2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG and CREDITS files to find out
38 who contributed the specific port. The boards.cfg file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
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
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arc Files generic to ARC architecture
136 /cpu CPU specific files
137 /arc700 Files specific to ARC 700 CPUs
138 /lib Architecture specific library files
139 /arm Files generic to ARM architecture
140 /cpu CPU specific files
141 /arm720t Files specific to ARM 720 CPUs
142 /arm920t Files specific to ARM 920 CPUs
143 /at91 Files specific to Atmel AT91RM9200 CPU
144 /imx Files specific to Freescale MC9328 i.MX CPUs
145 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
146 /arm926ejs Files specific to ARM 926 CPUs
147 /arm1136 Files specific to ARM 1136 CPUs
148 /pxa Files specific to Intel XScale PXA CPUs
149 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
150 /lib Architecture specific library files
151 /avr32 Files generic to AVR32 architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /blackfin Files generic to Analog Devices Blackfin architecture
155 /cpu CPU specific files
156 /lib Architecture specific library files
157 /m68k Files generic to m68k architecture
158 /cpu CPU specific files
159 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 /lib Architecture specific library files
165 /microblaze Files generic to microblaze architecture
166 /cpu CPU specific files
167 /lib Architecture specific library files
168 /mips Files generic to MIPS architecture
169 /cpu CPU specific files
170 /mips32 Files specific to MIPS32 CPUs
171 /mips64 Files specific to MIPS64 CPUs
172 /lib Architecture specific library files
173 /nds32 Files generic to NDS32 architecture
174 /cpu CPU specific files
175 /n1213 Files specific to Andes Technology N1213 CPUs
176 /lib Architecture specific library files
177 /nios2 Files generic to Altera NIOS2 architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /openrisc Files generic to OpenRISC architecture
181 /cpu CPU specific files
182 /lib Architecture specific library files
183 /powerpc Files generic to PowerPC architecture
184 /cpu CPU specific files
185 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
186 /mpc5xx Files specific to Freescale MPC5xx CPUs
187 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
188 /mpc8xx Files specific to Freescale MPC8xx CPUs
189 /mpc824x Files specific to Freescale MPC824x CPUs
190 /mpc8260 Files specific to Freescale MPC8260 CPUs
191 /mpc85xx Files specific to Freescale MPC85xx CPUs
192 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
193 /lib Architecture specific library files
194 /sh Files generic to SH architecture
195 /cpu CPU specific files
196 /sh2 Files specific to sh2 CPUs
197 /sh3 Files specific to sh3 CPUs
198 /sh4 Files specific to sh4 CPUs
199 /lib Architecture specific library files
200 /sparc Files generic to SPARC architecture
201 /cpu CPU specific files
202 /leon2 Files specific to Gaisler LEON2 SPARC CPU
203 /leon3 Files specific to Gaisler LEON3 SPARC CPU
204 /lib Architecture specific library files
205 /x86 Files generic to x86 architecture
206 /cpu CPU specific files
207 /lib Architecture specific library files
208 /api Machine/arch independent API for external apps
209 /board Board dependent files
210 /common Misc architecture independent functions
211 /disk Code for disk drive partition handling
212 /doc Documentation (don't expect too much)
213 /drivers Commonly used device drivers
214 /dts Contains Makefile for building internal U-Boot fdt.
215 /examples Example code for standalone applications, etc.
216 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
217 /include Header Files
218 /lib Files generic to all architectures
219 /libfdt Library files to support flattened device trees
220 /lzma Library files to support LZMA decompression
221 /lzo Library files to support LZO decompression
223 /post Power On Self Test
224 /spl Secondary Program Loader framework
225 /tools Tools to build S-Record or U-Boot images, etc.
227 Software Configuration:
228 =======================
230 Configuration is usually done using C preprocessor defines; the
231 rationale behind that is to avoid dead code whenever possible.
233 There are two classes of configuration variables:
235 * Configuration _OPTIONS_:
236 These are selectable by the user and have names beginning with
239 * Configuration _SETTINGS_:
240 These depend on the hardware etc. and should not be meddled with if
241 you don't know what you're doing; they have names beginning with
244 Later we will add a configuration tool - probably similar to or even
245 identical to what's used for the Linux kernel. Right now, we have to
246 do the configuration by hand, which means creating some symbolic
247 links and editing some configuration files. We use the TQM8xxL boards
251 Selection of Processor Architecture and Board Type:
252 ---------------------------------------------------
254 For all supported boards there are ready-to-use default
255 configurations available; just type "make <board_name>_defconfig".
257 Example: For a TQM823L module type:
260 make TQM823L_defconfig
262 For the Cogent platform, you need to specify the CPU type as well;
263 e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
264 directory according to the instructions in cogent/README.
270 U-Boot can be built natively to run on a Linux host using the 'sandbox'
271 board. This allows feature development which is not board- or architecture-
272 specific to be undertaken on a native platform. The sandbox is also used to
273 run some of U-Boot's tests.
275 See board/sandbox/README.sandbox for more details.
278 Configuration Options:
279 ----------------------
281 Configuration depends on the combination of board and CPU type; all
282 such information is kept in a configuration file
283 "include/configs/<board_name>.h".
285 Example: For a TQM823L module, all configuration settings are in
286 "include/configs/TQM823L.h".
289 Many of the options are named exactly as the corresponding Linux
290 kernel configuration options. The intention is to make it easier to
291 build a config tool - later.
294 The following options need to be configured:
296 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
298 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
300 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
301 Define exactly one, e.g. CONFIG_ATSTK1002
303 - CPU Module Type: (if CONFIG_COGENT is defined)
304 Define exactly one of
306 --- FIXME --- not tested yet:
307 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
308 CONFIG_CMA287_23, CONFIG_CMA287_50
310 - Motherboard Type: (if CONFIG_COGENT is defined)
311 Define exactly one of
312 CONFIG_CMA101, CONFIG_CMA102
314 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
315 Define one or more of
318 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
319 Define one or more of
320 CONFIG_LCD_HEARTBEAT - update a character position on
321 the LCD display every second with
324 - Marvell Family Member
325 CONFIG_SYS_MVFS - define it if you want to enable
326 multiple fs option at one time
327 for marvell soc family
329 - MPC824X Family Member (if CONFIG_MPC824X is defined)
330 Define exactly one of
331 CONFIG_MPC8240, CONFIG_MPC8245
333 - 8xx CPU Options: (if using an MPC8xx CPU)
334 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
335 get_gclk_freq() cannot work
336 e.g. if there is no 32KHz
337 reference PIT/RTC clock
338 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
341 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
342 CONFIG_SYS_8xx_CPUCLK_MIN
343 CONFIG_SYS_8xx_CPUCLK_MAX
344 CONFIG_8xx_CPUCLK_DEFAULT
345 See doc/README.MPC866
347 CONFIG_SYS_MEASURE_CPUCLK
349 Define this to measure the actual CPU clock instead
350 of relying on the correctness of the configured
351 values. Mostly useful for board bringup to make sure
352 the PLL is locked at the intended frequency. Note
353 that this requires a (stable) reference clock (32 kHz
354 RTC clock or CONFIG_SYS_8XX_XIN)
356 CONFIG_SYS_DELAYED_ICACHE
358 Define this option if you want to enable the
359 ICache only when Code runs from RAM.
364 Specifies that the core is a 64-bit PowerPC implementation (implements
365 the "64" category of the Power ISA). This is necessary for ePAPR
366 compliance, among other possible reasons.
368 CONFIG_SYS_FSL_TBCLK_DIV
370 Defines the core time base clock divider ratio compared to the
371 system clock. On most PQ3 devices this is 8, on newer QorIQ
372 devices it can be 16 or 32. The ratio varies from SoC to Soc.
374 CONFIG_SYS_FSL_PCIE_COMPAT
376 Defines the string to utilize when trying to match PCIe device
377 tree nodes for the given platform.
379 CONFIG_SYS_PPC_E500_DEBUG_TLB
381 Enables a temporary TLB entry to be used during boot to work
382 around limitations in e500v1 and e500v2 external debugger
383 support. This reduces the portions of the boot code where
384 breakpoints and single stepping do not work. The value of this
385 symbol should be set to the TLB1 entry to be used for this
388 CONFIG_SYS_FSL_ERRATUM_A004510
390 Enables a workaround for erratum A004510. If set,
391 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
392 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
394 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
395 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
397 Defines one or two SoC revisions (low 8 bits of SVR)
398 for which the A004510 workaround should be applied.
400 The rest of SVR is either not relevant to the decision
401 of whether the erratum is present (e.g. p2040 versus
402 p2041) or is implied by the build target, which controls
403 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
405 See Freescale App Note 4493 for more information about
408 CONFIG_A003399_NOR_WORKAROUND
409 Enables a workaround for IFC erratum A003399. It is only
410 requred during NOR boot.
412 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
414 This is the value to write into CCSR offset 0x18600
415 according to the A004510 workaround.
417 CONFIG_SYS_FSL_DSP_DDR_ADDR
418 This value denotes start offset of DDR memory which is
419 connected exclusively to the DSP cores.
421 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
422 This value denotes start offset of M2 memory
423 which is directly connected to the DSP core.
425 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
426 This value denotes start offset of M3 memory which is directly
427 connected to the DSP core.
429 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
430 This value denotes start offset of DSP CCSR space.
432 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
433 Single Source Clock is clocking mode present in some of FSL SoC's.
434 In this mode, a single differential clock is used to supply
435 clocks to the sysclock, ddrclock and usbclock.
437 CONFIG_SYS_CPC_REINIT_F
438 This CONFIG is defined when the CPC is configured as SRAM at the
439 time of U-boot entry and is required to be re-initialized.
442 Inidcates this SoC supports deep sleep feature. If deep sleep is
443 supported, core will start to execute uboot when wakes up.
445 - Generic CPU options:
446 CONFIG_SYS_GENERIC_GLOBAL_DATA
447 Defines global data is initialized in generic board board_init_f().
448 If this macro is defined, global data is created and cleared in
449 generic board board_init_f(). Without this macro, architecture/board
450 should initialize global data before calling board_init_f().
452 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
454 Defines the endianess of the CPU. Implementation of those
455 values is arch specific.
458 Freescale DDR driver in use. This type of DDR controller is
459 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
462 CONFIG_SYS_FSL_DDR_ADDR
463 Freescale DDR memory-mapped register base.
465 CONFIG_SYS_FSL_DDR_EMU
466 Specify emulator support for DDR. Some DDR features such as
467 deskew training are not available.
469 CONFIG_SYS_FSL_DDRC_GEN1
470 Freescale DDR1 controller.
472 CONFIG_SYS_FSL_DDRC_GEN2
473 Freescale DDR2 controller.
475 CONFIG_SYS_FSL_DDRC_GEN3
476 Freescale DDR3 controller.
478 CONFIG_SYS_FSL_DDRC_GEN4
479 Freescale DDR4 controller.
481 CONFIG_SYS_FSL_DDRC_ARM_GEN3
482 Freescale DDR3 controller for ARM-based SoCs.
485 Board config to use DDR1. It can be enabled for SoCs with
486 Freescale DDR1 or DDR2 controllers, depending on the board
490 Board config to use DDR2. It can be eanbeld for SoCs with
491 Freescale DDR2 or DDR3 controllers, depending on the board
495 Board config to use DDR3. It can be enabled for SoCs with
496 Freescale DDR3 or DDR3L controllers.
499 Board config to use DDR3L. It can be enabled for SoCs with
503 Board config to use DDR4. It can be enabled for SoCs with
506 CONFIG_SYS_FSL_IFC_BE
507 Defines the IFC controller register space as Big Endian
509 CONFIG_SYS_FSL_IFC_LE
510 Defines the IFC controller register space as Little Endian
512 CONFIG_SYS_FSL_PBL_PBI
513 It enables addition of RCW (Power on reset configuration) in built image.
514 Please refer doc/README.pblimage for more details
516 CONFIG_SYS_FSL_PBL_RCW
517 It adds PBI(pre-boot instructions) commands in u-boot build image.
518 PBI commands can be used to configure SoC before it starts the execution.
519 Please refer doc/README.pblimage for more details
522 It adds a target to create boot binary having SPL binary in PBI format
523 concatenated with u-boot binary.
525 CONFIG_SYS_FSL_DDR_BE
526 Defines the DDR controller register space as Big Endian
528 CONFIG_SYS_FSL_DDR_LE
529 Defines the DDR controller register space as Little Endian
531 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
532 Physical address from the view of DDR controllers. It is the
533 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
534 it could be different for ARM SoCs.
536 CONFIG_SYS_FSL_DDR_INTLV_256B
537 DDR controller interleaving on 256-byte. This is a special
538 interleaving mode, handled by Dickens for Freescale layerscape
541 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
542 Number of controllers used as main memory.
544 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
545 Number of controllers used for other than main memory.
547 CONFIG_SYS_FSL_SEC_BE
548 Defines the SEC controller register space as Big Endian
550 CONFIG_SYS_FSL_SEC_LE
551 Defines the SEC controller register space as Little Endian
553 - Intel Monahans options:
554 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
556 Defines the Monahans run mode to oscillator
557 ratio. Valid values are 8, 16, 24, 31. The core
558 frequency is this value multiplied by 13 MHz.
560 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
562 Defines the Monahans turbo mode to oscillator
563 ratio. Valid values are 1 (default if undefined) and
564 2. The core frequency as calculated above is multiplied
568 CONFIG_SYS_INIT_SP_OFFSET
570 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
571 pointer. This is needed for the temporary stack before
574 CONFIG_SYS_MIPS_CACHE_MODE
576 Cache operation mode for the MIPS CPU.
577 See also arch/mips/include/asm/mipsregs.h.
579 CONF_CM_CACHABLE_NO_WA
582 CONF_CM_CACHABLE_NONCOHERENT
586 CONF_CM_CACHABLE_ACCELERATED
588 CONFIG_SYS_XWAY_EBU_BOOTCFG
590 Special option for Lantiq XWAY SoCs for booting from NOR flash.
591 See also arch/mips/cpu/mips32/start.S.
593 CONFIG_XWAY_SWAP_BYTES
595 Enable compilation of tools/xway-swap-bytes needed for Lantiq
596 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
597 be swapped if a flash programmer is used.
600 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
602 Select high exception vectors of the ARM core, e.g., do not
603 clear the V bit of the c1 register of CP15.
605 CONFIG_SYS_THUMB_BUILD
607 Use this flag to build U-Boot using the Thumb instruction
608 set for ARM architectures. Thumb instruction set provides
609 better code density. For ARM architectures that support
610 Thumb2 this flag will result in Thumb2 code generated by
613 CONFIG_ARM_ERRATA_716044
614 CONFIG_ARM_ERRATA_742230
615 CONFIG_ARM_ERRATA_743622
616 CONFIG_ARM_ERRATA_751472
617 CONFIG_ARM_ERRATA_794072
618 CONFIG_ARM_ERRATA_761320
620 If set, the workarounds for these ARM errata are applied early
621 during U-Boot startup. Note that these options force the
622 workarounds to be applied; no CPU-type/version detection
623 exists, unlike the similar options in the Linux kernel. Do not
624 set these options unless they apply!
629 The frequency of the timer returned by get_timer().
630 get_timer() must operate in milliseconds and this CONFIG
631 option must be set to 1000.
633 - Linux Kernel Interface:
636 U-Boot stores all clock information in Hz
637 internally. For binary compatibility with older Linux
638 kernels (which expect the clocks passed in the
639 bd_info data to be in MHz) the environment variable
640 "clocks_in_mhz" can be defined so that U-Boot
641 converts clock data to MHZ before passing it to the
643 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
644 "clocks_in_mhz=1" is automatically included in the
647 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
649 When transferring memsize parameter to linux, some versions
650 expect it to be in bytes, others in MB.
651 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
655 New kernel versions are expecting firmware settings to be
656 passed using flattened device trees (based on open firmware
660 * New libfdt-based support
661 * Adds the "fdt" command
662 * The bootm command automatically updates the fdt
664 OF_CPU - The proper name of the cpus node (only required for
665 MPC512X and MPC5xxx based boards).
666 OF_SOC - The proper name of the soc node (only required for
667 MPC512X and MPC5xxx based boards).
668 OF_TBCLK - The timebase frequency.
669 OF_STDOUT_PATH - The path to the console device
671 boards with QUICC Engines require OF_QE to set UCC MAC
674 CONFIG_OF_BOARD_SETUP
676 Board code has addition modification that it wants to make
677 to the flat device tree before handing it off to the kernel
681 This define fills in the correct boot CPU in the boot
682 param header, the default value is zero if undefined.
686 U-Boot can detect if an IDE device is present or not.
687 If not, and this new config option is activated, U-Boot
688 removes the ATA node from the DTS before booting Linux,
689 so the Linux IDE driver does not probe the device and
690 crash. This is needed for buggy hardware (uc101) where
691 no pull down resistor is connected to the signal IDE5V_DD7.
693 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
695 This setting is mandatory for all boards that have only one
696 machine type and must be used to specify the machine type
697 number as it appears in the ARM machine registry
698 (see http://www.arm.linux.org.uk/developer/machines/).
699 Only boards that have multiple machine types supported
700 in a single configuration file and the machine type is
701 runtime discoverable, do not have to use this setting.
703 - vxWorks boot parameters:
705 bootvx constructs a valid bootline using the following
706 environments variables: bootfile, ipaddr, serverip, hostname.
707 It loads the vxWorks image pointed bootfile.
709 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
710 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
711 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
712 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
714 CONFIG_SYS_VXWORKS_ADD_PARAMS
716 Add it at the end of the bootline. E.g "u=username pw=secret"
718 Note: If a "bootargs" environment is defined, it will overwride
719 the defaults discussed just above.
721 - Cache Configuration:
722 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
723 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
724 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
726 - Cache Configuration for ARM:
727 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
729 CONFIG_SYS_PL310_BASE - Physical base address of PL310
730 controller register space
735 Define this if you want support for Amba PrimeCell PL010 UARTs.
739 Define this if you want support for Amba PrimeCell PL011 UARTs.
743 If you have Amba PrimeCell PL011 UARTs, set this variable to
744 the clock speed of the UARTs.
748 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
749 define this to a list of base addresses for each (supported)
750 port. See e.g. include/configs/versatile.h
752 CONFIG_PL011_SERIAL_RLCR
754 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
755 have separate receive and transmit line control registers. Set
756 this variable to initialize the extra register.
758 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
760 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
761 boot loader that has already initialized the UART. Define this
762 variable to flush the UART at init time.
764 CONFIG_SERIAL_HW_FLOW_CONTROL
766 Define this variable to enable hw flow control in serial driver.
767 Current user of this option is drivers/serial/nsl16550.c driver
770 Depending on board, define exactly one serial port
771 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
772 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
773 console by defining CONFIG_8xx_CONS_NONE
775 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
776 port routines must be defined elsewhere
777 (i.e. serial_init(), serial_getc(), ...)
780 Enables console device for a color framebuffer. Needs following
781 defines (cf. smiLynxEM, i8042)
782 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
784 VIDEO_HW_RECTFILL graphic chip supports
787 VIDEO_HW_BITBLT graphic chip supports
788 bit-blit (cf. smiLynxEM)
789 VIDEO_VISIBLE_COLS visible pixel columns
791 VIDEO_VISIBLE_ROWS visible pixel rows
792 VIDEO_PIXEL_SIZE bytes per pixel
793 VIDEO_DATA_FORMAT graphic data format
794 (0-5, cf. cfb_console.c)
795 VIDEO_FB_ADRS framebuffer address
796 VIDEO_KBD_INIT_FCT keyboard int fct
797 (i.e. i8042_kbd_init())
798 VIDEO_TSTC_FCT test char fct
800 VIDEO_GETC_FCT get char fct
802 CONFIG_CONSOLE_CURSOR cursor drawing on/off
803 (requires blink timer
805 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
806 CONFIG_CONSOLE_TIME display time/date info in
808 (requires CONFIG_CMD_DATE)
809 CONFIG_VIDEO_LOGO display Linux logo in
811 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
812 linux_logo.h for logo.
813 Requires CONFIG_VIDEO_LOGO
814 CONFIG_CONSOLE_EXTRA_INFO
815 additional board info beside
818 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
819 a limited number of ANSI escape sequences (cursor control,
820 erase functions and limited graphics rendition control).
822 When CONFIG_CFB_CONSOLE is defined, video console is
823 default i/o. Serial console can be forced with
824 environment 'console=serial'.
826 When CONFIG_SILENT_CONSOLE is defined, all console
827 messages (by U-Boot and Linux!) can be silenced with
828 the "silent" environment variable. See
829 doc/README.silent for more information.
831 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
833 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
837 CONFIG_BAUDRATE - in bps
838 Select one of the baudrates listed in
839 CONFIG_SYS_BAUDRATE_TABLE, see below.
840 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
842 - Console Rx buffer length
843 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
844 the maximum receive buffer length for the SMC.
845 This option is actual only for 82xx and 8xx possible.
846 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
847 must be defined, to setup the maximum idle timeout for
850 - Pre-Console Buffer:
851 Prior to the console being initialised (i.e. serial UART
852 initialised etc) all console output is silently discarded.
853 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
854 buffer any console messages prior to the console being
855 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
856 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
857 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
858 bytes are output before the console is initialised, the
859 earlier bytes are discarded.
861 'Sane' compilers will generate smaller code if
862 CONFIG_PRE_CON_BUF_SZ is a power of 2
864 - Safe printf() functions
865 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
866 the printf() functions. These are defined in
867 include/vsprintf.h and include snprintf(), vsnprintf() and
868 so on. Code size increase is approximately 300-500 bytes.
869 If this option is not given then these functions will
870 silently discard their buffer size argument - this means
871 you are not getting any overflow checking in this case.
873 - Boot Delay: CONFIG_BOOTDELAY - in seconds
874 Delay before automatically booting the default image;
875 set to -1 to disable autoboot.
876 set to -2 to autoboot with no delay and not check for abort
877 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
879 See doc/README.autoboot for these options that
880 work with CONFIG_BOOTDELAY. None are required.
881 CONFIG_BOOT_RETRY_TIME
882 CONFIG_BOOT_RETRY_MIN
883 CONFIG_AUTOBOOT_KEYED
884 CONFIG_AUTOBOOT_PROMPT
885 CONFIG_AUTOBOOT_DELAY_STR
886 CONFIG_AUTOBOOT_STOP_STR
887 CONFIG_AUTOBOOT_DELAY_STR2
888 CONFIG_AUTOBOOT_STOP_STR2
889 CONFIG_ZERO_BOOTDELAY_CHECK
890 CONFIG_RESET_TO_RETRY
894 Only needed when CONFIG_BOOTDELAY is enabled;
895 define a command string that is automatically executed
896 when no character is read on the console interface
897 within "Boot Delay" after reset.
900 This can be used to pass arguments to the bootm
901 command. The value of CONFIG_BOOTARGS goes into the
902 environment value "bootargs".
904 CONFIG_RAMBOOT and CONFIG_NFSBOOT
905 The value of these goes into the environment as
906 "ramboot" and "nfsboot" respectively, and can be used
907 as a convenience, when switching between booting from
911 CONFIG_BOOTCOUNT_LIMIT
912 Implements a mechanism for detecting a repeating reboot
914 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
917 If no softreset save registers are found on the hardware
918 "bootcount" is stored in the environment. To prevent a
919 saveenv on all reboots, the environment variable
920 "upgrade_available" is used. If "upgrade_available" is
921 0, "bootcount" is always 0, if "upgrade_available" is
922 1 "bootcount" is incremented in the environment.
923 So the Userspace Applikation must set the "upgrade_available"
924 and "bootcount" variable to 0, if a boot was successfully.
929 When this option is #defined, the existence of the
930 environment variable "preboot" will be checked
931 immediately before starting the CONFIG_BOOTDELAY
932 countdown and/or running the auto-boot command resp.
933 entering interactive mode.
935 This feature is especially useful when "preboot" is
936 automatically generated or modified. For an example
937 see the LWMON board specific code: here "preboot" is
938 modified when the user holds down a certain
939 combination of keys on the (special) keyboard when
942 - Serial Download Echo Mode:
944 If defined to 1, all characters received during a
945 serial download (using the "loads" command) are
946 echoed back. This might be needed by some terminal
947 emulations (like "cu"), but may as well just take
948 time on others. This setting #define's the initial
949 value of the "loads_echo" environment variable.
951 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
953 Select one of the baudrates listed in
954 CONFIG_SYS_BAUDRATE_TABLE, see below.
957 Monitor commands can be included or excluded
958 from the build by using the #include files
959 <config_cmd_all.h> and #undef'ing unwanted
960 commands, or using <config_cmd_default.h>
961 and augmenting with additional #define's
964 The default command configuration includes all commands
965 except those marked below with a "*".
967 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
968 CONFIG_CMD_ASKENV * ask for env variable
969 CONFIG_CMD_BDI bdinfo
970 CONFIG_CMD_BEDBUG * Include BedBug Debugger
971 CONFIG_CMD_BMP * BMP support
972 CONFIG_CMD_BSP * Board specific commands
973 CONFIG_CMD_BOOTD bootd
974 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
975 CONFIG_CMD_CACHE * icache, dcache
976 CONFIG_CMD_CLK * clock command support
977 CONFIG_CMD_CONSOLE coninfo
978 CONFIG_CMD_CRC32 * crc32
979 CONFIG_CMD_DATE * support for RTC, date/time...
980 CONFIG_CMD_DHCP * DHCP support
981 CONFIG_CMD_DIAG * Diagnostics
982 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
983 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
984 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
985 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
986 CONFIG_CMD_DTT * Digital Therm and Thermostat
987 CONFIG_CMD_ECHO echo arguments
988 CONFIG_CMD_EDITENV edit env variable
989 CONFIG_CMD_EEPROM * EEPROM read/write support
990 CONFIG_CMD_ELF * bootelf, bootvx
991 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
992 CONFIG_CMD_ENV_FLAGS * display details about env flags
993 CONFIG_CMD_ENV_EXISTS * check existence of env variable
994 CONFIG_CMD_EXPORTENV * export the environment
995 CONFIG_CMD_EXT2 * ext2 command support
996 CONFIG_CMD_EXT4 * ext4 command support
997 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
998 that work for multiple fs types
999 CONFIG_CMD_SAVEENV saveenv
1000 CONFIG_CMD_FDC * Floppy Disk Support
1001 CONFIG_CMD_FAT * FAT command support
1002 CONFIG_CMD_FLASH flinfo, erase, protect
1003 CONFIG_CMD_FPGA FPGA device initialization support
1004 CONFIG_CMD_FUSE * Device fuse support
1005 CONFIG_CMD_GETTIME * Get time since boot
1006 CONFIG_CMD_GO * the 'go' command (exec code)
1007 CONFIG_CMD_GREPENV * search environment
1008 CONFIG_CMD_HASH * calculate hash / digest
1009 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1010 CONFIG_CMD_I2C * I2C serial bus support
1011 CONFIG_CMD_IDE * IDE harddisk support
1012 CONFIG_CMD_IMI iminfo
1013 CONFIG_CMD_IMLS List all images found in NOR flash
1014 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1015 CONFIG_CMD_IMMAP * IMMR dump support
1016 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1017 CONFIG_CMD_IMPORTENV * import an environment
1018 CONFIG_CMD_INI * import data from an ini file into the env
1019 CONFIG_CMD_IRQ * irqinfo
1020 CONFIG_CMD_ITEST Integer/string test of 2 values
1021 CONFIG_CMD_JFFS2 * JFFS2 Support
1022 CONFIG_CMD_KGDB * kgdb
1023 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1024 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1026 CONFIG_CMD_LOADB loadb
1027 CONFIG_CMD_LOADS loads
1028 CONFIG_CMD_MD5SUM * print md5 message digest
1029 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1030 CONFIG_CMD_MEMINFO * Display detailed memory information
1031 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1033 CONFIG_CMD_MEMTEST * mtest
1034 CONFIG_CMD_MISC Misc functions like sleep etc
1035 CONFIG_CMD_MMC * MMC memory mapped support
1036 CONFIG_CMD_MII * MII utility commands
1037 CONFIG_CMD_MTDPARTS * MTD partition support
1038 CONFIG_CMD_NAND * NAND support
1039 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1040 CONFIG_CMD_NFS NFS support
1041 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1042 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1043 CONFIG_CMD_PCI * pciinfo
1044 CONFIG_CMD_PCMCIA * PCMCIA support
1045 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1047 CONFIG_CMD_PORTIO * Port I/O
1048 CONFIG_CMD_READ * Read raw data from partition
1049 CONFIG_CMD_REGINFO * Register dump
1050 CONFIG_CMD_RUN run command in env variable
1051 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1052 CONFIG_CMD_SAVES * save S record dump
1053 CONFIG_CMD_SCSI * SCSI Support
1054 CONFIG_CMD_SDRAM * print SDRAM configuration information
1055 (requires CONFIG_CMD_I2C)
1056 CONFIG_CMD_SETGETDCR Support for DCR Register access
1058 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1059 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1060 (requires CONFIG_CMD_MEMORY)
1061 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1062 CONFIG_CMD_SOURCE "source" command Support
1063 CONFIG_CMD_SPI * SPI serial bus support
1064 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1065 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1066 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1067 CONFIG_CMD_TIMER * access to the system tick timer
1068 CONFIG_CMD_USB * USB support
1069 CONFIG_CMD_CDP * Cisco Discover Protocol support
1070 CONFIG_CMD_MFSL * Microblaze FSL support
1071 CONFIG_CMD_XIMG Load part of Multi Image
1072 CONFIG_CMD_UUID * Generate random UUID or GUID string
1074 EXAMPLE: If you want all functions except of network
1075 support you can write:
1077 #include "config_cmd_all.h"
1078 #undef CONFIG_CMD_NET
1081 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1083 Note: Don't enable the "icache" and "dcache" commands
1084 (configuration option CONFIG_CMD_CACHE) unless you know
1085 what you (and your U-Boot users) are doing. Data
1086 cache cannot be enabled on systems like the 8xx or
1087 8260 (where accesses to the IMMR region must be
1088 uncached), and it cannot be disabled on all other
1089 systems where we (mis-) use the data cache to hold an
1090 initial stack and some data.
1093 XXX - this list needs to get updated!
1095 - Regular expression support:
1097 If this variable is defined, U-Boot is linked against
1098 the SLRE (Super Light Regular Expression) library,
1099 which adds regex support to some commands, as for
1100 example "env grep" and "setexpr".
1104 If this variable is defined, U-Boot will use a device tree
1105 to configure its devices, instead of relying on statically
1106 compiled #defines in the board file. This option is
1107 experimental and only available on a few boards. The device
1108 tree is available in the global data as gd->fdt_blob.
1110 U-Boot needs to get its device tree from somewhere. This can
1111 be done using one of the two options below:
1114 If this variable is defined, U-Boot will embed a device tree
1115 binary in its image. This device tree file should be in the
1116 board directory and called <soc>-<board>.dts. The binary file
1117 is then picked up in board_init_f() and made available through
1118 the global data structure as gd->blob.
1121 If this variable is defined, U-Boot will build a device tree
1122 binary. It will be called u-boot.dtb. Architecture-specific
1123 code will locate it at run-time. Generally this works by:
1125 cat u-boot.bin u-boot.dtb >image.bin
1127 and in fact, U-Boot does this for you, creating a file called
1128 u-boot-dtb.bin which is useful in the common case. You can
1129 still use the individual files if you need something more
1134 If this variable is defined, it enables watchdog
1135 support for the SoC. There must be support in the SoC
1136 specific code for a watchdog. For the 8xx and 8260
1137 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1138 register. When supported for a specific SoC is
1139 available, then no further board specific code should
1140 be needed to use it.
1143 When using a watchdog circuitry external to the used
1144 SoC, then define this variable and provide board
1145 specific code for the "hw_watchdog_reset" function.
1148 CONFIG_VERSION_VARIABLE
1149 If this variable is defined, an environment variable
1150 named "ver" is created by U-Boot showing the U-Boot
1151 version as printed by the "version" command.
1152 Any change to this variable will be reverted at the
1157 When CONFIG_CMD_DATE is selected, the type of the RTC
1158 has to be selected, too. Define exactly one of the
1161 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1162 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1163 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1164 CONFIG_RTC_MC146818 - use MC146818 RTC
1165 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1166 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1167 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1168 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1169 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1170 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1171 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1172 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1173 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1176 Note that if the RTC uses I2C, then the I2C interface
1177 must also be configured. See I2C Support, below.
1180 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1182 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1183 chip-ngpio pairs that tell the PCA953X driver the number of
1184 pins supported by a particular chip.
1186 Note that if the GPIO device uses I2C, then the I2C interface
1187 must also be configured. See I2C Support, below.
1190 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1191 accesses and can checksum them or write a list of them out
1192 to memory. See the 'iotrace' command for details. This is
1193 useful for testing device drivers since it can confirm that
1194 the driver behaves the same way before and after a code
1195 change. Currently this is supported on sandbox and arm. To
1196 add support for your architecture, add '#include <iotrace.h>'
1197 to the bottom of arch/<arch>/include/asm/io.h and test.
1199 Example output from the 'iotrace stats' command is below.
1200 Note that if the trace buffer is exhausted, the checksum will
1201 still continue to operate.
1204 Start: 10000000 (buffer start address)
1205 Size: 00010000 (buffer size)
1206 Offset: 00000120 (current buffer offset)
1207 Output: 10000120 (start + offset)
1208 Count: 00000018 (number of trace records)
1209 CRC32: 9526fb66 (CRC32 of all trace records)
1211 - Timestamp Support:
1213 When CONFIG_TIMESTAMP is selected, the timestamp
1214 (date and time) of an image is printed by image
1215 commands like bootm or iminfo. This option is
1216 automatically enabled when you select CONFIG_CMD_DATE .
1218 - Partition Labels (disklabels) Supported:
1219 Zero or more of the following:
1220 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1221 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1222 Intel architecture, USB sticks, etc.
1223 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1224 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1225 bootloader. Note 2TB partition limit; see
1227 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1229 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1230 CONFIG_CMD_SCSI) you must configure support for at
1231 least one non-MTD partition type as well.
1234 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1235 board configurations files but used nowhere!
1237 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1238 be performed by calling the function
1239 ide_set_reset(int reset)
1240 which has to be defined in a board specific file
1245 Set this to enable ATAPI support.
1250 Set this to enable support for disks larger than 137GB
1251 Also look at CONFIG_SYS_64BIT_LBA.
1252 Whithout these , LBA48 support uses 32bit variables and will 'only'
1253 support disks up to 2.1TB.
1255 CONFIG_SYS_64BIT_LBA:
1256 When enabled, makes the IDE subsystem use 64bit sector addresses.
1260 At the moment only there is only support for the
1261 SYM53C8XX SCSI controller; define
1262 CONFIG_SCSI_SYM53C8XX to enable it.
1264 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1265 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1266 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1267 maximum numbers of LUNs, SCSI ID's and target
1269 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1271 The environment variable 'scsidevs' is set to the number of
1272 SCSI devices found during the last scan.
1274 - NETWORK Support (PCI):
1276 Support for Intel 8254x/8257x gigabit chips.
1279 Utility code for direct access to the SPI bus on Intel 8257x.
1280 This does not do anything useful unless you set at least one
1281 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1283 CONFIG_E1000_SPI_GENERIC
1284 Allow generic access to the SPI bus on the Intel 8257x, for
1285 example with the "sspi" command.
1288 Management command for E1000 devices. When used on devices
1289 with SPI support you can reprogram the EEPROM from U-Boot.
1291 CONFIG_E1000_FALLBACK_MAC
1292 default MAC for empty EEPROM after production.
1295 Support for Intel 82557/82559/82559ER chips.
1296 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1297 write routine for first time initialisation.
1300 Support for Digital 2114x chips.
1301 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1302 modem chip initialisation (KS8761/QS6611).
1305 Support for National dp83815 chips.
1308 Support for National dp8382[01] gigabit chips.
1310 - NETWORK Support (other):
1312 CONFIG_DRIVER_AT91EMAC
1313 Support for AT91RM9200 EMAC.
1316 Define this to use reduced MII inteface
1318 CONFIG_DRIVER_AT91EMAC_QUIET
1319 If this defined, the driver is quiet.
1320 The driver doen't show link status messages.
1322 CONFIG_CALXEDA_XGMAC
1323 Support for the Calxeda XGMAC device
1326 Support for SMSC's LAN91C96 chips.
1328 CONFIG_LAN91C96_BASE
1329 Define this to hold the physical address
1330 of the LAN91C96's I/O space
1332 CONFIG_LAN91C96_USE_32_BIT
1333 Define this to enable 32 bit addressing
1336 Support for SMSC's LAN91C111 chip
1338 CONFIG_SMC91111_BASE
1339 Define this to hold the physical address
1340 of the device (I/O space)
1342 CONFIG_SMC_USE_32_BIT
1343 Define this if data bus is 32 bits
1345 CONFIG_SMC_USE_IOFUNCS
1346 Define this to use i/o functions instead of macros
1347 (some hardware wont work with macros)
1349 CONFIG_DRIVER_TI_EMAC
1350 Support for davinci emac
1352 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1353 Define this if you have more then 3 PHYs.
1356 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1358 CONFIG_FTGMAC100_EGIGA
1359 Define this to use GE link update with gigabit PHY.
1360 Define this if FTGMAC100 is connected to gigabit PHY.
1361 If your system has 10/100 PHY only, it might not occur
1362 wrong behavior. Because PHY usually return timeout or
1363 useless data when polling gigabit status and gigabit
1364 control registers. This behavior won't affect the
1365 correctnessof 10/100 link speed update.
1368 Support for SMSC's LAN911x and LAN921x chips
1371 Define this to hold the physical address
1372 of the device (I/O space)
1374 CONFIG_SMC911X_32_BIT
1375 Define this if data bus is 32 bits
1377 CONFIG_SMC911X_16_BIT
1378 Define this if data bus is 16 bits. If your processor
1379 automatically converts one 32 bit word to two 16 bit
1380 words you may also try CONFIG_SMC911X_32_BIT.
1383 Support for Renesas on-chip Ethernet controller
1385 CONFIG_SH_ETHER_USE_PORT
1386 Define the number of ports to be used
1388 CONFIG_SH_ETHER_PHY_ADDR
1389 Define the ETH PHY's address
1391 CONFIG_SH_ETHER_CACHE_WRITEBACK
1392 If this option is set, the driver enables cache flush.
1396 Support for PWM modul on the imx6.
1400 Support TPM devices.
1403 Support for i2c bus TPM devices. Only one device
1404 per system is supported at this time.
1406 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1407 Define the the i2c bus number for the TPM device
1409 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1410 Define the TPM's address on the i2c bus
1412 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1413 Define the burst count bytes upper limit
1415 CONFIG_TPM_ATMEL_TWI
1416 Support for Atmel TWI TPM device. Requires I2C support.
1419 Support for generic parallel port TPM devices. Only one device
1420 per system is supported at this time.
1422 CONFIG_TPM_TIS_BASE_ADDRESS
1423 Base address where the generic TPM device is mapped
1424 to. Contemporary x86 systems usually map it at
1428 Add tpm monitor functions.
1429 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1430 provides monitor access to authorized functions.
1433 Define this to enable the TPM support library which provides
1434 functional interfaces to some TPM commands.
1435 Requires support for a TPM device.
1437 CONFIG_TPM_AUTH_SESSIONS
1438 Define this to enable authorized functions in the TPM library.
1439 Requires CONFIG_TPM and CONFIG_SHA1.
1442 At the moment only the UHCI host controller is
1443 supported (PIP405, MIP405, MPC5200); define
1444 CONFIG_USB_UHCI to enable it.
1445 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1446 and define CONFIG_USB_STORAGE to enable the USB
1449 Supported are USB Keyboards and USB Floppy drives
1451 MPC5200 USB requires additional defines:
1453 for 528 MHz Clock: 0x0001bbbb
1457 for differential drivers: 0x00001000
1458 for single ended drivers: 0x00005000
1459 for differential drivers on PSC3: 0x00000100
1460 for single ended drivers on PSC3: 0x00004100
1461 CONFIG_SYS_USB_EVENT_POLL
1462 May be defined to allow interrupt polling
1463 instead of using asynchronous interrupts
1465 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1466 txfilltuning field in the EHCI controller on reset.
1468 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1469 HW module registers.
1472 Define the below if you wish to use the USB console.
1473 Once firmware is rebuilt from a serial console issue the
1474 command "setenv stdin usbtty; setenv stdout usbtty" and
1475 attach your USB cable. The Unix command "dmesg" should print
1476 it has found a new device. The environment variable usbtty
1477 can be set to gserial or cdc_acm to enable your device to
1478 appear to a USB host as a Linux gserial device or a
1479 Common Device Class Abstract Control Model serial device.
1480 If you select usbtty = gserial you should be able to enumerate
1482 # modprobe usbserial vendor=0xVendorID product=0xProductID
1483 else if using cdc_acm, simply setting the environment
1484 variable usbtty to be cdc_acm should suffice. The following
1485 might be defined in YourBoardName.h
1488 Define this to build a UDC device
1491 Define this to have a tty type of device available to
1492 talk to the UDC device
1495 Define this to enable the high speed support for usb
1496 device and usbtty. If this feature is enabled, a routine
1497 int is_usbd_high_speed(void)
1498 also needs to be defined by the driver to dynamically poll
1499 whether the enumeration has succeded at high speed or full
1502 CONFIG_SYS_CONSOLE_IS_IN_ENV
1503 Define this if you want stdin, stdout &/or stderr to
1507 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1508 Derive USB clock from external clock "blah"
1509 - CONFIG_SYS_USB_EXTC_CLK 0x02
1511 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1512 Derive USB clock from brgclk
1513 - CONFIG_SYS_USB_BRG_CLK 0x04
1515 If you have a USB-IF assigned VendorID then you may wish to
1516 define your own vendor specific values either in BoardName.h
1517 or directly in usbd_vendor_info.h. If you don't define
1518 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1519 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1520 should pretend to be a Linux device to it's target host.
1522 CONFIG_USBD_MANUFACTURER
1523 Define this string as the name of your company for
1524 - CONFIG_USBD_MANUFACTURER "my company"
1526 CONFIG_USBD_PRODUCT_NAME
1527 Define this string as the name of your product
1528 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1530 CONFIG_USBD_VENDORID
1531 Define this as your assigned Vendor ID from the USB
1532 Implementors Forum. This *must* be a genuine Vendor ID
1533 to avoid polluting the USB namespace.
1534 - CONFIG_USBD_VENDORID 0xFFFF
1536 CONFIG_USBD_PRODUCTID
1537 Define this as the unique Product ID
1539 - CONFIG_USBD_PRODUCTID 0xFFFF
1541 - ULPI Layer Support:
1542 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1543 the generic ULPI layer. The generic layer accesses the ULPI PHY
1544 via the platform viewport, so you need both the genric layer and
1545 the viewport enabled. Currently only Chipidea/ARC based
1546 viewport is supported.
1547 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1548 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1549 If your ULPI phy needs a different reference clock than the
1550 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1551 the appropriate value in Hz.
1554 The MMC controller on the Intel PXA is supported. To
1555 enable this define CONFIG_MMC. The MMC can be
1556 accessed from the boot prompt by mapping the device
1557 to physical memory similar to flash. Command line is
1558 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1559 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1562 Support for Renesas on-chip MMCIF controller
1564 CONFIG_SH_MMCIF_ADDR
1565 Define the base address of MMCIF registers
1568 Define the clock frequency for MMCIF
1571 Enable the generic MMC driver
1573 CONFIG_SUPPORT_EMMC_BOOT
1574 Enable some additional features of the eMMC boot partitions.
1576 CONFIG_SUPPORT_EMMC_RPMB
1577 Enable the commands for reading, writing and programming the
1578 key for the Replay Protection Memory Block partition in eMMC.
1580 - USB Device Firmware Update (DFU) class support:
1582 This enables the USB portion of the DFU USB class
1585 This enables the command "dfu" which is used to have
1586 U-Boot create a DFU class device via USB. This command
1587 requires that the "dfu_alt_info" environment variable be
1588 set and define the alt settings to expose to the host.
1591 This enables support for exposing (e)MMC devices via DFU.
1594 This enables support for exposing NAND devices via DFU.
1597 This enables support for exposing RAM via DFU.
1598 Note: DFU spec refer to non-volatile memory usage, but
1599 allow usages beyond the scope of spec - here RAM usage,
1600 one that would help mostly the developer.
1602 CONFIG_SYS_DFU_DATA_BUF_SIZE
1603 Dfu transfer uses a buffer before writing data to the
1604 raw storage device. Make the size (in bytes) of this buffer
1605 configurable. The size of this buffer is also configurable
1606 through the "dfu_bufsiz" environment variable.
1608 CONFIG_SYS_DFU_MAX_FILE_SIZE
1609 When updating files rather than the raw storage device,
1610 we use a static buffer to copy the file into and then write
1611 the buffer once we've been given the whole file. Define
1612 this to the maximum filesize (in bytes) for the buffer.
1613 Default is 4 MiB if undefined.
1615 DFU_DEFAULT_POLL_TIMEOUT
1616 Poll timeout [ms], is the timeout a device can send to the
1617 host. The host must wait for this timeout before sending
1618 a subsequent DFU_GET_STATUS request to the device.
1620 DFU_MANIFEST_POLL_TIMEOUT
1621 Poll timeout [ms], which the device sends to the host when
1622 entering dfuMANIFEST state. Host waits this timeout, before
1623 sending again an USB request to the device.
1625 - USB Device Android Fastboot support:
1627 This enables the command "fastboot" which enables the Android
1628 fastboot mode for the platform's USB device. Fastboot is a USB
1629 protocol for downloading images, flashing and device control
1630 used on Android devices.
1631 See doc/README.android-fastboot for more information.
1633 CONFIG_ANDROID_BOOT_IMAGE
1634 This enables support for booting images which use the Android
1635 image format header.
1637 CONFIG_USB_FASTBOOT_BUF_ADDR
1638 The fastboot protocol requires a large memory buffer for
1639 downloads. Define this to the starting RAM address to use for
1642 CONFIG_USB_FASTBOOT_BUF_SIZE
1643 The fastboot protocol requires a large memory buffer for
1644 downloads. This buffer should be as large as possible for a
1645 platform. Define this to the size available RAM for fastboot.
1647 CONFIG_FASTBOOT_FLASH
1648 The fastboot protocol includes a "flash" command for writing
1649 the downloaded image to a non-volatile storage device. Define
1650 this to enable the "fastboot flash" command.
1652 CONFIG_FASTBOOT_FLASH_MMC_DEV
1653 The fastboot "flash" command requires additional information
1654 regarding the non-volatile storage device. Define this to
1655 the eMMC device that fastboot should use to store the image.
1657 - Journaling Flash filesystem support:
1658 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1659 CONFIG_JFFS2_NAND_DEV
1660 Define these for a default partition on a NAND device
1662 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1663 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1664 Define these for a default partition on a NOR device
1666 CONFIG_SYS_JFFS_CUSTOM_PART
1667 Define this to create an own partition. You have to provide a
1668 function struct part_info* jffs2_part_info(int part_num)
1670 If you define only one JFFS2 partition you may also want to
1671 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1672 to disable the command chpart. This is the default when you
1673 have not defined a custom partition
1675 - FAT(File Allocation Table) filesystem write function support:
1678 Define this to enable support for saving memory data as a
1679 file in FAT formatted partition.
1681 This will also enable the command "fatwrite" enabling the
1682 user to write files to FAT.
1684 CBFS (Coreboot Filesystem) support
1687 Define this to enable support for reading from a Coreboot
1688 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1691 - FAT(File Allocation Table) filesystem cluster size:
1692 CONFIG_FS_FAT_MAX_CLUSTSIZE
1694 Define the max cluster size for fat operations else
1695 a default value of 65536 will be defined.
1700 Define this to enable standard (PC-Style) keyboard
1704 Standard PC keyboard driver with US (is default) and
1705 GERMAN key layout (switch via environment 'keymap=de') support.
1706 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1707 for cfb_console. Supports cursor blinking.
1710 Enables a Chrome OS keyboard using the CROS_EC interface.
1711 This uses CROS_EC to communicate with a second microcontroller
1712 which provides key scans on request.
1717 Define this to enable video support (for output to
1720 CONFIG_VIDEO_CT69000
1722 Enable Chips & Technologies 69000 Video chip
1724 CONFIG_VIDEO_SMI_LYNXEM
1725 Enable Silicon Motion SMI 712/710/810 Video chip. The
1726 video output is selected via environment 'videoout'
1727 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1730 For the CT69000 and SMI_LYNXEM drivers, videomode is
1731 selected via environment 'videomode'. Two different ways
1733 - "videomode=num" 'num' is a standard LiLo mode numbers.
1734 Following standard modes are supported (* is default):
1736 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1737 -------------+---------------------------------------------
1738 8 bits | 0x301* 0x303 0x305 0x161 0x307
1739 15 bits | 0x310 0x313 0x316 0x162 0x319
1740 16 bits | 0x311 0x314 0x317 0x163 0x31A
1741 24 bits | 0x312 0x315 0x318 ? 0x31B
1742 -------------+---------------------------------------------
1743 (i.e. setenv videomode 317; saveenv; reset;)
1745 - "videomode=bootargs" all the video parameters are parsed
1746 from the bootargs. (See drivers/video/videomodes.c)
1749 CONFIG_VIDEO_SED13806
1750 Enable Epson SED13806 driver. This driver supports 8bpp
1751 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1752 or CONFIG_VIDEO_SED13806_16BPP
1755 Enable the Freescale DIU video driver. Reference boards for
1756 SOCs that have a DIU should define this macro to enable DIU
1757 support, and should also define these other macros:
1763 CONFIG_VIDEO_SW_CURSOR
1764 CONFIG_VGA_AS_SINGLE_DEVICE
1766 CONFIG_VIDEO_BMP_LOGO
1768 The DIU driver will look for the 'video-mode' environment
1769 variable, and if defined, enable the DIU as a console during
1770 boot. See the documentation file README.video for a
1771 description of this variable.
1775 Enable the VGA video / BIOS for x86. The alternative if you
1776 are using coreboot is to use the coreboot frame buffer
1783 Define this to enable a custom keyboard support.
1784 This simply calls drv_keyboard_init() which must be
1785 defined in your board-specific files.
1786 The only board using this so far is RBC823.
1788 - LCD Support: CONFIG_LCD
1790 Define this to enable LCD support (for output to LCD
1791 display); also select one of the supported displays
1792 by defining one of these:
1796 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1798 CONFIG_NEC_NL6448AC33:
1800 NEC NL6448AC33-18. Active, color, single scan.
1802 CONFIG_NEC_NL6448BC20
1804 NEC NL6448BC20-08. 6.5", 640x480.
1805 Active, color, single scan.
1807 CONFIG_NEC_NL6448BC33_54
1809 NEC NL6448BC33-54. 10.4", 640x480.
1810 Active, color, single scan.
1814 Sharp 320x240. Active, color, single scan.
1815 It isn't 16x9, and I am not sure what it is.
1817 CONFIG_SHARP_LQ64D341
1819 Sharp LQ64D341 display, 640x480.
1820 Active, color, single scan.
1824 HLD1045 display, 640x480.
1825 Active, color, single scan.
1829 Optrex CBL50840-2 NF-FW 99 22 M5
1831 Hitachi LMG6912RPFC-00T
1835 320x240. Black & white.
1837 Normally display is black on white background; define
1838 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1840 CONFIG_LCD_ALIGNMENT
1842 Normally the LCD is page-aligned (tyically 4KB). If this is
1843 defined then the LCD will be aligned to this value instead.
1844 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1845 here, since it is cheaper to change data cache settings on
1846 a per-section basis.
1848 CONFIG_CONSOLE_SCROLL_LINES
1850 When the console need to be scrolled, this is the number of
1851 lines to scroll by. It defaults to 1. Increasing this makes
1852 the console jump but can help speed up operation when scrolling
1857 Support drawing of RLE8-compressed bitmaps on the LCD.
1861 Enables an 'i2c edid' command which can read EDID
1862 information over I2C from an attached LCD display.
1864 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1866 If this option is set, the environment is checked for
1867 a variable "splashimage". If found, the usual display
1868 of logo, copyright and system information on the LCD
1869 is suppressed and the BMP image at the address
1870 specified in "splashimage" is loaded instead. The
1871 console is redirected to the "nulldev", too. This
1872 allows for a "silent" boot where a splash screen is
1873 loaded very quickly after power-on.
1875 CONFIG_SPLASHIMAGE_GUARD
1877 If this option is set, then U-Boot will prevent the environment
1878 variable "splashimage" from being set to a problematic address
1879 (see README.displaying-bmps).
1880 This option is useful for targets where, due to alignment
1881 restrictions, an improperly aligned BMP image will cause a data
1882 abort. If you think you will not have problems with unaligned
1883 accesses (for example because your toolchain prevents them)
1884 there is no need to set this option.
1886 CONFIG_SPLASH_SCREEN_ALIGN
1888 If this option is set the splash image can be freely positioned
1889 on the screen. Environment variable "splashpos" specifies the
1890 position as "x,y". If a positive number is given it is used as
1891 number of pixel from left/top. If a negative number is given it
1892 is used as number of pixel from right/bottom. You can also
1893 specify 'm' for centering the image.
1896 setenv splashpos m,m
1897 => image at center of screen
1899 setenv splashpos 30,20
1900 => image at x = 30 and y = 20
1902 setenv splashpos -10,m
1903 => vertically centered image
1904 at x = dspWidth - bmpWidth - 9
1906 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1908 If this option is set, additionally to standard BMP
1909 images, gzipped BMP images can be displayed via the
1910 splashscreen support or the bmp command.
1912 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1914 If this option is set, 8-bit RLE compressed BMP images
1915 can be displayed via the splashscreen support or the
1918 - Do compresssing for memory range:
1921 If this option is set, it would use zlib deflate method
1922 to compress the specified memory at its best effort.
1924 - Compression support:
1927 Enabled by default to support gzip compressed images.
1931 If this option is set, support for bzip2 compressed
1932 images is included. If not, only uncompressed and gzip
1933 compressed images are supported.
1935 NOTE: the bzip2 algorithm requires a lot of RAM, so
1936 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1941 If this option is set, support for lzma compressed
1944 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1945 requires an amount of dynamic memory that is given by the
1948 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1950 Where lc and lp stand for, respectively, Literal context bits
1951 and Literal pos bits.
1953 This value is upper-bounded by 14MB in the worst case. Anyway,
1954 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1955 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1956 a very small buffer.
1958 Use the lzmainfo tool to determinate the lc and lp values and
1959 then calculate the amount of needed dynamic memory (ensuring
1960 the appropriate CONFIG_SYS_MALLOC_LEN value).
1964 If this option is set, support for LZO compressed images
1970 The address of PHY on MII bus.
1972 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1974 The clock frequency of the MII bus
1978 If this option is set, support for speed/duplex
1979 detection of gigabit PHY is included.
1981 CONFIG_PHY_RESET_DELAY
1983 Some PHY like Intel LXT971A need extra delay after
1984 reset before any MII register access is possible.
1985 For such PHY, set this option to the usec delay
1986 required. (minimum 300usec for LXT971A)
1988 CONFIG_PHY_CMD_DELAY (ppc4xx)
1990 Some PHY like Intel LXT971A need extra delay after
1991 command issued before MII status register can be read
2001 Define a default value for Ethernet address to use
2002 for the respective Ethernet interface, in case this
2003 is not determined automatically.
2008 Define a default value for the IP address to use for
2009 the default Ethernet interface, in case this is not
2010 determined through e.g. bootp.
2011 (Environment variable "ipaddr")
2013 - Server IP address:
2016 Defines a default value for the IP address of a TFTP
2017 server to contact when using the "tftboot" command.
2018 (Environment variable "serverip")
2020 CONFIG_KEEP_SERVERADDR
2022 Keeps the server's MAC address, in the env 'serveraddr'
2023 for passing to bootargs (like Linux's netconsole option)
2025 - Gateway IP address:
2028 Defines a default value for the IP address of the
2029 default router where packets to other networks are
2031 (Environment variable "gatewayip")
2036 Defines a default value for the subnet mask (or
2037 routing prefix) which is used to determine if an IP
2038 address belongs to the local subnet or needs to be
2039 forwarded through a router.
2040 (Environment variable "netmask")
2042 - Multicast TFTP Mode:
2045 Defines whether you want to support multicast TFTP as per
2046 rfc-2090; for example to work with atftp. Lets lots of targets
2047 tftp down the same boot image concurrently. Note: the Ethernet
2048 driver in use must provide a function: mcast() to join/leave a
2051 - BOOTP Recovery Mode:
2052 CONFIG_BOOTP_RANDOM_DELAY
2054 If you have many targets in a network that try to
2055 boot using BOOTP, you may want to avoid that all
2056 systems send out BOOTP requests at precisely the same
2057 moment (which would happen for instance at recovery
2058 from a power failure, when all systems will try to
2059 boot, thus flooding the BOOTP server. Defining
2060 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2061 inserted before sending out BOOTP requests. The
2062 following delays are inserted then:
2064 1st BOOTP request: delay 0 ... 1 sec
2065 2nd BOOTP request: delay 0 ... 2 sec
2066 3rd BOOTP request: delay 0 ... 4 sec
2068 BOOTP requests: delay 0 ... 8 sec
2070 CONFIG_BOOTP_ID_CACHE_SIZE
2072 BOOTP packets are uniquely identified using a 32-bit ID. The
2073 server will copy the ID from client requests to responses and
2074 U-Boot will use this to determine if it is the destination of
2075 an incoming response. Some servers will check that addresses
2076 aren't in use before handing them out (usually using an ARP
2077 ping) and therefore take up to a few hundred milliseconds to
2078 respond. Network congestion may also influence the time it
2079 takes for a response to make it back to the client. If that
2080 time is too long, U-Boot will retransmit requests. In order
2081 to allow earlier responses to still be accepted after these
2082 retransmissions, U-Boot's BOOTP client keeps a small cache of
2083 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2084 cache. The default is to keep IDs for up to four outstanding
2085 requests. Increasing this will allow U-Boot to accept offers
2086 from a BOOTP client in networks with unusually high latency.
2088 - DHCP Advanced Options:
2089 You can fine tune the DHCP functionality by defining
2090 CONFIG_BOOTP_* symbols:
2092 CONFIG_BOOTP_SUBNETMASK
2093 CONFIG_BOOTP_GATEWAY
2094 CONFIG_BOOTP_HOSTNAME
2095 CONFIG_BOOTP_NISDOMAIN
2096 CONFIG_BOOTP_BOOTPATH
2097 CONFIG_BOOTP_BOOTFILESIZE
2100 CONFIG_BOOTP_SEND_HOSTNAME
2101 CONFIG_BOOTP_NTPSERVER
2102 CONFIG_BOOTP_TIMEOFFSET
2103 CONFIG_BOOTP_VENDOREX
2104 CONFIG_BOOTP_MAY_FAIL
2106 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2107 environment variable, not the BOOTP server.
2109 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2110 after the configured retry count, the call will fail
2111 instead of starting over. This can be used to fail over
2112 to Link-local IP address configuration if the DHCP server
2115 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2116 serverip from a DHCP server, it is possible that more
2117 than one DNS serverip is offered to the client.
2118 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2119 serverip will be stored in the additional environment
2120 variable "dnsip2". The first DNS serverip is always
2121 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2124 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2125 to do a dynamic update of a DNS server. To do this, they
2126 need the hostname of the DHCP requester.
2127 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2128 of the "hostname" environment variable is passed as
2129 option 12 to the DHCP server.
2131 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2133 A 32bit value in microseconds for a delay between
2134 receiving a "DHCP Offer" and sending the "DHCP Request".
2135 This fixes a problem with certain DHCP servers that don't
2136 respond 100% of the time to a "DHCP request". E.g. On an
2137 AT91RM9200 processor running at 180MHz, this delay needed
2138 to be *at least* 15,000 usec before a Windows Server 2003
2139 DHCP server would reply 100% of the time. I recommend at
2140 least 50,000 usec to be safe. The alternative is to hope
2141 that one of the retries will be successful but note that
2142 the DHCP timeout and retry process takes a longer than
2145 - Link-local IP address negotiation:
2146 Negotiate with other link-local clients on the local network
2147 for an address that doesn't require explicit configuration.
2148 This is especially useful if a DHCP server cannot be guaranteed
2149 to exist in all environments that the device must operate.
2151 See doc/README.link-local for more information.
2154 CONFIG_CDP_DEVICE_ID
2156 The device id used in CDP trigger frames.
2158 CONFIG_CDP_DEVICE_ID_PREFIX
2160 A two character string which is prefixed to the MAC address
2165 A printf format string which contains the ascii name of
2166 the port. Normally is set to "eth%d" which sets
2167 eth0 for the first Ethernet, eth1 for the second etc.
2169 CONFIG_CDP_CAPABILITIES
2171 A 32bit integer which indicates the device capabilities;
2172 0x00000010 for a normal host which does not forwards.
2176 An ascii string containing the version of the software.
2180 An ascii string containing the name of the platform.
2184 A 32bit integer sent on the trigger.
2186 CONFIG_CDP_POWER_CONSUMPTION
2188 A 16bit integer containing the power consumption of the
2189 device in .1 of milliwatts.
2191 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2193 A byte containing the id of the VLAN.
2195 - Status LED: CONFIG_STATUS_LED
2197 Several configurations allow to display the current
2198 status using a LED. For instance, the LED will blink
2199 fast while running U-Boot code, stop blinking as
2200 soon as a reply to a BOOTP request was received, and
2201 start blinking slow once the Linux kernel is running
2202 (supported by a status LED driver in the Linux
2203 kernel). Defining CONFIG_STATUS_LED enables this
2209 The status LED can be connected to a GPIO pin.
2210 In such cases, the gpio_led driver can be used as a
2211 status LED backend implementation. Define CONFIG_GPIO_LED
2212 to include the gpio_led driver in the U-Boot binary.
2214 CONFIG_GPIO_LED_INVERTED_TABLE
2215 Some GPIO connected LEDs may have inverted polarity in which
2216 case the GPIO high value corresponds to LED off state and
2217 GPIO low value corresponds to LED on state.
2218 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2219 with a list of GPIO LEDs that have inverted polarity.
2221 - CAN Support: CONFIG_CAN_DRIVER
2223 Defining CONFIG_CAN_DRIVER enables CAN driver support
2224 on those systems that support this (optional)
2225 feature, like the TQM8xxL modules.
2227 - I2C Support: CONFIG_SYS_I2C
2229 This enable the NEW i2c subsystem, and will allow you to use
2230 i2c commands at the u-boot command line (as long as you set
2231 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2232 based realtime clock chips or other i2c devices. See
2233 common/cmd_i2c.c for a description of the command line
2236 ported i2c driver to the new framework:
2237 - drivers/i2c/soft_i2c.c:
2238 - activate first bus with CONFIG_SYS_I2C_SOFT define
2239 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2240 for defining speed and slave address
2241 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2242 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2243 for defining speed and slave address
2244 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2245 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2246 for defining speed and slave address
2247 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2248 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2249 for defining speed and slave address
2251 - drivers/i2c/fsl_i2c.c:
2252 - activate i2c driver with CONFIG_SYS_I2C_FSL
2253 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2254 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2255 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2257 - If your board supports a second fsl i2c bus, define
2258 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2259 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2260 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2263 - drivers/i2c/tegra_i2c.c:
2264 - activate this driver with CONFIG_SYS_I2C_TEGRA
2265 - This driver adds 4 i2c buses with a fix speed from
2266 100000 and the slave addr 0!
2268 - drivers/i2c/ppc4xx_i2c.c
2269 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2270 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2271 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2273 - drivers/i2c/i2c_mxc.c
2274 - activate this driver with CONFIG_SYS_I2C_MXC
2275 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2276 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2277 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2278 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2279 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2280 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2281 If thoses defines are not set, default value is 100000
2282 for speed, and 0 for slave.
2284 - drivers/i2c/rcar_i2c.c:
2285 - activate this driver with CONFIG_SYS_I2C_RCAR
2286 - This driver adds 4 i2c buses
2288 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2289 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2290 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2291 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2292 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2293 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2294 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2295 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2296 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2298 - drivers/i2c/sh_i2c.c:
2299 - activate this driver with CONFIG_SYS_I2C_SH
2300 - This driver adds from 2 to 5 i2c buses
2302 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2303 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2304 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2305 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2306 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2307 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2308 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2309 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2310 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2311 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2312 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2313 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2314 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2316 - drivers/i2c/omap24xx_i2c.c
2317 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2318 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2319 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2320 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2321 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2322 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2323 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2324 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2325 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2326 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2327 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2329 - drivers/i2c/zynq_i2c.c
2330 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2331 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2332 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2334 - drivers/i2c/s3c24x0_i2c.c:
2335 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2336 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2337 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2338 with a fix speed from 100000 and the slave addr 0!
2340 - drivers/i2c/ihs_i2c.c
2341 - activate this driver with CONFIG_SYS_I2C_IHS
2342 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2343 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2344 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2345 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2346 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2347 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2348 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2349 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2350 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2351 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2352 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2353 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2357 CONFIG_SYS_NUM_I2C_BUSES
2358 Hold the number of i2c busses you want to use. If you
2359 don't use/have i2c muxes on your i2c bus, this
2360 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2363 CONFIG_SYS_I2C_DIRECT_BUS
2364 define this, if you don't use i2c muxes on your hardware.
2365 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2368 CONFIG_SYS_I2C_MAX_HOPS
2369 define how many muxes are maximal consecutively connected
2370 on one i2c bus. If you not use i2c muxes, omit this
2373 CONFIG_SYS_I2C_BUSES
2374 hold a list of busses you want to use, only used if
2375 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2376 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2377 CONFIG_SYS_NUM_I2C_BUSES = 9:
2379 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2380 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2381 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2382 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2383 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2384 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2385 {1, {I2C_NULL_HOP}}, \
2386 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2387 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2391 bus 0 on adapter 0 without a mux
2392 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2393 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2394 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2395 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2396 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2397 bus 6 on adapter 1 without a mux
2398 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2399 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2401 If you do not have i2c muxes on your board, omit this define.
2403 - Legacy I2C Support: CONFIG_HARD_I2C
2405 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2406 provides the following compelling advantages:
2408 - more than one i2c adapter is usable
2409 - approved multibus support
2410 - better i2c mux support
2412 ** Please consider updating your I2C driver now. **
2414 These enable legacy I2C serial bus commands. Defining
2415 CONFIG_HARD_I2C will include the appropriate I2C driver
2416 for the selected CPU.
2418 This will allow you to use i2c commands at the u-boot
2419 command line (as long as you set CONFIG_CMD_I2C in
2420 CONFIG_COMMANDS) and communicate with i2c based realtime
2421 clock chips. See common/cmd_i2c.c for a description of the
2422 command line interface.
2424 CONFIG_HARD_I2C selects a hardware I2C controller.
2426 There are several other quantities that must also be
2427 defined when you define CONFIG_HARD_I2C.
2429 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2430 to be the frequency (in Hz) at which you wish your i2c bus
2431 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2432 the CPU's i2c node address).
2434 Now, the u-boot i2c code for the mpc8xx
2435 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2436 and so its address should therefore be cleared to 0 (See,
2437 eg, MPC823e User's Manual p.16-473). So, set
2438 CONFIG_SYS_I2C_SLAVE to 0.
2440 CONFIG_SYS_I2C_INIT_MPC5XXX
2442 When a board is reset during an i2c bus transfer
2443 chips might think that the current transfer is still
2444 in progress. Reset the slave devices by sending start
2445 commands until the slave device responds.
2447 That's all that's required for CONFIG_HARD_I2C.
2449 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2450 then the following macros need to be defined (examples are
2451 from include/configs/lwmon.h):
2455 (Optional). Any commands necessary to enable the I2C
2456 controller or configure ports.
2458 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2462 (Only for MPC8260 CPU). The I/O port to use (the code
2463 assumes both bits are on the same port). Valid values
2464 are 0..3 for ports A..D.
2468 The code necessary to make the I2C data line active
2469 (driven). If the data line is open collector, this
2472 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2476 The code necessary to make the I2C data line tri-stated
2477 (inactive). If the data line is open collector, this
2480 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2484 Code that returns true if the I2C data line is high,
2487 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2491 If <bit> is true, sets the I2C data line high. If it
2492 is false, it clears it (low).
2494 eg: #define I2C_SDA(bit) \
2495 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2496 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2500 If <bit> is true, sets the I2C clock line high. If it
2501 is false, it clears it (low).
2503 eg: #define I2C_SCL(bit) \
2504 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2505 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2509 This delay is invoked four times per clock cycle so this
2510 controls the rate of data transfer. The data rate thus
2511 is 1 / (I2C_DELAY * 4). Often defined to be something
2514 #define I2C_DELAY udelay(2)
2516 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2518 If your arch supports the generic GPIO framework (asm/gpio.h),
2519 then you may alternatively define the two GPIOs that are to be
2520 used as SCL / SDA. Any of the previous I2C_xxx macros will
2521 have GPIO-based defaults assigned to them as appropriate.
2523 You should define these to the GPIO value as given directly to
2524 the generic GPIO functions.
2526 CONFIG_SYS_I2C_INIT_BOARD
2528 When a board is reset during an i2c bus transfer
2529 chips might think that the current transfer is still
2530 in progress. On some boards it is possible to access
2531 the i2c SCLK line directly, either by using the
2532 processor pin as a GPIO or by having a second pin
2533 connected to the bus. If this option is defined a
2534 custom i2c_init_board() routine in boards/xxx/board.c
2535 is run early in the boot sequence.
2537 CONFIG_SYS_I2C_BOARD_LATE_INIT
2539 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2540 defined a custom i2c_board_late_init() routine in
2541 boards/xxx/board.c is run AFTER the operations in i2c_init()
2542 is completed. This callpoint can be used to unreset i2c bus
2543 using CPU i2c controller register accesses for CPUs whose i2c
2544 controller provide such a method. It is called at the end of
2545 i2c_init() to allow i2c_init operations to setup the i2c bus
2546 controller on the CPU (e.g. setting bus speed & slave address).
2548 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2550 This option enables configuration of bi_iic_fast[] flags
2551 in u-boot bd_info structure based on u-boot environment
2552 variable "i2cfast". (see also i2cfast)
2554 CONFIG_I2C_MULTI_BUS
2556 This option allows the use of multiple I2C buses, each of which
2557 must have a controller. At any point in time, only one bus is
2558 active. To switch to a different bus, use the 'i2c dev' command.
2559 Note that bus numbering is zero-based.
2561 CONFIG_SYS_I2C_NOPROBES
2563 This option specifies a list of I2C devices that will be skipped
2564 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2565 is set, specify a list of bus-device pairs. Otherwise, specify
2566 a 1D array of device addresses
2569 #undef CONFIG_I2C_MULTI_BUS
2570 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2572 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2574 #define CONFIG_I2C_MULTI_BUS
2575 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2577 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2579 CONFIG_SYS_SPD_BUS_NUM
2581 If defined, then this indicates the I2C bus number for DDR SPD.
2582 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2584 CONFIG_SYS_RTC_BUS_NUM
2586 If defined, then this indicates the I2C bus number for the RTC.
2587 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2589 CONFIG_SYS_DTT_BUS_NUM
2591 If defined, then this indicates the I2C bus number for the DTT.
2592 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2594 CONFIG_SYS_I2C_DTT_ADDR:
2596 If defined, specifies the I2C address of the DTT device.
2597 If not defined, then U-Boot uses predefined value for
2598 specified DTT device.
2600 CONFIG_SOFT_I2C_READ_REPEATED_START
2602 defining this will force the i2c_read() function in
2603 the soft_i2c driver to perform an I2C repeated start
2604 between writing the address pointer and reading the
2605 data. If this define is omitted the default behaviour
2606 of doing a stop-start sequence will be used. Most I2C
2607 devices can use either method, but some require one or
2610 - SPI Support: CONFIG_SPI
2612 Enables SPI driver (so far only tested with
2613 SPI EEPROM, also an instance works with Crystal A/D and
2614 D/As on the SACSng board)
2618 Enables the driver for SPI controller on SuperH. Currently
2619 only SH7757 is supported.
2623 Enables extended (16-bit) SPI EEPROM addressing.
2624 (symmetrical to CONFIG_I2C_X)
2628 Enables a software (bit-bang) SPI driver rather than
2629 using hardware support. This is a general purpose
2630 driver that only requires three general I/O port pins
2631 (two outputs, one input) to function. If this is
2632 defined, the board configuration must define several
2633 SPI configuration items (port pins to use, etc). For
2634 an example, see include/configs/sacsng.h.
2638 Enables a hardware SPI driver for general-purpose reads
2639 and writes. As with CONFIG_SOFT_SPI, the board configuration
2640 must define a list of chip-select function pointers.
2641 Currently supported on some MPC8xxx processors. For an
2642 example, see include/configs/mpc8349emds.h.
2646 Enables the driver for the SPI controllers on i.MX and MXC
2647 SoCs. Currently i.MX31/35/51 are supported.
2649 CONFIG_SYS_SPI_MXC_WAIT
2650 Timeout for waiting until spi transfer completed.
2651 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2653 - FPGA Support: CONFIG_FPGA
2655 Enables FPGA subsystem.
2657 CONFIG_FPGA_<vendor>
2659 Enables support for specific chip vendors.
2662 CONFIG_FPGA_<family>
2664 Enables support for FPGA family.
2665 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2669 Specify the number of FPGA devices to support.
2671 CONFIG_CMD_FPGA_LOADMK
2673 Enable support for fpga loadmk command
2675 CONFIG_CMD_FPGA_LOADP
2677 Enable support for fpga loadp command - load partial bitstream
2679 CONFIG_CMD_FPGA_LOADBP
2681 Enable support for fpga loadbp command - load partial bitstream
2684 CONFIG_SYS_FPGA_PROG_FEEDBACK
2686 Enable printing of hash marks during FPGA configuration.
2688 CONFIG_SYS_FPGA_CHECK_BUSY
2690 Enable checks on FPGA configuration interface busy
2691 status by the configuration function. This option
2692 will require a board or device specific function to
2697 If defined, a function that provides delays in the FPGA
2698 configuration driver.
2700 CONFIG_SYS_FPGA_CHECK_CTRLC
2701 Allow Control-C to interrupt FPGA configuration
2703 CONFIG_SYS_FPGA_CHECK_ERROR
2705 Check for configuration errors during FPGA bitfile
2706 loading. For example, abort during Virtex II
2707 configuration if the INIT_B line goes low (which
2708 indicated a CRC error).
2710 CONFIG_SYS_FPGA_WAIT_INIT
2712 Maximum time to wait for the INIT_B line to deassert
2713 after PROB_B has been deasserted during a Virtex II
2714 FPGA configuration sequence. The default time is 500
2717 CONFIG_SYS_FPGA_WAIT_BUSY
2719 Maximum time to wait for BUSY to deassert during
2720 Virtex II FPGA configuration. The default is 5 ms.
2722 CONFIG_SYS_FPGA_WAIT_CONFIG
2724 Time to wait after FPGA configuration. The default is
2727 - Configuration Management:
2730 If defined, this string will be added to the U-Boot
2731 version information (U_BOOT_VERSION)
2733 - Vendor Parameter Protection:
2735 U-Boot considers the values of the environment
2736 variables "serial#" (Board Serial Number) and
2737 "ethaddr" (Ethernet Address) to be parameters that
2738 are set once by the board vendor / manufacturer, and
2739 protects these variables from casual modification by
2740 the user. Once set, these variables are read-only,
2741 and write or delete attempts are rejected. You can
2742 change this behaviour:
2744 If CONFIG_ENV_OVERWRITE is #defined in your config
2745 file, the write protection for vendor parameters is
2746 completely disabled. Anybody can change or delete
2749 Alternatively, if you #define _both_ CONFIG_ETHADDR
2750 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2751 Ethernet address is installed in the environment,
2752 which can be changed exactly ONCE by the user. [The
2753 serial# is unaffected by this, i. e. it remains
2756 The same can be accomplished in a more flexible way
2757 for any variable by configuring the type of access
2758 to allow for those variables in the ".flags" variable
2759 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2764 Define this variable to enable the reservation of
2765 "protected RAM", i. e. RAM which is not overwritten
2766 by U-Boot. Define CONFIG_PRAM to hold the number of
2767 kB you want to reserve for pRAM. You can overwrite
2768 this default value by defining an environment
2769 variable "pram" to the number of kB you want to
2770 reserve. Note that the board info structure will
2771 still show the full amount of RAM. If pRAM is
2772 reserved, a new environment variable "mem" will
2773 automatically be defined to hold the amount of
2774 remaining RAM in a form that can be passed as boot
2775 argument to Linux, for instance like that:
2777 setenv bootargs ... mem=\${mem}
2780 This way you can tell Linux not to use this memory,
2781 either, which results in a memory region that will
2782 not be affected by reboots.
2784 *WARNING* If your board configuration uses automatic
2785 detection of the RAM size, you must make sure that
2786 this memory test is non-destructive. So far, the
2787 following board configurations are known to be
2790 IVMS8, IVML24, SPD8xx, TQM8xxL,
2791 HERMES, IP860, RPXlite, LWMON,
2794 - Access to physical memory region (> 4GB)
2795 Some basic support is provided for operations on memory not
2796 normally accessible to U-Boot - e.g. some architectures
2797 support access to more than 4GB of memory on 32-bit
2798 machines using physical address extension or similar.
2799 Define CONFIG_PHYSMEM to access this basic support, which
2800 currently only supports clearing the memory.
2805 Define this variable to stop the system in case of a
2806 fatal error, so that you have to reset it manually.
2807 This is probably NOT a good idea for an embedded
2808 system where you want the system to reboot
2809 automatically as fast as possible, but it may be
2810 useful during development since you can try to debug
2811 the conditions that lead to the situation.
2813 CONFIG_NET_RETRY_COUNT
2815 This variable defines the number of retries for
2816 network operations like ARP, RARP, TFTP, or BOOTP
2817 before giving up the operation. If not defined, a
2818 default value of 5 is used.
2822 Timeout waiting for an ARP reply in milliseconds.
2826 Timeout in milliseconds used in NFS protocol.
2827 If you encounter "ERROR: Cannot umount" in nfs command,
2828 try longer timeout such as
2829 #define CONFIG_NFS_TIMEOUT 10000UL
2831 - Command Interpreter:
2832 CONFIG_AUTO_COMPLETE
2834 Enable auto completion of commands using TAB.
2836 Note that this feature has NOT been implemented yet
2837 for the "hush" shell.
2840 CONFIG_SYS_HUSH_PARSER
2842 Define this variable to enable the "hush" shell (from
2843 Busybox) as command line interpreter, thus enabling
2844 powerful command line syntax like
2845 if...then...else...fi conditionals or `&&' and '||'
2846 constructs ("shell scripts").
2848 If undefined, you get the old, much simpler behaviour
2849 with a somewhat smaller memory footprint.
2852 CONFIG_SYS_PROMPT_HUSH_PS2
2854 This defines the secondary prompt string, which is
2855 printed when the command interpreter needs more input
2856 to complete a command. Usually "> ".
2860 In the current implementation, the local variables
2861 space and global environment variables space are
2862 separated. Local variables are those you define by
2863 simply typing `name=value'. To access a local
2864 variable later on, you have write `$name' or
2865 `${name}'; to execute the contents of a variable
2866 directly type `$name' at the command prompt.
2868 Global environment variables are those you use
2869 setenv/printenv to work with. To run a command stored
2870 in such a variable, you need to use the run command,
2871 and you must not use the '$' sign to access them.
2873 To store commands and special characters in a
2874 variable, please use double quotation marks
2875 surrounding the whole text of the variable, instead
2876 of the backslashes before semicolons and special
2879 - Commandline Editing and History:
2880 CONFIG_CMDLINE_EDITING
2882 Enable editing and History functions for interactive
2883 commandline input operations
2885 - Default Environment:
2886 CONFIG_EXTRA_ENV_SETTINGS
2888 Define this to contain any number of null terminated
2889 strings (variable = value pairs) that will be part of
2890 the default environment compiled into the boot image.
2892 For example, place something like this in your
2893 board's config file:
2895 #define CONFIG_EXTRA_ENV_SETTINGS \
2899 Warning: This method is based on knowledge about the
2900 internal format how the environment is stored by the
2901 U-Boot code. This is NOT an official, exported
2902 interface! Although it is unlikely that this format
2903 will change soon, there is no guarantee either.
2904 You better know what you are doing here.
2906 Note: overly (ab)use of the default environment is
2907 discouraged. Make sure to check other ways to preset
2908 the environment like the "source" command or the
2911 CONFIG_ENV_VARS_UBOOT_CONFIG
2913 Define this in order to add variables describing the
2914 U-Boot build configuration to the default environment.
2915 These will be named arch, cpu, board, vendor, and soc.
2917 Enabling this option will cause the following to be defined:
2925 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2927 Define this in order to add variables describing certain
2928 run-time determined information about the hardware to the
2929 environment. These will be named board_name, board_rev.
2931 CONFIG_DELAY_ENVIRONMENT
2933 Normally the environment is loaded when the board is
2934 intialised so that it is available to U-Boot. This inhibits
2935 that so that the environment is not available until
2936 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2937 this is instead controlled by the value of
2938 /config/load-environment.
2940 - DataFlash Support:
2941 CONFIG_HAS_DATAFLASH
2943 Defining this option enables DataFlash features and
2944 allows to read/write in Dataflash via the standard
2947 - Serial Flash support
2950 Defining this option enables SPI flash commands
2951 'sf probe/read/write/erase/update'.
2953 Usage requires an initial 'probe' to define the serial
2954 flash parameters, followed by read/write/erase/update
2957 The following defaults may be provided by the platform
2958 to handle the common case when only a single serial
2959 flash is present on the system.
2961 CONFIG_SF_DEFAULT_BUS Bus identifier
2962 CONFIG_SF_DEFAULT_CS Chip-select
2963 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2964 CONFIG_SF_DEFAULT_SPEED in Hz
2968 Define this option to include a destructive SPI flash
2971 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2973 Define this option to use the Bank addr/Extended addr
2974 support on SPI flashes which has size > 16Mbytes.
2976 CONFIG_SF_DUAL_FLASH Dual flash memories
2978 Define this option to use dual flash support where two flash
2979 memories can be connected with a given cs line.
2980 currently Xilinx Zynq qspi support these type of connections.
2982 CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
2983 enable the W#/Vpp signal to disable writing to the status
2984 register on ST MICRON flashes like the N25Q128.
2985 The status register write enable/disable bit, combined with
2986 the W#/VPP signal provides hardware data protection for the
2987 device as follows: When the enable/disable bit is set to 1,
2988 and the W#/VPP signal is driven LOW, the status register
2989 nonvolatile bits become read-only and the WRITE STATUS REGISTER
2990 operation will not execute. The only way to exit this
2991 hardware-protected mode is to drive W#/VPP HIGH.
2993 - SystemACE Support:
2996 Adding this option adds support for Xilinx SystemACE
2997 chips attached via some sort of local bus. The address
2998 of the chip must also be defined in the
2999 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3001 #define CONFIG_SYSTEMACE
3002 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3004 When SystemACE support is added, the "ace" device type
3005 becomes available to the fat commands, i.e. fatls.
3007 - TFTP Fixed UDP Port:
3010 If this is defined, the environment variable tftpsrcp
3011 is used to supply the TFTP UDP source port value.
3012 If tftpsrcp isn't defined, the normal pseudo-random port
3013 number generator is used.
3015 Also, the environment variable tftpdstp is used to supply
3016 the TFTP UDP destination port value. If tftpdstp isn't
3017 defined, the normal port 69 is used.
3019 The purpose for tftpsrcp is to allow a TFTP server to
3020 blindly start the TFTP transfer using the pre-configured
3021 target IP address and UDP port. This has the effect of
3022 "punching through" the (Windows XP) firewall, allowing
3023 the remainder of the TFTP transfer to proceed normally.
3024 A better solution is to properly configure the firewall,
3025 but sometimes that is not allowed.
3030 This enables a generic 'hash' command which can produce
3031 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3035 Enable the hash verify command (hash -v). This adds to code
3038 CONFIG_SHA1 - support SHA1 hashing
3039 CONFIG_SHA256 - support SHA256 hashing
3041 Note: There is also a sha1sum command, which should perhaps
3042 be deprecated in favour of 'hash sha1'.
3044 - Freescale i.MX specific commands:
3045 CONFIG_CMD_HDMIDETECT
3046 This enables 'hdmidet' command which returns true if an
3047 HDMI monitor is detected. This command is i.MX 6 specific.
3050 This enables the 'bmode' (bootmode) command for forcing
3051 a boot from specific media.
3053 This is useful for forcing the ROM's usb downloader to
3054 activate upon a watchdog reset which is nice when iterating
3055 on U-Boot. Using the reset button or running bmode normal
3056 will set it back to normal. This command currently
3057 supports i.MX53 and i.MX6.
3062 This enables the RSA algorithm used for FIT image verification
3063 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3065 The signing part is build into mkimage regardless of this
3068 - bootcount support:
3069 CONFIG_BOOTCOUNT_LIMIT
3071 This enables the bootcounter support, see:
3072 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3075 enable special bootcounter support on at91sam9xe based boards.
3077 enable special bootcounter support on blackfin based boards.
3079 enable special bootcounter support on da850 based boards.
3080 CONFIG_BOOTCOUNT_RAM
3081 enable support for the bootcounter in RAM
3082 CONFIG_BOOTCOUNT_I2C
3083 enable support for the bootcounter on an i2c (like RTC) device.
3084 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3085 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3087 CONFIG_BOOTCOUNT_ALEN = address len
3089 - Show boot progress:
3090 CONFIG_SHOW_BOOT_PROGRESS
3092 Defining this option allows to add some board-
3093 specific code (calling a user-provided function
3094 "show_boot_progress(int)") that enables you to show
3095 the system's boot progress on some display (for
3096 example, some LED's) on your board. At the moment,
3097 the following checkpoints are implemented:
3099 - Detailed boot stage timing
3101 Define this option to get detailed timing of each stage
3102 of the boot process.
3104 CONFIG_BOOTSTAGE_USER_COUNT
3105 This is the number of available user bootstage records.
3106 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
3107 a new ID will be allocated from this stash. If you exceed
3108 the limit, recording will stop.
3110 CONFIG_BOOTSTAGE_REPORT
3111 Define this to print a report before boot, similar to this:
3113 Timer summary in microseconds:
3116 3,575,678 3,575,678 board_init_f start
3117 3,575,695 17 arch_cpu_init A9
3118 3,575,777 82 arch_cpu_init done
3119 3,659,598 83,821 board_init_r start
3120 3,910,375 250,777 main_loop
3121 29,916,167 26,005,792 bootm_start
3122 30,361,327 445,160 start_kernel
3124 CONFIG_CMD_BOOTSTAGE
3125 Add a 'bootstage' command which supports printing a report
3126 and un/stashing of bootstage data.
3128 CONFIG_BOOTSTAGE_FDT
3129 Stash the bootstage information in the FDT. A root 'bootstage'
3130 node is created with each bootstage id as a child. Each child
3131 has a 'name' property and either 'mark' containing the
3132 mark time in microsecond, or 'accum' containing the
3133 accumulated time for that bootstage id in microseconds.
3138 name = "board_init_f";
3147 Code in the Linux kernel can find this in /proc/devicetree.
3149 Legacy uImage format:
3152 1 common/cmd_bootm.c before attempting to boot an image
3153 -1 common/cmd_bootm.c Image header has bad magic number
3154 2 common/cmd_bootm.c Image header has correct magic number
3155 -2 common/cmd_bootm.c Image header has bad checksum
3156 3 common/cmd_bootm.c Image header has correct checksum
3157 -3 common/cmd_bootm.c Image data has bad checksum
3158 4 common/cmd_bootm.c Image data has correct checksum
3159 -4 common/cmd_bootm.c Image is for unsupported architecture
3160 5 common/cmd_bootm.c Architecture check OK
3161 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3162 6 common/cmd_bootm.c Image Type check OK
3163 -6 common/cmd_bootm.c gunzip uncompression error
3164 -7 common/cmd_bootm.c Unimplemented compression type
3165 7 common/cmd_bootm.c Uncompression OK
3166 8 common/cmd_bootm.c No uncompress/copy overwrite error
3167 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3169 9 common/image.c Start initial ramdisk verification
3170 -10 common/image.c Ramdisk header has bad magic number
3171 -11 common/image.c Ramdisk header has bad checksum
3172 10 common/image.c Ramdisk header is OK
3173 -12 common/image.c Ramdisk data has bad checksum
3174 11 common/image.c Ramdisk data has correct checksum
3175 12 common/image.c Ramdisk verification complete, start loading
3176 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3177 13 common/image.c Start multifile image verification
3178 14 common/image.c No initial ramdisk, no multifile, continue.
3180 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3182 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3183 -31 post/post.c POST test failed, detected by post_output_backlog()
3184 -32 post/post.c POST test failed, detected by post_run_single()
3186 34 common/cmd_doc.c before loading a Image from a DOC device
3187 -35 common/cmd_doc.c Bad usage of "doc" command
3188 35 common/cmd_doc.c correct usage of "doc" command
3189 -36 common/cmd_doc.c No boot device
3190 36 common/cmd_doc.c correct boot device
3191 -37 common/cmd_doc.c Unknown Chip ID on boot device
3192 37 common/cmd_doc.c correct chip ID found, device available
3193 -38 common/cmd_doc.c Read Error on boot device
3194 38 common/cmd_doc.c reading Image header from DOC device OK
3195 -39 common/cmd_doc.c Image header has bad magic number
3196 39 common/cmd_doc.c Image header has correct magic number
3197 -40 common/cmd_doc.c Error reading Image from DOC device
3198 40 common/cmd_doc.c Image header has correct magic number
3199 41 common/cmd_ide.c before loading a Image from a IDE device
3200 -42 common/cmd_ide.c Bad usage of "ide" command
3201 42 common/cmd_ide.c correct usage of "ide" command
3202 -43 common/cmd_ide.c No boot device
3203 43 common/cmd_ide.c boot device found
3204 -44 common/cmd_ide.c Device not available
3205 44 common/cmd_ide.c Device available
3206 -45 common/cmd_ide.c wrong partition selected
3207 45 common/cmd_ide.c partition selected
3208 -46 common/cmd_ide.c Unknown partition table
3209 46 common/cmd_ide.c valid partition table found
3210 -47 common/cmd_ide.c Invalid partition type
3211 47 common/cmd_ide.c correct partition type
3212 -48 common/cmd_ide.c Error reading Image Header on boot device
3213 48 common/cmd_ide.c reading Image Header from IDE device OK
3214 -49 common/cmd_ide.c Image header has bad magic number
3215 49 common/cmd_ide.c Image header has correct magic number
3216 -50 common/cmd_ide.c Image header has bad checksum
3217 50 common/cmd_ide.c Image header has correct checksum
3218 -51 common/cmd_ide.c Error reading Image from IDE device
3219 51 common/cmd_ide.c reading Image from IDE device OK
3220 52 common/cmd_nand.c before loading a Image from a NAND device
3221 -53 common/cmd_nand.c Bad usage of "nand" command
3222 53 common/cmd_nand.c correct usage of "nand" command
3223 -54 common/cmd_nand.c No boot device
3224 54 common/cmd_nand.c boot device found
3225 -55 common/cmd_nand.c Unknown Chip ID on boot device
3226 55 common/cmd_nand.c correct chip ID found, device available
3227 -56 common/cmd_nand.c Error reading Image Header on boot device
3228 56 common/cmd_nand.c reading Image Header from NAND device OK
3229 -57 common/cmd_nand.c Image header has bad magic number
3230 57 common/cmd_nand.c Image header has correct magic number
3231 -58 common/cmd_nand.c Error reading Image from NAND device
3232 58 common/cmd_nand.c reading Image from NAND device OK
3234 -60 common/env_common.c Environment has a bad CRC, using default
3236 64 net/eth.c starting with Ethernet configuration.
3237 -64 net/eth.c no Ethernet found.
3238 65 net/eth.c Ethernet found.
3240 -80 common/cmd_net.c usage wrong
3241 80 common/cmd_net.c before calling NetLoop()
3242 -81 common/cmd_net.c some error in NetLoop() occurred
3243 81 common/cmd_net.c NetLoop() back without error
3244 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3245 82 common/cmd_net.c trying automatic boot
3246 83 common/cmd_net.c running "source" command
3247 -83 common/cmd_net.c some error in automatic boot or "source" command
3248 84 common/cmd_net.c end without errors
3253 100 common/cmd_bootm.c Kernel FIT Image has correct format
3254 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3255 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3256 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3257 102 common/cmd_bootm.c Kernel unit name specified
3258 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3259 103 common/cmd_bootm.c Found configuration node
3260 104 common/cmd_bootm.c Got kernel subimage node offset
3261 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3262 105 common/cmd_bootm.c Kernel subimage hash verification OK
3263 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3264 106 common/cmd_bootm.c Architecture check OK
3265 -106 common/cmd_bootm.c Kernel subimage has wrong type
3266 107 common/cmd_bootm.c Kernel subimage type OK
3267 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3268 108 common/cmd_bootm.c Got kernel subimage data/size
3269 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3270 -109 common/cmd_bootm.c Can't get kernel subimage type
3271 -110 common/cmd_bootm.c Can't get kernel subimage comp
3272 -111 common/cmd_bootm.c Can't get kernel subimage os
3273 -112 common/cmd_bootm.c Can't get kernel subimage load address
3274 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3276 120 common/image.c Start initial ramdisk verification
3277 -120 common/image.c Ramdisk FIT image has incorrect format
3278 121 common/image.c Ramdisk FIT image has correct format
3279 122 common/image.c No ramdisk subimage unit name, using configuration
3280 -122 common/image.c Can't get configuration for ramdisk subimage
3281 123 common/image.c Ramdisk unit name specified
3282 -124 common/image.c Can't get ramdisk subimage node offset
3283 125 common/image.c Got ramdisk subimage node offset
3284 -125 common/image.c Ramdisk subimage hash verification failed
3285 126 common/image.c Ramdisk subimage hash verification OK
3286 -126 common/image.c Ramdisk subimage for unsupported architecture
3287 127 common/image.c Architecture check OK
3288 -127 common/image.c Can't get ramdisk subimage data/size
3289 128 common/image.c Got ramdisk subimage data/size
3290 129 common/image.c Can't get ramdisk load address
3291 -129 common/image.c Got ramdisk load address
3293 -130 common/cmd_doc.c Incorrect FIT image format
3294 131 common/cmd_doc.c FIT image format OK
3296 -140 common/cmd_ide.c Incorrect FIT image format
3297 141 common/cmd_ide.c FIT image format OK
3299 -150 common/cmd_nand.c Incorrect FIT image format
3300 151 common/cmd_nand.c FIT image format OK
3302 - legacy image format:
3303 CONFIG_IMAGE_FORMAT_LEGACY
3304 enables the legacy image format support in U-Boot.
3307 enabled if CONFIG_FIT_SIGNATURE is not defined.
3309 CONFIG_DISABLE_IMAGE_LEGACY
3310 disable the legacy image format
3312 This define is introduced, as the legacy image format is
3313 enabled per default for backward compatibility.
3315 - FIT image support:
3317 Enable support for the FIT uImage format.
3319 CONFIG_FIT_BEST_MATCH
3320 When no configuration is explicitly selected, default to the
3321 one whose fdt's compatibility field best matches that of
3322 U-Boot itself. A match is considered "best" if it matches the
3323 most specific compatibility entry of U-Boot's fdt's root node.
3324 The order of entries in the configuration's fdt is ignored.
3326 CONFIG_FIT_SIGNATURE
3327 This option enables signature verification of FIT uImages,
3328 using a hash signed and verified using RSA. See
3329 doc/uImage.FIT/signature.txt for more details.
3331 WARNING: When relying on signed FIT images with required
3332 signature check the legacy image format is default
3333 disabled. If a board need legacy image format support
3334 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3336 CONFIG_FIT_DISABLE_SHA256
3337 Supporting SHA256 hashes has quite an impact on binary size.
3338 For constrained systems sha256 hash support can be disabled
3341 - Standalone program support:
3342 CONFIG_STANDALONE_LOAD_ADDR
3344 This option defines a board specific value for the
3345 address where standalone program gets loaded, thus
3346 overwriting the architecture dependent default
3349 - Frame Buffer Address:
3352 Define CONFIG_FB_ADDR if you want to use specific
3353 address for frame buffer. This is typically the case
3354 when using a graphics controller has separate video
3355 memory. U-Boot will then place the frame buffer at
3356 the given address instead of dynamically reserving it
3357 in system RAM by calling lcd_setmem(), which grabs
3358 the memory for the frame buffer depending on the
3359 configured panel size.
3361 Please see board_init_f function.
3363 - Automatic software updates via TFTP server
3365 CONFIG_UPDATE_TFTP_CNT_MAX
3366 CONFIG_UPDATE_TFTP_MSEC_MAX
3368 These options enable and control the auto-update feature;
3369 for a more detailed description refer to doc/README.update.
3371 - MTD Support (mtdparts command, UBI support)
3374 Adds the MTD device infrastructure from the Linux kernel.
3375 Needed for mtdparts command support.
3377 CONFIG_MTD_PARTITIONS
3379 Adds the MTD partitioning infrastructure from the Linux
3380 kernel. Needed for UBI support.
3382 CONFIG_MTD_NAND_VERIFY_WRITE
3383 verify if the written data is correct reread.
3388 Adds commands for interacting with MTD partitions formatted
3389 with the UBI flash translation layer
3391 Requires also defining CONFIG_RBTREE
3393 CONFIG_UBI_SILENCE_MSG
3395 Make the verbose messages from UBI stop printing. This leaves
3396 warnings and errors enabled.
3399 CONFIG_MTD_UBI_WL_THRESHOLD
3400 This parameter defines the maximum difference between the highest
3401 erase counter value and the lowest erase counter value of eraseblocks
3402 of UBI devices. When this threshold is exceeded, UBI starts performing
3403 wear leveling by means of moving data from eraseblock with low erase
3404 counter to eraseblocks with high erase counter.
3406 The default value should be OK for SLC NAND flashes, NOR flashes and
3407 other flashes which have eraseblock life-cycle 100000 or more.
3408 However, in case of MLC NAND flashes which typically have eraseblock
3409 life-cycle less than 10000, the threshold should be lessened (e.g.,
3410 to 128 or 256, although it does not have to be power of 2).
3414 CONFIG_MTD_UBI_BEB_LIMIT
3415 This option specifies the maximum bad physical eraseblocks UBI
3416 expects on the MTD device (per 1024 eraseblocks). If the
3417 underlying flash does not admit of bad eraseblocks (e.g. NOR
3418 flash), this value is ignored.
3420 NAND datasheets often specify the minimum and maximum NVM
3421 (Number of Valid Blocks) for the flashes' endurance lifetime.
3422 The maximum expected bad eraseblocks per 1024 eraseblocks
3423 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3424 which gives 20 for most NANDs (MaxNVB is basically the total
3425 count of eraseblocks on the chip).
3427 To put it differently, if this value is 20, UBI will try to
3428 reserve about 1.9% of physical eraseblocks for bad blocks
3429 handling. And that will be 1.9% of eraseblocks on the entire
3430 NAND chip, not just the MTD partition UBI attaches. This means
3431 that if you have, say, a NAND flash chip admits maximum 40 bad
3432 eraseblocks, and it is split on two MTD partitions of the same
3433 size, UBI will reserve 40 eraseblocks when attaching a
3438 CONFIG_MTD_UBI_FASTMAP
3439 Fastmap is a mechanism which allows attaching an UBI device
3440 in nearly constant time. Instead of scanning the whole MTD device it
3441 only has to locate a checkpoint (called fastmap) on the device.
3442 The on-flash fastmap contains all information needed to attach
3443 the device. Using fastmap makes only sense on large devices where
3444 attaching by scanning takes long. UBI will not automatically install
3445 a fastmap on old images, but you can set the UBI parameter
3446 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3447 that fastmap-enabled images are still usable with UBI implementations
3448 without fastmap support. On typical flash devices the whole fastmap
3449 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3451 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3452 Set this parameter to enable fastmap automatically on images
3459 Adds commands for interacting with UBI volumes formatted as
3460 UBIFS. UBIFS is read-only in u-boot.
3462 Requires UBI support as well as CONFIG_LZO
3464 CONFIG_UBIFS_SILENCE_MSG
3466 Make the verbose messages from UBIFS stop printing. This leaves
3467 warnings and errors enabled.
3471 Enable building of SPL globally.
3474 LDSCRIPT for linking the SPL binary.
3476 CONFIG_SPL_MAX_FOOTPRINT
3477 Maximum size in memory allocated to the SPL, BSS included.
3478 When defined, the linker checks that the actual memory
3479 used by SPL from _start to __bss_end does not exceed it.
3480 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3481 must not be both defined at the same time.
3484 Maximum size of the SPL image (text, data, rodata, and
3485 linker lists sections), BSS excluded.
3486 When defined, the linker checks that the actual size does
3489 CONFIG_SPL_TEXT_BASE
3490 TEXT_BASE for linking the SPL binary.
3492 CONFIG_SPL_RELOC_TEXT_BASE
3493 Address to relocate to. If unspecified, this is equal to
3494 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3496 CONFIG_SPL_BSS_START_ADDR
3497 Link address for the BSS within the SPL binary.
3499 CONFIG_SPL_BSS_MAX_SIZE
3500 Maximum size in memory allocated to the SPL BSS.
3501 When defined, the linker checks that the actual memory used
3502 by SPL from __bss_start to __bss_end does not exceed it.
3503 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3504 must not be both defined at the same time.
3507 Adress of the start of the stack SPL will use
3509 CONFIG_SPL_RELOC_STACK
3510 Adress of the start of the stack SPL will use after
3511 relocation. If unspecified, this is equal to
3514 CONFIG_SYS_SPL_MALLOC_START
3515 Starting address of the malloc pool used in SPL.
3517 CONFIG_SYS_SPL_MALLOC_SIZE
3518 The size of the malloc pool used in SPL.
3520 CONFIG_SPL_FRAMEWORK
3521 Enable the SPL framework under common/. This framework
3522 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3523 NAND loading of the Linux Kernel.
3526 Enable booting directly to an OS from SPL.
3527 See also: doc/README.falcon
3529 CONFIG_SPL_DISPLAY_PRINT
3530 For ARM, enable an optional function to print more information
3531 about the running system.
3533 CONFIG_SPL_INIT_MINIMAL
3534 Arch init code should be built for a very small image
3536 CONFIG_SPL_LIBCOMMON_SUPPORT
3537 Support for common/libcommon.o in SPL binary
3539 CONFIG_SPL_LIBDISK_SUPPORT
3540 Support for disk/libdisk.o in SPL binary
3542 CONFIG_SPL_I2C_SUPPORT
3543 Support for drivers/i2c/libi2c.o in SPL binary
3545 CONFIG_SPL_GPIO_SUPPORT
3546 Support for drivers/gpio/libgpio.o in SPL binary
3548 CONFIG_SPL_MMC_SUPPORT
3549 Support for drivers/mmc/libmmc.o in SPL binary
3551 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3552 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3553 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3554 Address, size and partition on the MMC to load U-Boot from
3555 when the MMC is being used in raw mode.
3557 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3558 Sector to load kernel uImage from when MMC is being
3559 used in raw mode (for Falcon mode)
3561 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3562 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3563 Sector and number of sectors to load kernel argument
3564 parameters from when MMC is being used in raw mode
3567 CONFIG_SPL_FAT_SUPPORT
3568 Support for fs/fat/libfat.o in SPL binary
3570 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3571 Filename to read to load U-Boot when reading from FAT
3573 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3574 Filename to read to load kernel uImage when reading
3575 from FAT (for Falcon mode)
3577 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3578 Filename to read to load kernel argument parameters
3579 when reading from FAT (for Falcon mode)
3581 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3582 Set this for NAND SPL on PPC mpc83xx targets, so that
3583 start.S waits for the rest of the SPL to load before
3584 continuing (the hardware starts execution after just
3585 loading the first page rather than the full 4K).
3587 CONFIG_SPL_SKIP_RELOCATE
3588 Avoid SPL relocation
3590 CONFIG_SPL_NAND_BASE
3591 Include nand_base.c in the SPL. Requires
3592 CONFIG_SPL_NAND_DRIVERS.
3594 CONFIG_SPL_NAND_DRIVERS
3595 SPL uses normal NAND drivers, not minimal drivers.
3598 Include standard software ECC in the SPL
3600 CONFIG_SPL_NAND_SIMPLE
3601 Support for NAND boot using simple NAND drivers that
3602 expose the cmd_ctrl() interface.
3604 CONFIG_SPL_MTD_SUPPORT
3605 Support for the MTD subsystem within SPL. Useful for
3606 environment on NAND support within SPL.
3608 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3609 Set for the SPL on PPC mpc8xxx targets, support for
3610 drivers/ddr/fsl/libddr.o in SPL binary.
3612 CONFIG_SPL_COMMON_INIT_DDR
3613 Set for common ddr init with serial presence detect in
3616 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3617 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3618 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3619 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3620 CONFIG_SYS_NAND_ECCBYTES
3621 Defines the size and behavior of the NAND that SPL uses
3624 CONFIG_SPL_NAND_BOOT
3625 Add support NAND boot
3627 CONFIG_SYS_NAND_U_BOOT_OFFS
3628 Location in NAND to read U-Boot from
3630 CONFIG_SYS_NAND_U_BOOT_DST
3631 Location in memory to load U-Boot to
3633 CONFIG_SYS_NAND_U_BOOT_SIZE
3634 Size of image to load
3636 CONFIG_SYS_NAND_U_BOOT_START
3637 Entry point in loaded image to jump to
3639 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3640 Define this if you need to first read the OOB and then the
3641 data. This is used for example on davinci plattforms.
3643 CONFIG_SPL_OMAP3_ID_NAND
3644 Support for an OMAP3-specific set of functions to return the
3645 ID and MFR of the first attached NAND chip, if present.
3647 CONFIG_SPL_SERIAL_SUPPORT
3648 Support for drivers/serial/libserial.o in SPL binary
3650 CONFIG_SPL_SPI_FLASH_SUPPORT
3651 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3653 CONFIG_SPL_SPI_SUPPORT
3654 Support for drivers/spi/libspi.o in SPL binary
3656 CONFIG_SPL_RAM_DEVICE
3657 Support for running image already present in ram, in SPL binary
3659 CONFIG_SPL_LIBGENERIC_SUPPORT
3660 Support for lib/libgeneric.o in SPL binary
3662 CONFIG_SPL_ENV_SUPPORT
3663 Support for the environment operating in SPL binary
3665 CONFIG_SPL_NET_SUPPORT
3666 Support for the net/libnet.o in SPL binary.
3667 It conflicts with SPL env from storage medium specified by
3668 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3671 Image offset to which the SPL should be padded before appending
3672 the SPL payload. By default, this is defined as
3673 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3674 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3675 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3678 Final target image containing SPL and payload. Some SPLs
3679 use an arch-specific makefile fragment instead, for
3680 example if more than one image needs to be produced.
3682 CONFIG_FIT_SPL_PRINT
3683 Printing information about a FIT image adds quite a bit of
3684 code to SPL. So this is normally disabled in SPL. Use this
3685 option to re-enable it. This will affect the output of the
3686 bootm command when booting a FIT image.
3690 Enable building of TPL globally.
3693 Image offset to which the TPL should be padded before appending
3694 the TPL payload. By default, this is defined as
3695 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3696 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3697 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3702 [so far only for SMDK2400 boards]
3704 - Modem support enable:
3705 CONFIG_MODEM_SUPPORT
3707 - RTS/CTS Flow control enable:
3710 - Modem debug support:
3711 CONFIG_MODEM_SUPPORT_DEBUG
3713 Enables debugging stuff (char screen[1024], dbg())
3714 for modem support. Useful only with BDI2000.
3716 - Interrupt support (PPC):
3718 There are common interrupt_init() and timer_interrupt()
3719 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3720 for CPU specific initialization. interrupt_init_cpu()
3721 should set decrementer_count to appropriate value. If
3722 CPU resets decrementer automatically after interrupt
3723 (ppc4xx) it should set decrementer_count to zero.
3724 timer_interrupt() calls timer_interrupt_cpu() for CPU
3725 specific handling. If board has watchdog / status_led
3726 / other_activity_monitor it works automatically from
3727 general timer_interrupt().
3731 In the target system modem support is enabled when a
3732 specific key (key combination) is pressed during
3733 power-on. Otherwise U-Boot will boot normally
3734 (autoboot). The key_pressed() function is called from
3735 board_init(). Currently key_pressed() is a dummy
3736 function, returning 1 and thus enabling modem
3739 If there are no modem init strings in the
3740 environment, U-Boot proceed to autoboot; the
3741 previous output (banner, info printfs) will be
3744 See also: doc/README.Modem
3746 Board initialization settings:
3747 ------------------------------
3749 During Initialization u-boot calls a number of board specific functions
3750 to allow the preparation of board specific prerequisites, e.g. pin setup
3751 before drivers are initialized. To enable these callbacks the
3752 following configuration macros have to be defined. Currently this is
3753 architecture specific, so please check arch/your_architecture/lib/board.c
3754 typically in board_init_f() and board_init_r().
3756 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3757 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3758 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3759 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3761 Configuration Settings:
3762 -----------------------
3764 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3765 Optionally it can be defined to support 64-bit memory commands.
3767 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3768 undefine this when you're short of memory.
3770 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3771 width of the commands listed in the 'help' command output.
3773 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3774 prompt for user input.
3776 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3778 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3780 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3782 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3783 the application (usually a Linux kernel) when it is
3786 - CONFIG_SYS_BAUDRATE_TABLE:
3787 List of legal baudrate settings for this board.
3789 - CONFIG_SYS_CONSOLE_INFO_QUIET
3790 Suppress display of console information at boot.
3792 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3793 If the board specific function
3794 extern int overwrite_console (void);
3795 returns 1, the stdin, stderr and stdout are switched to the
3796 serial port, else the settings in the environment are used.
3798 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3799 Enable the call to overwrite_console().
3801 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3802 Enable overwrite of previous console environment settings.
3804 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3805 Begin and End addresses of the area used by the
3808 - CONFIG_SYS_ALT_MEMTEST:
3809 Enable an alternate, more extensive memory test.
3811 - CONFIG_SYS_MEMTEST_SCRATCH:
3812 Scratch address used by the alternate memory test
3813 You only need to set this if address zero isn't writeable
3815 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3816 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3817 this specified memory area will get subtracted from the top
3818 (end) of RAM and won't get "touched" at all by U-Boot. By
3819 fixing up gd->ram_size the Linux kernel should gets passed
3820 the now "corrected" memory size and won't touch it either.
3821 This should work for arch/ppc and arch/powerpc. Only Linux
3822 board ports in arch/powerpc with bootwrapper support that
3823 recalculate the memory size from the SDRAM controller setup
3824 will have to get fixed in Linux additionally.
3826 This option can be used as a workaround for the 440EPx/GRx
3827 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3830 WARNING: Please make sure that this value is a multiple of
3831 the Linux page size (normally 4k). If this is not the case,
3832 then the end address of the Linux memory will be located at a
3833 non page size aligned address and this could cause major
3836 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3837 Enable temporary baudrate change while serial download
3839 - CONFIG_SYS_SDRAM_BASE:
3840 Physical start address of SDRAM. _Must_ be 0 here.
3842 - CONFIG_SYS_MBIO_BASE:
3843 Physical start address of Motherboard I/O (if using a
3846 - CONFIG_SYS_FLASH_BASE:
3847 Physical start address of Flash memory.
3849 - CONFIG_SYS_MONITOR_BASE:
3850 Physical start address of boot monitor code (set by
3851 make config files to be same as the text base address
3852 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3853 CONFIG_SYS_FLASH_BASE when booting from flash.
3855 - CONFIG_SYS_MONITOR_LEN:
3856 Size of memory reserved for monitor code, used to
3857 determine _at_compile_time_ (!) if the environment is
3858 embedded within the U-Boot image, or in a separate
3861 - CONFIG_SYS_MALLOC_LEN:
3862 Size of DRAM reserved for malloc() use.
3864 - CONFIG_SYS_MALLOC_F_LEN
3865 Size of the malloc() pool for use before relocation. If
3866 this is defined, then a very simple malloc() implementation
3867 will become available before relocation. The address is just
3868 below the global data, and the stack is moved down to make
3871 This feature allocates regions with increasing addresses
3872 within the region. calloc() is supported, but realloc()
3873 is not available. free() is supported but does nothing.
3874 The memory will be freed (or in fact just forgotton) when
3875 U-Boot relocates itself.
3877 Pre-relocation malloc() is only supported on ARM and sandbox
3878 at present but is fairly easy to enable for other archs.
3880 - CONFIG_SYS_BOOTM_LEN:
3881 Normally compressed uImages are limited to an
3882 uncompressed size of 8 MBytes. If this is not enough,
3883 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3884 to adjust this setting to your needs.
3886 - CONFIG_SYS_BOOTMAPSZ:
3887 Maximum size of memory mapped by the startup code of
3888 the Linux kernel; all data that must be processed by
3889 the Linux kernel (bd_info, boot arguments, FDT blob if
3890 used) must be put below this limit, unless "bootm_low"
3891 environment variable is defined and non-zero. In such case
3892 all data for the Linux kernel must be between "bootm_low"
3893 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3894 variable "bootm_mapsize" will override the value of
3895 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3896 then the value in "bootm_size" will be used instead.
3898 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3899 Enable initrd_high functionality. If defined then the
3900 initrd_high feature is enabled and the bootm ramdisk subcommand
3903 - CONFIG_SYS_BOOT_GET_CMDLINE:
3904 Enables allocating and saving kernel cmdline in space between
3905 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3907 - CONFIG_SYS_BOOT_GET_KBD:
3908 Enables allocating and saving a kernel copy of the bd_info in
3909 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3911 - CONFIG_SYS_MAX_FLASH_BANKS:
3912 Max number of Flash memory banks
3914 - CONFIG_SYS_MAX_FLASH_SECT:
3915 Max number of sectors on a Flash chip
3917 - CONFIG_SYS_FLASH_ERASE_TOUT:
3918 Timeout for Flash erase operations (in ms)
3920 - CONFIG_SYS_FLASH_WRITE_TOUT:
3921 Timeout for Flash write operations (in ms)
3923 - CONFIG_SYS_FLASH_LOCK_TOUT
3924 Timeout for Flash set sector lock bit operation (in ms)
3926 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3927 Timeout for Flash clear lock bits operation (in ms)
3929 - CONFIG_SYS_FLASH_PROTECTION
3930 If defined, hardware flash sectors protection is used
3931 instead of U-Boot software protection.
3933 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3935 Enable TFTP transfers directly to flash memory;
3936 without this option such a download has to be
3937 performed in two steps: (1) download to RAM, and (2)
3938 copy from RAM to flash.
3940 The two-step approach is usually more reliable, since
3941 you can check if the download worked before you erase
3942 the flash, but in some situations (when system RAM is
3943 too limited to allow for a temporary copy of the
3944 downloaded image) this option may be very useful.
3946 - CONFIG_SYS_FLASH_CFI:
3947 Define if the flash driver uses extra elements in the
3948 common flash structure for storing flash geometry.
3950 - CONFIG_FLASH_CFI_DRIVER
3951 This option also enables the building of the cfi_flash driver
3952 in the drivers directory
3954 - CONFIG_FLASH_CFI_MTD
3955 This option enables the building of the cfi_mtd driver
3956 in the drivers directory. The driver exports CFI flash
3959 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3960 Use buffered writes to flash.
3962 - CONFIG_FLASH_SPANSION_S29WS_N
3963 s29ws-n MirrorBit flash has non-standard addresses for buffered
3966 - CONFIG_SYS_FLASH_QUIET_TEST
3967 If this option is defined, the common CFI flash doesn't
3968 print it's warning upon not recognized FLASH banks. This
3969 is useful, if some of the configured banks are only
3970 optionally available.
3972 - CONFIG_FLASH_SHOW_PROGRESS
3973 If defined (must be an integer), print out countdown
3974 digits and dots. Recommended value: 45 (9..1) for 80
3975 column displays, 15 (3..1) for 40 column displays.
3977 - CONFIG_FLASH_VERIFY
3978 If defined, the content of the flash (destination) is compared
3979 against the source after the write operation. An error message
3980 will be printed when the contents are not identical.
3981 Please note that this option is useless in nearly all cases,
3982 since such flash programming errors usually are detected earlier
3983 while unprotecting/erasing/programming. Please only enable
3984 this option if you really know what you are doing.
3986 - CONFIG_SYS_RX_ETH_BUFFER:
3987 Defines the number of Ethernet receive buffers. On some
3988 Ethernet controllers it is recommended to set this value
3989 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3990 buffers can be full shortly after enabling the interface
3991 on high Ethernet traffic.
3992 Defaults to 4 if not defined.
3994 - CONFIG_ENV_MAX_ENTRIES
3996 Maximum number of entries in the hash table that is used
3997 internally to store the environment settings. The default
3998 setting is supposed to be generous and should work in most
3999 cases. This setting can be used to tune behaviour; see
4000 lib/hashtable.c for details.
4002 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4003 - CONFIG_ENV_FLAGS_LIST_STATIC
4004 Enable validation of the values given to environment variables when
4005 calling env set. Variables can be restricted to only decimal,
4006 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4007 the variables can also be restricted to IP address or MAC address.
4009 The format of the list is:
4010 type_attribute = [s|d|x|b|i|m]
4011 access_atribute = [a|r|o|c]
4012 attributes = type_attribute[access_atribute]
4013 entry = variable_name[:attributes]
4016 The type attributes are:
4017 s - String (default)
4020 b - Boolean ([1yYtT|0nNfF])
4024 The access attributes are:
4030 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4031 Define this to a list (string) to define the ".flags"
4032 envirnoment variable in the default or embedded environment.
4034 - CONFIG_ENV_FLAGS_LIST_STATIC
4035 Define this to a list (string) to define validation that
4036 should be done if an entry is not found in the ".flags"
4037 environment variable. To override a setting in the static
4038 list, simply add an entry for the same variable name to the
4041 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4042 If defined, don't allow the -f switch to env set override variable
4045 - CONFIG_SYS_GENERIC_BOARD
4046 This selects the architecture-generic board system instead of the
4047 architecture-specific board files. It is intended to move boards
4048 to this new framework over time. Defining this will disable the
4049 arch/foo/lib/board.c file and use common/board_f.c and
4050 common/board_r.c instead. To use this option your architecture
4051 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
4052 its config.mk file). If you find problems enabling this option on
4053 your board please report the problem and send patches!
4055 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4056 This is set by OMAP boards for the max time that reset should
4057 be asserted. See doc/README.omap-reset-time for details on how
4058 the value can be calulated on a given board.
4060 The following definitions that deal with the placement and management
4061 of environment data (variable area); in general, we support the
4062 following configurations:
4064 - CONFIG_BUILD_ENVCRC:
4066 Builds up envcrc with the target environment so that external utils
4067 may easily extract it and embed it in final U-Boot images.
4069 - CONFIG_ENV_IS_IN_FLASH:
4071 Define this if the environment is in flash memory.
4073 a) The environment occupies one whole flash sector, which is
4074 "embedded" in the text segment with the U-Boot code. This
4075 happens usually with "bottom boot sector" or "top boot
4076 sector" type flash chips, which have several smaller
4077 sectors at the start or the end. For instance, such a
4078 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4079 such a case you would place the environment in one of the
4080 4 kB sectors - with U-Boot code before and after it. With
4081 "top boot sector" type flash chips, you would put the
4082 environment in one of the last sectors, leaving a gap
4083 between U-Boot and the environment.
4085 - CONFIG_ENV_OFFSET:
4087 Offset of environment data (variable area) to the
4088 beginning of flash memory; for instance, with bottom boot
4089 type flash chips the second sector can be used: the offset
4090 for this sector is given here.
4092 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4096 This is just another way to specify the start address of
4097 the flash sector containing the environment (instead of
4100 - CONFIG_ENV_SECT_SIZE:
4102 Size of the sector containing the environment.
4105 b) Sometimes flash chips have few, equal sized, BIG sectors.
4106 In such a case you don't want to spend a whole sector for
4111 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4112 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4113 of this flash sector for the environment. This saves
4114 memory for the RAM copy of the environment.
4116 It may also save flash memory if you decide to use this
4117 when your environment is "embedded" within U-Boot code,
4118 since then the remainder of the flash sector could be used
4119 for U-Boot code. It should be pointed out that this is
4120 STRONGLY DISCOURAGED from a robustness point of view:
4121 updating the environment in flash makes it always
4122 necessary to erase the WHOLE sector. If something goes
4123 wrong before the contents has been restored from a copy in
4124 RAM, your target system will be dead.
4126 - CONFIG_ENV_ADDR_REDUND
4127 CONFIG_ENV_SIZE_REDUND
4129 These settings describe a second storage area used to hold
4130 a redundant copy of the environment data, so that there is
4131 a valid backup copy in case there is a power failure during
4132 a "saveenv" operation.
4134 BE CAREFUL! Any changes to the flash layout, and some changes to the
4135 source code will make it necessary to adapt <board>/u-boot.lds*
4139 - CONFIG_ENV_IS_IN_NVRAM:
4141 Define this if you have some non-volatile memory device
4142 (NVRAM, battery buffered SRAM) which you want to use for the
4148 These two #defines are used to determine the memory area you
4149 want to use for environment. It is assumed that this memory
4150 can just be read and written to, without any special
4153 BE CAREFUL! The first access to the environment happens quite early
4154 in U-Boot initalization (when we try to get the setting of for the
4155 console baudrate). You *MUST* have mapped your NVRAM area then, or
4158 Please note that even with NVRAM we still use a copy of the
4159 environment in RAM: we could work on NVRAM directly, but we want to
4160 keep settings there always unmodified except somebody uses "saveenv"
4161 to save the current settings.
4164 - CONFIG_ENV_IS_IN_EEPROM:
4166 Use this if you have an EEPROM or similar serial access
4167 device and a driver for it.
4169 - CONFIG_ENV_OFFSET:
4172 These two #defines specify the offset and size of the
4173 environment area within the total memory of your EEPROM.
4175 - CONFIG_SYS_I2C_EEPROM_ADDR:
4176 If defined, specified the chip address of the EEPROM device.
4177 The default address is zero.
4179 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4180 If defined, the number of bits used to address bytes in a
4181 single page in the EEPROM device. A 64 byte page, for example
4182 would require six bits.
4184 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4185 If defined, the number of milliseconds to delay between
4186 page writes. The default is zero milliseconds.
4188 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4189 The length in bytes of the EEPROM memory array address. Note
4190 that this is NOT the chip address length!
4192 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4193 EEPROM chips that implement "address overflow" are ones
4194 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4195 address and the extra bits end up in the "chip address" bit
4196 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4199 Note that we consider the length of the address field to
4200 still be one byte because the extra address bits are hidden
4201 in the chip address.
4203 - CONFIG_SYS_EEPROM_SIZE:
4204 The size in bytes of the EEPROM device.
4206 - CONFIG_ENV_EEPROM_IS_ON_I2C
4207 define this, if you have I2C and SPI activated, and your
4208 EEPROM, which holds the environment, is on the I2C bus.
4210 - CONFIG_I2C_ENV_EEPROM_BUS
4211 if you have an Environment on an EEPROM reached over
4212 I2C muxes, you can define here, how to reach this
4213 EEPROM. For example:
4215 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4217 EEPROM which holds the environment, is reached over
4218 a pca9547 i2c mux with address 0x70, channel 3.
4220 - CONFIG_ENV_IS_IN_DATAFLASH:
4222 Define this if you have a DataFlash memory device which you
4223 want to use for the environment.
4225 - CONFIG_ENV_OFFSET:
4229 These three #defines specify the offset and size of the
4230 environment area within the total memory of your DataFlash placed
4231 at the specified address.
4233 - CONFIG_ENV_IS_IN_SPI_FLASH:
4235 Define this if you have a SPI Flash memory device which you
4236 want to use for the environment.
4238 - CONFIG_ENV_OFFSET:
4241 These two #defines specify the offset and size of the
4242 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4243 aligned to an erase sector boundary.
4245 - CONFIG_ENV_SECT_SIZE:
4247 Define the SPI flash's sector size.
4249 - CONFIG_ENV_OFFSET_REDUND (optional):
4251 This setting describes a second storage area of CONFIG_ENV_SIZE
4252 size used to hold a redundant copy of the environment data, so
4253 that there is a valid backup copy in case there is a power failure
4254 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4255 aligned to an erase sector boundary.
4257 - CONFIG_ENV_SPI_BUS (optional):
4258 - CONFIG_ENV_SPI_CS (optional):
4260 Define the SPI bus and chip select. If not defined they will be 0.
4262 - CONFIG_ENV_SPI_MAX_HZ (optional):
4264 Define the SPI max work clock. If not defined then use 1MHz.
4266 - CONFIG_ENV_SPI_MODE (optional):
4268 Define the SPI work mode. If not defined then use SPI_MODE_3.
4270 - CONFIG_ENV_IS_IN_REMOTE:
4272 Define this if you have a remote memory space which you
4273 want to use for the local device's environment.
4278 These two #defines specify the address and size of the
4279 environment area within the remote memory space. The
4280 local device can get the environment from remote memory
4281 space by SRIO or PCIE links.
4283 BE CAREFUL! For some special cases, the local device can not use
4284 "saveenv" command. For example, the local device will get the
4285 environment stored in a remote NOR flash by SRIO or PCIE link,
4286 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4288 - CONFIG_ENV_IS_IN_NAND:
4290 Define this if you have a NAND device which you want to use
4291 for the environment.
4293 - CONFIG_ENV_OFFSET:
4296 These two #defines specify the offset and size of the environment
4297 area within the first NAND device. CONFIG_ENV_OFFSET must be
4298 aligned to an erase block boundary.
4300 - CONFIG_ENV_OFFSET_REDUND (optional):
4302 This setting describes a second storage area of CONFIG_ENV_SIZE
4303 size used to hold a redundant copy of the environment data, so
4304 that there is a valid backup copy in case there is a power failure
4305 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4306 aligned to an erase block boundary.
4308 - CONFIG_ENV_RANGE (optional):
4310 Specifies the length of the region in which the environment
4311 can be written. This should be a multiple of the NAND device's
4312 block size. Specifying a range with more erase blocks than
4313 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4314 the range to be avoided.
4316 - CONFIG_ENV_OFFSET_OOB (optional):
4318 Enables support for dynamically retrieving the offset of the
4319 environment from block zero's out-of-band data. The
4320 "nand env.oob" command can be used to record this offset.
4321 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4322 using CONFIG_ENV_OFFSET_OOB.
4324 - CONFIG_NAND_ENV_DST
4326 Defines address in RAM to which the nand_spl code should copy the
4327 environment. If redundant environment is used, it will be copied to
4328 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4330 - CONFIG_ENV_IS_IN_UBI:
4332 Define this if you have an UBI volume that you want to use for the
4333 environment. This has the benefit of wear-leveling the environment
4334 accesses, which is important on NAND.
4336 - CONFIG_ENV_UBI_PART:
4338 Define this to a string that is the mtd partition containing the UBI.
4340 - CONFIG_ENV_UBI_VOLUME:
4342 Define this to the name of the volume that you want to store the
4345 - CONFIG_ENV_UBI_VOLUME_REDUND:
4347 Define this to the name of another volume to store a second copy of
4348 the environment in. This will enable redundant environments in UBI.
4349 It is assumed that both volumes are in the same MTD partition.
4351 - CONFIG_UBI_SILENCE_MSG
4352 - CONFIG_UBIFS_SILENCE_MSG
4354 You will probably want to define these to avoid a really noisy system
4355 when storing the env in UBI.
4357 - CONFIG_ENV_IS_IN_FAT:
4358 Define this if you want to use the FAT file system for the environment.
4360 - FAT_ENV_INTERFACE:
4362 Define this to a string that is the name of the block device.
4364 - FAT_ENV_DEV_AND_PART:
4366 Define this to a string to specify the partition of the device. It can
4369 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4370 - "D:P": device D partition P. Error occurs if device D has no
4373 - "D" or "D:": device D partition 1 if device D has partition
4374 table, or the whole device D if has no partition
4376 - "D:auto": first partition in device D with bootable flag set.
4377 If none, first valid paratition in device D. If no
4378 partition table then means device D.
4382 It's a string of the FAT file name. This file use to store the
4386 This should be defined. Otherwise it cannot save the envrionment file.
4388 - CONFIG_ENV_IS_IN_MMC:
4390 Define this if you have an MMC device which you want to use for the
4393 - CONFIG_SYS_MMC_ENV_DEV:
4395 Specifies which MMC device the environment is stored in.
4397 - CONFIG_SYS_MMC_ENV_PART (optional):
4399 Specifies which MMC partition the environment is stored in. If not
4400 set, defaults to partition 0, the user area. Common values might be
4401 1 (first MMC boot partition), 2 (second MMC boot partition).
4403 - CONFIG_ENV_OFFSET:
4406 These two #defines specify the offset and size of the environment
4407 area within the specified MMC device.
4409 If offset is positive (the usual case), it is treated as relative to
4410 the start of the MMC partition. If offset is negative, it is treated
4411 as relative to the end of the MMC partition. This can be useful if
4412 your board may be fitted with different MMC devices, which have
4413 different sizes for the MMC partitions, and you always want the
4414 environment placed at the very end of the partition, to leave the
4415 maximum possible space before it, to store other data.
4417 These two values are in units of bytes, but must be aligned to an
4418 MMC sector boundary.
4420 - CONFIG_ENV_OFFSET_REDUND (optional):
4422 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4423 hold a redundant copy of the environment data. This provides a
4424 valid backup copy in case the other copy is corrupted, e.g. due
4425 to a power failure during a "saveenv" operation.
4427 This value may also be positive or negative; this is handled in the
4428 same way as CONFIG_ENV_OFFSET.
4430 This value is also in units of bytes, but must also be aligned to
4431 an MMC sector boundary.
4433 - CONFIG_ENV_SIZE_REDUND (optional):
4435 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4436 set. If this value is set, it must be set to the same value as
4439 - CONFIG_SYS_SPI_INIT_OFFSET
4441 Defines offset to the initial SPI buffer area in DPRAM. The
4442 area is used at an early stage (ROM part) if the environment
4443 is configured to reside in the SPI EEPROM: We need a 520 byte
4444 scratch DPRAM area. It is used between the two initialization
4445 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4446 to be a good choice since it makes it far enough from the
4447 start of the data area as well as from the stack pointer.
4449 Please note that the environment is read-only until the monitor
4450 has been relocated to RAM and a RAM copy of the environment has been
4451 created; also, when using EEPROM you will have to use getenv_f()
4452 until then to read environment variables.
4454 The environment is protected by a CRC32 checksum. Before the monitor
4455 is relocated into RAM, as a result of a bad CRC you will be working
4456 with the compiled-in default environment - *silently*!!! [This is
4457 necessary, because the first environment variable we need is the
4458 "baudrate" setting for the console - if we have a bad CRC, we don't
4459 have any device yet where we could complain.]
4461 Note: once the monitor has been relocated, then it will complain if
4462 the default environment is used; a new CRC is computed as soon as you
4463 use the "saveenv" command to store a valid environment.
4465 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4466 Echo the inverted Ethernet link state to the fault LED.
4468 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4469 also needs to be defined.
4471 - CONFIG_SYS_FAULT_MII_ADDR:
4472 MII address of the PHY to check for the Ethernet link state.
4474 - CONFIG_NS16550_MIN_FUNCTIONS:
4475 Define this if you desire to only have use of the NS16550_init
4476 and NS16550_putc functions for the serial driver located at
4477 drivers/serial/ns16550.c. This option is useful for saving
4478 space for already greatly restricted images, including but not
4479 limited to NAND_SPL configurations.
4481 - CONFIG_DISPLAY_BOARDINFO
4482 Display information about the board that U-Boot is running on
4483 when U-Boot starts up. The board function checkboard() is called
4486 - CONFIG_DISPLAY_BOARDINFO_LATE
4487 Similar to the previous option, but display this information
4488 later, once stdio is running and output goes to the LCD, if
4491 - CONFIG_BOARD_SIZE_LIMIT:
4492 Maximum size of the U-Boot image. When defined, the
4493 build system checks that the actual size does not
4496 Low Level (hardware related) configuration options:
4497 ---------------------------------------------------
4499 - CONFIG_SYS_CACHELINE_SIZE:
4500 Cache Line Size of the CPU.
4502 - CONFIG_SYS_DEFAULT_IMMR:
4503 Default address of the IMMR after system reset.
4505 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4506 and RPXsuper) to be able to adjust the position of
4507 the IMMR register after a reset.
4509 - CONFIG_SYS_CCSRBAR_DEFAULT:
4510 Default (power-on reset) physical address of CCSR on Freescale
4513 - CONFIG_SYS_CCSRBAR:
4514 Virtual address of CCSR. On a 32-bit build, this is typically
4515 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4517 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4518 for cross-platform code that uses that macro instead.
4520 - CONFIG_SYS_CCSRBAR_PHYS:
4521 Physical address of CCSR. CCSR can be relocated to a new
4522 physical address, if desired. In this case, this macro should
4523 be set to that address. Otherwise, it should be set to the
4524 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4525 is typically relocated on 36-bit builds. It is recommended
4526 that this macro be defined via the _HIGH and _LOW macros:
4528 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4529 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4531 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4532 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4533 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4534 used in assembly code, so it must not contain typecasts or
4535 integer size suffixes (e.g. "ULL").
4537 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4538 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4539 used in assembly code, so it must not contain typecasts or
4540 integer size suffixes (e.g. "ULL").
4542 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4543 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4544 forced to a value that ensures that CCSR is not relocated.
4546 - Floppy Disk Support:
4547 CONFIG_SYS_FDC_DRIVE_NUMBER
4549 the default drive number (default value 0)
4551 CONFIG_SYS_ISA_IO_STRIDE
4553 defines the spacing between FDC chipset registers
4556 CONFIG_SYS_ISA_IO_OFFSET
4558 defines the offset of register from address. It
4559 depends on which part of the data bus is connected to
4560 the FDC chipset. (default value 0)
4562 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4563 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4566 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4567 fdc_hw_init() is called at the beginning of the FDC
4568 setup. fdc_hw_init() must be provided by the board
4569 source code. It is used to make hardware dependant
4573 Most IDE controllers were designed to be connected with PCI
4574 interface. Only few of them were designed for AHB interface.
4575 When software is doing ATA command and data transfer to
4576 IDE devices through IDE-AHB controller, some additional
4577 registers accessing to these kind of IDE-AHB controller
4580 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4581 DO NOT CHANGE unless you know exactly what you're
4582 doing! (11-4) [MPC8xx/82xx systems only]
4584 - CONFIG_SYS_INIT_RAM_ADDR:
4586 Start address of memory area that can be used for
4587 initial data and stack; please note that this must be
4588 writable memory that is working WITHOUT special
4589 initialization, i. e. you CANNOT use normal RAM which
4590 will become available only after programming the
4591 memory controller and running certain initialization
4594 U-Boot uses the following memory types:
4595 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4596 - MPC824X: data cache
4597 - PPC4xx: data cache
4599 - CONFIG_SYS_GBL_DATA_OFFSET:
4601 Offset of the initial data structure in the memory
4602 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4603 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4604 data is located at the end of the available space
4605 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4606 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4607 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4608 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4611 On the MPC824X (or other systems that use the data
4612 cache for initial memory) the address chosen for
4613 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4614 point to an otherwise UNUSED address space between
4615 the top of RAM and the start of the PCI space.
4617 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4619 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4621 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4623 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4625 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4627 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4629 - CONFIG_SYS_OR_TIMING_SDRAM:
4632 - CONFIG_SYS_MAMR_PTA:
4633 periodic timer for refresh
4635 - CONFIG_SYS_DER: Debug Event Register (37-47)
4637 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4638 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4639 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4640 CONFIG_SYS_BR1_PRELIM:
4641 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4643 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4644 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4645 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4646 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4648 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4649 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4650 Machine Mode Register and Memory Periodic Timer
4651 Prescaler definitions (SDRAM timing)
4653 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4654 enable I2C microcode relocation patch (MPC8xx);
4655 define relocation offset in DPRAM [DSP2]
4657 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4658 enable SMC microcode relocation patch (MPC8xx);
4659 define relocation offset in DPRAM [SMC1]
4661 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4662 enable SPI microcode relocation patch (MPC8xx);
4663 define relocation offset in DPRAM [SCC4]
4665 - CONFIG_SYS_USE_OSCCLK:
4666 Use OSCM clock mode on MBX8xx board. Be careful,
4667 wrong setting might damage your board. Read
4668 doc/README.MBX before setting this variable!
4670 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4671 Offset of the bootmode word in DPRAM used by post
4672 (Power On Self Tests). This definition overrides
4673 #define'd default value in commproc.h resp.
4676 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4677 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4678 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4679 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4680 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4681 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4682 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4683 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4684 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4686 - CONFIG_PCI_DISABLE_PCIE:
4687 Disable PCI-Express on systems where it is supported but not
4690 - CONFIG_PCI_ENUM_ONLY
4691 Only scan through and get the devices on the busses.
4692 Don't do any setup work, presumably because someone or
4693 something has already done it, and we don't need to do it
4694 a second time. Useful for platforms that are pre-booted
4695 by coreboot or similar.
4697 - CONFIG_PCI_INDIRECT_BRIDGE:
4698 Enable support for indirect PCI bridges.
4701 Chip has SRIO or not
4704 Board has SRIO 1 port available
4707 Board has SRIO 2 port available
4709 - CONFIG_SRIO_PCIE_BOOT_MASTER
4710 Board can support master function for Boot from SRIO and PCIE
4712 - CONFIG_SYS_SRIOn_MEM_VIRT:
4713 Virtual Address of SRIO port 'n' memory region
4715 - CONFIG_SYS_SRIOn_MEM_PHYS:
4716 Physical Address of SRIO port 'n' memory region
4718 - CONFIG_SYS_SRIOn_MEM_SIZE:
4719 Size of SRIO port 'n' memory region
4721 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4722 Defined to tell the NAND controller that the NAND chip is using
4724 Not all NAND drivers use this symbol.
4725 Example of drivers that use it:
4726 - drivers/mtd/nand/ndfc.c
4727 - drivers/mtd/nand/mxc_nand.c
4729 - CONFIG_SYS_NDFC_EBC0_CFG
4730 Sets the EBC0_CFG register for the NDFC. If not defined
4731 a default value will be used.
4734 Get DDR timing information from an I2C EEPROM. Common
4735 with pluggable memory modules such as SODIMMs
4738 I2C address of the SPD EEPROM
4740 - CONFIG_SYS_SPD_BUS_NUM
4741 If SPD EEPROM is on an I2C bus other than the first
4742 one, specify here. Note that the value must resolve
4743 to something your driver can deal with.
4745 - CONFIG_SYS_DDR_RAW_TIMING
4746 Get DDR timing information from other than SPD. Common with
4747 soldered DDR chips onboard without SPD. DDR raw timing
4748 parameters are extracted from datasheet and hard-coded into
4749 header files or board specific files.
4751 - CONFIG_FSL_DDR_INTERACTIVE
4752 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4754 - CONFIG_SYS_83XX_DDR_USES_CS0
4755 Only for 83xx systems. If specified, then DDR should
4756 be configured using CS0 and CS1 instead of CS2 and CS3.
4758 - CONFIG_ETHER_ON_FEC[12]
4759 Define to enable FEC[12] on a 8xx series processor.
4761 - CONFIG_FEC[12]_PHY
4762 Define to the hardcoded PHY address which corresponds
4763 to the given FEC; i. e.
4764 #define CONFIG_FEC1_PHY 4
4765 means that the PHY with address 4 is connected to FEC1
4767 When set to -1, means to probe for first available.
4769 - CONFIG_FEC[12]_PHY_NORXERR
4770 The PHY does not have a RXERR line (RMII only).
4771 (so program the FEC to ignore it).
4774 Enable RMII mode for all FECs.
4775 Note that this is a global option, we can't
4776 have one FEC in standard MII mode and another in RMII mode.
4778 - CONFIG_CRC32_VERIFY
4779 Add a verify option to the crc32 command.
4782 => crc32 -v <address> <count> <crc32>
4784 Where address/count indicate a memory area
4785 and crc32 is the correct crc32 which the
4789 Add the "loopw" memory command. This only takes effect if
4790 the memory commands are activated globally (CONFIG_CMD_MEM).
4793 Add the "mdc" and "mwc" memory commands. These are cyclic
4798 This command will print 4 bytes (10,11,12,13) each 500 ms.
4800 => mwc.l 100 12345678 10
4801 This command will write 12345678 to address 100 all 10 ms.
4803 This only takes effect if the memory commands are activated
4804 globally (CONFIG_CMD_MEM).
4806 - CONFIG_SKIP_LOWLEVEL_INIT
4807 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4808 low level initializations (like setting up the memory
4809 controller) are omitted and/or U-Boot does not
4810 relocate itself into RAM.
4812 Normally this variable MUST NOT be defined. The only
4813 exception is when U-Boot is loaded (to RAM) by some
4814 other boot loader or by a debugger which performs
4815 these initializations itself.
4818 Modifies the behaviour of start.S when compiling a loader
4819 that is executed before the actual U-Boot. E.g. when
4820 compiling a NAND SPL.
4823 Modifies the behaviour of start.S when compiling a loader
4824 that is executed after the SPL and before the actual U-Boot.
4825 It is loaded by the SPL.
4827 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4828 Only for 85xx systems. If this variable is specified, the section
4829 .resetvec is not kept and the section .bootpg is placed in the
4830 previous 4k of the .text section.
4832 - CONFIG_ARCH_MAP_SYSMEM
4833 Generally U-Boot (and in particular the md command) uses
4834 effective address. It is therefore not necessary to regard
4835 U-Boot address as virtual addresses that need to be translated
4836 to physical addresses. However, sandbox requires this, since
4837 it maintains its own little RAM buffer which contains all
4838 addressable memory. This option causes some memory accesses
4839 to be mapped through map_sysmem() / unmap_sysmem().
4841 - CONFIG_USE_ARCH_MEMCPY
4842 CONFIG_USE_ARCH_MEMSET
4843 If these options are used a optimized version of memcpy/memset will
4844 be used if available. These functions may be faster under some
4845 conditions but may increase the binary size.
4847 - CONFIG_X86_RESET_VECTOR
4848 If defined, the x86 reset vector code is included. This is not
4849 needed when U-Boot is running from Coreboot.
4852 Defines the MPU clock speed (in MHz).
4854 NOTE : currently only supported on AM335x platforms.
4856 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4857 Enables the RTC32K OSC on AM33xx based plattforms
4859 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4860 Option to disable subpage write in NAND driver
4861 driver that uses this:
4862 drivers/mtd/nand/davinci_nand.c
4864 Freescale QE/FMAN Firmware Support:
4865 -----------------------------------
4867 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4868 loading of "firmware", which is encoded in the QE firmware binary format.
4869 This firmware often needs to be loaded during U-Boot booting, so macros
4870 are used to identify the storage device (NOR flash, SPI, etc) and the address
4873 - CONFIG_SYS_FMAN_FW_ADDR
4874 The address in the storage device where the FMAN microcode is located. The
4875 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4878 - CONFIG_SYS_QE_FW_ADDR
4879 The address in the storage device where the QE microcode is located. The
4880 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4883 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4884 The maximum possible size of the firmware. The firmware binary format
4885 has a field that specifies the actual size of the firmware, but it
4886 might not be possible to read any part of the firmware unless some
4887 local storage is allocated to hold the entire firmware first.
4889 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4890 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4891 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4892 virtual address in NOR flash.
4894 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4895 Specifies that QE/FMAN firmware is located in NAND flash.
4896 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4898 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4899 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4900 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4902 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4903 Specifies that QE/FMAN firmware is located on the primary SPI
4904 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4906 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4907 Specifies that QE/FMAN firmware is located in the remote (master)
4908 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4909 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4910 window->master inbound window->master LAW->the ucode address in
4911 master's memory space.
4913 Freescale Layerscape Management Complex Firmware Support:
4914 ---------------------------------------------------------
4915 The Freescale Layerscape Management Complex (MC) supports the loading of
4917 This firmware often needs to be loaded during U-Boot booting, so macros
4918 are used to identify the storage device (NOR flash, SPI, etc) and the address
4921 - CONFIG_FSL_MC_ENET
4922 Enable the MC driver for Layerscape SoCs.
4924 - CONFIG_SYS_LS_MC_FW_ADDR
4925 The address in the storage device where the firmware is located. The
4926 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
4929 - CONFIG_SYS_LS_MC_FW_LENGTH
4930 The maximum possible size of the firmware. The firmware binary format
4931 has a field that specifies the actual size of the firmware, but it
4932 might not be possible to read any part of the firmware unless some
4933 local storage is allocated to hold the entire firmware first.
4935 - CONFIG_SYS_LS_MC_FW_IN_NOR
4936 Specifies that MC firmware is located in NOR flash, mapped as
4937 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
4938 virtual address in NOR flash.
4940 Building the Software:
4941 ======================
4943 Building U-Boot has been tested in several native build environments
4944 and in many different cross environments. Of course we cannot support
4945 all possibly existing versions of cross development tools in all
4946 (potentially obsolete) versions. In case of tool chain problems we
4947 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4948 which is extensively used to build and test U-Boot.
4950 If you are not using a native environment, it is assumed that you
4951 have GNU cross compiling tools available in your path. In this case,
4952 you must set the environment variable CROSS_COMPILE in your shell.
4953 Note that no changes to the Makefile or any other source files are
4954 necessary. For example using the ELDK on a 4xx CPU, please enter:
4956 $ CROSS_COMPILE=ppc_4xx-
4957 $ export CROSS_COMPILE
4959 Note: If you wish to generate Windows versions of the utilities in
4960 the tools directory you can use the MinGW toolchain
4961 (http://www.mingw.org). Set your HOST tools to the MinGW
4962 toolchain and execute 'make tools'. For example:
4964 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4966 Binaries such as tools/mkimage.exe will be created which can
4967 be executed on computers running Windows.
4969 U-Boot is intended to be simple to build. After installing the
4970 sources you must configure U-Boot for one specific board type. This
4975 where "NAME_defconfig" is the name of one of the existing configu-
4976 rations; see boards.cfg for supported names.
4978 Note: for some board special configuration names may exist; check if
4979 additional information is available from the board vendor; for
4980 instance, the TQM823L systems are available without (standard)
4981 or with LCD support. You can select such additional "features"
4982 when choosing the configuration, i. e.
4984 make TQM823L_defconfig
4985 - will configure for a plain TQM823L, i. e. no LCD support
4987 make TQM823L_LCD_defconfig
4988 - will configure for a TQM823L with U-Boot console on LCD
4993 Finally, type "make all", and you should get some working U-Boot
4994 images ready for download to / installation on your system:
4996 - "u-boot.bin" is a raw binary image
4997 - "u-boot" is an image in ELF binary format
4998 - "u-boot.srec" is in Motorola S-Record format
5000 By default the build is performed locally and the objects are saved
5001 in the source directory. One of the two methods can be used to change
5002 this behavior and build U-Boot to some external directory:
5004 1. Add O= to the make command line invocations:
5006 make O=/tmp/build distclean
5007 make O=/tmp/build NAME_defconfig
5008 make O=/tmp/build all
5010 2. Set environment variable BUILD_DIR to point to the desired location:
5012 export BUILD_DIR=/tmp/build
5017 Note that the command line "O=" setting overrides the BUILD_DIR environment
5021 Please be aware that the Makefiles assume you are using GNU make, so
5022 for instance on NetBSD you might need to use "gmake" instead of
5026 If the system board that you have is not listed, then you will need
5027 to port U-Boot to your hardware platform. To do this, follow these
5030 1. Add a new configuration option for your board to the toplevel
5031 "boards.cfg" file, using the existing entries as examples.
5032 Follow the instructions there to keep the boards in order.
5033 2. Create a new directory to hold your board specific code. Add any
5034 files you need. In your board directory, you will need at least
5035 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5036 3. Create a new configuration file "include/configs/<board>.h" for
5038 3. If you're porting U-Boot to a new CPU, then also create a new
5039 directory to hold your CPU specific code. Add any files you need.
5040 4. Run "make <board>_defconfig" with your new name.
5041 5. Type "make", and you should get a working "u-boot.srec" file
5042 to be installed on your target system.
5043 6. Debug and solve any problems that might arise.
5044 [Of course, this last step is much harder than it sounds.]
5047 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5048 ==============================================================
5050 If you have modified U-Boot sources (for instance added a new board
5051 or support for new devices, a new CPU, etc.) you are expected to
5052 provide feedback to the other developers. The feedback normally takes
5053 the form of a "patch", i. e. a context diff against a certain (latest
5054 official or latest in the git repository) version of U-Boot sources.
5056 But before you submit such a patch, please verify that your modifi-
5057 cation did not break existing code. At least make sure that *ALL* of
5058 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5059 just run the "MAKEALL" script, which will configure and build U-Boot
5060 for ALL supported system. Be warned, this will take a while. You can
5061 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5062 environment variable to the script, i. e. to use the ELDK cross tools
5065 CROSS_COMPILE=ppc_8xx- MAKEALL
5067 or to build on a native PowerPC system you can type
5069 CROSS_COMPILE=' ' MAKEALL
5071 When using the MAKEALL script, the default behaviour is to build
5072 U-Boot in the source directory. This location can be changed by
5073 setting the BUILD_DIR environment variable. Also, for each target
5074 built, the MAKEALL script saves two log files (<target>.ERR and
5075 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5076 location can be changed by setting the MAKEALL_LOGDIR environment
5077 variable. For example:
5079 export BUILD_DIR=/tmp/build
5080 export MAKEALL_LOGDIR=/tmp/log
5081 CROSS_COMPILE=ppc_8xx- MAKEALL
5083 With the above settings build objects are saved in the /tmp/build,
5084 log files are saved in the /tmp/log and the source tree remains clean
5085 during the whole build process.
5088 See also "U-Boot Porting Guide" below.
5091 Monitor Commands - Overview:
5092 ============================
5094 go - start application at address 'addr'
5095 run - run commands in an environment variable
5096 bootm - boot application image from memory
5097 bootp - boot image via network using BootP/TFTP protocol
5098 bootz - boot zImage from memory
5099 tftpboot- boot image via network using TFTP protocol
5100 and env variables "ipaddr" and "serverip"
5101 (and eventually "gatewayip")
5102 tftpput - upload a file via network using TFTP protocol
5103 rarpboot- boot image via network using RARP/TFTP protocol
5104 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5105 loads - load S-Record file over serial line
5106 loadb - load binary file over serial line (kermit mode)
5108 mm - memory modify (auto-incrementing)
5109 nm - memory modify (constant address)
5110 mw - memory write (fill)
5112 cmp - memory compare
5113 crc32 - checksum calculation
5114 i2c - I2C sub-system
5115 sspi - SPI utility commands
5116 base - print or set address offset
5117 printenv- print environment variables
5118 setenv - set environment variables
5119 saveenv - save environment variables to persistent storage
5120 protect - enable or disable FLASH write protection
5121 erase - erase FLASH memory
5122 flinfo - print FLASH memory information
5123 nand - NAND memory operations (see doc/README.nand)
5124 bdinfo - print Board Info structure
5125 iminfo - print header information for application image
5126 coninfo - print console devices and informations
5127 ide - IDE sub-system
5128 loop - infinite loop on address range
5129 loopw - infinite write loop on address range
5130 mtest - simple RAM test
5131 icache - enable or disable instruction cache
5132 dcache - enable or disable data cache
5133 reset - Perform RESET of the CPU
5134 echo - echo args to console
5135 version - print monitor version
5136 help - print online help
5137 ? - alias for 'help'
5140 Monitor Commands - Detailed Description:
5141 ========================================
5145 For now: just type "help <command>".
5148 Environment Variables:
5149 ======================
5151 U-Boot supports user configuration using Environment Variables which
5152 can be made persistent by saving to Flash memory.
5154 Environment Variables are set using "setenv", printed using
5155 "printenv", and saved to Flash using "saveenv". Using "setenv"
5156 without a value can be used to delete a variable from the
5157 environment. As long as you don't save the environment you are
5158 working with an in-memory copy. In case the Flash area containing the
5159 environment is erased by accident, a default environment is provided.
5161 Some configuration options can be set using Environment Variables.
5163 List of environment variables (most likely not complete):
5165 baudrate - see CONFIG_BAUDRATE
5167 bootdelay - see CONFIG_BOOTDELAY
5169 bootcmd - see CONFIG_BOOTCOMMAND
5171 bootargs - Boot arguments when booting an RTOS image
5173 bootfile - Name of the image to load with TFTP
5175 bootm_low - Memory range available for image processing in the bootm
5176 command can be restricted. This variable is given as
5177 a hexadecimal number and defines lowest address allowed
5178 for use by the bootm command. See also "bootm_size"
5179 environment variable. Address defined by "bootm_low" is
5180 also the base of the initial memory mapping for the Linux
5181 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5184 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5185 This variable is given as a hexadecimal number and it
5186 defines the size of the memory region starting at base
5187 address bootm_low that is accessible by the Linux kernel
5188 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5189 as the default value if it is defined, and bootm_size is
5192 bootm_size - Memory range available for image processing in the bootm
5193 command can be restricted. This variable is given as
5194 a hexadecimal number and defines the size of the region
5195 allowed for use by the bootm command. See also "bootm_low"
5196 environment variable.
5198 updatefile - Location of the software update file on a TFTP server, used
5199 by the automatic software update feature. Please refer to
5200 documentation in doc/README.update for more details.
5202 autoload - if set to "no" (any string beginning with 'n'),
5203 "bootp" will just load perform a lookup of the
5204 configuration from the BOOTP server, but not try to
5205 load any image using TFTP
5207 autostart - if set to "yes", an image loaded using the "bootp",
5208 "rarpboot", "tftpboot" or "diskboot" commands will
5209 be automatically started (by internally calling
5212 If set to "no", a standalone image passed to the
5213 "bootm" command will be copied to the load address
5214 (and eventually uncompressed), but NOT be started.
5215 This can be used to load and uncompress arbitrary
5218 fdt_high - if set this restricts the maximum address that the
5219 flattened device tree will be copied into upon boot.
5220 For example, if you have a system with 1 GB memory
5221 at physical address 0x10000000, while Linux kernel
5222 only recognizes the first 704 MB as low memory, you
5223 may need to set fdt_high as 0x3C000000 to have the
5224 device tree blob be copied to the maximum address
5225 of the 704 MB low memory, so that Linux kernel can
5226 access it during the boot procedure.
5228 If this is set to the special value 0xFFFFFFFF then
5229 the fdt will not be copied at all on boot. For this
5230 to work it must reside in writable memory, have
5231 sufficient padding on the end of it for u-boot to
5232 add the information it needs into it, and the memory
5233 must be accessible by the kernel.
5235 fdtcontroladdr- if set this is the address of the control flattened
5236 device tree used by U-Boot when CONFIG_OF_CONTROL is
5239 i2cfast - (PPC405GP|PPC405EP only)
5240 if set to 'y' configures Linux I2C driver for fast
5241 mode (400kHZ). This environment variable is used in
5242 initialization code. So, for changes to be effective
5243 it must be saved and board must be reset.
5245 initrd_high - restrict positioning of initrd images:
5246 If this variable is not set, initrd images will be
5247 copied to the highest possible address in RAM; this
5248 is usually what you want since it allows for
5249 maximum initrd size. If for some reason you want to
5250 make sure that the initrd image is loaded below the
5251 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5252 variable to a value of "no" or "off" or "0".
5253 Alternatively, you can set it to a maximum upper
5254 address to use (U-Boot will still check that it
5255 does not overwrite the U-Boot stack and data).
5257 For instance, when you have a system with 16 MB
5258 RAM, and want to reserve 4 MB from use by Linux,
5259 you can do this by adding "mem=12M" to the value of
5260 the "bootargs" variable. However, now you must make
5261 sure that the initrd image is placed in the first
5262 12 MB as well - this can be done with
5264 setenv initrd_high 00c00000
5266 If you set initrd_high to 0xFFFFFFFF, this is an
5267 indication to U-Boot that all addresses are legal
5268 for the Linux kernel, including addresses in flash
5269 memory. In this case U-Boot will NOT COPY the
5270 ramdisk at all. This may be useful to reduce the
5271 boot time on your system, but requires that this
5272 feature is supported by your Linux kernel.
5274 ipaddr - IP address; needed for tftpboot command
5276 loadaddr - Default load address for commands like "bootp",
5277 "rarpboot", "tftpboot", "loadb" or "diskboot"
5279 loads_echo - see CONFIG_LOADS_ECHO
5281 serverip - TFTP server IP address; needed for tftpboot command
5283 bootretry - see CONFIG_BOOT_RETRY_TIME
5285 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5287 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5289 ethprime - controls which interface is used first.
5291 ethact - controls which interface is currently active.
5292 For example you can do the following
5294 => setenv ethact FEC
5295 => ping 192.168.0.1 # traffic sent on FEC
5296 => setenv ethact SCC
5297 => ping 10.0.0.1 # traffic sent on SCC
5299 ethrotate - When set to "no" U-Boot does not go through all
5300 available network interfaces.
5301 It just stays at the currently selected interface.
5303 netretry - When set to "no" each network operation will
5304 either succeed or fail without retrying.
5305 When set to "once" the network operation will
5306 fail when all the available network interfaces
5307 are tried once without success.
5308 Useful on scripts which control the retry operation
5311 npe_ucode - set load address for the NPE microcode
5313 silent_linux - If set then linux will be told to boot silently, by
5314 changing the console to be empty. If "yes" it will be
5315 made silent. If "no" it will not be made silent. If
5316 unset, then it will be made silent if the U-Boot console
5319 tftpsrcport - If this is set, the value is used for TFTP's
5322 tftpdstport - If this is set, the value is used for TFTP's UDP
5323 destination port instead of the Well Know Port 69.
5325 tftpblocksize - Block size to use for TFTP transfers; if not set,
5326 we use the TFTP server's default block size
5328 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5329 seconds, minimum value is 1000 = 1 second). Defines
5330 when a packet is considered to be lost so it has to
5331 be retransmitted. The default is 5000 = 5 seconds.
5332 Lowering this value may make downloads succeed
5333 faster in networks with high packet loss rates or
5334 with unreliable TFTP servers.
5336 vlan - When set to a value < 4095 the traffic over
5337 Ethernet is encapsulated/received over 802.1q
5340 The following image location variables contain the location of images
5341 used in booting. The "Image" column gives the role of the image and is
5342 not an environment variable name. The other columns are environment
5343 variable names. "File Name" gives the name of the file on a TFTP
5344 server, "RAM Address" gives the location in RAM the image will be
5345 loaded to, and "Flash Location" gives the image's address in NOR
5346 flash or offset in NAND flash.
5348 *Note* - these variables don't have to be defined for all boards, some
5349 boards currenlty use other variables for these purposes, and some
5350 boards use these variables for other purposes.
5352 Image File Name RAM Address Flash Location
5353 ----- --------- ----------- --------------
5354 u-boot u-boot u-boot_addr_r u-boot_addr
5355 Linux kernel bootfile kernel_addr_r kernel_addr
5356 device tree blob fdtfile fdt_addr_r fdt_addr
5357 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5359 The following environment variables may be used and automatically
5360 updated by the network boot commands ("bootp" and "rarpboot"),
5361 depending the information provided by your boot server:
5363 bootfile - see above
5364 dnsip - IP address of your Domain Name Server
5365 dnsip2 - IP address of your secondary Domain Name Server
5366 gatewayip - IP address of the Gateway (Router) to use
5367 hostname - Target hostname
5369 netmask - Subnet Mask
5370 rootpath - Pathname of the root filesystem on the NFS server
5371 serverip - see above
5374 There are two special Environment Variables:
5376 serial# - contains hardware identification information such
5377 as type string and/or serial number
5378 ethaddr - Ethernet address
5380 These variables can be set only once (usually during manufacturing of
5381 the board). U-Boot refuses to delete or overwrite these variables
5382 once they have been set once.
5385 Further special Environment Variables:
5387 ver - Contains the U-Boot version string as printed
5388 with the "version" command. This variable is
5389 readonly (see CONFIG_VERSION_VARIABLE).
5392 Please note that changes to some configuration parameters may take
5393 only effect after the next boot (yes, that's just like Windoze :-).
5396 Callback functions for environment variables:
5397 ---------------------------------------------
5399 For some environment variables, the behavior of u-boot needs to change
5400 when their values are changed. This functionailty allows functions to
5401 be associated with arbitrary variables. On creation, overwrite, or
5402 deletion, the callback will provide the opportunity for some side
5403 effect to happen or for the change to be rejected.
5405 The callbacks are named and associated with a function using the
5406 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5408 These callbacks are associated with variables in one of two ways. The
5409 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5410 in the board configuration to a string that defines a list of
5411 associations. The list must be in the following format:
5413 entry = variable_name[:callback_name]
5416 If the callback name is not specified, then the callback is deleted.
5417 Spaces are also allowed anywhere in the list.
5419 Callbacks can also be associated by defining the ".callbacks" variable
5420 with the same list format above. Any association in ".callbacks" will
5421 override any association in the static list. You can define
5422 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5423 ".callbacks" envirnoment variable in the default or embedded environment.
5426 Command Line Parsing:
5427 =====================
5429 There are two different command line parsers available with U-Boot:
5430 the old "simple" one, and the much more powerful "hush" shell:
5432 Old, simple command line parser:
5433 --------------------------------
5435 - supports environment variables (through setenv / saveenv commands)
5436 - several commands on one line, separated by ';'
5437 - variable substitution using "... ${name} ..." syntax
5438 - special characters ('$', ';') can be escaped by prefixing with '\',
5440 setenv bootcmd bootm \${address}
5441 - You can also escape text by enclosing in single apostrophes, for example:
5442 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5447 - similar to Bourne shell, with control structures like
5448 if...then...else...fi, for...do...done; while...do...done,
5449 until...do...done, ...
5450 - supports environment ("global") variables (through setenv / saveenv
5451 commands) and local shell variables (through standard shell syntax
5452 "name=value"); only environment variables can be used with "run"
5458 (1) If a command line (or an environment variable executed by a "run"
5459 command) contains several commands separated by semicolon, and
5460 one of these commands fails, then the remaining commands will be
5463 (2) If you execute several variables with one call to run (i. e.
5464 calling run with a list of variables as arguments), any failing
5465 command will cause "run" to terminate, i. e. the remaining
5466 variables are not executed.
5468 Note for Redundant Ethernet Interfaces:
5469 =======================================
5471 Some boards come with redundant Ethernet interfaces; U-Boot supports
5472 such configurations and is capable of automatic selection of a
5473 "working" interface when needed. MAC assignment works as follows:
5475 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5476 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5477 "eth1addr" (=>eth1), "eth2addr", ...
5479 If the network interface stores some valid MAC address (for instance
5480 in SROM), this is used as default address if there is NO correspon-
5481 ding setting in the environment; if the corresponding environment
5482 variable is set, this overrides the settings in the card; that means:
5484 o If the SROM has a valid MAC address, and there is no address in the
5485 environment, the SROM's address is used.
5487 o If there is no valid address in the SROM, and a definition in the
5488 environment exists, then the value from the environment variable is
5491 o If both the SROM and the environment contain a MAC address, and
5492 both addresses are the same, this MAC address is used.
5494 o If both the SROM and the environment contain a MAC address, and the
5495 addresses differ, the value from the environment is used and a
5498 o If neither SROM nor the environment contain a MAC address, an error
5501 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5502 will be programmed into hardware as part of the initialization process. This
5503 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5504 The naming convention is as follows:
5505 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5510 U-Boot is capable of booting (and performing other auxiliary operations on)
5511 images in two formats:
5513 New uImage format (FIT)
5514 -----------------------
5516 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5517 to Flattened Device Tree). It allows the use of images with multiple
5518 components (several kernels, ramdisks, etc.), with contents protected by
5519 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5525 Old image format is based on binary files which can be basically anything,
5526 preceded by a special header; see the definitions in include/image.h for
5527 details; basically, the header defines the following image properties:
5529 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5530 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5531 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5532 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5534 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5535 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5536 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5537 * Compression Type (uncompressed, gzip, bzip2)
5543 The header is marked by a special Magic Number, and both the header
5544 and the data portions of the image are secured against corruption by
5551 Although U-Boot should support any OS or standalone application
5552 easily, the main focus has always been on Linux during the design of
5555 U-Boot includes many features that so far have been part of some
5556 special "boot loader" code within the Linux kernel. Also, any
5557 "initrd" images to be used are no longer part of one big Linux image;
5558 instead, kernel and "initrd" are separate images. This implementation
5559 serves several purposes:
5561 - the same features can be used for other OS or standalone
5562 applications (for instance: using compressed images to reduce the
5563 Flash memory footprint)
5565 - it becomes much easier to port new Linux kernel versions because
5566 lots of low-level, hardware dependent stuff are done by U-Boot
5568 - the same Linux kernel image can now be used with different "initrd"
5569 images; of course this also means that different kernel images can
5570 be run with the same "initrd". This makes testing easier (you don't
5571 have to build a new "zImage.initrd" Linux image when you just
5572 change a file in your "initrd"). Also, a field-upgrade of the
5573 software is easier now.
5579 Porting Linux to U-Boot based systems:
5580 ---------------------------------------
5582 U-Boot cannot save you from doing all the necessary modifications to
5583 configure the Linux device drivers for use with your target hardware
5584 (no, we don't intend to provide a full virtual machine interface to
5587 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5589 Just make sure your machine specific header file (for instance
5590 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5591 Information structure as we define in include/asm-<arch>/u-boot.h,
5592 and make sure that your definition of IMAP_ADDR uses the same value
5593 as your U-Boot configuration in CONFIG_SYS_IMMR.
5595 Note that U-Boot now has a driver model, a unified model for drivers.
5596 If you are adding a new driver, plumb it into driver model. If there
5597 is no uclass available, you are encouraged to create one. See
5601 Configuring the Linux kernel:
5602 -----------------------------
5604 No specific requirements for U-Boot. Make sure you have some root
5605 device (initial ramdisk, NFS) for your target system.
5608 Building a Linux Image:
5609 -----------------------
5611 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5612 not used. If you use recent kernel source, a new build target
5613 "uImage" will exist which automatically builds an image usable by
5614 U-Boot. Most older kernels also have support for a "pImage" target,
5615 which was introduced for our predecessor project PPCBoot and uses a
5616 100% compatible format.
5620 make TQM850L_defconfig
5625 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5626 encapsulate a compressed Linux kernel image with header information,
5627 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5629 * build a standard "vmlinux" kernel image (in ELF binary format):
5631 * convert the kernel into a raw binary image:
5633 ${CROSS_COMPILE}-objcopy -O binary \
5634 -R .note -R .comment \
5635 -S vmlinux linux.bin
5637 * compress the binary image:
5641 * package compressed binary image for U-Boot:
5643 mkimage -A ppc -O linux -T kernel -C gzip \
5644 -a 0 -e 0 -n "Linux Kernel Image" \
5645 -d linux.bin.gz uImage
5648 The "mkimage" tool can also be used to create ramdisk images for use
5649 with U-Boot, either separated from the Linux kernel image, or
5650 combined into one file. "mkimage" encapsulates the images with a 64
5651 byte header containing information about target architecture,
5652 operating system, image type, compression method, entry points, time
5653 stamp, CRC32 checksums, etc.
5655 "mkimage" can be called in two ways: to verify existing images and
5656 print the header information, or to build new images.
5658 In the first form (with "-l" option) mkimage lists the information
5659 contained in the header of an existing U-Boot image; this includes
5660 checksum verification:
5662 tools/mkimage -l image
5663 -l ==> list image header information
5665 The second form (with "-d" option) is used to build a U-Boot image
5666 from a "data file" which is used as image payload:
5668 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5669 -n name -d data_file image
5670 -A ==> set architecture to 'arch'
5671 -O ==> set operating system to 'os'
5672 -T ==> set image type to 'type'
5673 -C ==> set compression type 'comp'
5674 -a ==> set load address to 'addr' (hex)
5675 -e ==> set entry point to 'ep' (hex)
5676 -n ==> set image name to 'name'
5677 -d ==> use image data from 'datafile'
5679 Right now, all Linux kernels for PowerPC systems use the same load
5680 address (0x00000000), but the entry point address depends on the
5683 - 2.2.x kernels have the entry point at 0x0000000C,
5684 - 2.3.x and later kernels have the entry point at 0x00000000.
5686 So a typical call to build a U-Boot image would read:
5688 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5689 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5690 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5691 > examples/uImage.TQM850L
5692 Image Name: 2.4.4 kernel for TQM850L
5693 Created: Wed Jul 19 02:34:59 2000
5694 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5695 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5696 Load Address: 0x00000000
5697 Entry Point: 0x00000000
5699 To verify the contents of the image (or check for corruption):
5701 -> tools/mkimage -l examples/uImage.TQM850L
5702 Image Name: 2.4.4 kernel for TQM850L
5703 Created: Wed Jul 19 02:34:59 2000
5704 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5705 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5706 Load Address: 0x00000000
5707 Entry Point: 0x00000000
5709 NOTE: for embedded systems where boot time is critical you can trade
5710 speed for memory and install an UNCOMPRESSED image instead: this
5711 needs more space in Flash, but boots much faster since it does not
5712 need to be uncompressed:
5714 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5715 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5716 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5717 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5718 > examples/uImage.TQM850L-uncompressed
5719 Image Name: 2.4.4 kernel for TQM850L
5720 Created: Wed Jul 19 02:34:59 2000
5721 Image Type: PowerPC Linux Kernel Image (uncompressed)
5722 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5723 Load Address: 0x00000000
5724 Entry Point: 0x00000000
5727 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5728 when your kernel is intended to use an initial ramdisk:
5730 -> tools/mkimage -n 'Simple Ramdisk Image' \
5731 > -A ppc -O linux -T ramdisk -C gzip \
5732 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5733 Image Name: Simple Ramdisk Image
5734 Created: Wed Jan 12 14:01:50 2000
5735 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5736 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5737 Load Address: 0x00000000
5738 Entry Point: 0x00000000
5740 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5741 option performs the converse operation of the mkimage's second form (the "-d"
5742 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5745 tools/dumpimage -i image -p position data_file
5746 -i ==> extract from the 'image' a specific 'data_file', \
5747 indexed by 'position'
5750 Installing a Linux Image:
5751 -------------------------
5753 To downloading a U-Boot image over the serial (console) interface,
5754 you must convert the image to S-Record format:
5756 objcopy -I binary -O srec examples/image examples/image.srec
5758 The 'objcopy' does not understand the information in the U-Boot
5759 image header, so the resulting S-Record file will be relative to
5760 address 0x00000000. To load it to a given address, you need to
5761 specify the target address as 'offset' parameter with the 'loads'
5764 Example: install the image to address 0x40100000 (which on the
5765 TQM8xxL is in the first Flash bank):
5767 => erase 40100000 401FFFFF
5773 ## Ready for S-Record download ...
5774 ~>examples/image.srec
5775 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5777 15989 15990 15991 15992
5778 [file transfer complete]
5780 ## Start Addr = 0x00000000
5783 You can check the success of the download using the 'iminfo' command;
5784 this includes a checksum verification so you can be sure no data
5785 corruption happened:
5789 ## Checking Image at 40100000 ...
5790 Image Name: 2.2.13 for initrd on TQM850L
5791 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5792 Data Size: 335725 Bytes = 327 kB = 0 MB
5793 Load Address: 00000000
5794 Entry Point: 0000000c
5795 Verifying Checksum ... OK
5801 The "bootm" command is used to boot an application that is stored in
5802 memory (RAM or Flash). In case of a Linux kernel image, the contents
5803 of the "bootargs" environment variable is passed to the kernel as
5804 parameters. You can check and modify this variable using the
5805 "printenv" and "setenv" commands:
5808 => printenv bootargs
5809 bootargs=root=/dev/ram
5811 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5813 => printenv bootargs
5814 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5817 ## Booting Linux kernel at 40020000 ...
5818 Image Name: 2.2.13 for NFS on TQM850L
5819 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5820 Data Size: 381681 Bytes = 372 kB = 0 MB
5821 Load Address: 00000000
5822 Entry Point: 0000000c
5823 Verifying Checksum ... OK
5824 Uncompressing Kernel Image ... OK
5825 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
5826 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5827 time_init: decrementer frequency = 187500000/60
5828 Calibrating delay loop... 49.77 BogoMIPS
5829 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5832 If you want to boot a Linux kernel with initial RAM disk, you pass
5833 the memory addresses of both the kernel and the initrd image (PPBCOOT
5834 format!) to the "bootm" command:
5836 => imi 40100000 40200000
5838 ## Checking Image at 40100000 ...
5839 Image Name: 2.2.13 for initrd on TQM850L
5840 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5841 Data Size: 335725 Bytes = 327 kB = 0 MB
5842 Load Address: 00000000
5843 Entry Point: 0000000c
5844 Verifying Checksum ... OK
5846 ## Checking Image at 40200000 ...
5847 Image Name: Simple Ramdisk Image
5848 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5849 Data Size: 566530 Bytes = 553 kB = 0 MB
5850 Load Address: 00000000
5851 Entry Point: 00000000
5852 Verifying Checksum ... OK
5854 => bootm 40100000 40200000
5855 ## Booting Linux kernel at 40100000 ...
5856 Image Name: 2.2.13 for initrd on TQM850L
5857 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5858 Data Size: 335725 Bytes = 327 kB = 0 MB
5859 Load Address: 00000000
5860 Entry Point: 0000000c
5861 Verifying Checksum ... OK
5862 Uncompressing Kernel Image ... OK
5863 ## Loading RAMDisk Image at 40200000 ...
5864 Image Name: Simple Ramdisk Image
5865 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5866 Data Size: 566530 Bytes = 553 kB = 0 MB
5867 Load Address: 00000000
5868 Entry Point: 00000000
5869 Verifying Checksum ... OK
5870 Loading Ramdisk ... OK
5871 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
5872 Boot arguments: root=/dev/ram
5873 time_init: decrementer frequency = 187500000/60
5874 Calibrating delay loop... 49.77 BogoMIPS
5876 RAMDISK: Compressed image found at block 0
5877 VFS: Mounted root (ext2 filesystem).
5881 Boot Linux and pass a flat device tree:
5884 First, U-Boot must be compiled with the appropriate defines. See the section
5885 titled "Linux Kernel Interface" above for a more in depth explanation. The
5886 following is an example of how to start a kernel and pass an updated
5892 oft=oftrees/mpc8540ads.dtb
5893 => tftp $oftaddr $oft
5894 Speed: 1000, full duplex
5896 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5897 Filename 'oftrees/mpc8540ads.dtb'.
5898 Load address: 0x300000
5901 Bytes transferred = 4106 (100a hex)
5902 => tftp $loadaddr $bootfile
5903 Speed: 1000, full duplex
5905 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5907 Load address: 0x200000
5908 Loading:############
5910 Bytes transferred = 1029407 (fb51f hex)
5915 => bootm $loadaddr - $oftaddr
5916 ## Booting image at 00200000 ...
5917 Image Name: Linux-2.6.17-dirty
5918 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5919 Data Size: 1029343 Bytes = 1005.2 kB
5920 Load Address: 00000000
5921 Entry Point: 00000000
5922 Verifying Checksum ... OK
5923 Uncompressing Kernel Image ... OK
5924 Booting using flat device tree at 0x300000
5925 Using MPC85xx ADS machine description
5926 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5930 More About U-Boot Image Types:
5931 ------------------------------
5933 U-Boot supports the following image types:
5935 "Standalone Programs" are directly runnable in the environment
5936 provided by U-Boot; it is expected that (if they behave
5937 well) you can continue to work in U-Boot after return from
5938 the Standalone Program.
5939 "OS Kernel Images" are usually images of some Embedded OS which
5940 will take over control completely. Usually these programs
5941 will install their own set of exception handlers, device
5942 drivers, set up the MMU, etc. - this means, that you cannot
5943 expect to re-enter U-Boot except by resetting the CPU.
5944 "RAMDisk Images" are more or less just data blocks, and their
5945 parameters (address, size) are passed to an OS kernel that is
5947 "Multi-File Images" contain several images, typically an OS
5948 (Linux) kernel image and one or more data images like
5949 RAMDisks. This construct is useful for instance when you want
5950 to boot over the network using BOOTP etc., where the boot
5951 server provides just a single image file, but you want to get
5952 for instance an OS kernel and a RAMDisk image.
5954 "Multi-File Images" start with a list of image sizes, each
5955 image size (in bytes) specified by an "uint32_t" in network
5956 byte order. This list is terminated by an "(uint32_t)0".
5957 Immediately after the terminating 0 follow the images, one by
5958 one, all aligned on "uint32_t" boundaries (size rounded up to
5959 a multiple of 4 bytes).
5961 "Firmware Images" are binary images containing firmware (like
5962 U-Boot or FPGA images) which usually will be programmed to
5965 "Script files" are command sequences that will be executed by
5966 U-Boot's command interpreter; this feature is especially
5967 useful when you configure U-Boot to use a real shell (hush)
5968 as command interpreter.
5970 Booting the Linux zImage:
5971 -------------------------
5973 On some platforms, it's possible to boot Linux zImage. This is done
5974 using the "bootz" command. The syntax of "bootz" command is the same
5975 as the syntax of "bootm" command.
5977 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5978 kernel with raw initrd images. The syntax is slightly different, the
5979 address of the initrd must be augmented by it's size, in the following
5980 format: "<initrd addres>:<initrd size>".
5986 One of the features of U-Boot is that you can dynamically load and
5987 run "standalone" applications, which can use some resources of
5988 U-Boot like console I/O functions or interrupt services.
5990 Two simple examples are included with the sources:
5995 'examples/hello_world.c' contains a small "Hello World" Demo
5996 application; it is automatically compiled when you build U-Boot.
5997 It's configured to run at address 0x00040004, so you can play with it
6001 ## Ready for S-Record download ...
6002 ~>examples/hello_world.srec
6003 1 2 3 4 5 6 7 8 9 10 11 ...
6004 [file transfer complete]
6006 ## Start Addr = 0x00040004
6008 => go 40004 Hello World! This is a test.
6009 ## Starting application at 0x00040004 ...
6020 Hit any key to exit ...
6022 ## Application terminated, rc = 0x0
6024 Another example, which demonstrates how to register a CPM interrupt
6025 handler with the U-Boot code, can be found in 'examples/timer.c'.
6026 Here, a CPM timer is set up to generate an interrupt every second.
6027 The interrupt service routine is trivial, just printing a '.'
6028 character, but this is just a demo program. The application can be
6029 controlled by the following keys:
6031 ? - print current values og the CPM Timer registers
6032 b - enable interrupts and start timer
6033 e - stop timer and disable interrupts
6034 q - quit application
6037 ## Ready for S-Record download ...
6038 ~>examples/timer.srec
6039 1 2 3 4 5 6 7 8 9 10 11 ...
6040 [file transfer complete]
6042 ## Start Addr = 0x00040004
6045 ## Starting application at 0x00040004 ...
6048 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6051 [q, b, e, ?] Set interval 1000000 us
6054 [q, b, e, ?] ........
6055 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6058 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6061 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6064 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6066 [q, b, e, ?] ...Stopping timer
6068 [q, b, e, ?] ## Application terminated, rc = 0x0
6074 Over time, many people have reported problems when trying to use the
6075 "minicom" terminal emulation program for serial download. I (wd)
6076 consider minicom to be broken, and recommend not to use it. Under
6077 Unix, I recommend to use C-Kermit for general purpose use (and
6078 especially for kermit binary protocol download ("loadb" command), and
6079 use "cu" for S-Record download ("loads" command). See
6080 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6081 for help with kermit.
6084 Nevertheless, if you absolutely want to use it try adding this
6085 configuration to your "File transfer protocols" section:
6087 Name Program Name U/D FullScr IO-Red. Multi
6088 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6089 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6095 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6096 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6098 Building requires a cross environment; it is known to work on
6099 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6100 need gmake since the Makefiles are not compatible with BSD make).
6101 Note that the cross-powerpc package does not install include files;
6102 attempting to build U-Boot will fail because <machine/ansi.h> is
6103 missing. This file has to be installed and patched manually:
6105 # cd /usr/pkg/cross/powerpc-netbsd/include
6107 # ln -s powerpc machine
6108 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6109 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6111 Native builds *don't* work due to incompatibilities between native
6112 and U-Boot include files.
6114 Booting assumes that (the first part of) the image booted is a
6115 stage-2 loader which in turn loads and then invokes the kernel
6116 proper. Loader sources will eventually appear in the NetBSD source
6117 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6118 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6121 Implementation Internals:
6122 =========================
6124 The following is not intended to be a complete description of every
6125 implementation detail. However, it should help to understand the
6126 inner workings of U-Boot and make it easier to port it to custom
6130 Initial Stack, Global Data:
6131 ---------------------------
6133 The implementation of U-Boot is complicated by the fact that U-Boot
6134 starts running out of ROM (flash memory), usually without access to
6135 system RAM (because the memory controller is not initialized yet).
6136 This means that we don't have writable Data or BSS segments, and BSS
6137 is not initialized as zero. To be able to get a C environment working
6138 at all, we have to allocate at least a minimal stack. Implementation
6139 options for this are defined and restricted by the CPU used: Some CPU
6140 models provide on-chip memory (like the IMMR area on MPC8xx and
6141 MPC826x processors), on others (parts of) the data cache can be
6142 locked as (mis-) used as memory, etc.
6144 Chris Hallinan posted a good summary of these issues to the
6145 U-Boot mailing list:
6147 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6148 From: "Chris Hallinan" <clh@net1plus.com>
6149 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6152 Correct me if I'm wrong, folks, but the way I understand it
6153 is this: Using DCACHE as initial RAM for Stack, etc, does not
6154 require any physical RAM backing up the cache. The cleverness
6155 is that the cache is being used as a temporary supply of
6156 necessary storage before the SDRAM controller is setup. It's
6157 beyond the scope of this list to explain the details, but you
6158 can see how this works by studying the cache architecture and
6159 operation in the architecture and processor-specific manuals.
6161 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6162 is another option for the system designer to use as an
6163 initial stack/RAM area prior to SDRAM being available. Either
6164 option should work for you. Using CS 4 should be fine if your
6165 board designers haven't used it for something that would
6166 cause you grief during the initial boot! It is frequently not
6169 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6170 with your processor/board/system design. The default value
6171 you will find in any recent u-boot distribution in
6172 walnut.h should work for you. I'd set it to a value larger
6173 than your SDRAM module. If you have a 64MB SDRAM module, set
6174 it above 400_0000. Just make sure your board has no resources
6175 that are supposed to respond to that address! That code in
6176 start.S has been around a while and should work as is when
6177 you get the config right.
6182 It is essential to remember this, since it has some impact on the C
6183 code for the initialization procedures:
6185 * Initialized global data (data segment) is read-only. Do not attempt
6188 * Do not use any uninitialized global data (or implicitely initialized
6189 as zero data - BSS segment) at all - this is undefined, initiali-
6190 zation is performed later (when relocating to RAM).
6192 * Stack space is very limited. Avoid big data buffers or things like
6195 Having only the stack as writable memory limits means we cannot use
6196 normal global data to share information beween the code. But it
6197 turned out that the implementation of U-Boot can be greatly
6198 simplified by making a global data structure (gd_t) available to all
6199 functions. We could pass a pointer to this data as argument to _all_
6200 functions, but this would bloat the code. Instead we use a feature of
6201 the GCC compiler (Global Register Variables) to share the data: we
6202 place a pointer (gd) to the global data into a register which we
6203 reserve for this purpose.
6205 When choosing a register for such a purpose we are restricted by the
6206 relevant (E)ABI specifications for the current architecture, and by
6207 GCC's implementation.
6209 For PowerPC, the following registers have specific use:
6211 R2: reserved for system use
6212 R3-R4: parameter passing and return values
6213 R5-R10: parameter passing
6214 R13: small data area pointer
6218 (U-Boot also uses R12 as internal GOT pointer. r12
6219 is a volatile register so r12 needs to be reset when
6220 going back and forth between asm and C)
6222 ==> U-Boot will use R2 to hold a pointer to the global data
6224 Note: on PPC, we could use a static initializer (since the
6225 address of the global data structure is known at compile time),
6226 but it turned out that reserving a register results in somewhat
6227 smaller code - although the code savings are not that big (on
6228 average for all boards 752 bytes for the whole U-Boot image,
6229 624 text + 127 data).
6231 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6232 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6234 ==> U-Boot will use P3 to hold a pointer to the global data
6236 On ARM, the following registers are used:
6238 R0: function argument word/integer result
6239 R1-R3: function argument word
6240 R9: platform specific
6241 R10: stack limit (used only if stack checking is enabled)
6242 R11: argument (frame) pointer
6243 R12: temporary workspace
6246 R15: program counter
6248 ==> U-Boot will use R9 to hold a pointer to the global data
6250 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6252 On Nios II, the ABI is documented here:
6253 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6255 ==> U-Boot will use gp to hold a pointer to the global data
6257 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6258 to access small data sections, so gp is free.
6260 On NDS32, the following registers are used:
6262 R0-R1: argument/return
6264 R15: temporary register for assembler
6265 R16: trampoline register
6266 R28: frame pointer (FP)
6267 R29: global pointer (GP)
6268 R30: link register (LP)
6269 R31: stack pointer (SP)
6270 PC: program counter (PC)
6272 ==> U-Boot will use R10 to hold a pointer to the global data
6274 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6275 or current versions of GCC may "optimize" the code too much.
6280 U-Boot runs in system state and uses physical addresses, i.e. the
6281 MMU is not used either for address mapping nor for memory protection.
6283 The available memory is mapped to fixed addresses using the memory
6284 controller. In this process, a contiguous block is formed for each
6285 memory type (Flash, SDRAM, SRAM), even when it consists of several
6286 physical memory banks.
6288 U-Boot is installed in the first 128 kB of the first Flash bank (on
6289 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6290 booting and sizing and initializing DRAM, the code relocates itself
6291 to the upper end of DRAM. Immediately below the U-Boot code some
6292 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6293 configuration setting]. Below that, a structure with global Board
6294 Info data is placed, followed by the stack (growing downward).
6296 Additionally, some exception handler code is copied to the low 8 kB
6297 of DRAM (0x00000000 ... 0x00001FFF).
6299 So a typical memory configuration with 16 MB of DRAM could look like
6302 0x0000 0000 Exception Vector code
6305 0x0000 2000 Free for Application Use
6311 0x00FB FF20 Monitor Stack (Growing downward)
6312 0x00FB FFAC Board Info Data and permanent copy of global data
6313 0x00FC 0000 Malloc Arena
6316 0x00FE 0000 RAM Copy of Monitor Code
6317 ... eventually: LCD or video framebuffer
6318 ... eventually: pRAM (Protected RAM - unchanged by reset)
6319 0x00FF FFFF [End of RAM]
6322 System Initialization:
6323 ----------------------
6325 In the reset configuration, U-Boot starts at the reset entry point
6326 (on most PowerPC systems at address 0x00000100). Because of the reset
6327 configuration for CS0# this is a mirror of the onboard Flash memory.
6328 To be able to re-map memory U-Boot then jumps to its link address.
6329 To be able to implement the initialization code in C, a (small!)
6330 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6331 which provide such a feature like MPC8xx or MPC8260), or in a locked
6332 part of the data cache. After that, U-Boot initializes the CPU core,
6333 the caches and the SIU.
6335 Next, all (potentially) available memory banks are mapped using a
6336 preliminary mapping. For example, we put them on 512 MB boundaries
6337 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6338 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6339 programmed for SDRAM access. Using the temporary configuration, a
6340 simple memory test is run that determines the size of the SDRAM
6343 When there is more than one SDRAM bank, and the banks are of
6344 different size, the largest is mapped first. For equal size, the first
6345 bank (CS2#) is mapped first. The first mapping is always for address
6346 0x00000000, with any additional banks following immediately to create
6347 contiguous memory starting from 0.
6349 Then, the monitor installs itself at the upper end of the SDRAM area
6350 and allocates memory for use by malloc() and for the global Board
6351 Info data; also, the exception vector code is copied to the low RAM
6352 pages, and the final stack is set up.
6354 Only after this relocation will you have a "normal" C environment;
6355 until that you are restricted in several ways, mostly because you are
6356 running from ROM, and because the code will have to be relocated to a
6360 U-Boot Porting Guide:
6361 ----------------------
6363 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6367 int main(int argc, char *argv[])
6369 sighandler_t no_more_time;
6371 signal(SIGALRM, no_more_time);
6372 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6374 if (available_money > available_manpower) {
6375 Pay consultant to port U-Boot;
6379 Download latest U-Boot source;
6381 Subscribe to u-boot mailing list;
6384 email("Hi, I am new to U-Boot, how do I get started?");
6387 Read the README file in the top level directory;
6388 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6389 Read applicable doc/*.README;
6390 Read the source, Luke;
6391 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6394 if (available_money > toLocalCurrency ($2500))
6397 Add a lot of aggravation and time;
6399 if (a similar board exists) { /* hopefully... */
6400 cp -a board/<similar> board/<myboard>
6401 cp include/configs/<similar>.h include/configs/<myboard>.h
6403 Create your own board support subdirectory;
6404 Create your own board include/configs/<myboard>.h file;
6406 Edit new board/<myboard> files
6407 Edit new include/configs/<myboard>.h
6412 Add / modify source code;
6416 email("Hi, I am having problems...");
6418 Send patch file to the U-Boot email list;
6419 if (reasonable critiques)
6420 Incorporate improvements from email list code review;
6422 Defend code as written;
6428 void no_more_time (int sig)
6437 All contributions to U-Boot should conform to the Linux kernel
6438 coding style; see the file "Documentation/CodingStyle" and the script
6439 "scripts/Lindent" in your Linux kernel source directory.
6441 Source files originating from a different project (for example the
6442 MTD subsystem) are generally exempt from these guidelines and are not
6443 reformated to ease subsequent migration to newer versions of those
6446 Please note that U-Boot is implemented in C (and to some small parts in
6447 Assembler); no C++ is used, so please do not use C++ style comments (//)
6450 Please also stick to the following formatting rules:
6451 - remove any trailing white space
6452 - use TAB characters for indentation and vertical alignment, not spaces
6453 - make sure NOT to use DOS '\r\n' line feeds
6454 - do not add more than 2 consecutive empty lines to source files
6455 - do not add trailing empty lines to source files
6457 Submissions which do not conform to the standards may be returned
6458 with a request to reformat the changes.
6464 Since the number of patches for U-Boot is growing, we need to
6465 establish some rules. Submissions which do not conform to these rules
6466 may be rejected, even when they contain important and valuable stuff.
6468 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6470 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6471 see http://lists.denx.de/mailman/listinfo/u-boot
6473 When you send a patch, please include the following information with
6476 * For bug fixes: a description of the bug and how your patch fixes
6477 this bug. Please try to include a way of demonstrating that the
6478 patch actually fixes something.
6480 * For new features: a description of the feature and your
6483 * A CHANGELOG entry as plaintext (separate from the patch)
6485 * For major contributions, your entry to the CREDITS file
6487 * When you add support for a new board, don't forget to add a
6488 maintainer e-mail address to the boards.cfg file, too.
6490 * If your patch adds new configuration options, don't forget to
6491 document these in the README file.
6493 * The patch itself. If you are using git (which is *strongly*
6494 recommended) you can easily generate the patch using the
6495 "git format-patch". If you then use "git send-email" to send it to
6496 the U-Boot mailing list, you will avoid most of the common problems
6497 with some other mail clients.
6499 If you cannot use git, use "diff -purN OLD NEW". If your version of
6500 diff does not support these options, then get the latest version of
6503 The current directory when running this command shall be the parent
6504 directory of the U-Boot source tree (i. e. please make sure that
6505 your patch includes sufficient directory information for the
6508 We prefer patches as plain text. MIME attachments are discouraged,
6509 and compressed attachments must not be used.
6511 * If one logical set of modifications affects or creates several
6512 files, all these changes shall be submitted in a SINGLE patch file.
6514 * Changesets that contain different, unrelated modifications shall be
6515 submitted as SEPARATE patches, one patch per changeset.
6520 * Before sending the patch, run the MAKEALL script on your patched
6521 source tree and make sure that no errors or warnings are reported
6522 for any of the boards.
6524 * Keep your modifications to the necessary minimum: A patch
6525 containing several unrelated changes or arbitrary reformats will be
6526 returned with a request to re-formatting / split it.
6528 * If you modify existing code, make sure that your new code does not
6529 add to the memory footprint of the code ;-) Small is beautiful!
6530 When adding new features, these should compile conditionally only
6531 (using #ifdef), and the resulting code with the new feature
6532 disabled must not need more memory than the old code without your
6535 * Remember that there is a size limit of 100 kB per message on the
6536 u-boot mailing list. Bigger patches will be moderated. If they are
6537 reasonable and not too big, they will be acknowledged. But patches
6538 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob