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 - vxWorks boot parameters:
447 bootvx constructs a valid bootline using the following
448 environments variables: bootfile, ipaddr, serverip, hostname.
449 It loads the vxWorks image pointed bootfile.
451 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
452 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
453 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
454 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
456 CONFIG_SYS_VXWORKS_ADD_PARAMS
458 Add it at the end of the bootline. E.g "u=username pw=secret"
460 Note: If a "bootargs" environment is defined, it will overwride
461 the defaults discussed just above.
463 - Cache Configuration:
464 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
465 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
466 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
468 - Cache Configuration for ARM:
469 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
471 CONFIG_SYS_PL310_BASE - Physical base address of PL310
472 controller register space
477 Define this if you want support for Amba PrimeCell PL010 UARTs.
481 Define this if you want support for Amba PrimeCell PL011 UARTs.
485 If you have Amba PrimeCell PL011 UARTs, set this variable to
486 the clock speed of the UARTs.
490 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
491 define this to a list of base addresses for each (supported)
492 port. See e.g. include/configs/versatile.h
494 CONFIG_PL011_SERIAL_RLCR
496 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
497 have separate receive and transmit line control registers. Set
498 this variable to initialize the extra register.
500 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
502 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
503 boot loader that has already initialized the UART. Define this
504 variable to flush the UART at init time.
508 Depending on board, define exactly one serial port
509 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
510 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
511 console by defining CONFIG_8xx_CONS_NONE
513 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
514 port routines must be defined elsewhere
515 (i.e. serial_init(), serial_getc(), ...)
518 Enables console device for a color framebuffer. Needs following
519 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
520 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
522 VIDEO_HW_RECTFILL graphic chip supports
525 VIDEO_HW_BITBLT graphic chip supports
526 bit-blit (cf. smiLynxEM)
527 VIDEO_VISIBLE_COLS visible pixel columns
529 VIDEO_VISIBLE_ROWS visible pixel rows
530 VIDEO_PIXEL_SIZE bytes per pixel
531 VIDEO_DATA_FORMAT graphic data format
532 (0-5, cf. cfb_console.c)
533 VIDEO_FB_ADRS framebuffer address
534 VIDEO_KBD_INIT_FCT keyboard int fct
535 (i.e. i8042_kbd_init())
536 VIDEO_TSTC_FCT test char fct
538 VIDEO_GETC_FCT get char fct
540 CONFIG_CONSOLE_CURSOR cursor drawing on/off
541 (requires blink timer
543 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
544 CONFIG_CONSOLE_TIME display time/date info in
546 (requires CONFIG_CMD_DATE)
547 CONFIG_VIDEO_LOGO display Linux logo in
549 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
550 linux_logo.h for logo.
551 Requires CONFIG_VIDEO_LOGO
552 CONFIG_CONSOLE_EXTRA_INFO
553 additional board info beside
556 When CONFIG_CFB_CONSOLE is defined, video console is
557 default i/o. Serial console can be forced with
558 environment 'console=serial'.
560 When CONFIG_SILENT_CONSOLE is defined, all console
561 messages (by U-Boot and Linux!) can be silenced with
562 the "silent" environment variable. See
563 doc/README.silent for more information.
566 CONFIG_BAUDRATE - in bps
567 Select one of the baudrates listed in
568 CONFIG_SYS_BAUDRATE_TABLE, see below.
569 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
571 - Console Rx buffer length
572 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
573 the maximum receive buffer length for the SMC.
574 This option is actual only for 82xx and 8xx possible.
575 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
576 must be defined, to setup the maximum idle timeout for
579 - Boot Delay: CONFIG_BOOTDELAY - in seconds
580 Delay before automatically booting the default image;
581 set to -1 to disable autoboot.
583 See doc/README.autoboot for these options that
584 work with CONFIG_BOOTDELAY. None are required.
585 CONFIG_BOOT_RETRY_TIME
586 CONFIG_BOOT_RETRY_MIN
587 CONFIG_AUTOBOOT_KEYED
588 CONFIG_AUTOBOOT_PROMPT
589 CONFIG_AUTOBOOT_DELAY_STR
590 CONFIG_AUTOBOOT_STOP_STR
591 CONFIG_AUTOBOOT_DELAY_STR2
592 CONFIG_AUTOBOOT_STOP_STR2
593 CONFIG_ZERO_BOOTDELAY_CHECK
594 CONFIG_RESET_TO_RETRY
598 Only needed when CONFIG_BOOTDELAY is enabled;
599 define a command string that is automatically executed
600 when no character is read on the console interface
601 within "Boot Delay" after reset.
604 This can be used to pass arguments to the bootm
605 command. The value of CONFIG_BOOTARGS goes into the
606 environment value "bootargs".
608 CONFIG_RAMBOOT and CONFIG_NFSBOOT
609 The value of these goes into the environment as
610 "ramboot" and "nfsboot" respectively, and can be used
611 as a convenience, when switching between booting from
617 When this option is #defined, the existence of the
618 environment variable "preboot" will be checked
619 immediately before starting the CONFIG_BOOTDELAY
620 countdown and/or running the auto-boot command resp.
621 entering interactive mode.
623 This feature is especially useful when "preboot" is
624 automatically generated or modified. For an example
625 see the LWMON board specific code: here "preboot" is
626 modified when the user holds down a certain
627 combination of keys on the (special) keyboard when
630 - Serial Download Echo Mode:
632 If defined to 1, all characters received during a
633 serial download (using the "loads" command) are
634 echoed back. This might be needed by some terminal
635 emulations (like "cu"), but may as well just take
636 time on others. This setting #define's the initial
637 value of the "loads_echo" environment variable.
639 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
641 Select one of the baudrates listed in
642 CONFIG_SYS_BAUDRATE_TABLE, see below.
645 Monitor commands can be included or excluded
646 from the build by using the #include files
647 "config_cmd_all.h" and #undef'ing unwanted
648 commands, or using "config_cmd_default.h"
649 and augmenting with additional #define's
652 The default command configuration includes all commands
653 except those marked below with a "*".
655 CONFIG_CMD_ASKENV * ask for env variable
656 CONFIG_CMD_BDI bdinfo
657 CONFIG_CMD_BEDBUG * Include BedBug Debugger
658 CONFIG_CMD_BMP * BMP support
659 CONFIG_CMD_BSP * Board specific commands
660 CONFIG_CMD_BOOTD bootd
661 CONFIG_CMD_CACHE * icache, dcache
662 CONFIG_CMD_CONSOLE coninfo
663 CONFIG_CMD_CRC32 * crc32
664 CONFIG_CMD_DATE * support for RTC, date/time...
665 CONFIG_CMD_DHCP * DHCP support
666 CONFIG_CMD_DIAG * Diagnostics
667 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
668 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
669 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
670 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
671 CONFIG_CMD_DTT * Digital Therm and Thermostat
672 CONFIG_CMD_ECHO echo arguments
673 CONFIG_CMD_EDITENV edit env variable
674 CONFIG_CMD_EEPROM * EEPROM read/write support
675 CONFIG_CMD_ELF * bootelf, bootvx
676 CONFIG_CMD_EXPORTENV * export the environment
677 CONFIG_CMD_SAVEENV saveenv
678 CONFIG_CMD_FDC * Floppy Disk Support
679 CONFIG_CMD_FAT * FAT partition support
680 CONFIG_CMD_FDOS * Dos diskette Support
681 CONFIG_CMD_FLASH flinfo, erase, protect
682 CONFIG_CMD_FPGA FPGA device initialization support
683 CONFIG_CMD_GO * the 'go' command (exec code)
684 CONFIG_CMD_GREPENV * search environment
685 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
686 CONFIG_CMD_I2C * I2C serial bus support
687 CONFIG_CMD_IDE * IDE harddisk support
688 CONFIG_CMD_IMI iminfo
689 CONFIG_CMD_IMLS List all found images
690 CONFIG_CMD_IMMAP * IMMR dump support
691 CONFIG_CMD_IMPORTENV * import an environment
692 CONFIG_CMD_IRQ * irqinfo
693 CONFIG_CMD_ITEST Integer/string test of 2 values
694 CONFIG_CMD_JFFS2 * JFFS2 Support
695 CONFIG_CMD_KGDB * kgdb
696 CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
697 CONFIG_CMD_LOADB loadb
698 CONFIG_CMD_LOADS loads
699 CONFIG_CMD_MD5SUM print md5 message digest
700 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
701 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
703 CONFIG_CMD_MISC Misc functions like sleep etc
704 CONFIG_CMD_MMC * MMC memory mapped support
705 CONFIG_CMD_MII * MII utility commands
706 CONFIG_CMD_MTDPARTS * MTD partition support
707 CONFIG_CMD_NAND * NAND support
708 CONFIG_CMD_NET bootp, tftpboot, rarpboot
709 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
710 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
711 CONFIG_CMD_PCI * pciinfo
712 CONFIG_CMD_PCMCIA * PCMCIA support
713 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
715 CONFIG_CMD_PORTIO * Port I/O
716 CONFIG_CMD_REGINFO * Register dump
717 CONFIG_CMD_RUN run command in env variable
718 CONFIG_CMD_SAVES * save S record dump
719 CONFIG_CMD_SCSI * SCSI Support
720 CONFIG_CMD_SDRAM * print SDRAM configuration information
721 (requires CONFIG_CMD_I2C)
722 CONFIG_CMD_SETGETDCR Support for DCR Register access
724 CONFIG_CMD_SHA1SUM print sha1 memory digest
725 (requires CONFIG_CMD_MEMORY)
726 CONFIG_CMD_SOURCE "source" command Support
727 CONFIG_CMD_SPI * SPI serial bus support
728 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
729 CONFIG_CMD_USB * USB support
730 CONFIG_CMD_CDP * Cisco Discover Protocol support
731 CONFIG_CMD_FSL * Microblaze FSL support
734 EXAMPLE: If you want all functions except of network
735 support you can write:
737 #include "config_cmd_all.h"
738 #undef CONFIG_CMD_NET
741 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
743 Note: Don't enable the "icache" and "dcache" commands
744 (configuration option CONFIG_CMD_CACHE) unless you know
745 what you (and your U-Boot users) are doing. Data
746 cache cannot be enabled on systems like the 8xx or
747 8260 (where accesses to the IMMR region must be
748 uncached), and it cannot be disabled on all other
749 systems where we (mis-) use the data cache to hold an
750 initial stack and some data.
753 XXX - this list needs to get updated!
757 If this variable is defined, it enables watchdog
758 support for the SoC. There must be support in the SoC
759 specific code for a watchdog. For the 8xx and 8260
760 CPUs, the SIU Watchdog feature is enabled in the SYPCR
761 register. When supported for a specific SoC is
762 available, then no further board specific code should
766 When using a watchdog circuitry external to the used
767 SoC, then define this variable and provide board
768 specific code for the "hw_watchdog_reset" function.
771 CONFIG_VERSION_VARIABLE
772 If this variable is defined, an environment variable
773 named "ver" is created by U-Boot showing the U-Boot
774 version as printed by the "version" command.
775 This variable is readonly.
779 When CONFIG_CMD_DATE is selected, the type of the RTC
780 has to be selected, too. Define exactly one of the
783 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
784 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
785 CONFIG_RTC_MC13783 - use MC13783 RTC
786 CONFIG_RTC_MC146818 - use MC146818 RTC
787 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
788 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
789 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
790 CONFIG_RTC_DS164x - use Dallas DS164x RTC
791 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
792 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
793 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
794 CONFIG_SYS_RV3029_TCR - enable trickle charger on
797 Note that if the RTC uses I2C, then the I2C interface
798 must also be configured. See I2C Support, below.
801 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
802 CONFIG_PCA953X_INFO - enable pca953x info command
804 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
805 chip-ngpio pairs that tell the PCA953X driver the number of
806 pins supported by a particular chip.
808 Note that if the GPIO device uses I2C, then the I2C interface
809 must also be configured. See I2C Support, below.
813 When CONFIG_TIMESTAMP is selected, the timestamp
814 (date and time) of an image is printed by image
815 commands like bootm or iminfo. This option is
816 automatically enabled when you select CONFIG_CMD_DATE .
819 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
820 and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION
822 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
823 CONFIG_CMD_SCSI) you must configure support for at
824 least one partition type as well.
827 CONFIG_IDE_RESET_ROUTINE - this is defined in several
828 board configurations files but used nowhere!
830 CONFIG_IDE_RESET - is this is defined, IDE Reset will
831 be performed by calling the function
832 ide_set_reset(int reset)
833 which has to be defined in a board specific file
838 Set this to enable ATAPI support.
843 Set this to enable support for disks larger than 137GB
844 Also look at CONFIG_SYS_64BIT_LBA.
845 Whithout these , LBA48 support uses 32bit variables and will 'only'
846 support disks up to 2.1TB.
848 CONFIG_SYS_64BIT_LBA:
849 When enabled, makes the IDE subsystem use 64bit sector addresses.
853 At the moment only there is only support for the
854 SYM53C8XX SCSI controller; define
855 CONFIG_SCSI_SYM53C8XX to enable it.
857 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
858 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
859 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
860 maximum numbers of LUNs, SCSI ID's and target
862 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
864 - NETWORK Support (PCI):
866 Support for Intel 8254x gigabit chips.
868 CONFIG_E1000_FALLBACK_MAC
869 default MAC for empty EEPROM after production.
872 Support for Intel 82557/82559/82559ER chips.
873 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
874 write routine for first time initialisation.
877 Support for Digital 2114x chips.
878 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
879 modem chip initialisation (KS8761/QS6611).
882 Support for National dp83815 chips.
885 Support for National dp8382[01] gigabit chips.
887 - NETWORK Support (other):
889 CONFIG_DRIVER_AT91EMAC
890 Support for AT91RM9200 EMAC.
893 Define this to use reduced MII inteface
895 CONFIG_DRIVER_AT91EMAC_QUIET
896 If this defined, the driver is quiet.
897 The driver doen't show link status messages.
899 CONFIG_DRIVER_LAN91C96
900 Support for SMSC's LAN91C96 chips.
903 Define this to hold the physical address
904 of the LAN91C96's I/O space
906 CONFIG_LAN91C96_USE_32_BIT
907 Define this to enable 32 bit addressing
909 CONFIG_DRIVER_SMC91111
910 Support for SMSC's LAN91C111 chip
913 Define this to hold the physical address
914 of the device (I/O space)
916 CONFIG_SMC_USE_32_BIT
917 Define this if data bus is 32 bits
919 CONFIG_SMC_USE_IOFUNCS
920 Define this to use i/o functions instead of macros
921 (some hardware wont work with macros)
924 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
926 CONFIG_FTGMAC100_EGIGA
927 Define this to use GE link update with gigabit PHY.
928 Define this if FTGMAC100 is connected to gigabit PHY.
929 If your system has 10/100 PHY only, it might not occur
930 wrong behavior. Because PHY usually return timeout or
931 useless data when polling gigabit status and gigabit
932 control registers. This behavior won't affect the
933 correctnessof 10/100 link speed update.
936 Support for SMSC's LAN911x and LAN921x chips
939 Define this to hold the physical address
940 of the device (I/O space)
942 CONFIG_SMC911X_32_BIT
943 Define this if data bus is 32 bits
945 CONFIG_SMC911X_16_BIT
946 Define this if data bus is 16 bits. If your processor
947 automatically converts one 32 bit word to two 16 bit
948 words you may also try CONFIG_SMC911X_32_BIT.
951 Support for Renesas on-chip Ethernet controller
953 CONFIG_SH_ETHER_USE_PORT
954 Define the number of ports to be used
956 CONFIG_SH_ETHER_PHY_ADDR
957 Define the ETH PHY's address
959 CONFIG_SH_ETHER_CACHE_WRITEBACK
960 If this option is set, the driver enables cache flush.
963 At the moment only the UHCI host controller is
964 supported (PIP405, MIP405, MPC5200); define
965 CONFIG_USB_UHCI to enable it.
966 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
967 and define CONFIG_USB_STORAGE to enable the USB
970 Supported are USB Keyboards and USB Floppy drives
972 MPC5200 USB requires additional defines:
974 for 528 MHz Clock: 0x0001bbbb
978 for differential drivers: 0x00001000
979 for single ended drivers: 0x00005000
980 for differential drivers on PSC3: 0x00000100
981 for single ended drivers on PSC3: 0x00004100
982 CONFIG_SYS_USB_EVENT_POLL
983 May be defined to allow interrupt polling
984 instead of using asynchronous interrupts
987 Define the below if you wish to use the USB console.
988 Once firmware is rebuilt from a serial console issue the
989 command "setenv stdin usbtty; setenv stdout usbtty" and
990 attach your USB cable. The Unix command "dmesg" should print
991 it has found a new device. The environment variable usbtty
992 can be set to gserial or cdc_acm to enable your device to
993 appear to a USB host as a Linux gserial device or a
994 Common Device Class Abstract Control Model serial device.
995 If you select usbtty = gserial you should be able to enumerate
997 # modprobe usbserial vendor=0xVendorID product=0xProductID
998 else if using cdc_acm, simply setting the environment
999 variable usbtty to be cdc_acm should suffice. The following
1000 might be defined in YourBoardName.h
1003 Define this to build a UDC device
1006 Define this to have a tty type of device available to
1007 talk to the UDC device
1009 CONFIG_SYS_CONSOLE_IS_IN_ENV
1010 Define this if you want stdin, stdout &/or stderr to
1014 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1015 Derive USB clock from external clock "blah"
1016 - CONFIG_SYS_USB_EXTC_CLK 0x02
1018 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1019 Derive USB clock from brgclk
1020 - CONFIG_SYS_USB_BRG_CLK 0x04
1022 If you have a USB-IF assigned VendorID then you may wish to
1023 define your own vendor specific values either in BoardName.h
1024 or directly in usbd_vendor_info.h. If you don't define
1025 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1026 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1027 should pretend to be a Linux device to it's target host.
1029 CONFIG_USBD_MANUFACTURER
1030 Define this string as the name of your company for
1031 - CONFIG_USBD_MANUFACTURER "my company"
1033 CONFIG_USBD_PRODUCT_NAME
1034 Define this string as the name of your product
1035 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1037 CONFIG_USBD_VENDORID
1038 Define this as your assigned Vendor ID from the USB
1039 Implementors Forum. This *must* be a genuine Vendor ID
1040 to avoid polluting the USB namespace.
1041 - CONFIG_USBD_VENDORID 0xFFFF
1043 CONFIG_USBD_PRODUCTID
1044 Define this as the unique Product ID
1046 - CONFIG_USBD_PRODUCTID 0xFFFF
1050 The MMC controller on the Intel PXA is supported. To
1051 enable this define CONFIG_MMC. The MMC can be
1052 accessed from the boot prompt by mapping the device
1053 to physical memory similar to flash. Command line is
1054 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1055 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1057 - Journaling Flash filesystem support:
1058 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1059 CONFIG_JFFS2_NAND_DEV
1060 Define these for a default partition on a NAND device
1062 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1063 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1064 Define these for a default partition on a NOR device
1066 CONFIG_SYS_JFFS_CUSTOM_PART
1067 Define this to create an own partition. You have to provide a
1068 function struct part_info* jffs2_part_info(int part_num)
1070 If you define only one JFFS2 partition you may also want to
1071 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1072 to disable the command chpart. This is the default when you
1073 have not defined a custom partition
1078 Define this to enable standard (PC-Style) keyboard
1082 Standard PC keyboard driver with US (is default) and
1083 GERMAN key layout (switch via environment 'keymap=de') support.
1084 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1085 for cfb_console. Supports cursor blinking.
1090 Define this to enable video support (for output to
1093 CONFIG_VIDEO_CT69000
1095 Enable Chips & Technologies 69000 Video chip
1097 CONFIG_VIDEO_SMI_LYNXEM
1098 Enable Silicon Motion SMI 712/710/810 Video chip. The
1099 video output is selected via environment 'videoout'
1100 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1103 For the CT69000 and SMI_LYNXEM drivers, videomode is
1104 selected via environment 'videomode'. Two different ways
1106 - "videomode=num" 'num' is a standard LiLo mode numbers.
1107 Following standard modes are supported (* is default):
1109 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1110 -------------+---------------------------------------------
1111 8 bits | 0x301* 0x303 0x305 0x161 0x307
1112 15 bits | 0x310 0x313 0x316 0x162 0x319
1113 16 bits | 0x311 0x314 0x317 0x163 0x31A
1114 24 bits | 0x312 0x315 0x318 ? 0x31B
1115 -------------+---------------------------------------------
1116 (i.e. setenv videomode 317; saveenv; reset;)
1118 - "videomode=bootargs" all the video parameters are parsed
1119 from the bootargs. (See drivers/video/videomodes.c)
1122 CONFIG_VIDEO_SED13806
1123 Enable Epson SED13806 driver. This driver supports 8bpp
1124 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1125 or CONFIG_VIDEO_SED13806_16BPP
1128 Enable the Freescale DIU video driver. Reference boards for
1129 SOCs that have a DIU should define this macro to enable DIU
1130 support, and should also define these other macros:
1136 CONFIG_VIDEO_SW_CURSOR
1137 CONFIG_VGA_AS_SINGLE_DEVICE
1139 CONFIG_VIDEO_BMP_LOGO
1141 The DIU driver will look for the 'video-mode' environment
1142 variable, and if defined, enable the DIU as a console during
1143 boot. See the documentation file README.video for a
1144 description of this variable.
1149 Define this to enable a custom keyboard support.
1150 This simply calls drv_keyboard_init() which must be
1151 defined in your board-specific files.
1152 The only board using this so far is RBC823.
1154 - LCD Support: CONFIG_LCD
1156 Define this to enable LCD support (for output to LCD
1157 display); also select one of the supported displays
1158 by defining one of these:
1162 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1164 CONFIG_NEC_NL6448AC33:
1166 NEC NL6448AC33-18. Active, color, single scan.
1168 CONFIG_NEC_NL6448BC20
1170 NEC NL6448BC20-08. 6.5", 640x480.
1171 Active, color, single scan.
1173 CONFIG_NEC_NL6448BC33_54
1175 NEC NL6448BC33-54. 10.4", 640x480.
1176 Active, color, single scan.
1180 Sharp 320x240. Active, color, single scan.
1181 It isn't 16x9, and I am not sure what it is.
1183 CONFIG_SHARP_LQ64D341
1185 Sharp LQ64D341 display, 640x480.
1186 Active, color, single scan.
1190 HLD1045 display, 640x480.
1191 Active, color, single scan.
1195 Optrex CBL50840-2 NF-FW 99 22 M5
1197 Hitachi LMG6912RPFC-00T
1201 320x240. Black & white.
1203 Normally display is black on white background; define
1204 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1206 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1208 If this option is set, the environment is checked for
1209 a variable "splashimage". If found, the usual display
1210 of logo, copyright and system information on the LCD
1211 is suppressed and the BMP image at the address
1212 specified in "splashimage" is loaded instead. The
1213 console is redirected to the "nulldev", too. This
1214 allows for a "silent" boot where a splash screen is
1215 loaded very quickly after power-on.
1217 CONFIG_SPLASH_SCREEN_ALIGN
1219 If this option is set the splash image can be freely positioned
1220 on the screen. Environment variable "splashpos" specifies the
1221 position as "x,y". If a positive number is given it is used as
1222 number of pixel from left/top. If a negative number is given it
1223 is used as number of pixel from right/bottom. You can also
1224 specify 'm' for centering the image.
1227 setenv splashpos m,m
1228 => image at center of screen
1230 setenv splashpos 30,20
1231 => image at x = 30 and y = 20
1233 setenv splashpos -10,m
1234 => vertically centered image
1235 at x = dspWidth - bmpWidth - 9
1237 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1239 If this option is set, additionally to standard BMP
1240 images, gzipped BMP images can be displayed via the
1241 splashscreen support or the bmp command.
1243 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1245 If this option is set, 8-bit RLE compressed BMP images
1246 can be displayed via the splashscreen support or the
1249 - Compression support:
1252 If this option is set, support for bzip2 compressed
1253 images is included. If not, only uncompressed and gzip
1254 compressed images are supported.
1256 NOTE: the bzip2 algorithm requires a lot of RAM, so
1257 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1262 If this option is set, support for lzma compressed
1265 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1266 requires an amount of dynamic memory that is given by the
1269 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1271 Where lc and lp stand for, respectively, Literal context bits
1272 and Literal pos bits.
1274 This value is upper-bounded by 14MB in the worst case. Anyway,
1275 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1276 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1277 a very small buffer.
1279 Use the lzmainfo tool to determinate the lc and lp values and
1280 then calculate the amount of needed dynamic memory (ensuring
1281 the appropriate CONFIG_SYS_MALLOC_LEN value).
1286 The address of PHY on MII bus.
1288 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1290 The clock frequency of the MII bus
1294 If this option is set, support for speed/duplex
1295 detection of gigabit PHY is included.
1297 CONFIG_PHY_RESET_DELAY
1299 Some PHY like Intel LXT971A need extra delay after
1300 reset before any MII register access is possible.
1301 For such PHY, set this option to the usec delay
1302 required. (minimum 300usec for LXT971A)
1304 CONFIG_PHY_CMD_DELAY (ppc4xx)
1306 Some PHY like Intel LXT971A need extra delay after
1307 command issued before MII status register can be read
1317 Define a default value for Ethernet address to use
1318 for the respective Ethernet interface, in case this
1319 is not determined automatically.
1324 Define a default value for the IP address to use for
1325 the default Ethernet interface, in case this is not
1326 determined through e.g. bootp.
1328 - Server IP address:
1331 Defines a default value for the IP address of a TFTP
1332 server to contact when using the "tftboot" command.
1334 CONFIG_KEEP_SERVERADDR
1336 Keeps the server's MAC address, in the env 'serveraddr'
1337 for passing to bootargs (like Linux's netconsole option)
1339 - Multicast TFTP Mode:
1342 Defines whether you want to support multicast TFTP as per
1343 rfc-2090; for example to work with atftp. Lets lots of targets
1344 tftp down the same boot image concurrently. Note: the Ethernet
1345 driver in use must provide a function: mcast() to join/leave a
1348 - BOOTP Recovery Mode:
1349 CONFIG_BOOTP_RANDOM_DELAY
1351 If you have many targets in a network that try to
1352 boot using BOOTP, you may want to avoid that all
1353 systems send out BOOTP requests at precisely the same
1354 moment (which would happen for instance at recovery
1355 from a power failure, when all systems will try to
1356 boot, thus flooding the BOOTP server. Defining
1357 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1358 inserted before sending out BOOTP requests. The
1359 following delays are inserted then:
1361 1st BOOTP request: delay 0 ... 1 sec
1362 2nd BOOTP request: delay 0 ... 2 sec
1363 3rd BOOTP request: delay 0 ... 4 sec
1365 BOOTP requests: delay 0 ... 8 sec
1367 - DHCP Advanced Options:
1368 You can fine tune the DHCP functionality by defining
1369 CONFIG_BOOTP_* symbols:
1371 CONFIG_BOOTP_SUBNETMASK
1372 CONFIG_BOOTP_GATEWAY
1373 CONFIG_BOOTP_HOSTNAME
1374 CONFIG_BOOTP_NISDOMAIN
1375 CONFIG_BOOTP_BOOTPATH
1376 CONFIG_BOOTP_BOOTFILESIZE
1379 CONFIG_BOOTP_SEND_HOSTNAME
1380 CONFIG_BOOTP_NTPSERVER
1381 CONFIG_BOOTP_TIMEOFFSET
1382 CONFIG_BOOTP_VENDOREX
1384 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1385 environment variable, not the BOOTP server.
1387 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1388 serverip from a DHCP server, it is possible that more
1389 than one DNS serverip is offered to the client.
1390 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1391 serverip will be stored in the additional environment
1392 variable "dnsip2". The first DNS serverip is always
1393 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1396 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1397 to do a dynamic update of a DNS server. To do this, they
1398 need the hostname of the DHCP requester.
1399 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1400 of the "hostname" environment variable is passed as
1401 option 12 to the DHCP server.
1403 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1405 A 32bit value in microseconds for a delay between
1406 receiving a "DHCP Offer" and sending the "DHCP Request".
1407 This fixes a problem with certain DHCP servers that don't
1408 respond 100% of the time to a "DHCP request". E.g. On an
1409 AT91RM9200 processor running at 180MHz, this delay needed
1410 to be *at least* 15,000 usec before a Windows Server 2003
1411 DHCP server would reply 100% of the time. I recommend at
1412 least 50,000 usec to be safe. The alternative is to hope
1413 that one of the retries will be successful but note that
1414 the DHCP timeout and retry process takes a longer than
1418 CONFIG_CDP_DEVICE_ID
1420 The device id used in CDP trigger frames.
1422 CONFIG_CDP_DEVICE_ID_PREFIX
1424 A two character string which is prefixed to the MAC address
1429 A printf format string which contains the ascii name of
1430 the port. Normally is set to "eth%d" which sets
1431 eth0 for the first Ethernet, eth1 for the second etc.
1433 CONFIG_CDP_CAPABILITIES
1435 A 32bit integer which indicates the device capabilities;
1436 0x00000010 for a normal host which does not forwards.
1440 An ascii string containing the version of the software.
1444 An ascii string containing the name of the platform.
1448 A 32bit integer sent on the trigger.
1450 CONFIG_CDP_POWER_CONSUMPTION
1452 A 16bit integer containing the power consumption of the
1453 device in .1 of milliwatts.
1455 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1457 A byte containing the id of the VLAN.
1459 - Status LED: CONFIG_STATUS_LED
1461 Several configurations allow to display the current
1462 status using a LED. For instance, the LED will blink
1463 fast while running U-Boot code, stop blinking as
1464 soon as a reply to a BOOTP request was received, and
1465 start blinking slow once the Linux kernel is running
1466 (supported by a status LED driver in the Linux
1467 kernel). Defining CONFIG_STATUS_LED enables this
1470 - CAN Support: CONFIG_CAN_DRIVER
1472 Defining CONFIG_CAN_DRIVER enables CAN driver support
1473 on those systems that support this (optional)
1474 feature, like the TQM8xxL modules.
1476 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1478 These enable I2C serial bus commands. Defining either of
1479 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1480 include the appropriate I2C driver for the selected CPU.
1482 This will allow you to use i2c commands at the u-boot
1483 command line (as long as you set CONFIG_CMD_I2C in
1484 CONFIG_COMMANDS) and communicate with i2c based realtime
1485 clock chips. See common/cmd_i2c.c for a description of the
1486 command line interface.
1488 CONFIG_HARD_I2C selects a hardware I2C controller.
1490 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1491 bit-banging) driver instead of CPM or similar hardware
1494 There are several other quantities that must also be
1495 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1497 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1498 to be the frequency (in Hz) at which you wish your i2c bus
1499 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1500 the CPU's i2c node address).
1502 Now, the u-boot i2c code for the mpc8xx
1503 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1504 and so its address should therefore be cleared to 0 (See,
1505 eg, MPC823e User's Manual p.16-473). So, set
1506 CONFIG_SYS_I2C_SLAVE to 0.
1508 CONFIG_SYS_I2C_INIT_MPC5XXX
1510 When a board is reset during an i2c bus transfer
1511 chips might think that the current transfer is still
1512 in progress. Reset the slave devices by sending start
1513 commands until the slave device responds.
1515 That's all that's required for CONFIG_HARD_I2C.
1517 If you use the software i2c interface (CONFIG_SOFT_I2C)
1518 then the following macros need to be defined (examples are
1519 from include/configs/lwmon.h):
1523 (Optional). Any commands necessary to enable the I2C
1524 controller or configure ports.
1526 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1530 (Only for MPC8260 CPU). The I/O port to use (the code
1531 assumes both bits are on the same port). Valid values
1532 are 0..3 for ports A..D.
1536 The code necessary to make the I2C data line active
1537 (driven). If the data line is open collector, this
1540 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1544 The code necessary to make the I2C data line tri-stated
1545 (inactive). If the data line is open collector, this
1548 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1552 Code that returns TRUE if the I2C data line is high,
1555 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1559 If <bit> is TRUE, sets the I2C data line high. If it
1560 is FALSE, it clears it (low).
1562 eg: #define I2C_SDA(bit) \
1563 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1564 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1568 If <bit> is TRUE, sets the I2C clock line high. If it
1569 is FALSE, it clears it (low).
1571 eg: #define I2C_SCL(bit) \
1572 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1573 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1577 This delay is invoked four times per clock cycle so this
1578 controls the rate of data transfer. The data rate thus
1579 is 1 / (I2C_DELAY * 4). Often defined to be something
1582 #define I2C_DELAY udelay(2)
1584 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1586 If your arch supports the generic GPIO framework (asm/gpio.h),
1587 then you may alternatively define the two GPIOs that are to be
1588 used as SCL / SDA. Any of the previous I2C_xxx macros will
1589 have GPIO-based defaults assigned to them as appropriate.
1591 You should define these to the GPIO value as given directly to
1592 the generic GPIO functions.
1594 CONFIG_SYS_I2C_INIT_BOARD
1596 When a board is reset during an i2c bus transfer
1597 chips might think that the current transfer is still
1598 in progress. On some boards it is possible to access
1599 the i2c SCLK line directly, either by using the
1600 processor pin as a GPIO or by having a second pin
1601 connected to the bus. If this option is defined a
1602 custom i2c_init_board() routine in boards/xxx/board.c
1603 is run early in the boot sequence.
1605 CONFIG_SYS_I2C_BOARD_LATE_INIT
1607 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1608 defined a custom i2c_board_late_init() routine in
1609 boards/xxx/board.c is run AFTER the operations in i2c_init()
1610 is completed. This callpoint can be used to unreset i2c bus
1611 using CPU i2c controller register accesses for CPUs whose i2c
1612 controller provide such a method. It is called at the end of
1613 i2c_init() to allow i2c_init operations to setup the i2c bus
1614 controller on the CPU (e.g. setting bus speed & slave address).
1616 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1618 This option enables configuration of bi_iic_fast[] flags
1619 in u-boot bd_info structure based on u-boot environment
1620 variable "i2cfast". (see also i2cfast)
1622 CONFIG_I2C_MULTI_BUS
1624 This option allows the use of multiple I2C buses, each of which
1625 must have a controller. At any point in time, only one bus is
1626 active. To switch to a different bus, use the 'i2c dev' command.
1627 Note that bus numbering is zero-based.
1629 CONFIG_SYS_I2C_NOPROBES
1631 This option specifies a list of I2C devices that will be skipped
1632 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1633 is set, specify a list of bus-device pairs. Otherwise, specify
1634 a 1D array of device addresses
1637 #undef CONFIG_I2C_MULTI_BUS
1638 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1640 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1642 #define CONFIG_I2C_MULTI_BUS
1643 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1645 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1647 CONFIG_SYS_SPD_BUS_NUM
1649 If defined, then this indicates the I2C bus number for DDR SPD.
1650 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1652 CONFIG_SYS_RTC_BUS_NUM
1654 If defined, then this indicates the I2C bus number for the RTC.
1655 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1657 CONFIG_SYS_DTT_BUS_NUM
1659 If defined, then this indicates the I2C bus number for the DTT.
1660 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1662 CONFIG_SYS_I2C_DTT_ADDR:
1664 If defined, specifies the I2C address of the DTT device.
1665 If not defined, then U-Boot uses predefined value for
1666 specified DTT device.
1670 Define this option if you want to use Freescale's I2C driver in
1671 drivers/i2c/fsl_i2c.c.
1675 Define this option if you have I2C devices reached over 1 .. n
1676 I2C Muxes like the pca9544a. This option addes a new I2C
1677 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1678 new I2C Bus to the existing I2C Busses. If you select the
1679 new Bus with "i2c dev", u-bbot sends first the commandos for
1680 the muxes to activate this new "bus".
1682 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1686 Adding a new I2C Bus reached over 2 pca9544a muxes
1687 The First mux with address 70 and channel 6
1688 The Second mux with address 71 and channel 4
1690 => i2c bus pca9544a:70:6:pca9544a:71:4
1692 Use the "i2c bus" command without parameter, to get a list
1693 of I2C Busses with muxes:
1696 Busses reached over muxes:
1698 reached over Mux(es):
1701 reached over Mux(es):
1706 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1707 u-boot sends First the Commando to the mux@70 to enable
1708 channel 6, and then the Commando to the mux@71 to enable
1711 After that, you can use the "normal" i2c commands as
1712 usual, to communicate with your I2C devices behind
1715 This option is actually implemented for the bitbanging
1716 algorithm in common/soft_i2c.c and for the Hardware I2C
1717 Bus on the MPC8260. But it should be not so difficult
1718 to add this option to other architectures.
1720 CONFIG_SOFT_I2C_READ_REPEATED_START
1722 defining this will force the i2c_read() function in
1723 the soft_i2c driver to perform an I2C repeated start
1724 between writing the address pointer and reading the
1725 data. If this define is omitted the default behaviour
1726 of doing a stop-start sequence will be used. Most I2C
1727 devices can use either method, but some require one or
1730 - SPI Support: CONFIG_SPI
1732 Enables SPI driver (so far only tested with
1733 SPI EEPROM, also an instance works with Crystal A/D and
1734 D/As on the SACSng board)
1738 Enables the driver for SPI controller on SuperH. Currently
1739 only SH7757 is supported.
1743 Enables extended (16-bit) SPI EEPROM addressing.
1744 (symmetrical to CONFIG_I2C_X)
1748 Enables a software (bit-bang) SPI driver rather than
1749 using hardware support. This is a general purpose
1750 driver that only requires three general I/O port pins
1751 (two outputs, one input) to function. If this is
1752 defined, the board configuration must define several
1753 SPI configuration items (port pins to use, etc). For
1754 an example, see include/configs/sacsng.h.
1758 Enables a hardware SPI driver for general-purpose reads
1759 and writes. As with CONFIG_SOFT_SPI, the board configuration
1760 must define a list of chip-select function pointers.
1761 Currently supported on some MPC8xxx processors. For an
1762 example, see include/configs/mpc8349emds.h.
1766 Enables the driver for the SPI controllers on i.MX and MXC
1767 SoCs. Currently only i.MX31 is supported.
1769 - FPGA Support: CONFIG_FPGA
1771 Enables FPGA subsystem.
1773 CONFIG_FPGA_<vendor>
1775 Enables support for specific chip vendors.
1778 CONFIG_FPGA_<family>
1780 Enables support for FPGA family.
1781 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1785 Specify the number of FPGA devices to support.
1787 CONFIG_SYS_FPGA_PROG_FEEDBACK
1789 Enable printing of hash marks during FPGA configuration.
1791 CONFIG_SYS_FPGA_CHECK_BUSY
1793 Enable checks on FPGA configuration interface busy
1794 status by the configuration function. This option
1795 will require a board or device specific function to
1800 If defined, a function that provides delays in the FPGA
1801 configuration driver.
1803 CONFIG_SYS_FPGA_CHECK_CTRLC
1804 Allow Control-C to interrupt FPGA configuration
1806 CONFIG_SYS_FPGA_CHECK_ERROR
1808 Check for configuration errors during FPGA bitfile
1809 loading. For example, abort during Virtex II
1810 configuration if the INIT_B line goes low (which
1811 indicated a CRC error).
1813 CONFIG_SYS_FPGA_WAIT_INIT
1815 Maximum time to wait for the INIT_B line to deassert
1816 after PROB_B has been deasserted during a Virtex II
1817 FPGA configuration sequence. The default time is 500
1820 CONFIG_SYS_FPGA_WAIT_BUSY
1822 Maximum time to wait for BUSY to deassert during
1823 Virtex II FPGA configuration. The default is 5 ms.
1825 CONFIG_SYS_FPGA_WAIT_CONFIG
1827 Time to wait after FPGA configuration. The default is
1830 - Configuration Management:
1833 If defined, this string will be added to the U-Boot
1834 version information (U_BOOT_VERSION)
1836 - Vendor Parameter Protection:
1838 U-Boot considers the values of the environment
1839 variables "serial#" (Board Serial Number) and
1840 "ethaddr" (Ethernet Address) to be parameters that
1841 are set once by the board vendor / manufacturer, and
1842 protects these variables from casual modification by
1843 the user. Once set, these variables are read-only,
1844 and write or delete attempts are rejected. You can
1845 change this behaviour:
1847 If CONFIG_ENV_OVERWRITE is #defined in your config
1848 file, the write protection for vendor parameters is
1849 completely disabled. Anybody can change or delete
1852 Alternatively, if you #define _both_ CONFIG_ETHADDR
1853 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1854 Ethernet address is installed in the environment,
1855 which can be changed exactly ONCE by the user. [The
1856 serial# is unaffected by this, i. e. it remains
1862 Define this variable to enable the reservation of
1863 "protected RAM", i. e. RAM which is not overwritten
1864 by U-Boot. Define CONFIG_PRAM to hold the number of
1865 kB you want to reserve for pRAM. You can overwrite
1866 this default value by defining an environment
1867 variable "pram" to the number of kB you want to
1868 reserve. Note that the board info structure will
1869 still show the full amount of RAM. If pRAM is
1870 reserved, a new environment variable "mem" will
1871 automatically be defined to hold the amount of
1872 remaining RAM in a form that can be passed as boot
1873 argument to Linux, for instance like that:
1875 setenv bootargs ... mem=\${mem}
1878 This way you can tell Linux not to use this memory,
1879 either, which results in a memory region that will
1880 not be affected by reboots.
1882 *WARNING* If your board configuration uses automatic
1883 detection of the RAM size, you must make sure that
1884 this memory test is non-destructive. So far, the
1885 following board configurations are known to be
1888 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1889 HERMES, IP860, RPXlite, LWMON, LANTEC,
1895 Define this variable to stop the system in case of a
1896 fatal error, so that you have to reset it manually.
1897 This is probably NOT a good idea for an embedded
1898 system where you want the system to reboot
1899 automatically as fast as possible, but it may be
1900 useful during development since you can try to debug
1901 the conditions that lead to the situation.
1903 CONFIG_NET_RETRY_COUNT
1905 This variable defines the number of retries for
1906 network operations like ARP, RARP, TFTP, or BOOTP
1907 before giving up the operation. If not defined, a
1908 default value of 5 is used.
1912 Timeout waiting for an ARP reply in milliseconds.
1914 - Command Interpreter:
1915 CONFIG_AUTO_COMPLETE
1917 Enable auto completion of commands using TAB.
1919 Note that this feature has NOT been implemented yet
1920 for the "hush" shell.
1923 CONFIG_SYS_HUSH_PARSER
1925 Define this variable to enable the "hush" shell (from
1926 Busybox) as command line interpreter, thus enabling
1927 powerful command line syntax like
1928 if...then...else...fi conditionals or `&&' and '||'
1929 constructs ("shell scripts").
1931 If undefined, you get the old, much simpler behaviour
1932 with a somewhat smaller memory footprint.
1935 CONFIG_SYS_PROMPT_HUSH_PS2
1937 This defines the secondary prompt string, which is
1938 printed when the command interpreter needs more input
1939 to complete a command. Usually "> ".
1943 In the current implementation, the local variables
1944 space and global environment variables space are
1945 separated. Local variables are those you define by
1946 simply typing `name=value'. To access a local
1947 variable later on, you have write `$name' or
1948 `${name}'; to execute the contents of a variable
1949 directly type `$name' at the command prompt.
1951 Global environment variables are those you use
1952 setenv/printenv to work with. To run a command stored
1953 in such a variable, you need to use the run command,
1954 and you must not use the '$' sign to access them.
1956 To store commands and special characters in a
1957 variable, please use double quotation marks
1958 surrounding the whole text of the variable, instead
1959 of the backslashes before semicolons and special
1962 - Commandline Editing and History:
1963 CONFIG_CMDLINE_EDITING
1965 Enable editing and History functions for interactive
1966 commandline input operations
1968 - Default Environment:
1969 CONFIG_EXTRA_ENV_SETTINGS
1971 Define this to contain any number of null terminated
1972 strings (variable = value pairs) that will be part of
1973 the default environment compiled into the boot image.
1975 For example, place something like this in your
1976 board's config file:
1978 #define CONFIG_EXTRA_ENV_SETTINGS \
1982 Warning: This method is based on knowledge about the
1983 internal format how the environment is stored by the
1984 U-Boot code. This is NOT an official, exported
1985 interface! Although it is unlikely that this format
1986 will change soon, there is no guarantee either.
1987 You better know what you are doing here.
1989 Note: overly (ab)use of the default environment is
1990 discouraged. Make sure to check other ways to preset
1991 the environment like the "source" command or the
1994 - DataFlash Support:
1995 CONFIG_HAS_DATAFLASH
1997 Defining this option enables DataFlash features and
1998 allows to read/write in Dataflash via the standard
2001 - SystemACE Support:
2004 Adding this option adds support for Xilinx SystemACE
2005 chips attached via some sort of local bus. The address
2006 of the chip must also be defined in the
2007 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2009 #define CONFIG_SYSTEMACE
2010 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2012 When SystemACE support is added, the "ace" device type
2013 becomes available to the fat commands, i.e. fatls.
2015 - TFTP Fixed UDP Port:
2018 If this is defined, the environment variable tftpsrcp
2019 is used to supply the TFTP UDP source port value.
2020 If tftpsrcp isn't defined, the normal pseudo-random port
2021 number generator is used.
2023 Also, the environment variable tftpdstp is used to supply
2024 the TFTP UDP destination port value. If tftpdstp isn't
2025 defined, the normal port 69 is used.
2027 The purpose for tftpsrcp is to allow a TFTP server to
2028 blindly start the TFTP transfer using the pre-configured
2029 target IP address and UDP port. This has the effect of
2030 "punching through" the (Windows XP) firewall, allowing
2031 the remainder of the TFTP transfer to proceed normally.
2032 A better solution is to properly configure the firewall,
2033 but sometimes that is not allowed.
2035 - Show boot progress:
2036 CONFIG_SHOW_BOOT_PROGRESS
2038 Defining this option allows to add some board-
2039 specific code (calling a user-provided function
2040 "show_boot_progress(int)") that enables you to show
2041 the system's boot progress on some display (for
2042 example, some LED's) on your board. At the moment,
2043 the following checkpoints are implemented:
2045 - Standalone program support:
2046 CONFIG_STANDALONE_LOAD_ADDR
2048 This option allows to define board specific values
2049 for the address where standalone program gets loaded,
2050 thus overwriting the architecutre dependent default
2053 - Frame Buffer Address:
2056 Define CONFIG_FB_ADDR if you want to use specific address for
2058 Then system will reserve the frame buffer address to defined address
2059 instead of lcd_setmem (this function grab the memory for frame buffer
2062 Please see board_init_f function.
2064 If you want this config option then,
2065 please define it at your board config file
2067 Legacy uImage format:
2070 1 common/cmd_bootm.c before attempting to boot an image
2071 -1 common/cmd_bootm.c Image header has bad magic number
2072 2 common/cmd_bootm.c Image header has correct magic number
2073 -2 common/cmd_bootm.c Image header has bad checksum
2074 3 common/cmd_bootm.c Image header has correct checksum
2075 -3 common/cmd_bootm.c Image data has bad checksum
2076 4 common/cmd_bootm.c Image data has correct checksum
2077 -4 common/cmd_bootm.c Image is for unsupported architecture
2078 5 common/cmd_bootm.c Architecture check OK
2079 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2080 6 common/cmd_bootm.c Image Type check OK
2081 -6 common/cmd_bootm.c gunzip uncompression error
2082 -7 common/cmd_bootm.c Unimplemented compression type
2083 7 common/cmd_bootm.c Uncompression OK
2084 8 common/cmd_bootm.c No uncompress/copy overwrite error
2085 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2087 9 common/image.c Start initial ramdisk verification
2088 -10 common/image.c Ramdisk header has bad magic number
2089 -11 common/image.c Ramdisk header has bad checksum
2090 10 common/image.c Ramdisk header is OK
2091 -12 common/image.c Ramdisk data has bad checksum
2092 11 common/image.c Ramdisk data has correct checksum
2093 12 common/image.c Ramdisk verification complete, start loading
2094 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2095 13 common/image.c Start multifile image verification
2096 14 common/image.c No initial ramdisk, no multifile, continue.
2098 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2100 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2101 -31 post/post.c POST test failed, detected by post_output_backlog()
2102 -32 post/post.c POST test failed, detected by post_run_single()
2104 34 common/cmd_doc.c before loading a Image from a DOC device
2105 -35 common/cmd_doc.c Bad usage of "doc" command
2106 35 common/cmd_doc.c correct usage of "doc" command
2107 -36 common/cmd_doc.c No boot device
2108 36 common/cmd_doc.c correct boot device
2109 -37 common/cmd_doc.c Unknown Chip ID on boot device
2110 37 common/cmd_doc.c correct chip ID found, device available
2111 -38 common/cmd_doc.c Read Error on boot device
2112 38 common/cmd_doc.c reading Image header from DOC device OK
2113 -39 common/cmd_doc.c Image header has bad magic number
2114 39 common/cmd_doc.c Image header has correct magic number
2115 -40 common/cmd_doc.c Error reading Image from DOC device
2116 40 common/cmd_doc.c Image header has correct magic number
2117 41 common/cmd_ide.c before loading a Image from a IDE device
2118 -42 common/cmd_ide.c Bad usage of "ide" command
2119 42 common/cmd_ide.c correct usage of "ide" command
2120 -43 common/cmd_ide.c No boot device
2121 43 common/cmd_ide.c boot device found
2122 -44 common/cmd_ide.c Device not available
2123 44 common/cmd_ide.c Device available
2124 -45 common/cmd_ide.c wrong partition selected
2125 45 common/cmd_ide.c partition selected
2126 -46 common/cmd_ide.c Unknown partition table
2127 46 common/cmd_ide.c valid partition table found
2128 -47 common/cmd_ide.c Invalid partition type
2129 47 common/cmd_ide.c correct partition type
2130 -48 common/cmd_ide.c Error reading Image Header on boot device
2131 48 common/cmd_ide.c reading Image Header from IDE device OK
2132 -49 common/cmd_ide.c Image header has bad magic number
2133 49 common/cmd_ide.c Image header has correct magic number
2134 -50 common/cmd_ide.c Image header has bad checksum
2135 50 common/cmd_ide.c Image header has correct checksum
2136 -51 common/cmd_ide.c Error reading Image from IDE device
2137 51 common/cmd_ide.c reading Image from IDE device OK
2138 52 common/cmd_nand.c before loading a Image from a NAND device
2139 -53 common/cmd_nand.c Bad usage of "nand" command
2140 53 common/cmd_nand.c correct usage of "nand" command
2141 -54 common/cmd_nand.c No boot device
2142 54 common/cmd_nand.c boot device found
2143 -55 common/cmd_nand.c Unknown Chip ID on boot device
2144 55 common/cmd_nand.c correct chip ID found, device available
2145 -56 common/cmd_nand.c Error reading Image Header on boot device
2146 56 common/cmd_nand.c reading Image Header from NAND device OK
2147 -57 common/cmd_nand.c Image header has bad magic number
2148 57 common/cmd_nand.c Image header has correct magic number
2149 -58 common/cmd_nand.c Error reading Image from NAND device
2150 58 common/cmd_nand.c reading Image from NAND device OK
2152 -60 common/env_common.c Environment has a bad CRC, using default
2154 64 net/eth.c starting with Ethernet configuration.
2155 -64 net/eth.c no Ethernet found.
2156 65 net/eth.c Ethernet found.
2158 -80 common/cmd_net.c usage wrong
2159 80 common/cmd_net.c before calling NetLoop()
2160 -81 common/cmd_net.c some error in NetLoop() occurred
2161 81 common/cmd_net.c NetLoop() back without error
2162 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2163 82 common/cmd_net.c trying automatic boot
2164 83 common/cmd_net.c running "source" command
2165 -83 common/cmd_net.c some error in automatic boot or "source" command
2166 84 common/cmd_net.c end without errors
2171 100 common/cmd_bootm.c Kernel FIT Image has correct format
2172 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2173 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2174 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2175 102 common/cmd_bootm.c Kernel unit name specified
2176 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2177 103 common/cmd_bootm.c Found configuration node
2178 104 common/cmd_bootm.c Got kernel subimage node offset
2179 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2180 105 common/cmd_bootm.c Kernel subimage hash verification OK
2181 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2182 106 common/cmd_bootm.c Architecture check OK
2183 -106 common/cmd_bootm.c Kernel subimage has wrong type
2184 107 common/cmd_bootm.c Kernel subimage type OK
2185 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2186 108 common/cmd_bootm.c Got kernel subimage data/size
2187 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2188 -109 common/cmd_bootm.c Can't get kernel subimage type
2189 -110 common/cmd_bootm.c Can't get kernel subimage comp
2190 -111 common/cmd_bootm.c Can't get kernel subimage os
2191 -112 common/cmd_bootm.c Can't get kernel subimage load address
2192 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2194 120 common/image.c Start initial ramdisk verification
2195 -120 common/image.c Ramdisk FIT image has incorrect format
2196 121 common/image.c Ramdisk FIT image has correct format
2197 122 common/image.c No ramdisk subimage unit name, using configuration
2198 -122 common/image.c Can't get configuration for ramdisk subimage
2199 123 common/image.c Ramdisk unit name specified
2200 -124 common/image.c Can't get ramdisk subimage node offset
2201 125 common/image.c Got ramdisk subimage node offset
2202 -125 common/image.c Ramdisk subimage hash verification failed
2203 126 common/image.c Ramdisk subimage hash verification OK
2204 -126 common/image.c Ramdisk subimage for unsupported architecture
2205 127 common/image.c Architecture check OK
2206 -127 common/image.c Can't get ramdisk subimage data/size
2207 128 common/image.c Got ramdisk subimage data/size
2208 129 common/image.c Can't get ramdisk load address
2209 -129 common/image.c Got ramdisk load address
2211 -130 common/cmd_doc.c Incorrect FIT image format
2212 131 common/cmd_doc.c FIT image format OK
2214 -140 common/cmd_ide.c Incorrect FIT image format
2215 141 common/cmd_ide.c FIT image format OK
2217 -150 common/cmd_nand.c Incorrect FIT image format
2218 151 common/cmd_nand.c FIT image format OK
2220 - Automatic software updates via TFTP server
2222 CONFIG_UPDATE_TFTP_CNT_MAX
2223 CONFIG_UPDATE_TFTP_MSEC_MAX
2225 These options enable and control the auto-update feature;
2226 for a more detailed description refer to doc/README.update.
2228 - MTD Support (mtdparts command, UBI support)
2231 Adds the MTD device infrastructure from the Linux kernel.
2232 Needed for mtdparts command support.
2234 CONFIG_MTD_PARTITIONS
2236 Adds the MTD partitioning infrastructure from the Linux
2237 kernel. Needed for UBI support.
2243 [so far only for SMDK2400 boards]
2245 - Modem support enable:
2246 CONFIG_MODEM_SUPPORT
2248 - RTS/CTS Flow control enable:
2251 - Modem debug support:
2252 CONFIG_MODEM_SUPPORT_DEBUG
2254 Enables debugging stuff (char screen[1024], dbg())
2255 for modem support. Useful only with BDI2000.
2257 - Interrupt support (PPC):
2259 There are common interrupt_init() and timer_interrupt()
2260 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2261 for CPU specific initialization. interrupt_init_cpu()
2262 should set decrementer_count to appropriate value. If
2263 CPU resets decrementer automatically after interrupt
2264 (ppc4xx) it should set decrementer_count to zero.
2265 timer_interrupt() calls timer_interrupt_cpu() for CPU
2266 specific handling. If board has watchdog / status_led
2267 / other_activity_monitor it works automatically from
2268 general timer_interrupt().
2272 In the target system modem support is enabled when a
2273 specific key (key combination) is pressed during
2274 power-on. Otherwise U-Boot will boot normally
2275 (autoboot). The key_pressed() function is called from
2276 board_init(). Currently key_pressed() is a dummy
2277 function, returning 1 and thus enabling modem
2280 If there are no modem init strings in the
2281 environment, U-Boot proceed to autoboot; the
2282 previous output (banner, info printfs) will be
2285 See also: doc/README.Modem
2288 Configuration Settings:
2289 -----------------------
2291 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2292 undefine this when you're short of memory.
2294 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2295 width of the commands listed in the 'help' command output.
2297 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2298 prompt for user input.
2300 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2302 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2304 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2306 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2307 the application (usually a Linux kernel) when it is
2310 - CONFIG_SYS_BAUDRATE_TABLE:
2311 List of legal baudrate settings for this board.
2313 - CONFIG_SYS_CONSOLE_INFO_QUIET
2314 Suppress display of console information at boot.
2316 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2317 If the board specific function
2318 extern int overwrite_console (void);
2319 returns 1, the stdin, stderr and stdout are switched to the
2320 serial port, else the settings in the environment are used.
2322 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2323 Enable the call to overwrite_console().
2325 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2326 Enable overwrite of previous console environment settings.
2328 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2329 Begin and End addresses of the area used by the
2332 - CONFIG_SYS_ALT_MEMTEST:
2333 Enable an alternate, more extensive memory test.
2335 - CONFIG_SYS_MEMTEST_SCRATCH:
2336 Scratch address used by the alternate memory test
2337 You only need to set this if address zero isn't writeable
2339 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2340 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2341 this specified memory area will get subtracted from the top
2342 (end) of RAM and won't get "touched" at all by U-Boot. By
2343 fixing up gd->ram_size the Linux kernel should gets passed
2344 the now "corrected" memory size and won't touch it either.
2345 This should work for arch/ppc and arch/powerpc. Only Linux
2346 board ports in arch/powerpc with bootwrapper support that
2347 recalculate the memory size from the SDRAM controller setup
2348 will have to get fixed in Linux additionally.
2350 This option can be used as a workaround for the 440EPx/GRx
2351 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2354 WARNING: Please make sure that this value is a multiple of
2355 the Linux page size (normally 4k). If this is not the case,
2356 then the end address of the Linux memory will be located at a
2357 non page size aligned address and this could cause major
2360 - CONFIG_SYS_TFTP_LOADADDR:
2361 Default load address for network file downloads
2363 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2364 Enable temporary baudrate change while serial download
2366 - CONFIG_SYS_SDRAM_BASE:
2367 Physical start address of SDRAM. _Must_ be 0 here.
2369 - CONFIG_SYS_MBIO_BASE:
2370 Physical start address of Motherboard I/O (if using a
2373 - CONFIG_SYS_FLASH_BASE:
2374 Physical start address of Flash memory.
2376 - CONFIG_SYS_MONITOR_BASE:
2377 Physical start address of boot monitor code (set by
2378 make config files to be same as the text base address
2379 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
2380 CONFIG_SYS_FLASH_BASE when booting from flash.
2382 - CONFIG_SYS_MONITOR_LEN:
2383 Size of memory reserved for monitor code, used to
2384 determine _at_compile_time_ (!) if the environment is
2385 embedded within the U-Boot image, or in a separate
2388 - CONFIG_SYS_MALLOC_LEN:
2389 Size of DRAM reserved for malloc() use.
2391 - CONFIG_SYS_BOOTM_LEN:
2392 Normally compressed uImages are limited to an
2393 uncompressed size of 8 MBytes. If this is not enough,
2394 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2395 to adjust this setting to your needs.
2397 - CONFIG_SYS_BOOTMAPSZ:
2398 Maximum size of memory mapped by the startup code of
2399 the Linux kernel; all data that must be processed by
2400 the Linux kernel (bd_info, boot arguments, FDT blob if
2401 used) must be put below this limit, unless "bootm_low"
2402 enviroment variable is defined and non-zero. In such case
2403 all data for the Linux kernel must be between "bootm_low"
2404 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
2405 variable "bootm_mapsize" will override the value of
2406 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
2407 then the value in "bootm_size" will be used instead.
2409 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
2410 Enable initrd_high functionality. If defined then the
2411 initrd_high feature is enabled and the bootm ramdisk subcommand
2414 - CONFIG_SYS_BOOT_GET_CMDLINE:
2415 Enables allocating and saving kernel cmdline in space between
2416 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2418 - CONFIG_SYS_BOOT_GET_KBD:
2419 Enables allocating and saving a kernel copy of the bd_info in
2420 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2422 - CONFIG_SYS_MAX_FLASH_BANKS:
2423 Max number of Flash memory banks
2425 - CONFIG_SYS_MAX_FLASH_SECT:
2426 Max number of sectors on a Flash chip
2428 - CONFIG_SYS_FLASH_ERASE_TOUT:
2429 Timeout for Flash erase operations (in ms)
2431 - CONFIG_SYS_FLASH_WRITE_TOUT:
2432 Timeout for Flash write operations (in ms)
2434 - CONFIG_SYS_FLASH_LOCK_TOUT
2435 Timeout for Flash set sector lock bit operation (in ms)
2437 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2438 Timeout for Flash clear lock bits operation (in ms)
2440 - CONFIG_SYS_FLASH_PROTECTION
2441 If defined, hardware flash sectors protection is used
2442 instead of U-Boot software protection.
2444 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2446 Enable TFTP transfers directly to flash memory;
2447 without this option such a download has to be
2448 performed in two steps: (1) download to RAM, and (2)
2449 copy from RAM to flash.
2451 The two-step approach is usually more reliable, since
2452 you can check if the download worked before you erase
2453 the flash, but in some situations (when system RAM is
2454 too limited to allow for a temporary copy of the
2455 downloaded image) this option may be very useful.
2457 - CONFIG_SYS_FLASH_CFI:
2458 Define if the flash driver uses extra elements in the
2459 common flash structure for storing flash geometry.
2461 - CONFIG_FLASH_CFI_DRIVER
2462 This option also enables the building of the cfi_flash driver
2463 in the drivers directory
2465 - CONFIG_FLASH_CFI_MTD
2466 This option enables the building of the cfi_mtd driver
2467 in the drivers directory. The driver exports CFI flash
2470 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2471 Use buffered writes to flash.
2473 - CONFIG_FLASH_SPANSION_S29WS_N
2474 s29ws-n MirrorBit flash has non-standard addresses for buffered
2477 - CONFIG_SYS_FLASH_QUIET_TEST
2478 If this option is defined, the common CFI flash doesn't
2479 print it's warning upon not recognized FLASH banks. This
2480 is useful, if some of the configured banks are only
2481 optionally available.
2483 - CONFIG_FLASH_SHOW_PROGRESS
2484 If defined (must be an integer), print out countdown
2485 digits and dots. Recommended value: 45 (9..1) for 80
2486 column displays, 15 (3..1) for 40 column displays.
2488 - CONFIG_SYS_RX_ETH_BUFFER:
2489 Defines the number of Ethernet receive buffers. On some
2490 Ethernet controllers it is recommended to set this value
2491 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2492 buffers can be full shortly after enabling the interface
2493 on high Ethernet traffic.
2494 Defaults to 4 if not defined.
2496 - CONFIG_ENV_MAX_ENTRIES
2498 Maximum number of entries in the hash table that is used
2499 internally to store the environment settings. The default
2500 setting is supposed to be generous and should work in most
2501 cases. This setting can be used to tune behaviour; see
2502 lib/hashtable.c for details.
2504 The following definitions that deal with the placement and management
2505 of environment data (variable area); in general, we support the
2506 following configurations:
2508 - CONFIG_ENV_IS_IN_FLASH:
2510 Define this if the environment is in flash memory.
2512 a) The environment occupies one whole flash sector, which is
2513 "embedded" in the text segment with the U-Boot code. This
2514 happens usually with "bottom boot sector" or "top boot
2515 sector" type flash chips, which have several smaller
2516 sectors at the start or the end. For instance, such a
2517 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2518 such a case you would place the environment in one of the
2519 4 kB sectors - with U-Boot code before and after it. With
2520 "top boot sector" type flash chips, you would put the
2521 environment in one of the last sectors, leaving a gap
2522 between U-Boot and the environment.
2524 - CONFIG_ENV_OFFSET:
2526 Offset of environment data (variable area) to the
2527 beginning of flash memory; for instance, with bottom boot
2528 type flash chips the second sector can be used: the offset
2529 for this sector is given here.
2531 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2535 This is just another way to specify the start address of
2536 the flash sector containing the environment (instead of
2539 - CONFIG_ENV_SECT_SIZE:
2541 Size of the sector containing the environment.
2544 b) Sometimes flash chips have few, equal sized, BIG sectors.
2545 In such a case you don't want to spend a whole sector for
2550 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2551 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2552 of this flash sector for the environment. This saves
2553 memory for the RAM copy of the environment.
2555 It may also save flash memory if you decide to use this
2556 when your environment is "embedded" within U-Boot code,
2557 since then the remainder of the flash sector could be used
2558 for U-Boot code. It should be pointed out that this is
2559 STRONGLY DISCOURAGED from a robustness point of view:
2560 updating the environment in flash makes it always
2561 necessary to erase the WHOLE sector. If something goes
2562 wrong before the contents has been restored from a copy in
2563 RAM, your target system will be dead.
2565 - CONFIG_ENV_ADDR_REDUND
2566 CONFIG_ENV_SIZE_REDUND
2568 These settings describe a second storage area used to hold
2569 a redundant copy of the environment data, so that there is
2570 a valid backup copy in case there is a power failure during
2571 a "saveenv" operation.
2573 BE CAREFUL! Any changes to the flash layout, and some changes to the
2574 source code will make it necessary to adapt <board>/u-boot.lds*
2578 - CONFIG_ENV_IS_IN_NVRAM:
2580 Define this if you have some non-volatile memory device
2581 (NVRAM, battery buffered SRAM) which you want to use for the
2587 These two #defines are used to determine the memory area you
2588 want to use for environment. It is assumed that this memory
2589 can just be read and written to, without any special
2592 BE CAREFUL! The first access to the environment happens quite early
2593 in U-Boot initalization (when we try to get the setting of for the
2594 console baudrate). You *MUST* have mapped your NVRAM area then, or
2597 Please note that even with NVRAM we still use a copy of the
2598 environment in RAM: we could work on NVRAM directly, but we want to
2599 keep settings there always unmodified except somebody uses "saveenv"
2600 to save the current settings.
2603 - CONFIG_ENV_IS_IN_EEPROM:
2605 Use this if you have an EEPROM or similar serial access
2606 device and a driver for it.
2608 - CONFIG_ENV_OFFSET:
2611 These two #defines specify the offset and size of the
2612 environment area within the total memory of your EEPROM.
2614 - CONFIG_SYS_I2C_EEPROM_ADDR:
2615 If defined, specified the chip address of the EEPROM device.
2616 The default address is zero.
2618 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2619 If defined, the number of bits used to address bytes in a
2620 single page in the EEPROM device. A 64 byte page, for example
2621 would require six bits.
2623 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2624 If defined, the number of milliseconds to delay between
2625 page writes. The default is zero milliseconds.
2627 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2628 The length in bytes of the EEPROM memory array address. Note
2629 that this is NOT the chip address length!
2631 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2632 EEPROM chips that implement "address overflow" are ones
2633 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2634 address and the extra bits end up in the "chip address" bit
2635 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2638 Note that we consider the length of the address field to
2639 still be one byte because the extra address bits are hidden
2640 in the chip address.
2642 - CONFIG_SYS_EEPROM_SIZE:
2643 The size in bytes of the EEPROM device.
2645 - CONFIG_ENV_EEPROM_IS_ON_I2C
2646 define this, if you have I2C and SPI activated, and your
2647 EEPROM, which holds the environment, is on the I2C bus.
2649 - CONFIG_I2C_ENV_EEPROM_BUS
2650 if you have an Environment on an EEPROM reached over
2651 I2C muxes, you can define here, how to reach this
2652 EEPROM. For example:
2654 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
2656 EEPROM which holds the environment, is reached over
2657 a pca9547 i2c mux with address 0x70, channel 3.
2659 - CONFIG_ENV_IS_IN_DATAFLASH:
2661 Define this if you have a DataFlash memory device which you
2662 want to use for the environment.
2664 - CONFIG_ENV_OFFSET:
2668 These three #defines specify the offset and size of the
2669 environment area within the total memory of your DataFlash placed
2670 at the specified address.
2672 - CONFIG_ENV_IS_IN_NAND:
2674 Define this if you have a NAND device which you want to use
2675 for the environment.
2677 - CONFIG_ENV_OFFSET:
2680 These two #defines specify the offset and size of the environment
2681 area within the first NAND device. CONFIG_ENV_OFFSET must be
2682 aligned to an erase block boundary.
2684 - CONFIG_ENV_OFFSET_REDUND (optional):
2686 This setting describes a second storage area of CONFIG_ENV_SIZE
2687 size used to hold a redundant copy of the environment data, so
2688 that there is a valid backup copy in case there is a power failure
2689 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
2690 aligned to an erase block boundary.
2692 - CONFIG_ENV_RANGE (optional):
2694 Specifies the length of the region in which the environment
2695 can be written. This should be a multiple of the NAND device's
2696 block size. Specifying a range with more erase blocks than
2697 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
2698 the range to be avoided.
2700 - CONFIG_ENV_OFFSET_OOB (optional):
2702 Enables support for dynamically retrieving the offset of the
2703 environment from block zero's out-of-band data. The
2704 "nand env.oob" command can be used to record this offset.
2705 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
2706 using CONFIG_ENV_OFFSET_OOB.
2708 - CONFIG_NAND_ENV_DST
2710 Defines address in RAM to which the nand_spl code should copy the
2711 environment. If redundant environment is used, it will be copied to
2712 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2714 - CONFIG_SYS_SPI_INIT_OFFSET
2716 Defines offset to the initial SPI buffer area in DPRAM. The
2717 area is used at an early stage (ROM part) if the environment
2718 is configured to reside in the SPI EEPROM: We need a 520 byte
2719 scratch DPRAM area. It is used between the two initialization
2720 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2721 to be a good choice since it makes it far enough from the
2722 start of the data area as well as from the stack pointer.
2724 Please note that the environment is read-only until the monitor
2725 has been relocated to RAM and a RAM copy of the environment has been
2726 created; also, when using EEPROM you will have to use getenv_f()
2727 until then to read environment variables.
2729 The environment is protected by a CRC32 checksum. Before the monitor
2730 is relocated into RAM, as a result of a bad CRC you will be working
2731 with the compiled-in default environment - *silently*!!! [This is
2732 necessary, because the first environment variable we need is the
2733 "baudrate" setting for the console - if we have a bad CRC, we don't
2734 have any device yet where we could complain.]
2736 Note: once the monitor has been relocated, then it will complain if
2737 the default environment is used; a new CRC is computed as soon as you
2738 use the "saveenv" command to store a valid environment.
2740 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2741 Echo the inverted Ethernet link state to the fault LED.
2743 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2744 also needs to be defined.
2746 - CONFIG_SYS_FAULT_MII_ADDR:
2747 MII address of the PHY to check for the Ethernet link state.
2749 - CONFIG_NS16550_MIN_FUNCTIONS:
2750 Define this if you desire to only have use of the NS16550_init
2751 and NS16550_putc functions for the serial driver located at
2752 drivers/serial/ns16550.c. This option is useful for saving
2753 space for already greatly restricted images, including but not
2754 limited to NAND_SPL configurations.
2756 Low Level (hardware related) configuration options:
2757 ---------------------------------------------------
2759 - CONFIG_SYS_CACHELINE_SIZE:
2760 Cache Line Size of the CPU.
2762 - CONFIG_SYS_DEFAULT_IMMR:
2763 Default address of the IMMR after system reset.
2765 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2766 and RPXsuper) to be able to adjust the position of
2767 the IMMR register after a reset.
2769 - Floppy Disk Support:
2770 CONFIG_SYS_FDC_DRIVE_NUMBER
2772 the default drive number (default value 0)
2774 CONFIG_SYS_ISA_IO_STRIDE
2776 defines the spacing between FDC chipset registers
2779 CONFIG_SYS_ISA_IO_OFFSET
2781 defines the offset of register from address. It
2782 depends on which part of the data bus is connected to
2783 the FDC chipset. (default value 0)
2785 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
2786 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
2789 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
2790 fdc_hw_init() is called at the beginning of the FDC
2791 setup. fdc_hw_init() must be provided by the board
2792 source code. It is used to make hardware dependant
2796 Most IDE controllers were designed to be connected with PCI
2797 interface. Only few of them were designed for AHB interface.
2798 When software is doing ATA command and data transfer to
2799 IDE devices through IDE-AHB controller, some additional
2800 registers accessing to these kind of IDE-AHB controller
2803 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
2804 DO NOT CHANGE unless you know exactly what you're
2805 doing! (11-4) [MPC8xx/82xx systems only]
2807 - CONFIG_SYS_INIT_RAM_ADDR:
2809 Start address of memory area that can be used for
2810 initial data and stack; please note that this must be
2811 writable memory that is working WITHOUT special
2812 initialization, i. e. you CANNOT use normal RAM which
2813 will become available only after programming the
2814 memory controller and running certain initialization
2817 U-Boot uses the following memory types:
2818 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2819 - MPC824X: data cache
2820 - PPC4xx: data cache
2822 - CONFIG_SYS_GBL_DATA_OFFSET:
2824 Offset of the initial data structure in the memory
2825 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2826 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
2827 data is located at the end of the available space
2828 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
2829 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
2830 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2831 CONFIG_SYS_GBL_DATA_OFFSET) downward.
2834 On the MPC824X (or other systems that use the data
2835 cache for initial memory) the address chosen for
2836 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
2837 point to an otherwise UNUSED address space between
2838 the top of RAM and the start of the PCI space.
2840 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
2842 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
2844 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
2846 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
2848 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2850 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
2852 - CONFIG_SYS_OR_TIMING_SDRAM:
2855 - CONFIG_SYS_MAMR_PTA:
2856 periodic timer for refresh
2858 - CONFIG_SYS_DER: Debug Event Register (37-47)
2860 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2861 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2862 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2863 CONFIG_SYS_BR1_PRELIM:
2864 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2866 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2867 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2868 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
2869 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2871 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
2872 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
2873 Machine Mode Register and Memory Periodic Timer
2874 Prescaler definitions (SDRAM timing)
2876 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
2877 enable I2C microcode relocation patch (MPC8xx);
2878 define relocation offset in DPRAM [DSP2]
2880 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
2881 enable SMC microcode relocation patch (MPC8xx);
2882 define relocation offset in DPRAM [SMC1]
2884 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
2885 enable SPI microcode relocation patch (MPC8xx);
2886 define relocation offset in DPRAM [SCC4]
2888 - CONFIG_SYS_USE_OSCCLK:
2889 Use OSCM clock mode on MBX8xx board. Be careful,
2890 wrong setting might damage your board. Read
2891 doc/README.MBX before setting this variable!
2893 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2894 Offset of the bootmode word in DPRAM used by post
2895 (Power On Self Tests). This definition overrides
2896 #define'd default value in commproc.h resp.
2899 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
2900 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
2901 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
2902 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
2903 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2904 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
2905 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
2906 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
2907 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
2909 - CONFIG_PCI_DISABLE_PCIE:
2910 Disable PCI-Express on systems where it is supported but not
2914 Chip has SRIO or not
2917 Board has SRIO 1 port available
2920 Board has SRIO 2 port available
2922 - CONFIG_SYS_SRIOn_MEM_VIRT:
2923 Virtual Address of SRIO port 'n' memory region
2925 - CONFIG_SYS_SRIOn_MEM_PHYS:
2926 Physical Address of SRIO port 'n' memory region
2928 - CONFIG_SYS_SRIOn_MEM_SIZE:
2929 Size of SRIO port 'n' memory region
2931 - CONFIG_SYS_NDFC_16
2932 Defined to tell the NDFC that the NAND chip is using a
2935 - CONFIG_SYS_NDFC_EBC0_CFG
2936 Sets the EBC0_CFG register for the NDFC. If not defined
2937 a default value will be used.
2940 Get DDR timing information from an I2C EEPROM. Common
2941 with pluggable memory modules such as SODIMMs
2944 I2C address of the SPD EEPROM
2946 - CONFIG_SYS_SPD_BUS_NUM
2947 If SPD EEPROM is on an I2C bus other than the first
2948 one, specify here. Note that the value must resolve
2949 to something your driver can deal with.
2951 - CONFIG_SYS_DDR_RAW_TIMING
2952 Get DDR timing information from other than SPD. Common with
2953 soldered DDR chips onboard without SPD. DDR raw timing
2954 parameters are extracted from datasheet and hard-coded into
2955 header files or board specific files.
2957 - CONFIG_SYS_83XX_DDR_USES_CS0
2958 Only for 83xx systems. If specified, then DDR should
2959 be configured using CS0 and CS1 instead of CS2 and CS3.
2961 - CONFIG_ETHER_ON_FEC[12]
2962 Define to enable FEC[12] on a 8xx series processor.
2964 - CONFIG_FEC[12]_PHY
2965 Define to the hardcoded PHY address which corresponds
2966 to the given FEC; i. e.
2967 #define CONFIG_FEC1_PHY 4
2968 means that the PHY with address 4 is connected to FEC1
2970 When set to -1, means to probe for first available.
2972 - CONFIG_FEC[12]_PHY_NORXERR
2973 The PHY does not have a RXERR line (RMII only).
2974 (so program the FEC to ignore it).
2977 Enable RMII mode for all FECs.
2978 Note that this is a global option, we can't
2979 have one FEC in standard MII mode and another in RMII mode.
2981 - CONFIG_CRC32_VERIFY
2982 Add a verify option to the crc32 command.
2985 => crc32 -v <address> <count> <crc32>
2987 Where address/count indicate a memory area
2988 and crc32 is the correct crc32 which the
2992 Add the "loopw" memory command. This only takes effect if
2993 the memory commands are activated globally (CONFIG_CMD_MEM).
2996 Add the "mdc" and "mwc" memory commands. These are cyclic
3001 This command will print 4 bytes (10,11,12,13) each 500 ms.
3003 => mwc.l 100 12345678 10
3004 This command will write 12345678 to address 100 all 10 ms.
3006 This only takes effect if the memory commands are activated
3007 globally (CONFIG_CMD_MEM).
3009 - CONFIG_SKIP_LOWLEVEL_INIT
3010 [ARM only] If this variable is defined, then certain
3011 low level initializations (like setting up the memory
3012 controller) are omitted and/or U-Boot does not
3013 relocate itself into RAM.
3015 Normally this variable MUST NOT be defined. The only
3016 exception is when U-Boot is loaded (to RAM) by some
3017 other boot loader or by a debugger which performs
3018 these initializations itself.
3021 Modifies the behaviour of start.S when compiling a loader
3022 that is executed before the actual U-Boot. E.g. when
3023 compiling a NAND SPL.
3025 - CONFIG_USE_ARCH_MEMCPY
3026 CONFIG_USE_ARCH_MEMSET
3027 If these options are used a optimized version of memcpy/memset will
3028 be used if available. These functions may be faster under some
3029 conditions but may increase the binary size.
3031 Building the Software:
3032 ======================
3034 Building U-Boot has been tested in several native build environments
3035 and in many different cross environments. Of course we cannot support
3036 all possibly existing versions of cross development tools in all
3037 (potentially obsolete) versions. In case of tool chain problems we
3038 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3039 which is extensively used to build and test U-Boot.
3041 If you are not using a native environment, it is assumed that you
3042 have GNU cross compiling tools available in your path. In this case,
3043 you must set the environment variable CROSS_COMPILE in your shell.
3044 Note that no changes to the Makefile or any other source files are
3045 necessary. For example using the ELDK on a 4xx CPU, please enter:
3047 $ CROSS_COMPILE=ppc_4xx-
3048 $ export CROSS_COMPILE
3050 Note: If you wish to generate Windows versions of the utilities in
3051 the tools directory you can use the MinGW toolchain
3052 (http://www.mingw.org). Set your HOST tools to the MinGW
3053 toolchain and execute 'make tools'. For example:
3055 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3057 Binaries such as tools/mkimage.exe will be created which can
3058 be executed on computers running Windows.
3060 U-Boot is intended to be simple to build. After installing the
3061 sources you must configure U-Boot for one specific board type. This
3066 where "NAME_config" is the name of one of the existing configu-
3067 rations; see the main Makefile for supported names.
3069 Note: for some board special configuration names may exist; check if
3070 additional information is available from the board vendor; for
3071 instance, the TQM823L systems are available without (standard)
3072 or with LCD support. You can select such additional "features"
3073 when choosing the configuration, i. e.
3076 - will configure for a plain TQM823L, i. e. no LCD support
3078 make TQM823L_LCD_config
3079 - will configure for a TQM823L with U-Boot console on LCD
3084 Finally, type "make all", and you should get some working U-Boot
3085 images ready for download to / installation on your system:
3087 - "u-boot.bin" is a raw binary image
3088 - "u-boot" is an image in ELF binary format
3089 - "u-boot.srec" is in Motorola S-Record format
3091 By default the build is performed locally and the objects are saved
3092 in the source directory. One of the two methods can be used to change
3093 this behavior and build U-Boot to some external directory:
3095 1. Add O= to the make command line invocations:
3097 make O=/tmp/build distclean
3098 make O=/tmp/build NAME_config
3099 make O=/tmp/build all
3101 2. Set environment variable BUILD_DIR to point to the desired location:
3103 export BUILD_DIR=/tmp/build
3108 Note that the command line "O=" setting overrides the BUILD_DIR environment
3112 Please be aware that the Makefiles assume you are using GNU make, so
3113 for instance on NetBSD you might need to use "gmake" instead of
3117 If the system board that you have is not listed, then you will need
3118 to port U-Boot to your hardware platform. To do this, follow these
3121 1. Add a new configuration option for your board to the toplevel
3122 "Makefile" and to the "MAKEALL" script, using the existing
3123 entries as examples. Note that here and at many other places
3124 boards and other names are listed in alphabetical sort order. Please
3126 2. Create a new directory to hold your board specific code. Add any
3127 files you need. In your board directory, you will need at least
3128 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
3129 3. Create a new configuration file "include/configs/<board>.h" for
3131 3. If you're porting U-Boot to a new CPU, then also create a new
3132 directory to hold your CPU specific code. Add any files you need.
3133 4. Run "make <board>_config" with your new name.
3134 5. Type "make", and you should get a working "u-boot.srec" file
3135 to be installed on your target system.
3136 6. Debug and solve any problems that might arise.
3137 [Of course, this last step is much harder than it sounds.]
3140 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3141 ==============================================================
3143 If you have modified U-Boot sources (for instance added a new board
3144 or support for new devices, a new CPU, etc.) you are expected to
3145 provide feedback to the other developers. The feedback normally takes
3146 the form of a "patch", i. e. a context diff against a certain (latest
3147 official or latest in the git repository) version of U-Boot sources.
3149 But before you submit such a patch, please verify that your modifi-
3150 cation did not break existing code. At least make sure that *ALL* of
3151 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3152 just run the "MAKEALL" script, which will configure and build U-Boot
3153 for ALL supported system. Be warned, this will take a while. You can
3154 select which (cross) compiler to use by passing a `CROSS_COMPILE'
3155 environment variable to the script, i. e. to use the ELDK cross tools
3158 CROSS_COMPILE=ppc_8xx- MAKEALL
3160 or to build on a native PowerPC system you can type
3162 CROSS_COMPILE=' ' MAKEALL
3164 When using the MAKEALL script, the default behaviour is to build
3165 U-Boot in the source directory. This location can be changed by
3166 setting the BUILD_DIR environment variable. Also, for each target
3167 built, the MAKEALL script saves two log files (<target>.ERR and
3168 <target>.MAKEALL) in the <source dir>/LOG directory. This default
3169 location can be changed by setting the MAKEALL_LOGDIR environment
3170 variable. For example:
3172 export BUILD_DIR=/tmp/build
3173 export MAKEALL_LOGDIR=/tmp/log
3174 CROSS_COMPILE=ppc_8xx- MAKEALL
3176 With the above settings build objects are saved in the /tmp/build,
3177 log files are saved in the /tmp/log and the source tree remains clean
3178 during the whole build process.
3181 See also "U-Boot Porting Guide" below.
3184 Monitor Commands - Overview:
3185 ============================
3187 go - start application at address 'addr'
3188 run - run commands in an environment variable
3189 bootm - boot application image from memory
3190 bootp - boot image via network using BootP/TFTP protocol
3191 tftpboot- boot image via network using TFTP protocol
3192 and env variables "ipaddr" and "serverip"
3193 (and eventually "gatewayip")
3194 rarpboot- boot image via network using RARP/TFTP protocol
3195 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3196 loads - load S-Record file over serial line
3197 loadb - load binary file over serial line (kermit mode)
3199 mm - memory modify (auto-incrementing)
3200 nm - memory modify (constant address)
3201 mw - memory write (fill)
3203 cmp - memory compare
3204 crc32 - checksum calculation
3205 i2c - I2C sub-system
3206 sspi - SPI utility commands
3207 base - print or set address offset
3208 printenv- print environment variables
3209 setenv - set environment variables
3210 saveenv - save environment variables to persistent storage
3211 protect - enable or disable FLASH write protection
3212 erase - erase FLASH memory
3213 flinfo - print FLASH memory information
3214 bdinfo - print Board Info structure
3215 iminfo - print header information for application image
3216 coninfo - print console devices and informations
3217 ide - IDE sub-system
3218 loop - infinite loop on address range
3219 loopw - infinite write loop on address range
3220 mtest - simple RAM test
3221 icache - enable or disable instruction cache
3222 dcache - enable or disable data cache
3223 reset - Perform RESET of the CPU
3224 echo - echo args to console
3225 version - print monitor version
3226 help - print online help
3227 ? - alias for 'help'
3230 Monitor Commands - Detailed Description:
3231 ========================================
3235 For now: just type "help <command>".
3238 Environment Variables:
3239 ======================
3241 U-Boot supports user configuration using Environment Variables which
3242 can be made persistent by saving to Flash memory.
3244 Environment Variables are set using "setenv", printed using
3245 "printenv", and saved to Flash using "saveenv". Using "setenv"
3246 without a value can be used to delete a variable from the
3247 environment. As long as you don't save the environment you are
3248 working with an in-memory copy. In case the Flash area containing the
3249 environment is erased by accident, a default environment is provided.
3251 Some configuration options can be set using Environment Variables.
3253 List of environment variables (most likely not complete):
3255 baudrate - see CONFIG_BAUDRATE
3257 bootdelay - see CONFIG_BOOTDELAY
3259 bootcmd - see CONFIG_BOOTCOMMAND
3261 bootargs - Boot arguments when booting an RTOS image
3263 bootfile - Name of the image to load with TFTP
3265 bootm_low - Memory range available for image processing in the bootm
3266 command can be restricted. This variable is given as
3267 a hexadecimal number and defines lowest address allowed
3268 for use by the bootm command. See also "bootm_size"
3269 environment variable. Address defined by "bootm_low" is
3270 also the base of the initial memory mapping for the Linux
3271 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
3274 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
3275 This variable is given as a hexadecimal number and it
3276 defines the size of the memory region starting at base
3277 address bootm_low that is accessible by the Linux kernel
3278 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
3279 as the default value if it is defined, and bootm_size is
3282 bootm_size - Memory range available for image processing in the bootm
3283 command can be restricted. This variable is given as
3284 a hexadecimal number and defines the size of the region
3285 allowed for use by the bootm command. See also "bootm_low"
3286 environment variable.
3288 updatefile - Location of the software update file on a TFTP server, used
3289 by the automatic software update feature. Please refer to
3290 documentation in doc/README.update for more details.
3292 autoload - if set to "no" (any string beginning with 'n'),
3293 "bootp" will just load perform a lookup of the
3294 configuration from the BOOTP server, but not try to
3295 load any image using TFTP
3297 autostart - if set to "yes", an image loaded using the "bootp",
3298 "rarpboot", "tftpboot" or "diskboot" commands will
3299 be automatically started (by internally calling
3302 If set to "no", a standalone image passed to the
3303 "bootm" command will be copied to the load address
3304 (and eventually uncompressed), but NOT be started.
3305 This can be used to load and uncompress arbitrary
3308 fdt_high - if set this restricts the maximum address that the
3309 flattened device tree will be copied into upon boot.
3310 If this is set to the special value 0xFFFFFFFF then
3311 the fdt will not be copied at all on boot. For this
3312 to work it must reside in writable memory, have
3313 sufficient padding on the end of it for u-boot to
3314 add the information it needs into it, and the memory
3315 must be accessible by the kernel.
3317 i2cfast - (PPC405GP|PPC405EP only)
3318 if set to 'y' configures Linux I2C driver for fast
3319 mode (400kHZ). This environment variable is used in
3320 initialization code. So, for changes to be effective
3321 it must be saved and board must be reset.
3323 initrd_high - restrict positioning of initrd images:
3324 If this variable is not set, initrd images will be
3325 copied to the highest possible address in RAM; this
3326 is usually what you want since it allows for
3327 maximum initrd size. If for some reason you want to
3328 make sure that the initrd image is loaded below the
3329 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3330 variable to a value of "no" or "off" or "0".
3331 Alternatively, you can set it to a maximum upper
3332 address to use (U-Boot will still check that it
3333 does not overwrite the U-Boot stack and data).
3335 For instance, when you have a system with 16 MB
3336 RAM, and want to reserve 4 MB from use by Linux,
3337 you can do this by adding "mem=12M" to the value of
3338 the "bootargs" variable. However, now you must make
3339 sure that the initrd image is placed in the first
3340 12 MB as well - this can be done with
3342 setenv initrd_high 00c00000
3344 If you set initrd_high to 0xFFFFFFFF, this is an
3345 indication to U-Boot that all addresses are legal
3346 for the Linux kernel, including addresses in flash
3347 memory. In this case U-Boot will NOT COPY the
3348 ramdisk at all. This may be useful to reduce the
3349 boot time on your system, but requires that this
3350 feature is supported by your Linux kernel.
3352 ipaddr - IP address; needed for tftpboot command
3354 loadaddr - Default load address for commands like "bootp",
3355 "rarpboot", "tftpboot", "loadb" or "diskboot"
3357 loads_echo - see CONFIG_LOADS_ECHO
3359 serverip - TFTP server IP address; needed for tftpboot command
3361 bootretry - see CONFIG_BOOT_RETRY_TIME
3363 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3365 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3367 ethprime - When CONFIG_NET_MULTI is enabled controls which
3368 interface is used first.
3370 ethact - When CONFIG_NET_MULTI is enabled controls which
3371 interface is currently active. For example you
3372 can do the following
3374 => setenv ethact FEC
3375 => ping 192.168.0.1 # traffic sent on FEC
3376 => setenv ethact SCC
3377 => ping 10.0.0.1 # traffic sent on SCC
3379 ethrotate - When set to "no" U-Boot does not go through all
3380 available network interfaces.
3381 It just stays at the currently selected interface.
3383 netretry - When set to "no" each network operation will
3384 either succeed or fail without retrying.
3385 When set to "once" the network operation will
3386 fail when all the available network interfaces
3387 are tried once without success.
3388 Useful on scripts which control the retry operation
3391 npe_ucode - set load address for the NPE microcode
3393 tftpsrcport - If this is set, the value is used for TFTP's
3396 tftpdstport - If this is set, the value is used for TFTP's UDP
3397 destination port instead of the Well Know Port 69.
3399 tftpblocksize - Block size to use for TFTP transfers; if not set,
3400 we use the TFTP server's default block size
3402 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3403 seconds, minimum value is 1000 = 1 second). Defines
3404 when a packet is considered to be lost so it has to
3405 be retransmitted. The default is 5000 = 5 seconds.
3406 Lowering this value may make downloads succeed
3407 faster in networks with high packet loss rates or
3408 with unreliable TFTP servers.
3410 vlan - When set to a value < 4095 the traffic over
3411 Ethernet is encapsulated/received over 802.1q
3414 The following environment variables may be used and automatically
3415 updated by the network boot commands ("bootp" and "rarpboot"),
3416 depending the information provided by your boot server:
3418 bootfile - see above
3419 dnsip - IP address of your Domain Name Server
3420 dnsip2 - IP address of your secondary Domain Name Server
3421 gatewayip - IP address of the Gateway (Router) to use
3422 hostname - Target hostname
3424 netmask - Subnet Mask
3425 rootpath - Pathname of the root filesystem on the NFS server
3426 serverip - see above
3429 There are two special Environment Variables:
3431 serial# - contains hardware identification information such
3432 as type string and/or serial number
3433 ethaddr - Ethernet address
3435 These variables can be set only once (usually during manufacturing of
3436 the board). U-Boot refuses to delete or overwrite these variables
3437 once they have been set once.
3440 Further special Environment Variables:
3442 ver - Contains the U-Boot version string as printed
3443 with the "version" command. This variable is
3444 readonly (see CONFIG_VERSION_VARIABLE).
3447 Please note that changes to some configuration parameters may take
3448 only effect after the next boot (yes, that's just like Windoze :-).
3451 Command Line Parsing:
3452 =====================
3454 There are two different command line parsers available with U-Boot:
3455 the old "simple" one, and the much more powerful "hush" shell:
3457 Old, simple command line parser:
3458 --------------------------------
3460 - supports environment variables (through setenv / saveenv commands)
3461 - several commands on one line, separated by ';'
3462 - variable substitution using "... ${name} ..." syntax
3463 - special characters ('$', ';') can be escaped by prefixing with '\',
3465 setenv bootcmd bootm \${address}
3466 - You can also escape text by enclosing in single apostrophes, for example:
3467 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3472 - similar to Bourne shell, with control structures like
3473 if...then...else...fi, for...do...done; while...do...done,
3474 until...do...done, ...
3475 - supports environment ("global") variables (through setenv / saveenv
3476 commands) and local shell variables (through standard shell syntax
3477 "name=value"); only environment variables can be used with "run"
3483 (1) If a command line (or an environment variable executed by a "run"
3484 command) contains several commands separated by semicolon, and
3485 one of these commands fails, then the remaining commands will be
3488 (2) If you execute several variables with one call to run (i. e.
3489 calling run with a list of variables as arguments), any failing
3490 command will cause "run" to terminate, i. e. the remaining
3491 variables are not executed.
3493 Note for Redundant Ethernet Interfaces:
3494 =======================================
3496 Some boards come with redundant Ethernet interfaces; U-Boot supports
3497 such configurations and is capable of automatic selection of a
3498 "working" interface when needed. MAC assignment works as follows:
3500 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3501 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3502 "eth1addr" (=>eth1), "eth2addr", ...
3504 If the network interface stores some valid MAC address (for instance
3505 in SROM), this is used as default address if there is NO correspon-
3506 ding setting in the environment; if the corresponding environment
3507 variable is set, this overrides the settings in the card; that means:
3509 o If the SROM has a valid MAC address, and there is no address in the
3510 environment, the SROM's address is used.
3512 o If there is no valid address in the SROM, and a definition in the
3513 environment exists, then the value from the environment variable is
3516 o If both the SROM and the environment contain a MAC address, and
3517 both addresses are the same, this MAC address is used.
3519 o If both the SROM and the environment contain a MAC address, and the
3520 addresses differ, the value from the environment is used and a
3523 o If neither SROM nor the environment contain a MAC address, an error
3526 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
3527 will be programmed into hardware as part of the initialization process. This
3528 may be skipped by setting the appropriate 'ethmacskip' environment variable.
3529 The naming convention is as follows:
3530 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
3535 U-Boot is capable of booting (and performing other auxiliary operations on)
3536 images in two formats:
3538 New uImage format (FIT)
3539 -----------------------
3541 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3542 to Flattened Device Tree). It allows the use of images with multiple
3543 components (several kernels, ramdisks, etc.), with contents protected by
3544 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3550 Old image format is based on binary files which can be basically anything,
3551 preceded by a special header; see the definitions in include/image.h for
3552 details; basically, the header defines the following image properties:
3554 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3555 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3556 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3557 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3559 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3560 IA64, MIPS, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3561 Currently supported: ARM, AVR32, Intel x86, MIPS, Nios II, PowerPC).
3562 * Compression Type (uncompressed, gzip, bzip2)
3568 The header is marked by a special Magic Number, and both the header
3569 and the data portions of the image are secured against corruption by
3576 Although U-Boot should support any OS or standalone application
3577 easily, the main focus has always been on Linux during the design of
3580 U-Boot includes many features that so far have been part of some
3581 special "boot loader" code within the Linux kernel. Also, any
3582 "initrd" images to be used are no longer part of one big Linux image;
3583 instead, kernel and "initrd" are separate images. This implementation
3584 serves several purposes:
3586 - the same features can be used for other OS or standalone
3587 applications (for instance: using compressed images to reduce the
3588 Flash memory footprint)
3590 - it becomes much easier to port new Linux kernel versions because
3591 lots of low-level, hardware dependent stuff are done by U-Boot
3593 - the same Linux kernel image can now be used with different "initrd"
3594 images; of course this also means that different kernel images can
3595 be run with the same "initrd". This makes testing easier (you don't
3596 have to build a new "zImage.initrd" Linux image when you just
3597 change a file in your "initrd"). Also, a field-upgrade of the
3598 software is easier now.
3604 Porting Linux to U-Boot based systems:
3605 ---------------------------------------
3607 U-Boot cannot save you from doing all the necessary modifications to
3608 configure the Linux device drivers for use with your target hardware
3609 (no, we don't intend to provide a full virtual machine interface to
3612 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
3614 Just make sure your machine specific header file (for instance
3615 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3616 Information structure as we define in include/asm-<arch>/u-boot.h,
3617 and make sure that your definition of IMAP_ADDR uses the same value
3618 as your U-Boot configuration in CONFIG_SYS_IMMR.
3621 Configuring the Linux kernel:
3622 -----------------------------
3624 No specific requirements for U-Boot. Make sure you have some root
3625 device (initial ramdisk, NFS) for your target system.
3628 Building a Linux Image:
3629 -----------------------
3631 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3632 not used. If you use recent kernel source, a new build target
3633 "uImage" will exist which automatically builds an image usable by
3634 U-Boot. Most older kernels also have support for a "pImage" target,
3635 which was introduced for our predecessor project PPCBoot and uses a
3636 100% compatible format.
3645 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3646 encapsulate a compressed Linux kernel image with header information,
3647 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3649 * build a standard "vmlinux" kernel image (in ELF binary format):
3651 * convert the kernel into a raw binary image:
3653 ${CROSS_COMPILE}-objcopy -O binary \
3654 -R .note -R .comment \
3655 -S vmlinux linux.bin
3657 * compress the binary image:
3661 * package compressed binary image for U-Boot:
3663 mkimage -A ppc -O linux -T kernel -C gzip \
3664 -a 0 -e 0 -n "Linux Kernel Image" \
3665 -d linux.bin.gz uImage
3668 The "mkimage" tool can also be used to create ramdisk images for use
3669 with U-Boot, either separated from the Linux kernel image, or
3670 combined into one file. "mkimage" encapsulates the images with a 64
3671 byte header containing information about target architecture,
3672 operating system, image type, compression method, entry points, time
3673 stamp, CRC32 checksums, etc.
3675 "mkimage" can be called in two ways: to verify existing images and
3676 print the header information, or to build new images.
3678 In the first form (with "-l" option) mkimage lists the information
3679 contained in the header of an existing U-Boot image; this includes
3680 checksum verification:
3682 tools/mkimage -l image
3683 -l ==> list image header information
3685 The second form (with "-d" option) is used to build a U-Boot image
3686 from a "data file" which is used as image payload:
3688 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3689 -n name -d data_file image
3690 -A ==> set architecture to 'arch'
3691 -O ==> set operating system to 'os'
3692 -T ==> set image type to 'type'
3693 -C ==> set compression type 'comp'
3694 -a ==> set load address to 'addr' (hex)
3695 -e ==> set entry point to 'ep' (hex)
3696 -n ==> set image name to 'name'
3697 -d ==> use image data from 'datafile'
3699 Right now, all Linux kernels for PowerPC systems use the same load
3700 address (0x00000000), but the entry point address depends on the
3703 - 2.2.x kernels have the entry point at 0x0000000C,
3704 - 2.3.x and later kernels have the entry point at 0x00000000.
3706 So a typical call to build a U-Boot image would read:
3708 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3709 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3710 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
3711 > examples/uImage.TQM850L
3712 Image Name: 2.4.4 kernel for TQM850L
3713 Created: Wed Jul 19 02:34:59 2000
3714 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3715 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3716 Load Address: 0x00000000
3717 Entry Point: 0x00000000
3719 To verify the contents of the image (or check for corruption):
3721 -> tools/mkimage -l examples/uImage.TQM850L
3722 Image Name: 2.4.4 kernel for TQM850L
3723 Created: Wed Jul 19 02:34:59 2000
3724 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3725 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3726 Load Address: 0x00000000
3727 Entry Point: 0x00000000
3729 NOTE: for embedded systems where boot time is critical you can trade
3730 speed for memory and install an UNCOMPRESSED image instead: this
3731 needs more space in Flash, but boots much faster since it does not
3732 need to be uncompressed:
3734 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
3735 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3736 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3737 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
3738 > examples/uImage.TQM850L-uncompressed
3739 Image Name: 2.4.4 kernel for TQM850L
3740 Created: Wed Jul 19 02:34:59 2000
3741 Image Type: PowerPC Linux Kernel Image (uncompressed)
3742 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3743 Load Address: 0x00000000
3744 Entry Point: 0x00000000
3747 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3748 when your kernel is intended to use an initial ramdisk:
3750 -> tools/mkimage -n 'Simple Ramdisk Image' \
3751 > -A ppc -O linux -T ramdisk -C gzip \
3752 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3753 Image Name: Simple Ramdisk Image
3754 Created: Wed Jan 12 14:01:50 2000
3755 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3756 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3757 Load Address: 0x00000000
3758 Entry Point: 0x00000000
3761 Installing a Linux Image:
3762 -------------------------
3764 To downloading a U-Boot image over the serial (console) interface,
3765 you must convert the image to S-Record format:
3767 objcopy -I binary -O srec examples/image examples/image.srec
3769 The 'objcopy' does not understand the information in the U-Boot
3770 image header, so the resulting S-Record file will be relative to
3771 address 0x00000000. To load it to a given address, you need to
3772 specify the target address as 'offset' parameter with the 'loads'
3775 Example: install the image to address 0x40100000 (which on the
3776 TQM8xxL is in the first Flash bank):
3778 => erase 40100000 401FFFFF
3784 ## Ready for S-Record download ...
3785 ~>examples/image.srec
3786 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3788 15989 15990 15991 15992
3789 [file transfer complete]
3791 ## Start Addr = 0x00000000
3794 You can check the success of the download using the 'iminfo' command;
3795 this includes a checksum verification so you can be sure no data
3796 corruption happened:
3800 ## Checking Image at 40100000 ...
3801 Image Name: 2.2.13 for initrd on TQM850L
3802 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3803 Data Size: 335725 Bytes = 327 kB = 0 MB
3804 Load Address: 00000000
3805 Entry Point: 0000000c
3806 Verifying Checksum ... OK
3812 The "bootm" command is used to boot an application that is stored in
3813 memory (RAM or Flash). In case of a Linux kernel image, the contents
3814 of the "bootargs" environment variable is passed to the kernel as
3815 parameters. You can check and modify this variable using the
3816 "printenv" and "setenv" commands:
3819 => printenv bootargs
3820 bootargs=root=/dev/ram
3822 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3824 => printenv bootargs
3825 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3828 ## Booting Linux kernel at 40020000 ...
3829 Image Name: 2.2.13 for NFS on TQM850L
3830 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3831 Data Size: 381681 Bytes = 372 kB = 0 MB
3832 Load Address: 00000000
3833 Entry Point: 0000000c
3834 Verifying Checksum ... OK
3835 Uncompressing Kernel Image ... OK
3836 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
3837 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3838 time_init: decrementer frequency = 187500000/60
3839 Calibrating delay loop... 49.77 BogoMIPS
3840 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3843 If you want to boot a Linux kernel with initial RAM disk, you pass
3844 the memory addresses of both the kernel and the initrd image (PPBCOOT
3845 format!) to the "bootm" command:
3847 => imi 40100000 40200000
3849 ## Checking Image at 40100000 ...
3850 Image Name: 2.2.13 for initrd on TQM850L
3851 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3852 Data Size: 335725 Bytes = 327 kB = 0 MB
3853 Load Address: 00000000
3854 Entry Point: 0000000c
3855 Verifying Checksum ... OK
3857 ## Checking Image at 40200000 ...
3858 Image Name: Simple Ramdisk Image
3859 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3860 Data Size: 566530 Bytes = 553 kB = 0 MB
3861 Load Address: 00000000
3862 Entry Point: 00000000
3863 Verifying Checksum ... OK
3865 => bootm 40100000 40200000
3866 ## Booting Linux kernel at 40100000 ...
3867 Image Name: 2.2.13 for initrd on TQM850L
3868 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3869 Data Size: 335725 Bytes = 327 kB = 0 MB
3870 Load Address: 00000000
3871 Entry Point: 0000000c
3872 Verifying Checksum ... OK
3873 Uncompressing Kernel Image ... OK
3874 ## Loading RAMDisk Image at 40200000 ...
3875 Image Name: Simple Ramdisk Image
3876 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3877 Data Size: 566530 Bytes = 553 kB = 0 MB
3878 Load Address: 00000000
3879 Entry Point: 00000000
3880 Verifying Checksum ... OK
3881 Loading Ramdisk ... OK
3882 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
3883 Boot arguments: root=/dev/ram
3884 time_init: decrementer frequency = 187500000/60
3885 Calibrating delay loop... 49.77 BogoMIPS
3887 RAMDISK: Compressed image found at block 0
3888 VFS: Mounted root (ext2 filesystem).
3892 Boot Linux and pass a flat device tree:
3895 First, U-Boot must be compiled with the appropriate defines. See the section
3896 titled "Linux Kernel Interface" above for a more in depth explanation. The
3897 following is an example of how to start a kernel and pass an updated
3903 oft=oftrees/mpc8540ads.dtb
3904 => tftp $oftaddr $oft
3905 Speed: 1000, full duplex
3907 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3908 Filename 'oftrees/mpc8540ads.dtb'.
3909 Load address: 0x300000
3912 Bytes transferred = 4106 (100a hex)
3913 => tftp $loadaddr $bootfile
3914 Speed: 1000, full duplex
3916 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3918 Load address: 0x200000
3919 Loading:############
3921 Bytes transferred = 1029407 (fb51f hex)
3926 => bootm $loadaddr - $oftaddr
3927 ## Booting image at 00200000 ...
3928 Image Name: Linux-2.6.17-dirty
3929 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3930 Data Size: 1029343 Bytes = 1005.2 kB
3931 Load Address: 00000000
3932 Entry Point: 00000000
3933 Verifying Checksum ... OK
3934 Uncompressing Kernel Image ... OK
3935 Booting using flat device tree at 0x300000
3936 Using MPC85xx ADS machine description
3937 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3941 More About U-Boot Image Types:
3942 ------------------------------
3944 U-Boot supports the following image types:
3946 "Standalone Programs" are directly runnable in the environment
3947 provided by U-Boot; it is expected that (if they behave
3948 well) you can continue to work in U-Boot after return from
3949 the Standalone Program.
3950 "OS Kernel Images" are usually images of some Embedded OS which
3951 will take over control completely. Usually these programs
3952 will install their own set of exception handlers, device
3953 drivers, set up the MMU, etc. - this means, that you cannot
3954 expect to re-enter U-Boot except by resetting the CPU.
3955 "RAMDisk Images" are more or less just data blocks, and their
3956 parameters (address, size) are passed to an OS kernel that is
3958 "Multi-File Images" contain several images, typically an OS
3959 (Linux) kernel image and one or more data images like
3960 RAMDisks. This construct is useful for instance when you want
3961 to boot over the network using BOOTP etc., where the boot
3962 server provides just a single image file, but you want to get
3963 for instance an OS kernel and a RAMDisk image.
3965 "Multi-File Images" start with a list of image sizes, each
3966 image size (in bytes) specified by an "uint32_t" in network
3967 byte order. This list is terminated by an "(uint32_t)0".
3968 Immediately after the terminating 0 follow the images, one by
3969 one, all aligned on "uint32_t" boundaries (size rounded up to
3970 a multiple of 4 bytes).
3972 "Firmware Images" are binary images containing firmware (like
3973 U-Boot or FPGA images) which usually will be programmed to
3976 "Script files" are command sequences that will be executed by
3977 U-Boot's command interpreter; this feature is especially
3978 useful when you configure U-Boot to use a real shell (hush)
3979 as command interpreter.
3985 One of the features of U-Boot is that you can dynamically load and
3986 run "standalone" applications, which can use some resources of
3987 U-Boot like console I/O functions or interrupt services.
3989 Two simple examples are included with the sources:
3994 'examples/hello_world.c' contains a small "Hello World" Demo
3995 application; it is automatically compiled when you build U-Boot.
3996 It's configured to run at address 0x00040004, so you can play with it
4000 ## Ready for S-Record download ...
4001 ~>examples/hello_world.srec
4002 1 2 3 4 5 6 7 8 9 10 11 ...
4003 [file transfer complete]
4005 ## Start Addr = 0x00040004
4007 => go 40004 Hello World! This is a test.
4008 ## Starting application at 0x00040004 ...
4019 Hit any key to exit ...
4021 ## Application terminated, rc = 0x0
4023 Another example, which demonstrates how to register a CPM interrupt
4024 handler with the U-Boot code, can be found in 'examples/timer.c'.
4025 Here, a CPM timer is set up to generate an interrupt every second.
4026 The interrupt service routine is trivial, just printing a '.'
4027 character, but this is just a demo program. The application can be
4028 controlled by the following keys:
4030 ? - print current values og the CPM Timer registers
4031 b - enable interrupts and start timer
4032 e - stop timer and disable interrupts
4033 q - quit application
4036 ## Ready for S-Record download ...
4037 ~>examples/timer.srec
4038 1 2 3 4 5 6 7 8 9 10 11 ...
4039 [file transfer complete]
4041 ## Start Addr = 0x00040004
4044 ## Starting application at 0x00040004 ...
4047 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
4050 [q, b, e, ?] Set interval 1000000 us
4053 [q, b, e, ?] ........
4054 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
4057 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
4060 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
4063 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
4065 [q, b, e, ?] ...Stopping timer
4067 [q, b, e, ?] ## Application terminated, rc = 0x0
4073 Over time, many people have reported problems when trying to use the
4074 "minicom" terminal emulation program for serial download. I (wd)
4075 consider minicom to be broken, and recommend not to use it. Under
4076 Unix, I recommend to use C-Kermit for general purpose use (and
4077 especially for kermit binary protocol download ("loadb" command), and
4078 use "cu" for S-Record download ("loads" command).
4080 Nevertheless, if you absolutely want to use it try adding this
4081 configuration to your "File transfer protocols" section:
4083 Name Program Name U/D FullScr IO-Red. Multi
4084 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
4085 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
4091 Starting at version 0.9.2, U-Boot supports NetBSD both as host
4092 (build U-Boot) and target system (boots NetBSD/mpc8xx).
4094 Building requires a cross environment; it is known to work on
4095 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
4096 need gmake since the Makefiles are not compatible with BSD make).
4097 Note that the cross-powerpc package does not install include files;
4098 attempting to build U-Boot will fail because <machine/ansi.h> is
4099 missing. This file has to be installed and patched manually:
4101 # cd /usr/pkg/cross/powerpc-netbsd/include
4103 # ln -s powerpc machine
4104 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
4105 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
4107 Native builds *don't* work due to incompatibilities between native
4108 and U-Boot include files.
4110 Booting assumes that (the first part of) the image booted is a
4111 stage-2 loader which in turn loads and then invokes the kernel
4112 proper. Loader sources will eventually appear in the NetBSD source
4113 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
4114 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
4117 Implementation Internals:
4118 =========================
4120 The following is not intended to be a complete description of every
4121 implementation detail. However, it should help to understand the
4122 inner workings of U-Boot and make it easier to port it to custom
4126 Initial Stack, Global Data:
4127 ---------------------------
4129 The implementation of U-Boot is complicated by the fact that U-Boot
4130 starts running out of ROM (flash memory), usually without access to
4131 system RAM (because the memory controller is not initialized yet).
4132 This means that we don't have writable Data or BSS segments, and BSS
4133 is not initialized as zero. To be able to get a C environment working
4134 at all, we have to allocate at least a minimal stack. Implementation
4135 options for this are defined and restricted by the CPU used: Some CPU
4136 models provide on-chip memory (like the IMMR area on MPC8xx and
4137 MPC826x processors), on others (parts of) the data cache can be
4138 locked as (mis-) used as memory, etc.
4140 Chris Hallinan posted a good summary of these issues to the
4141 U-Boot mailing list:
4143 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
4144 From: "Chris Hallinan" <clh@net1plus.com>
4145 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
4148 Correct me if I'm wrong, folks, but the way I understand it
4149 is this: Using DCACHE as initial RAM for Stack, etc, does not
4150 require any physical RAM backing up the cache. The cleverness
4151 is that the cache is being used as a temporary supply of
4152 necessary storage before the SDRAM controller is setup. It's
4153 beyond the scope of this list to explain the details, but you
4154 can see how this works by studying the cache architecture and
4155 operation in the architecture and processor-specific manuals.
4157 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4158 is another option for the system designer to use as an
4159 initial stack/RAM area prior to SDRAM being available. Either
4160 option should work for you. Using CS 4 should be fine if your
4161 board designers haven't used it for something that would
4162 cause you grief during the initial boot! It is frequently not
4165 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
4166 with your processor/board/system design. The default value
4167 you will find in any recent u-boot distribution in
4168 walnut.h should work for you. I'd set it to a value larger
4169 than your SDRAM module. If you have a 64MB SDRAM module, set
4170 it above 400_0000. Just make sure your board has no resources
4171 that are supposed to respond to that address! That code in
4172 start.S has been around a while and should work as is when
4173 you get the config right.
4178 It is essential to remember this, since it has some impact on the C
4179 code for the initialization procedures:
4181 * Initialized global data (data segment) is read-only. Do not attempt
4184 * Do not use any uninitialized global data (or implicitely initialized
4185 as zero data - BSS segment) at all - this is undefined, initiali-
4186 zation is performed later (when relocating to RAM).
4188 * Stack space is very limited. Avoid big data buffers or things like
4191 Having only the stack as writable memory limits means we cannot use
4192 normal global data to share information beween the code. But it
4193 turned out that the implementation of U-Boot can be greatly
4194 simplified by making a global data structure (gd_t) available to all
4195 functions. We could pass a pointer to this data as argument to _all_
4196 functions, but this would bloat the code. Instead we use a feature of
4197 the GCC compiler (Global Register Variables) to share the data: we
4198 place a pointer (gd) to the global data into a register which we
4199 reserve for this purpose.
4201 When choosing a register for such a purpose we are restricted by the
4202 relevant (E)ABI specifications for the current architecture, and by
4203 GCC's implementation.
4205 For PowerPC, the following registers have specific use:
4207 R2: reserved for system use
4208 R3-R4: parameter passing and return values
4209 R5-R10: parameter passing
4210 R13: small data area pointer
4214 (U-Boot also uses R12 as internal GOT pointer. r12
4215 is a volatile register so r12 needs to be reset when
4216 going back and forth between asm and C)
4218 ==> U-Boot will use R2 to hold a pointer to the global data
4220 Note: on PPC, we could use a static initializer (since the
4221 address of the global data structure is known at compile time),
4222 but it turned out that reserving a register results in somewhat
4223 smaller code - although the code savings are not that big (on
4224 average for all boards 752 bytes for the whole U-Boot image,
4225 624 text + 127 data).
4227 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
4228 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
4230 ==> U-Boot will use P3 to hold a pointer to the global data
4232 On ARM, the following registers are used:
4234 R0: function argument word/integer result
4235 R1-R3: function argument word
4237 R10: stack limit (used only if stack checking if enabled)
4238 R11: argument (frame) pointer
4239 R12: temporary workspace
4242 R15: program counter
4244 ==> U-Boot will use R8 to hold a pointer to the global data
4246 On Nios II, the ABI is documented here:
4247 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4249 ==> U-Boot will use gp to hold a pointer to the global data
4251 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4252 to access small data sections, so gp is free.
4254 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4255 or current versions of GCC may "optimize" the code too much.
4260 U-Boot runs in system state and uses physical addresses, i.e. the
4261 MMU is not used either for address mapping nor for memory protection.
4263 The available memory is mapped to fixed addresses using the memory
4264 controller. In this process, a contiguous block is formed for each
4265 memory type (Flash, SDRAM, SRAM), even when it consists of several
4266 physical memory banks.
4268 U-Boot is installed in the first 128 kB of the first Flash bank (on
4269 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4270 booting and sizing and initializing DRAM, the code relocates itself
4271 to the upper end of DRAM. Immediately below the U-Boot code some
4272 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
4273 configuration setting]. Below that, a structure with global Board
4274 Info data is placed, followed by the stack (growing downward).
4276 Additionally, some exception handler code is copied to the low 8 kB
4277 of DRAM (0x00000000 ... 0x00001FFF).
4279 So a typical memory configuration with 16 MB of DRAM could look like
4282 0x0000 0000 Exception Vector code
4285 0x0000 2000 Free for Application Use
4291 0x00FB FF20 Monitor Stack (Growing downward)
4292 0x00FB FFAC Board Info Data and permanent copy of global data
4293 0x00FC 0000 Malloc Arena
4296 0x00FE 0000 RAM Copy of Monitor Code
4297 ... eventually: LCD or video framebuffer
4298 ... eventually: pRAM (Protected RAM - unchanged by reset)
4299 0x00FF FFFF [End of RAM]
4302 System Initialization:
4303 ----------------------
4305 In the reset configuration, U-Boot starts at the reset entry point
4306 (on most PowerPC systems at address 0x00000100). Because of the reset
4307 configuration for CS0# this is a mirror of the onboard Flash memory.
4308 To be able to re-map memory U-Boot then jumps to its link address.
4309 To be able to implement the initialization code in C, a (small!)
4310 initial stack is set up in the internal Dual Ported RAM (in case CPUs
4311 which provide such a feature like MPC8xx or MPC8260), or in a locked
4312 part of the data cache. After that, U-Boot initializes the CPU core,
4313 the caches and the SIU.
4315 Next, all (potentially) available memory banks are mapped using a
4316 preliminary mapping. For example, we put them on 512 MB boundaries
4317 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4318 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4319 programmed for SDRAM access. Using the temporary configuration, a
4320 simple memory test is run that determines the size of the SDRAM
4323 When there is more than one SDRAM bank, and the banks are of
4324 different size, the largest is mapped first. For equal size, the first
4325 bank (CS2#) is mapped first. The first mapping is always for address
4326 0x00000000, with any additional banks following immediately to create
4327 contiguous memory starting from 0.
4329 Then, the monitor installs itself at the upper end of the SDRAM area
4330 and allocates memory for use by malloc() and for the global Board
4331 Info data; also, the exception vector code is copied to the low RAM
4332 pages, and the final stack is set up.
4334 Only after this relocation will you have a "normal" C environment;
4335 until that you are restricted in several ways, mostly because you are
4336 running from ROM, and because the code will have to be relocated to a
4340 U-Boot Porting Guide:
4341 ----------------------
4343 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4347 int main(int argc, char *argv[])
4349 sighandler_t no_more_time;
4351 signal(SIGALRM, no_more_time);
4352 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4354 if (available_money > available_manpower) {
4355 Pay consultant to port U-Boot;
4359 Download latest U-Boot source;
4361 Subscribe to u-boot mailing list;
4364 email("Hi, I am new to U-Boot, how do I get started?");
4367 Read the README file in the top level directory;
4368 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4369 Read applicable doc/*.README;
4370 Read the source, Luke;
4371 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4374 if (available_money > toLocalCurrency ($2500))
4377 Add a lot of aggravation and time;
4379 if (a similar board exists) { /* hopefully... */
4380 cp -a board/<similar> board/<myboard>
4381 cp include/configs/<similar>.h include/configs/<myboard>.h
4383 Create your own board support subdirectory;
4384 Create your own board include/configs/<myboard>.h file;
4386 Edit new board/<myboard> files
4387 Edit new include/configs/<myboard>.h
4392 Add / modify source code;
4396 email("Hi, I am having problems...");
4398 Send patch file to the U-Boot email list;
4399 if (reasonable critiques)
4400 Incorporate improvements from email list code review;
4402 Defend code as written;
4408 void no_more_time (int sig)
4417 All contributions to U-Boot should conform to the Linux kernel
4418 coding style; see the file "Documentation/CodingStyle" and the script
4419 "scripts/Lindent" in your Linux kernel source directory. In sources
4420 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
4421 spaces before parameters to function calls) is actually used.
4423 Source files originating from a different project (for example the
4424 MTD subsystem) are generally exempt from these guidelines and are not
4425 reformated to ease subsequent migration to newer versions of those
4428 Please note that U-Boot is implemented in C (and to some small parts in
4429 Assembler); no C++ is used, so please do not use C++ style comments (//)
4432 Please also stick to the following formatting rules:
4433 - remove any trailing white space
4434 - use TAB characters for indentation, not spaces
4435 - make sure NOT to use DOS '\r\n' line feeds
4436 - do not add more than 2 empty lines to source files
4437 - do not add trailing empty lines to source files
4439 Submissions which do not conform to the standards may be returned
4440 with a request to reformat the changes.
4446 Since the number of patches for U-Boot is growing, we need to
4447 establish some rules. Submissions which do not conform to these rules
4448 may be rejected, even when they contain important and valuable stuff.
4450 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4452 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4453 see http://lists.denx.de/mailman/listinfo/u-boot
4455 When you send a patch, please include the following information with
4458 * For bug fixes: a description of the bug and how your patch fixes
4459 this bug. Please try to include a way of demonstrating that the
4460 patch actually fixes something.
4462 * For new features: a description of the feature and your
4465 * A CHANGELOG entry as plaintext (separate from the patch)
4467 * For major contributions, your entry to the CREDITS file
4469 * When you add support for a new board, don't forget to add this
4470 board to the MAKEALL script, too.
4472 * If your patch adds new configuration options, don't forget to
4473 document these in the README file.
4475 * The patch itself. If you are using git (which is *strongly*
4476 recommended) you can easily generate the patch using the
4477 "git-format-patch". If you then use "git-send-email" to send it to
4478 the U-Boot mailing list, you will avoid most of the common problems
4479 with some other mail clients.
4481 If you cannot use git, use "diff -purN OLD NEW". If your version of
4482 diff does not support these options, then get the latest version of
4485 The current directory when running this command shall be the parent
4486 directory of the U-Boot source tree (i. e. please make sure that
4487 your patch includes sufficient directory information for the
4490 We prefer patches as plain text. MIME attachments are discouraged,
4491 and compressed attachments must not be used.
4493 * If one logical set of modifications affects or creates several
4494 files, all these changes shall be submitted in a SINGLE patch file.
4496 * Changesets that contain different, unrelated modifications shall be
4497 submitted as SEPARATE patches, one patch per changeset.
4502 * Before sending the patch, run the MAKEALL script on your patched
4503 source tree and make sure that no errors or warnings are reported
4504 for any of the boards.
4506 * Keep your modifications to the necessary minimum: A patch
4507 containing several unrelated changes or arbitrary reformats will be
4508 returned with a request to re-formatting / split it.
4510 * If you modify existing code, make sure that your new code does not
4511 add to the memory footprint of the code ;-) Small is beautiful!
4512 When adding new features, these should compile conditionally only
4513 (using #ifdef), and the resulting code with the new feature
4514 disabled must not need more memory than the old code without your
4517 * Remember that there is a size limit of 100 kB per message on the
4518 u-boot mailing list. Bigger patches will be moderated. If they are
4519 reasonable and not too big, they will be acknowledged. But patches
4520 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob