2 # (C) Copyright 2000 - 2011
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # See file CREDITS for list of people who contributed to this
8 # This program is free software; you can redistribute it and/or
9 # modify it under the terms of the GNU General Public License as
10 # published by the Free Software Foundation; either version 2 of
11 # the License, or (at your option) any later version.
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with this program; if not, write to the Free Software
20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27 This directory contains the source code for U-Boot, a boot loader for
28 Embedded boards based on PowerPC, ARM, MIPS and several other
29 processors, which can be installed in a boot ROM and used to
30 initialize and test the hardware or to download and run application
33 The development of U-Boot is closely related to Linux: some parts of
34 the source code originate in the Linux source tree, we have some
35 header files in common, and special provision has been made to
36 support booting of Linux images.
38 Some attention has been paid to make this software easily
39 configurable and extendable. For instance, all monitor commands are
40 implemented with the same call interface, so that it's very easy to
41 add new commands. Also, instead of permanently adding rarely used
42 code (for instance hardware test utilities) to the monitor, you can
43 load and run it dynamically.
49 In general, all boards for which a configuration option exists in the
50 Makefile have been tested to some extent and can be considered
51 "working". In fact, many of them are used in production systems.
53 In case of problems see the CHANGELOG and CREDITS files to find out
54 who contributed the specific port. The MAINTAINERS file lists board
61 In case you have questions about, problems with or contributions for
62 U-Boot you should send a message to the U-Boot mailing list at
63 <u-boot@lists.denx.de>. There is also an archive of previous traffic
64 on the mailing list - please search the archive before asking FAQ's.
65 Please see http://lists.denx.de/pipermail/u-boot and
66 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
69 Where to get source code:
70 =========================
72 The U-Boot source code is maintained in the git repository at
73 git://www.denx.de/git/u-boot.git ; you can browse it online at
74 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
76 The "snapshot" links on this page allow you to download tarballs of
77 any version you might be interested in. Official releases are also
78 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
81 Pre-built (and tested) images are available from
82 ftp://ftp.denx.de/pub/u-boot/images/
88 - start from 8xxrom sources
89 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
91 - make it easier to add custom boards
92 - make it possible to add other [PowerPC] CPUs
93 - extend functions, especially:
94 * Provide extended interface to Linux boot loader
97 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
98 - create ARMBoot project (http://sourceforge.net/projects/armboot)
99 - add other CPU families (starting with ARM)
100 - create U-Boot project (http://sourceforge.net/projects/u-boot)
101 - current project page: see http://www.denx.de/wiki/U-Boot
107 The "official" name of this project is "Das U-Boot". The spelling
108 "U-Boot" shall be used in all written text (documentation, comments
109 in source files etc.). Example:
111 This is the README file for the U-Boot project.
113 File names etc. shall be based on the string "u-boot". Examples:
115 include/asm-ppc/u-boot.h
117 #include <asm/u-boot.h>
119 Variable names, preprocessor constants etc. shall be either based on
120 the string "u_boot" or on "U_BOOT". Example:
122 U_BOOT_VERSION u_boot_logo
123 IH_OS_U_BOOT u_boot_hush_start
129 Starting with the release in October 2008, the names of the releases
130 were changed from numerical release numbers without deeper meaning
131 into a time stamp based numbering. Regular releases are identified by
132 names consisting of the calendar year and month of the release date.
133 Additional fields (if present) indicate release candidates or bug fix
134 releases in "stable" maintenance trees.
137 U-Boot v2009.11 - Release November 2009
138 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
139 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
145 /arch Architecture specific files
146 /arm Files generic to ARM architecture
147 /cpu CPU specific files
148 /arm720t Files specific to ARM 720 CPUs
149 /arm920t Files specific to ARM 920 CPUs
150 /at91rm9200 Files specific to Atmel AT91RM9200 CPU
151 /imx Files specific to Freescale MC9328 i.MX CPUs
152 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
153 /arm925t Files specific to ARM 925 CPUs
154 /arm926ejs Files specific to ARM 926 CPUs
155 /arm1136 Files specific to ARM 1136 CPUs
156 /ixp Files specific to Intel XScale IXP CPUs
157 /pxa Files specific to Intel XScale PXA CPUs
158 /s3c44b0 Files specific to Samsung S3C44B0 CPUs
159 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
160 /lib Architecture specific library files
161 /avr32 Files generic to AVR32 architecture
162 /cpu CPU specific files
163 /lib Architecture specific library files
164 /blackfin Files generic to Analog Devices Blackfin architecture
165 /cpu CPU specific files
166 /lib Architecture specific library files
167 /x86 Files generic to x86 architecture
168 /cpu CPU specific files
169 /lib Architecture specific library files
170 /m68k Files generic to m68k architecture
171 /cpu CPU specific files
172 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
173 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
174 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
175 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
176 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
177 /lib Architecture specific library files
178 /microblaze Files generic to microblaze architecture
179 /cpu CPU specific files
180 /lib Architecture specific library files
181 /mips Files generic to MIPS architecture
182 /cpu CPU specific files
183 /mips32 Files specific to MIPS32 CPUs
184 /lib Architecture specific library files
185 /nios2 Files generic to Altera NIOS2 architecture
186 /cpu CPU specific files
187 /lib Architecture specific library files
188 /powerpc Files generic to PowerPC architecture
189 /cpu CPU specific files
190 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
191 /mpc5xx Files specific to Freescale MPC5xx CPUs
192 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
193 /mpc8xx Files specific to Freescale MPC8xx CPUs
194 /mpc8220 Files specific to Freescale MPC8220 CPUs
195 /mpc824x Files specific to Freescale MPC824x CPUs
196 /mpc8260 Files specific to Freescale MPC8260 CPUs
197 /mpc85xx Files specific to Freescale MPC85xx CPUs
198 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
199 /lib Architecture specific library files
200 /sh Files generic to SH architecture
201 /cpu CPU specific files
202 /sh2 Files specific to sh2 CPUs
203 /sh3 Files specific to sh3 CPUs
204 /sh4 Files specific to sh4 CPUs
205 /lib Architecture specific library files
206 /sparc Files generic to SPARC architecture
207 /cpu CPU specific files
208 /leon2 Files specific to Gaisler LEON2 SPARC CPU
209 /leon3 Files specific to Gaisler LEON3 SPARC CPU
210 /lib Architecture specific library files
211 /api Machine/arch independent API for external apps
212 /board Board dependent files
213 /common Misc architecture independent functions
214 /disk Code for disk drive partition handling
215 /doc Documentation (don't expect too much)
216 /drivers Commonly used device drivers
217 /examples Example code for standalone applications, etc.
218 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
219 /include Header Files
220 /lib Files generic to all architectures
221 /libfdt Library files to support flattened device trees
222 /lzma Library files to support LZMA decompression
223 /lzo Library files to support LZO decompression
225 /post Power On Self Test
226 /rtc Real Time Clock drivers
227 /tools Tools to build S-Record or U-Boot images, etc.
229 Software Configuration:
230 =======================
232 Configuration is usually done using C preprocessor defines; the
233 rationale behind that is to avoid dead code whenever possible.
235 There are two classes of configuration variables:
237 * Configuration _OPTIONS_:
238 These are selectable by the user and have names beginning with
241 * Configuration _SETTINGS_:
242 These depend on the hardware etc. and should not be meddled with if
243 you don't know what you're doing; they have names beginning with
246 Later we will add a configuration tool - probably similar to or even
247 identical to what's used for the Linux kernel. Right now, we have to
248 do the configuration by hand, which means creating some symbolic
249 links and editing some configuration files. We use the TQM8xxL boards
253 Selection of Processor Architecture and Board Type:
254 ---------------------------------------------------
256 For all supported boards there are ready-to-use default
257 configurations available; just type "make <board_name>_config".
259 Example: For a TQM823L module type:
264 For the Cogent platform, you need to specify the CPU type as well;
265 e.g. "make cogent_mpc8xx_config". And also configure the cogent
266 directory according to the instructions in cogent/README.
269 Configuration Options:
270 ----------------------
272 Configuration depends on the combination of board and CPU type; all
273 such information is kept in a configuration file
274 "include/configs/<board_name>.h".
276 Example: For a TQM823L module, all configuration settings are in
277 "include/configs/TQM823L.h".
280 Many of the options are named exactly as the corresponding Linux
281 kernel configuration options. The intention is to make it easier to
282 build a config tool - later.
285 The following options need to be configured:
287 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
289 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
291 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
292 Define exactly one, e.g. CONFIG_ATSTK1002
294 - CPU Module Type: (if CONFIG_COGENT is defined)
295 Define exactly one of
297 --- FIXME --- not tested yet:
298 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
299 CONFIG_CMA287_23, CONFIG_CMA287_50
301 - Motherboard Type: (if CONFIG_COGENT is defined)
302 Define exactly one of
303 CONFIG_CMA101, CONFIG_CMA102
305 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
306 Define one or more of
309 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
310 Define one or more of
311 CONFIG_LCD_HEARTBEAT - update a character position on
312 the LCD display every second with
315 - Board flavour: (if CONFIG_MPC8260ADS is defined)
318 CONFIG_SYS_8260ADS - original MPC8260ADS
319 CONFIG_SYS_8266ADS - MPC8266ADS
320 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
321 CONFIG_SYS_8272ADS - MPC8272ADS
323 - Marvell Family Member
324 CONFIG_SYS_MVFS - define it if you want to enable
325 multiple fs option at one time
326 for marvell soc family
328 - MPC824X Family Member (if CONFIG_MPC824X is defined)
329 Define exactly one of
330 CONFIG_MPC8240, CONFIG_MPC8245
332 - 8xx CPU Options: (if using an MPC8xx CPU)
333 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
334 get_gclk_freq() cannot work
335 e.g. if there is no 32KHz
336 reference PIT/RTC clock
337 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
340 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
341 CONFIG_SYS_8xx_CPUCLK_MIN
342 CONFIG_SYS_8xx_CPUCLK_MAX
343 CONFIG_8xx_CPUCLK_DEFAULT
344 See doc/README.MPC866
346 CONFIG_SYS_MEASURE_CPUCLK
348 Define this to measure the actual CPU clock instead
349 of relying on the correctness of the configured
350 values. Mostly useful for board bringup to make sure
351 the PLL is locked at the intended frequency. Note
352 that this requires a (stable) reference clock (32 kHz
353 RTC clock or CONFIG_SYS_8XX_XIN)
355 CONFIG_SYS_DELAYED_ICACHE
357 Define this option if you want to enable the
358 ICache only when Code runs from RAM.
361 CONFIG_SYS_FSL_TBCLK_DIV
363 Defines the core time base clock divider ratio compared to the
364 system clock. On most PQ3 devices this is 8, on newer QorIQ
365 devices it can be 16 or 32. The ratio varies from SoC to Soc.
367 CONFIG_SYS_FSL_PCIE_COMPAT
369 Defines the string to utilize when trying to match PCIe device
370 tree nodes for the given platform.
372 - Intel Monahans options:
373 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
375 Defines the Monahans run mode to oscillator
376 ratio. Valid values are 8, 16, 24, 31. The core
377 frequency is this value multiplied by 13 MHz.
379 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
381 Defines the Monahans turbo mode to oscillator
382 ratio. Valid values are 1 (default if undefined) and
383 2. The core frequency as calculated above is multiplied
387 CONFIG_SYS_INIT_SP_OFFSET
389 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
390 pointer. This is needed for the temporary stack before
393 CONFIG_SYS_MIPS_CACHE_MODE
395 Cache operation mode for the MIPS CPU.
396 See also arch/mips/include/asm/mipsregs.h.
398 CONF_CM_CACHABLE_NO_WA
401 CONF_CM_CACHABLE_NONCOHERENT
405 CONF_CM_CACHABLE_ACCELERATED
407 CONFIG_SYS_XWAY_EBU_BOOTCFG
409 Special option for Lantiq XWAY SoCs for booting from NOR flash.
410 See also arch/mips/cpu/mips32/start.S.
412 CONFIG_XWAY_SWAP_BYTES
414 Enable compilation of tools/xway-swap-bytes needed for Lantiq
415 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
416 be swapped if a flash programmer is used.
418 - Linux Kernel Interface:
421 U-Boot stores all clock information in Hz
422 internally. For binary compatibility with older Linux
423 kernels (which expect the clocks passed in the
424 bd_info data to be in MHz) the environment variable
425 "clocks_in_mhz" can be defined so that U-Boot
426 converts clock data to MHZ before passing it to the
428 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
429 "clocks_in_mhz=1" is automatically included in the
432 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
434 When transferring memsize parameter to linux, some versions
435 expect it to be in bytes, others in MB.
436 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
440 New kernel versions are expecting firmware settings to be
441 passed using flattened device trees (based on open firmware
445 * New libfdt-based support
446 * Adds the "fdt" command
447 * The bootm command automatically updates the fdt
449 OF_CPU - The proper name of the cpus node (only required for
450 MPC512X and MPC5xxx based boards).
451 OF_SOC - The proper name of the soc node (only required for
452 MPC512X and MPC5xxx based boards).
453 OF_TBCLK - The timebase frequency.
454 OF_STDOUT_PATH - The path to the console device
456 boards with QUICC Engines require OF_QE to set UCC MAC
459 CONFIG_OF_BOARD_SETUP
461 Board code has addition modification that it wants to make
462 to the flat device tree before handing it off to the kernel
466 This define fills in the correct boot CPU in the boot
467 param header, the default value is zero if undefined.
471 U-Boot can detect if an IDE device is present or not.
472 If not, and this new config option is activated, U-Boot
473 removes the ATA node from the DTS before booting Linux,
474 so the Linux IDE driver does not probe the device and
475 crash. This is needed for buggy hardware (uc101) where
476 no pull down resistor is connected to the signal IDE5V_DD7.
478 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
480 This setting is mandatory for all boards that have only one
481 machine type and must be used to specify the machine type
482 number as it appears in the ARM machine registry
483 (see http://www.arm.linux.org.uk/developer/machines/).
484 Only boards that have multiple machine types supported
485 in a single configuration file and the machine type is
486 runtime discoverable, do not have to use this setting.
488 - vxWorks boot parameters:
490 bootvx constructs a valid bootline using the following
491 environments variables: bootfile, ipaddr, serverip, hostname.
492 It loads the vxWorks image pointed bootfile.
494 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
495 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
496 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
497 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
499 CONFIG_SYS_VXWORKS_ADD_PARAMS
501 Add it at the end of the bootline. E.g "u=username pw=secret"
503 Note: If a "bootargs" environment is defined, it will overwride
504 the defaults discussed just above.
506 - Cache Configuration:
507 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
508 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
509 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
511 - Cache Configuration for ARM:
512 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
514 CONFIG_SYS_PL310_BASE - Physical base address of PL310
515 controller register space
520 Define this if you want support for Amba PrimeCell PL010 UARTs.
524 Define this if you want support for Amba PrimeCell PL011 UARTs.
528 If you have Amba PrimeCell PL011 UARTs, set this variable to
529 the clock speed of the UARTs.
533 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
534 define this to a list of base addresses for each (supported)
535 port. See e.g. include/configs/versatile.h
537 CONFIG_PL011_SERIAL_RLCR
539 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
540 have separate receive and transmit line control registers. Set
541 this variable to initialize the extra register.
543 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
545 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
546 boot loader that has already initialized the UART. Define this
547 variable to flush the UART at init time.
551 Depending on board, define exactly one serial port
552 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
553 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
554 console by defining CONFIG_8xx_CONS_NONE
556 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
557 port routines must be defined elsewhere
558 (i.e. serial_init(), serial_getc(), ...)
561 Enables console device for a color framebuffer. Needs following
562 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
563 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
565 VIDEO_HW_RECTFILL graphic chip supports
568 VIDEO_HW_BITBLT graphic chip supports
569 bit-blit (cf. smiLynxEM)
570 VIDEO_VISIBLE_COLS visible pixel columns
572 VIDEO_VISIBLE_ROWS visible pixel rows
573 VIDEO_PIXEL_SIZE bytes per pixel
574 VIDEO_DATA_FORMAT graphic data format
575 (0-5, cf. cfb_console.c)
576 VIDEO_FB_ADRS framebuffer address
577 VIDEO_KBD_INIT_FCT keyboard int fct
578 (i.e. i8042_kbd_init())
579 VIDEO_TSTC_FCT test char fct
581 VIDEO_GETC_FCT get char fct
583 CONFIG_CONSOLE_CURSOR cursor drawing on/off
584 (requires blink timer
586 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
587 CONFIG_CONSOLE_TIME display time/date info in
589 (requires CONFIG_CMD_DATE)
590 CONFIG_VIDEO_LOGO display Linux logo in
592 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
593 linux_logo.h for logo.
594 Requires CONFIG_VIDEO_LOGO
595 CONFIG_CONSOLE_EXTRA_INFO
596 additional board info beside
599 When CONFIG_CFB_CONSOLE is defined, video console is
600 default i/o. Serial console can be forced with
601 environment 'console=serial'.
603 When CONFIG_SILENT_CONSOLE is defined, all console
604 messages (by U-Boot and Linux!) can be silenced with
605 the "silent" environment variable. See
606 doc/README.silent for more information.
609 CONFIG_BAUDRATE - in bps
610 Select one of the baudrates listed in
611 CONFIG_SYS_BAUDRATE_TABLE, see below.
612 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
614 - Console Rx buffer length
615 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
616 the maximum receive buffer length for the SMC.
617 This option is actual only for 82xx and 8xx possible.
618 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
619 must be defined, to setup the maximum idle timeout for
622 - Boot Delay: CONFIG_BOOTDELAY - in seconds
623 Delay before automatically booting the default image;
624 set to -1 to disable autoboot.
626 See doc/README.autoboot for these options that
627 work with CONFIG_BOOTDELAY. None are required.
628 CONFIG_BOOT_RETRY_TIME
629 CONFIG_BOOT_RETRY_MIN
630 CONFIG_AUTOBOOT_KEYED
631 CONFIG_AUTOBOOT_PROMPT
632 CONFIG_AUTOBOOT_DELAY_STR
633 CONFIG_AUTOBOOT_STOP_STR
634 CONFIG_AUTOBOOT_DELAY_STR2
635 CONFIG_AUTOBOOT_STOP_STR2
636 CONFIG_ZERO_BOOTDELAY_CHECK
637 CONFIG_RESET_TO_RETRY
641 Only needed when CONFIG_BOOTDELAY is enabled;
642 define a command string that is automatically executed
643 when no character is read on the console interface
644 within "Boot Delay" after reset.
647 This can be used to pass arguments to the bootm
648 command. The value of CONFIG_BOOTARGS goes into the
649 environment value "bootargs".
651 CONFIG_RAMBOOT and CONFIG_NFSBOOT
652 The value of these goes into the environment as
653 "ramboot" and "nfsboot" respectively, and can be used
654 as a convenience, when switching between booting from
660 When this option is #defined, the existence of the
661 environment variable "preboot" will be checked
662 immediately before starting the CONFIG_BOOTDELAY
663 countdown and/or running the auto-boot command resp.
664 entering interactive mode.
666 This feature is especially useful when "preboot" is
667 automatically generated or modified. For an example
668 see the LWMON board specific code: here "preboot" is
669 modified when the user holds down a certain
670 combination of keys on the (special) keyboard when
673 - Serial Download Echo Mode:
675 If defined to 1, all characters received during a
676 serial download (using the "loads" command) are
677 echoed back. This might be needed by some terminal
678 emulations (like "cu"), but may as well just take
679 time on others. This setting #define's the initial
680 value of the "loads_echo" environment variable.
682 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
684 Select one of the baudrates listed in
685 CONFIG_SYS_BAUDRATE_TABLE, see below.
688 Monitor commands can be included or excluded
689 from the build by using the #include files
690 "config_cmd_all.h" and #undef'ing unwanted
691 commands, or using "config_cmd_default.h"
692 and augmenting with additional #define's
695 The default command configuration includes all commands
696 except those marked below with a "*".
698 CONFIG_CMD_ASKENV * ask for env variable
699 CONFIG_CMD_BDI bdinfo
700 CONFIG_CMD_BEDBUG * Include BedBug Debugger
701 CONFIG_CMD_BMP * BMP support
702 CONFIG_CMD_BSP * Board specific commands
703 CONFIG_CMD_BOOTD bootd
704 CONFIG_CMD_CACHE * icache, dcache
705 CONFIG_CMD_CONSOLE coninfo
706 CONFIG_CMD_CRC32 * crc32
707 CONFIG_CMD_DATE * support for RTC, date/time...
708 CONFIG_CMD_DHCP * DHCP support
709 CONFIG_CMD_DIAG * Diagnostics
710 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
711 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
712 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
713 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
714 CONFIG_CMD_DTT * Digital Therm and Thermostat
715 CONFIG_CMD_ECHO echo arguments
716 CONFIG_CMD_EDITENV edit env variable
717 CONFIG_CMD_EEPROM * EEPROM read/write support
718 CONFIG_CMD_ELF * bootelf, bootvx
719 CONFIG_CMD_EXPORTENV * export the environment
720 CONFIG_CMD_SAVEENV saveenv
721 CONFIG_CMD_FDC * Floppy Disk Support
722 CONFIG_CMD_FAT * FAT partition support
723 CONFIG_CMD_FDOS * Dos diskette Support
724 CONFIG_CMD_FLASH flinfo, erase, protect
725 CONFIG_CMD_FPGA FPGA device initialization support
726 CONFIG_CMD_GO * the 'go' command (exec code)
727 CONFIG_CMD_GREPENV * search environment
728 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
729 CONFIG_CMD_I2C * I2C serial bus support
730 CONFIG_CMD_IDE * IDE harddisk support
731 CONFIG_CMD_IMI iminfo
732 CONFIG_CMD_IMLS List all found images
733 CONFIG_CMD_IMMAP * IMMR dump support
734 CONFIG_CMD_IMPORTENV * import an environment
735 CONFIG_CMD_IRQ * irqinfo
736 CONFIG_CMD_ITEST Integer/string test of 2 values
737 CONFIG_CMD_JFFS2 * JFFS2 Support
738 CONFIG_CMD_KGDB * kgdb
739 CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
740 CONFIG_CMD_LOADB loadb
741 CONFIG_CMD_LOADS loads
742 CONFIG_CMD_MD5SUM print md5 message digest
743 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
744 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
746 CONFIG_CMD_MISC Misc functions like sleep etc
747 CONFIG_CMD_MMC * MMC memory mapped support
748 CONFIG_CMD_MII * MII utility commands
749 CONFIG_CMD_MTDPARTS * MTD partition support
750 CONFIG_CMD_NAND * NAND support
751 CONFIG_CMD_NET bootp, tftpboot, rarpboot
752 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
753 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
754 CONFIG_CMD_PCI * pciinfo
755 CONFIG_CMD_PCMCIA * PCMCIA support
756 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
758 CONFIG_CMD_PORTIO * Port I/O
759 CONFIG_CMD_REGINFO * Register dump
760 CONFIG_CMD_RUN run command in env variable
761 CONFIG_CMD_SAVES * save S record dump
762 CONFIG_CMD_SCSI * SCSI Support
763 CONFIG_CMD_SDRAM * print SDRAM configuration information
764 (requires CONFIG_CMD_I2C)
765 CONFIG_CMD_SETGETDCR Support for DCR Register access
767 CONFIG_CMD_SHA1SUM print sha1 memory digest
768 (requires CONFIG_CMD_MEMORY)
769 CONFIG_CMD_SOURCE "source" command Support
770 CONFIG_CMD_SPI * SPI serial bus support
771 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
772 CONFIG_CMD_USB * USB support
773 CONFIG_CMD_CDP * Cisco Discover Protocol support
774 CONFIG_CMD_FSL * Microblaze FSL support
777 EXAMPLE: If you want all functions except of network
778 support you can write:
780 #include "config_cmd_all.h"
781 #undef CONFIG_CMD_NET
784 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
786 Note: Don't enable the "icache" and "dcache" commands
787 (configuration option CONFIG_CMD_CACHE) unless you know
788 what you (and your U-Boot users) are doing. Data
789 cache cannot be enabled on systems like the 8xx or
790 8260 (where accesses to the IMMR region must be
791 uncached), and it cannot be disabled on all other
792 systems where we (mis-) use the data cache to hold an
793 initial stack and some data.
796 XXX - this list needs to get updated!
800 If this variable is defined, it enables watchdog
801 support for the SoC. There must be support in the SoC
802 specific code for a watchdog. For the 8xx and 8260
803 CPUs, the SIU Watchdog feature is enabled in the SYPCR
804 register. When supported for a specific SoC is
805 available, then no further board specific code should
809 When using a watchdog circuitry external to the used
810 SoC, then define this variable and provide board
811 specific code for the "hw_watchdog_reset" function.
814 CONFIG_VERSION_VARIABLE
815 If this variable is defined, an environment variable
816 named "ver" is created by U-Boot showing the U-Boot
817 version as printed by the "version" command.
818 This variable is readonly.
822 When CONFIG_CMD_DATE is selected, the type of the RTC
823 has to be selected, too. Define exactly one of the
826 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
827 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
828 CONFIG_RTC_MC13783 - use MC13783 RTC
829 CONFIG_RTC_MC146818 - use MC146818 RTC
830 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
831 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
832 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
833 CONFIG_RTC_DS164x - use Dallas DS164x RTC
834 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
835 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
836 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
837 CONFIG_SYS_RV3029_TCR - enable trickle charger on
840 Note that if the RTC uses I2C, then the I2C interface
841 must also be configured. See I2C Support, below.
844 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
845 CONFIG_PCA953X_INFO - enable pca953x info command
847 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
848 chip-ngpio pairs that tell the PCA953X driver the number of
849 pins supported by a particular chip.
851 Note that if the GPIO device uses I2C, then the I2C interface
852 must also be configured. See I2C Support, below.
856 When CONFIG_TIMESTAMP is selected, the timestamp
857 (date and time) of an image is printed by image
858 commands like bootm or iminfo. This option is
859 automatically enabled when you select CONFIG_CMD_DATE .
862 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
863 and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION
865 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
866 CONFIG_CMD_SCSI) you must configure support for at
867 least one partition type as well.
870 CONFIG_IDE_RESET_ROUTINE - this is defined in several
871 board configurations files but used nowhere!
873 CONFIG_IDE_RESET - is this is defined, IDE Reset will
874 be performed by calling the function
875 ide_set_reset(int reset)
876 which has to be defined in a board specific file
881 Set this to enable ATAPI support.
886 Set this to enable support for disks larger than 137GB
887 Also look at CONFIG_SYS_64BIT_LBA.
888 Whithout these , LBA48 support uses 32bit variables and will 'only'
889 support disks up to 2.1TB.
891 CONFIG_SYS_64BIT_LBA:
892 When enabled, makes the IDE subsystem use 64bit sector addresses.
896 At the moment only there is only support for the
897 SYM53C8XX SCSI controller; define
898 CONFIG_SCSI_SYM53C8XX to enable it.
900 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
901 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
902 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
903 maximum numbers of LUNs, SCSI ID's and target
905 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
907 - NETWORK Support (PCI):
909 Support for Intel 8254x gigabit chips.
911 CONFIG_E1000_FALLBACK_MAC
912 default MAC for empty EEPROM after production.
915 Support for Intel 82557/82559/82559ER chips.
916 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
917 write routine for first time initialisation.
920 Support for Digital 2114x chips.
921 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
922 modem chip initialisation (KS8761/QS6611).
925 Support for National dp83815 chips.
928 Support for National dp8382[01] gigabit chips.
930 - NETWORK Support (other):
932 CONFIG_DRIVER_AT91EMAC
933 Support for AT91RM9200 EMAC.
936 Define this to use reduced MII inteface
938 CONFIG_DRIVER_AT91EMAC_QUIET
939 If this defined, the driver is quiet.
940 The driver doen't show link status messages.
942 CONFIG_DRIVER_LAN91C96
943 Support for SMSC's LAN91C96 chips.
946 Define this to hold the physical address
947 of the LAN91C96's I/O space
949 CONFIG_LAN91C96_USE_32_BIT
950 Define this to enable 32 bit addressing
952 CONFIG_DRIVER_SMC91111
953 Support for SMSC's LAN91C111 chip
956 Define this to hold the physical address
957 of the device (I/O space)
959 CONFIG_SMC_USE_32_BIT
960 Define this if data bus is 32 bits
962 CONFIG_SMC_USE_IOFUNCS
963 Define this to use i/o functions instead of macros
964 (some hardware wont work with macros)
967 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
969 CONFIG_FTGMAC100_EGIGA
970 Define this to use GE link update with gigabit PHY.
971 Define this if FTGMAC100 is connected to gigabit PHY.
972 If your system has 10/100 PHY only, it might not occur
973 wrong behavior. Because PHY usually return timeout or
974 useless data when polling gigabit status and gigabit
975 control registers. This behavior won't affect the
976 correctnessof 10/100 link speed update.
979 Support for SMSC's LAN911x and LAN921x chips
982 Define this to hold the physical address
983 of the device (I/O space)
985 CONFIG_SMC911X_32_BIT
986 Define this if data bus is 32 bits
988 CONFIG_SMC911X_16_BIT
989 Define this if data bus is 16 bits. If your processor
990 automatically converts one 32 bit word to two 16 bit
991 words you may also try CONFIG_SMC911X_32_BIT.
994 Support for Renesas on-chip Ethernet controller
996 CONFIG_SH_ETHER_USE_PORT
997 Define the number of ports to be used
999 CONFIG_SH_ETHER_PHY_ADDR
1000 Define the ETH PHY's address
1002 CONFIG_SH_ETHER_CACHE_WRITEBACK
1003 If this option is set, the driver enables cache flush.
1006 At the moment only the UHCI host controller is
1007 supported (PIP405, MIP405, MPC5200); define
1008 CONFIG_USB_UHCI to enable it.
1009 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1010 and define CONFIG_USB_STORAGE to enable the USB
1013 Supported are USB Keyboards and USB Floppy drives
1015 MPC5200 USB requires additional defines:
1017 for 528 MHz Clock: 0x0001bbbb
1021 for differential drivers: 0x00001000
1022 for single ended drivers: 0x00005000
1023 for differential drivers on PSC3: 0x00000100
1024 for single ended drivers on PSC3: 0x00004100
1025 CONFIG_SYS_USB_EVENT_POLL
1026 May be defined to allow interrupt polling
1027 instead of using asynchronous interrupts
1030 Define the below if you wish to use the USB console.
1031 Once firmware is rebuilt from a serial console issue the
1032 command "setenv stdin usbtty; setenv stdout usbtty" and
1033 attach your USB cable. The Unix command "dmesg" should print
1034 it has found a new device. The environment variable usbtty
1035 can be set to gserial or cdc_acm to enable your device to
1036 appear to a USB host as a Linux gserial device or a
1037 Common Device Class Abstract Control Model serial device.
1038 If you select usbtty = gserial you should be able to enumerate
1040 # modprobe usbserial vendor=0xVendorID product=0xProductID
1041 else if using cdc_acm, simply setting the environment
1042 variable usbtty to be cdc_acm should suffice. The following
1043 might be defined in YourBoardName.h
1046 Define this to build a UDC device
1049 Define this to have a tty type of device available to
1050 talk to the UDC device
1052 CONFIG_SYS_CONSOLE_IS_IN_ENV
1053 Define this if you want stdin, stdout &/or stderr to
1057 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1058 Derive USB clock from external clock "blah"
1059 - CONFIG_SYS_USB_EXTC_CLK 0x02
1061 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1062 Derive USB clock from brgclk
1063 - CONFIG_SYS_USB_BRG_CLK 0x04
1065 If you have a USB-IF assigned VendorID then you may wish to
1066 define your own vendor specific values either in BoardName.h
1067 or directly in usbd_vendor_info.h. If you don't define
1068 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1069 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1070 should pretend to be a Linux device to it's target host.
1072 CONFIG_USBD_MANUFACTURER
1073 Define this string as the name of your company for
1074 - CONFIG_USBD_MANUFACTURER "my company"
1076 CONFIG_USBD_PRODUCT_NAME
1077 Define this string as the name of your product
1078 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1080 CONFIG_USBD_VENDORID
1081 Define this as your assigned Vendor ID from the USB
1082 Implementors Forum. This *must* be a genuine Vendor ID
1083 to avoid polluting the USB namespace.
1084 - CONFIG_USBD_VENDORID 0xFFFF
1086 CONFIG_USBD_PRODUCTID
1087 Define this as the unique Product ID
1089 - CONFIG_USBD_PRODUCTID 0xFFFF
1093 The MMC controller on the Intel PXA is supported. To
1094 enable this define CONFIG_MMC. The MMC can be
1095 accessed from the boot prompt by mapping the device
1096 to physical memory similar to flash. Command line is
1097 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1098 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1101 Support for Renesas on-chip MMCIF controller
1103 CONFIG_SH_MMCIF_ADDR
1104 Define the base address of MMCIF registers
1107 Define the clock frequency for MMCIF
1109 - Journaling Flash filesystem support:
1110 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1111 CONFIG_JFFS2_NAND_DEV
1112 Define these for a default partition on a NAND device
1114 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1115 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1116 Define these for a default partition on a NOR device
1118 CONFIG_SYS_JFFS_CUSTOM_PART
1119 Define this to create an own partition. You have to provide a
1120 function struct part_info* jffs2_part_info(int part_num)
1122 If you define only one JFFS2 partition you may also want to
1123 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1124 to disable the command chpart. This is the default when you
1125 have not defined a custom partition
1130 Define this to enable standard (PC-Style) keyboard
1134 Standard PC keyboard driver with US (is default) and
1135 GERMAN key layout (switch via environment 'keymap=de') support.
1136 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1137 for cfb_console. Supports cursor blinking.
1142 Define this to enable video support (for output to
1145 CONFIG_VIDEO_CT69000
1147 Enable Chips & Technologies 69000 Video chip
1149 CONFIG_VIDEO_SMI_LYNXEM
1150 Enable Silicon Motion SMI 712/710/810 Video chip. The
1151 video output is selected via environment 'videoout'
1152 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1155 For the CT69000 and SMI_LYNXEM drivers, videomode is
1156 selected via environment 'videomode'. Two different ways
1158 - "videomode=num" 'num' is a standard LiLo mode numbers.
1159 Following standard modes are supported (* is default):
1161 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1162 -------------+---------------------------------------------
1163 8 bits | 0x301* 0x303 0x305 0x161 0x307
1164 15 bits | 0x310 0x313 0x316 0x162 0x319
1165 16 bits | 0x311 0x314 0x317 0x163 0x31A
1166 24 bits | 0x312 0x315 0x318 ? 0x31B
1167 -------------+---------------------------------------------
1168 (i.e. setenv videomode 317; saveenv; reset;)
1170 - "videomode=bootargs" all the video parameters are parsed
1171 from the bootargs. (See drivers/video/videomodes.c)
1174 CONFIG_VIDEO_SED13806
1175 Enable Epson SED13806 driver. This driver supports 8bpp
1176 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1177 or CONFIG_VIDEO_SED13806_16BPP
1180 Enable the Freescale DIU video driver. Reference boards for
1181 SOCs that have a DIU should define this macro to enable DIU
1182 support, and should also define these other macros:
1188 CONFIG_VIDEO_SW_CURSOR
1189 CONFIG_VGA_AS_SINGLE_DEVICE
1191 CONFIG_VIDEO_BMP_LOGO
1193 The DIU driver will look for the 'video-mode' environment
1194 variable, and if defined, enable the DIU as a console during
1195 boot. See the documentation file README.video for a
1196 description of this variable.
1201 Define this to enable a custom keyboard support.
1202 This simply calls drv_keyboard_init() which must be
1203 defined in your board-specific files.
1204 The only board using this so far is RBC823.
1206 - LCD Support: CONFIG_LCD
1208 Define this to enable LCD support (for output to LCD
1209 display); also select one of the supported displays
1210 by defining one of these:
1214 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1216 CONFIG_NEC_NL6448AC33:
1218 NEC NL6448AC33-18. Active, color, single scan.
1220 CONFIG_NEC_NL6448BC20
1222 NEC NL6448BC20-08. 6.5", 640x480.
1223 Active, color, single scan.
1225 CONFIG_NEC_NL6448BC33_54
1227 NEC NL6448BC33-54. 10.4", 640x480.
1228 Active, color, single scan.
1232 Sharp 320x240. Active, color, single scan.
1233 It isn't 16x9, and I am not sure what it is.
1235 CONFIG_SHARP_LQ64D341
1237 Sharp LQ64D341 display, 640x480.
1238 Active, color, single scan.
1242 HLD1045 display, 640x480.
1243 Active, color, single scan.
1247 Optrex CBL50840-2 NF-FW 99 22 M5
1249 Hitachi LMG6912RPFC-00T
1253 320x240. Black & white.
1255 Normally display is black on white background; define
1256 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1258 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1260 If this option is set, the environment is checked for
1261 a variable "splashimage". If found, the usual display
1262 of logo, copyright and system information on the LCD
1263 is suppressed and the BMP image at the address
1264 specified in "splashimage" is loaded instead. The
1265 console is redirected to the "nulldev", too. This
1266 allows for a "silent" boot where a splash screen is
1267 loaded very quickly after power-on.
1269 CONFIG_SPLASH_SCREEN_ALIGN
1271 If this option is set the splash image can be freely positioned
1272 on the screen. Environment variable "splashpos" specifies the
1273 position as "x,y". If a positive number is given it is used as
1274 number of pixel from left/top. If a negative number is given it
1275 is used as number of pixel from right/bottom. You can also
1276 specify 'm' for centering the image.
1279 setenv splashpos m,m
1280 => image at center of screen
1282 setenv splashpos 30,20
1283 => image at x = 30 and y = 20
1285 setenv splashpos -10,m
1286 => vertically centered image
1287 at x = dspWidth - bmpWidth - 9
1289 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1291 If this option is set, additionally to standard BMP
1292 images, gzipped BMP images can be displayed via the
1293 splashscreen support or the bmp command.
1295 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1297 If this option is set, 8-bit RLE compressed BMP images
1298 can be displayed via the splashscreen support or the
1301 - Compression support:
1304 If this option is set, support for bzip2 compressed
1305 images is included. If not, only uncompressed and gzip
1306 compressed images are supported.
1308 NOTE: the bzip2 algorithm requires a lot of RAM, so
1309 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1314 If this option is set, support for lzma compressed
1317 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1318 requires an amount of dynamic memory that is given by the
1321 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1323 Where lc and lp stand for, respectively, Literal context bits
1324 and Literal pos bits.
1326 This value is upper-bounded by 14MB in the worst case. Anyway,
1327 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1328 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1329 a very small buffer.
1331 Use the lzmainfo tool to determinate the lc and lp values and
1332 then calculate the amount of needed dynamic memory (ensuring
1333 the appropriate CONFIG_SYS_MALLOC_LEN value).
1338 The address of PHY on MII bus.
1340 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1342 The clock frequency of the MII bus
1346 If this option is set, support for speed/duplex
1347 detection of gigabit PHY is included.
1349 CONFIG_PHY_RESET_DELAY
1351 Some PHY like Intel LXT971A need extra delay after
1352 reset before any MII register access is possible.
1353 For such PHY, set this option to the usec delay
1354 required. (minimum 300usec for LXT971A)
1356 CONFIG_PHY_CMD_DELAY (ppc4xx)
1358 Some PHY like Intel LXT971A need extra delay after
1359 command issued before MII status register can be read
1369 Define a default value for Ethernet address to use
1370 for the respective Ethernet interface, in case this
1371 is not determined automatically.
1376 Define a default value for the IP address to use for
1377 the default Ethernet interface, in case this is not
1378 determined through e.g. bootp.
1380 - Server IP address:
1383 Defines a default value for the IP address of a TFTP
1384 server to contact when using the "tftboot" command.
1386 CONFIG_KEEP_SERVERADDR
1388 Keeps the server's MAC address, in the env 'serveraddr'
1389 for passing to bootargs (like Linux's netconsole option)
1391 - Multicast TFTP Mode:
1394 Defines whether you want to support multicast TFTP as per
1395 rfc-2090; for example to work with atftp. Lets lots of targets
1396 tftp down the same boot image concurrently. Note: the Ethernet
1397 driver in use must provide a function: mcast() to join/leave a
1400 - BOOTP Recovery Mode:
1401 CONFIG_BOOTP_RANDOM_DELAY
1403 If you have many targets in a network that try to
1404 boot using BOOTP, you may want to avoid that all
1405 systems send out BOOTP requests at precisely the same
1406 moment (which would happen for instance at recovery
1407 from a power failure, when all systems will try to
1408 boot, thus flooding the BOOTP server. Defining
1409 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1410 inserted before sending out BOOTP requests. The
1411 following delays are inserted then:
1413 1st BOOTP request: delay 0 ... 1 sec
1414 2nd BOOTP request: delay 0 ... 2 sec
1415 3rd BOOTP request: delay 0 ... 4 sec
1417 BOOTP requests: delay 0 ... 8 sec
1419 - DHCP Advanced Options:
1420 You can fine tune the DHCP functionality by defining
1421 CONFIG_BOOTP_* symbols:
1423 CONFIG_BOOTP_SUBNETMASK
1424 CONFIG_BOOTP_GATEWAY
1425 CONFIG_BOOTP_HOSTNAME
1426 CONFIG_BOOTP_NISDOMAIN
1427 CONFIG_BOOTP_BOOTPATH
1428 CONFIG_BOOTP_BOOTFILESIZE
1431 CONFIG_BOOTP_SEND_HOSTNAME
1432 CONFIG_BOOTP_NTPSERVER
1433 CONFIG_BOOTP_TIMEOFFSET
1434 CONFIG_BOOTP_VENDOREX
1436 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1437 environment variable, not the BOOTP server.
1439 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1440 serverip from a DHCP server, it is possible that more
1441 than one DNS serverip is offered to the client.
1442 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1443 serverip will be stored in the additional environment
1444 variable "dnsip2". The first DNS serverip is always
1445 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1448 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1449 to do a dynamic update of a DNS server. To do this, they
1450 need the hostname of the DHCP requester.
1451 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1452 of the "hostname" environment variable is passed as
1453 option 12 to the DHCP server.
1455 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1457 A 32bit value in microseconds for a delay between
1458 receiving a "DHCP Offer" and sending the "DHCP Request".
1459 This fixes a problem with certain DHCP servers that don't
1460 respond 100% of the time to a "DHCP request". E.g. On an
1461 AT91RM9200 processor running at 180MHz, this delay needed
1462 to be *at least* 15,000 usec before a Windows Server 2003
1463 DHCP server would reply 100% of the time. I recommend at
1464 least 50,000 usec to be safe. The alternative is to hope
1465 that one of the retries will be successful but note that
1466 the DHCP timeout and retry process takes a longer than
1470 CONFIG_CDP_DEVICE_ID
1472 The device id used in CDP trigger frames.
1474 CONFIG_CDP_DEVICE_ID_PREFIX
1476 A two character string which is prefixed to the MAC address
1481 A printf format string which contains the ascii name of
1482 the port. Normally is set to "eth%d" which sets
1483 eth0 for the first Ethernet, eth1 for the second etc.
1485 CONFIG_CDP_CAPABILITIES
1487 A 32bit integer which indicates the device capabilities;
1488 0x00000010 for a normal host which does not forwards.
1492 An ascii string containing the version of the software.
1496 An ascii string containing the name of the platform.
1500 A 32bit integer sent on the trigger.
1502 CONFIG_CDP_POWER_CONSUMPTION
1504 A 16bit integer containing the power consumption of the
1505 device in .1 of milliwatts.
1507 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1509 A byte containing the id of the VLAN.
1511 - Status LED: CONFIG_STATUS_LED
1513 Several configurations allow to display the current
1514 status using a LED. For instance, the LED will blink
1515 fast while running U-Boot code, stop blinking as
1516 soon as a reply to a BOOTP request was received, and
1517 start blinking slow once the Linux kernel is running
1518 (supported by a status LED driver in the Linux
1519 kernel). Defining CONFIG_STATUS_LED enables this
1522 - CAN Support: CONFIG_CAN_DRIVER
1524 Defining CONFIG_CAN_DRIVER enables CAN driver support
1525 on those systems that support this (optional)
1526 feature, like the TQM8xxL modules.
1528 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1530 These enable I2C serial bus commands. Defining either of
1531 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1532 include the appropriate I2C driver for the selected CPU.
1534 This will allow you to use i2c commands at the u-boot
1535 command line (as long as you set CONFIG_CMD_I2C in
1536 CONFIG_COMMANDS) and communicate with i2c based realtime
1537 clock chips. See common/cmd_i2c.c for a description of the
1538 command line interface.
1540 CONFIG_HARD_I2C selects a hardware I2C controller.
1542 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1543 bit-banging) driver instead of CPM or similar hardware
1546 There are several other quantities that must also be
1547 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1549 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1550 to be the frequency (in Hz) at which you wish your i2c bus
1551 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1552 the CPU's i2c node address).
1554 Now, the u-boot i2c code for the mpc8xx
1555 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1556 and so its address should therefore be cleared to 0 (See,
1557 eg, MPC823e User's Manual p.16-473). So, set
1558 CONFIG_SYS_I2C_SLAVE to 0.
1560 CONFIG_SYS_I2C_INIT_MPC5XXX
1562 When a board is reset during an i2c bus transfer
1563 chips might think that the current transfer is still
1564 in progress. Reset the slave devices by sending start
1565 commands until the slave device responds.
1567 That's all that's required for CONFIG_HARD_I2C.
1569 If you use the software i2c interface (CONFIG_SOFT_I2C)
1570 then the following macros need to be defined (examples are
1571 from include/configs/lwmon.h):
1575 (Optional). Any commands necessary to enable the I2C
1576 controller or configure ports.
1578 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1582 (Only for MPC8260 CPU). The I/O port to use (the code
1583 assumes both bits are on the same port). Valid values
1584 are 0..3 for ports A..D.
1588 The code necessary to make the I2C data line active
1589 (driven). If the data line is open collector, this
1592 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1596 The code necessary to make the I2C data line tri-stated
1597 (inactive). If the data line is open collector, this
1600 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1604 Code that returns TRUE if the I2C data line is high,
1607 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1611 If <bit> is TRUE, sets the I2C data line high. If it
1612 is FALSE, it clears it (low).
1614 eg: #define I2C_SDA(bit) \
1615 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1616 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1620 If <bit> is TRUE, sets the I2C clock line high. If it
1621 is FALSE, it clears it (low).
1623 eg: #define I2C_SCL(bit) \
1624 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1625 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1629 This delay is invoked four times per clock cycle so this
1630 controls the rate of data transfer. The data rate thus
1631 is 1 / (I2C_DELAY * 4). Often defined to be something
1634 #define I2C_DELAY udelay(2)
1636 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1638 If your arch supports the generic GPIO framework (asm/gpio.h),
1639 then you may alternatively define the two GPIOs that are to be
1640 used as SCL / SDA. Any of the previous I2C_xxx macros will
1641 have GPIO-based defaults assigned to them as appropriate.
1643 You should define these to the GPIO value as given directly to
1644 the generic GPIO functions.
1646 CONFIG_SYS_I2C_INIT_BOARD
1648 When a board is reset during an i2c bus transfer
1649 chips might think that the current transfer is still
1650 in progress. On some boards it is possible to access
1651 the i2c SCLK line directly, either by using the
1652 processor pin as a GPIO or by having a second pin
1653 connected to the bus. If this option is defined a
1654 custom i2c_init_board() routine in boards/xxx/board.c
1655 is run early in the boot sequence.
1657 CONFIG_SYS_I2C_BOARD_LATE_INIT
1659 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1660 defined a custom i2c_board_late_init() routine in
1661 boards/xxx/board.c is run AFTER the operations in i2c_init()
1662 is completed. This callpoint can be used to unreset i2c bus
1663 using CPU i2c controller register accesses for CPUs whose i2c
1664 controller provide such a method. It is called at the end of
1665 i2c_init() to allow i2c_init operations to setup the i2c bus
1666 controller on the CPU (e.g. setting bus speed & slave address).
1668 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1670 This option enables configuration of bi_iic_fast[] flags
1671 in u-boot bd_info structure based on u-boot environment
1672 variable "i2cfast". (see also i2cfast)
1674 CONFIG_I2C_MULTI_BUS
1676 This option allows the use of multiple I2C buses, each of which
1677 must have a controller. At any point in time, only one bus is
1678 active. To switch to a different bus, use the 'i2c dev' command.
1679 Note that bus numbering is zero-based.
1681 CONFIG_SYS_I2C_NOPROBES
1683 This option specifies a list of I2C devices that will be skipped
1684 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1685 is set, specify a list of bus-device pairs. Otherwise, specify
1686 a 1D array of device addresses
1689 #undef CONFIG_I2C_MULTI_BUS
1690 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1692 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1694 #define CONFIG_I2C_MULTI_BUS
1695 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1697 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1699 CONFIG_SYS_SPD_BUS_NUM
1701 If defined, then this indicates the I2C bus number for DDR SPD.
1702 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1704 CONFIG_SYS_RTC_BUS_NUM
1706 If defined, then this indicates the I2C bus number for the RTC.
1707 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1709 CONFIG_SYS_DTT_BUS_NUM
1711 If defined, then this indicates the I2C bus number for the DTT.
1712 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1714 CONFIG_SYS_I2C_DTT_ADDR:
1716 If defined, specifies the I2C address of the DTT device.
1717 If not defined, then U-Boot uses predefined value for
1718 specified DTT device.
1722 Define this option if you want to use Freescale's I2C driver in
1723 drivers/i2c/fsl_i2c.c.
1727 Define this option if you have I2C devices reached over 1 .. n
1728 I2C Muxes like the pca9544a. This option addes a new I2C
1729 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1730 new I2C Bus to the existing I2C Busses. If you select the
1731 new Bus with "i2c dev", u-bbot sends first the commandos for
1732 the muxes to activate this new "bus".
1734 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1738 Adding a new I2C Bus reached over 2 pca9544a muxes
1739 The First mux with address 70 and channel 6
1740 The Second mux with address 71 and channel 4
1742 => i2c bus pca9544a:70:6:pca9544a:71:4
1744 Use the "i2c bus" command without parameter, to get a list
1745 of I2C Busses with muxes:
1748 Busses reached over muxes:
1750 reached over Mux(es):
1753 reached over Mux(es):
1758 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1759 u-boot first sends the command to the mux@70 to enable
1760 channel 6, and then the command to the mux@71 to enable
1763 After that, you can use the "normal" i2c commands as
1764 usual to communicate with your I2C devices behind
1767 This option is actually implemented for the bitbanging
1768 algorithm in common/soft_i2c.c and for the Hardware I2C
1769 Bus on the MPC8260. But it should be not so difficult
1770 to add this option to other architectures.
1772 CONFIG_SOFT_I2C_READ_REPEATED_START
1774 defining this will force the i2c_read() function in
1775 the soft_i2c driver to perform an I2C repeated start
1776 between writing the address pointer and reading the
1777 data. If this define is omitted the default behaviour
1778 of doing a stop-start sequence will be used. Most I2C
1779 devices can use either method, but some require one or
1782 - SPI Support: CONFIG_SPI
1784 Enables SPI driver (so far only tested with
1785 SPI EEPROM, also an instance works with Crystal A/D and
1786 D/As on the SACSng board)
1790 Enables the driver for SPI controller on SuperH. Currently
1791 only SH7757 is supported.
1795 Enables extended (16-bit) SPI EEPROM addressing.
1796 (symmetrical to CONFIG_I2C_X)
1800 Enables a software (bit-bang) SPI driver rather than
1801 using hardware support. This is a general purpose
1802 driver that only requires three general I/O port pins
1803 (two outputs, one input) to function. If this is
1804 defined, the board configuration must define several
1805 SPI configuration items (port pins to use, etc). For
1806 an example, see include/configs/sacsng.h.
1810 Enables a hardware SPI driver for general-purpose reads
1811 and writes. As with CONFIG_SOFT_SPI, the board configuration
1812 must define a list of chip-select function pointers.
1813 Currently supported on some MPC8xxx processors. For an
1814 example, see include/configs/mpc8349emds.h.
1818 Enables the driver for the SPI controllers on i.MX and MXC
1819 SoCs. Currently only i.MX31 is supported.
1821 - FPGA Support: CONFIG_FPGA
1823 Enables FPGA subsystem.
1825 CONFIG_FPGA_<vendor>
1827 Enables support for specific chip vendors.
1830 CONFIG_FPGA_<family>
1832 Enables support for FPGA family.
1833 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1837 Specify the number of FPGA devices to support.
1839 CONFIG_SYS_FPGA_PROG_FEEDBACK
1841 Enable printing of hash marks during FPGA configuration.
1843 CONFIG_SYS_FPGA_CHECK_BUSY
1845 Enable checks on FPGA configuration interface busy
1846 status by the configuration function. This option
1847 will require a board or device specific function to
1852 If defined, a function that provides delays in the FPGA
1853 configuration driver.
1855 CONFIG_SYS_FPGA_CHECK_CTRLC
1856 Allow Control-C to interrupt FPGA configuration
1858 CONFIG_SYS_FPGA_CHECK_ERROR
1860 Check for configuration errors during FPGA bitfile
1861 loading. For example, abort during Virtex II
1862 configuration if the INIT_B line goes low (which
1863 indicated a CRC error).
1865 CONFIG_SYS_FPGA_WAIT_INIT
1867 Maximum time to wait for the INIT_B line to deassert
1868 after PROB_B has been deasserted during a Virtex II
1869 FPGA configuration sequence. The default time is 500
1872 CONFIG_SYS_FPGA_WAIT_BUSY
1874 Maximum time to wait for BUSY to deassert during
1875 Virtex II FPGA configuration. The default is 5 ms.
1877 CONFIG_SYS_FPGA_WAIT_CONFIG
1879 Time to wait after FPGA configuration. The default is
1882 - Configuration Management:
1885 If defined, this string will be added to the U-Boot
1886 version information (U_BOOT_VERSION)
1888 - Vendor Parameter Protection:
1890 U-Boot considers the values of the environment
1891 variables "serial#" (Board Serial Number) and
1892 "ethaddr" (Ethernet Address) to be parameters that
1893 are set once by the board vendor / manufacturer, and
1894 protects these variables from casual modification by
1895 the user. Once set, these variables are read-only,
1896 and write or delete attempts are rejected. You can
1897 change this behaviour:
1899 If CONFIG_ENV_OVERWRITE is #defined in your config
1900 file, the write protection for vendor parameters is
1901 completely disabled. Anybody can change or delete
1904 Alternatively, if you #define _both_ CONFIG_ETHADDR
1905 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1906 Ethernet address is installed in the environment,
1907 which can be changed exactly ONCE by the user. [The
1908 serial# is unaffected by this, i. e. it remains
1914 Define this variable to enable the reservation of
1915 "protected RAM", i. e. RAM which is not overwritten
1916 by U-Boot. Define CONFIG_PRAM to hold the number of
1917 kB you want to reserve for pRAM. You can overwrite
1918 this default value by defining an environment
1919 variable "pram" to the number of kB you want to
1920 reserve. Note that the board info structure will
1921 still show the full amount of RAM. If pRAM is
1922 reserved, a new environment variable "mem" will
1923 automatically be defined to hold the amount of
1924 remaining RAM in a form that can be passed as boot
1925 argument to Linux, for instance like that:
1927 setenv bootargs ... mem=\${mem}
1930 This way you can tell Linux not to use this memory,
1931 either, which results in a memory region that will
1932 not be affected by reboots.
1934 *WARNING* If your board configuration uses automatic
1935 detection of the RAM size, you must make sure that
1936 this memory test is non-destructive. So far, the
1937 following board configurations are known to be
1940 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1941 HERMES, IP860, RPXlite, LWMON, LANTEC,
1947 Define this variable to stop the system in case of a
1948 fatal error, so that you have to reset it manually.
1949 This is probably NOT a good idea for an embedded
1950 system where you want the system to reboot
1951 automatically as fast as possible, but it may be
1952 useful during development since you can try to debug
1953 the conditions that lead to the situation.
1955 CONFIG_NET_RETRY_COUNT
1957 This variable defines the number of retries for
1958 network operations like ARP, RARP, TFTP, or BOOTP
1959 before giving up the operation. If not defined, a
1960 default value of 5 is used.
1964 Timeout waiting for an ARP reply in milliseconds.
1966 - Command Interpreter:
1967 CONFIG_AUTO_COMPLETE
1969 Enable auto completion of commands using TAB.
1971 Note that this feature has NOT been implemented yet
1972 for the "hush" shell.
1975 CONFIG_SYS_HUSH_PARSER
1977 Define this variable to enable the "hush" shell (from
1978 Busybox) as command line interpreter, thus enabling
1979 powerful command line syntax like
1980 if...then...else...fi conditionals or `&&' and '||'
1981 constructs ("shell scripts").
1983 If undefined, you get the old, much simpler behaviour
1984 with a somewhat smaller memory footprint.
1987 CONFIG_SYS_PROMPT_HUSH_PS2
1989 This defines the secondary prompt string, which is
1990 printed when the command interpreter needs more input
1991 to complete a command. Usually "> ".
1995 In the current implementation, the local variables
1996 space and global environment variables space are
1997 separated. Local variables are those you define by
1998 simply typing `name=value'. To access a local
1999 variable later on, you have write `$name' or
2000 `${name}'; to execute the contents of a variable
2001 directly type `$name' at the command prompt.
2003 Global environment variables are those you use
2004 setenv/printenv to work with. To run a command stored
2005 in such a variable, you need to use the run command,
2006 and you must not use the '$' sign to access them.
2008 To store commands and special characters in a
2009 variable, please use double quotation marks
2010 surrounding the whole text of the variable, instead
2011 of the backslashes before semicolons and special
2014 - Commandline Editing and History:
2015 CONFIG_CMDLINE_EDITING
2017 Enable editing and History functions for interactive
2018 commandline input operations
2020 - Default Environment:
2021 CONFIG_EXTRA_ENV_SETTINGS
2023 Define this to contain any number of null terminated
2024 strings (variable = value pairs) that will be part of
2025 the default environment compiled into the boot image.
2027 For example, place something like this in your
2028 board's config file:
2030 #define CONFIG_EXTRA_ENV_SETTINGS \
2034 Warning: This method is based on knowledge about the
2035 internal format how the environment is stored by the
2036 U-Boot code. This is NOT an official, exported
2037 interface! Although it is unlikely that this format
2038 will change soon, there is no guarantee either.
2039 You better know what you are doing here.
2041 Note: overly (ab)use of the default environment is
2042 discouraged. Make sure to check other ways to preset
2043 the environment like the "source" command or the
2046 - DataFlash Support:
2047 CONFIG_HAS_DATAFLASH
2049 Defining this option enables DataFlash features and
2050 allows to read/write in Dataflash via the standard
2053 - SystemACE Support:
2056 Adding this option adds support for Xilinx SystemACE
2057 chips attached via some sort of local bus. The address
2058 of the chip must also be defined in the
2059 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2061 #define CONFIG_SYSTEMACE
2062 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2064 When SystemACE support is added, the "ace" device type
2065 becomes available to the fat commands, i.e. fatls.
2067 - TFTP Fixed UDP Port:
2070 If this is defined, the environment variable tftpsrcp
2071 is used to supply the TFTP UDP source port value.
2072 If tftpsrcp isn't defined, the normal pseudo-random port
2073 number generator is used.
2075 Also, the environment variable tftpdstp is used to supply
2076 the TFTP UDP destination port value. If tftpdstp isn't
2077 defined, the normal port 69 is used.
2079 The purpose for tftpsrcp is to allow a TFTP server to
2080 blindly start the TFTP transfer using the pre-configured
2081 target IP address and UDP port. This has the effect of
2082 "punching through" the (Windows XP) firewall, allowing
2083 the remainder of the TFTP transfer to proceed normally.
2084 A better solution is to properly configure the firewall,
2085 but sometimes that is not allowed.
2087 - Show boot progress:
2088 CONFIG_SHOW_BOOT_PROGRESS
2090 Defining this option allows to add some board-
2091 specific code (calling a user-provided function
2092 "show_boot_progress(int)") that enables you to show
2093 the system's boot progress on some display (for
2094 example, some LED's) on your board. At the moment,
2095 the following checkpoints are implemented:
2097 - Standalone program support:
2098 CONFIG_STANDALONE_LOAD_ADDR
2100 This option allows to define board specific values
2101 for the address where standalone program gets loaded,
2102 thus overwriting the architecutre dependent default
2105 - Frame Buffer Address:
2108 Define CONFIG_FB_ADDR if you want to use specific address for
2110 Then system will reserve the frame buffer address to defined address
2111 instead of lcd_setmem (this function grab the memory for frame buffer
2114 Please see board_init_f function.
2116 If you want this config option then,
2117 please define it at your board config file
2119 Legacy uImage format:
2122 1 common/cmd_bootm.c before attempting to boot an image
2123 -1 common/cmd_bootm.c Image header has bad magic number
2124 2 common/cmd_bootm.c Image header has correct magic number
2125 -2 common/cmd_bootm.c Image header has bad checksum
2126 3 common/cmd_bootm.c Image header has correct checksum
2127 -3 common/cmd_bootm.c Image data has bad checksum
2128 4 common/cmd_bootm.c Image data has correct checksum
2129 -4 common/cmd_bootm.c Image is for unsupported architecture
2130 5 common/cmd_bootm.c Architecture check OK
2131 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2132 6 common/cmd_bootm.c Image Type check OK
2133 -6 common/cmd_bootm.c gunzip uncompression error
2134 -7 common/cmd_bootm.c Unimplemented compression type
2135 7 common/cmd_bootm.c Uncompression OK
2136 8 common/cmd_bootm.c No uncompress/copy overwrite error
2137 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2139 9 common/image.c Start initial ramdisk verification
2140 -10 common/image.c Ramdisk header has bad magic number
2141 -11 common/image.c Ramdisk header has bad checksum
2142 10 common/image.c Ramdisk header is OK
2143 -12 common/image.c Ramdisk data has bad checksum
2144 11 common/image.c Ramdisk data has correct checksum
2145 12 common/image.c Ramdisk verification complete, start loading
2146 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2147 13 common/image.c Start multifile image verification
2148 14 common/image.c No initial ramdisk, no multifile, continue.
2150 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2152 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2153 -31 post/post.c POST test failed, detected by post_output_backlog()
2154 -32 post/post.c POST test failed, detected by post_run_single()
2156 34 common/cmd_doc.c before loading a Image from a DOC device
2157 -35 common/cmd_doc.c Bad usage of "doc" command
2158 35 common/cmd_doc.c correct usage of "doc" command
2159 -36 common/cmd_doc.c No boot device
2160 36 common/cmd_doc.c correct boot device
2161 -37 common/cmd_doc.c Unknown Chip ID on boot device
2162 37 common/cmd_doc.c correct chip ID found, device available
2163 -38 common/cmd_doc.c Read Error on boot device
2164 38 common/cmd_doc.c reading Image header from DOC device OK
2165 -39 common/cmd_doc.c Image header has bad magic number
2166 39 common/cmd_doc.c Image header has correct magic number
2167 -40 common/cmd_doc.c Error reading Image from DOC device
2168 40 common/cmd_doc.c Image header has correct magic number
2169 41 common/cmd_ide.c before loading a Image from a IDE device
2170 -42 common/cmd_ide.c Bad usage of "ide" command
2171 42 common/cmd_ide.c correct usage of "ide" command
2172 -43 common/cmd_ide.c No boot device
2173 43 common/cmd_ide.c boot device found
2174 -44 common/cmd_ide.c Device not available
2175 44 common/cmd_ide.c Device available
2176 -45 common/cmd_ide.c wrong partition selected
2177 45 common/cmd_ide.c partition selected
2178 -46 common/cmd_ide.c Unknown partition table
2179 46 common/cmd_ide.c valid partition table found
2180 -47 common/cmd_ide.c Invalid partition type
2181 47 common/cmd_ide.c correct partition type
2182 -48 common/cmd_ide.c Error reading Image Header on boot device
2183 48 common/cmd_ide.c reading Image Header from IDE device OK
2184 -49 common/cmd_ide.c Image header has bad magic number
2185 49 common/cmd_ide.c Image header has correct magic number
2186 -50 common/cmd_ide.c Image header has bad checksum
2187 50 common/cmd_ide.c Image header has correct checksum
2188 -51 common/cmd_ide.c Error reading Image from IDE device
2189 51 common/cmd_ide.c reading Image from IDE device OK
2190 52 common/cmd_nand.c before loading a Image from a NAND device
2191 -53 common/cmd_nand.c Bad usage of "nand" command
2192 53 common/cmd_nand.c correct usage of "nand" command
2193 -54 common/cmd_nand.c No boot device
2194 54 common/cmd_nand.c boot device found
2195 -55 common/cmd_nand.c Unknown Chip ID on boot device
2196 55 common/cmd_nand.c correct chip ID found, device available
2197 -56 common/cmd_nand.c Error reading Image Header on boot device
2198 56 common/cmd_nand.c reading Image Header from NAND device OK
2199 -57 common/cmd_nand.c Image header has bad magic number
2200 57 common/cmd_nand.c Image header has correct magic number
2201 -58 common/cmd_nand.c Error reading Image from NAND device
2202 58 common/cmd_nand.c reading Image from NAND device OK
2204 -60 common/env_common.c Environment has a bad CRC, using default
2206 64 net/eth.c starting with Ethernet configuration.
2207 -64 net/eth.c no Ethernet found.
2208 65 net/eth.c Ethernet found.
2210 -80 common/cmd_net.c usage wrong
2211 80 common/cmd_net.c before calling NetLoop()
2212 -81 common/cmd_net.c some error in NetLoop() occurred
2213 81 common/cmd_net.c NetLoop() back without error
2214 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2215 82 common/cmd_net.c trying automatic boot
2216 83 common/cmd_net.c running "source" command
2217 -83 common/cmd_net.c some error in automatic boot or "source" command
2218 84 common/cmd_net.c end without errors
2223 100 common/cmd_bootm.c Kernel FIT Image has correct format
2224 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2225 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2226 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2227 102 common/cmd_bootm.c Kernel unit name specified
2228 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2229 103 common/cmd_bootm.c Found configuration node
2230 104 common/cmd_bootm.c Got kernel subimage node offset
2231 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2232 105 common/cmd_bootm.c Kernel subimage hash verification OK
2233 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2234 106 common/cmd_bootm.c Architecture check OK
2235 -106 common/cmd_bootm.c Kernel subimage has wrong type
2236 107 common/cmd_bootm.c Kernel subimage type OK
2237 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2238 108 common/cmd_bootm.c Got kernel subimage data/size
2239 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2240 -109 common/cmd_bootm.c Can't get kernel subimage type
2241 -110 common/cmd_bootm.c Can't get kernel subimage comp
2242 -111 common/cmd_bootm.c Can't get kernel subimage os
2243 -112 common/cmd_bootm.c Can't get kernel subimage load address
2244 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2246 120 common/image.c Start initial ramdisk verification
2247 -120 common/image.c Ramdisk FIT image has incorrect format
2248 121 common/image.c Ramdisk FIT image has correct format
2249 122 common/image.c No ramdisk subimage unit name, using configuration
2250 -122 common/image.c Can't get configuration for ramdisk subimage
2251 123 common/image.c Ramdisk unit name specified
2252 -124 common/image.c Can't get ramdisk subimage node offset
2253 125 common/image.c Got ramdisk subimage node offset
2254 -125 common/image.c Ramdisk subimage hash verification failed
2255 126 common/image.c Ramdisk subimage hash verification OK
2256 -126 common/image.c Ramdisk subimage for unsupported architecture
2257 127 common/image.c Architecture check OK
2258 -127 common/image.c Can't get ramdisk subimage data/size
2259 128 common/image.c Got ramdisk subimage data/size
2260 129 common/image.c Can't get ramdisk load address
2261 -129 common/image.c Got ramdisk load address
2263 -130 common/cmd_doc.c Incorrect FIT image format
2264 131 common/cmd_doc.c FIT image format OK
2266 -140 common/cmd_ide.c Incorrect FIT image format
2267 141 common/cmd_ide.c FIT image format OK
2269 -150 common/cmd_nand.c Incorrect FIT image format
2270 151 common/cmd_nand.c FIT image format OK
2272 - Automatic software updates via TFTP server
2274 CONFIG_UPDATE_TFTP_CNT_MAX
2275 CONFIG_UPDATE_TFTP_MSEC_MAX
2277 These options enable and control the auto-update feature;
2278 for a more detailed description refer to doc/README.update.
2280 - MTD Support (mtdparts command, UBI support)
2283 Adds the MTD device infrastructure from the Linux kernel.
2284 Needed for mtdparts command support.
2286 CONFIG_MTD_PARTITIONS
2288 Adds the MTD partitioning infrastructure from the Linux
2289 kernel. Needed for UBI support.
2293 Enable building of SPL globally.
2295 CONFIG_SPL_TEXT_BASE
2296 TEXT_BASE for linking the SPL binary.
2299 LDSCRIPT for linking the SPL binary.
2301 CONFIG_SPL_LIBCOMMON_SUPPORT
2302 Support for common/libcommon.o in SPL binary
2304 CONFIG_SPL_LIBDISK_SUPPORT
2305 Support for disk/libdisk.o in SPL binary
2307 CONFIG_SPL_I2C_SUPPORT
2308 Support for drivers/i2c/libi2c.o in SPL binary
2310 CONFIG_SPL_GPIO_SUPPORT
2311 Support for drivers/gpio/libgpio.o in SPL binary
2313 CONFIG_SPL_MMC_SUPPORT
2314 Support for drivers/mmc/libmmc.o in SPL binary
2316 CONFIG_SPL_SERIAL_SUPPORT
2317 Support for drivers/serial/libserial.o in SPL binary
2319 CONFIG_SPL_SPI_FLASH_SUPPORT
2320 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
2322 CONFIG_SPL_SPI_SUPPORT
2323 Support for drivers/spi/libspi.o in SPL binary
2325 CONFIG_SPL_FAT_SUPPORT
2326 Support for fs/fat/libfat.o in SPL binary
2328 CONFIG_SPL_LIBGENERIC_SUPPORT
2329 Support for lib/libgeneric.o in SPL binary
2334 [so far only for SMDK2400 boards]
2336 - Modem support enable:
2337 CONFIG_MODEM_SUPPORT
2339 - RTS/CTS Flow control enable:
2342 - Modem debug support:
2343 CONFIG_MODEM_SUPPORT_DEBUG
2345 Enables debugging stuff (char screen[1024], dbg())
2346 for modem support. Useful only with BDI2000.
2348 - Interrupt support (PPC):
2350 There are common interrupt_init() and timer_interrupt()
2351 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2352 for CPU specific initialization. interrupt_init_cpu()
2353 should set decrementer_count to appropriate value. If
2354 CPU resets decrementer automatically after interrupt
2355 (ppc4xx) it should set decrementer_count to zero.
2356 timer_interrupt() calls timer_interrupt_cpu() for CPU
2357 specific handling. If board has watchdog / status_led
2358 / other_activity_monitor it works automatically from
2359 general timer_interrupt().
2363 In the target system modem support is enabled when a
2364 specific key (key combination) is pressed during
2365 power-on. Otherwise U-Boot will boot normally
2366 (autoboot). The key_pressed() function is called from
2367 board_init(). Currently key_pressed() is a dummy
2368 function, returning 1 and thus enabling modem
2371 If there are no modem init strings in the
2372 environment, U-Boot proceed to autoboot; the
2373 previous output (banner, info printfs) will be
2376 See also: doc/README.Modem
2379 Configuration Settings:
2380 -----------------------
2382 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2383 undefine this when you're short of memory.
2385 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2386 width of the commands listed in the 'help' command output.
2388 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2389 prompt for user input.
2391 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2393 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2395 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2397 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2398 the application (usually a Linux kernel) when it is
2401 - CONFIG_SYS_BAUDRATE_TABLE:
2402 List of legal baudrate settings for this board.
2404 - CONFIG_SYS_CONSOLE_INFO_QUIET
2405 Suppress display of console information at boot.
2407 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2408 If the board specific function
2409 extern int overwrite_console (void);
2410 returns 1, the stdin, stderr and stdout are switched to the
2411 serial port, else the settings in the environment are used.
2413 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2414 Enable the call to overwrite_console().
2416 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2417 Enable overwrite of previous console environment settings.
2419 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2420 Begin and End addresses of the area used by the
2423 - CONFIG_SYS_ALT_MEMTEST:
2424 Enable an alternate, more extensive memory test.
2426 - CONFIG_SYS_MEMTEST_SCRATCH:
2427 Scratch address used by the alternate memory test
2428 You only need to set this if address zero isn't writeable
2430 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2431 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2432 this specified memory area will get subtracted from the top
2433 (end) of RAM and won't get "touched" at all by U-Boot. By
2434 fixing up gd->ram_size the Linux kernel should gets passed
2435 the now "corrected" memory size and won't touch it either.
2436 This should work for arch/ppc and arch/powerpc. Only Linux
2437 board ports in arch/powerpc with bootwrapper support that
2438 recalculate the memory size from the SDRAM controller setup
2439 will have to get fixed in Linux additionally.
2441 This option can be used as a workaround for the 440EPx/GRx
2442 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2445 WARNING: Please make sure that this value is a multiple of
2446 the Linux page size (normally 4k). If this is not the case,
2447 then the end address of the Linux memory will be located at a
2448 non page size aligned address and this could cause major
2451 - CONFIG_SYS_TFTP_LOADADDR:
2452 Default load address for network file downloads
2454 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2455 Enable temporary baudrate change while serial download
2457 - CONFIG_SYS_SDRAM_BASE:
2458 Physical start address of SDRAM. _Must_ be 0 here.
2460 - CONFIG_SYS_MBIO_BASE:
2461 Physical start address of Motherboard I/O (if using a
2464 - CONFIG_SYS_FLASH_BASE:
2465 Physical start address of Flash memory.
2467 - CONFIG_SYS_MONITOR_BASE:
2468 Physical start address of boot monitor code (set by
2469 make config files to be same as the text base address
2470 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
2471 CONFIG_SYS_FLASH_BASE when booting from flash.
2473 - CONFIG_SYS_MONITOR_LEN:
2474 Size of memory reserved for monitor code, used to
2475 determine _at_compile_time_ (!) if the environment is
2476 embedded within the U-Boot image, or in a separate
2479 - CONFIG_SYS_MALLOC_LEN:
2480 Size of DRAM reserved for malloc() use.
2482 - CONFIG_SYS_BOOTM_LEN:
2483 Normally compressed uImages are limited to an
2484 uncompressed size of 8 MBytes. If this is not enough,
2485 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2486 to adjust this setting to your needs.
2488 - CONFIG_SYS_BOOTMAPSZ:
2489 Maximum size of memory mapped by the startup code of
2490 the Linux kernel; all data that must be processed by
2491 the Linux kernel (bd_info, boot arguments, FDT blob if
2492 used) must be put below this limit, unless "bootm_low"
2493 enviroment variable is defined and non-zero. In such case
2494 all data for the Linux kernel must be between "bootm_low"
2495 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
2496 variable "bootm_mapsize" will override the value of
2497 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
2498 then the value in "bootm_size" will be used instead.
2500 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
2501 Enable initrd_high functionality. If defined then the
2502 initrd_high feature is enabled and the bootm ramdisk subcommand
2505 - CONFIG_SYS_BOOT_GET_CMDLINE:
2506 Enables allocating and saving kernel cmdline in space between
2507 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2509 - CONFIG_SYS_BOOT_GET_KBD:
2510 Enables allocating and saving a kernel copy of the bd_info in
2511 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2513 - CONFIG_SYS_MAX_FLASH_BANKS:
2514 Max number of Flash memory banks
2516 - CONFIG_SYS_MAX_FLASH_SECT:
2517 Max number of sectors on a Flash chip
2519 - CONFIG_SYS_FLASH_ERASE_TOUT:
2520 Timeout for Flash erase operations (in ms)
2522 - CONFIG_SYS_FLASH_WRITE_TOUT:
2523 Timeout for Flash write operations (in ms)
2525 - CONFIG_SYS_FLASH_LOCK_TOUT
2526 Timeout for Flash set sector lock bit operation (in ms)
2528 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2529 Timeout for Flash clear lock bits operation (in ms)
2531 - CONFIG_SYS_FLASH_PROTECTION
2532 If defined, hardware flash sectors protection is used
2533 instead of U-Boot software protection.
2535 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2537 Enable TFTP transfers directly to flash memory;
2538 without this option such a download has to be
2539 performed in two steps: (1) download to RAM, and (2)
2540 copy from RAM to flash.
2542 The two-step approach is usually more reliable, since
2543 you can check if the download worked before you erase
2544 the flash, but in some situations (when system RAM is
2545 too limited to allow for a temporary copy of the
2546 downloaded image) this option may be very useful.
2548 - CONFIG_SYS_FLASH_CFI:
2549 Define if the flash driver uses extra elements in the
2550 common flash structure for storing flash geometry.
2552 - CONFIG_FLASH_CFI_DRIVER
2553 This option also enables the building of the cfi_flash driver
2554 in the drivers directory
2556 - CONFIG_FLASH_CFI_MTD
2557 This option enables the building of the cfi_mtd driver
2558 in the drivers directory. The driver exports CFI flash
2561 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2562 Use buffered writes to flash.
2564 - CONFIG_FLASH_SPANSION_S29WS_N
2565 s29ws-n MirrorBit flash has non-standard addresses for buffered
2568 - CONFIG_SYS_FLASH_QUIET_TEST
2569 If this option is defined, the common CFI flash doesn't
2570 print it's warning upon not recognized FLASH banks. This
2571 is useful, if some of the configured banks are only
2572 optionally available.
2574 - CONFIG_FLASH_SHOW_PROGRESS
2575 If defined (must be an integer), print out countdown
2576 digits and dots. Recommended value: 45 (9..1) for 80
2577 column displays, 15 (3..1) for 40 column displays.
2579 - CONFIG_SYS_RX_ETH_BUFFER:
2580 Defines the number of Ethernet receive buffers. On some
2581 Ethernet controllers it is recommended to set this value
2582 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2583 buffers can be full shortly after enabling the interface
2584 on high Ethernet traffic.
2585 Defaults to 4 if not defined.
2587 - CONFIG_ENV_MAX_ENTRIES
2589 Maximum number of entries in the hash table that is used
2590 internally to store the environment settings. The default
2591 setting is supposed to be generous and should work in most
2592 cases. This setting can be used to tune behaviour; see
2593 lib/hashtable.c for details.
2595 The following definitions that deal with the placement and management
2596 of environment data (variable area); in general, we support the
2597 following configurations:
2599 - CONFIG_BUILD_ENVCRC:
2601 Builds up envcrc with the target environment so that external utils
2602 may easily extract it and embed it in final U-Boot images.
2604 - CONFIG_ENV_IS_IN_FLASH:
2606 Define this if the environment is in flash memory.
2608 a) The environment occupies one whole flash sector, which is
2609 "embedded" in the text segment with the U-Boot code. This
2610 happens usually with "bottom boot sector" or "top boot
2611 sector" type flash chips, which have several smaller
2612 sectors at the start or the end. For instance, such a
2613 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2614 such a case you would place the environment in one of the
2615 4 kB sectors - with U-Boot code before and after it. With
2616 "top boot sector" type flash chips, you would put the
2617 environment in one of the last sectors, leaving a gap
2618 between U-Boot and the environment.
2620 - CONFIG_ENV_OFFSET:
2622 Offset of environment data (variable area) to the
2623 beginning of flash memory; for instance, with bottom boot
2624 type flash chips the second sector can be used: the offset
2625 for this sector is given here.
2627 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2631 This is just another way to specify the start address of
2632 the flash sector containing the environment (instead of
2635 - CONFIG_ENV_SECT_SIZE:
2637 Size of the sector containing the environment.
2640 b) Sometimes flash chips have few, equal sized, BIG sectors.
2641 In such a case you don't want to spend a whole sector for
2646 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2647 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2648 of this flash sector for the environment. This saves
2649 memory for the RAM copy of the environment.
2651 It may also save flash memory if you decide to use this
2652 when your environment is "embedded" within U-Boot code,
2653 since then the remainder of the flash sector could be used
2654 for U-Boot code. It should be pointed out that this is
2655 STRONGLY DISCOURAGED from a robustness point of view:
2656 updating the environment in flash makes it always
2657 necessary to erase the WHOLE sector. If something goes
2658 wrong before the contents has been restored from a copy in
2659 RAM, your target system will be dead.
2661 - CONFIG_ENV_ADDR_REDUND
2662 CONFIG_ENV_SIZE_REDUND
2664 These settings describe a second storage area used to hold
2665 a redundant copy of the environment data, so that there is
2666 a valid backup copy in case there is a power failure during
2667 a "saveenv" operation.
2669 BE CAREFUL! Any changes to the flash layout, and some changes to the
2670 source code will make it necessary to adapt <board>/u-boot.lds*
2674 - CONFIG_ENV_IS_IN_NVRAM:
2676 Define this if you have some non-volatile memory device
2677 (NVRAM, battery buffered SRAM) which you want to use for the
2683 These two #defines are used to determine the memory area you
2684 want to use for environment. It is assumed that this memory
2685 can just be read and written to, without any special
2688 BE CAREFUL! The first access to the environment happens quite early
2689 in U-Boot initalization (when we try to get the setting of for the
2690 console baudrate). You *MUST* have mapped your NVRAM area then, or
2693 Please note that even with NVRAM we still use a copy of the
2694 environment in RAM: we could work on NVRAM directly, but we want to
2695 keep settings there always unmodified except somebody uses "saveenv"
2696 to save the current settings.
2699 - CONFIG_ENV_IS_IN_EEPROM:
2701 Use this if you have an EEPROM or similar serial access
2702 device and a driver for it.
2704 - CONFIG_ENV_OFFSET:
2707 These two #defines specify the offset and size of the
2708 environment area within the total memory of your EEPROM.
2710 - CONFIG_SYS_I2C_EEPROM_ADDR:
2711 If defined, specified the chip address of the EEPROM device.
2712 The default address is zero.
2714 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2715 If defined, the number of bits used to address bytes in a
2716 single page in the EEPROM device. A 64 byte page, for example
2717 would require six bits.
2719 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2720 If defined, the number of milliseconds to delay between
2721 page writes. The default is zero milliseconds.
2723 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2724 The length in bytes of the EEPROM memory array address. Note
2725 that this is NOT the chip address length!
2727 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2728 EEPROM chips that implement "address overflow" are ones
2729 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2730 address and the extra bits end up in the "chip address" bit
2731 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2734 Note that we consider the length of the address field to
2735 still be one byte because the extra address bits are hidden
2736 in the chip address.
2738 - CONFIG_SYS_EEPROM_SIZE:
2739 The size in bytes of the EEPROM device.
2741 - CONFIG_ENV_EEPROM_IS_ON_I2C
2742 define this, if you have I2C and SPI activated, and your
2743 EEPROM, which holds the environment, is on the I2C bus.
2745 - CONFIG_I2C_ENV_EEPROM_BUS
2746 if you have an Environment on an EEPROM reached over
2747 I2C muxes, you can define here, how to reach this
2748 EEPROM. For example:
2750 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
2752 EEPROM which holds the environment, is reached over
2753 a pca9547 i2c mux with address 0x70, channel 3.
2755 - CONFIG_ENV_IS_IN_DATAFLASH:
2757 Define this if you have a DataFlash memory device which you
2758 want to use for the environment.
2760 - CONFIG_ENV_OFFSET:
2764 These three #defines specify the offset and size of the
2765 environment area within the total memory of your DataFlash placed
2766 at the specified address.
2768 - CONFIG_ENV_IS_IN_NAND:
2770 Define this if you have a NAND device which you want to use
2771 for the environment.
2773 - CONFIG_ENV_OFFSET:
2776 These two #defines specify the offset and size of the environment
2777 area within the first NAND device. CONFIG_ENV_OFFSET must be
2778 aligned to an erase block boundary.
2780 - CONFIG_ENV_OFFSET_REDUND (optional):
2782 This setting describes a second storage area of CONFIG_ENV_SIZE
2783 size used to hold a redundant copy of the environment data, so
2784 that there is a valid backup copy in case there is a power failure
2785 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
2786 aligned to an erase block boundary.
2788 - CONFIG_ENV_RANGE (optional):
2790 Specifies the length of the region in which the environment
2791 can be written. This should be a multiple of the NAND device's
2792 block size. Specifying a range with more erase blocks than
2793 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
2794 the range to be avoided.
2796 - CONFIG_ENV_OFFSET_OOB (optional):
2798 Enables support for dynamically retrieving the offset of the
2799 environment from block zero's out-of-band data. The
2800 "nand env.oob" command can be used to record this offset.
2801 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
2802 using CONFIG_ENV_OFFSET_OOB.
2804 - CONFIG_NAND_ENV_DST
2806 Defines address in RAM to which the nand_spl code should copy the
2807 environment. If redundant environment is used, it will be copied to
2808 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2810 - CONFIG_SYS_SPI_INIT_OFFSET
2812 Defines offset to the initial SPI buffer area in DPRAM. The
2813 area is used at an early stage (ROM part) if the environment
2814 is configured to reside in the SPI EEPROM: We need a 520 byte
2815 scratch DPRAM area. It is used between the two initialization
2816 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2817 to be a good choice since it makes it far enough from the
2818 start of the data area as well as from the stack pointer.
2820 Please note that the environment is read-only until the monitor
2821 has been relocated to RAM and a RAM copy of the environment has been
2822 created; also, when using EEPROM you will have to use getenv_f()
2823 until then to read environment variables.
2825 The environment is protected by a CRC32 checksum. Before the monitor
2826 is relocated into RAM, as a result of a bad CRC you will be working
2827 with the compiled-in default environment - *silently*!!! [This is
2828 necessary, because the first environment variable we need is the
2829 "baudrate" setting for the console - if we have a bad CRC, we don't
2830 have any device yet where we could complain.]
2832 Note: once the monitor has been relocated, then it will complain if
2833 the default environment is used; a new CRC is computed as soon as you
2834 use the "saveenv" command to store a valid environment.
2836 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2837 Echo the inverted Ethernet link state to the fault LED.
2839 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2840 also needs to be defined.
2842 - CONFIG_SYS_FAULT_MII_ADDR:
2843 MII address of the PHY to check for the Ethernet link state.
2845 - CONFIG_NS16550_MIN_FUNCTIONS:
2846 Define this if you desire to only have use of the NS16550_init
2847 and NS16550_putc functions for the serial driver located at
2848 drivers/serial/ns16550.c. This option is useful for saving
2849 space for already greatly restricted images, including but not
2850 limited to NAND_SPL configurations.
2852 Low Level (hardware related) configuration options:
2853 ---------------------------------------------------
2855 - CONFIG_SYS_CACHELINE_SIZE:
2856 Cache Line Size of the CPU.
2858 - CONFIG_SYS_DEFAULT_IMMR:
2859 Default address of the IMMR after system reset.
2861 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2862 and RPXsuper) to be able to adjust the position of
2863 the IMMR register after a reset.
2865 - Floppy Disk Support:
2866 CONFIG_SYS_FDC_DRIVE_NUMBER
2868 the default drive number (default value 0)
2870 CONFIG_SYS_ISA_IO_STRIDE
2872 defines the spacing between FDC chipset registers
2875 CONFIG_SYS_ISA_IO_OFFSET
2877 defines the offset of register from address. It
2878 depends on which part of the data bus is connected to
2879 the FDC chipset. (default value 0)
2881 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
2882 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
2885 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
2886 fdc_hw_init() is called at the beginning of the FDC
2887 setup. fdc_hw_init() must be provided by the board
2888 source code. It is used to make hardware dependant
2892 Most IDE controllers were designed to be connected with PCI
2893 interface. Only few of them were designed for AHB interface.
2894 When software is doing ATA command and data transfer to
2895 IDE devices through IDE-AHB controller, some additional
2896 registers accessing to these kind of IDE-AHB controller
2899 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
2900 DO NOT CHANGE unless you know exactly what you're
2901 doing! (11-4) [MPC8xx/82xx systems only]
2903 - CONFIG_SYS_INIT_RAM_ADDR:
2905 Start address of memory area that can be used for
2906 initial data and stack; please note that this must be
2907 writable memory that is working WITHOUT special
2908 initialization, i. e. you CANNOT use normal RAM which
2909 will become available only after programming the
2910 memory controller and running certain initialization
2913 U-Boot uses the following memory types:
2914 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2915 - MPC824X: data cache
2916 - PPC4xx: data cache
2918 - CONFIG_SYS_GBL_DATA_OFFSET:
2920 Offset of the initial data structure in the memory
2921 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2922 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
2923 data is located at the end of the available space
2924 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
2925 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
2926 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2927 CONFIG_SYS_GBL_DATA_OFFSET) downward.
2930 On the MPC824X (or other systems that use the data
2931 cache for initial memory) the address chosen for
2932 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
2933 point to an otherwise UNUSED address space between
2934 the top of RAM and the start of the PCI space.
2936 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
2938 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
2940 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
2942 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
2944 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2946 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
2948 - CONFIG_SYS_OR_TIMING_SDRAM:
2951 - CONFIG_SYS_MAMR_PTA:
2952 periodic timer for refresh
2954 - CONFIG_SYS_DER: Debug Event Register (37-47)
2956 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2957 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2958 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2959 CONFIG_SYS_BR1_PRELIM:
2960 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2962 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2963 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2964 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
2965 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2967 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
2968 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
2969 Machine Mode Register and Memory Periodic Timer
2970 Prescaler definitions (SDRAM timing)
2972 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
2973 enable I2C microcode relocation patch (MPC8xx);
2974 define relocation offset in DPRAM [DSP2]
2976 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
2977 enable SMC microcode relocation patch (MPC8xx);
2978 define relocation offset in DPRAM [SMC1]
2980 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
2981 enable SPI microcode relocation patch (MPC8xx);
2982 define relocation offset in DPRAM [SCC4]
2984 - CONFIG_SYS_USE_OSCCLK:
2985 Use OSCM clock mode on MBX8xx board. Be careful,
2986 wrong setting might damage your board. Read
2987 doc/README.MBX before setting this variable!
2989 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2990 Offset of the bootmode word in DPRAM used by post
2991 (Power On Self Tests). This definition overrides
2992 #define'd default value in commproc.h resp.
2995 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
2996 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
2997 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
2998 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
2999 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
3000 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
3001 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
3002 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
3003 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
3005 - CONFIG_PCI_DISABLE_PCIE:
3006 Disable PCI-Express on systems where it is supported but not
3010 Chip has SRIO or not
3013 Board has SRIO 1 port available
3016 Board has SRIO 2 port available
3018 - CONFIG_SYS_SRIOn_MEM_VIRT:
3019 Virtual Address of SRIO port 'n' memory region
3021 - CONFIG_SYS_SRIOn_MEM_PHYS:
3022 Physical Address of SRIO port 'n' memory region
3024 - CONFIG_SYS_SRIOn_MEM_SIZE:
3025 Size of SRIO port 'n' memory region
3027 - CONFIG_SYS_NDFC_16
3028 Defined to tell the NDFC that the NAND chip is using a
3031 - CONFIG_SYS_NDFC_EBC0_CFG
3032 Sets the EBC0_CFG register for the NDFC. If not defined
3033 a default value will be used.
3036 Get DDR timing information from an I2C EEPROM. Common
3037 with pluggable memory modules such as SODIMMs
3040 I2C address of the SPD EEPROM
3042 - CONFIG_SYS_SPD_BUS_NUM
3043 If SPD EEPROM is on an I2C bus other than the first
3044 one, specify here. Note that the value must resolve
3045 to something your driver can deal with.
3047 - CONFIG_SYS_DDR_RAW_TIMING
3048 Get DDR timing information from other than SPD. Common with
3049 soldered DDR chips onboard without SPD. DDR raw timing
3050 parameters are extracted from datasheet and hard-coded into
3051 header files or board specific files.
3053 - CONFIG_SYS_83XX_DDR_USES_CS0
3054 Only for 83xx systems. If specified, then DDR should
3055 be configured using CS0 and CS1 instead of CS2 and CS3.
3057 - CONFIG_ETHER_ON_FEC[12]
3058 Define to enable FEC[12] on a 8xx series processor.
3060 - CONFIG_FEC[12]_PHY
3061 Define to the hardcoded PHY address which corresponds
3062 to the given FEC; i. e.
3063 #define CONFIG_FEC1_PHY 4
3064 means that the PHY with address 4 is connected to FEC1
3066 When set to -1, means to probe for first available.
3068 - CONFIG_FEC[12]_PHY_NORXERR
3069 The PHY does not have a RXERR line (RMII only).
3070 (so program the FEC to ignore it).
3073 Enable RMII mode for all FECs.
3074 Note that this is a global option, we can't
3075 have one FEC in standard MII mode and another in RMII mode.
3077 - CONFIG_CRC32_VERIFY
3078 Add a verify option to the crc32 command.
3081 => crc32 -v <address> <count> <crc32>
3083 Where address/count indicate a memory area
3084 and crc32 is the correct crc32 which the
3088 Add the "loopw" memory command. This only takes effect if
3089 the memory commands are activated globally (CONFIG_CMD_MEM).
3092 Add the "mdc" and "mwc" memory commands. These are cyclic
3097 This command will print 4 bytes (10,11,12,13) each 500 ms.
3099 => mwc.l 100 12345678 10
3100 This command will write 12345678 to address 100 all 10 ms.
3102 This only takes effect if the memory commands are activated
3103 globally (CONFIG_CMD_MEM).
3105 - CONFIG_SKIP_LOWLEVEL_INIT
3106 [ARM, MIPS only] If this variable is defined, then certain
3107 low level initializations (like setting up the memory
3108 controller) are omitted and/or U-Boot does not
3109 relocate itself into RAM.
3111 Normally this variable MUST NOT be defined. The only
3112 exception is when U-Boot is loaded (to RAM) by some
3113 other boot loader or by a debugger which performs
3114 these initializations itself.
3117 Modifies the behaviour of start.S when compiling a loader
3118 that is executed before the actual U-Boot. E.g. when
3119 compiling a NAND SPL.
3121 - CONFIG_USE_ARCH_MEMCPY
3122 CONFIG_USE_ARCH_MEMSET
3123 If these options are used a optimized version of memcpy/memset will
3124 be used if available. These functions may be faster under some
3125 conditions but may increase the binary size.
3127 Building the Software:
3128 ======================
3130 Building U-Boot has been tested in several native build environments
3131 and in many different cross environments. Of course we cannot support
3132 all possibly existing versions of cross development tools in all
3133 (potentially obsolete) versions. In case of tool chain problems we
3134 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3135 which is extensively used to build and test U-Boot.
3137 If you are not using a native environment, it is assumed that you
3138 have GNU cross compiling tools available in your path. In this case,
3139 you must set the environment variable CROSS_COMPILE in your shell.
3140 Note that no changes to the Makefile or any other source files are
3141 necessary. For example using the ELDK on a 4xx CPU, please enter:
3143 $ CROSS_COMPILE=ppc_4xx-
3144 $ export CROSS_COMPILE
3146 Note: If you wish to generate Windows versions of the utilities in
3147 the tools directory you can use the MinGW toolchain
3148 (http://www.mingw.org). Set your HOST tools to the MinGW
3149 toolchain and execute 'make tools'. For example:
3151 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3153 Binaries such as tools/mkimage.exe will be created which can
3154 be executed on computers running Windows.
3156 U-Boot is intended to be simple to build. After installing the
3157 sources you must configure U-Boot for one specific board type. This
3162 where "NAME_config" is the name of one of the existing configu-
3163 rations; see the main Makefile for supported names.
3165 Note: for some board special configuration names may exist; check if
3166 additional information is available from the board vendor; for
3167 instance, the TQM823L systems are available without (standard)
3168 or with LCD support. You can select such additional "features"
3169 when choosing the configuration, i. e.
3172 - will configure for a plain TQM823L, i. e. no LCD support
3174 make TQM823L_LCD_config
3175 - will configure for a TQM823L with U-Boot console on LCD
3180 Finally, type "make all", and you should get some working U-Boot
3181 images ready for download to / installation on your system:
3183 - "u-boot.bin" is a raw binary image
3184 - "u-boot" is an image in ELF binary format
3185 - "u-boot.srec" is in Motorola S-Record format
3187 By default the build is performed locally and the objects are saved
3188 in the source directory. One of the two methods can be used to change
3189 this behavior and build U-Boot to some external directory:
3191 1. Add O= to the make command line invocations:
3193 make O=/tmp/build distclean
3194 make O=/tmp/build NAME_config
3195 make O=/tmp/build all
3197 2. Set environment variable BUILD_DIR to point to the desired location:
3199 export BUILD_DIR=/tmp/build
3204 Note that the command line "O=" setting overrides the BUILD_DIR environment
3208 Please be aware that the Makefiles assume you are using GNU make, so
3209 for instance on NetBSD you might need to use "gmake" instead of
3213 If the system board that you have is not listed, then you will need
3214 to port U-Boot to your hardware platform. To do this, follow these
3217 1. Add a new configuration option for your board to the toplevel
3218 "Makefile" and to the "MAKEALL" script, using the existing
3219 entries as examples. Note that here and at many other places
3220 boards and other names are listed in alphabetical sort order. Please
3222 2. Create a new directory to hold your board specific code. Add any
3223 files you need. In your board directory, you will need at least
3224 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
3225 3. Create a new configuration file "include/configs/<board>.h" for
3227 3. If you're porting U-Boot to a new CPU, then also create a new
3228 directory to hold your CPU specific code. Add any files you need.
3229 4. Run "make <board>_config" with your new name.
3230 5. Type "make", and you should get a working "u-boot.srec" file
3231 to be installed on your target system.
3232 6. Debug and solve any problems that might arise.
3233 [Of course, this last step is much harder than it sounds.]
3236 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3237 ==============================================================
3239 If you have modified U-Boot sources (for instance added a new board
3240 or support for new devices, a new CPU, etc.) you are expected to
3241 provide feedback to the other developers. The feedback normally takes
3242 the form of a "patch", i. e. a context diff against a certain (latest
3243 official or latest in the git repository) version of U-Boot sources.
3245 But before you submit such a patch, please verify that your modifi-
3246 cation did not break existing code. At least make sure that *ALL* of
3247 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3248 just run the "MAKEALL" script, which will configure and build U-Boot
3249 for ALL supported system. Be warned, this will take a while. You can
3250 select which (cross) compiler to use by passing a `CROSS_COMPILE'
3251 environment variable to the script, i. e. to use the ELDK cross tools
3254 CROSS_COMPILE=ppc_8xx- MAKEALL
3256 or to build on a native PowerPC system you can type
3258 CROSS_COMPILE=' ' MAKEALL
3260 When using the MAKEALL script, the default behaviour is to build
3261 U-Boot in the source directory. This location can be changed by
3262 setting the BUILD_DIR environment variable. Also, for each target
3263 built, the MAKEALL script saves two log files (<target>.ERR and
3264 <target>.MAKEALL) in the <source dir>/LOG directory. This default
3265 location can be changed by setting the MAKEALL_LOGDIR environment
3266 variable. For example:
3268 export BUILD_DIR=/tmp/build
3269 export MAKEALL_LOGDIR=/tmp/log
3270 CROSS_COMPILE=ppc_8xx- MAKEALL
3272 With the above settings build objects are saved in the /tmp/build,
3273 log files are saved in the /tmp/log and the source tree remains clean
3274 during the whole build process.
3277 See also "U-Boot Porting Guide" below.
3280 Monitor Commands - Overview:
3281 ============================
3283 go - start application at address 'addr'
3284 run - run commands in an environment variable
3285 bootm - boot application image from memory
3286 bootp - boot image via network using BootP/TFTP protocol
3287 tftpboot- boot image via network using TFTP protocol
3288 and env variables "ipaddr" and "serverip"
3289 (and eventually "gatewayip")
3290 rarpboot- boot image via network using RARP/TFTP protocol
3291 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3292 loads - load S-Record file over serial line
3293 loadb - load binary file over serial line (kermit mode)
3295 mm - memory modify (auto-incrementing)
3296 nm - memory modify (constant address)
3297 mw - memory write (fill)
3299 cmp - memory compare
3300 crc32 - checksum calculation
3301 i2c - I2C sub-system
3302 sspi - SPI utility commands
3303 base - print or set address offset
3304 printenv- print environment variables
3305 setenv - set environment variables
3306 saveenv - save environment variables to persistent storage
3307 protect - enable or disable FLASH write protection
3308 erase - erase FLASH memory
3309 flinfo - print FLASH memory information
3310 bdinfo - print Board Info structure
3311 iminfo - print header information for application image
3312 coninfo - print console devices and informations
3313 ide - IDE sub-system
3314 loop - infinite loop on address range
3315 loopw - infinite write loop on address range
3316 mtest - simple RAM test
3317 icache - enable or disable instruction cache
3318 dcache - enable or disable data cache
3319 reset - Perform RESET of the CPU
3320 echo - echo args to console
3321 version - print monitor version
3322 help - print online help
3323 ? - alias for 'help'
3326 Monitor Commands - Detailed Description:
3327 ========================================
3331 For now: just type "help <command>".
3334 Environment Variables:
3335 ======================
3337 U-Boot supports user configuration using Environment Variables which
3338 can be made persistent by saving to Flash memory.
3340 Environment Variables are set using "setenv", printed using
3341 "printenv", and saved to Flash using "saveenv". Using "setenv"
3342 without a value can be used to delete a variable from the
3343 environment. As long as you don't save the environment you are
3344 working with an in-memory copy. In case the Flash area containing the
3345 environment is erased by accident, a default environment is provided.
3347 Some configuration options can be set using Environment Variables.
3349 List of environment variables (most likely not complete):
3351 baudrate - see CONFIG_BAUDRATE
3353 bootdelay - see CONFIG_BOOTDELAY
3355 bootcmd - see CONFIG_BOOTCOMMAND
3357 bootargs - Boot arguments when booting an RTOS image
3359 bootfile - Name of the image to load with TFTP
3361 bootm_low - Memory range available for image processing in the bootm
3362 command can be restricted. This variable is given as
3363 a hexadecimal number and defines lowest address allowed
3364 for use by the bootm command. See also "bootm_size"
3365 environment variable. Address defined by "bootm_low" is
3366 also the base of the initial memory mapping for the Linux
3367 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
3370 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
3371 This variable is given as a hexadecimal number and it
3372 defines the size of the memory region starting at base
3373 address bootm_low that is accessible by the Linux kernel
3374 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
3375 as the default value if it is defined, and bootm_size is
3378 bootm_size - Memory range available for image processing in the bootm
3379 command can be restricted. This variable is given as
3380 a hexadecimal number and defines the size of the region
3381 allowed for use by the bootm command. See also "bootm_low"
3382 environment variable.
3384 updatefile - Location of the software update file on a TFTP server, used
3385 by the automatic software update feature. Please refer to
3386 documentation in doc/README.update for more details.
3388 autoload - if set to "no" (any string beginning with 'n'),
3389 "bootp" will just load perform a lookup of the
3390 configuration from the BOOTP server, but not try to
3391 load any image using TFTP
3393 autostart - if set to "yes", an image loaded using the "bootp",
3394 "rarpboot", "tftpboot" or "diskboot" commands will
3395 be automatically started (by internally calling
3398 If set to "no", a standalone image passed to the
3399 "bootm" command will be copied to the load address
3400 (and eventually uncompressed), but NOT be started.
3401 This can be used to load and uncompress arbitrary
3404 fdt_high - if set this restricts the maximum address that the
3405 flattened device tree will be copied into upon boot.
3406 If this is set to the special value 0xFFFFFFFF then
3407 the fdt will not be copied at all on boot. For this
3408 to work it must reside in writable memory, have
3409 sufficient padding on the end of it for u-boot to
3410 add the information it needs into it, and the memory
3411 must be accessible by the kernel.
3413 i2cfast - (PPC405GP|PPC405EP only)
3414 if set to 'y' configures Linux I2C driver for fast
3415 mode (400kHZ). This environment variable is used in
3416 initialization code. So, for changes to be effective
3417 it must be saved and board must be reset.
3419 initrd_high - restrict positioning of initrd images:
3420 If this variable is not set, initrd images will be
3421 copied to the highest possible address in RAM; this
3422 is usually what you want since it allows for
3423 maximum initrd size. If for some reason you want to
3424 make sure that the initrd image is loaded below the
3425 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3426 variable to a value of "no" or "off" or "0".
3427 Alternatively, you can set it to a maximum upper
3428 address to use (U-Boot will still check that it
3429 does not overwrite the U-Boot stack and data).
3431 For instance, when you have a system with 16 MB
3432 RAM, and want to reserve 4 MB from use by Linux,
3433 you can do this by adding "mem=12M" to the value of
3434 the "bootargs" variable. However, now you must make
3435 sure that the initrd image is placed in the first
3436 12 MB as well - this can be done with
3438 setenv initrd_high 00c00000
3440 If you set initrd_high to 0xFFFFFFFF, this is an
3441 indication to U-Boot that all addresses are legal
3442 for the Linux kernel, including addresses in flash
3443 memory. In this case U-Boot will NOT COPY the
3444 ramdisk at all. This may be useful to reduce the
3445 boot time on your system, but requires that this
3446 feature is supported by your Linux kernel.
3448 ipaddr - IP address; needed for tftpboot command
3450 loadaddr - Default load address for commands like "bootp",
3451 "rarpboot", "tftpboot", "loadb" or "diskboot"
3453 loads_echo - see CONFIG_LOADS_ECHO
3455 serverip - TFTP server IP address; needed for tftpboot command
3457 bootretry - see CONFIG_BOOT_RETRY_TIME
3459 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3461 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3463 ethprime - When CONFIG_NET_MULTI is enabled controls which
3464 interface is used first.
3466 ethact - When CONFIG_NET_MULTI is enabled controls which
3467 interface is currently active. For example you
3468 can do the following
3470 => setenv ethact FEC
3471 => ping 192.168.0.1 # traffic sent on FEC
3472 => setenv ethact SCC
3473 => ping 10.0.0.1 # traffic sent on SCC
3475 ethrotate - When set to "no" U-Boot does not go through all
3476 available network interfaces.
3477 It just stays at the currently selected interface.
3479 netretry - When set to "no" each network operation will
3480 either succeed or fail without retrying.
3481 When set to "once" the network operation will
3482 fail when all the available network interfaces
3483 are tried once without success.
3484 Useful on scripts which control the retry operation
3487 npe_ucode - set load address for the NPE microcode
3489 tftpsrcport - If this is set, the value is used for TFTP's
3492 tftpdstport - If this is set, the value is used for TFTP's UDP
3493 destination port instead of the Well Know Port 69.
3495 tftpblocksize - Block size to use for TFTP transfers; if not set,
3496 we use the TFTP server's default block size
3498 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3499 seconds, minimum value is 1000 = 1 second). Defines
3500 when a packet is considered to be lost so it has to
3501 be retransmitted. The default is 5000 = 5 seconds.
3502 Lowering this value may make downloads succeed
3503 faster in networks with high packet loss rates or
3504 with unreliable TFTP servers.
3506 vlan - When set to a value < 4095 the traffic over
3507 Ethernet is encapsulated/received over 802.1q
3510 The following environment variables may be used and automatically
3511 updated by the network boot commands ("bootp" and "rarpboot"),
3512 depending the information provided by your boot server:
3514 bootfile - see above
3515 dnsip - IP address of your Domain Name Server
3516 dnsip2 - IP address of your secondary Domain Name Server
3517 gatewayip - IP address of the Gateway (Router) to use
3518 hostname - Target hostname
3520 netmask - Subnet Mask
3521 rootpath - Pathname of the root filesystem on the NFS server
3522 serverip - see above
3525 There are two special Environment Variables:
3527 serial# - contains hardware identification information such
3528 as type string and/or serial number
3529 ethaddr - Ethernet address
3531 These variables can be set only once (usually during manufacturing of
3532 the board). U-Boot refuses to delete or overwrite these variables
3533 once they have been set once.
3536 Further special Environment Variables:
3538 ver - Contains the U-Boot version string as printed
3539 with the "version" command. This variable is
3540 readonly (see CONFIG_VERSION_VARIABLE).
3543 Please note that changes to some configuration parameters may take
3544 only effect after the next boot (yes, that's just like Windoze :-).
3547 Command Line Parsing:
3548 =====================
3550 There are two different command line parsers available with U-Boot:
3551 the old "simple" one, and the much more powerful "hush" shell:
3553 Old, simple command line parser:
3554 --------------------------------
3556 - supports environment variables (through setenv / saveenv commands)
3557 - several commands on one line, separated by ';'
3558 - variable substitution using "... ${name} ..." syntax
3559 - special characters ('$', ';') can be escaped by prefixing with '\',
3561 setenv bootcmd bootm \${address}
3562 - You can also escape text by enclosing in single apostrophes, for example:
3563 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3568 - similar to Bourne shell, with control structures like
3569 if...then...else...fi, for...do...done; while...do...done,
3570 until...do...done, ...
3571 - supports environment ("global") variables (through setenv / saveenv
3572 commands) and local shell variables (through standard shell syntax
3573 "name=value"); only environment variables can be used with "run"
3579 (1) If a command line (or an environment variable executed by a "run"
3580 command) contains several commands separated by semicolon, and
3581 one of these commands fails, then the remaining commands will be
3584 (2) If you execute several variables with one call to run (i. e.
3585 calling run with a list of variables as arguments), any failing
3586 command will cause "run" to terminate, i. e. the remaining
3587 variables are not executed.
3589 Note for Redundant Ethernet Interfaces:
3590 =======================================
3592 Some boards come with redundant Ethernet interfaces; U-Boot supports
3593 such configurations and is capable of automatic selection of a
3594 "working" interface when needed. MAC assignment works as follows:
3596 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3597 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3598 "eth1addr" (=>eth1), "eth2addr", ...
3600 If the network interface stores some valid MAC address (for instance
3601 in SROM), this is used as default address if there is NO correspon-
3602 ding setting in the environment; if the corresponding environment
3603 variable is set, this overrides the settings in the card; that means:
3605 o If the SROM has a valid MAC address, and there is no address in the
3606 environment, the SROM's address is used.
3608 o If there is no valid address in the SROM, and a definition in the
3609 environment exists, then the value from the environment variable is
3612 o If both the SROM and the environment contain a MAC address, and
3613 both addresses are the same, this MAC address is used.
3615 o If both the SROM and the environment contain a MAC address, and the
3616 addresses differ, the value from the environment is used and a
3619 o If neither SROM nor the environment contain a MAC address, an error
3622 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
3623 will be programmed into hardware as part of the initialization process. This
3624 may be skipped by setting the appropriate 'ethmacskip' environment variable.
3625 The naming convention is as follows:
3626 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
3631 U-Boot is capable of booting (and performing other auxiliary operations on)
3632 images in two formats:
3634 New uImage format (FIT)
3635 -----------------------
3637 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3638 to Flattened Device Tree). It allows the use of images with multiple
3639 components (several kernels, ramdisks, etc.), with contents protected by
3640 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3646 Old image format is based on binary files which can be basically anything,
3647 preceded by a special header; see the definitions in include/image.h for
3648 details; basically, the header defines the following image properties:
3650 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3651 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3652 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3653 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3655 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3656 IA64, MIPS, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3657 Currently supported: ARM, AVR32, Intel x86, MIPS, Nios II, PowerPC).
3658 * Compression Type (uncompressed, gzip, bzip2)
3664 The header is marked by a special Magic Number, and both the header
3665 and the data portions of the image are secured against corruption by
3672 Although U-Boot should support any OS or standalone application
3673 easily, the main focus has always been on Linux during the design of
3676 U-Boot includes many features that so far have been part of some
3677 special "boot loader" code within the Linux kernel. Also, any
3678 "initrd" images to be used are no longer part of one big Linux image;
3679 instead, kernel and "initrd" are separate images. This implementation
3680 serves several purposes:
3682 - the same features can be used for other OS or standalone
3683 applications (for instance: using compressed images to reduce the
3684 Flash memory footprint)
3686 - it becomes much easier to port new Linux kernel versions because
3687 lots of low-level, hardware dependent stuff are done by U-Boot
3689 - the same Linux kernel image can now be used with different "initrd"
3690 images; of course this also means that different kernel images can
3691 be run with the same "initrd". This makes testing easier (you don't
3692 have to build a new "zImage.initrd" Linux image when you just
3693 change a file in your "initrd"). Also, a field-upgrade of the
3694 software is easier now.
3700 Porting Linux to U-Boot based systems:
3701 ---------------------------------------
3703 U-Boot cannot save you from doing all the necessary modifications to
3704 configure the Linux device drivers for use with your target hardware
3705 (no, we don't intend to provide a full virtual machine interface to
3708 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
3710 Just make sure your machine specific header file (for instance
3711 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3712 Information structure as we define in include/asm-<arch>/u-boot.h,
3713 and make sure that your definition of IMAP_ADDR uses the same value
3714 as your U-Boot configuration in CONFIG_SYS_IMMR.
3717 Configuring the Linux kernel:
3718 -----------------------------
3720 No specific requirements for U-Boot. Make sure you have some root
3721 device (initial ramdisk, NFS) for your target system.
3724 Building a Linux Image:
3725 -----------------------
3727 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3728 not used. If you use recent kernel source, a new build target
3729 "uImage" will exist which automatically builds an image usable by
3730 U-Boot. Most older kernels also have support for a "pImage" target,
3731 which was introduced for our predecessor project PPCBoot and uses a
3732 100% compatible format.
3741 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3742 encapsulate a compressed Linux kernel image with header information,
3743 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3745 * build a standard "vmlinux" kernel image (in ELF binary format):
3747 * convert the kernel into a raw binary image:
3749 ${CROSS_COMPILE}-objcopy -O binary \
3750 -R .note -R .comment \
3751 -S vmlinux linux.bin
3753 * compress the binary image:
3757 * package compressed binary image for U-Boot:
3759 mkimage -A ppc -O linux -T kernel -C gzip \
3760 -a 0 -e 0 -n "Linux Kernel Image" \
3761 -d linux.bin.gz uImage
3764 The "mkimage" tool can also be used to create ramdisk images for use
3765 with U-Boot, either separated from the Linux kernel image, or
3766 combined into one file. "mkimage" encapsulates the images with a 64
3767 byte header containing information about target architecture,
3768 operating system, image type, compression method, entry points, time
3769 stamp, CRC32 checksums, etc.
3771 "mkimage" can be called in two ways: to verify existing images and
3772 print the header information, or to build new images.
3774 In the first form (with "-l" option) mkimage lists the information
3775 contained in the header of an existing U-Boot image; this includes
3776 checksum verification:
3778 tools/mkimage -l image
3779 -l ==> list image header information
3781 The second form (with "-d" option) is used to build a U-Boot image
3782 from a "data file" which is used as image payload:
3784 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3785 -n name -d data_file image
3786 -A ==> set architecture to 'arch'
3787 -O ==> set operating system to 'os'
3788 -T ==> set image type to 'type'
3789 -C ==> set compression type 'comp'
3790 -a ==> set load address to 'addr' (hex)
3791 -e ==> set entry point to 'ep' (hex)
3792 -n ==> set image name to 'name'
3793 -d ==> use image data from 'datafile'
3795 Right now, all Linux kernels for PowerPC systems use the same load
3796 address (0x00000000), but the entry point address depends on the
3799 - 2.2.x kernels have the entry point at 0x0000000C,
3800 - 2.3.x and later kernels have the entry point at 0x00000000.
3802 So a typical call to build a U-Boot image would read:
3804 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3805 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3806 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
3807 > examples/uImage.TQM850L
3808 Image Name: 2.4.4 kernel for TQM850L
3809 Created: Wed Jul 19 02:34:59 2000
3810 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3811 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3812 Load Address: 0x00000000
3813 Entry Point: 0x00000000
3815 To verify the contents of the image (or check for corruption):
3817 -> tools/mkimage -l examples/uImage.TQM850L
3818 Image Name: 2.4.4 kernel for TQM850L
3819 Created: Wed Jul 19 02:34:59 2000
3820 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3821 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3822 Load Address: 0x00000000
3823 Entry Point: 0x00000000
3825 NOTE: for embedded systems where boot time is critical you can trade
3826 speed for memory and install an UNCOMPRESSED image instead: this
3827 needs more space in Flash, but boots much faster since it does not
3828 need to be uncompressed:
3830 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
3831 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3832 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3833 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
3834 > examples/uImage.TQM850L-uncompressed
3835 Image Name: 2.4.4 kernel for TQM850L
3836 Created: Wed Jul 19 02:34:59 2000
3837 Image Type: PowerPC Linux Kernel Image (uncompressed)
3838 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3839 Load Address: 0x00000000
3840 Entry Point: 0x00000000
3843 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3844 when your kernel is intended to use an initial ramdisk:
3846 -> tools/mkimage -n 'Simple Ramdisk Image' \
3847 > -A ppc -O linux -T ramdisk -C gzip \
3848 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3849 Image Name: Simple Ramdisk Image
3850 Created: Wed Jan 12 14:01:50 2000
3851 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3852 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3853 Load Address: 0x00000000
3854 Entry Point: 0x00000000
3857 Installing a Linux Image:
3858 -------------------------
3860 To downloading a U-Boot image over the serial (console) interface,
3861 you must convert the image to S-Record format:
3863 objcopy -I binary -O srec examples/image examples/image.srec
3865 The 'objcopy' does not understand the information in the U-Boot
3866 image header, so the resulting S-Record file will be relative to
3867 address 0x00000000. To load it to a given address, you need to
3868 specify the target address as 'offset' parameter with the 'loads'
3871 Example: install the image to address 0x40100000 (which on the
3872 TQM8xxL is in the first Flash bank):
3874 => erase 40100000 401FFFFF
3880 ## Ready for S-Record download ...
3881 ~>examples/image.srec
3882 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3884 15989 15990 15991 15992
3885 [file transfer complete]
3887 ## Start Addr = 0x00000000
3890 You can check the success of the download using the 'iminfo' command;
3891 this includes a checksum verification so you can be sure no data
3892 corruption happened:
3896 ## Checking Image at 40100000 ...
3897 Image Name: 2.2.13 for initrd on TQM850L
3898 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3899 Data Size: 335725 Bytes = 327 kB = 0 MB
3900 Load Address: 00000000
3901 Entry Point: 0000000c
3902 Verifying Checksum ... OK
3908 The "bootm" command is used to boot an application that is stored in
3909 memory (RAM or Flash). In case of a Linux kernel image, the contents
3910 of the "bootargs" environment variable is passed to the kernel as
3911 parameters. You can check and modify this variable using the
3912 "printenv" and "setenv" commands:
3915 => printenv bootargs
3916 bootargs=root=/dev/ram
3918 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3920 => printenv bootargs
3921 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3924 ## Booting Linux kernel at 40020000 ...
3925 Image Name: 2.2.13 for NFS on TQM850L
3926 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3927 Data Size: 381681 Bytes = 372 kB = 0 MB
3928 Load Address: 00000000
3929 Entry Point: 0000000c
3930 Verifying Checksum ... OK
3931 Uncompressing Kernel Image ... OK
3932 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
3933 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3934 time_init: decrementer frequency = 187500000/60
3935 Calibrating delay loop... 49.77 BogoMIPS
3936 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3939 If you want to boot a Linux kernel with initial RAM disk, you pass
3940 the memory addresses of both the kernel and the initrd image (PPBCOOT
3941 format!) to the "bootm" command:
3943 => imi 40100000 40200000
3945 ## Checking Image at 40100000 ...
3946 Image Name: 2.2.13 for initrd on TQM850L
3947 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3948 Data Size: 335725 Bytes = 327 kB = 0 MB
3949 Load Address: 00000000
3950 Entry Point: 0000000c
3951 Verifying Checksum ... OK
3953 ## Checking Image at 40200000 ...
3954 Image Name: Simple Ramdisk Image
3955 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3956 Data Size: 566530 Bytes = 553 kB = 0 MB
3957 Load Address: 00000000
3958 Entry Point: 00000000
3959 Verifying Checksum ... OK
3961 => bootm 40100000 40200000
3962 ## Booting Linux kernel at 40100000 ...
3963 Image Name: 2.2.13 for initrd on TQM850L
3964 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3965 Data Size: 335725 Bytes = 327 kB = 0 MB
3966 Load Address: 00000000
3967 Entry Point: 0000000c
3968 Verifying Checksum ... OK
3969 Uncompressing Kernel Image ... OK
3970 ## Loading RAMDisk Image at 40200000 ...
3971 Image Name: Simple Ramdisk Image
3972 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3973 Data Size: 566530 Bytes = 553 kB = 0 MB
3974 Load Address: 00000000
3975 Entry Point: 00000000
3976 Verifying Checksum ... OK
3977 Loading Ramdisk ... OK
3978 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
3979 Boot arguments: root=/dev/ram
3980 time_init: decrementer frequency = 187500000/60
3981 Calibrating delay loop... 49.77 BogoMIPS
3983 RAMDISK: Compressed image found at block 0
3984 VFS: Mounted root (ext2 filesystem).
3988 Boot Linux and pass a flat device tree:
3991 First, U-Boot must be compiled with the appropriate defines. See the section
3992 titled "Linux Kernel Interface" above for a more in depth explanation. The
3993 following is an example of how to start a kernel and pass an updated
3999 oft=oftrees/mpc8540ads.dtb
4000 => tftp $oftaddr $oft
4001 Speed: 1000, full duplex
4003 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4004 Filename 'oftrees/mpc8540ads.dtb'.
4005 Load address: 0x300000
4008 Bytes transferred = 4106 (100a hex)
4009 => tftp $loadaddr $bootfile
4010 Speed: 1000, full duplex
4012 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4014 Load address: 0x200000
4015 Loading:############
4017 Bytes transferred = 1029407 (fb51f hex)
4022 => bootm $loadaddr - $oftaddr
4023 ## Booting image at 00200000 ...
4024 Image Name: Linux-2.6.17-dirty
4025 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4026 Data Size: 1029343 Bytes = 1005.2 kB
4027 Load Address: 00000000
4028 Entry Point: 00000000
4029 Verifying Checksum ... OK
4030 Uncompressing Kernel Image ... OK
4031 Booting using flat device tree at 0x300000
4032 Using MPC85xx ADS machine description
4033 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4037 More About U-Boot Image Types:
4038 ------------------------------
4040 U-Boot supports the following image types:
4042 "Standalone Programs" are directly runnable in the environment
4043 provided by U-Boot; it is expected that (if they behave
4044 well) you can continue to work in U-Boot after return from
4045 the Standalone Program.
4046 "OS Kernel Images" are usually images of some Embedded OS which
4047 will take over control completely. Usually these programs
4048 will install their own set of exception handlers, device
4049 drivers, set up the MMU, etc. - this means, that you cannot
4050 expect to re-enter U-Boot except by resetting the CPU.
4051 "RAMDisk Images" are more or less just data blocks, and their
4052 parameters (address, size) are passed to an OS kernel that is
4054 "Multi-File Images" contain several images, typically an OS
4055 (Linux) kernel image and one or more data images like
4056 RAMDisks. This construct is useful for instance when you want
4057 to boot over the network using BOOTP etc., where the boot
4058 server provides just a single image file, but you want to get
4059 for instance an OS kernel and a RAMDisk image.
4061 "Multi-File Images" start with a list of image sizes, each
4062 image size (in bytes) specified by an "uint32_t" in network
4063 byte order. This list is terminated by an "(uint32_t)0".
4064 Immediately after the terminating 0 follow the images, one by
4065 one, all aligned on "uint32_t" boundaries (size rounded up to
4066 a multiple of 4 bytes).
4068 "Firmware Images" are binary images containing firmware (like
4069 U-Boot or FPGA images) which usually will be programmed to
4072 "Script files" are command sequences that will be executed by
4073 U-Boot's command interpreter; this feature is especially
4074 useful when you configure U-Boot to use a real shell (hush)
4075 as command interpreter.
4081 One of the features of U-Boot is that you can dynamically load and
4082 run "standalone" applications, which can use some resources of
4083 U-Boot like console I/O functions or interrupt services.
4085 Two simple examples are included with the sources:
4090 'examples/hello_world.c' contains a small "Hello World" Demo
4091 application; it is automatically compiled when you build U-Boot.
4092 It's configured to run at address 0x00040004, so you can play with it
4096 ## Ready for S-Record download ...
4097 ~>examples/hello_world.srec
4098 1 2 3 4 5 6 7 8 9 10 11 ...
4099 [file transfer complete]
4101 ## Start Addr = 0x00040004
4103 => go 40004 Hello World! This is a test.
4104 ## Starting application at 0x00040004 ...
4115 Hit any key to exit ...
4117 ## Application terminated, rc = 0x0
4119 Another example, which demonstrates how to register a CPM interrupt
4120 handler with the U-Boot code, can be found in 'examples/timer.c'.
4121 Here, a CPM timer is set up to generate an interrupt every second.
4122 The interrupt service routine is trivial, just printing a '.'
4123 character, but this is just a demo program. The application can be
4124 controlled by the following keys:
4126 ? - print current values og the CPM Timer registers
4127 b - enable interrupts and start timer
4128 e - stop timer and disable interrupts
4129 q - quit application
4132 ## Ready for S-Record download ...
4133 ~>examples/timer.srec
4134 1 2 3 4 5 6 7 8 9 10 11 ...
4135 [file transfer complete]
4137 ## Start Addr = 0x00040004
4140 ## Starting application at 0x00040004 ...
4143 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
4146 [q, b, e, ?] Set interval 1000000 us
4149 [q, b, e, ?] ........
4150 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
4153 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
4156 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
4159 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
4161 [q, b, e, ?] ...Stopping timer
4163 [q, b, e, ?] ## Application terminated, rc = 0x0
4169 Over time, many people have reported problems when trying to use the
4170 "minicom" terminal emulation program for serial download. I (wd)
4171 consider minicom to be broken, and recommend not to use it. Under
4172 Unix, I recommend to use C-Kermit for general purpose use (and
4173 especially for kermit binary protocol download ("loadb" command), and
4174 use "cu" for S-Record download ("loads" command).
4176 Nevertheless, if you absolutely want to use it try adding this
4177 configuration to your "File transfer protocols" section:
4179 Name Program Name U/D FullScr IO-Red. Multi
4180 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
4181 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
4187 Starting at version 0.9.2, U-Boot supports NetBSD both as host
4188 (build U-Boot) and target system (boots NetBSD/mpc8xx).
4190 Building requires a cross environment; it is known to work on
4191 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
4192 need gmake since the Makefiles are not compatible with BSD make).
4193 Note that the cross-powerpc package does not install include files;
4194 attempting to build U-Boot will fail because <machine/ansi.h> is
4195 missing. This file has to be installed and patched manually:
4197 # cd /usr/pkg/cross/powerpc-netbsd/include
4199 # ln -s powerpc machine
4200 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
4201 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
4203 Native builds *don't* work due to incompatibilities between native
4204 and U-Boot include files.
4206 Booting assumes that (the first part of) the image booted is a
4207 stage-2 loader which in turn loads and then invokes the kernel
4208 proper. Loader sources will eventually appear in the NetBSD source
4209 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
4210 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
4213 Implementation Internals:
4214 =========================
4216 The following is not intended to be a complete description of every
4217 implementation detail. However, it should help to understand the
4218 inner workings of U-Boot and make it easier to port it to custom
4222 Initial Stack, Global Data:
4223 ---------------------------
4225 The implementation of U-Boot is complicated by the fact that U-Boot
4226 starts running out of ROM (flash memory), usually without access to
4227 system RAM (because the memory controller is not initialized yet).
4228 This means that we don't have writable Data or BSS segments, and BSS
4229 is not initialized as zero. To be able to get a C environment working
4230 at all, we have to allocate at least a minimal stack. Implementation
4231 options for this are defined and restricted by the CPU used: Some CPU
4232 models provide on-chip memory (like the IMMR area on MPC8xx and
4233 MPC826x processors), on others (parts of) the data cache can be
4234 locked as (mis-) used as memory, etc.
4236 Chris Hallinan posted a good summary of these issues to the
4237 U-Boot mailing list:
4239 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
4240 From: "Chris Hallinan" <clh@net1plus.com>
4241 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
4244 Correct me if I'm wrong, folks, but the way I understand it
4245 is this: Using DCACHE as initial RAM for Stack, etc, does not
4246 require any physical RAM backing up the cache. The cleverness
4247 is that the cache is being used as a temporary supply of
4248 necessary storage before the SDRAM controller is setup. It's
4249 beyond the scope of this list to explain the details, but you
4250 can see how this works by studying the cache architecture and
4251 operation in the architecture and processor-specific manuals.
4253 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4254 is another option for the system designer to use as an
4255 initial stack/RAM area prior to SDRAM being available. Either
4256 option should work for you. Using CS 4 should be fine if your
4257 board designers haven't used it for something that would
4258 cause you grief during the initial boot! It is frequently not
4261 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
4262 with your processor/board/system design. The default value
4263 you will find in any recent u-boot distribution in
4264 walnut.h should work for you. I'd set it to a value larger
4265 than your SDRAM module. If you have a 64MB SDRAM module, set
4266 it above 400_0000. Just make sure your board has no resources
4267 that are supposed to respond to that address! That code in
4268 start.S has been around a while and should work as is when
4269 you get the config right.
4274 It is essential to remember this, since it has some impact on the C
4275 code for the initialization procedures:
4277 * Initialized global data (data segment) is read-only. Do not attempt
4280 * Do not use any uninitialized global data (or implicitely initialized
4281 as zero data - BSS segment) at all - this is undefined, initiali-
4282 zation is performed later (when relocating to RAM).
4284 * Stack space is very limited. Avoid big data buffers or things like
4287 Having only the stack as writable memory limits means we cannot use
4288 normal global data to share information beween the code. But it
4289 turned out that the implementation of U-Boot can be greatly
4290 simplified by making a global data structure (gd_t) available to all
4291 functions. We could pass a pointer to this data as argument to _all_
4292 functions, but this would bloat the code. Instead we use a feature of
4293 the GCC compiler (Global Register Variables) to share the data: we
4294 place a pointer (gd) to the global data into a register which we
4295 reserve for this purpose.
4297 When choosing a register for such a purpose we are restricted by the
4298 relevant (E)ABI specifications for the current architecture, and by
4299 GCC's implementation.
4301 For PowerPC, the following registers have specific use:
4303 R2: reserved for system use
4304 R3-R4: parameter passing and return values
4305 R5-R10: parameter passing
4306 R13: small data area pointer
4310 (U-Boot also uses R12 as internal GOT pointer. r12
4311 is a volatile register so r12 needs to be reset when
4312 going back and forth between asm and C)
4314 ==> U-Boot will use R2 to hold a pointer to the global data
4316 Note: on PPC, we could use a static initializer (since the
4317 address of the global data structure is known at compile time),
4318 but it turned out that reserving a register results in somewhat
4319 smaller code - although the code savings are not that big (on
4320 average for all boards 752 bytes for the whole U-Boot image,
4321 624 text + 127 data).
4323 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
4324 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
4326 ==> U-Boot will use P3 to hold a pointer to the global data
4328 On ARM, the following registers are used:
4330 R0: function argument word/integer result
4331 R1-R3: function argument word
4333 R10: stack limit (used only if stack checking if enabled)
4334 R11: argument (frame) pointer
4335 R12: temporary workspace
4338 R15: program counter
4340 ==> U-Boot will use R8 to hold a pointer to the global data
4342 On Nios II, the ABI is documented here:
4343 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4345 ==> U-Boot will use gp to hold a pointer to the global data
4347 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4348 to access small data sections, so gp is free.
4350 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4351 or current versions of GCC may "optimize" the code too much.
4356 U-Boot runs in system state and uses physical addresses, i.e. the
4357 MMU is not used either for address mapping nor for memory protection.
4359 The available memory is mapped to fixed addresses using the memory
4360 controller. In this process, a contiguous block is formed for each
4361 memory type (Flash, SDRAM, SRAM), even when it consists of several
4362 physical memory banks.
4364 U-Boot is installed in the first 128 kB of the first Flash bank (on
4365 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4366 booting and sizing and initializing DRAM, the code relocates itself
4367 to the upper end of DRAM. Immediately below the U-Boot code some
4368 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
4369 configuration setting]. Below that, a structure with global Board
4370 Info data is placed, followed by the stack (growing downward).
4372 Additionally, some exception handler code is copied to the low 8 kB
4373 of DRAM (0x00000000 ... 0x00001FFF).
4375 So a typical memory configuration with 16 MB of DRAM could look like
4378 0x0000 0000 Exception Vector code
4381 0x0000 2000 Free for Application Use
4387 0x00FB FF20 Monitor Stack (Growing downward)
4388 0x00FB FFAC Board Info Data and permanent copy of global data
4389 0x00FC 0000 Malloc Arena
4392 0x00FE 0000 RAM Copy of Monitor Code
4393 ... eventually: LCD or video framebuffer
4394 ... eventually: pRAM (Protected RAM - unchanged by reset)
4395 0x00FF FFFF [End of RAM]
4398 System Initialization:
4399 ----------------------
4401 In the reset configuration, U-Boot starts at the reset entry point
4402 (on most PowerPC systems at address 0x00000100). Because of the reset
4403 configuration for CS0# this is a mirror of the onboard Flash memory.
4404 To be able to re-map memory U-Boot then jumps to its link address.
4405 To be able to implement the initialization code in C, a (small!)
4406 initial stack is set up in the internal Dual Ported RAM (in case CPUs
4407 which provide such a feature like MPC8xx or MPC8260), or in a locked
4408 part of the data cache. After that, U-Boot initializes the CPU core,
4409 the caches and the SIU.
4411 Next, all (potentially) available memory banks are mapped using a
4412 preliminary mapping. For example, we put them on 512 MB boundaries
4413 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4414 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4415 programmed for SDRAM access. Using the temporary configuration, a
4416 simple memory test is run that determines the size of the SDRAM
4419 When there is more than one SDRAM bank, and the banks are of
4420 different size, the largest is mapped first. For equal size, the first
4421 bank (CS2#) is mapped first. The first mapping is always for address
4422 0x00000000, with any additional banks following immediately to create
4423 contiguous memory starting from 0.
4425 Then, the monitor installs itself at the upper end of the SDRAM area
4426 and allocates memory for use by malloc() and for the global Board
4427 Info data; also, the exception vector code is copied to the low RAM
4428 pages, and the final stack is set up.
4430 Only after this relocation will you have a "normal" C environment;
4431 until that you are restricted in several ways, mostly because you are
4432 running from ROM, and because the code will have to be relocated to a
4436 U-Boot Porting Guide:
4437 ----------------------
4439 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4443 int main(int argc, char *argv[])
4445 sighandler_t no_more_time;
4447 signal(SIGALRM, no_more_time);
4448 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4450 if (available_money > available_manpower) {
4451 Pay consultant to port U-Boot;
4455 Download latest U-Boot source;
4457 Subscribe to u-boot mailing list;
4460 email("Hi, I am new to U-Boot, how do I get started?");
4463 Read the README file in the top level directory;
4464 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4465 Read applicable doc/*.README;
4466 Read the source, Luke;
4467 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4470 if (available_money > toLocalCurrency ($2500))
4473 Add a lot of aggravation and time;
4475 if (a similar board exists) { /* hopefully... */
4476 cp -a board/<similar> board/<myboard>
4477 cp include/configs/<similar>.h include/configs/<myboard>.h
4479 Create your own board support subdirectory;
4480 Create your own board include/configs/<myboard>.h file;
4482 Edit new board/<myboard> files
4483 Edit new include/configs/<myboard>.h
4488 Add / modify source code;
4492 email("Hi, I am having problems...");
4494 Send patch file to the U-Boot email list;
4495 if (reasonable critiques)
4496 Incorporate improvements from email list code review;
4498 Defend code as written;
4504 void no_more_time (int sig)
4513 All contributions to U-Boot should conform to the Linux kernel
4514 coding style; see the file "Documentation/CodingStyle" and the script
4515 "scripts/Lindent" in your Linux kernel source directory.
4517 Source files originating from a different project (for example the
4518 MTD subsystem) are generally exempt from these guidelines and are not
4519 reformated to ease subsequent migration to newer versions of those
4522 Please note that U-Boot is implemented in C (and to some small parts in
4523 Assembler); no C++ is used, so please do not use C++ style comments (//)
4526 Please also stick to the following formatting rules:
4527 - remove any trailing white space
4528 - use TAB characters for indentation and vertical alignment, not spaces
4529 - make sure NOT to use DOS '\r\n' line feeds
4530 - do not add more than 2 consecutive empty lines to source files
4531 - do not add trailing empty lines to source files
4533 Submissions which do not conform to the standards may be returned
4534 with a request to reformat the changes.
4540 Since the number of patches for U-Boot is growing, we need to
4541 establish some rules. Submissions which do not conform to these rules
4542 may be rejected, even when they contain important and valuable stuff.
4544 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4546 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4547 see http://lists.denx.de/mailman/listinfo/u-boot
4549 When you send a patch, please include the following information with
4552 * For bug fixes: a description of the bug and how your patch fixes
4553 this bug. Please try to include a way of demonstrating that the
4554 patch actually fixes something.
4556 * For new features: a description of the feature and your
4559 * A CHANGELOG entry as plaintext (separate from the patch)
4561 * For major contributions, your entry to the CREDITS file
4563 * When you add support for a new board, don't forget to add this
4564 board to the MAINTAINERS file, too.
4566 * If your patch adds new configuration options, don't forget to
4567 document these in the README file.
4569 * The patch itself. If you are using git (which is *strongly*
4570 recommended) you can easily generate the patch using the
4571 "git format-patch". If you then use "git send-email" to send it to
4572 the U-Boot mailing list, you will avoid most of the common problems
4573 with some other mail clients.
4575 If you cannot use git, use "diff -purN OLD NEW". If your version of
4576 diff does not support these options, then get the latest version of
4579 The current directory when running this command shall be the parent
4580 directory of the U-Boot source tree (i. e. please make sure that
4581 your patch includes sufficient directory information for the
4584 We prefer patches as plain text. MIME attachments are discouraged,
4585 and compressed attachments must not be used.
4587 * If one logical set of modifications affects or creates several
4588 files, all these changes shall be submitted in a SINGLE patch file.
4590 * Changesets that contain different, unrelated modifications shall be
4591 submitted as SEPARATE patches, one patch per changeset.
4596 * Before sending the patch, run the MAKEALL script on your patched
4597 source tree and make sure that no errors or warnings are reported
4598 for any of the boards.
4600 * Keep your modifications to the necessary minimum: A patch
4601 containing several unrelated changes or arbitrary reformats will be
4602 returned with a request to re-formatting / split it.
4604 * If you modify existing code, make sure that your new code does not
4605 add to the memory footprint of the code ;-) Small is beautiful!
4606 When adding new features, these should compile conditionally only
4607 (using #ifdef), and the resulting code with the new feature
4608 disabled must not need more memory than the old code without your
4611 * Remember that there is a size limit of 100 kB per message on the
4612 u-boot mailing list. Bigger patches will be moderated. If they are
4613 reasonable and not too big, they will be acknowledged. But patches
4614 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob