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 /lib Architecture specific library files
184 /nios2 Files generic to Altera NIOS2 architecture
185 /cpu CPU specific files
186 /lib Architecture specific library files
187 /powerpc Files generic to PowerPC architecture
188 /cpu CPU specific files
189 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
190 /mpc5xx Files specific to Freescale MPC5xx CPUs
191 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
192 /mpc8xx Files specific to Freescale MPC8xx CPUs
193 /mpc8220 Files specific to Freescale MPC8220 CPUs
194 /mpc824x Files specific to Freescale MPC824x CPUs
195 /mpc8260 Files specific to Freescale MPC8260 CPUs
196 /mpc85xx Files specific to Freescale MPC85xx CPUs
197 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
198 /lib Architecture specific library files
199 /sh Files generic to SH architecture
200 /cpu CPU specific files
201 /sh2 Files specific to sh2 CPUs
202 /sh3 Files specific to sh3 CPUs
203 /sh4 Files specific to sh4 CPUs
204 /lib Architecture specific library files
205 /sparc Files generic to SPARC architecture
206 /cpu CPU specific files
207 /leon2 Files specific to Gaisler LEON2 SPARC CPU
208 /leon3 Files specific to Gaisler LEON3 SPARC CPU
209 /lib Architecture specific library files
210 /api Machine/arch independent API for external apps
211 /board Board dependent files
212 /common Misc architecture independent functions
213 /disk Code for disk drive partition handling
214 /doc Documentation (don't expect too much)
215 /drivers Commonly used device drivers
216 /examples Example code for standalone applications, etc.
217 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
218 /include Header Files
219 /lib Files generic to all architectures
220 /libfdt Library files to support flattened device trees
221 /lzma Library files to support LZMA decompression
222 /lzo Library files to support LZO decompression
224 /post Power On Self Test
225 /rtc Real Time Clock drivers
226 /tools Tools to build S-Record or U-Boot images, etc.
228 Software Configuration:
229 =======================
231 Configuration is usually done using C preprocessor defines; the
232 rationale behind that is to avoid dead code whenever possible.
234 There are two classes of configuration variables:
236 * Configuration _OPTIONS_:
237 These are selectable by the user and have names beginning with
240 * Configuration _SETTINGS_:
241 These depend on the hardware etc. and should not be meddled with if
242 you don't know what you're doing; they have names beginning with
245 Later we will add a configuration tool - probably similar to or even
246 identical to what's used for the Linux kernel. Right now, we have to
247 do the configuration by hand, which means creating some symbolic
248 links and editing some configuration files. We use the TQM8xxL boards
252 Selection of Processor Architecture and Board Type:
253 ---------------------------------------------------
255 For all supported boards there are ready-to-use default
256 configurations available; just type "make <board_name>_config".
258 Example: For a TQM823L module type:
263 For the Cogent platform, you need to specify the CPU type as well;
264 e.g. "make cogent_mpc8xx_config". And also configure the cogent
265 directory according to the instructions in cogent/README.
268 Configuration Options:
269 ----------------------
271 Configuration depends on the combination of board and CPU type; all
272 such information is kept in a configuration file
273 "include/configs/<board_name>.h".
275 Example: For a TQM823L module, all configuration settings are in
276 "include/configs/TQM823L.h".
279 Many of the options are named exactly as the corresponding Linux
280 kernel configuration options. The intention is to make it easier to
281 build a config tool - later.
284 The following options need to be configured:
286 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
288 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
290 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
291 Define exactly one, e.g. CONFIG_ATSTK1002
293 - CPU Module Type: (if CONFIG_COGENT is defined)
294 Define exactly one of
296 --- FIXME --- not tested yet:
297 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
298 CONFIG_CMA287_23, CONFIG_CMA287_50
300 - Motherboard Type: (if CONFIG_COGENT is defined)
301 Define exactly one of
302 CONFIG_CMA101, CONFIG_CMA102
304 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
305 Define one or more of
308 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
309 Define one or more of
310 CONFIG_LCD_HEARTBEAT - update a character position on
311 the LCD display every second with
314 - Board flavour: (if CONFIG_MPC8260ADS is defined)
317 CONFIG_SYS_8260ADS - original MPC8260ADS
318 CONFIG_SYS_8266ADS - MPC8266ADS
319 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
320 CONFIG_SYS_8272ADS - MPC8272ADS
322 - Marvell Family Member
323 CONFIG_SYS_MVFS - define it if you want to enable
324 multiple fs option at one time
325 for marvell soc family
327 - MPC824X Family Member (if CONFIG_MPC824X is defined)
328 Define exactly one of
329 CONFIG_MPC8240, CONFIG_MPC8245
331 - 8xx CPU Options: (if using an MPC8xx CPU)
332 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
333 get_gclk_freq() cannot work
334 e.g. if there is no 32KHz
335 reference PIT/RTC clock
336 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
339 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
340 CONFIG_SYS_8xx_CPUCLK_MIN
341 CONFIG_SYS_8xx_CPUCLK_MAX
342 CONFIG_8xx_CPUCLK_DEFAULT
343 See doc/README.MPC866
345 CONFIG_SYS_MEASURE_CPUCLK
347 Define this to measure the actual CPU clock instead
348 of relying on the correctness of the configured
349 values. Mostly useful for board bringup to make sure
350 the PLL is locked at the intended frequency. Note
351 that this requires a (stable) reference clock (32 kHz
352 RTC clock or CONFIG_SYS_8XX_XIN)
354 CONFIG_SYS_DELAYED_ICACHE
356 Define this option if you want to enable the
357 ICache only when Code runs from RAM.
360 CONFIG_SYS_FSL_TBCLK_DIV
362 Defines the core time base clock divider ratio compared to the
363 system clock. On most PQ3 devices this is 8, on newer QorIQ
364 devices it can be 16 or 32. The ratio varies from SoC to Soc.
366 CONFIG_SYS_FSL_PCIE_COMPAT
368 Defines the string to utilize when trying to match PCIe device
369 tree nodes for the given platform.
371 - Intel Monahans options:
372 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
374 Defines the Monahans run mode to oscillator
375 ratio. Valid values are 8, 16, 24, 31. The core
376 frequency is this value multiplied by 13 MHz.
378 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
380 Defines the Monahans turbo mode to oscillator
381 ratio. Valid values are 1 (default if undefined) and
382 2. The core frequency as calculated above is multiplied
385 - Linux Kernel Interface:
388 U-Boot stores all clock information in Hz
389 internally. For binary compatibility with older Linux
390 kernels (which expect the clocks passed in the
391 bd_info data to be in MHz) the environment variable
392 "clocks_in_mhz" can be defined so that U-Boot
393 converts clock data to MHZ before passing it to the
395 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
396 "clocks_in_mhz=1" is automatically included in the
399 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
401 When transferring memsize parameter to linux, some versions
402 expect it to be in bytes, others in MB.
403 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
407 New kernel versions are expecting firmware settings to be
408 passed using flattened device trees (based on open firmware
412 * New libfdt-based support
413 * Adds the "fdt" command
414 * The bootm command automatically updates the fdt
416 OF_CPU - The proper name of the cpus node (only required for
417 MPC512X and MPC5xxx based boards).
418 OF_SOC - The proper name of the soc node (only required for
419 MPC512X and MPC5xxx based boards).
420 OF_TBCLK - The timebase frequency.
421 OF_STDOUT_PATH - The path to the console device
423 boards with QUICC Engines require OF_QE to set UCC MAC
426 CONFIG_OF_BOARD_SETUP
428 Board code has addition modification that it wants to make
429 to the flat device tree before handing it off to the kernel
433 This define fills in the correct boot CPU in the boot
434 param header, the default value is zero if undefined.
438 U-Boot can detect if an IDE device is present or not.
439 If not, and this new config option is activated, U-Boot
440 removes the ATA node from the DTS before booting Linux,
441 so the Linux IDE driver does not probe the device and
442 crash. This is needed for buggy hardware (uc101) where
443 no pull down resistor is connected to the signal IDE5V_DD7.
445 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
447 This setting is mandatory for all boards that have only one
448 machine type and must be used to specify the machine type
449 number as it appears in the ARM machine registry
450 (see http://www.arm.linux.org.uk/developer/machines/).
451 Only boards that have multiple machine types supported
452 in a single configuration file and the machine type is
453 runtime discoverable, do not have to use this setting.
455 - vxWorks boot parameters:
457 bootvx constructs a valid bootline using the following
458 environments variables: bootfile, ipaddr, serverip, hostname.
459 It loads the vxWorks image pointed bootfile.
461 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
462 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
463 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
464 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
466 CONFIG_SYS_VXWORKS_ADD_PARAMS
468 Add it at the end of the bootline. E.g "u=username pw=secret"
470 Note: If a "bootargs" environment is defined, it will overwride
471 the defaults discussed just above.
473 - Cache Configuration:
474 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
475 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
476 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
478 - Cache Configuration for ARM:
479 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
481 CONFIG_SYS_PL310_BASE - Physical base address of PL310
482 controller register space
487 Define this if you want support for Amba PrimeCell PL010 UARTs.
491 Define this if you want support for Amba PrimeCell PL011 UARTs.
495 If you have Amba PrimeCell PL011 UARTs, set this variable to
496 the clock speed of the UARTs.
500 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
501 define this to a list of base addresses for each (supported)
502 port. See e.g. include/configs/versatile.h
504 CONFIG_PL011_SERIAL_RLCR
506 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
507 have separate receive and transmit line control registers. Set
508 this variable to initialize the extra register.
510 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
512 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
513 boot loader that has already initialized the UART. Define this
514 variable to flush the UART at init time.
518 Depending on board, define exactly one serial port
519 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
520 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
521 console by defining CONFIG_8xx_CONS_NONE
523 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
524 port routines must be defined elsewhere
525 (i.e. serial_init(), serial_getc(), ...)
528 Enables console device for a color framebuffer. Needs following
529 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
530 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
532 VIDEO_HW_RECTFILL graphic chip supports
535 VIDEO_HW_BITBLT graphic chip supports
536 bit-blit (cf. smiLynxEM)
537 VIDEO_VISIBLE_COLS visible pixel columns
539 VIDEO_VISIBLE_ROWS visible pixel rows
540 VIDEO_PIXEL_SIZE bytes per pixel
541 VIDEO_DATA_FORMAT graphic data format
542 (0-5, cf. cfb_console.c)
543 VIDEO_FB_ADRS framebuffer address
544 VIDEO_KBD_INIT_FCT keyboard int fct
545 (i.e. i8042_kbd_init())
546 VIDEO_TSTC_FCT test char fct
548 VIDEO_GETC_FCT get char fct
550 CONFIG_CONSOLE_CURSOR cursor drawing on/off
551 (requires blink timer
553 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
554 CONFIG_CONSOLE_TIME display time/date info in
556 (requires CONFIG_CMD_DATE)
557 CONFIG_VIDEO_LOGO display Linux logo in
559 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
560 linux_logo.h for logo.
561 Requires CONFIG_VIDEO_LOGO
562 CONFIG_CONSOLE_EXTRA_INFO
563 additional board info beside
566 When CONFIG_CFB_CONSOLE is defined, video console is
567 default i/o. Serial console can be forced with
568 environment 'console=serial'.
570 When CONFIG_SILENT_CONSOLE is defined, all console
571 messages (by U-Boot and Linux!) can be silenced with
572 the "silent" environment variable. See
573 doc/README.silent for more information.
576 CONFIG_BAUDRATE - in bps
577 Select one of the baudrates listed in
578 CONFIG_SYS_BAUDRATE_TABLE, see below.
579 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
581 - Console Rx buffer length
582 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
583 the maximum receive buffer length for the SMC.
584 This option is actual only for 82xx and 8xx possible.
585 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
586 must be defined, to setup the maximum idle timeout for
589 - Boot Delay: CONFIG_BOOTDELAY - in seconds
590 Delay before automatically booting the default image;
591 set to -1 to disable autoboot.
593 See doc/README.autoboot for these options that
594 work with CONFIG_BOOTDELAY. None are required.
595 CONFIG_BOOT_RETRY_TIME
596 CONFIG_BOOT_RETRY_MIN
597 CONFIG_AUTOBOOT_KEYED
598 CONFIG_AUTOBOOT_PROMPT
599 CONFIG_AUTOBOOT_DELAY_STR
600 CONFIG_AUTOBOOT_STOP_STR
601 CONFIG_AUTOBOOT_DELAY_STR2
602 CONFIG_AUTOBOOT_STOP_STR2
603 CONFIG_ZERO_BOOTDELAY_CHECK
604 CONFIG_RESET_TO_RETRY
608 Only needed when CONFIG_BOOTDELAY is enabled;
609 define a command string that is automatically executed
610 when no character is read on the console interface
611 within "Boot Delay" after reset.
614 This can be used to pass arguments to the bootm
615 command. The value of CONFIG_BOOTARGS goes into the
616 environment value "bootargs".
618 CONFIG_RAMBOOT and CONFIG_NFSBOOT
619 The value of these goes into the environment as
620 "ramboot" and "nfsboot" respectively, and can be used
621 as a convenience, when switching between booting from
627 When this option is #defined, the existence of the
628 environment variable "preboot" will be checked
629 immediately before starting the CONFIG_BOOTDELAY
630 countdown and/or running the auto-boot command resp.
631 entering interactive mode.
633 This feature is especially useful when "preboot" is
634 automatically generated or modified. For an example
635 see the LWMON board specific code: here "preboot" is
636 modified when the user holds down a certain
637 combination of keys on the (special) keyboard when
640 - Serial Download Echo Mode:
642 If defined to 1, all characters received during a
643 serial download (using the "loads" command) are
644 echoed back. This might be needed by some terminal
645 emulations (like "cu"), but may as well just take
646 time on others. This setting #define's the initial
647 value of the "loads_echo" environment variable.
649 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
651 Select one of the baudrates listed in
652 CONFIG_SYS_BAUDRATE_TABLE, see below.
655 Monitor commands can be included or excluded
656 from the build by using the #include files
657 "config_cmd_all.h" and #undef'ing unwanted
658 commands, or using "config_cmd_default.h"
659 and augmenting with additional #define's
662 The default command configuration includes all commands
663 except those marked below with a "*".
665 CONFIG_CMD_ASKENV * ask for env variable
666 CONFIG_CMD_BDI bdinfo
667 CONFIG_CMD_BEDBUG * Include BedBug Debugger
668 CONFIG_CMD_BMP * BMP support
669 CONFIG_CMD_BSP * Board specific commands
670 CONFIG_CMD_BOOTD bootd
671 CONFIG_CMD_CACHE * icache, dcache
672 CONFIG_CMD_CONSOLE coninfo
673 CONFIG_CMD_CRC32 * crc32
674 CONFIG_CMD_DATE * support for RTC, date/time...
675 CONFIG_CMD_DHCP * DHCP support
676 CONFIG_CMD_DIAG * Diagnostics
677 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
678 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
679 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
680 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
681 CONFIG_CMD_DTT * Digital Therm and Thermostat
682 CONFIG_CMD_ECHO echo arguments
683 CONFIG_CMD_EDITENV edit env variable
684 CONFIG_CMD_EEPROM * EEPROM read/write support
685 CONFIG_CMD_ELF * bootelf, bootvx
686 CONFIG_CMD_EXPORTENV * export the environment
687 CONFIG_CMD_SAVEENV saveenv
688 CONFIG_CMD_FDC * Floppy Disk Support
689 CONFIG_CMD_FAT * FAT partition support
690 CONFIG_CMD_FDOS * Dos diskette Support
691 CONFIG_CMD_FLASH flinfo, erase, protect
692 CONFIG_CMD_FPGA FPGA device initialization support
693 CONFIG_CMD_GO * the 'go' command (exec code)
694 CONFIG_CMD_GREPENV * search environment
695 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
696 CONFIG_CMD_I2C * I2C serial bus support
697 CONFIG_CMD_IDE * IDE harddisk support
698 CONFIG_CMD_IMI iminfo
699 CONFIG_CMD_IMLS List all found images
700 CONFIG_CMD_IMMAP * IMMR dump support
701 CONFIG_CMD_IMPORTENV * import an environment
702 CONFIG_CMD_IRQ * irqinfo
703 CONFIG_CMD_ITEST Integer/string test of 2 values
704 CONFIG_CMD_JFFS2 * JFFS2 Support
705 CONFIG_CMD_KGDB * kgdb
706 CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
707 CONFIG_CMD_LOADB loadb
708 CONFIG_CMD_LOADS loads
709 CONFIG_CMD_MD5SUM print md5 message digest
710 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
711 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
713 CONFIG_CMD_MISC Misc functions like sleep etc
714 CONFIG_CMD_MMC * MMC memory mapped support
715 CONFIG_CMD_MII * MII utility commands
716 CONFIG_CMD_MTDPARTS * MTD partition support
717 CONFIG_CMD_NAND * NAND support
718 CONFIG_CMD_NET bootp, tftpboot, rarpboot
719 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
720 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
721 CONFIG_CMD_PCI * pciinfo
722 CONFIG_CMD_PCMCIA * PCMCIA support
723 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
725 CONFIG_CMD_PORTIO * Port I/O
726 CONFIG_CMD_REGINFO * Register dump
727 CONFIG_CMD_RUN run command in env variable
728 CONFIG_CMD_SAVES * save S record dump
729 CONFIG_CMD_SCSI * SCSI Support
730 CONFIG_CMD_SDRAM * print SDRAM configuration information
731 (requires CONFIG_CMD_I2C)
732 CONFIG_CMD_SETGETDCR Support for DCR Register access
734 CONFIG_CMD_SHA1SUM print sha1 memory digest
735 (requires CONFIG_CMD_MEMORY)
736 CONFIG_CMD_SOURCE "source" command Support
737 CONFIG_CMD_SPI * SPI serial bus support
738 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
739 CONFIG_CMD_USB * USB support
740 CONFIG_CMD_CDP * Cisco Discover Protocol support
741 CONFIG_CMD_FSL * Microblaze FSL support
744 EXAMPLE: If you want all functions except of network
745 support you can write:
747 #include "config_cmd_all.h"
748 #undef CONFIG_CMD_NET
751 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
753 Note: Don't enable the "icache" and "dcache" commands
754 (configuration option CONFIG_CMD_CACHE) unless you know
755 what you (and your U-Boot users) are doing. Data
756 cache cannot be enabled on systems like the 8xx or
757 8260 (where accesses to the IMMR region must be
758 uncached), and it cannot be disabled on all other
759 systems where we (mis-) use the data cache to hold an
760 initial stack and some data.
763 XXX - this list needs to get updated!
767 If this variable is defined, it enables watchdog
768 support for the SoC. There must be support in the SoC
769 specific code for a watchdog. For the 8xx and 8260
770 CPUs, the SIU Watchdog feature is enabled in the SYPCR
771 register. When supported for a specific SoC is
772 available, then no further board specific code should
776 When using a watchdog circuitry external to the used
777 SoC, then define this variable and provide board
778 specific code for the "hw_watchdog_reset" function.
781 CONFIG_VERSION_VARIABLE
782 If this variable is defined, an environment variable
783 named "ver" is created by U-Boot showing the U-Boot
784 version as printed by the "version" command.
785 This variable is readonly.
789 When CONFIG_CMD_DATE is selected, the type of the RTC
790 has to be selected, too. Define exactly one of the
793 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
794 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
795 CONFIG_RTC_MC13783 - use MC13783 RTC
796 CONFIG_RTC_MC146818 - use MC146818 RTC
797 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
798 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
799 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
800 CONFIG_RTC_DS164x - use Dallas DS164x RTC
801 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
802 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
803 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
804 CONFIG_SYS_RV3029_TCR - enable trickle charger on
807 Note that if the RTC uses I2C, then the I2C interface
808 must also be configured. See I2C Support, below.
811 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
812 CONFIG_PCA953X_INFO - enable pca953x info command
814 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
815 chip-ngpio pairs that tell the PCA953X driver the number of
816 pins supported by a particular chip.
818 Note that if the GPIO device uses I2C, then the I2C interface
819 must also be configured. See I2C Support, below.
823 When CONFIG_TIMESTAMP is selected, the timestamp
824 (date and time) of an image is printed by image
825 commands like bootm or iminfo. This option is
826 automatically enabled when you select CONFIG_CMD_DATE .
829 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
830 and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION
832 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
833 CONFIG_CMD_SCSI) you must configure support for at
834 least one partition type as well.
837 CONFIG_IDE_RESET_ROUTINE - this is defined in several
838 board configurations files but used nowhere!
840 CONFIG_IDE_RESET - is this is defined, IDE Reset will
841 be performed by calling the function
842 ide_set_reset(int reset)
843 which has to be defined in a board specific file
848 Set this to enable ATAPI support.
853 Set this to enable support for disks larger than 137GB
854 Also look at CONFIG_SYS_64BIT_LBA.
855 Whithout these , LBA48 support uses 32bit variables and will 'only'
856 support disks up to 2.1TB.
858 CONFIG_SYS_64BIT_LBA:
859 When enabled, makes the IDE subsystem use 64bit sector addresses.
863 At the moment only there is only support for the
864 SYM53C8XX SCSI controller; define
865 CONFIG_SCSI_SYM53C8XX to enable it.
867 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
868 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
869 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
870 maximum numbers of LUNs, SCSI ID's and target
872 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
874 - NETWORK Support (PCI):
876 Support for Intel 8254x gigabit chips.
878 CONFIG_E1000_FALLBACK_MAC
879 default MAC for empty EEPROM after production.
882 Support for Intel 82557/82559/82559ER chips.
883 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
884 write routine for first time initialisation.
887 Support for Digital 2114x chips.
888 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
889 modem chip initialisation (KS8761/QS6611).
892 Support for National dp83815 chips.
895 Support for National dp8382[01] gigabit chips.
897 - NETWORK Support (other):
899 CONFIG_DRIVER_AT91EMAC
900 Support for AT91RM9200 EMAC.
903 Define this to use reduced MII inteface
905 CONFIG_DRIVER_AT91EMAC_QUIET
906 If this defined, the driver is quiet.
907 The driver doen't show link status messages.
909 CONFIG_DRIVER_LAN91C96
910 Support for SMSC's LAN91C96 chips.
913 Define this to hold the physical address
914 of the LAN91C96's I/O space
916 CONFIG_LAN91C96_USE_32_BIT
917 Define this to enable 32 bit addressing
919 CONFIG_DRIVER_SMC91111
920 Support for SMSC's LAN91C111 chip
923 Define this to hold the physical address
924 of the device (I/O space)
926 CONFIG_SMC_USE_32_BIT
927 Define this if data bus is 32 bits
929 CONFIG_SMC_USE_IOFUNCS
930 Define this to use i/o functions instead of macros
931 (some hardware wont work with macros)
934 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
936 CONFIG_FTGMAC100_EGIGA
937 Define this to use GE link update with gigabit PHY.
938 Define this if FTGMAC100 is connected to gigabit PHY.
939 If your system has 10/100 PHY only, it might not occur
940 wrong behavior. Because PHY usually return timeout or
941 useless data when polling gigabit status and gigabit
942 control registers. This behavior won't affect the
943 correctnessof 10/100 link speed update.
946 Support for SMSC's LAN911x and LAN921x chips
949 Define this to hold the physical address
950 of the device (I/O space)
952 CONFIG_SMC911X_32_BIT
953 Define this if data bus is 32 bits
955 CONFIG_SMC911X_16_BIT
956 Define this if data bus is 16 bits. If your processor
957 automatically converts one 32 bit word to two 16 bit
958 words you may also try CONFIG_SMC911X_32_BIT.
961 Support for Renesas on-chip Ethernet controller
963 CONFIG_SH_ETHER_USE_PORT
964 Define the number of ports to be used
966 CONFIG_SH_ETHER_PHY_ADDR
967 Define the ETH PHY's address
969 CONFIG_SH_ETHER_CACHE_WRITEBACK
970 If this option is set, the driver enables cache flush.
973 At the moment only the UHCI host controller is
974 supported (PIP405, MIP405, MPC5200); define
975 CONFIG_USB_UHCI to enable it.
976 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
977 and define CONFIG_USB_STORAGE to enable the USB
980 Supported are USB Keyboards and USB Floppy drives
982 MPC5200 USB requires additional defines:
984 for 528 MHz Clock: 0x0001bbbb
988 for differential drivers: 0x00001000
989 for single ended drivers: 0x00005000
990 for differential drivers on PSC3: 0x00000100
991 for single ended drivers on PSC3: 0x00004100
992 CONFIG_SYS_USB_EVENT_POLL
993 May be defined to allow interrupt polling
994 instead of using asynchronous interrupts
997 Define the below if you wish to use the USB console.
998 Once firmware is rebuilt from a serial console issue the
999 command "setenv stdin usbtty; setenv stdout usbtty" and
1000 attach your USB cable. The Unix command "dmesg" should print
1001 it has found a new device. The environment variable usbtty
1002 can be set to gserial or cdc_acm to enable your device to
1003 appear to a USB host as a Linux gserial device or a
1004 Common Device Class Abstract Control Model serial device.
1005 If you select usbtty = gserial you should be able to enumerate
1007 # modprobe usbserial vendor=0xVendorID product=0xProductID
1008 else if using cdc_acm, simply setting the environment
1009 variable usbtty to be cdc_acm should suffice. The following
1010 might be defined in YourBoardName.h
1013 Define this to build a UDC device
1016 Define this to have a tty type of device available to
1017 talk to the UDC device
1019 CONFIG_SYS_CONSOLE_IS_IN_ENV
1020 Define this if you want stdin, stdout &/or stderr to
1024 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1025 Derive USB clock from external clock "blah"
1026 - CONFIG_SYS_USB_EXTC_CLK 0x02
1028 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1029 Derive USB clock from brgclk
1030 - CONFIG_SYS_USB_BRG_CLK 0x04
1032 If you have a USB-IF assigned VendorID then you may wish to
1033 define your own vendor specific values either in BoardName.h
1034 or directly in usbd_vendor_info.h. If you don't define
1035 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1036 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1037 should pretend to be a Linux device to it's target host.
1039 CONFIG_USBD_MANUFACTURER
1040 Define this string as the name of your company for
1041 - CONFIG_USBD_MANUFACTURER "my company"
1043 CONFIG_USBD_PRODUCT_NAME
1044 Define this string as the name of your product
1045 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1047 CONFIG_USBD_VENDORID
1048 Define this as your assigned Vendor ID from the USB
1049 Implementors Forum. This *must* be a genuine Vendor ID
1050 to avoid polluting the USB namespace.
1051 - CONFIG_USBD_VENDORID 0xFFFF
1053 CONFIG_USBD_PRODUCTID
1054 Define this as the unique Product ID
1056 - CONFIG_USBD_PRODUCTID 0xFFFF
1060 The MMC controller on the Intel PXA is supported. To
1061 enable this define CONFIG_MMC. The MMC can be
1062 accessed from the boot prompt by mapping the device
1063 to physical memory similar to flash. Command line is
1064 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1065 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1068 Support for Renesas on-chip MMCIF controller
1070 CONFIG_SH_MMCIF_ADDR
1071 Define the base address of MMCIF registers
1074 Define the clock frequency for MMCIF
1076 - Journaling Flash filesystem support:
1077 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1078 CONFIG_JFFS2_NAND_DEV
1079 Define these for a default partition on a NAND device
1081 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1082 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1083 Define these for a default partition on a NOR device
1085 CONFIG_SYS_JFFS_CUSTOM_PART
1086 Define this to create an own partition. You have to provide a
1087 function struct part_info* jffs2_part_info(int part_num)
1089 If you define only one JFFS2 partition you may also want to
1090 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1091 to disable the command chpart. This is the default when you
1092 have not defined a custom partition
1097 Define this to enable standard (PC-Style) keyboard
1101 Standard PC keyboard driver with US (is default) and
1102 GERMAN key layout (switch via environment 'keymap=de') support.
1103 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1104 for cfb_console. Supports cursor blinking.
1109 Define this to enable video support (for output to
1112 CONFIG_VIDEO_CT69000
1114 Enable Chips & Technologies 69000 Video chip
1116 CONFIG_VIDEO_SMI_LYNXEM
1117 Enable Silicon Motion SMI 712/710/810 Video chip. The
1118 video output is selected via environment 'videoout'
1119 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1122 For the CT69000 and SMI_LYNXEM drivers, videomode is
1123 selected via environment 'videomode'. Two different ways
1125 - "videomode=num" 'num' is a standard LiLo mode numbers.
1126 Following standard modes are supported (* is default):
1128 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1129 -------------+---------------------------------------------
1130 8 bits | 0x301* 0x303 0x305 0x161 0x307
1131 15 bits | 0x310 0x313 0x316 0x162 0x319
1132 16 bits | 0x311 0x314 0x317 0x163 0x31A
1133 24 bits | 0x312 0x315 0x318 ? 0x31B
1134 -------------+---------------------------------------------
1135 (i.e. setenv videomode 317; saveenv; reset;)
1137 - "videomode=bootargs" all the video parameters are parsed
1138 from the bootargs. (See drivers/video/videomodes.c)
1141 CONFIG_VIDEO_SED13806
1142 Enable Epson SED13806 driver. This driver supports 8bpp
1143 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1144 or CONFIG_VIDEO_SED13806_16BPP
1147 Enable the Freescale DIU video driver. Reference boards for
1148 SOCs that have a DIU should define this macro to enable DIU
1149 support, and should also define these other macros:
1155 CONFIG_VIDEO_SW_CURSOR
1156 CONFIG_VGA_AS_SINGLE_DEVICE
1158 CONFIG_VIDEO_BMP_LOGO
1160 The DIU driver will look for the 'video-mode' environment
1161 variable, and if defined, enable the DIU as a console during
1162 boot. See the documentation file README.video for a
1163 description of this variable.
1168 Define this to enable a custom keyboard support.
1169 This simply calls drv_keyboard_init() which must be
1170 defined in your board-specific files.
1171 The only board using this so far is RBC823.
1173 - LCD Support: CONFIG_LCD
1175 Define this to enable LCD support (for output to LCD
1176 display); also select one of the supported displays
1177 by defining one of these:
1181 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1183 CONFIG_NEC_NL6448AC33:
1185 NEC NL6448AC33-18. Active, color, single scan.
1187 CONFIG_NEC_NL6448BC20
1189 NEC NL6448BC20-08. 6.5", 640x480.
1190 Active, color, single scan.
1192 CONFIG_NEC_NL6448BC33_54
1194 NEC NL6448BC33-54. 10.4", 640x480.
1195 Active, color, single scan.
1199 Sharp 320x240. Active, color, single scan.
1200 It isn't 16x9, and I am not sure what it is.
1202 CONFIG_SHARP_LQ64D341
1204 Sharp LQ64D341 display, 640x480.
1205 Active, color, single scan.
1209 HLD1045 display, 640x480.
1210 Active, color, single scan.
1214 Optrex CBL50840-2 NF-FW 99 22 M5
1216 Hitachi LMG6912RPFC-00T
1220 320x240. Black & white.
1222 Normally display is black on white background; define
1223 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1225 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1227 If this option is set, the environment is checked for
1228 a variable "splashimage". If found, the usual display
1229 of logo, copyright and system information on the LCD
1230 is suppressed and the BMP image at the address
1231 specified in "splashimage" is loaded instead. The
1232 console is redirected to the "nulldev", too. This
1233 allows for a "silent" boot where a splash screen is
1234 loaded very quickly after power-on.
1236 CONFIG_SPLASH_SCREEN_ALIGN
1238 If this option is set the splash image can be freely positioned
1239 on the screen. Environment variable "splashpos" specifies the
1240 position as "x,y". If a positive number is given it is used as
1241 number of pixel from left/top. If a negative number is given it
1242 is used as number of pixel from right/bottom. You can also
1243 specify 'm' for centering the image.
1246 setenv splashpos m,m
1247 => image at center of screen
1249 setenv splashpos 30,20
1250 => image at x = 30 and y = 20
1252 setenv splashpos -10,m
1253 => vertically centered image
1254 at x = dspWidth - bmpWidth - 9
1256 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1258 If this option is set, additionally to standard BMP
1259 images, gzipped BMP images can be displayed via the
1260 splashscreen support or the bmp command.
1262 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1264 If this option is set, 8-bit RLE compressed BMP images
1265 can be displayed via the splashscreen support or the
1268 - Compression support:
1271 If this option is set, support for bzip2 compressed
1272 images is included. If not, only uncompressed and gzip
1273 compressed images are supported.
1275 NOTE: the bzip2 algorithm requires a lot of RAM, so
1276 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1281 If this option is set, support for lzma compressed
1284 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1285 requires an amount of dynamic memory that is given by the
1288 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1290 Where lc and lp stand for, respectively, Literal context bits
1291 and Literal pos bits.
1293 This value is upper-bounded by 14MB in the worst case. Anyway,
1294 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1295 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1296 a very small buffer.
1298 Use the lzmainfo tool to determinate the lc and lp values and
1299 then calculate the amount of needed dynamic memory (ensuring
1300 the appropriate CONFIG_SYS_MALLOC_LEN value).
1305 The address of PHY on MII bus.
1307 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1309 The clock frequency of the MII bus
1313 If this option is set, support for speed/duplex
1314 detection of gigabit PHY is included.
1316 CONFIG_PHY_RESET_DELAY
1318 Some PHY like Intel LXT971A need extra delay after
1319 reset before any MII register access is possible.
1320 For such PHY, set this option to the usec delay
1321 required. (minimum 300usec for LXT971A)
1323 CONFIG_PHY_CMD_DELAY (ppc4xx)
1325 Some PHY like Intel LXT971A need extra delay after
1326 command issued before MII status register can be read
1336 Define a default value for Ethernet address to use
1337 for the respective Ethernet interface, in case this
1338 is not determined automatically.
1343 Define a default value for the IP address to use for
1344 the default Ethernet interface, in case this is not
1345 determined through e.g. bootp.
1347 - Server IP address:
1350 Defines a default value for the IP address of a TFTP
1351 server to contact when using the "tftboot" command.
1353 CONFIG_KEEP_SERVERADDR
1355 Keeps the server's MAC address, in the env 'serveraddr'
1356 for passing to bootargs (like Linux's netconsole option)
1358 - Multicast TFTP Mode:
1361 Defines whether you want to support multicast TFTP as per
1362 rfc-2090; for example to work with atftp. Lets lots of targets
1363 tftp down the same boot image concurrently. Note: the Ethernet
1364 driver in use must provide a function: mcast() to join/leave a
1367 - BOOTP Recovery Mode:
1368 CONFIG_BOOTP_RANDOM_DELAY
1370 If you have many targets in a network that try to
1371 boot using BOOTP, you may want to avoid that all
1372 systems send out BOOTP requests at precisely the same
1373 moment (which would happen for instance at recovery
1374 from a power failure, when all systems will try to
1375 boot, thus flooding the BOOTP server. Defining
1376 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1377 inserted before sending out BOOTP requests. The
1378 following delays are inserted then:
1380 1st BOOTP request: delay 0 ... 1 sec
1381 2nd BOOTP request: delay 0 ... 2 sec
1382 3rd BOOTP request: delay 0 ... 4 sec
1384 BOOTP requests: delay 0 ... 8 sec
1386 - DHCP Advanced Options:
1387 You can fine tune the DHCP functionality by defining
1388 CONFIG_BOOTP_* symbols:
1390 CONFIG_BOOTP_SUBNETMASK
1391 CONFIG_BOOTP_GATEWAY
1392 CONFIG_BOOTP_HOSTNAME
1393 CONFIG_BOOTP_NISDOMAIN
1394 CONFIG_BOOTP_BOOTPATH
1395 CONFIG_BOOTP_BOOTFILESIZE
1398 CONFIG_BOOTP_SEND_HOSTNAME
1399 CONFIG_BOOTP_NTPSERVER
1400 CONFIG_BOOTP_TIMEOFFSET
1401 CONFIG_BOOTP_VENDOREX
1403 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1404 environment variable, not the BOOTP server.
1406 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1407 serverip from a DHCP server, it is possible that more
1408 than one DNS serverip is offered to the client.
1409 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1410 serverip will be stored in the additional environment
1411 variable "dnsip2". The first DNS serverip is always
1412 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1415 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1416 to do a dynamic update of a DNS server. To do this, they
1417 need the hostname of the DHCP requester.
1418 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1419 of the "hostname" environment variable is passed as
1420 option 12 to the DHCP server.
1422 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1424 A 32bit value in microseconds for a delay between
1425 receiving a "DHCP Offer" and sending the "DHCP Request".
1426 This fixes a problem with certain DHCP servers that don't
1427 respond 100% of the time to a "DHCP request". E.g. On an
1428 AT91RM9200 processor running at 180MHz, this delay needed
1429 to be *at least* 15,000 usec before a Windows Server 2003
1430 DHCP server would reply 100% of the time. I recommend at
1431 least 50,000 usec to be safe. The alternative is to hope
1432 that one of the retries will be successful but note that
1433 the DHCP timeout and retry process takes a longer than
1437 CONFIG_CDP_DEVICE_ID
1439 The device id used in CDP trigger frames.
1441 CONFIG_CDP_DEVICE_ID_PREFIX
1443 A two character string which is prefixed to the MAC address
1448 A printf format string which contains the ascii name of
1449 the port. Normally is set to "eth%d" which sets
1450 eth0 for the first Ethernet, eth1 for the second etc.
1452 CONFIG_CDP_CAPABILITIES
1454 A 32bit integer which indicates the device capabilities;
1455 0x00000010 for a normal host which does not forwards.
1459 An ascii string containing the version of the software.
1463 An ascii string containing the name of the platform.
1467 A 32bit integer sent on the trigger.
1469 CONFIG_CDP_POWER_CONSUMPTION
1471 A 16bit integer containing the power consumption of the
1472 device in .1 of milliwatts.
1474 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1476 A byte containing the id of the VLAN.
1478 - Status LED: CONFIG_STATUS_LED
1480 Several configurations allow to display the current
1481 status using a LED. For instance, the LED will blink
1482 fast while running U-Boot code, stop blinking as
1483 soon as a reply to a BOOTP request was received, and
1484 start blinking slow once the Linux kernel is running
1485 (supported by a status LED driver in the Linux
1486 kernel). Defining CONFIG_STATUS_LED enables this
1489 - CAN Support: CONFIG_CAN_DRIVER
1491 Defining CONFIG_CAN_DRIVER enables CAN driver support
1492 on those systems that support this (optional)
1493 feature, like the TQM8xxL modules.
1495 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1497 These enable I2C serial bus commands. Defining either of
1498 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1499 include the appropriate I2C driver for the selected CPU.
1501 This will allow you to use i2c commands at the u-boot
1502 command line (as long as you set CONFIG_CMD_I2C in
1503 CONFIG_COMMANDS) and communicate with i2c based realtime
1504 clock chips. See common/cmd_i2c.c for a description of the
1505 command line interface.
1507 CONFIG_HARD_I2C selects a hardware I2C controller.
1509 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1510 bit-banging) driver instead of CPM or similar hardware
1513 There are several other quantities that must also be
1514 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1516 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1517 to be the frequency (in Hz) at which you wish your i2c bus
1518 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1519 the CPU's i2c node address).
1521 Now, the u-boot i2c code for the mpc8xx
1522 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1523 and so its address should therefore be cleared to 0 (See,
1524 eg, MPC823e User's Manual p.16-473). So, set
1525 CONFIG_SYS_I2C_SLAVE to 0.
1527 CONFIG_SYS_I2C_INIT_MPC5XXX
1529 When a board is reset during an i2c bus transfer
1530 chips might think that the current transfer is still
1531 in progress. Reset the slave devices by sending start
1532 commands until the slave device responds.
1534 That's all that's required for CONFIG_HARD_I2C.
1536 If you use the software i2c interface (CONFIG_SOFT_I2C)
1537 then the following macros need to be defined (examples are
1538 from include/configs/lwmon.h):
1542 (Optional). Any commands necessary to enable the I2C
1543 controller or configure ports.
1545 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1549 (Only for MPC8260 CPU). The I/O port to use (the code
1550 assumes both bits are on the same port). Valid values
1551 are 0..3 for ports A..D.
1555 The code necessary to make the I2C data line active
1556 (driven). If the data line is open collector, this
1559 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1563 The code necessary to make the I2C data line tri-stated
1564 (inactive). If the data line is open collector, this
1567 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1571 Code that returns TRUE if the I2C data line is high,
1574 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1578 If <bit> is TRUE, sets the I2C data line high. If it
1579 is FALSE, it clears it (low).
1581 eg: #define I2C_SDA(bit) \
1582 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1583 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1587 If <bit> is TRUE, sets the I2C clock line high. If it
1588 is FALSE, it clears it (low).
1590 eg: #define I2C_SCL(bit) \
1591 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1592 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1596 This delay is invoked four times per clock cycle so this
1597 controls the rate of data transfer. The data rate thus
1598 is 1 / (I2C_DELAY * 4). Often defined to be something
1601 #define I2C_DELAY udelay(2)
1603 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1605 If your arch supports the generic GPIO framework (asm/gpio.h),
1606 then you may alternatively define the two GPIOs that are to be
1607 used as SCL / SDA. Any of the previous I2C_xxx macros will
1608 have GPIO-based defaults assigned to them as appropriate.
1610 You should define these to the GPIO value as given directly to
1611 the generic GPIO functions.
1613 CONFIG_SYS_I2C_INIT_BOARD
1615 When a board is reset during an i2c bus transfer
1616 chips might think that the current transfer is still
1617 in progress. On some boards it is possible to access
1618 the i2c SCLK line directly, either by using the
1619 processor pin as a GPIO or by having a second pin
1620 connected to the bus. If this option is defined a
1621 custom i2c_init_board() routine in boards/xxx/board.c
1622 is run early in the boot sequence.
1624 CONFIG_SYS_I2C_BOARD_LATE_INIT
1626 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1627 defined a custom i2c_board_late_init() routine in
1628 boards/xxx/board.c is run AFTER the operations in i2c_init()
1629 is completed. This callpoint can be used to unreset i2c bus
1630 using CPU i2c controller register accesses for CPUs whose i2c
1631 controller provide such a method. It is called at the end of
1632 i2c_init() to allow i2c_init operations to setup the i2c bus
1633 controller on the CPU (e.g. setting bus speed & slave address).
1635 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1637 This option enables configuration of bi_iic_fast[] flags
1638 in u-boot bd_info structure based on u-boot environment
1639 variable "i2cfast". (see also i2cfast)
1641 CONFIG_I2C_MULTI_BUS
1643 This option allows the use of multiple I2C buses, each of which
1644 must have a controller. At any point in time, only one bus is
1645 active. To switch to a different bus, use the 'i2c dev' command.
1646 Note that bus numbering is zero-based.
1648 CONFIG_SYS_I2C_NOPROBES
1650 This option specifies a list of I2C devices that will be skipped
1651 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1652 is set, specify a list of bus-device pairs. Otherwise, specify
1653 a 1D array of device addresses
1656 #undef CONFIG_I2C_MULTI_BUS
1657 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1659 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1661 #define CONFIG_I2C_MULTI_BUS
1662 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1664 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1666 CONFIG_SYS_SPD_BUS_NUM
1668 If defined, then this indicates the I2C bus number for DDR SPD.
1669 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1671 CONFIG_SYS_RTC_BUS_NUM
1673 If defined, then this indicates the I2C bus number for the RTC.
1674 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1676 CONFIG_SYS_DTT_BUS_NUM
1678 If defined, then this indicates the I2C bus number for the DTT.
1679 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1681 CONFIG_SYS_I2C_DTT_ADDR:
1683 If defined, specifies the I2C address of the DTT device.
1684 If not defined, then U-Boot uses predefined value for
1685 specified DTT device.
1689 Define this option if you want to use Freescale's I2C driver in
1690 drivers/i2c/fsl_i2c.c.
1694 Define this option if you have I2C devices reached over 1 .. n
1695 I2C Muxes like the pca9544a. This option addes a new I2C
1696 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1697 new I2C Bus to the existing I2C Busses. If you select the
1698 new Bus with "i2c dev", u-bbot sends first the commandos for
1699 the muxes to activate this new "bus".
1701 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1705 Adding a new I2C Bus reached over 2 pca9544a muxes
1706 The First mux with address 70 and channel 6
1707 The Second mux with address 71 and channel 4
1709 => i2c bus pca9544a:70:6:pca9544a:71:4
1711 Use the "i2c bus" command without parameter, to get a list
1712 of I2C Busses with muxes:
1715 Busses reached over muxes:
1717 reached over Mux(es):
1720 reached over Mux(es):
1725 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1726 u-boot sends First the Commando to the mux@70 to enable
1727 channel 6, and then the Commando to the mux@71 to enable
1730 After that, you can use the "normal" i2c commands as
1731 usual, to communicate with your I2C devices behind
1734 This option is actually implemented for the bitbanging
1735 algorithm in common/soft_i2c.c and for the Hardware I2C
1736 Bus on the MPC8260. But it should be not so difficult
1737 to add this option to other architectures.
1739 CONFIG_SOFT_I2C_READ_REPEATED_START
1741 defining this will force the i2c_read() function in
1742 the soft_i2c driver to perform an I2C repeated start
1743 between writing the address pointer and reading the
1744 data. If this define is omitted the default behaviour
1745 of doing a stop-start sequence will be used. Most I2C
1746 devices can use either method, but some require one or
1749 - SPI Support: CONFIG_SPI
1751 Enables SPI driver (so far only tested with
1752 SPI EEPROM, also an instance works with Crystal A/D and
1753 D/As on the SACSng board)
1757 Enables the driver for SPI controller on SuperH. Currently
1758 only SH7757 is supported.
1762 Enables extended (16-bit) SPI EEPROM addressing.
1763 (symmetrical to CONFIG_I2C_X)
1767 Enables a software (bit-bang) SPI driver rather than
1768 using hardware support. This is a general purpose
1769 driver that only requires three general I/O port pins
1770 (two outputs, one input) to function. If this is
1771 defined, the board configuration must define several
1772 SPI configuration items (port pins to use, etc). For
1773 an example, see include/configs/sacsng.h.
1777 Enables a hardware SPI driver for general-purpose reads
1778 and writes. As with CONFIG_SOFT_SPI, the board configuration
1779 must define a list of chip-select function pointers.
1780 Currently supported on some MPC8xxx processors. For an
1781 example, see include/configs/mpc8349emds.h.
1785 Enables the driver for the SPI controllers on i.MX and MXC
1786 SoCs. Currently only i.MX31 is supported.
1788 - FPGA Support: CONFIG_FPGA
1790 Enables FPGA subsystem.
1792 CONFIG_FPGA_<vendor>
1794 Enables support for specific chip vendors.
1797 CONFIG_FPGA_<family>
1799 Enables support for FPGA family.
1800 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1804 Specify the number of FPGA devices to support.
1806 CONFIG_SYS_FPGA_PROG_FEEDBACK
1808 Enable printing of hash marks during FPGA configuration.
1810 CONFIG_SYS_FPGA_CHECK_BUSY
1812 Enable checks on FPGA configuration interface busy
1813 status by the configuration function. This option
1814 will require a board or device specific function to
1819 If defined, a function that provides delays in the FPGA
1820 configuration driver.
1822 CONFIG_SYS_FPGA_CHECK_CTRLC
1823 Allow Control-C to interrupt FPGA configuration
1825 CONFIG_SYS_FPGA_CHECK_ERROR
1827 Check for configuration errors during FPGA bitfile
1828 loading. For example, abort during Virtex II
1829 configuration if the INIT_B line goes low (which
1830 indicated a CRC error).
1832 CONFIG_SYS_FPGA_WAIT_INIT
1834 Maximum time to wait for the INIT_B line to deassert
1835 after PROB_B has been deasserted during a Virtex II
1836 FPGA configuration sequence. The default time is 500
1839 CONFIG_SYS_FPGA_WAIT_BUSY
1841 Maximum time to wait for BUSY to deassert during
1842 Virtex II FPGA configuration. The default is 5 ms.
1844 CONFIG_SYS_FPGA_WAIT_CONFIG
1846 Time to wait after FPGA configuration. The default is
1849 - Configuration Management:
1852 If defined, this string will be added to the U-Boot
1853 version information (U_BOOT_VERSION)
1855 - Vendor Parameter Protection:
1857 U-Boot considers the values of the environment
1858 variables "serial#" (Board Serial Number) and
1859 "ethaddr" (Ethernet Address) to be parameters that
1860 are set once by the board vendor / manufacturer, and
1861 protects these variables from casual modification by
1862 the user. Once set, these variables are read-only,
1863 and write or delete attempts are rejected. You can
1864 change this behaviour:
1866 If CONFIG_ENV_OVERWRITE is #defined in your config
1867 file, the write protection for vendor parameters is
1868 completely disabled. Anybody can change or delete
1871 Alternatively, if you #define _both_ CONFIG_ETHADDR
1872 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1873 Ethernet address is installed in the environment,
1874 which can be changed exactly ONCE by the user. [The
1875 serial# is unaffected by this, i. e. it remains
1881 Define this variable to enable the reservation of
1882 "protected RAM", i. e. RAM which is not overwritten
1883 by U-Boot. Define CONFIG_PRAM to hold the number of
1884 kB you want to reserve for pRAM. You can overwrite
1885 this default value by defining an environment
1886 variable "pram" to the number of kB you want to
1887 reserve. Note that the board info structure will
1888 still show the full amount of RAM. If pRAM is
1889 reserved, a new environment variable "mem" will
1890 automatically be defined to hold the amount of
1891 remaining RAM in a form that can be passed as boot
1892 argument to Linux, for instance like that:
1894 setenv bootargs ... mem=\${mem}
1897 This way you can tell Linux not to use this memory,
1898 either, which results in a memory region that will
1899 not be affected by reboots.
1901 *WARNING* If your board configuration uses automatic
1902 detection of the RAM size, you must make sure that
1903 this memory test is non-destructive. So far, the
1904 following board configurations are known to be
1907 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1908 HERMES, IP860, RPXlite, LWMON, LANTEC,
1914 Define this variable to stop the system in case of a
1915 fatal error, so that you have to reset it manually.
1916 This is probably NOT a good idea for an embedded
1917 system where you want the system to reboot
1918 automatically as fast as possible, but it may be
1919 useful during development since you can try to debug
1920 the conditions that lead to the situation.
1922 CONFIG_NET_RETRY_COUNT
1924 This variable defines the number of retries for
1925 network operations like ARP, RARP, TFTP, or BOOTP
1926 before giving up the operation. If not defined, a
1927 default value of 5 is used.
1931 Timeout waiting for an ARP reply in milliseconds.
1933 - Command Interpreter:
1934 CONFIG_AUTO_COMPLETE
1936 Enable auto completion of commands using TAB.
1938 Note that this feature has NOT been implemented yet
1939 for the "hush" shell.
1942 CONFIG_SYS_HUSH_PARSER
1944 Define this variable to enable the "hush" shell (from
1945 Busybox) as command line interpreter, thus enabling
1946 powerful command line syntax like
1947 if...then...else...fi conditionals or `&&' and '||'
1948 constructs ("shell scripts").
1950 If undefined, you get the old, much simpler behaviour
1951 with a somewhat smaller memory footprint.
1954 CONFIG_SYS_PROMPT_HUSH_PS2
1956 This defines the secondary prompt string, which is
1957 printed when the command interpreter needs more input
1958 to complete a command. Usually "> ".
1962 In the current implementation, the local variables
1963 space and global environment variables space are
1964 separated. Local variables are those you define by
1965 simply typing `name=value'. To access a local
1966 variable later on, you have write `$name' or
1967 `${name}'; to execute the contents of a variable
1968 directly type `$name' at the command prompt.
1970 Global environment variables are those you use
1971 setenv/printenv to work with. To run a command stored
1972 in such a variable, you need to use the run command,
1973 and you must not use the '$' sign to access them.
1975 To store commands and special characters in a
1976 variable, please use double quotation marks
1977 surrounding the whole text of the variable, instead
1978 of the backslashes before semicolons and special
1981 - Commandline Editing and History:
1982 CONFIG_CMDLINE_EDITING
1984 Enable editing and History functions for interactive
1985 commandline input operations
1987 - Default Environment:
1988 CONFIG_EXTRA_ENV_SETTINGS
1990 Define this to contain any number of null terminated
1991 strings (variable = value pairs) that will be part of
1992 the default environment compiled into the boot image.
1994 For example, place something like this in your
1995 board's config file:
1997 #define CONFIG_EXTRA_ENV_SETTINGS \
2001 Warning: This method is based on knowledge about the
2002 internal format how the environment is stored by the
2003 U-Boot code. This is NOT an official, exported
2004 interface! Although it is unlikely that this format
2005 will change soon, there is no guarantee either.
2006 You better know what you are doing here.
2008 Note: overly (ab)use of the default environment is
2009 discouraged. Make sure to check other ways to preset
2010 the environment like the "source" command or the
2013 - DataFlash Support:
2014 CONFIG_HAS_DATAFLASH
2016 Defining this option enables DataFlash features and
2017 allows to read/write in Dataflash via the standard
2020 - SystemACE Support:
2023 Adding this option adds support for Xilinx SystemACE
2024 chips attached via some sort of local bus. The address
2025 of the chip must also be defined in the
2026 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2028 #define CONFIG_SYSTEMACE
2029 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2031 When SystemACE support is added, the "ace" device type
2032 becomes available to the fat commands, i.e. fatls.
2034 - TFTP Fixed UDP Port:
2037 If this is defined, the environment variable tftpsrcp
2038 is used to supply the TFTP UDP source port value.
2039 If tftpsrcp isn't defined, the normal pseudo-random port
2040 number generator is used.
2042 Also, the environment variable tftpdstp is used to supply
2043 the TFTP UDP destination port value. If tftpdstp isn't
2044 defined, the normal port 69 is used.
2046 The purpose for tftpsrcp is to allow a TFTP server to
2047 blindly start the TFTP transfer using the pre-configured
2048 target IP address and UDP port. This has the effect of
2049 "punching through" the (Windows XP) firewall, allowing
2050 the remainder of the TFTP transfer to proceed normally.
2051 A better solution is to properly configure the firewall,
2052 but sometimes that is not allowed.
2054 - Show boot progress:
2055 CONFIG_SHOW_BOOT_PROGRESS
2057 Defining this option allows to add some board-
2058 specific code (calling a user-provided function
2059 "show_boot_progress(int)") that enables you to show
2060 the system's boot progress on some display (for
2061 example, some LED's) on your board. At the moment,
2062 the following checkpoints are implemented:
2064 - Standalone program support:
2065 CONFIG_STANDALONE_LOAD_ADDR
2067 This option allows to define board specific values
2068 for the address where standalone program gets loaded,
2069 thus overwriting the architecutre dependent default
2072 - Frame Buffer Address:
2075 Define CONFIG_FB_ADDR if you want to use specific address for
2077 Then system will reserve the frame buffer address to defined address
2078 instead of lcd_setmem (this function grab the memory for frame buffer
2081 Please see board_init_f function.
2083 If you want this config option then,
2084 please define it at your board config file
2086 Legacy uImage format:
2089 1 common/cmd_bootm.c before attempting to boot an image
2090 -1 common/cmd_bootm.c Image header has bad magic number
2091 2 common/cmd_bootm.c Image header has correct magic number
2092 -2 common/cmd_bootm.c Image header has bad checksum
2093 3 common/cmd_bootm.c Image header has correct checksum
2094 -3 common/cmd_bootm.c Image data has bad checksum
2095 4 common/cmd_bootm.c Image data has correct checksum
2096 -4 common/cmd_bootm.c Image is for unsupported architecture
2097 5 common/cmd_bootm.c Architecture check OK
2098 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2099 6 common/cmd_bootm.c Image Type check OK
2100 -6 common/cmd_bootm.c gunzip uncompression error
2101 -7 common/cmd_bootm.c Unimplemented compression type
2102 7 common/cmd_bootm.c Uncompression OK
2103 8 common/cmd_bootm.c No uncompress/copy overwrite error
2104 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2106 9 common/image.c Start initial ramdisk verification
2107 -10 common/image.c Ramdisk header has bad magic number
2108 -11 common/image.c Ramdisk header has bad checksum
2109 10 common/image.c Ramdisk header is OK
2110 -12 common/image.c Ramdisk data has bad checksum
2111 11 common/image.c Ramdisk data has correct checksum
2112 12 common/image.c Ramdisk verification complete, start loading
2113 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2114 13 common/image.c Start multifile image verification
2115 14 common/image.c No initial ramdisk, no multifile, continue.
2117 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2119 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2120 -31 post/post.c POST test failed, detected by post_output_backlog()
2121 -32 post/post.c POST test failed, detected by post_run_single()
2123 34 common/cmd_doc.c before loading a Image from a DOC device
2124 -35 common/cmd_doc.c Bad usage of "doc" command
2125 35 common/cmd_doc.c correct usage of "doc" command
2126 -36 common/cmd_doc.c No boot device
2127 36 common/cmd_doc.c correct boot device
2128 -37 common/cmd_doc.c Unknown Chip ID on boot device
2129 37 common/cmd_doc.c correct chip ID found, device available
2130 -38 common/cmd_doc.c Read Error on boot device
2131 38 common/cmd_doc.c reading Image header from DOC device OK
2132 -39 common/cmd_doc.c Image header has bad magic number
2133 39 common/cmd_doc.c Image header has correct magic number
2134 -40 common/cmd_doc.c Error reading Image from DOC device
2135 40 common/cmd_doc.c Image header has correct magic number
2136 41 common/cmd_ide.c before loading a Image from a IDE device
2137 -42 common/cmd_ide.c Bad usage of "ide" command
2138 42 common/cmd_ide.c correct usage of "ide" command
2139 -43 common/cmd_ide.c No boot device
2140 43 common/cmd_ide.c boot device found
2141 -44 common/cmd_ide.c Device not available
2142 44 common/cmd_ide.c Device available
2143 -45 common/cmd_ide.c wrong partition selected
2144 45 common/cmd_ide.c partition selected
2145 -46 common/cmd_ide.c Unknown partition table
2146 46 common/cmd_ide.c valid partition table found
2147 -47 common/cmd_ide.c Invalid partition type
2148 47 common/cmd_ide.c correct partition type
2149 -48 common/cmd_ide.c Error reading Image Header on boot device
2150 48 common/cmd_ide.c reading Image Header from IDE device OK
2151 -49 common/cmd_ide.c Image header has bad magic number
2152 49 common/cmd_ide.c Image header has correct magic number
2153 -50 common/cmd_ide.c Image header has bad checksum
2154 50 common/cmd_ide.c Image header has correct checksum
2155 -51 common/cmd_ide.c Error reading Image from IDE device
2156 51 common/cmd_ide.c reading Image from IDE device OK
2157 52 common/cmd_nand.c before loading a Image from a NAND device
2158 -53 common/cmd_nand.c Bad usage of "nand" command
2159 53 common/cmd_nand.c correct usage of "nand" command
2160 -54 common/cmd_nand.c No boot device
2161 54 common/cmd_nand.c boot device found
2162 -55 common/cmd_nand.c Unknown Chip ID on boot device
2163 55 common/cmd_nand.c correct chip ID found, device available
2164 -56 common/cmd_nand.c Error reading Image Header on boot device
2165 56 common/cmd_nand.c reading Image Header from NAND device OK
2166 -57 common/cmd_nand.c Image header has bad magic number
2167 57 common/cmd_nand.c Image header has correct magic number
2168 -58 common/cmd_nand.c Error reading Image from NAND device
2169 58 common/cmd_nand.c reading Image from NAND device OK
2171 -60 common/env_common.c Environment has a bad CRC, using default
2173 64 net/eth.c starting with Ethernet configuration.
2174 -64 net/eth.c no Ethernet found.
2175 65 net/eth.c Ethernet found.
2177 -80 common/cmd_net.c usage wrong
2178 80 common/cmd_net.c before calling NetLoop()
2179 -81 common/cmd_net.c some error in NetLoop() occurred
2180 81 common/cmd_net.c NetLoop() back without error
2181 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2182 82 common/cmd_net.c trying automatic boot
2183 83 common/cmd_net.c running "source" command
2184 -83 common/cmd_net.c some error in automatic boot or "source" command
2185 84 common/cmd_net.c end without errors
2190 100 common/cmd_bootm.c Kernel FIT Image has correct format
2191 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2192 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2193 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2194 102 common/cmd_bootm.c Kernel unit name specified
2195 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2196 103 common/cmd_bootm.c Found configuration node
2197 104 common/cmd_bootm.c Got kernel subimage node offset
2198 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2199 105 common/cmd_bootm.c Kernel subimage hash verification OK
2200 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2201 106 common/cmd_bootm.c Architecture check OK
2202 -106 common/cmd_bootm.c Kernel subimage has wrong type
2203 107 common/cmd_bootm.c Kernel subimage type OK
2204 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2205 108 common/cmd_bootm.c Got kernel subimage data/size
2206 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2207 -109 common/cmd_bootm.c Can't get kernel subimage type
2208 -110 common/cmd_bootm.c Can't get kernel subimage comp
2209 -111 common/cmd_bootm.c Can't get kernel subimage os
2210 -112 common/cmd_bootm.c Can't get kernel subimage load address
2211 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2213 120 common/image.c Start initial ramdisk verification
2214 -120 common/image.c Ramdisk FIT image has incorrect format
2215 121 common/image.c Ramdisk FIT image has correct format
2216 122 common/image.c No ramdisk subimage unit name, using configuration
2217 -122 common/image.c Can't get configuration for ramdisk subimage
2218 123 common/image.c Ramdisk unit name specified
2219 -124 common/image.c Can't get ramdisk subimage node offset
2220 125 common/image.c Got ramdisk subimage node offset
2221 -125 common/image.c Ramdisk subimage hash verification failed
2222 126 common/image.c Ramdisk subimage hash verification OK
2223 -126 common/image.c Ramdisk subimage for unsupported architecture
2224 127 common/image.c Architecture check OK
2225 -127 common/image.c Can't get ramdisk subimage data/size
2226 128 common/image.c Got ramdisk subimage data/size
2227 129 common/image.c Can't get ramdisk load address
2228 -129 common/image.c Got ramdisk load address
2230 -130 common/cmd_doc.c Incorrect FIT image format
2231 131 common/cmd_doc.c FIT image format OK
2233 -140 common/cmd_ide.c Incorrect FIT image format
2234 141 common/cmd_ide.c FIT image format OK
2236 -150 common/cmd_nand.c Incorrect FIT image format
2237 151 common/cmd_nand.c FIT image format OK
2239 - Automatic software updates via TFTP server
2241 CONFIG_UPDATE_TFTP_CNT_MAX
2242 CONFIG_UPDATE_TFTP_MSEC_MAX
2244 These options enable and control the auto-update feature;
2245 for a more detailed description refer to doc/README.update.
2247 - MTD Support (mtdparts command, UBI support)
2250 Adds the MTD device infrastructure from the Linux kernel.
2251 Needed for mtdparts command support.
2253 CONFIG_MTD_PARTITIONS
2255 Adds the MTD partitioning infrastructure from the Linux
2256 kernel. Needed for UBI support.
2262 [so far only for SMDK2400 boards]
2264 - Modem support enable:
2265 CONFIG_MODEM_SUPPORT
2267 - RTS/CTS Flow control enable:
2270 - Modem debug support:
2271 CONFIG_MODEM_SUPPORT_DEBUG
2273 Enables debugging stuff (char screen[1024], dbg())
2274 for modem support. Useful only with BDI2000.
2276 - Interrupt support (PPC):
2278 There are common interrupt_init() and timer_interrupt()
2279 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2280 for CPU specific initialization. interrupt_init_cpu()
2281 should set decrementer_count to appropriate value. If
2282 CPU resets decrementer automatically after interrupt
2283 (ppc4xx) it should set decrementer_count to zero.
2284 timer_interrupt() calls timer_interrupt_cpu() for CPU
2285 specific handling. If board has watchdog / status_led
2286 / other_activity_monitor it works automatically from
2287 general timer_interrupt().
2291 In the target system modem support is enabled when a
2292 specific key (key combination) is pressed during
2293 power-on. Otherwise U-Boot will boot normally
2294 (autoboot). The key_pressed() function is called from
2295 board_init(). Currently key_pressed() is a dummy
2296 function, returning 1 and thus enabling modem
2299 If there are no modem init strings in the
2300 environment, U-Boot proceed to autoboot; the
2301 previous output (banner, info printfs) will be
2304 See also: doc/README.Modem
2307 Configuration Settings:
2308 -----------------------
2310 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2311 undefine this when you're short of memory.
2313 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2314 width of the commands listed in the 'help' command output.
2316 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2317 prompt for user input.
2319 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2321 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2323 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2325 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2326 the application (usually a Linux kernel) when it is
2329 - CONFIG_SYS_BAUDRATE_TABLE:
2330 List of legal baudrate settings for this board.
2332 - CONFIG_SYS_CONSOLE_INFO_QUIET
2333 Suppress display of console information at boot.
2335 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2336 If the board specific function
2337 extern int overwrite_console (void);
2338 returns 1, the stdin, stderr and stdout are switched to the
2339 serial port, else the settings in the environment are used.
2341 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2342 Enable the call to overwrite_console().
2344 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2345 Enable overwrite of previous console environment settings.
2347 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2348 Begin and End addresses of the area used by the
2351 - CONFIG_SYS_ALT_MEMTEST:
2352 Enable an alternate, more extensive memory test.
2354 - CONFIG_SYS_MEMTEST_SCRATCH:
2355 Scratch address used by the alternate memory test
2356 You only need to set this if address zero isn't writeable
2358 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2359 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2360 this specified memory area will get subtracted from the top
2361 (end) of RAM and won't get "touched" at all by U-Boot. By
2362 fixing up gd->ram_size the Linux kernel should gets passed
2363 the now "corrected" memory size and won't touch it either.
2364 This should work for arch/ppc and arch/powerpc. Only Linux
2365 board ports in arch/powerpc with bootwrapper support that
2366 recalculate the memory size from the SDRAM controller setup
2367 will have to get fixed in Linux additionally.
2369 This option can be used as a workaround for the 440EPx/GRx
2370 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2373 WARNING: Please make sure that this value is a multiple of
2374 the Linux page size (normally 4k). If this is not the case,
2375 then the end address of the Linux memory will be located at a
2376 non page size aligned address and this could cause major
2379 - CONFIG_SYS_TFTP_LOADADDR:
2380 Default load address for network file downloads
2382 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2383 Enable temporary baudrate change while serial download
2385 - CONFIG_SYS_SDRAM_BASE:
2386 Physical start address of SDRAM. _Must_ be 0 here.
2388 - CONFIG_SYS_MBIO_BASE:
2389 Physical start address of Motherboard I/O (if using a
2392 - CONFIG_SYS_FLASH_BASE:
2393 Physical start address of Flash memory.
2395 - CONFIG_SYS_MONITOR_BASE:
2396 Physical start address of boot monitor code (set by
2397 make config files to be same as the text base address
2398 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
2399 CONFIG_SYS_FLASH_BASE when booting from flash.
2401 - CONFIG_SYS_MONITOR_LEN:
2402 Size of memory reserved for monitor code, used to
2403 determine _at_compile_time_ (!) if the environment is
2404 embedded within the U-Boot image, or in a separate
2407 - CONFIG_SYS_MALLOC_LEN:
2408 Size of DRAM reserved for malloc() use.
2410 - CONFIG_SYS_BOOTM_LEN:
2411 Normally compressed uImages are limited to an
2412 uncompressed size of 8 MBytes. If this is not enough,
2413 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2414 to adjust this setting to your needs.
2416 - CONFIG_SYS_BOOTMAPSZ:
2417 Maximum size of memory mapped by the startup code of
2418 the Linux kernel; all data that must be processed by
2419 the Linux kernel (bd_info, boot arguments, FDT blob if
2420 used) must be put below this limit, unless "bootm_low"
2421 enviroment variable is defined and non-zero. In such case
2422 all data for the Linux kernel must be between "bootm_low"
2423 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
2424 variable "bootm_mapsize" will override the value of
2425 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
2426 then the value in "bootm_size" will be used instead.
2428 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
2429 Enable initrd_high functionality. If defined then the
2430 initrd_high feature is enabled and the bootm ramdisk subcommand
2433 - CONFIG_SYS_BOOT_GET_CMDLINE:
2434 Enables allocating and saving kernel cmdline in space between
2435 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2437 - CONFIG_SYS_BOOT_GET_KBD:
2438 Enables allocating and saving a kernel copy of the bd_info in
2439 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2441 - CONFIG_SYS_MAX_FLASH_BANKS:
2442 Max number of Flash memory banks
2444 - CONFIG_SYS_MAX_FLASH_SECT:
2445 Max number of sectors on a Flash chip
2447 - CONFIG_SYS_FLASH_ERASE_TOUT:
2448 Timeout for Flash erase operations (in ms)
2450 - CONFIG_SYS_FLASH_WRITE_TOUT:
2451 Timeout for Flash write operations (in ms)
2453 - CONFIG_SYS_FLASH_LOCK_TOUT
2454 Timeout for Flash set sector lock bit operation (in ms)
2456 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2457 Timeout for Flash clear lock bits operation (in ms)
2459 - CONFIG_SYS_FLASH_PROTECTION
2460 If defined, hardware flash sectors protection is used
2461 instead of U-Boot software protection.
2463 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2465 Enable TFTP transfers directly to flash memory;
2466 without this option such a download has to be
2467 performed in two steps: (1) download to RAM, and (2)
2468 copy from RAM to flash.
2470 The two-step approach is usually more reliable, since
2471 you can check if the download worked before you erase
2472 the flash, but in some situations (when system RAM is
2473 too limited to allow for a temporary copy of the
2474 downloaded image) this option may be very useful.
2476 - CONFIG_SYS_FLASH_CFI:
2477 Define if the flash driver uses extra elements in the
2478 common flash structure for storing flash geometry.
2480 - CONFIG_FLASH_CFI_DRIVER
2481 This option also enables the building of the cfi_flash driver
2482 in the drivers directory
2484 - CONFIG_FLASH_CFI_MTD
2485 This option enables the building of the cfi_mtd driver
2486 in the drivers directory. The driver exports CFI flash
2489 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2490 Use buffered writes to flash.
2492 - CONFIG_FLASH_SPANSION_S29WS_N
2493 s29ws-n MirrorBit flash has non-standard addresses for buffered
2496 - CONFIG_SYS_FLASH_QUIET_TEST
2497 If this option is defined, the common CFI flash doesn't
2498 print it's warning upon not recognized FLASH banks. This
2499 is useful, if some of the configured banks are only
2500 optionally available.
2502 - CONFIG_FLASH_SHOW_PROGRESS
2503 If defined (must be an integer), print out countdown
2504 digits and dots. Recommended value: 45 (9..1) for 80
2505 column displays, 15 (3..1) for 40 column displays.
2507 - CONFIG_SYS_RX_ETH_BUFFER:
2508 Defines the number of Ethernet receive buffers. On some
2509 Ethernet controllers it is recommended to set this value
2510 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2511 buffers can be full shortly after enabling the interface
2512 on high Ethernet traffic.
2513 Defaults to 4 if not defined.
2515 - CONFIG_ENV_MAX_ENTRIES
2517 Maximum number of entries in the hash table that is used
2518 internally to store the environment settings. The default
2519 setting is supposed to be generous and should work in most
2520 cases. This setting can be used to tune behaviour; see
2521 lib/hashtable.c for details.
2523 The following definitions that deal with the placement and management
2524 of environment data (variable area); in general, we support the
2525 following configurations:
2527 - CONFIG_ENV_IS_IN_FLASH:
2529 Define this if the environment is in flash memory.
2531 a) The environment occupies one whole flash sector, which is
2532 "embedded" in the text segment with the U-Boot code. This
2533 happens usually with "bottom boot sector" or "top boot
2534 sector" type flash chips, which have several smaller
2535 sectors at the start or the end. For instance, such a
2536 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2537 such a case you would place the environment in one of the
2538 4 kB sectors - with U-Boot code before and after it. With
2539 "top boot sector" type flash chips, you would put the
2540 environment in one of the last sectors, leaving a gap
2541 between U-Boot and the environment.
2543 - CONFIG_ENV_OFFSET:
2545 Offset of environment data (variable area) to the
2546 beginning of flash memory; for instance, with bottom boot
2547 type flash chips the second sector can be used: the offset
2548 for this sector is given here.
2550 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2554 This is just another way to specify the start address of
2555 the flash sector containing the environment (instead of
2558 - CONFIG_ENV_SECT_SIZE:
2560 Size of the sector containing the environment.
2563 b) Sometimes flash chips have few, equal sized, BIG sectors.
2564 In such a case you don't want to spend a whole sector for
2569 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2570 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2571 of this flash sector for the environment. This saves
2572 memory for the RAM copy of the environment.
2574 It may also save flash memory if you decide to use this
2575 when your environment is "embedded" within U-Boot code,
2576 since then the remainder of the flash sector could be used
2577 for U-Boot code. It should be pointed out that this is
2578 STRONGLY DISCOURAGED from a robustness point of view:
2579 updating the environment in flash makes it always
2580 necessary to erase the WHOLE sector. If something goes
2581 wrong before the contents has been restored from a copy in
2582 RAM, your target system will be dead.
2584 - CONFIG_ENV_ADDR_REDUND
2585 CONFIG_ENV_SIZE_REDUND
2587 These settings describe a second storage area used to hold
2588 a redundant copy of the environment data, so that there is
2589 a valid backup copy in case there is a power failure during
2590 a "saveenv" operation.
2592 BE CAREFUL! Any changes to the flash layout, and some changes to the
2593 source code will make it necessary to adapt <board>/u-boot.lds*
2597 - CONFIG_ENV_IS_IN_NVRAM:
2599 Define this if you have some non-volatile memory device
2600 (NVRAM, battery buffered SRAM) which you want to use for the
2606 These two #defines are used to determine the memory area you
2607 want to use for environment. It is assumed that this memory
2608 can just be read and written to, without any special
2611 BE CAREFUL! The first access to the environment happens quite early
2612 in U-Boot initalization (when we try to get the setting of for the
2613 console baudrate). You *MUST* have mapped your NVRAM area then, or
2616 Please note that even with NVRAM we still use a copy of the
2617 environment in RAM: we could work on NVRAM directly, but we want to
2618 keep settings there always unmodified except somebody uses "saveenv"
2619 to save the current settings.
2622 - CONFIG_ENV_IS_IN_EEPROM:
2624 Use this if you have an EEPROM or similar serial access
2625 device and a driver for it.
2627 - CONFIG_ENV_OFFSET:
2630 These two #defines specify the offset and size of the
2631 environment area within the total memory of your EEPROM.
2633 - CONFIG_SYS_I2C_EEPROM_ADDR:
2634 If defined, specified the chip address of the EEPROM device.
2635 The default address is zero.
2637 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2638 If defined, the number of bits used to address bytes in a
2639 single page in the EEPROM device. A 64 byte page, for example
2640 would require six bits.
2642 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2643 If defined, the number of milliseconds to delay between
2644 page writes. The default is zero milliseconds.
2646 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2647 The length in bytes of the EEPROM memory array address. Note
2648 that this is NOT the chip address length!
2650 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2651 EEPROM chips that implement "address overflow" are ones
2652 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2653 address and the extra bits end up in the "chip address" bit
2654 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2657 Note that we consider the length of the address field to
2658 still be one byte because the extra address bits are hidden
2659 in the chip address.
2661 - CONFIG_SYS_EEPROM_SIZE:
2662 The size in bytes of the EEPROM device.
2664 - CONFIG_ENV_EEPROM_IS_ON_I2C
2665 define this, if you have I2C and SPI activated, and your
2666 EEPROM, which holds the environment, is on the I2C bus.
2668 - CONFIG_I2C_ENV_EEPROM_BUS
2669 if you have an Environment on an EEPROM reached over
2670 I2C muxes, you can define here, how to reach this
2671 EEPROM. For example:
2673 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
2675 EEPROM which holds the environment, is reached over
2676 a pca9547 i2c mux with address 0x70, channel 3.
2678 - CONFIG_ENV_IS_IN_DATAFLASH:
2680 Define this if you have a DataFlash memory device which you
2681 want to use for the environment.
2683 - CONFIG_ENV_OFFSET:
2687 These three #defines specify the offset and size of the
2688 environment area within the total memory of your DataFlash placed
2689 at the specified address.
2691 - CONFIG_ENV_IS_IN_NAND:
2693 Define this if you have a NAND device which you want to use
2694 for the environment.
2696 - CONFIG_ENV_OFFSET:
2699 These two #defines specify the offset and size of the environment
2700 area within the first NAND device. CONFIG_ENV_OFFSET must be
2701 aligned to an erase block boundary.
2703 - CONFIG_ENV_OFFSET_REDUND (optional):
2705 This setting describes a second storage area of CONFIG_ENV_SIZE
2706 size used to hold a redundant copy of the environment data, so
2707 that there is a valid backup copy in case there is a power failure
2708 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
2709 aligned to an erase block boundary.
2711 - CONFIG_ENV_RANGE (optional):
2713 Specifies the length of the region in which the environment
2714 can be written. This should be a multiple of the NAND device's
2715 block size. Specifying a range with more erase blocks than
2716 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
2717 the range to be avoided.
2719 - CONFIG_ENV_OFFSET_OOB (optional):
2721 Enables support for dynamically retrieving the offset of the
2722 environment from block zero's out-of-band data. The
2723 "nand env.oob" command can be used to record this offset.
2724 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
2725 using CONFIG_ENV_OFFSET_OOB.
2727 - CONFIG_NAND_ENV_DST
2729 Defines address in RAM to which the nand_spl code should copy the
2730 environment. If redundant environment is used, it will be copied to
2731 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2733 - CONFIG_SYS_SPI_INIT_OFFSET
2735 Defines offset to the initial SPI buffer area in DPRAM. The
2736 area is used at an early stage (ROM part) if the environment
2737 is configured to reside in the SPI EEPROM: We need a 520 byte
2738 scratch DPRAM area. It is used between the two initialization
2739 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2740 to be a good choice since it makes it far enough from the
2741 start of the data area as well as from the stack pointer.
2743 Please note that the environment is read-only until the monitor
2744 has been relocated to RAM and a RAM copy of the environment has been
2745 created; also, when using EEPROM you will have to use getenv_f()
2746 until then to read environment variables.
2748 The environment is protected by a CRC32 checksum. Before the monitor
2749 is relocated into RAM, as a result of a bad CRC you will be working
2750 with the compiled-in default environment - *silently*!!! [This is
2751 necessary, because the first environment variable we need is the
2752 "baudrate" setting for the console - if we have a bad CRC, we don't
2753 have any device yet where we could complain.]
2755 Note: once the monitor has been relocated, then it will complain if
2756 the default environment is used; a new CRC is computed as soon as you
2757 use the "saveenv" command to store a valid environment.
2759 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2760 Echo the inverted Ethernet link state to the fault LED.
2762 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2763 also needs to be defined.
2765 - CONFIG_SYS_FAULT_MII_ADDR:
2766 MII address of the PHY to check for the Ethernet link state.
2768 - CONFIG_NS16550_MIN_FUNCTIONS:
2769 Define this if you desire to only have use of the NS16550_init
2770 and NS16550_putc functions for the serial driver located at
2771 drivers/serial/ns16550.c. This option is useful for saving
2772 space for already greatly restricted images, including but not
2773 limited to NAND_SPL configurations.
2775 Low Level (hardware related) configuration options:
2776 ---------------------------------------------------
2778 - CONFIG_SYS_CACHELINE_SIZE:
2779 Cache Line Size of the CPU.
2781 - CONFIG_SYS_DEFAULT_IMMR:
2782 Default address of the IMMR after system reset.
2784 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2785 and RPXsuper) to be able to adjust the position of
2786 the IMMR register after a reset.
2788 - Floppy Disk Support:
2789 CONFIG_SYS_FDC_DRIVE_NUMBER
2791 the default drive number (default value 0)
2793 CONFIG_SYS_ISA_IO_STRIDE
2795 defines the spacing between FDC chipset registers
2798 CONFIG_SYS_ISA_IO_OFFSET
2800 defines the offset of register from address. It
2801 depends on which part of the data bus is connected to
2802 the FDC chipset. (default value 0)
2804 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
2805 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
2808 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
2809 fdc_hw_init() is called at the beginning of the FDC
2810 setup. fdc_hw_init() must be provided by the board
2811 source code. It is used to make hardware dependant
2815 Most IDE controllers were designed to be connected with PCI
2816 interface. Only few of them were designed for AHB interface.
2817 When software is doing ATA command and data transfer to
2818 IDE devices through IDE-AHB controller, some additional
2819 registers accessing to these kind of IDE-AHB controller
2822 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
2823 DO NOT CHANGE unless you know exactly what you're
2824 doing! (11-4) [MPC8xx/82xx systems only]
2826 - CONFIG_SYS_INIT_RAM_ADDR:
2828 Start address of memory area that can be used for
2829 initial data and stack; please note that this must be
2830 writable memory that is working WITHOUT special
2831 initialization, i. e. you CANNOT use normal RAM which
2832 will become available only after programming the
2833 memory controller and running certain initialization
2836 U-Boot uses the following memory types:
2837 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2838 - MPC824X: data cache
2839 - PPC4xx: data cache
2841 - CONFIG_SYS_GBL_DATA_OFFSET:
2843 Offset of the initial data structure in the memory
2844 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2845 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
2846 data is located at the end of the available space
2847 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
2848 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
2849 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2850 CONFIG_SYS_GBL_DATA_OFFSET) downward.
2853 On the MPC824X (or other systems that use the data
2854 cache for initial memory) the address chosen for
2855 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
2856 point to an otherwise UNUSED address space between
2857 the top of RAM and the start of the PCI space.
2859 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
2861 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
2863 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
2865 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
2867 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2869 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
2871 - CONFIG_SYS_OR_TIMING_SDRAM:
2874 - CONFIG_SYS_MAMR_PTA:
2875 periodic timer for refresh
2877 - CONFIG_SYS_DER: Debug Event Register (37-47)
2879 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2880 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2881 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2882 CONFIG_SYS_BR1_PRELIM:
2883 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2885 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2886 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2887 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
2888 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2890 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
2891 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
2892 Machine Mode Register and Memory Periodic Timer
2893 Prescaler definitions (SDRAM timing)
2895 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
2896 enable I2C microcode relocation patch (MPC8xx);
2897 define relocation offset in DPRAM [DSP2]
2899 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
2900 enable SMC microcode relocation patch (MPC8xx);
2901 define relocation offset in DPRAM [SMC1]
2903 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
2904 enable SPI microcode relocation patch (MPC8xx);
2905 define relocation offset in DPRAM [SCC4]
2907 - CONFIG_SYS_USE_OSCCLK:
2908 Use OSCM clock mode on MBX8xx board. Be careful,
2909 wrong setting might damage your board. Read
2910 doc/README.MBX before setting this variable!
2912 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2913 Offset of the bootmode word in DPRAM used by post
2914 (Power On Self Tests). This definition overrides
2915 #define'd default value in commproc.h resp.
2918 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
2919 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
2920 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
2921 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
2922 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2923 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
2924 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
2925 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
2926 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
2928 - CONFIG_PCI_DISABLE_PCIE:
2929 Disable PCI-Express on systems where it is supported but not
2933 Chip has SRIO or not
2936 Board has SRIO 1 port available
2939 Board has SRIO 2 port available
2941 - CONFIG_SYS_SRIOn_MEM_VIRT:
2942 Virtual Address of SRIO port 'n' memory region
2944 - CONFIG_SYS_SRIOn_MEM_PHYS:
2945 Physical Address of SRIO port 'n' memory region
2947 - CONFIG_SYS_SRIOn_MEM_SIZE:
2948 Size of SRIO port 'n' memory region
2950 - CONFIG_SYS_NDFC_16
2951 Defined to tell the NDFC that the NAND chip is using a
2954 - CONFIG_SYS_NDFC_EBC0_CFG
2955 Sets the EBC0_CFG register for the NDFC. If not defined
2956 a default value will be used.
2959 Get DDR timing information from an I2C EEPROM. Common
2960 with pluggable memory modules such as SODIMMs
2963 I2C address of the SPD EEPROM
2965 - CONFIG_SYS_SPD_BUS_NUM
2966 If SPD EEPROM is on an I2C bus other than the first
2967 one, specify here. Note that the value must resolve
2968 to something your driver can deal with.
2970 - CONFIG_SYS_DDR_RAW_TIMING
2971 Get DDR timing information from other than SPD. Common with
2972 soldered DDR chips onboard without SPD. DDR raw timing
2973 parameters are extracted from datasheet and hard-coded into
2974 header files or board specific files.
2976 - CONFIG_SYS_83XX_DDR_USES_CS0
2977 Only for 83xx systems. If specified, then DDR should
2978 be configured using CS0 and CS1 instead of CS2 and CS3.
2980 - CONFIG_ETHER_ON_FEC[12]
2981 Define to enable FEC[12] on a 8xx series processor.
2983 - CONFIG_FEC[12]_PHY
2984 Define to the hardcoded PHY address which corresponds
2985 to the given FEC; i. e.
2986 #define CONFIG_FEC1_PHY 4
2987 means that the PHY with address 4 is connected to FEC1
2989 When set to -1, means to probe for first available.
2991 - CONFIG_FEC[12]_PHY_NORXERR
2992 The PHY does not have a RXERR line (RMII only).
2993 (so program the FEC to ignore it).
2996 Enable RMII mode for all FECs.
2997 Note that this is a global option, we can't
2998 have one FEC in standard MII mode and another in RMII mode.
3000 - CONFIG_CRC32_VERIFY
3001 Add a verify option to the crc32 command.
3004 => crc32 -v <address> <count> <crc32>
3006 Where address/count indicate a memory area
3007 and crc32 is the correct crc32 which the
3011 Add the "loopw" memory command. This only takes effect if
3012 the memory commands are activated globally (CONFIG_CMD_MEM).
3015 Add the "mdc" and "mwc" memory commands. These are cyclic
3020 This command will print 4 bytes (10,11,12,13) each 500 ms.
3022 => mwc.l 100 12345678 10
3023 This command will write 12345678 to address 100 all 10 ms.
3025 This only takes effect if the memory commands are activated
3026 globally (CONFIG_CMD_MEM).
3028 - CONFIG_SKIP_LOWLEVEL_INIT
3029 [ARM only] If this variable is defined, then certain
3030 low level initializations (like setting up the memory
3031 controller) are omitted and/or U-Boot does not
3032 relocate itself into RAM.
3034 Normally this variable MUST NOT be defined. The only
3035 exception is when U-Boot is loaded (to RAM) by some
3036 other boot loader or by a debugger which performs
3037 these initializations itself.
3040 Modifies the behaviour of start.S when compiling a loader
3041 that is executed before the actual U-Boot. E.g. when
3042 compiling a NAND SPL.
3044 - CONFIG_USE_ARCH_MEMCPY
3045 CONFIG_USE_ARCH_MEMSET
3046 If these options are used a optimized version of memcpy/memset will
3047 be used if available. These functions may be faster under some
3048 conditions but may increase the binary size.
3050 Building the Software:
3051 ======================
3053 Building U-Boot has been tested in several native build environments
3054 and in many different cross environments. Of course we cannot support
3055 all possibly existing versions of cross development tools in all
3056 (potentially obsolete) versions. In case of tool chain problems we
3057 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3058 which is extensively used to build and test U-Boot.
3060 If you are not using a native environment, it is assumed that you
3061 have GNU cross compiling tools available in your path. In this case,
3062 you must set the environment variable CROSS_COMPILE in your shell.
3063 Note that no changes to the Makefile or any other source files are
3064 necessary. For example using the ELDK on a 4xx CPU, please enter:
3066 $ CROSS_COMPILE=ppc_4xx-
3067 $ export CROSS_COMPILE
3069 Note: If you wish to generate Windows versions of the utilities in
3070 the tools directory you can use the MinGW toolchain
3071 (http://www.mingw.org). Set your HOST tools to the MinGW
3072 toolchain and execute 'make tools'. For example:
3074 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3076 Binaries such as tools/mkimage.exe will be created which can
3077 be executed on computers running Windows.
3079 U-Boot is intended to be simple to build. After installing the
3080 sources you must configure U-Boot for one specific board type. This
3085 where "NAME_config" is the name of one of the existing configu-
3086 rations; see the main Makefile for supported names.
3088 Note: for some board special configuration names may exist; check if
3089 additional information is available from the board vendor; for
3090 instance, the TQM823L systems are available without (standard)
3091 or with LCD support. You can select such additional "features"
3092 when choosing the configuration, i. e.
3095 - will configure for a plain TQM823L, i. e. no LCD support
3097 make TQM823L_LCD_config
3098 - will configure for a TQM823L with U-Boot console on LCD
3103 Finally, type "make all", and you should get some working U-Boot
3104 images ready for download to / installation on your system:
3106 - "u-boot.bin" is a raw binary image
3107 - "u-boot" is an image in ELF binary format
3108 - "u-boot.srec" is in Motorola S-Record format
3110 By default the build is performed locally and the objects are saved
3111 in the source directory. One of the two methods can be used to change
3112 this behavior and build U-Boot to some external directory:
3114 1. Add O= to the make command line invocations:
3116 make O=/tmp/build distclean
3117 make O=/tmp/build NAME_config
3118 make O=/tmp/build all
3120 2. Set environment variable BUILD_DIR to point to the desired location:
3122 export BUILD_DIR=/tmp/build
3127 Note that the command line "O=" setting overrides the BUILD_DIR environment
3131 Please be aware that the Makefiles assume you are using GNU make, so
3132 for instance on NetBSD you might need to use "gmake" instead of
3136 If the system board that you have is not listed, then you will need
3137 to port U-Boot to your hardware platform. To do this, follow these
3140 1. Add a new configuration option for your board to the toplevel
3141 "Makefile" and to the "MAKEALL" script, using the existing
3142 entries as examples. Note that here and at many other places
3143 boards and other names are listed in alphabetical sort order. Please
3145 2. Create a new directory to hold your board specific code. Add any
3146 files you need. In your board directory, you will need at least
3147 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
3148 3. Create a new configuration file "include/configs/<board>.h" for
3150 3. If you're porting U-Boot to a new CPU, then also create a new
3151 directory to hold your CPU specific code. Add any files you need.
3152 4. Run "make <board>_config" with your new name.
3153 5. Type "make", and you should get a working "u-boot.srec" file
3154 to be installed on your target system.
3155 6. Debug and solve any problems that might arise.
3156 [Of course, this last step is much harder than it sounds.]
3159 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3160 ==============================================================
3162 If you have modified U-Boot sources (for instance added a new board
3163 or support for new devices, a new CPU, etc.) you are expected to
3164 provide feedback to the other developers. The feedback normally takes
3165 the form of a "patch", i. e. a context diff against a certain (latest
3166 official or latest in the git repository) version of U-Boot sources.
3168 But before you submit such a patch, please verify that your modifi-
3169 cation did not break existing code. At least make sure that *ALL* of
3170 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3171 just run the "MAKEALL" script, which will configure and build U-Boot
3172 for ALL supported system. Be warned, this will take a while. You can
3173 select which (cross) compiler to use by passing a `CROSS_COMPILE'
3174 environment variable to the script, i. e. to use the ELDK cross tools
3177 CROSS_COMPILE=ppc_8xx- MAKEALL
3179 or to build on a native PowerPC system you can type
3181 CROSS_COMPILE=' ' MAKEALL
3183 When using the MAKEALL script, the default behaviour is to build
3184 U-Boot in the source directory. This location can be changed by
3185 setting the BUILD_DIR environment variable. Also, for each target
3186 built, the MAKEALL script saves two log files (<target>.ERR and
3187 <target>.MAKEALL) in the <source dir>/LOG directory. This default
3188 location can be changed by setting the MAKEALL_LOGDIR environment
3189 variable. For example:
3191 export BUILD_DIR=/tmp/build
3192 export MAKEALL_LOGDIR=/tmp/log
3193 CROSS_COMPILE=ppc_8xx- MAKEALL
3195 With the above settings build objects are saved in the /tmp/build,
3196 log files are saved in the /tmp/log and the source tree remains clean
3197 during the whole build process.
3200 See also "U-Boot Porting Guide" below.
3203 Monitor Commands - Overview:
3204 ============================
3206 go - start application at address 'addr'
3207 run - run commands in an environment variable
3208 bootm - boot application image from memory
3209 bootp - boot image via network using BootP/TFTP protocol
3210 tftpboot- boot image via network using TFTP protocol
3211 and env variables "ipaddr" and "serverip"
3212 (and eventually "gatewayip")
3213 rarpboot- boot image via network using RARP/TFTP protocol
3214 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3215 loads - load S-Record file over serial line
3216 loadb - load binary file over serial line (kermit mode)
3218 mm - memory modify (auto-incrementing)
3219 nm - memory modify (constant address)
3220 mw - memory write (fill)
3222 cmp - memory compare
3223 crc32 - checksum calculation
3224 i2c - I2C sub-system
3225 sspi - SPI utility commands
3226 base - print or set address offset
3227 printenv- print environment variables
3228 setenv - set environment variables
3229 saveenv - save environment variables to persistent storage
3230 protect - enable or disable FLASH write protection
3231 erase - erase FLASH memory
3232 flinfo - print FLASH memory information
3233 bdinfo - print Board Info structure
3234 iminfo - print header information for application image
3235 coninfo - print console devices and informations
3236 ide - IDE sub-system
3237 loop - infinite loop on address range
3238 loopw - infinite write loop on address range
3239 mtest - simple RAM test
3240 icache - enable or disable instruction cache
3241 dcache - enable or disable data cache
3242 reset - Perform RESET of the CPU
3243 echo - echo args to console
3244 version - print monitor version
3245 help - print online help
3246 ? - alias for 'help'
3249 Monitor Commands - Detailed Description:
3250 ========================================
3254 For now: just type "help <command>".
3257 Environment Variables:
3258 ======================
3260 U-Boot supports user configuration using Environment Variables which
3261 can be made persistent by saving to Flash memory.
3263 Environment Variables are set using "setenv", printed using
3264 "printenv", and saved to Flash using "saveenv". Using "setenv"
3265 without a value can be used to delete a variable from the
3266 environment. As long as you don't save the environment you are
3267 working with an in-memory copy. In case the Flash area containing the
3268 environment is erased by accident, a default environment is provided.
3270 Some configuration options can be set using Environment Variables.
3272 List of environment variables (most likely not complete):
3274 baudrate - see CONFIG_BAUDRATE
3276 bootdelay - see CONFIG_BOOTDELAY
3278 bootcmd - see CONFIG_BOOTCOMMAND
3280 bootargs - Boot arguments when booting an RTOS image
3282 bootfile - Name of the image to load with TFTP
3284 bootm_low - Memory range available for image processing in the bootm
3285 command can be restricted. This variable is given as
3286 a hexadecimal number and defines lowest address allowed
3287 for use by the bootm command. See also "bootm_size"
3288 environment variable. Address defined by "bootm_low" is
3289 also the base of the initial memory mapping for the Linux
3290 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
3293 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
3294 This variable is given as a hexadecimal number and it
3295 defines the size of the memory region starting at base
3296 address bootm_low that is accessible by the Linux kernel
3297 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
3298 as the default value if it is defined, and bootm_size is
3301 bootm_size - Memory range available for image processing in the bootm
3302 command can be restricted. This variable is given as
3303 a hexadecimal number and defines the size of the region
3304 allowed for use by the bootm command. See also "bootm_low"
3305 environment variable.
3307 updatefile - Location of the software update file on a TFTP server, used
3308 by the automatic software update feature. Please refer to
3309 documentation in doc/README.update for more details.
3311 autoload - if set to "no" (any string beginning with 'n'),
3312 "bootp" will just load perform a lookup of the
3313 configuration from the BOOTP server, but not try to
3314 load any image using TFTP
3316 autostart - if set to "yes", an image loaded using the "bootp",
3317 "rarpboot", "tftpboot" or "diskboot" commands will
3318 be automatically started (by internally calling
3321 If set to "no", a standalone image passed to the
3322 "bootm" command will be copied to the load address
3323 (and eventually uncompressed), but NOT be started.
3324 This can be used to load and uncompress arbitrary
3327 fdt_high - if set this restricts the maximum address that the
3328 flattened device tree will be copied into upon boot.
3329 If this is set to the special value 0xFFFFFFFF then
3330 the fdt will not be copied at all on boot. For this
3331 to work it must reside in writable memory, have
3332 sufficient padding on the end of it for u-boot to
3333 add the information it needs into it, and the memory
3334 must be accessible by the kernel.
3336 i2cfast - (PPC405GP|PPC405EP only)
3337 if set to 'y' configures Linux I2C driver for fast
3338 mode (400kHZ). This environment variable is used in
3339 initialization code. So, for changes to be effective
3340 it must be saved and board must be reset.
3342 initrd_high - restrict positioning of initrd images:
3343 If this variable is not set, initrd images will be
3344 copied to the highest possible address in RAM; this
3345 is usually what you want since it allows for
3346 maximum initrd size. If for some reason you want to
3347 make sure that the initrd image is loaded below the
3348 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3349 variable to a value of "no" or "off" or "0".
3350 Alternatively, you can set it to a maximum upper
3351 address to use (U-Boot will still check that it
3352 does not overwrite the U-Boot stack and data).
3354 For instance, when you have a system with 16 MB
3355 RAM, and want to reserve 4 MB from use by Linux,
3356 you can do this by adding "mem=12M" to the value of
3357 the "bootargs" variable. However, now you must make
3358 sure that the initrd image is placed in the first
3359 12 MB as well - this can be done with
3361 setenv initrd_high 00c00000
3363 If you set initrd_high to 0xFFFFFFFF, this is an
3364 indication to U-Boot that all addresses are legal
3365 for the Linux kernel, including addresses in flash
3366 memory. In this case U-Boot will NOT COPY the
3367 ramdisk at all. This may be useful to reduce the
3368 boot time on your system, but requires that this
3369 feature is supported by your Linux kernel.
3371 ipaddr - IP address; needed for tftpboot command
3373 loadaddr - Default load address for commands like "bootp",
3374 "rarpboot", "tftpboot", "loadb" or "diskboot"
3376 loads_echo - see CONFIG_LOADS_ECHO
3378 serverip - TFTP server IP address; needed for tftpboot command
3380 bootretry - see CONFIG_BOOT_RETRY_TIME
3382 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3384 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3386 ethprime - When CONFIG_NET_MULTI is enabled controls which
3387 interface is used first.
3389 ethact - When CONFIG_NET_MULTI is enabled controls which
3390 interface is currently active. For example you
3391 can do the following
3393 => setenv ethact FEC
3394 => ping 192.168.0.1 # traffic sent on FEC
3395 => setenv ethact SCC
3396 => ping 10.0.0.1 # traffic sent on SCC
3398 ethrotate - When set to "no" U-Boot does not go through all
3399 available network interfaces.
3400 It just stays at the currently selected interface.
3402 netretry - When set to "no" each network operation will
3403 either succeed or fail without retrying.
3404 When set to "once" the network operation will
3405 fail when all the available network interfaces
3406 are tried once without success.
3407 Useful on scripts which control the retry operation
3410 npe_ucode - set load address for the NPE microcode
3412 tftpsrcport - If this is set, the value is used for TFTP's
3415 tftpdstport - If this is set, the value is used for TFTP's UDP
3416 destination port instead of the Well Know Port 69.
3418 tftpblocksize - Block size to use for TFTP transfers; if not set,
3419 we use the TFTP server's default block size
3421 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3422 seconds, minimum value is 1000 = 1 second). Defines
3423 when a packet is considered to be lost so it has to
3424 be retransmitted. The default is 5000 = 5 seconds.
3425 Lowering this value may make downloads succeed
3426 faster in networks with high packet loss rates or
3427 with unreliable TFTP servers.
3429 vlan - When set to a value < 4095 the traffic over
3430 Ethernet is encapsulated/received over 802.1q
3433 The following environment variables may be used and automatically
3434 updated by the network boot commands ("bootp" and "rarpboot"),
3435 depending the information provided by your boot server:
3437 bootfile - see above
3438 dnsip - IP address of your Domain Name Server
3439 dnsip2 - IP address of your secondary Domain Name Server
3440 gatewayip - IP address of the Gateway (Router) to use
3441 hostname - Target hostname
3443 netmask - Subnet Mask
3444 rootpath - Pathname of the root filesystem on the NFS server
3445 serverip - see above
3448 There are two special Environment Variables:
3450 serial# - contains hardware identification information such
3451 as type string and/or serial number
3452 ethaddr - Ethernet address
3454 These variables can be set only once (usually during manufacturing of
3455 the board). U-Boot refuses to delete or overwrite these variables
3456 once they have been set once.
3459 Further special Environment Variables:
3461 ver - Contains the U-Boot version string as printed
3462 with the "version" command. This variable is
3463 readonly (see CONFIG_VERSION_VARIABLE).
3466 Please note that changes to some configuration parameters may take
3467 only effect after the next boot (yes, that's just like Windoze :-).
3470 Command Line Parsing:
3471 =====================
3473 There are two different command line parsers available with U-Boot:
3474 the old "simple" one, and the much more powerful "hush" shell:
3476 Old, simple command line parser:
3477 --------------------------------
3479 - supports environment variables (through setenv / saveenv commands)
3480 - several commands on one line, separated by ';'
3481 - variable substitution using "... ${name} ..." syntax
3482 - special characters ('$', ';') can be escaped by prefixing with '\',
3484 setenv bootcmd bootm \${address}
3485 - You can also escape text by enclosing in single apostrophes, for example:
3486 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3491 - similar to Bourne shell, with control structures like
3492 if...then...else...fi, for...do...done; while...do...done,
3493 until...do...done, ...
3494 - supports environment ("global") variables (through setenv / saveenv
3495 commands) and local shell variables (through standard shell syntax
3496 "name=value"); only environment variables can be used with "run"
3502 (1) If a command line (or an environment variable executed by a "run"
3503 command) contains several commands separated by semicolon, and
3504 one of these commands fails, then the remaining commands will be
3507 (2) If you execute several variables with one call to run (i. e.
3508 calling run with a list of variables as arguments), any failing
3509 command will cause "run" to terminate, i. e. the remaining
3510 variables are not executed.
3512 Note for Redundant Ethernet Interfaces:
3513 =======================================
3515 Some boards come with redundant Ethernet interfaces; U-Boot supports
3516 such configurations and is capable of automatic selection of a
3517 "working" interface when needed. MAC assignment works as follows:
3519 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3520 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3521 "eth1addr" (=>eth1), "eth2addr", ...
3523 If the network interface stores some valid MAC address (for instance
3524 in SROM), this is used as default address if there is NO correspon-
3525 ding setting in the environment; if the corresponding environment
3526 variable is set, this overrides the settings in the card; that means:
3528 o If the SROM has a valid MAC address, and there is no address in the
3529 environment, the SROM's address is used.
3531 o If there is no valid address in the SROM, and a definition in the
3532 environment exists, then the value from the environment variable is
3535 o If both the SROM and the environment contain a MAC address, and
3536 both addresses are the same, this MAC address is used.
3538 o If both the SROM and the environment contain a MAC address, and the
3539 addresses differ, the value from the environment is used and a
3542 o If neither SROM nor the environment contain a MAC address, an error
3545 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
3546 will be programmed into hardware as part of the initialization process. This
3547 may be skipped by setting the appropriate 'ethmacskip' environment variable.
3548 The naming convention is as follows:
3549 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
3554 U-Boot is capable of booting (and performing other auxiliary operations on)
3555 images in two formats:
3557 New uImage format (FIT)
3558 -----------------------
3560 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3561 to Flattened Device Tree). It allows the use of images with multiple
3562 components (several kernels, ramdisks, etc.), with contents protected by
3563 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3569 Old image format is based on binary files which can be basically anything,
3570 preceded by a special header; see the definitions in include/image.h for
3571 details; basically, the header defines the following image properties:
3573 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3574 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3575 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3576 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3578 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3579 IA64, MIPS, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3580 Currently supported: ARM, AVR32, Intel x86, MIPS, Nios II, PowerPC).
3581 * Compression Type (uncompressed, gzip, bzip2)
3587 The header is marked by a special Magic Number, and both the header
3588 and the data portions of the image are secured against corruption by
3595 Although U-Boot should support any OS or standalone application
3596 easily, the main focus has always been on Linux during the design of
3599 U-Boot includes many features that so far have been part of some
3600 special "boot loader" code within the Linux kernel. Also, any
3601 "initrd" images to be used are no longer part of one big Linux image;
3602 instead, kernel and "initrd" are separate images. This implementation
3603 serves several purposes:
3605 - the same features can be used for other OS or standalone
3606 applications (for instance: using compressed images to reduce the
3607 Flash memory footprint)
3609 - it becomes much easier to port new Linux kernel versions because
3610 lots of low-level, hardware dependent stuff are done by U-Boot
3612 - the same Linux kernel image can now be used with different "initrd"
3613 images; of course this also means that different kernel images can
3614 be run with the same "initrd". This makes testing easier (you don't
3615 have to build a new "zImage.initrd" Linux image when you just
3616 change a file in your "initrd"). Also, a field-upgrade of the
3617 software is easier now.
3623 Porting Linux to U-Boot based systems:
3624 ---------------------------------------
3626 U-Boot cannot save you from doing all the necessary modifications to
3627 configure the Linux device drivers for use with your target hardware
3628 (no, we don't intend to provide a full virtual machine interface to
3631 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
3633 Just make sure your machine specific header file (for instance
3634 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3635 Information structure as we define in include/asm-<arch>/u-boot.h,
3636 and make sure that your definition of IMAP_ADDR uses the same value
3637 as your U-Boot configuration in CONFIG_SYS_IMMR.
3640 Configuring the Linux kernel:
3641 -----------------------------
3643 No specific requirements for U-Boot. Make sure you have some root
3644 device (initial ramdisk, NFS) for your target system.
3647 Building a Linux Image:
3648 -----------------------
3650 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3651 not used. If you use recent kernel source, a new build target
3652 "uImage" will exist which automatically builds an image usable by
3653 U-Boot. Most older kernels also have support for a "pImage" target,
3654 which was introduced for our predecessor project PPCBoot and uses a
3655 100% compatible format.
3664 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3665 encapsulate a compressed Linux kernel image with header information,
3666 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3668 * build a standard "vmlinux" kernel image (in ELF binary format):
3670 * convert the kernel into a raw binary image:
3672 ${CROSS_COMPILE}-objcopy -O binary \
3673 -R .note -R .comment \
3674 -S vmlinux linux.bin
3676 * compress the binary image:
3680 * package compressed binary image for U-Boot:
3682 mkimage -A ppc -O linux -T kernel -C gzip \
3683 -a 0 -e 0 -n "Linux Kernel Image" \
3684 -d linux.bin.gz uImage
3687 The "mkimage" tool can also be used to create ramdisk images for use
3688 with U-Boot, either separated from the Linux kernel image, or
3689 combined into one file. "mkimage" encapsulates the images with a 64
3690 byte header containing information about target architecture,
3691 operating system, image type, compression method, entry points, time
3692 stamp, CRC32 checksums, etc.
3694 "mkimage" can be called in two ways: to verify existing images and
3695 print the header information, or to build new images.
3697 In the first form (with "-l" option) mkimage lists the information
3698 contained in the header of an existing U-Boot image; this includes
3699 checksum verification:
3701 tools/mkimage -l image
3702 -l ==> list image header information
3704 The second form (with "-d" option) is used to build a U-Boot image
3705 from a "data file" which is used as image payload:
3707 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3708 -n name -d data_file image
3709 -A ==> set architecture to 'arch'
3710 -O ==> set operating system to 'os'
3711 -T ==> set image type to 'type'
3712 -C ==> set compression type 'comp'
3713 -a ==> set load address to 'addr' (hex)
3714 -e ==> set entry point to 'ep' (hex)
3715 -n ==> set image name to 'name'
3716 -d ==> use image data from 'datafile'
3718 Right now, all Linux kernels for PowerPC systems use the same load
3719 address (0x00000000), but the entry point address depends on the
3722 - 2.2.x kernels have the entry point at 0x0000000C,
3723 - 2.3.x and later kernels have the entry point at 0x00000000.
3725 So a typical call to build a U-Boot image would read:
3727 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3728 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3729 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
3730 > examples/uImage.TQM850L
3731 Image Name: 2.4.4 kernel for TQM850L
3732 Created: Wed Jul 19 02:34:59 2000
3733 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3734 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3735 Load Address: 0x00000000
3736 Entry Point: 0x00000000
3738 To verify the contents of the image (or check for corruption):
3740 -> tools/mkimage -l examples/uImage.TQM850L
3741 Image Name: 2.4.4 kernel for TQM850L
3742 Created: Wed Jul 19 02:34:59 2000
3743 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3744 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3745 Load Address: 0x00000000
3746 Entry Point: 0x00000000
3748 NOTE: for embedded systems where boot time is critical you can trade
3749 speed for memory and install an UNCOMPRESSED image instead: this
3750 needs more space in Flash, but boots much faster since it does not
3751 need to be uncompressed:
3753 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
3754 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3755 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3756 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
3757 > examples/uImage.TQM850L-uncompressed
3758 Image Name: 2.4.4 kernel for TQM850L
3759 Created: Wed Jul 19 02:34:59 2000
3760 Image Type: PowerPC Linux Kernel Image (uncompressed)
3761 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3762 Load Address: 0x00000000
3763 Entry Point: 0x00000000
3766 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3767 when your kernel is intended to use an initial ramdisk:
3769 -> tools/mkimage -n 'Simple Ramdisk Image' \
3770 > -A ppc -O linux -T ramdisk -C gzip \
3771 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3772 Image Name: Simple Ramdisk Image
3773 Created: Wed Jan 12 14:01:50 2000
3774 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3775 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3776 Load Address: 0x00000000
3777 Entry Point: 0x00000000
3780 Installing a Linux Image:
3781 -------------------------
3783 To downloading a U-Boot image over the serial (console) interface,
3784 you must convert the image to S-Record format:
3786 objcopy -I binary -O srec examples/image examples/image.srec
3788 The 'objcopy' does not understand the information in the U-Boot
3789 image header, so the resulting S-Record file will be relative to
3790 address 0x00000000. To load it to a given address, you need to
3791 specify the target address as 'offset' parameter with the 'loads'
3794 Example: install the image to address 0x40100000 (which on the
3795 TQM8xxL is in the first Flash bank):
3797 => erase 40100000 401FFFFF
3803 ## Ready for S-Record download ...
3804 ~>examples/image.srec
3805 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3807 15989 15990 15991 15992
3808 [file transfer complete]
3810 ## Start Addr = 0x00000000
3813 You can check the success of the download using the 'iminfo' command;
3814 this includes a checksum verification so you can be sure no data
3815 corruption happened:
3819 ## Checking Image at 40100000 ...
3820 Image Name: 2.2.13 for initrd on TQM850L
3821 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3822 Data Size: 335725 Bytes = 327 kB = 0 MB
3823 Load Address: 00000000
3824 Entry Point: 0000000c
3825 Verifying Checksum ... OK
3831 The "bootm" command is used to boot an application that is stored in
3832 memory (RAM or Flash). In case of a Linux kernel image, the contents
3833 of the "bootargs" environment variable is passed to the kernel as
3834 parameters. You can check and modify this variable using the
3835 "printenv" and "setenv" commands:
3838 => printenv bootargs
3839 bootargs=root=/dev/ram
3841 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3843 => printenv bootargs
3844 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3847 ## Booting Linux kernel at 40020000 ...
3848 Image Name: 2.2.13 for NFS on TQM850L
3849 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3850 Data Size: 381681 Bytes = 372 kB = 0 MB
3851 Load Address: 00000000
3852 Entry Point: 0000000c
3853 Verifying Checksum ... OK
3854 Uncompressing Kernel Image ... OK
3855 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
3856 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3857 time_init: decrementer frequency = 187500000/60
3858 Calibrating delay loop... 49.77 BogoMIPS
3859 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3862 If you want to boot a Linux kernel with initial RAM disk, you pass
3863 the memory addresses of both the kernel and the initrd image (PPBCOOT
3864 format!) to the "bootm" command:
3866 => imi 40100000 40200000
3868 ## Checking Image at 40100000 ...
3869 Image Name: 2.2.13 for initrd on TQM850L
3870 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3871 Data Size: 335725 Bytes = 327 kB = 0 MB
3872 Load Address: 00000000
3873 Entry Point: 0000000c
3874 Verifying Checksum ... OK
3876 ## Checking Image at 40200000 ...
3877 Image Name: Simple Ramdisk Image
3878 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3879 Data Size: 566530 Bytes = 553 kB = 0 MB
3880 Load Address: 00000000
3881 Entry Point: 00000000
3882 Verifying Checksum ... OK
3884 => bootm 40100000 40200000
3885 ## Booting Linux kernel at 40100000 ...
3886 Image Name: 2.2.13 for initrd on TQM850L
3887 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3888 Data Size: 335725 Bytes = 327 kB = 0 MB
3889 Load Address: 00000000
3890 Entry Point: 0000000c
3891 Verifying Checksum ... OK
3892 Uncompressing Kernel Image ... OK
3893 ## Loading RAMDisk Image at 40200000 ...
3894 Image Name: Simple Ramdisk Image
3895 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3896 Data Size: 566530 Bytes = 553 kB = 0 MB
3897 Load Address: 00000000
3898 Entry Point: 00000000
3899 Verifying Checksum ... OK
3900 Loading Ramdisk ... OK
3901 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
3902 Boot arguments: root=/dev/ram
3903 time_init: decrementer frequency = 187500000/60
3904 Calibrating delay loop... 49.77 BogoMIPS
3906 RAMDISK: Compressed image found at block 0
3907 VFS: Mounted root (ext2 filesystem).
3911 Boot Linux and pass a flat device tree:
3914 First, U-Boot must be compiled with the appropriate defines. See the section
3915 titled "Linux Kernel Interface" above for a more in depth explanation. The
3916 following is an example of how to start a kernel and pass an updated
3922 oft=oftrees/mpc8540ads.dtb
3923 => tftp $oftaddr $oft
3924 Speed: 1000, full duplex
3926 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3927 Filename 'oftrees/mpc8540ads.dtb'.
3928 Load address: 0x300000
3931 Bytes transferred = 4106 (100a hex)
3932 => tftp $loadaddr $bootfile
3933 Speed: 1000, full duplex
3935 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3937 Load address: 0x200000
3938 Loading:############
3940 Bytes transferred = 1029407 (fb51f hex)
3945 => bootm $loadaddr - $oftaddr
3946 ## Booting image at 00200000 ...
3947 Image Name: Linux-2.6.17-dirty
3948 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3949 Data Size: 1029343 Bytes = 1005.2 kB
3950 Load Address: 00000000
3951 Entry Point: 00000000
3952 Verifying Checksum ... OK
3953 Uncompressing Kernel Image ... OK
3954 Booting using flat device tree at 0x300000
3955 Using MPC85xx ADS machine description
3956 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3960 More About U-Boot Image Types:
3961 ------------------------------
3963 U-Boot supports the following image types:
3965 "Standalone Programs" are directly runnable in the environment
3966 provided by U-Boot; it is expected that (if they behave
3967 well) you can continue to work in U-Boot after return from
3968 the Standalone Program.
3969 "OS Kernel Images" are usually images of some Embedded OS which
3970 will take over control completely. Usually these programs
3971 will install their own set of exception handlers, device
3972 drivers, set up the MMU, etc. - this means, that you cannot
3973 expect to re-enter U-Boot except by resetting the CPU.
3974 "RAMDisk Images" are more or less just data blocks, and their
3975 parameters (address, size) are passed to an OS kernel that is
3977 "Multi-File Images" contain several images, typically an OS
3978 (Linux) kernel image and one or more data images like
3979 RAMDisks. This construct is useful for instance when you want
3980 to boot over the network using BOOTP etc., where the boot
3981 server provides just a single image file, but you want to get
3982 for instance an OS kernel and a RAMDisk image.
3984 "Multi-File Images" start with a list of image sizes, each
3985 image size (in bytes) specified by an "uint32_t" in network
3986 byte order. This list is terminated by an "(uint32_t)0".
3987 Immediately after the terminating 0 follow the images, one by
3988 one, all aligned on "uint32_t" boundaries (size rounded up to
3989 a multiple of 4 bytes).
3991 "Firmware Images" are binary images containing firmware (like
3992 U-Boot or FPGA images) which usually will be programmed to
3995 "Script files" are command sequences that will be executed by
3996 U-Boot's command interpreter; this feature is especially
3997 useful when you configure U-Boot to use a real shell (hush)
3998 as command interpreter.
4004 One of the features of U-Boot is that you can dynamically load and
4005 run "standalone" applications, which can use some resources of
4006 U-Boot like console I/O functions or interrupt services.
4008 Two simple examples are included with the sources:
4013 'examples/hello_world.c' contains a small "Hello World" Demo
4014 application; it is automatically compiled when you build U-Boot.
4015 It's configured to run at address 0x00040004, so you can play with it
4019 ## Ready for S-Record download ...
4020 ~>examples/hello_world.srec
4021 1 2 3 4 5 6 7 8 9 10 11 ...
4022 [file transfer complete]
4024 ## Start Addr = 0x00040004
4026 => go 40004 Hello World! This is a test.
4027 ## Starting application at 0x00040004 ...
4038 Hit any key to exit ...
4040 ## Application terminated, rc = 0x0
4042 Another example, which demonstrates how to register a CPM interrupt
4043 handler with the U-Boot code, can be found in 'examples/timer.c'.
4044 Here, a CPM timer is set up to generate an interrupt every second.
4045 The interrupt service routine is trivial, just printing a '.'
4046 character, but this is just a demo program. The application can be
4047 controlled by the following keys:
4049 ? - print current values og the CPM Timer registers
4050 b - enable interrupts and start timer
4051 e - stop timer and disable interrupts
4052 q - quit application
4055 ## Ready for S-Record download ...
4056 ~>examples/timer.srec
4057 1 2 3 4 5 6 7 8 9 10 11 ...
4058 [file transfer complete]
4060 ## Start Addr = 0x00040004
4063 ## Starting application at 0x00040004 ...
4066 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
4069 [q, b, e, ?] Set interval 1000000 us
4072 [q, b, e, ?] ........
4073 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
4076 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
4079 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
4082 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
4084 [q, b, e, ?] ...Stopping timer
4086 [q, b, e, ?] ## Application terminated, rc = 0x0
4092 Over time, many people have reported problems when trying to use the
4093 "minicom" terminal emulation program for serial download. I (wd)
4094 consider minicom to be broken, and recommend not to use it. Under
4095 Unix, I recommend to use C-Kermit for general purpose use (and
4096 especially for kermit binary protocol download ("loadb" command), and
4097 use "cu" for S-Record download ("loads" command).
4099 Nevertheless, if you absolutely want to use it try adding this
4100 configuration to your "File transfer protocols" section:
4102 Name Program Name U/D FullScr IO-Red. Multi
4103 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
4104 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
4110 Starting at version 0.9.2, U-Boot supports NetBSD both as host
4111 (build U-Boot) and target system (boots NetBSD/mpc8xx).
4113 Building requires a cross environment; it is known to work on
4114 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
4115 need gmake since the Makefiles are not compatible with BSD make).
4116 Note that the cross-powerpc package does not install include files;
4117 attempting to build U-Boot will fail because <machine/ansi.h> is
4118 missing. This file has to be installed and patched manually:
4120 # cd /usr/pkg/cross/powerpc-netbsd/include
4122 # ln -s powerpc machine
4123 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
4124 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
4126 Native builds *don't* work due to incompatibilities between native
4127 and U-Boot include files.
4129 Booting assumes that (the first part of) the image booted is a
4130 stage-2 loader which in turn loads and then invokes the kernel
4131 proper. Loader sources will eventually appear in the NetBSD source
4132 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
4133 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
4136 Implementation Internals:
4137 =========================
4139 The following is not intended to be a complete description of every
4140 implementation detail. However, it should help to understand the
4141 inner workings of U-Boot and make it easier to port it to custom
4145 Initial Stack, Global Data:
4146 ---------------------------
4148 The implementation of U-Boot is complicated by the fact that U-Boot
4149 starts running out of ROM (flash memory), usually without access to
4150 system RAM (because the memory controller is not initialized yet).
4151 This means that we don't have writable Data or BSS segments, and BSS
4152 is not initialized as zero. To be able to get a C environment working
4153 at all, we have to allocate at least a minimal stack. Implementation
4154 options for this are defined and restricted by the CPU used: Some CPU
4155 models provide on-chip memory (like the IMMR area on MPC8xx and
4156 MPC826x processors), on others (parts of) the data cache can be
4157 locked as (mis-) used as memory, etc.
4159 Chris Hallinan posted a good summary of these issues to the
4160 U-Boot mailing list:
4162 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
4163 From: "Chris Hallinan" <clh@net1plus.com>
4164 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
4167 Correct me if I'm wrong, folks, but the way I understand it
4168 is this: Using DCACHE as initial RAM for Stack, etc, does not
4169 require any physical RAM backing up the cache. The cleverness
4170 is that the cache is being used as a temporary supply of
4171 necessary storage before the SDRAM controller is setup. It's
4172 beyond the scope of this list to explain the details, but you
4173 can see how this works by studying the cache architecture and
4174 operation in the architecture and processor-specific manuals.
4176 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4177 is another option for the system designer to use as an
4178 initial stack/RAM area prior to SDRAM being available. Either
4179 option should work for you. Using CS 4 should be fine if your
4180 board designers haven't used it for something that would
4181 cause you grief during the initial boot! It is frequently not
4184 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
4185 with your processor/board/system design. The default value
4186 you will find in any recent u-boot distribution in
4187 walnut.h should work for you. I'd set it to a value larger
4188 than your SDRAM module. If you have a 64MB SDRAM module, set
4189 it above 400_0000. Just make sure your board has no resources
4190 that are supposed to respond to that address! That code in
4191 start.S has been around a while and should work as is when
4192 you get the config right.
4197 It is essential to remember this, since it has some impact on the C
4198 code for the initialization procedures:
4200 * Initialized global data (data segment) is read-only. Do not attempt
4203 * Do not use any uninitialized global data (or implicitely initialized
4204 as zero data - BSS segment) at all - this is undefined, initiali-
4205 zation is performed later (when relocating to RAM).
4207 * Stack space is very limited. Avoid big data buffers or things like
4210 Having only the stack as writable memory limits means we cannot use
4211 normal global data to share information beween the code. But it
4212 turned out that the implementation of U-Boot can be greatly
4213 simplified by making a global data structure (gd_t) available to all
4214 functions. We could pass a pointer to this data as argument to _all_
4215 functions, but this would bloat the code. Instead we use a feature of
4216 the GCC compiler (Global Register Variables) to share the data: we
4217 place a pointer (gd) to the global data into a register which we
4218 reserve for this purpose.
4220 When choosing a register for such a purpose we are restricted by the
4221 relevant (E)ABI specifications for the current architecture, and by
4222 GCC's implementation.
4224 For PowerPC, the following registers have specific use:
4226 R2: reserved for system use
4227 R3-R4: parameter passing and return values
4228 R5-R10: parameter passing
4229 R13: small data area pointer
4233 (U-Boot also uses R12 as internal GOT pointer. r12
4234 is a volatile register so r12 needs to be reset when
4235 going back and forth between asm and C)
4237 ==> U-Boot will use R2 to hold a pointer to the global data
4239 Note: on PPC, we could use a static initializer (since the
4240 address of the global data structure is known at compile time),
4241 but it turned out that reserving a register results in somewhat
4242 smaller code - although the code savings are not that big (on
4243 average for all boards 752 bytes for the whole U-Boot image,
4244 624 text + 127 data).
4246 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
4247 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
4249 ==> U-Boot will use P3 to hold a pointer to the global data
4251 On ARM, the following registers are used:
4253 R0: function argument word/integer result
4254 R1-R3: function argument word
4256 R10: stack limit (used only if stack checking if enabled)
4257 R11: argument (frame) pointer
4258 R12: temporary workspace
4261 R15: program counter
4263 ==> U-Boot will use R8 to hold a pointer to the global data
4265 On Nios II, the ABI is documented here:
4266 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4268 ==> U-Boot will use gp to hold a pointer to the global data
4270 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4271 to access small data sections, so gp is free.
4273 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4274 or current versions of GCC may "optimize" the code too much.
4279 U-Boot runs in system state and uses physical addresses, i.e. the
4280 MMU is not used either for address mapping nor for memory protection.
4282 The available memory is mapped to fixed addresses using the memory
4283 controller. In this process, a contiguous block is formed for each
4284 memory type (Flash, SDRAM, SRAM), even when it consists of several
4285 physical memory banks.
4287 U-Boot is installed in the first 128 kB of the first Flash bank (on
4288 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4289 booting and sizing and initializing DRAM, the code relocates itself
4290 to the upper end of DRAM. Immediately below the U-Boot code some
4291 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
4292 configuration setting]. Below that, a structure with global Board
4293 Info data is placed, followed by the stack (growing downward).
4295 Additionally, some exception handler code is copied to the low 8 kB
4296 of DRAM (0x00000000 ... 0x00001FFF).
4298 So a typical memory configuration with 16 MB of DRAM could look like
4301 0x0000 0000 Exception Vector code
4304 0x0000 2000 Free for Application Use
4310 0x00FB FF20 Monitor Stack (Growing downward)
4311 0x00FB FFAC Board Info Data and permanent copy of global data
4312 0x00FC 0000 Malloc Arena
4315 0x00FE 0000 RAM Copy of Monitor Code
4316 ... eventually: LCD or video framebuffer
4317 ... eventually: pRAM (Protected RAM - unchanged by reset)
4318 0x00FF FFFF [End of RAM]
4321 System Initialization:
4322 ----------------------
4324 In the reset configuration, U-Boot starts at the reset entry point
4325 (on most PowerPC systems at address 0x00000100). Because of the reset
4326 configuration for CS0# this is a mirror of the onboard Flash memory.
4327 To be able to re-map memory U-Boot then jumps to its link address.
4328 To be able to implement the initialization code in C, a (small!)
4329 initial stack is set up in the internal Dual Ported RAM (in case CPUs
4330 which provide such a feature like MPC8xx or MPC8260), or in a locked
4331 part of the data cache. After that, U-Boot initializes the CPU core,
4332 the caches and the SIU.
4334 Next, all (potentially) available memory banks are mapped using a
4335 preliminary mapping. For example, we put them on 512 MB boundaries
4336 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4337 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4338 programmed for SDRAM access. Using the temporary configuration, a
4339 simple memory test is run that determines the size of the SDRAM
4342 When there is more than one SDRAM bank, and the banks are of
4343 different size, the largest is mapped first. For equal size, the first
4344 bank (CS2#) is mapped first. The first mapping is always for address
4345 0x00000000, with any additional banks following immediately to create
4346 contiguous memory starting from 0.
4348 Then, the monitor installs itself at the upper end of the SDRAM area
4349 and allocates memory for use by malloc() and for the global Board
4350 Info data; also, the exception vector code is copied to the low RAM
4351 pages, and the final stack is set up.
4353 Only after this relocation will you have a "normal" C environment;
4354 until that you are restricted in several ways, mostly because you are
4355 running from ROM, and because the code will have to be relocated to a
4359 U-Boot Porting Guide:
4360 ----------------------
4362 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4366 int main(int argc, char *argv[])
4368 sighandler_t no_more_time;
4370 signal(SIGALRM, no_more_time);
4371 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4373 if (available_money > available_manpower) {
4374 Pay consultant to port U-Boot;
4378 Download latest U-Boot source;
4380 Subscribe to u-boot mailing list;
4383 email("Hi, I am new to U-Boot, how do I get started?");
4386 Read the README file in the top level directory;
4387 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4388 Read applicable doc/*.README;
4389 Read the source, Luke;
4390 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4393 if (available_money > toLocalCurrency ($2500))
4396 Add a lot of aggravation and time;
4398 if (a similar board exists) { /* hopefully... */
4399 cp -a board/<similar> board/<myboard>
4400 cp include/configs/<similar>.h include/configs/<myboard>.h
4402 Create your own board support subdirectory;
4403 Create your own board include/configs/<myboard>.h file;
4405 Edit new board/<myboard> files
4406 Edit new include/configs/<myboard>.h
4411 Add / modify source code;
4415 email("Hi, I am having problems...");
4417 Send patch file to the U-Boot email list;
4418 if (reasonable critiques)
4419 Incorporate improvements from email list code review;
4421 Defend code as written;
4427 void no_more_time (int sig)
4436 All contributions to U-Boot should conform to the Linux kernel
4437 coding style; see the file "Documentation/CodingStyle" and the script
4438 "scripts/Lindent" in your Linux kernel source directory. In sources
4439 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
4440 spaces before parameters to function calls) is actually used.
4442 Source files originating from a different project (for example the
4443 MTD subsystem) are generally exempt from these guidelines and are not
4444 reformated to ease subsequent migration to newer versions of those
4447 Please note that U-Boot is implemented in C (and to some small parts in
4448 Assembler); no C++ is used, so please do not use C++ style comments (//)
4451 Please also stick to the following formatting rules:
4452 - remove any trailing white space
4453 - use TAB characters for indentation, not spaces
4454 - make sure NOT to use DOS '\r\n' line feeds
4455 - do not add more than 2 empty lines to source files
4456 - do not add trailing empty lines to source files
4458 Submissions which do not conform to the standards may be returned
4459 with a request to reformat the changes.
4465 Since the number of patches for U-Boot is growing, we need to
4466 establish some rules. Submissions which do not conform to these rules
4467 may be rejected, even when they contain important and valuable stuff.
4469 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4471 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4472 see http://lists.denx.de/mailman/listinfo/u-boot
4474 When you send a patch, please include the following information with
4477 * For bug fixes: a description of the bug and how your patch fixes
4478 this bug. Please try to include a way of demonstrating that the
4479 patch actually fixes something.
4481 * For new features: a description of the feature and your
4484 * A CHANGELOG entry as plaintext (separate from the patch)
4486 * For major contributions, your entry to the CREDITS file
4488 * When you add support for a new board, don't forget to add this
4489 board to the MAKEALL script, too.
4491 * If your patch adds new configuration options, don't forget to
4492 document these in the README file.
4494 * The patch itself. If you are using git (which is *strongly*
4495 recommended) you can easily generate the patch using the
4496 "git-format-patch". If you then use "git-send-email" to send it to
4497 the U-Boot mailing list, you will avoid most of the common problems
4498 with some other mail clients.
4500 If you cannot use git, use "diff -purN OLD NEW". If your version of
4501 diff does not support these options, then get the latest version of
4504 The current directory when running this command shall be the parent
4505 directory of the U-Boot source tree (i. e. please make sure that
4506 your patch includes sufficient directory information for the
4509 We prefer patches as plain text. MIME attachments are discouraged,
4510 and compressed attachments must not be used.
4512 * If one logical set of modifications affects or creates several
4513 files, all these changes shall be submitted in a SINGLE patch file.
4515 * Changesets that contain different, unrelated modifications shall be
4516 submitted as SEPARATE patches, one patch per changeset.
4521 * Before sending the patch, run the MAKEALL script on your patched
4522 source tree and make sure that no errors or warnings are reported
4523 for any of the boards.
4525 * Keep your modifications to the necessary minimum: A patch
4526 containing several unrelated changes or arbitrary reformats will be
4527 returned with a request to re-formatting / split it.
4529 * If you modify existing code, make sure that your new code does not
4530 add to the memory footprint of the code ;-) Small is beautiful!
4531 When adding new features, these should compile conditionally only
4532 (using #ifdef), and the resulting code with the new feature
4533 disabled must not need more memory than the old code without your
4536 * Remember that there is a size limit of 100 kB per message on the
4537 u-boot mailing list. Bigger patches will be moderated. If they are
4538 reasonable and not too big, they will be acknowledged. But patches
4539 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob