2 # (C) Copyright 2000 - 2011
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # See file CREDITS for list of people who contributed to this
8 # This program is free software; you can redistribute it and/or
9 # modify it under the terms of the GNU General Public License as
10 # published by the Free Software Foundation; either version 2 of
11 # the License, or (at your option) any later version.
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with this program; if not, write to the Free Software
20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27 This directory contains the source code for U-Boot, a boot loader for
28 Embedded boards based on PowerPC, ARM, MIPS and several other
29 processors, which can be installed in a boot ROM and used to
30 initialize and test the hardware or to download and run application
33 The development of U-Boot is closely related to Linux: some parts of
34 the source code originate in the Linux source tree, we have some
35 header files in common, and special provision has been made to
36 support booting of Linux images.
38 Some attention has been paid to make this software easily
39 configurable and extendable. For instance, all monitor commands are
40 implemented with the same call interface, so that it's very easy to
41 add new commands. Also, instead of permanently adding rarely used
42 code (for instance hardware test utilities) to the monitor, you can
43 load and run it dynamically.
49 In general, all boards for which a configuration option exists in the
50 Makefile have been tested to some extent and can be considered
51 "working". In fact, many of them are used in production systems.
53 In case of problems see the CHANGELOG and CREDITS files to find out
54 who contributed the specific port. The MAINTAINERS file lists board
61 In case you have questions about, problems with or contributions for
62 U-Boot you should send a message to the U-Boot mailing list at
63 <u-boot@lists.denx.de>. There is also an archive of previous traffic
64 on the mailing list - please search the archive before asking FAQ's.
65 Please see http://lists.denx.de/pipermail/u-boot and
66 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
69 Where to get source code:
70 =========================
72 The U-Boot source code is maintained in the git repository at
73 git://www.denx.de/git/u-boot.git ; you can browse it online at
74 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
76 The "snapshot" links on this page allow you to download tarballs of
77 any version you might be interested in. Official releases are also
78 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
81 Pre-built (and tested) images are available from
82 ftp://ftp.denx.de/pub/u-boot/images/
88 - start from 8xxrom sources
89 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
91 - make it easier to add custom boards
92 - make it possible to add other [PowerPC] CPUs
93 - extend functions, especially:
94 * Provide extended interface to Linux boot loader
97 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
98 - create ARMBoot project (http://sourceforge.net/projects/armboot)
99 - add other CPU families (starting with ARM)
100 - create U-Boot project (http://sourceforge.net/projects/u-boot)
101 - current project page: see http://www.denx.de/wiki/U-Boot
107 The "official" name of this project is "Das U-Boot". The spelling
108 "U-Boot" shall be used in all written text (documentation, comments
109 in source files etc.). Example:
111 This is the README file for the U-Boot project.
113 File names etc. shall be based on the string "u-boot". Examples:
115 include/asm-ppc/u-boot.h
117 #include <asm/u-boot.h>
119 Variable names, preprocessor constants etc. shall be either based on
120 the string "u_boot" or on "U_BOOT". Example:
122 U_BOOT_VERSION u_boot_logo
123 IH_OS_U_BOOT u_boot_hush_start
129 Starting with the release in October 2008, the names of the releases
130 were changed from numerical release numbers without deeper meaning
131 into a time stamp based numbering. Regular releases are identified by
132 names consisting of the calendar year and month of the release date.
133 Additional fields (if present) indicate release candidates or bug fix
134 releases in "stable" maintenance trees.
137 U-Boot v2009.11 - Release November 2009
138 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
139 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
145 /arch Architecture specific files
146 /arm Files generic to ARM architecture
147 /cpu CPU specific files
148 /arm720t Files specific to ARM 720 CPUs
149 /arm920t Files specific to ARM 920 CPUs
150 /at91rm9200 Files specific to Atmel AT91RM9200 CPU
151 /imx Files specific to Freescale MC9328 i.MX CPUs
152 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
153 /arm925t Files specific to ARM 925 CPUs
154 /arm926ejs Files specific to ARM 926 CPUs
155 /arm1136 Files specific to ARM 1136 CPUs
156 /ixp Files specific to Intel XScale IXP CPUs
157 /pxa Files specific to Intel XScale PXA CPUs
158 /s3c44b0 Files specific to Samsung S3C44B0 CPUs
159 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
160 /lib Architecture specific library files
161 /avr32 Files generic to AVR32 architecture
162 /cpu CPU specific files
163 /lib Architecture specific library files
164 /blackfin Files generic to Analog Devices Blackfin architecture
165 /cpu CPU specific files
166 /lib Architecture specific library files
167 /x86 Files generic to x86 architecture
168 /cpu CPU specific files
169 /lib Architecture specific library files
170 /m68k Files generic to m68k architecture
171 /cpu CPU specific files
172 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
173 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
174 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
175 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
176 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
177 /lib Architecture specific library files
178 /microblaze Files generic to microblaze architecture
179 /cpu CPU specific files
180 /lib Architecture specific library files
181 /mips Files generic to MIPS architecture
182 /cpu CPU specific files
183 /lib Architecture specific library files
184 /nios2 Files generic to Altera NIOS2 architecture
185 /cpu CPU specific files
186 /lib Architecture specific library files
187 /powerpc Files generic to PowerPC architecture
188 /cpu CPU specific files
189 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
190 /mpc5xx Files specific to Freescale MPC5xx CPUs
191 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
192 /mpc8xx Files specific to Freescale MPC8xx CPUs
193 /mpc8220 Files specific to Freescale MPC8220 CPUs
194 /mpc824x Files specific to Freescale MPC824x CPUs
195 /mpc8260 Files specific to Freescale MPC8260 CPUs
196 /mpc85xx Files specific to Freescale MPC85xx CPUs
197 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
198 /lib Architecture specific library files
199 /sh Files generic to SH architecture
200 /cpu CPU specific files
201 /sh2 Files specific to sh2 CPUs
202 /sh3 Files specific to sh3 CPUs
203 /sh4 Files specific to sh4 CPUs
204 /lib Architecture specific library files
205 /sparc Files generic to SPARC architecture
206 /cpu CPU specific files
207 /leon2 Files specific to Gaisler LEON2 SPARC CPU
208 /leon3 Files specific to Gaisler LEON3 SPARC CPU
209 /lib Architecture specific library files
210 /api Machine/arch independent API for external apps
211 /board Board dependent files
212 /common Misc architecture independent functions
213 /disk Code for disk drive partition handling
214 /doc Documentation (don't expect too much)
215 /drivers Commonly used device drivers
216 /examples Example code for standalone applications, etc.
217 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
218 /include Header Files
219 /lib Files generic to all architectures
220 /libfdt Library files to support flattened device trees
221 /lzma Library files to support LZMA decompression
222 /lzo Library files to support LZO decompression
224 /post Power On Self Test
225 /rtc Real Time Clock drivers
226 /tools Tools to build S-Record or U-Boot images, etc.
228 Software Configuration:
229 =======================
231 Configuration is usually done using C preprocessor defines; the
232 rationale behind that is to avoid dead code whenever possible.
234 There are two classes of configuration variables:
236 * Configuration _OPTIONS_:
237 These are selectable by the user and have names beginning with
240 * Configuration _SETTINGS_:
241 These depend on the hardware etc. and should not be meddled with if
242 you don't know what you're doing; they have names beginning with
245 Later we will add a configuration tool - probably similar to or even
246 identical to what's used for the Linux kernel. Right now, we have to
247 do the configuration by hand, which means creating some symbolic
248 links and editing some configuration files. We use the TQM8xxL boards
252 Selection of Processor Architecture and Board Type:
253 ---------------------------------------------------
255 For all supported boards there are ready-to-use default
256 configurations available; just type "make <board_name>_config".
258 Example: For a TQM823L module type:
263 For the Cogent platform, you need to specify the CPU type as well;
264 e.g. "make cogent_mpc8xx_config". And also configure the cogent
265 directory according to the instructions in cogent/README.
268 Configuration Options:
269 ----------------------
271 Configuration depends on the combination of board and CPU type; all
272 such information is kept in a configuration file
273 "include/configs/<board_name>.h".
275 Example: For a TQM823L module, all configuration settings are in
276 "include/configs/TQM823L.h".
279 Many of the options are named exactly as the corresponding Linux
280 kernel configuration options. The intention is to make it easier to
281 build a config tool - later.
284 The following options need to be configured:
286 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
288 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
290 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
291 Define exactly one, e.g. CONFIG_ATSTK1002
293 - CPU Module Type: (if CONFIG_COGENT is defined)
294 Define exactly one of
296 --- FIXME --- not tested yet:
297 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
298 CONFIG_CMA287_23, CONFIG_CMA287_50
300 - Motherboard Type: (if CONFIG_COGENT is defined)
301 Define exactly one of
302 CONFIG_CMA101, CONFIG_CMA102
304 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
305 Define one or more of
308 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
309 Define one or more of
310 CONFIG_LCD_HEARTBEAT - update a character position on
311 the LCD display every second with
314 - Board flavour: (if CONFIG_MPC8260ADS is defined)
317 CONFIG_SYS_8260ADS - original MPC8260ADS
318 CONFIG_SYS_8266ADS - MPC8266ADS
319 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
320 CONFIG_SYS_8272ADS - MPC8272ADS
322 - Marvell Family Member
323 CONFIG_SYS_MVFS - define it if you want to enable
324 multiple fs option at one time
325 for marvell soc family
327 - MPC824X Family Member (if CONFIG_MPC824X is defined)
328 Define exactly one of
329 CONFIG_MPC8240, CONFIG_MPC8245
331 - 8xx CPU Options: (if using an MPC8xx CPU)
332 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
333 get_gclk_freq() cannot work
334 e.g. if there is no 32KHz
335 reference PIT/RTC clock
336 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
339 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
340 CONFIG_SYS_8xx_CPUCLK_MIN
341 CONFIG_SYS_8xx_CPUCLK_MAX
342 CONFIG_8xx_CPUCLK_DEFAULT
343 See doc/README.MPC866
345 CONFIG_SYS_MEASURE_CPUCLK
347 Define this to measure the actual CPU clock instead
348 of relying on the correctness of the configured
349 values. Mostly useful for board bringup to make sure
350 the PLL is locked at the intended frequency. Note
351 that this requires a (stable) reference clock (32 kHz
352 RTC clock or CONFIG_SYS_8XX_XIN)
354 CONFIG_SYS_DELAYED_ICACHE
356 Define this option if you want to enable the
357 ICache only when Code runs from RAM.
360 CONFIG_SYS_FSL_TBCLK_DIV
362 Defines the core time base clock divider ratio compared to the
363 system clock. On most PQ3 devices this is 8, on newer QorIQ
364 devices it can be 16 or 32. The ratio varies from SoC to Soc.
366 CONFIG_SYS_FSL_PCIE_COMPAT
368 Defines the string to utilize when trying to match PCIe device
369 tree nodes for the given platform.
371 - Intel Monahans options:
372 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
374 Defines the Monahans run mode to oscillator
375 ratio. Valid values are 8, 16, 24, 31. The core
376 frequency is this value multiplied by 13 MHz.
378 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
380 Defines the Monahans turbo mode to oscillator
381 ratio. Valid values are 1 (default if undefined) and
382 2. The core frequency as calculated above is multiplied
385 - Linux Kernel Interface:
388 U-Boot stores all clock information in Hz
389 internally. For binary compatibility with older Linux
390 kernels (which expect the clocks passed in the
391 bd_info data to be in MHz) the environment variable
392 "clocks_in_mhz" can be defined so that U-Boot
393 converts clock data to MHZ before passing it to the
395 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
396 "clocks_in_mhz=1" is automatically included in the
399 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
401 When transferring memsize parameter to linux, some versions
402 expect it to be in bytes, others in MB.
403 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
407 New kernel versions are expecting firmware settings to be
408 passed using flattened device trees (based on open firmware
412 * New libfdt-based support
413 * Adds the "fdt" command
414 * The bootm command automatically updates the fdt
416 OF_CPU - The proper name of the cpus node (only required for
417 MPC512X and MPC5xxx based boards).
418 OF_SOC - The proper name of the soc node (only required for
419 MPC512X and MPC5xxx based boards).
420 OF_TBCLK - The timebase frequency.
421 OF_STDOUT_PATH - The path to the console device
423 boards with QUICC Engines require OF_QE to set UCC MAC
426 CONFIG_OF_BOARD_SETUP
428 Board code has addition modification that it wants to make
429 to the flat device tree before handing it off to the kernel
433 This define fills in the correct boot CPU in the boot
434 param header, the default value is zero if undefined.
438 U-Boot can detect if an IDE device is present or not.
439 If not, and this new config option is activated, U-Boot
440 removes the ATA node from the DTS before booting Linux,
441 so the Linux IDE driver does not probe the device and
442 crash. This is needed for buggy hardware (uc101) where
443 no pull down resistor is connected to the signal IDE5V_DD7.
445 - vxWorks boot parameters:
447 bootvx constructs a valid bootline using the following
448 environments variables: bootfile, ipaddr, serverip, hostname.
449 It loads the vxWorks image pointed bootfile.
451 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
452 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
453 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
454 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
456 CONFIG_SYS_VXWORKS_ADD_PARAMS
458 Add it at the end of the bootline. E.g "u=username pw=secret"
460 Note: If a "bootargs" environment is defined, it will overwride
461 the defaults discussed just above.
463 - Cache Configuration:
464 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
465 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
466 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
468 - Cache Configuration for ARM:
469 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
471 CONFIG_SYS_PL310_BASE - Physical base address of PL310
472 controller register space
477 Define this if you want support for Amba PrimeCell PL010 UARTs.
481 Define this if you want support for Amba PrimeCell PL011 UARTs.
485 If you have Amba PrimeCell PL011 UARTs, set this variable to
486 the clock speed of the UARTs.
490 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
491 define this to a list of base addresses for each (supported)
492 port. See e.g. include/configs/versatile.h
494 CONFIG_PL011_SERIAL_RLCR
496 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
497 have separate receive and transmit line control registers. Set
498 this variable to initialize the extra register.
500 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
502 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
503 boot loader that has already initialized the UART. Define this
504 variable to flush the UART at init time.
508 Depending on board, define exactly one serial port
509 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
510 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
511 console by defining CONFIG_8xx_CONS_NONE
513 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
514 port routines must be defined elsewhere
515 (i.e. serial_init(), serial_getc(), ...)
518 Enables console device for a color framebuffer. Needs following
519 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
520 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
522 VIDEO_HW_RECTFILL graphic chip supports
525 VIDEO_HW_BITBLT graphic chip supports
526 bit-blit (cf. smiLynxEM)
527 VIDEO_VISIBLE_COLS visible pixel columns
529 VIDEO_VISIBLE_ROWS visible pixel rows
530 VIDEO_PIXEL_SIZE bytes per pixel
531 VIDEO_DATA_FORMAT graphic data format
532 (0-5, cf. cfb_console.c)
533 VIDEO_FB_ADRS framebuffer address
534 VIDEO_KBD_INIT_FCT keyboard int fct
535 (i.e. i8042_kbd_init())
536 VIDEO_TSTC_FCT test char fct
538 VIDEO_GETC_FCT get char fct
540 CONFIG_CONSOLE_CURSOR cursor drawing on/off
541 (requires blink timer
543 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
544 CONFIG_CONSOLE_TIME display time/date info in
546 (requires CONFIG_CMD_DATE)
547 CONFIG_VIDEO_LOGO display Linux logo in
549 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
550 linux_logo.h for logo.
551 Requires CONFIG_VIDEO_LOGO
552 CONFIG_CONSOLE_EXTRA_INFO
553 additional board info beside
556 When CONFIG_CFB_CONSOLE is defined, video console is
557 default i/o. Serial console can be forced with
558 environment 'console=serial'.
560 When CONFIG_SILENT_CONSOLE is defined, all console
561 messages (by U-Boot and Linux!) can be silenced with
562 the "silent" environment variable. See
563 doc/README.silent for more information.
566 CONFIG_BAUDRATE - in bps
567 Select one of the baudrates listed in
568 CONFIG_SYS_BAUDRATE_TABLE, see below.
569 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
571 - Console Rx buffer length
572 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
573 the maximum receive buffer length for the SMC.
574 This option is actual only for 82xx and 8xx possible.
575 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
576 must be defined, to setup the maximum idle timeout for
579 - Boot Delay: CONFIG_BOOTDELAY - in seconds
580 Delay before automatically booting the default image;
581 set to -1 to disable autoboot.
583 See doc/README.autoboot for these options that
584 work with CONFIG_BOOTDELAY. None are required.
585 CONFIG_BOOT_RETRY_TIME
586 CONFIG_BOOT_RETRY_MIN
587 CONFIG_AUTOBOOT_KEYED
588 CONFIG_AUTOBOOT_PROMPT
589 CONFIG_AUTOBOOT_DELAY_STR
590 CONFIG_AUTOBOOT_STOP_STR
591 CONFIG_AUTOBOOT_DELAY_STR2
592 CONFIG_AUTOBOOT_STOP_STR2
593 CONFIG_ZERO_BOOTDELAY_CHECK
594 CONFIG_RESET_TO_RETRY
598 Only needed when CONFIG_BOOTDELAY is enabled;
599 define a command string that is automatically executed
600 when no character is read on the console interface
601 within "Boot Delay" after reset.
604 This can be used to pass arguments to the bootm
605 command. The value of CONFIG_BOOTARGS goes into the
606 environment value "bootargs".
608 CONFIG_RAMBOOT and CONFIG_NFSBOOT
609 The value of these goes into the environment as
610 "ramboot" and "nfsboot" respectively, and can be used
611 as a convenience, when switching between booting from
617 When this option is #defined, the existence of the
618 environment variable "preboot" will be checked
619 immediately before starting the CONFIG_BOOTDELAY
620 countdown and/or running the auto-boot command resp.
621 entering interactive mode.
623 This feature is especially useful when "preboot" is
624 automatically generated or modified. For an example
625 see the LWMON board specific code: here "preboot" is
626 modified when the user holds down a certain
627 combination of keys on the (special) keyboard when
630 - Serial Download Echo Mode:
632 If defined to 1, all characters received during a
633 serial download (using the "loads" command) are
634 echoed back. This might be needed by some terminal
635 emulations (like "cu"), but may as well just take
636 time on others. This setting #define's the initial
637 value of the "loads_echo" environment variable.
639 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
641 Select one of the baudrates listed in
642 CONFIG_SYS_BAUDRATE_TABLE, see below.
645 Monitor commands can be included or excluded
646 from the build by using the #include files
647 "config_cmd_all.h" and #undef'ing unwanted
648 commands, or using "config_cmd_default.h"
649 and augmenting with additional #define's
652 The default command configuration includes all commands
653 except those marked below with a "*".
655 CONFIG_CMD_ASKENV * ask for env variable
656 CONFIG_CMD_BDI bdinfo
657 CONFIG_CMD_BEDBUG * Include BedBug Debugger
658 CONFIG_CMD_BMP * BMP support
659 CONFIG_CMD_BSP * Board specific commands
660 CONFIG_CMD_BOOTD bootd
661 CONFIG_CMD_CACHE * icache, dcache
662 CONFIG_CMD_CONSOLE coninfo
663 CONFIG_CMD_CRC32 * crc32
664 CONFIG_CMD_DATE * support for RTC, date/time...
665 CONFIG_CMD_DHCP * DHCP support
666 CONFIG_CMD_DIAG * Diagnostics
667 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
668 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
669 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
670 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
671 CONFIG_CMD_DTT * Digital Therm and Thermostat
672 CONFIG_CMD_ECHO echo arguments
673 CONFIG_CMD_EDITENV edit env variable
674 CONFIG_CMD_EEPROM * EEPROM read/write support
675 CONFIG_CMD_ELF * bootelf, bootvx
676 CONFIG_CMD_EXPORTENV * export the environment
677 CONFIG_CMD_SAVEENV saveenv
678 CONFIG_CMD_FDC * Floppy Disk Support
679 CONFIG_CMD_FAT * FAT partition support
680 CONFIG_CMD_FDOS * Dos diskette Support
681 CONFIG_CMD_FLASH flinfo, erase, protect
682 CONFIG_CMD_FPGA FPGA device initialization support
683 CONFIG_CMD_GO * the 'go' command (exec code)
684 CONFIG_CMD_GREPENV * search environment
685 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
686 CONFIG_CMD_I2C * I2C serial bus support
687 CONFIG_CMD_IDE * IDE harddisk support
688 CONFIG_CMD_IMI iminfo
689 CONFIG_CMD_IMLS List all found images
690 CONFIG_CMD_IMMAP * IMMR dump support
691 CONFIG_CMD_IMPORTENV * import an environment
692 CONFIG_CMD_IRQ * irqinfo
693 CONFIG_CMD_ITEST Integer/string test of 2 values
694 CONFIG_CMD_JFFS2 * JFFS2 Support
695 CONFIG_CMD_KGDB * kgdb
696 CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
697 CONFIG_CMD_LOADB loadb
698 CONFIG_CMD_LOADS loads
699 CONFIG_CMD_MD5SUM print md5 message digest
700 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
701 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
703 CONFIG_CMD_MISC Misc functions like sleep etc
704 CONFIG_CMD_MMC * MMC memory mapped support
705 CONFIG_CMD_MII * MII utility commands
706 CONFIG_CMD_MTDPARTS * MTD partition support
707 CONFIG_CMD_NAND * NAND support
708 CONFIG_CMD_NET bootp, tftpboot, rarpboot
709 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
710 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
711 CONFIG_CMD_PCI * pciinfo
712 CONFIG_CMD_PCMCIA * PCMCIA support
713 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
715 CONFIG_CMD_PORTIO * Port I/O
716 CONFIG_CMD_REGINFO * Register dump
717 CONFIG_CMD_RUN run command in env variable
718 CONFIG_CMD_SAVES * save S record dump
719 CONFIG_CMD_SCSI * SCSI Support
720 CONFIG_CMD_SDRAM * print SDRAM configuration information
721 (requires CONFIG_CMD_I2C)
722 CONFIG_CMD_SETGETDCR Support for DCR Register access
724 CONFIG_CMD_SHA1SUM print sha1 memory digest
725 (requires CONFIG_CMD_MEMORY)
726 CONFIG_CMD_SOURCE "source" command Support
727 CONFIG_CMD_SPI * SPI serial bus support
728 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
729 CONFIG_CMD_USB * USB support
730 CONFIG_CMD_CDP * Cisco Discover Protocol support
731 CONFIG_CMD_FSL * Microblaze FSL support
734 EXAMPLE: If you want all functions except of network
735 support you can write:
737 #include "config_cmd_all.h"
738 #undef CONFIG_CMD_NET
741 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
743 Note: Don't enable the "icache" and "dcache" commands
744 (configuration option CONFIG_CMD_CACHE) unless you know
745 what you (and your U-Boot users) are doing. Data
746 cache cannot be enabled on systems like the 8xx or
747 8260 (where accesses to the IMMR region must be
748 uncached), and it cannot be disabled on all other
749 systems where we (mis-) use the data cache to hold an
750 initial stack and some data.
753 XXX - this list needs to get updated!
757 If this variable is defined, it enables watchdog
758 support for the SoC. There must be support in the SoC
759 specific code for a watchdog. For the 8xx and 8260
760 CPUs, the SIU Watchdog feature is enabled in the SYPCR
761 register. When supported for a specific SoC is
762 available, then no further board specific code should
766 When using a watchdog circuitry external to the used
767 SoC, then define this variable and provide board
768 specific code for the "hw_watchdog_reset" function.
771 CONFIG_VERSION_VARIABLE
772 If this variable is defined, an environment variable
773 named "ver" is created by U-Boot showing the U-Boot
774 version as printed by the "version" command.
775 This variable is readonly.
779 When CONFIG_CMD_DATE is selected, the type of the RTC
780 has to be selected, too. Define exactly one of the
783 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
784 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
785 CONFIG_RTC_MC13783 - use MC13783 RTC
786 CONFIG_RTC_MC146818 - use MC146818 RTC
787 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
788 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
789 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
790 CONFIG_RTC_DS164x - use Dallas DS164x RTC
791 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
792 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
793 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
794 CONFIG_SYS_RV3029_TCR - enable trickle charger on
797 Note that if the RTC uses I2C, then the I2C interface
798 must also be configured. See I2C Support, below.
801 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
802 CONFIG_PCA953X_INFO - enable pca953x info command
804 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
805 chip-ngpio pairs that tell the PCA953X driver the number of
806 pins supported by a particular chip.
808 Note that if the GPIO device uses I2C, then the I2C interface
809 must also be configured. See I2C Support, below.
813 When CONFIG_TIMESTAMP is selected, the timestamp
814 (date and time) of an image is printed by image
815 commands like bootm or iminfo. This option is
816 automatically enabled when you select CONFIG_CMD_DATE .
819 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
820 and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION
822 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
823 CONFIG_CMD_SCSI) you must configure support for at
824 least one partition type as well.
827 CONFIG_IDE_RESET_ROUTINE - this is defined in several
828 board configurations files but used nowhere!
830 CONFIG_IDE_RESET - is this is defined, IDE Reset will
831 be performed by calling the function
832 ide_set_reset(int reset)
833 which has to be defined in a board specific file
838 Set this to enable ATAPI support.
843 Set this to enable support for disks larger than 137GB
844 Also look at CONFIG_SYS_64BIT_LBA.
845 Whithout these , LBA48 support uses 32bit variables and will 'only'
846 support disks up to 2.1TB.
848 CONFIG_SYS_64BIT_LBA:
849 When enabled, makes the IDE subsystem use 64bit sector addresses.
853 At the moment only there is only support for the
854 SYM53C8XX SCSI controller; define
855 CONFIG_SCSI_SYM53C8XX to enable it.
857 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
858 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
859 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
860 maximum numbers of LUNs, SCSI ID's and target
862 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
864 - NETWORK Support (PCI):
866 Support for Intel 8254x gigabit chips.
868 CONFIG_E1000_FALLBACK_MAC
869 default MAC for empty EEPROM after production.
872 Support for Intel 82557/82559/82559ER chips.
873 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
874 write routine for first time initialisation.
877 Support for Digital 2114x chips.
878 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
879 modem chip initialisation (KS8761/QS6611).
882 Support for National dp83815 chips.
885 Support for National dp8382[01] gigabit chips.
887 - NETWORK Support (other):
889 CONFIG_DRIVER_AT91EMAC
890 Support for AT91RM9200 EMAC.
893 Define this to use reduced MII inteface
895 CONFIG_DRIVER_AT91EMAC_QUIET
896 If this defined, the driver is quiet.
897 The driver doen't show link status messages.
899 CONFIG_DRIVER_LAN91C96
900 Support for SMSC's LAN91C96 chips.
903 Define this to hold the physical address
904 of the LAN91C96's I/O space
906 CONFIG_LAN91C96_USE_32_BIT
907 Define this to enable 32 bit addressing
909 CONFIG_DRIVER_SMC91111
910 Support for SMSC's LAN91C111 chip
913 Define this to hold the physical address
914 of the device (I/O space)
916 CONFIG_SMC_USE_32_BIT
917 Define this if data bus is 32 bits
919 CONFIG_SMC_USE_IOFUNCS
920 Define this to use i/o functions instead of macros
921 (some hardware wont work with macros)
924 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
926 CONFIG_FTGMAC100_EGIGA
927 Define this to use GE link update with gigabit PHY.
928 Define this if FTGMAC100 is connected to gigabit PHY.
929 If your system has 10/100 PHY only, it might not occur
930 wrong behavior. Because PHY usually return timeout or
931 useless data when polling gigabit status and gigabit
932 control registers. This behavior won't affect the
933 correctnessof 10/100 link speed update.
936 Support for SMSC's LAN911x and LAN921x chips
939 Define this to hold the physical address
940 of the device (I/O space)
942 CONFIG_SMC911X_32_BIT
943 Define this if data bus is 32 bits
945 CONFIG_SMC911X_16_BIT
946 Define this if data bus is 16 bits. If your processor
947 automatically converts one 32 bit word to two 16 bit
948 words you may also try CONFIG_SMC911X_32_BIT.
951 Support for Renesas on-chip Ethernet controller
953 CONFIG_SH_ETHER_USE_PORT
954 Define the number of ports to be used
956 CONFIG_SH_ETHER_PHY_ADDR
957 Define the ETH PHY's address
959 CONFIG_SH_ETHER_CACHE_WRITEBACK
960 If this option is set, the driver enables cache flush.
963 At the moment only the UHCI host controller is
964 supported (PIP405, MIP405, MPC5200); define
965 CONFIG_USB_UHCI to enable it.
966 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
967 and define CONFIG_USB_STORAGE to enable the USB
970 Supported are USB Keyboards and USB Floppy drives
972 MPC5200 USB requires additional defines:
974 for 528 MHz Clock: 0x0001bbbb
978 for differential drivers: 0x00001000
979 for single ended drivers: 0x00005000
980 for differential drivers on PSC3: 0x00000100
981 for single ended drivers on PSC3: 0x00004100
982 CONFIG_SYS_USB_EVENT_POLL
983 May be defined to allow interrupt polling
984 instead of using asynchronous interrupts
987 Define the below if you wish to use the USB console.
988 Once firmware is rebuilt from a serial console issue the
989 command "setenv stdin usbtty; setenv stdout usbtty" and
990 attach your USB cable. The Unix command "dmesg" should print
991 it has found a new device. The environment variable usbtty
992 can be set to gserial or cdc_acm to enable your device to
993 appear to a USB host as a Linux gserial device or a
994 Common Device Class Abstract Control Model serial device.
995 If you select usbtty = gserial you should be able to enumerate
997 # modprobe usbserial vendor=0xVendorID product=0xProductID
998 else if using cdc_acm, simply setting the environment
999 variable usbtty to be cdc_acm should suffice. The following
1000 might be defined in YourBoardName.h
1003 Define this to build a UDC device
1006 Define this to have a tty type of device available to
1007 talk to the UDC device
1009 CONFIG_SYS_CONSOLE_IS_IN_ENV
1010 Define this if you want stdin, stdout &/or stderr to
1014 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1015 Derive USB clock from external clock "blah"
1016 - CONFIG_SYS_USB_EXTC_CLK 0x02
1018 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1019 Derive USB clock from brgclk
1020 - CONFIG_SYS_USB_BRG_CLK 0x04
1022 If you have a USB-IF assigned VendorID then you may wish to
1023 define your own vendor specific values either in BoardName.h
1024 or directly in usbd_vendor_info.h. If you don't define
1025 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1026 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1027 should pretend to be a Linux device to it's target host.
1029 CONFIG_USBD_MANUFACTURER
1030 Define this string as the name of your company for
1031 - CONFIG_USBD_MANUFACTURER "my company"
1033 CONFIG_USBD_PRODUCT_NAME
1034 Define this string as the name of your product
1035 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1037 CONFIG_USBD_VENDORID
1038 Define this as your assigned Vendor ID from the USB
1039 Implementors Forum. This *must* be a genuine Vendor ID
1040 to avoid polluting the USB namespace.
1041 - CONFIG_USBD_VENDORID 0xFFFF
1043 CONFIG_USBD_PRODUCTID
1044 Define this as the unique Product ID
1046 - CONFIG_USBD_PRODUCTID 0xFFFF
1050 The MMC controller on the Intel PXA is supported. To
1051 enable this define CONFIG_MMC. The MMC can be
1052 accessed from the boot prompt by mapping the device
1053 to physical memory similar to flash. Command line is
1054 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1055 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1057 - Journaling Flash filesystem support:
1058 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1059 CONFIG_JFFS2_NAND_DEV
1060 Define these for a default partition on a NAND device
1062 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1063 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1064 Define these for a default partition on a NOR device
1066 CONFIG_SYS_JFFS_CUSTOM_PART
1067 Define this to create an own partition. You have to provide a
1068 function struct part_info* jffs2_part_info(int part_num)
1070 If you define only one JFFS2 partition you may also want to
1071 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1072 to disable the command chpart. This is the default when you
1073 have not defined a custom partition
1078 Define this to enable standard (PC-Style) keyboard
1082 Standard PC keyboard driver with US (is default) and
1083 GERMAN key layout (switch via environment 'keymap=de') support.
1084 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1085 for cfb_console. Supports cursor blinking.
1090 Define this to enable video support (for output to
1093 CONFIG_VIDEO_CT69000
1095 Enable Chips & Technologies 69000 Video chip
1097 CONFIG_VIDEO_SMI_LYNXEM
1098 Enable Silicon Motion SMI 712/710/810 Video chip. The
1099 video output is selected via environment 'videoout'
1100 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1103 For the CT69000 and SMI_LYNXEM drivers, videomode is
1104 selected via environment 'videomode'. Two different ways
1106 - "videomode=num" 'num' is a standard LiLo mode numbers.
1107 Following standard modes are supported (* is default):
1109 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1110 -------------+---------------------------------------------
1111 8 bits | 0x301* 0x303 0x305 0x161 0x307
1112 15 bits | 0x310 0x313 0x316 0x162 0x319
1113 16 bits | 0x311 0x314 0x317 0x163 0x31A
1114 24 bits | 0x312 0x315 0x318 ? 0x31B
1115 -------------+---------------------------------------------
1116 (i.e. setenv videomode 317; saveenv; reset;)
1118 - "videomode=bootargs" all the video parameters are parsed
1119 from the bootargs. (See drivers/video/videomodes.c)
1122 CONFIG_VIDEO_SED13806
1123 Enable Epson SED13806 driver. This driver supports 8bpp
1124 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1125 or CONFIG_VIDEO_SED13806_16BPP
1128 Enable the Freescale DIU video driver. Reference boards for
1129 SOCs that have a DIU should define this macro to enable DIU
1130 support, and should also define these other macros:
1136 CONFIG_VIDEO_SW_CURSOR
1137 CONFIG_VGA_AS_SINGLE_DEVICE
1139 CONFIG_VIDEO_BMP_LOGO
1141 The DIU driver will look for the 'video-mode' environment
1142 variable, and if defined, enable the DIU as a console during
1143 boot. See the documentation file README.video for a
1144 description of this variable.
1149 Define this to enable a custom keyboard support.
1150 This simply calls drv_keyboard_init() which must be
1151 defined in your board-specific files.
1152 The only board using this so far is RBC823.
1154 - LCD Support: CONFIG_LCD
1156 Define this to enable LCD support (for output to LCD
1157 display); also select one of the supported displays
1158 by defining one of these:
1162 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1164 CONFIG_NEC_NL6448AC33:
1166 NEC NL6448AC33-18. Active, color, single scan.
1168 CONFIG_NEC_NL6448BC20
1170 NEC NL6448BC20-08. 6.5", 640x480.
1171 Active, color, single scan.
1173 CONFIG_NEC_NL6448BC33_54
1175 NEC NL6448BC33-54. 10.4", 640x480.
1176 Active, color, single scan.
1180 Sharp 320x240. Active, color, single scan.
1181 It isn't 16x9, and I am not sure what it is.
1183 CONFIG_SHARP_LQ64D341
1185 Sharp LQ64D341 display, 640x480.
1186 Active, color, single scan.
1190 HLD1045 display, 640x480.
1191 Active, color, single scan.
1195 Optrex CBL50840-2 NF-FW 99 22 M5
1197 Hitachi LMG6912RPFC-00T
1201 320x240. Black & white.
1203 Normally display is black on white background; define
1204 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1206 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1208 If this option is set, the environment is checked for
1209 a variable "splashimage". If found, the usual display
1210 of logo, copyright and system information on the LCD
1211 is suppressed and the BMP image at the address
1212 specified in "splashimage" is loaded instead. The
1213 console is redirected to the "nulldev", too. This
1214 allows for a "silent" boot where a splash screen is
1215 loaded very quickly after power-on.
1217 CONFIG_SPLASH_SCREEN_ALIGN
1219 If this option is set the splash image can be freely positioned
1220 on the screen. Environment variable "splashpos" specifies the
1221 position as "x,y". If a positive number is given it is used as
1222 number of pixel from left/top. If a negative number is given it
1223 is used as number of pixel from right/bottom. You can also
1224 specify 'm' for centering the image.
1227 setenv splashpos m,m
1228 => image at center of screen
1230 setenv splashpos 30,20
1231 => image at x = 30 and y = 20
1233 setenv splashpos -10,m
1234 => vertically centered image
1235 at x = dspWidth - bmpWidth - 9
1237 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1239 If this option is set, additionally to standard BMP
1240 images, gzipped BMP images can be displayed via the
1241 splashscreen support or the bmp command.
1243 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1245 If this option is set, 8-bit RLE compressed BMP images
1246 can be displayed via the splashscreen support or the
1249 - Compression support:
1252 If this option is set, support for bzip2 compressed
1253 images is included. If not, only uncompressed and gzip
1254 compressed images are supported.
1256 NOTE: the bzip2 algorithm requires a lot of RAM, so
1257 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1262 If this option is set, support for lzma compressed
1265 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1266 requires an amount of dynamic memory that is given by the
1269 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1271 Where lc and lp stand for, respectively, Literal context bits
1272 and Literal pos bits.
1274 This value is upper-bounded by 14MB in the worst case. Anyway,
1275 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1276 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1277 a very small buffer.
1279 Use the lzmainfo tool to determinate the lc and lp values and
1280 then calculate the amount of needed dynamic memory (ensuring
1281 the appropriate CONFIG_SYS_MALLOC_LEN value).
1286 The address of PHY on MII bus.
1288 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1290 The clock frequency of the MII bus
1294 If this option is set, support for speed/duplex
1295 detection of gigabit PHY is included.
1297 CONFIG_PHY_RESET_DELAY
1299 Some PHY like Intel LXT971A need extra delay after
1300 reset before any MII register access is possible.
1301 For such PHY, set this option to the usec delay
1302 required. (minimum 300usec for LXT971A)
1304 CONFIG_PHY_CMD_DELAY (ppc4xx)
1306 Some PHY like Intel LXT971A need extra delay after
1307 command issued before MII status register can be read
1317 Define a default value for Ethernet address to use
1318 for the respective Ethernet interface, in case this
1319 is not determined automatically.
1324 Define a default value for the IP address to use for
1325 the default Ethernet interface, in case this is not
1326 determined through e.g. bootp.
1328 - Server IP address:
1331 Defines a default value for the IP address of a TFTP
1332 server to contact when using the "tftboot" command.
1334 CONFIG_KEEP_SERVERADDR
1336 Keeps the server's MAC address, in the env 'serveraddr'
1337 for passing to bootargs (like Linux's netconsole option)
1339 - Multicast TFTP Mode:
1342 Defines whether you want to support multicast TFTP as per
1343 rfc-2090; for example to work with atftp. Lets lots of targets
1344 tftp down the same boot image concurrently. Note: the Ethernet
1345 driver in use must provide a function: mcast() to join/leave a
1348 - BOOTP Recovery Mode:
1349 CONFIG_BOOTP_RANDOM_DELAY
1351 If you have many targets in a network that try to
1352 boot using BOOTP, you may want to avoid that all
1353 systems send out BOOTP requests at precisely the same
1354 moment (which would happen for instance at recovery
1355 from a power failure, when all systems will try to
1356 boot, thus flooding the BOOTP server. Defining
1357 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1358 inserted before sending out BOOTP requests. The
1359 following delays are inserted then:
1361 1st BOOTP request: delay 0 ... 1 sec
1362 2nd BOOTP request: delay 0 ... 2 sec
1363 3rd BOOTP request: delay 0 ... 4 sec
1365 BOOTP requests: delay 0 ... 8 sec
1367 - DHCP Advanced Options:
1368 You can fine tune the DHCP functionality by defining
1369 CONFIG_BOOTP_* symbols:
1371 CONFIG_BOOTP_SUBNETMASK
1372 CONFIG_BOOTP_GATEWAY
1373 CONFIG_BOOTP_HOSTNAME
1374 CONFIG_BOOTP_NISDOMAIN
1375 CONFIG_BOOTP_BOOTPATH
1376 CONFIG_BOOTP_BOOTFILESIZE
1379 CONFIG_BOOTP_SEND_HOSTNAME
1380 CONFIG_BOOTP_NTPSERVER
1381 CONFIG_BOOTP_TIMEOFFSET
1382 CONFIG_BOOTP_VENDOREX
1384 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1385 environment variable, not the BOOTP server.
1387 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1388 serverip from a DHCP server, it is possible that more
1389 than one DNS serverip is offered to the client.
1390 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1391 serverip will be stored in the additional environment
1392 variable "dnsip2". The first DNS serverip is always
1393 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1396 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1397 to do a dynamic update of a DNS server. To do this, they
1398 need the hostname of the DHCP requester.
1399 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1400 of the "hostname" environment variable is passed as
1401 option 12 to the DHCP server.
1403 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1405 A 32bit value in microseconds for a delay between
1406 receiving a "DHCP Offer" and sending the "DHCP Request".
1407 This fixes a problem with certain DHCP servers that don't
1408 respond 100% of the time to a "DHCP request". E.g. On an
1409 AT91RM9200 processor running at 180MHz, this delay needed
1410 to be *at least* 15,000 usec before a Windows Server 2003
1411 DHCP server would reply 100% of the time. I recommend at
1412 least 50,000 usec to be safe. The alternative is to hope
1413 that one of the retries will be successful but note that
1414 the DHCP timeout and retry process takes a longer than
1418 CONFIG_CDP_DEVICE_ID
1420 The device id used in CDP trigger frames.
1422 CONFIG_CDP_DEVICE_ID_PREFIX
1424 A two character string which is prefixed to the MAC address
1429 A printf format string which contains the ascii name of
1430 the port. Normally is set to "eth%d" which sets
1431 eth0 for the first Ethernet, eth1 for the second etc.
1433 CONFIG_CDP_CAPABILITIES
1435 A 32bit integer which indicates the device capabilities;
1436 0x00000010 for a normal host which does not forwards.
1440 An ascii string containing the version of the software.
1444 An ascii string containing the name of the platform.
1448 A 32bit integer sent on the trigger.
1450 CONFIG_CDP_POWER_CONSUMPTION
1452 A 16bit integer containing the power consumption of the
1453 device in .1 of milliwatts.
1455 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1457 A byte containing the id of the VLAN.
1459 - Status LED: CONFIG_STATUS_LED
1461 Several configurations allow to display the current
1462 status using a LED. For instance, the LED will blink
1463 fast while running U-Boot code, stop blinking as
1464 soon as a reply to a BOOTP request was received, and
1465 start blinking slow once the Linux kernel is running
1466 (supported by a status LED driver in the Linux
1467 kernel). Defining CONFIG_STATUS_LED enables this
1470 - CAN Support: CONFIG_CAN_DRIVER
1472 Defining CONFIG_CAN_DRIVER enables CAN driver support
1473 on those systems that support this (optional)
1474 feature, like the TQM8xxL modules.
1476 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1478 These enable I2C serial bus commands. Defining either of
1479 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1480 include the appropriate I2C driver for the selected CPU.
1482 This will allow you to use i2c commands at the u-boot
1483 command line (as long as you set CONFIG_CMD_I2C in
1484 CONFIG_COMMANDS) and communicate with i2c based realtime
1485 clock chips. See common/cmd_i2c.c for a description of the
1486 command line interface.
1488 CONFIG_HARD_I2C selects a hardware I2C controller.
1490 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1491 bit-banging) driver instead of CPM or similar hardware
1494 There are several other quantities that must also be
1495 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1497 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1498 to be the frequency (in Hz) at which you wish your i2c bus
1499 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1500 the CPU's i2c node address).
1502 Now, the u-boot i2c code for the mpc8xx
1503 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1504 and so its address should therefore be cleared to 0 (See,
1505 eg, MPC823e User's Manual p.16-473). So, set
1506 CONFIG_SYS_I2C_SLAVE to 0.
1508 CONFIG_SYS_I2C_INIT_MPC5XXX
1510 When a board is reset during an i2c bus transfer
1511 chips might think that the current transfer is still
1512 in progress. Reset the slave devices by sending start
1513 commands until the slave device responds.
1515 That's all that's required for CONFIG_HARD_I2C.
1517 If you use the software i2c interface (CONFIG_SOFT_I2C)
1518 then the following macros need to be defined (examples are
1519 from include/configs/lwmon.h):
1523 (Optional). Any commands necessary to enable the I2C
1524 controller or configure ports.
1526 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1530 (Only for MPC8260 CPU). The I/O port to use (the code
1531 assumes both bits are on the same port). Valid values
1532 are 0..3 for ports A..D.
1536 The code necessary to make the I2C data line active
1537 (driven). If the data line is open collector, this
1540 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1544 The code necessary to make the I2C data line tri-stated
1545 (inactive). If the data line is open collector, this
1548 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1552 Code that returns TRUE if the I2C data line is high,
1555 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1559 If <bit> is TRUE, sets the I2C data line high. If it
1560 is FALSE, it clears it (low).
1562 eg: #define I2C_SDA(bit) \
1563 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1564 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1568 If <bit> is TRUE, sets the I2C clock line high. If it
1569 is FALSE, it clears it (low).
1571 eg: #define I2C_SCL(bit) \
1572 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1573 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1577 This delay is invoked four times per clock cycle so this
1578 controls the rate of data transfer. The data rate thus
1579 is 1 / (I2C_DELAY * 4). Often defined to be something
1582 #define I2C_DELAY udelay(2)
1584 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1586 If your arch supports the generic GPIO framework (asm/gpio.h),
1587 then you may alternatively define the two GPIOs that are to be
1588 used as SCL / SDA. Any of the previous I2C_xxx macros will
1589 have GPIO-based defaults assigned to them as appropriate.
1591 You should define these to the GPIO value as given directly to
1592 the generic GPIO functions.
1594 CONFIG_SYS_I2C_INIT_BOARD
1596 When a board is reset during an i2c bus transfer
1597 chips might think that the current transfer is still
1598 in progress. On some boards it is possible to access
1599 the i2c SCLK line directly, either by using the
1600 processor pin as a GPIO or by having a second pin
1601 connected to the bus. If this option is defined a
1602 custom i2c_init_board() routine in boards/xxx/board.c
1603 is run early in the boot sequence.
1605 CONFIG_SYS_I2C_BOARD_LATE_INIT
1607 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1608 defined a custom i2c_board_late_init() routine in
1609 boards/xxx/board.c is run AFTER the operations in i2c_init()
1610 is completed. This callpoint can be used to unreset i2c bus
1611 using CPU i2c controller register accesses for CPUs whose i2c
1612 controller provide such a method. It is called at the end of
1613 i2c_init() to allow i2c_init operations to setup the i2c bus
1614 controller on the CPU (e.g. setting bus speed & slave address).
1616 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1618 This option enables configuration of bi_iic_fast[] flags
1619 in u-boot bd_info structure based on u-boot environment
1620 variable "i2cfast". (see also i2cfast)
1622 CONFIG_I2C_MULTI_BUS
1624 This option allows the use of multiple I2C buses, each of which
1625 must have a controller. At any point in time, only one bus is
1626 active. To switch to a different bus, use the 'i2c dev' command.
1627 Note that bus numbering is zero-based.
1629 CONFIG_SYS_I2C_NOPROBES
1631 This option specifies a list of I2C devices that will be skipped
1632 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1633 is set, specify a list of bus-device pairs. Otherwise, specify
1634 a 1D array of device addresses
1637 #undef CONFIG_I2C_MULTI_BUS
1638 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1640 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1642 #define CONFIG_I2C_MULTI_BUS
1643 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1645 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1647 CONFIG_SYS_SPD_BUS_NUM
1649 If defined, then this indicates the I2C bus number for DDR SPD.
1650 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1652 CONFIG_SYS_RTC_BUS_NUM
1654 If defined, then this indicates the I2C bus number for the RTC.
1655 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1657 CONFIG_SYS_DTT_BUS_NUM
1659 If defined, then this indicates the I2C bus number for the DTT.
1660 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1662 CONFIG_SYS_I2C_DTT_ADDR:
1664 If defined, specifies the I2C address of the DTT device.
1665 If not defined, then U-Boot uses predefined value for
1666 specified DTT device.
1670 Define this option if you want to use Freescale's I2C driver in
1671 drivers/i2c/fsl_i2c.c.
1675 Define this option if you have I2C devices reached over 1 .. n
1676 I2C Muxes like the pca9544a. This option addes a new I2C
1677 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1678 new I2C Bus to the existing I2C Busses. If you select the
1679 new Bus with "i2c dev", u-bbot sends first the commandos for
1680 the muxes to activate this new "bus".
1682 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1686 Adding a new I2C Bus reached over 2 pca9544a muxes
1687 The First mux with address 70 and channel 6
1688 The Second mux with address 71 and channel 4
1690 => i2c bus pca9544a:70:6:pca9544a:71:4
1692 Use the "i2c bus" command without parameter, to get a list
1693 of I2C Busses with muxes:
1696 Busses reached over muxes:
1698 reached over Mux(es):
1701 reached over Mux(es):
1706 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1707 u-boot sends First the Commando to the mux@70 to enable
1708 channel 6, and then the Commando to the mux@71 to enable
1711 After that, you can use the "normal" i2c commands as
1712 usual, to communicate with your I2C devices behind
1715 This option is actually implemented for the bitbanging
1716 algorithm in common/soft_i2c.c and for the Hardware I2C
1717 Bus on the MPC8260. But it should be not so difficult
1718 to add this option to other architectures.
1720 CONFIG_SOFT_I2C_READ_REPEATED_START
1722 defining this will force the i2c_read() function in
1723 the soft_i2c driver to perform an I2C repeated start
1724 between writing the address pointer and reading the
1725 data. If this define is omitted the default behaviour
1726 of doing a stop-start sequence will be used. Most I2C
1727 devices can use either method, but some require one or
1730 - SPI Support: CONFIG_SPI
1732 Enables SPI driver (so far only tested with
1733 SPI EEPROM, also an instance works with Crystal A/D and
1734 D/As on the SACSng board)
1738 Enables the driver for SPI controller on SuperH. Currently
1739 only SH7757 is supported.
1743 Enables extended (16-bit) SPI EEPROM addressing.
1744 (symmetrical to CONFIG_I2C_X)
1748 Enables a software (bit-bang) SPI driver rather than
1749 using hardware support. This is a general purpose
1750 driver that only requires three general I/O port pins
1751 (two outputs, one input) to function. If this is
1752 defined, the board configuration must define several
1753 SPI configuration items (port pins to use, etc). For
1754 an example, see include/configs/sacsng.h.
1758 Enables a hardware SPI driver for general-purpose reads
1759 and writes. As with CONFIG_SOFT_SPI, the board configuration
1760 must define a list of chip-select function pointers.
1761 Currently supported on some MPC8xxx processors. For an
1762 example, see include/configs/mpc8349emds.h.
1766 Enables the driver for the SPI controllers on i.MX and MXC
1767 SoCs. Currently only i.MX31 is supported.
1769 - FPGA Support: CONFIG_FPGA
1771 Enables FPGA subsystem.
1773 CONFIG_FPGA_<vendor>
1775 Enables support for specific chip vendors.
1778 CONFIG_FPGA_<family>
1780 Enables support for FPGA family.
1781 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1785 Specify the number of FPGA devices to support.
1787 CONFIG_SYS_FPGA_PROG_FEEDBACK
1789 Enable printing of hash marks during FPGA configuration.
1791 CONFIG_SYS_FPGA_CHECK_BUSY
1793 Enable checks on FPGA configuration interface busy
1794 status by the configuration function. This option
1795 will require a board or device specific function to
1800 If defined, a function that provides delays in the FPGA
1801 configuration driver.
1803 CONFIG_SYS_FPGA_CHECK_CTRLC
1804 Allow Control-C to interrupt FPGA configuration
1806 CONFIG_SYS_FPGA_CHECK_ERROR
1808 Check for configuration errors during FPGA bitfile
1809 loading. For example, abort during Virtex II
1810 configuration if the INIT_B line goes low (which
1811 indicated a CRC error).
1813 CONFIG_SYS_FPGA_WAIT_INIT
1815 Maximum time to wait for the INIT_B line to deassert
1816 after PROB_B has been deasserted during a Virtex II
1817 FPGA configuration sequence. The default time is 500
1820 CONFIG_SYS_FPGA_WAIT_BUSY
1822 Maximum time to wait for BUSY to deassert during
1823 Virtex II FPGA configuration. The default is 5 ms.
1825 CONFIG_SYS_FPGA_WAIT_CONFIG
1827 Time to wait after FPGA configuration. The default is
1830 - Configuration Management:
1833 If defined, this string will be added to the U-Boot
1834 version information (U_BOOT_VERSION)
1836 - Vendor Parameter Protection:
1838 U-Boot considers the values of the environment
1839 variables "serial#" (Board Serial Number) and
1840 "ethaddr" (Ethernet Address) to be parameters that
1841 are set once by the board vendor / manufacturer, and
1842 protects these variables from casual modification by
1843 the user. Once set, these variables are read-only,
1844 and write or delete attempts are rejected. You can
1845 change this behaviour:
1847 If CONFIG_ENV_OVERWRITE is #defined in your config
1848 file, the write protection for vendor parameters is
1849 completely disabled. Anybody can change or delete
1852 Alternatively, if you #define _both_ CONFIG_ETHADDR
1853 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1854 Ethernet address is installed in the environment,
1855 which can be changed exactly ONCE by the user. [The
1856 serial# is unaffected by this, i. e. it remains
1862 Define this variable to enable the reservation of
1863 "protected RAM", i. e. RAM which is not overwritten
1864 by U-Boot. Define CONFIG_PRAM to hold the number of
1865 kB you want to reserve for pRAM. You can overwrite
1866 this default value by defining an environment
1867 variable "pram" to the number of kB you want to
1868 reserve. Note that the board info structure will
1869 still show the full amount of RAM. If pRAM is
1870 reserved, a new environment variable "mem" will
1871 automatically be defined to hold the amount of
1872 remaining RAM in a form that can be passed as boot
1873 argument to Linux, for instance like that:
1875 setenv bootargs ... mem=\${mem}
1878 This way you can tell Linux not to use this memory,
1879 either, which results in a memory region that will
1880 not be affected by reboots.
1882 *WARNING* If your board configuration uses automatic
1883 detection of the RAM size, you must make sure that
1884 this memory test is non-destructive. So far, the
1885 following board configurations are known to be
1888 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1889 HERMES, IP860, RPXlite, LWMON, LANTEC,
1895 Define this variable to stop the system in case of a
1896 fatal error, so that you have to reset it manually.
1897 This is probably NOT a good idea for an embedded
1898 system where you want the system to reboot
1899 automatically as fast as possible, but it may be
1900 useful during development since you can try to debug
1901 the conditions that lead to the situation.
1903 CONFIG_NET_RETRY_COUNT
1905 This variable defines the number of retries for
1906 network operations like ARP, RARP, TFTP, or BOOTP
1907 before giving up the operation. If not defined, a
1908 default value of 5 is used.
1912 Timeout waiting for an ARP reply in milliseconds.
1914 - Command Interpreter:
1915 CONFIG_AUTO_COMPLETE
1917 Enable auto completion of commands using TAB.
1919 Note that this feature has NOT been implemented yet
1920 for the "hush" shell.
1923 CONFIG_SYS_HUSH_PARSER
1925 Define this variable to enable the "hush" shell (from
1926 Busybox) as command line interpreter, thus enabling
1927 powerful command line syntax like
1928 if...then...else...fi conditionals or `&&' and '||'
1929 constructs ("shell scripts").
1931 If undefined, you get the old, much simpler behaviour
1932 with a somewhat smaller memory footprint.
1935 CONFIG_SYS_PROMPT_HUSH_PS2
1937 This defines the secondary prompt string, which is
1938 printed when the command interpreter needs more input
1939 to complete a command. Usually "> ".
1943 In the current implementation, the local variables
1944 space and global environment variables space are
1945 separated. Local variables are those you define by
1946 simply typing `name=value'. To access a local
1947 variable later on, you have write `$name' or
1948 `${name}'; to execute the contents of a variable
1949 directly type `$name' at the command prompt.
1951 Global environment variables are those you use
1952 setenv/printenv to work with. To run a command stored
1953 in such a variable, you need to use the run command,
1954 and you must not use the '$' sign to access them.
1956 To store commands and special characters in a
1957 variable, please use double quotation marks
1958 surrounding the whole text of the variable, instead
1959 of the backslashes before semicolons and special
1962 - Commandline Editing and History:
1963 CONFIG_CMDLINE_EDITING
1965 Enable editing and History functions for interactive
1966 commandline input operations
1968 - Default Environment:
1969 CONFIG_EXTRA_ENV_SETTINGS
1971 Define this to contain any number of null terminated
1972 strings (variable = value pairs) that will be part of
1973 the default environment compiled into the boot image.
1975 For example, place something like this in your
1976 board's config file:
1978 #define CONFIG_EXTRA_ENV_SETTINGS \
1982 Warning: This method is based on knowledge about the
1983 internal format how the environment is stored by the
1984 U-Boot code. This is NOT an official, exported
1985 interface! Although it is unlikely that this format
1986 will change soon, there is no guarantee either.
1987 You better know what you are doing here.
1989 Note: overly (ab)use of the default environment is
1990 discouraged. Make sure to check other ways to preset
1991 the environment like the "source" command or the
1994 - DataFlash Support:
1995 CONFIG_HAS_DATAFLASH
1997 Defining this option enables DataFlash features and
1998 allows to read/write in Dataflash via the standard
2001 - SystemACE Support:
2004 Adding this option adds support for Xilinx SystemACE
2005 chips attached via some sort of local bus. The address
2006 of the chip must also be defined in the
2007 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2009 #define CONFIG_SYSTEMACE
2010 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2012 When SystemACE support is added, the "ace" device type
2013 becomes available to the fat commands, i.e. fatls.
2015 - TFTP Fixed UDP Port:
2018 If this is defined, the environment variable tftpsrcp
2019 is used to supply the TFTP UDP source port value.
2020 If tftpsrcp isn't defined, the normal pseudo-random port
2021 number generator is used.
2023 Also, the environment variable tftpdstp is used to supply
2024 the TFTP UDP destination port value. If tftpdstp isn't
2025 defined, the normal port 69 is used.
2027 The purpose for tftpsrcp is to allow a TFTP server to
2028 blindly start the TFTP transfer using the pre-configured
2029 target IP address and UDP port. This has the effect of
2030 "punching through" the (Windows XP) firewall, allowing
2031 the remainder of the TFTP transfer to proceed normally.
2032 A better solution is to properly configure the firewall,
2033 but sometimes that is not allowed.
2035 - Show boot progress:
2036 CONFIG_SHOW_BOOT_PROGRESS
2038 Defining this option allows to add some board-
2039 specific code (calling a user-provided function
2040 "show_boot_progress(int)") that enables you to show
2041 the system's boot progress on some display (for
2042 example, some LED's) on your board. At the moment,
2043 the following checkpoints are implemented:
2045 - Standalone program support:
2046 CONFIG_STANDALONE_LOAD_ADDR
2048 This option allows to define board specific values
2049 for the address where standalone program gets loaded,
2050 thus overwriting the architecutre dependent default
2053 - Frame Buffer Address:
2056 Define CONFIG_FB_ADDR if you want to use specific address for
2058 Then system will reserve the frame buffer address to defined address
2059 instead of lcd_setmem (this function grab the memory for frame buffer
2062 Please see board_init_f function.
2064 If you want this config option then,
2065 please define it at your board config file
2067 Legacy uImage format:
2070 1 common/cmd_bootm.c before attempting to boot an image
2071 -1 common/cmd_bootm.c Image header has bad magic number
2072 2 common/cmd_bootm.c Image header has correct magic number
2073 -2 common/cmd_bootm.c Image header has bad checksum
2074 3 common/cmd_bootm.c Image header has correct checksum
2075 -3 common/cmd_bootm.c Image data has bad checksum
2076 4 common/cmd_bootm.c Image data has correct checksum
2077 -4 common/cmd_bootm.c Image is for unsupported architecture
2078 5 common/cmd_bootm.c Architecture check OK
2079 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2080 6 common/cmd_bootm.c Image Type check OK
2081 -6 common/cmd_bootm.c gunzip uncompression error
2082 -7 common/cmd_bootm.c Unimplemented compression type
2083 7 common/cmd_bootm.c Uncompression OK
2084 8 common/cmd_bootm.c No uncompress/copy overwrite error
2085 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2087 9 common/image.c Start initial ramdisk verification
2088 -10 common/image.c Ramdisk header has bad magic number
2089 -11 common/image.c Ramdisk header has bad checksum
2090 10 common/image.c Ramdisk header is OK
2091 -12 common/image.c Ramdisk data has bad checksum
2092 11 common/image.c Ramdisk data has correct checksum
2093 12 common/image.c Ramdisk verification complete, start loading
2094 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2095 13 common/image.c Start multifile image verification
2096 14 common/image.c No initial ramdisk, no multifile, continue.
2098 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2100 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2101 -31 post/post.c POST test failed, detected by post_output_backlog()
2102 -32 post/post.c POST test failed, detected by post_run_single()
2104 34 common/cmd_doc.c before loading a Image from a DOC device
2105 -35 common/cmd_doc.c Bad usage of "doc" command
2106 35 common/cmd_doc.c correct usage of "doc" command
2107 -36 common/cmd_doc.c No boot device
2108 36 common/cmd_doc.c correct boot device
2109 -37 common/cmd_doc.c Unknown Chip ID on boot device
2110 37 common/cmd_doc.c correct chip ID found, device available
2111 -38 common/cmd_doc.c Read Error on boot device
2112 38 common/cmd_doc.c reading Image header from DOC device OK
2113 -39 common/cmd_doc.c Image header has bad magic number
2114 39 common/cmd_doc.c Image header has correct magic number
2115 -40 common/cmd_doc.c Error reading Image from DOC device
2116 40 common/cmd_doc.c Image header has correct magic number
2117 41 common/cmd_ide.c before loading a Image from a IDE device
2118 -42 common/cmd_ide.c Bad usage of "ide" command
2119 42 common/cmd_ide.c correct usage of "ide" command
2120 -43 common/cmd_ide.c No boot device
2121 43 common/cmd_ide.c boot device found
2122 -44 common/cmd_ide.c Device not available
2123 44 common/cmd_ide.c Device available
2124 -45 common/cmd_ide.c wrong partition selected
2125 45 common/cmd_ide.c partition selected
2126 -46 common/cmd_ide.c Unknown partition table
2127 46 common/cmd_ide.c valid partition table found
2128 -47 common/cmd_ide.c Invalid partition type
2129 47 common/cmd_ide.c correct partition type
2130 -48 common/cmd_ide.c Error reading Image Header on boot device
2131 48 common/cmd_ide.c reading Image Header from IDE device OK
2132 -49 common/cmd_ide.c Image header has bad magic number
2133 49 common/cmd_ide.c Image header has correct magic number
2134 -50 common/cmd_ide.c Image header has bad checksum
2135 50 common/cmd_ide.c Image header has correct checksum
2136 -51 common/cmd_ide.c Error reading Image from IDE device
2137 51 common/cmd_ide.c reading Image from IDE device OK
2138 52 common/cmd_nand.c before loading a Image from a NAND device
2139 -53 common/cmd_nand.c Bad usage of "nand" command
2140 53 common/cmd_nand.c correct usage of "nand" command
2141 -54 common/cmd_nand.c No boot device
2142 54 common/cmd_nand.c boot device found
2143 -55 common/cmd_nand.c Unknown Chip ID on boot device
2144 55 common/cmd_nand.c correct chip ID found, device available
2145 -56 common/cmd_nand.c Error reading Image Header on boot device
2146 56 common/cmd_nand.c reading Image Header from NAND device OK
2147 -57 common/cmd_nand.c Image header has bad magic number
2148 57 common/cmd_nand.c Image header has correct magic number
2149 -58 common/cmd_nand.c Error reading Image from NAND device
2150 58 common/cmd_nand.c reading Image from NAND device OK
2152 -60 common/env_common.c Environment has a bad CRC, using default
2154 64 net/eth.c starting with Ethernet configuration.
2155 -64 net/eth.c no Ethernet found.
2156 65 net/eth.c Ethernet found.
2158 -80 common/cmd_net.c usage wrong
2159 80 common/cmd_net.c before calling NetLoop()
2160 -81 common/cmd_net.c some error in NetLoop() occurred
2161 81 common/cmd_net.c NetLoop() back without error
2162 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2163 82 common/cmd_net.c trying automatic boot
2164 83 common/cmd_net.c running "source" command
2165 -83 common/cmd_net.c some error in automatic boot or "source" command
2166 84 common/cmd_net.c end without errors
2171 100 common/cmd_bootm.c Kernel FIT Image has correct format
2172 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2173 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2174 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2175 102 common/cmd_bootm.c Kernel unit name specified
2176 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2177 103 common/cmd_bootm.c Found configuration node
2178 104 common/cmd_bootm.c Got kernel subimage node offset
2179 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2180 105 common/cmd_bootm.c Kernel subimage hash verification OK
2181 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2182 106 common/cmd_bootm.c Architecture check OK
2183 -106 common/cmd_bootm.c Kernel subimage has wrong type
2184 107 common/cmd_bootm.c Kernel subimage type OK
2185 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2186 108 common/cmd_bootm.c Got kernel subimage data/size
2187 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2188 -109 common/cmd_bootm.c Can't get kernel subimage type
2189 -110 common/cmd_bootm.c Can't get kernel subimage comp
2190 -111 common/cmd_bootm.c Can't get kernel subimage os
2191 -112 common/cmd_bootm.c Can't get kernel subimage load address
2192 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2194 120 common/image.c Start initial ramdisk verification
2195 -120 common/image.c Ramdisk FIT image has incorrect format
2196 121 common/image.c Ramdisk FIT image has correct format
2197 122 common/image.c No ramdisk subimage unit name, using configuration
2198 -122 common/image.c Can't get configuration for ramdisk subimage
2199 123 common/image.c Ramdisk unit name specified
2200 -124 common/image.c Can't get ramdisk subimage node offset
2201 125 common/image.c Got ramdisk subimage node offset
2202 -125 common/image.c Ramdisk subimage hash verification failed
2203 126 common/image.c Ramdisk subimage hash verification OK
2204 -126 common/image.c Ramdisk subimage for unsupported architecture
2205 127 common/image.c Architecture check OK
2206 -127 common/image.c Can't get ramdisk subimage data/size
2207 128 common/image.c Got ramdisk subimage data/size
2208 129 common/image.c Can't get ramdisk load address
2209 -129 common/image.c Got ramdisk load address
2211 -130 common/cmd_doc.c Incorrect FIT image format
2212 131 common/cmd_doc.c FIT image format OK
2214 -140 common/cmd_ide.c Incorrect FIT image format
2215 141 common/cmd_ide.c FIT image format OK
2217 -150 common/cmd_nand.c Incorrect FIT image format
2218 151 common/cmd_nand.c FIT image format OK
2220 - Automatic software updates via TFTP server
2222 CONFIG_UPDATE_TFTP_CNT_MAX
2223 CONFIG_UPDATE_TFTP_MSEC_MAX
2225 These options enable and control the auto-update feature;
2226 for a more detailed description refer to doc/README.update.
2228 - MTD Support (mtdparts command, UBI support)
2231 Adds the MTD device infrastructure from the Linux kernel.
2232 Needed for mtdparts command support.
2234 CONFIG_MTD_PARTITIONS
2236 Adds the MTD partitioning infrastructure from the Linux
2237 kernel. Needed for UBI support.
2243 [so far only for SMDK2400 boards]
2245 - Modem support enable:
2246 CONFIG_MODEM_SUPPORT
2248 - RTS/CTS Flow control enable:
2251 - Modem debug support:
2252 CONFIG_MODEM_SUPPORT_DEBUG
2254 Enables debugging stuff (char screen[1024], dbg())
2255 for modem support. Useful only with BDI2000.
2257 - Interrupt support (PPC):
2259 There are common interrupt_init() and timer_interrupt()
2260 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2261 for CPU specific initialization. interrupt_init_cpu()
2262 should set decrementer_count to appropriate value. If
2263 CPU resets decrementer automatically after interrupt
2264 (ppc4xx) it should set decrementer_count to zero.
2265 timer_interrupt() calls timer_interrupt_cpu() for CPU
2266 specific handling. If board has watchdog / status_led
2267 / other_activity_monitor it works automatically from
2268 general timer_interrupt().
2272 In the target system modem support is enabled when a
2273 specific key (key combination) is pressed during
2274 power-on. Otherwise U-Boot will boot normally
2275 (autoboot). The key_pressed() function is called from
2276 board_init(). Currently key_pressed() is a dummy
2277 function, returning 1 and thus enabling modem
2280 If there are no modem init strings in the
2281 environment, U-Boot proceed to autoboot; the
2282 previous output (banner, info printfs) will be
2285 See also: doc/README.Modem
2288 Configuration Settings:
2289 -----------------------
2291 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2292 undefine this when you're short of memory.
2294 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2295 width of the commands listed in the 'help' command output.
2297 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2298 prompt for user input.
2300 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2302 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2304 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2306 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2307 the application (usually a Linux kernel) when it is
2310 - CONFIG_SYS_BAUDRATE_TABLE:
2311 List of legal baudrate settings for this board.
2313 - CONFIG_SYS_CONSOLE_INFO_QUIET
2314 Suppress display of console information at boot.
2316 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2317 If the board specific function
2318 extern int overwrite_console (void);
2319 returns 1, the stdin, stderr and stdout are switched to the
2320 serial port, else the settings in the environment are used.
2322 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2323 Enable the call to overwrite_console().
2325 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2326 Enable overwrite of previous console environment settings.
2328 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2329 Begin and End addresses of the area used by the
2332 - CONFIG_SYS_ALT_MEMTEST:
2333 Enable an alternate, more extensive memory test.
2335 - CONFIG_SYS_MEMTEST_SCRATCH:
2336 Scratch address used by the alternate memory test
2337 You only need to set this if address zero isn't writeable
2339 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2340 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2341 this specified memory area will get subtracted from the top
2342 (end) of RAM and won't get "touched" at all by U-Boot. By
2343 fixing up gd->ram_size the Linux kernel should gets passed
2344 the now "corrected" memory size and won't touch it either.
2345 This should work for arch/ppc and arch/powerpc. Only Linux
2346 board ports in arch/powerpc with bootwrapper support that
2347 recalculate the memory size from the SDRAM controller setup
2348 will have to get fixed in Linux additionally.
2350 This option can be used as a workaround for the 440EPx/GRx
2351 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2354 WARNING: Please make sure that this value is a multiple of
2355 the Linux page size (normally 4k). If this is not the case,
2356 then the end address of the Linux memory will be located at a
2357 non page size aligned address and this could cause major
2360 - CONFIG_SYS_TFTP_LOADADDR:
2361 Default load address for network file downloads
2363 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2364 Enable temporary baudrate change while serial download
2366 - CONFIG_SYS_SDRAM_BASE:
2367 Physical start address of SDRAM. _Must_ be 0 here.
2369 - CONFIG_SYS_MBIO_BASE:
2370 Physical start address of Motherboard I/O (if using a
2373 - CONFIG_SYS_FLASH_BASE:
2374 Physical start address of Flash memory.
2376 - CONFIG_SYS_MONITOR_BASE:
2377 Physical start address of boot monitor code (set by
2378 make config files to be same as the text base address
2379 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
2380 CONFIG_SYS_FLASH_BASE when booting from flash.
2382 - CONFIG_SYS_MONITOR_LEN:
2383 Size of memory reserved for monitor code, used to
2384 determine _at_compile_time_ (!) if the environment is
2385 embedded within the U-Boot image, or in a separate
2388 - CONFIG_SYS_MALLOC_LEN:
2389 Size of DRAM reserved for malloc() use.
2391 - CONFIG_SYS_BOOTM_LEN:
2392 Normally compressed uImages are limited to an
2393 uncompressed size of 8 MBytes. If this is not enough,
2394 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2395 to adjust this setting to your needs.
2397 - CONFIG_SYS_BOOTMAPSZ:
2398 Maximum size of memory mapped by the startup code of
2399 the Linux kernel; all data that must be processed by
2400 the Linux kernel (bd_info, boot arguments, FDT blob if
2401 used) must be put below this limit, unless "bootm_low"
2402 enviroment variable is defined and non-zero. In such case
2403 all data for the Linux kernel must be between "bootm_low"
2404 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
2405 variable "bootm_mapsize" will override the value of
2406 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
2407 then the value in "bootm_size" will be used instead.
2409 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
2410 Enable initrd_high functionality. If defined then the
2411 initrd_high feature is enabled and the bootm ramdisk subcommand
2414 - CONFIG_SYS_BOOT_GET_CMDLINE:
2415 Enables allocating and saving kernel cmdline in space between
2416 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2418 - CONFIG_SYS_BOOT_GET_KBD:
2419 Enables allocating and saving a kernel copy of the bd_info in
2420 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2422 - CONFIG_SYS_MAX_FLASH_BANKS:
2423 Max number of Flash memory banks
2425 - CONFIG_SYS_MAX_FLASH_SECT:
2426 Max number of sectors on a Flash chip
2428 - CONFIG_SYS_FLASH_ERASE_TOUT:
2429 Timeout for Flash erase operations (in ms)
2431 - CONFIG_SYS_FLASH_WRITE_TOUT:
2432 Timeout for Flash write operations (in ms)
2434 - CONFIG_SYS_FLASH_LOCK_TOUT
2435 Timeout for Flash set sector lock bit operation (in ms)
2437 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2438 Timeout for Flash clear lock bits operation (in ms)
2440 - CONFIG_SYS_FLASH_PROTECTION
2441 If defined, hardware flash sectors protection is used
2442 instead of U-Boot software protection.
2444 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2446 Enable TFTP transfers directly to flash memory;
2447 without this option such a download has to be
2448 performed in two steps: (1) download to RAM, and (2)
2449 copy from RAM to flash.
2451 The two-step approach is usually more reliable, since
2452 you can check if the download worked before you erase
2453 the flash, but in some situations (when system RAM is
2454 too limited to allow for a temporary copy of the
2455 downloaded image) this option may be very useful.
2457 - CONFIG_SYS_FLASH_CFI:
2458 Define if the flash driver uses extra elements in the
2459 common flash structure for storing flash geometry.
2461 - CONFIG_FLASH_CFI_DRIVER
2462 This option also enables the building of the cfi_flash driver
2463 in the drivers directory
2465 - CONFIG_FLASH_CFI_MTD
2466 This option enables the building of the cfi_mtd driver
2467 in the drivers directory. The driver exports CFI flash
2470 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2471 Use buffered writes to flash.
2473 - CONFIG_FLASH_SPANSION_S29WS_N
2474 s29ws-n MirrorBit flash has non-standard addresses for buffered
2477 - CONFIG_SYS_FLASH_QUIET_TEST
2478 If this option is defined, the common CFI flash doesn't
2479 print it's warning upon not recognized FLASH banks. This
2480 is useful, if some of the configured banks are only
2481 optionally available.
2483 - CONFIG_FLASH_SHOW_PROGRESS
2484 If defined (must be an integer), print out countdown
2485 digits and dots. Recommended value: 45 (9..1) for 80
2486 column displays, 15 (3..1) for 40 column displays.
2488 - CONFIG_SYS_RX_ETH_BUFFER:
2489 Defines the number of Ethernet receive buffers. On some
2490 Ethernet controllers it is recommended to set this value
2491 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2492 buffers can be full shortly after enabling the interface
2493 on high Ethernet traffic.
2494 Defaults to 4 if not defined.
2496 - CONFIG_ENV_MAX_ENTRIES
2498 Maximum number of entries in the hash table that is used
2499 internally to store the environment settings. The default
2500 setting is supposed to be generous and should work in most
2501 cases. This setting can be used to tune behaviour; see
2502 lib/hashtable.c for details.
2504 The following definitions that deal with the placement and management
2505 of environment data (variable area); in general, we support the
2506 following configurations:
2508 - CONFIG_ENV_IS_IN_FLASH:
2510 Define this if the environment is in flash memory.
2512 a) The environment occupies one whole flash sector, which is
2513 "embedded" in the text segment with the U-Boot code. This
2514 happens usually with "bottom boot sector" or "top boot
2515 sector" type flash chips, which have several smaller
2516 sectors at the start or the end. For instance, such a
2517 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2518 such a case you would place the environment in one of the
2519 4 kB sectors - with U-Boot code before and after it. With
2520 "top boot sector" type flash chips, you would put the
2521 environment in one of the last sectors, leaving a gap
2522 between U-Boot and the environment.
2524 - CONFIG_ENV_OFFSET:
2526 Offset of environment data (variable area) to the
2527 beginning of flash memory; for instance, with bottom boot
2528 type flash chips the second sector can be used: the offset
2529 for this sector is given here.
2531 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2535 This is just another way to specify the start address of
2536 the flash sector containing the environment (instead of
2539 - CONFIG_ENV_SECT_SIZE:
2541 Size of the sector containing the environment.
2544 b) Sometimes flash chips have few, equal sized, BIG sectors.
2545 In such a case you don't want to spend a whole sector for
2550 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2551 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2552 of this flash sector for the environment. This saves
2553 memory for the RAM copy of the environment.
2555 It may also save flash memory if you decide to use this
2556 when your environment is "embedded" within U-Boot code,
2557 since then the remainder of the flash sector could be used
2558 for U-Boot code. It should be pointed out that this is
2559 STRONGLY DISCOURAGED from a robustness point of view:
2560 updating the environment in flash makes it always
2561 necessary to erase the WHOLE sector. If something goes
2562 wrong before the contents has been restored from a copy in
2563 RAM, your target system will be dead.
2565 - CONFIG_ENV_ADDR_REDUND
2566 CONFIG_ENV_SIZE_REDUND
2568 These settings describe a second storage area used to hold
2569 a redundant copy of the environment data, so that there is
2570 a valid backup copy in case there is a power failure during
2571 a "saveenv" operation.
2573 BE CAREFUL! Any changes to the flash layout, and some changes to the
2574 source code will make it necessary to adapt <board>/u-boot.lds*
2578 - CONFIG_ENV_IS_IN_NVRAM:
2580 Define this if you have some non-volatile memory device
2581 (NVRAM, battery buffered SRAM) which you want to use for the
2587 These two #defines are used to determine the memory area you
2588 want to use for environment. It is assumed that this memory
2589 can just be read and written to, without any special
2592 BE CAREFUL! The first access to the environment happens quite early
2593 in U-Boot initalization (when we try to get the setting of for the
2594 console baudrate). You *MUST* have mapped your NVRAM area then, or
2597 Please note that even with NVRAM we still use a copy of the
2598 environment in RAM: we could work on NVRAM directly, but we want to
2599 keep settings there always unmodified except somebody uses "saveenv"
2600 to save the current settings.
2603 - CONFIG_ENV_IS_IN_EEPROM:
2605 Use this if you have an EEPROM or similar serial access
2606 device and a driver for it.
2608 - CONFIG_ENV_OFFSET:
2611 These two #defines specify the offset and size of the
2612 environment area within the total memory of your EEPROM.
2614 - CONFIG_SYS_I2C_EEPROM_ADDR:
2615 If defined, specified the chip address of the EEPROM device.
2616 The default address is zero.
2618 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2619 If defined, the number of bits used to address bytes in a
2620 single page in the EEPROM device. A 64 byte page, for example
2621 would require six bits.
2623 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2624 If defined, the number of milliseconds to delay between
2625 page writes. The default is zero milliseconds.
2627 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2628 The length in bytes of the EEPROM memory array address. Note
2629 that this is NOT the chip address length!
2631 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2632 EEPROM chips that implement "address overflow" are ones
2633 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2634 address and the extra bits end up in the "chip address" bit
2635 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2638 Note that we consider the length of the address field to
2639 still be one byte because the extra address bits are hidden
2640 in the chip address.
2642 - CONFIG_SYS_EEPROM_SIZE:
2643 The size in bytes of the EEPROM device.
2645 - CONFIG_ENV_EEPROM_IS_ON_I2C
2646 define this, if you have I2C and SPI activated, and your
2647 EEPROM, which holds the environment, is on the I2C bus.
2649 - CONFIG_I2C_ENV_EEPROM_BUS
2650 if you have an Environment on an EEPROM reached over
2651 I2C muxes, you can define here, how to reach this
2652 EEPROM. For example:
2654 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
2656 EEPROM which holds the environment, is reached over
2657 a pca9547 i2c mux with address 0x70, channel 3.
2659 - CONFIG_ENV_IS_IN_DATAFLASH:
2661 Define this if you have a DataFlash memory device which you
2662 want to use for the environment.
2664 - CONFIG_ENV_OFFSET:
2668 These three #defines specify the offset and size of the
2669 environment area within the total memory of your DataFlash placed
2670 at the specified address.
2672 - CONFIG_ENV_IS_IN_NAND:
2674 Define this if you have a NAND device which you want to use
2675 for the environment.
2677 - CONFIG_ENV_OFFSET:
2680 These two #defines specify the offset and size of the environment
2681 area within the first NAND device. CONFIG_ENV_OFFSET must be
2682 aligned to an erase block boundary.
2684 - CONFIG_ENV_OFFSET_REDUND (optional):
2686 This setting describes a second storage area of CONFIG_ENV_SIZE
2687 size used to hold a redundant copy of the environment data, so
2688 that there is a valid backup copy in case there is a power failure
2689 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
2690 aligned to an erase block boundary.
2692 - CONFIG_ENV_RANGE (optional):
2694 Specifies the length of the region in which the environment
2695 can be written. This should be a multiple of the NAND device's
2696 block size. Specifying a range with more erase blocks than
2697 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
2698 the range to be avoided.
2700 - CONFIG_ENV_OFFSET_OOB (optional):
2702 Enables support for dynamically retrieving the offset of the
2703 environment from block zero's out-of-band data. The
2704 "nand env.oob" command can be used to record this offset.
2705 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
2706 using CONFIG_ENV_OFFSET_OOB.
2708 - CONFIG_NAND_ENV_DST
2710 Defines address in RAM to which the nand_spl code should copy the
2711 environment. If redundant environment is used, it will be copied to
2712 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2714 - CONFIG_SYS_SPI_INIT_OFFSET
2716 Defines offset to the initial SPI buffer area in DPRAM. The
2717 area is used at an early stage (ROM part) if the environment
2718 is configured to reside in the SPI EEPROM: We need a 520 byte
2719 scratch DPRAM area. It is used between the two initialization
2720 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2721 to be a good choice since it makes it far enough from the
2722 start of the data area as well as from the stack pointer.
2724 Please note that the environment is read-only until the monitor
2725 has been relocated to RAM and a RAM copy of the environment has been
2726 created; also, when using EEPROM you will have to use getenv_f()
2727 until then to read environment variables.
2729 The environment is protected by a CRC32 checksum. Before the monitor
2730 is relocated into RAM, as a result of a bad CRC you will be working
2731 with the compiled-in default environment - *silently*!!! [This is
2732 necessary, because the first environment variable we need is the
2733 "baudrate" setting for the console - if we have a bad CRC, we don't
2734 have any device yet where we could complain.]
2736 Note: once the monitor has been relocated, then it will complain if
2737 the default environment is used; a new CRC is computed as soon as you
2738 use the "saveenv" command to store a valid environment.
2740 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2741 Echo the inverted Ethernet link state to the fault LED.
2743 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2744 also needs to be defined.
2746 - CONFIG_SYS_FAULT_MII_ADDR:
2747 MII address of the PHY to check for the Ethernet link state.
2749 - CONFIG_NS16550_MIN_FUNCTIONS:
2750 Define this if you desire to only have use of the NS16550_init
2751 and NS16550_putc functions for the serial driver located at
2752 drivers/serial/ns16550.c. This option is useful for saving
2753 space for already greatly restricted images, including but not
2754 limited to NAND_SPL configurations.
2756 Low Level (hardware related) configuration options:
2757 ---------------------------------------------------
2759 - CONFIG_SYS_CACHELINE_SIZE:
2760 Cache Line Size of the CPU.
2762 - CONFIG_SYS_DEFAULT_IMMR:
2763 Default address of the IMMR after system reset.
2765 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2766 and RPXsuper) to be able to adjust the position of
2767 the IMMR register after a reset.
2769 - Floppy Disk Support:
2770 CONFIG_SYS_FDC_DRIVE_NUMBER
2772 the default drive number (default value 0)
2774 CONFIG_SYS_ISA_IO_STRIDE
2776 defines the spacing between FDC chipset registers
2779 CONFIG_SYS_ISA_IO_OFFSET
2781 defines the offset of register from address. It
2782 depends on which part of the data bus is connected to
2783 the FDC chipset. (default value 0)
2785 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
2786 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
2789 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
2790 fdc_hw_init() is called at the beginning of the FDC
2791 setup. fdc_hw_init() must be provided by the board
2792 source code. It is used to make hardware dependant
2796 Most IDE controllers were designed to be connected with PCI
2797 interface. Only few of them were designed for AHB interface.
2798 When software is doing ATA command and data transfer to
2799 IDE devices through IDE-AHB controller, some additional
2800 registers accessing to these kind of IDE-AHB controller
2803 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
2804 DO NOT CHANGE unless you know exactly what you're
2805 doing! (11-4) [MPC8xx/82xx systems only]
2807 - CONFIG_SYS_INIT_RAM_ADDR:
2809 Start address of memory area that can be used for
2810 initial data and stack; please note that this must be
2811 writable memory that is working WITHOUT special
2812 initialization, i. e. you CANNOT use normal RAM which
2813 will become available only after programming the
2814 memory controller and running certain initialization
2817 U-Boot uses the following memory types:
2818 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2819 - MPC824X: data cache
2820 - PPC4xx: data cache
2822 - CONFIG_SYS_GBL_DATA_OFFSET:
2824 Offset of the initial data structure in the memory
2825 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2826 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
2827 data is located at the end of the available space
2828 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
2829 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
2830 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2831 CONFIG_SYS_GBL_DATA_OFFSET) downward.
2834 On the MPC824X (or other systems that use the data
2835 cache for initial memory) the address chosen for
2836 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
2837 point to an otherwise UNUSED address space between
2838 the top of RAM and the start of the PCI space.
2840 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
2842 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
2844 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
2846 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
2848 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2850 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
2852 - CONFIG_SYS_OR_TIMING_SDRAM:
2855 - CONFIG_SYS_MAMR_PTA:
2856 periodic timer for refresh
2858 - CONFIG_SYS_DER: Debug Event Register (37-47)
2860 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2861 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2862 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2863 CONFIG_SYS_BR1_PRELIM:
2864 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2866 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2867 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2868 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
2869 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2871 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
2872 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
2873 Machine Mode Register and Memory Periodic Timer
2874 Prescaler definitions (SDRAM timing)
2876 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
2877 enable I2C microcode relocation patch (MPC8xx);
2878 define relocation offset in DPRAM [DSP2]
2880 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
2881 enable SMC microcode relocation patch (MPC8xx);
2882 define relocation offset in DPRAM [SMC1]
2884 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
2885 enable SPI microcode relocation patch (MPC8xx);
2886 define relocation offset in DPRAM [SCC4]
2888 - CONFIG_SYS_USE_OSCCLK:
2889 Use OSCM clock mode on MBX8xx board. Be careful,
2890 wrong setting might damage your board. Read
2891 doc/README.MBX before setting this variable!
2893 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2894 Offset of the bootmode word in DPRAM used by post
2895 (Power On Self Tests). This definition overrides
2896 #define'd default value in commproc.h resp.
2899 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
2900 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
2901 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
2902 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
2903 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2904 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
2905 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
2906 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
2907 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
2909 - CONFIG_PCI_DISABLE_PCIE:
2910 Disable PCI-Express on systems where it is supported but not
2914 Chip has SRIO or not
2917 Board has SRIO 1 port available
2920 Board has SRIO 2 port available
2922 - CONFIG_SYS_SRIOn_MEM_VIRT:
2923 Virtual Address of SRIO port 'n' memory region
2925 - CONFIG_SYS_SRIOn_MEM_PHYS:
2926 Physical Address of SRIO port 'n' memory region
2928 - CONFIG_SYS_SRIOn_MEM_SIZE:
2929 Size of SRIO port 'n' memory region
2931 - CONFIG_SYS_NDFC_16
2932 Defined to tell the NDFC that the NAND chip is using a
2935 - CONFIG_SYS_NDFC_EBC0_CFG
2936 Sets the EBC0_CFG register for the NDFC. If not defined
2937 a default value will be used.
2940 Get DDR timing information from an I2C EEPROM. Common
2941 with pluggable memory modules such as SODIMMs
2944 I2C address of the SPD EEPROM
2946 - CONFIG_SYS_SPD_BUS_NUM
2947 If SPD EEPROM is on an I2C bus other than the first
2948 one, specify here. Note that the value must resolve
2949 to something your driver can deal with.
2951 - CONFIG_SYS_83XX_DDR_USES_CS0
2952 Only for 83xx systems. If specified, then DDR should
2953 be configured using CS0 and CS1 instead of CS2 and CS3.
2955 - CONFIG_ETHER_ON_FEC[12]
2956 Define to enable FEC[12] on a 8xx series processor.
2958 - CONFIG_FEC[12]_PHY
2959 Define to the hardcoded PHY address which corresponds
2960 to the given FEC; i. e.
2961 #define CONFIG_FEC1_PHY 4
2962 means that the PHY with address 4 is connected to FEC1
2964 When set to -1, means to probe for first available.
2966 - CONFIG_FEC[12]_PHY_NORXERR
2967 The PHY does not have a RXERR line (RMII only).
2968 (so program the FEC to ignore it).
2971 Enable RMII mode for all FECs.
2972 Note that this is a global option, we can't
2973 have one FEC in standard MII mode and another in RMII mode.
2975 - CONFIG_CRC32_VERIFY
2976 Add a verify option to the crc32 command.
2979 => crc32 -v <address> <count> <crc32>
2981 Where address/count indicate a memory area
2982 and crc32 is the correct crc32 which the
2986 Add the "loopw" memory command. This only takes effect if
2987 the memory commands are activated globally (CONFIG_CMD_MEM).
2990 Add the "mdc" and "mwc" memory commands. These are cyclic
2995 This command will print 4 bytes (10,11,12,13) each 500 ms.
2997 => mwc.l 100 12345678 10
2998 This command will write 12345678 to address 100 all 10 ms.
3000 This only takes effect if the memory commands are activated
3001 globally (CONFIG_CMD_MEM).
3003 - CONFIG_SKIP_LOWLEVEL_INIT
3004 [ARM only] If this variable is defined, then certain
3005 low level initializations (like setting up the memory
3006 controller) are omitted and/or U-Boot does not
3007 relocate itself into RAM.
3009 Normally this variable MUST NOT be defined. The only
3010 exception is when U-Boot is loaded (to RAM) by some
3011 other boot loader or by a debugger which performs
3012 these initializations itself.
3015 Modifies the behaviour of start.S when compiling a loader
3016 that is executed before the actual U-Boot. E.g. when
3017 compiling a NAND SPL.
3019 - CONFIG_USE_ARCH_MEMCPY
3020 CONFIG_USE_ARCH_MEMSET
3021 If these options are used a optimized version of memcpy/memset will
3022 be used if available. These functions may be faster under some
3023 conditions but may increase the binary size.
3025 Building the Software:
3026 ======================
3028 Building U-Boot has been tested in several native build environments
3029 and in many different cross environments. Of course we cannot support
3030 all possibly existing versions of cross development tools in all
3031 (potentially obsolete) versions. In case of tool chain problems we
3032 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3033 which is extensively used to build and test U-Boot.
3035 If you are not using a native environment, it is assumed that you
3036 have GNU cross compiling tools available in your path. In this case,
3037 you must set the environment variable CROSS_COMPILE in your shell.
3038 Note that no changes to the Makefile or any other source files are
3039 necessary. For example using the ELDK on a 4xx CPU, please enter:
3041 $ CROSS_COMPILE=ppc_4xx-
3042 $ export CROSS_COMPILE
3044 Note: If you wish to generate Windows versions of the utilities in
3045 the tools directory you can use the MinGW toolchain
3046 (http://www.mingw.org). Set your HOST tools to the MinGW
3047 toolchain and execute 'make tools'. For example:
3049 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3051 Binaries such as tools/mkimage.exe will be created which can
3052 be executed on computers running Windows.
3054 U-Boot is intended to be simple to build. After installing the
3055 sources you must configure U-Boot for one specific board type. This
3060 where "NAME_config" is the name of one of the existing configu-
3061 rations; see the main Makefile for supported names.
3063 Note: for some board special configuration names may exist; check if
3064 additional information is available from the board vendor; for
3065 instance, the TQM823L systems are available without (standard)
3066 or with LCD support. You can select such additional "features"
3067 when choosing the configuration, i. e.
3070 - will configure for a plain TQM823L, i. e. no LCD support
3072 make TQM823L_LCD_config
3073 - will configure for a TQM823L with U-Boot console on LCD
3078 Finally, type "make all", and you should get some working U-Boot
3079 images ready for download to / installation on your system:
3081 - "u-boot.bin" is a raw binary image
3082 - "u-boot" is an image in ELF binary format
3083 - "u-boot.srec" is in Motorola S-Record format
3085 By default the build is performed locally and the objects are saved
3086 in the source directory. One of the two methods can be used to change
3087 this behavior and build U-Boot to some external directory:
3089 1. Add O= to the make command line invocations:
3091 make O=/tmp/build distclean
3092 make O=/tmp/build NAME_config
3093 make O=/tmp/build all
3095 2. Set environment variable BUILD_DIR to point to the desired location:
3097 export BUILD_DIR=/tmp/build
3102 Note that the command line "O=" setting overrides the BUILD_DIR environment
3106 Please be aware that the Makefiles assume you are using GNU make, so
3107 for instance on NetBSD you might need to use "gmake" instead of
3111 If the system board that you have is not listed, then you will need
3112 to port U-Boot to your hardware platform. To do this, follow these
3115 1. Add a new configuration option for your board to the toplevel
3116 "Makefile" and to the "MAKEALL" script, using the existing
3117 entries as examples. Note that here and at many other places
3118 boards and other names are listed in alphabetical sort order. Please
3120 2. Create a new directory to hold your board specific code. Add any
3121 files you need. In your board directory, you will need at least
3122 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
3123 3. Create a new configuration file "include/configs/<board>.h" for
3125 3. If you're porting U-Boot to a new CPU, then also create a new
3126 directory to hold your CPU specific code. Add any files you need.
3127 4. Run "make <board>_config" with your new name.
3128 5. Type "make", and you should get a working "u-boot.srec" file
3129 to be installed on your target system.
3130 6. Debug and solve any problems that might arise.
3131 [Of course, this last step is much harder than it sounds.]
3134 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3135 ==============================================================
3137 If you have modified U-Boot sources (for instance added a new board
3138 or support for new devices, a new CPU, etc.) you are expected to
3139 provide feedback to the other developers. The feedback normally takes
3140 the form of a "patch", i. e. a context diff against a certain (latest
3141 official or latest in the git repository) version of U-Boot sources.
3143 But before you submit such a patch, please verify that your modifi-
3144 cation did not break existing code. At least make sure that *ALL* of
3145 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3146 just run the "MAKEALL" script, which will configure and build U-Boot
3147 for ALL supported system. Be warned, this will take a while. You can
3148 select which (cross) compiler to use by passing a `CROSS_COMPILE'
3149 environment variable to the script, i. e. to use the ELDK cross tools
3152 CROSS_COMPILE=ppc_8xx- MAKEALL
3154 or to build on a native PowerPC system you can type
3156 CROSS_COMPILE=' ' MAKEALL
3158 When using the MAKEALL script, the default behaviour is to build
3159 U-Boot in the source directory. This location can be changed by
3160 setting the BUILD_DIR environment variable. Also, for each target
3161 built, the MAKEALL script saves two log files (<target>.ERR and
3162 <target>.MAKEALL) in the <source dir>/LOG directory. This default
3163 location can be changed by setting the MAKEALL_LOGDIR environment
3164 variable. For example:
3166 export BUILD_DIR=/tmp/build
3167 export MAKEALL_LOGDIR=/tmp/log
3168 CROSS_COMPILE=ppc_8xx- MAKEALL
3170 With the above settings build objects are saved in the /tmp/build,
3171 log files are saved in the /tmp/log and the source tree remains clean
3172 during the whole build process.
3175 See also "U-Boot Porting Guide" below.
3178 Monitor Commands - Overview:
3179 ============================
3181 go - start application at address 'addr'
3182 run - run commands in an environment variable
3183 bootm - boot application image from memory
3184 bootp - boot image via network using BootP/TFTP protocol
3185 tftpboot- boot image via network using TFTP protocol
3186 and env variables "ipaddr" and "serverip"
3187 (and eventually "gatewayip")
3188 rarpboot- boot image via network using RARP/TFTP protocol
3189 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3190 loads - load S-Record file over serial line
3191 loadb - load binary file over serial line (kermit mode)
3193 mm - memory modify (auto-incrementing)
3194 nm - memory modify (constant address)
3195 mw - memory write (fill)
3197 cmp - memory compare
3198 crc32 - checksum calculation
3199 i2c - I2C sub-system
3200 sspi - SPI utility commands
3201 base - print or set address offset
3202 printenv- print environment variables
3203 setenv - set environment variables
3204 saveenv - save environment variables to persistent storage
3205 protect - enable or disable FLASH write protection
3206 erase - erase FLASH memory
3207 flinfo - print FLASH memory information
3208 bdinfo - print Board Info structure
3209 iminfo - print header information for application image
3210 coninfo - print console devices and informations
3211 ide - IDE sub-system
3212 loop - infinite loop on address range
3213 loopw - infinite write loop on address range
3214 mtest - simple RAM test
3215 icache - enable or disable instruction cache
3216 dcache - enable or disable data cache
3217 reset - Perform RESET of the CPU
3218 echo - echo args to console
3219 version - print monitor version
3220 help - print online help
3221 ? - alias for 'help'
3224 Monitor Commands - Detailed Description:
3225 ========================================
3229 For now: just type "help <command>".
3232 Environment Variables:
3233 ======================
3235 U-Boot supports user configuration using Environment Variables which
3236 can be made persistent by saving to Flash memory.
3238 Environment Variables are set using "setenv", printed using
3239 "printenv", and saved to Flash using "saveenv". Using "setenv"
3240 without a value can be used to delete a variable from the
3241 environment. As long as you don't save the environment you are
3242 working with an in-memory copy. In case the Flash area containing the
3243 environment is erased by accident, a default environment is provided.
3245 Some configuration options can be set using Environment Variables.
3247 List of environment variables (most likely not complete):
3249 baudrate - see CONFIG_BAUDRATE
3251 bootdelay - see CONFIG_BOOTDELAY
3253 bootcmd - see CONFIG_BOOTCOMMAND
3255 bootargs - Boot arguments when booting an RTOS image
3257 bootfile - Name of the image to load with TFTP
3259 bootm_low - Memory range available for image processing in the bootm
3260 command can be restricted. This variable is given as
3261 a hexadecimal number and defines lowest address allowed
3262 for use by the bootm command. See also "bootm_size"
3263 environment variable. Address defined by "bootm_low" is
3264 also the base of the initial memory mapping for the Linux
3265 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
3268 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
3269 This variable is given as a hexadecimal number and it
3270 defines the size of the memory region starting at base
3271 address bootm_low that is accessible by the Linux kernel
3272 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
3273 as the default value if it is defined, and bootm_size is
3276 bootm_size - Memory range available for image processing in the bootm
3277 command can be restricted. This variable is given as
3278 a hexadecimal number and defines the size of the region
3279 allowed for use by the bootm command. See also "bootm_low"
3280 environment variable.
3282 updatefile - Location of the software update file on a TFTP server, used
3283 by the automatic software update feature. Please refer to
3284 documentation in doc/README.update for more details.
3286 autoload - if set to "no" (any string beginning with 'n'),
3287 "bootp" will just load perform a lookup of the
3288 configuration from the BOOTP server, but not try to
3289 load any image using TFTP
3291 autostart - if set to "yes", an image loaded using the "bootp",
3292 "rarpboot", "tftpboot" or "diskboot" commands will
3293 be automatically started (by internally calling
3296 If set to "no", a standalone image passed to the
3297 "bootm" command will be copied to the load address
3298 (and eventually uncompressed), but NOT be started.
3299 This can be used to load and uncompress arbitrary
3302 i2cfast - (PPC405GP|PPC405EP only)
3303 if set to 'y' configures Linux I2C driver for fast
3304 mode (400kHZ). This environment variable is used in
3305 initialization code. So, for changes to be effective
3306 it must be saved and board must be reset.
3308 initrd_high - restrict positioning of initrd images:
3309 If this variable is not set, initrd images will be
3310 copied to the highest possible address in RAM; this
3311 is usually what you want since it allows for
3312 maximum initrd size. If for some reason you want to
3313 make sure that the initrd image is loaded below the
3314 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3315 variable to a value of "no" or "off" or "0".
3316 Alternatively, you can set it to a maximum upper
3317 address to use (U-Boot will still check that it
3318 does not overwrite the U-Boot stack and data).
3320 For instance, when you have a system with 16 MB
3321 RAM, and want to reserve 4 MB from use by Linux,
3322 you can do this by adding "mem=12M" to the value of
3323 the "bootargs" variable. However, now you must make
3324 sure that the initrd image is placed in the first
3325 12 MB as well - this can be done with
3327 setenv initrd_high 00c00000
3329 If you set initrd_high to 0xFFFFFFFF, this is an
3330 indication to U-Boot that all addresses are legal
3331 for the Linux kernel, including addresses in flash
3332 memory. In this case U-Boot will NOT COPY the
3333 ramdisk at all. This may be useful to reduce the
3334 boot time on your system, but requires that this
3335 feature is supported by your Linux kernel.
3337 ipaddr - IP address; needed for tftpboot command
3339 loadaddr - Default load address for commands like "bootp",
3340 "rarpboot", "tftpboot", "loadb" or "diskboot"
3342 loads_echo - see CONFIG_LOADS_ECHO
3344 serverip - TFTP server IP address; needed for tftpboot command
3346 bootretry - see CONFIG_BOOT_RETRY_TIME
3348 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3350 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3352 ethprime - When CONFIG_NET_MULTI is enabled controls which
3353 interface is used first.
3355 ethact - When CONFIG_NET_MULTI is enabled controls which
3356 interface is currently active. For example you
3357 can do the following
3359 => setenv ethact FEC
3360 => ping 192.168.0.1 # traffic sent on FEC
3361 => setenv ethact SCC
3362 => ping 10.0.0.1 # traffic sent on SCC
3364 ethrotate - When set to "no" U-Boot does not go through all
3365 available network interfaces.
3366 It just stays at the currently selected interface.
3368 netretry - When set to "no" each network operation will
3369 either succeed or fail without retrying.
3370 When set to "once" the network operation will
3371 fail when all the available network interfaces
3372 are tried once without success.
3373 Useful on scripts which control the retry operation
3376 npe_ucode - set load address for the NPE microcode
3378 tftpsrcport - If this is set, the value is used for TFTP's
3381 tftpdstport - If this is set, the value is used for TFTP's UDP
3382 destination port instead of the Well Know Port 69.
3384 tftpblocksize - Block size to use for TFTP transfers; if not set,
3385 we use the TFTP server's default block size
3387 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3388 seconds, minimum value is 1000 = 1 second). Defines
3389 when a packet is considered to be lost so it has to
3390 be retransmitted. The default is 5000 = 5 seconds.
3391 Lowering this value may make downloads succeed
3392 faster in networks with high packet loss rates or
3393 with unreliable TFTP servers.
3395 vlan - When set to a value < 4095 the traffic over
3396 Ethernet is encapsulated/received over 802.1q
3399 The following environment variables may be used and automatically
3400 updated by the network boot commands ("bootp" and "rarpboot"),
3401 depending the information provided by your boot server:
3403 bootfile - see above
3404 dnsip - IP address of your Domain Name Server
3405 dnsip2 - IP address of your secondary Domain Name Server
3406 gatewayip - IP address of the Gateway (Router) to use
3407 hostname - Target hostname
3409 netmask - Subnet Mask
3410 rootpath - Pathname of the root filesystem on the NFS server
3411 serverip - see above
3414 There are two special Environment Variables:
3416 serial# - contains hardware identification information such
3417 as type string and/or serial number
3418 ethaddr - Ethernet address
3420 These variables can be set only once (usually during manufacturing of
3421 the board). U-Boot refuses to delete or overwrite these variables
3422 once they have been set once.
3425 Further special Environment Variables:
3427 ver - Contains the U-Boot version string as printed
3428 with the "version" command. This variable is
3429 readonly (see CONFIG_VERSION_VARIABLE).
3432 Please note that changes to some configuration parameters may take
3433 only effect after the next boot (yes, that's just like Windoze :-).
3436 Command Line Parsing:
3437 =====================
3439 There are two different command line parsers available with U-Boot:
3440 the old "simple" one, and the much more powerful "hush" shell:
3442 Old, simple command line parser:
3443 --------------------------------
3445 - supports environment variables (through setenv / saveenv commands)
3446 - several commands on one line, separated by ';'
3447 - variable substitution using "... ${name} ..." syntax
3448 - special characters ('$', ';') can be escaped by prefixing with '\',
3450 setenv bootcmd bootm \${address}
3451 - You can also escape text by enclosing in single apostrophes, for example:
3452 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3457 - similar to Bourne shell, with control structures like
3458 if...then...else...fi, for...do...done; while...do...done,
3459 until...do...done, ...
3460 - supports environment ("global") variables (through setenv / saveenv
3461 commands) and local shell variables (through standard shell syntax
3462 "name=value"); only environment variables can be used with "run"
3468 (1) If a command line (or an environment variable executed by a "run"
3469 command) contains several commands separated by semicolon, and
3470 one of these commands fails, then the remaining commands will be
3473 (2) If you execute several variables with one call to run (i. e.
3474 calling run with a list of variables as arguments), any failing
3475 command will cause "run" to terminate, i. e. the remaining
3476 variables are not executed.
3478 Note for Redundant Ethernet Interfaces:
3479 =======================================
3481 Some boards come with redundant Ethernet interfaces; U-Boot supports
3482 such configurations and is capable of automatic selection of a
3483 "working" interface when needed. MAC assignment works as follows:
3485 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3486 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3487 "eth1addr" (=>eth1), "eth2addr", ...
3489 If the network interface stores some valid MAC address (for instance
3490 in SROM), this is used as default address if there is NO correspon-
3491 ding setting in the environment; if the corresponding environment
3492 variable is set, this overrides the settings in the card; that means:
3494 o If the SROM has a valid MAC address, and there is no address in the
3495 environment, the SROM's address is used.
3497 o If there is no valid address in the SROM, and a definition in the
3498 environment exists, then the value from the environment variable is
3501 o If both the SROM and the environment contain a MAC address, and
3502 both addresses are the same, this MAC address is used.
3504 o If both the SROM and the environment contain a MAC address, and the
3505 addresses differ, the value from the environment is used and a
3508 o If neither SROM nor the environment contain a MAC address, an error
3511 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
3512 will be programmed into hardware as part of the initialization process. This
3513 may be skipped by setting the appropriate 'ethmacskip' environment variable.
3514 The naming convention is as follows:
3515 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
3520 U-Boot is capable of booting (and performing other auxiliary operations on)
3521 images in two formats:
3523 New uImage format (FIT)
3524 -----------------------
3526 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3527 to Flattened Device Tree). It allows the use of images with multiple
3528 components (several kernels, ramdisks, etc.), with contents protected by
3529 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3535 Old image format is based on binary files which can be basically anything,
3536 preceded by a special header; see the definitions in include/image.h for
3537 details; basically, the header defines the following image properties:
3539 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3540 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3541 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3542 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3544 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3545 IA64, MIPS, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3546 Currently supported: ARM, AVR32, Intel x86, MIPS, Nios II, PowerPC).
3547 * Compression Type (uncompressed, gzip, bzip2)
3553 The header is marked by a special Magic Number, and both the header
3554 and the data portions of the image are secured against corruption by
3561 Although U-Boot should support any OS or standalone application
3562 easily, the main focus has always been on Linux during the design of
3565 U-Boot includes many features that so far have been part of some
3566 special "boot loader" code within the Linux kernel. Also, any
3567 "initrd" images to be used are no longer part of one big Linux image;
3568 instead, kernel and "initrd" are separate images. This implementation
3569 serves several purposes:
3571 - the same features can be used for other OS or standalone
3572 applications (for instance: using compressed images to reduce the
3573 Flash memory footprint)
3575 - it becomes much easier to port new Linux kernel versions because
3576 lots of low-level, hardware dependent stuff are done by U-Boot
3578 - the same Linux kernel image can now be used with different "initrd"
3579 images; of course this also means that different kernel images can
3580 be run with the same "initrd". This makes testing easier (you don't
3581 have to build a new "zImage.initrd" Linux image when you just
3582 change a file in your "initrd"). Also, a field-upgrade of the
3583 software is easier now.
3589 Porting Linux to U-Boot based systems:
3590 ---------------------------------------
3592 U-Boot cannot save you from doing all the necessary modifications to
3593 configure the Linux device drivers for use with your target hardware
3594 (no, we don't intend to provide a full virtual machine interface to
3597 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
3599 Just make sure your machine specific header file (for instance
3600 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3601 Information structure as we define in include/asm-<arch>/u-boot.h,
3602 and make sure that your definition of IMAP_ADDR uses the same value
3603 as your U-Boot configuration in CONFIG_SYS_IMMR.
3606 Configuring the Linux kernel:
3607 -----------------------------
3609 No specific requirements for U-Boot. Make sure you have some root
3610 device (initial ramdisk, NFS) for your target system.
3613 Building a Linux Image:
3614 -----------------------
3616 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3617 not used. If you use recent kernel source, a new build target
3618 "uImage" will exist which automatically builds an image usable by
3619 U-Boot. Most older kernels also have support for a "pImage" target,
3620 which was introduced for our predecessor project PPCBoot and uses a
3621 100% compatible format.
3630 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3631 encapsulate a compressed Linux kernel image with header information,
3632 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3634 * build a standard "vmlinux" kernel image (in ELF binary format):
3636 * convert the kernel into a raw binary image:
3638 ${CROSS_COMPILE}-objcopy -O binary \
3639 -R .note -R .comment \
3640 -S vmlinux linux.bin
3642 * compress the binary image:
3646 * package compressed binary image for U-Boot:
3648 mkimage -A ppc -O linux -T kernel -C gzip \
3649 -a 0 -e 0 -n "Linux Kernel Image" \
3650 -d linux.bin.gz uImage
3653 The "mkimage" tool can also be used to create ramdisk images for use
3654 with U-Boot, either separated from the Linux kernel image, or
3655 combined into one file. "mkimage" encapsulates the images with a 64
3656 byte header containing information about target architecture,
3657 operating system, image type, compression method, entry points, time
3658 stamp, CRC32 checksums, etc.
3660 "mkimage" can be called in two ways: to verify existing images and
3661 print the header information, or to build new images.
3663 In the first form (with "-l" option) mkimage lists the information
3664 contained in the header of an existing U-Boot image; this includes
3665 checksum verification:
3667 tools/mkimage -l image
3668 -l ==> list image header information
3670 The second form (with "-d" option) is used to build a U-Boot image
3671 from a "data file" which is used as image payload:
3673 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3674 -n name -d data_file image
3675 -A ==> set architecture to 'arch'
3676 -O ==> set operating system to 'os'
3677 -T ==> set image type to 'type'
3678 -C ==> set compression type 'comp'
3679 -a ==> set load address to 'addr' (hex)
3680 -e ==> set entry point to 'ep' (hex)
3681 -n ==> set image name to 'name'
3682 -d ==> use image data from 'datafile'
3684 Right now, all Linux kernels for PowerPC systems use the same load
3685 address (0x00000000), but the entry point address depends on the
3688 - 2.2.x kernels have the entry point at 0x0000000C,
3689 - 2.3.x and later kernels have the entry point at 0x00000000.
3691 So a typical call to build a U-Boot image would read:
3693 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3694 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3695 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
3696 > examples/uImage.TQM850L
3697 Image Name: 2.4.4 kernel for TQM850L
3698 Created: Wed Jul 19 02:34:59 2000
3699 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3700 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3701 Load Address: 0x00000000
3702 Entry Point: 0x00000000
3704 To verify the contents of the image (or check for corruption):
3706 -> tools/mkimage -l examples/uImage.TQM850L
3707 Image Name: 2.4.4 kernel for TQM850L
3708 Created: Wed Jul 19 02:34:59 2000
3709 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3710 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3711 Load Address: 0x00000000
3712 Entry Point: 0x00000000
3714 NOTE: for embedded systems where boot time is critical you can trade
3715 speed for memory and install an UNCOMPRESSED image instead: this
3716 needs more space in Flash, but boots much faster since it does not
3717 need to be uncompressed:
3719 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
3720 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3721 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3722 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
3723 > examples/uImage.TQM850L-uncompressed
3724 Image Name: 2.4.4 kernel for TQM850L
3725 Created: Wed Jul 19 02:34:59 2000
3726 Image Type: PowerPC Linux Kernel Image (uncompressed)
3727 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3728 Load Address: 0x00000000
3729 Entry Point: 0x00000000
3732 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3733 when your kernel is intended to use an initial ramdisk:
3735 -> tools/mkimage -n 'Simple Ramdisk Image' \
3736 > -A ppc -O linux -T ramdisk -C gzip \
3737 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3738 Image Name: Simple Ramdisk Image
3739 Created: Wed Jan 12 14:01:50 2000
3740 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3741 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3742 Load Address: 0x00000000
3743 Entry Point: 0x00000000
3746 Installing a Linux Image:
3747 -------------------------
3749 To downloading a U-Boot image over the serial (console) interface,
3750 you must convert the image to S-Record format:
3752 objcopy -I binary -O srec examples/image examples/image.srec
3754 The 'objcopy' does not understand the information in the U-Boot
3755 image header, so the resulting S-Record file will be relative to
3756 address 0x00000000. To load it to a given address, you need to
3757 specify the target address as 'offset' parameter with the 'loads'
3760 Example: install the image to address 0x40100000 (which on the
3761 TQM8xxL is in the first Flash bank):
3763 => erase 40100000 401FFFFF
3769 ## Ready for S-Record download ...
3770 ~>examples/image.srec
3771 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3773 15989 15990 15991 15992
3774 [file transfer complete]
3776 ## Start Addr = 0x00000000
3779 You can check the success of the download using the 'iminfo' command;
3780 this includes a checksum verification so you can be sure no data
3781 corruption happened:
3785 ## Checking Image at 40100000 ...
3786 Image Name: 2.2.13 for initrd on TQM850L
3787 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3788 Data Size: 335725 Bytes = 327 kB = 0 MB
3789 Load Address: 00000000
3790 Entry Point: 0000000c
3791 Verifying Checksum ... OK
3797 The "bootm" command is used to boot an application that is stored in
3798 memory (RAM or Flash). In case of a Linux kernel image, the contents
3799 of the "bootargs" environment variable is passed to the kernel as
3800 parameters. You can check and modify this variable using the
3801 "printenv" and "setenv" commands:
3804 => printenv bootargs
3805 bootargs=root=/dev/ram
3807 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3809 => printenv bootargs
3810 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3813 ## Booting Linux kernel at 40020000 ...
3814 Image Name: 2.2.13 for NFS on TQM850L
3815 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3816 Data Size: 381681 Bytes = 372 kB = 0 MB
3817 Load Address: 00000000
3818 Entry Point: 0000000c
3819 Verifying Checksum ... OK
3820 Uncompressing Kernel Image ... OK
3821 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
3822 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3823 time_init: decrementer frequency = 187500000/60
3824 Calibrating delay loop... 49.77 BogoMIPS
3825 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3828 If you want to boot a Linux kernel with initial RAM disk, you pass
3829 the memory addresses of both the kernel and the initrd image (PPBCOOT
3830 format!) to the "bootm" command:
3832 => imi 40100000 40200000
3834 ## Checking Image at 40100000 ...
3835 Image Name: 2.2.13 for initrd on TQM850L
3836 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3837 Data Size: 335725 Bytes = 327 kB = 0 MB
3838 Load Address: 00000000
3839 Entry Point: 0000000c
3840 Verifying Checksum ... OK
3842 ## Checking Image at 40200000 ...
3843 Image Name: Simple Ramdisk Image
3844 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3845 Data Size: 566530 Bytes = 553 kB = 0 MB
3846 Load Address: 00000000
3847 Entry Point: 00000000
3848 Verifying Checksum ... OK
3850 => bootm 40100000 40200000
3851 ## Booting Linux kernel at 40100000 ...
3852 Image Name: 2.2.13 for initrd on TQM850L
3853 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3854 Data Size: 335725 Bytes = 327 kB = 0 MB
3855 Load Address: 00000000
3856 Entry Point: 0000000c
3857 Verifying Checksum ... OK
3858 Uncompressing Kernel Image ... OK
3859 ## Loading RAMDisk Image at 40200000 ...
3860 Image Name: Simple Ramdisk Image
3861 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3862 Data Size: 566530 Bytes = 553 kB = 0 MB
3863 Load Address: 00000000
3864 Entry Point: 00000000
3865 Verifying Checksum ... OK
3866 Loading Ramdisk ... OK
3867 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
3868 Boot arguments: root=/dev/ram
3869 time_init: decrementer frequency = 187500000/60
3870 Calibrating delay loop... 49.77 BogoMIPS
3872 RAMDISK: Compressed image found at block 0
3873 VFS: Mounted root (ext2 filesystem).
3877 Boot Linux and pass a flat device tree:
3880 First, U-Boot must be compiled with the appropriate defines. See the section
3881 titled "Linux Kernel Interface" above for a more in depth explanation. The
3882 following is an example of how to start a kernel and pass an updated
3888 oft=oftrees/mpc8540ads.dtb
3889 => tftp $oftaddr $oft
3890 Speed: 1000, full duplex
3892 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3893 Filename 'oftrees/mpc8540ads.dtb'.
3894 Load address: 0x300000
3897 Bytes transferred = 4106 (100a hex)
3898 => tftp $loadaddr $bootfile
3899 Speed: 1000, full duplex
3901 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3903 Load address: 0x200000
3904 Loading:############
3906 Bytes transferred = 1029407 (fb51f hex)
3911 => bootm $loadaddr - $oftaddr
3912 ## Booting image at 00200000 ...
3913 Image Name: Linux-2.6.17-dirty
3914 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3915 Data Size: 1029343 Bytes = 1005.2 kB
3916 Load Address: 00000000
3917 Entry Point: 00000000
3918 Verifying Checksum ... OK
3919 Uncompressing Kernel Image ... OK
3920 Booting using flat device tree at 0x300000
3921 Using MPC85xx ADS machine description
3922 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3926 More About U-Boot Image Types:
3927 ------------------------------
3929 U-Boot supports the following image types:
3931 "Standalone Programs" are directly runnable in the environment
3932 provided by U-Boot; it is expected that (if they behave
3933 well) you can continue to work in U-Boot after return from
3934 the Standalone Program.
3935 "OS Kernel Images" are usually images of some Embedded OS which
3936 will take over control completely. Usually these programs
3937 will install their own set of exception handlers, device
3938 drivers, set up the MMU, etc. - this means, that you cannot
3939 expect to re-enter U-Boot except by resetting the CPU.
3940 "RAMDisk Images" are more or less just data blocks, and their
3941 parameters (address, size) are passed to an OS kernel that is
3943 "Multi-File Images" contain several images, typically an OS
3944 (Linux) kernel image and one or more data images like
3945 RAMDisks. This construct is useful for instance when you want
3946 to boot over the network using BOOTP etc., where the boot
3947 server provides just a single image file, but you want to get
3948 for instance an OS kernel and a RAMDisk image.
3950 "Multi-File Images" start with a list of image sizes, each
3951 image size (in bytes) specified by an "uint32_t" in network
3952 byte order. This list is terminated by an "(uint32_t)0".
3953 Immediately after the terminating 0 follow the images, one by
3954 one, all aligned on "uint32_t" boundaries (size rounded up to
3955 a multiple of 4 bytes).
3957 "Firmware Images" are binary images containing firmware (like
3958 U-Boot or FPGA images) which usually will be programmed to
3961 "Script files" are command sequences that will be executed by
3962 U-Boot's command interpreter; this feature is especially
3963 useful when you configure U-Boot to use a real shell (hush)
3964 as command interpreter.
3970 One of the features of U-Boot is that you can dynamically load and
3971 run "standalone" applications, which can use some resources of
3972 U-Boot like console I/O functions or interrupt services.
3974 Two simple examples are included with the sources:
3979 'examples/hello_world.c' contains a small "Hello World" Demo
3980 application; it is automatically compiled when you build U-Boot.
3981 It's configured to run at address 0x00040004, so you can play with it
3985 ## Ready for S-Record download ...
3986 ~>examples/hello_world.srec
3987 1 2 3 4 5 6 7 8 9 10 11 ...
3988 [file transfer complete]
3990 ## Start Addr = 0x00040004
3992 => go 40004 Hello World! This is a test.
3993 ## Starting application at 0x00040004 ...
4004 Hit any key to exit ...
4006 ## Application terminated, rc = 0x0
4008 Another example, which demonstrates how to register a CPM interrupt
4009 handler with the U-Boot code, can be found in 'examples/timer.c'.
4010 Here, a CPM timer is set up to generate an interrupt every second.
4011 The interrupt service routine is trivial, just printing a '.'
4012 character, but this is just a demo program. The application can be
4013 controlled by the following keys:
4015 ? - print current values og the CPM Timer registers
4016 b - enable interrupts and start timer
4017 e - stop timer and disable interrupts
4018 q - quit application
4021 ## Ready for S-Record download ...
4022 ~>examples/timer.srec
4023 1 2 3 4 5 6 7 8 9 10 11 ...
4024 [file transfer complete]
4026 ## Start Addr = 0x00040004
4029 ## Starting application at 0x00040004 ...
4032 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
4035 [q, b, e, ?] Set interval 1000000 us
4038 [q, b, e, ?] ........
4039 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
4042 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
4045 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
4048 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
4050 [q, b, e, ?] ...Stopping timer
4052 [q, b, e, ?] ## Application terminated, rc = 0x0
4058 Over time, many people have reported problems when trying to use the
4059 "minicom" terminal emulation program for serial download. I (wd)
4060 consider minicom to be broken, and recommend not to use it. Under
4061 Unix, I recommend to use C-Kermit for general purpose use (and
4062 especially for kermit binary protocol download ("loadb" command), and
4063 use "cu" for S-Record download ("loads" command).
4065 Nevertheless, if you absolutely want to use it try adding this
4066 configuration to your "File transfer protocols" section:
4068 Name Program Name U/D FullScr IO-Red. Multi
4069 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
4070 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
4076 Starting at version 0.9.2, U-Boot supports NetBSD both as host
4077 (build U-Boot) and target system (boots NetBSD/mpc8xx).
4079 Building requires a cross environment; it is known to work on
4080 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
4081 need gmake since the Makefiles are not compatible with BSD make).
4082 Note that the cross-powerpc package does not install include files;
4083 attempting to build U-Boot will fail because <machine/ansi.h> is
4084 missing. This file has to be installed and patched manually:
4086 # cd /usr/pkg/cross/powerpc-netbsd/include
4088 # ln -s powerpc machine
4089 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
4090 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
4092 Native builds *don't* work due to incompatibilities between native
4093 and U-Boot include files.
4095 Booting assumes that (the first part of) the image booted is a
4096 stage-2 loader which in turn loads and then invokes the kernel
4097 proper. Loader sources will eventually appear in the NetBSD source
4098 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
4099 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
4102 Implementation Internals:
4103 =========================
4105 The following is not intended to be a complete description of every
4106 implementation detail. However, it should help to understand the
4107 inner workings of U-Boot and make it easier to port it to custom
4111 Initial Stack, Global Data:
4112 ---------------------------
4114 The implementation of U-Boot is complicated by the fact that U-Boot
4115 starts running out of ROM (flash memory), usually without access to
4116 system RAM (because the memory controller is not initialized yet).
4117 This means that we don't have writable Data or BSS segments, and BSS
4118 is not initialized as zero. To be able to get a C environment working
4119 at all, we have to allocate at least a minimal stack. Implementation
4120 options for this are defined and restricted by the CPU used: Some CPU
4121 models provide on-chip memory (like the IMMR area on MPC8xx and
4122 MPC826x processors), on others (parts of) the data cache can be
4123 locked as (mis-) used as memory, etc.
4125 Chris Hallinan posted a good summary of these issues to the
4126 U-Boot mailing list:
4128 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
4129 From: "Chris Hallinan" <clh@net1plus.com>
4130 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
4133 Correct me if I'm wrong, folks, but the way I understand it
4134 is this: Using DCACHE as initial RAM for Stack, etc, does not
4135 require any physical RAM backing up the cache. The cleverness
4136 is that the cache is being used as a temporary supply of
4137 necessary storage before the SDRAM controller is setup. It's
4138 beyond the scope of this list to explain the details, but you
4139 can see how this works by studying the cache architecture and
4140 operation in the architecture and processor-specific manuals.
4142 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4143 is another option for the system designer to use as an
4144 initial stack/RAM area prior to SDRAM being available. Either
4145 option should work for you. Using CS 4 should be fine if your
4146 board designers haven't used it for something that would
4147 cause you grief during the initial boot! It is frequently not
4150 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
4151 with your processor/board/system design. The default value
4152 you will find in any recent u-boot distribution in
4153 walnut.h should work for you. I'd set it to a value larger
4154 than your SDRAM module. If you have a 64MB SDRAM module, set
4155 it above 400_0000. Just make sure your board has no resources
4156 that are supposed to respond to that address! That code in
4157 start.S has been around a while and should work as is when
4158 you get the config right.
4163 It is essential to remember this, since it has some impact on the C
4164 code for the initialization procedures:
4166 * Initialized global data (data segment) is read-only. Do not attempt
4169 * Do not use any uninitialized global data (or implicitely initialized
4170 as zero data - BSS segment) at all - this is undefined, initiali-
4171 zation is performed later (when relocating to RAM).
4173 * Stack space is very limited. Avoid big data buffers or things like
4176 Having only the stack as writable memory limits means we cannot use
4177 normal global data to share information beween the code. But it
4178 turned out that the implementation of U-Boot can be greatly
4179 simplified by making a global data structure (gd_t) available to all
4180 functions. We could pass a pointer to this data as argument to _all_
4181 functions, but this would bloat the code. Instead we use a feature of
4182 the GCC compiler (Global Register Variables) to share the data: we
4183 place a pointer (gd) to the global data into a register which we
4184 reserve for this purpose.
4186 When choosing a register for such a purpose we are restricted by the
4187 relevant (E)ABI specifications for the current architecture, and by
4188 GCC's implementation.
4190 For PowerPC, the following registers have specific use:
4192 R2: reserved for system use
4193 R3-R4: parameter passing and return values
4194 R5-R10: parameter passing
4195 R13: small data area pointer
4199 (U-Boot also uses R12 as internal GOT pointer. r12
4200 is a volatile register so r12 needs to be reset when
4201 going back and forth between asm and C)
4203 ==> U-Boot will use R2 to hold a pointer to the global data
4205 Note: on PPC, we could use a static initializer (since the
4206 address of the global data structure is known at compile time),
4207 but it turned out that reserving a register results in somewhat
4208 smaller code - although the code savings are not that big (on
4209 average for all boards 752 bytes for the whole U-Boot image,
4210 624 text + 127 data).
4212 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
4213 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
4215 ==> U-Boot will use P3 to hold a pointer to the global data
4217 On ARM, the following registers are used:
4219 R0: function argument word/integer result
4220 R1-R3: function argument word
4222 R10: stack limit (used only if stack checking if enabled)
4223 R11: argument (frame) pointer
4224 R12: temporary workspace
4227 R15: program counter
4229 ==> U-Boot will use R8 to hold a pointer to the global data
4231 On Nios II, the ABI is documented here:
4232 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4234 ==> U-Boot will use gp to hold a pointer to the global data
4236 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4237 to access small data sections, so gp is free.
4239 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4240 or current versions of GCC may "optimize" the code too much.
4245 U-Boot runs in system state and uses physical addresses, i.e. the
4246 MMU is not used either for address mapping nor for memory protection.
4248 The available memory is mapped to fixed addresses using the memory
4249 controller. In this process, a contiguous block is formed for each
4250 memory type (Flash, SDRAM, SRAM), even when it consists of several
4251 physical memory banks.
4253 U-Boot is installed in the first 128 kB of the first Flash bank (on
4254 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4255 booting and sizing and initializing DRAM, the code relocates itself
4256 to the upper end of DRAM. Immediately below the U-Boot code some
4257 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
4258 configuration setting]. Below that, a structure with global Board
4259 Info data is placed, followed by the stack (growing downward).
4261 Additionally, some exception handler code is copied to the low 8 kB
4262 of DRAM (0x00000000 ... 0x00001FFF).
4264 So a typical memory configuration with 16 MB of DRAM could look like
4267 0x0000 0000 Exception Vector code
4270 0x0000 2000 Free for Application Use
4276 0x00FB FF20 Monitor Stack (Growing downward)
4277 0x00FB FFAC Board Info Data and permanent copy of global data
4278 0x00FC 0000 Malloc Arena
4281 0x00FE 0000 RAM Copy of Monitor Code
4282 ... eventually: LCD or video framebuffer
4283 ... eventually: pRAM (Protected RAM - unchanged by reset)
4284 0x00FF FFFF [End of RAM]
4287 System Initialization:
4288 ----------------------
4290 In the reset configuration, U-Boot starts at the reset entry point
4291 (on most PowerPC systems at address 0x00000100). Because of the reset
4292 configuration for CS0# this is a mirror of the onboard Flash memory.
4293 To be able to re-map memory U-Boot then jumps to its link address.
4294 To be able to implement the initialization code in C, a (small!)
4295 initial stack is set up in the internal Dual Ported RAM (in case CPUs
4296 which provide such a feature like MPC8xx or MPC8260), or in a locked
4297 part of the data cache. After that, U-Boot initializes the CPU core,
4298 the caches and the SIU.
4300 Next, all (potentially) available memory banks are mapped using a
4301 preliminary mapping. For example, we put them on 512 MB boundaries
4302 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4303 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4304 programmed for SDRAM access. Using the temporary configuration, a
4305 simple memory test is run that determines the size of the SDRAM
4308 When there is more than one SDRAM bank, and the banks are of
4309 different size, the largest is mapped first. For equal size, the first
4310 bank (CS2#) is mapped first. The first mapping is always for address
4311 0x00000000, with any additional banks following immediately to create
4312 contiguous memory starting from 0.
4314 Then, the monitor installs itself at the upper end of the SDRAM area
4315 and allocates memory for use by malloc() and for the global Board
4316 Info data; also, the exception vector code is copied to the low RAM
4317 pages, and the final stack is set up.
4319 Only after this relocation will you have a "normal" C environment;
4320 until that you are restricted in several ways, mostly because you are
4321 running from ROM, and because the code will have to be relocated to a
4325 U-Boot Porting Guide:
4326 ----------------------
4328 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4332 int main(int argc, char *argv[])
4334 sighandler_t no_more_time;
4336 signal(SIGALRM, no_more_time);
4337 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4339 if (available_money > available_manpower) {
4340 Pay consultant to port U-Boot;
4344 Download latest U-Boot source;
4346 Subscribe to u-boot mailing list;
4349 email("Hi, I am new to U-Boot, how do I get started?");
4352 Read the README file in the top level directory;
4353 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4354 Read applicable doc/*.README;
4355 Read the source, Luke;
4356 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4359 if (available_money > toLocalCurrency ($2500))
4362 Add a lot of aggravation and time;
4364 if (a similar board exists) { /* hopefully... */
4365 cp -a board/<similar> board/<myboard>
4366 cp include/configs/<similar>.h include/configs/<myboard>.h
4368 Create your own board support subdirectory;
4369 Create your own board include/configs/<myboard>.h file;
4371 Edit new board/<myboard> files
4372 Edit new include/configs/<myboard>.h
4377 Add / modify source code;
4381 email("Hi, I am having problems...");
4383 Send patch file to the U-Boot email list;
4384 if (reasonable critiques)
4385 Incorporate improvements from email list code review;
4387 Defend code as written;
4393 void no_more_time (int sig)
4402 All contributions to U-Boot should conform to the Linux kernel
4403 coding style; see the file "Documentation/CodingStyle" and the script
4404 "scripts/Lindent" in your Linux kernel source directory. In sources
4405 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
4406 spaces before parameters to function calls) is actually used.
4408 Source files originating from a different project (for example the
4409 MTD subsystem) are generally exempt from these guidelines and are not
4410 reformated to ease subsequent migration to newer versions of those
4413 Please note that U-Boot is implemented in C (and to some small parts in
4414 Assembler); no C++ is used, so please do not use C++ style comments (//)
4417 Please also stick to the following formatting rules:
4418 - remove any trailing white space
4419 - use TAB characters for indentation, not spaces
4420 - make sure NOT to use DOS '\r\n' line feeds
4421 - do not add more than 2 empty lines to source files
4422 - do not add trailing empty lines to source files
4424 Submissions which do not conform to the standards may be returned
4425 with a request to reformat the changes.
4431 Since the number of patches for U-Boot is growing, we need to
4432 establish some rules. Submissions which do not conform to these rules
4433 may be rejected, even when they contain important and valuable stuff.
4435 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4437 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4438 see http://lists.denx.de/mailman/listinfo/u-boot
4440 When you send a patch, please include the following information with
4443 * For bug fixes: a description of the bug and how your patch fixes
4444 this bug. Please try to include a way of demonstrating that the
4445 patch actually fixes something.
4447 * For new features: a description of the feature and your
4450 * A CHANGELOG entry as plaintext (separate from the patch)
4452 * For major contributions, your entry to the CREDITS file
4454 * When you add support for a new board, don't forget to add this
4455 board to the MAKEALL script, too.
4457 * If your patch adds new configuration options, don't forget to
4458 document these in the README file.
4460 * The patch itself. If you are using git (which is *strongly*
4461 recommended) you can easily generate the patch using the
4462 "git-format-patch". If you then use "git-send-email" to send it to
4463 the U-Boot mailing list, you will avoid most of the common problems
4464 with some other mail clients.
4466 If you cannot use git, use "diff -purN OLD NEW". If your version of
4467 diff does not support these options, then get the latest version of
4470 The current directory when running this command shall be the parent
4471 directory of the U-Boot source tree (i. e. please make sure that
4472 your patch includes sufficient directory information for the
4475 We prefer patches as plain text. MIME attachments are discouraged,
4476 and compressed attachments must not be used.
4478 * If one logical set of modifications affects or creates several
4479 files, all these changes shall be submitted in a SINGLE patch file.
4481 * Changesets that contain different, unrelated modifications shall be
4482 submitted as SEPARATE patches, one patch per changeset.
4487 * Before sending the patch, run the MAKEALL script on your patched
4488 source tree and make sure that no errors or warnings are reported
4489 for any of the boards.
4491 * Keep your modifications to the necessary minimum: A patch
4492 containing several unrelated changes or arbitrary reformats will be
4493 returned with a request to re-formatting / split it.
4495 * If you modify existing code, make sure that your new code does not
4496 add to the memory footprint of the code ;-) Small is beautiful!
4497 When adding new features, these should compile conditionally only
4498 (using #ifdef), and the resulting code with the new feature
4499 disabled must not need more memory than the old code without your
4502 * Remember that there is a size limit of 100 kB per message on the
4503 u-boot mailing list. Bigger patches will be moderated. If they are
4504 reasonable and not too big, they will be acknowledged. But patches
4505 bigger than the size limit should be avoided.
projects / kernel / u-boot.git / blob