2 # (C) Copyright 2000 - 2012
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
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 - Generic CPU options:
426 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
428 Defines the endianess of the CPU. Implementation of those
429 values is arch specific.
431 - Intel Monahans options:
432 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
434 Defines the Monahans run mode to oscillator
435 ratio. Valid values are 8, 16, 24, 31. The core
436 frequency is this value multiplied by 13 MHz.
438 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
440 Defines the Monahans turbo mode to oscillator
441 ratio. Valid values are 1 (default if undefined) and
442 2. The core frequency as calculated above is multiplied
446 CONFIG_SYS_INIT_SP_OFFSET
448 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
449 pointer. This is needed for the temporary stack before
452 CONFIG_SYS_MIPS_CACHE_MODE
454 Cache operation mode for the MIPS CPU.
455 See also arch/mips/include/asm/mipsregs.h.
457 CONF_CM_CACHABLE_NO_WA
460 CONF_CM_CACHABLE_NONCOHERENT
464 CONF_CM_CACHABLE_ACCELERATED
466 CONFIG_SYS_XWAY_EBU_BOOTCFG
468 Special option for Lantiq XWAY SoCs for booting from NOR flash.
469 See also arch/mips/cpu/mips32/start.S.
471 CONFIG_XWAY_SWAP_BYTES
473 Enable compilation of tools/xway-swap-bytes needed for Lantiq
474 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
475 be swapped if a flash programmer is used.
478 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
480 Select high exception vectors of the ARM core, e.g., do not
481 clear the V bit of the c1 register of CP15.
483 CONFIG_SYS_THUMB_BUILD
485 Use this flag to build U-Boot using the Thumb instruction
486 set for ARM architectures. Thumb instruction set provides
487 better code density. For ARM architectures that support
488 Thumb2 this flag will result in Thumb2 code generated by
491 CONFIG_ARM_ERRATA_716044
492 CONFIG_ARM_ERRATA_742230
493 CONFIG_ARM_ERRATA_743622
494 CONFIG_ARM_ERRATA_751472
496 If set, the workarounds for these ARM errata are applied early
497 during U-Boot startup. Note that these options force the
498 workarounds to be applied; no CPU-type/version detection
499 exists, unlike the similar options in the Linux kernel. Do not
500 set these options unless they apply!
505 The frequency of the timer returned by get_timer().
506 get_timer() must operate in milliseconds and this CONFIG
507 option must be set to 1000.
509 - Linux Kernel Interface:
512 U-Boot stores all clock information in Hz
513 internally. For binary compatibility with older Linux
514 kernels (which expect the clocks passed in the
515 bd_info data to be in MHz) the environment variable
516 "clocks_in_mhz" can be defined so that U-Boot
517 converts clock data to MHZ before passing it to the
519 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
520 "clocks_in_mhz=1" is automatically included in the
523 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
525 When transferring memsize parameter to linux, some versions
526 expect it to be in bytes, others in MB.
527 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
531 New kernel versions are expecting firmware settings to be
532 passed using flattened device trees (based on open firmware
536 * New libfdt-based support
537 * Adds the "fdt" command
538 * The bootm command automatically updates the fdt
540 OF_CPU - The proper name of the cpus node (only required for
541 MPC512X and MPC5xxx based boards).
542 OF_SOC - The proper name of the soc node (only required for
543 MPC512X and MPC5xxx based boards).
544 OF_TBCLK - The timebase frequency.
545 OF_STDOUT_PATH - The path to the console device
547 boards with QUICC Engines require OF_QE to set UCC MAC
550 CONFIG_OF_BOARD_SETUP
552 Board code has addition modification that it wants to make
553 to the flat device tree before handing it off to the kernel
557 This define fills in the correct boot CPU in the boot
558 param header, the default value is zero if undefined.
562 U-Boot can detect if an IDE device is present or not.
563 If not, and this new config option is activated, U-Boot
564 removes the ATA node from the DTS before booting Linux,
565 so the Linux IDE driver does not probe the device and
566 crash. This is needed for buggy hardware (uc101) where
567 no pull down resistor is connected to the signal IDE5V_DD7.
569 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
571 This setting is mandatory for all boards that have only one
572 machine type and must be used to specify the machine type
573 number as it appears in the ARM machine registry
574 (see http://www.arm.linux.org.uk/developer/machines/).
575 Only boards that have multiple machine types supported
576 in a single configuration file and the machine type is
577 runtime discoverable, do not have to use this setting.
579 - vxWorks boot parameters:
581 bootvx constructs a valid bootline using the following
582 environments variables: bootfile, ipaddr, serverip, hostname.
583 It loads the vxWorks image pointed bootfile.
585 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
586 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
587 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
588 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
590 CONFIG_SYS_VXWORKS_ADD_PARAMS
592 Add it at the end of the bootline. E.g "u=username pw=secret"
594 Note: If a "bootargs" environment is defined, it will overwride
595 the defaults discussed just above.
597 - Cache Configuration:
598 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
599 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
600 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
602 - Cache Configuration for ARM:
603 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
605 CONFIG_SYS_PL310_BASE - Physical base address of PL310
606 controller register space
611 Define this if you want support for Amba PrimeCell PL010 UARTs.
615 Define this if you want support for Amba PrimeCell PL011 UARTs.
619 If you have Amba PrimeCell PL011 UARTs, set this variable to
620 the clock speed of the UARTs.
624 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
625 define this to a list of base addresses for each (supported)
626 port. See e.g. include/configs/versatile.h
628 CONFIG_PL011_SERIAL_RLCR
630 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
631 have separate receive and transmit line control registers. Set
632 this variable to initialize the extra register.
634 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
636 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
637 boot loader that has already initialized the UART. Define this
638 variable to flush the UART at init time.
642 Depending on board, define exactly one serial port
643 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
644 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
645 console by defining CONFIG_8xx_CONS_NONE
647 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
648 port routines must be defined elsewhere
649 (i.e. serial_init(), serial_getc(), ...)
652 Enables console device for a color framebuffer. Needs following
653 defines (cf. smiLynxEM, i8042)
654 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
656 VIDEO_HW_RECTFILL graphic chip supports
659 VIDEO_HW_BITBLT graphic chip supports
660 bit-blit (cf. smiLynxEM)
661 VIDEO_VISIBLE_COLS visible pixel columns
663 VIDEO_VISIBLE_ROWS visible pixel rows
664 VIDEO_PIXEL_SIZE bytes per pixel
665 VIDEO_DATA_FORMAT graphic data format
666 (0-5, cf. cfb_console.c)
667 VIDEO_FB_ADRS framebuffer address
668 VIDEO_KBD_INIT_FCT keyboard int fct
669 (i.e. i8042_kbd_init())
670 VIDEO_TSTC_FCT test char fct
672 VIDEO_GETC_FCT get char fct
674 CONFIG_CONSOLE_CURSOR cursor drawing on/off
675 (requires blink timer
677 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
678 CONFIG_CONSOLE_TIME display time/date info in
680 (requires CONFIG_CMD_DATE)
681 CONFIG_VIDEO_LOGO display Linux logo in
683 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
684 linux_logo.h for logo.
685 Requires CONFIG_VIDEO_LOGO
686 CONFIG_CONSOLE_EXTRA_INFO
687 additional board info beside
690 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
691 a limited number of ANSI escape sequences (cursor control,
692 erase functions and limited graphics rendition control).
694 When CONFIG_CFB_CONSOLE is defined, video console is
695 default i/o. Serial console can be forced with
696 environment 'console=serial'.
698 When CONFIG_SILENT_CONSOLE is defined, all console
699 messages (by U-Boot and Linux!) can be silenced with
700 the "silent" environment variable. See
701 doc/README.silent for more information.
704 CONFIG_BAUDRATE - in bps
705 Select one of the baudrates listed in
706 CONFIG_SYS_BAUDRATE_TABLE, see below.
707 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
709 - Console Rx buffer length
710 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
711 the maximum receive buffer length for the SMC.
712 This option is actual only for 82xx and 8xx possible.
713 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
714 must be defined, to setup the maximum idle timeout for
717 - Pre-Console Buffer:
718 Prior to the console being initialised (i.e. serial UART
719 initialised etc) all console output is silently discarded.
720 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
721 buffer any console messages prior to the console being
722 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
723 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
724 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
725 bytes are output before the console is initialised, the
726 earlier bytes are discarded.
728 'Sane' compilers will generate smaller code if
729 CONFIG_PRE_CON_BUF_SZ is a power of 2
731 - Safe printf() functions
732 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
733 the printf() functions. These are defined in
734 include/vsprintf.h and include snprintf(), vsnprintf() and
735 so on. Code size increase is approximately 300-500 bytes.
736 If this option is not given then these functions will
737 silently discard their buffer size argument - this means
738 you are not getting any overflow checking in this case.
740 - Boot Delay: CONFIG_BOOTDELAY - in seconds
741 Delay before automatically booting the default image;
742 set to -1 to disable autoboot.
743 set to -2 to autoboot with no delay and not check for abort
744 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
746 See doc/README.autoboot for these options that
747 work with CONFIG_BOOTDELAY. None are required.
748 CONFIG_BOOT_RETRY_TIME
749 CONFIG_BOOT_RETRY_MIN
750 CONFIG_AUTOBOOT_KEYED
751 CONFIG_AUTOBOOT_PROMPT
752 CONFIG_AUTOBOOT_DELAY_STR
753 CONFIG_AUTOBOOT_STOP_STR
754 CONFIG_AUTOBOOT_DELAY_STR2
755 CONFIG_AUTOBOOT_STOP_STR2
756 CONFIG_ZERO_BOOTDELAY_CHECK
757 CONFIG_RESET_TO_RETRY
761 Only needed when CONFIG_BOOTDELAY is enabled;
762 define a command string that is automatically executed
763 when no character is read on the console interface
764 within "Boot Delay" after reset.
767 This can be used to pass arguments to the bootm
768 command. The value of CONFIG_BOOTARGS goes into the
769 environment value "bootargs".
771 CONFIG_RAMBOOT and CONFIG_NFSBOOT
772 The value of these goes into the environment as
773 "ramboot" and "nfsboot" respectively, and can be used
774 as a convenience, when switching between booting from
780 When this option is #defined, the existence of the
781 environment variable "preboot" will be checked
782 immediately before starting the CONFIG_BOOTDELAY
783 countdown and/or running the auto-boot command resp.
784 entering interactive mode.
786 This feature is especially useful when "preboot" is
787 automatically generated or modified. For an example
788 see the LWMON board specific code: here "preboot" is
789 modified when the user holds down a certain
790 combination of keys on the (special) keyboard when
793 - Serial Download Echo Mode:
795 If defined to 1, all characters received during a
796 serial download (using the "loads" command) are
797 echoed back. This might be needed by some terminal
798 emulations (like "cu"), but may as well just take
799 time on others. This setting #define's the initial
800 value of the "loads_echo" environment variable.
802 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
804 Select one of the baudrates listed in
805 CONFIG_SYS_BAUDRATE_TABLE, see below.
808 Monitor commands can be included or excluded
809 from the build by using the #include files
810 <config_cmd_all.h> and #undef'ing unwanted
811 commands, or using <config_cmd_default.h>
812 and augmenting with additional #define's
815 The default command configuration includes all commands
816 except those marked below with a "*".
818 CONFIG_CMD_ASKENV * ask for env variable
819 CONFIG_CMD_BDI bdinfo
820 CONFIG_CMD_BEDBUG * Include BedBug Debugger
821 CONFIG_CMD_BMP * BMP support
822 CONFIG_CMD_BSP * Board specific commands
823 CONFIG_CMD_BOOTD bootd
824 CONFIG_CMD_CACHE * icache, dcache
825 CONFIG_CMD_CONSOLE coninfo
826 CONFIG_CMD_CRC32 * crc32
827 CONFIG_CMD_DATE * support for RTC, date/time...
828 CONFIG_CMD_DHCP * DHCP support
829 CONFIG_CMD_DIAG * Diagnostics
830 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
831 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
832 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
833 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
834 CONFIG_CMD_DTT * Digital Therm and Thermostat
835 CONFIG_CMD_ECHO echo arguments
836 CONFIG_CMD_EDITENV edit env variable
837 CONFIG_CMD_EEPROM * EEPROM read/write support
838 CONFIG_CMD_ELF * bootelf, bootvx
839 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
840 CONFIG_CMD_ENV_FLAGS * display details about env flags
841 CONFIG_CMD_EXPORTENV * export the environment
842 CONFIG_CMD_EXT2 * ext2 command support
843 CONFIG_CMD_EXT4 * ext4 command support
844 CONFIG_CMD_SAVEENV saveenv
845 CONFIG_CMD_FDC * Floppy Disk Support
846 CONFIG_CMD_FAT * FAT command support
847 CONFIG_CMD_FDOS * Dos diskette Support
848 CONFIG_CMD_FLASH flinfo, erase, protect
849 CONFIG_CMD_FPGA FPGA device initialization support
850 CONFIG_CMD_FUSE Device fuse support
851 CONFIG_CMD_GETTIME * Get time since boot
852 CONFIG_CMD_GO * the 'go' command (exec code)
853 CONFIG_CMD_GREPENV * search environment
854 CONFIG_CMD_HASH * calculate hash / digest
855 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
856 CONFIG_CMD_I2C * I2C serial bus support
857 CONFIG_CMD_IDE * IDE harddisk support
858 CONFIG_CMD_IMI iminfo
859 CONFIG_CMD_IMLS List all images found in NOR flash
860 CONFIG_CMD_IMLS_NAND List all images found in NAND flash
861 CONFIG_CMD_IMMAP * IMMR dump support
862 CONFIG_CMD_IMPORTENV * import an environment
863 CONFIG_CMD_INI * import data from an ini file into the env
864 CONFIG_CMD_IRQ * irqinfo
865 CONFIG_CMD_ITEST Integer/string test of 2 values
866 CONFIG_CMD_JFFS2 * JFFS2 Support
867 CONFIG_CMD_KGDB * kgdb
868 CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
869 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
871 CONFIG_CMD_LOADB loadb
872 CONFIG_CMD_LOADS loads
873 CONFIG_CMD_MD5SUM print md5 message digest
874 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
875 CONFIG_CMD_MEMINFO * Display detailed memory information
876 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
878 CONFIG_CMD_MEMTEST mtest
879 CONFIG_CMD_MISC Misc functions like sleep etc
880 CONFIG_CMD_MMC * MMC memory mapped support
881 CONFIG_CMD_MII * MII utility commands
882 CONFIG_CMD_MTDPARTS * MTD partition support
883 CONFIG_CMD_NAND * NAND support
884 CONFIG_CMD_NET bootp, tftpboot, rarpboot
885 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
886 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
887 CONFIG_CMD_PCI * pciinfo
888 CONFIG_CMD_PCMCIA * PCMCIA support
889 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
891 CONFIG_CMD_PORTIO * Port I/O
892 CONFIG_CMD_READ * Read raw data from partition
893 CONFIG_CMD_REGINFO * Register dump
894 CONFIG_CMD_RUN run command in env variable
895 CONFIG_CMD_SANDBOX * sb command to access sandbox features
896 CONFIG_CMD_SAVES * save S record dump
897 CONFIG_CMD_SCSI * SCSI Support
898 CONFIG_CMD_SDRAM * print SDRAM configuration information
899 (requires CONFIG_CMD_I2C)
900 CONFIG_CMD_SETGETDCR Support for DCR Register access
902 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
903 CONFIG_CMD_SHA1SUM print sha1 memory digest
904 (requires CONFIG_CMD_MEMORY)
905 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
906 CONFIG_CMD_SOURCE "source" command Support
907 CONFIG_CMD_SPI * SPI serial bus support
908 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
909 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
910 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
911 CONFIG_CMD_TIMER * access to the system tick timer
912 CONFIG_CMD_USB * USB support
913 CONFIG_CMD_CDP * Cisco Discover Protocol support
914 CONFIG_CMD_MFSL * Microblaze FSL support
917 EXAMPLE: If you want all functions except of network
918 support you can write:
920 #include "config_cmd_all.h"
921 #undef CONFIG_CMD_NET
924 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
926 Note: Don't enable the "icache" and "dcache" commands
927 (configuration option CONFIG_CMD_CACHE) unless you know
928 what you (and your U-Boot users) are doing. Data
929 cache cannot be enabled on systems like the 8xx or
930 8260 (where accesses to the IMMR region must be
931 uncached), and it cannot be disabled on all other
932 systems where we (mis-) use the data cache to hold an
933 initial stack and some data.
936 XXX - this list needs to get updated!
938 - Regular expression support:
940 If this variable is defined, U-Boot is linked against
941 the SLRE (Super Light Regular Expression) library,
942 which adds regex support to some commands, as for
943 example "env grep" and "setexpr".
947 If this variable is defined, U-Boot will use a device tree
948 to configure its devices, instead of relying on statically
949 compiled #defines in the board file. This option is
950 experimental and only available on a few boards. The device
951 tree is available in the global data as gd->fdt_blob.
953 U-Boot needs to get its device tree from somewhere. This can
954 be done using one of the two options below:
957 If this variable is defined, U-Boot will embed a device tree
958 binary in its image. This device tree file should be in the
959 board directory and called <soc>-<board>.dts. The binary file
960 is then picked up in board_init_f() and made available through
961 the global data structure as gd->blob.
964 If this variable is defined, U-Boot will build a device tree
965 binary. It will be called u-boot.dtb. Architecture-specific
966 code will locate it at run-time. Generally this works by:
968 cat u-boot.bin u-boot.dtb >image.bin
970 and in fact, U-Boot does this for you, creating a file called
971 u-boot-dtb.bin which is useful in the common case. You can
972 still use the individual files if you need something more
977 If this variable is defined, it enables watchdog
978 support for the SoC. There must be support in the SoC
979 specific code for a watchdog. For the 8xx and 8260
980 CPUs, the SIU Watchdog feature is enabled in the SYPCR
981 register. When supported for a specific SoC is
982 available, then no further board specific code should
986 When using a watchdog circuitry external to the used
987 SoC, then define this variable and provide board
988 specific code for the "hw_watchdog_reset" function.
991 CONFIG_VERSION_VARIABLE
992 If this variable is defined, an environment variable
993 named "ver" is created by U-Boot showing the U-Boot
994 version as printed by the "version" command.
995 Any change to this variable will be reverted at the
1000 When CONFIG_CMD_DATE is selected, the type of the RTC
1001 has to be selected, too. Define exactly one of the
1004 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1005 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1006 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1007 CONFIG_RTC_MC146818 - use MC146818 RTC
1008 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1009 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1010 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1011 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1012 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1013 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1014 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1015 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1018 Note that if the RTC uses I2C, then the I2C interface
1019 must also be configured. See I2C Support, below.
1022 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1023 CONFIG_PCA953X_INFO - enable pca953x info command
1025 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1026 chip-ngpio pairs that tell the PCA953X driver the number of
1027 pins supported by a particular chip.
1029 Note that if the GPIO device uses I2C, then the I2C interface
1030 must also be configured. See I2C Support, below.
1032 - Timestamp Support:
1034 When CONFIG_TIMESTAMP is selected, the timestamp
1035 (date and time) of an image is printed by image
1036 commands like bootm or iminfo. This option is
1037 automatically enabled when you select CONFIG_CMD_DATE .
1039 - Partition Labels (disklabels) Supported:
1040 Zero or more of the following:
1041 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1042 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1043 Intel architecture, USB sticks, etc.
1044 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1045 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1046 bootloader. Note 2TB partition limit; see
1048 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1050 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1051 CONFIG_CMD_SCSI) you must configure support for at
1052 least one non-MTD partition type as well.
1055 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1056 board configurations files but used nowhere!
1058 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1059 be performed by calling the function
1060 ide_set_reset(int reset)
1061 which has to be defined in a board specific file
1066 Set this to enable ATAPI support.
1071 Set this to enable support for disks larger than 137GB
1072 Also look at CONFIG_SYS_64BIT_LBA.
1073 Whithout these , LBA48 support uses 32bit variables and will 'only'
1074 support disks up to 2.1TB.
1076 CONFIG_SYS_64BIT_LBA:
1077 When enabled, makes the IDE subsystem use 64bit sector addresses.
1081 At the moment only there is only support for the
1082 SYM53C8XX SCSI controller; define
1083 CONFIG_SCSI_SYM53C8XX to enable it.
1085 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1086 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1087 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1088 maximum numbers of LUNs, SCSI ID's and target
1090 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1092 The environment variable 'scsidevs' is set to the number of
1093 SCSI devices found during the last scan.
1095 - NETWORK Support (PCI):
1097 Support for Intel 8254x/8257x gigabit chips.
1100 Utility code for direct access to the SPI bus on Intel 8257x.
1101 This does not do anything useful unless you set at least one
1102 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1104 CONFIG_E1000_SPI_GENERIC
1105 Allow generic access to the SPI bus on the Intel 8257x, for
1106 example with the "sspi" command.
1109 Management command for E1000 devices. When used on devices
1110 with SPI support you can reprogram the EEPROM from U-Boot.
1112 CONFIG_E1000_FALLBACK_MAC
1113 default MAC for empty EEPROM after production.
1116 Support for Intel 82557/82559/82559ER chips.
1117 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1118 write routine for first time initialisation.
1121 Support for Digital 2114x chips.
1122 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1123 modem chip initialisation (KS8761/QS6611).
1126 Support for National dp83815 chips.
1129 Support for National dp8382[01] gigabit chips.
1131 - NETWORK Support (other):
1133 CONFIG_DRIVER_AT91EMAC
1134 Support for AT91RM9200 EMAC.
1137 Define this to use reduced MII inteface
1139 CONFIG_DRIVER_AT91EMAC_QUIET
1140 If this defined, the driver is quiet.
1141 The driver doen't show link status messages.
1143 CONFIG_CALXEDA_XGMAC
1144 Support for the Calxeda XGMAC device
1147 Support for SMSC's LAN91C96 chips.
1149 CONFIG_LAN91C96_BASE
1150 Define this to hold the physical address
1151 of the LAN91C96's I/O space
1153 CONFIG_LAN91C96_USE_32_BIT
1154 Define this to enable 32 bit addressing
1157 Support for SMSC's LAN91C111 chip
1159 CONFIG_SMC91111_BASE
1160 Define this to hold the physical address
1161 of the device (I/O space)
1163 CONFIG_SMC_USE_32_BIT
1164 Define this if data bus is 32 bits
1166 CONFIG_SMC_USE_IOFUNCS
1167 Define this to use i/o functions instead of macros
1168 (some hardware wont work with macros)
1170 CONFIG_DRIVER_TI_EMAC
1171 Support for davinci emac
1173 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1174 Define this if you have more then 3 PHYs.
1177 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1179 CONFIG_FTGMAC100_EGIGA
1180 Define this to use GE link update with gigabit PHY.
1181 Define this if FTGMAC100 is connected to gigabit PHY.
1182 If your system has 10/100 PHY only, it might not occur
1183 wrong behavior. Because PHY usually return timeout or
1184 useless data when polling gigabit status and gigabit
1185 control registers. This behavior won't affect the
1186 correctnessof 10/100 link speed update.
1189 Support for SMSC's LAN911x and LAN921x chips
1192 Define this to hold the physical address
1193 of the device (I/O space)
1195 CONFIG_SMC911X_32_BIT
1196 Define this if data bus is 32 bits
1198 CONFIG_SMC911X_16_BIT
1199 Define this if data bus is 16 bits. If your processor
1200 automatically converts one 32 bit word to two 16 bit
1201 words you may also try CONFIG_SMC911X_32_BIT.
1204 Support for Renesas on-chip Ethernet controller
1206 CONFIG_SH_ETHER_USE_PORT
1207 Define the number of ports to be used
1209 CONFIG_SH_ETHER_PHY_ADDR
1210 Define the ETH PHY's address
1212 CONFIG_SH_ETHER_CACHE_WRITEBACK
1213 If this option is set, the driver enables cache flush.
1217 Support TPM devices.
1220 Support for i2c bus TPM devices. Only one device
1221 per system is supported at this time.
1223 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1224 Define the the i2c bus number for the TPM device
1226 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1227 Define the TPM's address on the i2c bus
1229 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1230 Define the burst count bytes upper limit
1233 Support for generic parallel port TPM devices. Only one device
1234 per system is supported at this time.
1236 CONFIG_TPM_TIS_BASE_ADDRESS
1237 Base address where the generic TPM device is mapped
1238 to. Contemporary x86 systems usually map it at
1242 At the moment only the UHCI host controller is
1243 supported (PIP405, MIP405, MPC5200); define
1244 CONFIG_USB_UHCI to enable it.
1245 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1246 and define CONFIG_USB_STORAGE to enable the USB
1249 Supported are USB Keyboards and USB Floppy drives
1251 MPC5200 USB requires additional defines:
1253 for 528 MHz Clock: 0x0001bbbb
1257 for differential drivers: 0x00001000
1258 for single ended drivers: 0x00005000
1259 for differential drivers on PSC3: 0x00000100
1260 for single ended drivers on PSC3: 0x00004100
1261 CONFIG_SYS_USB_EVENT_POLL
1262 May be defined to allow interrupt polling
1263 instead of using asynchronous interrupts
1265 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1266 txfilltuning field in the EHCI controller on reset.
1268 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1269 interval for usb hub power-on delay.(minimum 100msec)
1272 Define the below if you wish to use the USB console.
1273 Once firmware is rebuilt from a serial console issue the
1274 command "setenv stdin usbtty; setenv stdout usbtty" and
1275 attach your USB cable. The Unix command "dmesg" should print
1276 it has found a new device. The environment variable usbtty
1277 can be set to gserial or cdc_acm to enable your device to
1278 appear to a USB host as a Linux gserial device or a
1279 Common Device Class Abstract Control Model serial device.
1280 If you select usbtty = gserial you should be able to enumerate
1282 # modprobe usbserial vendor=0xVendorID product=0xProductID
1283 else if using cdc_acm, simply setting the environment
1284 variable usbtty to be cdc_acm should suffice. The following
1285 might be defined in YourBoardName.h
1288 Define this to build a UDC device
1291 Define this to have a tty type of device available to
1292 talk to the UDC device
1295 Define this to enable the high speed support for usb
1296 device and usbtty. If this feature is enabled, a routine
1297 int is_usbd_high_speed(void)
1298 also needs to be defined by the driver to dynamically poll
1299 whether the enumeration has succeded at high speed or full
1302 CONFIG_SYS_CONSOLE_IS_IN_ENV
1303 Define this if you want stdin, stdout &/or stderr to
1307 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1308 Derive USB clock from external clock "blah"
1309 - CONFIG_SYS_USB_EXTC_CLK 0x02
1311 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1312 Derive USB clock from brgclk
1313 - CONFIG_SYS_USB_BRG_CLK 0x04
1315 If you have a USB-IF assigned VendorID then you may wish to
1316 define your own vendor specific values either in BoardName.h
1317 or directly in usbd_vendor_info.h. If you don't define
1318 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1319 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1320 should pretend to be a Linux device to it's target host.
1322 CONFIG_USBD_MANUFACTURER
1323 Define this string as the name of your company for
1324 - CONFIG_USBD_MANUFACTURER "my company"
1326 CONFIG_USBD_PRODUCT_NAME
1327 Define this string as the name of your product
1328 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1330 CONFIG_USBD_VENDORID
1331 Define this as your assigned Vendor ID from the USB
1332 Implementors Forum. This *must* be a genuine Vendor ID
1333 to avoid polluting the USB namespace.
1334 - CONFIG_USBD_VENDORID 0xFFFF
1336 CONFIG_USBD_PRODUCTID
1337 Define this as the unique Product ID
1339 - CONFIG_USBD_PRODUCTID 0xFFFF
1341 - ULPI Layer Support:
1342 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1343 the generic ULPI layer. The generic layer accesses the ULPI PHY
1344 via the platform viewport, so you need both the genric layer and
1345 the viewport enabled. Currently only Chipidea/ARC based
1346 viewport is supported.
1347 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1348 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1349 If your ULPI phy needs a different reference clock than the
1350 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1351 the appropriate value in Hz.
1354 The MMC controller on the Intel PXA is supported. To
1355 enable this define CONFIG_MMC. The MMC can be
1356 accessed from the boot prompt by mapping the device
1357 to physical memory similar to flash. Command line is
1358 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1359 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1362 Support for Renesas on-chip MMCIF controller
1364 CONFIG_SH_MMCIF_ADDR
1365 Define the base address of MMCIF registers
1368 Define the clock frequency for MMCIF
1370 - USB Device Firmware Update (DFU) class support:
1372 This enables the USB portion of the DFU USB class
1375 This enables the command "dfu" which is used to have
1376 U-Boot create a DFU class device via USB. This command
1377 requires that the "dfu_alt_info" environment variable be
1378 set and define the alt settings to expose to the host.
1381 This enables support for exposing (e)MMC devices via DFU.
1384 This enables support for exposing NAND devices via DFU.
1386 CONFIG_SYS_DFU_MAX_FILE_SIZE
1387 When updating files rather than the raw storage device,
1388 we use a static buffer to copy the file into and then write
1389 the buffer once we've been given the whole file. Define
1390 this to the maximum filesize (in bytes) for the buffer.
1391 Default is 4 MiB if undefined.
1393 - Journaling Flash filesystem support:
1394 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1395 CONFIG_JFFS2_NAND_DEV
1396 Define these for a default partition on a NAND device
1398 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1399 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1400 Define these for a default partition on a NOR device
1402 CONFIG_SYS_JFFS_CUSTOM_PART
1403 Define this to create an own partition. You have to provide a
1404 function struct part_info* jffs2_part_info(int part_num)
1406 If you define only one JFFS2 partition you may also want to
1407 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1408 to disable the command chpart. This is the default when you
1409 have not defined a custom partition
1411 - FAT(File Allocation Table) filesystem write function support:
1414 Define this to enable support for saving memory data as a
1415 file in FAT formatted partition.
1417 This will also enable the command "fatwrite" enabling the
1418 user to write files to FAT.
1420 CBFS (Coreboot Filesystem) support
1423 Define this to enable support for reading from a Coreboot
1424 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1430 Define this to enable standard (PC-Style) keyboard
1434 Standard PC keyboard driver with US (is default) and
1435 GERMAN key layout (switch via environment 'keymap=de') support.
1436 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1437 for cfb_console. Supports cursor blinking.
1442 Define this to enable video support (for output to
1445 CONFIG_VIDEO_CT69000
1447 Enable Chips & Technologies 69000 Video chip
1449 CONFIG_VIDEO_SMI_LYNXEM
1450 Enable Silicon Motion SMI 712/710/810 Video chip. The
1451 video output is selected via environment 'videoout'
1452 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1455 For the CT69000 and SMI_LYNXEM drivers, videomode is
1456 selected via environment 'videomode'. Two different ways
1458 - "videomode=num" 'num' is a standard LiLo mode numbers.
1459 Following standard modes are supported (* is default):
1461 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1462 -------------+---------------------------------------------
1463 8 bits | 0x301* 0x303 0x305 0x161 0x307
1464 15 bits | 0x310 0x313 0x316 0x162 0x319
1465 16 bits | 0x311 0x314 0x317 0x163 0x31A
1466 24 bits | 0x312 0x315 0x318 ? 0x31B
1467 -------------+---------------------------------------------
1468 (i.e. setenv videomode 317; saveenv; reset;)
1470 - "videomode=bootargs" all the video parameters are parsed
1471 from the bootargs. (See drivers/video/videomodes.c)
1474 CONFIG_VIDEO_SED13806
1475 Enable Epson SED13806 driver. This driver supports 8bpp
1476 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1477 or CONFIG_VIDEO_SED13806_16BPP
1480 Enable the Freescale DIU video driver. Reference boards for
1481 SOCs that have a DIU should define this macro to enable DIU
1482 support, and should also define these other macros:
1488 CONFIG_VIDEO_SW_CURSOR
1489 CONFIG_VGA_AS_SINGLE_DEVICE
1491 CONFIG_VIDEO_BMP_LOGO
1493 The DIU driver will look for the 'video-mode' environment
1494 variable, and if defined, enable the DIU as a console during
1495 boot. See the documentation file README.video for a
1496 description of this variable.
1500 Enable the VGA video / BIOS for x86. The alternative if you
1501 are using coreboot is to use the coreboot frame buffer
1508 Define this to enable a custom keyboard support.
1509 This simply calls drv_keyboard_init() which must be
1510 defined in your board-specific files.
1511 The only board using this so far is RBC823.
1513 - LCD Support: CONFIG_LCD
1515 Define this to enable LCD support (for output to LCD
1516 display); also select one of the supported displays
1517 by defining one of these:
1521 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1523 CONFIG_NEC_NL6448AC33:
1525 NEC NL6448AC33-18. Active, color, single scan.
1527 CONFIG_NEC_NL6448BC20
1529 NEC NL6448BC20-08. 6.5", 640x480.
1530 Active, color, single scan.
1532 CONFIG_NEC_NL6448BC33_54
1534 NEC NL6448BC33-54. 10.4", 640x480.
1535 Active, color, single scan.
1539 Sharp 320x240. Active, color, single scan.
1540 It isn't 16x9, and I am not sure what it is.
1542 CONFIG_SHARP_LQ64D341
1544 Sharp LQ64D341 display, 640x480.
1545 Active, color, single scan.
1549 HLD1045 display, 640x480.
1550 Active, color, single scan.
1554 Optrex CBL50840-2 NF-FW 99 22 M5
1556 Hitachi LMG6912RPFC-00T
1560 320x240. Black & white.
1562 Normally display is black on white background; define
1563 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1565 CONFIG_LCD_ALIGNMENT
1567 Normally the LCD is page-aligned (tyically 4KB). If this is
1568 defined then the LCD will be aligned to this value instead.
1569 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1570 here, since it is cheaper to change data cache settings on
1571 a per-section basis.
1573 CONFIG_CONSOLE_SCROLL_LINES
1575 When the console need to be scrolled, this is the number of
1576 lines to scroll by. It defaults to 1. Increasing this makes
1577 the console jump but can help speed up operation when scrolling
1582 Support drawing of RLE8-compressed bitmaps on the LCD.
1586 Enables an 'i2c edid' command which can read EDID
1587 information over I2C from an attached LCD display.
1589 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1591 If this option is set, the environment is checked for
1592 a variable "splashimage". If found, the usual display
1593 of logo, copyright and system information on the LCD
1594 is suppressed and the BMP image at the address
1595 specified in "splashimage" is loaded instead. The
1596 console is redirected to the "nulldev", too. This
1597 allows for a "silent" boot where a splash screen is
1598 loaded very quickly after power-on.
1600 CONFIG_SPLASHIMAGE_GUARD
1602 If this option is set, then U-Boot will prevent the environment
1603 variable "splashimage" from being set to a problematic address
1604 (see README.displaying-bmps and README.arm-unaligned-accesses).
1605 This option is useful for targets where, due to alignment
1606 restrictions, an improperly aligned BMP image will cause a data
1607 abort. If you think you will not have problems with unaligned
1608 accesses (for example because your toolchain prevents them)
1609 there is no need to set this option.
1611 CONFIG_SPLASH_SCREEN_ALIGN
1613 If this option is set the splash image can be freely positioned
1614 on the screen. Environment variable "splashpos" specifies the
1615 position as "x,y". If a positive number is given it is used as
1616 number of pixel from left/top. If a negative number is given it
1617 is used as number of pixel from right/bottom. You can also
1618 specify 'm' for centering the image.
1621 setenv splashpos m,m
1622 => image at center of screen
1624 setenv splashpos 30,20
1625 => image at x = 30 and y = 20
1627 setenv splashpos -10,m
1628 => vertically centered image
1629 at x = dspWidth - bmpWidth - 9
1631 CONFIG_SPLASH_SCREEN_PREPARE
1633 If this option is set then the board_splash_screen_prepare()
1634 function, which must be defined in your code, is called as part
1635 of the splash screen display sequence. It gives the board an
1636 opportunity to prepare the splash image data before it is
1637 processed and sent to the frame buffer by U-Boot.
1639 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1641 If this option is set, additionally to standard BMP
1642 images, gzipped BMP images can be displayed via the
1643 splashscreen support or the bmp command.
1645 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1647 If this option is set, 8-bit RLE compressed BMP images
1648 can be displayed via the splashscreen support or the
1651 - Do compresssing for memory range:
1654 If this option is set, it would use zlib deflate method
1655 to compress the specified memory at its best effort.
1657 - Compression support:
1660 If this option is set, support for bzip2 compressed
1661 images is included. If not, only uncompressed and gzip
1662 compressed images are supported.
1664 NOTE: the bzip2 algorithm requires a lot of RAM, so
1665 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1670 If this option is set, support for lzma compressed
1673 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1674 requires an amount of dynamic memory that is given by the
1677 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1679 Where lc and lp stand for, respectively, Literal context bits
1680 and Literal pos bits.
1682 This value is upper-bounded by 14MB in the worst case. Anyway,
1683 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1684 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1685 a very small buffer.
1687 Use the lzmainfo tool to determinate the lc and lp values and
1688 then calculate the amount of needed dynamic memory (ensuring
1689 the appropriate CONFIG_SYS_MALLOC_LEN value).
1694 The address of PHY on MII bus.
1696 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1698 The clock frequency of the MII bus
1702 If this option is set, support for speed/duplex
1703 detection of gigabit PHY is included.
1705 CONFIG_PHY_RESET_DELAY
1707 Some PHY like Intel LXT971A need extra delay after
1708 reset before any MII register access is possible.
1709 For such PHY, set this option to the usec delay
1710 required. (minimum 300usec for LXT971A)
1712 CONFIG_PHY_CMD_DELAY (ppc4xx)
1714 Some PHY like Intel LXT971A need extra delay after
1715 command issued before MII status register can be read
1725 Define a default value for Ethernet address to use
1726 for the respective Ethernet interface, in case this
1727 is not determined automatically.
1732 Define a default value for the IP address to use for
1733 the default Ethernet interface, in case this is not
1734 determined through e.g. bootp.
1735 (Environment variable "ipaddr")
1737 - Server IP address:
1740 Defines a default value for the IP address of a TFTP
1741 server to contact when using the "tftboot" command.
1742 (Environment variable "serverip")
1744 CONFIG_KEEP_SERVERADDR
1746 Keeps the server's MAC address, in the env 'serveraddr'
1747 for passing to bootargs (like Linux's netconsole option)
1749 - Gateway IP address:
1752 Defines a default value for the IP address of the
1753 default router where packets to other networks are
1755 (Environment variable "gatewayip")
1760 Defines a default value for the subnet mask (or
1761 routing prefix) which is used to determine if an IP
1762 address belongs to the local subnet or needs to be
1763 forwarded through a router.
1764 (Environment variable "netmask")
1766 - Multicast TFTP Mode:
1769 Defines whether you want to support multicast TFTP as per
1770 rfc-2090; for example to work with atftp. Lets lots of targets
1771 tftp down the same boot image concurrently. Note: the Ethernet
1772 driver in use must provide a function: mcast() to join/leave a
1775 - BOOTP Recovery Mode:
1776 CONFIG_BOOTP_RANDOM_DELAY
1778 If you have many targets in a network that try to
1779 boot using BOOTP, you may want to avoid that all
1780 systems send out BOOTP requests at precisely the same
1781 moment (which would happen for instance at recovery
1782 from a power failure, when all systems will try to
1783 boot, thus flooding the BOOTP server. Defining
1784 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1785 inserted before sending out BOOTP requests. The
1786 following delays are inserted then:
1788 1st BOOTP request: delay 0 ... 1 sec
1789 2nd BOOTP request: delay 0 ... 2 sec
1790 3rd BOOTP request: delay 0 ... 4 sec
1792 BOOTP requests: delay 0 ... 8 sec
1794 - DHCP Advanced Options:
1795 You can fine tune the DHCP functionality by defining
1796 CONFIG_BOOTP_* symbols:
1798 CONFIG_BOOTP_SUBNETMASK
1799 CONFIG_BOOTP_GATEWAY
1800 CONFIG_BOOTP_HOSTNAME
1801 CONFIG_BOOTP_NISDOMAIN
1802 CONFIG_BOOTP_BOOTPATH
1803 CONFIG_BOOTP_BOOTFILESIZE
1806 CONFIG_BOOTP_SEND_HOSTNAME
1807 CONFIG_BOOTP_NTPSERVER
1808 CONFIG_BOOTP_TIMEOFFSET
1809 CONFIG_BOOTP_VENDOREX
1810 CONFIG_BOOTP_MAY_FAIL
1812 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1813 environment variable, not the BOOTP server.
1815 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1816 after the configured retry count, the call will fail
1817 instead of starting over. This can be used to fail over
1818 to Link-local IP address configuration if the DHCP server
1821 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1822 serverip from a DHCP server, it is possible that more
1823 than one DNS serverip is offered to the client.
1824 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1825 serverip will be stored in the additional environment
1826 variable "dnsip2". The first DNS serverip is always
1827 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1830 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1831 to do a dynamic update of a DNS server. To do this, they
1832 need the hostname of the DHCP requester.
1833 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1834 of the "hostname" environment variable is passed as
1835 option 12 to the DHCP server.
1837 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1839 A 32bit value in microseconds for a delay between
1840 receiving a "DHCP Offer" and sending the "DHCP Request".
1841 This fixes a problem with certain DHCP servers that don't
1842 respond 100% of the time to a "DHCP request". E.g. On an
1843 AT91RM9200 processor running at 180MHz, this delay needed
1844 to be *at least* 15,000 usec before a Windows Server 2003
1845 DHCP server would reply 100% of the time. I recommend at
1846 least 50,000 usec to be safe. The alternative is to hope
1847 that one of the retries will be successful but note that
1848 the DHCP timeout and retry process takes a longer than
1851 - Link-local IP address negotiation:
1852 Negotiate with other link-local clients on the local network
1853 for an address that doesn't require explicit configuration.
1854 This is especially useful if a DHCP server cannot be guaranteed
1855 to exist in all environments that the device must operate.
1857 See doc/README.link-local for more information.
1860 CONFIG_CDP_DEVICE_ID
1862 The device id used in CDP trigger frames.
1864 CONFIG_CDP_DEVICE_ID_PREFIX
1866 A two character string which is prefixed to the MAC address
1871 A printf format string which contains the ascii name of
1872 the port. Normally is set to "eth%d" which sets
1873 eth0 for the first Ethernet, eth1 for the second etc.
1875 CONFIG_CDP_CAPABILITIES
1877 A 32bit integer which indicates the device capabilities;
1878 0x00000010 for a normal host which does not forwards.
1882 An ascii string containing the version of the software.
1886 An ascii string containing the name of the platform.
1890 A 32bit integer sent on the trigger.
1892 CONFIG_CDP_POWER_CONSUMPTION
1894 A 16bit integer containing the power consumption of the
1895 device in .1 of milliwatts.
1897 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1899 A byte containing the id of the VLAN.
1901 - Status LED: CONFIG_STATUS_LED
1903 Several configurations allow to display the current
1904 status using a LED. For instance, the LED will blink
1905 fast while running U-Boot code, stop blinking as
1906 soon as a reply to a BOOTP request was received, and
1907 start blinking slow once the Linux kernel is running
1908 (supported by a status LED driver in the Linux
1909 kernel). Defining CONFIG_STATUS_LED enables this
1912 - CAN Support: CONFIG_CAN_DRIVER
1914 Defining CONFIG_CAN_DRIVER enables CAN driver support
1915 on those systems that support this (optional)
1916 feature, like the TQM8xxL modules.
1918 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1920 These enable I2C serial bus commands. Defining either of
1921 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1922 include the appropriate I2C driver for the selected CPU.
1924 This will allow you to use i2c commands at the u-boot
1925 command line (as long as you set CONFIG_CMD_I2C in
1926 CONFIG_COMMANDS) and communicate with i2c based realtime
1927 clock chips. See common/cmd_i2c.c for a description of the
1928 command line interface.
1930 CONFIG_HARD_I2C selects a hardware I2C controller.
1932 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1933 bit-banging) driver instead of CPM or similar hardware
1936 There are several other quantities that must also be
1937 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1939 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1940 to be the frequency (in Hz) at which you wish your i2c bus
1941 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1942 the CPU's i2c node address).
1944 Now, the u-boot i2c code for the mpc8xx
1945 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1946 and so its address should therefore be cleared to 0 (See,
1947 eg, MPC823e User's Manual p.16-473). So, set
1948 CONFIG_SYS_I2C_SLAVE to 0.
1950 CONFIG_SYS_I2C_INIT_MPC5XXX
1952 When a board is reset during an i2c bus transfer
1953 chips might think that the current transfer is still
1954 in progress. Reset the slave devices by sending start
1955 commands until the slave device responds.
1957 That's all that's required for CONFIG_HARD_I2C.
1959 If you use the software i2c interface (CONFIG_SOFT_I2C)
1960 then the following macros need to be defined (examples are
1961 from include/configs/lwmon.h):
1965 (Optional). Any commands necessary to enable the I2C
1966 controller or configure ports.
1968 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1972 (Only for MPC8260 CPU). The I/O port to use (the code
1973 assumes both bits are on the same port). Valid values
1974 are 0..3 for ports A..D.
1978 The code necessary to make the I2C data line active
1979 (driven). If the data line is open collector, this
1982 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1986 The code necessary to make the I2C data line tri-stated
1987 (inactive). If the data line is open collector, this
1990 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1994 Code that returns true if the I2C data line is high,
1997 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2001 If <bit> is true, sets the I2C data line high. If it
2002 is false, it clears it (low).
2004 eg: #define I2C_SDA(bit) \
2005 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2006 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2010 If <bit> is true, sets the I2C clock line high. If it
2011 is false, it clears it (low).
2013 eg: #define I2C_SCL(bit) \
2014 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2015 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2019 This delay is invoked four times per clock cycle so this
2020 controls the rate of data transfer. The data rate thus
2021 is 1 / (I2C_DELAY * 4). Often defined to be something
2024 #define I2C_DELAY udelay(2)
2026 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2028 If your arch supports the generic GPIO framework (asm/gpio.h),
2029 then you may alternatively define the two GPIOs that are to be
2030 used as SCL / SDA. Any of the previous I2C_xxx macros will
2031 have GPIO-based defaults assigned to them as appropriate.
2033 You should define these to the GPIO value as given directly to
2034 the generic GPIO functions.
2036 CONFIG_SYS_I2C_INIT_BOARD
2038 When a board is reset during an i2c bus transfer
2039 chips might think that the current transfer is still
2040 in progress. On some boards it is possible to access
2041 the i2c SCLK line directly, either by using the
2042 processor pin as a GPIO or by having a second pin
2043 connected to the bus. If this option is defined a
2044 custom i2c_init_board() routine in boards/xxx/board.c
2045 is run early in the boot sequence.
2047 CONFIG_SYS_I2C_BOARD_LATE_INIT
2049 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2050 defined a custom i2c_board_late_init() routine in
2051 boards/xxx/board.c is run AFTER the operations in i2c_init()
2052 is completed. This callpoint can be used to unreset i2c bus
2053 using CPU i2c controller register accesses for CPUs whose i2c
2054 controller provide such a method. It is called at the end of
2055 i2c_init() to allow i2c_init operations to setup the i2c bus
2056 controller on the CPU (e.g. setting bus speed & slave address).
2058 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2060 This option enables configuration of bi_iic_fast[] flags
2061 in u-boot bd_info structure based on u-boot environment
2062 variable "i2cfast". (see also i2cfast)
2064 CONFIG_I2C_MULTI_BUS
2066 This option allows the use of multiple I2C buses, each of which
2067 must have a controller. At any point in time, only one bus is
2068 active. To switch to a different bus, use the 'i2c dev' command.
2069 Note that bus numbering is zero-based.
2071 CONFIG_SYS_I2C_NOPROBES
2073 This option specifies a list of I2C devices that will be skipped
2074 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2075 is set, specify a list of bus-device pairs. Otherwise, specify
2076 a 1D array of device addresses
2079 #undef CONFIG_I2C_MULTI_BUS
2080 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2082 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2084 #define CONFIG_I2C_MULTI_BUS
2085 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2087 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2089 CONFIG_SYS_SPD_BUS_NUM
2091 If defined, then this indicates the I2C bus number for DDR SPD.
2092 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2094 CONFIG_SYS_RTC_BUS_NUM
2096 If defined, then this indicates the I2C bus number for the RTC.
2097 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2099 CONFIG_SYS_DTT_BUS_NUM
2101 If defined, then this indicates the I2C bus number for the DTT.
2102 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2104 CONFIG_SYS_I2C_DTT_ADDR:
2106 If defined, specifies the I2C address of the DTT device.
2107 If not defined, then U-Boot uses predefined value for
2108 specified DTT device.
2112 Define this option if you want to use Freescale's I2C driver in
2113 drivers/i2c/fsl_i2c.c.
2117 Define this option if you have I2C devices reached over 1 .. n
2118 I2C Muxes like the pca9544a. This option addes a new I2C
2119 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
2120 new I2C Bus to the existing I2C Busses. If you select the
2121 new Bus with "i2c dev", u-bbot sends first the commandos for
2122 the muxes to activate this new "bus".
2124 CONFIG_I2C_MULTI_BUS must be also defined, to use this
2128 Adding a new I2C Bus reached over 2 pca9544a muxes
2129 The First mux with address 70 and channel 6
2130 The Second mux with address 71 and channel 4
2132 => i2c bus pca9544a:70:6:pca9544a:71:4
2134 Use the "i2c bus" command without parameter, to get a list
2135 of I2C Busses with muxes:
2138 Busses reached over muxes:
2140 reached over Mux(es):
2143 reached over Mux(es):
2148 If you now switch to the new I2C Bus 3 with "i2c dev 3"
2149 u-boot first sends the command to the mux@70 to enable
2150 channel 6, and then the command to the mux@71 to enable
2153 After that, you can use the "normal" i2c commands as
2154 usual to communicate with your I2C devices behind
2157 This option is actually implemented for the bitbanging
2158 algorithm in common/soft_i2c.c and for the Hardware I2C
2159 Bus on the MPC8260. But it should be not so difficult
2160 to add this option to other architectures.
2162 CONFIG_SOFT_I2C_READ_REPEATED_START
2164 defining this will force the i2c_read() function in
2165 the soft_i2c driver to perform an I2C repeated start
2166 between writing the address pointer and reading the
2167 data. If this define is omitted the default behaviour
2168 of doing a stop-start sequence will be used. Most I2C
2169 devices can use either method, but some require one or
2172 - SPI Support: CONFIG_SPI
2174 Enables SPI driver (so far only tested with
2175 SPI EEPROM, also an instance works with Crystal A/D and
2176 D/As on the SACSng board)
2180 Enables the driver for SPI controller on SuperH. Currently
2181 only SH7757 is supported.
2185 Enables extended (16-bit) SPI EEPROM addressing.
2186 (symmetrical to CONFIG_I2C_X)
2190 Enables a software (bit-bang) SPI driver rather than
2191 using hardware support. This is a general purpose
2192 driver that only requires three general I/O port pins
2193 (two outputs, one input) to function. If this is
2194 defined, the board configuration must define several
2195 SPI configuration items (port pins to use, etc). For
2196 an example, see include/configs/sacsng.h.
2200 Enables a hardware SPI driver for general-purpose reads
2201 and writes. As with CONFIG_SOFT_SPI, the board configuration
2202 must define a list of chip-select function pointers.
2203 Currently supported on some MPC8xxx processors. For an
2204 example, see include/configs/mpc8349emds.h.
2208 Enables the driver for the SPI controllers on i.MX and MXC
2209 SoCs. Currently i.MX31/35/51 are supported.
2211 - FPGA Support: CONFIG_FPGA
2213 Enables FPGA subsystem.
2215 CONFIG_FPGA_<vendor>
2217 Enables support for specific chip vendors.
2220 CONFIG_FPGA_<family>
2222 Enables support for FPGA family.
2223 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2227 Specify the number of FPGA devices to support.
2229 CONFIG_SYS_FPGA_PROG_FEEDBACK
2231 Enable printing of hash marks during FPGA configuration.
2233 CONFIG_SYS_FPGA_CHECK_BUSY
2235 Enable checks on FPGA configuration interface busy
2236 status by the configuration function. This option
2237 will require a board or device specific function to
2242 If defined, a function that provides delays in the FPGA
2243 configuration driver.
2245 CONFIG_SYS_FPGA_CHECK_CTRLC
2246 Allow Control-C to interrupt FPGA configuration
2248 CONFIG_SYS_FPGA_CHECK_ERROR
2250 Check for configuration errors during FPGA bitfile
2251 loading. For example, abort during Virtex II
2252 configuration if the INIT_B line goes low (which
2253 indicated a CRC error).
2255 CONFIG_SYS_FPGA_WAIT_INIT
2257 Maximum time to wait for the INIT_B line to deassert
2258 after PROB_B has been deasserted during a Virtex II
2259 FPGA configuration sequence. The default time is 500
2262 CONFIG_SYS_FPGA_WAIT_BUSY
2264 Maximum time to wait for BUSY to deassert during
2265 Virtex II FPGA configuration. The default is 5 ms.
2267 CONFIG_SYS_FPGA_WAIT_CONFIG
2269 Time to wait after FPGA configuration. The default is
2272 - Configuration Management:
2275 If defined, this string will be added to the U-Boot
2276 version information (U_BOOT_VERSION)
2278 - Vendor Parameter Protection:
2280 U-Boot considers the values of the environment
2281 variables "serial#" (Board Serial Number) and
2282 "ethaddr" (Ethernet Address) to be parameters that
2283 are set once by the board vendor / manufacturer, and
2284 protects these variables from casual modification by
2285 the user. Once set, these variables are read-only,
2286 and write or delete attempts are rejected. You can
2287 change this behaviour:
2289 If CONFIG_ENV_OVERWRITE is #defined in your config
2290 file, the write protection for vendor parameters is
2291 completely disabled. Anybody can change or delete
2294 Alternatively, if you #define _both_ CONFIG_ETHADDR
2295 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2296 Ethernet address is installed in the environment,
2297 which can be changed exactly ONCE by the user. [The
2298 serial# is unaffected by this, i. e. it remains
2301 The same can be accomplished in a more flexible way
2302 for any variable by configuring the type of access
2303 to allow for those variables in the ".flags" variable
2304 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2309 Define this variable to enable the reservation of
2310 "protected RAM", i. e. RAM which is not overwritten
2311 by U-Boot. Define CONFIG_PRAM to hold the number of
2312 kB you want to reserve for pRAM. You can overwrite
2313 this default value by defining an environment
2314 variable "pram" to the number of kB you want to
2315 reserve. Note that the board info structure will
2316 still show the full amount of RAM. If pRAM is
2317 reserved, a new environment variable "mem" will
2318 automatically be defined to hold the amount of
2319 remaining RAM in a form that can be passed as boot
2320 argument to Linux, for instance like that:
2322 setenv bootargs ... mem=\${mem}
2325 This way you can tell Linux not to use this memory,
2326 either, which results in a memory region that will
2327 not be affected by reboots.
2329 *WARNING* If your board configuration uses automatic
2330 detection of the RAM size, you must make sure that
2331 this memory test is non-destructive. So far, the
2332 following board configurations are known to be
2335 IVMS8, IVML24, SPD8xx, TQM8xxL,
2336 HERMES, IP860, RPXlite, LWMON,
2339 - Access to physical memory region (> 4GB)
2340 Some basic support is provided for operations on memory not
2341 normally accessible to U-Boot - e.g. some architectures
2342 support access to more than 4GB of memory on 32-bit
2343 machines using physical address extension or similar.
2344 Define CONFIG_PHYSMEM to access this basic support, which
2345 currently only supports clearing the memory.
2350 Define this variable to stop the system in case of a
2351 fatal error, so that you have to reset it manually.
2352 This is probably NOT a good idea for an embedded
2353 system where you want the system to reboot
2354 automatically as fast as possible, but it may be
2355 useful during development since you can try to debug
2356 the conditions that lead to the situation.
2358 CONFIG_NET_RETRY_COUNT
2360 This variable defines the number of retries for
2361 network operations like ARP, RARP, TFTP, or BOOTP
2362 before giving up the operation. If not defined, a
2363 default value of 5 is used.
2367 Timeout waiting for an ARP reply in milliseconds.
2371 Timeout in milliseconds used in NFS protocol.
2372 If you encounter "ERROR: Cannot umount" in nfs command,
2373 try longer timeout such as
2374 #define CONFIG_NFS_TIMEOUT 10000UL
2376 - Command Interpreter:
2377 CONFIG_AUTO_COMPLETE
2379 Enable auto completion of commands using TAB.
2381 Note that this feature has NOT been implemented yet
2382 for the "hush" shell.
2385 CONFIG_SYS_HUSH_PARSER
2387 Define this variable to enable the "hush" shell (from
2388 Busybox) as command line interpreter, thus enabling
2389 powerful command line syntax like
2390 if...then...else...fi conditionals or `&&' and '||'
2391 constructs ("shell scripts").
2393 If undefined, you get the old, much simpler behaviour
2394 with a somewhat smaller memory footprint.
2397 CONFIG_SYS_PROMPT_HUSH_PS2
2399 This defines the secondary prompt string, which is
2400 printed when the command interpreter needs more input
2401 to complete a command. Usually "> ".
2405 In the current implementation, the local variables
2406 space and global environment variables space are
2407 separated. Local variables are those you define by
2408 simply typing `name=value'. To access a local
2409 variable later on, you have write `$name' or
2410 `${name}'; to execute the contents of a variable
2411 directly type `$name' at the command prompt.
2413 Global environment variables are those you use
2414 setenv/printenv to work with. To run a command stored
2415 in such a variable, you need to use the run command,
2416 and you must not use the '$' sign to access them.
2418 To store commands and special characters in a
2419 variable, please use double quotation marks
2420 surrounding the whole text of the variable, instead
2421 of the backslashes before semicolons and special
2424 - Commandline Editing and History:
2425 CONFIG_CMDLINE_EDITING
2427 Enable editing and History functions for interactive
2428 commandline input operations
2430 - Default Environment:
2431 CONFIG_EXTRA_ENV_SETTINGS
2433 Define this to contain any number of null terminated
2434 strings (variable = value pairs) that will be part of
2435 the default environment compiled into the boot image.
2437 For example, place something like this in your
2438 board's config file:
2440 #define CONFIG_EXTRA_ENV_SETTINGS \
2444 Warning: This method is based on knowledge about the
2445 internal format how the environment is stored by the
2446 U-Boot code. This is NOT an official, exported
2447 interface! Although it is unlikely that this format
2448 will change soon, there is no guarantee either.
2449 You better know what you are doing here.
2451 Note: overly (ab)use of the default environment is
2452 discouraged. Make sure to check other ways to preset
2453 the environment like the "source" command or the
2456 CONFIG_ENV_VARS_UBOOT_CONFIG
2458 Define this in order to add variables describing the
2459 U-Boot build configuration to the default environment.
2460 These will be named arch, cpu, board, vendor, and soc.
2462 Enabling this option will cause the following to be defined:
2470 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2472 Define this in order to add variables describing certain
2473 run-time determined information about the hardware to the
2474 environment. These will be named board_name, board_rev.
2476 CONFIG_DELAY_ENVIRONMENT
2478 Normally the environment is loaded when the board is
2479 intialised so that it is available to U-Boot. This inhibits
2480 that so that the environment is not available until
2481 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2482 this is instead controlled by the value of
2483 /config/load-environment.
2485 - DataFlash Support:
2486 CONFIG_HAS_DATAFLASH
2488 Defining this option enables DataFlash features and
2489 allows to read/write in Dataflash via the standard
2492 - Serial Flash support
2495 Defining this option enables SPI flash commands
2496 'sf probe/read/write/erase/update'.
2498 Usage requires an initial 'probe' to define the serial
2499 flash parameters, followed by read/write/erase/update
2502 The following defaults may be provided by the platform
2503 to handle the common case when only a single serial
2504 flash is present on the system.
2506 CONFIG_SF_DEFAULT_BUS Bus identifier
2507 CONFIG_SF_DEFAULT_CS Chip-select
2508 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2509 CONFIG_SF_DEFAULT_SPEED in Hz
2513 Define this option to include a destructive SPI flash
2516 - SystemACE Support:
2519 Adding this option adds support for Xilinx SystemACE
2520 chips attached via some sort of local bus. The address
2521 of the chip must also be defined in the
2522 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2524 #define CONFIG_SYSTEMACE
2525 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2527 When SystemACE support is added, the "ace" device type
2528 becomes available to the fat commands, i.e. fatls.
2530 - TFTP Fixed UDP Port:
2533 If this is defined, the environment variable tftpsrcp
2534 is used to supply the TFTP UDP source port value.
2535 If tftpsrcp isn't defined, the normal pseudo-random port
2536 number generator is used.
2538 Also, the environment variable tftpdstp is used to supply
2539 the TFTP UDP destination port value. If tftpdstp isn't
2540 defined, the normal port 69 is used.
2542 The purpose for tftpsrcp is to allow a TFTP server to
2543 blindly start the TFTP transfer using the pre-configured
2544 target IP address and UDP port. This has the effect of
2545 "punching through" the (Windows XP) firewall, allowing
2546 the remainder of the TFTP transfer to proceed normally.
2547 A better solution is to properly configure the firewall,
2548 but sometimes that is not allowed.
2553 This enables a generic 'hash' command which can produce
2554 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2558 Enable the hash verify command (hash -v). This adds to code
2561 CONFIG_SHA1 - support SHA1 hashing
2562 CONFIG_SHA256 - support SHA256 hashing
2564 Note: There is also a sha1sum command, which should perhaps
2565 be deprecated in favour of 'hash sha1'.
2567 - Show boot progress:
2568 CONFIG_SHOW_BOOT_PROGRESS
2570 Defining this option allows to add some board-
2571 specific code (calling a user-provided function
2572 "show_boot_progress(int)") that enables you to show
2573 the system's boot progress on some display (for
2574 example, some LED's) on your board. At the moment,
2575 the following checkpoints are implemented:
2577 - Detailed boot stage timing
2579 Define this option to get detailed timing of each stage
2580 of the boot process.
2582 CONFIG_BOOTSTAGE_USER_COUNT
2583 This is the number of available user bootstage records.
2584 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2585 a new ID will be allocated from this stash. If you exceed
2586 the limit, recording will stop.
2588 CONFIG_BOOTSTAGE_REPORT
2589 Define this to print a report before boot, similar to this:
2591 Timer summary in microseconds:
2594 3,575,678 3,575,678 board_init_f start
2595 3,575,695 17 arch_cpu_init A9
2596 3,575,777 82 arch_cpu_init done
2597 3,659,598 83,821 board_init_r start
2598 3,910,375 250,777 main_loop
2599 29,916,167 26,005,792 bootm_start
2600 30,361,327 445,160 start_kernel
2602 CONFIG_CMD_BOOTSTAGE
2603 Add a 'bootstage' command which supports printing a report
2604 and un/stashing of bootstage data.
2606 CONFIG_BOOTSTAGE_FDT
2607 Stash the bootstage information in the FDT. A root 'bootstage'
2608 node is created with each bootstage id as a child. Each child
2609 has a 'name' property and either 'mark' containing the
2610 mark time in microsecond, or 'accum' containing the
2611 accumulated time for that bootstage id in microseconds.
2616 name = "board_init_f";
2625 Code in the Linux kernel can find this in /proc/devicetree.
2627 Legacy uImage format:
2630 1 common/cmd_bootm.c before attempting to boot an image
2631 -1 common/cmd_bootm.c Image header has bad magic number
2632 2 common/cmd_bootm.c Image header has correct magic number
2633 -2 common/cmd_bootm.c Image header has bad checksum
2634 3 common/cmd_bootm.c Image header has correct checksum
2635 -3 common/cmd_bootm.c Image data has bad checksum
2636 4 common/cmd_bootm.c Image data has correct checksum
2637 -4 common/cmd_bootm.c Image is for unsupported architecture
2638 5 common/cmd_bootm.c Architecture check OK
2639 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2640 6 common/cmd_bootm.c Image Type check OK
2641 -6 common/cmd_bootm.c gunzip uncompression error
2642 -7 common/cmd_bootm.c Unimplemented compression type
2643 7 common/cmd_bootm.c Uncompression OK
2644 8 common/cmd_bootm.c No uncompress/copy overwrite error
2645 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2647 9 common/image.c Start initial ramdisk verification
2648 -10 common/image.c Ramdisk header has bad magic number
2649 -11 common/image.c Ramdisk header has bad checksum
2650 10 common/image.c Ramdisk header is OK
2651 -12 common/image.c Ramdisk data has bad checksum
2652 11 common/image.c Ramdisk data has correct checksum
2653 12 common/image.c Ramdisk verification complete, start loading
2654 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2655 13 common/image.c Start multifile image verification
2656 14 common/image.c No initial ramdisk, no multifile, continue.
2658 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2660 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2661 -31 post/post.c POST test failed, detected by post_output_backlog()
2662 -32 post/post.c POST test failed, detected by post_run_single()
2664 34 common/cmd_doc.c before loading a Image from a DOC device
2665 -35 common/cmd_doc.c Bad usage of "doc" command
2666 35 common/cmd_doc.c correct usage of "doc" command
2667 -36 common/cmd_doc.c No boot device
2668 36 common/cmd_doc.c correct boot device
2669 -37 common/cmd_doc.c Unknown Chip ID on boot device
2670 37 common/cmd_doc.c correct chip ID found, device available
2671 -38 common/cmd_doc.c Read Error on boot device
2672 38 common/cmd_doc.c reading Image header from DOC device OK
2673 -39 common/cmd_doc.c Image header has bad magic number
2674 39 common/cmd_doc.c Image header has correct magic number
2675 -40 common/cmd_doc.c Error reading Image from DOC device
2676 40 common/cmd_doc.c Image header has correct magic number
2677 41 common/cmd_ide.c before loading a Image from a IDE device
2678 -42 common/cmd_ide.c Bad usage of "ide" command
2679 42 common/cmd_ide.c correct usage of "ide" command
2680 -43 common/cmd_ide.c No boot device
2681 43 common/cmd_ide.c boot device found
2682 -44 common/cmd_ide.c Device not available
2683 44 common/cmd_ide.c Device available
2684 -45 common/cmd_ide.c wrong partition selected
2685 45 common/cmd_ide.c partition selected
2686 -46 common/cmd_ide.c Unknown partition table
2687 46 common/cmd_ide.c valid partition table found
2688 -47 common/cmd_ide.c Invalid partition type
2689 47 common/cmd_ide.c correct partition type
2690 -48 common/cmd_ide.c Error reading Image Header on boot device
2691 48 common/cmd_ide.c reading Image Header from IDE device OK
2692 -49 common/cmd_ide.c Image header has bad magic number
2693 49 common/cmd_ide.c Image header has correct magic number
2694 -50 common/cmd_ide.c Image header has bad checksum
2695 50 common/cmd_ide.c Image header has correct checksum
2696 -51 common/cmd_ide.c Error reading Image from IDE device
2697 51 common/cmd_ide.c reading Image from IDE device OK
2698 52 common/cmd_nand.c before loading a Image from a NAND device
2699 -53 common/cmd_nand.c Bad usage of "nand" command
2700 53 common/cmd_nand.c correct usage of "nand" command
2701 -54 common/cmd_nand.c No boot device
2702 54 common/cmd_nand.c boot device found
2703 -55 common/cmd_nand.c Unknown Chip ID on boot device
2704 55 common/cmd_nand.c correct chip ID found, device available
2705 -56 common/cmd_nand.c Error reading Image Header on boot device
2706 56 common/cmd_nand.c reading Image Header from NAND device OK
2707 -57 common/cmd_nand.c Image header has bad magic number
2708 57 common/cmd_nand.c Image header has correct magic number
2709 -58 common/cmd_nand.c Error reading Image from NAND device
2710 58 common/cmd_nand.c reading Image from NAND device OK
2712 -60 common/env_common.c Environment has a bad CRC, using default
2714 64 net/eth.c starting with Ethernet configuration.
2715 -64 net/eth.c no Ethernet found.
2716 65 net/eth.c Ethernet found.
2718 -80 common/cmd_net.c usage wrong
2719 80 common/cmd_net.c before calling NetLoop()
2720 -81 common/cmd_net.c some error in NetLoop() occurred
2721 81 common/cmd_net.c NetLoop() back without error
2722 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2723 82 common/cmd_net.c trying automatic boot
2724 83 common/cmd_net.c running "source" command
2725 -83 common/cmd_net.c some error in automatic boot or "source" command
2726 84 common/cmd_net.c end without errors
2731 100 common/cmd_bootm.c Kernel FIT Image has correct format
2732 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2733 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2734 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2735 102 common/cmd_bootm.c Kernel unit name specified
2736 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2737 103 common/cmd_bootm.c Found configuration node
2738 104 common/cmd_bootm.c Got kernel subimage node offset
2739 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2740 105 common/cmd_bootm.c Kernel subimage hash verification OK
2741 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2742 106 common/cmd_bootm.c Architecture check OK
2743 -106 common/cmd_bootm.c Kernel subimage has wrong type
2744 107 common/cmd_bootm.c Kernel subimage type OK
2745 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2746 108 common/cmd_bootm.c Got kernel subimage data/size
2747 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2748 -109 common/cmd_bootm.c Can't get kernel subimage type
2749 -110 common/cmd_bootm.c Can't get kernel subimage comp
2750 -111 common/cmd_bootm.c Can't get kernel subimage os
2751 -112 common/cmd_bootm.c Can't get kernel subimage load address
2752 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2754 120 common/image.c Start initial ramdisk verification
2755 -120 common/image.c Ramdisk FIT image has incorrect format
2756 121 common/image.c Ramdisk FIT image has correct format
2757 122 common/image.c No ramdisk subimage unit name, using configuration
2758 -122 common/image.c Can't get configuration for ramdisk subimage
2759 123 common/image.c Ramdisk unit name specified
2760 -124 common/image.c Can't get ramdisk subimage node offset
2761 125 common/image.c Got ramdisk subimage node offset
2762 -125 common/image.c Ramdisk subimage hash verification failed
2763 126 common/image.c Ramdisk subimage hash verification OK
2764 -126 common/image.c Ramdisk subimage for unsupported architecture
2765 127 common/image.c Architecture check OK
2766 -127 common/image.c Can't get ramdisk subimage data/size
2767 128 common/image.c Got ramdisk subimage data/size
2768 129 common/image.c Can't get ramdisk load address
2769 -129 common/image.c Got ramdisk load address
2771 -130 common/cmd_doc.c Incorrect FIT image format
2772 131 common/cmd_doc.c FIT image format OK
2774 -140 common/cmd_ide.c Incorrect FIT image format
2775 141 common/cmd_ide.c FIT image format OK
2777 -150 common/cmd_nand.c Incorrect FIT image format
2778 151 common/cmd_nand.c FIT image format OK
2780 - FIT image support:
2782 Enable support for the FIT uImage format.
2784 CONFIG_FIT_BEST_MATCH
2785 When no configuration is explicitly selected, default to the
2786 one whose fdt's compatibility field best matches that of
2787 U-Boot itself. A match is considered "best" if it matches the
2788 most specific compatibility entry of U-Boot's fdt's root node.
2789 The order of entries in the configuration's fdt is ignored.
2791 - Standalone program support:
2792 CONFIG_STANDALONE_LOAD_ADDR
2794 This option defines a board specific value for the
2795 address where standalone program gets loaded, thus
2796 overwriting the architecture dependent default
2799 - Frame Buffer Address:
2802 Define CONFIG_FB_ADDR if you want to use specific
2803 address for frame buffer. This is typically the case
2804 when using a graphics controller has separate video
2805 memory. U-Boot will then place the frame buffer at
2806 the given address instead of dynamically reserving it
2807 in system RAM by calling lcd_setmem(), which grabs
2808 the memory for the frame buffer depending on the
2809 configured panel size.
2811 Please see board_init_f function.
2813 - Automatic software updates via TFTP server
2815 CONFIG_UPDATE_TFTP_CNT_MAX
2816 CONFIG_UPDATE_TFTP_MSEC_MAX
2818 These options enable and control the auto-update feature;
2819 for a more detailed description refer to doc/README.update.
2821 - MTD Support (mtdparts command, UBI support)
2824 Adds the MTD device infrastructure from the Linux kernel.
2825 Needed for mtdparts command support.
2827 CONFIG_MTD_PARTITIONS
2829 Adds the MTD partitioning infrastructure from the Linux
2830 kernel. Needed for UBI support.
2835 Adds commands for interacting with MTD partitions formatted
2836 with the UBI flash translation layer
2838 Requires also defining CONFIG_RBTREE
2840 CONFIG_UBI_SILENCE_MSG
2842 Make the verbose messages from UBI stop printing. This leaves
2843 warnings and errors enabled.
2848 Adds commands for interacting with UBI volumes formatted as
2849 UBIFS. UBIFS is read-only in u-boot.
2851 Requires UBI support as well as CONFIG_LZO
2853 CONFIG_UBIFS_SILENCE_MSG
2855 Make the verbose messages from UBIFS stop printing. This leaves
2856 warnings and errors enabled.
2860 Enable building of SPL globally.
2863 LDSCRIPT for linking the SPL binary.
2865 CONFIG_SPL_MAX_FOOTPRINT
2866 Maximum size in memory allocated to the SPL, BSS included.
2867 When defined, the linker checks that the actual memory
2868 used by SPL from _start to __bss_end does not exceed it.
2869 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2870 must not be both defined at the same time.
2873 Maximum size of the SPL image (text, data, rodata, and
2874 linker lists sections), BSS excluded.
2875 When defined, the linker checks that the actual size does
2878 CONFIG_SPL_TEXT_BASE
2879 TEXT_BASE for linking the SPL binary.
2881 CONFIG_SPL_RELOC_TEXT_BASE
2882 Address to relocate to. If unspecified, this is equal to
2883 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2885 CONFIG_SPL_BSS_START_ADDR
2886 Link address for the BSS within the SPL binary.
2888 CONFIG_SPL_BSS_MAX_SIZE
2889 Maximum size in memory allocated to the SPL BSS.
2890 When defined, the linker checks that the actual memory used
2891 by SPL from __bss_start to __bss_end does not exceed it.
2892 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2893 must not be both defined at the same time.
2896 Adress of the start of the stack SPL will use
2898 CONFIG_SPL_RELOC_STACK
2899 Adress of the start of the stack SPL will use after
2900 relocation. If unspecified, this is equal to
2903 CONFIG_SYS_SPL_MALLOC_START
2904 Starting address of the malloc pool used in SPL.
2906 CONFIG_SYS_SPL_MALLOC_SIZE
2907 The size of the malloc pool used in SPL.
2909 CONFIG_SPL_FRAMEWORK
2910 Enable the SPL framework under common/. This framework
2911 supports MMC, NAND and YMODEM loading of U-Boot and NAND
2912 NAND loading of the Linux Kernel.
2914 CONFIG_SPL_DISPLAY_PRINT
2915 For ARM, enable an optional function to print more information
2916 about the running system.
2918 CONFIG_SPL_INIT_MINIMAL
2919 Arch init code should be built for a very small image
2921 CONFIG_SPL_LIBCOMMON_SUPPORT
2922 Support for common/libcommon.o in SPL binary
2924 CONFIG_SPL_LIBDISK_SUPPORT
2925 Support for disk/libdisk.o in SPL binary
2927 CONFIG_SPL_I2C_SUPPORT
2928 Support for drivers/i2c/libi2c.o in SPL binary
2930 CONFIG_SPL_GPIO_SUPPORT
2931 Support for drivers/gpio/libgpio.o in SPL binary
2933 CONFIG_SPL_MMC_SUPPORT
2934 Support for drivers/mmc/libmmc.o in SPL binary
2936 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
2937 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
2938 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
2939 Address, size and partition on the MMC to load U-Boot from
2940 when the MMC is being used in raw mode.
2942 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
2943 Sector to load kernel uImage from when MMC is being
2944 used in raw mode (for Falcon mode)
2946 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
2947 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
2948 Sector and number of sectors to load kernel argument
2949 parameters from when MMC is being used in raw mode
2952 CONFIG_SPL_FAT_SUPPORT
2953 Support for fs/fat/libfat.o in SPL binary
2955 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
2956 Filename to read to load U-Boot when reading from FAT
2958 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
2959 Filename to read to load kernel uImage when reading
2960 from FAT (for Falcon mode)
2962 CONFIG_SPL_FAT_LOAD_ARGS_NAME
2963 Filename to read to load kernel argument parameters
2964 when reading from FAT (for Falcon mode)
2966 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
2967 Set this for NAND SPL on PPC mpc83xx targets, so that
2968 start.S waits for the rest of the SPL to load before
2969 continuing (the hardware starts execution after just
2970 loading the first page rather than the full 4K).
2972 CONFIG_SPL_NAND_BASE
2973 Include nand_base.c in the SPL. Requires
2974 CONFIG_SPL_NAND_DRIVERS.
2976 CONFIG_SPL_NAND_DRIVERS
2977 SPL uses normal NAND drivers, not minimal drivers.
2980 Include standard software ECC in the SPL
2982 CONFIG_SPL_NAND_SIMPLE
2983 Support for NAND boot using simple NAND drivers that
2984 expose the cmd_ctrl() interface.
2986 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
2987 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
2988 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
2989 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
2990 CONFIG_SYS_NAND_ECCBYTES
2991 Defines the size and behavior of the NAND that SPL uses
2994 CONFIG_SYS_NAND_U_BOOT_OFFS
2995 Location in NAND to read U-Boot from
2997 CONFIG_SYS_NAND_U_BOOT_DST
2998 Location in memory to load U-Boot to
3000 CONFIG_SYS_NAND_U_BOOT_SIZE
3001 Size of image to load
3003 CONFIG_SYS_NAND_U_BOOT_START
3004 Entry point in loaded image to jump to
3006 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3007 Define this if you need to first read the OOB and then the
3008 data. This is used for example on davinci plattforms.
3010 CONFIG_SPL_OMAP3_ID_NAND
3011 Support for an OMAP3-specific set of functions to return the
3012 ID and MFR of the first attached NAND chip, if present.
3014 CONFIG_SPL_SERIAL_SUPPORT
3015 Support for drivers/serial/libserial.o in SPL binary
3017 CONFIG_SPL_SPI_FLASH_SUPPORT
3018 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3020 CONFIG_SPL_SPI_SUPPORT
3021 Support for drivers/spi/libspi.o in SPL binary
3023 CONFIG_SPL_RAM_DEVICE
3024 Support for running image already present in ram, in SPL binary
3026 CONFIG_SPL_LIBGENERIC_SUPPORT
3027 Support for lib/libgeneric.o in SPL binary
3030 Image offset to which the SPL should be padded before appending
3031 the SPL payload. By default, this is defined as
3032 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3033 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3034 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3037 Final target image containing SPL and payload. Some SPLs
3038 use an arch-specific makefile fragment instead, for
3039 example if more than one image needs to be produced.
3041 CONFIG_FIT_SPL_PRINT
3042 Printing information about a FIT image adds quite a bit of
3043 code to SPL. So this is normally disabled in SPL. Use this
3044 option to re-enable it. This will affect the output of the
3045 bootm command when booting a FIT image.
3050 [so far only for SMDK2400 boards]
3052 - Modem support enable:
3053 CONFIG_MODEM_SUPPORT
3055 - RTS/CTS Flow control enable:
3058 - Modem debug support:
3059 CONFIG_MODEM_SUPPORT_DEBUG
3061 Enables debugging stuff (char screen[1024], dbg())
3062 for modem support. Useful only with BDI2000.
3064 - Interrupt support (PPC):
3066 There are common interrupt_init() and timer_interrupt()
3067 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3068 for CPU specific initialization. interrupt_init_cpu()
3069 should set decrementer_count to appropriate value. If
3070 CPU resets decrementer automatically after interrupt
3071 (ppc4xx) it should set decrementer_count to zero.
3072 timer_interrupt() calls timer_interrupt_cpu() for CPU
3073 specific handling. If board has watchdog / status_led
3074 / other_activity_monitor it works automatically from
3075 general timer_interrupt().
3079 In the target system modem support is enabled when a
3080 specific key (key combination) is pressed during
3081 power-on. Otherwise U-Boot will boot normally
3082 (autoboot). The key_pressed() function is called from
3083 board_init(). Currently key_pressed() is a dummy
3084 function, returning 1 and thus enabling modem
3087 If there are no modem init strings in the
3088 environment, U-Boot proceed to autoboot; the
3089 previous output (banner, info printfs) will be
3092 See also: doc/README.Modem
3094 Board initialization settings:
3095 ------------------------------
3097 During Initialization u-boot calls a number of board specific functions
3098 to allow the preparation of board specific prerequisites, e.g. pin setup
3099 before drivers are initialized. To enable these callbacks the
3100 following configuration macros have to be defined. Currently this is
3101 architecture specific, so please check arch/your_architecture/lib/board.c
3102 typically in board_init_f() and board_init_r().
3104 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3105 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3106 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3107 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3109 Configuration Settings:
3110 -----------------------
3112 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3113 undefine this when you're short of memory.
3115 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3116 width of the commands listed in the 'help' command output.
3118 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3119 prompt for user input.
3121 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3123 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3125 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3127 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3128 the application (usually a Linux kernel) when it is
3131 - CONFIG_SYS_BAUDRATE_TABLE:
3132 List of legal baudrate settings for this board.
3134 - CONFIG_SYS_CONSOLE_INFO_QUIET
3135 Suppress display of console information at boot.
3137 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3138 If the board specific function
3139 extern int overwrite_console (void);
3140 returns 1, the stdin, stderr and stdout are switched to the
3141 serial port, else the settings in the environment are used.
3143 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3144 Enable the call to overwrite_console().
3146 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3147 Enable overwrite of previous console environment settings.
3149 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3150 Begin and End addresses of the area used by the
3153 - CONFIG_SYS_ALT_MEMTEST:
3154 Enable an alternate, more extensive memory test.
3156 - CONFIG_SYS_MEMTEST_SCRATCH:
3157 Scratch address used by the alternate memory test
3158 You only need to set this if address zero isn't writeable
3160 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3161 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3162 this specified memory area will get subtracted from the top
3163 (end) of RAM and won't get "touched" at all by U-Boot. By
3164 fixing up gd->ram_size the Linux kernel should gets passed
3165 the now "corrected" memory size and won't touch it either.
3166 This should work for arch/ppc and arch/powerpc. Only Linux
3167 board ports in arch/powerpc with bootwrapper support that
3168 recalculate the memory size from the SDRAM controller setup
3169 will have to get fixed in Linux additionally.
3171 This option can be used as a workaround for the 440EPx/GRx
3172 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3175 WARNING: Please make sure that this value is a multiple of
3176 the Linux page size (normally 4k). If this is not the case,
3177 then the end address of the Linux memory will be located at a
3178 non page size aligned address and this could cause major
3181 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3182 Enable temporary baudrate change while serial download
3184 - CONFIG_SYS_SDRAM_BASE:
3185 Physical start address of SDRAM. _Must_ be 0 here.
3187 - CONFIG_SYS_MBIO_BASE:
3188 Physical start address of Motherboard I/O (if using a
3191 - CONFIG_SYS_FLASH_BASE:
3192 Physical start address of Flash memory.
3194 - CONFIG_SYS_MONITOR_BASE:
3195 Physical start address of boot monitor code (set by
3196 make config files to be same as the text base address
3197 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3198 CONFIG_SYS_FLASH_BASE when booting from flash.
3200 - CONFIG_SYS_MONITOR_LEN:
3201 Size of memory reserved for monitor code, used to
3202 determine _at_compile_time_ (!) if the environment is
3203 embedded within the U-Boot image, or in a separate
3206 - CONFIG_SYS_MALLOC_LEN:
3207 Size of DRAM reserved for malloc() use.
3209 - CONFIG_SYS_BOOTM_LEN:
3210 Normally compressed uImages are limited to an
3211 uncompressed size of 8 MBytes. If this is not enough,
3212 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3213 to adjust this setting to your needs.
3215 - CONFIG_SYS_BOOTMAPSZ:
3216 Maximum size of memory mapped by the startup code of
3217 the Linux kernel; all data that must be processed by
3218 the Linux kernel (bd_info, boot arguments, FDT blob if
3219 used) must be put below this limit, unless "bootm_low"
3220 enviroment variable is defined and non-zero. In such case
3221 all data for the Linux kernel must be between "bootm_low"
3222 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3223 variable "bootm_mapsize" will override the value of
3224 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3225 then the value in "bootm_size" will be used instead.
3227 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3228 Enable initrd_high functionality. If defined then the
3229 initrd_high feature is enabled and the bootm ramdisk subcommand
3232 - CONFIG_SYS_BOOT_GET_CMDLINE:
3233 Enables allocating and saving kernel cmdline in space between
3234 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3236 - CONFIG_SYS_BOOT_GET_KBD:
3237 Enables allocating and saving a kernel copy of the bd_info in
3238 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3240 - CONFIG_SYS_MAX_FLASH_BANKS:
3241 Max number of Flash memory banks
3243 - CONFIG_SYS_MAX_FLASH_SECT:
3244 Max number of sectors on a Flash chip
3246 - CONFIG_SYS_FLASH_ERASE_TOUT:
3247 Timeout for Flash erase operations (in ms)
3249 - CONFIG_SYS_FLASH_WRITE_TOUT:
3250 Timeout for Flash write operations (in ms)
3252 - CONFIG_SYS_FLASH_LOCK_TOUT
3253 Timeout for Flash set sector lock bit operation (in ms)
3255 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3256 Timeout for Flash clear lock bits operation (in ms)
3258 - CONFIG_SYS_FLASH_PROTECTION
3259 If defined, hardware flash sectors protection is used
3260 instead of U-Boot software protection.
3262 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3264 Enable TFTP transfers directly to flash memory;
3265 without this option such a download has to be
3266 performed in two steps: (1) download to RAM, and (2)
3267 copy from RAM to flash.
3269 The two-step approach is usually more reliable, since
3270 you can check if the download worked before you erase
3271 the flash, but in some situations (when system RAM is
3272 too limited to allow for a temporary copy of the
3273 downloaded image) this option may be very useful.
3275 - CONFIG_SYS_FLASH_CFI:
3276 Define if the flash driver uses extra elements in the
3277 common flash structure for storing flash geometry.
3279 - CONFIG_FLASH_CFI_DRIVER
3280 This option also enables the building of the cfi_flash driver
3281 in the drivers directory
3283 - CONFIG_FLASH_CFI_MTD
3284 This option enables the building of the cfi_mtd driver
3285 in the drivers directory. The driver exports CFI flash
3288 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3289 Use buffered writes to flash.
3291 - CONFIG_FLASH_SPANSION_S29WS_N
3292 s29ws-n MirrorBit flash has non-standard addresses for buffered
3295 - CONFIG_SYS_FLASH_QUIET_TEST
3296 If this option is defined, the common CFI flash doesn't
3297 print it's warning upon not recognized FLASH banks. This
3298 is useful, if some of the configured banks are only
3299 optionally available.
3301 - CONFIG_FLASH_SHOW_PROGRESS
3302 If defined (must be an integer), print out countdown
3303 digits and dots. Recommended value: 45 (9..1) for 80
3304 column displays, 15 (3..1) for 40 column displays.
3306 - CONFIG_FLASH_VERIFY
3307 If defined, the content of the flash (destination) is compared
3308 against the source after the write operation. An error message
3309 will be printed when the contents are not identical.
3310 Please note that this option is useless in nearly all cases,
3311 since such flash programming errors usually are detected earlier
3312 while unprotecting/erasing/programming. Please only enable
3313 this option if you really know what you are doing.
3315 - CONFIG_SYS_RX_ETH_BUFFER:
3316 Defines the number of Ethernet receive buffers. On some
3317 Ethernet controllers it is recommended to set this value
3318 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3319 buffers can be full shortly after enabling the interface
3320 on high Ethernet traffic.
3321 Defaults to 4 if not defined.
3323 - CONFIG_ENV_MAX_ENTRIES
3325 Maximum number of entries in the hash table that is used
3326 internally to store the environment settings. The default
3327 setting is supposed to be generous and should work in most
3328 cases. This setting can be used to tune behaviour; see
3329 lib/hashtable.c for details.
3331 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3332 - CONFIG_ENV_FLAGS_LIST_STATIC
3333 Enable validation of the values given to enviroment variables when
3334 calling env set. Variables can be restricted to only decimal,
3335 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3336 the variables can also be restricted to IP address or MAC address.
3338 The format of the list is:
3339 type_attribute = [s|d|x|b|i|m]
3340 access_atribute = [a|r|o|c]
3341 attributes = type_attribute[access_atribute]
3342 entry = variable_name[:attributes]
3345 The type attributes are:
3346 s - String (default)
3349 b - Boolean ([1yYtT|0nNfF])
3353 The access attributes are:
3359 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3360 Define this to a list (string) to define the ".flags"
3361 envirnoment variable in the default or embedded environment.
3363 - CONFIG_ENV_FLAGS_LIST_STATIC
3364 Define this to a list (string) to define validation that
3365 should be done if an entry is not found in the ".flags"
3366 environment variable. To override a setting in the static
3367 list, simply add an entry for the same variable name to the
3370 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3371 If defined, don't allow the -f switch to env set override variable
3374 - CONFIG_SYS_GENERIC_BOARD
3375 This selects the architecture-generic board system instead of the
3376 architecture-specific board files. It is intended to move boards
3377 to this new framework over time. Defining this will disable the
3378 arch/foo/lib/board.c file and use common/board_f.c and
3379 common/board_r.c instead. To use this option your architecture
3380 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3381 its config.mk file). If you find problems enabling this option on
3382 your board please report the problem and send patches!
3384 - CONFIG_SYS_SYM_OFFSETS
3385 This is set by architectures that use offsets for link symbols
3386 instead of absolute values. So bss_start is obtained using an
3387 offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
3388 directly. You should not need to touch this setting.
3390 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3391 This is set by OMAP boards for the max time that reset should
3392 be asserted. See doc/README.omap-reset-time for details on how
3393 the value can be calulated on a given board.
3395 The following definitions that deal with the placement and management
3396 of environment data (variable area); in general, we support the
3397 following configurations:
3399 - CONFIG_BUILD_ENVCRC:
3401 Builds up envcrc with the target environment so that external utils
3402 may easily extract it and embed it in final U-Boot images.
3404 - CONFIG_ENV_IS_IN_FLASH:
3406 Define this if the environment is in flash memory.
3408 a) The environment occupies one whole flash sector, which is
3409 "embedded" in the text segment with the U-Boot code. This
3410 happens usually with "bottom boot sector" or "top boot
3411 sector" type flash chips, which have several smaller
3412 sectors at the start or the end. For instance, such a
3413 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3414 such a case you would place the environment in one of the
3415 4 kB sectors - with U-Boot code before and after it. With
3416 "top boot sector" type flash chips, you would put the
3417 environment in one of the last sectors, leaving a gap
3418 between U-Boot and the environment.
3420 - CONFIG_ENV_OFFSET:
3422 Offset of environment data (variable area) to the
3423 beginning of flash memory; for instance, with bottom boot
3424 type flash chips the second sector can be used: the offset
3425 for this sector is given here.
3427 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3431 This is just another way to specify the start address of
3432 the flash sector containing the environment (instead of
3435 - CONFIG_ENV_SECT_SIZE:
3437 Size of the sector containing the environment.
3440 b) Sometimes flash chips have few, equal sized, BIG sectors.
3441 In such a case you don't want to spend a whole sector for
3446 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3447 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3448 of this flash sector for the environment. This saves
3449 memory for the RAM copy of the environment.
3451 It may also save flash memory if you decide to use this
3452 when your environment is "embedded" within U-Boot code,
3453 since then the remainder of the flash sector could be used
3454 for U-Boot code. It should be pointed out that this is
3455 STRONGLY DISCOURAGED from a robustness point of view:
3456 updating the environment in flash makes it always
3457 necessary to erase the WHOLE sector. If something goes
3458 wrong before the contents has been restored from a copy in
3459 RAM, your target system will be dead.
3461 - CONFIG_ENV_ADDR_REDUND
3462 CONFIG_ENV_SIZE_REDUND
3464 These settings describe a second storage area used to hold
3465 a redundant copy of the environment data, so that there is
3466 a valid backup copy in case there is a power failure during
3467 a "saveenv" operation.
3469 BE CAREFUL! Any changes to the flash layout, and some changes to the
3470 source code will make it necessary to adapt <board>/u-boot.lds*
3474 - CONFIG_ENV_IS_IN_NVRAM:
3476 Define this if you have some non-volatile memory device
3477 (NVRAM, battery buffered SRAM) which you want to use for the
3483 These two #defines are used to determine the memory area you
3484 want to use for environment. It is assumed that this memory
3485 can just be read and written to, without any special
3488 BE CAREFUL! The first access to the environment happens quite early
3489 in U-Boot initalization (when we try to get the setting of for the
3490 console baudrate). You *MUST* have mapped your NVRAM area then, or
3493 Please note that even with NVRAM we still use a copy of the
3494 environment in RAM: we could work on NVRAM directly, but we want to
3495 keep settings there always unmodified except somebody uses "saveenv"
3496 to save the current settings.
3499 - CONFIG_ENV_IS_IN_EEPROM:
3501 Use this if you have an EEPROM or similar serial access
3502 device and a driver for it.
3504 - CONFIG_ENV_OFFSET:
3507 These two #defines specify the offset and size of the
3508 environment area within the total memory of your EEPROM.
3510 - CONFIG_SYS_I2C_EEPROM_ADDR:
3511 If defined, specified the chip address of the EEPROM device.
3512 The default address is zero.
3514 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3515 If defined, the number of bits used to address bytes in a
3516 single page in the EEPROM device. A 64 byte page, for example
3517 would require six bits.
3519 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3520 If defined, the number of milliseconds to delay between
3521 page writes. The default is zero milliseconds.
3523 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3524 The length in bytes of the EEPROM memory array address. Note
3525 that this is NOT the chip address length!
3527 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3528 EEPROM chips that implement "address overflow" are ones
3529 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3530 address and the extra bits end up in the "chip address" bit
3531 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3534 Note that we consider the length of the address field to
3535 still be one byte because the extra address bits are hidden
3536 in the chip address.
3538 - CONFIG_SYS_EEPROM_SIZE:
3539 The size in bytes of the EEPROM device.
3541 - CONFIG_ENV_EEPROM_IS_ON_I2C
3542 define this, if you have I2C and SPI activated, and your
3543 EEPROM, which holds the environment, is on the I2C bus.
3545 - CONFIG_I2C_ENV_EEPROM_BUS
3546 if you have an Environment on an EEPROM reached over
3547 I2C muxes, you can define here, how to reach this
3548 EEPROM. For example:
3550 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
3552 EEPROM which holds the environment, is reached over
3553 a pca9547 i2c mux with address 0x70, channel 3.
3555 - CONFIG_ENV_IS_IN_DATAFLASH:
3557 Define this if you have a DataFlash memory device which you
3558 want to use for the environment.
3560 - CONFIG_ENV_OFFSET:
3564 These three #defines specify the offset and size of the
3565 environment area within the total memory of your DataFlash placed
3566 at the specified address.
3568 - CONFIG_ENV_IS_IN_REMOTE:
3570 Define this if you have a remote memory space which you
3571 want to use for the local device's environment.
3576 These two #defines specify the address and size of the
3577 environment area within the remote memory space. The
3578 local device can get the environment from remote memory
3579 space by SRIO or PCIE links.
3581 BE CAREFUL! For some special cases, the local device can not use
3582 "saveenv" command. For example, the local device will get the
3583 environment stored in a remote NOR flash by SRIO or PCIE link,
3584 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3586 - CONFIG_ENV_IS_IN_NAND:
3588 Define this if you have a NAND device which you want to use
3589 for the environment.
3591 - CONFIG_ENV_OFFSET:
3594 These two #defines specify the offset and size of the environment
3595 area within the first NAND device. CONFIG_ENV_OFFSET must be
3596 aligned to an erase block boundary.
3598 - CONFIG_ENV_OFFSET_REDUND (optional):
3600 This setting describes a second storage area of CONFIG_ENV_SIZE
3601 size used to hold a redundant copy of the environment data, so
3602 that there is a valid backup copy in case there is a power failure
3603 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3604 aligned to an erase block boundary.
3606 - CONFIG_ENV_RANGE (optional):
3608 Specifies the length of the region in which the environment
3609 can be written. This should be a multiple of the NAND device's
3610 block size. Specifying a range with more erase blocks than
3611 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3612 the range to be avoided.
3614 - CONFIG_ENV_OFFSET_OOB (optional):
3616 Enables support for dynamically retrieving the offset of the
3617 environment from block zero's out-of-band data. The
3618 "nand env.oob" command can be used to record this offset.
3619 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3620 using CONFIG_ENV_OFFSET_OOB.
3622 - CONFIG_NAND_ENV_DST
3624 Defines address in RAM to which the nand_spl code should copy the
3625 environment. If redundant environment is used, it will be copied to
3626 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3628 - CONFIG_ENV_IS_IN_UBI:
3630 Define this if you have an UBI volume that you want to use for the
3631 environment. This has the benefit of wear-leveling the environment
3632 accesses, which is important on NAND.
3634 - CONFIG_ENV_UBI_PART:
3636 Define this to a string that is the mtd partition containing the UBI.
3638 - CONFIG_ENV_UBI_VOLUME:
3640 Define this to the name of the volume that you want to store the
3643 - CONFIG_ENV_UBI_VOLUME_REDUND:
3645 Define this to the name of another volume to store a second copy of
3646 the environment in. This will enable redundant environments in UBI.
3647 It is assumed that both volumes are in the same MTD partition.
3649 - CONFIG_UBI_SILENCE_MSG
3650 - CONFIG_UBIFS_SILENCE_MSG
3652 You will probably want to define these to avoid a really noisy system
3653 when storing the env in UBI.
3655 - CONFIG_ENV_IS_IN_MMC:
3657 Define this if you have an MMC device which you want to use for the
3660 - CONFIG_SYS_MMC_ENV_DEV:
3662 Specifies which MMC device the environment is stored in.
3664 - CONFIG_SYS_MMC_ENV_PART (optional):
3666 Specifies which MMC partition the environment is stored in. If not
3667 set, defaults to partition 0, the user area. Common values might be
3668 1 (first MMC boot partition), 2 (second MMC boot partition).
3670 - CONFIG_ENV_OFFSET:
3673 These two #defines specify the offset and size of the environment
3674 area within the specified MMC device.
3676 If offset is positive (the usual case), it is treated as relative to
3677 the start of the MMC partition. If offset is negative, it is treated
3678 as relative to the end of the MMC partition. This can be useful if
3679 your board may be fitted with different MMC devices, which have
3680 different sizes for the MMC partitions, and you always want the
3681 environment placed at the very end of the partition, to leave the
3682 maximum possible space before it, to store other data.
3684 These two values are in units of bytes, but must be aligned to an
3685 MMC sector boundary.
3687 - CONFIG_ENV_OFFSET_REDUND (optional):
3689 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
3690 hold a redundant copy of the environment data. This provides a
3691 valid backup copy in case the other copy is corrupted, e.g. due
3692 to a power failure during a "saveenv" operation.
3694 This value may also be positive or negative; this is handled in the
3695 same way as CONFIG_ENV_OFFSET.
3697 This value is also in units of bytes, but must also be aligned to
3698 an MMC sector boundary.
3700 - CONFIG_ENV_SIZE_REDUND (optional):
3702 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
3703 set. If this value is set, it must be set to the same value as
3706 - CONFIG_SYS_SPI_INIT_OFFSET
3708 Defines offset to the initial SPI buffer area in DPRAM. The
3709 area is used at an early stage (ROM part) if the environment
3710 is configured to reside in the SPI EEPROM: We need a 520 byte
3711 scratch DPRAM area. It is used between the two initialization
3712 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3713 to be a good choice since it makes it far enough from the
3714 start of the data area as well as from the stack pointer.
3716 Please note that the environment is read-only until the monitor
3717 has been relocated to RAM and a RAM copy of the environment has been
3718 created; also, when using EEPROM you will have to use getenv_f()
3719 until then to read environment variables.
3721 The environment is protected by a CRC32 checksum. Before the monitor
3722 is relocated into RAM, as a result of a bad CRC you will be working
3723 with the compiled-in default environment - *silently*!!! [This is
3724 necessary, because the first environment variable we need is the
3725 "baudrate" setting for the console - if we have a bad CRC, we don't
3726 have any device yet where we could complain.]
3728 Note: once the monitor has been relocated, then it will complain if
3729 the default environment is used; a new CRC is computed as soon as you
3730 use the "saveenv" command to store a valid environment.
3732 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3733 Echo the inverted Ethernet link state to the fault LED.
3735 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3736 also needs to be defined.
3738 - CONFIG_SYS_FAULT_MII_ADDR:
3739 MII address of the PHY to check for the Ethernet link state.
3741 - CONFIG_NS16550_MIN_FUNCTIONS:
3742 Define this if you desire to only have use of the NS16550_init
3743 and NS16550_putc functions for the serial driver located at
3744 drivers/serial/ns16550.c. This option is useful for saving
3745 space for already greatly restricted images, including but not
3746 limited to NAND_SPL configurations.
3748 - CONFIG_DISPLAY_BOARDINFO
3749 Display information about the board that U-Boot is running on
3750 when U-Boot starts up. The board function checkboard() is called
3753 - CONFIG_DISPLAY_BOARDINFO_LATE
3754 Similar to the previous option, but display this information
3755 later, once stdio is running and output goes to the LCD, if
3758 Low Level (hardware related) configuration options:
3759 ---------------------------------------------------
3761 - CONFIG_SYS_CACHELINE_SIZE:
3762 Cache Line Size of the CPU.
3764 - CONFIG_SYS_DEFAULT_IMMR:
3765 Default address of the IMMR after system reset.
3767 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3768 and RPXsuper) to be able to adjust the position of
3769 the IMMR register after a reset.
3771 - CONFIG_SYS_CCSRBAR_DEFAULT:
3772 Default (power-on reset) physical address of CCSR on Freescale
3775 - CONFIG_SYS_CCSRBAR:
3776 Virtual address of CCSR. On a 32-bit build, this is typically
3777 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3779 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3780 for cross-platform code that uses that macro instead.
3782 - CONFIG_SYS_CCSRBAR_PHYS:
3783 Physical address of CCSR. CCSR can be relocated to a new
3784 physical address, if desired. In this case, this macro should
3785 be set to that address. Otherwise, it should be set to the
3786 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3787 is typically relocated on 36-bit builds. It is recommended
3788 that this macro be defined via the _HIGH and _LOW macros:
3790 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3791 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3793 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3794 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3795 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3796 used in assembly code, so it must not contain typecasts or
3797 integer size suffixes (e.g. "ULL").
3799 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3800 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3801 used in assembly code, so it must not contain typecasts or
3802 integer size suffixes (e.g. "ULL").
3804 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3805 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3806 forced to a value that ensures that CCSR is not relocated.
3808 - Floppy Disk Support:
3809 CONFIG_SYS_FDC_DRIVE_NUMBER
3811 the default drive number (default value 0)
3813 CONFIG_SYS_ISA_IO_STRIDE
3815 defines the spacing between FDC chipset registers
3818 CONFIG_SYS_ISA_IO_OFFSET
3820 defines the offset of register from address. It
3821 depends on which part of the data bus is connected to
3822 the FDC chipset. (default value 0)
3824 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3825 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3828 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3829 fdc_hw_init() is called at the beginning of the FDC
3830 setup. fdc_hw_init() must be provided by the board
3831 source code. It is used to make hardware dependant
3835 Most IDE controllers were designed to be connected with PCI
3836 interface. Only few of them were designed for AHB interface.
3837 When software is doing ATA command and data transfer to
3838 IDE devices through IDE-AHB controller, some additional
3839 registers accessing to these kind of IDE-AHB controller
3842 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3843 DO NOT CHANGE unless you know exactly what you're
3844 doing! (11-4) [MPC8xx/82xx systems only]
3846 - CONFIG_SYS_INIT_RAM_ADDR:
3848 Start address of memory area that can be used for
3849 initial data and stack; please note that this must be
3850 writable memory that is working WITHOUT special
3851 initialization, i. e. you CANNOT use normal RAM which
3852 will become available only after programming the
3853 memory controller and running certain initialization
3856 U-Boot uses the following memory types:
3857 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
3858 - MPC824X: data cache
3859 - PPC4xx: data cache
3861 - CONFIG_SYS_GBL_DATA_OFFSET:
3863 Offset of the initial data structure in the memory
3864 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3865 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3866 data is located at the end of the available space
3867 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3868 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
3869 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3870 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3873 On the MPC824X (or other systems that use the data
3874 cache for initial memory) the address chosen for
3875 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3876 point to an otherwise UNUSED address space between
3877 the top of RAM and the start of the PCI space.
3879 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
3881 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
3883 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
3885 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
3887 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
3889 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3891 - CONFIG_SYS_OR_TIMING_SDRAM:
3894 - CONFIG_SYS_MAMR_PTA:
3895 periodic timer for refresh
3897 - CONFIG_SYS_DER: Debug Event Register (37-47)
3899 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3900 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3901 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3902 CONFIG_SYS_BR1_PRELIM:
3903 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3905 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3906 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3907 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3908 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3910 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
3911 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
3912 Machine Mode Register and Memory Periodic Timer
3913 Prescaler definitions (SDRAM timing)
3915 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
3916 enable I2C microcode relocation patch (MPC8xx);
3917 define relocation offset in DPRAM [DSP2]
3919 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
3920 enable SMC microcode relocation patch (MPC8xx);
3921 define relocation offset in DPRAM [SMC1]
3923 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
3924 enable SPI microcode relocation patch (MPC8xx);
3925 define relocation offset in DPRAM [SCC4]
3927 - CONFIG_SYS_USE_OSCCLK:
3928 Use OSCM clock mode on MBX8xx board. Be careful,
3929 wrong setting might damage your board. Read
3930 doc/README.MBX before setting this variable!
3932 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
3933 Offset of the bootmode word in DPRAM used by post
3934 (Power On Self Tests). This definition overrides
3935 #define'd default value in commproc.h resp.
3938 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
3939 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
3940 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
3941 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
3942 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
3943 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
3944 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
3945 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
3946 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
3948 - CONFIG_PCI_DISABLE_PCIE:
3949 Disable PCI-Express on systems where it is supported but not
3952 - CONFIG_PCI_ENUM_ONLY
3953 Only scan through and get the devices on the busses.
3954 Don't do any setup work, presumably because someone or
3955 something has already done it, and we don't need to do it
3956 a second time. Useful for platforms that are pre-booted
3957 by coreboot or similar.
3959 - CONFIG_PCI_INDIRECT_BRIDGE:
3960 Enable support for indirect PCI bridges.
3963 Chip has SRIO or not
3966 Board has SRIO 1 port available
3969 Board has SRIO 2 port available
3971 - CONFIG_SYS_SRIOn_MEM_VIRT:
3972 Virtual Address of SRIO port 'n' memory region
3974 - CONFIG_SYS_SRIOn_MEM_PHYS:
3975 Physical Address of SRIO port 'n' memory region
3977 - CONFIG_SYS_SRIOn_MEM_SIZE:
3978 Size of SRIO port 'n' memory region
3980 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
3981 Defined to tell the NAND controller that the NAND chip is using
3983 Not all NAND drivers use this symbol.
3984 Example of drivers that use it:
3985 - drivers/mtd/nand/ndfc.c
3986 - drivers/mtd/nand/mxc_nand.c
3988 - CONFIG_SYS_NDFC_EBC0_CFG
3989 Sets the EBC0_CFG register for the NDFC. If not defined
3990 a default value will be used.
3993 Get DDR timing information from an I2C EEPROM. Common
3994 with pluggable memory modules such as SODIMMs
3997 I2C address of the SPD EEPROM
3999 - CONFIG_SYS_SPD_BUS_NUM
4000 If SPD EEPROM is on an I2C bus other than the first
4001 one, specify here. Note that the value must resolve
4002 to something your driver can deal with.
4004 - CONFIG_SYS_DDR_RAW_TIMING
4005 Get DDR timing information from other than SPD. Common with
4006 soldered DDR chips onboard without SPD. DDR raw timing
4007 parameters are extracted from datasheet and hard-coded into
4008 header files or board specific files.
4010 - CONFIG_FSL_DDR_INTERACTIVE
4011 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4013 - CONFIG_SYS_83XX_DDR_USES_CS0
4014 Only for 83xx systems. If specified, then DDR should
4015 be configured using CS0 and CS1 instead of CS2 and CS3.
4017 - CONFIG_ETHER_ON_FEC[12]
4018 Define to enable FEC[12] on a 8xx series processor.
4020 - CONFIG_FEC[12]_PHY
4021 Define to the hardcoded PHY address which corresponds
4022 to the given FEC; i. e.
4023 #define CONFIG_FEC1_PHY 4
4024 means that the PHY with address 4 is connected to FEC1
4026 When set to -1, means to probe for first available.
4028 - CONFIG_FEC[12]_PHY_NORXERR
4029 The PHY does not have a RXERR line (RMII only).
4030 (so program the FEC to ignore it).
4033 Enable RMII mode for all FECs.
4034 Note that this is a global option, we can't
4035 have one FEC in standard MII mode and another in RMII mode.
4037 - CONFIG_CRC32_VERIFY
4038 Add a verify option to the crc32 command.
4041 => crc32 -v <address> <count> <crc32>
4043 Where address/count indicate a memory area
4044 and crc32 is the correct crc32 which the
4048 Add the "loopw" memory command. This only takes effect if
4049 the memory commands are activated globally (CONFIG_CMD_MEM).
4052 Add the "mdc" and "mwc" memory commands. These are cyclic
4057 This command will print 4 bytes (10,11,12,13) each 500 ms.
4059 => mwc.l 100 12345678 10
4060 This command will write 12345678 to address 100 all 10 ms.
4062 This only takes effect if the memory commands are activated
4063 globally (CONFIG_CMD_MEM).
4065 - CONFIG_SKIP_LOWLEVEL_INIT
4066 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4067 low level initializations (like setting up the memory
4068 controller) are omitted and/or U-Boot does not
4069 relocate itself into RAM.
4071 Normally this variable MUST NOT be defined. The only
4072 exception is when U-Boot is loaded (to RAM) by some
4073 other boot loader or by a debugger which performs
4074 these initializations itself.
4077 Modifies the behaviour of start.S when compiling a loader
4078 that is executed before the actual U-Boot. E.g. when
4079 compiling a NAND SPL.
4081 - CONFIG_ARCH_MAP_SYSMEM
4082 Generally U-Boot (and in particular the md command) uses
4083 effective address. It is therefore not necessary to regard
4084 U-Boot address as virtual addresses that need to be translated
4085 to physical addresses. However, sandbox requires this, since
4086 it maintains its own little RAM buffer which contains all
4087 addressable memory. This option causes some memory accesses
4088 to be mapped through map_sysmem() / unmap_sysmem().
4090 - CONFIG_USE_ARCH_MEMCPY
4091 CONFIG_USE_ARCH_MEMSET
4092 If these options are used a optimized version of memcpy/memset will
4093 be used if available. These functions may be faster under some
4094 conditions but may increase the binary size.
4096 - CONFIG_X86_RESET_VECTOR
4097 If defined, the x86 reset vector code is included. This is not
4098 needed when U-Boot is running from Coreboot.
4101 Defines the MPU clock speed (in MHz).
4103 NOTE : currently only supported on AM335x platforms.
4105 Freescale QE/FMAN Firmware Support:
4106 -----------------------------------
4108 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4109 loading of "firmware", which is encoded in the QE firmware binary format.
4110 This firmware often needs to be loaded during U-Boot booting, so macros
4111 are used to identify the storage device (NOR flash, SPI, etc) and the address
4114 - CONFIG_SYS_QE_FMAN_FW_ADDR
4115 The address in the storage device where the firmware is located. The
4116 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4119 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4120 The maximum possible size of the firmware. The firmware binary format
4121 has a field that specifies the actual size of the firmware, but it
4122 might not be possible to read any part of the firmware unless some
4123 local storage is allocated to hold the entire firmware first.
4125 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4126 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4127 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4128 virtual address in NOR flash.
4130 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4131 Specifies that QE/FMAN firmware is located in NAND flash.
4132 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4134 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4135 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4136 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4138 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4139 Specifies that QE/FMAN firmware is located on the primary SPI
4140 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4142 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4143 Specifies that QE/FMAN firmware is located in the remote (master)
4144 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4145 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4146 window->master inbound window->master LAW->the ucode address in
4147 master's memory space.
4149 Building the Software:
4150 ======================
4152 Building U-Boot has been tested in several native build environments
4153 and in many different cross environments. Of course we cannot support
4154 all possibly existing versions of cross development tools in all
4155 (potentially obsolete) versions. In case of tool chain problems we
4156 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4157 which is extensively used to build and test U-Boot.
4159 If you are not using a native environment, it is assumed that you
4160 have GNU cross compiling tools available in your path. In this case,
4161 you must set the environment variable CROSS_COMPILE in your shell.
4162 Note that no changes to the Makefile or any other source files are
4163 necessary. For example using the ELDK on a 4xx CPU, please enter:
4165 $ CROSS_COMPILE=ppc_4xx-
4166 $ export CROSS_COMPILE
4168 Note: If you wish to generate Windows versions of the utilities in
4169 the tools directory you can use the MinGW toolchain
4170 (http://www.mingw.org). Set your HOST tools to the MinGW
4171 toolchain and execute 'make tools'. For example:
4173 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4175 Binaries such as tools/mkimage.exe will be created which can
4176 be executed on computers running Windows.
4178 U-Boot is intended to be simple to build. After installing the
4179 sources you must configure U-Boot for one specific board type. This
4184 where "NAME_config" is the name of one of the existing configu-
4185 rations; see boards.cfg for supported names.
4187 Note: for some board special configuration names may exist; check if
4188 additional information is available from the board vendor; for
4189 instance, the TQM823L systems are available without (standard)
4190 or with LCD support. You can select such additional "features"
4191 when choosing the configuration, i. e.
4194 - will configure for a plain TQM823L, i. e. no LCD support
4196 make TQM823L_LCD_config
4197 - will configure for a TQM823L with U-Boot console on LCD
4202 Finally, type "make all", and you should get some working U-Boot
4203 images ready for download to / installation on your system:
4205 - "u-boot.bin" is a raw binary image
4206 - "u-boot" is an image in ELF binary format
4207 - "u-boot.srec" is in Motorola S-Record format
4209 By default the build is performed locally and the objects are saved
4210 in the source directory. One of the two methods can be used to change
4211 this behavior and build U-Boot to some external directory:
4213 1. Add O= to the make command line invocations:
4215 make O=/tmp/build distclean
4216 make O=/tmp/build NAME_config
4217 make O=/tmp/build all
4219 2. Set environment variable BUILD_DIR to point to the desired location:
4221 export BUILD_DIR=/tmp/build
4226 Note that the command line "O=" setting overrides the BUILD_DIR environment
4230 Please be aware that the Makefiles assume you are using GNU make, so
4231 for instance on NetBSD you might need to use "gmake" instead of
4235 If the system board that you have is not listed, then you will need
4236 to port U-Boot to your hardware platform. To do this, follow these
4239 1. Add a new configuration option for your board to the toplevel
4240 "boards.cfg" file, using the existing entries as examples.
4241 Follow the instructions there to keep the boards in order.
4242 2. Create a new directory to hold your board specific code. Add any
4243 files you need. In your board directory, you will need at least
4244 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4245 3. Create a new configuration file "include/configs/<board>.h" for
4247 3. If you're porting U-Boot to a new CPU, then also create a new
4248 directory to hold your CPU specific code. Add any files you need.
4249 4. Run "make <board>_config" with your new name.
4250 5. Type "make", and you should get a working "u-boot.srec" file
4251 to be installed on your target system.
4252 6. Debug and solve any problems that might arise.
4253 [Of course, this last step is much harder than it sounds.]
4256 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4257 ==============================================================
4259 If you have modified U-Boot sources (for instance added a new board
4260 or support for new devices, a new CPU, etc.) you are expected to
4261 provide feedback to the other developers. The feedback normally takes
4262 the form of a "patch", i. e. a context diff against a certain (latest
4263 official or latest in the git repository) version of U-Boot sources.
4265 But before you submit such a patch, please verify that your modifi-
4266 cation did not break existing code. At least make sure that *ALL* of
4267 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4268 just run the "MAKEALL" script, which will configure and build U-Boot
4269 for ALL supported system. Be warned, this will take a while. You can
4270 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4271 environment variable to the script, i. e. to use the ELDK cross tools
4274 CROSS_COMPILE=ppc_8xx- MAKEALL
4276 or to build on a native PowerPC system you can type
4278 CROSS_COMPILE=' ' MAKEALL
4280 When using the MAKEALL script, the default behaviour is to build
4281 U-Boot in the source directory. This location can be changed by
4282 setting the BUILD_DIR environment variable. Also, for each target
4283 built, the MAKEALL script saves two log files (<target>.ERR and
4284 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4285 location can be changed by setting the MAKEALL_LOGDIR environment
4286 variable. For example:
4288 export BUILD_DIR=/tmp/build
4289 export MAKEALL_LOGDIR=/tmp/log
4290 CROSS_COMPILE=ppc_8xx- MAKEALL
4292 With the above settings build objects are saved in the /tmp/build,
4293 log files are saved in the /tmp/log and the source tree remains clean
4294 during the whole build process.
4297 See also "U-Boot Porting Guide" below.
4300 Monitor Commands - Overview:
4301 ============================
4303 go - start application at address 'addr'
4304 run - run commands in an environment variable
4305 bootm - boot application image from memory
4306 bootp - boot image via network using BootP/TFTP protocol
4307 bootz - boot zImage from memory
4308 tftpboot- boot image via network using TFTP protocol
4309 and env variables "ipaddr" and "serverip"
4310 (and eventually "gatewayip")
4311 tftpput - upload a file via network using TFTP protocol
4312 rarpboot- boot image via network using RARP/TFTP protocol
4313 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4314 loads - load S-Record file over serial line
4315 loadb - load binary file over serial line (kermit mode)
4317 mm - memory modify (auto-incrementing)
4318 nm - memory modify (constant address)
4319 mw - memory write (fill)
4321 cmp - memory compare
4322 crc32 - checksum calculation
4323 i2c - I2C sub-system
4324 sspi - SPI utility commands
4325 base - print or set address offset
4326 printenv- print environment variables
4327 setenv - set environment variables
4328 saveenv - save environment variables to persistent storage
4329 protect - enable or disable FLASH write protection
4330 erase - erase FLASH memory
4331 flinfo - print FLASH memory information
4332 nand - NAND memory operations (see doc/README.nand)
4333 bdinfo - print Board Info structure
4334 iminfo - print header information for application image
4335 coninfo - print console devices and informations
4336 ide - IDE sub-system
4337 loop - infinite loop on address range
4338 loopw - infinite write loop on address range
4339 mtest - simple RAM test
4340 icache - enable or disable instruction cache
4341 dcache - enable or disable data cache
4342 reset - Perform RESET of the CPU
4343 echo - echo args to console
4344 version - print monitor version
4345 help - print online help
4346 ? - alias for 'help'
4349 Monitor Commands - Detailed Description:
4350 ========================================
4354 For now: just type "help <command>".
4357 Environment Variables:
4358 ======================
4360 U-Boot supports user configuration using Environment Variables which
4361 can be made persistent by saving to Flash memory.
4363 Environment Variables are set using "setenv", printed using
4364 "printenv", and saved to Flash using "saveenv". Using "setenv"
4365 without a value can be used to delete a variable from the
4366 environment. As long as you don't save the environment you are
4367 working with an in-memory copy. In case the Flash area containing the
4368 environment is erased by accident, a default environment is provided.
4370 Some configuration options can be set using Environment Variables.
4372 List of environment variables (most likely not complete):
4374 baudrate - see CONFIG_BAUDRATE
4376 bootdelay - see CONFIG_BOOTDELAY
4378 bootcmd - see CONFIG_BOOTCOMMAND
4380 bootargs - Boot arguments when booting an RTOS image
4382 bootfile - Name of the image to load with TFTP
4384 bootm_low - Memory range available for image processing in the bootm
4385 command can be restricted. This variable is given as
4386 a hexadecimal number and defines lowest address allowed
4387 for use by the bootm command. See also "bootm_size"
4388 environment variable. Address defined by "bootm_low" is
4389 also the base of the initial memory mapping for the Linux
4390 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4393 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4394 This variable is given as a hexadecimal number and it
4395 defines the size of the memory region starting at base
4396 address bootm_low that is accessible by the Linux kernel
4397 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4398 as the default value if it is defined, and bootm_size is
4401 bootm_size - Memory range available for image processing in the bootm
4402 command can be restricted. This variable is given as
4403 a hexadecimal number and defines the size of the region
4404 allowed for use by the bootm command. See also "bootm_low"
4405 environment variable.
4407 updatefile - Location of the software update file on a TFTP server, used
4408 by the automatic software update feature. Please refer to
4409 documentation in doc/README.update for more details.
4411 autoload - if set to "no" (any string beginning with 'n'),
4412 "bootp" will just load perform a lookup of the
4413 configuration from the BOOTP server, but not try to
4414 load any image using TFTP
4416 autostart - if set to "yes", an image loaded using the "bootp",
4417 "rarpboot", "tftpboot" or "diskboot" commands will
4418 be automatically started (by internally calling
4421 If set to "no", a standalone image passed to the
4422 "bootm" command will be copied to the load address
4423 (and eventually uncompressed), but NOT be started.
4424 This can be used to load and uncompress arbitrary
4427 fdt_high - if set this restricts the maximum address that the
4428 flattened device tree will be copied into upon boot.
4429 For example, if you have a system with 1 GB memory
4430 at physical address 0x10000000, while Linux kernel
4431 only recognizes the first 704 MB as low memory, you
4432 may need to set fdt_high as 0x3C000000 to have the
4433 device tree blob be copied to the maximum address
4434 of the 704 MB low memory, so that Linux kernel can
4435 access it during the boot procedure.
4437 If this is set to the special value 0xFFFFFFFF then
4438 the fdt will not be copied at all on boot. For this
4439 to work it must reside in writable memory, have
4440 sufficient padding on the end of it for u-boot to
4441 add the information it needs into it, and the memory
4442 must be accessible by the kernel.
4444 fdtcontroladdr- if set this is the address of the control flattened
4445 device tree used by U-Boot when CONFIG_OF_CONTROL is
4448 i2cfast - (PPC405GP|PPC405EP only)
4449 if set to 'y' configures Linux I2C driver for fast
4450 mode (400kHZ). This environment variable is used in
4451 initialization code. So, for changes to be effective
4452 it must be saved and board must be reset.
4454 initrd_high - restrict positioning of initrd images:
4455 If this variable is not set, initrd images will be
4456 copied to the highest possible address in RAM; this
4457 is usually what you want since it allows for
4458 maximum initrd size. If for some reason you want to
4459 make sure that the initrd image is loaded below the
4460 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4461 variable to a value of "no" or "off" or "0".
4462 Alternatively, you can set it to a maximum upper
4463 address to use (U-Boot will still check that it
4464 does not overwrite the U-Boot stack and data).
4466 For instance, when you have a system with 16 MB
4467 RAM, and want to reserve 4 MB from use by Linux,
4468 you can do this by adding "mem=12M" to the value of
4469 the "bootargs" variable. However, now you must make
4470 sure that the initrd image is placed in the first
4471 12 MB as well - this can be done with
4473 setenv initrd_high 00c00000
4475 If you set initrd_high to 0xFFFFFFFF, this is an
4476 indication to U-Boot that all addresses are legal
4477 for the Linux kernel, including addresses in flash
4478 memory. In this case U-Boot will NOT COPY the
4479 ramdisk at all. This may be useful to reduce the
4480 boot time on your system, but requires that this
4481 feature is supported by your Linux kernel.
4483 ipaddr - IP address; needed for tftpboot command
4485 loadaddr - Default load address for commands like "bootp",
4486 "rarpboot", "tftpboot", "loadb" or "diskboot"
4488 loads_echo - see CONFIG_LOADS_ECHO
4490 serverip - TFTP server IP address; needed for tftpboot command
4492 bootretry - see CONFIG_BOOT_RETRY_TIME
4494 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4496 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4498 ethprime - controls which interface is used first.
4500 ethact - controls which interface is currently active.
4501 For example you can do the following
4503 => setenv ethact FEC
4504 => ping 192.168.0.1 # traffic sent on FEC
4505 => setenv ethact SCC
4506 => ping 10.0.0.1 # traffic sent on SCC
4508 ethrotate - When set to "no" U-Boot does not go through all
4509 available network interfaces.
4510 It just stays at the currently selected interface.
4512 netretry - When set to "no" each network operation will
4513 either succeed or fail without retrying.
4514 When set to "once" the network operation will
4515 fail when all the available network interfaces
4516 are tried once without success.
4517 Useful on scripts which control the retry operation
4520 npe_ucode - set load address for the NPE microcode
4522 tftpsrcport - If this is set, the value is used for TFTP's
4525 tftpdstport - If this is set, the value is used for TFTP's UDP
4526 destination port instead of the Well Know Port 69.
4528 tftpblocksize - Block size to use for TFTP transfers; if not set,
4529 we use the TFTP server's default block size
4531 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4532 seconds, minimum value is 1000 = 1 second). Defines
4533 when a packet is considered to be lost so it has to
4534 be retransmitted. The default is 5000 = 5 seconds.
4535 Lowering this value may make downloads succeed
4536 faster in networks with high packet loss rates or
4537 with unreliable TFTP servers.
4539 vlan - When set to a value < 4095 the traffic over
4540 Ethernet is encapsulated/received over 802.1q
4543 The following image location variables contain the location of images
4544 used in booting. The "Image" column gives the role of the image and is
4545 not an environment variable name. The other columns are environment
4546 variable names. "File Name" gives the name of the file on a TFTP
4547 server, "RAM Address" gives the location in RAM the image will be
4548 loaded to, and "Flash Location" gives the image's address in NOR
4549 flash or offset in NAND flash.
4551 *Note* - these variables don't have to be defined for all boards, some
4552 boards currenlty use other variables for these purposes, and some
4553 boards use these variables for other purposes.
4555 Image File Name RAM Address Flash Location
4556 ----- --------- ----------- --------------
4557 u-boot u-boot u-boot_addr_r u-boot_addr
4558 Linux kernel bootfile kernel_addr_r kernel_addr
4559 device tree blob fdtfile fdt_addr_r fdt_addr
4560 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4562 The following environment variables may be used and automatically
4563 updated by the network boot commands ("bootp" and "rarpboot"),
4564 depending the information provided by your boot server:
4566 bootfile - see above
4567 dnsip - IP address of your Domain Name Server
4568 dnsip2 - IP address of your secondary Domain Name Server
4569 gatewayip - IP address of the Gateway (Router) to use
4570 hostname - Target hostname
4572 netmask - Subnet Mask
4573 rootpath - Pathname of the root filesystem on the NFS server
4574 serverip - see above
4577 There are two special Environment Variables:
4579 serial# - contains hardware identification information such
4580 as type string and/or serial number
4581 ethaddr - Ethernet address
4583 These variables can be set only once (usually during manufacturing of
4584 the board). U-Boot refuses to delete or overwrite these variables
4585 once they have been set once.
4588 Further special Environment Variables:
4590 ver - Contains the U-Boot version string as printed
4591 with the "version" command. This variable is
4592 readonly (see CONFIG_VERSION_VARIABLE).
4595 Please note that changes to some configuration parameters may take
4596 only effect after the next boot (yes, that's just like Windoze :-).
4599 Callback functions for environment variables:
4600 ---------------------------------------------
4602 For some environment variables, the behavior of u-boot needs to change
4603 when their values are changed. This functionailty allows functions to
4604 be associated with arbitrary variables. On creation, overwrite, or
4605 deletion, the callback will provide the opportunity for some side
4606 effect to happen or for the change to be rejected.
4608 The callbacks are named and associated with a function using the
4609 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4611 These callbacks are associated with variables in one of two ways. The
4612 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4613 in the board configuration to a string that defines a list of
4614 associations. The list must be in the following format:
4616 entry = variable_name[:callback_name]
4619 If the callback name is not specified, then the callback is deleted.
4620 Spaces are also allowed anywhere in the list.
4622 Callbacks can also be associated by defining the ".callbacks" variable
4623 with the same list format above. Any association in ".callbacks" will
4624 override any association in the static list. You can define
4625 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4626 ".callbacks" envirnoment variable in the default or embedded environment.
4629 Command Line Parsing:
4630 =====================
4632 There are two different command line parsers available with U-Boot:
4633 the old "simple" one, and the much more powerful "hush" shell:
4635 Old, simple command line parser:
4636 --------------------------------
4638 - supports environment variables (through setenv / saveenv commands)
4639 - several commands on one line, separated by ';'
4640 - variable substitution using "... ${name} ..." syntax
4641 - special characters ('$', ';') can be escaped by prefixing with '\',
4643 setenv bootcmd bootm \${address}
4644 - You can also escape text by enclosing in single apostrophes, for example:
4645 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4650 - similar to Bourne shell, with control structures like
4651 if...then...else...fi, for...do...done; while...do...done,
4652 until...do...done, ...
4653 - supports environment ("global") variables (through setenv / saveenv
4654 commands) and local shell variables (through standard shell syntax
4655 "name=value"); only environment variables can be used with "run"
4661 (1) If a command line (or an environment variable executed by a "run"
4662 command) contains several commands separated by semicolon, and
4663 one of these commands fails, then the remaining commands will be
4666 (2) If you execute several variables with one call to run (i. e.
4667 calling run with a list of variables as arguments), any failing
4668 command will cause "run" to terminate, i. e. the remaining
4669 variables are not executed.
4671 Note for Redundant Ethernet Interfaces:
4672 =======================================
4674 Some boards come with redundant Ethernet interfaces; U-Boot supports
4675 such configurations and is capable of automatic selection of a
4676 "working" interface when needed. MAC assignment works as follows:
4678 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4679 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4680 "eth1addr" (=>eth1), "eth2addr", ...
4682 If the network interface stores some valid MAC address (for instance
4683 in SROM), this is used as default address if there is NO correspon-
4684 ding setting in the environment; if the corresponding environment
4685 variable is set, this overrides the settings in the card; that means:
4687 o If the SROM has a valid MAC address, and there is no address in the
4688 environment, the SROM's address is used.
4690 o If there is no valid address in the SROM, and a definition in the
4691 environment exists, then the value from the environment variable is
4694 o If both the SROM and the environment contain a MAC address, and
4695 both addresses are the same, this MAC address is used.
4697 o If both the SROM and the environment contain a MAC address, and the
4698 addresses differ, the value from the environment is used and a
4701 o If neither SROM nor the environment contain a MAC address, an error
4704 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4705 will be programmed into hardware as part of the initialization process. This
4706 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4707 The naming convention is as follows:
4708 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4713 U-Boot is capable of booting (and performing other auxiliary operations on)
4714 images in two formats:
4716 New uImage format (FIT)
4717 -----------------------
4719 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4720 to Flattened Device Tree). It allows the use of images with multiple
4721 components (several kernels, ramdisks, etc.), with contents protected by
4722 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4728 Old image format is based on binary files which can be basically anything,
4729 preceded by a special header; see the definitions in include/image.h for
4730 details; basically, the header defines the following image properties:
4732 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4733 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4734 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4735 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4737 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4738 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4739 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4740 * Compression Type (uncompressed, gzip, bzip2)
4746 The header is marked by a special Magic Number, and both the header
4747 and the data portions of the image are secured against corruption by
4754 Although U-Boot should support any OS or standalone application
4755 easily, the main focus has always been on Linux during the design of
4758 U-Boot includes many features that so far have been part of some
4759 special "boot loader" code within the Linux kernel. Also, any
4760 "initrd" images to be used are no longer part of one big Linux image;
4761 instead, kernel and "initrd" are separate images. This implementation
4762 serves several purposes:
4764 - the same features can be used for other OS or standalone
4765 applications (for instance: using compressed images to reduce the
4766 Flash memory footprint)
4768 - it becomes much easier to port new Linux kernel versions because
4769 lots of low-level, hardware dependent stuff are done by U-Boot
4771 - the same Linux kernel image can now be used with different "initrd"
4772 images; of course this also means that different kernel images can
4773 be run with the same "initrd". This makes testing easier (you don't
4774 have to build a new "zImage.initrd" Linux image when you just
4775 change a file in your "initrd"). Also, a field-upgrade of the
4776 software is easier now.
4782 Porting Linux to U-Boot based systems:
4783 ---------------------------------------
4785 U-Boot cannot save you from doing all the necessary modifications to
4786 configure the Linux device drivers for use with your target hardware
4787 (no, we don't intend to provide a full virtual machine interface to
4790 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4792 Just make sure your machine specific header file (for instance
4793 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4794 Information structure as we define in include/asm-<arch>/u-boot.h,
4795 and make sure that your definition of IMAP_ADDR uses the same value
4796 as your U-Boot configuration in CONFIG_SYS_IMMR.
4799 Configuring the Linux kernel:
4800 -----------------------------
4802 No specific requirements for U-Boot. Make sure you have some root
4803 device (initial ramdisk, NFS) for your target system.
4806 Building a Linux Image:
4807 -----------------------
4809 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4810 not used. If you use recent kernel source, a new build target
4811 "uImage" will exist which automatically builds an image usable by
4812 U-Boot. Most older kernels also have support for a "pImage" target,
4813 which was introduced for our predecessor project PPCBoot and uses a
4814 100% compatible format.
4823 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4824 encapsulate a compressed Linux kernel image with header information,
4825 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4827 * build a standard "vmlinux" kernel image (in ELF binary format):
4829 * convert the kernel into a raw binary image:
4831 ${CROSS_COMPILE}-objcopy -O binary \
4832 -R .note -R .comment \
4833 -S vmlinux linux.bin
4835 * compress the binary image:
4839 * package compressed binary image for U-Boot:
4841 mkimage -A ppc -O linux -T kernel -C gzip \
4842 -a 0 -e 0 -n "Linux Kernel Image" \
4843 -d linux.bin.gz uImage
4846 The "mkimage" tool can also be used to create ramdisk images for use
4847 with U-Boot, either separated from the Linux kernel image, or
4848 combined into one file. "mkimage" encapsulates the images with a 64
4849 byte header containing information about target architecture,
4850 operating system, image type, compression method, entry points, time
4851 stamp, CRC32 checksums, etc.
4853 "mkimage" can be called in two ways: to verify existing images and
4854 print the header information, or to build new images.
4856 In the first form (with "-l" option) mkimage lists the information
4857 contained in the header of an existing U-Boot image; this includes
4858 checksum verification:
4860 tools/mkimage -l image
4861 -l ==> list image header information
4863 The second form (with "-d" option) is used to build a U-Boot image
4864 from a "data file" which is used as image payload:
4866 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4867 -n name -d data_file image
4868 -A ==> set architecture to 'arch'
4869 -O ==> set operating system to 'os'
4870 -T ==> set image type to 'type'
4871 -C ==> set compression type 'comp'
4872 -a ==> set load address to 'addr' (hex)
4873 -e ==> set entry point to 'ep' (hex)
4874 -n ==> set image name to 'name'
4875 -d ==> use image data from 'datafile'
4877 Right now, all Linux kernels for PowerPC systems use the same load
4878 address (0x00000000), but the entry point address depends on the
4881 - 2.2.x kernels have the entry point at 0x0000000C,
4882 - 2.3.x and later kernels have the entry point at 0x00000000.
4884 So a typical call to build a U-Boot image would read:
4886 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4887 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4888 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4889 > examples/uImage.TQM850L
4890 Image Name: 2.4.4 kernel for TQM850L
4891 Created: Wed Jul 19 02:34:59 2000
4892 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4893 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4894 Load Address: 0x00000000
4895 Entry Point: 0x00000000
4897 To verify the contents of the image (or check for corruption):
4899 -> tools/mkimage -l 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 NOTE: for embedded systems where boot time is critical you can trade
4908 speed for memory and install an UNCOMPRESSED image instead: this
4909 needs more space in Flash, but boots much faster since it does not
4910 need to be uncompressed:
4912 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4913 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4914 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4915 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4916 > examples/uImage.TQM850L-uncompressed
4917 Image Name: 2.4.4 kernel for TQM850L
4918 Created: Wed Jul 19 02:34:59 2000
4919 Image Type: PowerPC Linux Kernel Image (uncompressed)
4920 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4921 Load Address: 0x00000000
4922 Entry Point: 0x00000000
4925 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4926 when your kernel is intended to use an initial ramdisk:
4928 -> tools/mkimage -n 'Simple Ramdisk Image' \
4929 > -A ppc -O linux -T ramdisk -C gzip \
4930 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4931 Image Name: Simple Ramdisk Image
4932 Created: Wed Jan 12 14:01:50 2000
4933 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4934 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4935 Load Address: 0x00000000
4936 Entry Point: 0x00000000
4939 Installing a Linux Image:
4940 -------------------------
4942 To downloading a U-Boot image over the serial (console) interface,
4943 you must convert the image to S-Record format:
4945 objcopy -I binary -O srec examples/image examples/image.srec
4947 The 'objcopy' does not understand the information in the U-Boot
4948 image header, so the resulting S-Record file will be relative to
4949 address 0x00000000. To load it to a given address, you need to
4950 specify the target address as 'offset' parameter with the 'loads'
4953 Example: install the image to address 0x40100000 (which on the
4954 TQM8xxL is in the first Flash bank):
4956 => erase 40100000 401FFFFF
4962 ## Ready for S-Record download ...
4963 ~>examples/image.srec
4964 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4966 15989 15990 15991 15992
4967 [file transfer complete]
4969 ## Start Addr = 0x00000000
4972 You can check the success of the download using the 'iminfo' command;
4973 this includes a checksum verification so you can be sure no data
4974 corruption happened:
4978 ## Checking Image at 40100000 ...
4979 Image Name: 2.2.13 for initrd on TQM850L
4980 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4981 Data Size: 335725 Bytes = 327 kB = 0 MB
4982 Load Address: 00000000
4983 Entry Point: 0000000c
4984 Verifying Checksum ... OK
4990 The "bootm" command is used to boot an application that is stored in
4991 memory (RAM or Flash). In case of a Linux kernel image, the contents
4992 of the "bootargs" environment variable is passed to the kernel as
4993 parameters. You can check and modify this variable using the
4994 "printenv" and "setenv" commands:
4997 => printenv bootargs
4998 bootargs=root=/dev/ram
5000 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5002 => printenv bootargs
5003 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5006 ## Booting Linux kernel at 40020000 ...
5007 Image Name: 2.2.13 for NFS on TQM850L
5008 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5009 Data Size: 381681 Bytes = 372 kB = 0 MB
5010 Load Address: 00000000
5011 Entry Point: 0000000c
5012 Verifying Checksum ... OK
5013 Uncompressing Kernel Image ... OK
5014 Linux version 2.2.13 (
[email protected]) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
5015 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5016 time_init: decrementer frequency = 187500000/60
5017 Calibrating delay loop... 49.77 BogoMIPS
5018 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5021 If you want to boot a Linux kernel with initial RAM disk, you pass
5022 the memory addresses of both the kernel and the initrd image (PPBCOOT
5023 format!) to the "bootm" command:
5025 => imi 40100000 40200000
5027 ## Checking Image at 40100000 ...
5028 Image Name: 2.2.13 for initrd on TQM850L
5029 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5030 Data Size: 335725 Bytes = 327 kB = 0 MB
5031 Load Address: 00000000
5032 Entry Point: 0000000c
5033 Verifying Checksum ... OK
5035 ## Checking Image at 40200000 ...
5036 Image Name: Simple Ramdisk Image
5037 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5038 Data Size: 566530 Bytes = 553 kB = 0 MB
5039 Load Address: 00000000
5040 Entry Point: 00000000
5041 Verifying Checksum ... OK
5043 => bootm 40100000 40200000
5044 ## Booting Linux kernel at 40100000 ...
5045 Image Name: 2.2.13 for initrd on TQM850L
5046 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5047 Data Size: 335725 Bytes = 327 kB = 0 MB
5048 Load Address: 00000000
5049 Entry Point: 0000000c
5050 Verifying Checksum ... OK
5051 Uncompressing Kernel Image ... OK
5052 ## Loading RAMDisk Image at 40200000 ...
5053 Image Name: Simple Ramdisk Image
5054 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5055 Data Size: 566530 Bytes = 553 kB = 0 MB
5056 Load Address: 00000000
5057 Entry Point: 00000000
5058 Verifying Checksum ... OK
5059 Loading Ramdisk ... OK
5060 Linux version 2.2.13 (
[email protected]) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
5061 Boot arguments: root=/dev/ram
5062 time_init: decrementer frequency = 187500000/60
5063 Calibrating delay loop... 49.77 BogoMIPS
5065 RAMDISK: Compressed image found at block 0
5066 VFS: Mounted root (ext2 filesystem).
5070 Boot Linux and pass a flat device tree:
5073 First, U-Boot must be compiled with the appropriate defines. See the section
5074 titled "Linux Kernel Interface" above for a more in depth explanation. The
5075 following is an example of how to start a kernel and pass an updated
5081 oft=oftrees/mpc8540ads.dtb
5082 => tftp $oftaddr $oft
5083 Speed: 1000, full duplex
5085 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5086 Filename 'oftrees/mpc8540ads.dtb'.
5087 Load address: 0x300000
5090 Bytes transferred = 4106 (100a hex)
5091 => tftp $loadaddr $bootfile
5092 Speed: 1000, full duplex
5094 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5096 Load address: 0x200000
5097 Loading:############
5099 Bytes transferred = 1029407 (fb51f hex)
5104 => bootm $loadaddr - $oftaddr
5105 ## Booting image at 00200000 ...
5106 Image Name: Linux-2.6.17-dirty
5107 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5108 Data Size: 1029343 Bytes = 1005.2 kB
5109 Load Address: 00000000
5110 Entry Point: 00000000
5111 Verifying Checksum ... OK
5112 Uncompressing Kernel Image ... OK
5113 Booting using flat device tree at 0x300000
5114 Using MPC85xx ADS machine description
5115 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5119 More About U-Boot Image Types:
5120 ------------------------------
5122 U-Boot supports the following image types:
5124 "Standalone Programs" are directly runnable in the environment
5125 provided by U-Boot; it is expected that (if they behave
5126 well) you can continue to work in U-Boot after return from
5127 the Standalone Program.
5128 "OS Kernel Images" are usually images of some Embedded OS which
5129 will take over control completely. Usually these programs
5130 will install their own set of exception handlers, device
5131 drivers, set up the MMU, etc. - this means, that you cannot
5132 expect to re-enter U-Boot except by resetting the CPU.
5133 "RAMDisk Images" are more or less just data blocks, and their
5134 parameters (address, size) are passed to an OS kernel that is
5136 "Multi-File Images" contain several images, typically an OS
5137 (Linux) kernel image and one or more data images like
5138 RAMDisks. This construct is useful for instance when you want
5139 to boot over the network using BOOTP etc., where the boot
5140 server provides just a single image file, but you want to get
5141 for instance an OS kernel and a RAMDisk image.
5143 "Multi-File Images" start with a list of image sizes, each
5144 image size (in bytes) specified by an "uint32_t" in network
5145 byte order. This list is terminated by an "(uint32_t)0".
5146 Immediately after the terminating 0 follow the images, one by
5147 one, all aligned on "uint32_t" boundaries (size rounded up to
5148 a multiple of 4 bytes).
5150 "Firmware Images" are binary images containing firmware (like
5151 U-Boot or FPGA images) which usually will be programmed to
5154 "Script files" are command sequences that will be executed by
5155 U-Boot's command interpreter; this feature is especially
5156 useful when you configure U-Boot to use a real shell (hush)
5157 as command interpreter.
5159 Booting the Linux zImage:
5160 -------------------------
5162 On some platforms, it's possible to boot Linux zImage. This is done
5163 using the "bootz" command. The syntax of "bootz" command is the same
5164 as the syntax of "bootm" command.
5166 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5167 kernel with raw initrd images. The syntax is slightly different, the
5168 address of the initrd must be augmented by it's size, in the following
5169 format: "<initrd addres>:<initrd size>".
5175 One of the features of U-Boot is that you can dynamically load and
5176 run "standalone" applications, which can use some resources of
5177 U-Boot like console I/O functions or interrupt services.
5179 Two simple examples are included with the sources:
5184 'examples/hello_world.c' contains a small "Hello World" Demo
5185 application; it is automatically compiled when you build U-Boot.
5186 It's configured to run at address 0x00040004, so you can play with it
5190 ## Ready for S-Record download ...
5191 ~>examples/hello_world.srec
5192 1 2 3 4 5 6 7 8 9 10 11 ...
5193 [file transfer complete]
5195 ## Start Addr = 0x00040004
5197 => go 40004 Hello World! This is a test.
5198 ## Starting application at 0x00040004 ...
5209 Hit any key to exit ...
5211 ## Application terminated, rc = 0x0
5213 Another example, which demonstrates how to register a CPM interrupt
5214 handler with the U-Boot code, can be found in 'examples/timer.c'.
5215 Here, a CPM timer is set up to generate an interrupt every second.
5216 The interrupt service routine is trivial, just printing a '.'
5217 character, but this is just a demo program. The application can be
5218 controlled by the following keys:
5220 ? - print current values og the CPM Timer registers
5221 b - enable interrupts and start timer
5222 e - stop timer and disable interrupts
5223 q - quit application
5226 ## Ready for S-Record download ...
5227 ~>examples/timer.srec
5228 1 2 3 4 5 6 7 8 9 10 11 ...
5229 [file transfer complete]
5231 ## Start Addr = 0x00040004
5234 ## Starting application at 0x00040004 ...
5237 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5240 [q, b, e, ?] Set interval 1000000 us
5243 [q, b, e, ?] ........
5244 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5247 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5250 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5253 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5255 [q, b, e, ?] ...Stopping timer
5257 [q, b, e, ?] ## Application terminated, rc = 0x0
5263 Over time, many people have reported problems when trying to use the
5264 "minicom" terminal emulation program for serial download. I (wd)
5265 consider minicom to be broken, and recommend not to use it. Under
5266 Unix, I recommend to use C-Kermit for general purpose use (and
5267 especially for kermit binary protocol download ("loadb" command), and
5268 use "cu" for S-Record download ("loads" command). See
5269 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5270 for help with kermit.
5273 Nevertheless, if you absolutely want to use it try adding this
5274 configuration to your "File transfer protocols" section:
5276 Name Program Name U/D FullScr IO-Red. Multi
5277 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5278 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5284 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5285 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5287 Building requires a cross environment; it is known to work on
5288 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5289 need gmake since the Makefiles are not compatible with BSD make).
5290 Note that the cross-powerpc package does not install include files;
5291 attempting to build U-Boot will fail because <machine/ansi.h> is
5292 missing. This file has to be installed and patched manually:
5294 # cd /usr/pkg/cross/powerpc-netbsd/include
5296 # ln -s powerpc machine
5297 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5298 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5300 Native builds *don't* work due to incompatibilities between native
5301 and U-Boot include files.
5303 Booting assumes that (the first part of) the image booted is a
5304 stage-2 loader which in turn loads and then invokes the kernel
5305 proper. Loader sources will eventually appear in the NetBSD source
5306 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5307 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5310 Implementation Internals:
5311 =========================
5313 The following is not intended to be a complete description of every
5314 implementation detail. However, it should help to understand the
5315 inner workings of U-Boot and make it easier to port it to custom
5319 Initial Stack, Global Data:
5320 ---------------------------
5322 The implementation of U-Boot is complicated by the fact that U-Boot
5323 starts running out of ROM (flash memory), usually without access to
5324 system RAM (because the memory controller is not initialized yet).
5325 This means that we don't have writable Data or BSS segments, and BSS
5326 is not initialized as zero. To be able to get a C environment working
5327 at all, we have to allocate at least a minimal stack. Implementation
5328 options for this are defined and restricted by the CPU used: Some CPU
5329 models provide on-chip memory (like the IMMR area on MPC8xx and
5330 MPC826x processors), on others (parts of) the data cache can be
5331 locked as (mis-) used as memory, etc.
5333 Chris Hallinan posted a good summary of these issues to the
5334 U-Boot mailing list:
5336 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5338 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5341 Correct me if I'm wrong, folks, but the way I understand it
5342 is this: Using DCACHE as initial RAM for Stack, etc, does not
5343 require any physical RAM backing up the cache. The cleverness
5344 is that the cache is being used as a temporary supply of
5345 necessary storage before the SDRAM controller is setup. It's
5346 beyond the scope of this list to explain the details, but you
5347 can see how this works by studying the cache architecture and
5348 operation in the architecture and processor-specific manuals.
5350 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5351 is another option for the system designer to use as an
5352 initial stack/RAM area prior to SDRAM being available. Either
5353 option should work for you. Using CS 4 should be fine if your
5354 board designers haven't used it for something that would
5355 cause you grief during the initial boot! It is frequently not
5358 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5359 with your processor/board/system design. The default value
5360 you will find in any recent u-boot distribution in
5361 walnut.h should work for you. I'd set it to a value larger
5362 than your SDRAM module. If you have a 64MB SDRAM module, set
5363 it above 400_0000. Just make sure your board has no resources
5364 that are supposed to respond to that address! That code in
5365 start.S has been around a while and should work as is when
5366 you get the config right.
5371 It is essential to remember this, since it has some impact on the C
5372 code for the initialization procedures:
5374 * Initialized global data (data segment) is read-only. Do not attempt
5377 * Do not use any uninitialized global data (or implicitely initialized
5378 as zero data - BSS segment) at all - this is undefined, initiali-
5379 zation is performed later (when relocating to RAM).
5381 * Stack space is very limited. Avoid big data buffers or things like
5384 Having only the stack as writable memory limits means we cannot use
5385 normal global data to share information beween the code. But it
5386 turned out that the implementation of U-Boot can be greatly
5387 simplified by making a global data structure (gd_t) available to all
5388 functions. We could pass a pointer to this data as argument to _all_
5389 functions, but this would bloat the code. Instead we use a feature of
5390 the GCC compiler (Global Register Variables) to share the data: we
5391 place a pointer (gd) to the global data into a register which we
5392 reserve for this purpose.
5394 When choosing a register for such a purpose we are restricted by the
5395 relevant (E)ABI specifications for the current architecture, and by
5396 GCC's implementation.
5398 For PowerPC, the following registers have specific use:
5400 R2: reserved for system use
5401 R3-R4: parameter passing and return values
5402 R5-R10: parameter passing
5403 R13: small data area pointer
5407 (U-Boot also uses R12 as internal GOT pointer. r12
5408 is a volatile register so r12 needs to be reset when
5409 going back and forth between asm and C)
5411 ==> U-Boot will use R2 to hold a pointer to the global data
5413 Note: on PPC, we could use a static initializer (since the
5414 address of the global data structure is known at compile time),
5415 but it turned out that reserving a register results in somewhat
5416 smaller code - although the code savings are not that big (on
5417 average for all boards 752 bytes for the whole U-Boot image,
5418 624 text + 127 data).
5420 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5421 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5423 ==> U-Boot will use P3 to hold a pointer to the global data
5425 On ARM, the following registers are used:
5427 R0: function argument word/integer result
5428 R1-R3: function argument word
5430 R10: stack limit (used only if stack checking if enabled)
5431 R11: argument (frame) pointer
5432 R12: temporary workspace
5435 R15: program counter
5437 ==> U-Boot will use R8 to hold a pointer to the global data
5439 On Nios II, the ABI is documented here:
5440 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5442 ==> U-Boot will use gp to hold a pointer to the global data
5444 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5445 to access small data sections, so gp is free.
5447 On NDS32, the following registers are used:
5449 R0-R1: argument/return
5451 R15: temporary register for assembler
5452 R16: trampoline register
5453 R28: frame pointer (FP)
5454 R29: global pointer (GP)
5455 R30: link register (LP)
5456 R31: stack pointer (SP)
5457 PC: program counter (PC)
5459 ==> U-Boot will use R10 to hold a pointer to the global data
5461 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5462 or current versions of GCC may "optimize" the code too much.
5467 U-Boot runs in system state and uses physical addresses, i.e. the
5468 MMU is not used either for address mapping nor for memory protection.
5470 The available memory is mapped to fixed addresses using the memory
5471 controller. In this process, a contiguous block is formed for each
5472 memory type (Flash, SDRAM, SRAM), even when it consists of several
5473 physical memory banks.
5475 U-Boot is installed in the first 128 kB of the first Flash bank (on
5476 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5477 booting and sizing and initializing DRAM, the code relocates itself
5478 to the upper end of DRAM. Immediately below the U-Boot code some
5479 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5480 configuration setting]. Below that, a structure with global Board
5481 Info data is placed, followed by the stack (growing downward).
5483 Additionally, some exception handler code is copied to the low 8 kB
5484 of DRAM (0x00000000 ... 0x00001FFF).
5486 So a typical memory configuration with 16 MB of DRAM could look like
5489 0x0000 0000 Exception Vector code
5492 0x0000 2000 Free for Application Use
5498 0x00FB FF20 Monitor Stack (Growing downward)
5499 0x00FB FFAC Board Info Data and permanent copy of global data
5500 0x00FC 0000 Malloc Arena
5503 0x00FE 0000 RAM Copy of Monitor Code
5504 ... eventually: LCD or video framebuffer
5505 ... eventually: pRAM (Protected RAM - unchanged by reset)
5506 0x00FF FFFF [End of RAM]
5509 System Initialization:
5510 ----------------------
5512 In the reset configuration, U-Boot starts at the reset entry point
5513 (on most PowerPC systems at address 0x00000100). Because of the reset
5514 configuration for CS0# this is a mirror of the onboard Flash memory.
5515 To be able to re-map memory U-Boot then jumps to its link address.
5516 To be able to implement the initialization code in C, a (small!)
5517 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5518 which provide such a feature like MPC8xx or MPC8260), or in a locked
5519 part of the data cache. After that, U-Boot initializes the CPU core,
5520 the caches and the SIU.
5522 Next, all (potentially) available memory banks are mapped using a
5523 preliminary mapping. For example, we put them on 512 MB boundaries
5524 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5525 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5526 programmed for SDRAM access. Using the temporary configuration, a
5527 simple memory test is run that determines the size of the SDRAM
5530 When there is more than one SDRAM bank, and the banks are of
5531 different size, the largest is mapped first. For equal size, the first
5532 bank (CS2#) is mapped first. The first mapping is always for address
5533 0x00000000, with any additional banks following immediately to create
5534 contiguous memory starting from 0.
5536 Then, the monitor installs itself at the upper end of the SDRAM area
5537 and allocates memory for use by malloc() and for the global Board
5538 Info data; also, the exception vector code is copied to the low RAM
5539 pages, and the final stack is set up.
5541 Only after this relocation will you have a "normal" C environment;
5542 until that you are restricted in several ways, mostly because you are
5543 running from ROM, and because the code will have to be relocated to a
5547 U-Boot Porting Guide:
5548 ----------------------
5550 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5554 int main(int argc, char *argv[])
5556 sighandler_t no_more_time;
5558 signal(SIGALRM, no_more_time);
5559 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5561 if (available_money > available_manpower) {
5562 Pay consultant to port U-Boot;
5566 Download latest U-Boot source;
5568 Subscribe to u-boot mailing list;
5571 email("Hi, I am new to U-Boot, how do I get started?");
5574 Read the README file in the top level directory;
5575 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5576 Read applicable doc/*.README;
5577 Read the source, Luke;
5578 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5581 if (available_money > toLocalCurrency ($2500))
5584 Add a lot of aggravation and time;
5586 if (a similar board exists) { /* hopefully... */
5587 cp -a board/<similar> board/<myboard>
5588 cp include/configs/<similar>.h include/configs/<myboard>.h
5590 Create your own board support subdirectory;
5591 Create your own board include/configs/<myboard>.h file;
5593 Edit new board/<myboard> files
5594 Edit new include/configs/<myboard>.h
5599 Add / modify source code;
5603 email("Hi, I am having problems...");
5605 Send patch file to the U-Boot email list;
5606 if (reasonable critiques)
5607 Incorporate improvements from email list code review;
5609 Defend code as written;
5615 void no_more_time (int sig)
5624 All contributions to U-Boot should conform to the Linux kernel
5625 coding style; see the file "Documentation/CodingStyle" and the script
5626 "scripts/Lindent" in your Linux kernel source directory.
5628 Source files originating from a different project (for example the
5629 MTD subsystem) are generally exempt from these guidelines and are not
5630 reformated to ease subsequent migration to newer versions of those
5633 Please note that U-Boot is implemented in C (and to some small parts in
5634 Assembler); no C++ is used, so please do not use C++ style comments (//)
5637 Please also stick to the following formatting rules:
5638 - remove any trailing white space
5639 - use TAB characters for indentation and vertical alignment, not spaces
5640 - make sure NOT to use DOS '\r\n' line feeds
5641 - do not add more than 2 consecutive empty lines to source files
5642 - do not add trailing empty lines to source files
5644 Submissions which do not conform to the standards may be returned
5645 with a request to reformat the changes.
5651 Since the number of patches for U-Boot is growing, we need to
5652 establish some rules. Submissions which do not conform to these rules
5653 may be rejected, even when they contain important and valuable stuff.
5655 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5658 see http://lists.denx.de/mailman/listinfo/u-boot
5660 When you send a patch, please include the following information with
5663 * For bug fixes: a description of the bug and how your patch fixes
5664 this bug. Please try to include a way of demonstrating that the
5665 patch actually fixes something.
5667 * For new features: a description of the feature and your
5670 * A CHANGELOG entry as plaintext (separate from the patch)
5672 * For major contributions, your entry to the CREDITS file
5674 * When you add support for a new board, don't forget to add this
5675 board to the MAINTAINERS file, too.
5677 * If your patch adds new configuration options, don't forget to
5678 document these in the README file.
5680 * The patch itself. If you are using git (which is *strongly*
5681 recommended) you can easily generate the patch using the
5682 "git format-patch". If you then use "git send-email" to send it to
5683 the U-Boot mailing list, you will avoid most of the common problems
5684 with some other mail clients.
5686 If you cannot use git, use "diff -purN OLD NEW". If your version of
5687 diff does not support these options, then get the latest version of
5690 The current directory when running this command shall be the parent
5691 directory of the U-Boot source tree (i. e. please make sure that
5692 your patch includes sufficient directory information for the
5695 We prefer patches as plain text. MIME attachments are discouraged,
5696 and compressed attachments must not be used.
5698 * If one logical set of modifications affects or creates several
5699 files, all these changes shall be submitted in a SINGLE patch file.
5701 * Changesets that contain different, unrelated modifications shall be
5702 submitted as SEPARATE patches, one patch per changeset.
5707 * Before sending the patch, run the MAKEALL script on your patched
5708 source tree and make sure that no errors or warnings are reported
5709 for any of the boards.
5711 * Keep your modifications to the necessary minimum: A patch
5712 containing several unrelated changes or arbitrary reformats will be
5713 returned with a request to re-formatting / split it.
5715 * If you modify existing code, make sure that your new code does not
5716 add to the memory footprint of the code ;-) Small is beautiful!
5717 When adding new features, these should compile conditionally only
5718 (using #ifdef), and the resulting code with the new feature
5719 disabled must not need more memory than the old code without your
5722 * Remember that there is a size limit of 100 kB per message on the
5723 u-boot mailing list. Bigger patches will be moderated. If they are
5724 reasonable and not too big, they will be acknowledged. But patches
5725 bigger than the size limit should be avoided.
projects / u-boot.git / blob