2 # (C) Copyright 2000 - 2005
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.
60 In case you have questions about, problems with or contributions for
61 U-Boot you should send a message to the U-Boot mailing list at
62 <u-boot-users@lists.sourceforge.net>. There is also an archive of
63 previous traffic on the mailing list - please search the archive
64 before asking FAQ's. Please see
65 http://lists.sourceforge.net/lists/listinfo/u-boot-users/
71 - start from 8xxrom sources
72 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
74 - make it easier to add custom boards
75 - make it possible to add other [PowerPC] CPUs
76 - extend functions, especially:
77 * Provide extended interface to Linux boot loader
80 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot
81 - create ARMBoot project (http://sourceforge.net/projects/armboot)
82 - add other CPU families (starting with ARM)
83 - create U-Boot project (http://sourceforge.net/projects/u-boot)
89 The "official" name of this project is "Das U-Boot". The spelling
90 "U-Boot" shall be used in all written text (documentation, comments
91 in source files etc.). Example:
93 This is the README file for the U-Boot project.
95 File names etc. shall be based on the string "u-boot". Examples:
97 include/asm-ppc/u-boot.h
99 #include <asm/u-boot.h>
101 Variable names, preprocessor constants etc. shall be either based on
102 the string "u_boot" or on "U_BOOT". Example:
104 U_BOOT_VERSION u_boot_logo
105 IH_OS_U_BOOT u_boot_hush_start
111 U-Boot uses a 3 level version number containing a version, a
112 sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2",
113 sub-version "34", and patchlevel "4".
115 The patchlevel is used to indicate certain stages of development
116 between released versions, i. e. officially released versions of
117 U-Boot will always have a patchlevel of "0".
123 - board Board dependent files
124 - common Misc architecture independent functions
125 - cpu CPU specific files
126 - 74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
127 - arm720t Files specific to ARM 720 CPUs
128 - arm920t Files specific to ARM 920 CPUs
129 - at91rm9200 Files specific to Atmel AT91RM9200 CPU
130 - imx Files specific to Freescale MC9328 i.MX CPUs
131 - s3c24x0 Files specific to Samsung S3C24X0 CPUs
132 - arm925t Files specific to ARM 925 CPUs
133 - arm926ejs Files specific to ARM 926 CPUs
134 - arm1136 Files specific to ARM 1136 CPUs
135 - at32ap Files specific to Atmel AVR32 AP CPUs
136 - i386 Files specific to i386 CPUs
137 - ixp Files specific to Intel XScale IXP CPUs
138 - mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
139 - mips Files specific to MIPS CPUs
140 - mpc5xx Files specific to Freescale MPC5xx CPUs
141 - mpc5xxx Files specific to Freescale MPC5xxx CPUs
142 - mpc8xx Files specific to Freescale MPC8xx CPUs
143 - mpc8220 Files specific to Freescale MPC8220 CPUs
144 - mpc824x Files specific to Freescale MPC824x CPUs
145 - mpc8260 Files specific to Freescale MPC8260 CPUs
146 - mpc85xx Files specific to Freescale MPC85xx CPUs
147 - nios Files specific to Altera NIOS CPUs
148 - nios2 Files specific to Altera Nios-II CPUs
149 - ppc4xx Files specific to AMCC PowerPC 4xx CPUs
150 - pxa Files specific to Intel XScale PXA CPUs
151 - s3c44b0 Files specific to Samsung S3C44B0 CPUs
152 - sa1100 Files specific to Intel StrongARM SA1100 CPUs
153 - disk Code for disk drive partition handling
154 - doc Documentation (don't expect too much)
155 - drivers Commonly used device drivers
156 - dtt Digital Thermometer and Thermostat drivers
157 - examples Example code for standalone applications, etc.
158 - include Header Files
159 - lib_arm Files generic to ARM architecture
160 - lib_avr32 Files generic to AVR32 architecture
161 - lib_generic Files generic to all architectures
162 - lib_i386 Files generic to i386 architecture
163 - lib_m68k Files generic to m68k architecture
164 - lib_mips Files generic to MIPS architecture
165 - lib_nios Files generic to NIOS architecture
166 - lib_ppc Files generic to PowerPC architecture
167 - libfdt Library files to support flattened device trees
168 - net Networking code
169 - post Power On Self Test
170 - rtc Real Time Clock drivers
171 - tools Tools to build S-Record or U-Boot images, etc.
173 Software Configuration:
174 =======================
176 Configuration is usually done using C preprocessor defines; the
177 rationale behind that is to avoid dead code whenever possible.
179 There are two classes of configuration variables:
181 * Configuration _OPTIONS_:
182 These are selectable by the user and have names beginning with
185 * Configuration _SETTINGS_:
186 These depend on the hardware etc. and should not be meddled with if
187 you don't know what you're doing; they have names beginning with
190 Later we will add a configuration tool - probably similar to or even
191 identical to what's used for the Linux kernel. Right now, we have to
192 do the configuration by hand, which means creating some symbolic
193 links and editing some configuration files. We use the TQM8xxL boards
197 Selection of Processor Architecture and Board Type:
198 ---------------------------------------------------
200 For all supported boards there are ready-to-use default
201 configurations available; just type "make <board_name>_config".
203 Example: For a TQM823L module type:
208 For the Cogent platform, you need to specify the cpu type as well;
209 e.g. "make cogent_mpc8xx_config". And also configure the cogent
210 directory according to the instructions in cogent/README.
213 Configuration Options:
214 ----------------------
216 Configuration depends on the combination of board and CPU type; all
217 such information is kept in a configuration file
218 "include/configs/<board_name>.h".
220 Example: For a TQM823L module, all configuration settings are in
221 "include/configs/TQM823L.h".
224 Many of the options are named exactly as the corresponding Linux
225 kernel configuration options. The intention is to make it easier to
226 build a config tool - later.
229 The following options need to be configured:
231 - CPU Type: Define exactly one of
235 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860
238 or CONFIG_MPC824X, CONFIG_MPC8260
255 MicroBlaze based CPUs:
256 ----------------------
260 ----------------------
264 ----------------------
267 - Board Type: Define exactly one of
269 PowerPC based boards:
270 ---------------------
272 CONFIG_ADCIOP CONFIG_FPS860L CONFIG_OXC
273 CONFIG_ADS860 CONFIG_GEN860T CONFIG_PCI405
274 CONFIG_AMX860 CONFIG_GENIETV CONFIG_PCIPPC2
275 CONFIG_AP1000 CONFIG_GTH CONFIG_PCIPPC6
276 CONFIG_AR405 CONFIG_gw8260 CONFIG_pcu_e
277 CONFIG_BAB7xx CONFIG_hermes CONFIG_PIP405
278 CONFIG_BC3450 CONFIG_hymod CONFIG_PM826
279 CONFIG_c2mon CONFIG_IAD210 CONFIG_ppmc8260
280 CONFIG_CANBT CONFIG_ICU862 CONFIG_QS823
281 CONFIG_CCM CONFIG_IP860 CONFIG_QS850
282 CONFIG_CMI CONFIG_IPHASE4539 CONFIG_QS860T
283 CONFIG_cogent_mpc8260 CONFIG_IVML24 CONFIG_RBC823
284 CONFIG_cogent_mpc8xx CONFIG_IVML24_128 CONFIG_RPXClassic
285 CONFIG_CPCI405 CONFIG_IVML24_256 CONFIG_RPXlite
286 CONFIG_CPCI4052 CONFIG_IVMS8 CONFIG_RPXsuper
287 CONFIG_CPCIISER4 CONFIG_IVMS8_128 CONFIG_rsdproto
288 CONFIG_CPU86 CONFIG_IVMS8_256 CONFIG_sacsng
289 CONFIG_CRAYL1 CONFIG_JSE CONFIG_Sandpoint8240
290 CONFIG_CSB272 CONFIG_LANTEC CONFIG_Sandpoint8245
291 CONFIG_CU824 CONFIG_LITE5200B CONFIG_sbc8260
292 CONFIG_DASA_SIM CONFIG_lwmon CONFIG_sbc8560
293 CONFIG_DB64360 CONFIG_MBX CONFIG_SM850
294 CONFIG_DB64460 CONFIG_MBX860T CONFIG_SPD823TS
295 CONFIG_DU405 CONFIG_MHPC CONFIG_STXGP3
296 CONFIG_DUET_ADS CONFIG_MIP405 CONFIG_SXNI855T
297 CONFIG_EBONY CONFIG_MOUSSE CONFIG_TQM823L
298 CONFIG_ELPPC CONFIG_MPC8260ADS CONFIG_TQM8260
299 CONFIG_ELPT860 CONFIG_MPC8540ADS CONFIG_TQM850L
300 CONFIG_ep8260 CONFIG_MPC8540EVAL CONFIG_TQM855L
301 CONFIG_ERIC CONFIG_MPC8560ADS CONFIG_TQM860L
302 CONFIG_ESTEEM192E CONFIG_MUSENKI CONFIG_TTTech
303 CONFIG_ETX094 CONFIG_MVS1 CONFIG_UTX8245
304 CONFIG_EVB64260 CONFIG_NETPHONE CONFIG_V37
305 CONFIG_FADS823 CONFIG_NETTA CONFIG_W7OLMC
306 CONFIG_FADS850SAR CONFIG_NETVIA CONFIG_W7OLMG
307 CONFIG_FADS860T CONFIG_NX823 CONFIG_WALNUT
308 CONFIG_FLAGADM CONFIG_OCRTC CONFIG_ZPC1900
309 CONFIG_FPS850L CONFIG_ORSG CONFIG_ZUMA
314 CONFIG_ARMADILLO, CONFIG_AT91RM9200DK, CONFIG_CERF250,
315 CONFIG_CSB637, CONFIG_DELTA, CONFIG_DNP1110,
316 CONFIG_EP7312, CONFIG_H2_OMAP1610, CONFIG_HHP_CRADLE,
317 CONFIG_IMPA7, CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610,
318 CONFIG_KB9202, CONFIG_LART, CONFIG_LPD7A400,
319 CONFIG_LUBBOCK, CONFIG_OSK_OMAP5912, CONFIG_OMAP2420H4,
320 CONFIG_PLEB2, CONFIG_SHANNON, CONFIG_P2_OMAP730,
321 CONFIG_SMDK2400, CONFIG_SMDK2410, CONFIG_TRAB,
324 MicroBlaze based boards:
325 ------------------------
330 ------------------------
332 CONFIG_PCI5441 CONFIG_PK1C20
333 CONFIG_EP1C20 CONFIG_EP1S10 CONFIG_EP1S40
340 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
341 Define exactly one of
345 - CPU Module Type: (if CONFIG_COGENT is defined)
346 Define exactly one of
348 --- FIXME --- not tested yet:
349 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
350 CONFIG_CMA287_23, CONFIG_CMA287_50
352 - Motherboard Type: (if CONFIG_COGENT is defined)
353 Define exactly one of
354 CONFIG_CMA101, CONFIG_CMA102
356 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
357 Define one or more of
360 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
361 Define one or more of
362 CONFIG_LCD_HEARTBEAT - update a character position on
363 the lcd display every second with
366 - Board flavour: (if CONFIG_MPC8260ADS is defined)
369 CFG_8260ADS - original MPC8260ADS
370 CFG_8266ADS - MPC8266ADS
371 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
372 CFG_8272ADS - MPC8272ADS
374 - MPC824X Family Member (if CONFIG_MPC824X is defined)
375 Define exactly one of
376 CONFIG_MPC8240, CONFIG_MPC8245
378 - 8xx CPU Options: (if using an MPC8xx cpu)
379 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
380 get_gclk_freq() cannot work
381 e.g. if there is no 32KHz
382 reference PIT/RTC clock
383 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
386 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
389 CONFIG_8xx_CPUCLK_DEFAULT
390 See doc/README.MPC866
394 Define this to measure the actual CPU clock instead
395 of relying on the correctness of the configured
396 values. Mostly useful for board bringup to make sure
397 the PLL is locked at the intended frequency. Note
398 that this requires a (stable) reference clock (32 kHz
399 RTC clock or CFG_8XX_XIN)
401 - Intel Monahans options:
402 CFG_MONAHANS_RUN_MODE_OSC_RATIO
404 Defines the Monahans run mode to oscillator
405 ratio. Valid values are 8, 16, 24, 31. The core
406 frequency is this value multiplied by 13 MHz.
408 CFG_MONAHANS_TURBO_RUN_MODE_RATIO
410 Defines the Monahans turbo mode to oscillator
411 ratio. Valid values are 1 (default if undefined) and
412 2. The core frequency as calculated above is multiplied
415 - Linux Kernel Interface:
418 U-Boot stores all clock information in Hz
419 internally. For binary compatibility with older Linux
420 kernels (which expect the clocks passed in the
421 bd_info data to be in MHz) the environment variable
422 "clocks_in_mhz" can be defined so that U-Boot
423 converts clock data to MHZ before passing it to the
425 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
426 "clocks_in_mhz=1" is automatically included in the
429 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
431 When transfering memsize parameter to linux, some versions
432 expect it to be in bytes, others in MB.
433 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
435 CONFIG_OF_LIBFDT / CONFIG_OF_FLAT_TREE
437 New kernel versions are expecting firmware settings to be
438 passed using flattened device trees (based on open firmware
442 * New libfdt-based support
443 * Adds the "fdt" command
444 * The bootm command does _not_ modify the fdt
447 * Deprecated, see CONFIG_OF_LIBFDT
448 * Original ft_build.c-based support
449 * Automatically modifies the dft as part of the bootm command
450 * The environment variable "disable_of", when set,
451 disables this functionality.
453 CONFIG_OF_FLAT_TREE_MAX_SIZE
455 The maximum size of the constructed OF tree.
457 OF_CPU - The proper name of the cpus node.
458 OF_SOC - The proper name of the soc node.
459 OF_TBCLK - The timebase frequency.
460 OF_STDOUT_PATH - The path to the console device
464 * CONFIG_OF_LIBFDT - enables the "fdt bd_t" command
465 * CONFIG_OF_FLAT_TREE - The resulting flat device tree
466 will have a copy of the bd_t. Space should be
467 pre-allocated in the dts for the bd_t.
469 CONFIG_OF_HAS_UBOOT_ENV
471 * CONFIG_OF_LIBFDT - enables the "fdt bd_t" command
472 * CONFIG_OF_FLAT_TREE - The resulting flat device tree
473 will have a copy of u-boot's environment variables
475 CONFIG_OF_BOARD_SETUP
477 Board code has addition modification that it wants to make
478 to the flat device tree before handing it off to the kernel
482 This define fills in the correct boot cpu in the boot
483 param header, the default value is zero if undefined.
488 Define this if you want support for Amba PrimeCell PL010 UARTs.
492 Define this if you want support for Amba PrimeCell PL011 UARTs.
496 If you have Amba PrimeCell PL011 UARTs, set this variable to
497 the clock speed of the UARTs.
501 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
502 define this to a list of base addresses for each (supported)
503 port. See e.g. include/configs/versatile.h
507 Depending on board, define exactly one serial port
508 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
509 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
510 console by defining CONFIG_8xx_CONS_NONE
512 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
513 port routines must be defined elsewhere
514 (i.e. serial_init(), serial_getc(), ...)
517 Enables console device for a color framebuffer. Needs following
518 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
519 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
521 VIDEO_HW_RECTFILL graphic chip supports
524 VIDEO_HW_BITBLT graphic chip supports
525 bit-blit (cf. smiLynxEM)
526 VIDEO_VISIBLE_COLS visible pixel columns
528 VIDEO_VISIBLE_ROWS visible pixel rows
529 VIDEO_PIXEL_SIZE bytes per pixel
530 VIDEO_DATA_FORMAT graphic data format
531 (0-5, cf. cfb_console.c)
532 VIDEO_FB_ADRS framebuffer address
533 VIDEO_KBD_INIT_FCT keyboard int fct
534 (i.e. i8042_kbd_init())
535 VIDEO_TSTC_FCT test char fct
537 VIDEO_GETC_FCT get char fct
539 CONFIG_CONSOLE_CURSOR cursor drawing on/off
540 (requires blink timer
542 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
543 CONFIG_CONSOLE_TIME display time/date info in
545 (requires CFG_CMD_DATE)
546 CONFIG_VIDEO_LOGO display Linux logo in
548 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
549 linux_logo.h for logo.
550 Requires CONFIG_VIDEO_LOGO
551 CONFIG_CONSOLE_EXTRA_INFO
552 addional board info beside
555 When CONFIG_CFB_CONSOLE is defined, video console is
556 default i/o. Serial console can be forced with
557 environment 'console=serial'.
559 When CONFIG_SILENT_CONSOLE is defined, all console
560 messages (by U-Boot and Linux!) can be silenced with
561 the "silent" environment variable. See
562 doc/README.silent for more information.
565 CONFIG_BAUDRATE - in bps
566 Select one of the baudrates listed in
567 CFG_BAUDRATE_TABLE, see below.
568 CFG_BRGCLK_PRESCALE, baudrate prescale
570 - Interrupt driven serial port input:
571 CONFIG_SERIAL_SOFTWARE_FIFO
574 Use an interrupt handler for receiving data on the
575 serial port. It also enables using hardware handshake
576 (RTS/CTS) and UART's built-in FIFO. Set the number of
577 bytes the interrupt driven input buffer should have.
579 Leave undefined to disable this feature, including
580 disable the buffer and hardware handshake.
582 - Console UART Number:
586 If defined internal UART1 (and not UART0) is used
587 as default U-Boot console.
589 - Boot Delay: CONFIG_BOOTDELAY - in seconds
590 Delay before automatically booting the default image;
591 set to -1 to disable autoboot.
593 See doc/README.autoboot for these options that
594 work with CONFIG_BOOTDELAY. None are required.
595 CONFIG_BOOT_RETRY_TIME
596 CONFIG_BOOT_RETRY_MIN
597 CONFIG_AUTOBOOT_KEYED
598 CONFIG_AUTOBOOT_PROMPT
599 CONFIG_AUTOBOOT_DELAY_STR
600 CONFIG_AUTOBOOT_STOP_STR
601 CONFIG_AUTOBOOT_DELAY_STR2
602 CONFIG_AUTOBOOT_STOP_STR2
603 CONFIG_ZERO_BOOTDELAY_CHECK
604 CONFIG_RESET_TO_RETRY
608 Only needed when CONFIG_BOOTDELAY is enabled;
609 define a command string that is automatically executed
610 when no character is read on the console interface
611 within "Boot Delay" after reset.
614 This can be used to pass arguments to the bootm
615 command. The value of CONFIG_BOOTARGS goes into the
616 environment value "bootargs".
618 CONFIG_RAMBOOT and CONFIG_NFSBOOT
619 The value of these goes into the environment as
620 "ramboot" and "nfsboot" respectively, and can be used
621 as a convenience, when switching between booting from
627 When this option is #defined, the existence of the
628 environment variable "preboot" will be checked
629 immediately before starting the CONFIG_BOOTDELAY
630 countdown and/or running the auto-boot command resp.
631 entering interactive mode.
633 This feature is especially useful when "preboot" is
634 automatically generated or modified. For an example
635 see the LWMON board specific code: here "preboot" is
636 modified when the user holds down a certain
637 combination of keys on the (special) keyboard when
640 - Serial Download Echo Mode:
642 If defined to 1, all characters received during a
643 serial download (using the "loads" command) are
644 echoed back. This might be needed by some terminal
645 emulations (like "cu"), but may as well just take
646 time on others. This setting #define's the initial
647 value of the "loads_echo" environment variable.
649 - Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
651 Select one of the baudrates listed in
652 CFG_BAUDRATE_TABLE, see below.
656 Most monitor functions can be selected (or
657 de-selected) by adjusting the definition of
658 CONFIG_COMMANDS; to select individual functions,
659 #define CONFIG_COMMANDS by "OR"ing any of the
662 #define enables commands:
663 -------------------------
664 CFG_CMD_ASKENV * ask for env variable
665 CFG_CMD_AUTOSCRIPT Autoscript Support
667 CFG_CMD_BEDBUG * Include BedBug Debugger
668 CFG_CMD_BMP * BMP support
669 CFG_CMD_BSP * Board specific commands
671 CFG_CMD_CACHE * icache, dcache
672 CFG_CMD_CONSOLE coninfo
673 CFG_CMD_DATE * support for RTC, date/time...
674 CFG_CMD_DHCP * DHCP support
675 CFG_CMD_DIAG * Diagnostics
676 CFG_CMD_DOC * Disk-On-Chip Support
677 CFG_CMD_DTT * Digital Therm and Thermostat
678 CFG_CMD_ECHO echo arguments
679 CFG_CMD_EEPROM * EEPROM read/write support
680 CFG_CMD_ELF * bootelf, bootvx
682 CFG_CMD_FDC * Floppy Disk Support
683 CFG_CMD_FAT * FAT partition support
684 CFG_CMD_FDOS * Dos diskette Support
685 CFG_CMD_FLASH flinfo, erase, protect
686 CFG_CMD_FPGA FPGA device initialization support
687 CFG_CMD_HWFLOW * RTS/CTS hw flow control
688 CFG_CMD_I2C * I2C serial bus support
689 CFG_CMD_IDE * IDE harddisk support
691 CFG_CMD_IMLS List all found images
692 CFG_CMD_IMMAP * IMMR dump support
693 CFG_CMD_IRQ * irqinfo
694 CFG_CMD_ITEST Integer/string test of 2 values
695 CFG_CMD_JFFS2 * JFFS2 Support
699 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
701 CFG_CMD_MISC Misc functions like sleep etc
702 CFG_CMD_MMC * MMC memory mapped support
703 CFG_CMD_MII * MII utility commands
704 CFG_CMD_NAND * NAND support
705 CFG_CMD_NET bootp, tftpboot, rarpboot
706 CFG_CMD_PCI * pciinfo
707 CFG_CMD_PCMCIA * PCMCIA support
708 CFG_CMD_PING * send ICMP ECHO_REQUEST to network host
709 CFG_CMD_PORTIO * Port I/O
710 CFG_CMD_REGINFO * Register dump
711 CFG_CMD_RUN run command in env variable
712 CFG_CMD_SAVES * save S record dump
713 CFG_CMD_SCSI * SCSI Support
714 CFG_CMD_SDRAM * print SDRAM configuration information
715 (requires CFG_CMD_I2C)
716 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
717 CFG_CMD_SPI * SPI serial bus support
718 CFG_CMD_USB * USB support
719 CFG_CMD_VFD * VFD support (TRAB)
720 CFG_CMD_BSP * Board SPecific functions
721 CFG_CMD_CDP * Cisco Discover Protocol support
722 CFG_CMD_FSL * Microblaze FSL support
723 -----------------------------------------------
726 CONFIG_CMD_DFL Default configuration; at the moment
727 this is includes all commands, except
728 the ones marked with "*" in the list
731 If you don't define CONFIG_COMMANDS it defaults to
732 CONFIG_CMD_DFL in include/cmd_confdefs.h. A board can
733 override the default settings in the respective
736 EXAMPLE: If you want all functions except of network
737 support you can write:
739 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
742 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
744 Note: Don't enable the "icache" and "dcache" commands
745 (configuration option CFG_CMD_CACHE) unless you know
746 what you (and your U-Boot users) are doing. Data
747 cache cannot be enabled on systems like the 8xx or
748 8260 (where accesses to the IMMR region must be
749 uncached), and it cannot be disabled on all other
750 systems where we (mis-) use the data cache to hold an
751 initial stack and some data.
754 XXX - this list needs to get updated!
758 If this variable is defined, it enables watchdog
759 support. There must be support in the platform specific
760 code for a watchdog. For the 8xx and 8260 CPUs, the
761 SIU Watchdog feature is enabled in the SYPCR
765 CONFIG_VERSION_VARIABLE
766 If this variable is defined, an environment variable
767 named "ver" is created by U-Boot showing the U-Boot
768 version as printed by the "version" command.
769 This variable is readonly.
773 When CFG_CMD_DATE is selected, the type of the RTC
774 has to be selected, too. Define exactly one of the
777 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
778 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
779 CONFIG_RTC_MC146818 - use MC146818 RTC
780 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
781 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
782 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
783 CONFIG_RTC_DS164x - use Dallas DS164x RTC
784 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
786 Note that if the RTC uses I2C, then the I2C interface
787 must also be configured. See I2C Support, below.
791 When CONFIG_TIMESTAMP is selected, the timestamp
792 (date and time) of an image is printed by image
793 commands like bootm or iminfo. This option is
794 automatically enabled when you select CFG_CMD_DATE .
797 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
798 and/or CONFIG_ISO_PARTITION
800 If IDE or SCSI support is enabled (CFG_CMD_IDE or
801 CFG_CMD_SCSI) you must configure support for at least
802 one partition type as well.
805 CONFIG_IDE_RESET_ROUTINE - this is defined in several
806 board configurations files but used nowhere!
808 CONFIG_IDE_RESET - is this is defined, IDE Reset will
809 be performed by calling the function
810 ide_set_reset(int reset)
811 which has to be defined in a board specific file
816 Set this to enable ATAPI support.
821 Set this to enable support for disks larger than 137GB
822 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL
823 Whithout these , LBA48 support uses 32bit variables and will 'only'
824 support disks up to 2.1TB.
827 When enabled, makes the IDE subsystem use 64bit sector addresses.
831 At the moment only there is only support for the
832 SYM53C8XX SCSI controller; define
833 CONFIG_SCSI_SYM53C8XX to enable it.
835 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
836 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
837 CFG_SCSI_MAX_LUN] can be adjusted to define the
838 maximum numbers of LUNs, SCSI ID's and target
840 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
842 - NETWORK Support (PCI):
844 Support for Intel 8254x gigabit chips.
847 Support for Intel 82557/82559/82559ER chips.
848 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
849 write routine for first time initialisation.
852 Support for Digital 2114x chips.
853 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
854 modem chip initialisation (KS8761/QS6611).
857 Support for National dp83815 chips.
860 Support for National dp8382[01] gigabit chips.
862 - NETWORK Support (other):
864 CONFIG_DRIVER_LAN91C96
865 Support for SMSC's LAN91C96 chips.
868 Define this to hold the physical address
869 of the LAN91C96's I/O space
871 CONFIG_LAN91C96_USE_32_BIT
872 Define this to enable 32 bit addressing
874 CONFIG_DRIVER_SMC91111
875 Support for SMSC's LAN91C111 chip
878 Define this to hold the physical address
879 of the device (I/O space)
881 CONFIG_SMC_USE_32_BIT
882 Define this if data bus is 32 bits
884 CONFIG_SMC_USE_IOFUNCS
885 Define this to use i/o functions instead of macros
886 (some hardware wont work with macros)
889 At the moment only the UHCI host controller is
890 supported (PIP405, MIP405, MPC5200); define
891 CONFIG_USB_UHCI to enable it.
892 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
893 and define CONFIG_USB_STORAGE to enable the USB
896 Supported are USB Keyboards and USB Floppy drives
898 MPC5200 USB requires additional defines:
900 for 528 MHz Clock: 0x0001bbbb
902 for differential drivers: 0x00001000
903 for single ended drivers: 0x00005000
905 May be defined to allow interrupt polling
906 instead of using asynchronous interrupts
909 Define the below if you wish to use the USB console.
910 Once firmware is rebuilt from a serial console issue the
911 command "setenv stdin usbtty; setenv stdout usbtty" and
912 attach your usb cable. The Unix command "dmesg" should print
913 it has found a new device. The environment variable usbtty
914 can be set to gserial or cdc_acm to enable your device to
915 appear to a USB host as a Linux gserial device or a
916 Common Device Class Abstract Control Model serial device.
917 If you select usbtty = gserial you should be able to enumerate
919 # modprobe usbserial vendor=0xVendorID product=0xProductID
920 else if using cdc_acm, simply setting the environment
921 variable usbtty to be cdc_acm should suffice. The following
922 might be defined in YourBoardName.h
925 Define this to build a UDC device
928 Define this to have a tty type of device available to
929 talk to the UDC device
931 CFG_CONSOLE_IS_IN_ENV
932 Define this if you want stdin, stdout &/or stderr to
936 CFG_USB_EXTC_CLK 0xBLAH
937 Derive USB clock from external clock "blah"
938 - CFG_USB_EXTC_CLK 0x02
940 CFG_USB_BRG_CLK 0xBLAH
941 Derive USB clock from brgclk
942 - CFG_USB_BRG_CLK 0x04
944 If you have a USB-IF assigned VendorID then you may wish to
945 define your own vendor specific values either in BoardName.h
946 or directly in usbd_vendor_info.h. If you don't define
947 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
948 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
949 should pretend to be a Linux device to it's target host.
951 CONFIG_USBD_MANUFACTURER
952 Define this string as the name of your company for
953 - CONFIG_USBD_MANUFACTURER "my company"
955 CONFIG_USBD_PRODUCT_NAME
956 Define this string as the name of your product
957 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
960 Define this as your assigned Vendor ID from the USB
961 Implementors Forum. This *must* be a genuine Vendor ID
962 to avoid polluting the USB namespace.
963 - CONFIG_USBD_VENDORID 0xFFFF
965 CONFIG_USBD_PRODUCTID
966 Define this as the unique Product ID
968 - CONFIG_USBD_PRODUCTID 0xFFFF
972 The MMC controller on the Intel PXA is supported. To
973 enable this define CONFIG_MMC. The MMC can be
974 accessed from the boot prompt by mapping the device
975 to physical memory similar to flash. Command line is
976 enabled with CFG_CMD_MMC. The MMC driver also works with
977 the FAT fs. This is enabled with CFG_CMD_FAT.
979 - Journaling Flash filesystem support:
980 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
981 CONFIG_JFFS2_NAND_DEV
982 Define these for a default partition on a NAND device
984 CFG_JFFS2_FIRST_SECTOR,
985 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS
986 Define these for a default partition on a NOR device
989 Define this to create an own partition. You have to provide a
990 function struct part_info* jffs2_part_info(int part_num)
992 If you define only one JFFS2 partition you may also want to
993 #define CFG_JFFS_SINGLE_PART 1
994 to disable the command chpart. This is the default when you
995 have not defined a custom partition
1000 Define this to enable standard (PC-Style) keyboard
1004 Standard PC keyboard driver with US (is default) and
1005 GERMAN key layout (switch via environment 'keymap=de') support.
1006 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1007 for cfb_console. Supports cursor blinking.
1012 Define this to enable video support (for output to
1015 CONFIG_VIDEO_CT69000
1017 Enable Chips & Technologies 69000 Video chip
1019 CONFIG_VIDEO_SMI_LYNXEM
1020 Enable Silicon Motion SMI 712/710/810 Video chip. The
1021 video output is selected via environment 'videoout'
1022 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1025 For the CT69000 and SMI_LYNXEM drivers, videomode is
1026 selected via environment 'videomode'. Two diferent ways
1028 - "videomode=num" 'num' is a standard LiLo mode numbers.
1029 Following standard modes are supported (* is default):
1031 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1032 -------------+---------------------------------------------
1033 8 bits | 0x301* 0x303 0x305 0x161 0x307
1034 15 bits | 0x310 0x313 0x316 0x162 0x319
1035 16 bits | 0x311 0x314 0x317 0x163 0x31A
1036 24 bits | 0x312 0x315 0x318 ? 0x31B
1037 -------------+---------------------------------------------
1038 (i.e. setenv videomode 317; saveenv; reset;)
1040 - "videomode=bootargs" all the video parameters are parsed
1041 from the bootargs. (See drivers/videomodes.c)
1044 CONFIG_VIDEO_SED13806
1045 Enable Epson SED13806 driver. This driver supports 8bpp
1046 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1047 or CONFIG_VIDEO_SED13806_16BPP
1052 Define this to enable a custom keyboard support.
1053 This simply calls drv_keyboard_init() which must be
1054 defined in your board-specific files.
1055 The only board using this so far is RBC823.
1057 - LCD Support: CONFIG_LCD
1059 Define this to enable LCD support (for output to LCD
1060 display); also select one of the supported displays
1061 by defining one of these:
1063 CONFIG_NEC_NL6448AC33:
1065 NEC NL6448AC33-18. Active, color, single scan.
1067 CONFIG_NEC_NL6448BC20
1069 NEC NL6448BC20-08. 6.5", 640x480.
1070 Active, color, single scan.
1072 CONFIG_NEC_NL6448BC33_54
1074 NEC NL6448BC33-54. 10.4", 640x480.
1075 Active, color, single scan.
1079 Sharp 320x240. Active, color, single scan.
1080 It isn't 16x9, and I am not sure what it is.
1082 CONFIG_SHARP_LQ64D341
1084 Sharp LQ64D341 display, 640x480.
1085 Active, color, single scan.
1089 HLD1045 display, 640x480.
1090 Active, color, single scan.
1094 Optrex CBL50840-2 NF-FW 99 22 M5
1096 Hitachi LMG6912RPFC-00T
1100 320x240. Black & white.
1102 Normally display is black on white background; define
1103 CFG_WHITE_ON_BLACK to get it inverted.
1105 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1107 If this option is set, the environment is checked for
1108 a variable "splashimage". If found, the usual display
1109 of logo, copyright and system information on the LCD
1110 is suppressed and the BMP image at the address
1111 specified in "splashimage" is loaded instead. The
1112 console is redirected to the "nulldev", too. This
1113 allows for a "silent" boot where a splash screen is
1114 loaded very quickly after power-on.
1116 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1118 If this option is set, additionally to standard BMP
1119 images, gzipped BMP images can be displayed via the
1120 splashscreen support or the bmp command.
1122 - Compression support:
1125 If this option is set, support for bzip2 compressed
1126 images is included. If not, only uncompressed and gzip
1127 compressed images are supported.
1129 NOTE: the bzip2 algorithm requires a lot of RAM, so
1130 the malloc area (as defined by CFG_MALLOC_LEN) should
1136 The address of PHY on MII bus.
1138 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1140 The clock frequency of the MII bus
1144 If this option is set, support for speed/duplex
1145 detection of Gigabit PHY is included.
1147 CONFIG_PHY_RESET_DELAY
1149 Some PHY like Intel LXT971A need extra delay after
1150 reset before any MII register access is possible.
1151 For such PHY, set this option to the usec delay
1152 required. (minimum 300usec for LXT971A)
1154 CONFIG_PHY_CMD_DELAY (ppc4xx)
1156 Some PHY like Intel LXT971A need extra delay after
1157 command issued before MII status register can be read
1164 Define a default value for ethernet address to use
1165 for the respective ethernet interface, in case this
1166 is not determined automatically.
1171 Define a default value for the IP address to use for
1172 the default ethernet interface, in case this is not
1173 determined through e.g. bootp.
1175 - Server IP address:
1178 Defines a default value for theIP address of a TFTP
1179 server to contact when using the "tftboot" command.
1181 - BOOTP Recovery Mode:
1182 CONFIG_BOOTP_RANDOM_DELAY
1184 If you have many targets in a network that try to
1185 boot using BOOTP, you may want to avoid that all
1186 systems send out BOOTP requests at precisely the same
1187 moment (which would happen for instance at recovery
1188 from a power failure, when all systems will try to
1189 boot, thus flooding the BOOTP server. Defining
1190 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1191 inserted before sending out BOOTP requests. The
1192 following delays are insterted then:
1194 1st BOOTP request: delay 0 ... 1 sec
1195 2nd BOOTP request: delay 0 ... 2 sec
1196 3rd BOOTP request: delay 0 ... 4 sec
1198 BOOTP requests: delay 0 ... 8 sec
1200 - DHCP Advanced Options:
1203 You can fine tune the DHCP functionality by adding
1204 these flags to the CONFIG_BOOTP_MASK define:
1206 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1207 serverip from a DHCP server, it is possible that more
1208 than one DNS serverip is offered to the client.
1209 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1210 serverip will be stored in the additional environment
1211 variable "dnsip2". The first DNS serverip is always
1212 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1213 is added to the CONFIG_BOOTP_MASK.
1215 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1216 to do a dynamic update of a DNS server. To do this, they
1217 need the hostname of the DHCP requester.
1218 If CONFIG_BOOP_SEND_HOSTNAME is added to the
1219 CONFIG_BOOTP_MASK, the content of the "hostname"
1220 environment variable is passed as option 12 to
1224 CONFIG_CDP_DEVICE_ID
1226 The device id used in CDP trigger frames.
1228 CONFIG_CDP_DEVICE_ID_PREFIX
1230 A two character string which is prefixed to the MAC address
1235 A printf format string which contains the ascii name of
1236 the port. Normally is set to "eth%d" which sets
1237 eth0 for the first ethernet, eth1 for the second etc.
1239 CONFIG_CDP_CAPABILITIES
1241 A 32bit integer which indicates the device capabilities;
1242 0x00000010 for a normal host which does not forwards.
1246 An ascii string containing the version of the software.
1250 An ascii string containing the name of the platform.
1254 A 32bit integer sent on the trigger.
1256 CONFIG_CDP_POWER_CONSUMPTION
1258 A 16bit integer containing the power consumption of the
1259 device in .1 of milliwatts.
1261 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1263 A byte containing the id of the VLAN.
1265 - Status LED: CONFIG_STATUS_LED
1267 Several configurations allow to display the current
1268 status using a LED. For instance, the LED will blink
1269 fast while running U-Boot code, stop blinking as
1270 soon as a reply to a BOOTP request was received, and
1271 start blinking slow once the Linux kernel is running
1272 (supported by a status LED driver in the Linux
1273 kernel). Defining CONFIG_STATUS_LED enables this
1276 - CAN Support: CONFIG_CAN_DRIVER
1278 Defining CONFIG_CAN_DRIVER enables CAN driver support
1279 on those systems that support this (optional)
1280 feature, like the TQM8xxL modules.
1282 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1284 These enable I2C serial bus commands. Defining either of
1285 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1286 include the appropriate I2C driver for the selected cpu.
1288 This will allow you to use i2c commands at the u-boot
1289 command line (as long as you set CFG_CMD_I2C in
1290 CONFIG_COMMANDS) and communicate with i2c based realtime
1291 clock chips. See common/cmd_i2c.c for a description of the
1292 command line interface.
1294 CONFIG_I2C_CMD_TREE is a recommended option that places
1295 all I2C commands under a single 'i2c' root command. The
1296 older 'imm', 'imd', 'iprobe' etc. commands are considered
1297 deprecated and may disappear in the future.
1299 CONFIG_HARD_I2C selects a hardware I2C controller.
1301 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1302 bit-banging) driver instead of CPM or similar hardware
1305 There are several other quantities that must also be
1306 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1308 In both cases you will need to define CFG_I2C_SPEED
1309 to be the frequency (in Hz) at which you wish your i2c bus
1310 to run and CFG_I2C_SLAVE to be the address of this node (ie
1311 the cpu's i2c node address).
1313 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1314 sets the cpu up as a master node and so its address should
1315 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1316 p.16-473). So, set CFG_I2C_SLAVE to 0.
1318 That's all that's required for CONFIG_HARD_I2C.
1320 If you use the software i2c interface (CONFIG_SOFT_I2C)
1321 then the following macros need to be defined (examples are
1322 from include/configs/lwmon.h):
1326 (Optional). Any commands necessary to enable the I2C
1327 controller or configure ports.
1329 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1333 (Only for MPC8260 CPU). The I/O port to use (the code
1334 assumes both bits are on the same port). Valid values
1335 are 0..3 for ports A..D.
1339 The code necessary to make the I2C data line active
1340 (driven). If the data line is open collector, this
1343 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1347 The code necessary to make the I2C data line tri-stated
1348 (inactive). If the data line is open collector, this
1351 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1355 Code that returns TRUE if the I2C data line is high,
1358 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1362 If <bit> is TRUE, sets the I2C data line high. If it
1363 is FALSE, it clears it (low).
1365 eg: #define I2C_SDA(bit) \
1366 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1367 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1371 If <bit> is TRUE, sets the I2C clock line high. If it
1372 is FALSE, it clears it (low).
1374 eg: #define I2C_SCL(bit) \
1375 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1376 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1380 This delay is invoked four times per clock cycle so this
1381 controls the rate of data transfer. The data rate thus
1382 is 1 / (I2C_DELAY * 4). Often defined to be something
1385 #define I2C_DELAY udelay(2)
1389 When a board is reset during an i2c bus transfer
1390 chips might think that the current transfer is still
1391 in progress. On some boards it is possible to access
1392 the i2c SCLK line directly, either by using the
1393 processor pin as a GPIO or by having a second pin
1394 connected to the bus. If this option is defined a
1395 custom i2c_init_board() routine in boards/xxx/board.c
1396 is run early in the boot sequence.
1398 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1400 This option enables configuration of bi_iic_fast[] flags
1401 in u-boot bd_info structure based on u-boot environment
1402 variable "i2cfast". (see also i2cfast)
1404 CONFIG_I2C_MULTI_BUS
1406 This option allows the use of multiple I2C buses, each of which
1407 must have a controller. At any point in time, only one bus is
1408 active. To switch to a different bus, use the 'i2c dev' command.
1409 Note that bus numbering is zero-based.
1413 This option specifies a list of I2C devices that will be skipped
1414 when the 'i2c probe' command is issued (or 'iprobe' using the legacy
1415 command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device
1416 pairs. Otherwise, specify a 1D array of device addresses
1419 #undef CONFIG_I2C_MULTI_BUS
1420 #define CFG_I2C_NOPROBES {0x50,0x68}
1422 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1424 #define CONFIG_I2C_MULTI_BUS
1425 #define CFG_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1427 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1431 If defined, then this indicates the I2C bus number for DDR SPD.
1432 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1436 If defined, then this indicates the I2C bus number for the RTC.
1437 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1441 If defined, then this indicates the I2C bus number for the DTT.
1442 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1446 Define this option if you want to use Freescale's I2C driver in
1450 - SPI Support: CONFIG_SPI
1452 Enables SPI driver (so far only tested with
1453 SPI EEPROM, also an instance works with Crystal A/D and
1454 D/As on the SACSng board)
1458 Enables extended (16-bit) SPI EEPROM addressing.
1459 (symmetrical to CONFIG_I2C_X)
1463 Enables a software (bit-bang) SPI driver rather than
1464 using hardware support. This is a general purpose
1465 driver that only requires three general I/O port pins
1466 (two outputs, one input) to function. If this is
1467 defined, the board configuration must define several
1468 SPI configuration items (port pins to use, etc). For
1469 an example, see include/configs/sacsng.h.
1471 - FPGA Support: CONFIG_FPGA_COUNT
1473 Specify the number of FPGA devices to support.
1477 Used to specify the types of FPGA devices. For example,
1478 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
1480 CFG_FPGA_PROG_FEEDBACK
1482 Enable printing of hash marks during FPGA configuration.
1486 Enable checks on FPGA configuration interface busy
1487 status by the configuration function. This option
1488 will require a board or device specific function to
1493 If defined, a function that provides delays in the FPGA
1494 configuration driver.
1496 CFG_FPGA_CHECK_CTRLC
1497 Allow Control-C to interrupt FPGA configuration
1499 CFG_FPGA_CHECK_ERROR
1501 Check for configuration errors during FPGA bitfile
1502 loading. For example, abort during Virtex II
1503 configuration if the INIT_B line goes low (which
1504 indicated a CRC error).
1508 Maximum time to wait for the INIT_B line to deassert
1509 after PROB_B has been deasserted during a Virtex II
1510 FPGA configuration sequence. The default time is 500
1515 Maximum time to wait for BUSY to deassert during
1516 Virtex II FPGA configuration. The default is 5 mS.
1518 CFG_FPGA_WAIT_CONFIG
1520 Time to wait after FPGA configuration. The default is
1523 - Configuration Management:
1526 If defined, this string will be added to the U-Boot
1527 version information (U_BOOT_VERSION)
1529 - Vendor Parameter Protection:
1531 U-Boot considers the values of the environment
1532 variables "serial#" (Board Serial Number) and
1533 "ethaddr" (Ethernet Address) to be parameters that
1534 are set once by the board vendor / manufacturer, and
1535 protects these variables from casual modification by
1536 the user. Once set, these variables are read-only,
1537 and write or delete attempts are rejected. You can
1538 change this behviour:
1540 If CONFIG_ENV_OVERWRITE is #defined in your config
1541 file, the write protection for vendor parameters is
1542 completely disabled. Anybody can change or delete
1545 Alternatively, if you #define _both_ CONFIG_ETHADDR
1546 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1547 ethernet address is installed in the environment,
1548 which can be changed exactly ONCE by the user. [The
1549 serial# is unaffected by this, i. e. it remains
1555 Define this variable to enable the reservation of
1556 "protected RAM", i. e. RAM which is not overwritten
1557 by U-Boot. Define CONFIG_PRAM to hold the number of
1558 kB you want to reserve for pRAM. You can overwrite
1559 this default value by defining an environment
1560 variable "pram" to the number of kB you want to
1561 reserve. Note that the board info structure will
1562 still show the full amount of RAM. If pRAM is
1563 reserved, a new environment variable "mem" will
1564 automatically be defined to hold the amount of
1565 remaining RAM in a form that can be passed as boot
1566 argument to Linux, for instance like that:
1568 setenv bootargs ... mem=\${mem}
1571 This way you can tell Linux not to use this memory,
1572 either, which results in a memory region that will
1573 not be affected by reboots.
1575 *WARNING* If your board configuration uses automatic
1576 detection of the RAM size, you must make sure that
1577 this memory test is non-destructive. So far, the
1578 following board configurations are known to be
1581 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1582 HERMES, IP860, RPXlite, LWMON, LANTEC,
1583 PCU_E, FLAGADM, TQM8260
1588 Define this variable to stop the system in case of a
1589 fatal error, so that you have to reset it manually.
1590 This is probably NOT a good idea for an embedded
1591 system where you want to system to reboot
1592 automatically as fast as possible, but it may be
1593 useful during development since you can try to debug
1594 the conditions that lead to the situation.
1596 CONFIG_NET_RETRY_COUNT
1598 This variable defines the number of retries for
1599 network operations like ARP, RARP, TFTP, or BOOTP
1600 before giving up the operation. If not defined, a
1601 default value of 5 is used.
1603 - Command Interpreter:
1604 CONFIG_AUTO_COMPLETE
1606 Enable auto completion of commands using TAB.
1608 Note that this feature has NOT been implemented yet
1609 for the "hush" shell.
1614 Define this variable to enable the "hush" shell (from
1615 Busybox) as command line interpreter, thus enabling
1616 powerful command line syntax like
1617 if...then...else...fi conditionals or `&&' and '||'
1618 constructs ("shell scripts").
1620 If undefined, you get the old, much simpler behaviour
1621 with a somewhat smaller memory footprint.
1626 This defines the secondary prompt string, which is
1627 printed when the command interpreter needs more input
1628 to complete a command. Usually "> ".
1632 In the current implementation, the local variables
1633 space and global environment variables space are
1634 separated. Local variables are those you define by
1635 simply typing `name=value'. To access a local
1636 variable later on, you have write `$name' or
1637 `${name}'; to execute the contents of a variable
1638 directly type `$name' at the command prompt.
1640 Global environment variables are those you use
1641 setenv/printenv to work with. To run a command stored
1642 in such a variable, you need to use the run command,
1643 and you must not use the '$' sign to access them.
1645 To store commands and special characters in a
1646 variable, please use double quotation marks
1647 surrounding the whole text of the variable, instead
1648 of the backslashes before semicolons and special
1651 - Commandline Editing and History:
1652 CONFIG_CMDLINE_EDITING
1654 Enable editiong and History functions for interactive
1655 commandline input operations
1657 - Default Environment:
1658 CONFIG_EXTRA_ENV_SETTINGS
1660 Define this to contain any number of null terminated
1661 strings (variable = value pairs) that will be part of
1662 the default environment compiled into the boot image.
1664 For example, place something like this in your
1665 board's config file:
1667 #define CONFIG_EXTRA_ENV_SETTINGS \
1671 Warning: This method is based on knowledge about the
1672 internal format how the environment is stored by the
1673 U-Boot code. This is NOT an official, exported
1674 interface! Although it is unlikely that this format
1675 will change soon, there is no guarantee either.
1676 You better know what you are doing here.
1678 Note: overly (ab)use of the default environment is
1679 discouraged. Make sure to check other ways to preset
1680 the environment like the autoscript function or the
1683 - DataFlash Support:
1684 CONFIG_HAS_DATAFLASH
1686 Defining this option enables DataFlash features and
1687 allows to read/write in Dataflash via the standard
1690 - SystemACE Support:
1693 Adding this option adds support for Xilinx SystemACE
1694 chips attached via some sort of local bus. The address
1695 of the chip must alsh be defined in the
1696 CFG_SYSTEMACE_BASE macro. For example:
1698 #define CONFIG_SYSTEMACE
1699 #define CFG_SYSTEMACE_BASE 0xf0000000
1701 When SystemACE support is added, the "ace" device type
1702 becomes available to the fat commands, i.e. fatls.
1704 - TFTP Fixed UDP Port:
1707 If this is defined, the environment variable tftpsrcp
1708 is used to supply the TFTP UDP source port value.
1709 If tftpsrcp isn't defined, the normal pseudo-random port
1710 number generator is used.
1712 Also, the environment variable tftpdstp is used to supply
1713 the TFTP UDP destination port value. If tftpdstp isn't
1714 defined, the normal port 69 is used.
1716 The purpose for tftpsrcp is to allow a TFTP server to
1717 blindly start the TFTP transfer using the pre-configured
1718 target IP address and UDP port. This has the effect of
1719 "punching through" the (Windows XP) firewall, allowing
1720 the remainder of the TFTP transfer to proceed normally.
1721 A better solution is to properly configure the firewall,
1722 but sometimes that is not allowed.
1724 - Show boot progress:
1725 CONFIG_SHOW_BOOT_PROGRESS
1727 Defining this option allows to add some board-
1728 specific code (calling a user-provided function
1729 "show_boot_progress(int)") that enables you to show
1730 the system's boot progress on some display (for
1731 example, some LED's) on your board. At the moment,
1732 the following checkpoints are implemented:
1735 1 common/cmd_bootm.c before attempting to boot an image
1736 -1 common/cmd_bootm.c Image header has bad magic number
1737 2 common/cmd_bootm.c Image header has correct magic number
1738 -2 common/cmd_bootm.c Image header has bad checksum
1739 3 common/cmd_bootm.c Image header has correct checksum
1740 -3 common/cmd_bootm.c Image data has bad checksum
1741 4 common/cmd_bootm.c Image data has correct checksum
1742 -4 common/cmd_bootm.c Image is for unsupported architecture
1743 5 common/cmd_bootm.c Architecture check OK
1744 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1745 6 common/cmd_bootm.c Image Type check OK
1746 -6 common/cmd_bootm.c gunzip uncompression error
1747 -7 common/cmd_bootm.c Unimplemented compression type
1748 7 common/cmd_bootm.c Uncompression OK
1749 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1750 8 common/cmd_bootm.c Image Type check OK
1751 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1752 9 common/cmd_bootm.c Start initial ramdisk verification
1753 -10 common/cmd_bootm.c Ramdisk header has bad magic number
1754 -11 common/cmd_bootm.c Ramdisk header has bad checksum
1755 10 common/cmd_bootm.c Ramdisk header is OK
1756 -12 common/cmd_bootm.c Ramdisk data has bad checksum
1757 11 common/cmd_bootm.c Ramdisk data has correct checksum
1758 12 common/cmd_bootm.c Ramdisk verification complete, start loading
1759 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk)
1760 13 common/cmd_bootm.c Start multifile image verification
1761 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue.
1762 15 common/cmd_bootm.c All preparation done, transferring control to OS
1764 -30 lib_ppc/board.c Fatal error, hang the system
1765 -31 post/post.c POST test failed, detected by post_output_backlog()
1766 -32 post/post.c POST test failed, detected by post_run_single()
1768 -1 common/cmd_doc.c Bad usage of "doc" command
1769 -1 common/cmd_doc.c No boot device
1770 -1 common/cmd_doc.c Unknown Chip ID on boot device
1771 -1 common/cmd_doc.c Read Error on boot device
1772 -1 common/cmd_doc.c Image header has bad magic number
1774 -1 common/cmd_ide.c Bad usage of "ide" command
1775 -1 common/cmd_ide.c No boot device
1776 -1 common/cmd_ide.c Unknown boot device
1777 -1 common/cmd_ide.c Unknown partition table
1778 -1 common/cmd_ide.c Invalid partition type
1779 -1 common/cmd_ide.c Read Error on boot device
1780 -1 common/cmd_ide.c Image header has bad magic number
1782 -1 common/cmd_nand.c Bad usage of "nand" command
1783 -1 common/cmd_nand.c No boot device
1784 -1 common/cmd_nand.c Unknown Chip ID on boot device
1785 -1 common/cmd_nand.c Read Error on boot device
1786 -1 common/cmd_nand.c Image header has bad magic number
1788 -1 common/env_common.c Environment has a bad CRC, using default
1794 [so far only for SMDK2400 and TRAB boards]
1796 - Modem support endable:
1797 CONFIG_MODEM_SUPPORT
1799 - RTS/CTS Flow control enable:
1802 - Modem debug support:
1803 CONFIG_MODEM_SUPPORT_DEBUG
1805 Enables debugging stuff (char screen[1024], dbg())
1806 for modem support. Useful only with BDI2000.
1808 - Interrupt support (PPC):
1810 There are common interrupt_init() and timer_interrupt()
1811 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
1812 for cpu specific initialization. interrupt_init_cpu()
1813 should set decrementer_count to appropriate value. If
1814 cpu resets decrementer automatically after interrupt
1815 (ppc4xx) it should set decrementer_count to zero.
1816 timer_interrupt() calls timer_interrupt_cpu() for cpu
1817 specific handling. If board has watchdog / status_led
1818 / other_activity_monitor it works automatically from
1819 general timer_interrupt().
1823 In the target system modem support is enabled when a
1824 specific key (key combination) is pressed during
1825 power-on. Otherwise U-Boot will boot normally
1826 (autoboot). The key_pressed() fuction is called from
1827 board_init(). Currently key_pressed() is a dummy
1828 function, returning 1 and thus enabling modem
1831 If there are no modem init strings in the
1832 environment, U-Boot proceed to autoboot; the
1833 previous output (banner, info printfs) will be
1836 See also: doc/README.Modem
1839 Configuration Settings:
1840 -----------------------
1842 - CFG_LONGHELP: Defined when you want long help messages included;
1843 undefine this when you're short of memory.
1845 - CFG_PROMPT: This is what U-Boot prints on the console to
1846 prompt for user input.
1848 - CFG_CBSIZE: Buffer size for input from the Console
1850 - CFG_PBSIZE: Buffer size for Console output
1852 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1854 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1855 the application (usually a Linux kernel) when it is
1858 - CFG_BAUDRATE_TABLE:
1859 List of legal baudrate settings for this board.
1861 - CFG_CONSOLE_INFO_QUIET
1862 Suppress display of console information at boot.
1864 - CFG_CONSOLE_IS_IN_ENV
1865 If the board specific function
1866 extern int overwrite_console (void);
1867 returns 1, the stdin, stderr and stdout are switched to the
1868 serial port, else the settings in the environment are used.
1870 - CFG_CONSOLE_OVERWRITE_ROUTINE
1871 Enable the call to overwrite_console().
1873 - CFG_CONSOLE_ENV_OVERWRITE
1874 Enable overwrite of previous console environment settings.
1876 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1877 Begin and End addresses of the area used by the
1881 Enable an alternate, more extensive memory test.
1883 - CFG_MEMTEST_SCRATCH:
1884 Scratch address used by the alternate memory test
1885 You only need to set this if address zero isn't writeable
1887 - CFG_TFTP_LOADADDR:
1888 Default load address for network file downloads
1890 - CFG_LOADS_BAUD_CHANGE:
1891 Enable temporary baudrate change while serial download
1894 Physical start address of SDRAM. _Must_ be 0 here.
1897 Physical start address of Motherboard I/O (if using a
1901 Physical start address of Flash memory.
1904 Physical start address of boot monitor code (set by
1905 make config files to be same as the text base address
1906 (TEXT_BASE) used when linking) - same as
1907 CFG_FLASH_BASE when booting from flash.
1910 Size of memory reserved for monitor code, used to
1911 determine _at_compile_time_ (!) if the environment is
1912 embedded within the U-Boot image, or in a separate
1916 Size of DRAM reserved for malloc() use.
1919 Normally compressed uImages are limited to an
1920 uncompressed size of 8 MBytes. If this is not enough,
1921 you can define CFG_BOOTM_LEN in your board config file
1922 to adjust this setting to your needs.
1925 Maximum size of memory mapped by the startup code of
1926 the Linux kernel; all data that must be processed by
1927 the Linux kernel (bd_info, boot arguments, eventually
1928 initrd image) must be put below this limit.
1930 - CFG_MAX_FLASH_BANKS:
1931 Max number of Flash memory banks
1933 - CFG_MAX_FLASH_SECT:
1934 Max number of sectors on a Flash chip
1936 - CFG_FLASH_ERASE_TOUT:
1937 Timeout for Flash erase operations (in ms)
1939 - CFG_FLASH_WRITE_TOUT:
1940 Timeout for Flash write operations (in ms)
1942 - CFG_FLASH_LOCK_TOUT
1943 Timeout for Flash set sector lock bit operation (in ms)
1945 - CFG_FLASH_UNLOCK_TOUT
1946 Timeout for Flash clear lock bits operation (in ms)
1948 - CFG_FLASH_PROTECTION
1949 If defined, hardware flash sectors protection is used
1950 instead of U-Boot software protection.
1952 - CFG_DIRECT_FLASH_TFTP:
1954 Enable TFTP transfers directly to flash memory;
1955 without this option such a download has to be
1956 performed in two steps: (1) download to RAM, and (2)
1957 copy from RAM to flash.
1959 The two-step approach is usually more reliable, since
1960 you can check if the download worked before you erase
1961 the flash, but in some situations (when sytem RAM is
1962 too limited to allow for a tempory copy of the
1963 downloaded image) this option may be very useful.
1966 Define if the flash driver uses extra elements in the
1967 common flash structure for storing flash geometry.
1969 - CFG_FLASH_CFI_DRIVER
1970 This option also enables the building of the cfi_flash driver
1971 in the drivers directory
1973 - CFG_FLASH_QUIET_TEST
1974 If this option is defined, the common CFI flash doesn't
1975 print it's warning upon not recognized FLASH banks. This
1976 is useful, if some of the configured banks are only
1977 optionally available.
1979 - CFG_RX_ETH_BUFFER:
1980 Defines the number of ethernet receive buffers. On some
1981 ethernet controllers it is recommended to set this value
1982 to 8 or even higher (EEPRO100 or 405 EMAC), since all
1983 buffers can be full shortly after enabling the interface
1984 on high ethernet traffic.
1985 Defaults to 4 if not defined.
1987 The following definitions that deal with the placement and management
1988 of environment data (variable area); in general, we support the
1989 following configurations:
1991 - CFG_ENV_IS_IN_FLASH:
1993 Define this if the environment is in flash memory.
1995 a) The environment occupies one whole flash sector, which is
1996 "embedded" in the text segment with the U-Boot code. This
1997 happens usually with "bottom boot sector" or "top boot
1998 sector" type flash chips, which have several smaller
1999 sectors at the start or the end. For instance, such a
2000 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2001 such a case you would place the environment in one of the
2002 4 kB sectors - with U-Boot code before and after it. With
2003 "top boot sector" type flash chips, you would put the
2004 environment in one of the last sectors, leaving a gap
2005 between U-Boot and the environment.
2009 Offset of environment data (variable area) to the
2010 beginning of flash memory; for instance, with bottom boot
2011 type flash chips the second sector can be used: the offset
2012 for this sector is given here.
2014 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
2018 This is just another way to specify the start address of
2019 the flash sector containing the environment (instead of
2022 - CFG_ENV_SECT_SIZE:
2024 Size of the sector containing the environment.
2027 b) Sometimes flash chips have few, equal sized, BIG sectors.
2028 In such a case you don't want to spend a whole sector for
2033 If you use this in combination with CFG_ENV_IS_IN_FLASH
2034 and CFG_ENV_SECT_SIZE, you can specify to use only a part
2035 of this flash sector for the environment. This saves
2036 memory for the RAM copy of the environment.
2038 It may also save flash memory if you decide to use this
2039 when your environment is "embedded" within U-Boot code,
2040 since then the remainder of the flash sector could be used
2041 for U-Boot code. It should be pointed out that this is
2042 STRONGLY DISCOURAGED from a robustness point of view:
2043 updating the environment in flash makes it always
2044 necessary to erase the WHOLE sector. If something goes
2045 wrong before the contents has been restored from a copy in
2046 RAM, your target system will be dead.
2048 - CFG_ENV_ADDR_REDUND
2051 These settings describe a second storage area used to hold
2052 a redundand copy of the environment data, so that there is
2053 a valid backup copy in case there is a power failure during
2054 a "saveenv" operation.
2056 BE CAREFUL! Any changes to the flash layout, and some changes to the
2057 source code will make it necessary to adapt <board>/u-boot.lds*
2061 - CFG_ENV_IS_IN_NVRAM:
2063 Define this if you have some non-volatile memory device
2064 (NVRAM, battery buffered SRAM) which you want to use for the
2070 These two #defines are used to determin the memory area you
2071 want to use for environment. It is assumed that this memory
2072 can just be read and written to, without any special
2075 BE CAREFUL! The first access to the environment happens quite early
2076 in U-Boot initalization (when we try to get the setting of for the
2077 console baudrate). You *MUST* have mappend your NVRAM area then, or
2080 Please note that even with NVRAM we still use a copy of the
2081 environment in RAM: we could work on NVRAM directly, but we want to
2082 keep settings there always unmodified except somebody uses "saveenv"
2083 to save the current settings.
2086 - CFG_ENV_IS_IN_EEPROM:
2088 Use this if you have an EEPROM or similar serial access
2089 device and a driver for it.
2094 These two #defines specify the offset and size of the
2095 environment area within the total memory of your EEPROM.
2097 - CFG_I2C_EEPROM_ADDR:
2098 If defined, specified the chip address of the EEPROM device.
2099 The default address is zero.
2101 - CFG_EEPROM_PAGE_WRITE_BITS:
2102 If defined, the number of bits used to address bytes in a
2103 single page in the EEPROM device. A 64 byte page, for example
2104 would require six bits.
2106 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
2107 If defined, the number of milliseconds to delay between
2108 page writes. The default is zero milliseconds.
2110 - CFG_I2C_EEPROM_ADDR_LEN:
2111 The length in bytes of the EEPROM memory array address. Note
2112 that this is NOT the chip address length!
2114 - CFG_I2C_EEPROM_ADDR_OVERFLOW:
2115 EEPROM chips that implement "address overflow" are ones
2116 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2117 address and the extra bits end up in the "chip address" bit
2118 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2121 Note that we consider the length of the address field to
2122 still be one byte because the extra address bits are hidden
2123 in the chip address.
2126 The size in bytes of the EEPROM device.
2129 - CFG_ENV_IS_IN_DATAFLASH:
2131 Define this if you have a DataFlash memory device which you
2132 want to use for the environment.
2138 These three #defines specify the offset and size of the
2139 environment area within the total memory of your DataFlash placed
2140 at the specified address.
2142 - CFG_ENV_IS_IN_NAND:
2144 Define this if you have a NAND device which you want to use
2145 for the environment.
2150 These two #defines specify the offset and size of the environment
2151 area within the first NAND device.
2153 - CFG_ENV_OFFSET_REDUND
2155 This setting describes a second storage area of CFG_ENV_SIZE
2156 size used to hold a redundant copy of the environment data,
2157 so that there is a valid backup copy in case there is a
2158 power failure during a "saveenv" operation.
2160 Note: CFG_ENV_OFFSET and CFG_ENV_OFFSET_REDUND must be aligned
2161 to a block boundary, and CFG_ENV_SIZE must be a multiple of
2162 the NAND devices block size.
2164 - CFG_SPI_INIT_OFFSET
2166 Defines offset to the initial SPI buffer area in DPRAM. The
2167 area is used at an early stage (ROM part) if the environment
2168 is configured to reside in the SPI EEPROM: We need a 520 byte
2169 scratch DPRAM area. It is used between the two initialization
2170 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2171 to be a good choice since it makes it far enough from the
2172 start of the data area as well as from the stack pointer.
2174 Please note that the environment is read-only as long as the monitor
2175 has been relocated to RAM and a RAM copy of the environment has been
2176 created; also, when using EEPROM you will have to use getenv_r()
2177 until then to read environment variables.
2179 The environment is protected by a CRC32 checksum. Before the monitor
2180 is relocated into RAM, as a result of a bad CRC you will be working
2181 with the compiled-in default environment - *silently*!!! [This is
2182 necessary, because the first environment variable we need is the
2183 "baudrate" setting for the console - if we have a bad CRC, we don't
2184 have any device yet where we could complain.]
2186 Note: once the monitor has been relocated, then it will complain if
2187 the default environment is used; a new CRC is computed as soon as you
2188 use the "saveenv" command to store a valid environment.
2190 - CFG_FAULT_ECHO_LINK_DOWN:
2191 Echo the inverted Ethernet link state to the fault LED.
2193 Note: If this option is active, then CFG_FAULT_MII_ADDR
2194 also needs to be defined.
2196 - CFG_FAULT_MII_ADDR:
2197 MII address of the PHY to check for the Ethernet link state.
2199 - CFG_64BIT_VSPRINTF:
2200 Makes vsprintf (and all *printf functions) support printing
2201 of 64bit values by using the L quantifier
2203 - CFG_64BIT_STRTOUL:
2204 Adds simple_strtoull that returns a 64bit value
2206 Low Level (hardware related) configuration options:
2207 ---------------------------------------------------
2209 - CFG_CACHELINE_SIZE:
2210 Cache Line Size of the CPU.
2213 Default address of the IMMR after system reset.
2215 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2216 and RPXsuper) to be able to adjust the position of
2217 the IMMR register after a reset.
2219 - Floppy Disk Support:
2220 CFG_FDC_DRIVE_NUMBER
2222 the default drive number (default value 0)
2226 defines the spacing between fdc chipset registers
2231 defines the offset of register from address. It
2232 depends on which part of the data bus is connected to
2233 the fdc chipset. (default value 0)
2235 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
2236 CFG_FDC_DRIVE_NUMBER are undefined, they take their
2239 if CFG_FDC_HW_INIT is defined, then the function
2240 fdc_hw_init() is called at the beginning of the FDC
2241 setup. fdc_hw_init() must be provided by the board
2242 source code. It is used to make hardware dependant
2245 - CFG_IMMR: Physical address of the Internal Memory.
2246 DO NOT CHANGE unless you know exactly what you're
2247 doing! (11-4) [MPC8xx/82xx systems only]
2249 - CFG_INIT_RAM_ADDR:
2251 Start address of memory area that can be used for
2252 initial data and stack; please note that this must be
2253 writable memory that is working WITHOUT special
2254 initialization, i. e. you CANNOT use normal RAM which
2255 will become available only after programming the
2256 memory controller and running certain initialization
2259 U-Boot uses the following memory types:
2260 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2261 - MPC824X: data cache
2262 - PPC4xx: data cache
2264 - CFG_GBL_DATA_OFFSET:
2266 Offset of the initial data structure in the memory
2267 area defined by CFG_INIT_RAM_ADDR. Usually
2268 CFG_GBL_DATA_OFFSET is chosen such that the initial
2269 data is located at the end of the available space
2270 (sometimes written as (CFG_INIT_RAM_END -
2271 CFG_INIT_DATA_SIZE), and the initial stack is just
2272 below that area (growing from (CFG_INIT_RAM_ADDR +
2273 CFG_GBL_DATA_OFFSET) downward.
2276 On the MPC824X (or other systems that use the data
2277 cache for initial memory) the address chosen for
2278 CFG_INIT_RAM_ADDR is basically arbitrary - it must
2279 point to an otherwise UNUSED address space between
2280 the top of RAM and the start of the PCI space.
2282 - CFG_SIUMCR: SIU Module Configuration (11-6)
2284 - CFG_SYPCR: System Protection Control (11-9)
2286 - CFG_TBSCR: Time Base Status and Control (11-26)
2288 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
2290 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2292 - CFG_SCCR: System Clock and reset Control Register (15-27)
2294 - CFG_OR_TIMING_SDRAM:
2298 periodic timer for refresh
2300 - CFG_DER: Debug Event Register (37-47)
2302 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
2303 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
2304 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
2306 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2308 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2309 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
2310 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
2311 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2313 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
2314 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
2315 Machine Mode Register and Memory Periodic Timer
2316 Prescaler definitions (SDRAM timing)
2318 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
2319 enable I2C microcode relocation patch (MPC8xx);
2320 define relocation offset in DPRAM [DSP2]
2322 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
2323 enable SPI microcode relocation patch (MPC8xx);
2324 define relocation offset in DPRAM [SCC4]
2327 Use OSCM clock mode on MBX8xx board. Be careful,
2328 wrong setting might damage your board. Read
2329 doc/README.MBX before setting this variable!
2331 - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2332 Offset of the bootmode word in DPRAM used by post
2333 (Power On Self Tests). This definition overrides
2334 #define'd default value in commproc.h resp.
2337 - CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
2338 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
2339 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
2340 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
2341 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2342 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
2343 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
2344 CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
2345 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2348 Get DDR timing information from an I2C EEPROM. Common with pluggable
2349 memory modules such as SODIMMs
2351 I2C address of the SPD EEPROM
2354 If SPD EEPROM is on an I2C bus other than the first one, specify here.
2355 Note that the value must resolve to something your driver can deal with.
2357 - CFG_83XX_DDR_USES_CS0
2358 Only for 83xx systems. If specified, then DDR should be configured
2359 using CS0 and CS1 instead of CS2 and CS3.
2361 - CFG_83XX_DDR_USES_CS0
2362 Only for 83xx systems. If specified, then DDR should be configured
2363 using CS0 and CS1 instead of CS2 and CS3.
2365 - CONFIG_ETHER_ON_FEC[12]
2366 Define to enable FEC[12] on a 8xx series processor.
2368 - CONFIG_FEC[12]_PHY
2369 Define to the hardcoded PHY address which corresponds
2370 to the given FEC; i. e.
2371 #define CONFIG_FEC1_PHY 4
2372 means that the PHY with address 4 is connected to FEC1
2374 When set to -1, means to probe for first available.
2376 - CONFIG_FEC[12]_PHY_NORXERR
2377 The PHY does not have a RXERR line (RMII only).
2378 (so program the FEC to ignore it).
2381 Enable RMII mode for all FECs.
2382 Note that this is a global option, we can't
2383 have one FEC in standard MII mode and another in RMII mode.
2385 - CONFIG_CRC32_VERIFY
2386 Add a verify option to the crc32 command.
2389 => crc32 -v <address> <count> <crc32>
2391 Where address/count indicate a memory area
2392 and crc32 is the correct crc32 which the
2396 Add the "loopw" memory command. This only takes effect if
2397 the memory commands are activated globally (CFG_CMD_MEM).
2400 Add the "mdc" and "mwc" memory commands. These are cyclic
2405 This command will print 4 bytes (10,11,12,13) each 500 ms.
2407 => mwc.l 100 12345678 10
2408 This command will write 12345678 to address 100 all 10 ms.
2410 This only takes effect if the memory commands are activated
2411 globally (CFG_CMD_MEM).
2413 - CONFIG_SKIP_LOWLEVEL_INIT
2414 - CONFIG_SKIP_RELOCATE_UBOOT
2416 [ARM only] If these variables are defined, then
2417 certain low level initializations (like setting up
2418 the memory controller) are omitted and/or U-Boot does
2419 not relocate itself into RAM.
2420 Normally these variables MUST NOT be defined. The
2421 only exception is when U-Boot is loaded (to RAM) by
2422 some other boot loader or by a debugger which
2423 performs these intializations itself.
2426 Building the Software:
2427 ======================
2429 Building U-Boot has been tested in native PPC environments (on a
2430 PowerBook G3 running LinuxPPC 2000) and in cross environments
2431 (running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
2434 If you are not using a native PPC environment, it is assumed that you
2435 have the GNU cross compiling tools available in your path and named
2436 with a prefix of "powerpc-linux-". If this is not the case, (e.g. if
2437 you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
2438 the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
2441 CROSS_COMPILE = ppc_4xx-
2444 U-Boot is intended to be simple to build. After installing the
2445 sources you must configure U-Boot for one specific board type. This
2450 where "NAME_config" is the name of one of the existing
2451 configurations; the following names are supported:
2453 ADCIOP_config FPS860L_config omap730p2_config
2454 ADS860_config GEN860T_config pcu_e_config
2456 AR405_config GENIETV_config PIP405_config
2457 at91rm9200dk_config GTH_config QS823_config
2458 CANBT_config hermes_config QS850_config
2459 cmi_mpc5xx_config hymod_config QS860T_config
2460 cogent_common_config IP860_config RPXlite_config
2461 cogent_mpc8260_config IVML24_config RPXlite_DW_config
2462 cogent_mpc8xx_config IVMS8_config RPXsuper_config
2463 CPCI405_config JSE_config rsdproto_config
2464 CPCIISER4_config LANTEC_config Sandpoint8240_config
2465 csb272_config lwmon_config sbc8260_config
2466 CU824_config MBX860T_config sbc8560_33_config
2467 DUET_ADS_config MBX_config sbc8560_66_config
2468 EBONY_config mpc7448hpc2_config SM850_config
2469 ELPT860_config MPC8260ADS_config SPD823TS_config
2470 ESTEEM192E_config MPC8540ADS_config stxgp3_config
2471 ETX094_config MPC8540EVAL_config SXNI855T_config
2472 FADS823_config NMPC8560ADS_config TQM823L_config
2473 FADS850SAR_config NETVIA_config TQM850L_config
2474 FADS860T_config omap1510inn_config TQM855L_config
2475 FPS850L_config omap1610h2_config TQM860L_config
2476 omap1610inn_config walnut_config
2477 omap5912osk_config Yukon8220_config
2478 omap2420h4_config ZPC1900_config
2480 Note: for some board special configuration names may exist; check if
2481 additional information is available from the board vendor; for
2482 instance, the TQM823L systems are available without (standard)
2483 or with LCD support. You can select such additional "features"
2484 when chosing the configuration, i. e.
2487 - will configure for a plain TQM823L, i. e. no LCD support
2489 make TQM823L_LCD_config
2490 - will configure for a TQM823L with U-Boot console on LCD
2495 Finally, type "make all", and you should get some working U-Boot
2496 images ready for download to / installation on your system:
2498 - "u-boot.bin" is a raw binary image
2499 - "u-boot" is an image in ELF binary format
2500 - "u-boot.srec" is in Motorola S-Record format
2502 By default the build is performed locally and the objects are saved
2503 in the source directory. One of the two methods can be used to change
2504 this behavior and build U-Boot to some external directory:
2506 1. Add O= to the make command line invocations:
2508 make O=/tmp/build distclean
2509 make O=/tmp/build NAME_config
2510 make O=/tmp/build all
2512 2. Set environment variable BUILD_DIR to point to the desired location:
2514 export BUILD_DIR=/tmp/build
2519 Note that the command line "O=" setting overrides the BUILD_DIR environment
2523 Please be aware that the Makefiles assume you are using GNU make, so
2524 for instance on NetBSD you might need to use "gmake" instead of
2528 If the system board that you have is not listed, then you will need
2529 to port U-Boot to your hardware platform. To do this, follow these
2532 1. Add a new configuration option for your board to the toplevel
2533 "Makefile" and to the "MAKEALL" script, using the existing
2534 entries as examples. Note that here and at many other places
2535 boards and other names are listed in alphabetical sort order. Please
2537 2. Create a new directory to hold your board specific code. Add any
2538 files you need. In your board directory, you will need at least
2539 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2540 3. Create a new configuration file "include/configs/<board>.h" for
2542 3. If you're porting U-Boot to a new CPU, then also create a new
2543 directory to hold your CPU specific code. Add any files you need.
2544 4. Run "make <board>_config" with your new name.
2545 5. Type "make", and you should get a working "u-boot.srec" file
2546 to be installed on your target system.
2547 6. Debug and solve any problems that might arise.
2548 [Of course, this last step is much harder than it sounds.]
2551 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2552 ==============================================================
2554 If you have modified U-Boot sources (for instance added a new board
2555 or support for new devices, a new CPU, etc.) you are expected to
2556 provide feedback to the other developers. The feedback normally takes
2557 the form of a "patch", i. e. a context diff against a certain (latest
2558 official or latest in CVS) version of U-Boot sources.
2560 But before you submit such a patch, please verify that your modifi-
2561 cation did not break existing code. At least make sure that *ALL* of
2562 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2563 just run the "MAKEALL" script, which will configure and build U-Boot
2564 for ALL supported system. Be warned, this will take a while. You can
2565 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2566 environment variable to the script, i. e. to use the cross tools from
2567 MontaVista's Hard Hat Linux you can type
2569 CROSS_COMPILE=ppc_8xx- MAKEALL
2571 or to build on a native PowerPC system you can type
2573 CROSS_COMPILE=' ' MAKEALL
2575 When using the MAKEALL script, the default behaviour is to build U-Boot
2576 in the source directory. This location can be changed by setting the
2577 BUILD_DIR environment variable. Also, for each target built, the MAKEALL
2578 script saves two log files (<target>.ERR and <target>.MAKEALL) in the
2579 <source dir>/LOG directory. This default location can be changed by
2580 setting the MAKEALL_LOGDIR environment variable. For example:
2582 export BUILD_DIR=/tmp/build
2583 export MAKEALL_LOGDIR=/tmp/log
2584 CROSS_COMPILE=ppc_8xx- MAKEALL
2586 With the above settings build objects are saved in the /tmp/build, log
2587 files are saved in the /tmp/log and the source tree remains clean during
2588 the whole build process.
2591 See also "U-Boot Porting Guide" below.
2594 Monitor Commands - Overview:
2595 ============================
2597 go - start application at address 'addr'
2598 run - run commands in an environment variable
2599 bootm - boot application image from memory
2600 bootp - boot image via network using BootP/TFTP protocol
2601 tftpboot- boot image via network using TFTP protocol
2602 and env variables "ipaddr" and "serverip"
2603 (and eventually "gatewayip")
2604 rarpboot- boot image via network using RARP/TFTP protocol
2605 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2606 loads - load S-Record file over serial line
2607 loadb - load binary file over serial line (kermit mode)
2609 mm - memory modify (auto-incrementing)
2610 nm - memory modify (constant address)
2611 mw - memory write (fill)
2613 cmp - memory compare
2614 crc32 - checksum calculation
2615 imd - i2c memory display
2616 imm - i2c memory modify (auto-incrementing)
2617 inm - i2c memory modify (constant address)
2618 imw - i2c memory write (fill)
2619 icrc32 - i2c checksum calculation
2620 iprobe - probe to discover valid I2C chip addresses
2621 iloop - infinite loop on address range
2622 isdram - print SDRAM configuration information
2623 sspi - SPI utility commands
2624 base - print or set address offset
2625 printenv- print environment variables
2626 setenv - set environment variables
2627 saveenv - save environment variables to persistent storage
2628 protect - enable or disable FLASH write protection
2629 erase - erase FLASH memory
2630 flinfo - print FLASH memory information
2631 bdinfo - print Board Info structure
2632 iminfo - print header information for application image
2633 coninfo - print console devices and informations
2634 ide - IDE sub-system
2635 loop - infinite loop on address range
2636 loopw - infinite write loop on address range
2637 mtest - simple RAM test
2638 icache - enable or disable instruction cache
2639 dcache - enable or disable data cache
2640 reset - Perform RESET of the CPU
2641 echo - echo args to console
2642 version - print monitor version
2643 help - print online help
2644 ? - alias for 'help'
2647 Monitor Commands - Detailed Description:
2648 ========================================
2652 For now: just type "help <command>".
2655 Environment Variables:
2656 ======================
2658 U-Boot supports user configuration using Environment Variables which
2659 can be made persistent by saving to Flash memory.
2661 Environment Variables are set using "setenv", printed using
2662 "printenv", and saved to Flash using "saveenv". Using "setenv"
2663 without a value can be used to delete a variable from the
2664 environment. As long as you don't save the environment you are
2665 working with an in-memory copy. In case the Flash area containing the
2666 environment is erased by accident, a default environment is provided.
2668 Some configuration options can be set using Environment Variables:
2670 baudrate - see CONFIG_BAUDRATE
2672 bootdelay - see CONFIG_BOOTDELAY
2674 bootcmd - see CONFIG_BOOTCOMMAND
2676 bootargs - Boot arguments when booting an RTOS image
2678 bootfile - Name of the image to load with TFTP
2680 autoload - if set to "no" (any string beginning with 'n'),
2681 "bootp" will just load perform a lookup of the
2682 configuration from the BOOTP server, but not try to
2683 load any image using TFTP
2685 autostart - if set to "yes", an image loaded using the "bootp",
2686 "rarpboot", "tftpboot" or "diskboot" commands will
2687 be automatically started (by internally calling
2690 If set to "no", a standalone image passed to the
2691 "bootm" command will be copied to the load address
2692 (and eventually uncompressed), but NOT be started.
2693 This can be used to load and uncompress arbitrary
2696 i2cfast - (PPC405GP|PPC405EP only)
2697 if set to 'y' configures Linux I2C driver for fast
2698 mode (400kHZ). This environment variable is used in
2699 initialization code. So, for changes to be effective
2700 it must be saved and board must be reset.
2702 initrd_high - restrict positioning of initrd images:
2703 If this variable is not set, initrd images will be
2704 copied to the highest possible address in RAM; this
2705 is usually what you want since it allows for
2706 maximum initrd size. If for some reason you want to
2707 make sure that the initrd image is loaded below the
2708 CFG_BOOTMAPSZ limit, you can set this environment
2709 variable to a value of "no" or "off" or "0".
2710 Alternatively, you can set it to a maximum upper
2711 address to use (U-Boot will still check that it
2712 does not overwrite the U-Boot stack and data).
2714 For instance, when you have a system with 16 MB
2715 RAM, and want to reserve 4 MB from use by Linux,
2716 you can do this by adding "mem=12M" to the value of
2717 the "bootargs" variable. However, now you must make
2718 sure that the initrd image is placed in the first
2719 12 MB as well - this can be done with
2721 setenv initrd_high 00c00000
2723 If you set initrd_high to 0xFFFFFFFF, this is an
2724 indication to U-Boot that all addresses are legal
2725 for the Linux kernel, including addresses in flash
2726 memory. In this case U-Boot will NOT COPY the
2727 ramdisk at all. This may be useful to reduce the
2728 boot time on your system, but requires that this
2729 feature is supported by your Linux kernel.
2731 ipaddr - IP address; needed for tftpboot command
2733 loadaddr - Default load address for commands like "bootp",
2734 "rarpboot", "tftpboot", "loadb" or "diskboot"
2736 loads_echo - see CONFIG_LOADS_ECHO
2738 serverip - TFTP server IP address; needed for tftpboot command
2740 bootretry - see CONFIG_BOOT_RETRY_TIME
2742 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
2744 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
2746 ethprime - When CONFIG_NET_MULTI is enabled controls which
2747 interface is used first.
2749 ethact - When CONFIG_NET_MULTI is enabled controls which
2750 interface is currently active. For example you
2751 can do the following
2753 => setenv ethact FEC ETHERNET
2754 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
2755 => setenv ethact SCC ETHERNET
2756 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
2758 netretry - When set to "no" each network operation will
2759 either succeed or fail without retrying.
2760 When set to "once" the network operation will
2761 fail when all the available network interfaces
2762 are tried once without success.
2763 Useful on scripts which control the retry operation
2766 tftpsrcport - If this is set, the value is used for TFTP's
2769 tftpdstport - If this is set, the value is used for TFTP's UDP
2770 destination port instead of the Well Know Port 69.
2772 vlan - When set to a value < 4095 the traffic over
2773 ethernet is encapsulated/received over 802.1q
2776 The following environment variables may be used and automatically
2777 updated by the network boot commands ("bootp" and "rarpboot"),
2778 depending the information provided by your boot server:
2780 bootfile - see above
2781 dnsip - IP address of your Domain Name Server
2782 dnsip2 - IP address of your secondary Domain Name Server
2783 gatewayip - IP address of the Gateway (Router) to use
2784 hostname - Target hostname
2786 netmask - Subnet Mask
2787 rootpath - Pathname of the root filesystem on the NFS server
2788 serverip - see above
2791 There are two special Environment Variables:
2793 serial# - contains hardware identification information such
2794 as type string and/or serial number
2795 ethaddr - Ethernet address
2797 These variables can be set only once (usually during manufacturing of
2798 the board). U-Boot refuses to delete or overwrite these variables
2799 once they have been set once.
2802 Further special Environment Variables:
2804 ver - Contains the U-Boot version string as printed
2805 with the "version" command. This variable is
2806 readonly (see CONFIG_VERSION_VARIABLE).
2809 Please note that changes to some configuration parameters may take
2810 only effect after the next boot (yes, that's just like Windoze :-).
2813 Command Line Parsing:
2814 =====================
2816 There are two different command line parsers available with U-Boot:
2817 the old "simple" one, and the much more powerful "hush" shell:
2819 Old, simple command line parser:
2820 --------------------------------
2822 - supports environment variables (through setenv / saveenv commands)
2823 - several commands on one line, separated by ';'
2824 - variable substitution using "... ${name} ..." syntax
2825 - special characters ('$', ';') can be escaped by prefixing with '\',
2827 setenv bootcmd bootm \${address}
2828 - You can also escape text by enclosing in single apostrophes, for example:
2829 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2834 - similar to Bourne shell, with control structures like
2835 if...then...else...fi, for...do...done; while...do...done,
2836 until...do...done, ...
2837 - supports environment ("global") variables (through setenv / saveenv
2838 commands) and local shell variables (through standard shell syntax
2839 "name=value"); only environment variables can be used with "run"
2845 (1) If a command line (or an environment variable executed by a "run"
2846 command) contains several commands separated by semicolon, and
2847 one of these commands fails, then the remaining commands will be
2850 (2) If you execute several variables with one call to run (i. e.
2851 calling run with a list af variables as arguments), any failing
2852 command will cause "run" to terminate, i. e. the remaining
2853 variables are not executed.
2855 Note for Redundant Ethernet Interfaces:
2856 =======================================
2858 Some boards come with redundant ethernet interfaces; U-Boot supports
2859 such configurations and is capable of automatic selection of a
2860 "working" interface when needed. MAC assignment works as follows:
2862 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2863 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2864 "eth1addr" (=>eth1), "eth2addr", ...
2866 If the network interface stores some valid MAC address (for instance
2867 in SROM), this is used as default address if there is NO correspon-
2868 ding setting in the environment; if the corresponding environment
2869 variable is set, this overrides the settings in the card; that means:
2871 o If the SROM has a valid MAC address, and there is no address in the
2872 environment, the SROM's address is used.
2874 o If there is no valid address in the SROM, and a definition in the
2875 environment exists, then the value from the environment variable is
2878 o If both the SROM and the environment contain a MAC address, and
2879 both addresses are the same, this MAC address is used.
2881 o If both the SROM and the environment contain a MAC address, and the
2882 addresses differ, the value from the environment is used and a
2885 o If neither SROM nor the environment contain a MAC address, an error
2892 The "boot" commands of this monitor operate on "image" files which
2893 can be basicly anything, preceeded by a special header; see the
2894 definitions in include/image.h for details; basicly, the header
2895 defines the following image properties:
2897 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2898 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2899 LynxOS, pSOS, QNX, RTEMS, ARTOS;
2900 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
2901 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
2902 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2903 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
2904 * Compression Type (uncompressed, gzip, bzip2)
2910 The header is marked by a special Magic Number, and both the header
2911 and the data portions of the image are secured against corruption by
2918 Although U-Boot should support any OS or standalone application
2919 easily, the main focus has always been on Linux during the design of
2922 U-Boot includes many features that so far have been part of some
2923 special "boot loader" code within the Linux kernel. Also, any
2924 "initrd" images to be used are no longer part of one big Linux image;
2925 instead, kernel and "initrd" are separate images. This implementation
2926 serves several purposes:
2928 - the same features can be used for other OS or standalone
2929 applications (for instance: using compressed images to reduce the
2930 Flash memory footprint)
2932 - it becomes much easier to port new Linux kernel versions because
2933 lots of low-level, hardware dependent stuff are done by U-Boot
2935 - the same Linux kernel image can now be used with different "initrd"
2936 images; of course this also means that different kernel images can
2937 be run with the same "initrd". This makes testing easier (you don't
2938 have to build a new "zImage.initrd" Linux image when you just
2939 change a file in your "initrd"). Also, a field-upgrade of the
2940 software is easier now.
2946 Porting Linux to U-Boot based systems:
2947 ---------------------------------------
2949 U-Boot cannot save you from doing all the necessary modifications to
2950 configure the Linux device drivers for use with your target hardware
2951 (no, we don't intend to provide a full virtual machine interface to
2954 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
2956 Just make sure your machine specific header file (for instance
2957 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
2958 Information structure as we define in include/u-boot.h, and make
2959 sure that your definition of IMAP_ADDR uses the same value as your
2960 U-Boot configuration in CFG_IMMR.
2963 Configuring the Linux kernel:
2964 -----------------------------
2966 No specific requirements for U-Boot. Make sure you have some root
2967 device (initial ramdisk, NFS) for your target system.
2970 Building a Linux Image:
2971 -----------------------
2973 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2974 not used. If you use recent kernel source, a new build target
2975 "uImage" will exist which automatically builds an image usable by
2976 U-Boot. Most older kernels also have support for a "pImage" target,
2977 which was introduced for our predecessor project PPCBoot and uses a
2978 100% compatible format.
2987 The "uImage" build target uses a special tool (in 'tools/mkimage') to
2988 encapsulate a compressed Linux kernel image with header information,
2989 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
2991 * build a standard "vmlinux" kernel image (in ELF binary format):
2993 * convert the kernel into a raw binary image:
2995 ${CROSS_COMPILE}-objcopy -O binary \
2996 -R .note -R .comment \
2997 -S vmlinux linux.bin
2999 * compress the binary image:
3003 * package compressed binary image for U-Boot:
3005 mkimage -A ppc -O linux -T kernel -C gzip \
3006 -a 0 -e 0 -n "Linux Kernel Image" \
3007 -d linux.bin.gz uImage
3010 The "mkimage" tool can also be used to create ramdisk images for use
3011 with U-Boot, either separated from the Linux kernel image, or
3012 combined into one file. "mkimage" encapsulates the images with a 64
3013 byte header containing information about target architecture,
3014 operating system, image type, compression method, entry points, time
3015 stamp, CRC32 checksums, etc.
3017 "mkimage" can be called in two ways: to verify existing images and
3018 print the header information, or to build new images.
3020 In the first form (with "-l" option) mkimage lists the information
3021 contained in the header of an existing U-Boot image; this includes
3022 checksum verification:
3024 tools/mkimage -l image
3025 -l ==> list image header information
3027 The second form (with "-d" option) is used to build a U-Boot image
3028 from a "data file" which is used as image payload:
3030 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3031 -n name -d data_file image
3032 -A ==> set architecture to 'arch'
3033 -O ==> set operating system to 'os'
3034 -T ==> set image type to 'type'
3035 -C ==> set compression type 'comp'
3036 -a ==> set load address to 'addr' (hex)
3037 -e ==> set entry point to 'ep' (hex)
3038 -n ==> set image name to 'name'
3039 -d ==> use image data from 'datafile'
3041 Right now, all Linux kernels for PowerPC systems use the same load
3042 address (0x00000000), but the entry point address depends on the
3045 - 2.2.x kernels have the entry point at 0x0000000C,
3046 - 2.3.x and later kernels have the entry point at 0x00000000.
3048 So a typical call to build a U-Boot image would read:
3050 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3051 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3052 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
3053 > examples/uImage.TQM850L
3054 Image Name: 2.4.4 kernel for TQM850L
3055 Created: Wed Jul 19 02:34:59 2000
3056 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3057 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3058 Load Address: 0x00000000
3059 Entry Point: 0x00000000
3061 To verify the contents of the image (or check for corruption):
3063 -> tools/mkimage -l examples/uImage.TQM850L
3064 Image Name: 2.4.4 kernel for TQM850L
3065 Created: Wed Jul 19 02:34:59 2000
3066 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3067 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3068 Load Address: 0x00000000
3069 Entry Point: 0x00000000
3071 NOTE: for embedded systems where boot time is critical you can trade
3072 speed for memory and install an UNCOMPRESSED image instead: this
3073 needs more space in Flash, but boots much faster since it does not
3074 need to be uncompressed:
3076 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
3077 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3078 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3079 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
3080 > examples/uImage.TQM850L-uncompressed
3081 Image Name: 2.4.4 kernel for TQM850L
3082 Created: Wed Jul 19 02:34:59 2000
3083 Image Type: PowerPC Linux Kernel Image (uncompressed)
3084 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3085 Load Address: 0x00000000
3086 Entry Point: 0x00000000
3089 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3090 when your kernel is intended to use an initial ramdisk:
3092 -> tools/mkimage -n 'Simple Ramdisk Image' \
3093 > -A ppc -O linux -T ramdisk -C gzip \
3094 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3095 Image Name: Simple Ramdisk Image
3096 Created: Wed Jan 12 14:01:50 2000
3097 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3098 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3099 Load Address: 0x00000000
3100 Entry Point: 0x00000000
3103 Installing a Linux Image:
3104 -------------------------
3106 To downloading a U-Boot image over the serial (console) interface,
3107 you must convert the image to S-Record format:
3109 objcopy -I binary -O srec examples/image examples/image.srec
3111 The 'objcopy' does not understand the information in the U-Boot
3112 image header, so the resulting S-Record file will be relative to
3113 address 0x00000000. To load it to a given address, you need to
3114 specify the target address as 'offset' parameter with the 'loads'
3117 Example: install the image to address 0x40100000 (which on the
3118 TQM8xxL is in the first Flash bank):
3120 => erase 40100000 401FFFFF
3126 ## Ready for S-Record download ...
3127 ~>examples/image.srec
3128 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3130 15989 15990 15991 15992
3131 [file transfer complete]
3133 ## Start Addr = 0x00000000
3136 You can check the success of the download using the 'iminfo' command;
3137 this includes a checksum verification so you can be sure no data
3138 corruption happened:
3142 ## Checking Image at 40100000 ...
3143 Image Name: 2.2.13 for initrd on TQM850L
3144 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3145 Data Size: 335725 Bytes = 327 kB = 0 MB
3146 Load Address: 00000000
3147 Entry Point: 0000000c
3148 Verifying Checksum ... OK
3154 The "bootm" command is used to boot an application that is stored in
3155 memory (RAM or Flash). In case of a Linux kernel image, the contents
3156 of the "bootargs" environment variable is passed to the kernel as
3157 parameters. You can check and modify this variable using the
3158 "printenv" and "setenv" commands:
3161 => printenv bootargs
3162 bootargs=root=/dev/ram
3164 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3166 => printenv bootargs
3167 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3170 ## Booting Linux kernel at 40020000 ...
3171 Image Name: 2.2.13 for NFS on TQM850L
3172 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3173 Data Size: 381681 Bytes = 372 kB = 0 MB
3174 Load Address: 00000000
3175 Entry Point: 0000000c
3176 Verifying Checksum ... OK
3177 Uncompressing Kernel Image ... OK
3178 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
3179 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3180 time_init: decrementer frequency = 187500000/60
3181 Calibrating delay loop... 49.77 BogoMIPS
3182 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3185 If you want to boot a Linux kernel with initial ram disk, you pass
3186 the memory addresses of both the kernel and the initrd image (PPBCOOT
3187 format!) to the "bootm" command:
3189 => imi 40100000 40200000
3191 ## Checking Image at 40100000 ...
3192 Image Name: 2.2.13 for initrd on TQM850L
3193 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3194 Data Size: 335725 Bytes = 327 kB = 0 MB
3195 Load Address: 00000000
3196 Entry Point: 0000000c
3197 Verifying Checksum ... OK
3199 ## Checking Image at 40200000 ...
3200 Image Name: Simple Ramdisk Image
3201 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3202 Data Size: 566530 Bytes = 553 kB = 0 MB
3203 Load Address: 00000000
3204 Entry Point: 00000000
3205 Verifying Checksum ... OK
3207 => bootm 40100000 40200000
3208 ## Booting Linux kernel at 40100000 ...
3209 Image Name: 2.2.13 for initrd on TQM850L
3210 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3211 Data Size: 335725 Bytes = 327 kB = 0 MB
3212 Load Address: 00000000
3213 Entry Point: 0000000c
3214 Verifying Checksum ... OK
3215 Uncompressing Kernel Image ... OK
3216 ## Loading RAMDisk Image at 40200000 ...
3217 Image Name: Simple Ramdisk Image
3218 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3219 Data Size: 566530 Bytes = 553 kB = 0 MB
3220 Load Address: 00000000
3221 Entry Point: 00000000
3222 Verifying Checksum ... OK
3223 Loading Ramdisk ... OK
3224 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
3225 Boot arguments: root=/dev/ram
3226 time_init: decrementer frequency = 187500000/60
3227 Calibrating delay loop... 49.77 BogoMIPS
3229 RAMDISK: Compressed image found at block 0
3230 VFS: Mounted root (ext2 filesystem).
3234 Boot Linux and pass a flat device tree:
3237 First, U-Boot must be compiled with the appropriate defines. See the section
3238 titled "Linux Kernel Interface" above for a more in depth explanation. The
3239 following is an example of how to start a kernel and pass an updated
3245 oft=oftrees/mpc8540ads.dtb
3246 => tftp $oftaddr $oft
3247 Speed: 1000, full duplex
3249 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3250 Filename 'oftrees/mpc8540ads.dtb'.
3251 Load address: 0x300000
3254 Bytes transferred = 4106 (100a hex)
3255 => tftp $loadaddr $bootfile
3256 Speed: 1000, full duplex
3258 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3260 Load address: 0x200000
3261 Loading:############
3263 Bytes transferred = 1029407 (fb51f hex)
3268 => bootm $loadaddr - $oftaddr
3269 ## Booting image at 00200000 ...
3270 Image Name: Linux-2.6.17-dirty
3271 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3272 Data Size: 1029343 Bytes = 1005.2 kB
3273 Load Address: 00000000
3274 Entry Point: 00000000
3275 Verifying Checksum ... OK
3276 Uncompressing Kernel Image ... OK
3277 Booting using flat device tree at 0x300000
3278 Using MPC85xx ADS machine description
3279 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3283 More About U-Boot Image Types:
3284 ------------------------------
3286 U-Boot supports the following image types:
3288 "Standalone Programs" are directly runnable in the environment
3289 provided by U-Boot; it is expected that (if they behave
3290 well) you can continue to work in U-Boot after return from
3291 the Standalone Program.
3292 "OS Kernel Images" are usually images of some Embedded OS which
3293 will take over control completely. Usually these programs
3294 will install their own set of exception handlers, device
3295 drivers, set up the MMU, etc. - this means, that you cannot
3296 expect to re-enter U-Boot except by resetting the CPU.
3297 "RAMDisk Images" are more or less just data blocks, and their
3298 parameters (address, size) are passed to an OS kernel that is
3300 "Multi-File Images" contain several images, typically an OS
3301 (Linux) kernel image and one or more data images like
3302 RAMDisks. This construct is useful for instance when you want
3303 to boot over the network using BOOTP etc., where the boot
3304 server provides just a single image file, but you want to get
3305 for instance an OS kernel and a RAMDisk image.
3307 "Multi-File Images" start with a list of image sizes, each
3308 image size (in bytes) specified by an "uint32_t" in network
3309 byte order. This list is terminated by an "(uint32_t)0".
3310 Immediately after the terminating 0 follow the images, one by
3311 one, all aligned on "uint32_t" boundaries (size rounded up to
3312 a multiple of 4 bytes).
3314 "Firmware Images" are binary images containing firmware (like
3315 U-Boot or FPGA images) which usually will be programmed to
3318 "Script files" are command sequences that will be executed by
3319 U-Boot's command interpreter; this feature is especially
3320 useful when you configure U-Boot to use a real shell (hush)
3321 as command interpreter.
3327 One of the features of U-Boot is that you can dynamically load and
3328 run "standalone" applications, which can use some resources of
3329 U-Boot like console I/O functions or interrupt services.
3331 Two simple examples are included with the sources:
3336 'examples/hello_world.c' contains a small "Hello World" Demo
3337 application; it is automatically compiled when you build U-Boot.
3338 It's configured to run at address 0x00040004, so you can play with it
3342 ## Ready for S-Record download ...
3343 ~>examples/hello_world.srec
3344 1 2 3 4 5 6 7 8 9 10 11 ...
3345 [file transfer complete]
3347 ## Start Addr = 0x00040004
3349 => go 40004 Hello World! This is a test.
3350 ## Starting application at 0x00040004 ...
3361 Hit any key to exit ...
3363 ## Application terminated, rc = 0x0
3365 Another example, which demonstrates how to register a CPM interrupt
3366 handler with the U-Boot code, can be found in 'examples/timer.c'.
3367 Here, a CPM timer is set up to generate an interrupt every second.
3368 The interrupt service routine is trivial, just printing a '.'
3369 character, but this is just a demo program. The application can be
3370 controlled by the following keys:
3372 ? - print current values og the CPM Timer registers
3373 b - enable interrupts and start timer
3374 e - stop timer and disable interrupts
3375 q - quit application
3378 ## Ready for S-Record download ...
3379 ~>examples/timer.srec
3380 1 2 3 4 5 6 7 8 9 10 11 ...
3381 [file transfer complete]
3383 ## Start Addr = 0x00040004
3386 ## Starting application at 0x00040004 ...
3389 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3392 [q, b, e, ?] Set interval 1000000 us
3395 [q, b, e, ?] ........
3396 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3399 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3402 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3405 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3407 [q, b, e, ?] ...Stopping timer
3409 [q, b, e, ?] ## Application terminated, rc = 0x0
3415 Over time, many people have reported problems when trying to use the
3416 "minicom" terminal emulation program for serial download. I (wd)
3417 consider minicom to be broken, and recommend not to use it. Under
3418 Unix, I recommend to use C-Kermit for general purpose use (and
3419 especially for kermit binary protocol download ("loadb" command), and
3420 use "cu" for S-Record download ("loads" command).
3422 Nevertheless, if you absolutely want to use it try adding this
3423 configuration to your "File transfer protocols" section:
3425 Name Program Name U/D FullScr IO-Red. Multi
3426 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3427 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3433 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3434 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3436 Building requires a cross environment; it is known to work on
3437 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3438 need gmake since the Makefiles are not compatible with BSD make).
3439 Note that the cross-powerpc package does not install include files;
3440 attempting to build U-Boot will fail because <machine/ansi.h> is
3441 missing. This file has to be installed and patched manually:
3443 # cd /usr/pkg/cross/powerpc-netbsd/include
3445 # ln -s powerpc machine
3446 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3447 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3449 Native builds *don't* work due to incompatibilities between native
3450 and U-Boot include files.
3452 Booting assumes that (the first part of) the image booted is a
3453 stage-2 loader which in turn loads and then invokes the kernel
3454 proper. Loader sources will eventually appear in the NetBSD source
3455 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3456 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3459 Implementation Internals:
3460 =========================
3462 The following is not intended to be a complete description of every
3463 implementation detail. However, it should help to understand the
3464 inner workings of U-Boot and make it easier to port it to custom
3468 Initial Stack, Global Data:
3469 ---------------------------
3471 The implementation of U-Boot is complicated by the fact that U-Boot
3472 starts running out of ROM (flash memory), usually without access to
3473 system RAM (because the memory controller is not initialized yet).
3474 This means that we don't have writable Data or BSS segments, and BSS
3475 is not initialized as zero. To be able to get a C environment working
3476 at all, we have to allocate at least a minimal stack. Implementation
3477 options for this are defined and restricted by the CPU used: Some CPU
3478 models provide on-chip memory (like the IMMR area on MPC8xx and
3479 MPC826x processors), on others (parts of) the data cache can be
3480 locked as (mis-) used as memory, etc.
3482 Chris Hallinan posted a good summary of these issues to the
3483 u-boot-users mailing list:
3485 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3486 From: "Chris Hallinan" <clh@net1plus.com>
3487 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3490 Correct me if I'm wrong, folks, but the way I understand it
3491 is this: Using DCACHE as initial RAM for Stack, etc, does not
3492 require any physical RAM backing up the cache. The cleverness
3493 is that the cache is being used as a temporary supply of
3494 necessary storage before the SDRAM controller is setup. It's
3495 beyond the scope of this list to expain the details, but you
3496 can see how this works by studying the cache architecture and
3497 operation in the architecture and processor-specific manuals.
3499 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3500 is another option for the system designer to use as an
3501 initial stack/ram area prior to SDRAM being available. Either
3502 option should work for you. Using CS 4 should be fine if your
3503 board designers haven't used it for something that would
3504 cause you grief during the initial boot! It is frequently not
3507 CFG_INIT_RAM_ADDR should be somewhere that won't interfere
3508 with your processor/board/system design. The default value
3509 you will find in any recent u-boot distribution in
3510 walnut.h should work for you. I'd set it to a value larger
3511 than your SDRAM module. If you have a 64MB SDRAM module, set
3512 it above 400_0000. Just make sure your board has no resources
3513 that are supposed to respond to that address! That code in
3514 start.S has been around a while and should work as is when
3515 you get the config right.
3520 It is essential to remember this, since it has some impact on the C
3521 code for the initialization procedures:
3523 * Initialized global data (data segment) is read-only. Do not attempt
3526 * Do not use any unitialized global data (or implicitely initialized
3527 as zero data - BSS segment) at all - this is undefined, initiali-
3528 zation is performed later (when relocating to RAM).
3530 * Stack space is very limited. Avoid big data buffers or things like
3533 Having only the stack as writable memory limits means we cannot use
3534 normal global data to share information beween the code. But it
3535 turned out that the implementation of U-Boot can be greatly
3536 simplified by making a global data structure (gd_t) available to all
3537 functions. We could pass a pointer to this data as argument to _all_
3538 functions, but this would bloat the code. Instead we use a feature of
3539 the GCC compiler (Global Register Variables) to share the data: we
3540 place a pointer (gd) to the global data into a register which we
3541 reserve for this purpose.
3543 When choosing a register for such a purpose we are restricted by the
3544 relevant (E)ABI specifications for the current architecture, and by
3545 GCC's implementation.
3547 For PowerPC, the following registers have specific use:
3550 R3-R4: parameter passing and return values
3551 R5-R10: parameter passing
3552 R13: small data area pointer
3556 (U-Boot also uses R14 as internal GOT pointer.)
3558 ==> U-Boot will use R29 to hold a pointer to the global data
3560 Note: on PPC, we could use a static initializer (since the
3561 address of the global data structure is known at compile time),
3562 but it turned out that reserving a register results in somewhat
3563 smaller code - although the code savings are not that big (on
3564 average for all boards 752 bytes for the whole U-Boot image,
3565 624 text + 127 data).
3567 On ARM, the following registers are used:
3569 R0: function argument word/integer result
3570 R1-R3: function argument word
3572 R10: stack limit (used only if stack checking if enabled)
3573 R11: argument (frame) pointer
3574 R12: temporary workspace
3577 R15: program counter
3579 ==> U-Boot will use R8 to hold a pointer to the global data
3581 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3582 or current versions of GCC may "optimize" the code too much.
3587 U-Boot runs in system state and uses physical addresses, i.e. the
3588 MMU is not used either for address mapping nor for memory protection.
3590 The available memory is mapped to fixed addresses using the memory
3591 controller. In this process, a contiguous block is formed for each
3592 memory type (Flash, SDRAM, SRAM), even when it consists of several
3593 physical memory banks.
3595 U-Boot is installed in the first 128 kB of the first Flash bank (on
3596 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3597 booting and sizing and initializing DRAM, the code relocates itself
3598 to the upper end of DRAM. Immediately below the U-Boot code some
3599 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
3600 configuration setting]. Below that, a structure with global Board
3601 Info data is placed, followed by the stack (growing downward).
3603 Additionally, some exception handler code is copied to the low 8 kB
3604 of DRAM (0x00000000 ... 0x00001FFF).
3606 So a typical memory configuration with 16 MB of DRAM could look like
3609 0x0000 0000 Exception Vector code
3612 0x0000 2000 Free for Application Use
3618 0x00FB FF20 Monitor Stack (Growing downward)
3619 0x00FB FFAC Board Info Data and permanent copy of global data
3620 0x00FC 0000 Malloc Arena
3623 0x00FE 0000 RAM Copy of Monitor Code
3624 ... eventually: LCD or video framebuffer
3625 ... eventually: pRAM (Protected RAM - unchanged by reset)
3626 0x00FF FFFF [End of RAM]
3629 System Initialization:
3630 ----------------------
3632 In the reset configuration, U-Boot starts at the reset entry point
3633 (on most PowerPC systens at address 0x00000100). Because of the reset
3634 configuration for CS0# this is a mirror of the onboard Flash memory.
3635 To be able to re-map memory U-Boot then jumps to its link address.
3636 To be able to implement the initialization code in C, a (small!)
3637 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3638 which provide such a feature like MPC8xx or MPC8260), or in a locked
3639 part of the data cache. After that, U-Boot initializes the CPU core,
3640 the caches and the SIU.
3642 Next, all (potentially) available memory banks are mapped using a
3643 preliminary mapping. For example, we put them on 512 MB boundaries
3644 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3645 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3646 programmed for SDRAM access. Using the temporary configuration, a
3647 simple memory test is run that determines the size of the SDRAM
3650 When there is more than one SDRAM bank, and the banks are of
3651 different size, the largest is mapped first. For equal size, the first
3652 bank (CS2#) is mapped first. The first mapping is always for address
3653 0x00000000, with any additional banks following immediately to create
3654 contiguous memory starting from 0.
3656 Then, the monitor installs itself at the upper end of the SDRAM area
3657 and allocates memory for use by malloc() and for the global Board
3658 Info data; also, the exception vector code is copied to the low RAM
3659 pages, and the final stack is set up.
3661 Only after this relocation will you have a "normal" C environment;
3662 until that you are restricted in several ways, mostly because you are
3663 running from ROM, and because the code will have to be relocated to a
3667 U-Boot Porting Guide:
3668 ----------------------
3670 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3674 int main (int argc, char *argv[])
3676 sighandler_t no_more_time;
3678 signal (SIGALRM, no_more_time);
3679 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3681 if (available_money > available_manpower) {
3682 pay consultant to port U-Boot;
3686 Download latest U-Boot source;
3688 Subscribe to u-boot-users mailing list;
3691 email ("Hi, I am new to U-Boot, how do I get started?");
3695 Read the README file in the top level directory;
3696 Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
3697 Read the source, Luke;
3700 if (available_money > toLocalCurrency ($2500)) {
3703 Add a lot of aggravation and time;
3706 Create your own board support subdirectory;
3708 Create your own board config file;
3712 Add / modify source code;
3716 email ("Hi, I am having problems...");
3718 Send patch file to Wolfgang;
3723 void no_more_time (int sig)
3732 All contributions to U-Boot should conform to the Linux kernel
3733 coding style; see the file "Documentation/CodingStyle" and the script
3734 "scripts/Lindent" in your Linux kernel source directory. In sources
3735 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
3736 spaces before parameters to function calls) is actually used.
3738 Source files originating from a different project (for example the
3739 MTD subsystem) are generally exempt from these guidelines and are not
3740 reformated to ease subsequent migration to newer versions of those
3743 Please note that U-Boot is implemented in C (and to some small parts in
3744 Assembler); no C++ is used, so please do not use C++ style comments (//)
3747 Please also stick to the following formatting rules:
3748 - remove any trailing white space
3749 - use TAB characters for indentation, not spaces
3750 - make sure NOT to use DOS '\r\n' line feeds
3751 - do not add more than 2 empty lines to source files
3752 - do not add trailing empty lines to source files
3754 Submissions which do not conform to the standards may be returned
3755 with a request to reformat the changes.
3761 Since the number of patches for U-Boot is growing, we need to
3762 establish some rules. Submissions which do not conform to these rules
3763 may be rejected, even when they contain important and valuable stuff.
3765 Patches shall be sent to the u-boot-users mailing list.
3767 When you send a patch, please include the following information with
3770 * For bug fixes: a description of the bug and how your patch fixes
3771 this bug. Please try to include a way of demonstrating that the
3772 patch actually fixes something.
3774 * For new features: a description of the feature and your
3777 * A CHANGELOG entry as plaintext (separate from the patch)
3779 * For major contributions, your entry to the CREDITS file
3781 * When you add support for a new board, don't forget to add this
3782 board to the MAKEALL script, too.
3784 * If your patch adds new configuration options, don't forget to
3785 document these in the README file.
3787 * The patch itself. If you are accessing the CVS repository use "cvs
3788 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
3789 version of diff does not support these options, then get the latest
3790 version of GNU diff.
3792 The current directory when running this command shall be the top
3793 level directory of the U-Boot source tree, or it's parent directory
3794 (i. e. please make sure that your patch includes sufficient
3795 directory information for the affected files).
3797 We accept patches as plain text, MIME attachments or as uuencoded
3800 * If one logical set of modifications affects or creates several
3801 files, all these changes shall be submitted in a SINGLE patch file.
3803 * Changesets that contain different, unrelated modifications shall be
3804 submitted as SEPARATE patches, one patch per changeset.
3809 * Before sending the patch, run the MAKEALL script on your patched
3810 source tree and make sure that no errors or warnings are reported
3811 for any of the boards.
3813 * Keep your modifications to the necessary minimum: A patch
3814 containing several unrelated changes or arbitrary reformats will be
3815 returned with a request to re-formatting / split it.
3817 * If you modify existing code, make sure that your new code does not
3818 add to the memory footprint of the code ;-) Small is beautiful!
3819 When adding new features, these should compile conditionally only
3820 (using #ifdef), and the resulting code with the new feature
3821 disabled must not need more memory than the old code without your
3824 * Remember that there is a size limit of 40 kB per message on the
3825 u-boot-users mailing list. Compression may help.
projects / platform / kernel / u-boot.git / blob