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 /i386 Files generic to i386 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_DATE * support for RTC, date/time...
629 CONFIG_CMD_DHCP * DHCP support
630 CONFIG_CMD_DIAG * Diagnostics
631 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
632 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
633 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
634 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
635 CONFIG_CMD_DTT * Digital Therm and Thermostat
636 CONFIG_CMD_ECHO echo arguments
637 CONFIG_CMD_EDITENV edit env variable
638 CONFIG_CMD_EEPROM * EEPROM read/write support
639 CONFIG_CMD_ELF * bootelf, bootvx
640 CONFIG_CMD_SAVEENV saveenv
641 CONFIG_CMD_FDC * Floppy Disk Support
642 CONFIG_CMD_FAT * FAT partition support
643 CONFIG_CMD_FDOS * Dos diskette Support
644 CONFIG_CMD_FLASH flinfo, erase, protect
645 CONFIG_CMD_FPGA FPGA device initialization support
646 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
647 CONFIG_CMD_I2C * I2C serial bus support
648 CONFIG_CMD_IDE * IDE harddisk support
649 CONFIG_CMD_IMI iminfo
650 CONFIG_CMD_IMLS List all found images
651 CONFIG_CMD_IMMAP * IMMR dump support
652 CONFIG_CMD_IRQ * irqinfo
653 CONFIG_CMD_ITEST Integer/string test of 2 values
654 CONFIG_CMD_JFFS2 * JFFS2 Support
655 CONFIG_CMD_KGDB * kgdb
656 CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
657 CONFIG_CMD_LOADB loadb
658 CONFIG_CMD_LOADS loads
659 CONFIG_CMD_MD5SUM print md5 message digest
660 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
661 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
663 CONFIG_CMD_MISC Misc functions like sleep etc
664 CONFIG_CMD_MMC * MMC memory mapped support
665 CONFIG_CMD_MII * MII utility commands
666 CONFIG_CMD_MTDPARTS * MTD partition support
667 CONFIG_CMD_NAND * NAND support
668 CONFIG_CMD_NET bootp, tftpboot, rarpboot
669 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
670 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
671 CONFIG_CMD_PCI * pciinfo
672 CONFIG_CMD_PCMCIA * PCMCIA support
673 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
675 CONFIG_CMD_PORTIO * Port I/O
676 CONFIG_CMD_REGINFO * Register dump
677 CONFIG_CMD_RUN run command in env variable
678 CONFIG_CMD_SAVES * save S record dump
679 CONFIG_CMD_SCSI * SCSI Support
680 CONFIG_CMD_SDRAM * print SDRAM configuration information
681 (requires CONFIG_CMD_I2C)
682 CONFIG_CMD_SETGETDCR Support for DCR Register access
684 CONFIG_CMD_SHA1SUM print sha1 memory digest
685 (requires CONFIG_CMD_MEMORY)
686 CONFIG_CMD_SOURCE "source" command Support
687 CONFIG_CMD_SPI * SPI serial bus support
688 CONFIG_CMD_USB * USB support
689 CONFIG_CMD_VFD * VFD support (TRAB)
690 CONFIG_CMD_CDP * Cisco Discover Protocol support
691 CONFIG_CMD_FSL * Microblaze FSL support
694 EXAMPLE: If you want all functions except of network
695 support you can write:
697 #include "config_cmd_all.h"
698 #undef CONFIG_CMD_NET
701 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
703 Note: Don't enable the "icache" and "dcache" commands
704 (configuration option CONFIG_CMD_CACHE) unless you know
705 what you (and your U-Boot users) are doing. Data
706 cache cannot be enabled on systems like the 8xx or
707 8260 (where accesses to the IMMR region must be
708 uncached), and it cannot be disabled on all other
709 systems where we (mis-) use the data cache to hold an
710 initial stack and some data.
713 XXX - this list needs to get updated!
717 If this variable is defined, it enables watchdog
718 support. There must be support in the platform specific
719 code for a watchdog. For the 8xx and 8260 CPUs, the
720 SIU Watchdog feature is enabled in the SYPCR
724 CONFIG_VERSION_VARIABLE
725 If this variable is defined, an environment variable
726 named "ver" is created by U-Boot showing the U-Boot
727 version as printed by the "version" command.
728 This variable is readonly.
732 When CONFIG_CMD_DATE is selected, the type of the RTC
733 has to be selected, too. Define exactly one of the
736 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
737 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
738 CONFIG_RTC_MC13783 - use MC13783 RTC
739 CONFIG_RTC_MC146818 - use MC146818 RTC
740 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
741 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
742 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
743 CONFIG_RTC_DS164x - use Dallas DS164x RTC
744 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
745 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
746 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
748 Note that if the RTC uses I2C, then the I2C interface
749 must also be configured. See I2C Support, below.
752 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
753 CONFIG_PCA953X_INFO - enable pca953x info command
755 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
756 chip-ngpio pairs that tell the PCA953X driver the number of
757 pins supported by a particular chip.
759 Note that if the GPIO device uses I2C, then the I2C interface
760 must also be configured. See I2C Support, below.
764 When CONFIG_TIMESTAMP is selected, the timestamp
765 (date and time) of an image is printed by image
766 commands like bootm or iminfo. This option is
767 automatically enabled when you select CONFIG_CMD_DATE .
770 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
771 and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION
773 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
774 CONFIG_CMD_SCSI) you must configure support for at
775 least one partition type as well.
778 CONFIG_IDE_RESET_ROUTINE - this is defined in several
779 board configurations files but used nowhere!
781 CONFIG_IDE_RESET - is this is defined, IDE Reset will
782 be performed by calling the function
783 ide_set_reset(int reset)
784 which has to be defined in a board specific file
789 Set this to enable ATAPI support.
794 Set this to enable support for disks larger than 137GB
795 Also look at CONFIG_SYS_64BIT_LBA.
796 Whithout these , LBA48 support uses 32bit variables and will 'only'
797 support disks up to 2.1TB.
799 CONFIG_SYS_64BIT_LBA:
800 When enabled, makes the IDE subsystem use 64bit sector addresses.
804 At the moment only there is only support for the
805 SYM53C8XX SCSI controller; define
806 CONFIG_SCSI_SYM53C8XX to enable it.
808 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
809 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
810 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
811 maximum numbers of LUNs, SCSI ID's and target
813 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
815 - NETWORK Support (PCI):
817 Support for Intel 8254x gigabit chips.
819 CONFIG_E1000_FALLBACK_MAC
820 default MAC for empty EEPROM after production.
823 Support for Intel 82557/82559/82559ER chips.
824 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
825 write routine for first time initialisation.
828 Support for Digital 2114x chips.
829 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
830 modem chip initialisation (KS8761/QS6611).
833 Support for National dp83815 chips.
836 Support for National dp8382[01] gigabit chips.
838 - NETWORK Support (other):
840 CONFIG_DRIVER_AT91EMAC
841 Support for AT91RM9200 EMAC.
844 Define this to use reduced MII inteface
846 CONFIG_DRIVER_AT91EMAC_QUIET
847 If this defined, the driver is quiet.
848 The driver doen't show link status messages.
850 CONFIG_DRIVER_LAN91C96
851 Support for SMSC's LAN91C96 chips.
854 Define this to hold the physical address
855 of the LAN91C96's I/O space
857 CONFIG_LAN91C96_USE_32_BIT
858 Define this to enable 32 bit addressing
860 CONFIG_DRIVER_SMC91111
861 Support for SMSC's LAN91C111 chip
864 Define this to hold the physical address
865 of the device (I/O space)
867 CONFIG_SMC_USE_32_BIT
868 Define this if data bus is 32 bits
870 CONFIG_SMC_USE_IOFUNCS
871 Define this to use i/o functions instead of macros
872 (some hardware wont work with macros)
875 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
877 CONFIG_FTGMAC100_EGIGA
878 Define this to use GE link update with gigabit PHY.
879 Define this if FTGMAC100 is connected to gigabit PHY.
880 If your system has 10/100 PHY only, it might not occur
881 wrong behavior. Because PHY usually return timeout or
882 useless data when polling gigabit status and gigabit
883 control registers. This behavior won't affect the
884 correctnessof 10/100 link speed update.
887 Support for SMSC's LAN911x and LAN921x chips
890 Define this to hold the physical address
891 of the device (I/O space)
893 CONFIG_SMC911X_32_BIT
894 Define this if data bus is 32 bits
896 CONFIG_SMC911X_16_BIT
897 Define this if data bus is 16 bits. If your processor
898 automatically converts one 32 bit word to two 16 bit
899 words you may also try CONFIG_SMC911X_32_BIT.
902 Support for Renesas on-chip Ethernet controller
904 CONFIG_SH_ETHER_USE_PORT
905 Define the number of ports to be used
907 CONFIG_SH_ETHER_PHY_ADDR
908 Define the ETH PHY's address
910 CONFIG_SH_ETHER_CACHE_WRITEBACK
911 If this option is set, the driver enables cache flush.
914 At the moment only the UHCI host controller is
915 supported (PIP405, MIP405, MPC5200); define
916 CONFIG_USB_UHCI to enable it.
917 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
918 and define CONFIG_USB_STORAGE to enable the USB
921 Supported are USB Keyboards and USB Floppy drives
923 MPC5200 USB requires additional defines:
925 for 528 MHz Clock: 0x0001bbbb
929 for differential drivers: 0x00001000
930 for single ended drivers: 0x00005000
931 for differential drivers on PSC3: 0x00000100
932 for single ended drivers on PSC3: 0x00004100
933 CONFIG_SYS_USB_EVENT_POLL
934 May be defined to allow interrupt polling
935 instead of using asynchronous interrupts
938 Define the below if you wish to use the USB console.
939 Once firmware is rebuilt from a serial console issue the
940 command "setenv stdin usbtty; setenv stdout usbtty" and
941 attach your USB cable. The Unix command "dmesg" should print
942 it has found a new device. The environment variable usbtty
943 can be set to gserial or cdc_acm to enable your device to
944 appear to a USB host as a Linux gserial device or a
945 Common Device Class Abstract Control Model serial device.
946 If you select usbtty = gserial you should be able to enumerate
948 # modprobe usbserial vendor=0xVendorID product=0xProductID
949 else if using cdc_acm, simply setting the environment
950 variable usbtty to be cdc_acm should suffice. The following
951 might be defined in YourBoardName.h
954 Define this to build a UDC device
957 Define this to have a tty type of device available to
958 talk to the UDC device
960 CONFIG_SYS_CONSOLE_IS_IN_ENV
961 Define this if you want stdin, stdout &/or stderr to
965 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
966 Derive USB clock from external clock "blah"
967 - CONFIG_SYS_USB_EXTC_CLK 0x02
969 CONFIG_SYS_USB_BRG_CLK 0xBLAH
970 Derive USB clock from brgclk
971 - CONFIG_SYS_USB_BRG_CLK 0x04
973 If you have a USB-IF assigned VendorID then you may wish to
974 define your own vendor specific values either in BoardName.h
975 or directly in usbd_vendor_info.h. If you don't define
976 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
977 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
978 should pretend to be a Linux device to it's target host.
980 CONFIG_USBD_MANUFACTURER
981 Define this string as the name of your company for
982 - CONFIG_USBD_MANUFACTURER "my company"
984 CONFIG_USBD_PRODUCT_NAME
985 Define this string as the name of your product
986 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
989 Define this as your assigned Vendor ID from the USB
990 Implementors Forum. This *must* be a genuine Vendor ID
991 to avoid polluting the USB namespace.
992 - CONFIG_USBD_VENDORID 0xFFFF
994 CONFIG_USBD_PRODUCTID
995 Define this as the unique Product ID
997 - CONFIG_USBD_PRODUCTID 0xFFFF
1001 The MMC controller on the Intel PXA is supported. To
1002 enable this define CONFIG_MMC. The MMC can be
1003 accessed from the boot prompt by mapping the device
1004 to physical memory similar to flash. Command line is
1005 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1006 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1008 - Journaling Flash filesystem support:
1009 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1010 CONFIG_JFFS2_NAND_DEV
1011 Define these for a default partition on a NAND device
1013 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1014 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1015 Define these for a default partition on a NOR device
1017 CONFIG_SYS_JFFS_CUSTOM_PART
1018 Define this to create an own partition. You have to provide a
1019 function struct part_info* jffs2_part_info(int part_num)
1021 If you define only one JFFS2 partition you may also want to
1022 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1023 to disable the command chpart. This is the default when you
1024 have not defined a custom partition
1029 Define this to enable standard (PC-Style) keyboard
1033 Standard PC keyboard driver with US (is default) and
1034 GERMAN key layout (switch via environment 'keymap=de') support.
1035 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1036 for cfb_console. Supports cursor blinking.
1041 Define this to enable video support (for output to
1044 CONFIG_VIDEO_CT69000
1046 Enable Chips & Technologies 69000 Video chip
1048 CONFIG_VIDEO_SMI_LYNXEM
1049 Enable Silicon Motion SMI 712/710/810 Video chip. The
1050 video output is selected via environment 'videoout'
1051 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1054 For the CT69000 and SMI_LYNXEM drivers, videomode is
1055 selected via environment 'videomode'. Two different ways
1057 - "videomode=num" 'num' is a standard LiLo mode numbers.
1058 Following standard modes are supported (* is default):
1060 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1061 -------------+---------------------------------------------
1062 8 bits | 0x301* 0x303 0x305 0x161 0x307
1063 15 bits | 0x310 0x313 0x316 0x162 0x319
1064 16 bits | 0x311 0x314 0x317 0x163 0x31A
1065 24 bits | 0x312 0x315 0x318 ? 0x31B
1066 -------------+---------------------------------------------
1067 (i.e. setenv videomode 317; saveenv; reset;)
1069 - "videomode=bootargs" all the video parameters are parsed
1070 from the bootargs. (See drivers/video/videomodes.c)
1073 CONFIG_VIDEO_SED13806
1074 Enable Epson SED13806 driver. This driver supports 8bpp
1075 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1076 or CONFIG_VIDEO_SED13806_16BPP
1079 Enable the Freescale DIU video driver. Reference boards for
1080 SOCs that have a DIU should define this macro to enable DIU
1081 support, and should also define these other macros:
1087 CONFIG_VIDEO_SW_CURSOR
1088 CONFIG_VGA_AS_SINGLE_DEVICE
1090 CONFIG_VIDEO_BMP_LOGO
1092 The DIU driver will look for the 'monitor' environment variable,
1093 and if defined, enable the DIU as a console during boot. This
1094 variable should be set to one of these values:
1096 '0' Output video to the DVI connector
1097 '1' Output video to the LVDS connector
1098 '2' Output video to the Dual-Link LVDS connector
1103 Define this to enable a custom keyboard support.
1104 This simply calls drv_keyboard_init() which must be
1105 defined in your board-specific files.
1106 The only board using this so far is RBC823.
1108 - LCD Support: CONFIG_LCD
1110 Define this to enable LCD support (for output to LCD
1111 display); also select one of the supported displays
1112 by defining one of these:
1116 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1118 CONFIG_NEC_NL6448AC33:
1120 NEC NL6448AC33-18. Active, color, single scan.
1122 CONFIG_NEC_NL6448BC20
1124 NEC NL6448BC20-08. 6.5", 640x480.
1125 Active, color, single scan.
1127 CONFIG_NEC_NL6448BC33_54
1129 NEC NL6448BC33-54. 10.4", 640x480.
1130 Active, color, single scan.
1134 Sharp 320x240. Active, color, single scan.
1135 It isn't 16x9, and I am not sure what it is.
1137 CONFIG_SHARP_LQ64D341
1139 Sharp LQ64D341 display, 640x480.
1140 Active, color, single scan.
1144 HLD1045 display, 640x480.
1145 Active, color, single scan.
1149 Optrex CBL50840-2 NF-FW 99 22 M5
1151 Hitachi LMG6912RPFC-00T
1155 320x240. Black & white.
1157 Normally display is black on white background; define
1158 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1160 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1162 If this option is set, the environment is checked for
1163 a variable "splashimage". If found, the usual display
1164 of logo, copyright and system information on the LCD
1165 is suppressed and the BMP image at the address
1166 specified in "splashimage" is loaded instead. The
1167 console is redirected to the "nulldev", too. This
1168 allows for a "silent" boot where a splash screen is
1169 loaded very quickly after power-on.
1171 CONFIG_SPLASH_SCREEN_ALIGN
1173 If this option is set the splash image can be freely positioned
1174 on the screen. Environment variable "splashpos" specifies the
1175 position as "x,y". If a positive number is given it is used as
1176 number of pixel from left/top. If a negative number is given it
1177 is used as number of pixel from right/bottom. You can also
1178 specify 'm' for centering the image.
1181 setenv splashpos m,m
1182 => image at center of screen
1184 setenv splashpos 30,20
1185 => image at x = 30 and y = 20
1187 setenv splashpos -10,m
1188 => vertically centered image
1189 at x = dspWidth - bmpWidth - 9
1191 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1193 If this option is set, additionally to standard BMP
1194 images, gzipped BMP images can be displayed via the
1195 splashscreen support or the bmp command.
1197 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1199 If this option is set, 8-bit RLE compressed BMP images
1200 can be displayed via the splashscreen support or the
1203 - Compression support:
1206 If this option is set, support for bzip2 compressed
1207 images is included. If not, only uncompressed and gzip
1208 compressed images are supported.
1210 NOTE: the bzip2 algorithm requires a lot of RAM, so
1211 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1216 If this option is set, support for lzma compressed
1219 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1220 requires an amount of dynamic memory that is given by the
1223 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1225 Where lc and lp stand for, respectively, Literal context bits
1226 and Literal pos bits.
1228 This value is upper-bounded by 14MB in the worst case. Anyway,
1229 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1230 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1231 a very small buffer.
1233 Use the lzmainfo tool to determinate the lc and lp values and
1234 then calculate the amount of needed dynamic memory (ensuring
1235 the appropriate CONFIG_SYS_MALLOC_LEN value).
1240 The address of PHY on MII bus.
1242 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1244 The clock frequency of the MII bus
1248 If this option is set, support for speed/duplex
1249 detection of gigabit PHY is included.
1251 CONFIG_PHY_RESET_DELAY
1253 Some PHY like Intel LXT971A need extra delay after
1254 reset before any MII register access is possible.
1255 For such PHY, set this option to the usec delay
1256 required. (minimum 300usec for LXT971A)
1258 CONFIG_PHY_CMD_DELAY (ppc4xx)
1260 Some PHY like Intel LXT971A need extra delay after
1261 command issued before MII status register can be read
1271 Define a default value for Ethernet address to use
1272 for the respective Ethernet interface, in case this
1273 is not determined automatically.
1278 Define a default value for the IP address to use for
1279 the default Ethernet interface, in case this is not
1280 determined through e.g. bootp.
1282 - Server IP address:
1285 Defines a default value for the IP address of a TFTP
1286 server to contact when using the "tftboot" command.
1288 CONFIG_KEEP_SERVERADDR
1290 Keeps the server's MAC address, in the env 'serveraddr'
1291 for passing to bootargs (like Linux's netconsole option)
1293 - Multicast TFTP Mode:
1296 Defines whether you want to support multicast TFTP as per
1297 rfc-2090; for example to work with atftp. Lets lots of targets
1298 tftp down the same boot image concurrently. Note: the Ethernet
1299 driver in use must provide a function: mcast() to join/leave a
1302 CONFIG_BOOTP_RANDOM_DELAY
1303 - BOOTP Recovery Mode:
1304 CONFIG_BOOTP_RANDOM_DELAY
1306 If you have many targets in a network that try to
1307 boot using BOOTP, you may want to avoid that all
1308 systems send out BOOTP requests at precisely the same
1309 moment (which would happen for instance at recovery
1310 from a power failure, when all systems will try to
1311 boot, thus flooding the BOOTP server. Defining
1312 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1313 inserted before sending out BOOTP requests. The
1314 following delays are inserted then:
1316 1st BOOTP request: delay 0 ... 1 sec
1317 2nd BOOTP request: delay 0 ... 2 sec
1318 3rd BOOTP request: delay 0 ... 4 sec
1320 BOOTP requests: delay 0 ... 8 sec
1322 - DHCP Advanced Options:
1323 You can fine tune the DHCP functionality by defining
1324 CONFIG_BOOTP_* symbols:
1326 CONFIG_BOOTP_SUBNETMASK
1327 CONFIG_BOOTP_GATEWAY
1328 CONFIG_BOOTP_HOSTNAME
1329 CONFIG_BOOTP_NISDOMAIN
1330 CONFIG_BOOTP_BOOTPATH
1331 CONFIG_BOOTP_BOOTFILESIZE
1334 CONFIG_BOOTP_SEND_HOSTNAME
1335 CONFIG_BOOTP_NTPSERVER
1336 CONFIG_BOOTP_TIMEOFFSET
1337 CONFIG_BOOTP_VENDOREX
1339 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1340 environment variable, not the BOOTP server.
1342 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1343 serverip from a DHCP server, it is possible that more
1344 than one DNS serverip is offered to the client.
1345 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1346 serverip will be stored in the additional environment
1347 variable "dnsip2". The first DNS serverip is always
1348 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1351 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1352 to do a dynamic update of a DNS server. To do this, they
1353 need the hostname of the DHCP requester.
1354 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1355 of the "hostname" environment variable is passed as
1356 option 12 to the DHCP server.
1358 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1360 A 32bit value in microseconds for a delay between
1361 receiving a "DHCP Offer" and sending the "DHCP Request".
1362 This fixes a problem with certain DHCP servers that don't
1363 respond 100% of the time to a "DHCP request". E.g. On an
1364 AT91RM9200 processor running at 180MHz, this delay needed
1365 to be *at least* 15,000 usec before a Windows Server 2003
1366 DHCP server would reply 100% of the time. I recommend at
1367 least 50,000 usec to be safe. The alternative is to hope
1368 that one of the retries will be successful but note that
1369 the DHCP timeout and retry process takes a longer than
1373 CONFIG_CDP_DEVICE_ID
1375 The device id used in CDP trigger frames.
1377 CONFIG_CDP_DEVICE_ID_PREFIX
1379 A two character string which is prefixed to the MAC address
1384 A printf format string which contains the ascii name of
1385 the port. Normally is set to "eth%d" which sets
1386 eth0 for the first Ethernet, eth1 for the second etc.
1388 CONFIG_CDP_CAPABILITIES
1390 A 32bit integer which indicates the device capabilities;
1391 0x00000010 for a normal host which does not forwards.
1395 An ascii string containing the version of the software.
1399 An ascii string containing the name of the platform.
1403 A 32bit integer sent on the trigger.
1405 CONFIG_CDP_POWER_CONSUMPTION
1407 A 16bit integer containing the power consumption of the
1408 device in .1 of milliwatts.
1410 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1412 A byte containing the id of the VLAN.
1414 - Status LED: CONFIG_STATUS_LED
1416 Several configurations allow to display the current
1417 status using a LED. For instance, the LED will blink
1418 fast while running U-Boot code, stop blinking as
1419 soon as a reply to a BOOTP request was received, and
1420 start blinking slow once the Linux kernel is running
1421 (supported by a status LED driver in the Linux
1422 kernel). Defining CONFIG_STATUS_LED enables this
1425 - CAN Support: CONFIG_CAN_DRIVER
1427 Defining CONFIG_CAN_DRIVER enables CAN driver support
1428 on those systems that support this (optional)
1429 feature, like the TQM8xxL modules.
1431 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1433 These enable I2C serial bus commands. Defining either of
1434 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1435 include the appropriate I2C driver for the selected CPU.
1437 This will allow you to use i2c commands at the u-boot
1438 command line (as long as you set CONFIG_CMD_I2C in
1439 CONFIG_COMMANDS) and communicate with i2c based realtime
1440 clock chips. See common/cmd_i2c.c for a description of the
1441 command line interface.
1443 CONFIG_HARD_I2C selects a hardware I2C controller.
1445 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1446 bit-banging) driver instead of CPM or similar hardware
1449 There are several other quantities that must also be
1450 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1452 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1453 to be the frequency (in Hz) at which you wish your i2c bus
1454 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1455 the CPU's i2c node address).
1457 Now, the u-boot i2c code for the mpc8xx
1458 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1459 and so its address should therefore be cleared to 0 (See,
1460 eg, MPC823e User's Manual p.16-473). So, set
1461 CONFIG_SYS_I2C_SLAVE to 0.
1463 CONFIG_SYS_I2C_INIT_MPC5XXX
1465 When a board is reset during an i2c bus transfer
1466 chips might think that the current transfer is still
1467 in progress. Reset the slave devices by sending start
1468 commands until the slave device responds.
1470 That's all that's required for CONFIG_HARD_I2C.
1472 If you use the software i2c interface (CONFIG_SOFT_I2C)
1473 then the following macros need to be defined (examples are
1474 from include/configs/lwmon.h):
1478 (Optional). Any commands necessary to enable the I2C
1479 controller or configure ports.
1481 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1485 (Only for MPC8260 CPU). The I/O port to use (the code
1486 assumes both bits are on the same port). Valid values
1487 are 0..3 for ports A..D.
1491 The code necessary to make the I2C data line active
1492 (driven). If the data line is open collector, this
1495 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1499 The code necessary to make the I2C data line tri-stated
1500 (inactive). If the data line is open collector, this
1503 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1507 Code that returns TRUE if the I2C data line is high,
1510 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1514 If <bit> is TRUE, sets the I2C data line high. If it
1515 is FALSE, it clears it (low).
1517 eg: #define I2C_SDA(bit) \
1518 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1519 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1523 If <bit> is TRUE, sets the I2C clock line high. If it
1524 is FALSE, it clears it (low).
1526 eg: #define I2C_SCL(bit) \
1527 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1528 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1532 This delay is invoked four times per clock cycle so this
1533 controls the rate of data transfer. The data rate thus
1534 is 1 / (I2C_DELAY * 4). Often defined to be something
1537 #define I2C_DELAY udelay(2)
1539 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1541 If your arch supports the generic GPIO framework (asm/gpio.h),
1542 then you may alternatively define the two GPIOs that are to be
1543 used as SCL / SDA. Any of the previous I2C_xxx macros will
1544 have GPIO-based defaults assigned to them as appropriate.
1546 You should define these to the GPIO value as given directly to
1547 the generic GPIO functions.
1549 CONFIG_SYS_I2C_INIT_BOARD
1551 When a board is reset during an i2c bus transfer
1552 chips might think that the current transfer is still
1553 in progress. On some boards it is possible to access
1554 the i2c SCLK line directly, either by using the
1555 processor pin as a GPIO or by having a second pin
1556 connected to the bus. If this option is defined a
1557 custom i2c_init_board() routine in boards/xxx/board.c
1558 is run early in the boot sequence.
1560 CONFIG_SYS_I2C_BOARD_LATE_INIT
1562 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1563 defined a custom i2c_board_late_init() routine in
1564 boards/xxx/board.c is run AFTER the operations in i2c_init()
1565 is completed. This callpoint can be used to unreset i2c bus
1566 using CPU i2c controller register accesses for CPUs whose i2c
1567 controller provide such a method. It is called at the end of
1568 i2c_init() to allow i2c_init operations to setup the i2c bus
1569 controller on the CPU (e.g. setting bus speed & slave address).
1571 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1573 This option enables configuration of bi_iic_fast[] flags
1574 in u-boot bd_info structure based on u-boot environment
1575 variable "i2cfast". (see also i2cfast)
1577 CONFIG_I2C_MULTI_BUS
1579 This option allows the use of multiple I2C buses, each of which
1580 must have a controller. At any point in time, only one bus is
1581 active. To switch to a different bus, use the 'i2c dev' command.
1582 Note that bus numbering is zero-based.
1584 CONFIG_SYS_I2C_NOPROBES
1586 This option specifies a list of I2C devices that will be skipped
1587 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1588 is set, specify a list of bus-device pairs. Otherwise, specify
1589 a 1D array of device addresses
1592 #undef CONFIG_I2C_MULTI_BUS
1593 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1595 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1597 #define CONFIG_I2C_MULTI_BUS
1598 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1600 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1602 CONFIG_SYS_SPD_BUS_NUM
1604 If defined, then this indicates the I2C bus number for DDR SPD.
1605 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1607 CONFIG_SYS_RTC_BUS_NUM
1609 If defined, then this indicates the I2C bus number for the RTC.
1610 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1612 CONFIG_SYS_DTT_BUS_NUM
1614 If defined, then this indicates the I2C bus number for the DTT.
1615 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1617 CONFIG_SYS_I2C_DTT_ADDR:
1619 If defined, specifies the I2C address of the DTT device.
1620 If not defined, then U-Boot uses predefined value for
1621 specified DTT device.
1625 Define this option if you want to use Freescale's I2C driver in
1626 drivers/i2c/fsl_i2c.c.
1630 Define this option if you have I2C devices reached over 1 .. n
1631 I2C Muxes like the pca9544a. This option addes a new I2C
1632 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1633 new I2C Bus to the existing I2C Busses. If you select the
1634 new Bus with "i2c dev", u-bbot sends first the commandos for
1635 the muxes to activate this new "bus".
1637 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1641 Adding a new I2C Bus reached over 2 pca9544a muxes
1642 The First mux with address 70 and channel 6
1643 The Second mux with address 71 and channel 4
1645 => i2c bus pca9544a:70:6:pca9544a:71:4
1647 Use the "i2c bus" command without parameter, to get a list
1648 of I2C Busses with muxes:
1651 Busses reached over muxes:
1653 reached over Mux(es):
1656 reached over Mux(es):
1661 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1662 u-boot sends First the Commando to the mux@70 to enable
1663 channel 6, and then the Commando to the mux@71 to enable
1666 After that, you can use the "normal" i2c commands as
1667 usual, to communicate with your I2C devices behind
1670 This option is actually implemented for the bitbanging
1671 algorithm in common/soft_i2c.c and for the Hardware I2C
1672 Bus on the MPC8260. But it should be not so difficult
1673 to add this option to other architectures.
1675 CONFIG_SOFT_I2C_READ_REPEATED_START
1677 defining this will force the i2c_read() function in
1678 the soft_i2c driver to perform an I2C repeated start
1679 between writing the address pointer and reading the
1680 data. If this define is omitted the default behaviour
1681 of doing a stop-start sequence will be used. Most I2C
1682 devices can use either method, but some require one or
1685 - SPI Support: CONFIG_SPI
1687 Enables SPI driver (so far only tested with
1688 SPI EEPROM, also an instance works with Crystal A/D and
1689 D/As on the SACSng board)
1693 Enables the driver for SPI controller on SuperH. Currently
1694 only SH7757 is supported.
1698 Enables extended (16-bit) SPI EEPROM addressing.
1699 (symmetrical to CONFIG_I2C_X)
1703 Enables a software (bit-bang) SPI driver rather than
1704 using hardware support. This is a general purpose
1705 driver that only requires three general I/O port pins
1706 (two outputs, one input) to function. If this is
1707 defined, the board configuration must define several
1708 SPI configuration items (port pins to use, etc). For
1709 an example, see include/configs/sacsng.h.
1713 Enables a hardware SPI driver for general-purpose reads
1714 and writes. As with CONFIG_SOFT_SPI, the board configuration
1715 must define a list of chip-select function pointers.
1716 Currently supported on some MPC8xxx processors. For an
1717 example, see include/configs/mpc8349emds.h.
1721 Enables the driver for the SPI controllers on i.MX and MXC
1722 SoCs. Currently only i.MX31 is supported.
1724 - FPGA Support: CONFIG_FPGA
1726 Enables FPGA subsystem.
1728 CONFIG_FPGA_<vendor>
1730 Enables support for specific chip vendors.
1733 CONFIG_FPGA_<family>
1735 Enables support for FPGA family.
1736 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1740 Specify the number of FPGA devices to support.
1742 CONFIG_SYS_FPGA_PROG_FEEDBACK
1744 Enable printing of hash marks during FPGA configuration.
1746 CONFIG_SYS_FPGA_CHECK_BUSY
1748 Enable checks on FPGA configuration interface busy
1749 status by the configuration function. This option
1750 will require a board or device specific function to
1755 If defined, a function that provides delays in the FPGA
1756 configuration driver.
1758 CONFIG_SYS_FPGA_CHECK_CTRLC
1759 Allow Control-C to interrupt FPGA configuration
1761 CONFIG_SYS_FPGA_CHECK_ERROR
1763 Check for configuration errors during FPGA bitfile
1764 loading. For example, abort during Virtex II
1765 configuration if the INIT_B line goes low (which
1766 indicated a CRC error).
1768 CONFIG_SYS_FPGA_WAIT_INIT
1770 Maximum time to wait for the INIT_B line to deassert
1771 after PROB_B has been deasserted during a Virtex II
1772 FPGA configuration sequence. The default time is 500
1775 CONFIG_SYS_FPGA_WAIT_BUSY
1777 Maximum time to wait for BUSY to deassert during
1778 Virtex II FPGA configuration. The default is 5 ms.
1780 CONFIG_SYS_FPGA_WAIT_CONFIG
1782 Time to wait after FPGA configuration. The default is
1785 - Configuration Management:
1788 If defined, this string will be added to the U-Boot
1789 version information (U_BOOT_VERSION)
1791 - Vendor Parameter Protection:
1793 U-Boot considers the values of the environment
1794 variables "serial#" (Board Serial Number) and
1795 "ethaddr" (Ethernet Address) to be parameters that
1796 are set once by the board vendor / manufacturer, and
1797 protects these variables from casual modification by
1798 the user. Once set, these variables are read-only,
1799 and write or delete attempts are rejected. You can
1800 change this behaviour:
1802 If CONFIG_ENV_OVERWRITE is #defined in your config
1803 file, the write protection for vendor parameters is
1804 completely disabled. Anybody can change or delete
1807 Alternatively, if you #define _both_ CONFIG_ETHADDR
1808 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1809 Ethernet address is installed in the environment,
1810 which can be changed exactly ONCE by the user. [The
1811 serial# is unaffected by this, i. e. it remains
1817 Define this variable to enable the reservation of
1818 "protected RAM", i. e. RAM which is not overwritten
1819 by U-Boot. Define CONFIG_PRAM to hold the number of
1820 kB you want to reserve for pRAM. You can overwrite
1821 this default value by defining an environment
1822 variable "pram" to the number of kB you want to
1823 reserve. Note that the board info structure will
1824 still show the full amount of RAM. If pRAM is
1825 reserved, a new environment variable "mem" will
1826 automatically be defined to hold the amount of
1827 remaining RAM in a form that can be passed as boot
1828 argument to Linux, for instance like that:
1830 setenv bootargs ... mem=\${mem}
1833 This way you can tell Linux not to use this memory,
1834 either, which results in a memory region that will
1835 not be affected by reboots.
1837 *WARNING* If your board configuration uses automatic
1838 detection of the RAM size, you must make sure that
1839 this memory test is non-destructive. So far, the
1840 following board configurations are known to be
1843 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1844 HERMES, IP860, RPXlite, LWMON, LANTEC,
1850 Define this variable to stop the system in case of a
1851 fatal error, so that you have to reset it manually.
1852 This is probably NOT a good idea for an embedded
1853 system where you want the system to reboot
1854 automatically as fast as possible, but it may be
1855 useful during development since you can try to debug
1856 the conditions that lead to the situation.
1858 CONFIG_NET_RETRY_COUNT
1860 This variable defines the number of retries for
1861 network operations like ARP, RARP, TFTP, or BOOTP
1862 before giving up the operation. If not defined, a
1863 default value of 5 is used.
1867 Timeout waiting for an ARP reply in milliseconds.
1869 - Command Interpreter:
1870 CONFIG_AUTO_COMPLETE
1872 Enable auto completion of commands using TAB.
1874 Note that this feature has NOT been implemented yet
1875 for the "hush" shell.
1878 CONFIG_SYS_HUSH_PARSER
1880 Define this variable to enable the "hush" shell (from
1881 Busybox) as command line interpreter, thus enabling
1882 powerful command line syntax like
1883 if...then...else...fi conditionals or `&&' and '||'
1884 constructs ("shell scripts").
1886 If undefined, you get the old, much simpler behaviour
1887 with a somewhat smaller memory footprint.
1890 CONFIG_SYS_PROMPT_HUSH_PS2
1892 This defines the secondary prompt string, which is
1893 printed when the command interpreter needs more input
1894 to complete a command. Usually "> ".
1898 In the current implementation, the local variables
1899 space and global environment variables space are
1900 separated. Local variables are those you define by
1901 simply typing `name=value'. To access a local
1902 variable later on, you have write `$name' or
1903 `${name}'; to execute the contents of a variable
1904 directly type `$name' at the command prompt.
1906 Global environment variables are those you use
1907 setenv/printenv to work with. To run a command stored
1908 in such a variable, you need to use the run command,
1909 and you must not use the '$' sign to access them.
1911 To store commands and special characters in a
1912 variable, please use double quotation marks
1913 surrounding the whole text of the variable, instead
1914 of the backslashes before semicolons and special
1917 - Commandline Editing and History:
1918 CONFIG_CMDLINE_EDITING
1920 Enable editing and History functions for interactive
1921 commandline input operations
1923 - Default Environment:
1924 CONFIG_EXTRA_ENV_SETTINGS
1926 Define this to contain any number of null terminated
1927 strings (variable = value pairs) that will be part of
1928 the default environment compiled into the boot image.
1930 For example, place something like this in your
1931 board's config file:
1933 #define CONFIG_EXTRA_ENV_SETTINGS \
1937 Warning: This method is based on knowledge about the
1938 internal format how the environment is stored by the
1939 U-Boot code. This is NOT an official, exported
1940 interface! Although it is unlikely that this format
1941 will change soon, there is no guarantee either.
1942 You better know what you are doing here.
1944 Note: overly (ab)use of the default environment is
1945 discouraged. Make sure to check other ways to preset
1946 the environment like the "source" command or the
1949 - DataFlash Support:
1950 CONFIG_HAS_DATAFLASH
1952 Defining this option enables DataFlash features and
1953 allows to read/write in Dataflash via the standard
1956 - SystemACE Support:
1959 Adding this option adds support for Xilinx SystemACE
1960 chips attached via some sort of local bus. The address
1961 of the chip must also be defined in the
1962 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
1964 #define CONFIG_SYSTEMACE
1965 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
1967 When SystemACE support is added, the "ace" device type
1968 becomes available to the fat commands, i.e. fatls.
1970 - TFTP Fixed UDP Port:
1973 If this is defined, the environment variable tftpsrcp
1974 is used to supply the TFTP UDP source port value.
1975 If tftpsrcp isn't defined, the normal pseudo-random port
1976 number generator is used.
1978 Also, the environment variable tftpdstp is used to supply
1979 the TFTP UDP destination port value. If tftpdstp isn't
1980 defined, the normal port 69 is used.
1982 The purpose for tftpsrcp is to allow a TFTP server to
1983 blindly start the TFTP transfer using the pre-configured
1984 target IP address and UDP port. This has the effect of
1985 "punching through" the (Windows XP) firewall, allowing
1986 the remainder of the TFTP transfer to proceed normally.
1987 A better solution is to properly configure the firewall,
1988 but sometimes that is not allowed.
1990 - Show boot progress:
1991 CONFIG_SHOW_BOOT_PROGRESS
1993 Defining this option allows to add some board-
1994 specific code (calling a user-provided function
1995 "show_boot_progress(int)") that enables you to show
1996 the system's boot progress on some display (for
1997 example, some LED's) on your board. At the moment,
1998 the following checkpoints are implemented:
2000 Legacy uImage format:
2003 1 common/cmd_bootm.c before attempting to boot an image
2004 -1 common/cmd_bootm.c Image header has bad magic number
2005 2 common/cmd_bootm.c Image header has correct magic number
2006 -2 common/cmd_bootm.c Image header has bad checksum
2007 3 common/cmd_bootm.c Image header has correct checksum
2008 -3 common/cmd_bootm.c Image data has bad checksum
2009 4 common/cmd_bootm.c Image data has correct checksum
2010 -4 common/cmd_bootm.c Image is for unsupported architecture
2011 5 common/cmd_bootm.c Architecture check OK
2012 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2013 6 common/cmd_bootm.c Image Type check OK
2014 -6 common/cmd_bootm.c gunzip uncompression error
2015 -7 common/cmd_bootm.c Unimplemented compression type
2016 7 common/cmd_bootm.c Uncompression OK
2017 8 common/cmd_bootm.c No uncompress/copy overwrite error
2018 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2020 9 common/image.c Start initial ramdisk verification
2021 -10 common/image.c Ramdisk header has bad magic number
2022 -11 common/image.c Ramdisk header has bad checksum
2023 10 common/image.c Ramdisk header is OK
2024 -12 common/image.c Ramdisk data has bad checksum
2025 11 common/image.c Ramdisk data has correct checksum
2026 12 common/image.c Ramdisk verification complete, start loading
2027 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2028 13 common/image.c Start multifile image verification
2029 14 common/image.c No initial ramdisk, no multifile, continue.
2031 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2033 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2034 -31 post/post.c POST test failed, detected by post_output_backlog()
2035 -32 post/post.c POST test failed, detected by post_run_single()
2037 34 common/cmd_doc.c before loading a Image from a DOC device
2038 -35 common/cmd_doc.c Bad usage of "doc" command
2039 35 common/cmd_doc.c correct usage of "doc" command
2040 -36 common/cmd_doc.c No boot device
2041 36 common/cmd_doc.c correct boot device
2042 -37 common/cmd_doc.c Unknown Chip ID on boot device
2043 37 common/cmd_doc.c correct chip ID found, device available
2044 -38 common/cmd_doc.c Read Error on boot device
2045 38 common/cmd_doc.c reading Image header from DOC device OK
2046 -39 common/cmd_doc.c Image header has bad magic number
2047 39 common/cmd_doc.c Image header has correct magic number
2048 -40 common/cmd_doc.c Error reading Image from DOC device
2049 40 common/cmd_doc.c Image header has correct magic number
2050 41 common/cmd_ide.c before loading a Image from a IDE device
2051 -42 common/cmd_ide.c Bad usage of "ide" command
2052 42 common/cmd_ide.c correct usage of "ide" command
2053 -43 common/cmd_ide.c No boot device
2054 43 common/cmd_ide.c boot device found
2055 -44 common/cmd_ide.c Device not available
2056 44 common/cmd_ide.c Device available
2057 -45 common/cmd_ide.c wrong partition selected
2058 45 common/cmd_ide.c partition selected
2059 -46 common/cmd_ide.c Unknown partition table
2060 46 common/cmd_ide.c valid partition table found
2061 -47 common/cmd_ide.c Invalid partition type
2062 47 common/cmd_ide.c correct partition type
2063 -48 common/cmd_ide.c Error reading Image Header on boot device
2064 48 common/cmd_ide.c reading Image Header from IDE device OK
2065 -49 common/cmd_ide.c Image header has bad magic number
2066 49 common/cmd_ide.c Image header has correct magic number
2067 -50 common/cmd_ide.c Image header has bad checksum
2068 50 common/cmd_ide.c Image header has correct checksum
2069 -51 common/cmd_ide.c Error reading Image from IDE device
2070 51 common/cmd_ide.c reading Image from IDE device OK
2071 52 common/cmd_nand.c before loading a Image from a NAND device
2072 -53 common/cmd_nand.c Bad usage of "nand" command
2073 53 common/cmd_nand.c correct usage of "nand" command
2074 -54 common/cmd_nand.c No boot device
2075 54 common/cmd_nand.c boot device found
2076 -55 common/cmd_nand.c Unknown Chip ID on boot device
2077 55 common/cmd_nand.c correct chip ID found, device available
2078 -56 common/cmd_nand.c Error reading Image Header on boot device
2079 56 common/cmd_nand.c reading Image Header from NAND device OK
2080 -57 common/cmd_nand.c Image header has bad magic number
2081 57 common/cmd_nand.c Image header has correct magic number
2082 -58 common/cmd_nand.c Error reading Image from NAND device
2083 58 common/cmd_nand.c reading Image from NAND device OK
2085 -60 common/env_common.c Environment has a bad CRC, using default
2087 64 net/eth.c starting with Ethernet configuration.
2088 -64 net/eth.c no Ethernet found.
2089 65 net/eth.c Ethernet found.
2091 -80 common/cmd_net.c usage wrong
2092 80 common/cmd_net.c before calling NetLoop()
2093 -81 common/cmd_net.c some error in NetLoop() occurred
2094 81 common/cmd_net.c NetLoop() back without error
2095 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2096 82 common/cmd_net.c trying automatic boot
2097 83 common/cmd_net.c running "source" command
2098 -83 common/cmd_net.c some error in automatic boot or "source" command
2099 84 common/cmd_net.c end without errors
2104 100 common/cmd_bootm.c Kernel FIT Image has correct format
2105 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2106 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2107 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2108 102 common/cmd_bootm.c Kernel unit name specified
2109 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2110 103 common/cmd_bootm.c Found configuration node
2111 104 common/cmd_bootm.c Got kernel subimage node offset
2112 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2113 105 common/cmd_bootm.c Kernel subimage hash verification OK
2114 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2115 106 common/cmd_bootm.c Architecture check OK
2116 -106 common/cmd_bootm.c Kernel subimage has wrong type
2117 107 common/cmd_bootm.c Kernel subimage type OK
2118 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2119 108 common/cmd_bootm.c Got kernel subimage data/size
2120 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2121 -109 common/cmd_bootm.c Can't get kernel subimage type
2122 -110 common/cmd_bootm.c Can't get kernel subimage comp
2123 -111 common/cmd_bootm.c Can't get kernel subimage os
2124 -112 common/cmd_bootm.c Can't get kernel subimage load address
2125 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2127 120 common/image.c Start initial ramdisk verification
2128 -120 common/image.c Ramdisk FIT image has incorrect format
2129 121 common/image.c Ramdisk FIT image has correct format
2130 122 common/image.c No ramdisk subimage unit name, using configuration
2131 -122 common/image.c Can't get configuration for ramdisk subimage
2132 123 common/image.c Ramdisk unit name specified
2133 -124 common/image.c Can't get ramdisk subimage node offset
2134 125 common/image.c Got ramdisk subimage node offset
2135 -125 common/image.c Ramdisk subimage hash verification failed
2136 126 common/image.c Ramdisk subimage hash verification OK
2137 -126 common/image.c Ramdisk subimage for unsupported architecture
2138 127 common/image.c Architecture check OK
2139 -127 common/image.c Can't get ramdisk subimage data/size
2140 128 common/image.c Got ramdisk subimage data/size
2141 129 common/image.c Can't get ramdisk load address
2142 -129 common/image.c Got ramdisk load address
2144 -130 common/cmd_doc.c Incorrect FIT image format
2145 131 common/cmd_doc.c FIT image format OK
2147 -140 common/cmd_ide.c Incorrect FIT image format
2148 141 common/cmd_ide.c FIT image format OK
2150 -150 common/cmd_nand.c Incorrect FIT image format
2151 151 common/cmd_nand.c FIT image format OK
2153 - Automatic software updates via TFTP server
2155 CONFIG_UPDATE_TFTP_CNT_MAX
2156 CONFIG_UPDATE_TFTP_MSEC_MAX
2158 These options enable and control the auto-update feature;
2159 for a more detailed description refer to doc/README.update.
2161 - MTD Support (mtdparts command, UBI support)
2164 Adds the MTD device infrastructure from the Linux kernel.
2165 Needed for mtdparts command support.
2167 CONFIG_MTD_PARTITIONS
2169 Adds the MTD partitioning infrastructure from the Linux
2170 kernel. Needed for UBI support.
2176 [so far only for SMDK2400 and TRAB boards]
2178 - Modem support enable:
2179 CONFIG_MODEM_SUPPORT
2181 - RTS/CTS Flow control enable:
2184 - Modem debug support:
2185 CONFIG_MODEM_SUPPORT_DEBUG
2187 Enables debugging stuff (char screen[1024], dbg())
2188 for modem support. Useful only with BDI2000.
2190 - Interrupt support (PPC):
2192 There are common interrupt_init() and timer_interrupt()
2193 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2194 for CPU specific initialization. interrupt_init_cpu()
2195 should set decrementer_count to appropriate value. If
2196 CPU resets decrementer automatically after interrupt
2197 (ppc4xx) it should set decrementer_count to zero.
2198 timer_interrupt() calls timer_interrupt_cpu() for CPU
2199 specific handling. If board has watchdog / status_led
2200 / other_activity_monitor it works automatically from
2201 general timer_interrupt().
2205 In the target system modem support is enabled when a
2206 specific key (key combination) is pressed during
2207 power-on. Otherwise U-Boot will boot normally
2208 (autoboot). The key_pressed() function is called from
2209 board_init(). Currently key_pressed() is a dummy
2210 function, returning 1 and thus enabling modem
2213 If there are no modem init strings in the
2214 environment, U-Boot proceed to autoboot; the
2215 previous output (banner, info printfs) will be
2218 See also: doc/README.Modem
2221 Configuration Settings:
2222 -----------------------
2224 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2225 undefine this when you're short of memory.
2227 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2228 width of the commands listed in the 'help' command output.
2230 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2231 prompt for user input.
2233 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2235 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2237 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2239 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2240 the application (usually a Linux kernel) when it is
2243 - CONFIG_SYS_BAUDRATE_TABLE:
2244 List of legal baudrate settings for this board.
2246 - CONFIG_SYS_CONSOLE_INFO_QUIET
2247 Suppress display of console information at boot.
2249 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2250 If the board specific function
2251 extern int overwrite_console (void);
2252 returns 1, the stdin, stderr and stdout are switched to the
2253 serial port, else the settings in the environment are used.
2255 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2256 Enable the call to overwrite_console().
2258 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2259 Enable overwrite of previous console environment settings.
2261 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2262 Begin and End addresses of the area used by the
2265 - CONFIG_SYS_ALT_MEMTEST:
2266 Enable an alternate, more extensive memory test.
2268 - CONFIG_SYS_MEMTEST_SCRATCH:
2269 Scratch address used by the alternate memory test
2270 You only need to set this if address zero isn't writeable
2272 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2273 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2274 this specified memory area will get subtracted from the top
2275 (end) of RAM and won't get "touched" at all by U-Boot. By
2276 fixing up gd->ram_size the Linux kernel should gets passed
2277 the now "corrected" memory size and won't touch it either.
2278 This should work for arch/ppc and arch/powerpc. Only Linux
2279 board ports in arch/powerpc with bootwrapper support that
2280 recalculate the memory size from the SDRAM controller setup
2281 will have to get fixed in Linux additionally.
2283 This option can be used as a workaround for the 440EPx/GRx
2284 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2287 WARNING: Please make sure that this value is a multiple of
2288 the Linux page size (normally 4k). If this is not the case,
2289 then the end address of the Linux memory will be located at a
2290 non page size aligned address and this could cause major
2293 - CONFIG_SYS_TFTP_LOADADDR:
2294 Default load address for network file downloads
2296 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2297 Enable temporary baudrate change while serial download
2299 - CONFIG_SYS_SDRAM_BASE:
2300 Physical start address of SDRAM. _Must_ be 0 here.
2302 - CONFIG_SYS_MBIO_BASE:
2303 Physical start address of Motherboard I/O (if using a
2306 - CONFIG_SYS_FLASH_BASE:
2307 Physical start address of Flash memory.
2309 - CONFIG_SYS_MONITOR_BASE:
2310 Physical start address of boot monitor code (set by
2311 make config files to be same as the text base address
2312 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
2313 CONFIG_SYS_FLASH_BASE when booting from flash.
2315 - CONFIG_SYS_MONITOR_LEN:
2316 Size of memory reserved for monitor code, used to
2317 determine _at_compile_time_ (!) if the environment is
2318 embedded within the U-Boot image, or in a separate
2321 - CONFIG_SYS_MALLOC_LEN:
2322 Size of DRAM reserved for malloc() use.
2324 - CONFIG_SYS_BOOTM_LEN:
2325 Normally compressed uImages are limited to an
2326 uncompressed size of 8 MBytes. If this is not enough,
2327 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2328 to adjust this setting to your needs.
2330 - CONFIG_SYS_BOOTMAPSZ:
2331 Maximum size of memory mapped by the startup code of
2332 the Linux kernel; all data that must be processed by
2333 the Linux kernel (bd_info, boot arguments, FDT blob if
2334 used) must be put below this limit, unless "bootm_low"
2335 enviroment variable is defined and non-zero. In such case
2336 all data for the Linux kernel must be between "bootm_low"
2337 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ.
2339 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
2340 Enable initrd_high functionality. If defined then the
2341 initrd_high feature is enabled and the bootm ramdisk subcommand
2344 - CONFIG_SYS_BOOT_GET_CMDLINE:
2345 Enables allocating and saving kernel cmdline in space between
2346 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2348 - CONFIG_SYS_BOOT_GET_KBD:
2349 Enables allocating and saving a kernel copy of the bd_info in
2350 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2352 - CONFIG_SYS_MAX_FLASH_BANKS:
2353 Max number of Flash memory banks
2355 - CONFIG_SYS_MAX_FLASH_SECT:
2356 Max number of sectors on a Flash chip
2358 - CONFIG_SYS_FLASH_ERASE_TOUT:
2359 Timeout for Flash erase operations (in ms)
2361 - CONFIG_SYS_FLASH_WRITE_TOUT:
2362 Timeout for Flash write operations (in ms)
2364 - CONFIG_SYS_FLASH_LOCK_TOUT
2365 Timeout for Flash set sector lock bit operation (in ms)
2367 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2368 Timeout for Flash clear lock bits operation (in ms)
2370 - CONFIG_SYS_FLASH_PROTECTION
2371 If defined, hardware flash sectors protection is used
2372 instead of U-Boot software protection.
2374 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2376 Enable TFTP transfers directly to flash memory;
2377 without this option such a download has to be
2378 performed in two steps: (1) download to RAM, and (2)
2379 copy from RAM to flash.
2381 The two-step approach is usually more reliable, since
2382 you can check if the download worked before you erase
2383 the flash, but in some situations (when system RAM is
2384 too limited to allow for a temporary copy of the
2385 downloaded image) this option may be very useful.
2387 - CONFIG_SYS_FLASH_CFI:
2388 Define if the flash driver uses extra elements in the
2389 common flash structure for storing flash geometry.
2391 - CONFIG_FLASH_CFI_DRIVER
2392 This option also enables the building of the cfi_flash driver
2393 in the drivers directory
2395 - CONFIG_FLASH_CFI_MTD
2396 This option enables the building of the cfi_mtd driver
2397 in the drivers directory. The driver exports CFI flash
2400 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2401 Use buffered writes to flash.
2403 - CONFIG_FLASH_SPANSION_S29WS_N
2404 s29ws-n MirrorBit flash has non-standard addresses for buffered
2407 - CONFIG_SYS_FLASH_QUIET_TEST
2408 If this option is defined, the common CFI flash doesn't
2409 print it's warning upon not recognized FLASH banks. This
2410 is useful, if some of the configured banks are only
2411 optionally available.
2413 - CONFIG_FLASH_SHOW_PROGRESS
2414 If defined (must be an integer), print out countdown
2415 digits and dots. Recommended value: 45 (9..1) for 80
2416 column displays, 15 (3..1) for 40 column displays.
2418 - CONFIG_SYS_RX_ETH_BUFFER:
2419 Defines the number of Ethernet receive buffers. On some
2420 Ethernet controllers it is recommended to set this value
2421 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2422 buffers can be full shortly after enabling the interface
2423 on high Ethernet traffic.
2424 Defaults to 4 if not defined.
2426 - CONFIG_ENV_MAX_ENTRIES
2428 Maximum number of entries in the hash table that is used
2429 internally to store the environment settings. The default
2430 setting is supposed to be generous and should work in most
2431 cases. This setting can be used to tune behaviour; see
2432 lib/hashtable.c for details.
2434 The following definitions that deal with the placement and management
2435 of environment data (variable area); in general, we support the
2436 following configurations:
2438 - CONFIG_ENV_IS_IN_FLASH:
2440 Define this if the environment is in flash memory.
2442 a) The environment occupies one whole flash sector, which is
2443 "embedded" in the text segment with the U-Boot code. This
2444 happens usually with "bottom boot sector" or "top boot
2445 sector" type flash chips, which have several smaller
2446 sectors at the start or the end. For instance, such a
2447 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2448 such a case you would place the environment in one of the
2449 4 kB sectors - with U-Boot code before and after it. With
2450 "top boot sector" type flash chips, you would put the
2451 environment in one of the last sectors, leaving a gap
2452 between U-Boot and the environment.
2454 - CONFIG_ENV_OFFSET:
2456 Offset of environment data (variable area) to the
2457 beginning of flash memory; for instance, with bottom boot
2458 type flash chips the second sector can be used: the offset
2459 for this sector is given here.
2461 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2465 This is just another way to specify the start address of
2466 the flash sector containing the environment (instead of
2469 - CONFIG_ENV_SECT_SIZE:
2471 Size of the sector containing the environment.
2474 b) Sometimes flash chips have few, equal sized, BIG sectors.
2475 In such a case you don't want to spend a whole sector for
2480 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2481 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2482 of this flash sector for the environment. This saves
2483 memory for the RAM copy of the environment.
2485 It may also save flash memory if you decide to use this
2486 when your environment is "embedded" within U-Boot code,
2487 since then the remainder of the flash sector could be used
2488 for U-Boot code. It should be pointed out that this is
2489 STRONGLY DISCOURAGED from a robustness point of view:
2490 updating the environment in flash makes it always
2491 necessary to erase the WHOLE sector. If something goes
2492 wrong before the contents has been restored from a copy in
2493 RAM, your target system will be dead.
2495 - CONFIG_ENV_ADDR_REDUND
2496 CONFIG_ENV_SIZE_REDUND
2498 These settings describe a second storage area used to hold
2499 a redundant copy of the environment data, so that there is
2500 a valid backup copy in case there is a power failure during
2501 a "saveenv" operation.
2503 BE CAREFUL! Any changes to the flash layout, and some changes to the
2504 source code will make it necessary to adapt <board>/u-boot.lds*
2508 - CONFIG_ENV_IS_IN_NVRAM:
2510 Define this if you have some non-volatile memory device
2511 (NVRAM, battery buffered SRAM) which you want to use for the
2517 These two #defines are used to determine the memory area you
2518 want to use for environment. It is assumed that this memory
2519 can just be read and written to, without any special
2522 BE CAREFUL! The first access to the environment happens quite early
2523 in U-Boot initalization (when we try to get the setting of for the
2524 console baudrate). You *MUST* have mapped your NVRAM area then, or
2527 Please note that even with NVRAM we still use a copy of the
2528 environment in RAM: we could work on NVRAM directly, but we want to
2529 keep settings there always unmodified except somebody uses "saveenv"
2530 to save the current settings.
2533 - CONFIG_ENV_IS_IN_EEPROM:
2535 Use this if you have an EEPROM or similar serial access
2536 device and a driver for it.
2538 - CONFIG_ENV_OFFSET:
2541 These two #defines specify the offset and size of the
2542 environment area within the total memory of your EEPROM.
2544 - CONFIG_SYS_I2C_EEPROM_ADDR:
2545 If defined, specified the chip address of the EEPROM device.
2546 The default address is zero.
2548 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2549 If defined, the number of bits used to address bytes in a
2550 single page in the EEPROM device. A 64 byte page, for example
2551 would require six bits.
2553 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2554 If defined, the number of milliseconds to delay between
2555 page writes. The default is zero milliseconds.
2557 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2558 The length in bytes of the EEPROM memory array address. Note
2559 that this is NOT the chip address length!
2561 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2562 EEPROM chips that implement "address overflow" are ones
2563 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2564 address and the extra bits end up in the "chip address" bit
2565 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2568 Note that we consider the length of the address field to
2569 still be one byte because the extra address bits are hidden
2570 in the chip address.
2572 - CONFIG_SYS_EEPROM_SIZE:
2573 The size in bytes of the EEPROM device.
2575 - CONFIG_ENV_EEPROM_IS_ON_I2C
2576 define this, if you have I2C and SPI activated, and your
2577 EEPROM, which holds the environment, is on the I2C bus.
2579 - CONFIG_I2C_ENV_EEPROM_BUS
2580 if you have an Environment on an EEPROM reached over
2581 I2C muxes, you can define here, how to reach this
2582 EEPROM. For example:
2584 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
2586 EEPROM which holds the environment, is reached over
2587 a pca9547 i2c mux with address 0x70, channel 3.
2589 - CONFIG_ENV_IS_IN_DATAFLASH:
2591 Define this if you have a DataFlash memory device which you
2592 want to use for the environment.
2594 - CONFIG_ENV_OFFSET:
2598 These three #defines specify the offset and size of the
2599 environment area within the total memory of your DataFlash placed
2600 at the specified address.
2602 - CONFIG_ENV_IS_IN_NAND:
2604 Define this if you have a NAND device which you want to use
2605 for the environment.
2607 - CONFIG_ENV_OFFSET:
2610 These two #defines specify the offset and size of the environment
2611 area within the first NAND device. CONFIG_ENV_OFFSET must be
2612 aligned to an erase block boundary.
2614 - CONFIG_ENV_OFFSET_REDUND (optional):
2616 This setting describes a second storage area of CONFIG_ENV_SIZE
2617 size used to hold a redundant copy of the environment data, so
2618 that there is a valid backup copy in case there is a power failure
2619 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
2620 aligned to an erase block boundary.
2622 - CONFIG_ENV_RANGE (optional):
2624 Specifies the length of the region in which the environment
2625 can be written. This should be a multiple of the NAND device's
2626 block size. Specifying a range with more erase blocks than
2627 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
2628 the range to be avoided.
2630 - CONFIG_ENV_OFFSET_OOB (optional):
2632 Enables support for dynamically retrieving the offset of the
2633 environment from block zero's out-of-band data. The
2634 "nand env.oob" command can be used to record this offset.
2635 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
2636 using CONFIG_ENV_OFFSET_OOB.
2638 - CONFIG_NAND_ENV_DST
2640 Defines address in RAM to which the nand_spl code should copy the
2641 environment. If redundant environment is used, it will be copied to
2642 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2644 - CONFIG_SYS_SPI_INIT_OFFSET
2646 Defines offset to the initial SPI buffer area in DPRAM. The
2647 area is used at an early stage (ROM part) if the environment
2648 is configured to reside in the SPI EEPROM: We need a 520 byte
2649 scratch DPRAM area. It is used between the two initialization
2650 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2651 to be a good choice since it makes it far enough from the
2652 start of the data area as well as from the stack pointer.
2654 Please note that the environment is read-only until the monitor
2655 has been relocated to RAM and a RAM copy of the environment has been
2656 created; also, when using EEPROM you will have to use getenv_f()
2657 until then to read environment variables.
2659 The environment is protected by a CRC32 checksum. Before the monitor
2660 is relocated into RAM, as a result of a bad CRC you will be working
2661 with the compiled-in default environment - *silently*!!! [This is
2662 necessary, because the first environment variable we need is the
2663 "baudrate" setting for the console - if we have a bad CRC, we don't
2664 have any device yet where we could complain.]
2666 Note: once the monitor has been relocated, then it will complain if
2667 the default environment is used; a new CRC is computed as soon as you
2668 use the "saveenv" command to store a valid environment.
2670 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2671 Echo the inverted Ethernet link state to the fault LED.
2673 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2674 also needs to be defined.
2676 - CONFIG_SYS_FAULT_MII_ADDR:
2677 MII address of the PHY to check for the Ethernet link state.
2679 - CONFIG_NS16550_MIN_FUNCTIONS:
2680 Define this if you desire to only have use of the NS16550_init
2681 and NS16550_putc functions for the serial driver located at
2682 drivers/serial/ns16550.c. This option is useful for saving
2683 space for already greatly restricted images, including but not
2684 limited to NAND_SPL configurations.
2686 Low Level (hardware related) configuration options:
2687 ---------------------------------------------------
2689 - CONFIG_SYS_CACHELINE_SIZE:
2690 Cache Line Size of the CPU.
2692 - CONFIG_SYS_DEFAULT_IMMR:
2693 Default address of the IMMR after system reset.
2695 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2696 and RPXsuper) to be able to adjust the position of
2697 the IMMR register after a reset.
2699 - Floppy Disk Support:
2700 CONFIG_SYS_FDC_DRIVE_NUMBER
2702 the default drive number (default value 0)
2704 CONFIG_SYS_ISA_IO_STRIDE
2706 defines the spacing between FDC chipset registers
2709 CONFIG_SYS_ISA_IO_OFFSET
2711 defines the offset of register from address. It
2712 depends on which part of the data bus is connected to
2713 the FDC chipset. (default value 0)
2715 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
2716 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
2719 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
2720 fdc_hw_init() is called at the beginning of the FDC
2721 setup. fdc_hw_init() must be provided by the board
2722 source code. It is used to make hardware dependant
2725 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
2726 DO NOT CHANGE unless you know exactly what you're
2727 doing! (11-4) [MPC8xx/82xx systems only]
2729 - CONFIG_SYS_INIT_RAM_ADDR:
2731 Start address of memory area that can be used for
2732 initial data and stack; please note that this must be
2733 writable memory that is working WITHOUT special
2734 initialization, i. e. you CANNOT use normal RAM which
2735 will become available only after programming the
2736 memory controller and running certain initialization
2739 U-Boot uses the following memory types:
2740 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2741 - MPC824X: data cache
2742 - PPC4xx: data cache
2744 - CONFIG_SYS_GBL_DATA_OFFSET:
2746 Offset of the initial data structure in the memory
2747 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2748 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
2749 data is located at the end of the available space
2750 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
2751 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
2752 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2753 CONFIG_SYS_GBL_DATA_OFFSET) downward.
2756 On the MPC824X (or other systems that use the data
2757 cache for initial memory) the address chosen for
2758 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
2759 point to an otherwise UNUSED address space between
2760 the top of RAM and the start of the PCI space.
2762 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
2764 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
2766 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
2768 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
2770 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2772 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
2774 - CONFIG_SYS_OR_TIMING_SDRAM:
2777 - CONFIG_SYS_MAMR_PTA:
2778 periodic timer for refresh
2780 - CONFIG_SYS_DER: Debug Event Register (37-47)
2782 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2783 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2784 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2785 CONFIG_SYS_BR1_PRELIM:
2786 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2788 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2789 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2790 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
2791 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2793 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
2794 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
2795 Machine Mode Register and Memory Periodic Timer
2796 Prescaler definitions (SDRAM timing)
2798 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
2799 enable I2C microcode relocation patch (MPC8xx);
2800 define relocation offset in DPRAM [DSP2]
2802 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
2803 enable SMC microcode relocation patch (MPC8xx);
2804 define relocation offset in DPRAM [SMC1]
2806 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
2807 enable SPI microcode relocation patch (MPC8xx);
2808 define relocation offset in DPRAM [SCC4]
2810 - CONFIG_SYS_USE_OSCCLK:
2811 Use OSCM clock mode on MBX8xx board. Be careful,
2812 wrong setting might damage your board. Read
2813 doc/README.MBX before setting this variable!
2815 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2816 Offset of the bootmode word in DPRAM used by post
2817 (Power On Self Tests). This definition overrides
2818 #define'd default value in commproc.h resp.
2821 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
2822 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
2823 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
2824 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
2825 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2826 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
2827 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
2828 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
2829 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
2831 - CONFIG_PCI_DISABLE_PCIE:
2832 Disable PCI-Express on systems where it is supported but not
2836 Chip has SRIO or not
2839 Board has SRIO 1 port available
2842 Board has SRIO 2 port available
2844 - CONFIG_SYS_SRIOn_MEM_VIRT:
2845 Virtual Address of SRIO port 'n' memory region
2847 - CONFIG_SYS_SRIOn_MEM_PHYS:
2848 Physical Address of SRIO port 'n' memory region
2850 - CONFIG_SYS_SRIOn_MEM_SIZE:
2851 Size of SRIO port 'n' memory region
2854 Get DDR timing information from an I2C EEPROM. Common
2855 with pluggable memory modules such as SODIMMs
2858 I2C address of the SPD EEPROM
2860 - CONFIG_SYS_SPD_BUS_NUM
2861 If SPD EEPROM is on an I2C bus other than the first
2862 one, specify here. Note that the value must resolve
2863 to something your driver can deal with.
2865 - CONFIG_SYS_83XX_DDR_USES_CS0
2866 Only for 83xx systems. If specified, then DDR should
2867 be configured using CS0 and CS1 instead of CS2 and CS3.
2869 - CONFIG_ETHER_ON_FEC[12]
2870 Define to enable FEC[12] on a 8xx series processor.
2872 - CONFIG_FEC[12]_PHY
2873 Define to the hardcoded PHY address which corresponds
2874 to the given FEC; i. e.
2875 #define CONFIG_FEC1_PHY 4
2876 means that the PHY with address 4 is connected to FEC1
2878 When set to -1, means to probe for first available.
2880 - CONFIG_FEC[12]_PHY_NORXERR
2881 The PHY does not have a RXERR line (RMII only).
2882 (so program the FEC to ignore it).
2885 Enable RMII mode for all FECs.
2886 Note that this is a global option, we can't
2887 have one FEC in standard MII mode and another in RMII mode.
2889 - CONFIG_CRC32_VERIFY
2890 Add a verify option to the crc32 command.
2893 => crc32 -v <address> <count> <crc32>
2895 Where address/count indicate a memory area
2896 and crc32 is the correct crc32 which the
2900 Add the "loopw" memory command. This only takes effect if
2901 the memory commands are activated globally (CONFIG_CMD_MEM).
2904 Add the "mdc" and "mwc" memory commands. These are cyclic
2909 This command will print 4 bytes (10,11,12,13) each 500 ms.
2911 => mwc.l 100 12345678 10
2912 This command will write 12345678 to address 100 all 10 ms.
2914 This only takes effect if the memory commands are activated
2915 globally (CONFIG_CMD_MEM).
2917 - CONFIG_SKIP_LOWLEVEL_INIT
2918 [ARM only] If this variable is defined, then certain
2919 low level initializations (like setting up the memory
2920 controller) are omitted and/or U-Boot does not
2921 relocate itself into RAM.
2923 Normally this variable MUST NOT be defined. The only
2924 exception is when U-Boot is loaded (to RAM) by some
2925 other boot loader or by a debugger which performs
2926 these initializations itself.
2929 Modifies the behaviour of start.S when compiling a loader
2930 that is executed before the actual U-Boot. E.g. when
2931 compiling a NAND SPL.
2933 Building the Software:
2934 ======================
2936 Building U-Boot has been tested in several native build environments
2937 and in many different cross environments. Of course we cannot support
2938 all possibly existing versions of cross development tools in all
2939 (potentially obsolete) versions. In case of tool chain problems we
2940 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2941 which is extensively used to build and test U-Boot.
2943 If you are not using a native environment, it is assumed that you
2944 have GNU cross compiling tools available in your path. In this case,
2945 you must set the environment variable CROSS_COMPILE in your shell.
2946 Note that no changes to the Makefile or any other source files are
2947 necessary. For example using the ELDK on a 4xx CPU, please enter:
2949 $ CROSS_COMPILE=ppc_4xx-
2950 $ export CROSS_COMPILE
2952 Note: If you wish to generate Windows versions of the utilities in
2953 the tools directory you can use the MinGW toolchain
2954 (http://www.mingw.org). Set your HOST tools to the MinGW
2955 toolchain and execute 'make tools'. For example:
2957 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
2959 Binaries such as tools/mkimage.exe will be created which can
2960 be executed on computers running Windows.
2962 U-Boot is intended to be simple to build. After installing the
2963 sources you must configure U-Boot for one specific board type. This
2968 where "NAME_config" is the name of one of the existing configu-
2969 rations; see the main Makefile for supported names.
2971 Note: for some board special configuration names may exist; check if
2972 additional information is available from the board vendor; for
2973 instance, the TQM823L systems are available without (standard)
2974 or with LCD support. You can select such additional "features"
2975 when choosing the configuration, i. e.
2978 - will configure for a plain TQM823L, i. e. no LCD support
2980 make TQM823L_LCD_config
2981 - will configure for a TQM823L with U-Boot console on LCD
2986 Finally, type "make all", and you should get some working U-Boot
2987 images ready for download to / installation on your system:
2989 - "u-boot.bin" is a raw binary image
2990 - "u-boot" is an image in ELF binary format
2991 - "u-boot.srec" is in Motorola S-Record format
2993 By default the build is performed locally and the objects are saved
2994 in the source directory. One of the two methods can be used to change
2995 this behavior and build U-Boot to some external directory:
2997 1. Add O= to the make command line invocations:
2999 make O=/tmp/build distclean
3000 make O=/tmp/build NAME_config
3001 make O=/tmp/build all
3003 2. Set environment variable BUILD_DIR to point to the desired location:
3005 export BUILD_DIR=/tmp/build
3010 Note that the command line "O=" setting overrides the BUILD_DIR environment
3014 Please be aware that the Makefiles assume you are using GNU make, so
3015 for instance on NetBSD you might need to use "gmake" instead of
3019 If the system board that you have is not listed, then you will need
3020 to port U-Boot to your hardware platform. To do this, follow these
3023 1. Add a new configuration option for your board to the toplevel
3024 "Makefile" and to the "MAKEALL" script, using the existing
3025 entries as examples. Note that here and at many other places
3026 boards and other names are listed in alphabetical sort order. Please
3028 2. Create a new directory to hold your board specific code. Add any
3029 files you need. In your board directory, you will need at least
3030 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
3031 3. Create a new configuration file "include/configs/<board>.h" for
3033 3. If you're porting U-Boot to a new CPU, then also create a new
3034 directory to hold your CPU specific code. Add any files you need.
3035 4. Run "make <board>_config" with your new name.
3036 5. Type "make", and you should get a working "u-boot.srec" file
3037 to be installed on your target system.
3038 6. Debug and solve any problems that might arise.
3039 [Of course, this last step is much harder than it sounds.]
3042 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3043 ==============================================================
3045 If you have modified U-Boot sources (for instance added a new board
3046 or support for new devices, a new CPU, etc.) you are expected to
3047 provide feedback to the other developers. The feedback normally takes
3048 the form of a "patch", i. e. a context diff against a certain (latest
3049 official or latest in the git repository) version of U-Boot sources.
3051 But before you submit such a patch, please verify that your modifi-
3052 cation did not break existing code. At least make sure that *ALL* of
3053 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3054 just run the "MAKEALL" script, which will configure and build U-Boot
3055 for ALL supported system. Be warned, this will take a while. You can
3056 select which (cross) compiler to use by passing a `CROSS_COMPILE'
3057 environment variable to the script, i. e. to use the ELDK cross tools
3060 CROSS_COMPILE=ppc_8xx- MAKEALL
3062 or to build on a native PowerPC system you can type
3064 CROSS_COMPILE=' ' MAKEALL
3066 When using the MAKEALL script, the default behaviour is to build
3067 U-Boot in the source directory. This location can be changed by
3068 setting the BUILD_DIR environment variable. Also, for each target
3069 built, the MAKEALL script saves two log files (<target>.ERR and
3070 <target>.MAKEALL) in the <source dir>/LOG directory. This default
3071 location can be changed by setting the MAKEALL_LOGDIR environment
3072 variable. For example:
3074 export BUILD_DIR=/tmp/build
3075 export MAKEALL_LOGDIR=/tmp/log
3076 CROSS_COMPILE=ppc_8xx- MAKEALL
3078 With the above settings build objects are saved in the /tmp/build,
3079 log files are saved in the /tmp/log and the source tree remains clean
3080 during the whole build process.
3083 See also "U-Boot Porting Guide" below.
3086 Monitor Commands - Overview:
3087 ============================
3089 go - start application at address 'addr'
3090 run - run commands in an environment variable
3091 bootm - boot application image from memory
3092 bootp - boot image via network using BootP/TFTP protocol
3093 tftpboot- boot image via network using TFTP protocol
3094 and env variables "ipaddr" and "serverip"
3095 (and eventually "gatewayip")
3096 rarpboot- boot image via network using RARP/TFTP protocol
3097 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3098 loads - load S-Record file over serial line
3099 loadb - load binary file over serial line (kermit mode)
3101 mm - memory modify (auto-incrementing)
3102 nm - memory modify (constant address)
3103 mw - memory write (fill)
3105 cmp - memory compare
3106 crc32 - checksum calculation
3107 i2c - I2C sub-system
3108 sspi - SPI utility commands
3109 base - print or set address offset
3110 printenv- print environment variables
3111 setenv - set environment variables
3112 saveenv - save environment variables to persistent storage
3113 protect - enable or disable FLASH write protection
3114 erase - erase FLASH memory
3115 flinfo - print FLASH memory information
3116 bdinfo - print Board Info structure
3117 iminfo - print header information for application image
3118 coninfo - print console devices and informations
3119 ide - IDE sub-system
3120 loop - infinite loop on address range
3121 loopw - infinite write loop on address range
3122 mtest - simple RAM test
3123 icache - enable or disable instruction cache
3124 dcache - enable or disable data cache
3125 reset - Perform RESET of the CPU
3126 echo - echo args to console
3127 version - print monitor version
3128 help - print online help
3129 ? - alias for 'help'
3132 Monitor Commands - Detailed Description:
3133 ========================================
3137 For now: just type "help <command>".
3140 Environment Variables:
3141 ======================
3143 U-Boot supports user configuration using Environment Variables which
3144 can be made persistent by saving to Flash memory.
3146 Environment Variables are set using "setenv", printed using
3147 "printenv", and saved to Flash using "saveenv". Using "setenv"
3148 without a value can be used to delete a variable from the
3149 environment. As long as you don't save the environment you are
3150 working with an in-memory copy. In case the Flash area containing the
3151 environment is erased by accident, a default environment is provided.
3153 Some configuration options can be set using Environment Variables.
3155 List of environment variables (most likely not complete):
3157 baudrate - see CONFIG_BAUDRATE
3159 bootdelay - see CONFIG_BOOTDELAY
3161 bootcmd - see CONFIG_BOOTCOMMAND
3163 bootargs - Boot arguments when booting an RTOS image
3165 bootfile - Name of the image to load with TFTP
3167 bootm_low - Memory range available for image processing in the bootm
3168 command can be restricted. This variable is given as
3169 a hexadecimal number and defines lowest address allowed
3170 for use by the bootm command. See also "bootm_size"
3171 environment variable. Address defined by "bootm_low" is
3172 also the base of the initial memory mapping for the Linux
3173 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ.
3175 bootm_size - Memory range available for image processing in the bootm
3176 command can be restricted. This variable is given as
3177 a hexadecimal number and defines the size of the region
3178 allowed for use by the bootm command. See also "bootm_low"
3179 environment variable.
3181 updatefile - Location of the software update file on a TFTP server, used
3182 by the automatic software update feature. Please refer to
3183 documentation in doc/README.update for more details.
3185 autoload - if set to "no" (any string beginning with 'n'),
3186 "bootp" will just load perform a lookup of the
3187 configuration from the BOOTP server, but not try to
3188 load any image using TFTP
3190 autostart - if set to "yes", an image loaded using the "bootp",
3191 "rarpboot", "tftpboot" or "diskboot" commands will
3192 be automatically started (by internally calling
3195 If set to "no", a standalone image passed to the
3196 "bootm" command will be copied to the load address
3197 (and eventually uncompressed), but NOT be started.
3198 This can be used to load and uncompress arbitrary
3201 i2cfast - (PPC405GP|PPC405EP only)
3202 if set to 'y' configures Linux I2C driver for fast
3203 mode (400kHZ). This environment variable is used in
3204 initialization code. So, for changes to be effective
3205 it must be saved and board must be reset.
3207 initrd_high - restrict positioning of initrd images:
3208 If this variable is not set, initrd images will be
3209 copied to the highest possible address in RAM; this
3210 is usually what you want since it allows for
3211 maximum initrd size. If for some reason you want to
3212 make sure that the initrd image is loaded below the
3213 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3214 variable to a value of "no" or "off" or "0".
3215 Alternatively, you can set it to a maximum upper
3216 address to use (U-Boot will still check that it
3217 does not overwrite the U-Boot stack and data).
3219 For instance, when you have a system with 16 MB
3220 RAM, and want to reserve 4 MB from use by Linux,
3221 you can do this by adding "mem=12M" to the value of
3222 the "bootargs" variable. However, now you must make
3223 sure that the initrd image is placed in the first
3224 12 MB as well - this can be done with
3226 setenv initrd_high 00c00000
3228 If you set initrd_high to 0xFFFFFFFF, this is an
3229 indication to U-Boot that all addresses are legal
3230 for the Linux kernel, including addresses in flash
3231 memory. In this case U-Boot will NOT COPY the
3232 ramdisk at all. This may be useful to reduce the
3233 boot time on your system, but requires that this
3234 feature is supported by your Linux kernel.
3236 ipaddr - IP address; needed for tftpboot command
3238 loadaddr - Default load address for commands like "bootp",
3239 "rarpboot", "tftpboot", "loadb" or "diskboot"
3241 loads_echo - see CONFIG_LOADS_ECHO
3243 serverip - TFTP server IP address; needed for tftpboot command
3245 bootretry - see CONFIG_BOOT_RETRY_TIME
3247 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3249 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3251 ethprime - When CONFIG_NET_MULTI is enabled controls which
3252 interface is used first.
3254 ethact - When CONFIG_NET_MULTI is enabled controls which
3255 interface is currently active. For example you
3256 can do the following
3258 => setenv ethact FEC
3259 => ping 192.168.0.1 # traffic sent on FEC
3260 => setenv ethact SCC
3261 => ping 10.0.0.1 # traffic sent on SCC
3263 ethrotate - When set to "no" U-Boot does not go through all
3264 available network interfaces.
3265 It just stays at the currently selected interface.
3267 netretry - When set to "no" each network operation will
3268 either succeed or fail without retrying.
3269 When set to "once" the network operation will
3270 fail when all the available network interfaces
3271 are tried once without success.
3272 Useful on scripts which control the retry operation
3275 npe_ucode - set load address for the NPE microcode
3277 tftpsrcport - If this is set, the value is used for TFTP's
3280 tftpdstport - If this is set, the value is used for TFTP's UDP
3281 destination port instead of the Well Know Port 69.
3283 tftpblocksize - Block size to use for TFTP transfers; if not set,
3284 we use the TFTP server's default block size
3286 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3287 seconds, minimum value is 1000 = 1 second). Defines
3288 when a packet is considered to be lost so it has to
3289 be retransmitted. The default is 5000 = 5 seconds.
3290 Lowering this value may make downloads succeed
3291 faster in networks with high packet loss rates or
3292 with unreliable TFTP servers.
3294 vlan - When set to a value < 4095 the traffic over
3295 Ethernet is encapsulated/received over 802.1q
3298 The following environment variables may be used and automatically
3299 updated by the network boot commands ("bootp" and "rarpboot"),
3300 depending the information provided by your boot server:
3302 bootfile - see above
3303 dnsip - IP address of your Domain Name Server
3304 dnsip2 - IP address of your secondary Domain Name Server
3305 gatewayip - IP address of the Gateway (Router) to use
3306 hostname - Target hostname
3308 netmask - Subnet Mask
3309 rootpath - Pathname of the root filesystem on the NFS server
3310 serverip - see above
3313 There are two special Environment Variables:
3315 serial# - contains hardware identification information such
3316 as type string and/or serial number
3317 ethaddr - Ethernet address
3319 These variables can be set only once (usually during manufacturing of
3320 the board). U-Boot refuses to delete or overwrite these variables
3321 once they have been set once.
3324 Further special Environment Variables:
3326 ver - Contains the U-Boot version string as printed
3327 with the "version" command. This variable is
3328 readonly (see CONFIG_VERSION_VARIABLE).
3331 Please note that changes to some configuration parameters may take
3332 only effect after the next boot (yes, that's just like Windoze :-).
3335 Command Line Parsing:
3336 =====================
3338 There are two different command line parsers available with U-Boot:
3339 the old "simple" one, and the much more powerful "hush" shell:
3341 Old, simple command line parser:
3342 --------------------------------
3344 - supports environment variables (through setenv / saveenv commands)
3345 - several commands on one line, separated by ';'
3346 - variable substitution using "... ${name} ..." syntax
3347 - special characters ('$', ';') can be escaped by prefixing with '\',
3349 setenv bootcmd bootm \${address}
3350 - You can also escape text by enclosing in single apostrophes, for example:
3351 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3356 - similar to Bourne shell, with control structures like
3357 if...then...else...fi, for...do...done; while...do...done,
3358 until...do...done, ...
3359 - supports environment ("global") variables (through setenv / saveenv
3360 commands) and local shell variables (through standard shell syntax
3361 "name=value"); only environment variables can be used with "run"
3367 (1) If a command line (or an environment variable executed by a "run"
3368 command) contains several commands separated by semicolon, and
3369 one of these commands fails, then the remaining commands will be
3372 (2) If you execute several variables with one call to run (i. e.
3373 calling run with a list of variables as arguments), any failing
3374 command will cause "run" to terminate, i. e. the remaining
3375 variables are not executed.
3377 Note for Redundant Ethernet Interfaces:
3378 =======================================
3380 Some boards come with redundant Ethernet interfaces; U-Boot supports
3381 such configurations and is capable of automatic selection of a
3382 "working" interface when needed. MAC assignment works as follows:
3384 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3385 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3386 "eth1addr" (=>eth1), "eth2addr", ...
3388 If the network interface stores some valid MAC address (for instance
3389 in SROM), this is used as default address if there is NO correspon-
3390 ding setting in the environment; if the corresponding environment
3391 variable is set, this overrides the settings in the card; that means:
3393 o If the SROM has a valid MAC address, and there is no address in the
3394 environment, the SROM's address is used.
3396 o If there is no valid address in the SROM, and a definition in the
3397 environment exists, then the value from the environment variable is
3400 o If both the SROM and the environment contain a MAC address, and
3401 both addresses are the same, this MAC address is used.
3403 o If both the SROM and the environment contain a MAC address, and the
3404 addresses differ, the value from the environment is used and a
3407 o If neither SROM nor the environment contain a MAC address, an error
3410 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
3411 will be programmed into hardware as part of the initialization process. This
3412 may be skipped by setting the appropriate 'ethmacskip' environment variable.
3413 The naming convention is as follows:
3414 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
3419 U-Boot is capable of booting (and performing other auxiliary operations on)
3420 images in two formats:
3422 New uImage format (FIT)
3423 -----------------------
3425 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3426 to Flattened Device Tree). It allows the use of images with multiple
3427 components (several kernels, ramdisks, etc.), with contents protected by
3428 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3434 Old image format is based on binary files which can be basically anything,
3435 preceded by a special header; see the definitions in include/image.h for
3436 details; basically, the header defines the following image properties:
3438 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3439 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3440 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3441 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3443 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3444 IA64, MIPS, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3445 Currently supported: ARM, AVR32, Intel x86, MIPS, Nios II, PowerPC).
3446 * Compression Type (uncompressed, gzip, bzip2)
3452 The header is marked by a special Magic Number, and both the header
3453 and the data portions of the image are secured against corruption by
3460 Although U-Boot should support any OS or standalone application
3461 easily, the main focus has always been on Linux during the design of
3464 U-Boot includes many features that so far have been part of some
3465 special "boot loader" code within the Linux kernel. Also, any
3466 "initrd" images to be used are no longer part of one big Linux image;
3467 instead, kernel and "initrd" are separate images. This implementation
3468 serves several purposes:
3470 - the same features can be used for other OS or standalone
3471 applications (for instance: using compressed images to reduce the
3472 Flash memory footprint)
3474 - it becomes much easier to port new Linux kernel versions because
3475 lots of low-level, hardware dependent stuff are done by U-Boot
3477 - the same Linux kernel image can now be used with different "initrd"
3478 images; of course this also means that different kernel images can
3479 be run with the same "initrd". This makes testing easier (you don't
3480 have to build a new "zImage.initrd" Linux image when you just
3481 change a file in your "initrd"). Also, a field-upgrade of the
3482 software is easier now.
3488 Porting Linux to U-Boot based systems:
3489 ---------------------------------------
3491 U-Boot cannot save you from doing all the necessary modifications to
3492 configure the Linux device drivers for use with your target hardware
3493 (no, we don't intend to provide a full virtual machine interface to
3496 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
3498 Just make sure your machine specific header file (for instance
3499 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3500 Information structure as we define in include/asm-<arch>/u-boot.h,
3501 and make sure that your definition of IMAP_ADDR uses the same value
3502 as your U-Boot configuration in CONFIG_SYS_IMMR.
3505 Configuring the Linux kernel:
3506 -----------------------------
3508 No specific requirements for U-Boot. Make sure you have some root
3509 device (initial ramdisk, NFS) for your target system.
3512 Building a Linux Image:
3513 -----------------------
3515 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3516 not used. If you use recent kernel source, a new build target
3517 "uImage" will exist which automatically builds an image usable by
3518 U-Boot. Most older kernels also have support for a "pImage" target,
3519 which was introduced for our predecessor project PPCBoot and uses a
3520 100% compatible format.
3529 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3530 encapsulate a compressed Linux kernel image with header information,
3531 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3533 * build a standard "vmlinux" kernel image (in ELF binary format):
3535 * convert the kernel into a raw binary image:
3537 ${CROSS_COMPILE}-objcopy -O binary \
3538 -R .note -R .comment \
3539 -S vmlinux linux.bin
3541 * compress the binary image:
3545 * package compressed binary image for U-Boot:
3547 mkimage -A ppc -O linux -T kernel -C gzip \
3548 -a 0 -e 0 -n "Linux Kernel Image" \
3549 -d linux.bin.gz uImage
3552 The "mkimage" tool can also be used to create ramdisk images for use
3553 with U-Boot, either separated from the Linux kernel image, or
3554 combined into one file. "mkimage" encapsulates the images with a 64
3555 byte header containing information about target architecture,
3556 operating system, image type, compression method, entry points, time
3557 stamp, CRC32 checksums, etc.
3559 "mkimage" can be called in two ways: to verify existing images and
3560 print the header information, or to build new images.
3562 In the first form (with "-l" option) mkimage lists the information
3563 contained in the header of an existing U-Boot image; this includes
3564 checksum verification:
3566 tools/mkimage -l image
3567 -l ==> list image header information
3569 The second form (with "-d" option) is used to build a U-Boot image
3570 from a "data file" which is used as image payload:
3572 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3573 -n name -d data_file image
3574 -A ==> set architecture to 'arch'
3575 -O ==> set operating system to 'os'
3576 -T ==> set image type to 'type'
3577 -C ==> set compression type 'comp'
3578 -a ==> set load address to 'addr' (hex)
3579 -e ==> set entry point to 'ep' (hex)
3580 -n ==> set image name to 'name'
3581 -d ==> use image data from 'datafile'
3583 Right now, all Linux kernels for PowerPC systems use the same load
3584 address (0x00000000), but the entry point address depends on the
3587 - 2.2.x kernels have the entry point at 0x0000000C,
3588 - 2.3.x and later kernels have the entry point at 0x00000000.
3590 So a typical call to build a U-Boot image would read:
3592 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3593 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3594 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
3595 > examples/uImage.TQM850L
3596 Image Name: 2.4.4 kernel for TQM850L
3597 Created: Wed Jul 19 02:34:59 2000
3598 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3599 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3600 Load Address: 0x00000000
3601 Entry Point: 0x00000000
3603 To verify the contents of the image (or check for corruption):
3605 -> tools/mkimage -l examples/uImage.TQM850L
3606 Image Name: 2.4.4 kernel for TQM850L
3607 Created: Wed Jul 19 02:34:59 2000
3608 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3609 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3610 Load Address: 0x00000000
3611 Entry Point: 0x00000000
3613 NOTE: for embedded systems where boot time is critical you can trade
3614 speed for memory and install an UNCOMPRESSED image instead: this
3615 needs more space in Flash, but boots much faster since it does not
3616 need to be uncompressed:
3618 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
3619 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3620 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3621 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
3622 > examples/uImage.TQM850L-uncompressed
3623 Image Name: 2.4.4 kernel for TQM850L
3624 Created: Wed Jul 19 02:34:59 2000
3625 Image Type: PowerPC Linux Kernel Image (uncompressed)
3626 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3627 Load Address: 0x00000000
3628 Entry Point: 0x00000000
3631 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3632 when your kernel is intended to use an initial ramdisk:
3634 -> tools/mkimage -n 'Simple Ramdisk Image' \
3635 > -A ppc -O linux -T ramdisk -C gzip \
3636 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3637 Image Name: Simple Ramdisk Image
3638 Created: Wed Jan 12 14:01:50 2000
3639 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3640 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3641 Load Address: 0x00000000
3642 Entry Point: 0x00000000
3645 Installing a Linux Image:
3646 -------------------------
3648 To downloading a U-Boot image over the serial (console) interface,
3649 you must convert the image to S-Record format:
3651 objcopy -I binary -O srec examples/image examples/image.srec
3653 The 'objcopy' does not understand the information in the U-Boot
3654 image header, so the resulting S-Record file will be relative to
3655 address 0x00000000. To load it to a given address, you need to
3656 specify the target address as 'offset' parameter with the 'loads'
3659 Example: install the image to address 0x40100000 (which on the
3660 TQM8xxL is in the first Flash bank):
3662 => erase 40100000 401FFFFF
3668 ## Ready for S-Record download ...
3669 ~>examples/image.srec
3670 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3672 15989 15990 15991 15992
3673 [file transfer complete]
3675 ## Start Addr = 0x00000000
3678 You can check the success of the download using the 'iminfo' command;
3679 this includes a checksum verification so you can be sure no data
3680 corruption happened:
3684 ## Checking Image at 40100000 ...
3685 Image Name: 2.2.13 for initrd on TQM850L
3686 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3687 Data Size: 335725 Bytes = 327 kB = 0 MB
3688 Load Address: 00000000
3689 Entry Point: 0000000c
3690 Verifying Checksum ... OK
3696 The "bootm" command is used to boot an application that is stored in
3697 memory (RAM or Flash). In case of a Linux kernel image, the contents
3698 of the "bootargs" environment variable is passed to the kernel as
3699 parameters. You can check and modify this variable using the
3700 "printenv" and "setenv" commands:
3703 => printenv bootargs
3704 bootargs=root=/dev/ram
3706 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3708 => printenv bootargs
3709 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3712 ## Booting Linux kernel at 40020000 ...
3713 Image Name: 2.2.13 for NFS on TQM850L
3714 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3715 Data Size: 381681 Bytes = 372 kB = 0 MB
3716 Load Address: 00000000
3717 Entry Point: 0000000c
3718 Verifying Checksum ... OK
3719 Uncompressing Kernel Image ... OK
3720 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
3721 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3722 time_init: decrementer frequency = 187500000/60
3723 Calibrating delay loop... 49.77 BogoMIPS
3724 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3727 If you want to boot a Linux kernel with initial RAM disk, you pass
3728 the memory addresses of both the kernel and the initrd image (PPBCOOT
3729 format!) to the "bootm" command:
3731 => imi 40100000 40200000
3733 ## Checking Image at 40100000 ...
3734 Image Name: 2.2.13 for initrd on TQM850L
3735 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3736 Data Size: 335725 Bytes = 327 kB = 0 MB
3737 Load Address: 00000000
3738 Entry Point: 0000000c
3739 Verifying Checksum ... OK
3741 ## Checking Image at 40200000 ...
3742 Image Name: Simple Ramdisk Image
3743 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3744 Data Size: 566530 Bytes = 553 kB = 0 MB
3745 Load Address: 00000000
3746 Entry Point: 00000000
3747 Verifying Checksum ... OK
3749 => bootm 40100000 40200000
3750 ## Booting Linux kernel at 40100000 ...
3751 Image Name: 2.2.13 for initrd on TQM850L
3752 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3753 Data Size: 335725 Bytes = 327 kB = 0 MB
3754 Load Address: 00000000
3755 Entry Point: 0000000c
3756 Verifying Checksum ... OK
3757 Uncompressing Kernel Image ... OK
3758 ## Loading RAMDisk Image at 40200000 ...
3759 Image Name: Simple Ramdisk Image
3760 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3761 Data Size: 566530 Bytes = 553 kB = 0 MB
3762 Load Address: 00000000
3763 Entry Point: 00000000
3764 Verifying Checksum ... OK
3765 Loading Ramdisk ... OK
3766 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
3767 Boot arguments: root=/dev/ram
3768 time_init: decrementer frequency = 187500000/60
3769 Calibrating delay loop... 49.77 BogoMIPS
3771 RAMDISK: Compressed image found at block 0
3772 VFS: Mounted root (ext2 filesystem).
3776 Boot Linux and pass a flat device tree:
3779 First, U-Boot must be compiled with the appropriate defines. See the section
3780 titled "Linux Kernel Interface" above for a more in depth explanation. The
3781 following is an example of how to start a kernel and pass an updated
3787 oft=oftrees/mpc8540ads.dtb
3788 => tftp $oftaddr $oft
3789 Speed: 1000, full duplex
3791 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3792 Filename 'oftrees/mpc8540ads.dtb'.
3793 Load address: 0x300000
3796 Bytes transferred = 4106 (100a hex)
3797 => tftp $loadaddr $bootfile
3798 Speed: 1000, full duplex
3800 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3802 Load address: 0x200000
3803 Loading:############
3805 Bytes transferred = 1029407 (fb51f hex)
3810 => bootm $loadaddr - $oftaddr
3811 ## Booting image at 00200000 ...
3812 Image Name: Linux-2.6.17-dirty
3813 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3814 Data Size: 1029343 Bytes = 1005.2 kB
3815 Load Address: 00000000
3816 Entry Point: 00000000
3817 Verifying Checksum ... OK
3818 Uncompressing Kernel Image ... OK
3819 Booting using flat device tree at 0x300000
3820 Using MPC85xx ADS machine description
3821 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3825 More About U-Boot Image Types:
3826 ------------------------------
3828 U-Boot supports the following image types:
3830 "Standalone Programs" are directly runnable in the environment
3831 provided by U-Boot; it is expected that (if they behave
3832 well) you can continue to work in U-Boot after return from
3833 the Standalone Program.
3834 "OS Kernel Images" are usually images of some Embedded OS which
3835 will take over control completely. Usually these programs
3836 will install their own set of exception handlers, device
3837 drivers, set up the MMU, etc. - this means, that you cannot
3838 expect to re-enter U-Boot except by resetting the CPU.
3839 "RAMDisk Images" are more or less just data blocks, and their
3840 parameters (address, size) are passed to an OS kernel that is
3842 "Multi-File Images" contain several images, typically an OS
3843 (Linux) kernel image and one or more data images like
3844 RAMDisks. This construct is useful for instance when you want
3845 to boot over the network using BOOTP etc., where the boot
3846 server provides just a single image file, but you want to get
3847 for instance an OS kernel and a RAMDisk image.
3849 "Multi-File Images" start with a list of image sizes, each
3850 image size (in bytes) specified by an "uint32_t" in network
3851 byte order. This list is terminated by an "(uint32_t)0".
3852 Immediately after the terminating 0 follow the images, one by
3853 one, all aligned on "uint32_t" boundaries (size rounded up to
3854 a multiple of 4 bytes).
3856 "Firmware Images" are binary images containing firmware (like
3857 U-Boot or FPGA images) which usually will be programmed to
3860 "Script files" are command sequences that will be executed by
3861 U-Boot's command interpreter; this feature is especially
3862 useful when you configure U-Boot to use a real shell (hush)
3863 as command interpreter.
3869 One of the features of U-Boot is that you can dynamically load and
3870 run "standalone" applications, which can use some resources of
3871 U-Boot like console I/O functions or interrupt services.
3873 Two simple examples are included with the sources:
3878 'examples/hello_world.c' contains a small "Hello World" Demo
3879 application; it is automatically compiled when you build U-Boot.
3880 It's configured to run at address 0x00040004, so you can play with it
3884 ## Ready for S-Record download ...
3885 ~>examples/hello_world.srec
3886 1 2 3 4 5 6 7 8 9 10 11 ...
3887 [file transfer complete]
3889 ## Start Addr = 0x00040004
3891 => go 40004 Hello World! This is a test.
3892 ## Starting application at 0x00040004 ...
3903 Hit any key to exit ...
3905 ## Application terminated, rc = 0x0
3907 Another example, which demonstrates how to register a CPM interrupt
3908 handler with the U-Boot code, can be found in 'examples/timer.c'.
3909 Here, a CPM timer is set up to generate an interrupt every second.
3910 The interrupt service routine is trivial, just printing a '.'
3911 character, but this is just a demo program. The application can be
3912 controlled by the following keys:
3914 ? - print current values og the CPM Timer registers
3915 b - enable interrupts and start timer
3916 e - stop timer and disable interrupts
3917 q - quit application
3920 ## Ready for S-Record download ...
3921 ~>examples/timer.srec
3922 1 2 3 4 5 6 7 8 9 10 11 ...
3923 [file transfer complete]
3925 ## Start Addr = 0x00040004
3928 ## Starting application at 0x00040004 ...
3931 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3934 [q, b, e, ?] Set interval 1000000 us
3937 [q, b, e, ?] ........
3938 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3941 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3944 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3947 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3949 [q, b, e, ?] ...Stopping timer
3951 [q, b, e, ?] ## Application terminated, rc = 0x0
3957 Over time, many people have reported problems when trying to use the
3958 "minicom" terminal emulation program for serial download. I (wd)
3959 consider minicom to be broken, and recommend not to use it. Under
3960 Unix, I recommend to use C-Kermit for general purpose use (and
3961 especially for kermit binary protocol download ("loadb" command), and
3962 use "cu" for S-Record download ("loads" command).
3964 Nevertheless, if you absolutely want to use it try adding this
3965 configuration to your "File transfer protocols" section:
3967 Name Program Name U/D FullScr IO-Red. Multi
3968 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3969 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3975 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3976 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3978 Building requires a cross environment; it is known to work on
3979 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3980 need gmake since the Makefiles are not compatible with BSD make).
3981 Note that the cross-powerpc package does not install include files;
3982 attempting to build U-Boot will fail because <machine/ansi.h> is
3983 missing. This file has to be installed and patched manually:
3985 # cd /usr/pkg/cross/powerpc-netbsd/include
3987 # ln -s powerpc machine
3988 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3989 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3991 Native builds *don't* work due to incompatibilities between native
3992 and U-Boot include files.
3994 Booting assumes that (the first part of) the image booted is a
3995 stage-2 loader which in turn loads and then invokes the kernel
3996 proper. Loader sources will eventually appear in the NetBSD source
3997 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3998 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
4001 Implementation Internals:
4002 =========================
4004 The following is not intended to be a complete description of every
4005 implementation detail. However, it should help to understand the
4006 inner workings of U-Boot and make it easier to port it to custom
4010 Initial Stack, Global Data:
4011 ---------------------------
4013 The implementation of U-Boot is complicated by the fact that U-Boot
4014 starts running out of ROM (flash memory), usually without access to
4015 system RAM (because the memory controller is not initialized yet).
4016 This means that we don't have writable Data or BSS segments, and BSS
4017 is not initialized as zero. To be able to get a C environment working
4018 at all, we have to allocate at least a minimal stack. Implementation
4019 options for this are defined and restricted by the CPU used: Some CPU
4020 models provide on-chip memory (like the IMMR area on MPC8xx and
4021 MPC826x processors), on others (parts of) the data cache can be
4022 locked as (mis-) used as memory, etc.
4024 Chris Hallinan posted a good summary of these issues to the
4025 U-Boot mailing list:
4027 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
4028 From: "Chris Hallinan" <clh@net1plus.com>
4029 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
4032 Correct me if I'm wrong, folks, but the way I understand it
4033 is this: Using DCACHE as initial RAM for Stack, etc, does not
4034 require any physical RAM backing up the cache. The cleverness
4035 is that the cache is being used as a temporary supply of
4036 necessary storage before the SDRAM controller is setup. It's
4037 beyond the scope of this list to explain the details, but you
4038 can see how this works by studying the cache architecture and
4039 operation in the architecture and processor-specific manuals.
4041 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4042 is another option for the system designer to use as an
4043 initial stack/RAM area prior to SDRAM being available. Either
4044 option should work for you. Using CS 4 should be fine if your
4045 board designers haven't used it for something that would
4046 cause you grief during the initial boot! It is frequently not
4049 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
4050 with your processor/board/system design. The default value
4051 you will find in any recent u-boot distribution in
4052 walnut.h should work for you. I'd set it to a value larger
4053 than your SDRAM module. If you have a 64MB SDRAM module, set
4054 it above 400_0000. Just make sure your board has no resources
4055 that are supposed to respond to that address! That code in
4056 start.S has been around a while and should work as is when
4057 you get the config right.
4062 It is essential to remember this, since it has some impact on the C
4063 code for the initialization procedures:
4065 * Initialized global data (data segment) is read-only. Do not attempt
4068 * Do not use any uninitialized global data (or implicitely initialized
4069 as zero data - BSS segment) at all - this is undefined, initiali-
4070 zation is performed later (when relocating to RAM).
4072 * Stack space is very limited. Avoid big data buffers or things like
4075 Having only the stack as writable memory limits means we cannot use
4076 normal global data to share information beween the code. But it
4077 turned out that the implementation of U-Boot can be greatly
4078 simplified by making a global data structure (gd_t) available to all
4079 functions. We could pass a pointer to this data as argument to _all_
4080 functions, but this would bloat the code. Instead we use a feature of
4081 the GCC compiler (Global Register Variables) to share the data: we
4082 place a pointer (gd) to the global data into a register which we
4083 reserve for this purpose.
4085 When choosing a register for such a purpose we are restricted by the
4086 relevant (E)ABI specifications for the current architecture, and by
4087 GCC's implementation.
4089 For PowerPC, the following registers have specific use:
4091 R2: reserved for system use
4092 R3-R4: parameter passing and return values
4093 R5-R10: parameter passing
4094 R13: small data area pointer
4098 (U-Boot also uses R12 as internal GOT pointer. r12
4099 is a volatile register so r12 needs to be reset when
4100 going back and forth between asm and C)
4102 ==> U-Boot will use R2 to hold a pointer to the global data
4104 Note: on PPC, we could use a static initializer (since the
4105 address of the global data structure is known at compile time),
4106 but it turned out that reserving a register results in somewhat
4107 smaller code - although the code savings are not that big (on
4108 average for all boards 752 bytes for the whole U-Boot image,
4109 624 text + 127 data).
4111 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
4112 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
4114 ==> U-Boot will use P3 to hold a pointer to the global data
4116 On ARM, the following registers are used:
4118 R0: function argument word/integer result
4119 R1-R3: function argument word
4121 R10: stack limit (used only if stack checking if enabled)
4122 R11: argument (frame) pointer
4123 R12: temporary workspace
4126 R15: program counter
4128 ==> U-Boot will use R8 to hold a pointer to the global data
4130 On Nios II, the ABI is documented here:
4131 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4133 ==> U-Boot will use gp to hold a pointer to the global data
4135 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4136 to access small data sections, so gp is free.
4138 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4139 or current versions of GCC may "optimize" the code too much.
4144 U-Boot runs in system state and uses physical addresses, i.e. the
4145 MMU is not used either for address mapping nor for memory protection.
4147 The available memory is mapped to fixed addresses using the memory
4148 controller. In this process, a contiguous block is formed for each
4149 memory type (Flash, SDRAM, SRAM), even when it consists of several
4150 physical memory banks.
4152 U-Boot is installed in the first 128 kB of the first Flash bank (on
4153 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4154 booting and sizing and initializing DRAM, the code relocates itself
4155 to the upper end of DRAM. Immediately below the U-Boot code some
4156 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
4157 configuration setting]. Below that, a structure with global Board
4158 Info data is placed, followed by the stack (growing downward).
4160 Additionally, some exception handler code is copied to the low 8 kB
4161 of DRAM (0x00000000 ... 0x00001FFF).
4163 So a typical memory configuration with 16 MB of DRAM could look like
4166 0x0000 0000 Exception Vector code
4169 0x0000 2000 Free for Application Use
4175 0x00FB FF20 Monitor Stack (Growing downward)
4176 0x00FB FFAC Board Info Data and permanent copy of global data
4177 0x00FC 0000 Malloc Arena
4180 0x00FE 0000 RAM Copy of Monitor Code
4181 ... eventually: LCD or video framebuffer
4182 ... eventually: pRAM (Protected RAM - unchanged by reset)
4183 0x00FF FFFF [End of RAM]
4186 System Initialization:
4187 ----------------------
4189 In the reset configuration, U-Boot starts at the reset entry point
4190 (on most PowerPC systems at address 0x00000100). Because of the reset
4191 configuration for CS0# this is a mirror of the onboard Flash memory.
4192 To be able to re-map memory U-Boot then jumps to its link address.
4193 To be able to implement the initialization code in C, a (small!)
4194 initial stack is set up in the internal Dual Ported RAM (in case CPUs
4195 which provide such a feature like MPC8xx or MPC8260), or in a locked
4196 part of the data cache. After that, U-Boot initializes the CPU core,
4197 the caches and the SIU.
4199 Next, all (potentially) available memory banks are mapped using a
4200 preliminary mapping. For example, we put them on 512 MB boundaries
4201 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4202 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4203 programmed for SDRAM access. Using the temporary configuration, a
4204 simple memory test is run that determines the size of the SDRAM
4207 When there is more than one SDRAM bank, and the banks are of
4208 different size, the largest is mapped first. For equal size, the first
4209 bank (CS2#) is mapped first. The first mapping is always for address
4210 0x00000000, with any additional banks following immediately to create
4211 contiguous memory starting from 0.
4213 Then, the monitor installs itself at the upper end of the SDRAM area
4214 and allocates memory for use by malloc() and for the global Board
4215 Info data; also, the exception vector code is copied to the low RAM
4216 pages, and the final stack is set up.
4218 Only after this relocation will you have a "normal" C environment;
4219 until that you are restricted in several ways, mostly because you are
4220 running from ROM, and because the code will have to be relocated to a
4224 U-Boot Porting Guide:
4225 ----------------------
4227 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4231 int main(int argc, char *argv[])
4233 sighandler_t no_more_time;
4235 signal(SIGALRM, no_more_time);
4236 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4238 if (available_money > available_manpower) {
4239 Pay consultant to port U-Boot;
4243 Download latest U-Boot source;
4245 Subscribe to u-boot mailing list;
4248 email("Hi, I am new to U-Boot, how do I get started?");
4251 Read the README file in the top level directory;
4252 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4253 Read applicable doc/*.README;
4254 Read the source, Luke;
4255 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4258 if (available_money > toLocalCurrency ($2500))
4261 Add a lot of aggravation and time;
4263 if (a similar board exists) { /* hopefully... */
4264 cp -a board/<similar> board/<myboard>
4265 cp include/configs/<similar>.h include/configs/<myboard>.h
4267 Create your own board support subdirectory;
4268 Create your own board include/configs/<myboard>.h file;
4270 Edit new board/<myboard> files
4271 Edit new include/configs/<myboard>.h
4276 Add / modify source code;
4280 email("Hi, I am having problems...");
4282 Send patch file to the U-Boot email list;
4283 if (reasonable critiques)
4284 Incorporate improvements from email list code review;
4286 Defend code as written;
4292 void no_more_time (int sig)
4301 All contributions to U-Boot should conform to the Linux kernel
4302 coding style; see the file "Documentation/CodingStyle" and the script
4303 "scripts/Lindent" in your Linux kernel source directory. In sources
4304 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
4305 spaces before parameters to function calls) is actually used.
4307 Source files originating from a different project (for example the
4308 MTD subsystem) are generally exempt from these guidelines and are not
4309 reformated to ease subsequent migration to newer versions of those
4312 Please note that U-Boot is implemented in C (and to some small parts in
4313 Assembler); no C++ is used, so please do not use C++ style comments (//)
4316 Please also stick to the following formatting rules:
4317 - remove any trailing white space
4318 - use TAB characters for indentation, not spaces
4319 - make sure NOT to use DOS '\r\n' line feeds
4320 - do not add more than 2 empty lines to source files
4321 - do not add trailing empty lines to source files
4323 Submissions which do not conform to the standards may be returned
4324 with a request to reformat the changes.
4330 Since the number of patches for U-Boot is growing, we need to
4331 establish some rules. Submissions which do not conform to these rules
4332 may be rejected, even when they contain important and valuable stuff.
4334 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4336 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4337 see http://lists.denx.de/mailman/listinfo/u-boot
4339 When you send a patch, please include the following information with
4342 * For bug fixes: a description of the bug and how your patch fixes
4343 this bug. Please try to include a way of demonstrating that the
4344 patch actually fixes something.
4346 * For new features: a description of the feature and your
4349 * A CHANGELOG entry as plaintext (separate from the patch)
4351 * For major contributions, your entry to the CREDITS file
4353 * When you add support for a new board, don't forget to add this
4354 board to the MAKEALL script, too.
4356 * If your patch adds new configuration options, don't forget to
4357 document these in the README file.
4359 * The patch itself. If you are using git (which is *strongly*
4360 recommended) you can easily generate the patch using the
4361 "git-format-patch". If you then use "git-send-email" to send it to
4362 the U-Boot mailing list, you will avoid most of the common problems
4363 with some other mail clients.
4365 If you cannot use git, use "diff -purN OLD NEW". If your version of
4366 diff does not support these options, then get the latest version of
4369 The current directory when running this command shall be the parent
4370 directory of the U-Boot source tree (i. e. please make sure that
4371 your patch includes sufficient directory information for the
4374 We prefer patches as plain text. MIME attachments are discouraged,
4375 and compressed attachments must not be used.
4377 * If one logical set of modifications affects or creates several
4378 files, all these changes shall be submitted in a SINGLE patch file.
4380 * Changesets that contain different, unrelated modifications shall be
4381 submitted as SEPARATE patches, one patch per changeset.
4386 * Before sending the patch, run the MAKEALL script on your patched
4387 source tree and make sure that no errors or warnings are reported
4388 for any of the boards.
4390 * Keep your modifications to the necessary minimum: A patch
4391 containing several unrelated changes or arbitrary reformats will be
4392 returned with a request to re-formatting / split it.
4394 * If you modify existing code, make sure that your new code does not
4395 add to the memory footprint of the code ;-) Small is beautiful!
4396 When adding new features, these should compile conditionally only
4397 (using #ifdef), and the resulting code with the new feature
4398 disabled must not need more memory than the old code without your
4401 * Remember that there is a size limit of 100 kB per message on the
4402 u-boot mailing list. Bigger patches will be moderated. If they are
4403 reasonable and not too big, they will be acknowledged. But patches
4404 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob