1769 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
1770 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
3f4978c7
HS
1771
1772 If you do not have i2c muxes on your board, omit this define.
1773
ce3b5d69 1774- Legacy I2C Support:
ea818dbb 1775 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
b37c7e5e
WD
1776 then the following macros need to be defined (examples are
1777 from include/configs/lwmon.h):
c609719b
WD
1778
1779 I2C_INIT
1780
b37c7e5e 1781 (Optional). Any commands necessary to enable the I2C
43d9616c 1782 controller or configure ports.
c609719b 1783
ba56f625 1784 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
b37c7e5e 1785
c609719b
WD
1786 I2C_ACTIVE
1787
1788 The code necessary to make the I2C data line active
1789 (driven). If the data line is open collector, this
1790 define can be null.
1791
b37c7e5e
WD
1792 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1793
c609719b
WD
1794 I2C_TRISTATE
1795
1796 The code necessary to make the I2C data line tri-stated
1797 (inactive). If the data line is open collector, this
1798 define can be null.
1799
b37c7e5e
WD
1800 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1801
c609719b
WD
1802 I2C_READ
1803
472d5460
YS
1804 Code that returns true if the I2C data line is high,
1805 false if it is low.
c609719b 1806
b37c7e5e
WD
1807 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1808
c609719b
WD
1809 I2C_SDA(bit)
1810
472d5460
YS
1811 If <bit> is true, sets the I2C data line high. If it
1812 is false, it clears it (low).
c609719b 1813
b37c7e5e 1814 eg: #define I2C_SDA(bit) \
2535d602 1815 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
ba56f625 1816 else immr->im_cpm.cp_pbdat &= ~PB_SDA
b37c7e5e 1817
c609719b
WD
1818 I2C_SCL(bit)
1819
472d5460
YS
1820 If <bit> is true, sets the I2C clock line high. If it
1821 is false, it clears it (low).
c609719b 1822
b37c7e5e 1823 eg: #define I2C_SCL(bit) \
2535d602 1824 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
ba56f625 1825 else immr->im_cpm.cp_pbdat &= ~PB_SCL
b37c7e5e 1826
c609719b
WD
1827 I2C_DELAY
1828
1829 This delay is invoked four times per clock cycle so this
1830 controls the rate of data transfer. The data rate thus
b37c7e5e 1831 is 1 / (I2C_DELAY * 4). Often defined to be something
945af8d7
WD
1832 like:
1833
b37c7e5e 1834 #define I2C_DELAY udelay(2)
c609719b 1835
793b5726
MF
1836 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1837
1838 If your arch supports the generic GPIO framework (asm/gpio.h),
1839 then you may alternatively define the two GPIOs that are to be
1840 used as SCL / SDA. Any of the previous I2C_xxx macros will
1841 have GPIO-based defaults assigned to them as appropriate.
1842
1843 You should define these to the GPIO value as given directly to
1844 the generic GPIO functions.
1845
6d0f6bcf 1846 CONFIG_SYS_I2C_INIT_BOARD
47cd00fa 1847
8bde7f77
WD
1848 When a board is reset during an i2c bus transfer
1849 chips might think that the current transfer is still
1850 in progress. On some boards it is possible to access
1851 the i2c SCLK line directly, either by using the
1852 processor pin as a GPIO or by having a second pin
1853 connected to the bus. If this option is defined a
1854 custom i2c_init_board() routine in boards/xxx/board.c
1855 is run early in the boot sequence.
47cd00fa 1856
bb99ad6d
BW
1857 CONFIG_I2C_MULTI_BUS
1858
1859 This option allows the use of multiple I2C buses, each of which
c0f40859
WD
1860 must have a controller. At any point in time, only one bus is
1861 active. To switch to a different bus, use the 'i2c dev' command.
bb99ad6d
BW
1862 Note that bus numbering is zero-based.
1863
6d0f6bcf 1864 CONFIG_SYS_I2C_NOPROBES
bb99ad6d
BW
1865
1866 This option specifies a list of I2C devices that will be skipped
c0f40859 1867 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
0f89c54b
PT
1868 is set, specify a list of bus-device pairs. Otherwise, specify
1869 a 1D array of device addresses
bb99ad6d
BW
1870
1871 e.g.
1872 #undef CONFIG_I2C_MULTI_BUS
c0f40859 1873 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
bb99ad6d
BW
1874
1875 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1876
c0f40859 1877 #define CONFIG_I2C_MULTI_BUS
945a18e6 1878 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
bb99ad6d
BW
1879
1880 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1881
6d0f6bcf 1882 CONFIG_SYS_SPD_BUS_NUM
be5e6181
TT
1883
1884 If defined, then this indicates the I2C bus number for DDR SPD.
1885 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1886
6d0f6bcf 1887 CONFIG_SYS_RTC_BUS_NUM
0dc018ec
SR
1888
1889 If defined, then this indicates the I2C bus number for the RTC.
1890 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1891
2ac6985a
AD
1892 CONFIG_SOFT_I2C_READ_REPEATED_START
1893
1894 defining this will force the i2c_read() function in
1895 the soft_i2c driver to perform an I2C repeated start
1896 between writing the address pointer and reading the
1897 data. If this define is omitted the default behaviour
1898 of doing a stop-start sequence will be used. Most I2C
1899 devices can use either method, but some require one or
1900 the other.
be5e6181 1901
c609719b
WD
1902- SPI Support: CONFIG_SPI
1903
1904 Enables SPI driver (so far only tested with
1905 SPI EEPROM, also an instance works with Crystal A/D and
1906 D/As on the SACSng board)
1907
c609719b
WD
1908 CONFIG_SOFT_SPI
1909
43d9616c
WD
1910 Enables a software (bit-bang) SPI driver rather than
1911 using hardware support. This is a general purpose
1912 driver that only requires three general I/O port pins
1913 (two outputs, one input) to function. If this is
1914 defined, the board configuration must define several
1915 SPI configuration items (port pins to use, etc). For
1916 an example, see include/configs/sacsng.h.
c609719b 1917
f659b573
HS
1918 CONFIG_SYS_SPI_MXC_WAIT
1919 Timeout for waiting until spi transfer completed.
1920 default: (CONFIG_SYS_HZ/100) /* 10 ms */
1921
0133502e 1922- FPGA Support: CONFIG_FPGA
c609719b 1923
0133502e
MF
1924 Enables FPGA subsystem.
1925
1926 CONFIG_FPGA_<vendor>
1927
1928 Enables support for specific chip vendors.
1929 (ALTERA, XILINX)
c609719b 1930
0133502e 1931 CONFIG_FPGA_<family>
c609719b 1932
0133502e
MF
1933 Enables support for FPGA family.
1934 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1935
1936 CONFIG_FPGA_COUNT
1937
1938 Specify the number of FPGA devices to support.
c609719b 1939
6d0f6bcf 1940 CONFIG_SYS_FPGA_PROG_FEEDBACK
c609719b 1941
8bde7f77 1942 Enable printing of hash marks during FPGA configuration.
c609719b 1943
6d0f6bcf 1944 CONFIG_SYS_FPGA_CHECK_BUSY
c609719b 1945
43d9616c
WD
1946 Enable checks on FPGA configuration interface busy
1947 status by the configuration function. This option
1948 will require a board or device specific function to
1949 be written.
c609719b
WD
1950
1951 CONFIG_FPGA_DELAY
1952
1953 If defined, a function that provides delays in the FPGA
1954 configuration driver.
1955
6d0f6bcf 1956 CONFIG_SYS_FPGA_CHECK_CTRLC
c609719b
WD
1957 Allow Control-C to interrupt FPGA configuration
1958
6d0f6bcf 1959 CONFIG_SYS_FPGA_CHECK_ERROR
c609719b 1960
43d9616c
WD
1961 Check for configuration errors during FPGA bitfile
1962 loading. For example, abort during Virtex II
1963 configuration if the INIT_B line goes low (which
1964 indicated a CRC error).
c609719b 1965
6d0f6bcf 1966 CONFIG_SYS_FPGA_WAIT_INIT
c609719b 1967
b445bbb4
JM
1968 Maximum time to wait for the INIT_B line to de-assert
1969 after PROB_B has been de-asserted during a Virtex II
43d9616c 1970 FPGA configuration sequence. The default time is 500
11ccc33f 1971 ms.
c609719b 1972
6d0f6bcf 1973 CONFIG_SYS_FPGA_WAIT_BUSY
c609719b 1974
b445bbb4 1975 Maximum time to wait for BUSY to de-assert during
11ccc33f 1976 Virtex II FPGA configuration. The default is 5 ms.
c609719b 1977
6d0f6bcf 1978 CONFIG_SYS_FPGA_WAIT_CONFIG
c609719b 1979
43d9616c 1980 Time to wait after FPGA configuration. The default is
11ccc33f 1981 200 ms.
c609719b
WD
1982
1983- Configuration Management:
b2b8a696 1984
c609719b
WD
1985 CONFIG_IDENT_STRING
1986
43d9616c
WD
1987 If defined, this string will be added to the U-Boot
1988 version information (U_BOOT_VERSION)
c609719b
WD
1989
1990- Vendor Parameter Protection:
1991
43d9616c
WD
1992 U-Boot considers the values of the environment
1993 variables "serial#" (Board Serial Number) and
7152b1d0 1994 "ethaddr" (Ethernet Address) to be parameters that
43d9616c
WD
1995 are set once by the board vendor / manufacturer, and
1996 protects these variables from casual modification by
1997 the user. Once set, these variables are read-only,
1998 and write or delete attempts are rejected. You can
11ccc33f 1999 change this behaviour:
c609719b
WD
2000
2001 If CONFIG_ENV_OVERWRITE is #defined in your config
2002 file, the write protection for vendor parameters is
47cd00fa 2003 completely disabled. Anybody can change or delete
c609719b
WD
2004 these parameters.
2005
92ac5208
JH
2006 Alternatively, if you define _both_ an ethaddr in the
2007 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
11ccc33f 2008 Ethernet address is installed in the environment,
c609719b
WD
2009 which can be changed exactly ONCE by the user. [The
2010 serial# is unaffected by this, i. e. it remains
2011 read-only.]
2012
2598090b
JH
2013 The same can be accomplished in a more flexible way
2014 for any variable by configuring the type of access
2015 to allow for those variables in the ".flags" variable
2016 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2017
c609719b
WD
2018- Protected RAM:
2019 CONFIG_PRAM
2020
2021 Define this variable to enable the reservation of
2022 "protected RAM", i. e. RAM which is not overwritten
2023 by U-Boot. Define CONFIG_PRAM to hold the number of
2024 kB you want to reserve for pRAM. You can overwrite
2025 this default value by defining an environment
2026 variable "pram" to the number of kB you want to
2027 reserve. Note that the board info structure will
2028 still show the full amount of RAM. If pRAM is
2029 reserved, a new environment variable "mem" will
2030 automatically be defined to hold the amount of
2031 remaining RAM in a form that can be passed as boot
2032 argument to Linux, for instance like that:
2033
fe126d8b 2034 setenv bootargs ... mem=\${mem}
c609719b
WD
2035 saveenv
2036
2037 This way you can tell Linux not to use this memory,
2038 either, which results in a memory region that will
2039 not be affected by reboots.
2040
2041 *WARNING* If your board configuration uses automatic
2042 detection of the RAM size, you must make sure that
2043 this memory test is non-destructive. So far, the
2044 following board configurations are known to be
2045 "pRAM-clean":
2046
5b8e76c3 2047 IVMS8, IVML24, SPD8xx,
1b0757ec 2048 HERMES, IP860, RPXlite, LWMON,
2eb48ff7 2049 FLAGADM
c609719b 2050
40fef049
GB
2051- Access to physical memory region (> 4GB)
2052 Some basic support is provided for operations on memory not
2053 normally accessible to U-Boot - e.g. some architectures
2054 support access to more than 4GB of memory on 32-bit
2055 machines using physical address extension or similar.
2056 Define CONFIG_PHYSMEM to access this basic support, which
2057 currently only supports clearing the memory.
2058
c609719b 2059- Error Recovery:
c609719b
WD
2060 CONFIG_NET_RETRY_COUNT
2061
43d9616c
WD
2062 This variable defines the number of retries for
2063 network operations like ARP, RARP, TFTP, or BOOTP
2064 before giving up the operation. If not defined, a
2065 default value of 5 is used.
c609719b 2066
40cb90ee
GL
2067 CONFIG_ARP_TIMEOUT
2068
2069 Timeout waiting for an ARP reply in milliseconds.
2070
48a3e999
TK
2071 CONFIG_NFS_TIMEOUT
2072
2073 Timeout in milliseconds used in NFS protocol.
2074 If you encounter "ERROR: Cannot umount" in nfs command,
2075 try longer timeout such as
2076 #define CONFIG_NFS_TIMEOUT 10000UL
2077
c609719b 2078- Command Interpreter:
6d0f6bcf 2079 CONFIG_SYS_PROMPT_HUSH_PS2
c609719b
WD
2080
2081 This defines the secondary prompt string, which is
2082 printed when the command interpreter needs more input
2083 to complete a command. Usually "> ".
2084
2085 Note:
2086
8bde7f77
WD
2087 In the current implementation, the local variables
2088 space and global environment variables space are
2089 separated. Local variables are those you define by
2090 simply typing `name=value'. To access a local
2091 variable later on, you have write `$name' or
2092 `${name}'; to execute the contents of a variable
2093 directly type `$name' at the command prompt.
c609719b 2094
43d9616c
WD
2095 Global environment variables are those you use
2096 setenv/printenv to work with. To run a command stored
2097 in such a variable, you need to use the run command,
2098 and you must not use the '$' sign to access them.
c609719b
WD
2099
2100 To store commands and special characters in a
2101 variable, please use double quotation marks
2102 surrounding the whole text of the variable, instead
2103 of the backslashes before semicolons and special
2104 symbols.
2105
b445bbb4 2106- Command Line Editing and History:
f3b267b3
MV
2107 CONFIG_CMDLINE_PS_SUPPORT
2108
2109 Enable support for changing the command prompt string
2110 at run-time. Only static string is supported so far.
2111 The string is obtained from environment variables PS1
2112 and PS2.
2113
a8c7c708 2114- Default Environment:
c609719b
WD
2115 CONFIG_EXTRA_ENV_SETTINGS
2116
43d9616c
WD
2117 Define this to contain any number of null terminated
2118 strings (variable = value pairs) that will be part of
7152b1d0 2119 the default environment compiled into the boot image.
2262cfee 2120
43d9616c
WD
2121 For example, place something like this in your
2122 board's config file:
c609719b
WD
2123
2124 #define CONFIG_EXTRA_ENV_SETTINGS \
2125 "myvar1=value1\0" \
2126 "myvar2=value2\0"
2127
43d9616c
WD
2128 Warning: This method is based on knowledge about the
2129 internal format how the environment is stored by the
2130 U-Boot code. This is NOT an official, exported
2131 interface! Although it is unlikely that this format
7152b1d0 2132 will change soon, there is no guarantee either.
c609719b
WD
2133 You better know what you are doing here.
2134
43d9616c
WD
2135 Note: overly (ab)use of the default environment is
2136 discouraged. Make sure to check other ways to preset
74de7aef 2137 the environment like the "source" command or the
43d9616c 2138 boot command first.
c609719b 2139
06fd8538
SG
2140 CONFIG_DELAY_ENVIRONMENT
2141
2142 Normally the environment is loaded when the board is
b445bbb4 2143 initialised so that it is available to U-Boot. This inhibits
06fd8538
SG
2144 that so that the environment is not available until
2145 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2146 this is instead controlled by the value of
2147 /config/load-environment.
2148
f61ec45e 2149- Serial Flash support
00fd59dd 2150 Usage requires an initial 'sf probe' to define the serial
f61ec45e
EN
2151 flash parameters, followed by read/write/erase/update
2152 commands.
2153
2154 The following defaults may be provided by the platform
2155 to handle the common case when only a single serial
2156 flash is present on the system.
2157
2158 CONFIG_SF_DEFAULT_BUS Bus identifier
2159 CONFIG_SF_DEFAULT_CS Chip-select
2160 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2161 CONFIG_SF_DEFAULT_SPEED in Hz
2162
3f85ce27 2163
ecb0ccd9
WD
2164- TFTP Fixed UDP Port:
2165 CONFIG_TFTP_PORT
2166
28cb9375 2167 If this is defined, the environment variable tftpsrcp
ecb0ccd9 2168 is used to supply the TFTP UDP source port value.
28cb9375 2169 If tftpsrcp isn't defined, the normal pseudo-random port
ecb0ccd9
WD
2170 number generator is used.
2171
28cb9375
WD
2172 Also, the environment variable tftpdstp is used to supply
2173 the TFTP UDP destination port value. If tftpdstp isn't
2174 defined, the normal port 69 is used.
2175
2176 The purpose for tftpsrcp is to allow a TFTP server to
ecb0ccd9
WD
2177 blindly start the TFTP transfer using the pre-configured
2178 target IP address and UDP port. This has the effect of
2179 "punching through" the (Windows XP) firewall, allowing
2180 the remainder of the TFTP transfer to proceed normally.
2181 A better solution is to properly configure the firewall,
2182 but sometimes that is not allowed.
2183
a8c7c708 2184- Show boot progress:
c609719b
WD
2185 CONFIG_SHOW_BOOT_PROGRESS
2186
43d9616c
WD
2187 Defining this option allows to add some board-
2188 specific code (calling a user-provided function
2189 "show_boot_progress(int)") that enables you to show
2190 the system's boot progress on some display (for
2191 example, some LED's) on your board. At the moment,
2192 the following checkpoints are implemented:
c609719b 2193
94fd1316 2194
1372cce2
MB
2195Legacy uImage format:
2196
c609719b
WD
2197 Arg Where When
2198 1 common/cmd_bootm.c before attempting to boot an image
ba56f625 2199 -1 common/cmd_bootm.c Image header has bad magic number
c609719b 2200 2 common/cmd_bootm.c Image header has correct magic number
ba56f625 2201 -2 common/cmd_bootm.c Image header has bad checksum
c609719b 2202 3 common/cmd_bootm.c Image header has correct checksum
ba56f625 2203 -3 common/cmd_bootm.c Image data has bad checksum
c609719b
WD
2204 4 common/cmd_bootm.c Image data has correct checksum
2205 -4 common/cmd_bootm.c Image is for unsupported architecture
2206 5 common/cmd_bootm.c Architecture check OK
1372cce2 2207 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
c609719b
WD
2208 6 common/cmd_bootm.c Image Type check OK
2209 -6 common/cmd_bootm.c gunzip uncompression error
2210 -7 common/cmd_bootm.c Unimplemented compression type
2211 7 common/cmd_bootm.c Uncompression OK
1372cce2 2212 8 common/cmd_bootm.c No uncompress/copy overwrite error
c609719b 2213 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1372cce2
MB
2214
2215 9 common/image.c Start initial ramdisk verification
2216 -10 common/image.c Ramdisk header has bad magic number
2217 -11 common/image.c Ramdisk header has bad checksum
2218 10 common/image.c Ramdisk header is OK
2219 -12 common/image.c Ramdisk data has bad checksum
2220 11 common/image.c Ramdisk data has correct checksum
2221 12 common/image.c Ramdisk verification complete, start loading
11ccc33f 2222 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
1372cce2
MB
2223 13 common/image.c Start multifile image verification
2224 14 common/image.c No initial ramdisk, no multifile, continue.
2225
c0f40859 2226 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
c609719b 2227
a47a12be 2228 -30 arch/powerpc/lib/board.c Fatal error, hang the system
11dadd54
WD
2229 -31 post/post.c POST test failed, detected by post_output_backlog()
2230 -32 post/post.c POST test failed, detected by post_run_single()
63e73c9a 2231
566a494f
HS
2232 34 common/cmd_doc.c before loading a Image from a DOC device
2233 -35 common/cmd_doc.c Bad usage of "doc" command
2234 35 common/cmd_doc.c correct usage of "doc" command
2235 -36 common/cmd_doc.c No boot device
2236 36 common/cmd_doc.c correct boot device
2237 -37 common/cmd_doc.c Unknown Chip ID on boot device
2238 37 common/cmd_doc.c correct chip ID found, device available
2239 -38 common/cmd_doc.c Read Error on boot device
2240 38 common/cmd_doc.c reading Image header from DOC device OK
2241 -39 common/cmd_doc.c Image header has bad magic number
2242 39 common/cmd_doc.c Image header has correct magic number
2243 -40 common/cmd_doc.c Error reading Image from DOC device
2244 40 common/cmd_doc.c Image header has correct magic number
2245 41 common/cmd_ide.c before loading a Image from a IDE device
2246 -42 common/cmd_ide.c Bad usage of "ide" command
2247 42 common/cmd_ide.c correct usage of "ide" command
2248 -43 common/cmd_ide.c No boot device
2249 43 common/cmd_ide.c boot device found
2250 -44 common/cmd_ide.c Device not available
2251 44 common/cmd_ide.c Device available
2252 -45 common/cmd_ide.c wrong partition selected
2253 45 common/cmd_ide.c partition selected
2254 -46 common/cmd_ide.c Unknown partition table
2255 46 common/cmd_ide.c valid partition table found
2256 -47 common/cmd_ide.c Invalid partition type
2257 47 common/cmd_ide.c correct partition type
2258 -48 common/cmd_ide.c Error reading Image Header on boot device
2259 48 common/cmd_ide.c reading Image Header from IDE device OK
2260 -49 common/cmd_ide.c Image header has bad magic number
2261 49 common/cmd_ide.c Image header has correct magic number
2262 -50 common/cmd_ide.c Image header has bad checksum
2263 50 common/cmd_ide.c Image header has correct checksum
2264 -51 common/cmd_ide.c Error reading Image from IDE device
2265 51 common/cmd_ide.c reading Image from IDE device OK
2266 52 common/cmd_nand.c before loading a Image from a NAND device
2267 -53 common/cmd_nand.c Bad usage of "nand" command
2268 53 common/cmd_nand.c correct usage of "nand" command
2269 -54 common/cmd_nand.c No boot device
2270 54 common/cmd_nand.c boot device found
2271 -55 common/cmd_nand.c Unknown Chip ID on boot device
2272 55 common/cmd_nand.c correct chip ID found, device available
2273 -56 common/cmd_nand.c Error reading Image Header on boot device
2274 56 common/cmd_nand.c reading Image Header from NAND device OK
2275 -57 common/cmd_nand.c Image header has bad magic number
2276 57 common/cmd_nand.c Image header has correct magic number
2277 -58 common/cmd_nand.c Error reading Image from NAND device
2278 58 common/cmd_nand.c reading Image from NAND device OK
2279
2280 -60 common/env_common.c Environment has a bad CRC, using default
2281
11ccc33f 2282 64 net/eth.c starting with Ethernet configuration.
566a494f
HS
2283 -64 net/eth.c no Ethernet found.
2284 65 net/eth.c Ethernet found.
2285
2286 -80 common/cmd_net.c usage wrong
bc0571fc
JH
2287 80 common/cmd_net.c before calling net_loop()
2288 -81 common/cmd_net.c some error in net_loop() occurred
2289 81 common/cmd_net.c net_loop() back without error
566a494f
HS
2290 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2291 82 common/cmd_net.c trying automatic boot
74de7aef
WD
2292 83 common/cmd_net.c running "source" command
2293 -83 common/cmd_net.c some error in automatic boot or "source" command
566a494f 2294 84 common/cmd_net.c end without errors
c609719b 2295
1372cce2
MB
2296FIT uImage format:
2297
2298 Arg Where When
2299 100 common/cmd_bootm.c Kernel FIT Image has correct format
2300 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2301 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2302 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2303 102 common/cmd_bootm.c Kernel unit name specified
2304 -103 common/cmd_bootm.c Can't get kernel subimage node offset
f773bea8 2305 103 common/cmd_bootm.c Found configuration node
1372cce2
MB
2306 104 common/cmd_bootm.c Got kernel subimage node offset
2307 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2308 105 common/cmd_bootm.c Kernel subimage hash verification OK
2309 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2310 106 common/cmd_bootm.c Architecture check OK
11ccc33f
MZ
2311 -106 common/cmd_bootm.c Kernel subimage has wrong type
2312 107 common/cmd_bootm.c Kernel subimage type OK
1372cce2
MB
2313 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2314 108 common/cmd_bootm.c Got kernel subimage data/size
2315 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2316 -109 common/cmd_bootm.c Can't get kernel subimage type
2317 -110 common/cmd_bootm.c Can't get kernel subimage comp
2318 -111 common/cmd_bootm.c Can't get kernel subimage os
2319 -112 common/cmd_bootm.c Can't get kernel subimage load address
2320 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2321
2322 120 common/image.c Start initial ramdisk verification
2323 -120 common/image.c Ramdisk FIT image has incorrect format
2324 121 common/image.c Ramdisk FIT image has correct format
11ccc33f 2325 122 common/image.c No ramdisk subimage unit name, using configuration
1372cce2
MB
2326 -122 common/image.c Can't get configuration for ramdisk subimage
2327 123 common/image.c Ramdisk unit name specified
2328 -124 common/image.c Can't get ramdisk subimage node offset
2329 125 common/image.c Got ramdisk subimage node offset
2330 -125 common/image.c Ramdisk subimage hash verification failed
2331 126 common/image.c Ramdisk subimage hash verification OK
2332 -126 common/image.c Ramdisk subimage for unsupported architecture
2333 127 common/image.c Architecture check OK
2334 -127 common/image.c Can't get ramdisk subimage data/size
2335 128 common/image.c Got ramdisk subimage data/size
2336 129 common/image.c Can't get ramdisk load address
2337 -129 common/image.c Got ramdisk load address
2338
11ccc33f 2339 -130 common/cmd_doc.c Incorrect FIT image format
1372cce2
MB
2340 131 common/cmd_doc.c FIT image format OK
2341
11ccc33f 2342 -140 common/cmd_ide.c Incorrect FIT image format
1372cce2
MB
2343 141 common/cmd_ide.c FIT image format OK
2344
11ccc33f 2345 -150 common/cmd_nand.c Incorrect FIT image format
1372cce2
MB
2346 151 common/cmd_nand.c FIT image format OK
2347
4cf2609b
WD
2348- Standalone program support:
2349 CONFIG_STANDALONE_LOAD_ADDR
2350
6feff899
WD
2351 This option defines a board specific value for the
2352 address where standalone program gets loaded, thus
2353 overwriting the architecture dependent default
4cf2609b
WD
2354 settings.
2355
2356- Frame Buffer Address:
2357 CONFIG_FB_ADDR
2358
2359 Define CONFIG_FB_ADDR if you want to use specific
44a53b57
WD
2360 address for frame buffer. This is typically the case
2361 when using a graphics controller has separate video
2362 memory. U-Boot will then place the frame buffer at
2363 the given address instead of dynamically reserving it
2364 in system RAM by calling lcd_setmem(), which grabs
2365 the memory for the frame buffer depending on the
2366 configured panel size.
4cf2609b
WD
2367
2368 Please see board_init_f function.
2369
cccfc2ab
DZ
2370- Automatic software updates via TFTP server
2371 CONFIG_UPDATE_TFTP
2372 CONFIG_UPDATE_TFTP_CNT_MAX
2373 CONFIG_UPDATE_TFTP_MSEC_MAX
2374
2375 These options enable and control the auto-update feature;
2376 for a more detailed description refer to doc/README.update.
2377
2378- MTD Support (mtdparts command, UBI support)
ff94bc40
HS
2379 CONFIG_MTD_UBI_WL_THRESHOLD
2380 This parameter defines the maximum difference between the highest
2381 erase counter value and the lowest erase counter value of eraseblocks
2382 of UBI devices. When this threshold is exceeded, UBI starts performing
2383 wear leveling by means of moving data from eraseblock with low erase
2384 counter to eraseblocks with high erase counter.
2385
2386 The default value should be OK for SLC NAND flashes, NOR flashes and
2387 other flashes which have eraseblock life-cycle 100000 or more.
2388 However, in case of MLC NAND flashes which typically have eraseblock
2389 life-cycle less than 10000, the threshold should be lessened (e.g.,
2390 to 128 or 256, although it does not have to be power of 2).
2391
2392 default: 4096
c654b517 2393
ff94bc40
HS
2394 CONFIG_MTD_UBI_BEB_LIMIT
2395 This option specifies the maximum bad physical eraseblocks UBI
2396 expects on the MTD device (per 1024 eraseblocks). If the
2397 underlying flash does not admit of bad eraseblocks (e.g. NOR
2398 flash), this value is ignored.
2399
2400 NAND datasheets often specify the minimum and maximum NVM
2401 (Number of Valid Blocks) for the flashes' endurance lifetime.
2402 The maximum expected bad eraseblocks per 1024 eraseblocks
2403 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
2404 which gives 20 for most NANDs (MaxNVB is basically the total
2405 count of eraseblocks on the chip).
2406
2407 To put it differently, if this value is 20, UBI will try to
2408 reserve about 1.9% of physical eraseblocks for bad blocks
2409 handling. And that will be 1.9% of eraseblocks on the entire
2410 NAND chip, not just the MTD partition UBI attaches. This means
2411 that if you have, say, a NAND flash chip admits maximum 40 bad
2412 eraseblocks, and it is split on two MTD partitions of the same
2413 size, UBI will reserve 40 eraseblocks when attaching a
2414 partition.
2415
2416 default: 20
2417
2418 CONFIG_MTD_UBI_FASTMAP
2419 Fastmap is a mechanism which allows attaching an UBI device
2420 in nearly constant time. Instead of scanning the whole MTD device it
2421 only has to locate a checkpoint (called fastmap) on the device.
2422 The on-flash fastmap contains all information needed to attach
2423 the device. Using fastmap makes only sense on large devices where
2424 attaching by scanning takes long. UBI will not automatically install
2425 a fastmap on old images, but you can set the UBI parameter
2426 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
2427 that fastmap-enabled images are still usable with UBI implementations
2428 without fastmap support. On typical flash devices the whole fastmap
2429 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
2430
2431 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
2432 Set this parameter to enable fastmap automatically on images
2433 without a fastmap.
2434 default: 0
2435
0195a7bb
HS
2436 CONFIG_MTD_UBI_FM_DEBUG
2437 Enable UBI fastmap debug
2438 default: 0
2439
6a11cf48 2440- SPL framework
04e5ae79
WD
2441 CONFIG_SPL
2442 Enable building of SPL globally.
6a11cf48 2443
95579793
TR
2444 CONFIG_SPL_LDSCRIPT
2445 LDSCRIPT for linking the SPL binary.
2446
6ebc3461
AA
2447 CONFIG_SPL_MAX_FOOTPRINT
2448 Maximum size in memory allocated to the SPL, BSS included.
2449 When defined, the linker checks that the actual memory
2450 used by SPL from _start to __bss_end does not exceed it.
8960af8b 2451 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
6ebc3461
AA
2452 must not be both defined at the same time.
2453
95579793 2454 CONFIG_SPL_MAX_SIZE
6ebc3461
AA
2455 Maximum size of the SPL image (text, data, rodata, and
2456 linker lists sections), BSS excluded.
2457 When defined, the linker checks that the actual size does
2458 not exceed it.
95579793 2459
04e5ae79
WD
2460 CONFIG_SPL_TEXT_BASE
2461 TEXT_BASE for linking the SPL binary.
6a11cf48 2462
94a45bb1
SW
2463 CONFIG_SPL_RELOC_TEXT_BASE
2464 Address to relocate to. If unspecified, this is equal to
2465 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2466
95579793
TR
2467 CONFIG_SPL_BSS_START_ADDR
2468 Link address for the BSS within the SPL binary.
2469
2470 CONFIG_SPL_BSS_MAX_SIZE
6ebc3461
AA
2471 Maximum size in memory allocated to the SPL BSS.
2472 When defined, the linker checks that the actual memory used
2473 by SPL from __bss_start to __bss_end does not exceed it.
8960af8b 2474 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
6ebc3461 2475 must not be both defined at the same time.
95579793
TR
2476
2477 CONFIG_SPL_STACK
2478 Adress of the start of the stack SPL will use
2479
8c80eb3b
AA
2480 CONFIG_SPL_PANIC_ON_RAW_IMAGE
2481 When defined, SPL will panic() if the image it has
2482 loaded does not have a signature.
2483 Defining this is useful when code which loads images
2484 in SPL cannot guarantee that absolutely all read errors
2485 will be caught.
2486 An example is the LPC32XX MLC NAND driver, which will
2487 consider that a completely unreadable NAND block is bad,
2488 and thus should be skipped silently.
2489
94a45bb1
SW
2490 CONFIG_SPL_RELOC_STACK
2491 Adress of the start of the stack SPL will use after
2492 relocation. If unspecified, this is equal to
2493 CONFIG_SPL_STACK.
2494
95579793
TR
2495 CONFIG_SYS_SPL_MALLOC_START
2496 Starting address of the malloc pool used in SPL.
9ac4fc82
FE
2497 When this option is set the full malloc is used in SPL and
2498 it is set up by spl_init() and before that, the simple malloc()
2499 can be used if CONFIG_SYS_MALLOC_F is defined.
95579793
TR
2500
2501 CONFIG_SYS_SPL_MALLOC_SIZE
2502 The size of the malloc pool used in SPL.
6a11cf48 2503
9607faf2
TR
2504 CONFIG_SPL_OS_BOOT
2505 Enable booting directly to an OS from SPL.
2506 See also: doc/README.falcon
2507
861a86f4
TR
2508 CONFIG_SPL_DISPLAY_PRINT
2509 For ARM, enable an optional function to print more information
2510 about the running system.
2511
4b919725
SW
2512 CONFIG_SPL_INIT_MINIMAL
2513 Arch init code should be built for a very small image
2514
b97300b6
PK
2515 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
2516 Partition on the MMC to load U-Boot from when the MMC is being
2517 used in raw mode
2518
2b75b0ad
PK
2519 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
2520 Sector to load kernel uImage from when MMC is being
2521 used in raw mode (for Falcon mode)
2522
2523 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
2524 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
2525 Sector and number of sectors to load kernel argument
2526 parameters from when MMC is being used in raw mode
2527 (for falcon mode)
2528
e2ccdf89
PK
2529 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
2530 Partition on the MMC to load U-Boot from when the MMC is being
2531 used in fs mode
2532
fae81c72
GG
2533 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
2534 Filename to read to load U-Boot when reading from filesystem
2535
2536 CONFIG_SPL_FS_LOAD_KERNEL_NAME
7ad2cc79 2537 Filename to read to load kernel uImage when reading
fae81c72 2538 from filesystem (for Falcon mode)
7ad2cc79 2539
fae81c72 2540 CONFIG_SPL_FS_LOAD_ARGS_NAME
7ad2cc79 2541 Filename to read to load kernel argument parameters
fae81c72 2542 when reading from filesystem (for Falcon mode)
7ad2cc79 2543
06f60ae3
SW
2544 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
2545 Set this for NAND SPL on PPC mpc83xx targets, so that
2546 start.S waits for the rest of the SPL to load before
2547 continuing (the hardware starts execution after just
2548 loading the first page rather than the full 4K).
2549
651fcf60
PK
2550 CONFIG_SPL_SKIP_RELOCATE
2551 Avoid SPL relocation
2552
6f2f01b9
SW
2553 CONFIG_SPL_NAND_BASE
2554 Include nand_base.c in the SPL. Requires
2555 CONFIG_SPL_NAND_DRIVERS.
2556
2557 CONFIG_SPL_NAND_DRIVERS
2558 SPL uses normal NAND drivers, not minimal drivers.
2559
15e207fa
JK
2560 CONFIG_SPL_NAND_IDENT
2561 SPL uses the chip ID list to identify the NAND flash.
2562 Requires CONFIG_SPL_NAND_BASE.
2563
6f2f01b9
SW
2564 CONFIG_SPL_NAND_ECC
2565 Include standard software ECC in the SPL
2566
95579793 2567 CONFIG_SPL_NAND_SIMPLE
7d4b7955
SW
2568 Support for NAND boot using simple NAND drivers that
2569 expose the cmd_ctrl() interface.
95579793 2570
6f4e7d3c
TG
2571 CONFIG_SPL_UBI
2572 Support for a lightweight UBI (fastmap) scanner and
2573 loader
2574
0c3117b1
HS
2575 CONFIG_SPL_NAND_RAW_ONLY
2576 Support to boot only raw u-boot.bin images. Use this only
2577 if you need to save space.
2578
7c8eea59
YZ
2579 CONFIG_SPL_COMMON_INIT_DDR
2580 Set for common ddr init with serial presence detect in
2581 SPL binary.
2582
95579793
TR
2583 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
2584 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
2585 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
2586 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
2587 CONFIG_SYS_NAND_ECCBYTES
2588 Defines the size and behavior of the NAND that SPL uses
7d4b7955 2589 to read U-Boot
95579793 2590
fbe76ae4
PK
2591 CONFIG_SPL_NAND_BOOT
2592 Add support NAND boot
2593
95579793 2594 CONFIG_SYS_NAND_U_BOOT_OFFS
7d4b7955
SW
2595 Location in NAND to read U-Boot from
2596
2597 CONFIG_SYS_NAND_U_BOOT_DST
2598 Location in memory to load U-Boot to
2599
2600 CONFIG_SYS_NAND_U_BOOT_SIZE
2601 Size of image to load
95579793
TR
2602
2603 CONFIG_SYS_NAND_U_BOOT_START
7d4b7955 2604 Entry point in loaded image to jump to
95579793
TR
2605
2606 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
2607 Define this if you need to first read the OOB and then the
b445bbb4 2608 data. This is used, for example, on davinci platforms.
95579793 2609
c57b953d
PM
2610 CONFIG_SPL_RAM_DEVICE
2611 Support for running image already present in ram, in SPL binary
6a11cf48 2612
74752baa 2613 CONFIG_SPL_PAD_TO
6113d3f2
BT
2614 Image offset to which the SPL should be padded before appending
2615 the SPL payload. By default, this is defined as
2616 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
2617 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
2618 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
74752baa 2619
ca2fca22
SW
2620 CONFIG_SPL_TARGET
2621 Final target image containing SPL and payload. Some SPLs
2622 use an arch-specific makefile fragment instead, for
2623 example if more than one image needs to be produced.
2624
b527b9c6 2625 CONFIG_SPL_FIT_PRINT
87ebee39
SG
2626 Printing information about a FIT image adds quite a bit of
2627 code to SPL. So this is normally disabled in SPL. Use this
2628 option to re-enable it. This will affect the output of the
2629 bootm command when booting a FIT image.
2630
3aa29de0
YZ
2631- TPL framework
2632 CONFIG_TPL
2633 Enable building of TPL globally.
2634
2635 CONFIG_TPL_PAD_TO
2636 Image offset to which the TPL should be padded before appending
2637 the TPL payload. By default, this is defined as
93e14596
WD
2638 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
2639 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
2640 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3aa29de0 2641
a8c7c708
WD
2642- Interrupt support (PPC):
2643
d4ca31c4
WD
2644 There are common interrupt_init() and timer_interrupt()
2645 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
11ccc33f 2646 for CPU specific initialization. interrupt_init_cpu()
d4ca31c4 2647 should set decrementer_count to appropriate value. If
11ccc33f 2648 CPU resets decrementer automatically after interrupt
d4ca31c4 2649 (ppc4xx) it should set decrementer_count to zero.
11ccc33f 2650 timer_interrupt() calls timer_interrupt_cpu() for CPU
d4ca31c4
WD
2651 specific handling. If board has watchdog / status_led
2652 / other_activity_monitor it works automatically from
2653 general timer_interrupt().
a8c7c708 2654
c609719b 2655
9660e442
HR
2656Board initialization settings:
2657------------------------------
2658
2659During Initialization u-boot calls a number of board specific functions
2660to allow the preparation of board specific prerequisites, e.g. pin setup
2661before drivers are initialized. To enable these callbacks the
2662following configuration macros have to be defined. Currently this is
2663architecture specific, so please check arch/your_architecture/lib/board.c
2664typically in board_init_f() and board_init_r().
2665
2666- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
2667- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
2668- CONFIG_BOARD_LATE_INIT: Call board_late_init()
2669- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
c609719b 2670
c609719b
WD
2671Configuration Settings:
2672-----------------------
2673
4d1fd7f1
YS
2674- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
2675 Optionally it can be defined to support 64-bit memory commands.
2676
6d0f6bcf 2677- CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
c609719b
WD
2678 undefine this when you're short of memory.
2679
2fb2604d
PT
2680- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2681 width of the commands listed in the 'help' command output.
2682
6d0f6bcf 2683- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
c609719b
WD
2684 prompt for user input.
2685
6d0f6bcf 2686- CONFIG_SYS_CBSIZE: Buffer size for input from the Console
c609719b 2687
6d0f6bcf 2688- CONFIG_SYS_PBSIZE: Buffer size for Console output
c609719b 2689
6d0f6bcf 2690- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
c609719b 2691
6d0f6bcf 2692- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
c609719b
WD
2693 the application (usually a Linux kernel) when it is
2694 booted
2695
6d0f6bcf 2696- CONFIG_SYS_BAUDRATE_TABLE:
c609719b
WD
2697 List of legal baudrate settings for this board.
2698
6d0f6bcf 2699- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
c609719b
WD
2700 Begin and End addresses of the area used by the
2701 simple memory test.
2702
6d0f6bcf 2703- CONFIG_SYS_MEMTEST_SCRATCH:
5f535fe1
WD
2704 Scratch address used by the alternate memory test
2705 You only need to set this if address zero isn't writeable
2706
e8149522 2707- CONFIG_SYS_MEM_RESERVE_SECURE
e61a7534 2708 Only implemented for ARMv8 for now.
e8149522
YS
2709 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
2710 is substracted from total RAM and won't be reported to OS.
2711 This memory can be used as secure memory. A variable
e61a7534 2712 gd->arch.secure_ram is used to track the location. In systems
e8149522
YS
2713 the RAM base is not zero, or RAM is divided into banks,
2714 this variable needs to be recalcuated to get the address.
2715
aabd7ddb 2716- CONFIG_SYS_MEM_TOP_HIDE:
6d0f6bcf 2717 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
14f73ca6 2718 this specified memory area will get subtracted from the top
11ccc33f 2719 (end) of RAM and won't get "touched" at all by U-Boot. By
14f73ca6
SR
2720 fixing up gd->ram_size the Linux kernel should gets passed
2721 the now "corrected" memory size and won't touch it either.
2722 This should work for arch/ppc and arch/powerpc. Only Linux
5e12e75d 2723 board ports in arch/powerpc with bootwrapper support that
14f73ca6 2724 recalculate the memory size from the SDRAM controller setup
5e12e75d 2725 will have to get fixed in Linux additionally.
14f73ca6
SR
2726
2727 This option can be used as a workaround for the 440EPx/GRx
2728 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2729 be touched.
2730
2731 WARNING: Please make sure that this value is a multiple of
2732 the Linux page size (normally 4k). If this is not the case,
2733 then the end address of the Linux memory will be located at a
2734 non page size aligned address and this could cause major
2735 problems.
2736
6d0f6bcf 2737- CONFIG_SYS_LOADS_BAUD_CHANGE:
c609719b
WD
2738 Enable temporary baudrate change while serial download
2739
6d0f6bcf 2740- CONFIG_SYS_SDRAM_BASE:
c609719b
WD
2741 Physical start address of SDRAM. _Must_ be 0 here.
2742
6d0f6bcf 2743- CONFIG_SYS_FLASH_BASE:
c609719b
WD
2744 Physical start address of Flash memory.
2745
6d0f6bcf 2746- CONFIG_SYS_MONITOR_BASE:
c609719b
WD
2747 Physical start address of boot monitor code (set by
2748 make config files to be same as the text base address
14d0a02a 2749 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
6d0f6bcf 2750 CONFIG_SYS_FLASH_BASE when booting from flash.
c609719b 2751
6d0f6bcf 2752- CONFIG_SYS_MONITOR_LEN:
8bde7f77
WD
2753 Size of memory reserved for monitor code, used to
2754 determine _at_compile_time_ (!) if the environment is
2755 embedded within the U-Boot image, or in a separate
2756 flash sector.
c609719b 2757
6d0f6bcf 2758- CONFIG_SYS_MALLOC_LEN:
c609719b
WD
2759 Size of DRAM reserved for malloc() use.
2760
d59476b6
SG
2761- CONFIG_SYS_MALLOC_F_LEN
2762 Size of the malloc() pool for use before relocation. If
2763 this is defined, then a very simple malloc() implementation
2764 will become available before relocation. The address is just
2765 below the global data, and the stack is moved down to make
2766 space.
2767
2768 This feature allocates regions with increasing addresses
2769 within the region. calloc() is supported, but realloc()
2770 is not available. free() is supported but does nothing.
b445bbb4 2771 The memory will be freed (or in fact just forgotten) when
d59476b6
SG
2772 U-Boot relocates itself.
2773
38687ae6
SG
2774- CONFIG_SYS_MALLOC_SIMPLE
2775 Provides a simple and small malloc() and calloc() for those
2776 boards which do not use the full malloc in SPL (which is
2777 enabled with CONFIG_SYS_SPL_MALLOC_START).
2778
1dfdd9ba
TR
2779- CONFIG_SYS_NONCACHED_MEMORY:
2780 Size of non-cached memory area. This area of memory will be
2781 typically located right below the malloc() area and mapped
2782 uncached in the MMU. This is useful for drivers that would
2783 otherwise require a lot of explicit cache maintenance. For
2784 some drivers it's also impossible to properly maintain the
2785 cache. For example if the regions that need to be flushed
2786 are not a multiple of the cache-line size, *and* padding
2787 cannot be allocated between the regions to align them (i.e.
2788 if the HW requires a contiguous array of regions, and the
2789 size of each region is not cache-aligned), then a flush of
2790 one region may result in overwriting data that hardware has
2791 written to another region in the same cache-line. This can
2792 happen for example in network drivers where descriptors for
2793 buffers are typically smaller than the CPU cache-line (e.g.
2794 16 bytes vs. 32 or 64 bytes).
2795
2796 Non-cached memory is only supported on 32-bit ARM at present.
2797
6d0f6bcf 2798- CONFIG_SYS_BOOTM_LEN:
15940c9a
SR
2799 Normally compressed uImages are limited to an
2800 uncompressed size of 8 MBytes. If this is not enough,
6d0f6bcf 2801 you can define CONFIG_SYS_BOOTM_LEN in your board config file
15940c9a
SR
2802 to adjust this setting to your needs.
2803
6d0f6bcf 2804- CONFIG_SYS_BOOTMAPSZ:
c609719b
WD
2805 Maximum size of memory mapped by the startup code of
2806 the Linux kernel; all data that must be processed by
7d721e34
BS
2807 the Linux kernel (bd_info, boot arguments, FDT blob if
2808 used) must be put below this limit, unless "bootm_low"
1bce2aeb 2809 environment variable is defined and non-zero. In such case
7d721e34 2810 all data for the Linux kernel must be between "bootm_low"
c0f40859 2811 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
c3624e6e
GL
2812 variable "bootm_mapsize" will override the value of
2813 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
2814 then the value in "bootm_size" will be used instead.
c609719b 2815
fca43cc8
JR
2816- CONFIG_SYS_BOOT_RAMDISK_HIGH:
2817 Enable initrd_high functionality. If defined then the
2818 initrd_high feature is enabled and the bootm ramdisk subcommand
2819 is enabled.
2820
2821- CONFIG_SYS_BOOT_GET_CMDLINE:
2822 Enables allocating and saving kernel cmdline in space between
2823 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2824
2825- CONFIG_SYS_BOOT_GET_KBD:
2826 Enables allocating and saving a kernel copy of the bd_info in
2827 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2828
6d0f6bcf 2829- CONFIG_SYS_MAX_FLASH_BANKS:
c609719b
WD
2830 Max number of Flash memory banks
2831
6d0f6bcf 2832- CONFIG_SYS_MAX_FLASH_SECT:
c609719b
WD
2833 Max number of sectors on a Flash chip
2834
6d0f6bcf 2835- CONFIG_SYS_FLASH_ERASE_TOUT:
c609719b
WD
2836 Timeout for Flash erase operations (in ms)
2837
6d0f6bcf 2838- CONFIG_SYS_FLASH_WRITE_TOUT:
c609719b
WD
2839 Timeout for Flash write operations (in ms)
2840
6d0f6bcf 2841- CONFIG_SYS_FLASH_LOCK_TOUT
8564acf9
WD
2842 Timeout for Flash set sector lock bit operation (in ms)
2843
6d0f6bcf 2844- CONFIG_SYS_FLASH_UNLOCK_TOUT
8564acf9
WD
2845 Timeout for Flash clear lock bits operation (in ms)
2846
6d0f6bcf 2847- CONFIG_SYS_FLASH_PROTECTION
8564acf9
WD
2848 If defined, hardware flash sectors protection is used
2849 instead of U-Boot software protection.
2850
6d0f6bcf 2851- CONFIG_SYS_DIRECT_FLASH_TFTP:
c609719b
WD
2852
2853 Enable TFTP transfers directly to flash memory;
2854 without this option such a download has to be
2855 performed in two steps: (1) download to RAM, and (2)
2856 copy from RAM to flash.
2857
2858 The two-step approach is usually more reliable, since
2859 you can check if the download worked before you erase
11ccc33f
MZ
2860 the flash, but in some situations (when system RAM is
2861 too limited to allow for a temporary copy of the
c609719b
WD
2862 downloaded image) this option may be very useful.
2863
6d0f6bcf 2864- CONFIG_SYS_FLASH_CFI:
43d9616c 2865 Define if the flash driver uses extra elements in the
5653fc33
WD
2866 common flash structure for storing flash geometry.
2867
00b1883a 2868- CONFIG_FLASH_CFI_DRIVER
5653fc33
WD
2869 This option also enables the building of the cfi_flash driver
2870 in the drivers directory
c609719b 2871
91809ed5
PZ
2872- CONFIG_FLASH_CFI_MTD
2873 This option enables the building of the cfi_mtd driver
2874 in the drivers directory. The driver exports CFI flash
2875 to the MTD layer.
2876
6d0f6bcf 2877- CONFIG_SYS_FLASH_USE_BUFFER_WRITE
96ef831f
GL
2878 Use buffered writes to flash.
2879
2880- CONFIG_FLASH_SPANSION_S29WS_N
2881 s29ws-n MirrorBit flash has non-standard addresses for buffered
2882 write commands.
2883
6d0f6bcf 2884- CONFIG_SYS_FLASH_QUIET_TEST
5568e613
SR
2885 If this option is defined, the common CFI flash doesn't
2886 print it's warning upon not recognized FLASH banks. This
2887 is useful, if some of the configured banks are only
2888 optionally available.
2889
9a042e9c
JVB
2890- CONFIG_FLASH_SHOW_PROGRESS
2891 If defined (must be an integer), print out countdown
2892 digits and dots. Recommended value: 45 (9..1) for 80
2893 column displays, 15 (3..1) for 40 column displays.
2894
352ef3f1
SR
2895- CONFIG_FLASH_VERIFY
2896 If defined, the content of the flash (destination) is compared
2897 against the source after the write operation. An error message
2898 will be printed when the contents are not identical.
2899 Please note that this option is useless in nearly all cases,
2900 since such flash programming errors usually are detected earlier
2901 while unprotecting/erasing/programming. Please only enable
2902 this option if you really know what you are doing.
2903
6d0f6bcf 2904- CONFIG_SYS_RX_ETH_BUFFER:
11ccc33f
MZ
2905 Defines the number of Ethernet receive buffers. On some
2906 Ethernet controllers it is recommended to set this value
53cf9435
SR
2907 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2908 buffers can be full shortly after enabling the interface
11ccc33f 2909 on high Ethernet traffic.
53cf9435
SR
2910 Defaults to 4 if not defined.
2911
ea882baf
WD
2912- CONFIG_ENV_MAX_ENTRIES
2913
071bc923
WD
2914 Maximum number of entries in the hash table that is used
2915 internally to store the environment settings. The default
2916 setting is supposed to be generous and should work in most
2917 cases. This setting can be used to tune behaviour; see
2918 lib/hashtable.c for details.
ea882baf 2919
2598090b
JH
2920- CONFIG_ENV_FLAGS_LIST_DEFAULT
2921- CONFIG_ENV_FLAGS_LIST_STATIC
1bce2aeb 2922 Enable validation of the values given to environment variables when
2598090b
JH
2923 calling env set. Variables can be restricted to only decimal,
2924 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
2925 the variables can also be restricted to IP address or MAC address.
2926
2927 The format of the list is:
2928 type_attribute = [s|d|x|b|i|m]
b445bbb4
JM
2929 access_attribute = [a|r|o|c]
2930 attributes = type_attribute[access_attribute]
2598090b
JH
2931 entry = variable_name[:attributes]
2932 list = entry[,list]
2933
2934 The type attributes are:
2935 s - String (default)
2936 d - Decimal
2937 x - Hexadecimal
2938 b - Boolean ([1yYtT|0nNfF])
2939 i - IP address
2940 m - MAC address
2941
267541f7
JH
2942 The access attributes are:
2943 a - Any (default)
2944 r - Read-only
2945 o - Write-once
2946 c - Change-default
2947
2598090b
JH
2948 - CONFIG_ENV_FLAGS_LIST_DEFAULT
2949 Define this to a list (string) to define the ".flags"
b445bbb4 2950 environment variable in the default or embedded environment.
2598090b
JH
2951
2952 - CONFIG_ENV_FLAGS_LIST_STATIC
2953 Define this to a list (string) to define validation that
2954 should be done if an entry is not found in the ".flags"
2955 environment variable. To override a setting in the static
2956 list, simply add an entry for the same variable name to the
2957 ".flags" variable.
2958
bdf1fe4e
JH
2959 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
2960 regular expression. This allows multiple variables to define the same
2961 flags without explicitly listing them for each variable.
2962
267541f7
JH
2963- CONFIG_ENV_ACCESS_IGNORE_FORCE
2964 If defined, don't allow the -f switch to env set override variable
2965 access flags.
2966
c609719b
WD
2967The following definitions that deal with the placement and management
2968of environment data (variable area); in general, we support the
2969following configurations:
2970
c3eb3fe4
MF
2971- CONFIG_BUILD_ENVCRC:
2972
2973 Builds up envcrc with the target environment so that external utils
2974 may easily extract it and embed it in final U-Boot images.
2975
c609719b 2976BE CAREFUL! The first access to the environment happens quite early
b445bbb4 2977in U-Boot initialization (when we try to get the setting of for the
11ccc33f 2978console baudrate). You *MUST* have mapped your NVRAM area then, or
c609719b
WD
2979U-Boot will hang.
2980
2981Please note that even with NVRAM we still use a copy of the
2982environment in RAM: we could work on NVRAM directly, but we want to
2983keep settings there always unmodified except somebody uses "saveenv"
2984to save the current settings.
2985
0a85a9e7
LG
2986BE CAREFUL! For some special cases, the local device can not use
2987"saveenv" command. For example, the local device will get the
fc54c7fa
LG
2988environment stored in a remote NOR flash by SRIO or PCIE link,
2989but it can not erase, write this NOR flash by SRIO or PCIE interface.
0a85a9e7 2990
b74ab737
GL
2991- CONFIG_NAND_ENV_DST
2992
2993 Defines address in RAM to which the nand_spl code should copy the
2994 environment. If redundant environment is used, it will be copied to
2995 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2996
e881cb56 2997Please note that the environment is read-only until the monitor
c609719b 2998has been relocated to RAM and a RAM copy of the environment has been
00caae6d 2999created; also, when using EEPROM you will have to use env_get_f()
c609719b
WD
3000until then to read environment variables.
3001
85ec0bcc
WD
3002The environment is protected by a CRC32 checksum. Before the monitor
3003is relocated into RAM, as a result of a bad CRC you will be working
3004with the compiled-in default environment - *silently*!!! [This is
3005necessary, because the first environment variable we need is the
3006"baudrate" setting for the console - if we have a bad CRC, we don't
3007have any device yet where we could complain.]
c609719b
WD
3008
3009Note: once the monitor has been relocated, then it will complain if
3010the default environment is used; a new CRC is computed as soon as you
85ec0bcc 3011use the "saveenv" command to store a valid environment.
c609719b 3012
6d0f6bcf 3013- CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
42d1f039 3014 Echo the inverted Ethernet link state to the fault LED.
fc3e2165 3015
6d0f6bcf 3016 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
fc3e2165
WD
3017 also needs to be defined.
3018
6d0f6bcf 3019- CONFIG_SYS_FAULT_MII_ADDR:
42d1f039 3020 MII address of the PHY to check for the Ethernet link state.
c609719b 3021
f5675aa5
RM
3022- CONFIG_NS16550_MIN_FUNCTIONS:
3023 Define this if you desire to only have use of the NS16550_init
3024 and NS16550_putc functions for the serial driver located at
3025 drivers/serial/ns16550.c. This option is useful for saving
3026 space for already greatly restricted images, including but not
3027 limited to NAND_SPL configurations.
3028
b2b92f53
SG
3029- CONFIG_DISPLAY_BOARDINFO
3030 Display information about the board that U-Boot is running on
3031 when U-Boot starts up. The board function checkboard() is called
3032 to do this.
3033
e2e3e2b1
SG
3034- CONFIG_DISPLAY_BOARDINFO_LATE
3035 Similar to the previous option, but display this information
3036 later, once stdio is running and output goes to the LCD, if
3037 present.
3038
feb85801
SS
3039- CONFIG_BOARD_SIZE_LIMIT:
3040 Maximum size of the U-Boot image. When defined, the
3041 build system checks that the actual size does not
3042 exceed it.
3043
c609719b 3044Low Level (hardware related) configuration options:
dc7c9a1a 3045---------------------------------------------------
c609719b 3046
6d0f6bcf 3047- CONFIG_SYS_CACHELINE_SIZE:
c609719b
WD
3048 Cache Line Size of the CPU.
3049
e46fedfe
TT
3050- CONFIG_SYS_CCSRBAR_DEFAULT:
3051 Default (power-on reset) physical address of CCSR on Freescale
3052 PowerPC SOCs.
3053
3054- CONFIG_SYS_CCSRBAR:
3055 Virtual address of CCSR. On a 32-bit build, this is typically
3056 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3057
e46fedfe
TT
3058- CONFIG_SYS_CCSRBAR_PHYS:
3059 Physical address of CCSR. CCSR can be relocated to a new
3060 physical address, if desired. In this case, this macro should
c0f40859 3061 be set to that address. Otherwise, it should be set to the
e46fedfe
TT
3062 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3063 is typically relocated on 36-bit builds. It is recommended
3064 that this macro be defined via the _HIGH and _LOW macros:
3065
3066 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3067 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3068
3069- CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4cf2609b
WD
3070 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3071 either 0 (32-bit build) or 0xF (36-bit build). This macro is
e46fedfe
TT
3072 used in assembly code, so it must not contain typecasts or
3073 integer size suffixes (e.g. "ULL").
3074
3075- CONFIG_SYS_CCSRBAR_PHYS_LOW:
3076 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3077 used in assembly code, so it must not contain typecasts or
3078 integer size suffixes (e.g. "ULL").
3079
3080- CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3081 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3082 forced to a value that ensures that CCSR is not relocated.
3083
7f6c2cbc 3084- Floppy Disk Support:
6d0f6bcf 3085 CONFIG_SYS_FDC_DRIVE_NUMBER
7f6c2cbc
WD
3086
3087 the default drive number (default value 0)
3088
6d0f6bcf 3089 CONFIG_SYS_ISA_IO_STRIDE
7f6c2cbc 3090
11ccc33f 3091 defines the spacing between FDC chipset registers
7f6c2cbc
WD
3092 (default value 1)
3093
6d0f6bcf 3094 CONFIG_SYS_ISA_IO_OFFSET
7f6c2cbc 3095
43d9616c
WD
3096 defines the offset of register from address. It
3097 depends on which part of the data bus is connected to
11ccc33f 3098 the FDC chipset. (default value 0)
7f6c2cbc 3099
6d0f6bcf
JCPV
3100 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3101 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
43d9616c 3102 default value.
7f6c2cbc 3103
6d0f6bcf 3104 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
43d9616c
WD
3105 fdc_hw_init() is called at the beginning of the FDC
3106 setup. fdc_hw_init() must be provided by the board
b445bbb4 3107 source code. It is used to make hardware-dependent
43d9616c 3108 initializations.
7f6c2cbc 3109
0abddf82
ML
3110- CONFIG_IDE_AHB:
3111 Most IDE controllers were designed to be connected with PCI
3112 interface. Only few of them were designed for AHB interface.
3113 When software is doing ATA command and data transfer to
3114 IDE devices through IDE-AHB controller, some additional
3115 registers accessing to these kind of IDE-AHB controller
b445bbb4 3116 is required.
0abddf82 3117
6d0f6bcf 3118- CONFIG_SYS_IMMR: Physical address of the Internal Memory.
efe2a4d5 3119 DO NOT CHANGE unless you know exactly what you're
907208c4 3120 doing! (11-4) [MPC8xx systems only]
c609719b 3121
6d0f6bcf 3122- CONFIG_SYS_INIT_RAM_ADDR:
c609719b 3123
7152b1d0 3124 Start address of memory area that can be used for
c609719b
WD
3125 initial data and stack; please note that this must be
3126 writable memory that is working WITHOUT special
3127 initialization, i. e. you CANNOT use normal RAM which
3128 will become available only after programming the
3129 memory controller and running certain initialization
3130 sequences.
3131
3132 U-Boot uses the following memory types:
907208c4 3133 - MPC8xx: IMMR (internal memory of the CPU)
c609719b 3134
6d0f6bcf 3135- CONFIG_SYS_GBL_DATA_OFFSET:
c609719b
WD
3136
3137 Offset of the initial data structure in the memory
6d0f6bcf
JCPV
3138 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3139 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
c609719b 3140 data is located at the end of the available space
553f0982 3141 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
acd51f9d 3142 GENERATED_GBL_DATA_SIZE), and the initial stack is just
6d0f6bcf
JCPV
3143 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3144 CONFIG_SYS_GBL_DATA_OFFSET) downward.
c609719b
WD
3145
3146 Note:
3147 On the MPC824X (or other systems that use the data
3148 cache for initial memory) the address chosen for
6d0f6bcf 3149 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
c609719b
WD
3150 point to an otherwise UNUSED address space between
3151 the top of RAM and the start of the PCI space.
3152
6d0f6bcf 3153- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
c609719b 3154
6d0f6bcf 3155- CONFIG_SYS_OR_TIMING_SDRAM:
c609719b
WD
3156 SDRAM timing
3157
6d0f6bcf 3158- CONFIG_SYS_MAMR_PTA:
c609719b
WD
3159 periodic timer for refresh
3160
6d0f6bcf
JCPV
3161- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3162 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3163 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3164 CONFIG_SYS_BR1_PRELIM:
c609719b
WD
3165 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3166
3167- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
6d0f6bcf
JCPV
3168 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3169 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
c609719b
WD
3170 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3171
69fd2d3b 3172- CONFIG_PCI_ENUM_ONLY
b445bbb4 3173 Only scan through and get the devices on the buses.
69fd2d3b
AS
3174 Don't do any setup work, presumably because someone or
3175 something has already done it, and we don't need to do it
3176 a second time. Useful for platforms that are pre-booted
3177 by coreboot or similar.
3178
842033e6
GJ
3179- CONFIG_PCI_INDIRECT_BRIDGE:
3180 Enable support for indirect PCI bridges.
3181
a09b9b68
KG
3182- CONFIG_SYS_SRIO:
3183 Chip has SRIO or not
3184
3185- CONFIG_SRIO1:
3186 Board has SRIO 1 port available
3187
3188- CONFIG_SRIO2:
3189 Board has SRIO 2 port available
3190
c8b28152
LG
3191- CONFIG_SRIO_PCIE_BOOT_MASTER
3192 Board can support master function for Boot from SRIO and PCIE
3193
a09b9b68
KG
3194- CONFIG_SYS_SRIOn_MEM_VIRT:
3195 Virtual Address of SRIO port 'n' memory region
3196
3197- CONFIG_SYS_SRIOn_MEM_PHYS:
3198 Physical Address of SRIO port 'n' memory region
3199
3200- CONFIG_SYS_SRIOn_MEM_SIZE:
3201 Size of SRIO port 'n' memory region
3202
66bd1846
FE
3203- CONFIG_SYS_NAND_BUSWIDTH_16BIT
3204 Defined to tell the NAND controller that the NAND chip is using
3205 a 16 bit bus.
3206 Not all NAND drivers use this symbol.
a430e916 3207 Example of drivers that use it:
a430fa06
MR
3208 - drivers/mtd/nand/raw/ndfc.c
3209 - drivers/mtd/nand/raw/mxc_nand.c
eced4626
AW
3210
3211- CONFIG_SYS_NDFC_EBC0_CFG
3212 Sets the EBC0_CFG register for the NDFC. If not defined
3213 a default value will be used.
3214
bb99ad6d 3215- CONFIG_SPD_EEPROM
218ca724
WD
3216 Get DDR timing information from an I2C EEPROM. Common
3217 with pluggable memory modules such as SODIMMs
3218
bb99ad6d
BW
3219 SPD_EEPROM_ADDRESS
3220 I2C address of the SPD EEPROM
3221
6d0f6bcf 3222- CONFIG_SYS_SPD_BUS_NUM
218ca724
WD
3223 If SPD EEPROM is on an I2C bus other than the first
3224 one, specify here. Note that the value must resolve
3225 to something your driver can deal with.
bb99ad6d 3226
1b3e3c4f
YS
3227- CONFIG_SYS_DDR_RAW_TIMING
3228 Get DDR timing information from other than SPD. Common with
3229 soldered DDR chips onboard without SPD. DDR raw timing
3230 parameters are extracted from datasheet and hard-coded into
3231 header files or board specific files.
3232
6f5e1dc5
YS
3233- CONFIG_FSL_DDR_INTERACTIVE
3234 Enable interactive DDR debugging. See doc/README.fsl-ddr.
3235
e32d59a2
YS
3236- CONFIG_FSL_DDR_SYNC_REFRESH
3237 Enable sync of refresh for multiple controllers.
3238
4516ff81
YS
3239- CONFIG_FSL_DDR_BIST
3240 Enable built-in memory test for Freescale DDR controllers.
3241
6d0f6bcf 3242- CONFIG_SYS_83XX_DDR_USES_CS0
218ca724
WD
3243 Only for 83xx systems. If specified, then DDR should
3244 be configured using CS0 and CS1 instead of CS2 and CS3.
2ad6b513 3245
c26e454d
WD
3246- CONFIG_RMII
3247 Enable RMII mode for all FECs.
3248 Note that this is a global option, we can't
3249 have one FEC in standard MII mode and another in RMII mode.
3250
5cf91d6b
WD
3251- CONFIG_CRC32_VERIFY
3252 Add a verify option to the crc32 command.
3253 The syntax is:
3254
3255 => crc32 -v <address> <count> <crc32>
3256
3257 Where address/count indicate a memory area
3258 and crc32 is the correct crc32 which the
3259 area should have.
3260
56523f12
WD
3261- CONFIG_LOOPW
3262 Add the "loopw" memory command. This only takes effect if
493f420e 3263 the memory commands are activated globally (CONFIG_CMD_MEMORY).
56523f12 3264
7b466641
SR
3265- CONFIG_MX_CYCLIC
3266 Add the "mdc" and "mwc" memory commands. These are cyclic
3267 "md/mw" commands.
3268 Examples:
3269
efe2a4d5 3270 => mdc.b 10 4 500
7b466641
SR
3271 This command will print 4 bytes (10,11,12,13) each 500 ms.
3272
efe2a4d5 3273 => mwc.l 100 12345678 10
7b466641
SR
3274 This command will write 12345678 to address 100 all 10 ms.
3275
efe2a4d5 3276 This only takes effect if the memory commands are activated
493f420e 3277 globally (CONFIG_CMD_MEMORY).
7b466641 3278
8aa1a2d1 3279- CONFIG_SKIP_LOWLEVEL_INIT
3fafced7 3280 [ARM, NDS32, MIPS, RISC-V only] If this variable is defined, then certain
844f07d8
WD
3281 low level initializations (like setting up the memory
3282 controller) are omitted and/or U-Boot does not
3283 relocate itself into RAM.
3284
3285 Normally this variable MUST NOT be defined. The only
3286 exception is when U-Boot is loaded (to RAM) by some
3287 other boot loader or by a debugger which performs
3288 these initializations itself.
8aa1a2d1 3289
b5bd0982
SG
3290- CONFIG_SKIP_LOWLEVEL_INIT_ONLY
3291 [ARM926EJ-S only] This allows just the call to lowlevel_init()
90211f77 3292 to be skipped. The normal CP15 init (such as enabling the
b5bd0982
SG
3293 instruction cache) is still performed.
3294
401bb30b 3295- CONFIG_SPL_BUILD
df81238b
ML
3296 Modifies the behaviour of start.S when compiling a loader
3297 that is executed before the actual U-Boot. E.g. when
3298 compiling a NAND SPL.
400558b5 3299
3aa29de0
YZ
3300- CONFIG_TPL_BUILD
3301 Modifies the behaviour of start.S when compiling a loader
3302 that is executed after the SPL and before the actual U-Boot.
3303 It is loaded by the SPL.
3304
5df572f0
YZ
3305- CONFIG_SYS_MPC85XX_NO_RESETVEC
3306 Only for 85xx systems. If this variable is specified, the section
3307 .resetvec is not kept and the section .bootpg is placed in the
3308 previous 4k of the .text section.
3309
4213fc29
SG
3310- CONFIG_ARCH_MAP_SYSMEM
3311 Generally U-Boot (and in particular the md command) uses
3312 effective address. It is therefore not necessary to regard
3313 U-Boot address as virtual addresses that need to be translated
3314 to physical addresses. However, sandbox requires this, since
3315 it maintains its own little RAM buffer which contains all
3316 addressable memory. This option causes some memory accesses
3317 to be mapped through map_sysmem() / unmap_sysmem().
3318
588a13f7
SG
3319- CONFIG_X86_RESET_VECTOR
3320 If defined, the x86 reset vector code is included. This is not
3321 needed when U-Boot is running from Coreboot.
b16f521a 3322
999d7d32
KM
3323- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
3324 Option to disable subpage write in NAND driver
3325 driver that uses this:
a430fa06 3326 drivers/mtd/nand/raw/davinci_nand.c
999d7d32 3327
f2717b47
TT
3328Freescale QE/FMAN Firmware Support:
3329-----------------------------------
3330
3331The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
3332loading of "firmware", which is encoded in the QE firmware binary format.
3333This firmware often needs to be loaded during U-Boot booting, so macros
3334are used to identify the storage device (NOR flash, SPI, etc) and the address
3335within that device.
3336
dcf1d774
ZQ
3337- CONFIG_SYS_FMAN_FW_ADDR
3338 The address in the storage device where the FMAN microcode is located. The
3339 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3340 is also specified.
3341
3342- CONFIG_SYS_QE_FW_ADDR
3343 The address in the storage device where the QE microcode is located. The
f2717b47
TT
3344 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3345 is also specified.
3346
3347- CONFIG_SYS_QE_FMAN_FW_LENGTH
3348 The maximum possible size of the firmware. The firmware binary format
3349 has a field that specifies the actual size of the firmware, but it
3350 might not be possible to read any part of the firmware unless some
3351 local storage is allocated to hold the entire firmware first.
3352
3353- CONFIG_SYS_QE_FMAN_FW_IN_NOR
3354 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
3355 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
3356 virtual address in NOR flash.
3357
3358- CONFIG_SYS_QE_FMAN_FW_IN_NAND
3359 Specifies that QE/FMAN firmware is located in NAND flash.
3360 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
3361
3362- CONFIG_SYS_QE_FMAN_FW_IN_MMC
3363 Specifies that QE/FMAN firmware is located on the primary SD/MMC
3364 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3365
292dc6c5
LG
3366- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
3367 Specifies that QE/FMAN firmware is located in the remote (master)
3368 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
fc54c7fa
LG
3369 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
3370 window->master inbound window->master LAW->the ucode address in
3371 master's memory space.
f2717b47 3372
b940ca64
GR
3373Freescale Layerscape Management Complex Firmware Support:
3374---------------------------------------------------------
3375The Freescale Layerscape Management Complex (MC) supports the loading of
3376"firmware".
3377This firmware often needs to be loaded during U-Boot booting, so macros
3378are used to identify the storage device (NOR flash, SPI, etc) and the address
3379within that device.
3380
3381- CONFIG_FSL_MC_ENET
3382 Enable the MC driver for Layerscape SoCs.
3383
5c055089
PK
3384Freescale Layerscape Debug Server Support:
3385-------------------------------------------
3386The Freescale Layerscape Debug Server Support supports the loading of
3387"Debug Server firmware" and triggering SP boot-rom.
3388This firmware often needs to be loaded during U-Boot booting.
3389
c0492141
YS
3390- CONFIG_SYS_MC_RSV_MEM_ALIGN
3391 Define alignment of reserved memory MC requires
5c055089 3392
f3f431a7
PK
3393Reproducible builds
3394-------------------
3395
3396In order to achieve reproducible builds, timestamps used in the U-Boot build
3397process have to be set to a fixed value.
3398
3399This is done using the SOURCE_DATE_EPOCH environment variable.
3400SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
3401option for U-Boot or an environment variable in U-Boot.
3402
3403SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
3404
c609719b
WD
3405Building the Software:
3406======================
3407
218ca724
WD
3408Building U-Boot has been tested in several native build environments
3409and in many different cross environments. Of course we cannot support
3410all possibly existing versions of cross development tools in all
3411(potentially obsolete) versions. In case of tool chain problems we
3412recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3413which is extensively used to build and test U-Boot.
c609719b 3414
218ca724
WD
3415If you are not using a native environment, it is assumed that you
3416have GNU cross compiling tools available in your path. In this case,
3417you must set the environment variable CROSS_COMPILE in your shell.
3418Note that no changes to the Makefile or any other source files are
3419necessary. For example using the ELDK on a 4xx CPU, please enter:
c609719b 3420
218ca724
WD
3421 $ CROSS_COMPILE=ppc_4xx-
3422 $ export CROSS_COMPILE
c609719b 3423
2f8d396b
PT
3424Note: If you wish to generate Windows versions of the utilities in
3425 the tools directory you can use the MinGW toolchain
3426 (http://www.mingw.org). Set your HOST tools to the MinGW
3427 toolchain and execute 'make tools'. For example:
3428
3429 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3430
3431 Binaries such as tools/mkimage.exe will be created which can
3432 be executed on computers running Windows.
3433
218ca724
WD
3434U-Boot is intended to be simple to build. After installing the
3435sources you must configure U-Boot for one specific board type. This
c609719b
WD
3436is done by typing:
3437
ab584d67 3438 make NAME_defconfig
c609719b 3439
ab584d67 3440where "NAME_defconfig" is the name of one of the existing configu-
4d675ae6 3441rations; see boards.cfg for supported names.
db01a2ea 3442
2729af9d
WD
3443Note: for some board special configuration names may exist; check if
3444 additional information is available from the board vendor; for
3445 instance, the TQM823L systems are available without (standard)
3446 or with LCD support. You can select such additional "features"
11ccc33f 3447 when choosing the configuration, i. e.
2729af9d 3448
ab584d67 3449 make TQM823L_defconfig
2729af9d
WD
3450 - will configure for a plain TQM823L, i. e. no LCD support
3451
ab584d67 3452 make TQM823L_LCD_defconfig
2729af9d
WD
3453 - will configure for a TQM823L with U-Boot console on LCD
3454
3455 etc.
3456
3457
3458Finally, type "make all", and you should get some working U-Boot
3459images ready for download to / installation on your system:
3460
3461- "u-boot.bin" is a raw binary image
3462- "u-boot" is an image in ELF binary format
3463- "u-boot.srec" is in Motorola S-Record format
3464
baf31249
MB
3465By default the build is performed locally and the objects are saved
3466in the source directory. One of the two methods can be used to change
3467this behavior and build U-Boot to some external directory:
3468
34691. Add O= to the make command line invocations:
3470
3471 make O=/tmp/build distclean
ab584d67 3472 make O=/tmp/build NAME_defconfig
baf31249
MB
3473 make O=/tmp/build all
3474
adbba996 34752. Set environment variable KBUILD_OUTPUT to point to the desired location:
baf31249 3476
adbba996 3477 export KBUILD_OUTPUT=/tmp/build
baf31249 3478 make distclean
ab584d67 3479 make NAME_defconfig
baf31249
MB
3480 make all
3481
adbba996 3482Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
baf31249
MB
3483variable.
3484
215bb1c1
DS
3485User specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by
3486setting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS.
3487For example to treat all compiler warnings as errors:
3488
3489 make KCFLAGS=-Werror
2729af9d
WD
3490
3491Please be aware that the Makefiles assume you are using GNU make, so
3492for instance on NetBSD you might need to use "gmake" instead of
3493native "make".
3494
3495
3496If the system board that you have is not listed, then you will need
3497to port U-Boot to your hardware platform. To do this, follow these
3498steps:
3499
3c1496cd 35001. Create a new directory to hold your board specific code. Add any
2729af9d 3501 files you need. In your board directory, you will need at least
3c1496cd
PS
3502 the "Makefile" and a "<board>.c".
35032. Create a new configuration file "include/configs/<board>.h" for
3504 your board.
2729af9d
WD
35053. If you're porting U-Boot to a new CPU, then also create a new
3506 directory to hold your CPU specific code. Add any files you need.
ab584d67 35074. Run "make <board>_defconfig" with your new name.
2729af9d
WD
35085. Type "make", and you should get a working "u-boot.srec" file
3509 to be installed on your target system.
35106. Debug and solve any problems that might arise.
3511 [Of course, this last step is much harder than it sounds.]
3512
3513
3514Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3515==============================================================
3516
218ca724
WD
3517If you have modified U-Boot sources (for instance added a new board
3518or support for new devices, a new CPU, etc.) you are expected to
2729af9d
WD
3519provide feedback to the other developers. The feedback normally takes
3520the form of a "patch", i. e. a context diff against a certain (latest
218ca724 3521official or latest in the git repository) version of U-Boot sources.
2729af9d 3522
218ca724
WD
3523But before you submit such a patch, please verify that your modifi-
3524cation did not break existing code. At least make sure that *ALL* of
2729af9d 3525the supported boards compile WITHOUT ANY compiler warnings. To do so,
6de80f21
SG
3526just run the buildman script (tools/buildman/buildman), which will
3527configure and build U-Boot for ALL supported system. Be warned, this
3528will take a while. Please see the buildman README, or run 'buildman -H'
3529for documentation.
baf31249
MB
3530
3531
2729af9d
WD
3532See also "U-Boot Porting Guide" below.
3533
3534
3535Monitor Commands - Overview:
3536============================
3537
3538go - start application at address 'addr'
3539run - run commands in an environment variable
3540bootm - boot application image from memory
3541bootp - boot image via network using BootP/TFTP protocol
44f074c7 3542bootz - boot zImage from memory
2729af9d
WD
3543tftpboot- boot image via network using TFTP protocol
3544 and env variables "ipaddr" and "serverip"
3545 (and eventually "gatewayip")
1fb7cd49 3546tftpput - upload a file via network using TFTP protocol
2729af9d
WD
3547rarpboot- boot image via network using RARP/TFTP protocol
3548diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3549loads - load S-Record file over serial line
3550loadb - load binary file over serial line (kermit mode)
3551md - memory display
3552mm - memory modify (auto-incrementing)
3553nm - memory modify (constant address)
3554mw - memory write (fill)
3555cp - memory copy
3556cmp - memory compare
3557crc32 - checksum calculation
0f89c54b 3558i2c - I2C sub-system
2729af9d
WD
3559sspi - SPI utility commands
3560base - print or set address offset
3561printenv- print environment variables
3562setenv - set environment variables
3563saveenv - save environment variables to persistent storage
3564protect - enable or disable FLASH write protection
3565erase - erase FLASH memory
3566flinfo - print FLASH memory information
10635afa 3567nand - NAND memory operations (see doc/README.nand)
2729af9d
WD
3568bdinfo - print Board Info structure
3569iminfo - print header information for application image
3570coninfo - print console devices and informations
3571ide - IDE sub-system
3572loop - infinite loop on address range
56523f12 3573loopw - infinite write loop on address range
2729af9d
WD
3574mtest - simple RAM test
3575icache - enable or disable instruction cache
3576dcache - enable or disable data cache
3577reset - Perform RESET of the CPU
3578echo - echo args to console
3579version - print monitor version
3580help - print online help
3581? - alias for 'help'
3582
3583
3584Monitor Commands - Detailed Description:
3585========================================
3586
3587TODO.
3588
3589For now: just type "help <command>".
3590
3591
3592Environment Variables:
3593======================
3594
3595U-Boot supports user configuration using Environment Variables which
3596can be made persistent by saving to Flash memory.
c609719b 3597
2729af9d
WD
3598Environment Variables are set using "setenv", printed using
3599"printenv", and saved to Flash using "saveenv". Using "setenv"
3600without a value can be used to delete a variable from the
3601environment. As long as you don't save the environment you are
3602working with an in-memory copy. In case the Flash area containing the
3603environment is erased by accident, a default environment is provided.
c609719b 3604
c96f86ee
WD
3605Some configuration options can be set using Environment Variables.
3606
3607List of environment variables (most likely not complete):
c609719b 3608
2729af9d 3609 baudrate - see CONFIG_BAUDRATE
c609719b 3610
2729af9d 3611 bootdelay - see CONFIG_BOOTDELAY
c609719b 3612
2729af9d 3613 bootcmd - see CONFIG_BOOTCOMMAND
4a6fd34b 3614
2729af9d 3615 bootargs - Boot arguments when booting an RTOS image
c609719b 3616
2729af9d 3617 bootfile - Name of the image to load with TFTP
c609719b 3618
7d721e34
BS
3619 bootm_low - Memory range available for image processing in the bootm
3620 command can be restricted. This variable is given as
3621 a hexadecimal number and defines lowest address allowed
3622 for use by the bootm command. See also "bootm_size"
3623 environment variable. Address defined by "bootm_low" is
3624 also the base of the initial memory mapping for the Linux
c3624e6e
GL
3625 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
3626 bootm_mapsize.
3627
c0f40859 3628 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
c3624e6e
GL
3629 This variable is given as a hexadecimal number and it
3630 defines the size of the memory region starting at base
3631 address bootm_low that is accessible by the Linux kernel
3632 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
3633 as the default value if it is defined, and bootm_size is
3634 used otherwise.
7d721e34
BS
3635
3636 bootm_size - Memory range available for image processing in the bootm
3637 command can be restricted. This variable is given as
3638 a hexadecimal number and defines the size of the region
3639 allowed for use by the bootm command. See also "bootm_low"
3640 environment variable.
3641
4bae9090
BS
3642 updatefile - Location of the software update file on a TFTP server, used
3643 by the automatic software update feature. Please refer to
3644 documentation in doc/README.update for more details.
3645
2729af9d
WD
3646 autoload - if set to "no" (any string beginning with 'n'),
3647 "bootp" will just load perform a lookup of the
3648 configuration from the BOOTP server, but not try to
3649 load any image using TFTP
c609719b 3650
2729af9d
WD
3651 autostart - if set to "yes", an image loaded using the "bootp",
3652 "rarpboot", "tftpboot" or "diskboot" commands will
3653 be automatically started (by internally calling
3654 "bootm")
38b99261 3655
2729af9d
WD
3656 If set to "no", a standalone image passed to the
3657 "bootm" command will be copied to the load address
3658 (and eventually uncompressed), but NOT be started.
3659 This can be used to load and uncompress arbitrary
3660 data.
c609719b 3661
a28afca5
DL
3662 fdt_high - if set this restricts the maximum address that the
3663 flattened device tree will be copied into upon boot.
fa34f6b2
SG
3664 For example, if you have a system with 1 GB memory
3665 at physical address 0x10000000, while Linux kernel
3666 only recognizes the first 704 MB as low memory, you
3667 may need to set fdt_high as 0x3C000000 to have the
3668 device tree blob be copied to the maximum address
3669 of the 704 MB low memory, so that Linux kernel can
3670 access it during the boot procedure.
3671
a28afca5
DL
3672 If this is set to the special value 0xFFFFFFFF then
3673 the fdt will not be copied at all on boot. For this
3674 to work it must reside in writable memory, have
3675 sufficient padding on the end of it for u-boot to
3676 add the information it needs into it, and the memory
3677 must be accessible by the kernel.
3678
eea63e05
SG
3679 fdtcontroladdr- if set this is the address of the control flattened
3680 device tree used by U-Boot when CONFIG_OF_CONTROL is
3681 defined.
3682
17ea1177
WD
3683 i2cfast - (PPC405GP|PPC405EP only)
3684 if set to 'y' configures Linux I2C driver for fast
3685 mode (400kHZ). This environment variable is used in
3686 initialization code. So, for changes to be effective
3687 it must be saved and board must be reset.
3688
2729af9d
WD
3689 initrd_high - restrict positioning of initrd images:
3690 If this variable is not set, initrd images will be
3691 copied to the highest possible address in RAM; this
3692 is usually what you want since it allows for
3693 maximum initrd size. If for some reason you want to
3694 make sure that the initrd image is loaded below the
6d0f6bcf 3695 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
2729af9d
WD
3696 variable to a value of "no" or "off" or "0".
3697 Alternatively, you can set it to a maximum upper
3698 address to use (U-Boot will still check that it
3699 does not overwrite the U-Boot stack and data).
c609719b 3700
2729af9d
WD
3701 For instance, when you have a system with 16 MB
3702 RAM, and want to reserve 4 MB from use by Linux,
3703 you can do this by adding "mem=12M" to the value of
3704 the "bootargs" variable. However, now you must make
3705 sure that the initrd image is placed in the first
3706 12 MB as well - this can be done with
c609719b 3707
2729af9d 3708 setenv initrd_high 00c00000
c609719b 3709
2729af9d
WD
3710 If you set initrd_high to 0xFFFFFFFF, this is an
3711 indication to U-Boot that all addresses are legal
3712 for the Linux kernel, including addresses in flash
3713 memory. In this case U-Boot will NOT COPY the
3714 ramdisk at all. This may be useful to reduce the
3715 boot time on your system, but requires that this
3716 feature is supported by your Linux kernel.
c609719b 3717
2729af9d 3718 ipaddr - IP address; needed for tftpboot command
c609719b 3719
2729af9d
WD
3720 loadaddr - Default load address for commands like "bootp",
3721 "rarpboot", "tftpboot", "loadb" or "diskboot"
c609719b 3722
2729af9d 3723 loads_echo - see CONFIG_LOADS_ECHO
a3d991bd 3724
2729af9d 3725 serverip - TFTP server IP address; needed for tftpboot command
a3d991bd 3726
2729af9d 3727 bootretry - see CONFIG_BOOT_RETRY_TIME
a3d991bd 3728
2729af9d 3729 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
a3d991bd 3730
2729af9d 3731 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
c609719b 3732
e2a53458 3733 ethprime - controls which interface is used first.
c609719b 3734
e2a53458
MF
3735 ethact - controls which interface is currently active.
3736 For example you can do the following
c609719b 3737
48690d80
HS
3738 => setenv ethact FEC
3739 => ping 192.168.0.1 # traffic sent on FEC
3740 => setenv ethact SCC
3741 => ping 10.0.0.1 # traffic sent on SCC
c609719b 3742
e1692577
MF
3743 ethrotate - When set to "no" U-Boot does not go through all
3744 available network interfaces.
3745 It just stays at the currently selected interface.
3746
c96f86ee 3747 netretry - When set to "no" each network operation will
2729af9d
WD
3748 either succeed or fail without retrying.
3749 When set to "once" the network operation will
3750 fail when all the available network interfaces
3751 are tried once without success.
3752 Useful on scripts which control the retry operation
3753 themselves.
c609719b 3754
b4e2f89d 3755 npe_ucode - set load address for the NPE microcode
a1cf027a 3756
b445bbb4 3757 silent_linux - If set then Linux will be told to boot silently, by
8d51aacd
SG
3758 changing the console to be empty. If "yes" it will be
3759 made silent. If "no" it will not be made silent. If
3760 unset, then it will be made silent if the U-Boot console
3761 is silent.
3762
f5fb7346 3763 tftpsrcp - If this is set, the value is used for TFTP's
ecb0ccd9
WD
3764 UDP source port.
3765
f5fb7346 3766 tftpdstp - If this is set, the value is used for TFTP's UDP
28cb9375
WD
3767 destination port instead of the Well Know Port 69.
3768
c96f86ee
WD
3769 tftpblocksize - Block size to use for TFTP transfers; if not set,
3770 we use the TFTP server's default block size
3771
3772 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3773 seconds, minimum value is 1000 = 1 second). Defines
3774 when a packet is considered to be lost so it has to
3775 be retransmitted. The default is 5000 = 5 seconds.
3776 Lowering this value may make downloads succeed
3777 faster in networks with high packet loss rates or
3778 with unreliable TFTP servers.
3779
f5fb7346
AA
3780 tftptimeoutcountmax - maximum count of TFTP timeouts (no
3781 unit, minimum value = 0). Defines how many timeouts
3782 can happen during a single file transfer before that
3783 transfer is aborted. The default is 10, and 0 means
3784 'no timeouts allowed'. Increasing this value may help
3785 downloads succeed with high packet loss rates, or with
3786 unreliable TFTP servers or client hardware.
3787
c96f86ee 3788 vlan - When set to a value < 4095 the traffic over
11ccc33f 3789 Ethernet is encapsulated/received over 802.1q
2729af9d 3790 VLAN tagged frames.
c609719b 3791
50768f5b
AM
3792 bootpretryperiod - Period during which BOOTP/DHCP sends retries.
3793 Unsigned value, in milliseconds. If not set, the period will
3794 be either the default (28000), or a value based on
3795 CONFIG_NET_RETRY_COUNT, if defined. This value has
3796 precedence over the valu based on CONFIG_NET_RETRY_COUNT.
3797
dc0b7b0e
JH
3798The following image location variables contain the location of images
3799used in booting. The "Image" column gives the role of the image and is
3800not an environment variable name. The other columns are environment
3801variable names. "File Name" gives the name of the file on a TFTP
3802server, "RAM Address" gives the location in RAM the image will be
3803loaded to, and "Flash Location" gives the image's address in NOR
3804flash or offset in NAND flash.
3805
3806*Note* - these variables don't have to be defined for all boards, some
aed9fed9 3807boards currently use other variables for these purposes, and some
dc0b7b0e
JH
3808boards use these variables for other purposes.
3809
c0f40859
WD
3810Image File Name RAM Address Flash Location
3811----- --------- ----------- --------------
3812u-boot u-boot u-boot_addr_r u-boot_addr
3813Linux kernel bootfile kernel_addr_r kernel_addr
3814device tree blob fdtfile fdt_addr_r fdt_addr
3815ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
dc0b7b0e 3816
2729af9d
WD
3817The following environment variables may be used and automatically
3818updated by the network boot commands ("bootp" and "rarpboot"),
3819depending the information provided by your boot server:
c609719b 3820
2729af9d
WD
3821 bootfile - see above
3822 dnsip - IP address of your Domain Name Server
3823 dnsip2 - IP address of your secondary Domain Name Server
3824 gatewayip - IP address of the Gateway (Router) to use
3825 hostname - Target hostname
3826 ipaddr - see above
3827 netmask - Subnet Mask
3828 rootpath - Pathname of the root filesystem on the NFS server
3829 serverip - see above
c1551ea8 3830
c1551ea8 3831
2729af9d 3832There are two special Environment Variables:
c1551ea8 3833
2729af9d
WD
3834 serial# - contains hardware identification information such
3835 as type string and/or serial number
3836 ethaddr - Ethernet address
c609719b 3837
2729af9d
WD
3838These variables can be set only once (usually during manufacturing of
3839the board). U-Boot refuses to delete or overwrite these variables
3840once they have been set once.
c609719b 3841
f07771cc 3842
2729af9d 3843Further special Environment Variables:
f07771cc 3844
2729af9d
WD
3845 ver - Contains the U-Boot version string as printed
3846 with the "version" command. This variable is
3847 readonly (see CONFIG_VERSION_VARIABLE).
f07771cc 3848
f07771cc 3849
2729af9d
WD
3850Please note that changes to some configuration parameters may take
3851only effect after the next boot (yes, that's just like Windoze :-).
f07771cc 3852
f07771cc 3853
170ab110
JH
3854Callback functions for environment variables:
3855---------------------------------------------
3856
3857For some environment variables, the behavior of u-boot needs to change
b445bbb4 3858when their values are changed. This functionality allows functions to
170ab110
JH
3859be associated with arbitrary variables. On creation, overwrite, or
3860deletion, the callback will provide the opportunity for some side
3861effect to happen or for the change to be rejected.
3862
3863The callbacks are named and associated with a function using the
3864U_BOOT_ENV_CALLBACK macro in your board or driver code.
3865
3866These callbacks are associated with variables in one of two ways. The
3867static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
3868in the board configuration to a string that defines a list of
3869associations. The list must be in the following format:
3870
3871 entry = variable_name[:callback_name]
3872 list = entry[,list]
3873
3874If the callback name is not specified, then the callback is deleted.
3875Spaces are also allowed anywhere in the list.
3876
3877Callbacks can also be associated by defining the ".callbacks" variable
3878with the same list format above. Any association in ".callbacks" will
3879override any association in the static list. You can define
3880CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
b445bbb4 3881".callbacks" environment variable in the default or embedded environment.
170ab110 3882
bdf1fe4e
JH
3883If CONFIG_REGEX is defined, the variable_name above is evaluated as a
3884regular expression. This allows multiple variables to be connected to
3885the same callback without explicitly listing them all out.
3886
1b04047a
HS
3887The signature of the callback functions is:
3888
3889 int callback(const char *name, const char *value, enum env_op op, int flags)
3890
3891* name - changed environment variable
3892* value - new value of the environment variable
3893* op - operation (create, overwrite, or delete)
3894* flags - attributes of the environment variable change, see flags H_* in
3895 include/search.h
3896
3897The return value is 0 if the variable change is accepted and 1 otherwise.
170ab110 3898
2729af9d
WD
3899Command Line Parsing:
3900=====================
f07771cc 3901
2729af9d
WD
3902There are two different command line parsers available with U-Boot:
3903the old "simple" one, and the much more powerful "hush" shell:
c609719b 3904
2729af9d
WD
3905Old, simple command line parser:
3906--------------------------------
c609719b 3907
2729af9d
WD
3908- supports environment variables (through setenv / saveenv commands)
3909- several commands on one line, separated by ';'
fe126d8b 3910- variable substitution using "... ${name} ..." syntax
2729af9d
WD
3911- special characters ('$', ';') can be escaped by prefixing with '\',
3912 for example:
fe126d8b 3913 setenv bootcmd bootm \${address}
2729af9d
WD
3914- You can also escape text by enclosing in single apostrophes, for example:
3915 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
c609719b 3916
2729af9d
WD
3917Hush shell:
3918-----------
c609719b 3919
2729af9d
WD
3920- similar to Bourne shell, with control structures like
3921 if...then...else...fi, for...do...done; while...do...done,
3922 until...do...done, ...
3923- supports environment ("global") variables (through setenv / saveenv
3924 commands) and local shell variables (through standard shell syntax
3925 "name=value"); only environment variables can be used with "run"
3926 command
3927
3928General rules:
3929--------------
c609719b 3930
2729af9d
WD
3931(1) If a command line (or an environment variable executed by a "run"
3932 command) contains several commands separated by semicolon, and
3933 one of these commands fails, then the remaining commands will be
3934 executed anyway.
c609719b 3935
2729af9d 3936(2) If you execute several variables with one call to run (i. e.
11ccc33f 3937 calling run with a list of variables as arguments), any failing
2729af9d
WD
3938 command will cause "run" to terminate, i. e. the remaining
3939 variables are not executed.
c609719b 3940
2729af9d
WD
3941Note for Redundant Ethernet Interfaces:
3942=======================================
c609719b 3943
11ccc33f 3944Some boards come with redundant Ethernet interfaces; U-Boot supports
2729af9d
WD
3945such configurations and is capable of automatic selection of a
3946"working" interface when needed. MAC assignment works as follows:
c609719b 3947
2729af9d
WD
3948Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3949MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3950"eth1addr" (=>eth1), "eth2addr", ...
c609719b 3951
2729af9d
WD
3952If the network interface stores some valid MAC address (for instance
3953in SROM), this is used as default address if there is NO correspon-
3954ding setting in the environment; if the corresponding environment
3955variable is set, this overrides the settings in the card; that means:
c609719b 3956
2729af9d
WD
3957o If the SROM has a valid MAC address, and there is no address in the
3958 environment, the SROM's address is used.
c609719b 3959
2729af9d
WD
3960o If there is no valid address in the SROM, and a definition in the
3961 environment exists, then the value from the environment variable is
3962 used.
c609719b 3963
2729af9d
WD
3964o If both the SROM and the environment contain a MAC address, and
3965 both addresses are the same, this MAC address is used.
c609719b 3966
2729af9d
WD
3967o If both the SROM and the environment contain a MAC address, and the
3968 addresses differ, the value from the environment is used and a
3969 warning is printed.
c609719b 3970
2729af9d 3971o If neither SROM nor the environment contain a MAC address, an error
bef1014b
JH
3972 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
3973 a random, locally-assigned MAC is used.
c609719b 3974
ecee9324 3975If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
c0f40859 3976will be programmed into hardware as part of the initialization process. This
ecee9324
BW
3977may be skipped by setting the appropriate 'ethmacskip' environment variable.
3978The naming convention is as follows:
3979"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
c609719b 3980
2729af9d
WD
3981Image Formats:
3982==============
c609719b 3983
3310c549
MB
3984U-Boot is capable of booting (and performing other auxiliary operations on)
3985images in two formats:
3986
3987New uImage format (FIT)
3988-----------------------
3989
3990Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3991to Flattened Device Tree). It allows the use of images with multiple
3992components (several kernels, ramdisks, etc.), with contents protected by
3993SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3994
3995
3996Old uImage format
3997-----------------
3998
3999Old image format is based on binary files which can be basically anything,
4000preceded by a special header; see the definitions in include/image.h for
4001details; basically, the header defines the following image properties:
c609719b 4002
2729af9d
WD
4003* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4004 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
f5ed9e39
PT
4005 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4006 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4007 INTEGRITY).
daab59ac 4008* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
afc1ce82 4009 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
daab59ac 4010 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC).
2729af9d
WD
4011* Compression Type (uncompressed, gzip, bzip2)
4012* Load Address
4013* Entry Point
4014* Image Name
4015* Image Timestamp
c609719b 4016
2729af9d
WD
4017The header is marked by a special Magic Number, and both the header
4018and the data portions of the image are secured against corruption by
4019CRC32 checksums.
c609719b
WD
4020
4021
2729af9d
WD
4022Linux Support:
4023==============
c609719b 4024
2729af9d
WD
4025Although U-Boot should support any OS or standalone application
4026easily, the main focus has always been on Linux during the design of
4027U-Boot.
c609719b 4028
2729af9d
WD
4029U-Boot includes many features that so far have been part of some
4030special "boot loader" code within the Linux kernel. Also, any
4031"initrd" images to be used are no longer part of one big Linux image;
4032instead, kernel and "initrd" are separate images. This implementation
4033serves several purposes:
c609719b 4034
2729af9d
WD
4035- the same features can be used for other OS or standalone
4036 applications (for instance: using compressed images to reduce the
4037 Flash memory footprint)
c609719b 4038
2729af9d
WD
4039- it becomes much easier to port new Linux kernel versions because
4040 lots of low-level, hardware dependent stuff are done by U-Boot
c609719b 4041
2729af9d
WD
4042- the same Linux kernel image can now be used with different "initrd"
4043 images; of course this also means that different kernel images can
4044 be run with the same "initrd". This makes testing easier (you don't
4045 have to build a new "zImage.initrd" Linux image when you just
4046 change a file in your "initrd"). Also, a field-upgrade of the
4047 software is easier now.
c609719b 4048
c609719b 4049
2729af9d
WD
4050Linux HOWTO:
4051============
c609719b 4052
2729af9d
WD
4053Porting Linux to U-Boot based systems:
4054---------------------------------------
c609719b 4055
2729af9d
WD
4056U-Boot cannot save you from doing all the necessary modifications to
4057configure the Linux device drivers for use with your target hardware
4058(no, we don't intend to provide a full virtual machine interface to
4059Linux :-).
c609719b 4060
a47a12be 4061But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
24ee89b9 4062
2729af9d
WD
4063Just make sure your machine specific header file (for instance
4064include/asm-ppc/tqm8xx.h) includes the same definition of the Board
1dc30693
MH
4065Information structure as we define in include/asm-<arch>/u-boot.h,
4066and make sure that your definition of IMAP_ADDR uses the same value
6d0f6bcf 4067as your U-Boot configuration in CONFIG_SYS_IMMR.
24ee89b9 4068
2eb31b13
SG
4069Note that U-Boot now has a driver model, a unified model for drivers.
4070If you are adding a new driver, plumb it into driver model. If there
4071is no uclass available, you are encouraged to create one. See
4072doc/driver-model.
4073
c609719b 4074
2729af9d
WD
4075Configuring the Linux kernel:
4076-----------------------------
c609719b 4077
2729af9d
WD
4078No specific requirements for U-Boot. Make sure you have some root
4079device (initial ramdisk, NFS) for your target system.
4080
4081
4082Building a Linux Image:
4083-----------------------
c609719b 4084
2729af9d
WD
4085With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4086not used. If you use recent kernel source, a new build target
4087"uImage" will exist which automatically builds an image usable by
4088U-Boot. Most older kernels also have support for a "pImage" target,
4089which was introduced for our predecessor project PPCBoot and uses a
4090100% compatible format.
4091
4092Example:
4093
ab584d67 4094 make TQM850L_defconfig
2729af9d
WD
4095 make oldconfig
4096 make dep
4097 make uImage
4098
4099The "uImage" build target uses a special tool (in 'tools/mkimage') to
4100encapsulate a compressed Linux kernel image with header information,
4101CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4102
4103* build a standard "vmlinux" kernel image (in ELF binary format):
4104
4105* convert the kernel into a raw binary image:
4106
4107 ${CROSS_COMPILE}-objcopy -O binary \
4108 -R .note -R .comment \
4109 -S vmlinux linux.bin
4110
4111* compress the binary image:
4112
4113 gzip -9 linux.bin
4114
4115* package compressed binary image for U-Boot:
4116
4117 mkimage -A ppc -O linux -T kernel -C gzip \
4118 -a 0 -e 0 -n "Linux Kernel Image" \
4119 -d linux.bin.gz uImage
c609719b 4120
c609719b 4121
2729af9d
WD
4122The "mkimage" tool can also be used to create ramdisk images for use
4123with U-Boot, either separated from the Linux kernel image, or
4124combined into one file. "mkimage" encapsulates the images with a 64
4125byte header containing information about target architecture,
4126operating system, image type, compression method, entry points, time
4127stamp, CRC32 checksums, etc.
4128
4129"mkimage" can be called in two ways: to verify existing images and
4130print the header information, or to build new images.
4131
4132In the first form (with "-l" option) mkimage lists the information
4133contained in the header of an existing U-Boot image; this includes
4134checksum verification:
c609719b 4135
2729af9d
WD
4136 tools/mkimage -l image
4137 -l ==> list image header information
4138
4139The second form (with "-d" option) is used to build a U-Boot image
4140from a "data file" which is used as image payload:
4141
4142 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4143 -n name -d data_file image
4144 -A ==> set architecture to 'arch'
4145 -O ==> set operating system to 'os'
4146 -T ==> set image type to 'type'
4147 -C ==> set compression type 'comp'
4148 -a ==> set load address to 'addr' (hex)
4149 -e ==> set entry point to 'ep' (hex)
4150 -n ==> set image name to 'name'
4151 -d ==> use image data from 'datafile'
4152
69459791
WD
4153Right now, all Linux kernels for PowerPC systems use the same load
4154address (0x00000000), but the entry point address depends on the
4155kernel version:
2729af9d
WD
4156
4157- 2.2.x kernels have the entry point at 0x0000000C,
4158- 2.3.x and later kernels have the entry point at 0x00000000.
4159
4160So a typical call to build a U-Boot image would read:
4161
4162 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4163 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
a47a12be 4164 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
2729af9d
WD
4165 > examples/uImage.TQM850L
4166 Image Name: 2.4.4 kernel for TQM850L
4167 Created: Wed Jul 19 02:34:59 2000
4168 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4169 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4170 Load Address: 0x00000000
4171 Entry Point: 0x00000000
4172
4173To verify the contents of the image (or check for corruption):
4174
4175 -> tools/mkimage -l examples/uImage.TQM850L
4176 Image Name: 2.4.4 kernel for TQM850L
4177 Created: Wed Jul 19 02:34:59 2000
4178 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4179 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4180 Load Address: 0x00000000
4181 Entry Point: 0x00000000
4182
4183NOTE: for embedded systems where boot time is critical you can trade
4184speed for memory and install an UNCOMPRESSED image instead: this
4185needs more space in Flash, but boots much faster since it does not
4186need to be uncompressed:
4187
a47a12be 4188 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
2729af9d
WD
4189 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4190 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
a47a12be 4191 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
2729af9d
WD
4192 > examples/uImage.TQM850L-uncompressed
4193 Image Name: 2.4.4 kernel for TQM850L
4194 Created: Wed Jul 19 02:34:59 2000
4195 Image Type: PowerPC Linux Kernel Image (uncompressed)
4196 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4197 Load Address: 0x00000000
4198 Entry Point: 0x00000000
4199
4200
4201Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4202when your kernel is intended to use an initial ramdisk:
4203
4204 -> tools/mkimage -n 'Simple Ramdisk Image' \
4205 > -A ppc -O linux -T ramdisk -C gzip \
4206 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4207 Image Name: Simple Ramdisk Image
4208 Created: Wed Jan 12 14:01:50 2000
4209 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4210 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4211 Load Address: 0x00000000
4212 Entry Point: 0x00000000
4213
a804b5ce
GMF
4214The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
4215option performs the converse operation of the mkimage's second form (the "-d"
4216option). Given an image built by mkimage, the dumpimage extracts a "data file"
4217from the image:
4218
f41f5b7c
GMF
4219 tools/dumpimage -i image -T type -p position data_file
4220 -i ==> extract from the 'image' a specific 'data_file'
4221 -T ==> set image type to 'type'
4222 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
a804b5ce 4223
2729af9d
WD
4224
4225Installing a Linux Image:
4226-------------------------
4227
4228To downloading a U-Boot image over the serial (console) interface,
4229you must convert the image to S-Record format:
4230
4231 objcopy -I binary -O srec examples/image examples/image.srec
4232
4233The 'objcopy' does not understand the information in the U-Boot
4234image header, so the resulting S-Record file will be relative to
4235address 0x00000000. To load it to a given address, you need to
4236specify the target address as 'offset' parameter with the 'loads'
4237command.
4238
4239Example: install the image to address 0x40100000 (which on the
4240TQM8xxL is in the first Flash bank):
4241
4242 => erase 40100000 401FFFFF
4243
4244 .......... done
4245 Erased 8 sectors
4246
4247 => loads 40100000
4248 ## Ready for S-Record download ...
4249 ~>examples/image.srec
4250 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4251 ...
4252 15989 15990 15991 15992
4253 [file transfer complete]
4254 [connected]
4255 ## Start Addr = 0x00000000
4256
4257
4258You can check the success of the download using the 'iminfo' command;
218ca724 4259this includes a checksum verification so you can be sure no data
2729af9d
WD
4260corruption happened:
4261
4262 => imi 40100000
4263
4264 ## Checking Image at 40100000 ...
4265 Image Name: 2.2.13 for initrd on TQM850L
4266 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4267 Data Size: 335725 Bytes = 327 kB = 0 MB
4268 Load Address: 00000000
4269 Entry Point: 0000000c
4270 Verifying Checksum ... OK
4271
4272
4273Boot Linux:
4274-----------
4275
4276The "bootm" command is used to boot an application that is stored in
4277memory (RAM or Flash). In case of a Linux kernel image, the contents
4278of the "bootargs" environment variable is passed to the kernel as
4279parameters. You can check and modify this variable using the
4280"printenv" and "setenv" commands:
4281
4282
4283 => printenv bootargs
4284 bootargs=root=/dev/ram
4285
4286 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4287
4288 => printenv bootargs
4289 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4290
4291 => bootm 40020000
4292 ## Booting Linux kernel at 40020000 ...
4293 Image Name: 2.2.13 for NFS on TQM850L
4294 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4295 Data Size: 381681 Bytes = 372 kB = 0 MB
4296 Load Address: 00000000
4297 Entry Point: 0000000c
4298 Verifying Checksum ... OK
4299 Uncompressing Kernel Image ... OK
4300 Linux version 2.2.13 ([email protected]) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
4301 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4302 time_init: decrementer frequency = 187500000/60
4303 Calibrating delay loop... 49.77 BogoMIPS
4304 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
4305 ...
4306
11ccc33f 4307If you want to boot a Linux kernel with initial RAM disk, you pass
2729af9d
WD
4308the memory addresses of both the kernel and the initrd image (PPBCOOT
4309format!) to the "bootm" command:
4310
4311 => imi 40100000 40200000
4312
4313 ## Checking Image at 40100000 ...
4314 Image Name: 2.2.13 for initrd on TQM850L
4315 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4316 Data Size: 335725 Bytes = 327 kB = 0 MB
4317 Load Address: 00000000
4318 Entry Point: 0000000c
4319 Verifying Checksum ... OK
4320
4321 ## Checking Image at 40200000 ...
4322 Image Name: Simple Ramdisk Image
4323 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4324 Data Size: 566530 Bytes = 553 kB = 0 MB
4325 Load Address: 00000000
4326 Entry Point: 00000000
4327 Verifying Checksum ... OK
4328
4329 => bootm 40100000 40200000
4330 ## Booting Linux kernel at 40100000 ...
4331 Image Name: 2.2.13 for initrd on TQM850L
4332 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4333 Data Size: 335725 Bytes = 327 kB = 0 MB
4334 Load Address: 00000000
4335 Entry Point: 0000000c
4336 Verifying Checksum ... OK
4337 Uncompressing Kernel Image ... OK
4338 ## Loading RAMDisk Image at 40200000 ...
4339 Image Name: Simple Ramdisk Image
4340 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4341 Data Size: 566530 Bytes = 553 kB = 0 MB
4342 Load Address: 00000000
4343 Entry Point: 00000000
4344 Verifying Checksum ... OK
4345 Loading Ramdisk ... OK
4346 Linux version 2.2.13 ([email protected]) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
4347 Boot arguments: root=/dev/ram
4348 time_init: decrementer frequency = 187500000/60
4349 Calibrating delay loop... 49.77 BogoMIPS
4350 ...
4351 RAMDISK: Compressed image found at block 0
4352 VFS: Mounted root (ext2 filesystem).
4353
4354 bash#
4355
0267768e
MM
4356Boot Linux and pass a flat device tree:
4357-----------
4358
4359First, U-Boot must be compiled with the appropriate defines. See the section
4360titled "Linux Kernel Interface" above for a more in depth explanation. The
4361following is an example of how to start a kernel and pass an updated
4362flat device tree:
4363
4364=> print oftaddr
4365oftaddr=0x300000
4366=> print oft
4367oft=oftrees/mpc8540ads.dtb
4368=> tftp $oftaddr $oft
4369Speed: 1000, full duplex
4370Using TSEC0 device
4371TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4372Filename 'oftrees/mpc8540ads.dtb'.
4373Load address: 0x300000
4374Loading: #
4375done
4376Bytes transferred = 4106 (100a hex)
4377=> tftp $loadaddr $bootfile
4378Speed: 1000, full duplex
4379Using TSEC0 device
4380TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4381Filename 'uImage'.
4382Load address: 0x200000
4383Loading:############
4384done
4385Bytes transferred = 1029407 (fb51f hex)
4386=> print loadaddr
4387loadaddr=200000
4388=> print oftaddr
4389oftaddr=0x300000
4390=> bootm $loadaddr - $oftaddr
4391## Booting image at 00200000 ...
a9398e01
WD
4392 Image Name: Linux-2.6.17-dirty
4393 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4394 Data Size: 1029343 Bytes = 1005.2 kB
0267768e 4395 Load Address: 00000000
a9398e01 4396 Entry Point: 00000000
0267768e
MM
4397 Verifying Checksum ... OK
4398 Uncompressing Kernel Image ... OK
4399Booting using flat device tree at 0x300000
4400Using MPC85xx ADS machine description
4401Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4402[snip]
4403
4404
2729af9d
WD
4405More About U-Boot Image Types:
4406------------------------------
4407
4408U-Boot supports the following image types:
4409
4410 "Standalone Programs" are directly runnable in the environment
4411 provided by U-Boot; it is expected that (if they behave
4412 well) you can continue to work in U-Boot after return from
4413 the Standalone Program.
4414 "OS Kernel Images" are usually images of some Embedded OS which
4415 will take over control completely. Usually these programs
4416 will install their own set of exception handlers, device
4417 drivers, set up the MMU, etc. - this means, that you cannot
4418 expect to re-enter U-Boot except by resetting the CPU.
4419 "RAMDisk Images" are more or less just data blocks, and their
4420 parameters (address, size) are passed to an OS kernel that is
4421 being started.
4422 "Multi-File Images" contain several images, typically an OS
4423 (Linux) kernel image and one or more data images like
4424 RAMDisks. This construct is useful for instance when you want
4425 to boot over the network using BOOTP etc., where the boot
4426 server provides just a single image file, but you want to get
4427 for instance an OS kernel and a RAMDisk image.
4428
4429 "Multi-File Images" start with a list of image sizes, each
4430 image size (in bytes) specified by an "uint32_t" in network
4431 byte order. This list is terminated by an "(uint32_t)0".
4432 Immediately after the terminating 0 follow the images, one by
4433 one, all aligned on "uint32_t" boundaries (size rounded up to
4434 a multiple of 4 bytes).
4435
4436 "Firmware Images" are binary images containing firmware (like
4437 U-Boot or FPGA images) which usually will be programmed to
4438 flash memory.
4439
4440 "Script files" are command sequences that will be executed by
4441 U-Boot's command interpreter; this feature is especially
4442 useful when you configure U-Boot to use a real shell (hush)
4443 as command interpreter.
4444
44f074c7
MV
4445Booting the Linux zImage:
4446-------------------------
4447
4448On some platforms, it's possible to boot Linux zImage. This is done
4449using the "bootz" command. The syntax of "bootz" command is the same
4450as the syntax of "bootm" command.
4451
8ac28563 4452Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
017e1f3f
MV
4453kernel with raw initrd images. The syntax is slightly different, the
4454address of the initrd must be augmented by it's size, in the following
4455format: "<initrd addres>:<initrd size>".
4456
2729af9d
WD
4457
4458Standalone HOWTO:
4459=================
4460
4461One of the features of U-Boot is that you can dynamically load and
4462run "standalone" applications, which can use some resources of
4463U-Boot like console I/O functions or interrupt services.
4464
4465Two simple examples are included with the sources:
4466
4467"Hello World" Demo:
4468-------------------
4469
4470'examples/hello_world.c' contains a small "Hello World" Demo
4471application; it is automatically compiled when you build U-Boot.
4472It's configured to run at address 0x00040004, so you can play with it
4473like that:
4474
4475 => loads
4476 ## Ready for S-Record download ...
4477 ~>examples/hello_world.srec
4478 1 2 3 4 5 6 7 8 9 10 11 ...
4479 [file transfer complete]
4480 [connected]
4481 ## Start Addr = 0x00040004
4482
4483 => go 40004 Hello World! This is a test.
4484 ## Starting application at 0x00040004 ...
4485 Hello World
4486 argc = 7
4487 argv[0] = "40004"
4488 argv[1] = "Hello"
4489 argv[2] = "World!"
4490 argv[3] = "This"
4491 argv[4] = "is"
4492 argv[5] = "a"
4493 argv[6] = "test."
4494 argv[7] = "<NULL>"
4495 Hit any key to exit ...
4496
4497 ## Application terminated, rc = 0x0
4498
4499Another example, which demonstrates how to register a CPM interrupt
4500handler with the U-Boot code, can be found in 'examples/timer.c'.
4501Here, a CPM timer is set up to generate an interrupt every second.
4502The interrupt service routine is trivial, just printing a '.'
4503character, but this is just a demo program. The application can be
4504controlled by the following keys:
4505
4506 ? - print current values og the CPM Timer registers
4507 b - enable interrupts and start timer
4508 e - stop timer and disable interrupts
4509 q - quit application
4510
4511 => loads
4512 ## Ready for S-Record download ...
4513 ~>examples/timer.srec
4514 1 2 3 4 5 6 7 8 9 10 11 ...
4515 [file transfer complete]
4516 [connected]
4517 ## Start Addr = 0x00040004
4518
4519 => go 40004
4520 ## Starting application at 0x00040004 ...
4521 TIMERS=0xfff00980
4522 Using timer 1
4523 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
4524
4525Hit 'b':
4526 [q, b, e, ?] Set interval 1000000 us
4527 Enabling timer
4528Hit '?':
4529 [q, b, e, ?] ........
4530 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
4531Hit '?':
4532 [q, b, e, ?] .
4533 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
4534Hit '?':
4535 [q, b, e, ?] .
4536 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
4537Hit '?':
4538 [q, b, e, ?] .
4539 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
4540Hit 'e':
4541 [q, b, e, ?] ...Stopping timer
4542Hit 'q':
4543 [q, b, e, ?] ## Application terminated, rc = 0x0
4544
4545
4546Minicom warning:
4547================
4548
4549Over time, many people have reported problems when trying to use the
4550"minicom" terminal emulation program for serial download. I (wd)
4551consider minicom to be broken, and recommend not to use it. Under
4552Unix, I recommend to use C-Kermit for general purpose use (and
4553especially for kermit binary protocol download ("loadb" command), and
e53515a2
KP
4554use "cu" for S-Record download ("loads" command). See
4555http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
4556for help with kermit.
4557
2729af9d
WD
4558
4559Nevertheless, if you absolutely want to use it try adding this
4560configuration to your "File transfer protocols" section:
4561
4562 Name Program Name U/D FullScr IO-Red. Multi
4563 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
4564 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
4565
4566
4567NetBSD Notes:
4568=============
4569
4570Starting at version 0.9.2, U-Boot supports NetBSD both as host
4571(build U-Boot) and target system (boots NetBSD/mpc8xx).
4572
4573Building requires a cross environment; it is known to work on
4574NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
4575need gmake since the Makefiles are not compatible with BSD make).
4576Note that the cross-powerpc package does not install include files;
4577attempting to build U-Boot will fail because <machine/ansi.h> is
4578missing. This file has to be installed and patched manually:
4579
4580 # cd /usr/pkg/cross/powerpc-netbsd/include
4581 # mkdir powerpc
4582 # ln -s powerpc machine
4583 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
4584 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
4585
4586Native builds *don't* work due to incompatibilities between native
4587and U-Boot include files.
4588
4589Booting assumes that (the first part of) the image booted is a
4590stage-2 loader which in turn loads and then invokes the kernel
4591proper. Loader sources will eventually appear in the NetBSD source
4592tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
2a8af187 4593meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
2729af9d
WD
4594
4595
4596Implementation Internals:
4597=========================
4598
4599The following is not intended to be a complete description of every
4600implementation detail. However, it should help to understand the
4601inner workings of U-Boot and make it easier to port it to custom
4602hardware.
4603
4604
4605Initial Stack, Global Data:
4606---------------------------
4607
4608The implementation of U-Boot is complicated by the fact that U-Boot
4609starts running out of ROM (flash memory), usually without access to
4610system RAM (because the memory controller is not initialized yet).
4611This means that we don't have writable Data or BSS segments, and BSS
4612is not initialized as zero. To be able to get a C environment working
4613at all, we have to allocate at least a minimal stack. Implementation
4614options for this are defined and restricted by the CPU used: Some CPU
4615models provide on-chip memory (like the IMMR area on MPC8xx and
4616MPC826x processors), on others (parts of) the data cache can be
4617locked as (mis-) used as memory, etc.
4618
218ca724 4619 Chris Hallinan posted a good summary of these issues to the
0668236b 4620 U-Boot mailing list:
2729af9d
WD
4621
4622 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
4623 From: "Chris Hallinan" <[email protected]>
4624 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
4625 ...
4626
4627 Correct me if I'm wrong, folks, but the way I understand it
4628 is this: Using DCACHE as initial RAM for Stack, etc, does not
4629 require any physical RAM backing up the cache. The cleverness
4630 is that the cache is being used as a temporary supply of
4631 necessary storage before the SDRAM controller is setup. It's
11ccc33f 4632 beyond the scope of this list to explain the details, but you
2729af9d
WD
4633 can see how this works by studying the cache architecture and
4634 operation in the architecture and processor-specific manuals.
4635
4636 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4637 is another option for the system designer to use as an
11ccc33f 4638 initial stack/RAM area prior to SDRAM being available. Either
2729af9d
WD
4639 option should work for you. Using CS 4 should be fine if your
4640 board designers haven't used it for something that would
4641 cause you grief during the initial boot! It is frequently not
4642 used.
4643
6d0f6bcf 4644 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
2729af9d
WD
4645 with your processor/board/system design. The default value
4646 you will find in any recent u-boot distribution in
8a316c9b 4647 walnut.h should work for you. I'd set it to a value larger
2729af9d
WD
4648 than your SDRAM module. If you have a 64MB SDRAM module, set
4649 it above 400_0000. Just make sure your board has no resources
4650 that are supposed to respond to that address! That code in
4651 start.S has been around a while and should work as is when
4652 you get the config right.
4653
4654 -Chris Hallinan
4655 DS4.COM, Inc.
4656
4657It is essential to remember this, since it has some impact on the C
4658code for the initialization procedures:
4659
4660* Initialized global data (data segment) is read-only. Do not attempt
4661 to write it.
4662
b445bbb4 4663* Do not use any uninitialized global data (or implicitly initialized
2729af9d
WD
4664 as zero data - BSS segment) at all - this is undefined, initiali-
4665 zation is performed later (when relocating to RAM).
4666
4667* Stack space is very limited. Avoid big data buffers or things like
4668 that.
4669
4670Having only the stack as writable memory limits means we cannot use
b445bbb4 4671normal global data to share information between the code. But it
2729af9d
WD
4672turned out that the implementation of U-Boot can be greatly
4673simplified by making a global data structure (gd_t) available to all
4674functions. We could pass a pointer to this data as argument to _all_
4675functions, but this would bloat the code. Instead we use a feature of
4676the GCC compiler (Global Register Variables) to share the data: we
4677place a pointer (gd) to the global data into a register which we
4678reserve for this purpose.
4679
4680When choosing a register for such a purpose we are restricted by the
4681relevant (E)ABI specifications for the current architecture, and by
4682GCC's implementation.
4683
4684For PowerPC, the following registers have specific use:
4685 R1: stack pointer
e7670f6c 4686 R2: reserved for system use
2729af9d
WD
4687 R3-R4: parameter passing and return values
4688 R5-R10: parameter passing
4689 R13: small data area pointer
4690 R30: GOT pointer
4691 R31: frame pointer
4692
e6bee808
JT
4693 (U-Boot also uses R12 as internal GOT pointer. r12
4694 is a volatile register so r12 needs to be reset when
4695 going back and forth between asm and C)
2729af9d 4696
e7670f6c 4697 ==> U-Boot will use R2 to hold a pointer to the global data
2729af9d
WD
4698
4699 Note: on PPC, we could use a static initializer (since the
4700 address of the global data structure is known at compile time),
4701 but it turned out that reserving a register results in somewhat
4702 smaller code - although the code savings are not that big (on
4703 average for all boards 752 bytes for the whole U-Boot image,
4704 624 text + 127 data).
4705
4706On ARM, the following registers are used:
4707
4708 R0: function argument word/integer result
4709 R1-R3: function argument word
12eba1b4
JH
4710 R9: platform specific
4711 R10: stack limit (used only if stack checking is enabled)
2729af9d
WD
4712 R11: argument (frame) pointer
4713 R12: temporary workspace
4714 R13: stack pointer
4715 R14: link register
4716 R15: program counter
4717
12eba1b4
JH
4718 ==> U-Boot will use R9 to hold a pointer to the global data
4719
4720 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
2729af9d 4721
0df01fd3
TC
4722On Nios II, the ABI is documented here:
4723 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4724
4725 ==> U-Boot will use gp to hold a pointer to the global data
4726
4727 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4728 to access small data sections, so gp is free.
4729
afc1ce82
ML
4730On NDS32, the following registers are used:
4731
4732 R0-R1: argument/return
4733 R2-R5: argument
4734 R15: temporary register for assembler
4735 R16: trampoline register
4736 R28: frame pointer (FP)
4737 R29: global pointer (GP)
4738 R30: link register (LP)
4739 R31: stack pointer (SP)
4740 PC: program counter (PC)
4741
4742 ==> U-Boot will use R10 to hold a pointer to the global data
4743
d87080b7
WD
4744NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4745or current versions of GCC may "optimize" the code too much.
2729af9d 4746
3fafced7
RC
4747On RISC-V, the following registers are used:
4748
4749 x0: hard-wired zero (zero)
4750 x1: return address (ra)
4751 x2: stack pointer (sp)
4752 x3: global pointer (gp)
4753 x4: thread pointer (tp)
4754 x5: link register (t0)
4755 x8: frame pointer (fp)
4756 x10-x11: arguments/return values (a0-1)
4757 x12-x17: arguments (a2-7)
4758 x28-31: temporaries (t3-6)
4759 pc: program counter (pc)
4760
4761 ==> U-Boot will use gp to hold a pointer to the global data
4762
2729af9d
WD
4763Memory Management:
4764------------------
4765
4766U-Boot runs in system state and uses physical addresses, i.e. the
4767MMU is not used either for address mapping nor for memory protection.
4768
4769The available memory is mapped to fixed addresses using the memory
4770controller. In this process, a contiguous block is formed for each
4771memory type (Flash, SDRAM, SRAM), even when it consists of several
4772physical memory banks.
4773
4774U-Boot is installed in the first 128 kB of the first Flash bank (on
4775TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4776booting and sizing and initializing DRAM, the code relocates itself
4777to the upper end of DRAM. Immediately below the U-Boot code some
6d0f6bcf 4778memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
2729af9d
WD
4779configuration setting]. Below that, a structure with global Board
4780Info data is placed, followed by the stack (growing downward).
4781
4782Additionally, some exception handler code is copied to the low 8 kB
4783of DRAM (0x00000000 ... 0x00001FFF).
4784
4785So a typical memory configuration with 16 MB of DRAM could look like
4786this:
4787
4788 0x0000 0000 Exception Vector code
4789 :
4790 0x0000 1FFF
4791 0x0000 2000 Free for Application Use
4792 :
4793 :
4794
4795 :
4796 :
4797 0x00FB FF20 Monitor Stack (Growing downward)
4798 0x00FB FFAC Board Info Data and permanent copy of global data
4799 0x00FC 0000 Malloc Arena
4800 :
4801 0x00FD FFFF
4802 0x00FE 0000 RAM Copy of Monitor Code
4803 ... eventually: LCD or video framebuffer
4804 ... eventually: pRAM (Protected RAM - unchanged by reset)
4805 0x00FF FFFF [End of RAM]
4806
4807
4808System Initialization:
4809----------------------
c609719b 4810
2729af9d 4811In the reset configuration, U-Boot starts at the reset entry point
11ccc33f 4812(on most PowerPC systems at address 0x00000100). Because of the reset
b445bbb4 4813configuration for CS0# this is a mirror of the on board Flash memory.
2729af9d
WD
4814To be able to re-map memory U-Boot then jumps to its link address.
4815To be able to implement the initialization code in C, a (small!)
4816initial stack is set up in the internal Dual Ported RAM (in case CPUs
2eb48ff7
HS
4817which provide such a feature like), or in a locked part of the data
4818cache. After that, U-Boot initializes the CPU core, the caches and
4819the SIU.
2729af9d
WD
4820
4821Next, all (potentially) available memory banks are mapped using a
4822preliminary mapping. For example, we put them on 512 MB boundaries
4823(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4824on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4825programmed for SDRAM access. Using the temporary configuration, a
4826simple memory test is run that determines the size of the SDRAM
4827banks.
4828
4829When there is more than one SDRAM bank, and the banks are of
4830different size, the largest is mapped first. For equal size, the first
4831bank (CS2#) is mapped first. The first mapping is always for address
48320x00000000, with any additional banks following immediately to create
4833contiguous memory starting from 0.
4834
4835Then, the monitor installs itself at the upper end of the SDRAM area
4836and allocates memory for use by malloc() and for the global Board
4837Info data; also, the exception vector code is copied to the low RAM
4838pages, and the final stack is set up.
4839
4840Only after this relocation will you have a "normal" C environment;
4841until that you are restricted in several ways, mostly because you are
4842running from ROM, and because the code will have to be relocated to a
4843new address in RAM.
4844
4845
4846U-Boot Porting Guide:
4847----------------------
c609719b 4848
2729af9d
WD
4849[Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4850list, October 2002]
c609719b
WD
4851
4852
6c3fef28 4853int main(int argc, char *argv[])
2729af9d
WD
4854{
4855 sighandler_t no_more_time;
c609719b 4856
6c3fef28
JVB
4857 signal(SIGALRM, no_more_time);
4858 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
c609719b 4859
2729af9d 4860 if (available_money > available_manpower) {
6c3fef28 4861 Pay consultant to port U-Boot;
c609719b
WD
4862 return 0;
4863 }
4864
2729af9d
WD
4865 Download latest U-Boot source;
4866
0668236b 4867 Subscribe to u-boot mailing list;
2729af9d 4868
6c3fef28
JVB
4869 if (clueless)
4870 email("Hi, I am new to U-Boot, how do I get started?");
2729af9d
WD
4871
4872 while (learning) {
4873 Read the README file in the top level directory;
6c3fef28
JVB
4874 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4875 Read applicable doc/*.README;
2729af9d 4876 Read the source, Luke;
6c3fef28 4877 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
2729af9d
WD
4878 }
4879
6c3fef28
JVB
4880 if (available_money > toLocalCurrency ($2500))
4881 Buy a BDI3000;
4882 else
2729af9d 4883 Add a lot of aggravation and time;
2729af9d 4884
6c3fef28
JVB
4885 if (a similar board exists) { /* hopefully... */
4886 cp -a board/<similar> board/<myboard>
4887 cp include/configs/<similar>.h include/configs/<myboard>.h
4888 } else {
4889 Create your own board support subdirectory;
4890 Create your own board include/configs/<myboard>.h file;
4891 }
4892 Edit new board/<myboard> files
4893 Edit new include/configs/<myboard>.h
4894
4895 while (!accepted) {
4896 while (!running) {
4897 do {
4898 Add / modify source code;
4899 } until (compiles);
4900 Debug;
4901 if (clueless)
4902 email("Hi, I am having problems...");
4903 }
4904 Send patch file to the U-Boot email list;
4905 if (reasonable critiques)
4906 Incorporate improvements from email list code review;
4907 else
4908 Defend code as written;
2729af9d 4909 }
2729af9d
WD
4910
4911 return 0;
4912}
4913
4914void no_more_time (int sig)
4915{
4916 hire_a_guru();
4917}
4918
c609719b 4919
2729af9d
WD
4920Coding Standards:
4921-----------------
c609719b 4922
2729af9d 4923All contributions to U-Boot should conform to the Linux kernel
659208da
BS
4924coding style; see the kernel coding style guide at
4925https://www.kernel.org/doc/html/latest/process/coding-style.html, and the
4926script "scripts/Lindent" in your Linux kernel source directory.
2c051651
DZ
4927
4928Source files originating from a different project (for example the
4929MTD subsystem) are generally exempt from these guidelines and are not
b445bbb4 4930reformatted to ease subsequent migration to newer versions of those
2c051651
DZ
4931sources.
4932
4933Please note that U-Boot is implemented in C (and to some small parts in
4934Assembler); no C++ is used, so please do not use C++ style comments (//)
4935in your code.
c609719b 4936
2729af9d
WD
4937Please also stick to the following formatting rules:
4938- remove any trailing white space
7ca9296e 4939- use TAB characters for indentation and vertical alignment, not spaces
2729af9d 4940- make sure NOT to use DOS '\r\n' line feeds
7ca9296e 4941- do not add more than 2 consecutive empty lines to source files
2729af9d 4942- do not add trailing empty lines to source files
180d3f74 4943
2729af9d
WD
4944Submissions which do not conform to the standards may be returned
4945with a request to reformat the changes.
c609719b
WD
4946
4947
2729af9d
WD
4948Submitting Patches:
4949-------------------
c609719b 4950
2729af9d
WD
4951Since the number of patches for U-Boot is growing, we need to
4952establish some rules. Submissions which do not conform to these rules
4953may be rejected, even when they contain important and valuable stuff.
c609719b 4954
0d28f34b 4955Please see http://www.denx.de/wiki/U-Boot/Patches for details.
218ca724 4956
0668236b 4957Patches shall be sent to the u-boot mailing list <[email protected]>;
1dade18e 4958see https://lists.denx.de/listinfo/u-boot
0668236b 4959
2729af9d
WD
4960When you send a patch, please include the following information with
4961it:
c609719b 4962
2729af9d
WD
4963* For bug fixes: a description of the bug and how your patch fixes
4964 this bug. Please try to include a way of demonstrating that the
4965 patch actually fixes something.
c609719b 4966
2729af9d
WD
4967* For new features: a description of the feature and your
4968 implementation.
c609719b 4969
2729af9d 4970* A CHANGELOG entry as plaintext (separate from the patch)
c609719b 4971
7207b366
RD
4972* For major contributions, add a MAINTAINERS file with your
4973 information and associated file and directory references.
c609719b 4974
27af930e
AA
4975* When you add support for a new board, don't forget to add a
4976 maintainer e-mail address to the boards.cfg file, too.
c609719b 4977
2729af9d
WD
4978* If your patch adds new configuration options, don't forget to
4979 document these in the README file.
c609719b 4980
218ca724
WD
4981* The patch itself. If you are using git (which is *strongly*
4982 recommended) you can easily generate the patch using the
7ca9296e 4983 "git format-patch". If you then use "git send-email" to send it to
218ca724
WD
4984 the U-Boot mailing list, you will avoid most of the common problems
4985 with some other mail clients.
4986
4987 If you cannot use git, use "diff -purN OLD NEW". If your version of
4988 diff does not support these options, then get the latest version of
4989 GNU diff.
c609719b 4990
218ca724
WD
4991 The current directory when running this command shall be the parent
4992 directory of the U-Boot source tree (i. e. please make sure that
4993 your patch includes sufficient directory information for the
4994 affected files).
6dff5529 4995
218ca724
WD
4996 We prefer patches as plain text. MIME attachments are discouraged,
4997 and compressed attachments must not be used.
c609719b 4998
2729af9d
WD
4999* If one logical set of modifications affects or creates several
5000 files, all these changes shall be submitted in a SINGLE patch file.
52f52c14 5001
2729af9d
WD
5002* Changesets that contain different, unrelated modifications shall be
5003 submitted as SEPARATE patches, one patch per changeset.
8bde7f77 5004
52f52c14 5005
2729af9d 5006Notes:
c609719b 5007
6de80f21 5008* Before sending the patch, run the buildman script on your patched
2729af9d
WD
5009 source tree and make sure that no errors or warnings are reported
5010 for any of the boards.
c609719b 5011
2729af9d
WD
5012* Keep your modifications to the necessary minimum: A patch
5013 containing several unrelated changes or arbitrary reformats will be
5014 returned with a request to re-formatting / split it.
c609719b 5015
2729af9d
WD
5016* If you modify existing code, make sure that your new code does not
5017 add to the memory footprint of the code ;-) Small is beautiful!
5018 When adding new features, these should compile conditionally only
5019 (using #ifdef), and the resulting code with the new feature
5020 disabled must not need more memory than the old code without your
5021 modification.
90dc6704 5022
0668236b
WD
5023* Remember that there is a size limit of 100 kB per message on the
5024 u-boot mailing list. Bigger patches will be moderated. If they are
5025 reasonable and not too big, they will be acknowledged. But patches
5026 bigger than the size limit should be avoided.
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