2 # (C) Copyright 2000 - 2012
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # See file CREDITS for list of people who contributed to this
8 # This program is free software; you can redistribute it and/or
9 # modify it under the terms of the GNU General Public License as
10 # published by the Free Software Foundation; either version 2 of
11 # the License, or (at your option) any later version.
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with this program; if not, write to the Free Software
20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27 This directory contains the source code for U-Boot, a boot loader for
28 Embedded boards based on PowerPC, ARM, MIPS and several other
29 processors, which can be installed in a boot ROM and used to
30 initialize and test the hardware or to download and run application
33 The development of U-Boot is closely related to Linux: some parts of
34 the source code originate in the Linux source tree, we have some
35 header files in common, and special provision has been made to
36 support booting of Linux images.
38 Some attention has been paid to make this software easily
39 configurable and extendable. For instance, all monitor commands are
40 implemented with the same call interface, so that it's very easy to
41 add new commands. Also, instead of permanently adding rarely used
42 code (for instance hardware test utilities) to the monitor, you can
43 load and run it dynamically.
49 In general, all boards for which a configuration option exists in the
50 Makefile have been tested to some extent and can be considered
51 "working". In fact, many of them are used in production systems.
53 In case of problems see the CHANGELOG and CREDITS files to find out
54 who contributed the specific port. The MAINTAINERS file lists board
57 Note: There is no CHANGELOG file in the actual U-Boot source tree;
58 it can be created dynamically from the Git log using:
66 In case you have questions about, problems with or contributions for
67 U-Boot you should send a message to the U-Boot mailing list at
68 <u-boot@lists.denx.de>. There is also an archive of previous traffic
69 on the mailing list - please search the archive before asking FAQ's.
70 Please see http://lists.denx.de/pipermail/u-boot and
71 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
74 Where to get source code:
75 =========================
77 The U-Boot source code is maintained in the git repository at
78 git://www.denx.de/git/u-boot.git ; you can browse it online at
79 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
81 The "snapshot" links on this page allow you to download tarballs of
82 any version you might be interested in. Official releases are also
83 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
86 Pre-built (and tested) images are available from
87 ftp://ftp.denx.de/pub/u-boot/images/
93 - start from 8xxrom sources
94 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
96 - make it easier to add custom boards
97 - make it possible to add other [PowerPC] CPUs
98 - extend functions, especially:
99 * Provide extended interface to Linux boot loader
102 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
103 - create ARMBoot project (http://sourceforge.net/projects/armboot)
104 - add other CPU families (starting with ARM)
105 - create U-Boot project (http://sourceforge.net/projects/u-boot)
106 - current project page: see http://www.denx.de/wiki/U-Boot
112 The "official" name of this project is "Das U-Boot". The spelling
113 "U-Boot" shall be used in all written text (documentation, comments
114 in source files etc.). Example:
116 This is the README file for the U-Boot project.
118 File names etc. shall be based on the string "u-boot". Examples:
120 include/asm-ppc/u-boot.h
122 #include <asm/u-boot.h>
124 Variable names, preprocessor constants etc. shall be either based on
125 the string "u_boot" or on "U_BOOT". Example:
127 U_BOOT_VERSION u_boot_logo
128 IH_OS_U_BOOT u_boot_hush_start
134 Starting with the release in October 2008, the names of the releases
135 were changed from numerical release numbers without deeper meaning
136 into a time stamp based numbering. Regular releases are identified by
137 names consisting of the calendar year and month of the release date.
138 Additional fields (if present) indicate release candidates or bug fix
139 releases in "stable" maintenance trees.
142 U-Boot v2009.11 - Release November 2009
143 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
144 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
150 /arch Architecture specific files
151 /arm Files generic to ARM architecture
152 /cpu CPU specific files
153 /arm720t Files specific to ARM 720 CPUs
154 /arm920t Files specific to ARM 920 CPUs
155 /at91 Files specific to Atmel AT91RM9200 CPU
156 /imx Files specific to Freescale MC9328 i.MX CPUs
157 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
158 /arm925t Files specific to ARM 925 CPUs
159 /arm926ejs Files specific to ARM 926 CPUs
160 /arm1136 Files specific to ARM 1136 CPUs
161 /ixp Files specific to Intel XScale IXP CPUs
162 /pxa Files specific to Intel XScale PXA CPUs
163 /s3c44b0 Files specific to Samsung S3C44B0 CPUs
164 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
165 /lib Architecture specific library files
166 /avr32 Files generic to AVR32 architecture
167 /cpu CPU specific files
168 /lib Architecture specific library files
169 /blackfin Files generic to Analog Devices Blackfin architecture
170 /cpu CPU specific files
171 /lib Architecture specific library files
172 /x86 Files generic to x86 architecture
173 /cpu CPU specific files
174 /lib Architecture specific library files
175 /m68k Files generic to m68k architecture
176 /cpu CPU specific files
177 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
178 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
179 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
180 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
181 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
182 /lib Architecture specific library files
183 /microblaze Files generic to microblaze architecture
184 /cpu CPU specific files
185 /lib Architecture specific library files
186 /mips Files generic to MIPS architecture
187 /cpu CPU specific files
188 /mips32 Files specific to MIPS32 CPUs
189 /xburst Files specific to Ingenic XBurst CPUs
190 /lib Architecture specific library files
191 /nds32 Files generic to NDS32 architecture
192 /cpu CPU specific files
193 /n1213 Files specific to Andes Technology N1213 CPUs
194 /lib Architecture specific library files
195 /nios2 Files generic to Altera NIOS2 architecture
196 /cpu CPU specific files
197 /lib Architecture specific library files
198 /powerpc Files generic to PowerPC architecture
199 /cpu CPU specific files
200 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
201 /mpc5xx Files specific to Freescale MPC5xx CPUs
202 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
203 /mpc8xx Files specific to Freescale MPC8xx CPUs
204 /mpc824x Files specific to Freescale MPC824x CPUs
205 /mpc8260 Files specific to Freescale MPC8260 CPUs
206 /mpc85xx Files specific to Freescale MPC85xx CPUs
207 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
208 /lib Architecture specific library files
209 /sh Files generic to SH architecture
210 /cpu CPU specific files
211 /sh2 Files specific to sh2 CPUs
212 /sh3 Files specific to sh3 CPUs
213 /sh4 Files specific to sh4 CPUs
214 /lib Architecture specific library files
215 /sparc Files generic to SPARC architecture
216 /cpu CPU specific files
217 /leon2 Files specific to Gaisler LEON2 SPARC CPU
218 /leon3 Files specific to Gaisler LEON3 SPARC CPU
219 /lib Architecture specific library files
220 /api Machine/arch independent API for external apps
221 /board Board dependent files
222 /common Misc architecture independent functions
223 /disk Code for disk drive partition handling
224 /doc Documentation (don't expect too much)
225 /drivers Commonly used device drivers
226 /examples Example code for standalone applications, etc.
227 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
228 /include Header Files
229 /lib Files generic to all architectures
230 /libfdt Library files to support flattened device trees
231 /lzma Library files to support LZMA decompression
232 /lzo Library files to support LZO decompression
234 /post Power On Self Test
235 /rtc Real Time Clock drivers
236 /tools Tools to build S-Record or U-Boot images, etc.
238 Software Configuration:
239 =======================
241 Configuration is usually done using C preprocessor defines; the
242 rationale behind that is to avoid dead code whenever possible.
244 There are two classes of configuration variables:
246 * Configuration _OPTIONS_:
247 These are selectable by the user and have names beginning with
250 * Configuration _SETTINGS_:
251 These depend on the hardware etc. and should not be meddled with if
252 you don't know what you're doing; they have names beginning with
255 Later we will add a configuration tool - probably similar to or even
256 identical to what's used for the Linux kernel. Right now, we have to
257 do the configuration by hand, which means creating some symbolic
258 links and editing some configuration files. We use the TQM8xxL boards
262 Selection of Processor Architecture and Board Type:
263 ---------------------------------------------------
265 For all supported boards there are ready-to-use default
266 configurations available; just type "make <board_name>_config".
268 Example: For a TQM823L module type:
273 For the Cogent platform, you need to specify the CPU type as well;
274 e.g. "make cogent_mpc8xx_config". And also configure the cogent
275 directory according to the instructions in cogent/README.
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 - Board flavour: (if CONFIG_MPC8260ADS is defined)
327 CONFIG_SYS_8260ADS - original MPC8260ADS
328 CONFIG_SYS_8266ADS - MPC8266ADS
329 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
330 CONFIG_SYS_8272ADS - MPC8272ADS
332 - Marvell Family Member
333 CONFIG_SYS_MVFS - define it if you want to enable
334 multiple fs option at one time
335 for marvell soc family
337 - MPC824X Family Member (if CONFIG_MPC824X is defined)
338 Define exactly one of
339 CONFIG_MPC8240, CONFIG_MPC8245
341 - 8xx CPU Options: (if using an MPC8xx CPU)
342 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
343 get_gclk_freq() cannot work
344 e.g. if there is no 32KHz
345 reference PIT/RTC clock
346 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
349 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
350 CONFIG_SYS_8xx_CPUCLK_MIN
351 CONFIG_SYS_8xx_CPUCLK_MAX
352 CONFIG_8xx_CPUCLK_DEFAULT
353 See doc/README.MPC866
355 CONFIG_SYS_MEASURE_CPUCLK
357 Define this to measure the actual CPU clock instead
358 of relying on the correctness of the configured
359 values. Mostly useful for board bringup to make sure
360 the PLL is locked at the intended frequency. Note
361 that this requires a (stable) reference clock (32 kHz
362 RTC clock or CONFIG_SYS_8XX_XIN)
364 CONFIG_SYS_DELAYED_ICACHE
366 Define this option if you want to enable the
367 ICache only when Code runs from RAM.
372 Specifies that the core is a 64-bit PowerPC implementation (implements
373 the "64" category of the Power ISA). This is necessary for ePAPR
374 compliance, among other possible reasons.
376 CONFIG_SYS_FSL_TBCLK_DIV
378 Defines the core time base clock divider ratio compared to the
379 system clock. On most PQ3 devices this is 8, on newer QorIQ
380 devices it can be 16 or 32. The ratio varies from SoC to Soc.
382 CONFIG_SYS_FSL_PCIE_COMPAT
384 Defines the string to utilize when trying to match PCIe device
385 tree nodes for the given platform.
387 CONFIG_SYS_PPC_E500_DEBUG_TLB
389 Enables a temporary TLB entry to be used during boot to work
390 around limitations in e500v1 and e500v2 external debugger
391 support. This reduces the portions of the boot code where
392 breakpoints and single stepping do not work. The value of this
393 symbol should be set to the TLB1 entry to be used for this
396 CONFIG_SYS_FSL_ERRATUM_A004510
398 Enables a workaround for erratum A004510. If set,
399 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
400 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
402 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
403 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
405 Defines one or two SoC revisions (low 8 bits of SVR)
406 for which the A004510 workaround should be applied.
408 The rest of SVR is either not relevant to the decision
409 of whether the erratum is present (e.g. p2040 versus
410 p2041) or is implied by the build target, which controls
411 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
413 See Freescale App Note 4493 for more information about
416 CONFIG_A003399_NOR_WORKAROUND
417 Enables a workaround for IFC erratum A003399. It is only
418 requred during NOR boot.
420 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
422 This is the value to write into CCSR offset 0x18600
423 according to the A004510 workaround.
425 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
426 This value denotes start offset of M2 memory
427 which is directly connected to the DSP core.
429 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
430 This value denotes start offset of DSP CCSR space.
432 - Generic CPU options:
433 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
435 Defines the endianess of the CPU. Implementation of those
436 values is arch specific.
438 - Intel Monahans options:
439 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
441 Defines the Monahans run mode to oscillator
442 ratio. Valid values are 8, 16, 24, 31. The core
443 frequency is this value multiplied by 13 MHz.
445 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
447 Defines the Monahans turbo mode to oscillator
448 ratio. Valid values are 1 (default if undefined) and
449 2. The core frequency as calculated above is multiplied
453 CONFIG_SYS_INIT_SP_OFFSET
455 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
456 pointer. This is needed for the temporary stack before
459 CONFIG_SYS_MIPS_CACHE_MODE
461 Cache operation mode for the MIPS CPU.
462 See also arch/mips/include/asm/mipsregs.h.
464 CONF_CM_CACHABLE_NO_WA
467 CONF_CM_CACHABLE_NONCOHERENT
471 CONF_CM_CACHABLE_ACCELERATED
473 CONFIG_SYS_XWAY_EBU_BOOTCFG
475 Special option for Lantiq XWAY SoCs for booting from NOR flash.
476 See also arch/mips/cpu/mips32/start.S.
478 CONFIG_XWAY_SWAP_BYTES
480 Enable compilation of tools/xway-swap-bytes needed for Lantiq
481 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
482 be swapped if a flash programmer is used.
485 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
487 Select high exception vectors of the ARM core, e.g., do not
488 clear the V bit of the c1 register of CP15.
490 CONFIG_SYS_THUMB_BUILD
492 Use this flag to build U-Boot using the Thumb instruction
493 set for ARM architectures. Thumb instruction set provides
494 better code density. For ARM architectures that support
495 Thumb2 this flag will result in Thumb2 code generated by
498 CONFIG_ARM_ERRATA_716044
499 CONFIG_ARM_ERRATA_742230
500 CONFIG_ARM_ERRATA_743622
501 CONFIG_ARM_ERRATA_751472
503 If set, the workarounds for these ARM errata are applied early
504 during U-Boot startup. Note that these options force the
505 workarounds to be applied; no CPU-type/version detection
506 exists, unlike the similar options in the Linux kernel. Do not
507 set these options unless they apply!
512 The frequency of the timer returned by get_timer().
513 get_timer() must operate in milliseconds and this CONFIG
514 option must be set to 1000.
516 - Linux Kernel Interface:
519 U-Boot stores all clock information in Hz
520 internally. For binary compatibility with older Linux
521 kernels (which expect the clocks passed in the
522 bd_info data to be in MHz) the environment variable
523 "clocks_in_mhz" can be defined so that U-Boot
524 converts clock data to MHZ before passing it to the
526 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
527 "clocks_in_mhz=1" is automatically included in the
530 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
532 When transferring memsize parameter to linux, some versions
533 expect it to be in bytes, others in MB.
534 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
538 New kernel versions are expecting firmware settings to be
539 passed using flattened device trees (based on open firmware
543 * New libfdt-based support
544 * Adds the "fdt" command
545 * The bootm command automatically updates the fdt
547 OF_CPU - The proper name of the cpus node (only required for
548 MPC512X and MPC5xxx based boards).
549 OF_SOC - The proper name of the soc node (only required for
550 MPC512X and MPC5xxx based boards).
551 OF_TBCLK - The timebase frequency.
552 OF_STDOUT_PATH - The path to the console device
554 boards with QUICC Engines require OF_QE to set UCC MAC
557 CONFIG_OF_BOARD_SETUP
559 Board code has addition modification that it wants to make
560 to the flat device tree before handing it off to the kernel
564 This define fills in the correct boot CPU in the boot
565 param header, the default value is zero if undefined.
569 U-Boot can detect if an IDE device is present or not.
570 If not, and this new config option is activated, U-Boot
571 removes the ATA node from the DTS before booting Linux,
572 so the Linux IDE driver does not probe the device and
573 crash. This is needed for buggy hardware (uc101) where
574 no pull down resistor is connected to the signal IDE5V_DD7.
576 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
578 This setting is mandatory for all boards that have only one
579 machine type and must be used to specify the machine type
580 number as it appears in the ARM machine registry
581 (see http://www.arm.linux.org.uk/developer/machines/).
582 Only boards that have multiple machine types supported
583 in a single configuration file and the machine type is
584 runtime discoverable, do not have to use this setting.
586 - vxWorks boot parameters:
588 bootvx constructs a valid bootline using the following
589 environments variables: bootfile, ipaddr, serverip, hostname.
590 It loads the vxWorks image pointed bootfile.
592 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
593 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
594 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
595 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
597 CONFIG_SYS_VXWORKS_ADD_PARAMS
599 Add it at the end of the bootline. E.g "u=username pw=secret"
601 Note: If a "bootargs" environment is defined, it will overwride
602 the defaults discussed just above.
604 - Cache Configuration:
605 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
606 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
607 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
609 - Cache Configuration for ARM:
610 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
612 CONFIG_SYS_PL310_BASE - Physical base address of PL310
613 controller register space
618 Define this if you want support for Amba PrimeCell PL010 UARTs.
622 Define this if you want support for Amba PrimeCell PL011 UARTs.
626 If you have Amba PrimeCell PL011 UARTs, set this variable to
627 the clock speed of the UARTs.
631 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
632 define this to a list of base addresses for each (supported)
633 port. See e.g. include/configs/versatile.h
635 CONFIG_PL011_SERIAL_RLCR
637 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
638 have separate receive and transmit line control registers. Set
639 this variable to initialize the extra register.
641 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
643 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
644 boot loader that has already initialized the UART. Define this
645 variable to flush the UART at init time.
649 Depending on board, define exactly one serial port
650 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
651 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
652 console by defining CONFIG_8xx_CONS_NONE
654 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
655 port routines must be defined elsewhere
656 (i.e. serial_init(), serial_getc(), ...)
659 Enables console device for a color framebuffer. Needs following
660 defines (cf. smiLynxEM, i8042)
661 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
663 VIDEO_HW_RECTFILL graphic chip supports
666 VIDEO_HW_BITBLT graphic chip supports
667 bit-blit (cf. smiLynxEM)
668 VIDEO_VISIBLE_COLS visible pixel columns
670 VIDEO_VISIBLE_ROWS visible pixel rows
671 VIDEO_PIXEL_SIZE bytes per pixel
672 VIDEO_DATA_FORMAT graphic data format
673 (0-5, cf. cfb_console.c)
674 VIDEO_FB_ADRS framebuffer address
675 VIDEO_KBD_INIT_FCT keyboard int fct
676 (i.e. i8042_kbd_init())
677 VIDEO_TSTC_FCT test char fct
679 VIDEO_GETC_FCT get char fct
681 CONFIG_CONSOLE_CURSOR cursor drawing on/off
682 (requires blink timer
684 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
685 CONFIG_CONSOLE_TIME display time/date info in
687 (requires CONFIG_CMD_DATE)
688 CONFIG_VIDEO_LOGO display Linux logo in
690 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
691 linux_logo.h for logo.
692 Requires CONFIG_VIDEO_LOGO
693 CONFIG_CONSOLE_EXTRA_INFO
694 additional board info beside
697 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
698 a limited number of ANSI escape sequences (cursor control,
699 erase functions and limited graphics rendition control).
701 When CONFIG_CFB_CONSOLE is defined, video console is
702 default i/o. Serial console can be forced with
703 environment 'console=serial'.
705 When CONFIG_SILENT_CONSOLE is defined, all console
706 messages (by U-Boot and Linux!) can be silenced with
707 the "silent" environment variable. See
708 doc/README.silent for more information.
711 CONFIG_BAUDRATE - in bps
712 Select one of the baudrates listed in
713 CONFIG_SYS_BAUDRATE_TABLE, see below.
714 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
716 - Console Rx buffer length
717 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
718 the maximum receive buffer length for the SMC.
719 This option is actual only for 82xx and 8xx possible.
720 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
721 must be defined, to setup the maximum idle timeout for
724 - Pre-Console Buffer:
725 Prior to the console being initialised (i.e. serial UART
726 initialised etc) all console output is silently discarded.
727 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
728 buffer any console messages prior to the console being
729 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
730 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
731 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
732 bytes are output before the console is initialised, the
733 earlier bytes are discarded.
735 'Sane' compilers will generate smaller code if
736 CONFIG_PRE_CON_BUF_SZ is a power of 2
738 - Safe printf() functions
739 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
740 the printf() functions. These are defined in
741 include/vsprintf.h and include snprintf(), vsnprintf() and
742 so on. Code size increase is approximately 300-500 bytes.
743 If this option is not given then these functions will
744 silently discard their buffer size argument - this means
745 you are not getting any overflow checking in this case.
747 - Boot Delay: CONFIG_BOOTDELAY - in seconds
748 Delay before automatically booting the default image;
749 set to -1 to disable autoboot.
750 set to -2 to autoboot with no delay and not check for abort
751 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
753 See doc/README.autoboot for these options that
754 work with CONFIG_BOOTDELAY. None are required.
755 CONFIG_BOOT_RETRY_TIME
756 CONFIG_BOOT_RETRY_MIN
757 CONFIG_AUTOBOOT_KEYED
758 CONFIG_AUTOBOOT_PROMPT
759 CONFIG_AUTOBOOT_DELAY_STR
760 CONFIG_AUTOBOOT_STOP_STR
761 CONFIG_AUTOBOOT_DELAY_STR2
762 CONFIG_AUTOBOOT_STOP_STR2
763 CONFIG_ZERO_BOOTDELAY_CHECK
764 CONFIG_RESET_TO_RETRY
768 Only needed when CONFIG_BOOTDELAY is enabled;
769 define a command string that is automatically executed
770 when no character is read on the console interface
771 within "Boot Delay" after reset.
774 This can be used to pass arguments to the bootm
775 command. The value of CONFIG_BOOTARGS goes into the
776 environment value "bootargs".
778 CONFIG_RAMBOOT and CONFIG_NFSBOOT
779 The value of these goes into the environment as
780 "ramboot" and "nfsboot" respectively, and can be used
781 as a convenience, when switching between booting from
787 When this option is #defined, the existence of the
788 environment variable "preboot" will be checked
789 immediately before starting the CONFIG_BOOTDELAY
790 countdown and/or running the auto-boot command resp.
791 entering interactive mode.
793 This feature is especially useful when "preboot" is
794 automatically generated or modified. For an example
795 see the LWMON board specific code: here "preboot" is
796 modified when the user holds down a certain
797 combination of keys on the (special) keyboard when
800 - Serial Download Echo Mode:
802 If defined to 1, all characters received during a
803 serial download (using the "loads" command) are
804 echoed back. This might be needed by some terminal
805 emulations (like "cu"), but may as well just take
806 time on others. This setting #define's the initial
807 value of the "loads_echo" environment variable.
809 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
811 Select one of the baudrates listed in
812 CONFIG_SYS_BAUDRATE_TABLE, see below.
815 Monitor commands can be included or excluded
816 from the build by using the #include files
817 <config_cmd_all.h> and #undef'ing unwanted
818 commands, or using <config_cmd_default.h>
819 and augmenting with additional #define's
822 The default command configuration includes all commands
823 except those marked below with a "*".
825 CONFIG_CMD_ASKENV * ask for env variable
826 CONFIG_CMD_BDI bdinfo
827 CONFIG_CMD_BEDBUG * Include BedBug Debugger
828 CONFIG_CMD_BMP * BMP support
829 CONFIG_CMD_BSP * Board specific commands
830 CONFIG_CMD_BOOTD bootd
831 CONFIG_CMD_CACHE * icache, dcache
832 CONFIG_CMD_CONSOLE coninfo
833 CONFIG_CMD_CRC32 * crc32
834 CONFIG_CMD_DATE * support for RTC, date/time...
835 CONFIG_CMD_DHCP * DHCP support
836 CONFIG_CMD_DIAG * Diagnostics
837 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
838 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
839 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
840 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
841 CONFIG_CMD_DTT * Digital Therm and Thermostat
842 CONFIG_CMD_ECHO echo arguments
843 CONFIG_CMD_EDITENV edit env variable
844 CONFIG_CMD_EEPROM * EEPROM read/write support
845 CONFIG_CMD_ELF * bootelf, bootvx
846 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
847 CONFIG_CMD_ENV_FLAGS * display details about env flags
848 CONFIG_CMD_EXPORTENV * export the environment
849 CONFIG_CMD_EXT2 * ext2 command support
850 CONFIG_CMD_EXT4 * ext4 command support
851 CONFIG_CMD_SAVEENV saveenv
852 CONFIG_CMD_FDC * Floppy Disk Support
853 CONFIG_CMD_FAT * FAT command support
854 CONFIG_CMD_FDOS * Dos diskette Support
855 CONFIG_CMD_FLASH flinfo, erase, protect
856 CONFIG_CMD_FPGA FPGA device initialization support
857 CONFIG_CMD_FUSE Device fuse support
858 CONFIG_CMD_GETTIME * Get time since boot
859 CONFIG_CMD_GO * the 'go' command (exec code)
860 CONFIG_CMD_GREPENV * search environment
861 CONFIG_CMD_HASH * calculate hash / digest
862 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
863 CONFIG_CMD_I2C * I2C serial bus support
864 CONFIG_CMD_IDE * IDE harddisk support
865 CONFIG_CMD_IMI iminfo
866 CONFIG_CMD_IMLS List all images found in NOR flash
867 CONFIG_CMD_IMLS_NAND List all images found in NAND flash
868 CONFIG_CMD_IMMAP * IMMR dump support
869 CONFIG_CMD_IMPORTENV * import an environment
870 CONFIG_CMD_INI * import data from an ini file into the env
871 CONFIG_CMD_IRQ * irqinfo
872 CONFIG_CMD_ITEST Integer/string test of 2 values
873 CONFIG_CMD_JFFS2 * JFFS2 Support
874 CONFIG_CMD_KGDB * kgdb
875 CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
876 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
878 CONFIG_CMD_LOADB loadb
879 CONFIG_CMD_LOADS loads
880 CONFIG_CMD_MD5SUM print md5 message digest
881 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
882 CONFIG_CMD_MEMINFO * Display detailed memory information
883 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
885 CONFIG_CMD_MEMTEST mtest
886 CONFIG_CMD_MISC Misc functions like sleep etc
887 CONFIG_CMD_MMC * MMC memory mapped support
888 CONFIG_CMD_MII * MII utility commands
889 CONFIG_CMD_MTDPARTS * MTD partition support
890 CONFIG_CMD_NAND * NAND support
891 CONFIG_CMD_NET bootp, tftpboot, rarpboot
892 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
893 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
894 CONFIG_CMD_PCI * pciinfo
895 CONFIG_CMD_PCMCIA * PCMCIA support
896 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
898 CONFIG_CMD_PORTIO * Port I/O
899 CONFIG_CMD_READ * Read raw data from partition
900 CONFIG_CMD_REGINFO * Register dump
901 CONFIG_CMD_RUN run command in env variable
902 CONFIG_CMD_SANDBOX * sb command to access sandbox features
903 CONFIG_CMD_SAVES * save S record dump
904 CONFIG_CMD_SCSI * SCSI Support
905 CONFIG_CMD_SDRAM * print SDRAM configuration information
906 (requires CONFIG_CMD_I2C)
907 CONFIG_CMD_SETGETDCR Support for DCR Register access
909 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
910 CONFIG_CMD_SHA1SUM print sha1 memory digest
911 (requires CONFIG_CMD_MEMORY)
912 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
913 CONFIG_CMD_SOURCE "source" command Support
914 CONFIG_CMD_SPI * SPI serial bus support
915 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
916 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
917 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
918 CONFIG_CMD_TIMER * access to the system tick timer
919 CONFIG_CMD_USB * USB support
920 CONFIG_CMD_CDP * Cisco Discover Protocol support
921 CONFIG_CMD_MFSL * Microblaze FSL support
924 EXAMPLE: If you want all functions except of network
925 support you can write:
927 #include "config_cmd_all.h"
928 #undef CONFIG_CMD_NET
931 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
933 Note: Don't enable the "icache" and "dcache" commands
934 (configuration option CONFIG_CMD_CACHE) unless you know
935 what you (and your U-Boot users) are doing. Data
936 cache cannot be enabled on systems like the 8xx or
937 8260 (where accesses to the IMMR region must be
938 uncached), and it cannot be disabled on all other
939 systems where we (mis-) use the data cache to hold an
940 initial stack and some data.
943 XXX - this list needs to get updated!
945 - Regular expression support:
947 If this variable is defined, U-Boot is linked against
948 the SLRE (Super Light Regular Expression) library,
949 which adds regex support to some commands, as for
950 example "env grep" and "setexpr".
954 If this variable is defined, U-Boot will use a device tree
955 to configure its devices, instead of relying on statically
956 compiled #defines in the board file. This option is
957 experimental and only available on a few boards. The device
958 tree is available in the global data as gd->fdt_blob.
960 U-Boot needs to get its device tree from somewhere. This can
961 be done using one of the two options below:
964 If this variable is defined, U-Boot will embed a device tree
965 binary in its image. This device tree file should be in the
966 board directory and called <soc>-<board>.dts. The binary file
967 is then picked up in board_init_f() and made available through
968 the global data structure as gd->blob.
971 If this variable is defined, U-Boot will build a device tree
972 binary. It will be called u-boot.dtb. Architecture-specific
973 code will locate it at run-time. Generally this works by:
975 cat u-boot.bin u-boot.dtb >image.bin
977 and in fact, U-Boot does this for you, creating a file called
978 u-boot-dtb.bin which is useful in the common case. You can
979 still use the individual files if you need something more
984 If this variable is defined, it enables watchdog
985 support for the SoC. There must be support in the SoC
986 specific code for a watchdog. For the 8xx and 8260
987 CPUs, the SIU Watchdog feature is enabled in the SYPCR
988 register. When supported for a specific SoC is
989 available, then no further board specific code should
993 When using a watchdog circuitry external to the used
994 SoC, then define this variable and provide board
995 specific code for the "hw_watchdog_reset" function.
998 CONFIG_VERSION_VARIABLE
999 If this variable is defined, an environment variable
1000 named "ver" is created by U-Boot showing the U-Boot
1001 version as printed by the "version" command.
1002 Any change to this variable will be reverted at the
1007 When CONFIG_CMD_DATE is selected, the type of the RTC
1008 has to be selected, too. Define exactly one of the
1011 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1012 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1013 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1014 CONFIG_RTC_MC146818 - use MC146818 RTC
1015 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1016 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1017 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1018 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1019 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1020 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1021 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1022 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1025 Note that if the RTC uses I2C, then the I2C interface
1026 must also be configured. See I2C Support, below.
1029 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1030 CONFIG_PCA953X_INFO - enable pca953x info command
1032 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1033 chip-ngpio pairs that tell the PCA953X driver the number of
1034 pins supported by a particular chip.
1036 Note that if the GPIO device uses I2C, then the I2C interface
1037 must also be configured. See I2C Support, below.
1039 - Timestamp Support:
1041 When CONFIG_TIMESTAMP is selected, the timestamp
1042 (date and time) of an image is printed by image
1043 commands like bootm or iminfo. This option is
1044 automatically enabled when you select CONFIG_CMD_DATE .
1046 - Partition Labels (disklabels) Supported:
1047 Zero or more of the following:
1048 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1049 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1050 Intel architecture, USB sticks, etc.
1051 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1052 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1053 bootloader. Note 2TB partition limit; see
1055 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1057 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1058 CONFIG_CMD_SCSI) you must configure support for at
1059 least one non-MTD partition type as well.
1062 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1063 board configurations files but used nowhere!
1065 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1066 be performed by calling the function
1067 ide_set_reset(int reset)
1068 which has to be defined in a board specific file
1073 Set this to enable ATAPI support.
1078 Set this to enable support for disks larger than 137GB
1079 Also look at CONFIG_SYS_64BIT_LBA.
1080 Whithout these , LBA48 support uses 32bit variables and will 'only'
1081 support disks up to 2.1TB.
1083 CONFIG_SYS_64BIT_LBA:
1084 When enabled, makes the IDE subsystem use 64bit sector addresses.
1088 At the moment only there is only support for the
1089 SYM53C8XX SCSI controller; define
1090 CONFIG_SCSI_SYM53C8XX to enable it.
1092 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1093 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1094 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1095 maximum numbers of LUNs, SCSI ID's and target
1097 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1099 The environment variable 'scsidevs' is set to the number of
1100 SCSI devices found during the last scan.
1102 - NETWORK Support (PCI):
1104 Support for Intel 8254x/8257x gigabit chips.
1107 Utility code for direct access to the SPI bus on Intel 8257x.
1108 This does not do anything useful unless you set at least one
1109 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1111 CONFIG_E1000_SPI_GENERIC
1112 Allow generic access to the SPI bus on the Intel 8257x, for
1113 example with the "sspi" command.
1116 Management command for E1000 devices. When used on devices
1117 with SPI support you can reprogram the EEPROM from U-Boot.
1119 CONFIG_E1000_FALLBACK_MAC
1120 default MAC for empty EEPROM after production.
1123 Support for Intel 82557/82559/82559ER chips.
1124 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1125 write routine for first time initialisation.
1128 Support for Digital 2114x chips.
1129 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1130 modem chip initialisation (KS8761/QS6611).
1133 Support for National dp83815 chips.
1136 Support for National dp8382[01] gigabit chips.
1138 - NETWORK Support (other):
1140 CONFIG_DRIVER_AT91EMAC
1141 Support for AT91RM9200 EMAC.
1144 Define this to use reduced MII inteface
1146 CONFIG_DRIVER_AT91EMAC_QUIET
1147 If this defined, the driver is quiet.
1148 The driver doen't show link status messages.
1150 CONFIG_CALXEDA_XGMAC
1151 Support for the Calxeda XGMAC device
1154 Support for SMSC's LAN91C96 chips.
1156 CONFIG_LAN91C96_BASE
1157 Define this to hold the physical address
1158 of the LAN91C96's I/O space
1160 CONFIG_LAN91C96_USE_32_BIT
1161 Define this to enable 32 bit addressing
1164 Support for SMSC's LAN91C111 chip
1166 CONFIG_SMC91111_BASE
1167 Define this to hold the physical address
1168 of the device (I/O space)
1170 CONFIG_SMC_USE_32_BIT
1171 Define this if data bus is 32 bits
1173 CONFIG_SMC_USE_IOFUNCS
1174 Define this to use i/o functions instead of macros
1175 (some hardware wont work with macros)
1177 CONFIG_DRIVER_TI_EMAC
1178 Support for davinci emac
1180 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1181 Define this if you have more then 3 PHYs.
1184 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1186 CONFIG_FTGMAC100_EGIGA
1187 Define this to use GE link update with gigabit PHY.
1188 Define this if FTGMAC100 is connected to gigabit PHY.
1189 If your system has 10/100 PHY only, it might not occur
1190 wrong behavior. Because PHY usually return timeout or
1191 useless data when polling gigabit status and gigabit
1192 control registers. This behavior won't affect the
1193 correctnessof 10/100 link speed update.
1196 Support for SMSC's LAN911x and LAN921x chips
1199 Define this to hold the physical address
1200 of the device (I/O space)
1202 CONFIG_SMC911X_32_BIT
1203 Define this if data bus is 32 bits
1205 CONFIG_SMC911X_16_BIT
1206 Define this if data bus is 16 bits. If your processor
1207 automatically converts one 32 bit word to two 16 bit
1208 words you may also try CONFIG_SMC911X_32_BIT.
1211 Support for Renesas on-chip Ethernet controller
1213 CONFIG_SH_ETHER_USE_PORT
1214 Define the number of ports to be used
1216 CONFIG_SH_ETHER_PHY_ADDR
1217 Define the ETH PHY's address
1219 CONFIG_SH_ETHER_CACHE_WRITEBACK
1220 If this option is set, the driver enables cache flush.
1224 Support TPM devices.
1227 Support for i2c bus TPM devices. Only one device
1228 per system is supported at this time.
1230 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1231 Define the the i2c bus number for the TPM device
1233 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1234 Define the TPM's address on the i2c bus
1236 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1237 Define the burst count bytes upper limit
1240 Support for generic parallel port TPM devices. Only one device
1241 per system is supported at this time.
1243 CONFIG_TPM_TIS_BASE_ADDRESS
1244 Base address where the generic TPM device is mapped
1245 to. Contemporary x86 systems usually map it at
1249 At the moment only the UHCI host controller is
1250 supported (PIP405, MIP405, MPC5200); define
1251 CONFIG_USB_UHCI to enable it.
1252 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1253 and define CONFIG_USB_STORAGE to enable the USB
1256 Supported are USB Keyboards and USB Floppy drives
1258 MPC5200 USB requires additional defines:
1260 for 528 MHz Clock: 0x0001bbbb
1264 for differential drivers: 0x00001000
1265 for single ended drivers: 0x00005000
1266 for differential drivers on PSC3: 0x00000100
1267 for single ended drivers on PSC3: 0x00004100
1268 CONFIG_SYS_USB_EVENT_POLL
1269 May be defined to allow interrupt polling
1270 instead of using asynchronous interrupts
1272 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1273 txfilltuning field in the EHCI controller on reset.
1275 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1276 interval for usb hub power-on delay.(minimum 100msec)
1279 Define the below if you wish to use the USB console.
1280 Once firmware is rebuilt from a serial console issue the
1281 command "setenv stdin usbtty; setenv stdout usbtty" and
1282 attach your USB cable. The Unix command "dmesg" should print
1283 it has found a new device. The environment variable usbtty
1284 can be set to gserial or cdc_acm to enable your device to
1285 appear to a USB host as a Linux gserial device or a
1286 Common Device Class Abstract Control Model serial device.
1287 If you select usbtty = gserial you should be able to enumerate
1289 # modprobe usbserial vendor=0xVendorID product=0xProductID
1290 else if using cdc_acm, simply setting the environment
1291 variable usbtty to be cdc_acm should suffice. The following
1292 might be defined in YourBoardName.h
1295 Define this to build a UDC device
1298 Define this to have a tty type of device available to
1299 talk to the UDC device
1302 Define this to enable the high speed support for usb
1303 device and usbtty. If this feature is enabled, a routine
1304 int is_usbd_high_speed(void)
1305 also needs to be defined by the driver to dynamically poll
1306 whether the enumeration has succeded at high speed or full
1309 CONFIG_SYS_CONSOLE_IS_IN_ENV
1310 Define this if you want stdin, stdout &/or stderr to
1314 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1315 Derive USB clock from external clock "blah"
1316 - CONFIG_SYS_USB_EXTC_CLK 0x02
1318 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1319 Derive USB clock from brgclk
1320 - CONFIG_SYS_USB_BRG_CLK 0x04
1322 If you have a USB-IF assigned VendorID then you may wish to
1323 define your own vendor specific values either in BoardName.h
1324 or directly in usbd_vendor_info.h. If you don't define
1325 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1326 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1327 should pretend to be a Linux device to it's target host.
1329 CONFIG_USBD_MANUFACTURER
1330 Define this string as the name of your company for
1331 - CONFIG_USBD_MANUFACTURER "my company"
1333 CONFIG_USBD_PRODUCT_NAME
1334 Define this string as the name of your product
1335 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1337 CONFIG_USBD_VENDORID
1338 Define this as your assigned Vendor ID from the USB
1339 Implementors Forum. This *must* be a genuine Vendor ID
1340 to avoid polluting the USB namespace.
1341 - CONFIG_USBD_VENDORID 0xFFFF
1343 CONFIG_USBD_PRODUCTID
1344 Define this as the unique Product ID
1346 - CONFIG_USBD_PRODUCTID 0xFFFF
1348 - ULPI Layer Support:
1349 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1350 the generic ULPI layer. The generic layer accesses the ULPI PHY
1351 via the platform viewport, so you need both the genric layer and
1352 the viewport enabled. Currently only Chipidea/ARC based
1353 viewport is supported.
1354 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1355 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1356 If your ULPI phy needs a different reference clock than the
1357 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1358 the appropriate value in Hz.
1361 The MMC controller on the Intel PXA is supported. To
1362 enable this define CONFIG_MMC. The MMC can be
1363 accessed from the boot prompt by mapping the device
1364 to physical memory similar to flash. Command line is
1365 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1366 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1369 Support for Renesas on-chip MMCIF controller
1371 CONFIG_SH_MMCIF_ADDR
1372 Define the base address of MMCIF registers
1375 Define the clock frequency for MMCIF
1377 - USB Device Firmware Update (DFU) class support:
1379 This enables the USB portion of the DFU USB class
1382 This enables the command "dfu" which is used to have
1383 U-Boot create a DFU class device via USB. This command
1384 requires that the "dfu_alt_info" environment variable be
1385 set and define the alt settings to expose to the host.
1388 This enables support for exposing (e)MMC devices via DFU.
1391 This enables support for exposing NAND devices via DFU.
1393 CONFIG_SYS_DFU_MAX_FILE_SIZE
1394 When updating files rather than the raw storage device,
1395 we use a static buffer to copy the file into and then write
1396 the buffer once we've been given the whole file. Define
1397 this to the maximum filesize (in bytes) for the buffer.
1398 Default is 4 MiB if undefined.
1400 - Journaling Flash filesystem support:
1401 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1402 CONFIG_JFFS2_NAND_DEV
1403 Define these for a default partition on a NAND device
1405 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1406 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1407 Define these for a default partition on a NOR device
1409 CONFIG_SYS_JFFS_CUSTOM_PART
1410 Define this to create an own partition. You have to provide a
1411 function struct part_info* jffs2_part_info(int part_num)
1413 If you define only one JFFS2 partition you may also want to
1414 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1415 to disable the command chpart. This is the default when you
1416 have not defined a custom partition
1418 - FAT(File Allocation Table) filesystem write function support:
1421 Define this to enable support for saving memory data as a
1422 file in FAT formatted partition.
1424 This will also enable the command "fatwrite" enabling the
1425 user to write files to FAT.
1427 CBFS (Coreboot Filesystem) support
1430 Define this to enable support for reading from a Coreboot
1431 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1437 Define this to enable standard (PC-Style) keyboard
1441 Standard PC keyboard driver with US (is default) and
1442 GERMAN key layout (switch via environment 'keymap=de') support.
1443 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1444 for cfb_console. Supports cursor blinking.
1449 Define this to enable video support (for output to
1452 CONFIG_VIDEO_CT69000
1454 Enable Chips & Technologies 69000 Video chip
1456 CONFIG_VIDEO_SMI_LYNXEM
1457 Enable Silicon Motion SMI 712/710/810 Video chip. The
1458 video output is selected via environment 'videoout'
1459 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1462 For the CT69000 and SMI_LYNXEM drivers, videomode is
1463 selected via environment 'videomode'. Two different ways
1465 - "videomode=num" 'num' is a standard LiLo mode numbers.
1466 Following standard modes are supported (* is default):
1468 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1469 -------------+---------------------------------------------
1470 8 bits | 0x301* 0x303 0x305 0x161 0x307
1471 15 bits | 0x310 0x313 0x316 0x162 0x319
1472 16 bits | 0x311 0x314 0x317 0x163 0x31A
1473 24 bits | 0x312 0x315 0x318 ? 0x31B
1474 -------------+---------------------------------------------
1475 (i.e. setenv videomode 317; saveenv; reset;)
1477 - "videomode=bootargs" all the video parameters are parsed
1478 from the bootargs. (See drivers/video/videomodes.c)
1481 CONFIG_VIDEO_SED13806
1482 Enable Epson SED13806 driver. This driver supports 8bpp
1483 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1484 or CONFIG_VIDEO_SED13806_16BPP
1487 Enable the Freescale DIU video driver. Reference boards for
1488 SOCs that have a DIU should define this macro to enable DIU
1489 support, and should also define these other macros:
1495 CONFIG_VIDEO_SW_CURSOR
1496 CONFIG_VGA_AS_SINGLE_DEVICE
1498 CONFIG_VIDEO_BMP_LOGO
1500 The DIU driver will look for the 'video-mode' environment
1501 variable, and if defined, enable the DIU as a console during
1502 boot. See the documentation file README.video for a
1503 description of this variable.
1507 Enable the VGA video / BIOS for x86. The alternative if you
1508 are using coreboot is to use the coreboot frame buffer
1515 Define this to enable a custom keyboard support.
1516 This simply calls drv_keyboard_init() which must be
1517 defined in your board-specific files.
1518 The only board using this so far is RBC823.
1520 - LCD Support: CONFIG_LCD
1522 Define this to enable LCD support (for output to LCD
1523 display); also select one of the supported displays
1524 by defining one of these:
1528 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1530 CONFIG_NEC_NL6448AC33:
1532 NEC NL6448AC33-18. Active, color, single scan.
1534 CONFIG_NEC_NL6448BC20
1536 NEC NL6448BC20-08. 6.5", 640x480.
1537 Active, color, single scan.
1539 CONFIG_NEC_NL6448BC33_54
1541 NEC NL6448BC33-54. 10.4", 640x480.
1542 Active, color, single scan.
1546 Sharp 320x240. Active, color, single scan.
1547 It isn't 16x9, and I am not sure what it is.
1549 CONFIG_SHARP_LQ64D341
1551 Sharp LQ64D341 display, 640x480.
1552 Active, color, single scan.
1556 HLD1045 display, 640x480.
1557 Active, color, single scan.
1561 Optrex CBL50840-2 NF-FW 99 22 M5
1563 Hitachi LMG6912RPFC-00T
1567 320x240. Black & white.
1569 Normally display is black on white background; define
1570 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1572 CONFIG_LCD_ALIGNMENT
1574 Normally the LCD is page-aligned (tyically 4KB). If this is
1575 defined then the LCD will be aligned to this value instead.
1576 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1577 here, since it is cheaper to change data cache settings on
1578 a per-section basis.
1580 CONFIG_CONSOLE_SCROLL_LINES
1582 When the console need to be scrolled, this is the number of
1583 lines to scroll by. It defaults to 1. Increasing this makes
1584 the console jump but can help speed up operation when scrolling
1589 Support drawing of RLE8-compressed bitmaps on the LCD.
1593 Enables an 'i2c edid' command which can read EDID
1594 information over I2C from an attached LCD display.
1596 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1598 If this option is set, the environment is checked for
1599 a variable "splashimage". If found, the usual display
1600 of logo, copyright and system information on the LCD
1601 is suppressed and the BMP image at the address
1602 specified in "splashimage" is loaded instead. The
1603 console is redirected to the "nulldev", too. This
1604 allows for a "silent" boot where a splash screen is
1605 loaded very quickly after power-on.
1607 CONFIG_SPLASHIMAGE_GUARD
1609 If this option is set, then U-Boot will prevent the environment
1610 variable "splashimage" from being set to a problematic address
1611 (see README.displaying-bmps and README.arm-unaligned-accesses).
1612 This option is useful for targets where, due to alignment
1613 restrictions, an improperly aligned BMP image will cause a data
1614 abort. If you think you will not have problems with unaligned
1615 accesses (for example because your toolchain prevents them)
1616 there is no need to set this option.
1618 CONFIG_SPLASH_SCREEN_ALIGN
1620 If this option is set the splash image can be freely positioned
1621 on the screen. Environment variable "splashpos" specifies the
1622 position as "x,y". If a positive number is given it is used as
1623 number of pixel from left/top. If a negative number is given it
1624 is used as number of pixel from right/bottom. You can also
1625 specify 'm' for centering the image.
1628 setenv splashpos m,m
1629 => image at center of screen
1631 setenv splashpos 30,20
1632 => image at x = 30 and y = 20
1634 setenv splashpos -10,m
1635 => vertically centered image
1636 at x = dspWidth - bmpWidth - 9
1638 CONFIG_SPLASH_SCREEN_PREPARE
1640 If this option is set then the board_splash_screen_prepare()
1641 function, which must be defined in your code, is called as part
1642 of the splash screen display sequence. It gives the board an
1643 opportunity to prepare the splash image data before it is
1644 processed and sent to the frame buffer by U-Boot.
1646 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1648 If this option is set, additionally to standard BMP
1649 images, gzipped BMP images can be displayed via the
1650 splashscreen support or the bmp command.
1652 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1654 If this option is set, 8-bit RLE compressed BMP images
1655 can be displayed via the splashscreen support or the
1658 - Do compresssing for memory range:
1661 If this option is set, it would use zlib deflate method
1662 to compress the specified memory at its best effort.
1664 - Compression support:
1667 If this option is set, support for bzip2 compressed
1668 images is included. If not, only uncompressed and gzip
1669 compressed images are supported.
1671 NOTE: the bzip2 algorithm requires a lot of RAM, so
1672 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1677 If this option is set, support for lzma compressed
1680 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1681 requires an amount of dynamic memory that is given by the
1684 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1686 Where lc and lp stand for, respectively, Literal context bits
1687 and Literal pos bits.
1689 This value is upper-bounded by 14MB in the worst case. Anyway,
1690 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1691 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1692 a very small buffer.
1694 Use the lzmainfo tool to determinate the lc and lp values and
1695 then calculate the amount of needed dynamic memory (ensuring
1696 the appropriate CONFIG_SYS_MALLOC_LEN value).
1701 The address of PHY on MII bus.
1703 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1705 The clock frequency of the MII bus
1709 If this option is set, support for speed/duplex
1710 detection of gigabit PHY is included.
1712 CONFIG_PHY_RESET_DELAY
1714 Some PHY like Intel LXT971A need extra delay after
1715 reset before any MII register access is possible.
1716 For such PHY, set this option to the usec delay
1717 required. (minimum 300usec for LXT971A)
1719 CONFIG_PHY_CMD_DELAY (ppc4xx)
1721 Some PHY like Intel LXT971A need extra delay after
1722 command issued before MII status register can be read
1732 Define a default value for Ethernet address to use
1733 for the respective Ethernet interface, in case this
1734 is not determined automatically.
1739 Define a default value for the IP address to use for
1740 the default Ethernet interface, in case this is not
1741 determined through e.g. bootp.
1742 (Environment variable "ipaddr")
1744 - Server IP address:
1747 Defines a default value for the IP address of a TFTP
1748 server to contact when using the "tftboot" command.
1749 (Environment variable "serverip")
1751 CONFIG_KEEP_SERVERADDR
1753 Keeps the server's MAC address, in the env 'serveraddr'
1754 for passing to bootargs (like Linux's netconsole option)
1756 - Gateway IP address:
1759 Defines a default value for the IP address of the
1760 default router where packets to other networks are
1762 (Environment variable "gatewayip")
1767 Defines a default value for the subnet mask (or
1768 routing prefix) which is used to determine if an IP
1769 address belongs to the local subnet or needs to be
1770 forwarded through a router.
1771 (Environment variable "netmask")
1773 - Multicast TFTP Mode:
1776 Defines whether you want to support multicast TFTP as per
1777 rfc-2090; for example to work with atftp. Lets lots of targets
1778 tftp down the same boot image concurrently. Note: the Ethernet
1779 driver in use must provide a function: mcast() to join/leave a
1782 - BOOTP Recovery Mode:
1783 CONFIG_BOOTP_RANDOM_DELAY
1785 If you have many targets in a network that try to
1786 boot using BOOTP, you may want to avoid that all
1787 systems send out BOOTP requests at precisely the same
1788 moment (which would happen for instance at recovery
1789 from a power failure, when all systems will try to
1790 boot, thus flooding the BOOTP server. Defining
1791 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1792 inserted before sending out BOOTP requests. The
1793 following delays are inserted then:
1795 1st BOOTP request: delay 0 ... 1 sec
1796 2nd BOOTP request: delay 0 ... 2 sec
1797 3rd BOOTP request: delay 0 ... 4 sec
1799 BOOTP requests: delay 0 ... 8 sec
1801 - DHCP Advanced Options:
1802 You can fine tune the DHCP functionality by defining
1803 CONFIG_BOOTP_* symbols:
1805 CONFIG_BOOTP_SUBNETMASK
1806 CONFIG_BOOTP_GATEWAY
1807 CONFIG_BOOTP_HOSTNAME
1808 CONFIG_BOOTP_NISDOMAIN
1809 CONFIG_BOOTP_BOOTPATH
1810 CONFIG_BOOTP_BOOTFILESIZE
1813 CONFIG_BOOTP_SEND_HOSTNAME
1814 CONFIG_BOOTP_NTPSERVER
1815 CONFIG_BOOTP_TIMEOFFSET
1816 CONFIG_BOOTP_VENDOREX
1817 CONFIG_BOOTP_MAY_FAIL
1819 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1820 environment variable, not the BOOTP server.
1822 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1823 after the configured retry count, the call will fail
1824 instead of starting over. This can be used to fail over
1825 to Link-local IP address configuration if the DHCP server
1828 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1829 serverip from a DHCP server, it is possible that more
1830 than one DNS serverip is offered to the client.
1831 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1832 serverip will be stored in the additional environment
1833 variable "dnsip2". The first DNS serverip is always
1834 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1837 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1838 to do a dynamic update of a DNS server. To do this, they
1839 need the hostname of the DHCP requester.
1840 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1841 of the "hostname" environment variable is passed as
1842 option 12 to the DHCP server.
1844 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1846 A 32bit value in microseconds for a delay between
1847 receiving a "DHCP Offer" and sending the "DHCP Request".
1848 This fixes a problem with certain DHCP servers that don't
1849 respond 100% of the time to a "DHCP request". E.g. On an
1850 AT91RM9200 processor running at 180MHz, this delay needed
1851 to be *at least* 15,000 usec before a Windows Server 2003
1852 DHCP server would reply 100% of the time. I recommend at
1853 least 50,000 usec to be safe. The alternative is to hope
1854 that one of the retries will be successful but note that
1855 the DHCP timeout and retry process takes a longer than
1858 - Link-local IP address negotiation:
1859 Negotiate with other link-local clients on the local network
1860 for an address that doesn't require explicit configuration.
1861 This is especially useful if a DHCP server cannot be guaranteed
1862 to exist in all environments that the device must operate.
1864 See doc/README.link-local for more information.
1867 CONFIG_CDP_DEVICE_ID
1869 The device id used in CDP trigger frames.
1871 CONFIG_CDP_DEVICE_ID_PREFIX
1873 A two character string which is prefixed to the MAC address
1878 A printf format string which contains the ascii name of
1879 the port. Normally is set to "eth%d" which sets
1880 eth0 for the first Ethernet, eth1 for the second etc.
1882 CONFIG_CDP_CAPABILITIES
1884 A 32bit integer which indicates the device capabilities;
1885 0x00000010 for a normal host which does not forwards.
1889 An ascii string containing the version of the software.
1893 An ascii string containing the name of the platform.
1897 A 32bit integer sent on the trigger.
1899 CONFIG_CDP_POWER_CONSUMPTION
1901 A 16bit integer containing the power consumption of the
1902 device in .1 of milliwatts.
1904 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1906 A byte containing the id of the VLAN.
1908 - Status LED: CONFIG_STATUS_LED
1910 Several configurations allow to display the current
1911 status using a LED. For instance, the LED will blink
1912 fast while running U-Boot code, stop blinking as
1913 soon as a reply to a BOOTP request was received, and
1914 start blinking slow once the Linux kernel is running
1915 (supported by a status LED driver in the Linux
1916 kernel). Defining CONFIG_STATUS_LED enables this
1919 - CAN Support: CONFIG_CAN_DRIVER
1921 Defining CONFIG_CAN_DRIVER enables CAN driver support
1922 on those systems that support this (optional)
1923 feature, like the TQM8xxL modules.
1925 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1927 These enable I2C serial bus commands. Defining either of
1928 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1929 include the appropriate I2C driver for the selected CPU.
1931 This will allow you to use i2c commands at the u-boot
1932 command line (as long as you set CONFIG_CMD_I2C in
1933 CONFIG_COMMANDS) and communicate with i2c based realtime
1934 clock chips. See common/cmd_i2c.c for a description of the
1935 command line interface.
1937 CONFIG_HARD_I2C selects a hardware I2C controller.
1939 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1940 bit-banging) driver instead of CPM or similar hardware
1943 There are several other quantities that must also be
1944 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1946 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1947 to be the frequency (in Hz) at which you wish your i2c bus
1948 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1949 the CPU's i2c node address).
1951 Now, the u-boot i2c code for the mpc8xx
1952 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1953 and so its address should therefore be cleared to 0 (See,
1954 eg, MPC823e User's Manual p.16-473). So, set
1955 CONFIG_SYS_I2C_SLAVE to 0.
1957 CONFIG_SYS_I2C_INIT_MPC5XXX
1959 When a board is reset during an i2c bus transfer
1960 chips might think that the current transfer is still
1961 in progress. Reset the slave devices by sending start
1962 commands until the slave device responds.
1964 That's all that's required for CONFIG_HARD_I2C.
1966 If you use the software i2c interface (CONFIG_SOFT_I2C)
1967 then the following macros need to be defined (examples are
1968 from include/configs/lwmon.h):
1972 (Optional). Any commands necessary to enable the I2C
1973 controller or configure ports.
1975 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1979 (Only for MPC8260 CPU). The I/O port to use (the code
1980 assumes both bits are on the same port). Valid values
1981 are 0..3 for ports A..D.
1985 The code necessary to make the I2C data line active
1986 (driven). If the data line is open collector, this
1989 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1993 The code necessary to make the I2C data line tri-stated
1994 (inactive). If the data line is open collector, this
1997 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2001 Code that returns true if the I2C data line is high,
2004 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2008 If <bit> is true, sets the I2C data line high. If it
2009 is false, it clears it (low).
2011 eg: #define I2C_SDA(bit) \
2012 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2013 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2017 If <bit> is true, sets the I2C clock line high. If it
2018 is false, it clears it (low).
2020 eg: #define I2C_SCL(bit) \
2021 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2022 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2026 This delay is invoked four times per clock cycle so this
2027 controls the rate of data transfer. The data rate thus
2028 is 1 / (I2C_DELAY * 4). Often defined to be something
2031 #define I2C_DELAY udelay(2)
2033 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2035 If your arch supports the generic GPIO framework (asm/gpio.h),
2036 then you may alternatively define the two GPIOs that are to be
2037 used as SCL / SDA. Any of the previous I2C_xxx macros will
2038 have GPIO-based defaults assigned to them as appropriate.
2040 You should define these to the GPIO value as given directly to
2041 the generic GPIO functions.
2043 CONFIG_SYS_I2C_INIT_BOARD
2045 When a board is reset during an i2c bus transfer
2046 chips might think that the current transfer is still
2047 in progress. On some boards it is possible to access
2048 the i2c SCLK line directly, either by using the
2049 processor pin as a GPIO or by having a second pin
2050 connected to the bus. If this option is defined a
2051 custom i2c_init_board() routine in boards/xxx/board.c
2052 is run early in the boot sequence.
2054 CONFIG_SYS_I2C_BOARD_LATE_INIT
2056 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2057 defined a custom i2c_board_late_init() routine in
2058 boards/xxx/board.c is run AFTER the operations in i2c_init()
2059 is completed. This callpoint can be used to unreset i2c bus
2060 using CPU i2c controller register accesses for CPUs whose i2c
2061 controller provide such a method. It is called at the end of
2062 i2c_init() to allow i2c_init operations to setup the i2c bus
2063 controller on the CPU (e.g. setting bus speed & slave address).
2065 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2067 This option enables configuration of bi_iic_fast[] flags
2068 in u-boot bd_info structure based on u-boot environment
2069 variable "i2cfast". (see also i2cfast)
2071 CONFIG_I2C_MULTI_BUS
2073 This option allows the use of multiple I2C buses, each of which
2074 must have a controller. At any point in time, only one bus is
2075 active. To switch to a different bus, use the 'i2c dev' command.
2076 Note that bus numbering is zero-based.
2078 CONFIG_SYS_I2C_NOPROBES
2080 This option specifies a list of I2C devices that will be skipped
2081 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2082 is set, specify a list of bus-device pairs. Otherwise, specify
2083 a 1D array of device addresses
2086 #undef CONFIG_I2C_MULTI_BUS
2087 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2089 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2091 #define CONFIG_I2C_MULTI_BUS
2092 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2094 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2096 CONFIG_SYS_SPD_BUS_NUM
2098 If defined, then this indicates the I2C bus number for DDR SPD.
2099 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2101 CONFIG_SYS_RTC_BUS_NUM
2103 If defined, then this indicates the I2C bus number for the RTC.
2104 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2106 CONFIG_SYS_DTT_BUS_NUM
2108 If defined, then this indicates the I2C bus number for the DTT.
2109 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2111 CONFIG_SYS_I2C_DTT_ADDR:
2113 If defined, specifies the I2C address of the DTT device.
2114 If not defined, then U-Boot uses predefined value for
2115 specified DTT device.
2119 Define this option if you want to use Freescale's I2C driver in
2120 drivers/i2c/fsl_i2c.c.
2124 Define this option if you have I2C devices reached over 1 .. n
2125 I2C Muxes like the pca9544a. This option addes a new I2C
2126 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
2127 new I2C Bus to the existing I2C Busses. If you select the
2128 new Bus with "i2c dev", u-bbot sends first the commandos for
2129 the muxes to activate this new "bus".
2131 CONFIG_I2C_MULTI_BUS must be also defined, to use this
2135 Adding a new I2C Bus reached over 2 pca9544a muxes
2136 The First mux with address 70 and channel 6
2137 The Second mux with address 71 and channel 4
2139 => i2c bus pca9544a:70:6:pca9544a:71:4
2141 Use the "i2c bus" command without parameter, to get a list
2142 of I2C Busses with muxes:
2145 Busses reached over muxes:
2147 reached over Mux(es):
2150 reached over Mux(es):
2155 If you now switch to the new I2C Bus 3 with "i2c dev 3"
2156 u-boot first sends the command to the mux@70 to enable
2157 channel 6, and then the command to the mux@71 to enable
2160 After that, you can use the "normal" i2c commands as
2161 usual to communicate with your I2C devices behind
2164 This option is actually implemented for the bitbanging
2165 algorithm in common/soft_i2c.c and for the Hardware I2C
2166 Bus on the MPC8260. But it should be not so difficult
2167 to add this option to other architectures.
2169 CONFIG_SOFT_I2C_READ_REPEATED_START
2171 defining this will force the i2c_read() function in
2172 the soft_i2c driver to perform an I2C repeated start
2173 between writing the address pointer and reading the
2174 data. If this define is omitted the default behaviour
2175 of doing a stop-start sequence will be used. Most I2C
2176 devices can use either method, but some require one or
2179 - SPI Support: CONFIG_SPI
2181 Enables SPI driver (so far only tested with
2182 SPI EEPROM, also an instance works with Crystal A/D and
2183 D/As on the SACSng board)
2187 Enables the driver for SPI controller on SuperH. Currently
2188 only SH7757 is supported.
2192 Enables extended (16-bit) SPI EEPROM addressing.
2193 (symmetrical to CONFIG_I2C_X)
2197 Enables a software (bit-bang) SPI driver rather than
2198 using hardware support. This is a general purpose
2199 driver that only requires three general I/O port pins
2200 (two outputs, one input) to function. If this is
2201 defined, the board configuration must define several
2202 SPI configuration items (port pins to use, etc). For
2203 an example, see include/configs/sacsng.h.
2207 Enables a hardware SPI driver for general-purpose reads
2208 and writes. As with CONFIG_SOFT_SPI, the board configuration
2209 must define a list of chip-select function pointers.
2210 Currently supported on some MPC8xxx processors. For an
2211 example, see include/configs/mpc8349emds.h.
2215 Enables the driver for the SPI controllers on i.MX and MXC
2216 SoCs. Currently i.MX31/35/51 are supported.
2218 - FPGA Support: CONFIG_FPGA
2220 Enables FPGA subsystem.
2222 CONFIG_FPGA_<vendor>
2224 Enables support for specific chip vendors.
2227 CONFIG_FPGA_<family>
2229 Enables support for FPGA family.
2230 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2234 Specify the number of FPGA devices to support.
2236 CONFIG_SYS_FPGA_PROG_FEEDBACK
2238 Enable printing of hash marks during FPGA configuration.
2240 CONFIG_SYS_FPGA_CHECK_BUSY
2242 Enable checks on FPGA configuration interface busy
2243 status by the configuration function. This option
2244 will require a board or device specific function to
2249 If defined, a function that provides delays in the FPGA
2250 configuration driver.
2252 CONFIG_SYS_FPGA_CHECK_CTRLC
2253 Allow Control-C to interrupt FPGA configuration
2255 CONFIG_SYS_FPGA_CHECK_ERROR
2257 Check for configuration errors during FPGA bitfile
2258 loading. For example, abort during Virtex II
2259 configuration if the INIT_B line goes low (which
2260 indicated a CRC error).
2262 CONFIG_SYS_FPGA_WAIT_INIT
2264 Maximum time to wait for the INIT_B line to deassert
2265 after PROB_B has been deasserted during a Virtex II
2266 FPGA configuration sequence. The default time is 500
2269 CONFIG_SYS_FPGA_WAIT_BUSY
2271 Maximum time to wait for BUSY to deassert during
2272 Virtex II FPGA configuration. The default is 5 ms.
2274 CONFIG_SYS_FPGA_WAIT_CONFIG
2276 Time to wait after FPGA configuration. The default is
2279 - Configuration Management:
2282 If defined, this string will be added to the U-Boot
2283 version information (U_BOOT_VERSION)
2285 - Vendor Parameter Protection:
2287 U-Boot considers the values of the environment
2288 variables "serial#" (Board Serial Number) and
2289 "ethaddr" (Ethernet Address) to be parameters that
2290 are set once by the board vendor / manufacturer, and
2291 protects these variables from casual modification by
2292 the user. Once set, these variables are read-only,
2293 and write or delete attempts are rejected. You can
2294 change this behaviour:
2296 If CONFIG_ENV_OVERWRITE is #defined in your config
2297 file, the write protection for vendor parameters is
2298 completely disabled. Anybody can change or delete
2301 Alternatively, if you #define _both_ CONFIG_ETHADDR
2302 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2303 Ethernet address is installed in the environment,
2304 which can be changed exactly ONCE by the user. [The
2305 serial# is unaffected by this, i. e. it remains
2308 The same can be accomplished in a more flexible way
2309 for any variable by configuring the type of access
2310 to allow for those variables in the ".flags" variable
2311 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2316 Define this variable to enable the reservation of
2317 "protected RAM", i. e. RAM which is not overwritten
2318 by U-Boot. Define CONFIG_PRAM to hold the number of
2319 kB you want to reserve for pRAM. You can overwrite
2320 this default value by defining an environment
2321 variable "pram" to the number of kB you want to
2322 reserve. Note that the board info structure will
2323 still show the full amount of RAM. If pRAM is
2324 reserved, a new environment variable "mem" will
2325 automatically be defined to hold the amount of
2326 remaining RAM in a form that can be passed as boot
2327 argument to Linux, for instance like that:
2329 setenv bootargs ... mem=\${mem}
2332 This way you can tell Linux not to use this memory,
2333 either, which results in a memory region that will
2334 not be affected by reboots.
2336 *WARNING* If your board configuration uses automatic
2337 detection of the RAM size, you must make sure that
2338 this memory test is non-destructive. So far, the
2339 following board configurations are known to be
2342 IVMS8, IVML24, SPD8xx, TQM8xxL,
2343 HERMES, IP860, RPXlite, LWMON,
2346 - Access to physical memory region (> 4GB)
2347 Some basic support is provided for operations on memory not
2348 normally accessible to U-Boot - e.g. some architectures
2349 support access to more than 4GB of memory on 32-bit
2350 machines using physical address extension or similar.
2351 Define CONFIG_PHYSMEM to access this basic support, which
2352 currently only supports clearing the memory.
2357 Define this variable to stop the system in case of a
2358 fatal error, so that you have to reset it manually.
2359 This is probably NOT a good idea for an embedded
2360 system where you want the system to reboot
2361 automatically as fast as possible, but it may be
2362 useful during development since you can try to debug
2363 the conditions that lead to the situation.
2365 CONFIG_NET_RETRY_COUNT
2367 This variable defines the number of retries for
2368 network operations like ARP, RARP, TFTP, or BOOTP
2369 before giving up the operation. If not defined, a
2370 default value of 5 is used.
2374 Timeout waiting for an ARP reply in milliseconds.
2378 Timeout in milliseconds used in NFS protocol.
2379 If you encounter "ERROR: Cannot umount" in nfs command,
2380 try longer timeout such as
2381 #define CONFIG_NFS_TIMEOUT 10000UL
2383 - Command Interpreter:
2384 CONFIG_AUTO_COMPLETE
2386 Enable auto completion of commands using TAB.
2388 Note that this feature has NOT been implemented yet
2389 for the "hush" shell.
2392 CONFIG_SYS_HUSH_PARSER
2394 Define this variable to enable the "hush" shell (from
2395 Busybox) as command line interpreter, thus enabling
2396 powerful command line syntax like
2397 if...then...else...fi conditionals or `&&' and '||'
2398 constructs ("shell scripts").
2400 If undefined, you get the old, much simpler behaviour
2401 with a somewhat smaller memory footprint.
2404 CONFIG_SYS_PROMPT_HUSH_PS2
2406 This defines the secondary prompt string, which is
2407 printed when the command interpreter needs more input
2408 to complete a command. Usually "> ".
2412 In the current implementation, the local variables
2413 space and global environment variables space are
2414 separated. Local variables are those you define by
2415 simply typing `name=value'. To access a local
2416 variable later on, you have write `$name' or
2417 `${name}'; to execute the contents of a variable
2418 directly type `$name' at the command prompt.
2420 Global environment variables are those you use
2421 setenv/printenv to work with. To run a command stored
2422 in such a variable, you need to use the run command,
2423 and you must not use the '$' sign to access them.
2425 To store commands and special characters in a
2426 variable, please use double quotation marks
2427 surrounding the whole text of the variable, instead
2428 of the backslashes before semicolons and special
2431 - Commandline Editing and History:
2432 CONFIG_CMDLINE_EDITING
2434 Enable editing and History functions for interactive
2435 commandline input operations
2437 - Default Environment:
2438 CONFIG_EXTRA_ENV_SETTINGS
2440 Define this to contain any number of null terminated
2441 strings (variable = value pairs) that will be part of
2442 the default environment compiled into the boot image.
2444 For example, place something like this in your
2445 board's config file:
2447 #define CONFIG_EXTRA_ENV_SETTINGS \
2451 Warning: This method is based on knowledge about the
2452 internal format how the environment is stored by the
2453 U-Boot code. This is NOT an official, exported
2454 interface! Although it is unlikely that this format
2455 will change soon, there is no guarantee either.
2456 You better know what you are doing here.
2458 Note: overly (ab)use of the default environment is
2459 discouraged. Make sure to check other ways to preset
2460 the environment like the "source" command or the
2463 CONFIG_ENV_VARS_UBOOT_CONFIG
2465 Define this in order to add variables describing the
2466 U-Boot build configuration to the default environment.
2467 These will be named arch, cpu, board, vendor, and soc.
2469 Enabling this option will cause the following to be defined:
2477 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2479 Define this in order to add variables describing certain
2480 run-time determined information about the hardware to the
2481 environment. These will be named board_name, board_rev.
2483 CONFIG_DELAY_ENVIRONMENT
2485 Normally the environment is loaded when the board is
2486 intialised so that it is available to U-Boot. This inhibits
2487 that so that the environment is not available until
2488 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2489 this is instead controlled by the value of
2490 /config/load-environment.
2492 - DataFlash Support:
2493 CONFIG_HAS_DATAFLASH
2495 Defining this option enables DataFlash features and
2496 allows to read/write in Dataflash via the standard
2499 - Serial Flash support
2502 Defining this option enables SPI flash commands
2503 'sf probe/read/write/erase/update'.
2505 Usage requires an initial 'probe' to define the serial
2506 flash parameters, followed by read/write/erase/update
2509 The following defaults may be provided by the platform
2510 to handle the common case when only a single serial
2511 flash is present on the system.
2513 CONFIG_SF_DEFAULT_BUS Bus identifier
2514 CONFIG_SF_DEFAULT_CS Chip-select
2515 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2516 CONFIG_SF_DEFAULT_SPEED in Hz
2520 Define this option to include a destructive SPI flash
2523 - SystemACE Support:
2526 Adding this option adds support for Xilinx SystemACE
2527 chips attached via some sort of local bus. The address
2528 of the chip must also be defined in the
2529 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2531 #define CONFIG_SYSTEMACE
2532 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2534 When SystemACE support is added, the "ace" device type
2535 becomes available to the fat commands, i.e. fatls.
2537 - TFTP Fixed UDP Port:
2540 If this is defined, the environment variable tftpsrcp
2541 is used to supply the TFTP UDP source port value.
2542 If tftpsrcp isn't defined, the normal pseudo-random port
2543 number generator is used.
2545 Also, the environment variable tftpdstp is used to supply
2546 the TFTP UDP destination port value. If tftpdstp isn't
2547 defined, the normal port 69 is used.
2549 The purpose for tftpsrcp is to allow a TFTP server to
2550 blindly start the TFTP transfer using the pre-configured
2551 target IP address and UDP port. This has the effect of
2552 "punching through" the (Windows XP) firewall, allowing
2553 the remainder of the TFTP transfer to proceed normally.
2554 A better solution is to properly configure the firewall,
2555 but sometimes that is not allowed.
2560 This enables a generic 'hash' command which can produce
2561 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2565 Enable the hash verify command (hash -v). This adds to code
2568 CONFIG_SHA1 - support SHA1 hashing
2569 CONFIG_SHA256 - support SHA256 hashing
2571 Note: There is also a sha1sum command, which should perhaps
2572 be deprecated in favour of 'hash sha1'.
2574 - Show boot progress:
2575 CONFIG_SHOW_BOOT_PROGRESS
2577 Defining this option allows to add some board-
2578 specific code (calling a user-provided function
2579 "show_boot_progress(int)") that enables you to show
2580 the system's boot progress on some display (for
2581 example, some LED's) on your board. At the moment,
2582 the following checkpoints are implemented:
2584 - Detailed boot stage timing
2586 Define this option to get detailed timing of each stage
2587 of the boot process.
2589 CONFIG_BOOTSTAGE_USER_COUNT
2590 This is the number of available user bootstage records.
2591 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2592 a new ID will be allocated from this stash. If you exceed
2593 the limit, recording will stop.
2595 CONFIG_BOOTSTAGE_REPORT
2596 Define this to print a report before boot, similar to this:
2598 Timer summary in microseconds:
2601 3,575,678 3,575,678 board_init_f start
2602 3,575,695 17 arch_cpu_init A9
2603 3,575,777 82 arch_cpu_init done
2604 3,659,598 83,821 board_init_r start
2605 3,910,375 250,777 main_loop
2606 29,916,167 26,005,792 bootm_start
2607 30,361,327 445,160 start_kernel
2609 CONFIG_CMD_BOOTSTAGE
2610 Add a 'bootstage' command which supports printing a report
2611 and un/stashing of bootstage data.
2613 CONFIG_BOOTSTAGE_FDT
2614 Stash the bootstage information in the FDT. A root 'bootstage'
2615 node is created with each bootstage id as a child. Each child
2616 has a 'name' property and either 'mark' containing the
2617 mark time in microsecond, or 'accum' containing the
2618 accumulated time for that bootstage id in microseconds.
2623 name = "board_init_f";
2632 Code in the Linux kernel can find this in /proc/devicetree.
2634 Legacy uImage format:
2637 1 common/cmd_bootm.c before attempting to boot an image
2638 -1 common/cmd_bootm.c Image header has bad magic number
2639 2 common/cmd_bootm.c Image header has correct magic number
2640 -2 common/cmd_bootm.c Image header has bad checksum
2641 3 common/cmd_bootm.c Image header has correct checksum
2642 -3 common/cmd_bootm.c Image data has bad checksum
2643 4 common/cmd_bootm.c Image data has correct checksum
2644 -4 common/cmd_bootm.c Image is for unsupported architecture
2645 5 common/cmd_bootm.c Architecture check OK
2646 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2647 6 common/cmd_bootm.c Image Type check OK
2648 -6 common/cmd_bootm.c gunzip uncompression error
2649 -7 common/cmd_bootm.c Unimplemented compression type
2650 7 common/cmd_bootm.c Uncompression OK
2651 8 common/cmd_bootm.c No uncompress/copy overwrite error
2652 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2654 9 common/image.c Start initial ramdisk verification
2655 -10 common/image.c Ramdisk header has bad magic number
2656 -11 common/image.c Ramdisk header has bad checksum
2657 10 common/image.c Ramdisk header is OK
2658 -12 common/image.c Ramdisk data has bad checksum
2659 11 common/image.c Ramdisk data has correct checksum
2660 12 common/image.c Ramdisk verification complete, start loading
2661 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2662 13 common/image.c Start multifile image verification
2663 14 common/image.c No initial ramdisk, no multifile, continue.
2665 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2667 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2668 -31 post/post.c POST test failed, detected by post_output_backlog()
2669 -32 post/post.c POST test failed, detected by post_run_single()
2671 34 common/cmd_doc.c before loading a Image from a DOC device
2672 -35 common/cmd_doc.c Bad usage of "doc" command
2673 35 common/cmd_doc.c correct usage of "doc" command
2674 -36 common/cmd_doc.c No boot device
2675 36 common/cmd_doc.c correct boot device
2676 -37 common/cmd_doc.c Unknown Chip ID on boot device
2677 37 common/cmd_doc.c correct chip ID found, device available
2678 -38 common/cmd_doc.c Read Error on boot device
2679 38 common/cmd_doc.c reading Image header from DOC device OK
2680 -39 common/cmd_doc.c Image header has bad magic number
2681 39 common/cmd_doc.c Image header has correct magic number
2682 -40 common/cmd_doc.c Error reading Image from DOC device
2683 40 common/cmd_doc.c Image header has correct magic number
2684 41 common/cmd_ide.c before loading a Image from a IDE device
2685 -42 common/cmd_ide.c Bad usage of "ide" command
2686 42 common/cmd_ide.c correct usage of "ide" command
2687 -43 common/cmd_ide.c No boot device
2688 43 common/cmd_ide.c boot device found
2689 -44 common/cmd_ide.c Device not available
2690 44 common/cmd_ide.c Device available
2691 -45 common/cmd_ide.c wrong partition selected
2692 45 common/cmd_ide.c partition selected
2693 -46 common/cmd_ide.c Unknown partition table
2694 46 common/cmd_ide.c valid partition table found
2695 -47 common/cmd_ide.c Invalid partition type
2696 47 common/cmd_ide.c correct partition type
2697 -48 common/cmd_ide.c Error reading Image Header on boot device
2698 48 common/cmd_ide.c reading Image Header from IDE device OK
2699 -49 common/cmd_ide.c Image header has bad magic number
2700 49 common/cmd_ide.c Image header has correct magic number
2701 -50 common/cmd_ide.c Image header has bad checksum
2702 50 common/cmd_ide.c Image header has correct checksum
2703 -51 common/cmd_ide.c Error reading Image from IDE device
2704 51 common/cmd_ide.c reading Image from IDE device OK
2705 52 common/cmd_nand.c before loading a Image from a NAND device
2706 -53 common/cmd_nand.c Bad usage of "nand" command
2707 53 common/cmd_nand.c correct usage of "nand" command
2708 -54 common/cmd_nand.c No boot device
2709 54 common/cmd_nand.c boot device found
2710 -55 common/cmd_nand.c Unknown Chip ID on boot device
2711 55 common/cmd_nand.c correct chip ID found, device available
2712 -56 common/cmd_nand.c Error reading Image Header on boot device
2713 56 common/cmd_nand.c reading Image Header from NAND device OK
2714 -57 common/cmd_nand.c Image header has bad magic number
2715 57 common/cmd_nand.c Image header has correct magic number
2716 -58 common/cmd_nand.c Error reading Image from NAND device
2717 58 common/cmd_nand.c reading Image from NAND device OK
2719 -60 common/env_common.c Environment has a bad CRC, using default
2721 64 net/eth.c starting with Ethernet configuration.
2722 -64 net/eth.c no Ethernet found.
2723 65 net/eth.c Ethernet found.
2725 -80 common/cmd_net.c usage wrong
2726 80 common/cmd_net.c before calling NetLoop()
2727 -81 common/cmd_net.c some error in NetLoop() occurred
2728 81 common/cmd_net.c NetLoop() back without error
2729 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2730 82 common/cmd_net.c trying automatic boot
2731 83 common/cmd_net.c running "source" command
2732 -83 common/cmd_net.c some error in automatic boot or "source" command
2733 84 common/cmd_net.c end without errors
2738 100 common/cmd_bootm.c Kernel FIT Image has correct format
2739 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2740 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2741 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2742 102 common/cmd_bootm.c Kernel unit name specified
2743 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2744 103 common/cmd_bootm.c Found configuration node
2745 104 common/cmd_bootm.c Got kernel subimage node offset
2746 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2747 105 common/cmd_bootm.c Kernel subimage hash verification OK
2748 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2749 106 common/cmd_bootm.c Architecture check OK
2750 -106 common/cmd_bootm.c Kernel subimage has wrong type
2751 107 common/cmd_bootm.c Kernel subimage type OK
2752 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2753 108 common/cmd_bootm.c Got kernel subimage data/size
2754 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2755 -109 common/cmd_bootm.c Can't get kernel subimage type
2756 -110 common/cmd_bootm.c Can't get kernel subimage comp
2757 -111 common/cmd_bootm.c Can't get kernel subimage os
2758 -112 common/cmd_bootm.c Can't get kernel subimage load address
2759 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2761 120 common/image.c Start initial ramdisk verification
2762 -120 common/image.c Ramdisk FIT image has incorrect format
2763 121 common/image.c Ramdisk FIT image has correct format
2764 122 common/image.c No ramdisk subimage unit name, using configuration
2765 -122 common/image.c Can't get configuration for ramdisk subimage
2766 123 common/image.c Ramdisk unit name specified
2767 -124 common/image.c Can't get ramdisk subimage node offset
2768 125 common/image.c Got ramdisk subimage node offset
2769 -125 common/image.c Ramdisk subimage hash verification failed
2770 126 common/image.c Ramdisk subimage hash verification OK
2771 -126 common/image.c Ramdisk subimage for unsupported architecture
2772 127 common/image.c Architecture check OK
2773 -127 common/image.c Can't get ramdisk subimage data/size
2774 128 common/image.c Got ramdisk subimage data/size
2775 129 common/image.c Can't get ramdisk load address
2776 -129 common/image.c Got ramdisk load address
2778 -130 common/cmd_doc.c Incorrect FIT image format
2779 131 common/cmd_doc.c FIT image format OK
2781 -140 common/cmd_ide.c Incorrect FIT image format
2782 141 common/cmd_ide.c FIT image format OK
2784 -150 common/cmd_nand.c Incorrect FIT image format
2785 151 common/cmd_nand.c FIT image format OK
2787 - FIT image support:
2789 Enable support for the FIT uImage format.
2791 CONFIG_FIT_BEST_MATCH
2792 When no configuration is explicitly selected, default to the
2793 one whose fdt's compatibility field best matches that of
2794 U-Boot itself. A match is considered "best" if it matches the
2795 most specific compatibility entry of U-Boot's fdt's root node.
2796 The order of entries in the configuration's fdt is ignored.
2798 - Standalone program support:
2799 CONFIG_STANDALONE_LOAD_ADDR
2801 This option defines a board specific value for the
2802 address where standalone program gets loaded, thus
2803 overwriting the architecture dependent default
2806 - Frame Buffer Address:
2809 Define CONFIG_FB_ADDR if you want to use specific
2810 address for frame buffer. This is typically the case
2811 when using a graphics controller has separate video
2812 memory. U-Boot will then place the frame buffer at
2813 the given address instead of dynamically reserving it
2814 in system RAM by calling lcd_setmem(), which grabs
2815 the memory for the frame buffer depending on the
2816 configured panel size.
2818 Please see board_init_f function.
2820 - Automatic software updates via TFTP server
2822 CONFIG_UPDATE_TFTP_CNT_MAX
2823 CONFIG_UPDATE_TFTP_MSEC_MAX
2825 These options enable and control the auto-update feature;
2826 for a more detailed description refer to doc/README.update.
2828 - MTD Support (mtdparts command, UBI support)
2831 Adds the MTD device infrastructure from the Linux kernel.
2832 Needed for mtdparts command support.
2834 CONFIG_MTD_PARTITIONS
2836 Adds the MTD partitioning infrastructure from the Linux
2837 kernel. Needed for UBI support.
2842 Adds commands for interacting with MTD partitions formatted
2843 with the UBI flash translation layer
2845 Requires also defining CONFIG_RBTREE
2847 CONFIG_UBI_SILENCE_MSG
2849 Make the verbose messages from UBI stop printing. This leaves
2850 warnings and errors enabled.
2855 Adds commands for interacting with UBI volumes formatted as
2856 UBIFS. UBIFS is read-only in u-boot.
2858 Requires UBI support as well as CONFIG_LZO
2860 CONFIG_UBIFS_SILENCE_MSG
2862 Make the verbose messages from UBIFS stop printing. This leaves
2863 warnings and errors enabled.
2867 Enable building of SPL globally.
2870 LDSCRIPT for linking the SPL binary.
2872 CONFIG_SPL_MAX_FOOTPRINT
2873 Maximum size in memory allocated to the SPL, BSS included.
2874 When defined, the linker checks that the actual memory
2875 used by SPL from _start to __bss_end does not exceed it.
2876 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2877 must not be both defined at the same time.
2880 Maximum size of the SPL image (text, data, rodata, and
2881 linker lists sections), BSS excluded.
2882 When defined, the linker checks that the actual size does
2885 CONFIG_SPL_TEXT_BASE
2886 TEXT_BASE for linking the SPL binary.
2888 CONFIG_SPL_RELOC_TEXT_BASE
2889 Address to relocate to. If unspecified, this is equal to
2890 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2892 CONFIG_SPL_BSS_START_ADDR
2893 Link address for the BSS within the SPL binary.
2895 CONFIG_SPL_BSS_MAX_SIZE
2896 Maximum size in memory allocated to the SPL BSS.
2897 When defined, the linker checks that the actual memory used
2898 by SPL from __bss_start to __bss_end does not exceed it.
2899 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2900 must not be both defined at the same time.
2903 Adress of the start of the stack SPL will use
2905 CONFIG_SPL_RELOC_STACK
2906 Adress of the start of the stack SPL will use after
2907 relocation. If unspecified, this is equal to
2910 CONFIG_SYS_SPL_MALLOC_START
2911 Starting address of the malloc pool used in SPL.
2913 CONFIG_SYS_SPL_MALLOC_SIZE
2914 The size of the malloc pool used in SPL.
2916 CONFIG_SPL_FRAMEWORK
2917 Enable the SPL framework under common/. This framework
2918 supports MMC, NAND and YMODEM loading of U-Boot and NAND
2919 NAND loading of the Linux Kernel.
2921 CONFIG_SPL_DISPLAY_PRINT
2922 For ARM, enable an optional function to print more information
2923 about the running system.
2925 CONFIG_SPL_INIT_MINIMAL
2926 Arch init code should be built for a very small image
2928 CONFIG_SPL_LIBCOMMON_SUPPORT
2929 Support for common/libcommon.o in SPL binary
2931 CONFIG_SPL_LIBDISK_SUPPORT
2932 Support for disk/libdisk.o in SPL binary
2934 CONFIG_SPL_I2C_SUPPORT
2935 Support for drivers/i2c/libi2c.o in SPL binary
2937 CONFIG_SPL_GPIO_SUPPORT
2938 Support for drivers/gpio/libgpio.o in SPL binary
2940 CONFIG_SPL_MMC_SUPPORT
2941 Support for drivers/mmc/libmmc.o in SPL binary
2943 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
2944 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
2945 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
2946 Address, size and partition on the MMC to load U-Boot from
2947 when the MMC is being used in raw mode.
2949 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
2950 Sector to load kernel uImage from when MMC is being
2951 used in raw mode (for Falcon mode)
2953 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
2954 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
2955 Sector and number of sectors to load kernel argument
2956 parameters from when MMC is being used in raw mode
2959 CONFIG_SPL_FAT_SUPPORT
2960 Support for fs/fat/libfat.o in SPL binary
2962 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
2963 Filename to read to load U-Boot when reading from FAT
2965 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
2966 Filename to read to load kernel uImage when reading
2967 from FAT (for Falcon mode)
2969 CONFIG_SPL_FAT_LOAD_ARGS_NAME
2970 Filename to read to load kernel argument parameters
2971 when reading from FAT (for Falcon mode)
2973 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
2974 Set this for NAND SPL on PPC mpc83xx targets, so that
2975 start.S waits for the rest of the SPL to load before
2976 continuing (the hardware starts execution after just
2977 loading the first page rather than the full 4K).
2979 CONFIG_SPL_NAND_BASE
2980 Include nand_base.c in the SPL. Requires
2981 CONFIG_SPL_NAND_DRIVERS.
2983 CONFIG_SPL_NAND_DRIVERS
2984 SPL uses normal NAND drivers, not minimal drivers.
2987 Include standard software ECC in the SPL
2989 CONFIG_SPL_NAND_SIMPLE
2990 Support for NAND boot using simple NAND drivers that
2991 expose the cmd_ctrl() interface.
2993 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
2994 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
2995 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
2996 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
2997 CONFIG_SYS_NAND_ECCBYTES
2998 Defines the size and behavior of the NAND that SPL uses
3001 CONFIG_SYS_NAND_U_BOOT_OFFS
3002 Location in NAND to read U-Boot from
3004 CONFIG_SYS_NAND_U_BOOT_DST
3005 Location in memory to load U-Boot to
3007 CONFIG_SYS_NAND_U_BOOT_SIZE
3008 Size of image to load
3010 CONFIG_SYS_NAND_U_BOOT_START
3011 Entry point in loaded image to jump to
3013 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3014 Define this if you need to first read the OOB and then the
3015 data. This is used for example on davinci plattforms.
3017 CONFIG_SPL_OMAP3_ID_NAND
3018 Support for an OMAP3-specific set of functions to return the
3019 ID and MFR of the first attached NAND chip, if present.
3021 CONFIG_SPL_SERIAL_SUPPORT
3022 Support for drivers/serial/libserial.o in SPL binary
3024 CONFIG_SPL_SPI_FLASH_SUPPORT
3025 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3027 CONFIG_SPL_SPI_SUPPORT
3028 Support for drivers/spi/libspi.o in SPL binary
3030 CONFIG_SPL_RAM_DEVICE
3031 Support for running image already present in ram, in SPL binary
3033 CONFIG_SPL_LIBGENERIC_SUPPORT
3034 Support for lib/libgeneric.o in SPL binary
3037 Image offset to which the SPL should be padded before appending
3038 the SPL payload. By default, this is defined as
3039 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3040 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3041 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3044 Final target image containing SPL and payload. Some SPLs
3045 use an arch-specific makefile fragment instead, for
3046 example if more than one image needs to be produced.
3048 CONFIG_FIT_SPL_PRINT
3049 Printing information about a FIT image adds quite a bit of
3050 code to SPL. So this is normally disabled in SPL. Use this
3051 option to re-enable it. This will affect the output of the
3052 bootm command when booting a FIT image.
3057 [so far only for SMDK2400 boards]
3059 - Modem support enable:
3060 CONFIG_MODEM_SUPPORT
3062 - RTS/CTS Flow control enable:
3065 - Modem debug support:
3066 CONFIG_MODEM_SUPPORT_DEBUG
3068 Enables debugging stuff (char screen[1024], dbg())
3069 for modem support. Useful only with BDI2000.
3071 - Interrupt support (PPC):
3073 There are common interrupt_init() and timer_interrupt()
3074 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3075 for CPU specific initialization. interrupt_init_cpu()
3076 should set decrementer_count to appropriate value. If
3077 CPU resets decrementer automatically after interrupt
3078 (ppc4xx) it should set decrementer_count to zero.
3079 timer_interrupt() calls timer_interrupt_cpu() for CPU
3080 specific handling. If board has watchdog / status_led
3081 / other_activity_monitor it works automatically from
3082 general timer_interrupt().
3086 In the target system modem support is enabled when a
3087 specific key (key combination) is pressed during
3088 power-on. Otherwise U-Boot will boot normally
3089 (autoboot). The key_pressed() function is called from
3090 board_init(). Currently key_pressed() is a dummy
3091 function, returning 1 and thus enabling modem
3094 If there are no modem init strings in the
3095 environment, U-Boot proceed to autoboot; the
3096 previous output (banner, info printfs) will be
3099 See also: doc/README.Modem
3101 Board initialization settings:
3102 ------------------------------
3104 During Initialization u-boot calls a number of board specific functions
3105 to allow the preparation of board specific prerequisites, e.g. pin setup
3106 before drivers are initialized. To enable these callbacks the
3107 following configuration macros have to be defined. Currently this is
3108 architecture specific, so please check arch/your_architecture/lib/board.c
3109 typically in board_init_f() and board_init_r().
3111 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3112 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3113 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3114 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3116 Configuration Settings:
3117 -----------------------
3119 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3120 undefine this when you're short of memory.
3122 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3123 width of the commands listed in the 'help' command output.
3125 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3126 prompt for user input.
3128 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3130 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3132 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3134 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3135 the application (usually a Linux kernel) when it is
3138 - CONFIG_SYS_BAUDRATE_TABLE:
3139 List of legal baudrate settings for this board.
3141 - CONFIG_SYS_CONSOLE_INFO_QUIET
3142 Suppress display of console information at boot.
3144 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3145 If the board specific function
3146 extern int overwrite_console (void);
3147 returns 1, the stdin, stderr and stdout are switched to the
3148 serial port, else the settings in the environment are used.
3150 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3151 Enable the call to overwrite_console().
3153 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3154 Enable overwrite of previous console environment settings.
3156 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3157 Begin and End addresses of the area used by the
3160 - CONFIG_SYS_ALT_MEMTEST:
3161 Enable an alternate, more extensive memory test.
3163 - CONFIG_SYS_MEMTEST_SCRATCH:
3164 Scratch address used by the alternate memory test
3165 You only need to set this if address zero isn't writeable
3167 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3168 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3169 this specified memory area will get subtracted from the top
3170 (end) of RAM and won't get "touched" at all by U-Boot. By
3171 fixing up gd->ram_size the Linux kernel should gets passed
3172 the now "corrected" memory size and won't touch it either.
3173 This should work for arch/ppc and arch/powerpc. Only Linux
3174 board ports in arch/powerpc with bootwrapper support that
3175 recalculate the memory size from the SDRAM controller setup
3176 will have to get fixed in Linux additionally.
3178 This option can be used as a workaround for the 440EPx/GRx
3179 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3182 WARNING: Please make sure that this value is a multiple of
3183 the Linux page size (normally 4k). If this is not the case,
3184 then the end address of the Linux memory will be located at a
3185 non page size aligned address and this could cause major
3188 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3189 Enable temporary baudrate change while serial download
3191 - CONFIG_SYS_SDRAM_BASE:
3192 Physical start address of SDRAM. _Must_ be 0 here.
3194 - CONFIG_SYS_MBIO_BASE:
3195 Physical start address of Motherboard I/O (if using a
3198 - CONFIG_SYS_FLASH_BASE:
3199 Physical start address of Flash memory.
3201 - CONFIG_SYS_MONITOR_BASE:
3202 Physical start address of boot monitor code (set by
3203 make config files to be same as the text base address
3204 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3205 CONFIG_SYS_FLASH_BASE when booting from flash.
3207 - CONFIG_SYS_MONITOR_LEN:
3208 Size of memory reserved for monitor code, used to
3209 determine _at_compile_time_ (!) if the environment is
3210 embedded within the U-Boot image, or in a separate
3213 - CONFIG_SYS_MALLOC_LEN:
3214 Size of DRAM reserved for malloc() use.
3216 - CONFIG_SYS_BOOTM_LEN:
3217 Normally compressed uImages are limited to an
3218 uncompressed size of 8 MBytes. If this is not enough,
3219 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3220 to adjust this setting to your needs.
3222 - CONFIG_SYS_BOOTMAPSZ:
3223 Maximum size of memory mapped by the startup code of
3224 the Linux kernel; all data that must be processed by
3225 the Linux kernel (bd_info, boot arguments, FDT blob if
3226 used) must be put below this limit, unless "bootm_low"
3227 enviroment variable is defined and non-zero. In such case
3228 all data for the Linux kernel must be between "bootm_low"
3229 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3230 variable "bootm_mapsize" will override the value of
3231 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3232 then the value in "bootm_size" will be used instead.
3234 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3235 Enable initrd_high functionality. If defined then the
3236 initrd_high feature is enabled and the bootm ramdisk subcommand
3239 - CONFIG_SYS_BOOT_GET_CMDLINE:
3240 Enables allocating and saving kernel cmdline in space between
3241 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3243 - CONFIG_SYS_BOOT_GET_KBD:
3244 Enables allocating and saving a kernel copy of the bd_info in
3245 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3247 - CONFIG_SYS_MAX_FLASH_BANKS:
3248 Max number of Flash memory banks
3250 - CONFIG_SYS_MAX_FLASH_SECT:
3251 Max number of sectors on a Flash chip
3253 - CONFIG_SYS_FLASH_ERASE_TOUT:
3254 Timeout for Flash erase operations (in ms)
3256 - CONFIG_SYS_FLASH_WRITE_TOUT:
3257 Timeout for Flash write operations (in ms)
3259 - CONFIG_SYS_FLASH_LOCK_TOUT
3260 Timeout for Flash set sector lock bit operation (in ms)
3262 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3263 Timeout for Flash clear lock bits operation (in ms)
3265 - CONFIG_SYS_FLASH_PROTECTION
3266 If defined, hardware flash sectors protection is used
3267 instead of U-Boot software protection.
3269 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3271 Enable TFTP transfers directly to flash memory;
3272 without this option such a download has to be
3273 performed in two steps: (1) download to RAM, and (2)
3274 copy from RAM to flash.
3276 The two-step approach is usually more reliable, since
3277 you can check if the download worked before you erase
3278 the flash, but in some situations (when system RAM is
3279 too limited to allow for a temporary copy of the
3280 downloaded image) this option may be very useful.
3282 - CONFIG_SYS_FLASH_CFI:
3283 Define if the flash driver uses extra elements in the
3284 common flash structure for storing flash geometry.
3286 - CONFIG_FLASH_CFI_DRIVER
3287 This option also enables the building of the cfi_flash driver
3288 in the drivers directory
3290 - CONFIG_FLASH_CFI_MTD
3291 This option enables the building of the cfi_mtd driver
3292 in the drivers directory. The driver exports CFI flash
3295 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3296 Use buffered writes to flash.
3298 - CONFIG_FLASH_SPANSION_S29WS_N
3299 s29ws-n MirrorBit flash has non-standard addresses for buffered
3302 - CONFIG_SYS_FLASH_QUIET_TEST
3303 If this option is defined, the common CFI flash doesn't
3304 print it's warning upon not recognized FLASH banks. This
3305 is useful, if some of the configured banks are only
3306 optionally available.
3308 - CONFIG_FLASH_SHOW_PROGRESS
3309 If defined (must be an integer), print out countdown
3310 digits and dots. Recommended value: 45 (9..1) for 80
3311 column displays, 15 (3..1) for 40 column displays.
3313 - CONFIG_FLASH_VERIFY
3314 If defined, the content of the flash (destination) is compared
3315 against the source after the write operation. An error message
3316 will be printed when the contents are not identical.
3317 Please note that this option is useless in nearly all cases,
3318 since such flash programming errors usually are detected earlier
3319 while unprotecting/erasing/programming. Please only enable
3320 this option if you really know what you are doing.
3322 - CONFIG_SYS_RX_ETH_BUFFER:
3323 Defines the number of Ethernet receive buffers. On some
3324 Ethernet controllers it is recommended to set this value
3325 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3326 buffers can be full shortly after enabling the interface
3327 on high Ethernet traffic.
3328 Defaults to 4 if not defined.
3330 - CONFIG_ENV_MAX_ENTRIES
3332 Maximum number of entries in the hash table that is used
3333 internally to store the environment settings. The default
3334 setting is supposed to be generous and should work in most
3335 cases. This setting can be used to tune behaviour; see
3336 lib/hashtable.c for details.
3338 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3339 - CONFIG_ENV_FLAGS_LIST_STATIC
3340 Enable validation of the values given to enviroment variables when
3341 calling env set. Variables can be restricted to only decimal,
3342 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3343 the variables can also be restricted to IP address or MAC address.
3345 The format of the list is:
3346 type_attribute = [s|d|x|b|i|m]
3347 access_atribute = [a|r|o|c]
3348 attributes = type_attribute[access_atribute]
3349 entry = variable_name[:attributes]
3352 The type attributes are:
3353 s - String (default)
3356 b - Boolean ([1yYtT|0nNfF])
3360 The access attributes are:
3366 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3367 Define this to a list (string) to define the ".flags"
3368 envirnoment variable in the default or embedded environment.
3370 - CONFIG_ENV_FLAGS_LIST_STATIC
3371 Define this to a list (string) to define validation that
3372 should be done if an entry is not found in the ".flags"
3373 environment variable. To override a setting in the static
3374 list, simply add an entry for the same variable name to the
3377 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3378 If defined, don't allow the -f switch to env set override variable
3381 - CONFIG_SYS_GENERIC_BOARD
3382 This selects the architecture-generic board system instead of the
3383 architecture-specific board files. It is intended to move boards
3384 to this new framework over time. Defining this will disable the
3385 arch/foo/lib/board.c file and use common/board_f.c and
3386 common/board_r.c instead. To use this option your architecture
3387 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3388 its config.mk file). If you find problems enabling this option on
3389 your board please report the problem and send patches!
3391 - CONFIG_SYS_SYM_OFFSETS
3392 This is set by architectures that use offsets for link symbols
3393 instead of absolute values. So bss_start is obtained using an
3394 offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
3395 directly. You should not need to touch this setting.
3397 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3398 This is set by OMAP boards for the max time that reset should
3399 be asserted. See doc/README.omap-reset-time for details on how
3400 the value can be calulated on a given board.
3402 The following definitions that deal with the placement and management
3403 of environment data (variable area); in general, we support the
3404 following configurations:
3406 - CONFIG_BUILD_ENVCRC:
3408 Builds up envcrc with the target environment so that external utils
3409 may easily extract it and embed it in final U-Boot images.
3411 - CONFIG_ENV_IS_IN_FLASH:
3413 Define this if the environment is in flash memory.
3415 a) The environment occupies one whole flash sector, which is
3416 "embedded" in the text segment with the U-Boot code. This
3417 happens usually with "bottom boot sector" or "top boot
3418 sector" type flash chips, which have several smaller
3419 sectors at the start or the end. For instance, such a
3420 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3421 such a case you would place the environment in one of the
3422 4 kB sectors - with U-Boot code before and after it. With
3423 "top boot sector" type flash chips, you would put the
3424 environment in one of the last sectors, leaving a gap
3425 between U-Boot and the environment.
3427 - CONFIG_ENV_OFFSET:
3429 Offset of environment data (variable area) to the
3430 beginning of flash memory; for instance, with bottom boot
3431 type flash chips the second sector can be used: the offset
3432 for this sector is given here.
3434 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3438 This is just another way to specify the start address of
3439 the flash sector containing the environment (instead of
3442 - CONFIG_ENV_SECT_SIZE:
3444 Size of the sector containing the environment.
3447 b) Sometimes flash chips have few, equal sized, BIG sectors.
3448 In such a case you don't want to spend a whole sector for
3453 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3454 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3455 of this flash sector for the environment. This saves
3456 memory for the RAM copy of the environment.
3458 It may also save flash memory if you decide to use this
3459 when your environment is "embedded" within U-Boot code,
3460 since then the remainder of the flash sector could be used
3461 for U-Boot code. It should be pointed out that this is
3462 STRONGLY DISCOURAGED from a robustness point of view:
3463 updating the environment in flash makes it always
3464 necessary to erase the WHOLE sector. If something goes
3465 wrong before the contents has been restored from a copy in
3466 RAM, your target system will be dead.
3468 - CONFIG_ENV_ADDR_REDUND
3469 CONFIG_ENV_SIZE_REDUND
3471 These settings describe a second storage area used to hold
3472 a redundant copy of the environment data, so that there is
3473 a valid backup copy in case there is a power failure during
3474 a "saveenv" operation.
3476 BE CAREFUL! Any changes to the flash layout, and some changes to the
3477 source code will make it necessary to adapt <board>/u-boot.lds*
3481 - CONFIG_ENV_IS_IN_NVRAM:
3483 Define this if you have some non-volatile memory device
3484 (NVRAM, battery buffered SRAM) which you want to use for the
3490 These two #defines are used to determine the memory area you
3491 want to use for environment. It is assumed that this memory
3492 can just be read and written to, without any special
3495 BE CAREFUL! The first access to the environment happens quite early
3496 in U-Boot initalization (when we try to get the setting of for the
3497 console baudrate). You *MUST* have mapped your NVRAM area then, or
3500 Please note that even with NVRAM we still use a copy of the
3501 environment in RAM: we could work on NVRAM directly, but we want to
3502 keep settings there always unmodified except somebody uses "saveenv"
3503 to save the current settings.
3506 - CONFIG_ENV_IS_IN_EEPROM:
3508 Use this if you have an EEPROM or similar serial access
3509 device and a driver for it.
3511 - CONFIG_ENV_OFFSET:
3514 These two #defines specify the offset and size of the
3515 environment area within the total memory of your EEPROM.
3517 - CONFIG_SYS_I2C_EEPROM_ADDR:
3518 If defined, specified the chip address of the EEPROM device.
3519 The default address is zero.
3521 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3522 If defined, the number of bits used to address bytes in a
3523 single page in the EEPROM device. A 64 byte page, for example
3524 would require six bits.
3526 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3527 If defined, the number of milliseconds to delay between
3528 page writes. The default is zero milliseconds.
3530 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3531 The length in bytes of the EEPROM memory array address. Note
3532 that this is NOT the chip address length!
3534 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3535 EEPROM chips that implement "address overflow" are ones
3536 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3537 address and the extra bits end up in the "chip address" bit
3538 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3541 Note that we consider the length of the address field to
3542 still be one byte because the extra address bits are hidden
3543 in the chip address.
3545 - CONFIG_SYS_EEPROM_SIZE:
3546 The size in bytes of the EEPROM device.
3548 - CONFIG_ENV_EEPROM_IS_ON_I2C
3549 define this, if you have I2C and SPI activated, and your
3550 EEPROM, which holds the environment, is on the I2C bus.
3552 - CONFIG_I2C_ENV_EEPROM_BUS
3553 if you have an Environment on an EEPROM reached over
3554 I2C muxes, you can define here, how to reach this
3555 EEPROM. For example:
3557 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
3559 EEPROM which holds the environment, is reached over
3560 a pca9547 i2c mux with address 0x70, channel 3.
3562 - CONFIG_ENV_IS_IN_DATAFLASH:
3564 Define this if you have a DataFlash memory device which you
3565 want to use for the environment.
3567 - CONFIG_ENV_OFFSET:
3571 These three #defines specify the offset and size of the
3572 environment area within the total memory of your DataFlash placed
3573 at the specified address.
3575 - CONFIG_ENV_IS_IN_REMOTE:
3577 Define this if you have a remote memory space which you
3578 want to use for the local device's environment.
3583 These two #defines specify the address and size of the
3584 environment area within the remote memory space. The
3585 local device can get the environment from remote memory
3586 space by SRIO or PCIE links.
3588 BE CAREFUL! For some special cases, the local device can not use
3589 "saveenv" command. For example, the local device will get the
3590 environment stored in a remote NOR flash by SRIO or PCIE link,
3591 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3593 - CONFIG_ENV_IS_IN_NAND:
3595 Define this if you have a NAND device which you want to use
3596 for the environment.
3598 - CONFIG_ENV_OFFSET:
3601 These two #defines specify the offset and size of the environment
3602 area within the first NAND device. CONFIG_ENV_OFFSET must be
3603 aligned to an erase block boundary.
3605 - CONFIG_ENV_OFFSET_REDUND (optional):
3607 This setting describes a second storage area of CONFIG_ENV_SIZE
3608 size used to hold a redundant copy of the environment data, so
3609 that there is a valid backup copy in case there is a power failure
3610 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3611 aligned to an erase block boundary.
3613 - CONFIG_ENV_RANGE (optional):
3615 Specifies the length of the region in which the environment
3616 can be written. This should be a multiple of the NAND device's
3617 block size. Specifying a range with more erase blocks than
3618 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3619 the range to be avoided.
3621 - CONFIG_ENV_OFFSET_OOB (optional):
3623 Enables support for dynamically retrieving the offset of the
3624 environment from block zero's out-of-band data. The
3625 "nand env.oob" command can be used to record this offset.
3626 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3627 using CONFIG_ENV_OFFSET_OOB.
3629 - CONFIG_NAND_ENV_DST
3631 Defines address in RAM to which the nand_spl code should copy the
3632 environment. If redundant environment is used, it will be copied to
3633 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3635 - CONFIG_ENV_IS_IN_UBI:
3637 Define this if you have an UBI volume that you want to use for the
3638 environment. This has the benefit of wear-leveling the environment
3639 accesses, which is important on NAND.
3641 - CONFIG_ENV_UBI_PART:
3643 Define this to a string that is the mtd partition containing the UBI.
3645 - CONFIG_ENV_UBI_VOLUME:
3647 Define this to the name of the volume that you want to store the
3650 - CONFIG_ENV_UBI_VOLUME_REDUND:
3652 Define this to the name of another volume to store a second copy of
3653 the environment in. This will enable redundant environments in UBI.
3654 It is assumed that both volumes are in the same MTD partition.
3656 - CONFIG_UBI_SILENCE_MSG
3657 - CONFIG_UBIFS_SILENCE_MSG
3659 You will probably want to define these to avoid a really noisy system
3660 when storing the env in UBI.
3662 - CONFIG_ENV_IS_IN_MMC:
3664 Define this if you have an MMC device which you want to use for the
3667 - CONFIG_SYS_MMC_ENV_DEV:
3669 Specifies which MMC device the environment is stored in.
3671 - CONFIG_SYS_MMC_ENV_PART (optional):
3673 Specifies which MMC partition the environment is stored in. If not
3674 set, defaults to partition 0, the user area. Common values might be
3675 1 (first MMC boot partition), 2 (second MMC boot partition).
3677 - CONFIG_ENV_OFFSET:
3680 These two #defines specify the offset and size of the environment
3681 area within the specified MMC device.
3683 If offset is positive (the usual case), it is treated as relative to
3684 the start of the MMC partition. If offset is negative, it is treated
3685 as relative to the end of the MMC partition. This can be useful if
3686 your board may be fitted with different MMC devices, which have
3687 different sizes for the MMC partitions, and you always want the
3688 environment placed at the very end of the partition, to leave the
3689 maximum possible space before it, to store other data.
3691 These two values are in units of bytes, but must be aligned to an
3692 MMC sector boundary.
3694 - CONFIG_ENV_OFFSET_REDUND (optional):
3696 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
3697 hold a redundant copy of the environment data. This provides a
3698 valid backup copy in case the other copy is corrupted, e.g. due
3699 to a power failure during a "saveenv" operation.
3701 This value may also be positive or negative; this is handled in the
3702 same way as CONFIG_ENV_OFFSET.
3704 This value is also in units of bytes, but must also be aligned to
3705 an MMC sector boundary.
3707 - CONFIG_ENV_SIZE_REDUND (optional):
3709 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
3710 set. If this value is set, it must be set to the same value as
3713 - CONFIG_SYS_SPI_INIT_OFFSET
3715 Defines offset to the initial SPI buffer area in DPRAM. The
3716 area is used at an early stage (ROM part) if the environment
3717 is configured to reside in the SPI EEPROM: We need a 520 byte
3718 scratch DPRAM area. It is used between the two initialization
3719 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3720 to be a good choice since it makes it far enough from the
3721 start of the data area as well as from the stack pointer.
3723 Please note that the environment is read-only until the monitor
3724 has been relocated to RAM and a RAM copy of the environment has been
3725 created; also, when using EEPROM you will have to use getenv_f()
3726 until then to read environment variables.
3728 The environment is protected by a CRC32 checksum. Before the monitor
3729 is relocated into RAM, as a result of a bad CRC you will be working
3730 with the compiled-in default environment - *silently*!!! [This is
3731 necessary, because the first environment variable we need is the
3732 "baudrate" setting for the console - if we have a bad CRC, we don't
3733 have any device yet where we could complain.]
3735 Note: once the monitor has been relocated, then it will complain if
3736 the default environment is used; a new CRC is computed as soon as you
3737 use the "saveenv" command to store a valid environment.
3739 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3740 Echo the inverted Ethernet link state to the fault LED.
3742 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3743 also needs to be defined.
3745 - CONFIG_SYS_FAULT_MII_ADDR:
3746 MII address of the PHY to check for the Ethernet link state.
3748 - CONFIG_NS16550_MIN_FUNCTIONS:
3749 Define this if you desire to only have use of the NS16550_init
3750 and NS16550_putc functions for the serial driver located at
3751 drivers/serial/ns16550.c. This option is useful for saving
3752 space for already greatly restricted images, including but not
3753 limited to NAND_SPL configurations.
3755 - CONFIG_DISPLAY_BOARDINFO
3756 Display information about the board that U-Boot is running on
3757 when U-Boot starts up. The board function checkboard() is called
3760 - CONFIG_DISPLAY_BOARDINFO_LATE
3761 Similar to the previous option, but display this information
3762 later, once stdio is running and output goes to the LCD, if
3765 Low Level (hardware related) configuration options:
3766 ---------------------------------------------------
3768 - CONFIG_SYS_CACHELINE_SIZE:
3769 Cache Line Size of the CPU.
3771 - CONFIG_SYS_DEFAULT_IMMR:
3772 Default address of the IMMR after system reset.
3774 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3775 and RPXsuper) to be able to adjust the position of
3776 the IMMR register after a reset.
3778 - CONFIG_SYS_CCSRBAR_DEFAULT:
3779 Default (power-on reset) physical address of CCSR on Freescale
3782 - CONFIG_SYS_CCSRBAR:
3783 Virtual address of CCSR. On a 32-bit build, this is typically
3784 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3786 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3787 for cross-platform code that uses that macro instead.
3789 - CONFIG_SYS_CCSRBAR_PHYS:
3790 Physical address of CCSR. CCSR can be relocated to a new
3791 physical address, if desired. In this case, this macro should
3792 be set to that address. Otherwise, it should be set to the
3793 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3794 is typically relocated on 36-bit builds. It is recommended
3795 that this macro be defined via the _HIGH and _LOW macros:
3797 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3798 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3800 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3801 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3802 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3803 used in assembly code, so it must not contain typecasts or
3804 integer size suffixes (e.g. "ULL").
3806 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3807 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3808 used in assembly code, so it must not contain typecasts or
3809 integer size suffixes (e.g. "ULL").
3811 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3812 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3813 forced to a value that ensures that CCSR is not relocated.
3815 - Floppy Disk Support:
3816 CONFIG_SYS_FDC_DRIVE_NUMBER
3818 the default drive number (default value 0)
3820 CONFIG_SYS_ISA_IO_STRIDE
3822 defines the spacing between FDC chipset registers
3825 CONFIG_SYS_ISA_IO_OFFSET
3827 defines the offset of register from address. It
3828 depends on which part of the data bus is connected to
3829 the FDC chipset. (default value 0)
3831 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3832 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3835 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3836 fdc_hw_init() is called at the beginning of the FDC
3837 setup. fdc_hw_init() must be provided by the board
3838 source code. It is used to make hardware dependant
3842 Most IDE controllers were designed to be connected with PCI
3843 interface. Only few of them were designed for AHB interface.
3844 When software is doing ATA command and data transfer to
3845 IDE devices through IDE-AHB controller, some additional
3846 registers accessing to these kind of IDE-AHB controller
3849 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3850 DO NOT CHANGE unless you know exactly what you're
3851 doing! (11-4) [MPC8xx/82xx systems only]
3853 - CONFIG_SYS_INIT_RAM_ADDR:
3855 Start address of memory area that can be used for
3856 initial data and stack; please note that this must be
3857 writable memory that is working WITHOUT special
3858 initialization, i. e. you CANNOT use normal RAM which
3859 will become available only after programming the
3860 memory controller and running certain initialization
3863 U-Boot uses the following memory types:
3864 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
3865 - MPC824X: data cache
3866 - PPC4xx: data cache
3868 - CONFIG_SYS_GBL_DATA_OFFSET:
3870 Offset of the initial data structure in the memory
3871 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3872 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3873 data is located at the end of the available space
3874 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3875 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
3876 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3877 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3880 On the MPC824X (or other systems that use the data
3881 cache for initial memory) the address chosen for
3882 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3883 point to an otherwise UNUSED address space between
3884 the top of RAM and the start of the PCI space.
3886 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
3888 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
3890 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
3892 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
3894 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
3896 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3898 - CONFIG_SYS_OR_TIMING_SDRAM:
3901 - CONFIG_SYS_MAMR_PTA:
3902 periodic timer for refresh
3904 - CONFIG_SYS_DER: Debug Event Register (37-47)
3906 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3907 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3908 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3909 CONFIG_SYS_BR1_PRELIM:
3910 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3912 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3913 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3914 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3915 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3917 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
3918 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
3919 Machine Mode Register and Memory Periodic Timer
3920 Prescaler definitions (SDRAM timing)
3922 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
3923 enable I2C microcode relocation patch (MPC8xx);
3924 define relocation offset in DPRAM [DSP2]
3926 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
3927 enable SMC microcode relocation patch (MPC8xx);
3928 define relocation offset in DPRAM [SMC1]
3930 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
3931 enable SPI microcode relocation patch (MPC8xx);
3932 define relocation offset in DPRAM [SCC4]
3934 - CONFIG_SYS_USE_OSCCLK:
3935 Use OSCM clock mode on MBX8xx board. Be careful,
3936 wrong setting might damage your board. Read
3937 doc/README.MBX before setting this variable!
3939 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
3940 Offset of the bootmode word in DPRAM used by post
3941 (Power On Self Tests). This definition overrides
3942 #define'd default value in commproc.h resp.
3945 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
3946 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
3947 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
3948 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
3949 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
3950 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
3951 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
3952 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
3953 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
3955 - CONFIG_PCI_DISABLE_PCIE:
3956 Disable PCI-Express on systems where it is supported but not
3959 - CONFIG_PCI_ENUM_ONLY
3960 Only scan through and get the devices on the busses.
3961 Don't do any setup work, presumably because someone or
3962 something has already done it, and we don't need to do it
3963 a second time. Useful for platforms that are pre-booted
3964 by coreboot or similar.
3966 - CONFIG_PCI_INDIRECT_BRIDGE:
3967 Enable support for indirect PCI bridges.
3970 Chip has SRIO or not
3973 Board has SRIO 1 port available
3976 Board has SRIO 2 port available
3978 - CONFIG_SRIO_PCIE_BOOT_MASTER
3979 Board can support master function for Boot from SRIO and PCIE
3981 - CONFIG_SYS_SRIOn_MEM_VIRT:
3982 Virtual Address of SRIO port 'n' memory region
3984 - CONFIG_SYS_SRIOn_MEM_PHYS:
3985 Physical Address of SRIO port 'n' memory region
3987 - CONFIG_SYS_SRIOn_MEM_SIZE:
3988 Size of SRIO port 'n' memory region
3990 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
3991 Defined to tell the NAND controller that the NAND chip is using
3993 Not all NAND drivers use this symbol.
3994 Example of drivers that use it:
3995 - drivers/mtd/nand/ndfc.c
3996 - drivers/mtd/nand/mxc_nand.c
3998 - CONFIG_SYS_NDFC_EBC0_CFG
3999 Sets the EBC0_CFG register for the NDFC. If not defined
4000 a default value will be used.
4003 Get DDR timing information from an I2C EEPROM. Common
4004 with pluggable memory modules such as SODIMMs
4007 I2C address of the SPD EEPROM
4009 - CONFIG_SYS_SPD_BUS_NUM
4010 If SPD EEPROM is on an I2C bus other than the first
4011 one, specify here. Note that the value must resolve
4012 to something your driver can deal with.
4014 - CONFIG_SYS_DDR_RAW_TIMING
4015 Get DDR timing information from other than SPD. Common with
4016 soldered DDR chips onboard without SPD. DDR raw timing
4017 parameters are extracted from datasheet and hard-coded into
4018 header files or board specific files.
4020 - CONFIG_FSL_DDR_INTERACTIVE
4021 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4023 - CONFIG_SYS_83XX_DDR_USES_CS0
4024 Only for 83xx systems. If specified, then DDR should
4025 be configured using CS0 and CS1 instead of CS2 and CS3.
4027 - CONFIG_ETHER_ON_FEC[12]
4028 Define to enable FEC[12] on a 8xx series processor.
4030 - CONFIG_FEC[12]_PHY
4031 Define to the hardcoded PHY address which corresponds
4032 to the given FEC; i. e.
4033 #define CONFIG_FEC1_PHY 4
4034 means that the PHY with address 4 is connected to FEC1
4036 When set to -1, means to probe for first available.
4038 - CONFIG_FEC[12]_PHY_NORXERR
4039 The PHY does not have a RXERR line (RMII only).
4040 (so program the FEC to ignore it).
4043 Enable RMII mode for all FECs.
4044 Note that this is a global option, we can't
4045 have one FEC in standard MII mode and another in RMII mode.
4047 - CONFIG_CRC32_VERIFY
4048 Add a verify option to the crc32 command.
4051 => crc32 -v <address> <count> <crc32>
4053 Where address/count indicate a memory area
4054 and crc32 is the correct crc32 which the
4058 Add the "loopw" memory command. This only takes effect if
4059 the memory commands are activated globally (CONFIG_CMD_MEM).
4062 Add the "mdc" and "mwc" memory commands. These are cyclic
4067 This command will print 4 bytes (10,11,12,13) each 500 ms.
4069 => mwc.l 100 12345678 10
4070 This command will write 12345678 to address 100 all 10 ms.
4072 This only takes effect if the memory commands are activated
4073 globally (CONFIG_CMD_MEM).
4075 - CONFIG_SKIP_LOWLEVEL_INIT
4076 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4077 low level initializations (like setting up the memory
4078 controller) are omitted and/or U-Boot does not
4079 relocate itself into RAM.
4081 Normally this variable MUST NOT be defined. The only
4082 exception is when U-Boot is loaded (to RAM) by some
4083 other boot loader or by a debugger which performs
4084 these initializations itself.
4087 Modifies the behaviour of start.S when compiling a loader
4088 that is executed before the actual U-Boot. E.g. when
4089 compiling a NAND SPL.
4091 - CONFIG_ARCH_MAP_SYSMEM
4092 Generally U-Boot (and in particular the md command) uses
4093 effective address. It is therefore not necessary to regard
4094 U-Boot address as virtual addresses that need to be translated
4095 to physical addresses. However, sandbox requires this, since
4096 it maintains its own little RAM buffer which contains all
4097 addressable memory. This option causes some memory accesses
4098 to be mapped through map_sysmem() / unmap_sysmem().
4100 - CONFIG_USE_ARCH_MEMCPY
4101 CONFIG_USE_ARCH_MEMSET
4102 If these options are used a optimized version of memcpy/memset will
4103 be used if available. These functions may be faster under some
4104 conditions but may increase the binary size.
4106 - CONFIG_X86_RESET_VECTOR
4107 If defined, the x86 reset vector code is included. This is not
4108 needed when U-Boot is running from Coreboot.
4111 Defines the MPU clock speed (in MHz).
4113 NOTE : currently only supported on AM335x platforms.
4115 Freescale QE/FMAN Firmware Support:
4116 -----------------------------------
4118 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4119 loading of "firmware", which is encoded in the QE firmware binary format.
4120 This firmware often needs to be loaded during U-Boot booting, so macros
4121 are used to identify the storage device (NOR flash, SPI, etc) and the address
4124 - CONFIG_SYS_QE_FMAN_FW_ADDR
4125 The address in the storage device where the firmware is located. The
4126 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4129 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4130 The maximum possible size of the firmware. The firmware binary format
4131 has a field that specifies the actual size of the firmware, but it
4132 might not be possible to read any part of the firmware unless some
4133 local storage is allocated to hold the entire firmware first.
4135 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4136 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4137 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4138 virtual address in NOR flash.
4140 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4141 Specifies that QE/FMAN firmware is located in NAND flash.
4142 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4144 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4145 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4146 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4148 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4149 Specifies that QE/FMAN firmware is located on the primary SPI
4150 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4152 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4153 Specifies that QE/FMAN firmware is located in the remote (master)
4154 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4155 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4156 window->master inbound window->master LAW->the ucode address in
4157 master's memory space.
4159 Building the Software:
4160 ======================
4162 Building U-Boot has been tested in several native build environments
4163 and in many different cross environments. Of course we cannot support
4164 all possibly existing versions of cross development tools in all
4165 (potentially obsolete) versions. In case of tool chain problems we
4166 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4167 which is extensively used to build and test U-Boot.
4169 If you are not using a native environment, it is assumed that you
4170 have GNU cross compiling tools available in your path. In this case,
4171 you must set the environment variable CROSS_COMPILE in your shell.
4172 Note that no changes to the Makefile or any other source files are
4173 necessary. For example using the ELDK on a 4xx CPU, please enter:
4175 $ CROSS_COMPILE=ppc_4xx-
4176 $ export CROSS_COMPILE
4178 Note: If you wish to generate Windows versions of the utilities in
4179 the tools directory you can use the MinGW toolchain
4180 (http://www.mingw.org). Set your HOST tools to the MinGW
4181 toolchain and execute 'make tools'. For example:
4183 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4185 Binaries such as tools/mkimage.exe will be created which can
4186 be executed on computers running Windows.
4188 U-Boot is intended to be simple to build. After installing the
4189 sources you must configure U-Boot for one specific board type. This
4194 where "NAME_config" is the name of one of the existing configu-
4195 rations; see boards.cfg for supported names.
4197 Note: for some board special configuration names may exist; check if
4198 additional information is available from the board vendor; for
4199 instance, the TQM823L systems are available without (standard)
4200 or with LCD support. You can select such additional "features"
4201 when choosing the configuration, i. e.
4204 - will configure for a plain TQM823L, i. e. no LCD support
4206 make TQM823L_LCD_config
4207 - will configure for a TQM823L with U-Boot console on LCD
4212 Finally, type "make all", and you should get some working U-Boot
4213 images ready for download to / installation on your system:
4215 - "u-boot.bin" is a raw binary image
4216 - "u-boot" is an image in ELF binary format
4217 - "u-boot.srec" is in Motorola S-Record format
4219 By default the build is performed locally and the objects are saved
4220 in the source directory. One of the two methods can be used to change
4221 this behavior and build U-Boot to some external directory:
4223 1. Add O= to the make command line invocations:
4225 make O=/tmp/build distclean
4226 make O=/tmp/build NAME_config
4227 make O=/tmp/build all
4229 2. Set environment variable BUILD_DIR to point to the desired location:
4231 export BUILD_DIR=/tmp/build
4236 Note that the command line "O=" setting overrides the BUILD_DIR environment
4240 Please be aware that the Makefiles assume you are using GNU make, so
4241 for instance on NetBSD you might need to use "gmake" instead of
4245 If the system board that you have is not listed, then you will need
4246 to port U-Boot to your hardware platform. To do this, follow these
4249 1. Add a new configuration option for your board to the toplevel
4250 "boards.cfg" file, using the existing entries as examples.
4251 Follow the instructions there to keep the boards in order.
4252 2. Create a new directory to hold your board specific code. Add any
4253 files you need. In your board directory, you will need at least
4254 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4255 3. Create a new configuration file "include/configs/<board>.h" for
4257 3. If you're porting U-Boot to a new CPU, then also create a new
4258 directory to hold your CPU specific code. Add any files you need.
4259 4. Run "make <board>_config" with your new name.
4260 5. Type "make", and you should get a working "u-boot.srec" file
4261 to be installed on your target system.
4262 6. Debug and solve any problems that might arise.
4263 [Of course, this last step is much harder than it sounds.]
4266 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4267 ==============================================================
4269 If you have modified U-Boot sources (for instance added a new board
4270 or support for new devices, a new CPU, etc.) you are expected to
4271 provide feedback to the other developers. The feedback normally takes
4272 the form of a "patch", i. e. a context diff against a certain (latest
4273 official or latest in the git repository) version of U-Boot sources.
4275 But before you submit such a patch, please verify that your modifi-
4276 cation did not break existing code. At least make sure that *ALL* of
4277 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4278 just run the "MAKEALL" script, which will configure and build U-Boot
4279 for ALL supported system. Be warned, this will take a while. You can
4280 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4281 environment variable to the script, i. e. to use the ELDK cross tools
4284 CROSS_COMPILE=ppc_8xx- MAKEALL
4286 or to build on a native PowerPC system you can type
4288 CROSS_COMPILE=' ' MAKEALL
4290 When using the MAKEALL script, the default behaviour is to build
4291 U-Boot in the source directory. This location can be changed by
4292 setting the BUILD_DIR environment variable. Also, for each target
4293 built, the MAKEALL script saves two log files (<target>.ERR and
4294 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4295 location can be changed by setting the MAKEALL_LOGDIR environment
4296 variable. For example:
4298 export BUILD_DIR=/tmp/build
4299 export MAKEALL_LOGDIR=/tmp/log
4300 CROSS_COMPILE=ppc_8xx- MAKEALL
4302 With the above settings build objects are saved in the /tmp/build,
4303 log files are saved in the /tmp/log and the source tree remains clean
4304 during the whole build process.
4307 See also "U-Boot Porting Guide" below.
4310 Monitor Commands - Overview:
4311 ============================
4313 go - start application at address 'addr'
4314 run - run commands in an environment variable
4315 bootm - boot application image from memory
4316 bootp - boot image via network using BootP/TFTP protocol
4317 bootz - boot zImage from memory
4318 tftpboot- boot image via network using TFTP protocol
4319 and env variables "ipaddr" and "serverip"
4320 (and eventually "gatewayip")
4321 tftpput - upload a file via network using TFTP protocol
4322 rarpboot- boot image via network using RARP/TFTP protocol
4323 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4324 loads - load S-Record file over serial line
4325 loadb - load binary file over serial line (kermit mode)
4327 mm - memory modify (auto-incrementing)
4328 nm - memory modify (constant address)
4329 mw - memory write (fill)
4331 cmp - memory compare
4332 crc32 - checksum calculation
4333 i2c - I2C sub-system
4334 sspi - SPI utility commands
4335 base - print or set address offset
4336 printenv- print environment variables
4337 setenv - set environment variables
4338 saveenv - save environment variables to persistent storage
4339 protect - enable or disable FLASH write protection
4340 erase - erase FLASH memory
4341 flinfo - print FLASH memory information
4342 nand - NAND memory operations (see doc/README.nand)
4343 bdinfo - print Board Info structure
4344 iminfo - print header information for application image
4345 coninfo - print console devices and informations
4346 ide - IDE sub-system
4347 loop - infinite loop on address range
4348 loopw - infinite write loop on address range
4349 mtest - simple RAM test
4350 icache - enable or disable instruction cache
4351 dcache - enable or disable data cache
4352 reset - Perform RESET of the CPU
4353 echo - echo args to console
4354 version - print monitor version
4355 help - print online help
4356 ? - alias for 'help'
4359 Monitor Commands - Detailed Description:
4360 ========================================
4364 For now: just type "help <command>".
4367 Environment Variables:
4368 ======================
4370 U-Boot supports user configuration using Environment Variables which
4371 can be made persistent by saving to Flash memory.
4373 Environment Variables are set using "setenv", printed using
4374 "printenv", and saved to Flash using "saveenv". Using "setenv"
4375 without a value can be used to delete a variable from the
4376 environment. As long as you don't save the environment you are
4377 working with an in-memory copy. In case the Flash area containing the
4378 environment is erased by accident, a default environment is provided.
4380 Some configuration options can be set using Environment Variables.
4382 List of environment variables (most likely not complete):
4384 baudrate - see CONFIG_BAUDRATE
4386 bootdelay - see CONFIG_BOOTDELAY
4388 bootcmd - see CONFIG_BOOTCOMMAND
4390 bootargs - Boot arguments when booting an RTOS image
4392 bootfile - Name of the image to load with TFTP
4394 bootm_low - Memory range available for image processing in the bootm
4395 command can be restricted. This variable is given as
4396 a hexadecimal number and defines lowest address allowed
4397 for use by the bootm command. See also "bootm_size"
4398 environment variable. Address defined by "bootm_low" is
4399 also the base of the initial memory mapping for the Linux
4400 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4403 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4404 This variable is given as a hexadecimal number and it
4405 defines the size of the memory region starting at base
4406 address bootm_low that is accessible by the Linux kernel
4407 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4408 as the default value if it is defined, and bootm_size is
4411 bootm_size - Memory range available for image processing in the bootm
4412 command can be restricted. This variable is given as
4413 a hexadecimal number and defines the size of the region
4414 allowed for use by the bootm command. See also "bootm_low"
4415 environment variable.
4417 updatefile - Location of the software update file on a TFTP server, used
4418 by the automatic software update feature. Please refer to
4419 documentation in doc/README.update for more details.
4421 autoload - if set to "no" (any string beginning with 'n'),
4422 "bootp" will just load perform a lookup of the
4423 configuration from the BOOTP server, but not try to
4424 load any image using TFTP
4426 autostart - if set to "yes", an image loaded using the "bootp",
4427 "rarpboot", "tftpboot" or "diskboot" commands will
4428 be automatically started (by internally calling
4431 If set to "no", a standalone image passed to the
4432 "bootm" command will be copied to the load address
4433 (and eventually uncompressed), but NOT be started.
4434 This can be used to load and uncompress arbitrary
4437 fdt_high - if set this restricts the maximum address that the
4438 flattened device tree will be copied into upon boot.
4439 For example, if you have a system with 1 GB memory
4440 at physical address 0x10000000, while Linux kernel
4441 only recognizes the first 704 MB as low memory, you
4442 may need to set fdt_high as 0x3C000000 to have the
4443 device tree blob be copied to the maximum address
4444 of the 704 MB low memory, so that Linux kernel can
4445 access it during the boot procedure.
4447 If this is set to the special value 0xFFFFFFFF then
4448 the fdt will not be copied at all on boot. For this
4449 to work it must reside in writable memory, have
4450 sufficient padding on the end of it for u-boot to
4451 add the information it needs into it, and the memory
4452 must be accessible by the kernel.
4454 fdtcontroladdr- if set this is the address of the control flattened
4455 device tree used by U-Boot when CONFIG_OF_CONTROL is
4458 i2cfast - (PPC405GP|PPC405EP only)
4459 if set to 'y' configures Linux I2C driver for fast
4460 mode (400kHZ). This environment variable is used in
4461 initialization code. So, for changes to be effective
4462 it must be saved and board must be reset.
4464 initrd_high - restrict positioning of initrd images:
4465 If this variable is not set, initrd images will be
4466 copied to the highest possible address in RAM; this
4467 is usually what you want since it allows for
4468 maximum initrd size. If for some reason you want to
4469 make sure that the initrd image is loaded below the
4470 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4471 variable to a value of "no" or "off" or "0".
4472 Alternatively, you can set it to a maximum upper
4473 address to use (U-Boot will still check that it
4474 does not overwrite the U-Boot stack and data).
4476 For instance, when you have a system with 16 MB
4477 RAM, and want to reserve 4 MB from use by Linux,
4478 you can do this by adding "mem=12M" to the value of
4479 the "bootargs" variable. However, now you must make
4480 sure that the initrd image is placed in the first
4481 12 MB as well - this can be done with
4483 setenv initrd_high 00c00000
4485 If you set initrd_high to 0xFFFFFFFF, this is an
4486 indication to U-Boot that all addresses are legal
4487 for the Linux kernel, including addresses in flash
4488 memory. In this case U-Boot will NOT COPY the
4489 ramdisk at all. This may be useful to reduce the
4490 boot time on your system, but requires that this
4491 feature is supported by your Linux kernel.
4493 ipaddr - IP address; needed for tftpboot command
4495 loadaddr - Default load address for commands like "bootp",
4496 "rarpboot", "tftpboot", "loadb" or "diskboot"
4498 loads_echo - see CONFIG_LOADS_ECHO
4500 serverip - TFTP server IP address; needed for tftpboot command
4502 bootretry - see CONFIG_BOOT_RETRY_TIME
4504 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4506 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4508 ethprime - controls which interface is used first.
4510 ethact - controls which interface is currently active.
4511 For example you can do the following
4513 => setenv ethact FEC
4514 => ping 192.168.0.1 # traffic sent on FEC
4515 => setenv ethact SCC
4516 => ping 10.0.0.1 # traffic sent on SCC
4518 ethrotate - When set to "no" U-Boot does not go through all
4519 available network interfaces.
4520 It just stays at the currently selected interface.
4522 netretry - When set to "no" each network operation will
4523 either succeed or fail without retrying.
4524 When set to "once" the network operation will
4525 fail when all the available network interfaces
4526 are tried once without success.
4527 Useful on scripts which control the retry operation
4530 npe_ucode - set load address for the NPE microcode
4532 tftpsrcport - If this is set, the value is used for TFTP's
4535 tftpdstport - If this is set, the value is used for TFTP's UDP
4536 destination port instead of the Well Know Port 69.
4538 tftpblocksize - Block size to use for TFTP transfers; if not set,
4539 we use the TFTP server's default block size
4541 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4542 seconds, minimum value is 1000 = 1 second). Defines
4543 when a packet is considered to be lost so it has to
4544 be retransmitted. The default is 5000 = 5 seconds.
4545 Lowering this value may make downloads succeed
4546 faster in networks with high packet loss rates or
4547 with unreliable TFTP servers.
4549 vlan - When set to a value < 4095 the traffic over
4550 Ethernet is encapsulated/received over 802.1q
4553 The following image location variables contain the location of images
4554 used in booting. The "Image" column gives the role of the image and is
4555 not an environment variable name. The other columns are environment
4556 variable names. "File Name" gives the name of the file on a TFTP
4557 server, "RAM Address" gives the location in RAM the image will be
4558 loaded to, and "Flash Location" gives the image's address in NOR
4559 flash or offset in NAND flash.
4561 *Note* - these variables don't have to be defined for all boards, some
4562 boards currenlty use other variables for these purposes, and some
4563 boards use these variables for other purposes.
4565 Image File Name RAM Address Flash Location
4566 ----- --------- ----------- --------------
4567 u-boot u-boot u-boot_addr_r u-boot_addr
4568 Linux kernel bootfile kernel_addr_r kernel_addr
4569 device tree blob fdtfile fdt_addr_r fdt_addr
4570 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4572 The following environment variables may be used and automatically
4573 updated by the network boot commands ("bootp" and "rarpboot"),
4574 depending the information provided by your boot server:
4576 bootfile - see above
4577 dnsip - IP address of your Domain Name Server
4578 dnsip2 - IP address of your secondary Domain Name Server
4579 gatewayip - IP address of the Gateway (Router) to use
4580 hostname - Target hostname
4582 netmask - Subnet Mask
4583 rootpath - Pathname of the root filesystem on the NFS server
4584 serverip - see above
4587 There are two special Environment Variables:
4589 serial# - contains hardware identification information such
4590 as type string and/or serial number
4591 ethaddr - Ethernet address
4593 These variables can be set only once (usually during manufacturing of
4594 the board). U-Boot refuses to delete or overwrite these variables
4595 once they have been set once.
4598 Further special Environment Variables:
4600 ver - Contains the U-Boot version string as printed
4601 with the "version" command. This variable is
4602 readonly (see CONFIG_VERSION_VARIABLE).
4605 Please note that changes to some configuration parameters may take
4606 only effect after the next boot (yes, that's just like Windoze :-).
4609 Callback functions for environment variables:
4610 ---------------------------------------------
4612 For some environment variables, the behavior of u-boot needs to change
4613 when their values are changed. This functionailty allows functions to
4614 be associated with arbitrary variables. On creation, overwrite, or
4615 deletion, the callback will provide the opportunity for some side
4616 effect to happen or for the change to be rejected.
4618 The callbacks are named and associated with a function using the
4619 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4621 These callbacks are associated with variables in one of two ways. The
4622 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4623 in the board configuration to a string that defines a list of
4624 associations. The list must be in the following format:
4626 entry = variable_name[:callback_name]
4629 If the callback name is not specified, then the callback is deleted.
4630 Spaces are also allowed anywhere in the list.
4632 Callbacks can also be associated by defining the ".callbacks" variable
4633 with the same list format above. Any association in ".callbacks" will
4634 override any association in the static list. You can define
4635 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4636 ".callbacks" envirnoment variable in the default or embedded environment.
4639 Command Line Parsing:
4640 =====================
4642 There are two different command line parsers available with U-Boot:
4643 the old "simple" one, and the much more powerful "hush" shell:
4645 Old, simple command line parser:
4646 --------------------------------
4648 - supports environment variables (through setenv / saveenv commands)
4649 - several commands on one line, separated by ';'
4650 - variable substitution using "... ${name} ..." syntax
4651 - special characters ('$', ';') can be escaped by prefixing with '\',
4653 setenv bootcmd bootm \${address}
4654 - You can also escape text by enclosing in single apostrophes, for example:
4655 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4660 - similar to Bourne shell, with control structures like
4661 if...then...else...fi, for...do...done; while...do...done,
4662 until...do...done, ...
4663 - supports environment ("global") variables (through setenv / saveenv
4664 commands) and local shell variables (through standard shell syntax
4665 "name=value"); only environment variables can be used with "run"
4671 (1) If a command line (or an environment variable executed by a "run"
4672 command) contains several commands separated by semicolon, and
4673 one of these commands fails, then the remaining commands will be
4676 (2) If you execute several variables with one call to run (i. e.
4677 calling run with a list of variables as arguments), any failing
4678 command will cause "run" to terminate, i. e. the remaining
4679 variables are not executed.
4681 Note for Redundant Ethernet Interfaces:
4682 =======================================
4684 Some boards come with redundant Ethernet interfaces; U-Boot supports
4685 such configurations and is capable of automatic selection of a
4686 "working" interface when needed. MAC assignment works as follows:
4688 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4689 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4690 "eth1addr" (=>eth1), "eth2addr", ...
4692 If the network interface stores some valid MAC address (for instance
4693 in SROM), this is used as default address if there is NO correspon-
4694 ding setting in the environment; if the corresponding environment
4695 variable is set, this overrides the settings in the card; that means:
4697 o If the SROM has a valid MAC address, and there is no address in the
4698 environment, the SROM's address is used.
4700 o If there is no valid address in the SROM, and a definition in the
4701 environment exists, then the value from the environment variable is
4704 o If both the SROM and the environment contain a MAC address, and
4705 both addresses are the same, this MAC address is used.
4707 o If both the SROM and the environment contain a MAC address, and the
4708 addresses differ, the value from the environment is used and a
4711 o If neither SROM nor the environment contain a MAC address, an error
4714 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4715 will be programmed into hardware as part of the initialization process. This
4716 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4717 The naming convention is as follows:
4718 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4723 U-Boot is capable of booting (and performing other auxiliary operations on)
4724 images in two formats:
4726 New uImage format (FIT)
4727 -----------------------
4729 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4730 to Flattened Device Tree). It allows the use of images with multiple
4731 components (several kernels, ramdisks, etc.), with contents protected by
4732 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4738 Old image format is based on binary files which can be basically anything,
4739 preceded by a special header; see the definitions in include/image.h for
4740 details; basically, the header defines the following image properties:
4742 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4743 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4744 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4745 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4747 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4748 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4749 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4750 * Compression Type (uncompressed, gzip, bzip2)
4756 The header is marked by a special Magic Number, and both the header
4757 and the data portions of the image are secured against corruption by
4764 Although U-Boot should support any OS or standalone application
4765 easily, the main focus has always been on Linux during the design of
4768 U-Boot includes many features that so far have been part of some
4769 special "boot loader" code within the Linux kernel. Also, any
4770 "initrd" images to be used are no longer part of one big Linux image;
4771 instead, kernel and "initrd" are separate images. This implementation
4772 serves several purposes:
4774 - the same features can be used for other OS or standalone
4775 applications (for instance: using compressed images to reduce the
4776 Flash memory footprint)
4778 - it becomes much easier to port new Linux kernel versions because
4779 lots of low-level, hardware dependent stuff are done by U-Boot
4781 - the same Linux kernel image can now be used with different "initrd"
4782 images; of course this also means that different kernel images can
4783 be run with the same "initrd". This makes testing easier (you don't
4784 have to build a new "zImage.initrd" Linux image when you just
4785 change a file in your "initrd"). Also, a field-upgrade of the
4786 software is easier now.
4792 Porting Linux to U-Boot based systems:
4793 ---------------------------------------
4795 U-Boot cannot save you from doing all the necessary modifications to
4796 configure the Linux device drivers for use with your target hardware
4797 (no, we don't intend to provide a full virtual machine interface to
4800 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4802 Just make sure your machine specific header file (for instance
4803 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4804 Information structure as we define in include/asm-<arch>/u-boot.h,
4805 and make sure that your definition of IMAP_ADDR uses the same value
4806 as your U-Boot configuration in CONFIG_SYS_IMMR.
4809 Configuring the Linux kernel:
4810 -----------------------------
4812 No specific requirements for U-Boot. Make sure you have some root
4813 device (initial ramdisk, NFS) for your target system.
4816 Building a Linux Image:
4817 -----------------------
4819 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4820 not used. If you use recent kernel source, a new build target
4821 "uImage" will exist which automatically builds an image usable by
4822 U-Boot. Most older kernels also have support for a "pImage" target,
4823 which was introduced for our predecessor project PPCBoot and uses a
4824 100% compatible format.
4833 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4834 encapsulate a compressed Linux kernel image with header information,
4835 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4837 * build a standard "vmlinux" kernel image (in ELF binary format):
4839 * convert the kernel into a raw binary image:
4841 ${CROSS_COMPILE}-objcopy -O binary \
4842 -R .note -R .comment \
4843 -S vmlinux linux.bin
4845 * compress the binary image:
4849 * package compressed binary image for U-Boot:
4851 mkimage -A ppc -O linux -T kernel -C gzip \
4852 -a 0 -e 0 -n "Linux Kernel Image" \
4853 -d linux.bin.gz uImage
4856 The "mkimage" tool can also be used to create ramdisk images for use
4857 with U-Boot, either separated from the Linux kernel image, or
4858 combined into one file. "mkimage" encapsulates the images with a 64
4859 byte header containing information about target architecture,
4860 operating system, image type, compression method, entry points, time
4861 stamp, CRC32 checksums, etc.
4863 "mkimage" can be called in two ways: to verify existing images and
4864 print the header information, or to build new images.
4866 In the first form (with "-l" option) mkimage lists the information
4867 contained in the header of an existing U-Boot image; this includes
4868 checksum verification:
4870 tools/mkimage -l image
4871 -l ==> list image header information
4873 The second form (with "-d" option) is used to build a U-Boot image
4874 from a "data file" which is used as image payload:
4876 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4877 -n name -d data_file image
4878 -A ==> set architecture to 'arch'
4879 -O ==> set operating system to 'os'
4880 -T ==> set image type to 'type'
4881 -C ==> set compression type 'comp'
4882 -a ==> set load address to 'addr' (hex)
4883 -e ==> set entry point to 'ep' (hex)
4884 -n ==> set image name to 'name'
4885 -d ==> use image data from 'datafile'
4887 Right now, all Linux kernels for PowerPC systems use the same load
4888 address (0x00000000), but the entry point address depends on the
4891 - 2.2.x kernels have the entry point at 0x0000000C,
4892 - 2.3.x and later kernels have the entry point at 0x00000000.
4894 So a typical call to build a U-Boot image would read:
4896 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4897 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4898 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4899 > examples/uImage.TQM850L
4900 Image Name: 2.4.4 kernel for TQM850L
4901 Created: Wed Jul 19 02:34:59 2000
4902 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4903 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4904 Load Address: 0x00000000
4905 Entry Point: 0x00000000
4907 To verify the contents of the image (or check for corruption):
4909 -> tools/mkimage -l examples/uImage.TQM850L
4910 Image Name: 2.4.4 kernel for TQM850L
4911 Created: Wed Jul 19 02:34:59 2000
4912 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4913 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4914 Load Address: 0x00000000
4915 Entry Point: 0x00000000
4917 NOTE: for embedded systems where boot time is critical you can trade
4918 speed for memory and install an UNCOMPRESSED image instead: this
4919 needs more space in Flash, but boots much faster since it does not
4920 need to be uncompressed:
4922 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4923 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4924 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4925 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4926 > examples/uImage.TQM850L-uncompressed
4927 Image Name: 2.4.4 kernel for TQM850L
4928 Created: Wed Jul 19 02:34:59 2000
4929 Image Type: PowerPC Linux Kernel Image (uncompressed)
4930 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4931 Load Address: 0x00000000
4932 Entry Point: 0x00000000
4935 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4936 when your kernel is intended to use an initial ramdisk:
4938 -> tools/mkimage -n 'Simple Ramdisk Image' \
4939 > -A ppc -O linux -T ramdisk -C gzip \
4940 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4941 Image Name: Simple Ramdisk Image
4942 Created: Wed Jan 12 14:01:50 2000
4943 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4944 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4945 Load Address: 0x00000000
4946 Entry Point: 0x00000000
4949 Installing a Linux Image:
4950 -------------------------
4952 To downloading a U-Boot image over the serial (console) interface,
4953 you must convert the image to S-Record format:
4955 objcopy -I binary -O srec examples/image examples/image.srec
4957 The 'objcopy' does not understand the information in the U-Boot
4958 image header, so the resulting S-Record file will be relative to
4959 address 0x00000000. To load it to a given address, you need to
4960 specify the target address as 'offset' parameter with the 'loads'
4963 Example: install the image to address 0x40100000 (which on the
4964 TQM8xxL is in the first Flash bank):
4966 => erase 40100000 401FFFFF
4972 ## Ready for S-Record download ...
4973 ~>examples/image.srec
4974 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4976 15989 15990 15991 15992
4977 [file transfer complete]
4979 ## Start Addr = 0x00000000
4982 You can check the success of the download using the 'iminfo' command;
4983 this includes a checksum verification so you can be sure no data
4984 corruption happened:
4988 ## Checking Image at 40100000 ...
4989 Image Name: 2.2.13 for initrd on TQM850L
4990 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4991 Data Size: 335725 Bytes = 327 kB = 0 MB
4992 Load Address: 00000000
4993 Entry Point: 0000000c
4994 Verifying Checksum ... OK
5000 The "bootm" command is used to boot an application that is stored in
5001 memory (RAM or Flash). In case of a Linux kernel image, the contents
5002 of the "bootargs" environment variable is passed to the kernel as
5003 parameters. You can check and modify this variable using the
5004 "printenv" and "setenv" commands:
5007 => printenv bootargs
5008 bootargs=root=/dev/ram
5010 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5012 => printenv bootargs
5013 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5016 ## Booting Linux kernel at 40020000 ...
5017 Image Name: 2.2.13 for NFS on TQM850L
5018 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5019 Data Size: 381681 Bytes = 372 kB = 0 MB
5020 Load Address: 00000000
5021 Entry Point: 0000000c
5022 Verifying Checksum ... OK
5023 Uncompressing Kernel Image ... OK
5024 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
5025 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5026 time_init: decrementer frequency = 187500000/60
5027 Calibrating delay loop... 49.77 BogoMIPS
5028 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5031 If you want to boot a Linux kernel with initial RAM disk, you pass
5032 the memory addresses of both the kernel and the initrd image (PPBCOOT
5033 format!) to the "bootm" command:
5035 => imi 40100000 40200000
5037 ## Checking Image at 40100000 ...
5038 Image Name: 2.2.13 for initrd on TQM850L
5039 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5040 Data Size: 335725 Bytes = 327 kB = 0 MB
5041 Load Address: 00000000
5042 Entry Point: 0000000c
5043 Verifying Checksum ... OK
5045 ## Checking Image at 40200000 ...
5046 Image Name: Simple Ramdisk Image
5047 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5048 Data Size: 566530 Bytes = 553 kB = 0 MB
5049 Load Address: 00000000
5050 Entry Point: 00000000
5051 Verifying Checksum ... OK
5053 => bootm 40100000 40200000
5054 ## Booting Linux kernel at 40100000 ...
5055 Image Name: 2.2.13 for initrd on TQM850L
5056 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5057 Data Size: 335725 Bytes = 327 kB = 0 MB
5058 Load Address: 00000000
5059 Entry Point: 0000000c
5060 Verifying Checksum ... OK
5061 Uncompressing Kernel Image ... OK
5062 ## Loading RAMDisk Image at 40200000 ...
5063 Image Name: Simple Ramdisk Image
5064 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5065 Data Size: 566530 Bytes = 553 kB = 0 MB
5066 Load Address: 00000000
5067 Entry Point: 00000000
5068 Verifying Checksum ... OK
5069 Loading Ramdisk ... OK
5070 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
5071 Boot arguments: root=/dev/ram
5072 time_init: decrementer frequency = 187500000/60
5073 Calibrating delay loop... 49.77 BogoMIPS
5075 RAMDISK: Compressed image found at block 0
5076 VFS: Mounted root (ext2 filesystem).
5080 Boot Linux and pass a flat device tree:
5083 First, U-Boot must be compiled with the appropriate defines. See the section
5084 titled "Linux Kernel Interface" above for a more in depth explanation. The
5085 following is an example of how to start a kernel and pass an updated
5091 oft=oftrees/mpc8540ads.dtb
5092 => tftp $oftaddr $oft
5093 Speed: 1000, full duplex
5095 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5096 Filename 'oftrees/mpc8540ads.dtb'.
5097 Load address: 0x300000
5100 Bytes transferred = 4106 (100a hex)
5101 => tftp $loadaddr $bootfile
5102 Speed: 1000, full duplex
5104 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5106 Load address: 0x200000
5107 Loading:############
5109 Bytes transferred = 1029407 (fb51f hex)
5114 => bootm $loadaddr - $oftaddr
5115 ## Booting image at 00200000 ...
5116 Image Name: Linux-2.6.17-dirty
5117 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5118 Data Size: 1029343 Bytes = 1005.2 kB
5119 Load Address: 00000000
5120 Entry Point: 00000000
5121 Verifying Checksum ... OK
5122 Uncompressing Kernel Image ... OK
5123 Booting using flat device tree at 0x300000
5124 Using MPC85xx ADS machine description
5125 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5129 More About U-Boot Image Types:
5130 ------------------------------
5132 U-Boot supports the following image types:
5134 "Standalone Programs" are directly runnable in the environment
5135 provided by U-Boot; it is expected that (if they behave
5136 well) you can continue to work in U-Boot after return from
5137 the Standalone Program.
5138 "OS Kernel Images" are usually images of some Embedded OS which
5139 will take over control completely. Usually these programs
5140 will install their own set of exception handlers, device
5141 drivers, set up the MMU, etc. - this means, that you cannot
5142 expect to re-enter U-Boot except by resetting the CPU.
5143 "RAMDisk Images" are more or less just data blocks, and their
5144 parameters (address, size) are passed to an OS kernel that is
5146 "Multi-File Images" contain several images, typically an OS
5147 (Linux) kernel image and one or more data images like
5148 RAMDisks. This construct is useful for instance when you want
5149 to boot over the network using BOOTP etc., where the boot
5150 server provides just a single image file, but you want to get
5151 for instance an OS kernel and a RAMDisk image.
5153 "Multi-File Images" start with a list of image sizes, each
5154 image size (in bytes) specified by an "uint32_t" in network
5155 byte order. This list is terminated by an "(uint32_t)0".
5156 Immediately after the terminating 0 follow the images, one by
5157 one, all aligned on "uint32_t" boundaries (size rounded up to
5158 a multiple of 4 bytes).
5160 "Firmware Images" are binary images containing firmware (like
5161 U-Boot or FPGA images) which usually will be programmed to
5164 "Script files" are command sequences that will be executed by
5165 U-Boot's command interpreter; this feature is especially
5166 useful when you configure U-Boot to use a real shell (hush)
5167 as command interpreter.
5169 Booting the Linux zImage:
5170 -------------------------
5172 On some platforms, it's possible to boot Linux zImage. This is done
5173 using the "bootz" command. The syntax of "bootz" command is the same
5174 as the syntax of "bootm" command.
5176 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5177 kernel with raw initrd images. The syntax is slightly different, the
5178 address of the initrd must be augmented by it's size, in the following
5179 format: "<initrd addres>:<initrd size>".
5185 One of the features of U-Boot is that you can dynamically load and
5186 run "standalone" applications, which can use some resources of
5187 U-Boot like console I/O functions or interrupt services.
5189 Two simple examples are included with the sources:
5194 'examples/hello_world.c' contains a small "Hello World" Demo
5195 application; it is automatically compiled when you build U-Boot.
5196 It's configured to run at address 0x00040004, so you can play with it
5200 ## Ready for S-Record download ...
5201 ~>examples/hello_world.srec
5202 1 2 3 4 5 6 7 8 9 10 11 ...
5203 [file transfer complete]
5205 ## Start Addr = 0x00040004
5207 => go 40004 Hello World! This is a test.
5208 ## Starting application at 0x00040004 ...
5219 Hit any key to exit ...
5221 ## Application terminated, rc = 0x0
5223 Another example, which demonstrates how to register a CPM interrupt
5224 handler with the U-Boot code, can be found in 'examples/timer.c'.
5225 Here, a CPM timer is set up to generate an interrupt every second.
5226 The interrupt service routine is trivial, just printing a '.'
5227 character, but this is just a demo program. The application can be
5228 controlled by the following keys:
5230 ? - print current values og the CPM Timer registers
5231 b - enable interrupts and start timer
5232 e - stop timer and disable interrupts
5233 q - quit application
5236 ## Ready for S-Record download ...
5237 ~>examples/timer.srec
5238 1 2 3 4 5 6 7 8 9 10 11 ...
5239 [file transfer complete]
5241 ## Start Addr = 0x00040004
5244 ## Starting application at 0x00040004 ...
5247 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5250 [q, b, e, ?] Set interval 1000000 us
5253 [q, b, e, ?] ........
5254 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5257 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5260 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5263 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5265 [q, b, e, ?] ...Stopping timer
5267 [q, b, e, ?] ## Application terminated, rc = 0x0
5273 Over time, many people have reported problems when trying to use the
5274 "minicom" terminal emulation program for serial download. I (wd)
5275 consider minicom to be broken, and recommend not to use it. Under
5276 Unix, I recommend to use C-Kermit for general purpose use (and
5277 especially for kermit binary protocol download ("loadb" command), and
5278 use "cu" for S-Record download ("loads" command). See
5279 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5280 for help with kermit.
5283 Nevertheless, if you absolutely want to use it try adding this
5284 configuration to your "File transfer protocols" section:
5286 Name Program Name U/D FullScr IO-Red. Multi
5287 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5288 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5294 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5295 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5297 Building requires a cross environment; it is known to work on
5298 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5299 need gmake since the Makefiles are not compatible with BSD make).
5300 Note that the cross-powerpc package does not install include files;
5301 attempting to build U-Boot will fail because <machine/ansi.h> is
5302 missing. This file has to be installed and patched manually:
5304 # cd /usr/pkg/cross/powerpc-netbsd/include
5306 # ln -s powerpc machine
5307 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5308 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5310 Native builds *don't* work due to incompatibilities between native
5311 and U-Boot include files.
5313 Booting assumes that (the first part of) the image booted is a
5314 stage-2 loader which in turn loads and then invokes the kernel
5315 proper. Loader sources will eventually appear in the NetBSD source
5316 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5317 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5320 Implementation Internals:
5321 =========================
5323 The following is not intended to be a complete description of every
5324 implementation detail. However, it should help to understand the
5325 inner workings of U-Boot and make it easier to port it to custom
5329 Initial Stack, Global Data:
5330 ---------------------------
5332 The implementation of U-Boot is complicated by the fact that U-Boot
5333 starts running out of ROM (flash memory), usually without access to
5334 system RAM (because the memory controller is not initialized yet).
5335 This means that we don't have writable Data or BSS segments, and BSS
5336 is not initialized as zero. To be able to get a C environment working
5337 at all, we have to allocate at least a minimal stack. Implementation
5338 options for this are defined and restricted by the CPU used: Some CPU
5339 models provide on-chip memory (like the IMMR area on MPC8xx and
5340 MPC826x processors), on others (parts of) the data cache can be
5341 locked as (mis-) used as memory, etc.
5343 Chris Hallinan posted a good summary of these issues to the
5344 U-Boot mailing list:
5346 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5347 From: "Chris Hallinan" <clh@net1plus.com>
5348 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5351 Correct me if I'm wrong, folks, but the way I understand it
5352 is this: Using DCACHE as initial RAM for Stack, etc, does not
5353 require any physical RAM backing up the cache. The cleverness
5354 is that the cache is being used as a temporary supply of
5355 necessary storage before the SDRAM controller is setup. It's
5356 beyond the scope of this list to explain the details, but you
5357 can see how this works by studying the cache architecture and
5358 operation in the architecture and processor-specific manuals.
5360 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5361 is another option for the system designer to use as an
5362 initial stack/RAM area prior to SDRAM being available. Either
5363 option should work for you. Using CS 4 should be fine if your
5364 board designers haven't used it for something that would
5365 cause you grief during the initial boot! It is frequently not
5368 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5369 with your processor/board/system design. The default value
5370 you will find in any recent u-boot distribution in
5371 walnut.h should work for you. I'd set it to a value larger
5372 than your SDRAM module. If you have a 64MB SDRAM module, set
5373 it above 400_0000. Just make sure your board has no resources
5374 that are supposed to respond to that address! That code in
5375 start.S has been around a while and should work as is when
5376 you get the config right.
5381 It is essential to remember this, since it has some impact on the C
5382 code for the initialization procedures:
5384 * Initialized global data (data segment) is read-only. Do not attempt
5387 * Do not use any uninitialized global data (or implicitely initialized
5388 as zero data - BSS segment) at all - this is undefined, initiali-
5389 zation is performed later (when relocating to RAM).
5391 * Stack space is very limited. Avoid big data buffers or things like
5394 Having only the stack as writable memory limits means we cannot use
5395 normal global data to share information beween the code. But it
5396 turned out that the implementation of U-Boot can be greatly
5397 simplified by making a global data structure (gd_t) available to all
5398 functions. We could pass a pointer to this data as argument to _all_
5399 functions, but this would bloat the code. Instead we use a feature of
5400 the GCC compiler (Global Register Variables) to share the data: we
5401 place a pointer (gd) to the global data into a register which we
5402 reserve for this purpose.
5404 When choosing a register for such a purpose we are restricted by the
5405 relevant (E)ABI specifications for the current architecture, and by
5406 GCC's implementation.
5408 For PowerPC, the following registers have specific use:
5410 R2: reserved for system use
5411 R3-R4: parameter passing and return values
5412 R5-R10: parameter passing
5413 R13: small data area pointer
5417 (U-Boot also uses R12 as internal GOT pointer. r12
5418 is a volatile register so r12 needs to be reset when
5419 going back and forth between asm and C)
5421 ==> U-Boot will use R2 to hold a pointer to the global data
5423 Note: on PPC, we could use a static initializer (since the
5424 address of the global data structure is known at compile time),
5425 but it turned out that reserving a register results in somewhat
5426 smaller code - although the code savings are not that big (on
5427 average for all boards 752 bytes for the whole U-Boot image,
5428 624 text + 127 data).
5430 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5431 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5433 ==> U-Boot will use P3 to hold a pointer to the global data
5435 On ARM, the following registers are used:
5437 R0: function argument word/integer result
5438 R1-R3: function argument word
5440 R10: stack limit (used only if stack checking if enabled)
5441 R11: argument (frame) pointer
5442 R12: temporary workspace
5445 R15: program counter
5447 ==> U-Boot will use R8 to hold a pointer to the global data
5449 On Nios II, the ABI is documented here:
5450 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5452 ==> U-Boot will use gp to hold a pointer to the global data
5454 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5455 to access small data sections, so gp is free.
5457 On NDS32, the following registers are used:
5459 R0-R1: argument/return
5461 R15: temporary register for assembler
5462 R16: trampoline register
5463 R28: frame pointer (FP)
5464 R29: global pointer (GP)
5465 R30: link register (LP)
5466 R31: stack pointer (SP)
5467 PC: program counter (PC)
5469 ==> U-Boot will use R10 to hold a pointer to the global data
5471 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5472 or current versions of GCC may "optimize" the code too much.
5477 U-Boot runs in system state and uses physical addresses, i.e. the
5478 MMU is not used either for address mapping nor for memory protection.
5480 The available memory is mapped to fixed addresses using the memory
5481 controller. In this process, a contiguous block is formed for each
5482 memory type (Flash, SDRAM, SRAM), even when it consists of several
5483 physical memory banks.
5485 U-Boot is installed in the first 128 kB of the first Flash bank (on
5486 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5487 booting and sizing and initializing DRAM, the code relocates itself
5488 to the upper end of DRAM. Immediately below the U-Boot code some
5489 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5490 configuration setting]. Below that, a structure with global Board
5491 Info data is placed, followed by the stack (growing downward).
5493 Additionally, some exception handler code is copied to the low 8 kB
5494 of DRAM (0x00000000 ... 0x00001FFF).
5496 So a typical memory configuration with 16 MB of DRAM could look like
5499 0x0000 0000 Exception Vector code
5502 0x0000 2000 Free for Application Use
5508 0x00FB FF20 Monitor Stack (Growing downward)
5509 0x00FB FFAC Board Info Data and permanent copy of global data
5510 0x00FC 0000 Malloc Arena
5513 0x00FE 0000 RAM Copy of Monitor Code
5514 ... eventually: LCD or video framebuffer
5515 ... eventually: pRAM (Protected RAM - unchanged by reset)
5516 0x00FF FFFF [End of RAM]
5519 System Initialization:
5520 ----------------------
5522 In the reset configuration, U-Boot starts at the reset entry point
5523 (on most PowerPC systems at address 0x00000100). Because of the reset
5524 configuration for CS0# this is a mirror of the onboard Flash memory.
5525 To be able to re-map memory U-Boot then jumps to its link address.
5526 To be able to implement the initialization code in C, a (small!)
5527 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5528 which provide such a feature like MPC8xx or MPC8260), or in a locked
5529 part of the data cache. After that, U-Boot initializes the CPU core,
5530 the caches and the SIU.
5532 Next, all (potentially) available memory banks are mapped using a
5533 preliminary mapping. For example, we put them on 512 MB boundaries
5534 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5535 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5536 programmed for SDRAM access. Using the temporary configuration, a
5537 simple memory test is run that determines the size of the SDRAM
5540 When there is more than one SDRAM bank, and the banks are of
5541 different size, the largest is mapped first. For equal size, the first
5542 bank (CS2#) is mapped first. The first mapping is always for address
5543 0x00000000, with any additional banks following immediately to create
5544 contiguous memory starting from 0.
5546 Then, the monitor installs itself at the upper end of the SDRAM area
5547 and allocates memory for use by malloc() and for the global Board
5548 Info data; also, the exception vector code is copied to the low RAM
5549 pages, and the final stack is set up.
5551 Only after this relocation will you have a "normal" C environment;
5552 until that you are restricted in several ways, mostly because you are
5553 running from ROM, and because the code will have to be relocated to a
5557 U-Boot Porting Guide:
5558 ----------------------
5560 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5564 int main(int argc, char *argv[])
5566 sighandler_t no_more_time;
5568 signal(SIGALRM, no_more_time);
5569 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5571 if (available_money > available_manpower) {
5572 Pay consultant to port U-Boot;
5576 Download latest U-Boot source;
5578 Subscribe to u-boot mailing list;
5581 email("Hi, I am new to U-Boot, how do I get started?");
5584 Read the README file in the top level directory;
5585 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5586 Read applicable doc/*.README;
5587 Read the source, Luke;
5588 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5591 if (available_money > toLocalCurrency ($2500))
5594 Add a lot of aggravation and time;
5596 if (a similar board exists) { /* hopefully... */
5597 cp -a board/<similar> board/<myboard>
5598 cp include/configs/<similar>.h include/configs/<myboard>.h
5600 Create your own board support subdirectory;
5601 Create your own board include/configs/<myboard>.h file;
5603 Edit new board/<myboard> files
5604 Edit new include/configs/<myboard>.h
5609 Add / modify source code;
5613 email("Hi, I am having problems...");
5615 Send patch file to the U-Boot email list;
5616 if (reasonable critiques)
5617 Incorporate improvements from email list code review;
5619 Defend code as written;
5625 void no_more_time (int sig)
5634 All contributions to U-Boot should conform to the Linux kernel
5635 coding style; see the file "Documentation/CodingStyle" and the script
5636 "scripts/Lindent" in your Linux kernel source directory.
5638 Source files originating from a different project (for example the
5639 MTD subsystem) are generally exempt from these guidelines and are not
5640 reformated to ease subsequent migration to newer versions of those
5643 Please note that U-Boot is implemented in C (and to some small parts in
5644 Assembler); no C++ is used, so please do not use C++ style comments (//)
5647 Please also stick to the following formatting rules:
5648 - remove any trailing white space
5649 - use TAB characters for indentation and vertical alignment, not spaces
5650 - make sure NOT to use DOS '\r\n' line feeds
5651 - do not add more than 2 consecutive empty lines to source files
5652 - do not add trailing empty lines to source files
5654 Submissions which do not conform to the standards may be returned
5655 with a request to reformat the changes.
5661 Since the number of patches for U-Boot is growing, we need to
5662 establish some rules. Submissions which do not conform to these rules
5663 may be rejected, even when they contain important and valuable stuff.
5665 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5667 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5668 see http://lists.denx.de/mailman/listinfo/u-boot
5670 When you send a patch, please include the following information with
5673 * For bug fixes: a description of the bug and how your patch fixes
5674 this bug. Please try to include a way of demonstrating that the
5675 patch actually fixes something.
5677 * For new features: a description of the feature and your
5680 * A CHANGELOG entry as plaintext (separate from the patch)
5682 * For major contributions, your entry to the CREDITS file
5684 * When you add support for a new board, don't forget to add this
5685 board to the MAINTAINERS file, too.
5687 * If your patch adds new configuration options, don't forget to
5688 document these in the README file.
5690 * The patch itself. If you are using git (which is *strongly*
5691 recommended) you can easily generate the patch using the
5692 "git format-patch". If you then use "git send-email" to send it to
5693 the U-Boot mailing list, you will avoid most of the common problems
5694 with some other mail clients.
5696 If you cannot use git, use "diff -purN OLD NEW". If your version of
5697 diff does not support these options, then get the latest version of
5700 The current directory when running this command shall be the parent
5701 directory of the U-Boot source tree (i. e. please make sure that
5702 your patch includes sufficient directory information for the
5705 We prefer patches as plain text. MIME attachments are discouraged,
5706 and compressed attachments must not be used.
5708 * If one logical set of modifications affects or creates several
5709 files, all these changes shall be submitted in a SINGLE patch file.
5711 * Changesets that contain different, unrelated modifications shall be
5712 submitted as SEPARATE patches, one patch per changeset.
5717 * Before sending the patch, run the MAKEALL script on your patched
5718 source tree and make sure that no errors or warnings are reported
5719 for any of the boards.
5721 * Keep your modifications to the necessary minimum: A patch
5722 containing several unrelated changes or arbitrary reformats will be
5723 returned with a request to re-formatting / split it.
5725 * If you modify existing code, make sure that your new code does not
5726 add to the memory footprint of the code ;-) Small is beautiful!
5727 When adding new features, these should compile conditionally only
5728 (using #ifdef), and the resulting code with the new feature
5729 disabled must not need more memory than the old code without your
5732 * Remember that there is a size limit of 100 kB per message on the
5733 u-boot mailing list. Bigger patches will be moderated. If they are
5734 reasonable and not too big, they will be acknowledged. But patches
5735 bigger than the size limit should be avoided.
projects / u-boot / blob