2 # (C) Copyright 2000 - 2009
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.
359 - Intel Monahans options:
360 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
362 Defines the Monahans run mode to oscillator
363 ratio. Valid values are 8, 16, 24, 31. The core
364 frequency is this value multiplied by 13 MHz.
366 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
368 Defines the Monahans turbo mode to oscillator
369 ratio. Valid values are 1 (default if undefined) and
370 2. The core frequency as calculated above is multiplied
373 - Linux Kernel Interface:
376 U-Boot stores all clock information in Hz
377 internally. For binary compatibility with older Linux
378 kernels (which expect the clocks passed in the
379 bd_info data to be in MHz) the environment variable
380 "clocks_in_mhz" can be defined so that U-Boot
381 converts clock data to MHZ before passing it to the
383 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
384 "clocks_in_mhz=1" is automatically included in the
387 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
389 When transferring memsize parameter to linux, some versions
390 expect it to be in bytes, others in MB.
391 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
395 New kernel versions are expecting firmware settings to be
396 passed using flattened device trees (based on open firmware
400 * New libfdt-based support
401 * Adds the "fdt" command
402 * The bootm command automatically updates the fdt
404 OF_CPU - The proper name of the cpus node (only required for
405 MPC512X and MPC5xxx based boards).
406 OF_SOC - The proper name of the soc node (only required for
407 MPC512X and MPC5xxx based boards).
408 OF_TBCLK - The timebase frequency.
409 OF_STDOUT_PATH - The path to the console device
411 boards with QUICC Engines require OF_QE to set UCC MAC
414 CONFIG_OF_BOARD_SETUP
416 Board code has addition modification that it wants to make
417 to the flat device tree before handing it off to the kernel
421 This define fills in the correct boot CPU in the boot
422 param header, the default value is zero if undefined.
426 U-Boot can detect if an IDE device is present or not.
427 If not, and this new config option is activated, U-Boot
428 removes the ATA node from the DTS before booting Linux,
429 so the Linux IDE driver does not probe the device and
430 crash. This is needed for buggy hardware (uc101) where
431 no pull down resistor is connected to the signal IDE5V_DD7.
433 - vxWorks boot parameters:
435 bootvx constructs a valid bootline using the following
436 environments variables: bootfile, ipaddr, serverip, hostname.
437 It loads the vxWorks image pointed bootfile.
439 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
440 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
441 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
442 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
444 CONFIG_SYS_VXWORKS_ADD_PARAMS
446 Add it at the end of the bootline. E.g "u=username pw=secret"
448 Note: If a "bootargs" environment is defined, it will overwride
449 the defaults discussed just above.
454 Define this if you want support for Amba PrimeCell PL010 UARTs.
458 Define this if you want support for Amba PrimeCell PL011 UARTs.
462 If you have Amba PrimeCell PL011 UARTs, set this variable to
463 the clock speed of the UARTs.
467 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
468 define this to a list of base addresses for each (supported)
469 port. See e.g. include/configs/versatile.h
473 Depending on board, define exactly one serial port
474 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
475 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
476 console by defining CONFIG_8xx_CONS_NONE
478 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
479 port routines must be defined elsewhere
480 (i.e. serial_init(), serial_getc(), ...)
483 Enables console device for a color framebuffer. Needs following
484 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
485 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
487 VIDEO_HW_RECTFILL graphic chip supports
490 VIDEO_HW_BITBLT graphic chip supports
491 bit-blit (cf. smiLynxEM)
492 VIDEO_VISIBLE_COLS visible pixel columns
494 VIDEO_VISIBLE_ROWS visible pixel rows
495 VIDEO_PIXEL_SIZE bytes per pixel
496 VIDEO_DATA_FORMAT graphic data format
497 (0-5, cf. cfb_console.c)
498 VIDEO_FB_ADRS framebuffer address
499 VIDEO_KBD_INIT_FCT keyboard int fct
500 (i.e. i8042_kbd_init())
501 VIDEO_TSTC_FCT test char fct
503 VIDEO_GETC_FCT get char fct
505 CONFIG_CONSOLE_CURSOR cursor drawing on/off
506 (requires blink timer
508 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
509 CONFIG_CONSOLE_TIME display time/date info in
511 (requires CONFIG_CMD_DATE)
512 CONFIG_VIDEO_LOGO display Linux logo in
514 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
515 linux_logo.h for logo.
516 Requires CONFIG_VIDEO_LOGO
517 CONFIG_CONSOLE_EXTRA_INFO
518 additional board info beside
521 When CONFIG_CFB_CONSOLE is defined, video console is
522 default i/o. Serial console can be forced with
523 environment 'console=serial'.
525 When CONFIG_SILENT_CONSOLE is defined, all console
526 messages (by U-Boot and Linux!) can be silenced with
527 the "silent" environment variable. See
528 doc/README.silent for more information.
531 CONFIG_BAUDRATE - in bps
532 Select one of the baudrates listed in
533 CONFIG_SYS_BAUDRATE_TABLE, see below.
534 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
536 - Console Rx buffer length
537 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
538 the maximum receive buffer length for the SMC.
539 This option is actual only for 82xx and 8xx possible.
540 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
541 must be defined, to setup the maximum idle timeout for
544 - Boot Delay: CONFIG_BOOTDELAY - in seconds
545 Delay before automatically booting the default image;
546 set to -1 to disable autoboot.
548 See doc/README.autoboot for these options that
549 work with CONFIG_BOOTDELAY. None are required.
550 CONFIG_BOOT_RETRY_TIME
551 CONFIG_BOOT_RETRY_MIN
552 CONFIG_AUTOBOOT_KEYED
553 CONFIG_AUTOBOOT_PROMPT
554 CONFIG_AUTOBOOT_DELAY_STR
555 CONFIG_AUTOBOOT_STOP_STR
556 CONFIG_AUTOBOOT_DELAY_STR2
557 CONFIG_AUTOBOOT_STOP_STR2
558 CONFIG_ZERO_BOOTDELAY_CHECK
559 CONFIG_RESET_TO_RETRY
563 Only needed when CONFIG_BOOTDELAY is enabled;
564 define a command string that is automatically executed
565 when no character is read on the console interface
566 within "Boot Delay" after reset.
569 This can be used to pass arguments to the bootm
570 command. The value of CONFIG_BOOTARGS goes into the
571 environment value "bootargs".
573 CONFIG_RAMBOOT and CONFIG_NFSBOOT
574 The value of these goes into the environment as
575 "ramboot" and "nfsboot" respectively, and can be used
576 as a convenience, when switching between booting from
582 When this option is #defined, the existence of the
583 environment variable "preboot" will be checked
584 immediately before starting the CONFIG_BOOTDELAY
585 countdown and/or running the auto-boot command resp.
586 entering interactive mode.
588 This feature is especially useful when "preboot" is
589 automatically generated or modified. For an example
590 see the LWMON board specific code: here "preboot" is
591 modified when the user holds down a certain
592 combination of keys on the (special) keyboard when
595 - Serial Download Echo Mode:
597 If defined to 1, all characters received during a
598 serial download (using the "loads" command) are
599 echoed back. This might be needed by some terminal
600 emulations (like "cu"), but may as well just take
601 time on others. This setting #define's the initial
602 value of the "loads_echo" environment variable.
604 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
606 Select one of the baudrates listed in
607 CONFIG_SYS_BAUDRATE_TABLE, see below.
610 Monitor commands can be included or excluded
611 from the build by using the #include files
612 "config_cmd_all.h" and #undef'ing unwanted
613 commands, or using "config_cmd_default.h"
614 and augmenting with additional #define's
617 The default command configuration includes all commands
618 except those marked below with a "*".
620 CONFIG_CMD_ASKENV * ask for env variable
621 CONFIG_CMD_BDI bdinfo
622 CONFIG_CMD_BEDBUG * Include BedBug Debugger
623 CONFIG_CMD_BMP * BMP support
624 CONFIG_CMD_BSP * Board specific commands
625 CONFIG_CMD_BOOTD bootd
626 CONFIG_CMD_CACHE * icache, dcache
627 CONFIG_CMD_CONSOLE coninfo
628 CONFIG_CMD_CRC32 * crc32
629 CONFIG_CMD_DATE * support for RTC, date/time...
630 CONFIG_CMD_DHCP * DHCP support
631 CONFIG_CMD_DIAG * Diagnostics
632 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
633 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
634 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
635 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
636 CONFIG_CMD_DTT * Digital Therm and Thermostat
637 CONFIG_CMD_ECHO echo arguments
638 CONFIG_CMD_EDITENV edit env variable
639 CONFIG_CMD_EEPROM * EEPROM read/write support
640 CONFIG_CMD_ELF * bootelf, bootvx
641 CONFIG_CMD_EXPORTENV * export the environment
642 CONFIG_CMD_SAVEENV saveenv
643 CONFIG_CMD_FDC * Floppy Disk Support
644 CONFIG_CMD_FAT * FAT partition support
645 CONFIG_CMD_FDOS * Dos diskette Support
646 CONFIG_CMD_FLASH flinfo, erase, protect
647 CONFIG_CMD_FPGA FPGA device initialization support
648 CONFIG_CMD_GO * the 'go' command (exec code)
649 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
650 CONFIG_CMD_I2C * I2C serial bus support
651 CONFIG_CMD_IDE * IDE harddisk support
652 CONFIG_CMD_IMI iminfo
653 CONFIG_CMD_IMLS List all found images
654 CONFIG_CMD_IMMAP * IMMR dump support
655 CONFIG_CMD_IMPORTENV * import an environment
656 CONFIG_CMD_IRQ * irqinfo
657 CONFIG_CMD_ITEST Integer/string test of 2 values
658 CONFIG_CMD_JFFS2 * JFFS2 Support
659 CONFIG_CMD_KGDB * kgdb
660 CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
661 CONFIG_CMD_LOADB loadb
662 CONFIG_CMD_LOADS loads
663 CONFIG_CMD_MD5SUM print md5 message digest
664 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
665 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
667 CONFIG_CMD_MISC Misc functions like sleep etc
668 CONFIG_CMD_MMC * MMC memory mapped support
669 CONFIG_CMD_MII * MII utility commands
670 CONFIG_CMD_MTDPARTS * MTD partition support
671 CONFIG_CMD_NAND * NAND support
672 CONFIG_CMD_NET bootp, tftpboot, rarpboot
673 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
674 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
675 CONFIG_CMD_PCI * pciinfo
676 CONFIG_CMD_PCMCIA * PCMCIA support
677 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
679 CONFIG_CMD_PORTIO * Port I/O
680 CONFIG_CMD_REGINFO * Register dump
681 CONFIG_CMD_RUN run command in env variable
682 CONFIG_CMD_SAVES * save S record dump
683 CONFIG_CMD_SCSI * SCSI Support
684 CONFIG_CMD_SDRAM * print SDRAM configuration information
685 (requires CONFIG_CMD_I2C)
686 CONFIG_CMD_SETGETDCR Support for DCR Register access
688 CONFIG_CMD_SHA1SUM print sha1 memory digest
689 (requires CONFIG_CMD_MEMORY)
690 CONFIG_CMD_SOURCE "source" command Support
691 CONFIG_CMD_SPI * SPI serial bus support
692 CONFIG_CMD_USB * USB support
693 CONFIG_CMD_VFD * VFD support (TRAB)
694 CONFIG_CMD_CDP * Cisco Discover Protocol support
695 CONFIG_CMD_FSL * Microblaze FSL support
698 EXAMPLE: If you want all functions except of network
699 support you can write:
701 #include "config_cmd_all.h"
702 #undef CONFIG_CMD_NET
705 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
707 Note: Don't enable the "icache" and "dcache" commands
708 (configuration option CONFIG_CMD_CACHE) unless you know
709 what you (and your U-Boot users) are doing. Data
710 cache cannot be enabled on systems like the 8xx or
711 8260 (where accesses to the IMMR region must be
712 uncached), and it cannot be disabled on all other
713 systems where we (mis-) use the data cache to hold an
714 initial stack and some data.
717 XXX - this list needs to get updated!
721 If this variable is defined, it enables watchdog
722 support. There must be support in the platform specific
723 code for a watchdog. For the 8xx and 8260 CPUs, the
724 SIU Watchdog feature is enabled in the SYPCR
728 CONFIG_VERSION_VARIABLE
729 If this variable is defined, an environment variable
730 named "ver" is created by U-Boot showing the U-Boot
731 version as printed by the "version" command.
732 This variable is readonly.
736 When CONFIG_CMD_DATE is selected, the type of the RTC
737 has to be selected, too. Define exactly one of the
740 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
741 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
742 CONFIG_RTC_MC13783 - use MC13783 RTC
743 CONFIG_RTC_MC146818 - use MC146818 RTC
744 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
745 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
746 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
747 CONFIG_RTC_DS164x - use Dallas DS164x RTC
748 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
749 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
750 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
751 CONFIG_SYS_RV3029_TCR - enable trickle charger on
754 Note that if the RTC uses I2C, then the I2C interface
755 must also be configured. See I2C Support, below.
758 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
759 CONFIG_PCA953X_INFO - enable pca953x info command
761 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
762 chip-ngpio pairs that tell the PCA953X driver the number of
763 pins supported by a particular chip.
765 Note that if the GPIO device uses I2C, then the I2C interface
766 must also be configured. See I2C Support, below.
770 When CONFIG_TIMESTAMP is selected, the timestamp
771 (date and time) of an image is printed by image
772 commands like bootm or iminfo. This option is
773 automatically enabled when you select CONFIG_CMD_DATE .
776 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
777 and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION
779 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
780 CONFIG_CMD_SCSI) you must configure support for at
781 least one partition type as well.
784 CONFIG_IDE_RESET_ROUTINE - this is defined in several
785 board configurations files but used nowhere!
787 CONFIG_IDE_RESET - is this is defined, IDE Reset will
788 be performed by calling the function
789 ide_set_reset(int reset)
790 which has to be defined in a board specific file
795 Set this to enable ATAPI support.
800 Set this to enable support for disks larger than 137GB
801 Also look at CONFIG_SYS_64BIT_LBA.
802 Whithout these , LBA48 support uses 32bit variables and will 'only'
803 support disks up to 2.1TB.
805 CONFIG_SYS_64BIT_LBA:
806 When enabled, makes the IDE subsystem use 64bit sector addresses.
810 At the moment only there is only support for the
811 SYM53C8XX SCSI controller; define
812 CONFIG_SCSI_SYM53C8XX to enable it.
814 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
815 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
816 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
817 maximum numbers of LUNs, SCSI ID's and target
819 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
821 - NETWORK Support (PCI):
823 Support for Intel 8254x gigabit chips.
825 CONFIG_E1000_FALLBACK_MAC
826 default MAC for empty EEPROM after production.
829 Support for Intel 82557/82559/82559ER chips.
830 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
831 write routine for first time initialisation.
834 Support for Digital 2114x chips.
835 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
836 modem chip initialisation (KS8761/QS6611).
839 Support for National dp83815 chips.
842 Support for National dp8382[01] gigabit chips.
844 - NETWORK Support (other):
846 CONFIG_DRIVER_AT91EMAC
847 Support for AT91RM9200 EMAC.
850 Define this to use reduced MII inteface
852 CONFIG_DRIVER_AT91EMAC_QUIET
853 If this defined, the driver is quiet.
854 The driver doen't show link status messages.
856 CONFIG_DRIVER_LAN91C96
857 Support for SMSC's LAN91C96 chips.
860 Define this to hold the physical address
861 of the LAN91C96's I/O space
863 CONFIG_LAN91C96_USE_32_BIT
864 Define this to enable 32 bit addressing
866 CONFIG_DRIVER_SMC91111
867 Support for SMSC's LAN91C111 chip
870 Define this to hold the physical address
871 of the device (I/O space)
873 CONFIG_SMC_USE_32_BIT
874 Define this if data bus is 32 bits
876 CONFIG_SMC_USE_IOFUNCS
877 Define this to use i/o functions instead of macros
878 (some hardware wont work with macros)
881 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
883 CONFIG_FTGMAC100_EGIGA
884 Define this to use GE link update with gigabit PHY.
885 Define this if FTGMAC100 is connected to gigabit PHY.
886 If your system has 10/100 PHY only, it might not occur
887 wrong behavior. Because PHY usually return timeout or
888 useless data when polling gigabit status and gigabit
889 control registers. This behavior won't affect the
890 correctnessof 10/100 link speed update.
893 Support for SMSC's LAN911x and LAN921x chips
896 Define this to hold the physical address
897 of the device (I/O space)
899 CONFIG_SMC911X_32_BIT
900 Define this if data bus is 32 bits
902 CONFIG_SMC911X_16_BIT
903 Define this if data bus is 16 bits. If your processor
904 automatically converts one 32 bit word to two 16 bit
905 words you may also try CONFIG_SMC911X_32_BIT.
908 Support for Renesas on-chip Ethernet controller
910 CONFIG_SH_ETHER_USE_PORT
911 Define the number of ports to be used
913 CONFIG_SH_ETHER_PHY_ADDR
914 Define the ETH PHY's address
916 CONFIG_SH_ETHER_CACHE_WRITEBACK
917 If this option is set, the driver enables cache flush.
920 At the moment only the UHCI host controller is
921 supported (PIP405, MIP405, MPC5200); define
922 CONFIG_USB_UHCI to enable it.
923 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
924 and define CONFIG_USB_STORAGE to enable the USB
927 Supported are USB Keyboards and USB Floppy drives
929 MPC5200 USB requires additional defines:
931 for 528 MHz Clock: 0x0001bbbb
935 for differential drivers: 0x00001000
936 for single ended drivers: 0x00005000
937 for differential drivers on PSC3: 0x00000100
938 for single ended drivers on PSC3: 0x00004100
939 CONFIG_SYS_USB_EVENT_POLL
940 May be defined to allow interrupt polling
941 instead of using asynchronous interrupts
944 Define the below if you wish to use the USB console.
945 Once firmware is rebuilt from a serial console issue the
946 command "setenv stdin usbtty; setenv stdout usbtty" and
947 attach your USB cable. The Unix command "dmesg" should print
948 it has found a new device. The environment variable usbtty
949 can be set to gserial or cdc_acm to enable your device to
950 appear to a USB host as a Linux gserial device or a
951 Common Device Class Abstract Control Model serial device.
952 If you select usbtty = gserial you should be able to enumerate
954 # modprobe usbserial vendor=0xVendorID product=0xProductID
955 else if using cdc_acm, simply setting the environment
956 variable usbtty to be cdc_acm should suffice. The following
957 might be defined in YourBoardName.h
960 Define this to build a UDC device
963 Define this to have a tty type of device available to
964 talk to the UDC device
966 CONFIG_SYS_CONSOLE_IS_IN_ENV
967 Define this if you want stdin, stdout &/or stderr to
971 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
972 Derive USB clock from external clock "blah"
973 - CONFIG_SYS_USB_EXTC_CLK 0x02
975 CONFIG_SYS_USB_BRG_CLK 0xBLAH
976 Derive USB clock from brgclk
977 - CONFIG_SYS_USB_BRG_CLK 0x04
979 If you have a USB-IF assigned VendorID then you may wish to
980 define your own vendor specific values either in BoardName.h
981 or directly in usbd_vendor_info.h. If you don't define
982 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
983 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
984 should pretend to be a Linux device to it's target host.
986 CONFIG_USBD_MANUFACTURER
987 Define this string as the name of your company for
988 - CONFIG_USBD_MANUFACTURER "my company"
990 CONFIG_USBD_PRODUCT_NAME
991 Define this string as the name of your product
992 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
995 Define this as your assigned Vendor ID from the USB
996 Implementors Forum. This *must* be a genuine Vendor ID
997 to avoid polluting the USB namespace.
998 - CONFIG_USBD_VENDORID 0xFFFF
1000 CONFIG_USBD_PRODUCTID
1001 Define this as the unique Product ID
1003 - CONFIG_USBD_PRODUCTID 0xFFFF
1007 The MMC controller on the Intel PXA is supported. To
1008 enable this define CONFIG_MMC. The MMC can be
1009 accessed from the boot prompt by mapping the device
1010 to physical memory similar to flash. Command line is
1011 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1012 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1014 - Journaling Flash filesystem support:
1015 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1016 CONFIG_JFFS2_NAND_DEV
1017 Define these for a default partition on a NAND device
1019 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1020 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1021 Define these for a default partition on a NOR device
1023 CONFIG_SYS_JFFS_CUSTOM_PART
1024 Define this to create an own partition. You have to provide a
1025 function struct part_info* jffs2_part_info(int part_num)
1027 If you define only one JFFS2 partition you may also want to
1028 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1029 to disable the command chpart. This is the default when you
1030 have not defined a custom partition
1035 Define this to enable standard (PC-Style) keyboard
1039 Standard PC keyboard driver with US (is default) and
1040 GERMAN key layout (switch via environment 'keymap=de') support.
1041 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1042 for cfb_console. Supports cursor blinking.
1047 Define this to enable video support (for output to
1050 CONFIG_VIDEO_CT69000
1052 Enable Chips & Technologies 69000 Video chip
1054 CONFIG_VIDEO_SMI_LYNXEM
1055 Enable Silicon Motion SMI 712/710/810 Video chip. The
1056 video output is selected via environment 'videoout'
1057 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1060 For the CT69000 and SMI_LYNXEM drivers, videomode is
1061 selected via environment 'videomode'. Two different ways
1063 - "videomode=num" 'num' is a standard LiLo mode numbers.
1064 Following standard modes are supported (* is default):
1066 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1067 -------------+---------------------------------------------
1068 8 bits | 0x301* 0x303 0x305 0x161 0x307
1069 15 bits | 0x310 0x313 0x316 0x162 0x319
1070 16 bits | 0x311 0x314 0x317 0x163 0x31A
1071 24 bits | 0x312 0x315 0x318 ? 0x31B
1072 -------------+---------------------------------------------
1073 (i.e. setenv videomode 317; saveenv; reset;)
1075 - "videomode=bootargs" all the video parameters are parsed
1076 from the bootargs. (See drivers/video/videomodes.c)
1079 CONFIG_VIDEO_SED13806
1080 Enable Epson SED13806 driver. This driver supports 8bpp
1081 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1082 or CONFIG_VIDEO_SED13806_16BPP
1085 Enable the Freescale DIU video driver. Reference boards for
1086 SOCs that have a DIU should define this macro to enable DIU
1087 support, and should also define these other macros:
1093 CONFIG_VIDEO_SW_CURSOR
1094 CONFIG_VGA_AS_SINGLE_DEVICE
1096 CONFIG_VIDEO_BMP_LOGO
1098 The DIU driver will look for the 'monitor' environment variable,
1099 and if defined, enable the DIU as a console during boot. This
1100 variable should be set to one of these values:
1102 '0' Output video to the DVI connector
1103 '1' Output video to the LVDS connector
1104 '2' Output video to the Dual-Link LVDS connector
1109 Define this to enable a custom keyboard support.
1110 This simply calls drv_keyboard_init() which must be
1111 defined in your board-specific files.
1112 The only board using this so far is RBC823.
1114 - LCD Support: CONFIG_LCD
1116 Define this to enable LCD support (for output to LCD
1117 display); also select one of the supported displays
1118 by defining one of these:
1122 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1124 CONFIG_NEC_NL6448AC33:
1126 NEC NL6448AC33-18. Active, color, single scan.
1128 CONFIG_NEC_NL6448BC20
1130 NEC NL6448BC20-08. 6.5", 640x480.
1131 Active, color, single scan.
1133 CONFIG_NEC_NL6448BC33_54
1135 NEC NL6448BC33-54. 10.4", 640x480.
1136 Active, color, single scan.
1140 Sharp 320x240. Active, color, single scan.
1141 It isn't 16x9, and I am not sure what it is.
1143 CONFIG_SHARP_LQ64D341
1145 Sharp LQ64D341 display, 640x480.
1146 Active, color, single scan.
1150 HLD1045 display, 640x480.
1151 Active, color, single scan.
1155 Optrex CBL50840-2 NF-FW 99 22 M5
1157 Hitachi LMG6912RPFC-00T
1161 320x240. Black & white.
1163 Normally display is black on white background; define
1164 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1166 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1168 If this option is set, the environment is checked for
1169 a variable "splashimage". If found, the usual display
1170 of logo, copyright and system information on the LCD
1171 is suppressed and the BMP image at the address
1172 specified in "splashimage" is loaded instead. The
1173 console is redirected to the "nulldev", too. This
1174 allows for a "silent" boot where a splash screen is
1175 loaded very quickly after power-on.
1177 CONFIG_SPLASH_SCREEN_ALIGN
1179 If this option is set the splash image can be freely positioned
1180 on the screen. Environment variable "splashpos" specifies the
1181 position as "x,y". If a positive number is given it is used as
1182 number of pixel from left/top. If a negative number is given it
1183 is used as number of pixel from right/bottom. You can also
1184 specify 'm' for centering the image.
1187 setenv splashpos m,m
1188 => image at center of screen
1190 setenv splashpos 30,20
1191 => image at x = 30 and y = 20
1193 setenv splashpos -10,m
1194 => vertically centered image
1195 at x = dspWidth - bmpWidth - 9
1197 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1199 If this option is set, additionally to standard BMP
1200 images, gzipped BMP images can be displayed via the
1201 splashscreen support or the bmp command.
1203 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1205 If this option is set, 8-bit RLE compressed BMP images
1206 can be displayed via the splashscreen support or the
1209 - Compression support:
1212 If this option is set, support for bzip2 compressed
1213 images is included. If not, only uncompressed and gzip
1214 compressed images are supported.
1216 NOTE: the bzip2 algorithm requires a lot of RAM, so
1217 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1222 If this option is set, support for lzma compressed
1225 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1226 requires an amount of dynamic memory that is given by the
1229 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1231 Where lc and lp stand for, respectively, Literal context bits
1232 and Literal pos bits.
1234 This value is upper-bounded by 14MB in the worst case. Anyway,
1235 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1236 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1237 a very small buffer.
1239 Use the lzmainfo tool to determinate the lc and lp values and
1240 then calculate the amount of needed dynamic memory (ensuring
1241 the appropriate CONFIG_SYS_MALLOC_LEN value).
1246 The address of PHY on MII bus.
1248 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1250 The clock frequency of the MII bus
1254 If this option is set, support for speed/duplex
1255 detection of gigabit PHY is included.
1257 CONFIG_PHY_RESET_DELAY
1259 Some PHY like Intel LXT971A need extra delay after
1260 reset before any MII register access is possible.
1261 For such PHY, set this option to the usec delay
1262 required. (minimum 300usec for LXT971A)
1264 CONFIG_PHY_CMD_DELAY (ppc4xx)
1266 Some PHY like Intel LXT971A need extra delay after
1267 command issued before MII status register can be read
1277 Define a default value for Ethernet address to use
1278 for the respective Ethernet interface, in case this
1279 is not determined automatically.
1284 Define a default value for the IP address to use for
1285 the default Ethernet interface, in case this is not
1286 determined through e.g. bootp.
1288 - Server IP address:
1291 Defines a default value for the IP address of a TFTP
1292 server to contact when using the "tftboot" command.
1294 CONFIG_KEEP_SERVERADDR
1296 Keeps the server's MAC address, in the env 'serveraddr'
1297 for passing to bootargs (like Linux's netconsole option)
1299 - Multicast TFTP Mode:
1302 Defines whether you want to support multicast TFTP as per
1303 rfc-2090; for example to work with atftp. Lets lots of targets
1304 tftp down the same boot image concurrently. Note: the Ethernet
1305 driver in use must provide a function: mcast() to join/leave a
1308 CONFIG_BOOTP_RANDOM_DELAY
1309 - BOOTP Recovery Mode:
1310 CONFIG_BOOTP_RANDOM_DELAY
1312 If you have many targets in a network that try to
1313 boot using BOOTP, you may want to avoid that all
1314 systems send out BOOTP requests at precisely the same
1315 moment (which would happen for instance at recovery
1316 from a power failure, when all systems will try to
1317 boot, thus flooding the BOOTP server. Defining
1318 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1319 inserted before sending out BOOTP requests. The
1320 following delays are inserted then:
1322 1st BOOTP request: delay 0 ... 1 sec
1323 2nd BOOTP request: delay 0 ... 2 sec
1324 3rd BOOTP request: delay 0 ... 4 sec
1326 BOOTP requests: delay 0 ... 8 sec
1328 - DHCP Advanced Options:
1329 You can fine tune the DHCP functionality by defining
1330 CONFIG_BOOTP_* symbols:
1332 CONFIG_BOOTP_SUBNETMASK
1333 CONFIG_BOOTP_GATEWAY
1334 CONFIG_BOOTP_HOSTNAME
1335 CONFIG_BOOTP_NISDOMAIN
1336 CONFIG_BOOTP_BOOTPATH
1337 CONFIG_BOOTP_BOOTFILESIZE
1340 CONFIG_BOOTP_SEND_HOSTNAME
1341 CONFIG_BOOTP_NTPSERVER
1342 CONFIG_BOOTP_TIMEOFFSET
1343 CONFIG_BOOTP_VENDOREX
1345 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1346 environment variable, not the BOOTP server.
1348 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1349 serverip from a DHCP server, it is possible that more
1350 than one DNS serverip is offered to the client.
1351 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1352 serverip will be stored in the additional environment
1353 variable "dnsip2". The first DNS serverip is always
1354 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1357 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1358 to do a dynamic update of a DNS server. To do this, they
1359 need the hostname of the DHCP requester.
1360 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1361 of the "hostname" environment variable is passed as
1362 option 12 to the DHCP server.
1364 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1366 A 32bit value in microseconds for a delay between
1367 receiving a "DHCP Offer" and sending the "DHCP Request".
1368 This fixes a problem with certain DHCP servers that don't
1369 respond 100% of the time to a "DHCP request". E.g. On an
1370 AT91RM9200 processor running at 180MHz, this delay needed
1371 to be *at least* 15,000 usec before a Windows Server 2003
1372 DHCP server would reply 100% of the time. I recommend at
1373 least 50,000 usec to be safe. The alternative is to hope
1374 that one of the retries will be successful but note that
1375 the DHCP timeout and retry process takes a longer than
1379 CONFIG_CDP_DEVICE_ID
1381 The device id used in CDP trigger frames.
1383 CONFIG_CDP_DEVICE_ID_PREFIX
1385 A two character string which is prefixed to the MAC address
1390 A printf format string which contains the ascii name of
1391 the port. Normally is set to "eth%d" which sets
1392 eth0 for the first Ethernet, eth1 for the second etc.
1394 CONFIG_CDP_CAPABILITIES
1396 A 32bit integer which indicates the device capabilities;
1397 0x00000010 for a normal host which does not forwards.
1401 An ascii string containing the version of the software.
1405 An ascii string containing the name of the platform.
1409 A 32bit integer sent on the trigger.
1411 CONFIG_CDP_POWER_CONSUMPTION
1413 A 16bit integer containing the power consumption of the
1414 device in .1 of milliwatts.
1416 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1418 A byte containing the id of the VLAN.
1420 - Status LED: CONFIG_STATUS_LED
1422 Several configurations allow to display the current
1423 status using a LED. For instance, the LED will blink
1424 fast while running U-Boot code, stop blinking as
1425 soon as a reply to a BOOTP request was received, and
1426 start blinking slow once the Linux kernel is running
1427 (supported by a status LED driver in the Linux
1428 kernel). Defining CONFIG_STATUS_LED enables this
1431 - CAN Support: CONFIG_CAN_DRIVER
1433 Defining CONFIG_CAN_DRIVER enables CAN driver support
1434 on those systems that support this (optional)
1435 feature, like the TQM8xxL modules.
1437 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1439 These enable I2C serial bus commands. Defining either of
1440 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1441 include the appropriate I2C driver for the selected CPU.
1443 This will allow you to use i2c commands at the u-boot
1444 command line (as long as you set CONFIG_CMD_I2C in
1445 CONFIG_COMMANDS) and communicate with i2c based realtime
1446 clock chips. See common/cmd_i2c.c for a description of the
1447 command line interface.
1449 CONFIG_HARD_I2C selects a hardware I2C controller.
1451 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1452 bit-banging) driver instead of CPM or similar hardware
1455 There are several other quantities that must also be
1456 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1458 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1459 to be the frequency (in Hz) at which you wish your i2c bus
1460 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1461 the CPU's i2c node address).
1463 Now, the u-boot i2c code for the mpc8xx
1464 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1465 and so its address should therefore be cleared to 0 (See,
1466 eg, MPC823e User's Manual p.16-473). So, set
1467 CONFIG_SYS_I2C_SLAVE to 0.
1469 CONFIG_SYS_I2C_INIT_MPC5XXX
1471 When a board is reset during an i2c bus transfer
1472 chips might think that the current transfer is still
1473 in progress. Reset the slave devices by sending start
1474 commands until the slave device responds.
1476 That's all that's required for CONFIG_HARD_I2C.
1478 If you use the software i2c interface (CONFIG_SOFT_I2C)
1479 then the following macros need to be defined (examples are
1480 from include/configs/lwmon.h):
1484 (Optional). Any commands necessary to enable the I2C
1485 controller or configure ports.
1487 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1491 (Only for MPC8260 CPU). The I/O port to use (the code
1492 assumes both bits are on the same port). Valid values
1493 are 0..3 for ports A..D.
1497 The code necessary to make the I2C data line active
1498 (driven). If the data line is open collector, this
1501 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1505 The code necessary to make the I2C data line tri-stated
1506 (inactive). If the data line is open collector, this
1509 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1513 Code that returns TRUE if the I2C data line is high,
1516 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1520 If <bit> is TRUE, sets the I2C data line high. If it
1521 is FALSE, it clears it (low).
1523 eg: #define I2C_SDA(bit) \
1524 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1525 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1529 If <bit> is TRUE, sets the I2C clock line high. If it
1530 is FALSE, it clears it (low).
1532 eg: #define I2C_SCL(bit) \
1533 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1534 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1538 This delay is invoked four times per clock cycle so this
1539 controls the rate of data transfer. The data rate thus
1540 is 1 / (I2C_DELAY * 4). Often defined to be something
1543 #define I2C_DELAY udelay(2)
1545 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1547 If your arch supports the generic GPIO framework (asm/gpio.h),
1548 then you may alternatively define the two GPIOs that are to be
1549 used as SCL / SDA. Any of the previous I2C_xxx macros will
1550 have GPIO-based defaults assigned to them as appropriate.
1552 You should define these to the GPIO value as given directly to
1553 the generic GPIO functions.
1555 CONFIG_SYS_I2C_INIT_BOARD
1557 When a board is reset during an i2c bus transfer
1558 chips might think that the current transfer is still
1559 in progress. On some boards it is possible to access
1560 the i2c SCLK line directly, either by using the
1561 processor pin as a GPIO or by having a second pin
1562 connected to the bus. If this option is defined a
1563 custom i2c_init_board() routine in boards/xxx/board.c
1564 is run early in the boot sequence.
1566 CONFIG_SYS_I2C_BOARD_LATE_INIT
1568 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1569 defined a custom i2c_board_late_init() routine in
1570 boards/xxx/board.c is run AFTER the operations in i2c_init()
1571 is completed. This callpoint can be used to unreset i2c bus
1572 using CPU i2c controller register accesses for CPUs whose i2c
1573 controller provide such a method. It is called at the end of
1574 i2c_init() to allow i2c_init operations to setup the i2c bus
1575 controller on the CPU (e.g. setting bus speed & slave address).
1577 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1579 This option enables configuration of bi_iic_fast[] flags
1580 in u-boot bd_info structure based on u-boot environment
1581 variable "i2cfast". (see also i2cfast)
1583 CONFIG_I2C_MULTI_BUS
1585 This option allows the use of multiple I2C buses, each of which
1586 must have a controller. At any point in time, only one bus is
1587 active. To switch to a different bus, use the 'i2c dev' command.
1588 Note that bus numbering is zero-based.
1590 CONFIG_SYS_I2C_NOPROBES
1592 This option specifies a list of I2C devices that will be skipped
1593 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1594 is set, specify a list of bus-device pairs. Otherwise, specify
1595 a 1D array of device addresses
1598 #undef CONFIG_I2C_MULTI_BUS
1599 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1601 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1603 #define CONFIG_I2C_MULTI_BUS
1604 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1606 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1608 CONFIG_SYS_SPD_BUS_NUM
1610 If defined, then this indicates the I2C bus number for DDR SPD.
1611 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1613 CONFIG_SYS_RTC_BUS_NUM
1615 If defined, then this indicates the I2C bus number for the RTC.
1616 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1618 CONFIG_SYS_DTT_BUS_NUM
1620 If defined, then this indicates the I2C bus number for the DTT.
1621 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1623 CONFIG_SYS_I2C_DTT_ADDR:
1625 If defined, specifies the I2C address of the DTT device.
1626 If not defined, then U-Boot uses predefined value for
1627 specified DTT device.
1631 Define this option if you want to use Freescale's I2C driver in
1632 drivers/i2c/fsl_i2c.c.
1636 Define this option if you have I2C devices reached over 1 .. n
1637 I2C Muxes like the pca9544a. This option addes a new I2C
1638 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1639 new I2C Bus to the existing I2C Busses. If you select the
1640 new Bus with "i2c dev", u-bbot sends first the commandos for
1641 the muxes to activate this new "bus".
1643 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1647 Adding a new I2C Bus reached over 2 pca9544a muxes
1648 The First mux with address 70 and channel 6
1649 The Second mux with address 71 and channel 4
1651 => i2c bus pca9544a:70:6:pca9544a:71:4
1653 Use the "i2c bus" command without parameter, to get a list
1654 of I2C Busses with muxes:
1657 Busses reached over muxes:
1659 reached over Mux(es):
1662 reached over Mux(es):
1667 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1668 u-boot sends First the Commando to the mux@70 to enable
1669 channel 6, and then the Commando to the mux@71 to enable
1672 After that, you can use the "normal" i2c commands as
1673 usual, to communicate with your I2C devices behind
1676 This option is actually implemented for the bitbanging
1677 algorithm in common/soft_i2c.c and for the Hardware I2C
1678 Bus on the MPC8260. But it should be not so difficult
1679 to add this option to other architectures.
1681 CONFIG_SOFT_I2C_READ_REPEATED_START
1683 defining this will force the i2c_read() function in
1684 the soft_i2c driver to perform an I2C repeated start
1685 between writing the address pointer and reading the
1686 data. If this define is omitted the default behaviour
1687 of doing a stop-start sequence will be used. Most I2C
1688 devices can use either method, but some require one or
1691 - SPI Support: CONFIG_SPI
1693 Enables SPI driver (so far only tested with
1694 SPI EEPROM, also an instance works with Crystal A/D and
1695 D/As on the SACSng board)
1699 Enables the driver for SPI controller on SuperH. Currently
1700 only SH7757 is supported.
1704 Enables extended (16-bit) SPI EEPROM addressing.
1705 (symmetrical to CONFIG_I2C_X)
1709 Enables a software (bit-bang) SPI driver rather than
1710 using hardware support. This is a general purpose
1711 driver that only requires three general I/O port pins
1712 (two outputs, one input) to function. If this is
1713 defined, the board configuration must define several
1714 SPI configuration items (port pins to use, etc). For
1715 an example, see include/configs/sacsng.h.
1719 Enables a hardware SPI driver for general-purpose reads
1720 and writes. As with CONFIG_SOFT_SPI, the board configuration
1721 must define a list of chip-select function pointers.
1722 Currently supported on some MPC8xxx processors. For an
1723 example, see include/configs/mpc8349emds.h.
1727 Enables the driver for the SPI controllers on i.MX and MXC
1728 SoCs. Currently only i.MX31 is supported.
1730 - FPGA Support: CONFIG_FPGA
1732 Enables FPGA subsystem.
1734 CONFIG_FPGA_<vendor>
1736 Enables support for specific chip vendors.
1739 CONFIG_FPGA_<family>
1741 Enables support for FPGA family.
1742 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1746 Specify the number of FPGA devices to support.
1748 CONFIG_SYS_FPGA_PROG_FEEDBACK
1750 Enable printing of hash marks during FPGA configuration.
1752 CONFIG_SYS_FPGA_CHECK_BUSY
1754 Enable checks on FPGA configuration interface busy
1755 status by the configuration function. This option
1756 will require a board or device specific function to
1761 If defined, a function that provides delays in the FPGA
1762 configuration driver.
1764 CONFIG_SYS_FPGA_CHECK_CTRLC
1765 Allow Control-C to interrupt FPGA configuration
1767 CONFIG_SYS_FPGA_CHECK_ERROR
1769 Check for configuration errors during FPGA bitfile
1770 loading. For example, abort during Virtex II
1771 configuration if the INIT_B line goes low (which
1772 indicated a CRC error).
1774 CONFIG_SYS_FPGA_WAIT_INIT
1776 Maximum time to wait for the INIT_B line to deassert
1777 after PROB_B has been deasserted during a Virtex II
1778 FPGA configuration sequence. The default time is 500
1781 CONFIG_SYS_FPGA_WAIT_BUSY
1783 Maximum time to wait for BUSY to deassert during
1784 Virtex II FPGA configuration. The default is 5 ms.
1786 CONFIG_SYS_FPGA_WAIT_CONFIG
1788 Time to wait after FPGA configuration. The default is
1791 - Configuration Management:
1794 If defined, this string will be added to the U-Boot
1795 version information (U_BOOT_VERSION)
1797 - Vendor Parameter Protection:
1799 U-Boot considers the values of the environment
1800 variables "serial#" (Board Serial Number) and
1801 "ethaddr" (Ethernet Address) to be parameters that
1802 are set once by the board vendor / manufacturer, and
1803 protects these variables from casual modification by
1804 the user. Once set, these variables are read-only,
1805 and write or delete attempts are rejected. You can
1806 change this behaviour:
1808 If CONFIG_ENV_OVERWRITE is #defined in your config
1809 file, the write protection for vendor parameters is
1810 completely disabled. Anybody can change or delete
1813 Alternatively, if you #define _both_ CONFIG_ETHADDR
1814 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1815 Ethernet address is installed in the environment,
1816 which can be changed exactly ONCE by the user. [The
1817 serial# is unaffected by this, i. e. it remains
1823 Define this variable to enable the reservation of
1824 "protected RAM", i. e. RAM which is not overwritten
1825 by U-Boot. Define CONFIG_PRAM to hold the number of
1826 kB you want to reserve for pRAM. You can overwrite
1827 this default value by defining an environment
1828 variable "pram" to the number of kB you want to
1829 reserve. Note that the board info structure will
1830 still show the full amount of RAM. If pRAM is
1831 reserved, a new environment variable "mem" will
1832 automatically be defined to hold the amount of
1833 remaining RAM in a form that can be passed as boot
1834 argument to Linux, for instance like that:
1836 setenv bootargs ... mem=\${mem}
1839 This way you can tell Linux not to use this memory,
1840 either, which results in a memory region that will
1841 not be affected by reboots.
1843 *WARNING* If your board configuration uses automatic
1844 detection of the RAM size, you must make sure that
1845 this memory test is non-destructive. So far, the
1846 following board configurations are known to be
1849 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1850 HERMES, IP860, RPXlite, LWMON, LANTEC,
1856 Define this variable to stop the system in case of a
1857 fatal error, so that you have to reset it manually.
1858 This is probably NOT a good idea for an embedded
1859 system where you want the system to reboot
1860 automatically as fast as possible, but it may be
1861 useful during development since you can try to debug
1862 the conditions that lead to the situation.
1864 CONFIG_NET_RETRY_COUNT
1866 This variable defines the number of retries for
1867 network operations like ARP, RARP, TFTP, or BOOTP
1868 before giving up the operation. If not defined, a
1869 default value of 5 is used.
1873 Timeout waiting for an ARP reply in milliseconds.
1875 - Command Interpreter:
1876 CONFIG_AUTO_COMPLETE
1878 Enable auto completion of commands using TAB.
1880 Note that this feature has NOT been implemented yet
1881 for the "hush" shell.
1884 CONFIG_SYS_HUSH_PARSER
1886 Define this variable to enable the "hush" shell (from
1887 Busybox) as command line interpreter, thus enabling
1888 powerful command line syntax like
1889 if...then...else...fi conditionals or `&&' and '||'
1890 constructs ("shell scripts").
1892 If undefined, you get the old, much simpler behaviour
1893 with a somewhat smaller memory footprint.
1896 CONFIG_SYS_PROMPT_HUSH_PS2
1898 This defines the secondary prompt string, which is
1899 printed when the command interpreter needs more input
1900 to complete a command. Usually "> ".
1904 In the current implementation, the local variables
1905 space and global environment variables space are
1906 separated. Local variables are those you define by
1907 simply typing `name=value'. To access a local
1908 variable later on, you have write `$name' or
1909 `${name}'; to execute the contents of a variable
1910 directly type `$name' at the command prompt.
1912 Global environment variables are those you use
1913 setenv/printenv to work with. To run a command stored
1914 in such a variable, you need to use the run command,
1915 and you must not use the '$' sign to access them.
1917 To store commands and special characters in a
1918 variable, please use double quotation marks
1919 surrounding the whole text of the variable, instead
1920 of the backslashes before semicolons and special
1923 - Commandline Editing and History:
1924 CONFIG_CMDLINE_EDITING
1926 Enable editing and History functions for interactive
1927 commandline input operations
1929 - Default Environment:
1930 CONFIG_EXTRA_ENV_SETTINGS
1932 Define this to contain any number of null terminated
1933 strings (variable = value pairs) that will be part of
1934 the default environment compiled into the boot image.
1936 For example, place something like this in your
1937 board's config file:
1939 #define CONFIG_EXTRA_ENV_SETTINGS \
1943 Warning: This method is based on knowledge about the
1944 internal format how the environment is stored by the
1945 U-Boot code. This is NOT an official, exported
1946 interface! Although it is unlikely that this format
1947 will change soon, there is no guarantee either.
1948 You better know what you are doing here.
1950 Note: overly (ab)use of the default environment is
1951 discouraged. Make sure to check other ways to preset
1952 the environment like the "source" command or the
1955 - DataFlash Support:
1956 CONFIG_HAS_DATAFLASH
1958 Defining this option enables DataFlash features and
1959 allows to read/write in Dataflash via the standard
1962 - SystemACE Support:
1965 Adding this option adds support for Xilinx SystemACE
1966 chips attached via some sort of local bus. The address
1967 of the chip must also be defined in the
1968 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
1970 #define CONFIG_SYSTEMACE
1971 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
1973 When SystemACE support is added, the "ace" device type
1974 becomes available to the fat commands, i.e. fatls.
1976 - TFTP Fixed UDP Port:
1979 If this is defined, the environment variable tftpsrcp
1980 is used to supply the TFTP UDP source port value.
1981 If tftpsrcp isn't defined, the normal pseudo-random port
1982 number generator is used.
1984 Also, the environment variable tftpdstp is used to supply
1985 the TFTP UDP destination port value. If tftpdstp isn't
1986 defined, the normal port 69 is used.
1988 The purpose for tftpsrcp is to allow a TFTP server to
1989 blindly start the TFTP transfer using the pre-configured
1990 target IP address and UDP port. This has the effect of
1991 "punching through" the (Windows XP) firewall, allowing
1992 the remainder of the TFTP transfer to proceed normally.
1993 A better solution is to properly configure the firewall,
1994 but sometimes that is not allowed.
1996 - Show boot progress:
1997 CONFIG_SHOW_BOOT_PROGRESS
1999 Defining this option allows to add some board-
2000 specific code (calling a user-provided function
2001 "show_boot_progress(int)") that enables you to show
2002 the system's boot progress on some display (for
2003 example, some LED's) on your board. At the moment,
2004 the following checkpoints are implemented:
2006 - Standalone program support:
2007 CONFIG_STANDALONE_LOAD_ADDR
2009 This option allows to define board specific values
2010 for the address where standalone program gets loaded,
2011 thus overwriting the architecutre dependent default
2014 - Frame Buffer Address:
2017 Define CONFIG_FB_ADDR if you want to use specific address for
2019 Then system will reserve the frame buffer address to defined address
2020 instead of lcd_setmem (this function grab the memory for frame buffer
2023 Please see board_init_f function.
2025 If you want this config option then,
2026 please define it at your board config file
2028 Legacy uImage format:
2031 1 common/cmd_bootm.c before attempting to boot an image
2032 -1 common/cmd_bootm.c Image header has bad magic number
2033 2 common/cmd_bootm.c Image header has correct magic number
2034 -2 common/cmd_bootm.c Image header has bad checksum
2035 3 common/cmd_bootm.c Image header has correct checksum
2036 -3 common/cmd_bootm.c Image data has bad checksum
2037 4 common/cmd_bootm.c Image data has correct checksum
2038 -4 common/cmd_bootm.c Image is for unsupported architecture
2039 5 common/cmd_bootm.c Architecture check OK
2040 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2041 6 common/cmd_bootm.c Image Type check OK
2042 -6 common/cmd_bootm.c gunzip uncompression error
2043 -7 common/cmd_bootm.c Unimplemented compression type
2044 7 common/cmd_bootm.c Uncompression OK
2045 8 common/cmd_bootm.c No uncompress/copy overwrite error
2046 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2048 9 common/image.c Start initial ramdisk verification
2049 -10 common/image.c Ramdisk header has bad magic number
2050 -11 common/image.c Ramdisk header has bad checksum
2051 10 common/image.c Ramdisk header is OK
2052 -12 common/image.c Ramdisk data has bad checksum
2053 11 common/image.c Ramdisk data has correct checksum
2054 12 common/image.c Ramdisk verification complete, start loading
2055 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2056 13 common/image.c Start multifile image verification
2057 14 common/image.c No initial ramdisk, no multifile, continue.
2059 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2061 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2062 -31 post/post.c POST test failed, detected by post_output_backlog()
2063 -32 post/post.c POST test failed, detected by post_run_single()
2065 34 common/cmd_doc.c before loading a Image from a DOC device
2066 -35 common/cmd_doc.c Bad usage of "doc" command
2067 35 common/cmd_doc.c correct usage of "doc" command
2068 -36 common/cmd_doc.c No boot device
2069 36 common/cmd_doc.c correct boot device
2070 -37 common/cmd_doc.c Unknown Chip ID on boot device
2071 37 common/cmd_doc.c correct chip ID found, device available
2072 -38 common/cmd_doc.c Read Error on boot device
2073 38 common/cmd_doc.c reading Image header from DOC device OK
2074 -39 common/cmd_doc.c Image header has bad magic number
2075 39 common/cmd_doc.c Image header has correct magic number
2076 -40 common/cmd_doc.c Error reading Image from DOC device
2077 40 common/cmd_doc.c Image header has correct magic number
2078 41 common/cmd_ide.c before loading a Image from a IDE device
2079 -42 common/cmd_ide.c Bad usage of "ide" command
2080 42 common/cmd_ide.c correct usage of "ide" command
2081 -43 common/cmd_ide.c No boot device
2082 43 common/cmd_ide.c boot device found
2083 -44 common/cmd_ide.c Device not available
2084 44 common/cmd_ide.c Device available
2085 -45 common/cmd_ide.c wrong partition selected
2086 45 common/cmd_ide.c partition selected
2087 -46 common/cmd_ide.c Unknown partition table
2088 46 common/cmd_ide.c valid partition table found
2089 -47 common/cmd_ide.c Invalid partition type
2090 47 common/cmd_ide.c correct partition type
2091 -48 common/cmd_ide.c Error reading Image Header on boot device
2092 48 common/cmd_ide.c reading Image Header from IDE device OK
2093 -49 common/cmd_ide.c Image header has bad magic number
2094 49 common/cmd_ide.c Image header has correct magic number
2095 -50 common/cmd_ide.c Image header has bad checksum
2096 50 common/cmd_ide.c Image header has correct checksum
2097 -51 common/cmd_ide.c Error reading Image from IDE device
2098 51 common/cmd_ide.c reading Image from IDE device OK
2099 52 common/cmd_nand.c before loading a Image from a NAND device
2100 -53 common/cmd_nand.c Bad usage of "nand" command
2101 53 common/cmd_nand.c correct usage of "nand" command
2102 -54 common/cmd_nand.c No boot device
2103 54 common/cmd_nand.c boot device found
2104 -55 common/cmd_nand.c Unknown Chip ID on boot device
2105 55 common/cmd_nand.c correct chip ID found, device available
2106 -56 common/cmd_nand.c Error reading Image Header on boot device
2107 56 common/cmd_nand.c reading Image Header from NAND device OK
2108 -57 common/cmd_nand.c Image header has bad magic number
2109 57 common/cmd_nand.c Image header has correct magic number
2110 -58 common/cmd_nand.c Error reading Image from NAND device
2111 58 common/cmd_nand.c reading Image from NAND device OK
2113 -60 common/env_common.c Environment has a bad CRC, using default
2115 64 net/eth.c starting with Ethernet configuration.
2116 -64 net/eth.c no Ethernet found.
2117 65 net/eth.c Ethernet found.
2119 -80 common/cmd_net.c usage wrong
2120 80 common/cmd_net.c before calling NetLoop()
2121 -81 common/cmd_net.c some error in NetLoop() occurred
2122 81 common/cmd_net.c NetLoop() back without error
2123 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2124 82 common/cmd_net.c trying automatic boot
2125 83 common/cmd_net.c running "source" command
2126 -83 common/cmd_net.c some error in automatic boot or "source" command
2127 84 common/cmd_net.c end without errors
2132 100 common/cmd_bootm.c Kernel FIT Image has correct format
2133 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2134 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2135 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2136 102 common/cmd_bootm.c Kernel unit name specified
2137 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2138 103 common/cmd_bootm.c Found configuration node
2139 104 common/cmd_bootm.c Got kernel subimage node offset
2140 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2141 105 common/cmd_bootm.c Kernel subimage hash verification OK
2142 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2143 106 common/cmd_bootm.c Architecture check OK
2144 -106 common/cmd_bootm.c Kernel subimage has wrong type
2145 107 common/cmd_bootm.c Kernel subimage type OK
2146 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2147 108 common/cmd_bootm.c Got kernel subimage data/size
2148 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2149 -109 common/cmd_bootm.c Can't get kernel subimage type
2150 -110 common/cmd_bootm.c Can't get kernel subimage comp
2151 -111 common/cmd_bootm.c Can't get kernel subimage os
2152 -112 common/cmd_bootm.c Can't get kernel subimage load address
2153 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2155 120 common/image.c Start initial ramdisk verification
2156 -120 common/image.c Ramdisk FIT image has incorrect format
2157 121 common/image.c Ramdisk FIT image has correct format
2158 122 common/image.c No ramdisk subimage unit name, using configuration
2159 -122 common/image.c Can't get configuration for ramdisk subimage
2160 123 common/image.c Ramdisk unit name specified
2161 -124 common/image.c Can't get ramdisk subimage node offset
2162 125 common/image.c Got ramdisk subimage node offset
2163 -125 common/image.c Ramdisk subimage hash verification failed
2164 126 common/image.c Ramdisk subimage hash verification OK
2165 -126 common/image.c Ramdisk subimage for unsupported architecture
2166 127 common/image.c Architecture check OK
2167 -127 common/image.c Can't get ramdisk subimage data/size
2168 128 common/image.c Got ramdisk subimage data/size
2169 129 common/image.c Can't get ramdisk load address
2170 -129 common/image.c Got ramdisk load address
2172 -130 common/cmd_doc.c Incorrect FIT image format
2173 131 common/cmd_doc.c FIT image format OK
2175 -140 common/cmd_ide.c Incorrect FIT image format
2176 141 common/cmd_ide.c FIT image format OK
2178 -150 common/cmd_nand.c Incorrect FIT image format
2179 151 common/cmd_nand.c FIT image format OK
2181 - Automatic software updates via TFTP server
2183 CONFIG_UPDATE_TFTP_CNT_MAX
2184 CONFIG_UPDATE_TFTP_MSEC_MAX
2186 These options enable and control the auto-update feature;
2187 for a more detailed description refer to doc/README.update.
2189 - MTD Support (mtdparts command, UBI support)
2192 Adds the MTD device infrastructure from the Linux kernel.
2193 Needed for mtdparts command support.
2195 CONFIG_MTD_PARTITIONS
2197 Adds the MTD partitioning infrastructure from the Linux
2198 kernel. Needed for UBI support.
2204 [so far only for SMDK2400 and TRAB boards]
2206 - Modem support enable:
2207 CONFIG_MODEM_SUPPORT
2209 - RTS/CTS Flow control enable:
2212 - Modem debug support:
2213 CONFIG_MODEM_SUPPORT_DEBUG
2215 Enables debugging stuff (char screen[1024], dbg())
2216 for modem support. Useful only with BDI2000.
2218 - Interrupt support (PPC):
2220 There are common interrupt_init() and timer_interrupt()
2221 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2222 for CPU specific initialization. interrupt_init_cpu()
2223 should set decrementer_count to appropriate value. If
2224 CPU resets decrementer automatically after interrupt
2225 (ppc4xx) it should set decrementer_count to zero.
2226 timer_interrupt() calls timer_interrupt_cpu() for CPU
2227 specific handling. If board has watchdog / status_led
2228 / other_activity_monitor it works automatically from
2229 general timer_interrupt().
2233 In the target system modem support is enabled when a
2234 specific key (key combination) is pressed during
2235 power-on. Otherwise U-Boot will boot normally
2236 (autoboot). The key_pressed() function is called from
2237 board_init(). Currently key_pressed() is a dummy
2238 function, returning 1 and thus enabling modem
2241 If there are no modem init strings in the
2242 environment, U-Boot proceed to autoboot; the
2243 previous output (banner, info printfs) will be
2246 See also: doc/README.Modem
2249 Configuration Settings:
2250 -----------------------
2252 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2253 undefine this when you're short of memory.
2255 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2256 width of the commands listed in the 'help' command output.
2258 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2259 prompt for user input.
2261 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2263 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2265 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2267 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2268 the application (usually a Linux kernel) when it is
2271 - CONFIG_SYS_BAUDRATE_TABLE:
2272 List of legal baudrate settings for this board.
2274 - CONFIG_SYS_CONSOLE_INFO_QUIET
2275 Suppress display of console information at boot.
2277 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2278 If the board specific function
2279 extern int overwrite_console (void);
2280 returns 1, the stdin, stderr and stdout are switched to the
2281 serial port, else the settings in the environment are used.
2283 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2284 Enable the call to overwrite_console().
2286 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2287 Enable overwrite of previous console environment settings.
2289 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2290 Begin and End addresses of the area used by the
2293 - CONFIG_SYS_ALT_MEMTEST:
2294 Enable an alternate, more extensive memory test.
2296 - CONFIG_SYS_MEMTEST_SCRATCH:
2297 Scratch address used by the alternate memory test
2298 You only need to set this if address zero isn't writeable
2300 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2301 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2302 this specified memory area will get subtracted from the top
2303 (end) of RAM and won't get "touched" at all by U-Boot. By
2304 fixing up gd->ram_size the Linux kernel should gets passed
2305 the now "corrected" memory size and won't touch it either.
2306 This should work for arch/ppc and arch/powerpc. Only Linux
2307 board ports in arch/powerpc with bootwrapper support that
2308 recalculate the memory size from the SDRAM controller setup
2309 will have to get fixed in Linux additionally.
2311 This option can be used as a workaround for the 440EPx/GRx
2312 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2315 WARNING: Please make sure that this value is a multiple of
2316 the Linux page size (normally 4k). If this is not the case,
2317 then the end address of the Linux memory will be located at a
2318 non page size aligned address and this could cause major
2321 - CONFIG_SYS_TFTP_LOADADDR:
2322 Default load address for network file downloads
2324 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2325 Enable temporary baudrate change while serial download
2327 - CONFIG_SYS_SDRAM_BASE:
2328 Physical start address of SDRAM. _Must_ be 0 here.
2330 - CONFIG_SYS_MBIO_BASE:
2331 Physical start address of Motherboard I/O (if using a
2334 - CONFIG_SYS_FLASH_BASE:
2335 Physical start address of Flash memory.
2337 - CONFIG_SYS_MONITOR_BASE:
2338 Physical start address of boot monitor code (set by
2339 make config files to be same as the text base address
2340 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
2341 CONFIG_SYS_FLASH_BASE when booting from flash.
2343 - CONFIG_SYS_MONITOR_LEN:
2344 Size of memory reserved for monitor code, used to
2345 determine _at_compile_time_ (!) if the environment is
2346 embedded within the U-Boot image, or in a separate
2349 - CONFIG_SYS_MALLOC_LEN:
2350 Size of DRAM reserved for malloc() use.
2352 - CONFIG_SYS_BOOTM_LEN:
2353 Normally compressed uImages are limited to an
2354 uncompressed size of 8 MBytes. If this is not enough,
2355 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2356 to adjust this setting to your needs.
2358 - CONFIG_SYS_BOOTMAPSZ:
2359 Maximum size of memory mapped by the startup code of
2360 the Linux kernel; all data that must be processed by
2361 the Linux kernel (bd_info, boot arguments, FDT blob if
2362 used) must be put below this limit, unless "bootm_low"
2363 enviroment variable is defined and non-zero. In such case
2364 all data for the Linux kernel must be between "bootm_low"
2365 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ.
2367 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
2368 Enable initrd_high functionality. If defined then the
2369 initrd_high feature is enabled and the bootm ramdisk subcommand
2372 - CONFIG_SYS_BOOT_GET_CMDLINE:
2373 Enables allocating and saving kernel cmdline in space between
2374 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2376 - CONFIG_SYS_BOOT_GET_KBD:
2377 Enables allocating and saving a kernel copy of the bd_info in
2378 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2380 - CONFIG_SYS_MAX_FLASH_BANKS:
2381 Max number of Flash memory banks
2383 - CONFIG_SYS_MAX_FLASH_SECT:
2384 Max number of sectors on a Flash chip
2386 - CONFIG_SYS_FLASH_ERASE_TOUT:
2387 Timeout for Flash erase operations (in ms)
2389 - CONFIG_SYS_FLASH_WRITE_TOUT:
2390 Timeout for Flash write operations (in ms)
2392 - CONFIG_SYS_FLASH_LOCK_TOUT
2393 Timeout for Flash set sector lock bit operation (in ms)
2395 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2396 Timeout for Flash clear lock bits operation (in ms)
2398 - CONFIG_SYS_FLASH_PROTECTION
2399 If defined, hardware flash sectors protection is used
2400 instead of U-Boot software protection.
2402 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2404 Enable TFTP transfers directly to flash memory;
2405 without this option such a download has to be
2406 performed in two steps: (1) download to RAM, and (2)
2407 copy from RAM to flash.
2409 The two-step approach is usually more reliable, since
2410 you can check if the download worked before you erase
2411 the flash, but in some situations (when system RAM is
2412 too limited to allow for a temporary copy of the
2413 downloaded image) this option may be very useful.
2415 - CONFIG_SYS_FLASH_CFI:
2416 Define if the flash driver uses extra elements in the
2417 common flash structure for storing flash geometry.
2419 - CONFIG_FLASH_CFI_DRIVER
2420 This option also enables the building of the cfi_flash driver
2421 in the drivers directory
2423 - CONFIG_FLASH_CFI_MTD
2424 This option enables the building of the cfi_mtd driver
2425 in the drivers directory. The driver exports CFI flash
2428 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2429 Use buffered writes to flash.
2431 - CONFIG_FLASH_SPANSION_S29WS_N
2432 s29ws-n MirrorBit flash has non-standard addresses for buffered
2435 - CONFIG_SYS_FLASH_QUIET_TEST
2436 If this option is defined, the common CFI flash doesn't
2437 print it's warning upon not recognized FLASH banks. This
2438 is useful, if some of the configured banks are only
2439 optionally available.
2441 - CONFIG_FLASH_SHOW_PROGRESS
2442 If defined (must be an integer), print out countdown
2443 digits and dots. Recommended value: 45 (9..1) for 80
2444 column displays, 15 (3..1) for 40 column displays.
2446 - CONFIG_SYS_RX_ETH_BUFFER:
2447 Defines the number of Ethernet receive buffers. On some
2448 Ethernet controllers it is recommended to set this value
2449 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2450 buffers can be full shortly after enabling the interface
2451 on high Ethernet traffic.
2452 Defaults to 4 if not defined.
2454 - CONFIG_ENV_MAX_ENTRIES
2456 Maximum number of entries in the hash table that is used
2457 internally to store the environment settings. The default
2458 setting is supposed to be generous and should work in most
2459 cases. This setting can be used to tune behaviour; see
2460 lib/hashtable.c for details.
2462 The following definitions that deal with the placement and management
2463 of environment data (variable area); in general, we support the
2464 following configurations:
2466 - CONFIG_ENV_IS_IN_FLASH:
2468 Define this if the environment is in flash memory.
2470 a) The environment occupies one whole flash sector, which is
2471 "embedded" in the text segment with the U-Boot code. This
2472 happens usually with "bottom boot sector" or "top boot
2473 sector" type flash chips, which have several smaller
2474 sectors at the start or the end. For instance, such a
2475 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2476 such a case you would place the environment in one of the
2477 4 kB sectors - with U-Boot code before and after it. With
2478 "top boot sector" type flash chips, you would put the
2479 environment in one of the last sectors, leaving a gap
2480 between U-Boot and the environment.
2482 - CONFIG_ENV_OFFSET:
2484 Offset of environment data (variable area) to the
2485 beginning of flash memory; for instance, with bottom boot
2486 type flash chips the second sector can be used: the offset
2487 for this sector is given here.
2489 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2493 This is just another way to specify the start address of
2494 the flash sector containing the environment (instead of
2497 - CONFIG_ENV_SECT_SIZE:
2499 Size of the sector containing the environment.
2502 b) Sometimes flash chips have few, equal sized, BIG sectors.
2503 In such a case you don't want to spend a whole sector for
2508 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2509 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2510 of this flash sector for the environment. This saves
2511 memory for the RAM copy of the environment.
2513 It may also save flash memory if you decide to use this
2514 when your environment is "embedded" within U-Boot code,
2515 since then the remainder of the flash sector could be used
2516 for U-Boot code. It should be pointed out that this is
2517 STRONGLY DISCOURAGED from a robustness point of view:
2518 updating the environment in flash makes it always
2519 necessary to erase the WHOLE sector. If something goes
2520 wrong before the contents has been restored from a copy in
2521 RAM, your target system will be dead.
2523 - CONFIG_ENV_ADDR_REDUND
2524 CONFIG_ENV_SIZE_REDUND
2526 These settings describe a second storage area used to hold
2527 a redundant copy of the environment data, so that there is
2528 a valid backup copy in case there is a power failure during
2529 a "saveenv" operation.
2531 BE CAREFUL! Any changes to the flash layout, and some changes to the
2532 source code will make it necessary to adapt <board>/u-boot.lds*
2536 - CONFIG_ENV_IS_IN_NVRAM:
2538 Define this if you have some non-volatile memory device
2539 (NVRAM, battery buffered SRAM) which you want to use for the
2545 These two #defines are used to determine the memory area you
2546 want to use for environment. It is assumed that this memory
2547 can just be read and written to, without any special
2550 BE CAREFUL! The first access to the environment happens quite early
2551 in U-Boot initalization (when we try to get the setting of for the
2552 console baudrate). You *MUST* have mapped your NVRAM area then, or
2555 Please note that even with NVRAM we still use a copy of the
2556 environment in RAM: we could work on NVRAM directly, but we want to
2557 keep settings there always unmodified except somebody uses "saveenv"
2558 to save the current settings.
2561 - CONFIG_ENV_IS_IN_EEPROM:
2563 Use this if you have an EEPROM or similar serial access
2564 device and a driver for it.
2566 - CONFIG_ENV_OFFSET:
2569 These two #defines specify the offset and size of the
2570 environment area within the total memory of your EEPROM.
2572 - CONFIG_SYS_I2C_EEPROM_ADDR:
2573 If defined, specified the chip address of the EEPROM device.
2574 The default address is zero.
2576 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2577 If defined, the number of bits used to address bytes in a
2578 single page in the EEPROM device. A 64 byte page, for example
2579 would require six bits.
2581 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2582 If defined, the number of milliseconds to delay between
2583 page writes. The default is zero milliseconds.
2585 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2586 The length in bytes of the EEPROM memory array address. Note
2587 that this is NOT the chip address length!
2589 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2590 EEPROM chips that implement "address overflow" are ones
2591 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2592 address and the extra bits end up in the "chip address" bit
2593 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2596 Note that we consider the length of the address field to
2597 still be one byte because the extra address bits are hidden
2598 in the chip address.
2600 - CONFIG_SYS_EEPROM_SIZE:
2601 The size in bytes of the EEPROM device.
2603 - CONFIG_ENV_EEPROM_IS_ON_I2C
2604 define this, if you have I2C and SPI activated, and your
2605 EEPROM, which holds the environment, is on the I2C bus.
2607 - CONFIG_I2C_ENV_EEPROM_BUS
2608 if you have an Environment on an EEPROM reached over
2609 I2C muxes, you can define here, how to reach this
2610 EEPROM. For example:
2612 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
2614 EEPROM which holds the environment, is reached over
2615 a pca9547 i2c mux with address 0x70, channel 3.
2617 - CONFIG_ENV_IS_IN_DATAFLASH:
2619 Define this if you have a DataFlash memory device which you
2620 want to use for the environment.
2622 - CONFIG_ENV_OFFSET:
2626 These three #defines specify the offset and size of the
2627 environment area within the total memory of your DataFlash placed
2628 at the specified address.
2630 - CONFIG_ENV_IS_IN_NAND:
2632 Define this if you have a NAND device which you want to use
2633 for the environment.
2635 - CONFIG_ENV_OFFSET:
2638 These two #defines specify the offset and size of the environment
2639 area within the first NAND device. CONFIG_ENV_OFFSET must be
2640 aligned to an erase block boundary.
2642 - CONFIG_ENV_OFFSET_REDUND (optional):
2644 This setting describes a second storage area of CONFIG_ENV_SIZE
2645 size used to hold a redundant copy of the environment data, so
2646 that there is a valid backup copy in case there is a power failure
2647 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
2648 aligned to an erase block boundary.
2650 - CONFIG_ENV_RANGE (optional):
2652 Specifies the length of the region in which the environment
2653 can be written. This should be a multiple of the NAND device's
2654 block size. Specifying a range with more erase blocks than
2655 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
2656 the range to be avoided.
2658 - CONFIG_ENV_OFFSET_OOB (optional):
2660 Enables support for dynamically retrieving the offset of the
2661 environment from block zero's out-of-band data. The
2662 "nand env.oob" command can be used to record this offset.
2663 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
2664 using CONFIG_ENV_OFFSET_OOB.
2666 - CONFIG_NAND_ENV_DST
2668 Defines address in RAM to which the nand_spl code should copy the
2669 environment. If redundant environment is used, it will be copied to
2670 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2672 - CONFIG_SYS_SPI_INIT_OFFSET
2674 Defines offset to the initial SPI buffer area in DPRAM. The
2675 area is used at an early stage (ROM part) if the environment
2676 is configured to reside in the SPI EEPROM: We need a 520 byte
2677 scratch DPRAM area. It is used between the two initialization
2678 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2679 to be a good choice since it makes it far enough from the
2680 start of the data area as well as from the stack pointer.
2682 Please note that the environment is read-only until the monitor
2683 has been relocated to RAM and a RAM copy of the environment has been
2684 created; also, when using EEPROM you will have to use getenv_f()
2685 until then to read environment variables.
2687 The environment is protected by a CRC32 checksum. Before the monitor
2688 is relocated into RAM, as a result of a bad CRC you will be working
2689 with the compiled-in default environment - *silently*!!! [This is
2690 necessary, because the first environment variable we need is the
2691 "baudrate" setting for the console - if we have a bad CRC, we don't
2692 have any device yet where we could complain.]
2694 Note: once the monitor has been relocated, then it will complain if
2695 the default environment is used; a new CRC is computed as soon as you
2696 use the "saveenv" command to store a valid environment.
2698 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2699 Echo the inverted Ethernet link state to the fault LED.
2701 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2702 also needs to be defined.
2704 - CONFIG_SYS_FAULT_MII_ADDR:
2705 MII address of the PHY to check for the Ethernet link state.
2707 - CONFIG_NS16550_MIN_FUNCTIONS:
2708 Define this if you desire to only have use of the NS16550_init
2709 and NS16550_putc functions for the serial driver located at
2710 drivers/serial/ns16550.c. This option is useful for saving
2711 space for already greatly restricted images, including but not
2712 limited to NAND_SPL configurations.
2714 Low Level (hardware related) configuration options:
2715 ---------------------------------------------------
2717 - CONFIG_SYS_CACHELINE_SIZE:
2718 Cache Line Size of the CPU.
2720 - CONFIG_SYS_DEFAULT_IMMR:
2721 Default address of the IMMR after system reset.
2723 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2724 and RPXsuper) to be able to adjust the position of
2725 the IMMR register after a reset.
2727 - Floppy Disk Support:
2728 CONFIG_SYS_FDC_DRIVE_NUMBER
2730 the default drive number (default value 0)
2732 CONFIG_SYS_ISA_IO_STRIDE
2734 defines the spacing between FDC chipset registers
2737 CONFIG_SYS_ISA_IO_OFFSET
2739 defines the offset of register from address. It
2740 depends on which part of the data bus is connected to
2741 the FDC chipset. (default value 0)
2743 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
2744 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
2747 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
2748 fdc_hw_init() is called at the beginning of the FDC
2749 setup. fdc_hw_init() must be provided by the board
2750 source code. It is used to make hardware dependant
2753 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
2754 DO NOT CHANGE unless you know exactly what you're
2755 doing! (11-4) [MPC8xx/82xx systems only]
2757 - CONFIG_SYS_INIT_RAM_ADDR:
2759 Start address of memory area that can be used for
2760 initial data and stack; please note that this must be
2761 writable memory that is working WITHOUT special
2762 initialization, i. e. you CANNOT use normal RAM which
2763 will become available only after programming the
2764 memory controller and running certain initialization
2767 U-Boot uses the following memory types:
2768 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2769 - MPC824X: data cache
2770 - PPC4xx: data cache
2772 - CONFIG_SYS_GBL_DATA_OFFSET:
2774 Offset of the initial data structure in the memory
2775 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2776 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
2777 data is located at the end of the available space
2778 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
2779 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
2780 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2781 CONFIG_SYS_GBL_DATA_OFFSET) downward.
2784 On the MPC824X (or other systems that use the data
2785 cache for initial memory) the address chosen for
2786 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
2787 point to an otherwise UNUSED address space between
2788 the top of RAM and the start of the PCI space.
2790 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
2792 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
2794 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
2796 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
2798 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2800 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
2802 - CONFIG_SYS_OR_TIMING_SDRAM:
2805 - CONFIG_SYS_MAMR_PTA:
2806 periodic timer for refresh
2808 - CONFIG_SYS_DER: Debug Event Register (37-47)
2810 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2811 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2812 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2813 CONFIG_SYS_BR1_PRELIM:
2814 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2816 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2817 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2818 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
2819 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2821 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
2822 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
2823 Machine Mode Register and Memory Periodic Timer
2824 Prescaler definitions (SDRAM timing)
2826 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
2827 enable I2C microcode relocation patch (MPC8xx);
2828 define relocation offset in DPRAM [DSP2]
2830 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
2831 enable SMC microcode relocation patch (MPC8xx);
2832 define relocation offset in DPRAM [SMC1]
2834 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
2835 enable SPI microcode relocation patch (MPC8xx);
2836 define relocation offset in DPRAM [SCC4]
2838 - CONFIG_SYS_USE_OSCCLK:
2839 Use OSCM clock mode on MBX8xx board. Be careful,
2840 wrong setting might damage your board. Read
2841 doc/README.MBX before setting this variable!
2843 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2844 Offset of the bootmode word in DPRAM used by post
2845 (Power On Self Tests). This definition overrides
2846 #define'd default value in commproc.h resp.
2849 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
2850 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
2851 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
2852 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
2853 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2854 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
2855 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
2856 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
2857 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
2859 - CONFIG_PCI_DISABLE_PCIE:
2860 Disable PCI-Express on systems where it is supported but not
2864 Chip has SRIO or not
2867 Board has SRIO 1 port available
2870 Board has SRIO 2 port available
2872 - CONFIG_SYS_SRIOn_MEM_VIRT:
2873 Virtual Address of SRIO port 'n' memory region
2875 - CONFIG_SYS_SRIOn_MEM_PHYS:
2876 Physical Address of SRIO port 'n' memory region
2878 - CONFIG_SYS_SRIOn_MEM_SIZE:
2879 Size of SRIO port 'n' memory region
2882 Get DDR timing information from an I2C EEPROM. Common
2883 with pluggable memory modules such as SODIMMs
2886 I2C address of the SPD EEPROM
2888 - CONFIG_SYS_SPD_BUS_NUM
2889 If SPD EEPROM is on an I2C bus other than the first
2890 one, specify here. Note that the value must resolve
2891 to something your driver can deal with.
2893 - CONFIG_SYS_83XX_DDR_USES_CS0
2894 Only for 83xx systems. If specified, then DDR should
2895 be configured using CS0 and CS1 instead of CS2 and CS3.
2897 - CONFIG_ETHER_ON_FEC[12]
2898 Define to enable FEC[12] on a 8xx series processor.
2900 - CONFIG_FEC[12]_PHY
2901 Define to the hardcoded PHY address which corresponds
2902 to the given FEC; i. e.
2903 #define CONFIG_FEC1_PHY 4
2904 means that the PHY with address 4 is connected to FEC1
2906 When set to -1, means to probe for first available.
2908 - CONFIG_FEC[12]_PHY_NORXERR
2909 The PHY does not have a RXERR line (RMII only).
2910 (so program the FEC to ignore it).
2913 Enable RMII mode for all FECs.
2914 Note that this is a global option, we can't
2915 have one FEC in standard MII mode and another in RMII mode.
2917 - CONFIG_CRC32_VERIFY
2918 Add a verify option to the crc32 command.
2921 => crc32 -v <address> <count> <crc32>
2923 Where address/count indicate a memory area
2924 and crc32 is the correct crc32 which the
2928 Add the "loopw" memory command. This only takes effect if
2929 the memory commands are activated globally (CONFIG_CMD_MEM).
2932 Add the "mdc" and "mwc" memory commands. These are cyclic
2937 This command will print 4 bytes (10,11,12,13) each 500 ms.
2939 => mwc.l 100 12345678 10
2940 This command will write 12345678 to address 100 all 10 ms.
2942 This only takes effect if the memory commands are activated
2943 globally (CONFIG_CMD_MEM).
2945 - CONFIG_SKIP_LOWLEVEL_INIT
2946 [ARM only] If this variable is defined, then certain
2947 low level initializations (like setting up the memory
2948 controller) are omitted and/or U-Boot does not
2949 relocate itself into RAM.
2951 Normally this variable MUST NOT be defined. The only
2952 exception is when U-Boot is loaded (to RAM) by some
2953 other boot loader or by a debugger which performs
2954 these initializations itself.
2957 Modifies the behaviour of start.S when compiling a loader
2958 that is executed before the actual U-Boot. E.g. when
2959 compiling a NAND SPL.
2961 - CONFIG_USE_ARCH_MEMCPY
2962 CONFIG_USE_ARCH_MEMSET
2963 If these options are used a optimized version of memcpy/memset will
2964 be used if available. These functions may be faster under some
2965 conditions but may increase the binary size.
2967 Building the Software:
2968 ======================
2970 Building U-Boot has been tested in several native build environments
2971 and in many different cross environments. Of course we cannot support
2972 all possibly existing versions of cross development tools in all
2973 (potentially obsolete) versions. In case of tool chain problems we
2974 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2975 which is extensively used to build and test U-Boot.
2977 If you are not using a native environment, it is assumed that you
2978 have GNU cross compiling tools available in your path. In this case,
2979 you must set the environment variable CROSS_COMPILE in your shell.
2980 Note that no changes to the Makefile or any other source files are
2981 necessary. For example using the ELDK on a 4xx CPU, please enter:
2983 $ CROSS_COMPILE=ppc_4xx-
2984 $ export CROSS_COMPILE
2986 Note: If you wish to generate Windows versions of the utilities in
2987 the tools directory you can use the MinGW toolchain
2988 (http://www.mingw.org). Set your HOST tools to the MinGW
2989 toolchain and execute 'make tools'. For example:
2991 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
2993 Binaries such as tools/mkimage.exe will be created which can
2994 be executed on computers running Windows.
2996 U-Boot is intended to be simple to build. After installing the
2997 sources you must configure U-Boot for one specific board type. This
3002 where "NAME_config" is the name of one of the existing configu-
3003 rations; see the main Makefile for supported names.
3005 Note: for some board special configuration names may exist; check if
3006 additional information is available from the board vendor; for
3007 instance, the TQM823L systems are available without (standard)
3008 or with LCD support. You can select such additional "features"
3009 when choosing the configuration, i. e.
3012 - will configure for a plain TQM823L, i. e. no LCD support
3014 make TQM823L_LCD_config
3015 - will configure for a TQM823L with U-Boot console on LCD
3020 Finally, type "make all", and you should get some working U-Boot
3021 images ready for download to / installation on your system:
3023 - "u-boot.bin" is a raw binary image
3024 - "u-boot" is an image in ELF binary format
3025 - "u-boot.srec" is in Motorola S-Record format
3027 By default the build is performed locally and the objects are saved
3028 in the source directory. One of the two methods can be used to change
3029 this behavior and build U-Boot to some external directory:
3031 1. Add O= to the make command line invocations:
3033 make O=/tmp/build distclean
3034 make O=/tmp/build NAME_config
3035 make O=/tmp/build all
3037 2. Set environment variable BUILD_DIR to point to the desired location:
3039 export BUILD_DIR=/tmp/build
3044 Note that the command line "O=" setting overrides the BUILD_DIR environment
3048 Please be aware that the Makefiles assume you are using GNU make, so
3049 for instance on NetBSD you might need to use "gmake" instead of
3053 If the system board that you have is not listed, then you will need
3054 to port U-Boot to your hardware platform. To do this, follow these
3057 1. Add a new configuration option for your board to the toplevel
3058 "Makefile" and to the "MAKEALL" script, using the existing
3059 entries as examples. Note that here and at many other places
3060 boards and other names are listed in alphabetical sort order. Please
3062 2. Create a new directory to hold your board specific code. Add any
3063 files you need. In your board directory, you will need at least
3064 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
3065 3. Create a new configuration file "include/configs/<board>.h" for
3067 3. If you're porting U-Boot to a new CPU, then also create a new
3068 directory to hold your CPU specific code. Add any files you need.
3069 4. Run "make <board>_config" with your new name.
3070 5. Type "make", and you should get a working "u-boot.srec" file
3071 to be installed on your target system.
3072 6. Debug and solve any problems that might arise.
3073 [Of course, this last step is much harder than it sounds.]
3076 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3077 ==============================================================
3079 If you have modified U-Boot sources (for instance added a new board
3080 or support for new devices, a new CPU, etc.) you are expected to
3081 provide feedback to the other developers. The feedback normally takes
3082 the form of a "patch", i. e. a context diff against a certain (latest
3083 official or latest in the git repository) version of U-Boot sources.
3085 But before you submit such a patch, please verify that your modifi-
3086 cation did not break existing code. At least make sure that *ALL* of
3087 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3088 just run the "MAKEALL" script, which will configure and build U-Boot
3089 for ALL supported system. Be warned, this will take a while. You can
3090 select which (cross) compiler to use by passing a `CROSS_COMPILE'
3091 environment variable to the script, i. e. to use the ELDK cross tools
3094 CROSS_COMPILE=ppc_8xx- MAKEALL
3096 or to build on a native PowerPC system you can type
3098 CROSS_COMPILE=' ' MAKEALL
3100 When using the MAKEALL script, the default behaviour is to build
3101 U-Boot in the source directory. This location can be changed by
3102 setting the BUILD_DIR environment variable. Also, for each target
3103 built, the MAKEALL script saves two log files (<target>.ERR and
3104 <target>.MAKEALL) in the <source dir>/LOG directory. This default
3105 location can be changed by setting the MAKEALL_LOGDIR environment
3106 variable. For example:
3108 export BUILD_DIR=/tmp/build
3109 export MAKEALL_LOGDIR=/tmp/log
3110 CROSS_COMPILE=ppc_8xx- MAKEALL
3112 With the above settings build objects are saved in the /tmp/build,
3113 log files are saved in the /tmp/log and the source tree remains clean
3114 during the whole build process.
3117 See also "U-Boot Porting Guide" below.
3120 Monitor Commands - Overview:
3121 ============================
3123 go - start application at address 'addr'
3124 run - run commands in an environment variable
3125 bootm - boot application image from memory
3126 bootp - boot image via network using BootP/TFTP protocol
3127 tftpboot- boot image via network using TFTP protocol
3128 and env variables "ipaddr" and "serverip"
3129 (and eventually "gatewayip")
3130 rarpboot- boot image via network using RARP/TFTP protocol
3131 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3132 loads - load S-Record file over serial line
3133 loadb - load binary file over serial line (kermit mode)
3135 mm - memory modify (auto-incrementing)
3136 nm - memory modify (constant address)
3137 mw - memory write (fill)
3139 cmp - memory compare
3140 crc32 - checksum calculation
3141 i2c - I2C sub-system
3142 sspi - SPI utility commands
3143 base - print or set address offset
3144 printenv- print environment variables
3145 setenv - set environment variables
3146 saveenv - save environment variables to persistent storage
3147 protect - enable or disable FLASH write protection
3148 erase - erase FLASH memory
3149 flinfo - print FLASH memory information
3150 bdinfo - print Board Info structure
3151 iminfo - print header information for application image
3152 coninfo - print console devices and informations
3153 ide - IDE sub-system
3154 loop - infinite loop on address range
3155 loopw - infinite write loop on address range
3156 mtest - simple RAM test
3157 icache - enable or disable instruction cache
3158 dcache - enable or disable data cache
3159 reset - Perform RESET of the CPU
3160 echo - echo args to console
3161 version - print monitor version
3162 help - print online help
3163 ? - alias for 'help'
3166 Monitor Commands - Detailed Description:
3167 ========================================
3171 For now: just type "help <command>".
3174 Environment Variables:
3175 ======================
3177 U-Boot supports user configuration using Environment Variables which
3178 can be made persistent by saving to Flash memory.
3180 Environment Variables are set using "setenv", printed using
3181 "printenv", and saved to Flash using "saveenv". Using "setenv"
3182 without a value can be used to delete a variable from the
3183 environment. As long as you don't save the environment you are
3184 working with an in-memory copy. In case the Flash area containing the
3185 environment is erased by accident, a default environment is provided.
3187 Some configuration options can be set using Environment Variables.
3189 List of environment variables (most likely not complete):
3191 baudrate - see CONFIG_BAUDRATE
3193 bootdelay - see CONFIG_BOOTDELAY
3195 bootcmd - see CONFIG_BOOTCOMMAND
3197 bootargs - Boot arguments when booting an RTOS image
3199 bootfile - Name of the image to load with TFTP
3201 bootm_low - Memory range available for image processing in the bootm
3202 command can be restricted. This variable is given as
3203 a hexadecimal number and defines lowest address allowed
3204 for use by the bootm command. See also "bootm_size"
3205 environment variable. Address defined by "bootm_low" is
3206 also the base of the initial memory mapping for the Linux
3207 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ.
3209 bootm_size - Memory range available for image processing in the bootm
3210 command can be restricted. This variable is given as
3211 a hexadecimal number and defines the size of the region
3212 allowed for use by the bootm command. See also "bootm_low"
3213 environment variable.
3215 updatefile - Location of the software update file on a TFTP server, used
3216 by the automatic software update feature. Please refer to
3217 documentation in doc/README.update for more details.
3219 autoload - if set to "no" (any string beginning with 'n'),
3220 "bootp" will just load perform a lookup of the
3221 configuration from the BOOTP server, but not try to
3222 load any image using TFTP
3224 autostart - if set to "yes", an image loaded using the "bootp",
3225 "rarpboot", "tftpboot" or "diskboot" commands will
3226 be automatically started (by internally calling
3229 If set to "no", a standalone image passed to the
3230 "bootm" command will be copied to the load address
3231 (and eventually uncompressed), but NOT be started.
3232 This can be used to load and uncompress arbitrary
3235 i2cfast - (PPC405GP|PPC405EP only)
3236 if set to 'y' configures Linux I2C driver for fast
3237 mode (400kHZ). This environment variable is used in
3238 initialization code. So, for changes to be effective
3239 it must be saved and board must be reset.
3241 initrd_high - restrict positioning of initrd images:
3242 If this variable is not set, initrd images will be
3243 copied to the highest possible address in RAM; this
3244 is usually what you want since it allows for
3245 maximum initrd size. If for some reason you want to
3246 make sure that the initrd image is loaded below the
3247 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3248 variable to a value of "no" or "off" or "0".
3249 Alternatively, you can set it to a maximum upper
3250 address to use (U-Boot will still check that it
3251 does not overwrite the U-Boot stack and data).
3253 For instance, when you have a system with 16 MB
3254 RAM, and want to reserve 4 MB from use by Linux,
3255 you can do this by adding "mem=12M" to the value of
3256 the "bootargs" variable. However, now you must make
3257 sure that the initrd image is placed in the first
3258 12 MB as well - this can be done with
3260 setenv initrd_high 00c00000
3262 If you set initrd_high to 0xFFFFFFFF, this is an
3263 indication to U-Boot that all addresses are legal
3264 for the Linux kernel, including addresses in flash
3265 memory. In this case U-Boot will NOT COPY the
3266 ramdisk at all. This may be useful to reduce the
3267 boot time on your system, but requires that this
3268 feature is supported by your Linux kernel.
3270 ipaddr - IP address; needed for tftpboot command
3272 loadaddr - Default load address for commands like "bootp",
3273 "rarpboot", "tftpboot", "loadb" or "diskboot"
3275 loads_echo - see CONFIG_LOADS_ECHO
3277 serverip - TFTP server IP address; needed for tftpboot command
3279 bootretry - see CONFIG_BOOT_RETRY_TIME
3281 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3283 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3285 ethprime - When CONFIG_NET_MULTI is enabled controls which
3286 interface is used first.
3288 ethact - When CONFIG_NET_MULTI is enabled controls which
3289 interface is currently active. For example you
3290 can do the following
3292 => setenv ethact FEC
3293 => ping 192.168.0.1 # traffic sent on FEC
3294 => setenv ethact SCC
3295 => ping 10.0.0.1 # traffic sent on SCC
3297 ethrotate - When set to "no" U-Boot does not go through all
3298 available network interfaces.
3299 It just stays at the currently selected interface.
3301 netretry - When set to "no" each network operation will
3302 either succeed or fail without retrying.
3303 When set to "once" the network operation will
3304 fail when all the available network interfaces
3305 are tried once without success.
3306 Useful on scripts which control the retry operation
3309 npe_ucode - set load address for the NPE microcode
3311 tftpsrcport - If this is set, the value is used for TFTP's
3314 tftpdstport - If this is set, the value is used for TFTP's UDP
3315 destination port instead of the Well Know Port 69.
3317 tftpblocksize - Block size to use for TFTP transfers; if not set,
3318 we use the TFTP server's default block size
3320 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3321 seconds, minimum value is 1000 = 1 second). Defines
3322 when a packet is considered to be lost so it has to
3323 be retransmitted. The default is 5000 = 5 seconds.
3324 Lowering this value may make downloads succeed
3325 faster in networks with high packet loss rates or
3326 with unreliable TFTP servers.
3328 vlan - When set to a value < 4095 the traffic over
3329 Ethernet is encapsulated/received over 802.1q
3332 The following environment variables may be used and automatically
3333 updated by the network boot commands ("bootp" and "rarpboot"),
3334 depending the information provided by your boot server:
3336 bootfile - see above
3337 dnsip - IP address of your Domain Name Server
3338 dnsip2 - IP address of your secondary Domain Name Server
3339 gatewayip - IP address of the Gateway (Router) to use
3340 hostname - Target hostname
3342 netmask - Subnet Mask
3343 rootpath - Pathname of the root filesystem on the NFS server
3344 serverip - see above
3347 There are two special Environment Variables:
3349 serial# - contains hardware identification information such
3350 as type string and/or serial number
3351 ethaddr - Ethernet address
3353 These variables can be set only once (usually during manufacturing of
3354 the board). U-Boot refuses to delete or overwrite these variables
3355 once they have been set once.
3358 Further special Environment Variables:
3360 ver - Contains the U-Boot version string as printed
3361 with the "version" command. This variable is
3362 readonly (see CONFIG_VERSION_VARIABLE).
3365 Please note that changes to some configuration parameters may take
3366 only effect after the next boot (yes, that's just like Windoze :-).
3369 Command Line Parsing:
3370 =====================
3372 There are two different command line parsers available with U-Boot:
3373 the old "simple" one, and the much more powerful "hush" shell:
3375 Old, simple command line parser:
3376 --------------------------------
3378 - supports environment variables (through setenv / saveenv commands)
3379 - several commands on one line, separated by ';'
3380 - variable substitution using "... ${name} ..." syntax
3381 - special characters ('$', ';') can be escaped by prefixing with '\',
3383 setenv bootcmd bootm \${address}
3384 - You can also escape text by enclosing in single apostrophes, for example:
3385 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3390 - similar to Bourne shell, with control structures like
3391 if...then...else...fi, for...do...done; while...do...done,
3392 until...do...done, ...
3393 - supports environment ("global") variables (through setenv / saveenv
3394 commands) and local shell variables (through standard shell syntax
3395 "name=value"); only environment variables can be used with "run"
3401 (1) If a command line (or an environment variable executed by a "run"
3402 command) contains several commands separated by semicolon, and
3403 one of these commands fails, then the remaining commands will be
3406 (2) If you execute several variables with one call to run (i. e.
3407 calling run with a list of variables as arguments), any failing
3408 command will cause "run" to terminate, i. e. the remaining
3409 variables are not executed.
3411 Note for Redundant Ethernet Interfaces:
3412 =======================================
3414 Some boards come with redundant Ethernet interfaces; U-Boot supports
3415 such configurations and is capable of automatic selection of a
3416 "working" interface when needed. MAC assignment works as follows:
3418 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3419 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3420 "eth1addr" (=>eth1), "eth2addr", ...
3422 If the network interface stores some valid MAC address (for instance
3423 in SROM), this is used as default address if there is NO correspon-
3424 ding setting in the environment; if the corresponding environment
3425 variable is set, this overrides the settings in the card; that means:
3427 o If the SROM has a valid MAC address, and there is no address in the
3428 environment, the SROM's address is used.
3430 o If there is no valid address in the SROM, and a definition in the
3431 environment exists, then the value from the environment variable is
3434 o If both the SROM and the environment contain a MAC address, and
3435 both addresses are the same, this MAC address is used.
3437 o If both the SROM and the environment contain a MAC address, and the
3438 addresses differ, the value from the environment is used and a
3441 o If neither SROM nor the environment contain a MAC address, an error
3444 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
3445 will be programmed into hardware as part of the initialization process. This
3446 may be skipped by setting the appropriate 'ethmacskip' environment variable.
3447 The naming convention is as follows:
3448 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
3453 U-Boot is capable of booting (and performing other auxiliary operations on)
3454 images in two formats:
3456 New uImage format (FIT)
3457 -----------------------
3459 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3460 to Flattened Device Tree). It allows the use of images with multiple
3461 components (several kernels, ramdisks, etc.), with contents protected by
3462 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3468 Old image format is based on binary files which can be basically anything,
3469 preceded by a special header; see the definitions in include/image.h for
3470 details; basically, the header defines the following image properties:
3472 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3473 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3474 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3475 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3477 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3478 IA64, MIPS, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3479 Currently supported: ARM, AVR32, Intel x86, MIPS, Nios II, PowerPC).
3480 * Compression Type (uncompressed, gzip, bzip2)
3486 The header is marked by a special Magic Number, and both the header
3487 and the data portions of the image are secured against corruption by
3494 Although U-Boot should support any OS or standalone application
3495 easily, the main focus has always been on Linux during the design of
3498 U-Boot includes many features that so far have been part of some
3499 special "boot loader" code within the Linux kernel. Also, any
3500 "initrd" images to be used are no longer part of one big Linux image;
3501 instead, kernel and "initrd" are separate images. This implementation
3502 serves several purposes:
3504 - the same features can be used for other OS or standalone
3505 applications (for instance: using compressed images to reduce the
3506 Flash memory footprint)
3508 - it becomes much easier to port new Linux kernel versions because
3509 lots of low-level, hardware dependent stuff are done by U-Boot
3511 - the same Linux kernel image can now be used with different "initrd"
3512 images; of course this also means that different kernel images can
3513 be run with the same "initrd". This makes testing easier (you don't
3514 have to build a new "zImage.initrd" Linux image when you just
3515 change a file in your "initrd"). Also, a field-upgrade of the
3516 software is easier now.
3522 Porting Linux to U-Boot based systems:
3523 ---------------------------------------
3525 U-Boot cannot save you from doing all the necessary modifications to
3526 configure the Linux device drivers for use with your target hardware
3527 (no, we don't intend to provide a full virtual machine interface to
3530 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
3532 Just make sure your machine specific header file (for instance
3533 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3534 Information structure as we define in include/asm-<arch>/u-boot.h,
3535 and make sure that your definition of IMAP_ADDR uses the same value
3536 as your U-Boot configuration in CONFIG_SYS_IMMR.
3539 Configuring the Linux kernel:
3540 -----------------------------
3542 No specific requirements for U-Boot. Make sure you have some root
3543 device (initial ramdisk, NFS) for your target system.
3546 Building a Linux Image:
3547 -----------------------
3549 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3550 not used. If you use recent kernel source, a new build target
3551 "uImage" will exist which automatically builds an image usable by
3552 U-Boot. Most older kernels also have support for a "pImage" target,
3553 which was introduced for our predecessor project PPCBoot and uses a
3554 100% compatible format.
3563 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3564 encapsulate a compressed Linux kernel image with header information,
3565 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3567 * build a standard "vmlinux" kernel image (in ELF binary format):
3569 * convert the kernel into a raw binary image:
3571 ${CROSS_COMPILE}-objcopy -O binary \
3572 -R .note -R .comment \
3573 -S vmlinux linux.bin
3575 * compress the binary image:
3579 * package compressed binary image for U-Boot:
3581 mkimage -A ppc -O linux -T kernel -C gzip \
3582 -a 0 -e 0 -n "Linux Kernel Image" \
3583 -d linux.bin.gz uImage
3586 The "mkimage" tool can also be used to create ramdisk images for use
3587 with U-Boot, either separated from the Linux kernel image, or
3588 combined into one file. "mkimage" encapsulates the images with a 64
3589 byte header containing information about target architecture,
3590 operating system, image type, compression method, entry points, time
3591 stamp, CRC32 checksums, etc.
3593 "mkimage" can be called in two ways: to verify existing images and
3594 print the header information, or to build new images.
3596 In the first form (with "-l" option) mkimage lists the information
3597 contained in the header of an existing U-Boot image; this includes
3598 checksum verification:
3600 tools/mkimage -l image
3601 -l ==> list image header information
3603 The second form (with "-d" option) is used to build a U-Boot image
3604 from a "data file" which is used as image payload:
3606 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3607 -n name -d data_file image
3608 -A ==> set architecture to 'arch'
3609 -O ==> set operating system to 'os'
3610 -T ==> set image type to 'type'
3611 -C ==> set compression type 'comp'
3612 -a ==> set load address to 'addr' (hex)
3613 -e ==> set entry point to 'ep' (hex)
3614 -n ==> set image name to 'name'
3615 -d ==> use image data from 'datafile'
3617 Right now, all Linux kernels for PowerPC systems use the same load
3618 address (0x00000000), but the entry point address depends on the
3621 - 2.2.x kernels have the entry point at 0x0000000C,
3622 - 2.3.x and later kernels have the entry point at 0x00000000.
3624 So a typical call to build a U-Boot image would read:
3626 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3627 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3628 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
3629 > examples/uImage.TQM850L
3630 Image Name: 2.4.4 kernel for TQM850L
3631 Created: Wed Jul 19 02:34:59 2000
3632 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3633 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3634 Load Address: 0x00000000
3635 Entry Point: 0x00000000
3637 To verify the contents of the image (or check for corruption):
3639 -> tools/mkimage -l examples/uImage.TQM850L
3640 Image Name: 2.4.4 kernel for TQM850L
3641 Created: Wed Jul 19 02:34:59 2000
3642 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3643 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3644 Load Address: 0x00000000
3645 Entry Point: 0x00000000
3647 NOTE: for embedded systems where boot time is critical you can trade
3648 speed for memory and install an UNCOMPRESSED image instead: this
3649 needs more space in Flash, but boots much faster since it does not
3650 need to be uncompressed:
3652 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
3653 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3654 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3655 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
3656 > examples/uImage.TQM850L-uncompressed
3657 Image Name: 2.4.4 kernel for TQM850L
3658 Created: Wed Jul 19 02:34:59 2000
3659 Image Type: PowerPC Linux Kernel Image (uncompressed)
3660 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3661 Load Address: 0x00000000
3662 Entry Point: 0x00000000
3665 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3666 when your kernel is intended to use an initial ramdisk:
3668 -> tools/mkimage -n 'Simple Ramdisk Image' \
3669 > -A ppc -O linux -T ramdisk -C gzip \
3670 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3671 Image Name: Simple Ramdisk Image
3672 Created: Wed Jan 12 14:01:50 2000
3673 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3674 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3675 Load Address: 0x00000000
3676 Entry Point: 0x00000000
3679 Installing a Linux Image:
3680 -------------------------
3682 To downloading a U-Boot image over the serial (console) interface,
3683 you must convert the image to S-Record format:
3685 objcopy -I binary -O srec examples/image examples/image.srec
3687 The 'objcopy' does not understand the information in the U-Boot
3688 image header, so the resulting S-Record file will be relative to
3689 address 0x00000000. To load it to a given address, you need to
3690 specify the target address as 'offset' parameter with the 'loads'
3693 Example: install the image to address 0x40100000 (which on the
3694 TQM8xxL is in the first Flash bank):
3696 => erase 40100000 401FFFFF
3702 ## Ready for S-Record download ...
3703 ~>examples/image.srec
3704 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3706 15989 15990 15991 15992
3707 [file transfer complete]
3709 ## Start Addr = 0x00000000
3712 You can check the success of the download using the 'iminfo' command;
3713 this includes a checksum verification so you can be sure no data
3714 corruption happened:
3718 ## Checking Image at 40100000 ...
3719 Image Name: 2.2.13 for initrd on TQM850L
3720 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3721 Data Size: 335725 Bytes = 327 kB = 0 MB
3722 Load Address: 00000000
3723 Entry Point: 0000000c
3724 Verifying Checksum ... OK
3730 The "bootm" command is used to boot an application that is stored in
3731 memory (RAM or Flash). In case of a Linux kernel image, the contents
3732 of the "bootargs" environment variable is passed to the kernel as
3733 parameters. You can check and modify this variable using the
3734 "printenv" and "setenv" commands:
3737 => printenv bootargs
3738 bootargs=root=/dev/ram
3740 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3742 => printenv bootargs
3743 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3746 ## Booting Linux kernel at 40020000 ...
3747 Image Name: 2.2.13 for NFS on TQM850L
3748 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3749 Data Size: 381681 Bytes = 372 kB = 0 MB
3750 Load Address: 00000000
3751 Entry Point: 0000000c
3752 Verifying Checksum ... OK
3753 Uncompressing Kernel Image ... OK
3754 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
3755 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3756 time_init: decrementer frequency = 187500000/60
3757 Calibrating delay loop... 49.77 BogoMIPS
3758 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3761 If you want to boot a Linux kernel with initial RAM disk, you pass
3762 the memory addresses of both the kernel and the initrd image (PPBCOOT
3763 format!) to the "bootm" command:
3765 => imi 40100000 40200000
3767 ## Checking Image at 40100000 ...
3768 Image Name: 2.2.13 for initrd on TQM850L
3769 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3770 Data Size: 335725 Bytes = 327 kB = 0 MB
3771 Load Address: 00000000
3772 Entry Point: 0000000c
3773 Verifying Checksum ... OK
3775 ## Checking Image at 40200000 ...
3776 Image Name: Simple Ramdisk Image
3777 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3778 Data Size: 566530 Bytes = 553 kB = 0 MB
3779 Load Address: 00000000
3780 Entry Point: 00000000
3781 Verifying Checksum ... OK
3783 => bootm 40100000 40200000
3784 ## Booting Linux kernel at 40100000 ...
3785 Image Name: 2.2.13 for initrd on TQM850L
3786 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3787 Data Size: 335725 Bytes = 327 kB = 0 MB
3788 Load Address: 00000000
3789 Entry Point: 0000000c
3790 Verifying Checksum ... OK
3791 Uncompressing Kernel Image ... OK
3792 ## Loading RAMDisk Image at 40200000 ...
3793 Image Name: Simple Ramdisk Image
3794 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3795 Data Size: 566530 Bytes = 553 kB = 0 MB
3796 Load Address: 00000000
3797 Entry Point: 00000000
3798 Verifying Checksum ... OK
3799 Loading Ramdisk ... OK
3800 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
3801 Boot arguments: root=/dev/ram
3802 time_init: decrementer frequency = 187500000/60
3803 Calibrating delay loop... 49.77 BogoMIPS
3805 RAMDISK: Compressed image found at block 0
3806 VFS: Mounted root (ext2 filesystem).
3810 Boot Linux and pass a flat device tree:
3813 First, U-Boot must be compiled with the appropriate defines. See the section
3814 titled "Linux Kernel Interface" above for a more in depth explanation. The
3815 following is an example of how to start a kernel and pass an updated
3821 oft=oftrees/mpc8540ads.dtb
3822 => tftp $oftaddr $oft
3823 Speed: 1000, full duplex
3825 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3826 Filename 'oftrees/mpc8540ads.dtb'.
3827 Load address: 0x300000
3830 Bytes transferred = 4106 (100a hex)
3831 => tftp $loadaddr $bootfile
3832 Speed: 1000, full duplex
3834 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3836 Load address: 0x200000
3837 Loading:############
3839 Bytes transferred = 1029407 (fb51f hex)
3844 => bootm $loadaddr - $oftaddr
3845 ## Booting image at 00200000 ...
3846 Image Name: Linux-2.6.17-dirty
3847 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3848 Data Size: 1029343 Bytes = 1005.2 kB
3849 Load Address: 00000000
3850 Entry Point: 00000000
3851 Verifying Checksum ... OK
3852 Uncompressing Kernel Image ... OK
3853 Booting using flat device tree at 0x300000
3854 Using MPC85xx ADS machine description
3855 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3859 More About U-Boot Image Types:
3860 ------------------------------
3862 U-Boot supports the following image types:
3864 "Standalone Programs" are directly runnable in the environment
3865 provided by U-Boot; it is expected that (if they behave
3866 well) you can continue to work in U-Boot after return from
3867 the Standalone Program.
3868 "OS Kernel Images" are usually images of some Embedded OS which
3869 will take over control completely. Usually these programs
3870 will install their own set of exception handlers, device
3871 drivers, set up the MMU, etc. - this means, that you cannot
3872 expect to re-enter U-Boot except by resetting the CPU.
3873 "RAMDisk Images" are more or less just data blocks, and their
3874 parameters (address, size) are passed to an OS kernel that is
3876 "Multi-File Images" contain several images, typically an OS
3877 (Linux) kernel image and one or more data images like
3878 RAMDisks. This construct is useful for instance when you want
3879 to boot over the network using BOOTP etc., where the boot
3880 server provides just a single image file, but you want to get
3881 for instance an OS kernel and a RAMDisk image.
3883 "Multi-File Images" start with a list of image sizes, each
3884 image size (in bytes) specified by an "uint32_t" in network
3885 byte order. This list is terminated by an "(uint32_t)0".
3886 Immediately after the terminating 0 follow the images, one by
3887 one, all aligned on "uint32_t" boundaries (size rounded up to
3888 a multiple of 4 bytes).
3890 "Firmware Images" are binary images containing firmware (like
3891 U-Boot or FPGA images) which usually will be programmed to
3894 "Script files" are command sequences that will be executed by
3895 U-Boot's command interpreter; this feature is especially
3896 useful when you configure U-Boot to use a real shell (hush)
3897 as command interpreter.
3903 One of the features of U-Boot is that you can dynamically load and
3904 run "standalone" applications, which can use some resources of
3905 U-Boot like console I/O functions or interrupt services.
3907 Two simple examples are included with the sources:
3912 'examples/hello_world.c' contains a small "Hello World" Demo
3913 application; it is automatically compiled when you build U-Boot.
3914 It's configured to run at address 0x00040004, so you can play with it
3918 ## Ready for S-Record download ...
3919 ~>examples/hello_world.srec
3920 1 2 3 4 5 6 7 8 9 10 11 ...
3921 [file transfer complete]
3923 ## Start Addr = 0x00040004
3925 => go 40004 Hello World! This is a test.
3926 ## Starting application at 0x00040004 ...
3937 Hit any key to exit ...
3939 ## Application terminated, rc = 0x0
3941 Another example, which demonstrates how to register a CPM interrupt
3942 handler with the U-Boot code, can be found in 'examples/timer.c'.
3943 Here, a CPM timer is set up to generate an interrupt every second.
3944 The interrupt service routine is trivial, just printing a '.'
3945 character, but this is just a demo program. The application can be
3946 controlled by the following keys:
3948 ? - print current values og the CPM Timer registers
3949 b - enable interrupts and start timer
3950 e - stop timer and disable interrupts
3951 q - quit application
3954 ## Ready for S-Record download ...
3955 ~>examples/timer.srec
3956 1 2 3 4 5 6 7 8 9 10 11 ...
3957 [file transfer complete]
3959 ## Start Addr = 0x00040004
3962 ## Starting application at 0x00040004 ...
3965 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3968 [q, b, e, ?] Set interval 1000000 us
3971 [q, b, e, ?] ........
3972 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3975 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3978 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3981 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3983 [q, b, e, ?] ...Stopping timer
3985 [q, b, e, ?] ## Application terminated, rc = 0x0
3991 Over time, many people have reported problems when trying to use the
3992 "minicom" terminal emulation program for serial download. I (wd)
3993 consider minicom to be broken, and recommend not to use it. Under
3994 Unix, I recommend to use C-Kermit for general purpose use (and
3995 especially for kermit binary protocol download ("loadb" command), and
3996 use "cu" for S-Record download ("loads" command).
3998 Nevertheless, if you absolutely want to use it try adding this
3999 configuration to your "File transfer protocols" section:
4001 Name Program Name U/D FullScr IO-Red. Multi
4002 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
4003 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
4009 Starting at version 0.9.2, U-Boot supports NetBSD both as host
4010 (build U-Boot) and target system (boots NetBSD/mpc8xx).
4012 Building requires a cross environment; it is known to work on
4013 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
4014 need gmake since the Makefiles are not compatible with BSD make).
4015 Note that the cross-powerpc package does not install include files;
4016 attempting to build U-Boot will fail because <machine/ansi.h> is
4017 missing. This file has to be installed and patched manually:
4019 # cd /usr/pkg/cross/powerpc-netbsd/include
4021 # ln -s powerpc machine
4022 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
4023 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
4025 Native builds *don't* work due to incompatibilities between native
4026 and U-Boot include files.
4028 Booting assumes that (the first part of) the image booted is a
4029 stage-2 loader which in turn loads and then invokes the kernel
4030 proper. Loader sources will eventually appear in the NetBSD source
4031 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
4032 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
4035 Implementation Internals:
4036 =========================
4038 The following is not intended to be a complete description of every
4039 implementation detail. However, it should help to understand the
4040 inner workings of U-Boot and make it easier to port it to custom
4044 Initial Stack, Global Data:
4045 ---------------------------
4047 The implementation of U-Boot is complicated by the fact that U-Boot
4048 starts running out of ROM (flash memory), usually without access to
4049 system RAM (because the memory controller is not initialized yet).
4050 This means that we don't have writable Data or BSS segments, and BSS
4051 is not initialized as zero. To be able to get a C environment working
4052 at all, we have to allocate at least a minimal stack. Implementation
4053 options for this are defined and restricted by the CPU used: Some CPU
4054 models provide on-chip memory (like the IMMR area on MPC8xx and
4055 MPC826x processors), on others (parts of) the data cache can be
4056 locked as (mis-) used as memory, etc.
4058 Chris Hallinan posted a good summary of these issues to the
4059 U-Boot mailing list:
4061 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
4062 From: "Chris Hallinan" <clh@net1plus.com>
4063 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
4066 Correct me if I'm wrong, folks, but the way I understand it
4067 is this: Using DCACHE as initial RAM for Stack, etc, does not
4068 require any physical RAM backing up the cache. The cleverness
4069 is that the cache is being used as a temporary supply of
4070 necessary storage before the SDRAM controller is setup. It's
4071 beyond the scope of this list to explain the details, but you
4072 can see how this works by studying the cache architecture and
4073 operation in the architecture and processor-specific manuals.
4075 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4076 is another option for the system designer to use as an
4077 initial stack/RAM area prior to SDRAM being available. Either
4078 option should work for you. Using CS 4 should be fine if your
4079 board designers haven't used it for something that would
4080 cause you grief during the initial boot! It is frequently not
4083 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
4084 with your processor/board/system design. The default value
4085 you will find in any recent u-boot distribution in
4086 walnut.h should work for you. I'd set it to a value larger
4087 than your SDRAM module. If you have a 64MB SDRAM module, set
4088 it above 400_0000. Just make sure your board has no resources
4089 that are supposed to respond to that address! That code in
4090 start.S has been around a while and should work as is when
4091 you get the config right.
4096 It is essential to remember this, since it has some impact on the C
4097 code for the initialization procedures:
4099 * Initialized global data (data segment) is read-only. Do not attempt
4102 * Do not use any uninitialized global data (or implicitely initialized
4103 as zero data - BSS segment) at all - this is undefined, initiali-
4104 zation is performed later (when relocating to RAM).
4106 * Stack space is very limited. Avoid big data buffers or things like
4109 Having only the stack as writable memory limits means we cannot use
4110 normal global data to share information beween the code. But it
4111 turned out that the implementation of U-Boot can be greatly
4112 simplified by making a global data structure (gd_t) available to all
4113 functions. We could pass a pointer to this data as argument to _all_
4114 functions, but this would bloat the code. Instead we use a feature of
4115 the GCC compiler (Global Register Variables) to share the data: we
4116 place a pointer (gd) to the global data into a register which we
4117 reserve for this purpose.
4119 When choosing a register for such a purpose we are restricted by the
4120 relevant (E)ABI specifications for the current architecture, and by
4121 GCC's implementation.
4123 For PowerPC, the following registers have specific use:
4125 R2: reserved for system use
4126 R3-R4: parameter passing and return values
4127 R5-R10: parameter passing
4128 R13: small data area pointer
4132 (U-Boot also uses R12 as internal GOT pointer. r12
4133 is a volatile register so r12 needs to be reset when
4134 going back and forth between asm and C)
4136 ==> U-Boot will use R2 to hold a pointer to the global data
4138 Note: on PPC, we could use a static initializer (since the
4139 address of the global data structure is known at compile time),
4140 but it turned out that reserving a register results in somewhat
4141 smaller code - although the code savings are not that big (on
4142 average for all boards 752 bytes for the whole U-Boot image,
4143 624 text + 127 data).
4145 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
4146 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
4148 ==> U-Boot will use P3 to hold a pointer to the global data
4150 On ARM, the following registers are used:
4152 R0: function argument word/integer result
4153 R1-R3: function argument word
4155 R10: stack limit (used only if stack checking if enabled)
4156 R11: argument (frame) pointer
4157 R12: temporary workspace
4160 R15: program counter
4162 ==> U-Boot will use R8 to hold a pointer to the global data
4164 On Nios II, the ABI is documented here:
4165 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4167 ==> U-Boot will use gp to hold a pointer to the global data
4169 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4170 to access small data sections, so gp is free.
4172 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4173 or current versions of GCC may "optimize" the code too much.
4178 U-Boot runs in system state and uses physical addresses, i.e. the
4179 MMU is not used either for address mapping nor for memory protection.
4181 The available memory is mapped to fixed addresses using the memory
4182 controller. In this process, a contiguous block is formed for each
4183 memory type (Flash, SDRAM, SRAM), even when it consists of several
4184 physical memory banks.
4186 U-Boot is installed in the first 128 kB of the first Flash bank (on
4187 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4188 booting and sizing and initializing DRAM, the code relocates itself
4189 to the upper end of DRAM. Immediately below the U-Boot code some
4190 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
4191 configuration setting]. Below that, a structure with global Board
4192 Info data is placed, followed by the stack (growing downward).
4194 Additionally, some exception handler code is copied to the low 8 kB
4195 of DRAM (0x00000000 ... 0x00001FFF).
4197 So a typical memory configuration with 16 MB of DRAM could look like
4200 0x0000 0000 Exception Vector code
4203 0x0000 2000 Free for Application Use
4209 0x00FB FF20 Monitor Stack (Growing downward)
4210 0x00FB FFAC Board Info Data and permanent copy of global data
4211 0x00FC 0000 Malloc Arena
4214 0x00FE 0000 RAM Copy of Monitor Code
4215 ... eventually: LCD or video framebuffer
4216 ... eventually: pRAM (Protected RAM - unchanged by reset)
4217 0x00FF FFFF [End of RAM]
4220 System Initialization:
4221 ----------------------
4223 In the reset configuration, U-Boot starts at the reset entry point
4224 (on most PowerPC systems at address 0x00000100). Because of the reset
4225 configuration for CS0# this is a mirror of the onboard Flash memory.
4226 To be able to re-map memory U-Boot then jumps to its link address.
4227 To be able to implement the initialization code in C, a (small!)
4228 initial stack is set up in the internal Dual Ported RAM (in case CPUs
4229 which provide such a feature like MPC8xx or MPC8260), or in a locked
4230 part of the data cache. After that, U-Boot initializes the CPU core,
4231 the caches and the SIU.
4233 Next, all (potentially) available memory banks are mapped using a
4234 preliminary mapping. For example, we put them on 512 MB boundaries
4235 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4236 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4237 programmed for SDRAM access. Using the temporary configuration, a
4238 simple memory test is run that determines the size of the SDRAM
4241 When there is more than one SDRAM bank, and the banks are of
4242 different size, the largest is mapped first. For equal size, the first
4243 bank (CS2#) is mapped first. The first mapping is always for address
4244 0x00000000, with any additional banks following immediately to create
4245 contiguous memory starting from 0.
4247 Then, the monitor installs itself at the upper end of the SDRAM area
4248 and allocates memory for use by malloc() and for the global Board
4249 Info data; also, the exception vector code is copied to the low RAM
4250 pages, and the final stack is set up.
4252 Only after this relocation will you have a "normal" C environment;
4253 until that you are restricted in several ways, mostly because you are
4254 running from ROM, and because the code will have to be relocated to a
4258 U-Boot Porting Guide:
4259 ----------------------
4261 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4265 int main(int argc, char *argv[])
4267 sighandler_t no_more_time;
4269 signal(SIGALRM, no_more_time);
4270 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4272 if (available_money > available_manpower) {
4273 Pay consultant to port U-Boot;
4277 Download latest U-Boot source;
4279 Subscribe to u-boot mailing list;
4282 email("Hi, I am new to U-Boot, how do I get started?");
4285 Read the README file in the top level directory;
4286 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4287 Read applicable doc/*.README;
4288 Read the source, Luke;
4289 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4292 if (available_money > toLocalCurrency ($2500))
4295 Add a lot of aggravation and time;
4297 if (a similar board exists) { /* hopefully... */
4298 cp -a board/<similar> board/<myboard>
4299 cp include/configs/<similar>.h include/configs/<myboard>.h
4301 Create your own board support subdirectory;
4302 Create your own board include/configs/<myboard>.h file;
4304 Edit new board/<myboard> files
4305 Edit new include/configs/<myboard>.h
4310 Add / modify source code;
4314 email("Hi, I am having problems...");
4316 Send patch file to the U-Boot email list;
4317 if (reasonable critiques)
4318 Incorporate improvements from email list code review;
4320 Defend code as written;
4326 void no_more_time (int sig)
4335 All contributions to U-Boot should conform to the Linux kernel
4336 coding style; see the file "Documentation/CodingStyle" and the script
4337 "scripts/Lindent" in your Linux kernel source directory. In sources
4338 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
4339 spaces before parameters to function calls) is actually used.
4341 Source files originating from a different project (for example the
4342 MTD subsystem) are generally exempt from these guidelines and are not
4343 reformated to ease subsequent migration to newer versions of those
4346 Please note that U-Boot is implemented in C (and to some small parts in
4347 Assembler); no C++ is used, so please do not use C++ style comments (//)
4350 Please also stick to the following formatting rules:
4351 - remove any trailing white space
4352 - use TAB characters for indentation, not spaces
4353 - make sure NOT to use DOS '\r\n' line feeds
4354 - do not add more than 2 empty lines to source files
4355 - do not add trailing empty lines to source files
4357 Submissions which do not conform to the standards may be returned
4358 with a request to reformat the changes.
4364 Since the number of patches for U-Boot is growing, we need to
4365 establish some rules. Submissions which do not conform to these rules
4366 may be rejected, even when they contain important and valuable stuff.
4368 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4370 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4371 see http://lists.denx.de/mailman/listinfo/u-boot
4373 When you send a patch, please include the following information with
4376 * For bug fixes: a description of the bug and how your patch fixes
4377 this bug. Please try to include a way of demonstrating that the
4378 patch actually fixes something.
4380 * For new features: a description of the feature and your
4383 * A CHANGELOG entry as plaintext (separate from the patch)
4385 * For major contributions, your entry to the CREDITS file
4387 * When you add support for a new board, don't forget to add this
4388 board to the MAKEALL script, too.
4390 * If your patch adds new configuration options, don't forget to
4391 document these in the README file.
4393 * The patch itself. If you are using git (which is *strongly*
4394 recommended) you can easily generate the patch using the
4395 "git-format-patch". If you then use "git-send-email" to send it to
4396 the U-Boot mailing list, you will avoid most of the common problems
4397 with some other mail clients.
4399 If you cannot use git, use "diff -purN OLD NEW". If your version of
4400 diff does not support these options, then get the latest version of
4403 The current directory when running this command shall be the parent
4404 directory of the U-Boot source tree (i. e. please make sure that
4405 your patch includes sufficient directory information for the
4408 We prefer patches as plain text. MIME attachments are discouraged,
4409 and compressed attachments must not be used.
4411 * If one logical set of modifications affects or creates several
4412 files, all these changes shall be submitted in a SINGLE patch file.
4414 * Changesets that contain different, unrelated modifications shall be
4415 submitted as SEPARATE patches, one patch per changeset.
4420 * Before sending the patch, run the MAKEALL script on your patched
4421 source tree and make sure that no errors or warnings are reported
4422 for any of the boards.
4424 * Keep your modifications to the necessary minimum: A patch
4425 containing several unrelated changes or arbitrary reformats will be
4426 returned with a request to re-formatting / split it.
4428 * If you modify existing code, make sure that your new code does not
4429 add to the memory footprint of the code ;-) Small is beautiful!
4430 When adding new features, these should compile conditionally only
4431 (using #ifdef), and the resulting code with the new feature
4432 disabled must not need more memory than the old code without your
4435 * Remember that there is a size limit of 100 kB per message on the
4436 u-boot mailing list. Bigger patches will be moderated. If they are
4437 reasonable and not too big, they will be acknowledged. But patches
4438 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob