2 # (C) Copyright 2000 - 2009
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # See file CREDITS for list of people who contributed to this
8 # This program is free software; you can redistribute it and/or
9 # modify it under the terms of the GNU General Public License as
10 # published by the Free Software Foundation; either version 2 of
11 # the License, or (at your option) any later version.
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with this program; if not, write to the Free Software
20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27 This directory contains the source code for U-Boot, a boot loader for
28 Embedded boards based on PowerPC, ARM, MIPS and several other
29 processors, which can be installed in a boot ROM and used to
30 initialize and test the hardware or to download and run application
33 The development of U-Boot is closely related to Linux: some parts of
34 the source code originate in the Linux source tree, we have some
35 header files in common, and special provision has been made to
36 support booting of Linux images.
38 Some attention has been paid to make this software easily
39 configurable and extendable. For instance, all monitor commands are
40 implemented with the same call interface, so that it's very easy to
41 add new commands. Also, instead of permanently adding rarely used
42 code (for instance hardware test utilities) to the monitor, you can
43 load and run it dynamically.
49 In general, all boards for which a configuration option exists in the
50 Makefile have been tested to some extent and can be considered
51 "working". In fact, many of them are used in production systems.
53 In case of problems see the CHANGELOG and CREDITS files to find out
54 who contributed the specific port. The MAINTAINERS file lists board
61 In case you have questions about, problems with or contributions for
62 U-Boot you should send a message to the U-Boot mailing list at
63 <u-boot@lists.denx.de>. There is also an archive of previous traffic
64 on the mailing list - please search the archive before asking FAQ's.
65 Please see http://lists.denx.de/pipermail/u-boot and
66 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
69 Where to get source code:
70 =========================
72 The U-Boot source code is maintained in the git repository at
73 git://www.denx.de/git/u-boot.git ; you can browse it online at
74 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
76 The "snapshot" links on this page allow you to download tarballs of
77 any version you might be interested in. Official releases are also
78 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
81 Pre-built (and tested) images are available from
82 ftp://ftp.denx.de/pub/u-boot/images/
88 - start from 8xxrom sources
89 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
91 - make it easier to add custom boards
92 - make it possible to add other [PowerPC] CPUs
93 - extend functions, especially:
94 * Provide extended interface to Linux boot loader
97 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
98 - create ARMBoot project (http://sourceforge.net/projects/armboot)
99 - add other CPU families (starting with ARM)
100 - create U-Boot project (http://sourceforge.net/projects/u-boot)
101 - current project page: see http://www.denx.de/wiki/U-Boot
107 The "official" name of this project is "Das U-Boot". The spelling
108 "U-Boot" shall be used in all written text (documentation, comments
109 in source files etc.). Example:
111 This is the README file for the U-Boot project.
113 File names etc. shall be based on the string "u-boot". Examples:
115 include/asm-ppc/u-boot.h
117 #include <asm/u-boot.h>
119 Variable names, preprocessor constants etc. shall be either based on
120 the string "u_boot" or on "U_BOOT". Example:
122 U_BOOT_VERSION u_boot_logo
123 IH_OS_U_BOOT u_boot_hush_start
129 U-Boot uses a 3 level version number containing a version, a
130 sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2",
131 sub-version "34", and patchlevel "4".
133 The patchlevel is used to indicate certain stages of development
134 between released versions, i. e. officially released versions of
135 U-Boot will always have a patchlevel of "0".
141 /arch Architecture specific files
142 /arm Files generic to ARM architecture
143 /cpu CPU specific files
144 /arm720t Files specific to ARM 720 CPUs
145 /arm920t Files specific to ARM 920 CPUs
146 /at91rm9200 Files specific to Atmel AT91RM9200 CPU
147 /imx Files specific to Freescale MC9328 i.MX CPUs
148 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
149 /arm925t Files specific to ARM 925 CPUs
150 /arm926ejs Files specific to ARM 926 CPUs
151 /arm1136 Files specific to ARM 1136 CPUs
152 /ixp Files specific to Intel XScale IXP CPUs
153 /pxa Files specific to Intel XScale PXA CPUs
154 /s3c44b0 Files specific to Samsung S3C44B0 CPUs
155 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
156 /lib Architecture specific library files
157 /avr32 Files generic to AVR32 architecture
158 /cpu CPU specific files
159 /lib Architecture specific library files
160 /blackfin Files generic to Analog Devices Blackfin architecture
161 /cpu CPU specific files
162 /lib Architecture specific library files
163 /i386 Files generic to i386 architecture
164 /cpu CPU specific files
165 /lib Architecture specific library files
166 /m68k Files generic to m68k architecture
167 /cpu CPU specific files
168 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
169 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
170 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
171 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
172 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
173 /lib Architecture specific library files
174 /microblaze Files generic to microblaze architecture
175 /cpu CPU specific files
176 /lib Architecture specific library files
177 /mips Files generic to MIPS architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /nios2 Files generic to Altera NIOS2 architecture
181 /cpu CPU specific files
182 /lib Architecture specific library files
183 /powerpc Files generic to PowerPC architecture
184 /cpu CPU specific files
185 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
186 /mpc5xx Files specific to Freescale MPC5xx CPUs
187 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
188 /mpc8xx Files specific to Freescale MPC8xx CPUs
189 /mpc8220 Files specific to Freescale MPC8220 CPUs
190 /mpc824x Files specific to Freescale MPC824x CPUs
191 /mpc8260 Files specific to Freescale MPC8260 CPUs
192 /mpc85xx Files specific to Freescale MPC85xx CPUs
193 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
194 /lib Architecture specific library files
195 /sh Files generic to SH architecture
196 /cpu CPU specific files
197 /sh2 Files specific to sh2 CPUs
198 /sh3 Files specific to sh3 CPUs
199 /sh4 Files specific to sh4 CPUs
200 /lib Architecture specific library files
201 /sparc Files generic to SPARC architecture
202 /cpu CPU specific files
203 /leon2 Files specific to Gaisler LEON2 SPARC CPU
204 /leon3 Files specific to Gaisler LEON3 SPARC CPU
205 /lib Architecture specific library files
206 /api Machine/arch independent API for external apps
207 /board Board dependent files
208 /common Misc architecture independent functions
209 /disk Code for disk drive partition handling
210 /doc Documentation (don't expect too much)
211 /drivers Commonly used device drivers
212 /examples Example code for standalone applications, etc.
213 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
214 /include Header Files
215 /lib Files generic to all architectures
216 /libfdt Library files to support flattened device trees
217 /lzma Library files to support LZMA decompression
218 /lzo Library files to support LZO decompression
220 /post Power On Self Test
221 /rtc Real Time Clock drivers
222 /tools Tools to build S-Record or U-Boot images, etc.
224 Software Configuration:
225 =======================
227 Configuration is usually done using C preprocessor defines; the
228 rationale behind that is to avoid dead code whenever possible.
230 There are two classes of configuration variables:
232 * Configuration _OPTIONS_:
233 These are selectable by the user and have names beginning with
236 * Configuration _SETTINGS_:
237 These depend on the hardware etc. and should not be meddled with if
238 you don't know what you're doing; they have names beginning with
241 Later we will add a configuration tool - probably similar to or even
242 identical to what's used for the Linux kernel. Right now, we have to
243 do the configuration by hand, which means creating some symbolic
244 links and editing some configuration files. We use the TQM8xxL boards
248 Selection of Processor Architecture and Board Type:
249 ---------------------------------------------------
251 For all supported boards there are ready-to-use default
252 configurations available; just type "make <board_name>_config".
254 Example: For a TQM823L module type:
259 For the Cogent platform, you need to specify the CPU type as well;
260 e.g. "make cogent_mpc8xx_config". And also configure the cogent
261 directory according to the instructions in cogent/README.
264 Configuration Options:
265 ----------------------
267 Configuration depends on the combination of board and CPU type; all
268 such information is kept in a configuration file
269 "include/configs/<board_name>.h".
271 Example: For a TQM823L module, all configuration settings are in
272 "include/configs/TQM823L.h".
275 Many of the options are named exactly as the corresponding Linux
276 kernel configuration options. The intention is to make it easier to
277 build a config tool - later.
280 The following options need to be configured:
282 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
284 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
286 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
287 Define exactly one, e.g. CONFIG_ATSTK1002
289 - CPU Module Type: (if CONFIG_COGENT is defined)
290 Define exactly one of
292 --- FIXME --- not tested yet:
293 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
294 CONFIG_CMA287_23, CONFIG_CMA287_50
296 - Motherboard Type: (if CONFIG_COGENT is defined)
297 Define exactly one of
298 CONFIG_CMA101, CONFIG_CMA102
300 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
301 Define one or more of
304 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
305 Define one or more of
306 CONFIG_LCD_HEARTBEAT - update a character position on
307 the LCD display every second with
310 - Board flavour: (if CONFIG_MPC8260ADS is defined)
313 CONFIG_SYS_8260ADS - original MPC8260ADS
314 CONFIG_SYS_8266ADS - MPC8266ADS
315 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
316 CONFIG_SYS_8272ADS - MPC8272ADS
318 - MPC824X Family Member (if CONFIG_MPC824X is defined)
319 Define exactly one of
320 CONFIG_MPC8240, CONFIG_MPC8245
322 - 8xx CPU Options: (if using an MPC8xx CPU)
323 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
324 get_gclk_freq() cannot work
325 e.g. if there is no 32KHz
326 reference PIT/RTC clock
327 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
330 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
331 CONFIG_SYS_8xx_CPUCLK_MIN
332 CONFIG_SYS_8xx_CPUCLK_MAX
333 CONFIG_8xx_CPUCLK_DEFAULT
334 See doc/README.MPC866
336 CONFIG_SYS_MEASURE_CPUCLK
338 Define this to measure the actual CPU clock instead
339 of relying on the correctness of the configured
340 values. Mostly useful for board bringup to make sure
341 the PLL is locked at the intended frequency. Note
342 that this requires a (stable) reference clock (32 kHz
343 RTC clock or CONFIG_SYS_8XX_XIN)
345 CONFIG_SYS_DELAYED_ICACHE
347 Define this option if you want to enable the
348 ICache only when Code runs from RAM.
350 - Intel Monahans options:
351 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
353 Defines the Monahans run mode to oscillator
354 ratio. Valid values are 8, 16, 24, 31. The core
355 frequency is this value multiplied by 13 MHz.
357 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
359 Defines the Monahans turbo mode to oscillator
360 ratio. Valid values are 1 (default if undefined) and
361 2. The core frequency as calculated above is multiplied
364 - Linux Kernel Interface:
367 U-Boot stores all clock information in Hz
368 internally. For binary compatibility with older Linux
369 kernels (which expect the clocks passed in the
370 bd_info data to be in MHz) the environment variable
371 "clocks_in_mhz" can be defined so that U-Boot
372 converts clock data to MHZ before passing it to the
374 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
375 "clocks_in_mhz=1" is automatically included in the
378 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
380 When transferring memsize parameter to linux, some versions
381 expect it to be in bytes, others in MB.
382 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
386 New kernel versions are expecting firmware settings to be
387 passed using flattened device trees (based on open firmware
391 * New libfdt-based support
392 * Adds the "fdt" command
393 * The bootm command automatically updates the fdt
395 OF_CPU - The proper name of the cpus node (only required for
396 MPC512X and MPC5xxx based boards).
397 OF_SOC - The proper name of the soc node (only required for
398 MPC512X and MPC5xxx based boards).
399 OF_TBCLK - The timebase frequency.
400 OF_STDOUT_PATH - The path to the console device
402 boards with QUICC Engines require OF_QE to set UCC MAC
405 CONFIG_OF_BOARD_SETUP
407 Board code has addition modification that it wants to make
408 to the flat device tree before handing it off to the kernel
412 This define fills in the correct boot CPU in the boot
413 param header, the default value is zero if undefined.
417 U-Boot can detect if an IDE device is present or not.
418 If not, and this new config option is activated, U-Boot
419 removes the ATA node from the DTS before booting Linux,
420 so the Linux IDE driver does not probe the device and
421 crash. This is needed for buggy hardware (uc101) where
422 no pull down resistor is connected to the signal IDE5V_DD7.
424 - vxWorks boot parameters:
426 bootvx constructs a valid bootline using the following
427 environments variables: bootfile, ipaddr, serverip, hostname.
428 It loads the vxWorks image pointed bootfile.
430 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
431 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
432 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
433 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
435 CONFIG_SYS_VXWORKS_ADD_PARAMS
437 Add it at the end of the bootline. E.g "u=username pw=secret"
439 Note: If a "bootargs" environment is defined, it will overwride
440 the defaults discussed just above.
445 Define this if you want support for Amba PrimeCell PL010 UARTs.
449 Define this if you want support for Amba PrimeCell PL011 UARTs.
453 If you have Amba PrimeCell PL011 UARTs, set this variable to
454 the clock speed of the UARTs.
458 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
459 define this to a list of base addresses for each (supported)
460 port. See e.g. include/configs/versatile.h
464 Depending on board, define exactly one serial port
465 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
466 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
467 console by defining CONFIG_8xx_CONS_NONE
469 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
470 port routines must be defined elsewhere
471 (i.e. serial_init(), serial_getc(), ...)
474 Enables console device for a color framebuffer. Needs following
475 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
476 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
478 VIDEO_HW_RECTFILL graphic chip supports
481 VIDEO_HW_BITBLT graphic chip supports
482 bit-blit (cf. smiLynxEM)
483 VIDEO_VISIBLE_COLS visible pixel columns
485 VIDEO_VISIBLE_ROWS visible pixel rows
486 VIDEO_PIXEL_SIZE bytes per pixel
487 VIDEO_DATA_FORMAT graphic data format
488 (0-5, cf. cfb_console.c)
489 VIDEO_FB_ADRS framebuffer address
490 VIDEO_KBD_INIT_FCT keyboard int fct
491 (i.e. i8042_kbd_init())
492 VIDEO_TSTC_FCT test char fct
494 VIDEO_GETC_FCT get char fct
496 CONFIG_CONSOLE_CURSOR cursor drawing on/off
497 (requires blink timer
499 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
500 CONFIG_CONSOLE_TIME display time/date info in
502 (requires CONFIG_CMD_DATE)
503 CONFIG_VIDEO_LOGO display Linux logo in
505 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
506 linux_logo.h for logo.
507 Requires CONFIG_VIDEO_LOGO
508 CONFIG_CONSOLE_EXTRA_INFO
509 additional board info beside
512 When CONFIG_CFB_CONSOLE is defined, video console is
513 default i/o. Serial console can be forced with
514 environment 'console=serial'.
516 When CONFIG_SILENT_CONSOLE is defined, all console
517 messages (by U-Boot and Linux!) can be silenced with
518 the "silent" environment variable. See
519 doc/README.silent for more information.
522 CONFIG_BAUDRATE - in bps
523 Select one of the baudrates listed in
524 CONFIG_SYS_BAUDRATE_TABLE, see below.
525 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
527 - Console Rx buffer length
528 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
529 the maximum receive buffer length for the SMC.
530 This option is actual only for 82xx and 8xx possible.
531 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
532 must be defined, to setup the maximum idle timeout for
535 - Interrupt driven serial port input:
536 CONFIG_SERIAL_SOFTWARE_FIFO
539 Use an interrupt handler for receiving data on the
540 serial port. It also enables using hardware handshake
541 (RTS/CTS) and UART's built-in FIFO. Set the number of
542 bytes the interrupt driven input buffer should have.
544 Leave undefined to disable this feature, including
545 disable the buffer and hardware handshake.
547 - Console UART Number:
551 If defined internal UART1 (and not UART0) is used
552 as default U-Boot console.
554 - Boot Delay: CONFIG_BOOTDELAY - in seconds
555 Delay before automatically booting the default image;
556 set to -1 to disable autoboot.
558 See doc/README.autoboot for these options that
559 work with CONFIG_BOOTDELAY. None are required.
560 CONFIG_BOOT_RETRY_TIME
561 CONFIG_BOOT_RETRY_MIN
562 CONFIG_AUTOBOOT_KEYED
563 CONFIG_AUTOBOOT_PROMPT
564 CONFIG_AUTOBOOT_DELAY_STR
565 CONFIG_AUTOBOOT_STOP_STR
566 CONFIG_AUTOBOOT_DELAY_STR2
567 CONFIG_AUTOBOOT_STOP_STR2
568 CONFIG_ZERO_BOOTDELAY_CHECK
569 CONFIG_RESET_TO_RETRY
573 Only needed when CONFIG_BOOTDELAY is enabled;
574 define a command string that is automatically executed
575 when no character is read on the console interface
576 within "Boot Delay" after reset.
579 This can be used to pass arguments to the bootm
580 command. The value of CONFIG_BOOTARGS goes into the
581 environment value "bootargs".
583 CONFIG_RAMBOOT and CONFIG_NFSBOOT
584 The value of these goes into the environment as
585 "ramboot" and "nfsboot" respectively, and can be used
586 as a convenience, when switching between booting from
592 When this option is #defined, the existence of the
593 environment variable "preboot" will be checked
594 immediately before starting the CONFIG_BOOTDELAY
595 countdown and/or running the auto-boot command resp.
596 entering interactive mode.
598 This feature is especially useful when "preboot" is
599 automatically generated or modified. For an example
600 see the LWMON board specific code: here "preboot" is
601 modified when the user holds down a certain
602 combination of keys on the (special) keyboard when
605 - Serial Download Echo Mode:
607 If defined to 1, all characters received during a
608 serial download (using the "loads" command) are
609 echoed back. This might be needed by some terminal
610 emulations (like "cu"), but may as well just take
611 time on others. This setting #define's the initial
612 value of the "loads_echo" environment variable.
614 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
616 Select one of the baudrates listed in
617 CONFIG_SYS_BAUDRATE_TABLE, see below.
620 Monitor commands can be included or excluded
621 from the build by using the #include files
622 "config_cmd_all.h" and #undef'ing unwanted
623 commands, or using "config_cmd_default.h"
624 and augmenting with additional #define's
627 The default command configuration includes all commands
628 except those marked below with a "*".
630 CONFIG_CMD_ASKENV * ask for env variable
631 CONFIG_CMD_BDI bdinfo
632 CONFIG_CMD_BEDBUG * Include BedBug Debugger
633 CONFIG_CMD_BMP * BMP support
634 CONFIG_CMD_BSP * Board specific commands
635 CONFIG_CMD_BOOTD bootd
636 CONFIG_CMD_CACHE * icache, dcache
637 CONFIG_CMD_CONSOLE coninfo
638 CONFIG_CMD_DATE * support for RTC, date/time...
639 CONFIG_CMD_DHCP * DHCP support
640 CONFIG_CMD_DIAG * Diagnostics
641 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
642 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
643 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
644 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
645 CONFIG_CMD_DTT * Digital Therm and Thermostat
646 CONFIG_CMD_ECHO echo arguments
647 CONFIG_CMD_EDITENV edit env variable
648 CONFIG_CMD_EEPROM * EEPROM read/write support
649 CONFIG_CMD_ELF * bootelf, bootvx
650 CONFIG_CMD_SAVEENV saveenv
651 CONFIG_CMD_FDC * Floppy Disk Support
652 CONFIG_CMD_FAT * FAT partition support
653 CONFIG_CMD_FDOS * Dos diskette Support
654 CONFIG_CMD_FLASH flinfo, erase, protect
655 CONFIG_CMD_FPGA FPGA device initialization support
656 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
657 CONFIG_CMD_I2C * I2C serial bus support
658 CONFIG_CMD_IDE * IDE harddisk support
659 CONFIG_CMD_IMI iminfo
660 CONFIG_CMD_IMLS List all found images
661 CONFIG_CMD_IMMAP * IMMR dump support
662 CONFIG_CMD_IRQ * irqinfo
663 CONFIG_CMD_ITEST Integer/string test of 2 values
664 CONFIG_CMD_JFFS2 * JFFS2 Support
665 CONFIG_CMD_KGDB * kgdb
666 CONFIG_CMD_LOADB loadb
667 CONFIG_CMD_LOADS loads
668 CONFIG_CMD_MD5SUM print md5 message digest
669 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
670 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
672 CONFIG_CMD_MISC Misc functions like sleep etc
673 CONFIG_CMD_MMC * MMC memory mapped support
674 CONFIG_CMD_MII * MII utility commands
675 CONFIG_CMD_MTDPARTS * MTD partition support
676 CONFIG_CMD_NAND * NAND support
677 CONFIG_CMD_NET bootp, tftpboot, rarpboot
678 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
679 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
680 CONFIG_CMD_PCI * pciinfo
681 CONFIG_CMD_PCMCIA * PCMCIA support
682 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
684 CONFIG_CMD_PORTIO * Port I/O
685 CONFIG_CMD_REGINFO * Register dump
686 CONFIG_CMD_RUN run command in env variable
687 CONFIG_CMD_SAVES * save S record dump
688 CONFIG_CMD_SCSI * SCSI Support
689 CONFIG_CMD_SDRAM * print SDRAM configuration information
690 (requires CONFIG_CMD_I2C)
691 CONFIG_CMD_SETGETDCR Support for DCR Register access
693 CONFIG_CMD_SHA1 print sha1 memory digest
694 (requires CONFIG_CMD_MEMORY)
695 CONFIG_CMD_SOURCE "source" command Support
696 CONFIG_CMD_SPI * SPI serial bus support
697 CONFIG_CMD_USB * USB support
698 CONFIG_CMD_VFD * VFD support (TRAB)
699 CONFIG_CMD_CDP * Cisco Discover Protocol support
700 CONFIG_CMD_FSL * Microblaze FSL support
703 EXAMPLE: If you want all functions except of network
704 support you can write:
706 #include "config_cmd_all.h"
707 #undef CONFIG_CMD_NET
710 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
712 Note: Don't enable the "icache" and "dcache" commands
713 (configuration option CONFIG_CMD_CACHE) unless you know
714 what you (and your U-Boot users) are doing. Data
715 cache cannot be enabled on systems like the 8xx or
716 8260 (where accesses to the IMMR region must be
717 uncached), and it cannot be disabled on all other
718 systems where we (mis-) use the data cache to hold an
719 initial stack and some data.
722 XXX - this list needs to get updated!
726 If this variable is defined, it enables watchdog
727 support. There must be support in the platform specific
728 code for a watchdog. For the 8xx and 8260 CPUs, the
729 SIU Watchdog feature is enabled in the SYPCR
733 CONFIG_VERSION_VARIABLE
734 If this variable is defined, an environment variable
735 named "ver" is created by U-Boot showing the U-Boot
736 version as printed by the "version" command.
737 This variable is readonly.
741 When CONFIG_CMD_DATE is selected, the type of the RTC
742 has to be selected, too. Define exactly one of the
745 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
746 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
747 CONFIG_RTC_MC13783 - use MC13783 RTC
748 CONFIG_RTC_MC146818 - use MC146818 RTC
749 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
750 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
751 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
752 CONFIG_RTC_DS164x - use Dallas DS164x RTC
753 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
754 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
755 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
757 Note that if the RTC uses I2C, then the I2C interface
758 must also be configured. See I2C Support, below.
761 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
762 CONFIG_PCA953X_INFO - enable pca953x info command
764 Note that if the GPIO device uses I2C, then the I2C interface
765 must also be configured. See I2C Support, below.
769 When CONFIG_TIMESTAMP is selected, the timestamp
770 (date and time) of an image is printed by image
771 commands like bootm or iminfo. This option is
772 automatically enabled when you select CONFIG_CMD_DATE .
775 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
776 and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION
778 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
779 CONFIG_CMD_SCSI) you must configure support for at
780 least one partition type as well.
783 CONFIG_IDE_RESET_ROUTINE - this is defined in several
784 board configurations files but used nowhere!
786 CONFIG_IDE_RESET - is this is defined, IDE Reset will
787 be performed by calling the function
788 ide_set_reset(int reset)
789 which has to be defined in a board specific file
794 Set this to enable ATAPI support.
799 Set this to enable support for disks larger than 137GB
800 Also look at CONFIG_SYS_64BIT_LBA.
801 Whithout these , LBA48 support uses 32bit variables and will 'only'
802 support disks up to 2.1TB.
804 CONFIG_SYS_64BIT_LBA:
805 When enabled, makes the IDE subsystem use 64bit sector addresses.
809 At the moment only there is only support for the
810 SYM53C8XX SCSI controller; define
811 CONFIG_SCSI_SYM53C8XX to enable it.
813 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
814 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
815 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
816 maximum numbers of LUNs, SCSI ID's and target
818 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
820 - NETWORK Support (PCI):
822 Support for Intel 8254x gigabit chips.
824 CONFIG_E1000_FALLBACK_MAC
825 default MAC for empty EEPROM after production.
828 Support for Intel 82557/82559/82559ER chips.
829 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
830 write routine for first time initialisation.
833 Support for Digital 2114x chips.
834 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
835 modem chip initialisation (KS8761/QS6611).
838 Support for National dp83815 chips.
841 Support for National dp8382[01] gigabit chips.
843 - NETWORK Support (other):
845 CONFIG_DRIVER_AT91EMAC
846 Support for AT91RM9200 EMAC.
849 Define this to use reduced MII inteface
851 CONFIG_DRIVER_AT91EMAC_QUIET
852 If this defined, the driver is quiet.
853 The driver doen't show link status messages.
855 CONFIG_DRIVER_LAN91C96
856 Support for SMSC's LAN91C96 chips.
859 Define this to hold the physical address
860 of the LAN91C96's I/O space
862 CONFIG_LAN91C96_USE_32_BIT
863 Define this to enable 32 bit addressing
865 CONFIG_DRIVER_SMC91111
866 Support for SMSC's LAN91C111 chip
869 Define this to hold the physical address
870 of the device (I/O space)
872 CONFIG_SMC_USE_32_BIT
873 Define this if data bus is 32 bits
875 CONFIG_SMC_USE_IOFUNCS
876 Define this to use i/o functions instead of macros
877 (some hardware wont work with macros)
880 Support for SMSC's LAN911x and LAN921x chips
883 Define this to hold the physical address
884 of the device (I/O space)
886 CONFIG_SMC911X_32_BIT
887 Define this if data bus is 32 bits
889 CONFIG_SMC911X_16_BIT
890 Define this if data bus is 16 bits. If your processor
891 automatically converts one 32 bit word to two 16 bit
892 words you may also try CONFIG_SMC911X_32_BIT.
895 At the moment only the UHCI host controller is
896 supported (PIP405, MIP405, MPC5200); define
897 CONFIG_USB_UHCI to enable it.
898 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
899 and define CONFIG_USB_STORAGE to enable the USB
902 Supported are USB Keyboards and USB Floppy drives
904 MPC5200 USB requires additional defines:
906 for 528 MHz Clock: 0x0001bbbb
910 for differential drivers: 0x00001000
911 for single ended drivers: 0x00005000
912 for differential drivers on PSC3: 0x00000100
913 for single ended drivers on PSC3: 0x00004100
914 CONFIG_SYS_USB_EVENT_POLL
915 May be defined to allow interrupt polling
916 instead of using asynchronous interrupts
919 Define the below if you wish to use the USB console.
920 Once firmware is rebuilt from a serial console issue the
921 command "setenv stdin usbtty; setenv stdout usbtty" and
922 attach your USB cable. The Unix command "dmesg" should print
923 it has found a new device. The environment variable usbtty
924 can be set to gserial or cdc_acm to enable your device to
925 appear to a USB host as a Linux gserial device or a
926 Common Device Class Abstract Control Model serial device.
927 If you select usbtty = gserial you should be able to enumerate
929 # modprobe usbserial vendor=0xVendorID product=0xProductID
930 else if using cdc_acm, simply setting the environment
931 variable usbtty to be cdc_acm should suffice. The following
932 might be defined in YourBoardName.h
935 Define this to build a UDC device
938 Define this to have a tty type of device available to
939 talk to the UDC device
941 CONFIG_SYS_CONSOLE_IS_IN_ENV
942 Define this if you want stdin, stdout &/or stderr to
946 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
947 Derive USB clock from external clock "blah"
948 - CONFIG_SYS_USB_EXTC_CLK 0x02
950 CONFIG_SYS_USB_BRG_CLK 0xBLAH
951 Derive USB clock from brgclk
952 - CONFIG_SYS_USB_BRG_CLK 0x04
954 If you have a USB-IF assigned VendorID then you may wish to
955 define your own vendor specific values either in BoardName.h
956 or directly in usbd_vendor_info.h. If you don't define
957 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
958 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
959 should pretend to be a Linux device to it's target host.
961 CONFIG_USBD_MANUFACTURER
962 Define this string as the name of your company for
963 - CONFIG_USBD_MANUFACTURER "my company"
965 CONFIG_USBD_PRODUCT_NAME
966 Define this string as the name of your product
967 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
970 Define this as your assigned Vendor ID from the USB
971 Implementors Forum. This *must* be a genuine Vendor ID
972 to avoid polluting the USB namespace.
973 - CONFIG_USBD_VENDORID 0xFFFF
975 CONFIG_USBD_PRODUCTID
976 Define this as the unique Product ID
978 - CONFIG_USBD_PRODUCTID 0xFFFF
982 The MMC controller on the Intel PXA is supported. To
983 enable this define CONFIG_MMC. The MMC can be
984 accessed from the boot prompt by mapping the device
985 to physical memory similar to flash. Command line is
986 enabled with CONFIG_CMD_MMC. The MMC driver also works with
987 the FAT fs. This is enabled with CONFIG_CMD_FAT.
989 - Journaling Flash filesystem support:
990 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
991 CONFIG_JFFS2_NAND_DEV
992 Define these for a default partition on a NAND device
994 CONFIG_SYS_JFFS2_FIRST_SECTOR,
995 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
996 Define these for a default partition on a NOR device
998 CONFIG_SYS_JFFS_CUSTOM_PART
999 Define this to create an own partition. You have to provide a
1000 function struct part_info* jffs2_part_info(int part_num)
1002 If you define only one JFFS2 partition you may also want to
1003 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1004 to disable the command chpart. This is the default when you
1005 have not defined a custom partition
1010 Define this to enable standard (PC-Style) keyboard
1014 Standard PC keyboard driver with US (is default) and
1015 GERMAN key layout (switch via environment 'keymap=de') support.
1016 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1017 for cfb_console. Supports cursor blinking.
1022 Define this to enable video support (for output to
1025 CONFIG_VIDEO_CT69000
1027 Enable Chips & Technologies 69000 Video chip
1029 CONFIG_VIDEO_SMI_LYNXEM
1030 Enable Silicon Motion SMI 712/710/810 Video chip. The
1031 video output is selected via environment 'videoout'
1032 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1035 For the CT69000 and SMI_LYNXEM drivers, videomode is
1036 selected via environment 'videomode'. Two different ways
1038 - "videomode=num" 'num' is a standard LiLo mode numbers.
1039 Following standard modes are supported (* is default):
1041 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1042 -------------+---------------------------------------------
1043 8 bits | 0x301* 0x303 0x305 0x161 0x307
1044 15 bits | 0x310 0x313 0x316 0x162 0x319
1045 16 bits | 0x311 0x314 0x317 0x163 0x31A
1046 24 bits | 0x312 0x315 0x318 ? 0x31B
1047 -------------+---------------------------------------------
1048 (i.e. setenv videomode 317; saveenv; reset;)
1050 - "videomode=bootargs" all the video parameters are parsed
1051 from the bootargs. (See drivers/video/videomodes.c)
1054 CONFIG_VIDEO_SED13806
1055 Enable Epson SED13806 driver. This driver supports 8bpp
1056 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1057 or CONFIG_VIDEO_SED13806_16BPP
1062 Define this to enable a custom keyboard support.
1063 This simply calls drv_keyboard_init() which must be
1064 defined in your board-specific files.
1065 The only board using this so far is RBC823.
1067 - LCD Support: CONFIG_LCD
1069 Define this to enable LCD support (for output to LCD
1070 display); also select one of the supported displays
1071 by defining one of these:
1075 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1077 CONFIG_NEC_NL6448AC33:
1079 NEC NL6448AC33-18. Active, color, single scan.
1081 CONFIG_NEC_NL6448BC20
1083 NEC NL6448BC20-08. 6.5", 640x480.
1084 Active, color, single scan.
1086 CONFIG_NEC_NL6448BC33_54
1088 NEC NL6448BC33-54. 10.4", 640x480.
1089 Active, color, single scan.
1093 Sharp 320x240. Active, color, single scan.
1094 It isn't 16x9, and I am not sure what it is.
1096 CONFIG_SHARP_LQ64D341
1098 Sharp LQ64D341 display, 640x480.
1099 Active, color, single scan.
1103 HLD1045 display, 640x480.
1104 Active, color, single scan.
1108 Optrex CBL50840-2 NF-FW 99 22 M5
1110 Hitachi LMG6912RPFC-00T
1114 320x240. Black & white.
1116 Normally display is black on white background; define
1117 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1119 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1121 If this option is set, the environment is checked for
1122 a variable "splashimage". If found, the usual display
1123 of logo, copyright and system information on the LCD
1124 is suppressed and the BMP image at the address
1125 specified in "splashimage" is loaded instead. The
1126 console is redirected to the "nulldev", too. This
1127 allows for a "silent" boot where a splash screen is
1128 loaded very quickly after power-on.
1130 CONFIG_SPLASH_SCREEN_ALIGN
1132 If this option is set the splash image can be freely positioned
1133 on the screen. Environment variable "splashpos" specifies the
1134 position as "x,y". If a positive number is given it is used as
1135 number of pixel from left/top. If a negative number is given it
1136 is used as number of pixel from right/bottom. You can also
1137 specify 'm' for centering the image.
1140 setenv splashpos m,m
1141 => image at center of screen
1143 setenv splashpos 30,20
1144 => image at x = 30 and y = 20
1146 setenv splashpos -10,m
1147 => vertically centered image
1148 at x = dspWidth - bmpWidth - 9
1150 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1152 If this option is set, additionally to standard BMP
1153 images, gzipped BMP images can be displayed via the
1154 splashscreen support or the bmp command.
1156 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1158 If this option is set, 8-bit RLE compressed BMP images
1159 can be displayed via the splashscreen support or the
1162 - Compression support:
1165 If this option is set, support for bzip2 compressed
1166 images is included. If not, only uncompressed and gzip
1167 compressed images are supported.
1169 NOTE: the bzip2 algorithm requires a lot of RAM, so
1170 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1175 If this option is set, support for lzma compressed
1178 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1179 requires an amount of dynamic memory that is given by the
1182 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1184 Where lc and lp stand for, respectively, Literal context bits
1185 and Literal pos bits.
1187 This value is upper-bounded by 14MB in the worst case. Anyway,
1188 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1189 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1190 a very small buffer.
1192 Use the lzmainfo tool to determinate the lc and lp values and
1193 then calculate the amount of needed dynamic memory (ensuring
1194 the appropriate CONFIG_SYS_MALLOC_LEN value).
1199 The address of PHY on MII bus.
1201 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1203 The clock frequency of the MII bus
1207 If this option is set, support for speed/duplex
1208 detection of gigabit PHY is included.
1210 CONFIG_PHY_RESET_DELAY
1212 Some PHY like Intel LXT971A need extra delay after
1213 reset before any MII register access is possible.
1214 For such PHY, set this option to the usec delay
1215 required. (minimum 300usec for LXT971A)
1217 CONFIG_PHY_CMD_DELAY (ppc4xx)
1219 Some PHY like Intel LXT971A need extra delay after
1220 command issued before MII status register can be read
1230 Define a default value for Ethernet address to use
1231 for the respective Ethernet interface, in case this
1232 is not determined automatically.
1237 Define a default value for the IP address to use for
1238 the default Ethernet interface, in case this is not
1239 determined through e.g. bootp.
1241 - Server IP address:
1244 Defines a default value for the IP address of a TFTP
1245 server to contact when using the "tftboot" command.
1247 CONFIG_KEEP_SERVERADDR
1249 Keeps the server's MAC address, in the env 'serveraddr'
1250 for passing to bootargs (like Linux's netconsole option)
1252 - Multicast TFTP Mode:
1255 Defines whether you want to support multicast TFTP as per
1256 rfc-2090; for example to work with atftp. Lets lots of targets
1257 tftp down the same boot image concurrently. Note: the Ethernet
1258 driver in use must provide a function: mcast() to join/leave a
1261 CONFIG_BOOTP_RANDOM_DELAY
1262 - BOOTP Recovery Mode:
1263 CONFIG_BOOTP_RANDOM_DELAY
1265 If you have many targets in a network that try to
1266 boot using BOOTP, you may want to avoid that all
1267 systems send out BOOTP requests at precisely the same
1268 moment (which would happen for instance at recovery
1269 from a power failure, when all systems will try to
1270 boot, thus flooding the BOOTP server. Defining
1271 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1272 inserted before sending out BOOTP requests. The
1273 following delays are inserted then:
1275 1st BOOTP request: delay 0 ... 1 sec
1276 2nd BOOTP request: delay 0 ... 2 sec
1277 3rd BOOTP request: delay 0 ... 4 sec
1279 BOOTP requests: delay 0 ... 8 sec
1281 - DHCP Advanced Options:
1282 You can fine tune the DHCP functionality by defining
1283 CONFIG_BOOTP_* symbols:
1285 CONFIG_BOOTP_SUBNETMASK
1286 CONFIG_BOOTP_GATEWAY
1287 CONFIG_BOOTP_HOSTNAME
1288 CONFIG_BOOTP_NISDOMAIN
1289 CONFIG_BOOTP_BOOTPATH
1290 CONFIG_BOOTP_BOOTFILESIZE
1293 CONFIG_BOOTP_SEND_HOSTNAME
1294 CONFIG_BOOTP_NTPSERVER
1295 CONFIG_BOOTP_TIMEOFFSET
1296 CONFIG_BOOTP_VENDOREX
1298 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1299 environment variable, not the BOOTP server.
1301 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1302 serverip from a DHCP server, it is possible that more
1303 than one DNS serverip is offered to the client.
1304 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1305 serverip will be stored in the additional environment
1306 variable "dnsip2". The first DNS serverip is always
1307 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1310 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1311 to do a dynamic update of a DNS server. To do this, they
1312 need the hostname of the DHCP requester.
1313 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1314 of the "hostname" environment variable is passed as
1315 option 12 to the DHCP server.
1317 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1319 A 32bit value in microseconds for a delay between
1320 receiving a "DHCP Offer" and sending the "DHCP Request".
1321 This fixes a problem with certain DHCP servers that don't
1322 respond 100% of the time to a "DHCP request". E.g. On an
1323 AT91RM9200 processor running at 180MHz, this delay needed
1324 to be *at least* 15,000 usec before a Windows Server 2003
1325 DHCP server would reply 100% of the time. I recommend at
1326 least 50,000 usec to be safe. The alternative is to hope
1327 that one of the retries will be successful but note that
1328 the DHCP timeout and retry process takes a longer than
1332 CONFIG_CDP_DEVICE_ID
1334 The device id used in CDP trigger frames.
1336 CONFIG_CDP_DEVICE_ID_PREFIX
1338 A two character string which is prefixed to the MAC address
1343 A printf format string which contains the ascii name of
1344 the port. Normally is set to "eth%d" which sets
1345 eth0 for the first Ethernet, eth1 for the second etc.
1347 CONFIG_CDP_CAPABILITIES
1349 A 32bit integer which indicates the device capabilities;
1350 0x00000010 for a normal host which does not forwards.
1354 An ascii string containing the version of the software.
1358 An ascii string containing the name of the platform.
1362 A 32bit integer sent on the trigger.
1364 CONFIG_CDP_POWER_CONSUMPTION
1366 A 16bit integer containing the power consumption of the
1367 device in .1 of milliwatts.
1369 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1371 A byte containing the id of the VLAN.
1373 - Status LED: CONFIG_STATUS_LED
1375 Several configurations allow to display the current
1376 status using a LED. For instance, the LED will blink
1377 fast while running U-Boot code, stop blinking as
1378 soon as a reply to a BOOTP request was received, and
1379 start blinking slow once the Linux kernel is running
1380 (supported by a status LED driver in the Linux
1381 kernel). Defining CONFIG_STATUS_LED enables this
1384 - CAN Support: CONFIG_CAN_DRIVER
1386 Defining CONFIG_CAN_DRIVER enables CAN driver support
1387 on those systems that support this (optional)
1388 feature, like the TQM8xxL modules.
1390 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1392 These enable I2C serial bus commands. Defining either of
1393 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1394 include the appropriate I2C driver for the selected CPU.
1396 This will allow you to use i2c commands at the u-boot
1397 command line (as long as you set CONFIG_CMD_I2C in
1398 CONFIG_COMMANDS) and communicate with i2c based realtime
1399 clock chips. See common/cmd_i2c.c for a description of the
1400 command line interface.
1402 CONFIG_HARD_I2C selects a hardware I2C controller.
1404 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1405 bit-banging) driver instead of CPM or similar hardware
1408 There are several other quantities that must also be
1409 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1411 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1412 to be the frequency (in Hz) at which you wish your i2c bus
1413 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1414 the CPU's i2c node address).
1416 Now, the u-boot i2c code for the mpc8xx
1417 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1418 and so its address should therefore be cleared to 0 (See,
1419 eg, MPC823e User's Manual p.16-473). So, set
1420 CONFIG_SYS_I2C_SLAVE to 0.
1422 CONFIG_SYS_I2C_INIT_MPC5XXX
1424 When a board is reset during an i2c bus transfer
1425 chips might think that the current transfer is still
1426 in progress. Reset the slave devices by sending start
1427 commands until the slave device responds.
1429 That's all that's required for CONFIG_HARD_I2C.
1431 If you use the software i2c interface (CONFIG_SOFT_I2C)
1432 then the following macros need to be defined (examples are
1433 from include/configs/lwmon.h):
1437 (Optional). Any commands necessary to enable the I2C
1438 controller or configure ports.
1440 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1444 (Only for MPC8260 CPU). The I/O port to use (the code
1445 assumes both bits are on the same port). Valid values
1446 are 0..3 for ports A..D.
1450 The code necessary to make the I2C data line active
1451 (driven). If the data line is open collector, this
1454 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1458 The code necessary to make the I2C data line tri-stated
1459 (inactive). If the data line is open collector, this
1462 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1466 Code that returns TRUE if the I2C data line is high,
1469 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1473 If <bit> is TRUE, sets the I2C data line high. If it
1474 is FALSE, it clears it (low).
1476 eg: #define I2C_SDA(bit) \
1477 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1478 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1482 If <bit> is TRUE, sets the I2C clock line high. If it
1483 is FALSE, it clears it (low).
1485 eg: #define I2C_SCL(bit) \
1486 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1487 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1491 This delay is invoked four times per clock cycle so this
1492 controls the rate of data transfer. The data rate thus
1493 is 1 / (I2C_DELAY * 4). Often defined to be something
1496 #define I2C_DELAY udelay(2)
1498 CONFIG_SYS_I2C_INIT_BOARD
1500 When a board is reset during an i2c bus transfer
1501 chips might think that the current transfer is still
1502 in progress. On some boards it is possible to access
1503 the i2c SCLK line directly, either by using the
1504 processor pin as a GPIO or by having a second pin
1505 connected to the bus. If this option is defined a
1506 custom i2c_init_board() routine in boards/xxx/board.c
1507 is run early in the boot sequence.
1509 CONFIG_SYS_I2C_BOARD_LATE_INIT
1511 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1512 defined a custom i2c_board_late_init() routine in
1513 boards/xxx/board.c is run AFTER the operations in i2c_init()
1514 is completed. This callpoint can be used to unreset i2c bus
1515 using CPU i2c controller register accesses for CPUs whose i2c
1516 controller provide such a method. It is called at the end of
1517 i2c_init() to allow i2c_init operations to setup the i2c bus
1518 controller on the CPU (e.g. setting bus speed & slave address).
1520 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1522 This option enables configuration of bi_iic_fast[] flags
1523 in u-boot bd_info structure based on u-boot environment
1524 variable "i2cfast". (see also i2cfast)
1526 CONFIG_I2C_MULTI_BUS
1528 This option allows the use of multiple I2C buses, each of which
1529 must have a controller. At any point in time, only one bus is
1530 active. To switch to a different bus, use the 'i2c dev' command.
1531 Note that bus numbering is zero-based.
1533 CONFIG_SYS_I2C_NOPROBES
1535 This option specifies a list of I2C devices that will be skipped
1536 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1537 is set, specify a list of bus-device pairs. Otherwise, specify
1538 a 1D array of device addresses
1541 #undef CONFIG_I2C_MULTI_BUS
1542 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1544 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1546 #define CONFIG_I2C_MULTI_BUS
1547 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1549 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1551 CONFIG_SYS_SPD_BUS_NUM
1553 If defined, then this indicates the I2C bus number for DDR SPD.
1554 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1556 CONFIG_SYS_RTC_BUS_NUM
1558 If defined, then this indicates the I2C bus number for the RTC.
1559 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1561 CONFIG_SYS_DTT_BUS_NUM
1563 If defined, then this indicates the I2C bus number for the DTT.
1564 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1566 CONFIG_SYS_I2C_DTT_ADDR:
1568 If defined, specifies the I2C address of the DTT device.
1569 If not defined, then U-Boot uses predefined value for
1570 specified DTT device.
1574 Define this option if you want to use Freescale's I2C driver in
1575 drivers/i2c/fsl_i2c.c.
1579 Define this option if you have I2C devices reached over 1 .. n
1580 I2C Muxes like the pca9544a. This option addes a new I2C
1581 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1582 new I2C Bus to the existing I2C Busses. If you select the
1583 new Bus with "i2c dev", u-bbot sends first the commandos for
1584 the muxes to activate this new "bus".
1586 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1590 Adding a new I2C Bus reached over 2 pca9544a muxes
1591 The First mux with address 70 and channel 6
1592 The Second mux with address 71 and channel 4
1594 => i2c bus pca9544a:70:6:pca9544a:71:4
1596 Use the "i2c bus" command without parameter, to get a list
1597 of I2C Busses with muxes:
1600 Busses reached over muxes:
1602 reached over Mux(es):
1605 reached over Mux(es):
1610 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1611 u-boot sends First the Commando to the mux@70 to enable
1612 channel 6, and then the Commando to the mux@71 to enable
1615 After that, you can use the "normal" i2c commands as
1616 usual, to communicate with your I2C devices behind
1619 This option is actually implemented for the bitbanging
1620 algorithm in common/soft_i2c.c and for the Hardware I2C
1621 Bus on the MPC8260. But it should be not so difficult
1622 to add this option to other architectures.
1624 CONFIG_SOFT_I2C_READ_REPEATED_START
1626 defining this will force the i2c_read() function in
1627 the soft_i2c driver to perform an I2C repeated start
1628 between writing the address pointer and reading the
1629 data. If this define is omitted the default behaviour
1630 of doing a stop-start sequence will be used. Most I2C
1631 devices can use either method, but some require one or
1634 - SPI Support: CONFIG_SPI
1636 Enables SPI driver (so far only tested with
1637 SPI EEPROM, also an instance works with Crystal A/D and
1638 D/As on the SACSng board)
1642 Enables extended (16-bit) SPI EEPROM addressing.
1643 (symmetrical to CONFIG_I2C_X)
1647 Enables a software (bit-bang) SPI driver rather than
1648 using hardware support. This is a general purpose
1649 driver that only requires three general I/O port pins
1650 (two outputs, one input) to function. If this is
1651 defined, the board configuration must define several
1652 SPI configuration items (port pins to use, etc). For
1653 an example, see include/configs/sacsng.h.
1657 Enables a hardware SPI driver for general-purpose reads
1658 and writes. As with CONFIG_SOFT_SPI, the board configuration
1659 must define a list of chip-select function pointers.
1660 Currently supported on some MPC8xxx processors. For an
1661 example, see include/configs/mpc8349emds.h.
1665 Enables the driver for the SPI controllers on i.MX and MXC
1666 SoCs. Currently only i.MX31 is supported.
1668 - FPGA Support: CONFIG_FPGA
1670 Enables FPGA subsystem.
1672 CONFIG_FPGA_<vendor>
1674 Enables support for specific chip vendors.
1677 CONFIG_FPGA_<family>
1679 Enables support for FPGA family.
1680 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1684 Specify the number of FPGA devices to support.
1686 CONFIG_SYS_FPGA_PROG_FEEDBACK
1688 Enable printing of hash marks during FPGA configuration.
1690 CONFIG_SYS_FPGA_CHECK_BUSY
1692 Enable checks on FPGA configuration interface busy
1693 status by the configuration function. This option
1694 will require a board or device specific function to
1699 If defined, a function that provides delays in the FPGA
1700 configuration driver.
1702 CONFIG_SYS_FPGA_CHECK_CTRLC
1703 Allow Control-C to interrupt FPGA configuration
1705 CONFIG_SYS_FPGA_CHECK_ERROR
1707 Check for configuration errors during FPGA bitfile
1708 loading. For example, abort during Virtex II
1709 configuration if the INIT_B line goes low (which
1710 indicated a CRC error).
1712 CONFIG_SYS_FPGA_WAIT_INIT
1714 Maximum time to wait for the INIT_B line to deassert
1715 after PROB_B has been deasserted during a Virtex II
1716 FPGA configuration sequence. The default time is 500
1719 CONFIG_SYS_FPGA_WAIT_BUSY
1721 Maximum time to wait for BUSY to deassert during
1722 Virtex II FPGA configuration. The default is 5 ms.
1724 CONFIG_SYS_FPGA_WAIT_CONFIG
1726 Time to wait after FPGA configuration. The default is
1729 - Configuration Management:
1732 If defined, this string will be added to the U-Boot
1733 version information (U_BOOT_VERSION)
1735 - Vendor Parameter Protection:
1737 U-Boot considers the values of the environment
1738 variables "serial#" (Board Serial Number) and
1739 "ethaddr" (Ethernet Address) to be parameters that
1740 are set once by the board vendor / manufacturer, and
1741 protects these variables from casual modification by
1742 the user. Once set, these variables are read-only,
1743 and write or delete attempts are rejected. You can
1744 change this behaviour:
1746 If CONFIG_ENV_OVERWRITE is #defined in your config
1747 file, the write protection for vendor parameters is
1748 completely disabled. Anybody can change or delete
1751 Alternatively, if you #define _both_ CONFIG_ETHADDR
1752 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1753 Ethernet address is installed in the environment,
1754 which can be changed exactly ONCE by the user. [The
1755 serial# is unaffected by this, i. e. it remains
1761 Define this variable to enable the reservation of
1762 "protected RAM", i. e. RAM which is not overwritten
1763 by U-Boot. Define CONFIG_PRAM to hold the number of
1764 kB you want to reserve for pRAM. You can overwrite
1765 this default value by defining an environment
1766 variable "pram" to the number of kB you want to
1767 reserve. Note that the board info structure will
1768 still show the full amount of RAM. If pRAM is
1769 reserved, a new environment variable "mem" will
1770 automatically be defined to hold the amount of
1771 remaining RAM in a form that can be passed as boot
1772 argument to Linux, for instance like that:
1774 setenv bootargs ... mem=\${mem}
1777 This way you can tell Linux not to use this memory,
1778 either, which results in a memory region that will
1779 not be affected by reboots.
1781 *WARNING* If your board configuration uses automatic
1782 detection of the RAM size, you must make sure that
1783 this memory test is non-destructive. So far, the
1784 following board configurations are known to be
1787 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1788 HERMES, IP860, RPXlite, LWMON, LANTEC,
1789 PCU_E, FLAGADM, TQM8260
1794 Define this variable to stop the system in case of a
1795 fatal error, so that you have to reset it manually.
1796 This is probably NOT a good idea for an embedded
1797 system where you want the system to reboot
1798 automatically as fast as possible, but it may be
1799 useful during development since you can try to debug
1800 the conditions that lead to the situation.
1802 CONFIG_NET_RETRY_COUNT
1804 This variable defines the number of retries for
1805 network operations like ARP, RARP, TFTP, or BOOTP
1806 before giving up the operation. If not defined, a
1807 default value of 5 is used.
1811 Timeout waiting for an ARP reply in milliseconds.
1813 - Command Interpreter:
1814 CONFIG_AUTO_COMPLETE
1816 Enable auto completion of commands using TAB.
1818 Note that this feature has NOT been implemented yet
1819 for the "hush" shell.
1822 CONFIG_SYS_HUSH_PARSER
1824 Define this variable to enable the "hush" shell (from
1825 Busybox) as command line interpreter, thus enabling
1826 powerful command line syntax like
1827 if...then...else...fi conditionals or `&&' and '||'
1828 constructs ("shell scripts").
1830 If undefined, you get the old, much simpler behaviour
1831 with a somewhat smaller memory footprint.
1834 CONFIG_SYS_PROMPT_HUSH_PS2
1836 This defines the secondary prompt string, which is
1837 printed when the command interpreter needs more input
1838 to complete a command. Usually "> ".
1842 In the current implementation, the local variables
1843 space and global environment variables space are
1844 separated. Local variables are those you define by
1845 simply typing `name=value'. To access a local
1846 variable later on, you have write `$name' or
1847 `${name}'; to execute the contents of a variable
1848 directly type `$name' at the command prompt.
1850 Global environment variables are those you use
1851 setenv/printenv to work with. To run a command stored
1852 in such a variable, you need to use the run command,
1853 and you must not use the '$' sign to access them.
1855 To store commands and special characters in a
1856 variable, please use double quotation marks
1857 surrounding the whole text of the variable, instead
1858 of the backslashes before semicolons and special
1861 - Commandline Editing and History:
1862 CONFIG_CMDLINE_EDITING
1864 Enable editing and History functions for interactive
1865 commandline input operations
1867 - Default Environment:
1868 CONFIG_EXTRA_ENV_SETTINGS
1870 Define this to contain any number of null terminated
1871 strings (variable = value pairs) that will be part of
1872 the default environment compiled into the boot image.
1874 For example, place something like this in your
1875 board's config file:
1877 #define CONFIG_EXTRA_ENV_SETTINGS \
1881 Warning: This method is based on knowledge about the
1882 internal format how the environment is stored by the
1883 U-Boot code. This is NOT an official, exported
1884 interface! Although it is unlikely that this format
1885 will change soon, there is no guarantee either.
1886 You better know what you are doing here.
1888 Note: overly (ab)use of the default environment is
1889 discouraged. Make sure to check other ways to preset
1890 the environment like the "source" command or the
1893 - DataFlash Support:
1894 CONFIG_HAS_DATAFLASH
1896 Defining this option enables DataFlash features and
1897 allows to read/write in Dataflash via the standard
1900 - SystemACE Support:
1903 Adding this option adds support for Xilinx SystemACE
1904 chips attached via some sort of local bus. The address
1905 of the chip must also be defined in the
1906 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
1908 #define CONFIG_SYSTEMACE
1909 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
1911 When SystemACE support is added, the "ace" device type
1912 becomes available to the fat commands, i.e. fatls.
1914 - TFTP Fixed UDP Port:
1917 If this is defined, the environment variable tftpsrcp
1918 is used to supply the TFTP UDP source port value.
1919 If tftpsrcp isn't defined, the normal pseudo-random port
1920 number generator is used.
1922 Also, the environment variable tftpdstp is used to supply
1923 the TFTP UDP destination port value. If tftpdstp isn't
1924 defined, the normal port 69 is used.
1926 The purpose for tftpsrcp is to allow a TFTP server to
1927 blindly start the TFTP transfer using the pre-configured
1928 target IP address and UDP port. This has the effect of
1929 "punching through" the (Windows XP) firewall, allowing
1930 the remainder of the TFTP transfer to proceed normally.
1931 A better solution is to properly configure the firewall,
1932 but sometimes that is not allowed.
1934 - Show boot progress:
1935 CONFIG_SHOW_BOOT_PROGRESS
1937 Defining this option allows to add some board-
1938 specific code (calling a user-provided function
1939 "show_boot_progress(int)") that enables you to show
1940 the system's boot progress on some display (for
1941 example, some LED's) on your board. At the moment,
1942 the following checkpoints are implemented:
1944 Legacy uImage format:
1947 1 common/cmd_bootm.c before attempting to boot an image
1948 -1 common/cmd_bootm.c Image header has bad magic number
1949 2 common/cmd_bootm.c Image header has correct magic number
1950 -2 common/cmd_bootm.c Image header has bad checksum
1951 3 common/cmd_bootm.c Image header has correct checksum
1952 -3 common/cmd_bootm.c Image data has bad checksum
1953 4 common/cmd_bootm.c Image data has correct checksum
1954 -4 common/cmd_bootm.c Image is for unsupported architecture
1955 5 common/cmd_bootm.c Architecture check OK
1956 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
1957 6 common/cmd_bootm.c Image Type check OK
1958 -6 common/cmd_bootm.c gunzip uncompression error
1959 -7 common/cmd_bootm.c Unimplemented compression type
1960 7 common/cmd_bootm.c Uncompression OK
1961 8 common/cmd_bootm.c No uncompress/copy overwrite error
1962 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1964 9 common/image.c Start initial ramdisk verification
1965 -10 common/image.c Ramdisk header has bad magic number
1966 -11 common/image.c Ramdisk header has bad checksum
1967 10 common/image.c Ramdisk header is OK
1968 -12 common/image.c Ramdisk data has bad checksum
1969 11 common/image.c Ramdisk data has correct checksum
1970 12 common/image.c Ramdisk verification complete, start loading
1971 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
1972 13 common/image.c Start multifile image verification
1973 14 common/image.c No initial ramdisk, no multifile, continue.
1975 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
1977 -30 arch/powerpc/lib/board.c Fatal error, hang the system
1978 -31 post/post.c POST test failed, detected by post_output_backlog()
1979 -32 post/post.c POST test failed, detected by post_run_single()
1981 34 common/cmd_doc.c before loading a Image from a DOC device
1982 -35 common/cmd_doc.c Bad usage of "doc" command
1983 35 common/cmd_doc.c correct usage of "doc" command
1984 -36 common/cmd_doc.c No boot device
1985 36 common/cmd_doc.c correct boot device
1986 -37 common/cmd_doc.c Unknown Chip ID on boot device
1987 37 common/cmd_doc.c correct chip ID found, device available
1988 -38 common/cmd_doc.c Read Error on boot device
1989 38 common/cmd_doc.c reading Image header from DOC device OK
1990 -39 common/cmd_doc.c Image header has bad magic number
1991 39 common/cmd_doc.c Image header has correct magic number
1992 -40 common/cmd_doc.c Error reading Image from DOC device
1993 40 common/cmd_doc.c Image header has correct magic number
1994 41 common/cmd_ide.c before loading a Image from a IDE device
1995 -42 common/cmd_ide.c Bad usage of "ide" command
1996 42 common/cmd_ide.c correct usage of "ide" command
1997 -43 common/cmd_ide.c No boot device
1998 43 common/cmd_ide.c boot device found
1999 -44 common/cmd_ide.c Device not available
2000 44 common/cmd_ide.c Device available
2001 -45 common/cmd_ide.c wrong partition selected
2002 45 common/cmd_ide.c partition selected
2003 -46 common/cmd_ide.c Unknown partition table
2004 46 common/cmd_ide.c valid partition table found
2005 -47 common/cmd_ide.c Invalid partition type
2006 47 common/cmd_ide.c correct partition type
2007 -48 common/cmd_ide.c Error reading Image Header on boot device
2008 48 common/cmd_ide.c reading Image Header from IDE device OK
2009 -49 common/cmd_ide.c Image header has bad magic number
2010 49 common/cmd_ide.c Image header has correct magic number
2011 -50 common/cmd_ide.c Image header has bad checksum
2012 50 common/cmd_ide.c Image header has correct checksum
2013 -51 common/cmd_ide.c Error reading Image from IDE device
2014 51 common/cmd_ide.c reading Image from IDE device OK
2015 52 common/cmd_nand.c before loading a Image from a NAND device
2016 -53 common/cmd_nand.c Bad usage of "nand" command
2017 53 common/cmd_nand.c correct usage of "nand" command
2018 -54 common/cmd_nand.c No boot device
2019 54 common/cmd_nand.c boot device found
2020 -55 common/cmd_nand.c Unknown Chip ID on boot device
2021 55 common/cmd_nand.c correct chip ID found, device available
2022 -56 common/cmd_nand.c Error reading Image Header on boot device
2023 56 common/cmd_nand.c reading Image Header from NAND device OK
2024 -57 common/cmd_nand.c Image header has bad magic number
2025 57 common/cmd_nand.c Image header has correct magic number
2026 -58 common/cmd_nand.c Error reading Image from NAND device
2027 58 common/cmd_nand.c reading Image from NAND device OK
2029 -60 common/env_common.c Environment has a bad CRC, using default
2031 64 net/eth.c starting with Ethernet configuration.
2032 -64 net/eth.c no Ethernet found.
2033 65 net/eth.c Ethernet found.
2035 -80 common/cmd_net.c usage wrong
2036 80 common/cmd_net.c before calling NetLoop()
2037 -81 common/cmd_net.c some error in NetLoop() occurred
2038 81 common/cmd_net.c NetLoop() back without error
2039 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2040 82 common/cmd_net.c trying automatic boot
2041 83 common/cmd_net.c running "source" command
2042 -83 common/cmd_net.c some error in automatic boot or "source" command
2043 84 common/cmd_net.c end without errors
2048 100 common/cmd_bootm.c Kernel FIT Image has correct format
2049 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2050 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2051 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2052 102 common/cmd_bootm.c Kernel unit name specified
2053 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2054 103 common/cmd_bootm.c Found configuration node
2055 104 common/cmd_bootm.c Got kernel subimage node offset
2056 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2057 105 common/cmd_bootm.c Kernel subimage hash verification OK
2058 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2059 106 common/cmd_bootm.c Architecture check OK
2060 -106 common/cmd_bootm.c Kernel subimage has wrong type
2061 107 common/cmd_bootm.c Kernel subimage type OK
2062 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2063 108 common/cmd_bootm.c Got kernel subimage data/size
2064 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2065 -109 common/cmd_bootm.c Can't get kernel subimage type
2066 -110 common/cmd_bootm.c Can't get kernel subimage comp
2067 -111 common/cmd_bootm.c Can't get kernel subimage os
2068 -112 common/cmd_bootm.c Can't get kernel subimage load address
2069 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2071 120 common/image.c Start initial ramdisk verification
2072 -120 common/image.c Ramdisk FIT image has incorrect format
2073 121 common/image.c Ramdisk FIT image has correct format
2074 122 common/image.c No ramdisk subimage unit name, using configuration
2075 -122 common/image.c Can't get configuration for ramdisk subimage
2076 123 common/image.c Ramdisk unit name specified
2077 -124 common/image.c Can't get ramdisk subimage node offset
2078 125 common/image.c Got ramdisk subimage node offset
2079 -125 common/image.c Ramdisk subimage hash verification failed
2080 126 common/image.c Ramdisk subimage hash verification OK
2081 -126 common/image.c Ramdisk subimage for unsupported architecture
2082 127 common/image.c Architecture check OK
2083 -127 common/image.c Can't get ramdisk subimage data/size
2084 128 common/image.c Got ramdisk subimage data/size
2085 129 common/image.c Can't get ramdisk load address
2086 -129 common/image.c Got ramdisk load address
2088 -130 common/cmd_doc.c Incorrect FIT image format
2089 131 common/cmd_doc.c FIT image format OK
2091 -140 common/cmd_ide.c Incorrect FIT image format
2092 141 common/cmd_ide.c FIT image format OK
2094 -150 common/cmd_nand.c Incorrect FIT image format
2095 151 common/cmd_nand.c FIT image format OK
2097 - Automatic software updates via TFTP server
2099 CONFIG_UPDATE_TFTP_CNT_MAX
2100 CONFIG_UPDATE_TFTP_MSEC_MAX
2102 These options enable and control the auto-update feature;
2103 for a more detailed description refer to doc/README.update.
2105 - MTD Support (mtdparts command, UBI support)
2108 Adds the MTD device infrastructure from the Linux kernel.
2109 Needed for mtdparts command support.
2111 CONFIG_MTD_PARTITIONS
2113 Adds the MTD partitioning infrastructure from the Linux
2114 kernel. Needed for UBI support.
2120 [so far only for SMDK2400 and TRAB boards]
2122 - Modem support enable:
2123 CONFIG_MODEM_SUPPORT
2125 - RTS/CTS Flow control enable:
2128 - Modem debug support:
2129 CONFIG_MODEM_SUPPORT_DEBUG
2131 Enables debugging stuff (char screen[1024], dbg())
2132 for modem support. Useful only with BDI2000.
2134 - Interrupt support (PPC):
2136 There are common interrupt_init() and timer_interrupt()
2137 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2138 for CPU specific initialization. interrupt_init_cpu()
2139 should set decrementer_count to appropriate value. If
2140 CPU resets decrementer automatically after interrupt
2141 (ppc4xx) it should set decrementer_count to zero.
2142 timer_interrupt() calls timer_interrupt_cpu() for CPU
2143 specific handling. If board has watchdog / status_led
2144 / other_activity_monitor it works automatically from
2145 general timer_interrupt().
2149 In the target system modem support is enabled when a
2150 specific key (key combination) is pressed during
2151 power-on. Otherwise U-Boot will boot normally
2152 (autoboot). The key_pressed() function is called from
2153 board_init(). Currently key_pressed() is a dummy
2154 function, returning 1 and thus enabling modem
2157 If there are no modem init strings in the
2158 environment, U-Boot proceed to autoboot; the
2159 previous output (banner, info printfs) will be
2162 See also: doc/README.Modem
2165 Configuration Settings:
2166 -----------------------
2168 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2169 undefine this when you're short of memory.
2171 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2172 width of the commands listed in the 'help' command output.
2174 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2175 prompt for user input.
2177 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2179 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2181 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2183 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2184 the application (usually a Linux kernel) when it is
2187 - CONFIG_SYS_BAUDRATE_TABLE:
2188 List of legal baudrate settings for this board.
2190 - CONFIG_SYS_CONSOLE_INFO_QUIET
2191 Suppress display of console information at boot.
2193 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2194 If the board specific function
2195 extern int overwrite_console (void);
2196 returns 1, the stdin, stderr and stdout are switched to the
2197 serial port, else the settings in the environment are used.
2199 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2200 Enable the call to overwrite_console().
2202 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2203 Enable overwrite of previous console environment settings.
2205 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2206 Begin and End addresses of the area used by the
2209 - CONFIG_SYS_ALT_MEMTEST:
2210 Enable an alternate, more extensive memory test.
2212 - CONFIG_SYS_MEMTEST_SCRATCH:
2213 Scratch address used by the alternate memory test
2214 You only need to set this if address zero isn't writeable
2216 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2217 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2218 this specified memory area will get subtracted from the top
2219 (end) of RAM and won't get "touched" at all by U-Boot. By
2220 fixing up gd->ram_size the Linux kernel should gets passed
2221 the now "corrected" memory size and won't touch it either.
2222 This should work for arch/ppc and arch/powerpc. Only Linux
2223 board ports in arch/powerpc with bootwrapper support that
2224 recalculate the memory size from the SDRAM controller setup
2225 will have to get fixed in Linux additionally.
2227 This option can be used as a workaround for the 440EPx/GRx
2228 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2231 WARNING: Please make sure that this value is a multiple of
2232 the Linux page size (normally 4k). If this is not the case,
2233 then the end address of the Linux memory will be located at a
2234 non page size aligned address and this could cause major
2237 - CONFIG_SYS_TFTP_LOADADDR:
2238 Default load address for network file downloads
2240 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2241 Enable temporary baudrate change while serial download
2243 - CONFIG_SYS_SDRAM_BASE:
2244 Physical start address of SDRAM. _Must_ be 0 here.
2246 - CONFIG_SYS_MBIO_BASE:
2247 Physical start address of Motherboard I/O (if using a
2250 - CONFIG_SYS_FLASH_BASE:
2251 Physical start address of Flash memory.
2253 - CONFIG_SYS_MONITOR_BASE:
2254 Physical start address of boot monitor code (set by
2255 make config files to be same as the text base address
2256 (TEXT_BASE) used when linking) - same as
2257 CONFIG_SYS_FLASH_BASE when booting from flash.
2259 - CONFIG_SYS_MONITOR_LEN:
2260 Size of memory reserved for monitor code, used to
2261 determine _at_compile_time_ (!) if the environment is
2262 embedded within the U-Boot image, or in a separate
2265 - CONFIG_SYS_MALLOC_LEN:
2266 Size of DRAM reserved for malloc() use.
2268 - CONFIG_SYS_BOOTM_LEN:
2269 Normally compressed uImages are limited to an
2270 uncompressed size of 8 MBytes. If this is not enough,
2271 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2272 to adjust this setting to your needs.
2274 - CONFIG_SYS_BOOTMAPSZ:
2275 Maximum size of memory mapped by the startup code of
2276 the Linux kernel; all data that must be processed by
2277 the Linux kernel (bd_info, boot arguments, FDT blob if
2278 used) must be put below this limit, unless "bootm_low"
2279 enviroment variable is defined and non-zero. In such case
2280 all data for the Linux kernel must be between "bootm_low"
2281 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ.
2283 - CONFIG_SYS_MAX_FLASH_BANKS:
2284 Max number of Flash memory banks
2286 - CONFIG_SYS_MAX_FLASH_SECT:
2287 Max number of sectors on a Flash chip
2289 - CONFIG_SYS_FLASH_ERASE_TOUT:
2290 Timeout for Flash erase operations (in ms)
2292 - CONFIG_SYS_FLASH_WRITE_TOUT:
2293 Timeout for Flash write operations (in ms)
2295 - CONFIG_SYS_FLASH_LOCK_TOUT
2296 Timeout for Flash set sector lock bit operation (in ms)
2298 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2299 Timeout for Flash clear lock bits operation (in ms)
2301 - CONFIG_SYS_FLASH_PROTECTION
2302 If defined, hardware flash sectors protection is used
2303 instead of U-Boot software protection.
2305 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2307 Enable TFTP transfers directly to flash memory;
2308 without this option such a download has to be
2309 performed in two steps: (1) download to RAM, and (2)
2310 copy from RAM to flash.
2312 The two-step approach is usually more reliable, since
2313 you can check if the download worked before you erase
2314 the flash, but in some situations (when system RAM is
2315 too limited to allow for a temporary copy of the
2316 downloaded image) this option may be very useful.
2318 - CONFIG_SYS_FLASH_CFI:
2319 Define if the flash driver uses extra elements in the
2320 common flash structure for storing flash geometry.
2322 - CONFIG_FLASH_CFI_DRIVER
2323 This option also enables the building of the cfi_flash driver
2324 in the drivers directory
2326 - CONFIG_FLASH_CFI_MTD
2327 This option enables the building of the cfi_mtd driver
2328 in the drivers directory. The driver exports CFI flash
2331 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2332 Use buffered writes to flash.
2334 - CONFIG_FLASH_SPANSION_S29WS_N
2335 s29ws-n MirrorBit flash has non-standard addresses for buffered
2338 - CONFIG_SYS_FLASH_QUIET_TEST
2339 If this option is defined, the common CFI flash doesn't
2340 print it's warning upon not recognized FLASH banks. This
2341 is useful, if some of the configured banks are only
2342 optionally available.
2344 - CONFIG_FLASH_SHOW_PROGRESS
2345 If defined (must be an integer), print out countdown
2346 digits and dots. Recommended value: 45 (9..1) for 80
2347 column displays, 15 (3..1) for 40 column displays.
2349 - CONFIG_SYS_RX_ETH_BUFFER:
2350 Defines the number of Ethernet receive buffers. On some
2351 Ethernet controllers it is recommended to set this value
2352 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2353 buffers can be full shortly after enabling the interface
2354 on high Ethernet traffic.
2355 Defaults to 4 if not defined.
2357 The following definitions that deal with the placement and management
2358 of environment data (variable area); in general, we support the
2359 following configurations:
2361 - CONFIG_ENV_IS_IN_FLASH:
2363 Define this if the environment is in flash memory.
2365 a) The environment occupies one whole flash sector, which is
2366 "embedded" in the text segment with the U-Boot code. This
2367 happens usually with "bottom boot sector" or "top boot
2368 sector" type flash chips, which have several smaller
2369 sectors at the start or the end. For instance, such a
2370 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2371 such a case you would place the environment in one of the
2372 4 kB sectors - with U-Boot code before and after it. With
2373 "top boot sector" type flash chips, you would put the
2374 environment in one of the last sectors, leaving a gap
2375 between U-Boot and the environment.
2377 - CONFIG_ENV_OFFSET:
2379 Offset of environment data (variable area) to the
2380 beginning of flash memory; for instance, with bottom boot
2381 type flash chips the second sector can be used: the offset
2382 for this sector is given here.
2384 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2388 This is just another way to specify the start address of
2389 the flash sector containing the environment (instead of
2392 - CONFIG_ENV_SECT_SIZE:
2394 Size of the sector containing the environment.
2397 b) Sometimes flash chips have few, equal sized, BIG sectors.
2398 In such a case you don't want to spend a whole sector for
2403 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2404 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2405 of this flash sector for the environment. This saves
2406 memory for the RAM copy of the environment.
2408 It may also save flash memory if you decide to use this
2409 when your environment is "embedded" within U-Boot code,
2410 since then the remainder of the flash sector could be used
2411 for U-Boot code. It should be pointed out that this is
2412 STRONGLY DISCOURAGED from a robustness point of view:
2413 updating the environment in flash makes it always
2414 necessary to erase the WHOLE sector. If something goes
2415 wrong before the contents has been restored from a copy in
2416 RAM, your target system will be dead.
2418 - CONFIG_ENV_ADDR_REDUND
2419 CONFIG_ENV_SIZE_REDUND
2421 These settings describe a second storage area used to hold
2422 a redundant copy of the environment data, so that there is
2423 a valid backup copy in case there is a power failure during
2424 a "saveenv" operation.
2426 BE CAREFUL! Any changes to the flash layout, and some changes to the
2427 source code will make it necessary to adapt <board>/u-boot.lds*
2431 - CONFIG_ENV_IS_IN_NVRAM:
2433 Define this if you have some non-volatile memory device
2434 (NVRAM, battery buffered SRAM) which you want to use for the
2440 These two #defines are used to determine the memory area you
2441 want to use for environment. It is assumed that this memory
2442 can just be read and written to, without any special
2445 BE CAREFUL! The first access to the environment happens quite early
2446 in U-Boot initalization (when we try to get the setting of for the
2447 console baudrate). You *MUST* have mapped your NVRAM area then, or
2450 Please note that even with NVRAM we still use a copy of the
2451 environment in RAM: we could work on NVRAM directly, but we want to
2452 keep settings there always unmodified except somebody uses "saveenv"
2453 to save the current settings.
2456 - CONFIG_ENV_IS_IN_EEPROM:
2458 Use this if you have an EEPROM or similar serial access
2459 device and a driver for it.
2461 - CONFIG_ENV_OFFSET:
2464 These two #defines specify the offset and size of the
2465 environment area within the total memory of your EEPROM.
2467 - CONFIG_SYS_I2C_EEPROM_ADDR:
2468 If defined, specified the chip address of the EEPROM device.
2469 The default address is zero.
2471 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2472 If defined, the number of bits used to address bytes in a
2473 single page in the EEPROM device. A 64 byte page, for example
2474 would require six bits.
2476 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2477 If defined, the number of milliseconds to delay between
2478 page writes. The default is zero milliseconds.
2480 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2481 The length in bytes of the EEPROM memory array address. Note
2482 that this is NOT the chip address length!
2484 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2485 EEPROM chips that implement "address overflow" are ones
2486 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2487 address and the extra bits end up in the "chip address" bit
2488 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2491 Note that we consider the length of the address field to
2492 still be one byte because the extra address bits are hidden
2493 in the chip address.
2495 - CONFIG_SYS_EEPROM_SIZE:
2496 The size in bytes of the EEPROM device.
2498 - CONFIG_ENV_EEPROM_IS_ON_I2C
2499 define this, if you have I2C and SPI activated, and your
2500 EEPROM, which holds the environment, is on the I2C bus.
2502 - CONFIG_I2C_ENV_EEPROM_BUS
2503 if you have an Environment on an EEPROM reached over
2504 I2C muxes, you can define here, how to reach this
2505 EEPROM. For example:
2507 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
2509 EEPROM which holds the environment, is reached over
2510 a pca9547 i2c mux with address 0x70, channel 3.
2512 - CONFIG_ENV_IS_IN_DATAFLASH:
2514 Define this if you have a DataFlash memory device which you
2515 want to use for the environment.
2517 - CONFIG_ENV_OFFSET:
2521 These three #defines specify the offset and size of the
2522 environment area within the total memory of your DataFlash placed
2523 at the specified address.
2525 - CONFIG_ENV_IS_IN_NAND:
2527 Define this if you have a NAND device which you want to use
2528 for the environment.
2530 - CONFIG_ENV_OFFSET:
2533 These two #defines specify the offset and size of the environment
2534 area within the first NAND device.
2536 - CONFIG_ENV_OFFSET_REDUND
2538 This setting describes a second storage area of CONFIG_ENV_SIZE
2539 size used to hold a redundant copy of the environment data,
2540 so that there is a valid backup copy in case there is a
2541 power failure during a "saveenv" operation.
2543 Note: CONFIG_ENV_OFFSET and CONFIG_ENV_OFFSET_REDUND must be aligned
2544 to a block boundary, and CONFIG_ENV_SIZE must be a multiple of
2545 the NAND devices block size.
2547 - CONFIG_NAND_ENV_DST
2549 Defines address in RAM to which the nand_spl code should copy the
2550 environment. If redundant environment is used, it will be copied to
2551 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2553 - CONFIG_SYS_SPI_INIT_OFFSET
2555 Defines offset to the initial SPI buffer area in DPRAM. The
2556 area is used at an early stage (ROM part) if the environment
2557 is configured to reside in the SPI EEPROM: We need a 520 byte
2558 scratch DPRAM area. It is used between the two initialization
2559 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2560 to be a good choice since it makes it far enough from the
2561 start of the data area as well as from the stack pointer.
2563 Please note that the environment is read-only until the monitor
2564 has been relocated to RAM and a RAM copy of the environment has been
2565 created; also, when using EEPROM you will have to use getenv_r()
2566 until then to read environment variables.
2568 The environment is protected by a CRC32 checksum. Before the monitor
2569 is relocated into RAM, as a result of a bad CRC you will be working
2570 with the compiled-in default environment - *silently*!!! [This is
2571 necessary, because the first environment variable we need is the
2572 "baudrate" setting for the console - if we have a bad CRC, we don't
2573 have any device yet where we could complain.]
2575 Note: once the monitor has been relocated, then it will complain if
2576 the default environment is used; a new CRC is computed as soon as you
2577 use the "saveenv" command to store a valid environment.
2579 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2580 Echo the inverted Ethernet link state to the fault LED.
2582 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2583 also needs to be defined.
2585 - CONFIG_SYS_FAULT_MII_ADDR:
2586 MII address of the PHY to check for the Ethernet link state.
2588 - CONFIG_NS16550_MIN_FUNCTIONS:
2589 Define this if you desire to only have use of the NS16550_init
2590 and NS16550_putc functions for the serial driver located at
2591 drivers/serial/ns16550.c. This option is useful for saving
2592 space for already greatly restricted images, including but not
2593 limited to NAND_SPL configurations.
2595 Low Level (hardware related) configuration options:
2596 ---------------------------------------------------
2598 - CONFIG_SYS_CACHELINE_SIZE:
2599 Cache Line Size of the CPU.
2601 - CONFIG_SYS_DEFAULT_IMMR:
2602 Default address of the IMMR after system reset.
2604 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2605 and RPXsuper) to be able to adjust the position of
2606 the IMMR register after a reset.
2608 - Floppy Disk Support:
2609 CONFIG_SYS_FDC_DRIVE_NUMBER
2611 the default drive number (default value 0)
2613 CONFIG_SYS_ISA_IO_STRIDE
2615 defines the spacing between FDC chipset registers
2618 CONFIG_SYS_ISA_IO_OFFSET
2620 defines the offset of register from address. It
2621 depends on which part of the data bus is connected to
2622 the FDC chipset. (default value 0)
2624 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
2625 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
2628 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
2629 fdc_hw_init() is called at the beginning of the FDC
2630 setup. fdc_hw_init() must be provided by the board
2631 source code. It is used to make hardware dependant
2634 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
2635 DO NOT CHANGE unless you know exactly what you're
2636 doing! (11-4) [MPC8xx/82xx systems only]
2638 - CONFIG_SYS_INIT_RAM_ADDR:
2640 Start address of memory area that can be used for
2641 initial data and stack; please note that this must be
2642 writable memory that is working WITHOUT special
2643 initialization, i. e. you CANNOT use normal RAM which
2644 will become available only after programming the
2645 memory controller and running certain initialization
2648 U-Boot uses the following memory types:
2649 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2650 - MPC824X: data cache
2651 - PPC4xx: data cache
2653 - CONFIG_SYS_GBL_DATA_OFFSET:
2655 Offset of the initial data structure in the memory
2656 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2657 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
2658 data is located at the end of the available space
2659 (sometimes written as (CONFIG_SYS_INIT_RAM_END -
2660 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
2661 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2662 CONFIG_SYS_GBL_DATA_OFFSET) downward.
2665 On the MPC824X (or other systems that use the data
2666 cache for initial memory) the address chosen for
2667 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
2668 point to an otherwise UNUSED address space between
2669 the top of RAM and the start of the PCI space.
2671 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
2673 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
2675 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
2677 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
2679 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2681 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
2683 - CONFIG_SYS_OR_TIMING_SDRAM:
2686 - CONFIG_SYS_MAMR_PTA:
2687 periodic timer for refresh
2689 - CONFIG_SYS_DER: Debug Event Register (37-47)
2691 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2692 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2693 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2694 CONFIG_SYS_BR1_PRELIM:
2695 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2697 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2698 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2699 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
2700 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2702 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
2703 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
2704 Machine Mode Register and Memory Periodic Timer
2705 Prescaler definitions (SDRAM timing)
2707 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
2708 enable I2C microcode relocation patch (MPC8xx);
2709 define relocation offset in DPRAM [DSP2]
2711 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
2712 enable SMC microcode relocation patch (MPC8xx);
2713 define relocation offset in DPRAM [SMC1]
2715 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
2716 enable SPI microcode relocation patch (MPC8xx);
2717 define relocation offset in DPRAM [SCC4]
2719 - CONFIG_SYS_USE_OSCCLK:
2720 Use OSCM clock mode on MBX8xx board. Be careful,
2721 wrong setting might damage your board. Read
2722 doc/README.MBX before setting this variable!
2724 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2725 Offset of the bootmode word in DPRAM used by post
2726 (Power On Self Tests). This definition overrides
2727 #define'd default value in commproc.h resp.
2730 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
2731 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
2732 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
2733 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
2734 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2735 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
2736 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
2737 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
2738 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
2740 - CONFIG_PCI_DISABLE_PCIE:
2741 Disable PCI-Express on systems where it is supported but not
2745 Get DDR timing information from an I2C EEPROM. Common
2746 with pluggable memory modules such as SODIMMs
2749 I2C address of the SPD EEPROM
2751 - CONFIG_SYS_SPD_BUS_NUM
2752 If SPD EEPROM is on an I2C bus other than the first
2753 one, specify here. Note that the value must resolve
2754 to something your driver can deal with.
2756 - CONFIG_SYS_83XX_DDR_USES_CS0
2757 Only for 83xx systems. If specified, then DDR should
2758 be configured using CS0 and CS1 instead of CS2 and CS3.
2760 - CONFIG_ETHER_ON_FEC[12]
2761 Define to enable FEC[12] on a 8xx series processor.
2763 - CONFIG_FEC[12]_PHY
2764 Define to the hardcoded PHY address which corresponds
2765 to the given FEC; i. e.
2766 #define CONFIG_FEC1_PHY 4
2767 means that the PHY with address 4 is connected to FEC1
2769 When set to -1, means to probe for first available.
2771 - CONFIG_FEC[12]_PHY_NORXERR
2772 The PHY does not have a RXERR line (RMII only).
2773 (so program the FEC to ignore it).
2776 Enable RMII mode for all FECs.
2777 Note that this is a global option, we can't
2778 have one FEC in standard MII mode and another in RMII mode.
2780 - CONFIG_CRC32_VERIFY
2781 Add a verify option to the crc32 command.
2784 => crc32 -v <address> <count> <crc32>
2786 Where address/count indicate a memory area
2787 and crc32 is the correct crc32 which the
2791 Add the "loopw" memory command. This only takes effect if
2792 the memory commands are activated globally (CONFIG_CMD_MEM).
2795 Add the "mdc" and "mwc" memory commands. These are cyclic
2800 This command will print 4 bytes (10,11,12,13) each 500 ms.
2802 => mwc.l 100 12345678 10
2803 This command will write 12345678 to address 100 all 10 ms.
2805 This only takes effect if the memory commands are activated
2806 globally (CONFIG_CMD_MEM).
2808 - CONFIG_SKIP_LOWLEVEL_INIT
2809 - CONFIG_SKIP_RELOCATE_UBOOT
2811 [ARM only] If these variables are defined, then
2812 certain low level initializations (like setting up
2813 the memory controller) are omitted and/or U-Boot does
2814 not relocate itself into RAM.
2815 Normally these variables MUST NOT be defined. The
2816 only exception is when U-Boot is loaded (to RAM) by
2817 some other boot loader or by a debugger which
2818 performs these initializations itself.
2822 Modifies the behaviour of start.S when compiling a loader
2823 that is executed before the actual U-Boot. E.g. when
2824 compiling a NAND SPL.
2826 Building the Software:
2827 ======================
2829 Building U-Boot has been tested in several native build environments
2830 and in many different cross environments. Of course we cannot support
2831 all possibly existing versions of cross development tools in all
2832 (potentially obsolete) versions. In case of tool chain problems we
2833 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2834 which is extensively used to build and test U-Boot.
2836 If you are not using a native environment, it is assumed that you
2837 have GNU cross compiling tools available in your path. In this case,
2838 you must set the environment variable CROSS_COMPILE in your shell.
2839 Note that no changes to the Makefile or any other source files are
2840 necessary. For example using the ELDK on a 4xx CPU, please enter:
2842 $ CROSS_COMPILE=ppc_4xx-
2843 $ export CROSS_COMPILE
2845 Note: If you wish to generate Windows versions of the utilities in
2846 the tools directory you can use the MinGW toolchain
2847 (http://www.mingw.org). Set your HOST tools to the MinGW
2848 toolchain and execute 'make tools'. For example:
2850 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
2852 Binaries such as tools/mkimage.exe will be created which can
2853 be executed on computers running Windows.
2855 U-Boot is intended to be simple to build. After installing the
2856 sources you must configure U-Boot for one specific board type. This
2861 where "NAME_config" is the name of one of the existing configu-
2862 rations; see the main Makefile for supported names.
2864 Note: for some board special configuration names may exist; check if
2865 additional information is available from the board vendor; for
2866 instance, the TQM823L systems are available without (standard)
2867 or with LCD support. You can select such additional "features"
2868 when choosing the configuration, i. e.
2871 - will configure for a plain TQM823L, i. e. no LCD support
2873 make TQM823L_LCD_config
2874 - will configure for a TQM823L with U-Boot console on LCD
2879 Finally, type "make all", and you should get some working U-Boot
2880 images ready for download to / installation on your system:
2882 - "u-boot.bin" is a raw binary image
2883 - "u-boot" is an image in ELF binary format
2884 - "u-boot.srec" is in Motorola S-Record format
2886 By default the build is performed locally and the objects are saved
2887 in the source directory. One of the two methods can be used to change
2888 this behavior and build U-Boot to some external directory:
2890 1. Add O= to the make command line invocations:
2892 make O=/tmp/build distclean
2893 make O=/tmp/build NAME_config
2894 make O=/tmp/build all
2896 2. Set environment variable BUILD_DIR to point to the desired location:
2898 export BUILD_DIR=/tmp/build
2903 Note that the command line "O=" setting overrides the BUILD_DIR environment
2907 Please be aware that the Makefiles assume you are using GNU make, so
2908 for instance on NetBSD you might need to use "gmake" instead of
2912 If the system board that you have is not listed, then you will need
2913 to port U-Boot to your hardware platform. To do this, follow these
2916 1. Add a new configuration option for your board to the toplevel
2917 "Makefile" and to the "MAKEALL" script, using the existing
2918 entries as examples. Note that here and at many other places
2919 boards and other names are listed in alphabetical sort order. Please
2921 2. Create a new directory to hold your board specific code. Add any
2922 files you need. In your board directory, you will need at least
2923 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2924 3. Create a new configuration file "include/configs/<board>.h" for
2926 3. If you're porting U-Boot to a new CPU, then also create a new
2927 directory to hold your CPU specific code. Add any files you need.
2928 4. Run "make <board>_config" with your new name.
2929 5. Type "make", and you should get a working "u-boot.srec" file
2930 to be installed on your target system.
2931 6. Debug and solve any problems that might arise.
2932 [Of course, this last step is much harder than it sounds.]
2935 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2936 ==============================================================
2938 If you have modified U-Boot sources (for instance added a new board
2939 or support for new devices, a new CPU, etc.) you are expected to
2940 provide feedback to the other developers. The feedback normally takes
2941 the form of a "patch", i. e. a context diff against a certain (latest
2942 official or latest in the git repository) version of U-Boot sources.
2944 But before you submit such a patch, please verify that your modifi-
2945 cation did not break existing code. At least make sure that *ALL* of
2946 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2947 just run the "MAKEALL" script, which will configure and build U-Boot
2948 for ALL supported system. Be warned, this will take a while. You can
2949 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2950 environment variable to the script, i. e. to use the ELDK cross tools
2953 CROSS_COMPILE=ppc_8xx- MAKEALL
2955 or to build on a native PowerPC system you can type
2957 CROSS_COMPILE=' ' MAKEALL
2959 When using the MAKEALL script, the default behaviour is to build
2960 U-Boot in the source directory. This location can be changed by
2961 setting the BUILD_DIR environment variable. Also, for each target
2962 built, the MAKEALL script saves two log files (<target>.ERR and
2963 <target>.MAKEALL) in the <source dir>/LOG directory. This default
2964 location can be changed by setting the MAKEALL_LOGDIR environment
2965 variable. For example:
2967 export BUILD_DIR=/tmp/build
2968 export MAKEALL_LOGDIR=/tmp/log
2969 CROSS_COMPILE=ppc_8xx- MAKEALL
2971 With the above settings build objects are saved in the /tmp/build,
2972 log files are saved in the /tmp/log and the source tree remains clean
2973 during the whole build process.
2976 See also "U-Boot Porting Guide" below.
2979 Monitor Commands - Overview:
2980 ============================
2982 go - start application at address 'addr'
2983 run - run commands in an environment variable
2984 bootm - boot application image from memory
2985 bootp - boot image via network using BootP/TFTP protocol
2986 tftpboot- boot image via network using TFTP protocol
2987 and env variables "ipaddr" and "serverip"
2988 (and eventually "gatewayip")
2989 rarpboot- boot image via network using RARP/TFTP protocol
2990 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2991 loads - load S-Record file over serial line
2992 loadb - load binary file over serial line (kermit mode)
2994 mm - memory modify (auto-incrementing)
2995 nm - memory modify (constant address)
2996 mw - memory write (fill)
2998 cmp - memory compare
2999 crc32 - checksum calculation
3000 i2c - I2C sub-system
3001 sspi - SPI utility commands
3002 base - print or set address offset
3003 printenv- print environment variables
3004 setenv - set environment variables
3005 saveenv - save environment variables to persistent storage
3006 protect - enable or disable FLASH write protection
3007 erase - erase FLASH memory
3008 flinfo - print FLASH memory information
3009 bdinfo - print Board Info structure
3010 iminfo - print header information for application image
3011 coninfo - print console devices and informations
3012 ide - IDE sub-system
3013 loop - infinite loop on address range
3014 loopw - infinite write loop on address range
3015 mtest - simple RAM test
3016 icache - enable or disable instruction cache
3017 dcache - enable or disable data cache
3018 reset - Perform RESET of the CPU
3019 echo - echo args to console
3020 version - print monitor version
3021 help - print online help
3022 ? - alias for 'help'
3025 Monitor Commands - Detailed Description:
3026 ========================================
3030 For now: just type "help <command>".
3033 Environment Variables:
3034 ======================
3036 U-Boot supports user configuration using Environment Variables which
3037 can be made persistent by saving to Flash memory.
3039 Environment Variables are set using "setenv", printed using
3040 "printenv", and saved to Flash using "saveenv". Using "setenv"
3041 without a value can be used to delete a variable from the
3042 environment. As long as you don't save the environment you are
3043 working with an in-memory copy. In case the Flash area containing the
3044 environment is erased by accident, a default environment is provided.
3046 Some configuration options can be set using Environment Variables.
3048 List of environment variables (most likely not complete):
3050 baudrate - see CONFIG_BAUDRATE
3052 bootdelay - see CONFIG_BOOTDELAY
3054 bootcmd - see CONFIG_BOOTCOMMAND
3056 bootargs - Boot arguments when booting an RTOS image
3058 bootfile - Name of the image to load with TFTP
3060 bootm_low - Memory range available for image processing in the bootm
3061 command can be restricted. This variable is given as
3062 a hexadecimal number and defines lowest address allowed
3063 for use by the bootm command. See also "bootm_size"
3064 environment variable. Address defined by "bootm_low" is
3065 also the base of the initial memory mapping for the Linux
3066 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ.
3068 bootm_size - Memory range available for image processing in the bootm
3069 command can be restricted. This variable is given as
3070 a hexadecimal number and defines the size of the region
3071 allowed for use by the bootm command. See also "bootm_low"
3072 environment variable.
3074 updatefile - Location of the software update file on a TFTP server, used
3075 by the automatic software update feature. Please refer to
3076 documentation in doc/README.update for more details.
3078 autoload - if set to "no" (any string beginning with 'n'),
3079 "bootp" will just load perform a lookup of the
3080 configuration from the BOOTP server, but not try to
3081 load any image using TFTP
3083 autostart - if set to "yes", an image loaded using the "bootp",
3084 "rarpboot", "tftpboot" or "diskboot" commands will
3085 be automatically started (by internally calling
3088 If set to "no", a standalone image passed to the
3089 "bootm" command will be copied to the load address
3090 (and eventually uncompressed), but NOT be started.
3091 This can be used to load and uncompress arbitrary
3094 i2cfast - (PPC405GP|PPC405EP only)
3095 if set to 'y' configures Linux I2C driver for fast
3096 mode (400kHZ). This environment variable is used in
3097 initialization code. So, for changes to be effective
3098 it must be saved and board must be reset.
3100 initrd_high - restrict positioning of initrd images:
3101 If this variable is not set, initrd images will be
3102 copied to the highest possible address in RAM; this
3103 is usually what you want since it allows for
3104 maximum initrd size. If for some reason you want to
3105 make sure that the initrd image is loaded below the
3106 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3107 variable to a value of "no" or "off" or "0".
3108 Alternatively, you can set it to a maximum upper
3109 address to use (U-Boot will still check that it
3110 does not overwrite the U-Boot stack and data).
3112 For instance, when you have a system with 16 MB
3113 RAM, and want to reserve 4 MB from use by Linux,
3114 you can do this by adding "mem=12M" to the value of
3115 the "bootargs" variable. However, now you must make
3116 sure that the initrd image is placed in the first
3117 12 MB as well - this can be done with
3119 setenv initrd_high 00c00000
3121 If you set initrd_high to 0xFFFFFFFF, this is an
3122 indication to U-Boot that all addresses are legal
3123 for the Linux kernel, including addresses in flash
3124 memory. In this case U-Boot will NOT COPY the
3125 ramdisk at all. This may be useful to reduce the
3126 boot time on your system, but requires that this
3127 feature is supported by your Linux kernel.
3129 ipaddr - IP address; needed for tftpboot command
3131 loadaddr - Default load address for commands like "bootp",
3132 "rarpboot", "tftpboot", "loadb" or "diskboot"
3134 loads_echo - see CONFIG_LOADS_ECHO
3136 serverip - TFTP server IP address; needed for tftpboot command
3138 bootretry - see CONFIG_BOOT_RETRY_TIME
3140 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3142 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3144 ethprime - When CONFIG_NET_MULTI is enabled controls which
3145 interface is used first.
3147 ethact - When CONFIG_NET_MULTI is enabled controls which
3148 interface is currently active. For example you
3149 can do the following
3151 => setenv ethact FEC ETHERNET
3152 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
3153 => setenv ethact SCC ETHERNET
3154 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
3156 ethrotate - When set to "no" U-Boot does not go through all
3157 available network interfaces.
3158 It just stays at the currently selected interface.
3160 netretry - When set to "no" each network operation will
3161 either succeed or fail without retrying.
3162 When set to "once" the network operation will
3163 fail when all the available network interfaces
3164 are tried once without success.
3165 Useful on scripts which control the retry operation
3168 npe_ucode - set load address for the NPE microcode
3170 tftpsrcport - If this is set, the value is used for TFTP's
3173 tftpdstport - If this is set, the value is used for TFTP's UDP
3174 destination port instead of the Well Know Port 69.
3176 tftpblocksize - Block size to use for TFTP transfers; if not set,
3177 we use the TFTP server's default block size
3179 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3180 seconds, minimum value is 1000 = 1 second). Defines
3181 when a packet is considered to be lost so it has to
3182 be retransmitted. The default is 5000 = 5 seconds.
3183 Lowering this value may make downloads succeed
3184 faster in networks with high packet loss rates or
3185 with unreliable TFTP servers.
3187 vlan - When set to a value < 4095 the traffic over
3188 Ethernet is encapsulated/received over 802.1q
3191 The following environment variables may be used and automatically
3192 updated by the network boot commands ("bootp" and "rarpboot"),
3193 depending the information provided by your boot server:
3195 bootfile - see above
3196 dnsip - IP address of your Domain Name Server
3197 dnsip2 - IP address of your secondary Domain Name Server
3198 gatewayip - IP address of the Gateway (Router) to use
3199 hostname - Target hostname
3201 netmask - Subnet Mask
3202 rootpath - Pathname of the root filesystem on the NFS server
3203 serverip - see above
3206 There are two special Environment Variables:
3208 serial# - contains hardware identification information such
3209 as type string and/or serial number
3210 ethaddr - Ethernet address
3212 These variables can be set only once (usually during manufacturing of
3213 the board). U-Boot refuses to delete or overwrite these variables
3214 once they have been set once.
3217 Further special Environment Variables:
3219 ver - Contains the U-Boot version string as printed
3220 with the "version" command. This variable is
3221 readonly (see CONFIG_VERSION_VARIABLE).
3224 Please note that changes to some configuration parameters may take
3225 only effect after the next boot (yes, that's just like Windoze :-).
3228 Command Line Parsing:
3229 =====================
3231 There are two different command line parsers available with U-Boot:
3232 the old "simple" one, and the much more powerful "hush" shell:
3234 Old, simple command line parser:
3235 --------------------------------
3237 - supports environment variables (through setenv / saveenv commands)
3238 - several commands on one line, separated by ';'
3239 - variable substitution using "... ${name} ..." syntax
3240 - special characters ('$', ';') can be escaped by prefixing with '\',
3242 setenv bootcmd bootm \${address}
3243 - You can also escape text by enclosing in single apostrophes, for example:
3244 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3249 - similar to Bourne shell, with control structures like
3250 if...then...else...fi, for...do...done; while...do...done,
3251 until...do...done, ...
3252 - supports environment ("global") variables (through setenv / saveenv
3253 commands) and local shell variables (through standard shell syntax
3254 "name=value"); only environment variables can be used with "run"
3260 (1) If a command line (or an environment variable executed by a "run"
3261 command) contains several commands separated by semicolon, and
3262 one of these commands fails, then the remaining commands will be
3265 (2) If you execute several variables with one call to run (i. e.
3266 calling run with a list of variables as arguments), any failing
3267 command will cause "run" to terminate, i. e. the remaining
3268 variables are not executed.
3270 Note for Redundant Ethernet Interfaces:
3271 =======================================
3273 Some boards come with redundant Ethernet interfaces; U-Boot supports
3274 such configurations and is capable of automatic selection of a
3275 "working" interface when needed. MAC assignment works as follows:
3277 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3278 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3279 "eth1addr" (=>eth1), "eth2addr", ...
3281 If the network interface stores some valid MAC address (for instance
3282 in SROM), this is used as default address if there is NO correspon-
3283 ding setting in the environment; if the corresponding environment
3284 variable is set, this overrides the settings in the card; that means:
3286 o If the SROM has a valid MAC address, and there is no address in the
3287 environment, the SROM's address is used.
3289 o If there is no valid address in the SROM, and a definition in the
3290 environment exists, then the value from the environment variable is
3293 o If both the SROM and the environment contain a MAC address, and
3294 both addresses are the same, this MAC address is used.
3296 o If both the SROM and the environment contain a MAC address, and the
3297 addresses differ, the value from the environment is used and a
3300 o If neither SROM nor the environment contain a MAC address, an error
3303 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
3304 will be programmed into hardware as part of the initialization process. This
3305 may be skipped by setting the appropriate 'ethmacskip' environment variable.
3306 The naming convention is as follows:
3307 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
3312 U-Boot is capable of booting (and performing other auxiliary operations on)
3313 images in two formats:
3315 New uImage format (FIT)
3316 -----------------------
3318 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3319 to Flattened Device Tree). It allows the use of images with multiple
3320 components (several kernels, ramdisks, etc.), with contents protected by
3321 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3327 Old image format is based on binary files which can be basically anything,
3328 preceded by a special header; see the definitions in include/image.h for
3329 details; basically, the header defines the following image properties:
3331 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3332 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3333 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3334 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3336 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3337 IA64, MIPS, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3338 Currently supported: ARM, AVR32, Intel x86, MIPS, Nios II, PowerPC).
3339 * Compression Type (uncompressed, gzip, bzip2)
3345 The header is marked by a special Magic Number, and both the header
3346 and the data portions of the image are secured against corruption by
3353 Although U-Boot should support any OS or standalone application
3354 easily, the main focus has always been on Linux during the design of
3357 U-Boot includes many features that so far have been part of some
3358 special "boot loader" code within the Linux kernel. Also, any
3359 "initrd" images to be used are no longer part of one big Linux image;
3360 instead, kernel and "initrd" are separate images. This implementation
3361 serves several purposes:
3363 - the same features can be used for other OS or standalone
3364 applications (for instance: using compressed images to reduce the
3365 Flash memory footprint)
3367 - it becomes much easier to port new Linux kernel versions because
3368 lots of low-level, hardware dependent stuff are done by U-Boot
3370 - the same Linux kernel image can now be used with different "initrd"
3371 images; of course this also means that different kernel images can
3372 be run with the same "initrd". This makes testing easier (you don't
3373 have to build a new "zImage.initrd" Linux image when you just
3374 change a file in your "initrd"). Also, a field-upgrade of the
3375 software is easier now.
3381 Porting Linux to U-Boot based systems:
3382 ---------------------------------------
3384 U-Boot cannot save you from doing all the necessary modifications to
3385 configure the Linux device drivers for use with your target hardware
3386 (no, we don't intend to provide a full virtual machine interface to
3389 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
3391 Just make sure your machine specific header file (for instance
3392 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3393 Information structure as we define in include/asm-<arch>/u-boot.h,
3394 and make sure that your definition of IMAP_ADDR uses the same value
3395 as your U-Boot configuration in CONFIG_SYS_IMMR.
3398 Configuring the Linux kernel:
3399 -----------------------------
3401 No specific requirements for U-Boot. Make sure you have some root
3402 device (initial ramdisk, NFS) for your target system.
3405 Building a Linux Image:
3406 -----------------------
3408 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3409 not used. If you use recent kernel source, a new build target
3410 "uImage" will exist which automatically builds an image usable by
3411 U-Boot. Most older kernels also have support for a "pImage" target,
3412 which was introduced for our predecessor project PPCBoot and uses a
3413 100% compatible format.
3422 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3423 encapsulate a compressed Linux kernel image with header information,
3424 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3426 * build a standard "vmlinux" kernel image (in ELF binary format):
3428 * convert the kernel into a raw binary image:
3430 ${CROSS_COMPILE}-objcopy -O binary \
3431 -R .note -R .comment \
3432 -S vmlinux linux.bin
3434 * compress the binary image:
3438 * package compressed binary image for U-Boot:
3440 mkimage -A ppc -O linux -T kernel -C gzip \
3441 -a 0 -e 0 -n "Linux Kernel Image" \
3442 -d linux.bin.gz uImage
3445 The "mkimage" tool can also be used to create ramdisk images for use
3446 with U-Boot, either separated from the Linux kernel image, or
3447 combined into one file. "mkimage" encapsulates the images with a 64
3448 byte header containing information about target architecture,
3449 operating system, image type, compression method, entry points, time
3450 stamp, CRC32 checksums, etc.
3452 "mkimage" can be called in two ways: to verify existing images and
3453 print the header information, or to build new images.
3455 In the first form (with "-l" option) mkimage lists the information
3456 contained in the header of an existing U-Boot image; this includes
3457 checksum verification:
3459 tools/mkimage -l image
3460 -l ==> list image header information
3462 The second form (with "-d" option) is used to build a U-Boot image
3463 from a "data file" which is used as image payload:
3465 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3466 -n name -d data_file image
3467 -A ==> set architecture to 'arch'
3468 -O ==> set operating system to 'os'
3469 -T ==> set image type to 'type'
3470 -C ==> set compression type 'comp'
3471 -a ==> set load address to 'addr' (hex)
3472 -e ==> set entry point to 'ep' (hex)
3473 -n ==> set image name to 'name'
3474 -d ==> use image data from 'datafile'
3476 Right now, all Linux kernels for PowerPC systems use the same load
3477 address (0x00000000), but the entry point address depends on the
3480 - 2.2.x kernels have the entry point at 0x0000000C,
3481 - 2.3.x and later kernels have the entry point at 0x00000000.
3483 So a typical call to build a U-Boot image would read:
3485 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3486 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3487 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
3488 > examples/uImage.TQM850L
3489 Image Name: 2.4.4 kernel for TQM850L
3490 Created: Wed Jul 19 02:34:59 2000
3491 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3492 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3493 Load Address: 0x00000000
3494 Entry Point: 0x00000000
3496 To verify the contents of the image (or check for corruption):
3498 -> tools/mkimage -l examples/uImage.TQM850L
3499 Image Name: 2.4.4 kernel for TQM850L
3500 Created: Wed Jul 19 02:34:59 2000
3501 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3502 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3503 Load Address: 0x00000000
3504 Entry Point: 0x00000000
3506 NOTE: for embedded systems where boot time is critical you can trade
3507 speed for memory and install an UNCOMPRESSED image instead: this
3508 needs more space in Flash, but boots much faster since it does not
3509 need to be uncompressed:
3511 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
3512 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3513 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3514 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
3515 > examples/uImage.TQM850L-uncompressed
3516 Image Name: 2.4.4 kernel for TQM850L
3517 Created: Wed Jul 19 02:34:59 2000
3518 Image Type: PowerPC Linux Kernel Image (uncompressed)
3519 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3520 Load Address: 0x00000000
3521 Entry Point: 0x00000000
3524 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3525 when your kernel is intended to use an initial ramdisk:
3527 -> tools/mkimage -n 'Simple Ramdisk Image' \
3528 > -A ppc -O linux -T ramdisk -C gzip \
3529 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3530 Image Name: Simple Ramdisk Image
3531 Created: Wed Jan 12 14:01:50 2000
3532 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3533 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3534 Load Address: 0x00000000
3535 Entry Point: 0x00000000
3538 Installing a Linux Image:
3539 -------------------------
3541 To downloading a U-Boot image over the serial (console) interface,
3542 you must convert the image to S-Record format:
3544 objcopy -I binary -O srec examples/image examples/image.srec
3546 The 'objcopy' does not understand the information in the U-Boot
3547 image header, so the resulting S-Record file will be relative to
3548 address 0x00000000. To load it to a given address, you need to
3549 specify the target address as 'offset' parameter with the 'loads'
3552 Example: install the image to address 0x40100000 (which on the
3553 TQM8xxL is in the first Flash bank):
3555 => erase 40100000 401FFFFF
3561 ## Ready for S-Record download ...
3562 ~>examples/image.srec
3563 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3565 15989 15990 15991 15992
3566 [file transfer complete]
3568 ## Start Addr = 0x00000000
3571 You can check the success of the download using the 'iminfo' command;
3572 this includes a checksum verification so you can be sure no data
3573 corruption happened:
3577 ## Checking Image at 40100000 ...
3578 Image Name: 2.2.13 for initrd on TQM850L
3579 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3580 Data Size: 335725 Bytes = 327 kB = 0 MB
3581 Load Address: 00000000
3582 Entry Point: 0000000c
3583 Verifying Checksum ... OK
3589 The "bootm" command is used to boot an application that is stored in
3590 memory (RAM or Flash). In case of a Linux kernel image, the contents
3591 of the "bootargs" environment variable is passed to the kernel as
3592 parameters. You can check and modify this variable using the
3593 "printenv" and "setenv" commands:
3596 => printenv bootargs
3597 bootargs=root=/dev/ram
3599 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3601 => printenv bootargs
3602 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3605 ## Booting Linux kernel at 40020000 ...
3606 Image Name: 2.2.13 for NFS on TQM850L
3607 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3608 Data Size: 381681 Bytes = 372 kB = 0 MB
3609 Load Address: 00000000
3610 Entry Point: 0000000c
3611 Verifying Checksum ... OK
3612 Uncompressing Kernel Image ... OK
3613 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
3614 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3615 time_init: decrementer frequency = 187500000/60
3616 Calibrating delay loop... 49.77 BogoMIPS
3617 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3620 If you want to boot a Linux kernel with initial RAM disk, you pass
3621 the memory addresses of both the kernel and the initrd image (PPBCOOT
3622 format!) to the "bootm" command:
3624 => imi 40100000 40200000
3626 ## Checking Image at 40100000 ...
3627 Image Name: 2.2.13 for initrd on TQM850L
3628 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3629 Data Size: 335725 Bytes = 327 kB = 0 MB
3630 Load Address: 00000000
3631 Entry Point: 0000000c
3632 Verifying Checksum ... OK
3634 ## Checking Image at 40200000 ...
3635 Image Name: Simple Ramdisk Image
3636 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3637 Data Size: 566530 Bytes = 553 kB = 0 MB
3638 Load Address: 00000000
3639 Entry Point: 00000000
3640 Verifying Checksum ... OK
3642 => bootm 40100000 40200000
3643 ## Booting Linux kernel at 40100000 ...
3644 Image Name: 2.2.13 for initrd on TQM850L
3645 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3646 Data Size: 335725 Bytes = 327 kB = 0 MB
3647 Load Address: 00000000
3648 Entry Point: 0000000c
3649 Verifying Checksum ... OK
3650 Uncompressing Kernel Image ... OK
3651 ## Loading RAMDisk Image at 40200000 ...
3652 Image Name: Simple Ramdisk Image
3653 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3654 Data Size: 566530 Bytes = 553 kB = 0 MB
3655 Load Address: 00000000
3656 Entry Point: 00000000
3657 Verifying Checksum ... OK
3658 Loading Ramdisk ... OK
3659 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
3660 Boot arguments: root=/dev/ram
3661 time_init: decrementer frequency = 187500000/60
3662 Calibrating delay loop... 49.77 BogoMIPS
3664 RAMDISK: Compressed image found at block 0
3665 VFS: Mounted root (ext2 filesystem).
3669 Boot Linux and pass a flat device tree:
3672 First, U-Boot must be compiled with the appropriate defines. See the section
3673 titled "Linux Kernel Interface" above for a more in depth explanation. The
3674 following is an example of how to start a kernel and pass an updated
3680 oft=oftrees/mpc8540ads.dtb
3681 => tftp $oftaddr $oft
3682 Speed: 1000, full duplex
3684 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3685 Filename 'oftrees/mpc8540ads.dtb'.
3686 Load address: 0x300000
3689 Bytes transferred = 4106 (100a hex)
3690 => tftp $loadaddr $bootfile
3691 Speed: 1000, full duplex
3693 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3695 Load address: 0x200000
3696 Loading:############
3698 Bytes transferred = 1029407 (fb51f hex)
3703 => bootm $loadaddr - $oftaddr
3704 ## Booting image at 00200000 ...
3705 Image Name: Linux-2.6.17-dirty
3706 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3707 Data Size: 1029343 Bytes = 1005.2 kB
3708 Load Address: 00000000
3709 Entry Point: 00000000
3710 Verifying Checksum ... OK
3711 Uncompressing Kernel Image ... OK
3712 Booting using flat device tree at 0x300000
3713 Using MPC85xx ADS machine description
3714 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3718 More About U-Boot Image Types:
3719 ------------------------------
3721 U-Boot supports the following image types:
3723 "Standalone Programs" are directly runnable in the environment
3724 provided by U-Boot; it is expected that (if they behave
3725 well) you can continue to work in U-Boot after return from
3726 the Standalone Program.
3727 "OS Kernel Images" are usually images of some Embedded OS which
3728 will take over control completely. Usually these programs
3729 will install their own set of exception handlers, device
3730 drivers, set up the MMU, etc. - this means, that you cannot
3731 expect to re-enter U-Boot except by resetting the CPU.
3732 "RAMDisk Images" are more or less just data blocks, and their
3733 parameters (address, size) are passed to an OS kernel that is
3735 "Multi-File Images" contain several images, typically an OS
3736 (Linux) kernel image and one or more data images like
3737 RAMDisks. This construct is useful for instance when you want
3738 to boot over the network using BOOTP etc., where the boot
3739 server provides just a single image file, but you want to get
3740 for instance an OS kernel and a RAMDisk image.
3742 "Multi-File Images" start with a list of image sizes, each
3743 image size (in bytes) specified by an "uint32_t" in network
3744 byte order. This list is terminated by an "(uint32_t)0".
3745 Immediately after the terminating 0 follow the images, one by
3746 one, all aligned on "uint32_t" boundaries (size rounded up to
3747 a multiple of 4 bytes).
3749 "Firmware Images" are binary images containing firmware (like
3750 U-Boot or FPGA images) which usually will be programmed to
3753 "Script files" are command sequences that will be executed by
3754 U-Boot's command interpreter; this feature is especially
3755 useful when you configure U-Boot to use a real shell (hush)
3756 as command interpreter.
3762 One of the features of U-Boot is that you can dynamically load and
3763 run "standalone" applications, which can use some resources of
3764 U-Boot like console I/O functions or interrupt services.
3766 Two simple examples are included with the sources:
3771 'examples/hello_world.c' contains a small "Hello World" Demo
3772 application; it is automatically compiled when you build U-Boot.
3773 It's configured to run at address 0x00040004, so you can play with it
3777 ## Ready for S-Record download ...
3778 ~>examples/hello_world.srec
3779 1 2 3 4 5 6 7 8 9 10 11 ...
3780 [file transfer complete]
3782 ## Start Addr = 0x00040004
3784 => go 40004 Hello World! This is a test.
3785 ## Starting application at 0x00040004 ...
3796 Hit any key to exit ...
3798 ## Application terminated, rc = 0x0
3800 Another example, which demonstrates how to register a CPM interrupt
3801 handler with the U-Boot code, can be found in 'examples/timer.c'.
3802 Here, a CPM timer is set up to generate an interrupt every second.
3803 The interrupt service routine is trivial, just printing a '.'
3804 character, but this is just a demo program. The application can be
3805 controlled by the following keys:
3807 ? - print current values og the CPM Timer registers
3808 b - enable interrupts and start timer
3809 e - stop timer and disable interrupts
3810 q - quit application
3813 ## Ready for S-Record download ...
3814 ~>examples/timer.srec
3815 1 2 3 4 5 6 7 8 9 10 11 ...
3816 [file transfer complete]
3818 ## Start Addr = 0x00040004
3821 ## Starting application at 0x00040004 ...
3824 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3827 [q, b, e, ?] Set interval 1000000 us
3830 [q, b, e, ?] ........
3831 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3834 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3837 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3840 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3842 [q, b, e, ?] ...Stopping timer
3844 [q, b, e, ?] ## Application terminated, rc = 0x0
3850 Over time, many people have reported problems when trying to use the
3851 "minicom" terminal emulation program for serial download. I (wd)
3852 consider minicom to be broken, and recommend not to use it. Under
3853 Unix, I recommend to use C-Kermit for general purpose use (and
3854 especially for kermit binary protocol download ("loadb" command), and
3855 use "cu" for S-Record download ("loads" command).
3857 Nevertheless, if you absolutely want to use it try adding this
3858 configuration to your "File transfer protocols" section:
3860 Name Program Name U/D FullScr IO-Red. Multi
3861 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3862 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3868 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3869 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3871 Building requires a cross environment; it is known to work on
3872 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3873 need gmake since the Makefiles are not compatible with BSD make).
3874 Note that the cross-powerpc package does not install include files;
3875 attempting to build U-Boot will fail because <machine/ansi.h> is
3876 missing. This file has to be installed and patched manually:
3878 # cd /usr/pkg/cross/powerpc-netbsd/include
3880 # ln -s powerpc machine
3881 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3882 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3884 Native builds *don't* work due to incompatibilities between native
3885 and U-Boot include files.
3887 Booting assumes that (the first part of) the image booted is a
3888 stage-2 loader which in turn loads and then invokes the kernel
3889 proper. Loader sources will eventually appear in the NetBSD source
3890 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3891 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3894 Implementation Internals:
3895 =========================
3897 The following is not intended to be a complete description of every
3898 implementation detail. However, it should help to understand the
3899 inner workings of U-Boot and make it easier to port it to custom
3903 Initial Stack, Global Data:
3904 ---------------------------
3906 The implementation of U-Boot is complicated by the fact that U-Boot
3907 starts running out of ROM (flash memory), usually without access to
3908 system RAM (because the memory controller is not initialized yet).
3909 This means that we don't have writable Data or BSS segments, and BSS
3910 is not initialized as zero. To be able to get a C environment working
3911 at all, we have to allocate at least a minimal stack. Implementation
3912 options for this are defined and restricted by the CPU used: Some CPU
3913 models provide on-chip memory (like the IMMR area on MPC8xx and
3914 MPC826x processors), on others (parts of) the data cache can be
3915 locked as (mis-) used as memory, etc.
3917 Chris Hallinan posted a good summary of these issues to the
3918 U-Boot mailing list:
3920 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3921 From: "Chris Hallinan" <clh@net1plus.com>
3922 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3925 Correct me if I'm wrong, folks, but the way I understand it
3926 is this: Using DCACHE as initial RAM for Stack, etc, does not
3927 require any physical RAM backing up the cache. The cleverness
3928 is that the cache is being used as a temporary supply of
3929 necessary storage before the SDRAM controller is setup. It's
3930 beyond the scope of this list to explain the details, but you
3931 can see how this works by studying the cache architecture and
3932 operation in the architecture and processor-specific manuals.
3934 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3935 is another option for the system designer to use as an
3936 initial stack/RAM area prior to SDRAM being available. Either
3937 option should work for you. Using CS 4 should be fine if your
3938 board designers haven't used it for something that would
3939 cause you grief during the initial boot! It is frequently not
3942 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
3943 with your processor/board/system design. The default value
3944 you will find in any recent u-boot distribution in
3945 walnut.h should work for you. I'd set it to a value larger
3946 than your SDRAM module. If you have a 64MB SDRAM module, set
3947 it above 400_0000. Just make sure your board has no resources
3948 that are supposed to respond to that address! That code in
3949 start.S has been around a while and should work as is when
3950 you get the config right.
3955 It is essential to remember this, since it has some impact on the C
3956 code for the initialization procedures:
3958 * Initialized global data (data segment) is read-only. Do not attempt
3961 * Do not use any uninitialized global data (or implicitely initialized
3962 as zero data - BSS segment) at all - this is undefined, initiali-
3963 zation is performed later (when relocating to RAM).
3965 * Stack space is very limited. Avoid big data buffers or things like
3968 Having only the stack as writable memory limits means we cannot use
3969 normal global data to share information beween the code. But it
3970 turned out that the implementation of U-Boot can be greatly
3971 simplified by making a global data structure (gd_t) available to all
3972 functions. We could pass a pointer to this data as argument to _all_
3973 functions, but this would bloat the code. Instead we use a feature of
3974 the GCC compiler (Global Register Variables) to share the data: we
3975 place a pointer (gd) to the global data into a register which we
3976 reserve for this purpose.
3978 When choosing a register for such a purpose we are restricted by the
3979 relevant (E)ABI specifications for the current architecture, and by
3980 GCC's implementation.
3982 For PowerPC, the following registers have specific use:
3984 R2: reserved for system use
3985 R3-R4: parameter passing and return values
3986 R5-R10: parameter passing
3987 R13: small data area pointer
3991 (U-Boot also uses R12 as internal GOT pointer. r12
3992 is a volatile register so r12 needs to be reset when
3993 going back and forth between asm and C)
3995 ==> U-Boot will use R2 to hold a pointer to the global data
3997 Note: on PPC, we could use a static initializer (since the
3998 address of the global data structure is known at compile time),
3999 but it turned out that reserving a register results in somewhat
4000 smaller code - although the code savings are not that big (on
4001 average for all boards 752 bytes for the whole U-Boot image,
4002 624 text + 127 data).
4004 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
4005 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
4007 ==> U-Boot will use P3 to hold a pointer to the global data
4009 On ARM, the following registers are used:
4011 R0: function argument word/integer result
4012 R1-R3: function argument word
4014 R10: stack limit (used only if stack checking if enabled)
4015 R11: argument (frame) pointer
4016 R12: temporary workspace
4019 R15: program counter
4021 ==> U-Boot will use R8 to hold a pointer to the global data
4023 On Nios II, the ABI is documented here:
4024 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4026 ==> U-Boot will use gp to hold a pointer to the global data
4028 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4029 to access small data sections, so gp is free.
4031 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4032 or current versions of GCC may "optimize" the code too much.
4037 U-Boot runs in system state and uses physical addresses, i.e. the
4038 MMU is not used either for address mapping nor for memory protection.
4040 The available memory is mapped to fixed addresses using the memory
4041 controller. In this process, a contiguous block is formed for each
4042 memory type (Flash, SDRAM, SRAM), even when it consists of several
4043 physical memory banks.
4045 U-Boot is installed in the first 128 kB of the first Flash bank (on
4046 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4047 booting and sizing and initializing DRAM, the code relocates itself
4048 to the upper end of DRAM. Immediately below the U-Boot code some
4049 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
4050 configuration setting]. Below that, a structure with global Board
4051 Info data is placed, followed by the stack (growing downward).
4053 Additionally, some exception handler code is copied to the low 8 kB
4054 of DRAM (0x00000000 ... 0x00001FFF).
4056 So a typical memory configuration with 16 MB of DRAM could look like
4059 0x0000 0000 Exception Vector code
4062 0x0000 2000 Free for Application Use
4068 0x00FB FF20 Monitor Stack (Growing downward)
4069 0x00FB FFAC Board Info Data and permanent copy of global data
4070 0x00FC 0000 Malloc Arena
4073 0x00FE 0000 RAM Copy of Monitor Code
4074 ... eventually: LCD or video framebuffer
4075 ... eventually: pRAM (Protected RAM - unchanged by reset)
4076 0x00FF FFFF [End of RAM]
4079 System Initialization:
4080 ----------------------
4082 In the reset configuration, U-Boot starts at the reset entry point
4083 (on most PowerPC systems at address 0x00000100). Because of the reset
4084 configuration for CS0# this is a mirror of the onboard Flash memory.
4085 To be able to re-map memory U-Boot then jumps to its link address.
4086 To be able to implement the initialization code in C, a (small!)
4087 initial stack is set up in the internal Dual Ported RAM (in case CPUs
4088 which provide such a feature like MPC8xx or MPC8260), or in a locked
4089 part of the data cache. After that, U-Boot initializes the CPU core,
4090 the caches and the SIU.
4092 Next, all (potentially) available memory banks are mapped using a
4093 preliminary mapping. For example, we put them on 512 MB boundaries
4094 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4095 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4096 programmed for SDRAM access. Using the temporary configuration, a
4097 simple memory test is run that determines the size of the SDRAM
4100 When there is more than one SDRAM bank, and the banks are of
4101 different size, the largest is mapped first. For equal size, the first
4102 bank (CS2#) is mapped first. The first mapping is always for address
4103 0x00000000, with any additional banks following immediately to create
4104 contiguous memory starting from 0.
4106 Then, the monitor installs itself at the upper end of the SDRAM area
4107 and allocates memory for use by malloc() and for the global Board
4108 Info data; also, the exception vector code is copied to the low RAM
4109 pages, and the final stack is set up.
4111 Only after this relocation will you have a "normal" C environment;
4112 until that you are restricted in several ways, mostly because you are
4113 running from ROM, and because the code will have to be relocated to a
4117 U-Boot Porting Guide:
4118 ----------------------
4120 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4124 int main(int argc, char *argv[])
4126 sighandler_t no_more_time;
4128 signal(SIGALRM, no_more_time);
4129 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4131 if (available_money > available_manpower) {
4132 Pay consultant to port U-Boot;
4136 Download latest U-Boot source;
4138 Subscribe to u-boot mailing list;
4141 email("Hi, I am new to U-Boot, how do I get started?");
4144 Read the README file in the top level directory;
4145 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4146 Read applicable doc/*.README;
4147 Read the source, Luke;
4148 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4151 if (available_money > toLocalCurrency ($2500))
4154 Add a lot of aggravation and time;
4156 if (a similar board exists) { /* hopefully... */
4157 cp -a board/<similar> board/<myboard>
4158 cp include/configs/<similar>.h include/configs/<myboard>.h
4160 Create your own board support subdirectory;
4161 Create your own board include/configs/<myboard>.h file;
4163 Edit new board/<myboard> files
4164 Edit new include/configs/<myboard>.h
4169 Add / modify source code;
4173 email("Hi, I am having problems...");
4175 Send patch file to the U-Boot email list;
4176 if (reasonable critiques)
4177 Incorporate improvements from email list code review;
4179 Defend code as written;
4185 void no_more_time (int sig)
4194 All contributions to U-Boot should conform to the Linux kernel
4195 coding style; see the file "Documentation/CodingStyle" and the script
4196 "scripts/Lindent" in your Linux kernel source directory. In sources
4197 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
4198 spaces before parameters to function calls) is actually used.
4200 Source files originating from a different project (for example the
4201 MTD subsystem) are generally exempt from these guidelines and are not
4202 reformated to ease subsequent migration to newer versions of those
4205 Please note that U-Boot is implemented in C (and to some small parts in
4206 Assembler); no C++ is used, so please do not use C++ style comments (//)
4209 Please also stick to the following formatting rules:
4210 - remove any trailing white space
4211 - use TAB characters for indentation, not spaces
4212 - make sure NOT to use DOS '\r\n' line feeds
4213 - do not add more than 2 empty lines to source files
4214 - do not add trailing empty lines to source files
4216 Submissions which do not conform to the standards may be returned
4217 with a request to reformat the changes.
4223 Since the number of patches for U-Boot is growing, we need to
4224 establish some rules. Submissions which do not conform to these rules
4225 may be rejected, even when they contain important and valuable stuff.
4227 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4229 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4230 see http://lists.denx.de/mailman/listinfo/u-boot
4232 When you send a patch, please include the following information with
4235 * For bug fixes: a description of the bug and how your patch fixes
4236 this bug. Please try to include a way of demonstrating that the
4237 patch actually fixes something.
4239 * For new features: a description of the feature and your
4242 * A CHANGELOG entry as plaintext (separate from the patch)
4244 * For major contributions, your entry to the CREDITS file
4246 * When you add support for a new board, don't forget to add this
4247 board to the MAKEALL script, too.
4249 * If your patch adds new configuration options, don't forget to
4250 document these in the README file.
4252 * The patch itself. If you are using git (which is *strongly*
4253 recommended) you can easily generate the patch using the
4254 "git-format-patch". If you then use "git-send-email" to send it to
4255 the U-Boot mailing list, you will avoid most of the common problems
4256 with some other mail clients.
4258 If you cannot use git, use "diff -purN OLD NEW". If your version of
4259 diff does not support these options, then get the latest version of
4262 The current directory when running this command shall be the parent
4263 directory of the U-Boot source tree (i. e. please make sure that
4264 your patch includes sufficient directory information for the
4267 We prefer patches as plain text. MIME attachments are discouraged,
4268 and compressed attachments must not be used.
4270 * If one logical set of modifications affects or creates several
4271 files, all these changes shall be submitted in a SINGLE patch file.
4273 * Changesets that contain different, unrelated modifications shall be
4274 submitted as SEPARATE patches, one patch per changeset.
4279 * Before sending the patch, run the MAKEALL script on your patched
4280 source tree and make sure that no errors or warnings are reported
4281 for any of the boards.
4283 * Keep your modifications to the necessary minimum: A patch
4284 containing several unrelated changes or arbitrary reformats will be
4285 returned with a request to re-formatting / split it.
4287 * If you modify existing code, make sure that your new code does not
4288 add to the memory footprint of the code ;-) Small is beautiful!
4289 When adding new features, these should compile conditionally only
4290 (using #ifdef), and the resulting code with the new feature
4291 disabled must not need more memory than the old code without your
4294 * Remember that there is a size limit of 100 kB per message on the
4295 u-boot mailing list. Bigger patches will be moderated. If they are
4296 reasonable and not too big, they will be acknowledged. But patches
4297 bigger than the size limit should be avoided.
projects / u-boot / blob