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 - net Networking code
168 - post Power On Self Test
169 - rtc Real Time Clock drivers
170 - tools Tools to build S-Record or U-Boot images, etc.
172 Software Configuration:
173 =======================
175 Configuration is usually done using C preprocessor defines; the
176 rationale behind that is to avoid dead code whenever possible.
178 There are two classes of configuration variables:
180 * Configuration _OPTIONS_:
181 These are selectable by the user and have names beginning with
184 * Configuration _SETTINGS_:
185 These depend on the hardware etc. and should not be meddled with if
186 you don't know what you're doing; they have names beginning with
189 Later we will add a configuration tool - probably similar to or even
190 identical to what's used for the Linux kernel. Right now, we have to
191 do the configuration by hand, which means creating some symbolic
192 links and editing some configuration files. We use the TQM8xxL boards
196 Selection of Processor Architecture and Board Type:
197 ---------------------------------------------------
199 For all supported boards there are ready-to-use default
200 configurations available; just type "make <board_name>_config".
202 Example: For a TQM823L module type:
207 For the Cogent platform, you need to specify the cpu type as well;
208 e.g. "make cogent_mpc8xx_config". And also configure the cogent
209 directory according to the instructions in cogent/README.
212 Configuration Options:
213 ----------------------
215 Configuration depends on the combination of board and CPU type; all
216 such information is kept in a configuration file
217 "include/configs/<board_name>.h".
219 Example: For a TQM823L module, all configuration settings are in
220 "include/configs/TQM823L.h".
223 Many of the options are named exactly as the corresponding Linux
224 kernel configuration options. The intention is to make it easier to
225 build a config tool - later.
228 The following options need to be configured:
230 - CPU Type: Define exactly one of
234 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860
237 or CONFIG_MPC824X, CONFIG_MPC8260
254 MicroBlaze based CPUs:
255 ----------------------
259 ----------------------
263 ----------------------
266 - Board Type: Define exactly one of
268 PowerPC based boards:
269 ---------------------
271 CONFIG_ADCIOP CONFIG_FPS860L CONFIG_OXC
272 CONFIG_ADS860 CONFIG_GEN860T CONFIG_PCI405
273 CONFIG_AMX860 CONFIG_GENIETV CONFIG_PCIPPC2
274 CONFIG_AP1000 CONFIG_GTH CONFIG_PCIPPC6
275 CONFIG_AR405 CONFIG_gw8260 CONFIG_pcu_e
276 CONFIG_BAB7xx CONFIG_hermes CONFIG_PIP405
277 CONFIG_BC3450 CONFIG_hymod CONFIG_PM826
278 CONFIG_c2mon CONFIG_IAD210 CONFIG_ppmc8260
279 CONFIG_CANBT CONFIG_ICU862 CONFIG_QS823
280 CONFIG_CCM CONFIG_IP860 CONFIG_QS850
281 CONFIG_CMI CONFIG_IPHASE4539 CONFIG_QS860T
282 CONFIG_cogent_mpc8260 CONFIG_IVML24 CONFIG_RBC823
283 CONFIG_cogent_mpc8xx CONFIG_IVML24_128 CONFIG_RPXClassic
284 CONFIG_CPCI405 CONFIG_IVML24_256 CONFIG_RPXlite
285 CONFIG_CPCI4052 CONFIG_IVMS8 CONFIG_RPXsuper
286 CONFIG_CPCIISER4 CONFIG_IVMS8_128 CONFIG_rsdproto
287 CONFIG_CPU86 CONFIG_IVMS8_256 CONFIG_sacsng
288 CONFIG_CRAYL1 CONFIG_JSE CONFIG_Sandpoint8240
289 CONFIG_CSB272 CONFIG_LANTEC CONFIG_Sandpoint8245
290 CONFIG_CU824 CONFIG_LITE5200B CONFIG_sbc8260
291 CONFIG_DASA_SIM CONFIG_lwmon CONFIG_sbc8560
292 CONFIG_DB64360 CONFIG_MBX CONFIG_SM850
293 CONFIG_DB64460 CONFIG_MBX860T CONFIG_SPD823TS
294 CONFIG_DU405 CONFIG_MHPC CONFIG_STXGP3
295 CONFIG_DUET_ADS CONFIG_MIP405 CONFIG_SXNI855T
296 CONFIG_EBONY CONFIG_MOUSSE CONFIG_TQM823L
297 CONFIG_ELPPC CONFIG_MPC8260ADS CONFIG_TQM8260
298 CONFIG_ELPT860 CONFIG_MPC8540ADS CONFIG_TQM850L
299 CONFIG_ep8260 CONFIG_MPC8540EVAL CONFIG_TQM855L
300 CONFIG_ERIC CONFIG_MPC8560ADS CONFIG_TQM860L
301 CONFIG_ESTEEM192E CONFIG_MUSENKI CONFIG_TTTech
302 CONFIG_ETX094 CONFIG_MVS1 CONFIG_UTX8245
303 CONFIG_EVB64260 CONFIG_NETPHONE CONFIG_V37
304 CONFIG_FADS823 CONFIG_NETTA CONFIG_W7OLMC
305 CONFIG_FADS850SAR CONFIG_NETVIA CONFIG_W7OLMG
306 CONFIG_FADS860T CONFIG_NX823 CONFIG_WALNUT
307 CONFIG_FLAGADM CONFIG_OCRTC CONFIG_ZPC1900
308 CONFIG_FPS850L CONFIG_ORSG CONFIG_ZUMA
313 CONFIG_ARMADILLO, CONFIG_AT91RM9200DK, CONFIG_CERF250,
314 CONFIG_CSB637, CONFIG_DELTA, CONFIG_DNP1110,
315 CONFIG_EP7312, CONFIG_H2_OMAP1610, CONFIG_HHP_CRADLE,
316 CONFIG_IMPA7, CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610,
317 CONFIG_KB9202, CONFIG_LART, CONFIG_LPD7A400,
318 CONFIG_LUBBOCK, CONFIG_OSK_OMAP5912, CONFIG_OMAP2420H4,
319 CONFIG_PLEB2, CONFIG_SHANNON, CONFIG_P2_OMAP730,
320 CONFIG_SMDK2400, CONFIG_SMDK2410, CONFIG_TRAB,
323 MicroBlaze based boards:
324 ------------------------
329 ------------------------
331 CONFIG_PCI5441 CONFIG_PK1C20
332 CONFIG_EP1C20 CONFIG_EP1S10 CONFIG_EP1S40
339 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
340 Define exactly one of
344 - CPU Module Type: (if CONFIG_COGENT is defined)
345 Define exactly one of
347 --- FIXME --- not tested yet:
348 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
349 CONFIG_CMA287_23, CONFIG_CMA287_50
351 - Motherboard Type: (if CONFIG_COGENT is defined)
352 Define exactly one of
353 CONFIG_CMA101, CONFIG_CMA102
355 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
356 Define one or more of
359 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
360 Define one or more of
361 CONFIG_LCD_HEARTBEAT - update a character position on
362 the lcd display every second with
365 - Board flavour: (if CONFIG_MPC8260ADS is defined)
368 CFG_8260ADS - original MPC8260ADS
369 CFG_8266ADS - MPC8266ADS
370 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
371 CFG_8272ADS - MPC8272ADS
373 - MPC824X Family Member (if CONFIG_MPC824X is defined)
374 Define exactly one of
375 CONFIG_MPC8240, CONFIG_MPC8245
377 - 8xx CPU Options: (if using an MPC8xx cpu)
378 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
379 get_gclk_freq() cannot work
380 e.g. if there is no 32KHz
381 reference PIT/RTC clock
382 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
385 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
388 CONFIG_8xx_CPUCLK_DEFAULT
389 See doc/README.MPC866
393 Define this to measure the actual CPU clock instead
394 of relying on the correctness of the configured
395 values. Mostly useful for board bringup to make sure
396 the PLL is locked at the intended frequency. Note
397 that this requires a (stable) reference clock (32 kHz
398 RTC clock or CFG_8XX_XIN)
400 - Intel Monahans options:
401 CFG_MONAHANS_RUN_MODE_OSC_RATIO
403 Defines the Monahans run mode to oscillator
404 ratio. Valid values are 8, 16, 24, 31. The core
405 frequency is this value multiplied by 13 MHz.
407 CFG_MONAHANS_TURBO_RUN_MODE_RATIO
409 Defines the Monahans turbo mode to oscillator
410 ratio. Valid values are 1 (default if undefined) and
411 2. The core frequency as calculated above is multiplied
414 - Linux Kernel Interface:
417 U-Boot stores all clock information in Hz
418 internally. For binary compatibility with older Linux
419 kernels (which expect the clocks passed in the
420 bd_info data to be in MHz) the environment variable
421 "clocks_in_mhz" can be defined so that U-Boot
422 converts clock data to MHZ before passing it to the
424 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
425 "clocks_in_mhz=1" is automatically included in the
428 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
430 When transfering memsize parameter to linux, some versions
431 expect it to be in bytes, others in MB.
432 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
436 New kernel versions are expecting firmware settings to be
437 passed using flat open firmware trees.
438 The environment variable "disable_of", when set, disables this
441 CONFIG_OF_FLAT_TREE_MAX_SIZE
443 The maximum size of the constructed OF tree.
445 OF_CPU - The proper name of the cpus node.
446 OF_SOC - The proper name of the soc node.
447 OF_TBCLK - The timebase frequency.
448 OF_STDOUT_PATH - The path to the console device
452 The resulting flat device tree will have a copy of the bd_t.
453 Space should be pre-allocated in the dts for the bd_t.
455 CONFIG_OF_HAS_UBOOT_ENV
457 The resulting flat device tree will have a copy of u-boot's
458 environment variables
460 CONFIG_OF_BOARD_SETUP
462 Board code has addition modification that it wants to make
463 to the flat device tree before handing it off to the kernel
467 This define fills in the correct boot cpu in the boot
468 param header, the default value is zero if undefined.
473 Define this if you want support for Amba PrimeCell PL010 UARTs.
477 Define this if you want support for Amba PrimeCell PL011 UARTs.
481 If you have Amba PrimeCell PL011 UARTs, set this variable to
482 the clock speed of the UARTs.
486 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
487 define this to a list of base addresses for each (supported)
488 port. See e.g. include/configs/versatile.h
492 Depending on board, define exactly one serial port
493 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
494 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
495 console by defining CONFIG_8xx_CONS_NONE
497 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
498 port routines must be defined elsewhere
499 (i.e. serial_init(), serial_getc(), ...)
502 Enables console device for a color framebuffer. Needs following
503 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
504 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
506 VIDEO_HW_RECTFILL graphic chip supports
509 VIDEO_HW_BITBLT graphic chip supports
510 bit-blit (cf. smiLynxEM)
511 VIDEO_VISIBLE_COLS visible pixel columns
513 VIDEO_VISIBLE_ROWS visible pixel rows
514 VIDEO_PIXEL_SIZE bytes per pixel
515 VIDEO_DATA_FORMAT graphic data format
516 (0-5, cf. cfb_console.c)
517 VIDEO_FB_ADRS framebuffer address
518 VIDEO_KBD_INIT_FCT keyboard int fct
519 (i.e. i8042_kbd_init())
520 VIDEO_TSTC_FCT test char fct
522 VIDEO_GETC_FCT get char fct
524 CONFIG_CONSOLE_CURSOR cursor drawing on/off
525 (requires blink timer
527 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
528 CONFIG_CONSOLE_TIME display time/date info in
530 (requires CFG_CMD_DATE)
531 CONFIG_VIDEO_LOGO display Linux logo in
533 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
534 linux_logo.h for logo.
535 Requires CONFIG_VIDEO_LOGO
536 CONFIG_CONSOLE_EXTRA_INFO
537 addional board info beside
540 When CONFIG_CFB_CONSOLE is defined, video console is
541 default i/o. Serial console can be forced with
542 environment 'console=serial'.
544 When CONFIG_SILENT_CONSOLE is defined, all console
545 messages (by U-Boot and Linux!) can be silenced with
546 the "silent" environment variable. See
547 doc/README.silent for more information.
550 CONFIG_BAUDRATE - in bps
551 Select one of the baudrates listed in
552 CFG_BAUDRATE_TABLE, see below.
553 CFG_BRGCLK_PRESCALE, baudrate prescale
555 - Interrupt driven serial port input:
556 CONFIG_SERIAL_SOFTWARE_FIFO
559 Use an interrupt handler for receiving data on the
560 serial port. It also enables using hardware handshake
561 (RTS/CTS) and UART's built-in FIFO. Set the number of
562 bytes the interrupt driven input buffer should have.
564 Leave undefined to disable this feature, including
565 disable the buffer and hardware handshake.
567 - Console UART Number:
571 If defined internal UART1 (and not UART0) is used
572 as default U-Boot console.
574 - Boot Delay: CONFIG_BOOTDELAY - in seconds
575 Delay before automatically booting the default image;
576 set to -1 to disable autoboot.
578 See doc/README.autoboot for these options that
579 work with CONFIG_BOOTDELAY. None are required.
580 CONFIG_BOOT_RETRY_TIME
581 CONFIG_BOOT_RETRY_MIN
582 CONFIG_AUTOBOOT_KEYED
583 CONFIG_AUTOBOOT_PROMPT
584 CONFIG_AUTOBOOT_DELAY_STR
585 CONFIG_AUTOBOOT_STOP_STR
586 CONFIG_AUTOBOOT_DELAY_STR2
587 CONFIG_AUTOBOOT_STOP_STR2
588 CONFIG_ZERO_BOOTDELAY_CHECK
589 CONFIG_RESET_TO_RETRY
593 Only needed when CONFIG_BOOTDELAY is enabled;
594 define a command string that is automatically executed
595 when no character is read on the console interface
596 within "Boot Delay" after reset.
599 This can be used to pass arguments to the bootm
600 command. The value of CONFIG_BOOTARGS goes into the
601 environment value "bootargs".
603 CONFIG_RAMBOOT and CONFIG_NFSBOOT
604 The value of these goes into the environment as
605 "ramboot" and "nfsboot" respectively, and can be used
606 as a convenience, when switching between booting from
612 When this option is #defined, the existence of the
613 environment variable "preboot" will be checked
614 immediately before starting the CONFIG_BOOTDELAY
615 countdown and/or running the auto-boot command resp.
616 entering interactive mode.
618 This feature is especially useful when "preboot" is
619 automatically generated or modified. For an example
620 see the LWMON board specific code: here "preboot" is
621 modified when the user holds down a certain
622 combination of keys on the (special) keyboard when
625 - Serial Download Echo Mode:
627 If defined to 1, all characters received during a
628 serial download (using the "loads" command) are
629 echoed back. This might be needed by some terminal
630 emulations (like "cu"), but may as well just take
631 time on others. This setting #define's the initial
632 value of the "loads_echo" environment variable.
634 - Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
636 Select one of the baudrates listed in
637 CFG_BAUDRATE_TABLE, see below.
641 Most monitor functions can be selected (or
642 de-selected) by adjusting the definition of
643 CONFIG_COMMANDS; to select individual functions,
644 #define CONFIG_COMMANDS by "OR"ing any of the
647 #define enables commands:
648 -------------------------
649 CFG_CMD_ASKENV * ask for env variable
650 CFG_CMD_AUTOSCRIPT Autoscript Support
652 CFG_CMD_BEDBUG * Include BedBug Debugger
653 CFG_CMD_BMP * BMP support
654 CFG_CMD_BSP * Board specific commands
656 CFG_CMD_CACHE * icache, dcache
657 CFG_CMD_CONSOLE coninfo
658 CFG_CMD_DATE * support for RTC, date/time...
659 CFG_CMD_DHCP * DHCP support
660 CFG_CMD_DIAG * Diagnostics
661 CFG_CMD_DOC * Disk-On-Chip Support
662 CFG_CMD_DTT * Digital Therm and Thermostat
663 CFG_CMD_ECHO echo arguments
664 CFG_CMD_EEPROM * EEPROM read/write support
665 CFG_CMD_ELF * bootelf, bootvx
667 CFG_CMD_FDC * Floppy Disk Support
668 CFG_CMD_FAT * FAT partition support
669 CFG_CMD_FDOS * Dos diskette Support
670 CFG_CMD_FLASH flinfo, erase, protect
671 CFG_CMD_FPGA FPGA device initialization support
672 CFG_CMD_HWFLOW * RTS/CTS hw flow control
673 CFG_CMD_I2C * I2C serial bus support
674 CFG_CMD_IDE * IDE harddisk support
676 CFG_CMD_IMLS List all found images
677 CFG_CMD_IMMAP * IMMR dump support
678 CFG_CMD_IRQ * irqinfo
679 CFG_CMD_ITEST Integer/string test of 2 values
680 CFG_CMD_JFFS2 * JFFS2 Support
684 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
686 CFG_CMD_MISC Misc functions like sleep etc
687 CFG_CMD_MMC * MMC memory mapped support
688 CFG_CMD_MII * MII utility commands
689 CFG_CMD_NAND * NAND support
690 CFG_CMD_NET bootp, tftpboot, rarpboot
691 CFG_CMD_PCI * pciinfo
692 CFG_CMD_PCMCIA * PCMCIA support
693 CFG_CMD_PING * send ICMP ECHO_REQUEST to network host
694 CFG_CMD_PORTIO * Port I/O
695 CFG_CMD_REGINFO * Register dump
696 CFG_CMD_RUN run command in env variable
697 CFG_CMD_SAVES * save S record dump
698 CFG_CMD_SCSI * SCSI Support
699 CFG_CMD_SDRAM * print SDRAM configuration information
700 (requires CFG_CMD_I2C)
701 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
702 CFG_CMD_SPI * SPI serial bus support
703 CFG_CMD_USB * USB support
704 CFG_CMD_VFD * VFD support (TRAB)
705 CFG_CMD_BSP * Board SPecific functions
706 CFG_CMD_CDP * Cisco Discover Protocol support
707 -----------------------------------------------
710 CONFIG_CMD_DFL Default configuration; at the moment
711 this is includes all commands, except
712 the ones marked with "*" in the list
715 If you don't define CONFIG_COMMANDS it defaults to
716 CONFIG_CMD_DFL in include/cmd_confdefs.h. A board can
717 override the default settings in the respective
720 EXAMPLE: If you want all functions except of network
721 support you can write:
723 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
726 Note: Don't enable the "icache" and "dcache" commands
727 (configuration option CFG_CMD_CACHE) unless you know
728 what you (and your U-Boot users) are doing. Data
729 cache cannot be enabled on systems like the 8xx or
730 8260 (where accesses to the IMMR region must be
731 uncached), and it cannot be disabled on all other
732 systems where we (mis-) use the data cache to hold an
733 initial stack and some data.
736 XXX - this list needs to get updated!
740 If this variable is defined, it enables watchdog
741 support. There must be support in the platform specific
742 code for a watchdog. For the 8xx and 8260 CPUs, the
743 SIU Watchdog feature is enabled in the SYPCR
747 CONFIG_VERSION_VARIABLE
748 If this variable is defined, an environment variable
749 named "ver" is created by U-Boot showing the U-Boot
750 version as printed by the "version" command.
751 This variable is readonly.
755 When CFG_CMD_DATE is selected, the type of the RTC
756 has to be selected, too. Define exactly one of the
759 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
760 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
761 CONFIG_RTC_MC146818 - use MC146818 RTC
762 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
763 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
764 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
765 CONFIG_RTC_DS164x - use Dallas DS164x RTC
766 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
768 Note that if the RTC uses I2C, then the I2C interface
769 must also be configured. See I2C Support, below.
773 When CONFIG_TIMESTAMP is selected, the timestamp
774 (date and time) of an image is printed by image
775 commands like bootm or iminfo. This option is
776 automatically enabled when you select CFG_CMD_DATE .
779 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
780 and/or CONFIG_ISO_PARTITION
782 If IDE or SCSI support is enabled (CFG_CMD_IDE or
783 CFG_CMD_SCSI) you must configure support for at least
784 one partition type as well.
787 CONFIG_IDE_RESET_ROUTINE - this is defined in several
788 board configurations files but used nowhere!
790 CONFIG_IDE_RESET - is this is defined, IDE Reset will
791 be performed by calling the function
792 ide_set_reset(int reset)
793 which has to be defined in a board specific file
798 Set this to enable ATAPI support.
803 Set this to enable support for disks larger than 137GB
804 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL
805 Whithout these , LBA48 support uses 32bit variables and will 'only'
806 support disks up to 2.1TB.
809 When enabled, makes the IDE subsystem use 64bit sector addresses.
813 At the moment only there is only support for the
814 SYM53C8XX SCSI controller; define
815 CONFIG_SCSI_SYM53C8XX to enable it.
817 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
818 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
819 CFG_SCSI_MAX_LUN] can be adjusted to define the
820 maximum numbers of LUNs, SCSI ID's and target
822 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
824 - NETWORK Support (PCI):
826 Support for Intel 8254x gigabit chips.
829 Support for Intel 82557/82559/82559ER chips.
830 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
831 write routine for first time initialisation.
834 Support for Digital 2114x chips.
835 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
836 modem chip initialisation (KS8761/QS6611).
839 Support for National dp83815 chips.
842 Support for National dp8382[01] gigabit chips.
844 - NETWORK Support (other):
846 CONFIG_DRIVER_LAN91C96
847 Support for SMSC's LAN91C96 chips.
850 Define this to hold the physical address
851 of the LAN91C96's I/O space
853 CONFIG_LAN91C96_USE_32_BIT
854 Define this to enable 32 bit addressing
856 CONFIG_DRIVER_SMC91111
857 Support for SMSC's LAN91C111 chip
860 Define this to hold the physical address
861 of the device (I/O space)
863 CONFIG_SMC_USE_32_BIT
864 Define this if data bus is 32 bits
866 CONFIG_SMC_USE_IOFUNCS
867 Define this to use i/o functions instead of macros
868 (some hardware wont work with macros)
871 At the moment only the UHCI host controller is
872 supported (PIP405, MIP405, MPC5200); define
873 CONFIG_USB_UHCI to enable it.
874 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
875 and define CONFIG_USB_STORAGE to enable the USB
878 Supported are USB Keyboards and USB Floppy drives
880 MPC5200 USB requires additional defines:
882 for 528 MHz Clock: 0x0001bbbb
884 for differential drivers: 0x00001000
885 for single ended drivers: 0x00005000
888 Define the below if you wish to use the USB console.
889 Once firmware is rebuilt from a serial console issue the
890 command "setenv stdin usbtty; setenv stdout usbtty" and
891 attach your usb cable. The Unix command "dmesg" should print
892 it has found a new device. The environment variable usbtty
893 can be set to gserial or cdc_acm to enable your device to
894 appear to a USB host as a Linux gserial device or a
895 Common Device Class Abstract Control Model serial device.
896 If you select usbtty = gserial you should be able to enumerate
898 # modprobe usbserial vendor=0xVendorID product=0xProductID
899 else if using cdc_acm, simply setting the environment
900 variable usbtty to be cdc_acm should suffice. The following
901 might be defined in YourBoardName.h
904 Define this to build a UDC device
907 Define this to have a tty type of device available to
908 talk to the UDC device
910 CFG_CONSOLE_IS_IN_ENV
911 Define this if you want stdin, stdout &/or stderr to
915 CFG_USB_EXTC_CLK 0xBLAH
916 Derive USB clock from external clock "blah"
917 - CFG_USB_EXTC_CLK 0x02
919 CFG_USB_BRG_CLK 0xBLAH
920 Derive USB clock from brgclk
921 - CFG_USB_BRG_CLK 0x04
923 If you have a USB-IF assigned VendorID then you may wish to
924 define your own vendor specific values either in BoardName.h
925 or directly in usbd_vendor_info.h. If you don't define
926 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
927 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
928 should pretend to be a Linux device to it's target host.
930 CONFIG_USBD_MANUFACTURER
931 Define this string as the name of your company for
932 - CONFIG_USBD_MANUFACTURER "my company"
934 CONFIG_USBD_PRODUCT_NAME
935 Define this string as the name of your product
936 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
939 Define this as your assigned Vendor ID from the USB
940 Implementors Forum. This *must* be a genuine Vendor ID
941 to avoid polluting the USB namespace.
942 - CONFIG_USBD_VENDORID 0xFFFF
944 CONFIG_USBD_PRODUCTID
945 Define this as the unique Product ID
947 - CONFIG_USBD_PRODUCTID 0xFFFF
951 The MMC controller on the Intel PXA is supported. To
952 enable this define CONFIG_MMC. The MMC can be
953 accessed from the boot prompt by mapping the device
954 to physical memory similar to flash. Command line is
955 enabled with CFG_CMD_MMC. The MMC driver also works with
956 the FAT fs. This is enabled with CFG_CMD_FAT.
958 - Journaling Flash filesystem support:
959 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
960 CONFIG_JFFS2_NAND_DEV
961 Define these for a default partition on a NAND device
963 CFG_JFFS2_FIRST_SECTOR,
964 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS
965 Define these for a default partition on a NOR device
968 Define this to create an own partition. You have to provide a
969 function struct part_info* jffs2_part_info(int part_num)
971 If you define only one JFFS2 partition you may also want to
972 #define CFG_JFFS_SINGLE_PART 1
973 to disable the command chpart. This is the default when you
974 have not defined a custom partition
979 Define this to enable standard (PC-Style) keyboard
983 Standard PC keyboard driver with US (is default) and
984 GERMAN key layout (switch via environment 'keymap=de') support.
985 Export function i8042_kbd_init, i8042_tstc and i8042_getc
986 for cfb_console. Supports cursor blinking.
991 Define this to enable video support (for output to
996 Enable Chips & Technologies 69000 Video chip
998 CONFIG_VIDEO_SMI_LYNXEM
999 Enable Silicon Motion SMI 712/710/810 Video chip. The
1000 video output is selected via environment 'videoout'
1001 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1004 For the CT69000 and SMI_LYNXEM drivers, videomode is
1005 selected via environment 'videomode'. Two diferent ways
1007 - "videomode=num" 'num' is a standard LiLo mode numbers.
1008 Following standard modes are supported (* is default):
1010 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1011 -------------+---------------------------------------------
1012 8 bits | 0x301* 0x303 0x305 0x161 0x307
1013 15 bits | 0x310 0x313 0x316 0x162 0x319
1014 16 bits | 0x311 0x314 0x317 0x163 0x31A
1015 24 bits | 0x312 0x315 0x318 ? 0x31B
1016 -------------+---------------------------------------------
1017 (i.e. setenv videomode 317; saveenv; reset;)
1019 - "videomode=bootargs" all the video parameters are parsed
1020 from the bootargs. (See drivers/videomodes.c)
1023 CONFIG_VIDEO_SED13806
1024 Enable Epson SED13806 driver. This driver supports 8bpp
1025 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1026 or CONFIG_VIDEO_SED13806_16BPP
1031 Define this to enable a custom keyboard support.
1032 This simply calls drv_keyboard_init() which must be
1033 defined in your board-specific files.
1034 The only board using this so far is RBC823.
1036 - LCD Support: CONFIG_LCD
1038 Define this to enable LCD support (for output to LCD
1039 display); also select one of the supported displays
1040 by defining one of these:
1042 CONFIG_NEC_NL6448AC33:
1044 NEC NL6448AC33-18. Active, color, single scan.
1046 CONFIG_NEC_NL6448BC20
1048 NEC NL6448BC20-08. 6.5", 640x480.
1049 Active, color, single scan.
1051 CONFIG_NEC_NL6448BC33_54
1053 NEC NL6448BC33-54. 10.4", 640x480.
1054 Active, color, single scan.
1058 Sharp 320x240. Active, color, single scan.
1059 It isn't 16x9, and I am not sure what it is.
1061 CONFIG_SHARP_LQ64D341
1063 Sharp LQ64D341 display, 640x480.
1064 Active, color, single scan.
1068 HLD1045 display, 640x480.
1069 Active, color, single scan.
1073 Optrex CBL50840-2 NF-FW 99 22 M5
1075 Hitachi LMG6912RPFC-00T
1079 320x240. Black & white.
1081 Normally display is black on white background; define
1082 CFG_WHITE_ON_BLACK to get it inverted.
1084 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1086 If this option is set, the environment is checked for
1087 a variable "splashimage". If found, the usual display
1088 of logo, copyright and system information on the LCD
1089 is suppressed and the BMP image at the address
1090 specified in "splashimage" is loaded instead. The
1091 console is redirected to the "nulldev", too. This
1092 allows for a "silent" boot where a splash screen is
1093 loaded very quickly after power-on.
1095 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1097 If this option is set, additionally to standard BMP
1098 images, gzipped BMP images can be displayed via the
1099 splashscreen support or the bmp command.
1101 - Compression support:
1104 If this option is set, support for bzip2 compressed
1105 images is included. If not, only uncompressed and gzip
1106 compressed images are supported.
1108 NOTE: the bzip2 algorithm requires a lot of RAM, so
1109 the malloc area (as defined by CFG_MALLOC_LEN) should
1115 The address of PHY on MII bus.
1117 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1119 The clock frequency of the MII bus
1123 If this option is set, support for speed/duplex
1124 detection of Gigabit PHY is included.
1126 CONFIG_PHY_RESET_DELAY
1128 Some PHY like Intel LXT971A need extra delay after
1129 reset before any MII register access is possible.
1130 For such PHY, set this option to the usec delay
1131 required. (minimum 300usec for LXT971A)
1133 CONFIG_PHY_CMD_DELAY (ppc4xx)
1135 Some PHY like Intel LXT971A need extra delay after
1136 command issued before MII status register can be read
1143 Define a default value for ethernet address to use
1144 for the respective ethernet interface, in case this
1145 is not determined automatically.
1150 Define a default value for the IP address to use for
1151 the default ethernet interface, in case this is not
1152 determined through e.g. bootp.
1154 - Server IP address:
1157 Defines a default value for theIP address of a TFTP
1158 server to contact when using the "tftboot" command.
1160 - BOOTP Recovery Mode:
1161 CONFIG_BOOTP_RANDOM_DELAY
1163 If you have many targets in a network that try to
1164 boot using BOOTP, you may want to avoid that all
1165 systems send out BOOTP requests at precisely the same
1166 moment (which would happen for instance at recovery
1167 from a power failure, when all systems will try to
1168 boot, thus flooding the BOOTP server. Defining
1169 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1170 inserted before sending out BOOTP requests. The
1171 following delays are insterted then:
1173 1st BOOTP request: delay 0 ... 1 sec
1174 2nd BOOTP request: delay 0 ... 2 sec
1175 3rd BOOTP request: delay 0 ... 4 sec
1177 BOOTP requests: delay 0 ... 8 sec
1179 - DHCP Advanced Options:
1182 You can fine tune the DHCP functionality by adding
1183 these flags to the CONFIG_BOOTP_MASK define:
1185 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1186 serverip from a DHCP server, it is possible that more
1187 than one DNS serverip is offered to the client.
1188 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1189 serverip will be stored in the additional environment
1190 variable "dnsip2". The first DNS serverip is always
1191 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1192 is added to the CONFIG_BOOTP_MASK.
1194 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1195 to do a dynamic update of a DNS server. To do this, they
1196 need the hostname of the DHCP requester.
1197 If CONFIG_BOOP_SEND_HOSTNAME is added to the
1198 CONFIG_BOOTP_MASK, the content of the "hostname"
1199 environment variable is passed as option 12 to
1203 CONFIG_CDP_DEVICE_ID
1205 The device id used in CDP trigger frames.
1207 CONFIG_CDP_DEVICE_ID_PREFIX
1209 A two character string which is prefixed to the MAC address
1214 A printf format string which contains the ascii name of
1215 the port. Normally is set to "eth%d" which sets
1216 eth0 for the first ethernet, eth1 for the second etc.
1218 CONFIG_CDP_CAPABILITIES
1220 A 32bit integer which indicates the device capabilities;
1221 0x00000010 for a normal host which does not forwards.
1225 An ascii string containing the version of the software.
1229 An ascii string containing the name of the platform.
1233 A 32bit integer sent on the trigger.
1235 CONFIG_CDP_POWER_CONSUMPTION
1237 A 16bit integer containing the power consumption of the
1238 device in .1 of milliwatts.
1240 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1242 A byte containing the id of the VLAN.
1244 - Status LED: CONFIG_STATUS_LED
1246 Several configurations allow to display the current
1247 status using a LED. For instance, the LED will blink
1248 fast while running U-Boot code, stop blinking as
1249 soon as a reply to a BOOTP request was received, and
1250 start blinking slow once the Linux kernel is running
1251 (supported by a status LED driver in the Linux
1252 kernel). Defining CONFIG_STATUS_LED enables this
1255 - CAN Support: CONFIG_CAN_DRIVER
1257 Defining CONFIG_CAN_DRIVER enables CAN driver support
1258 on those systems that support this (optional)
1259 feature, like the TQM8xxL modules.
1261 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1263 These enable I2C serial bus commands. Defining either of
1264 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1265 include the appropriate I2C driver for the selected cpu.
1267 This will allow you to use i2c commands at the u-boot
1268 command line (as long as you set CFG_CMD_I2C in
1269 CONFIG_COMMANDS) and communicate with i2c based realtime
1270 clock chips. See common/cmd_i2c.c for a description of the
1271 command line interface.
1273 CONFIG_I2C_CMD_TREE is a recommended option that places
1274 all I2C commands under a single 'i2c' root command. The
1275 older 'imm', 'imd', 'iprobe' etc. commands are considered
1276 deprecated and may disappear in the future.
1278 CONFIG_HARD_I2C selects a hardware I2C controller.
1280 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1281 bit-banging) driver instead of CPM or similar hardware
1284 There are several other quantities that must also be
1285 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1287 In both cases you will need to define CFG_I2C_SPEED
1288 to be the frequency (in Hz) at which you wish your i2c bus
1289 to run and CFG_I2C_SLAVE to be the address of this node (ie
1290 the cpu's i2c node address).
1292 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1293 sets the cpu up as a master node and so its address should
1294 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1295 p.16-473). So, set CFG_I2C_SLAVE to 0.
1297 That's all that's required for CONFIG_HARD_I2C.
1299 If you use the software i2c interface (CONFIG_SOFT_I2C)
1300 then the following macros need to be defined (examples are
1301 from include/configs/lwmon.h):
1305 (Optional). Any commands necessary to enable the I2C
1306 controller or configure ports.
1308 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1312 (Only for MPC8260 CPU). The I/O port to use (the code
1313 assumes both bits are on the same port). Valid values
1314 are 0..3 for ports A..D.
1318 The code necessary to make the I2C data line active
1319 (driven). If the data line is open collector, this
1322 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1326 The code necessary to make the I2C data line tri-stated
1327 (inactive). If the data line is open collector, this
1330 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1334 Code that returns TRUE if the I2C data line is high,
1337 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1341 If <bit> is TRUE, sets the I2C data line high. If it
1342 is FALSE, it clears it (low).
1344 eg: #define I2C_SDA(bit) \
1345 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1346 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1350 If <bit> is TRUE, sets the I2C clock line high. If it
1351 is FALSE, it clears it (low).
1353 eg: #define I2C_SCL(bit) \
1354 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1355 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1359 This delay is invoked four times per clock cycle so this
1360 controls the rate of data transfer. The data rate thus
1361 is 1 / (I2C_DELAY * 4). Often defined to be something
1364 #define I2C_DELAY udelay(2)
1368 When a board is reset during an i2c bus transfer
1369 chips might think that the current transfer is still
1370 in progress. On some boards it is possible to access
1371 the i2c SCLK line directly, either by using the
1372 processor pin as a GPIO or by having a second pin
1373 connected to the bus. If this option is defined a
1374 custom i2c_init_board() routine in boards/xxx/board.c
1375 is run early in the boot sequence.
1377 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1379 This option enables configuration of bi_iic_fast[] flags
1380 in u-boot bd_info structure based on u-boot environment
1381 variable "i2cfast". (see also i2cfast)
1383 CONFIG_I2C_MULTI_BUS
1385 This option allows the use of multiple I2C buses, each of which
1386 must have a controller. At any point in time, only one bus is
1387 active. To switch to a different bus, use the 'i2c dev' command.
1388 Note that bus numbering is zero-based.
1392 This option specifies a list of I2C devices that will be skipped
1393 when the 'i2c probe' command is issued (or 'iprobe' using the legacy
1394 command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device
1395 pairs. Otherwise, specify a 1D array of device addresses
1398 #undef CONFIG_I2C_MULTI_BUS
1399 #define CFG_I2C_NOPROBES {0x50,0x68}
1401 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1403 #define CONFIG_I2C_MULTI_BUS
1404 #define CFG_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1406 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1410 If defined, then this indicates the I2C bus number for DDR SPD.
1411 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1415 If defined, then this indicates the I2C bus number for the RTC.
1416 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1420 If defined, then this indicates the I2C bus number for the DTT.
1421 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1425 Define this option if you want to use Freescale's I2C driver in
1429 - SPI Support: CONFIG_SPI
1431 Enables SPI driver (so far only tested with
1432 SPI EEPROM, also an instance works with Crystal A/D and
1433 D/As on the SACSng board)
1437 Enables extended (16-bit) SPI EEPROM addressing.
1438 (symmetrical to CONFIG_I2C_X)
1442 Enables a software (bit-bang) SPI driver rather than
1443 using hardware support. This is a general purpose
1444 driver that only requires three general I/O port pins
1445 (two outputs, one input) to function. If this is
1446 defined, the board configuration must define several
1447 SPI configuration items (port pins to use, etc). For
1448 an example, see include/configs/sacsng.h.
1450 - FPGA Support: CONFIG_FPGA_COUNT
1452 Specify the number of FPGA devices to support.
1456 Used to specify the types of FPGA devices. For example,
1457 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
1459 CFG_FPGA_PROG_FEEDBACK
1461 Enable printing of hash marks during FPGA configuration.
1465 Enable checks on FPGA configuration interface busy
1466 status by the configuration function. This option
1467 will require a board or device specific function to
1472 If defined, a function that provides delays in the FPGA
1473 configuration driver.
1475 CFG_FPGA_CHECK_CTRLC
1476 Allow Control-C to interrupt FPGA configuration
1478 CFG_FPGA_CHECK_ERROR
1480 Check for configuration errors during FPGA bitfile
1481 loading. For example, abort during Virtex II
1482 configuration if the INIT_B line goes low (which
1483 indicated a CRC error).
1487 Maximum time to wait for the INIT_B line to deassert
1488 after PROB_B has been deasserted during a Virtex II
1489 FPGA configuration sequence. The default time is 500
1494 Maximum time to wait for BUSY to deassert during
1495 Virtex II FPGA configuration. The default is 5 mS.
1497 CFG_FPGA_WAIT_CONFIG
1499 Time to wait after FPGA configuration. The default is
1502 - Configuration Management:
1505 If defined, this string will be added to the U-Boot
1506 version information (U_BOOT_VERSION)
1508 - Vendor Parameter Protection:
1510 U-Boot considers the values of the environment
1511 variables "serial#" (Board Serial Number) and
1512 "ethaddr" (Ethernet Address) to be parameters that
1513 are set once by the board vendor / manufacturer, and
1514 protects these variables from casual modification by
1515 the user. Once set, these variables are read-only,
1516 and write or delete attempts are rejected. You can
1517 change this behviour:
1519 If CONFIG_ENV_OVERWRITE is #defined in your config
1520 file, the write protection for vendor parameters is
1521 completely disabled. Anybody can change or delete
1524 Alternatively, if you #define _both_ CONFIG_ETHADDR
1525 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1526 ethernet address is installed in the environment,
1527 which can be changed exactly ONCE by the user. [The
1528 serial# is unaffected by this, i. e. it remains
1534 Define this variable to enable the reservation of
1535 "protected RAM", i. e. RAM which is not overwritten
1536 by U-Boot. Define CONFIG_PRAM to hold the number of
1537 kB you want to reserve for pRAM. You can overwrite
1538 this default value by defining an environment
1539 variable "pram" to the number of kB you want to
1540 reserve. Note that the board info structure will
1541 still show the full amount of RAM. If pRAM is
1542 reserved, a new environment variable "mem" will
1543 automatically be defined to hold the amount of
1544 remaining RAM in a form that can be passed as boot
1545 argument to Linux, for instance like that:
1547 setenv bootargs ... mem=\${mem}
1550 This way you can tell Linux not to use this memory,
1551 either, which results in a memory region that will
1552 not be affected by reboots.
1554 *WARNING* If your board configuration uses automatic
1555 detection of the RAM size, you must make sure that
1556 this memory test is non-destructive. So far, the
1557 following board configurations are known to be
1560 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1561 HERMES, IP860, RPXlite, LWMON, LANTEC,
1562 PCU_E, FLAGADM, TQM8260
1567 Define this variable to stop the system in case of a
1568 fatal error, so that you have to reset it manually.
1569 This is probably NOT a good idea for an embedded
1570 system where you want to system to reboot
1571 automatically as fast as possible, but it may be
1572 useful during development since you can try to debug
1573 the conditions that lead to the situation.
1575 CONFIG_NET_RETRY_COUNT
1577 This variable defines the number of retries for
1578 network operations like ARP, RARP, TFTP, or BOOTP
1579 before giving up the operation. If not defined, a
1580 default value of 5 is used.
1582 - Command Interpreter:
1583 CONFIG_AUTO_COMPLETE
1585 Enable auto completion of commands using TAB.
1587 Note that this feature has NOT been implemented yet
1588 for the "hush" shell.
1593 Define this variable to enable the "hush" shell (from
1594 Busybox) as command line interpreter, thus enabling
1595 powerful command line syntax like
1596 if...then...else...fi conditionals or `&&' and '||'
1597 constructs ("shell scripts").
1599 If undefined, you get the old, much simpler behaviour
1600 with a somewhat smaller memory footprint.
1605 This defines the secondary prompt string, which is
1606 printed when the command interpreter needs more input
1607 to complete a command. Usually "> ".
1611 In the current implementation, the local variables
1612 space and global environment variables space are
1613 separated. Local variables are those you define by
1614 simply typing `name=value'. To access a local
1615 variable later on, you have write `$name' or
1616 `${name}'; to execute the contents of a variable
1617 directly type `$name' at the command prompt.
1619 Global environment variables are those you use
1620 setenv/printenv to work with. To run a command stored
1621 in such a variable, you need to use the run command,
1622 and you must not use the '$' sign to access them.
1624 To store commands and special characters in a
1625 variable, please use double quotation marks
1626 surrounding the whole text of the variable, instead
1627 of the backslashes before semicolons and special
1630 - Commandline Editing and History:
1631 CONFIG_CMDLINE_EDITING
1633 Enable editiong and History functions for interactive
1634 commandline input operations
1636 - Default Environment:
1637 CONFIG_EXTRA_ENV_SETTINGS
1639 Define this to contain any number of null terminated
1640 strings (variable = value pairs) that will be part of
1641 the default environment compiled into the boot image.
1643 For example, place something like this in your
1644 board's config file:
1646 #define CONFIG_EXTRA_ENV_SETTINGS \
1650 Warning: This method is based on knowledge about the
1651 internal format how the environment is stored by the
1652 U-Boot code. This is NOT an official, exported
1653 interface! Although it is unlikely that this format
1654 will change soon, there is no guarantee either.
1655 You better know what you are doing here.
1657 Note: overly (ab)use of the default environment is
1658 discouraged. Make sure to check other ways to preset
1659 the environment like the autoscript function or the
1662 - DataFlash Support:
1663 CONFIG_HAS_DATAFLASH
1665 Defining this option enables DataFlash features and
1666 allows to read/write in Dataflash via the standard
1669 - SystemACE Support:
1672 Adding this option adds support for Xilinx SystemACE
1673 chips attached via some sort of local bus. The address
1674 of the chip must alsh be defined in the
1675 CFG_SYSTEMACE_BASE macro. For example:
1677 #define CONFIG_SYSTEMACE
1678 #define CFG_SYSTEMACE_BASE 0xf0000000
1680 When SystemACE support is added, the "ace" device type
1681 becomes available to the fat commands, i.e. fatls.
1683 - TFTP Fixed UDP Port:
1686 If this is defined, the environment variable tftpsrcp
1687 is used to supply the TFTP UDP source port value.
1688 If tftpsrcp isn't defined, the normal pseudo-random port
1689 number generator is used.
1691 Also, the environment variable tftpdstp is used to supply
1692 the TFTP UDP destination port value. If tftpdstp isn't
1693 defined, the normal port 69 is used.
1695 The purpose for tftpsrcp is to allow a TFTP server to
1696 blindly start the TFTP transfer using the pre-configured
1697 target IP address and UDP port. This has the effect of
1698 "punching through" the (Windows XP) firewall, allowing
1699 the remainder of the TFTP transfer to proceed normally.
1700 A better solution is to properly configure the firewall,
1701 but sometimes that is not allowed.
1703 - Show boot progress:
1704 CONFIG_SHOW_BOOT_PROGRESS
1706 Defining this option allows to add some board-
1707 specific code (calling a user-provided function
1708 "show_boot_progress(int)") that enables you to show
1709 the system's boot progress on some display (for
1710 example, some LED's) on your board. At the moment,
1711 the following checkpoints are implemented:
1714 1 common/cmd_bootm.c before attempting to boot an image
1715 -1 common/cmd_bootm.c Image header has bad magic number
1716 2 common/cmd_bootm.c Image header has correct magic number
1717 -2 common/cmd_bootm.c Image header has bad checksum
1718 3 common/cmd_bootm.c Image header has correct checksum
1719 -3 common/cmd_bootm.c Image data has bad checksum
1720 4 common/cmd_bootm.c Image data has correct checksum
1721 -4 common/cmd_bootm.c Image is for unsupported architecture
1722 5 common/cmd_bootm.c Architecture check OK
1723 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1724 6 common/cmd_bootm.c Image Type check OK
1725 -6 common/cmd_bootm.c gunzip uncompression error
1726 -7 common/cmd_bootm.c Unimplemented compression type
1727 7 common/cmd_bootm.c Uncompression OK
1728 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1729 8 common/cmd_bootm.c Image Type check OK
1730 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1731 9 common/cmd_bootm.c Start initial ramdisk verification
1732 -10 common/cmd_bootm.c Ramdisk header has bad magic number
1733 -11 common/cmd_bootm.c Ramdisk header has bad checksum
1734 10 common/cmd_bootm.c Ramdisk header is OK
1735 -12 common/cmd_bootm.c Ramdisk data has bad checksum
1736 11 common/cmd_bootm.c Ramdisk data has correct checksum
1737 12 common/cmd_bootm.c Ramdisk verification complete, start loading
1738 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk)
1739 13 common/cmd_bootm.c Start multifile image verification
1740 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue.
1741 15 common/cmd_bootm.c All preparation done, transferring control to OS
1743 -30 lib_ppc/board.c Fatal error, hang the system
1744 -31 post/post.c POST test failed, detected by post_output_backlog()
1745 -32 post/post.c POST test failed, detected by post_run_single()
1747 -1 common/cmd_doc.c Bad usage of "doc" command
1748 -1 common/cmd_doc.c No boot device
1749 -1 common/cmd_doc.c Unknown Chip ID on boot device
1750 -1 common/cmd_doc.c Read Error on boot device
1751 -1 common/cmd_doc.c Image header has bad magic number
1753 -1 common/cmd_ide.c Bad usage of "ide" command
1754 -1 common/cmd_ide.c No boot device
1755 -1 common/cmd_ide.c Unknown boot device
1756 -1 common/cmd_ide.c Unknown partition table
1757 -1 common/cmd_ide.c Invalid partition type
1758 -1 common/cmd_ide.c Read Error on boot device
1759 -1 common/cmd_ide.c Image header has bad magic number
1761 -1 common/cmd_nand.c Bad usage of "nand" command
1762 -1 common/cmd_nand.c No boot device
1763 -1 common/cmd_nand.c Unknown Chip ID on boot device
1764 -1 common/cmd_nand.c Read Error on boot device
1765 -1 common/cmd_nand.c Image header has bad magic number
1767 -1 common/env_common.c Environment has a bad CRC, using default
1773 [so far only for SMDK2400 and TRAB boards]
1775 - Modem support endable:
1776 CONFIG_MODEM_SUPPORT
1778 - RTS/CTS Flow control enable:
1781 - Modem debug support:
1782 CONFIG_MODEM_SUPPORT_DEBUG
1784 Enables debugging stuff (char screen[1024], dbg())
1785 for modem support. Useful only with BDI2000.
1787 - Interrupt support (PPC):
1789 There are common interrupt_init() and timer_interrupt()
1790 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
1791 for cpu specific initialization. interrupt_init_cpu()
1792 should set decrementer_count to appropriate value. If
1793 cpu resets decrementer automatically after interrupt
1794 (ppc4xx) it should set decrementer_count to zero.
1795 timer_interrupt() calls timer_interrupt_cpu() for cpu
1796 specific handling. If board has watchdog / status_led
1797 / other_activity_monitor it works automatically from
1798 general timer_interrupt().
1802 In the target system modem support is enabled when a
1803 specific key (key combination) is pressed during
1804 power-on. Otherwise U-Boot will boot normally
1805 (autoboot). The key_pressed() fuction is called from
1806 board_init(). Currently key_pressed() is a dummy
1807 function, returning 1 and thus enabling modem
1810 If there are no modem init strings in the
1811 environment, U-Boot proceed to autoboot; the
1812 previous output (banner, info printfs) will be
1815 See also: doc/README.Modem
1818 Configuration Settings:
1819 -----------------------
1821 - CFG_LONGHELP: Defined when you want long help messages included;
1822 undefine this when you're short of memory.
1824 - CFG_PROMPT: This is what U-Boot prints on the console to
1825 prompt for user input.
1827 - CFG_CBSIZE: Buffer size for input from the Console
1829 - CFG_PBSIZE: Buffer size for Console output
1831 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1833 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1834 the application (usually a Linux kernel) when it is
1837 - CFG_BAUDRATE_TABLE:
1838 List of legal baudrate settings for this board.
1840 - CFG_CONSOLE_INFO_QUIET
1841 Suppress display of console information at boot.
1843 - CFG_CONSOLE_IS_IN_ENV
1844 If the board specific function
1845 extern int overwrite_console (void);
1846 returns 1, the stdin, stderr and stdout are switched to the
1847 serial port, else the settings in the environment are used.
1849 - CFG_CONSOLE_OVERWRITE_ROUTINE
1850 Enable the call to overwrite_console().
1852 - CFG_CONSOLE_ENV_OVERWRITE
1853 Enable overwrite of previous console environment settings.
1855 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1856 Begin and End addresses of the area used by the
1860 Enable an alternate, more extensive memory test.
1862 - CFG_MEMTEST_SCRATCH:
1863 Scratch address used by the alternate memory test
1864 You only need to set this if address zero isn't writeable
1866 - CFG_TFTP_LOADADDR:
1867 Default load address for network file downloads
1869 - CFG_LOADS_BAUD_CHANGE:
1870 Enable temporary baudrate change while serial download
1873 Physical start address of SDRAM. _Must_ be 0 here.
1876 Physical start address of Motherboard I/O (if using a
1880 Physical start address of Flash memory.
1883 Physical start address of boot monitor code (set by
1884 make config files to be same as the text base address
1885 (TEXT_BASE) used when linking) - same as
1886 CFG_FLASH_BASE when booting from flash.
1889 Size of memory reserved for monitor code, used to
1890 determine _at_compile_time_ (!) if the environment is
1891 embedded within the U-Boot image, or in a separate
1895 Size of DRAM reserved for malloc() use.
1898 Normally compressed uImages are limited to an
1899 uncompressed size of 8 MBytes. If this is not enough,
1900 you can define CFG_BOOTM_LEN in your board config file
1901 to adjust this setting to your needs.
1904 Maximum size of memory mapped by the startup code of
1905 the Linux kernel; all data that must be processed by
1906 the Linux kernel (bd_info, boot arguments, eventually
1907 initrd image) must be put below this limit.
1909 - CFG_MAX_FLASH_BANKS:
1910 Max number of Flash memory banks
1912 - CFG_MAX_FLASH_SECT:
1913 Max number of sectors on a Flash chip
1915 - CFG_FLASH_ERASE_TOUT:
1916 Timeout for Flash erase operations (in ms)
1918 - CFG_FLASH_WRITE_TOUT:
1919 Timeout for Flash write operations (in ms)
1921 - CFG_FLASH_LOCK_TOUT
1922 Timeout for Flash set sector lock bit operation (in ms)
1924 - CFG_FLASH_UNLOCK_TOUT
1925 Timeout for Flash clear lock bits operation (in ms)
1927 - CFG_FLASH_PROTECTION
1928 If defined, hardware flash sectors protection is used
1929 instead of U-Boot software protection.
1931 - CFG_DIRECT_FLASH_TFTP:
1933 Enable TFTP transfers directly to flash memory;
1934 without this option such a download has to be
1935 performed in two steps: (1) download to RAM, and (2)
1936 copy from RAM to flash.
1938 The two-step approach is usually more reliable, since
1939 you can check if the download worked before you erase
1940 the flash, but in some situations (when sytem RAM is
1941 too limited to allow for a tempory copy of the
1942 downloaded image) this option may be very useful.
1945 Define if the flash driver uses extra elements in the
1946 common flash structure for storing flash geometry.
1948 - CFG_FLASH_CFI_DRIVER
1949 This option also enables the building of the cfi_flash driver
1950 in the drivers directory
1952 - CFG_FLASH_QUIET_TEST
1953 If this option is defined, the common CFI flash doesn't
1954 print it's warning upon not recognized FLASH banks. This
1955 is useful, if some of the configured banks are only
1956 optionally available.
1958 - CFG_RX_ETH_BUFFER:
1959 Defines the number of ethernet receive buffers. On some
1960 ethernet controllers it is recommended to set this value
1961 to 8 or even higher (EEPRO100 or 405 EMAC), since all
1962 buffers can be full shortly after enabling the interface
1963 on high ethernet traffic.
1964 Defaults to 4 if not defined.
1966 The following definitions that deal with the placement and management
1967 of environment data (variable area); in general, we support the
1968 following configurations:
1970 - CFG_ENV_IS_IN_FLASH:
1972 Define this if the environment is in flash memory.
1974 a) The environment occupies one whole flash sector, which is
1975 "embedded" in the text segment with the U-Boot code. This
1976 happens usually with "bottom boot sector" or "top boot
1977 sector" type flash chips, which have several smaller
1978 sectors at the start or the end. For instance, such a
1979 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
1980 such a case you would place the environment in one of the
1981 4 kB sectors - with U-Boot code before and after it. With
1982 "top boot sector" type flash chips, you would put the
1983 environment in one of the last sectors, leaving a gap
1984 between U-Boot and the environment.
1988 Offset of environment data (variable area) to the
1989 beginning of flash memory; for instance, with bottom boot
1990 type flash chips the second sector can be used: the offset
1991 for this sector is given here.
1993 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
1997 This is just another way to specify the start address of
1998 the flash sector containing the environment (instead of
2001 - CFG_ENV_SECT_SIZE:
2003 Size of the sector containing the environment.
2006 b) Sometimes flash chips have few, equal sized, BIG sectors.
2007 In such a case you don't want to spend a whole sector for
2012 If you use this in combination with CFG_ENV_IS_IN_FLASH
2013 and CFG_ENV_SECT_SIZE, you can specify to use only a part
2014 of this flash sector for the environment. This saves
2015 memory for the RAM copy of the environment.
2017 It may also save flash memory if you decide to use this
2018 when your environment is "embedded" within U-Boot code,
2019 since then the remainder of the flash sector could be used
2020 for U-Boot code. It should be pointed out that this is
2021 STRONGLY DISCOURAGED from a robustness point of view:
2022 updating the environment in flash makes it always
2023 necessary to erase the WHOLE sector. If something goes
2024 wrong before the contents has been restored from a copy in
2025 RAM, your target system will be dead.
2027 - CFG_ENV_ADDR_REDUND
2030 These settings describe a second storage area used to hold
2031 a redundand copy of the environment data, so that there is
2032 a valid backup copy in case there is a power failure during
2033 a "saveenv" operation.
2035 BE CAREFUL! Any changes to the flash layout, and some changes to the
2036 source code will make it necessary to adapt <board>/u-boot.lds*
2040 - CFG_ENV_IS_IN_NVRAM:
2042 Define this if you have some non-volatile memory device
2043 (NVRAM, battery buffered SRAM) which you want to use for the
2049 These two #defines are used to determin the memory area you
2050 want to use for environment. It is assumed that this memory
2051 can just be read and written to, without any special
2054 BE CAREFUL! The first access to the environment happens quite early
2055 in U-Boot initalization (when we try to get the setting of for the
2056 console baudrate). You *MUST* have mappend your NVRAM area then, or
2059 Please note that even with NVRAM we still use a copy of the
2060 environment in RAM: we could work on NVRAM directly, but we want to
2061 keep settings there always unmodified except somebody uses "saveenv"
2062 to save the current settings.
2065 - CFG_ENV_IS_IN_EEPROM:
2067 Use this if you have an EEPROM or similar serial access
2068 device and a driver for it.
2073 These two #defines specify the offset and size of the
2074 environment area within the total memory of your EEPROM.
2076 - CFG_I2C_EEPROM_ADDR:
2077 If defined, specified the chip address of the EEPROM device.
2078 The default address is zero.
2080 - CFG_EEPROM_PAGE_WRITE_BITS:
2081 If defined, the number of bits used to address bytes in a
2082 single page in the EEPROM device. A 64 byte page, for example
2083 would require six bits.
2085 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
2086 If defined, the number of milliseconds to delay between
2087 page writes. The default is zero milliseconds.
2089 - CFG_I2C_EEPROM_ADDR_LEN:
2090 The length in bytes of the EEPROM memory array address. Note
2091 that this is NOT the chip address length!
2093 - CFG_I2C_EEPROM_ADDR_OVERFLOW:
2094 EEPROM chips that implement "address overflow" are ones
2095 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2096 address and the extra bits end up in the "chip address" bit
2097 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2100 Note that we consider the length of the address field to
2101 still be one byte because the extra address bits are hidden
2102 in the chip address.
2105 The size in bytes of the EEPROM device.
2108 - CFG_ENV_IS_IN_DATAFLASH:
2110 Define this if you have a DataFlash memory device which you
2111 want to use for the environment.
2117 These three #defines specify the offset and size of the
2118 environment area within the total memory of your DataFlash placed
2119 at the specified address.
2121 - CFG_ENV_IS_IN_NAND:
2123 Define this if you have a NAND device which you want to use
2124 for the environment.
2129 These two #defines specify the offset and size of the environment
2130 area within the first NAND device.
2132 - CFG_ENV_OFFSET_REDUND
2134 This setting describes a second storage area of CFG_ENV_SIZE
2135 size used to hold a redundant copy of the environment data,
2136 so that there is a valid backup copy in case there is a
2137 power failure during a "saveenv" operation.
2139 Note: CFG_ENV_OFFSET and CFG_ENV_OFFSET_REDUND must be aligned
2140 to a block boundary, and CFG_ENV_SIZE must be a multiple of
2141 the NAND devices block size.
2143 - CFG_SPI_INIT_OFFSET
2145 Defines offset to the initial SPI buffer area in DPRAM. The
2146 area is used at an early stage (ROM part) if the environment
2147 is configured to reside in the SPI EEPROM: We need a 520 byte
2148 scratch DPRAM area. It is used between the two initialization
2149 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2150 to be a good choice since it makes it far enough from the
2151 start of the data area as well as from the stack pointer.
2153 Please note that the environment is read-only as long as the monitor
2154 has been relocated to RAM and a RAM copy of the environment has been
2155 created; also, when using EEPROM you will have to use getenv_r()
2156 until then to read environment variables.
2158 The environment is protected by a CRC32 checksum. Before the monitor
2159 is relocated into RAM, as a result of a bad CRC you will be working
2160 with the compiled-in default environment - *silently*!!! [This is
2161 necessary, because the first environment variable we need is the
2162 "baudrate" setting for the console - if we have a bad CRC, we don't
2163 have any device yet where we could complain.]
2165 Note: once the monitor has been relocated, then it will complain if
2166 the default environment is used; a new CRC is computed as soon as you
2167 use the "saveenv" command to store a valid environment.
2169 - CFG_FAULT_ECHO_LINK_DOWN:
2170 Echo the inverted Ethernet link state to the fault LED.
2172 Note: If this option is active, then CFG_FAULT_MII_ADDR
2173 also needs to be defined.
2175 - CFG_FAULT_MII_ADDR:
2176 MII address of the PHY to check for the Ethernet link state.
2178 - CFG_64BIT_VSPRINTF:
2179 Makes vsprintf (and all *printf functions) support printing
2180 of 64bit values by using the L quantifier
2182 - CFG_64BIT_STRTOUL:
2183 Adds simple_strtoull that returns a 64bit value
2185 Low Level (hardware related) configuration options:
2186 ---------------------------------------------------
2188 - CFG_CACHELINE_SIZE:
2189 Cache Line Size of the CPU.
2192 Default address of the IMMR after system reset.
2194 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2195 and RPXsuper) to be able to adjust the position of
2196 the IMMR register after a reset.
2198 - Floppy Disk Support:
2199 CFG_FDC_DRIVE_NUMBER
2201 the default drive number (default value 0)
2205 defines the spacing between fdc chipset registers
2210 defines the offset of register from address. It
2211 depends on which part of the data bus is connected to
2212 the fdc chipset. (default value 0)
2214 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
2215 CFG_FDC_DRIVE_NUMBER are undefined, they take their
2218 if CFG_FDC_HW_INIT is defined, then the function
2219 fdc_hw_init() is called at the beginning of the FDC
2220 setup. fdc_hw_init() must be provided by the board
2221 source code. It is used to make hardware dependant
2224 - CFG_IMMR: Physical address of the Internal Memory.
2225 DO NOT CHANGE unless you know exactly what you're
2226 doing! (11-4) [MPC8xx/82xx systems only]
2228 - CFG_INIT_RAM_ADDR:
2230 Start address of memory area that can be used for
2231 initial data and stack; please note that this must be
2232 writable memory that is working WITHOUT special
2233 initialization, i. e. you CANNOT use normal RAM which
2234 will become available only after programming the
2235 memory controller and running certain initialization
2238 U-Boot uses the following memory types:
2239 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2240 - MPC824X: data cache
2241 - PPC4xx: data cache
2243 - CFG_GBL_DATA_OFFSET:
2245 Offset of the initial data structure in the memory
2246 area defined by CFG_INIT_RAM_ADDR. Usually
2247 CFG_GBL_DATA_OFFSET is chosen such that the initial
2248 data is located at the end of the available space
2249 (sometimes written as (CFG_INIT_RAM_END -
2250 CFG_INIT_DATA_SIZE), and the initial stack is just
2251 below that area (growing from (CFG_INIT_RAM_ADDR +
2252 CFG_GBL_DATA_OFFSET) downward.
2255 On the MPC824X (or other systems that use the data
2256 cache for initial memory) the address chosen for
2257 CFG_INIT_RAM_ADDR is basically arbitrary - it must
2258 point to an otherwise UNUSED address space between
2259 the top of RAM and the start of the PCI space.
2261 - CFG_SIUMCR: SIU Module Configuration (11-6)
2263 - CFG_SYPCR: System Protection Control (11-9)
2265 - CFG_TBSCR: Time Base Status and Control (11-26)
2267 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
2269 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2271 - CFG_SCCR: System Clock and reset Control Register (15-27)
2273 - CFG_OR_TIMING_SDRAM:
2277 periodic timer for refresh
2279 - CFG_DER: Debug Event Register (37-47)
2281 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
2282 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
2283 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
2285 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2287 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2288 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
2289 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
2290 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2292 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
2293 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
2294 Machine Mode Register and Memory Periodic Timer
2295 Prescaler definitions (SDRAM timing)
2297 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
2298 enable I2C microcode relocation patch (MPC8xx);
2299 define relocation offset in DPRAM [DSP2]
2301 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
2302 enable SPI microcode relocation patch (MPC8xx);
2303 define relocation offset in DPRAM [SCC4]
2306 Use OSCM clock mode on MBX8xx board. Be careful,
2307 wrong setting might damage your board. Read
2308 doc/README.MBX before setting this variable!
2310 - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2311 Offset of the bootmode word in DPRAM used by post
2312 (Power On Self Tests). This definition overrides
2313 #define'd default value in commproc.h resp.
2316 - CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
2317 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
2318 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
2319 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
2320 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2321 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
2322 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
2323 CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
2324 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2327 Get DDR timing information from an I2C EEPROM. Common with pluggable
2328 memory modules such as SODIMMs
2330 I2C address of the SPD EEPROM
2333 If SPD EEPROM is on an I2C bus other than the first one, specify here.
2334 Note that the value must resolve to something your driver can deal with.
2336 - CFG_83XX_DDR_USES_CS0
2337 Only for 83xx systems. If specified, then DDR should be configured
2338 using CS0 and CS1 instead of CS2 and CS3.
2340 - CFG_83XX_DDR_USES_CS0
2341 Only for 83xx systems. If specified, then DDR should be configured
2342 using CS0 and CS1 instead of CS2 and CS3.
2344 - CONFIG_ETHER_ON_FEC[12]
2345 Define to enable FEC[12] on a 8xx series processor.
2347 - CONFIG_FEC[12]_PHY
2348 Define to the hardcoded PHY address which corresponds
2349 to the given FEC; i. e.
2350 #define CONFIG_FEC1_PHY 4
2351 means that the PHY with address 4 is connected to FEC1
2353 When set to -1, means to probe for first available.
2355 - CONFIG_FEC[12]_PHY_NORXERR
2356 The PHY does not have a RXERR line (RMII only).
2357 (so program the FEC to ignore it).
2360 Enable RMII mode for all FECs.
2361 Note that this is a global option, we can't
2362 have one FEC in standard MII mode and another in RMII mode.
2364 - CONFIG_CRC32_VERIFY
2365 Add a verify option to the crc32 command.
2368 => crc32 -v <address> <count> <crc32>
2370 Where address/count indicate a memory area
2371 and crc32 is the correct crc32 which the
2375 Add the "loopw" memory command. This only takes effect if
2376 the memory commands are activated globally (CFG_CMD_MEM).
2379 Add the "mdc" and "mwc" memory commands. These are cyclic
2384 This command will print 4 bytes (10,11,12,13) each 500 ms.
2386 => mwc.l 100 12345678 10
2387 This command will write 12345678 to address 100 all 10 ms.
2389 This only takes effect if the memory commands are activated
2390 globally (CFG_CMD_MEM).
2392 - CONFIG_SKIP_LOWLEVEL_INIT
2393 - CONFIG_SKIP_RELOCATE_UBOOT
2395 [ARM only] If these variables are defined, then
2396 certain low level initializations (like setting up
2397 the memory controller) are omitted and/or U-Boot does
2398 not relocate itself into RAM.
2399 Normally these variables MUST NOT be defined. The
2400 only exception is when U-Boot is loaded (to RAM) by
2401 some other boot loader or by a debugger which
2402 performs these intializations itself.
2405 Building the Software:
2406 ======================
2408 Building U-Boot has been tested in native PPC environments (on a
2409 PowerBook G3 running LinuxPPC 2000) and in cross environments
2410 (running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
2413 If you are not using a native PPC environment, it is assumed that you
2414 have the GNU cross compiling tools available in your path and named
2415 with a prefix of "powerpc-linux-". If this is not the case, (e.g. if
2416 you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
2417 the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
2420 CROSS_COMPILE = ppc_4xx-
2423 U-Boot is intended to be simple to build. After installing the
2424 sources you must configure U-Boot for one specific board type. This
2429 where "NAME_config" is the name of one of the existing
2430 configurations; the following names are supported:
2432 ADCIOP_config FPS860L_config omap730p2_config
2433 ADS860_config GEN860T_config pcu_e_config
2435 AR405_config GENIETV_config PIP405_config
2436 at91rm9200dk_config GTH_config QS823_config
2437 CANBT_config hermes_config QS850_config
2438 cmi_mpc5xx_config hymod_config QS860T_config
2439 cogent_common_config IP860_config RPXlite_config
2440 cogent_mpc8260_config IVML24_config RPXlite_DW_config
2441 cogent_mpc8xx_config IVMS8_config RPXsuper_config
2442 CPCI405_config JSE_config rsdproto_config
2443 CPCIISER4_config LANTEC_config Sandpoint8240_config
2444 csb272_config lwmon_config sbc8260_config
2445 CU824_config MBX860T_config sbc8560_33_config
2446 DUET_ADS_config MBX_config sbc8560_66_config
2447 EBONY_config MPC8260ADS_config SM850_config
2448 ELPT860_config MPC8540ADS_config SPD823TS_config
2449 ESTEEM192E_config MPC8540EVAL_config stxgp3_config
2450 ETX094_config MPC8560ADS_config SXNI855T_config
2451 FADS823_config NETVIA_config TQM823L_config
2452 FADS850SAR_config omap1510inn_config TQM850L_config
2453 FADS860T_config omap1610h2_config TQM855L_config
2454 FPS850L_config omap1610inn_config TQM860L_config
2455 omap5912osk_config walnut_config
2456 omap2420h4_config Yukon8220_config
2459 Note: for some board special configuration names may exist; check if
2460 additional information is available from the board vendor; for
2461 instance, the TQM823L systems are available without (standard)
2462 or with LCD support. You can select such additional "features"
2463 when chosing the configuration, i. e.
2466 - will configure for a plain TQM823L, i. e. no LCD support
2468 make TQM823L_LCD_config
2469 - will configure for a TQM823L with U-Boot console on LCD
2474 Finally, type "make all", and you should get some working U-Boot
2475 images ready for download to / installation on your system:
2477 - "u-boot.bin" is a raw binary image
2478 - "u-boot" is an image in ELF binary format
2479 - "u-boot.srec" is in Motorola S-Record format
2481 By default the build is performed locally and the objects are saved
2482 in the source directory. One of the two methods can be used to change
2483 this behavior and build U-Boot to some external directory:
2485 1. Add O= to the make command line invocations:
2487 make O=/tmp/build distclean
2488 make O=/tmp/build NAME_config
2489 make O=/tmp/build all
2491 2. Set environment variable BUILD_DIR to point to the desired location:
2493 export BUILD_DIR=/tmp/build
2498 Note that the command line "O=" setting overrides the BUILD_DIR environment
2502 Please be aware that the Makefiles assume you are using GNU make, so
2503 for instance on NetBSD you might need to use "gmake" instead of
2507 If the system board that you have is not listed, then you will need
2508 to port U-Boot to your hardware platform. To do this, follow these
2511 1. Add a new configuration option for your board to the toplevel
2512 "Makefile" and to the "MAKEALL" script, using the existing
2513 entries as examples. Note that here and at many other places
2514 boards and other names are listed in alphabetical sort order. Please
2516 2. Create a new directory to hold your board specific code. Add any
2517 files you need. In your board directory, you will need at least
2518 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2519 3. Create a new configuration file "include/configs/<board>.h" for
2521 3. If you're porting U-Boot to a new CPU, then also create a new
2522 directory to hold your CPU specific code. Add any files you need.
2523 4. Run "make <board>_config" with your new name.
2524 5. Type "make", and you should get a working "u-boot.srec" file
2525 to be installed on your target system.
2526 6. Debug and solve any problems that might arise.
2527 [Of course, this last step is much harder than it sounds.]
2530 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2531 ==============================================================
2533 If you have modified U-Boot sources (for instance added a new board
2534 or support for new devices, a new CPU, etc.) you are expected to
2535 provide feedback to the other developers. The feedback normally takes
2536 the form of a "patch", i. e. a context diff against a certain (latest
2537 official or latest in CVS) version of U-Boot sources.
2539 But before you submit such a patch, please verify that your modifi-
2540 cation did not break existing code. At least make sure that *ALL* of
2541 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2542 just run the "MAKEALL" script, which will configure and build U-Boot
2543 for ALL supported system. Be warned, this will take a while. You can
2544 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2545 environment variable to the script, i. e. to use the cross tools from
2546 MontaVista's Hard Hat Linux you can type
2548 CROSS_COMPILE=ppc_8xx- MAKEALL
2550 or to build on a native PowerPC system you can type
2552 CROSS_COMPILE=' ' MAKEALL
2554 When using the MAKEALL script, the default behaviour is to build U-Boot
2555 in the source directory. This location can be changed by setting the
2556 BUILD_DIR environment variable. Also, for each target built, the MAKEALL
2557 script saves two log files (<target>.ERR and <target>.MAKEALL) in the
2558 <source dir>/LOG directory. This default location can be changed by
2559 setting the MAKEALL_LOGDIR environment variable. For example:
2561 export BUILD_DIR=/tmp/build
2562 export MAKEALL_LOGDIR=/tmp/log
2563 CROSS_COMPILE=ppc_8xx- MAKEALL
2565 With the above settings build objects are saved in the /tmp/build, log
2566 files are saved in the /tmp/log and the source tree remains clean during
2567 the whole build process.
2570 See also "U-Boot Porting Guide" below.
2573 Monitor Commands - Overview:
2574 ============================
2576 go - start application at address 'addr'
2577 run - run commands in an environment variable
2578 bootm - boot application image from memory
2579 bootp - boot image via network using BootP/TFTP protocol
2580 tftpboot- boot image via network using TFTP protocol
2581 and env variables "ipaddr" and "serverip"
2582 (and eventually "gatewayip")
2583 rarpboot- boot image via network using RARP/TFTP protocol
2584 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2585 loads - load S-Record file over serial line
2586 loadb - load binary file over serial line (kermit mode)
2588 mm - memory modify (auto-incrementing)
2589 nm - memory modify (constant address)
2590 mw - memory write (fill)
2592 cmp - memory compare
2593 crc32 - checksum calculation
2594 imd - i2c memory display
2595 imm - i2c memory modify (auto-incrementing)
2596 inm - i2c memory modify (constant address)
2597 imw - i2c memory write (fill)
2598 icrc32 - i2c checksum calculation
2599 iprobe - probe to discover valid I2C chip addresses
2600 iloop - infinite loop on address range
2601 isdram - print SDRAM configuration information
2602 sspi - SPI utility commands
2603 base - print or set address offset
2604 printenv- print environment variables
2605 setenv - set environment variables
2606 saveenv - save environment variables to persistent storage
2607 protect - enable or disable FLASH write protection
2608 erase - erase FLASH memory
2609 flinfo - print FLASH memory information
2610 bdinfo - print Board Info structure
2611 iminfo - print header information for application image
2612 coninfo - print console devices and informations
2613 ide - IDE sub-system
2614 loop - infinite loop on address range
2615 loopw - infinite write loop on address range
2616 mtest - simple RAM test
2617 icache - enable or disable instruction cache
2618 dcache - enable or disable data cache
2619 reset - Perform RESET of the CPU
2620 echo - echo args to console
2621 version - print monitor version
2622 help - print online help
2623 ? - alias for 'help'
2626 Monitor Commands - Detailed Description:
2627 ========================================
2631 For now: just type "help <command>".
2634 Environment Variables:
2635 ======================
2637 U-Boot supports user configuration using Environment Variables which
2638 can be made persistent by saving to Flash memory.
2640 Environment Variables are set using "setenv", printed using
2641 "printenv", and saved to Flash using "saveenv". Using "setenv"
2642 without a value can be used to delete a variable from the
2643 environment. As long as you don't save the environment you are
2644 working with an in-memory copy. In case the Flash area containing the
2645 environment is erased by accident, a default environment is provided.
2647 Some configuration options can be set using Environment Variables:
2649 baudrate - see CONFIG_BAUDRATE
2651 bootdelay - see CONFIG_BOOTDELAY
2653 bootcmd - see CONFIG_BOOTCOMMAND
2655 bootargs - Boot arguments when booting an RTOS image
2657 bootfile - Name of the image to load with TFTP
2659 autoload - if set to "no" (any string beginning with 'n'),
2660 "bootp" will just load perform a lookup of the
2661 configuration from the BOOTP server, but not try to
2662 load any image using TFTP
2664 autostart - if set to "yes", an image loaded using the "bootp",
2665 "rarpboot", "tftpboot" or "diskboot" commands will
2666 be automatically started (by internally calling
2669 If set to "no", a standalone image passed to the
2670 "bootm" command will be copied to the load address
2671 (and eventually uncompressed), but NOT be started.
2672 This can be used to load and uncompress arbitrary
2675 i2cfast - (PPC405GP|PPC405EP only)
2676 if set to 'y' configures Linux I2C driver for fast
2677 mode (400kHZ). This environment variable is used in
2678 initialization code. So, for changes to be effective
2679 it must be saved and board must be reset.
2681 initrd_high - restrict positioning of initrd images:
2682 If this variable is not set, initrd images will be
2683 copied to the highest possible address in RAM; this
2684 is usually what you want since it allows for
2685 maximum initrd size. If for some reason you want to
2686 make sure that the initrd image is loaded below the
2687 CFG_BOOTMAPSZ limit, you can set this environment
2688 variable to a value of "no" or "off" or "0".
2689 Alternatively, you can set it to a maximum upper
2690 address to use (U-Boot will still check that it
2691 does not overwrite the U-Boot stack and data).
2693 For instance, when you have a system with 16 MB
2694 RAM, and want to reserve 4 MB from use by Linux,
2695 you can do this by adding "mem=12M" to the value of
2696 the "bootargs" variable. However, now you must make
2697 sure that the initrd image is placed in the first
2698 12 MB as well - this can be done with
2700 setenv initrd_high 00c00000
2702 If you set initrd_high to 0xFFFFFFFF, this is an
2703 indication to U-Boot that all addresses are legal
2704 for the Linux kernel, including addresses in flash
2705 memory. In this case U-Boot will NOT COPY the
2706 ramdisk at all. This may be useful to reduce the
2707 boot time on your system, but requires that this
2708 feature is supported by your Linux kernel.
2710 ipaddr - IP address; needed for tftpboot command
2712 loadaddr - Default load address for commands like "bootp",
2713 "rarpboot", "tftpboot", "loadb" or "diskboot"
2715 loads_echo - see CONFIG_LOADS_ECHO
2717 serverip - TFTP server IP address; needed for tftpboot command
2719 bootretry - see CONFIG_BOOT_RETRY_TIME
2721 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
2723 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
2725 ethprime - When CONFIG_NET_MULTI is enabled controls which
2726 interface is used first.
2728 ethact - When CONFIG_NET_MULTI is enabled controls which
2729 interface is currently active. For example you
2730 can do the following
2732 => setenv ethact FEC ETHERNET
2733 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
2734 => setenv ethact SCC ETHERNET
2735 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
2737 netretry - When set to "no" each network operation will
2738 either succeed or fail without retrying.
2739 When set to "once" the network operation will
2740 fail when all the available network interfaces
2741 are tried once without success.
2742 Useful on scripts which control the retry operation
2745 tftpsrcport - If this is set, the value is used for TFTP's
2748 tftpdstport - If this is set, the value is used for TFTP's UDP
2749 destination port instead of the Well Know Port 69.
2751 vlan - When set to a value < 4095 the traffic over
2752 ethernet is encapsulated/received over 802.1q
2755 The following environment variables may be used and automatically
2756 updated by the network boot commands ("bootp" and "rarpboot"),
2757 depending the information provided by your boot server:
2759 bootfile - see above
2760 dnsip - IP address of your Domain Name Server
2761 dnsip2 - IP address of your secondary Domain Name Server
2762 gatewayip - IP address of the Gateway (Router) to use
2763 hostname - Target hostname
2765 netmask - Subnet Mask
2766 rootpath - Pathname of the root filesystem on the NFS server
2767 serverip - see above
2770 There are two special Environment Variables:
2772 serial# - contains hardware identification information such
2773 as type string and/or serial number
2774 ethaddr - Ethernet address
2776 These variables can be set only once (usually during manufacturing of
2777 the board). U-Boot refuses to delete or overwrite these variables
2778 once they have been set once.
2781 Further special Environment Variables:
2783 ver - Contains the U-Boot version string as printed
2784 with the "version" command. This variable is
2785 readonly (see CONFIG_VERSION_VARIABLE).
2788 Please note that changes to some configuration parameters may take
2789 only effect after the next boot (yes, that's just like Windoze :-).
2792 Command Line Parsing:
2793 =====================
2795 There are two different command line parsers available with U-Boot:
2796 the old "simple" one, and the much more powerful "hush" shell:
2798 Old, simple command line parser:
2799 --------------------------------
2801 - supports environment variables (through setenv / saveenv commands)
2802 - several commands on one line, separated by ';'
2803 - variable substitution using "... ${name} ..." syntax
2804 - special characters ('$', ';') can be escaped by prefixing with '\',
2806 setenv bootcmd bootm \${address}
2807 - You can also escape text by enclosing in single apostrophes, for example:
2808 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2813 - similar to Bourne shell, with control structures like
2814 if...then...else...fi, for...do...done; while...do...done,
2815 until...do...done, ...
2816 - supports environment ("global") variables (through setenv / saveenv
2817 commands) and local shell variables (through standard shell syntax
2818 "name=value"); only environment variables can be used with "run"
2824 (1) If a command line (or an environment variable executed by a "run"
2825 command) contains several commands separated by semicolon, and
2826 one of these commands fails, then the remaining commands will be
2829 (2) If you execute several variables with one call to run (i. e.
2830 calling run with a list af variables as arguments), any failing
2831 command will cause "run" to terminate, i. e. the remaining
2832 variables are not executed.
2834 Note for Redundant Ethernet Interfaces:
2835 =======================================
2837 Some boards come with redundant ethernet interfaces; U-Boot supports
2838 such configurations and is capable of automatic selection of a
2839 "working" interface when needed. MAC assignment works as follows:
2841 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2842 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2843 "eth1addr" (=>eth1), "eth2addr", ...
2845 If the network interface stores some valid MAC address (for instance
2846 in SROM), this is used as default address if there is NO correspon-
2847 ding setting in the environment; if the corresponding environment
2848 variable is set, this overrides the settings in the card; that means:
2850 o If the SROM has a valid MAC address, and there is no address in the
2851 environment, the SROM's address is used.
2853 o If there is no valid address in the SROM, and a definition in the
2854 environment exists, then the value from the environment variable is
2857 o If both the SROM and the environment contain a MAC address, and
2858 both addresses are the same, this MAC address is used.
2860 o If both the SROM and the environment contain a MAC address, and the
2861 addresses differ, the value from the environment is used and a
2864 o If neither SROM nor the environment contain a MAC address, an error
2871 The "boot" commands of this monitor operate on "image" files which
2872 can be basicly anything, preceeded by a special header; see the
2873 definitions in include/image.h for details; basicly, the header
2874 defines the following image properties:
2876 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2877 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2878 LynxOS, pSOS, QNX, RTEMS, ARTOS;
2879 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
2880 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
2881 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2882 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
2883 * Compression Type (uncompressed, gzip, bzip2)
2889 The header is marked by a special Magic Number, and both the header
2890 and the data portions of the image are secured against corruption by
2897 Although U-Boot should support any OS or standalone application
2898 easily, the main focus has always been on Linux during the design of
2901 U-Boot includes many features that so far have been part of some
2902 special "boot loader" code within the Linux kernel. Also, any
2903 "initrd" images to be used are no longer part of one big Linux image;
2904 instead, kernel and "initrd" are separate images. This implementation
2905 serves several purposes:
2907 - the same features can be used for other OS or standalone
2908 applications (for instance: using compressed images to reduce the
2909 Flash memory footprint)
2911 - it becomes much easier to port new Linux kernel versions because
2912 lots of low-level, hardware dependent stuff are done by U-Boot
2914 - the same Linux kernel image can now be used with different "initrd"
2915 images; of course this also means that different kernel images can
2916 be run with the same "initrd". This makes testing easier (you don't
2917 have to build a new "zImage.initrd" Linux image when you just
2918 change a file in your "initrd"). Also, a field-upgrade of the
2919 software is easier now.
2925 Porting Linux to U-Boot based systems:
2926 ---------------------------------------
2928 U-Boot cannot save you from doing all the necessary modifications to
2929 configure the Linux device drivers for use with your target hardware
2930 (no, we don't intend to provide a full virtual machine interface to
2933 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
2935 Just make sure your machine specific header file (for instance
2936 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
2937 Information structure as we define in include/u-boot.h, and make
2938 sure that your definition of IMAP_ADDR uses the same value as your
2939 U-Boot configuration in CFG_IMMR.
2942 Configuring the Linux kernel:
2943 -----------------------------
2945 No specific requirements for U-Boot. Make sure you have some root
2946 device (initial ramdisk, NFS) for your target system.
2949 Building a Linux Image:
2950 -----------------------
2952 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2953 not used. If you use recent kernel source, a new build target
2954 "uImage" will exist which automatically builds an image usable by
2955 U-Boot. Most older kernels also have support for a "pImage" target,
2956 which was introduced for our predecessor project PPCBoot and uses a
2957 100% compatible format.
2966 The "uImage" build target uses a special tool (in 'tools/mkimage') to
2967 encapsulate a compressed Linux kernel image with header information,
2968 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
2970 * build a standard "vmlinux" kernel image (in ELF binary format):
2972 * convert the kernel into a raw binary image:
2974 ${CROSS_COMPILE}-objcopy -O binary \
2975 -R .note -R .comment \
2976 -S vmlinux linux.bin
2978 * compress the binary image:
2982 * package compressed binary image for U-Boot:
2984 mkimage -A ppc -O linux -T kernel -C gzip \
2985 -a 0 -e 0 -n "Linux Kernel Image" \
2986 -d linux.bin.gz uImage
2989 The "mkimage" tool can also be used to create ramdisk images for use
2990 with U-Boot, either separated from the Linux kernel image, or
2991 combined into one file. "mkimage" encapsulates the images with a 64
2992 byte header containing information about target architecture,
2993 operating system, image type, compression method, entry points, time
2994 stamp, CRC32 checksums, etc.
2996 "mkimage" can be called in two ways: to verify existing images and
2997 print the header information, or to build new images.
2999 In the first form (with "-l" option) mkimage lists the information
3000 contained in the header of an existing U-Boot image; this includes
3001 checksum verification:
3003 tools/mkimage -l image
3004 -l ==> list image header information
3006 The second form (with "-d" option) is used to build a U-Boot image
3007 from a "data file" which is used as image payload:
3009 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3010 -n name -d data_file image
3011 -A ==> set architecture to 'arch'
3012 -O ==> set operating system to 'os'
3013 -T ==> set image type to 'type'
3014 -C ==> set compression type 'comp'
3015 -a ==> set load address to 'addr' (hex)
3016 -e ==> set entry point to 'ep' (hex)
3017 -n ==> set image name to 'name'
3018 -d ==> use image data from 'datafile'
3020 Right now, all Linux kernels for PowerPC systems use the same load
3021 address (0x00000000), but the entry point address depends on the
3024 - 2.2.x kernels have the entry point at 0x0000000C,
3025 - 2.3.x and later kernels have the entry point at 0x00000000.
3027 So a typical call to build a U-Boot image would read:
3029 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3030 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3031 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
3032 > examples/uImage.TQM850L
3033 Image Name: 2.4.4 kernel for TQM850L
3034 Created: Wed Jul 19 02:34:59 2000
3035 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3036 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3037 Load Address: 0x00000000
3038 Entry Point: 0x00000000
3040 To verify the contents of the image (or check for corruption):
3042 -> tools/mkimage -l examples/uImage.TQM850L
3043 Image Name: 2.4.4 kernel for TQM850L
3044 Created: Wed Jul 19 02:34:59 2000
3045 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3046 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3047 Load Address: 0x00000000
3048 Entry Point: 0x00000000
3050 NOTE: for embedded systems where boot time is critical you can trade
3051 speed for memory and install an UNCOMPRESSED image instead: this
3052 needs more space in Flash, but boots much faster since it does not
3053 need to be uncompressed:
3055 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
3056 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3057 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3058 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
3059 > examples/uImage.TQM850L-uncompressed
3060 Image Name: 2.4.4 kernel for TQM850L
3061 Created: Wed Jul 19 02:34:59 2000
3062 Image Type: PowerPC Linux Kernel Image (uncompressed)
3063 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3064 Load Address: 0x00000000
3065 Entry Point: 0x00000000
3068 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3069 when your kernel is intended to use an initial ramdisk:
3071 -> tools/mkimage -n 'Simple Ramdisk Image' \
3072 > -A ppc -O linux -T ramdisk -C gzip \
3073 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3074 Image Name: Simple Ramdisk Image
3075 Created: Wed Jan 12 14:01:50 2000
3076 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3077 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3078 Load Address: 0x00000000
3079 Entry Point: 0x00000000
3082 Installing a Linux Image:
3083 -------------------------
3085 To downloading a U-Boot image over the serial (console) interface,
3086 you must convert the image to S-Record format:
3088 objcopy -I binary -O srec examples/image examples/image.srec
3090 The 'objcopy' does not understand the information in the U-Boot
3091 image header, so the resulting S-Record file will be relative to
3092 address 0x00000000. To load it to a given address, you need to
3093 specify the target address as 'offset' parameter with the 'loads'
3096 Example: install the image to address 0x40100000 (which on the
3097 TQM8xxL is in the first Flash bank):
3099 => erase 40100000 401FFFFF
3105 ## Ready for S-Record download ...
3106 ~>examples/image.srec
3107 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3109 15989 15990 15991 15992
3110 [file transfer complete]
3112 ## Start Addr = 0x00000000
3115 You can check the success of the download using the 'iminfo' command;
3116 this includes a checksum verification so you can be sure no data
3117 corruption happened:
3121 ## Checking Image at 40100000 ...
3122 Image Name: 2.2.13 for initrd on TQM850L
3123 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3124 Data Size: 335725 Bytes = 327 kB = 0 MB
3125 Load Address: 00000000
3126 Entry Point: 0000000c
3127 Verifying Checksum ... OK
3133 The "bootm" command is used to boot an application that is stored in
3134 memory (RAM or Flash). In case of a Linux kernel image, the contents
3135 of the "bootargs" environment variable is passed to the kernel as
3136 parameters. You can check and modify this variable using the
3137 "printenv" and "setenv" commands:
3140 => printenv bootargs
3141 bootargs=root=/dev/ram
3143 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3145 => printenv bootargs
3146 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3149 ## Booting Linux kernel at 40020000 ...
3150 Image Name: 2.2.13 for NFS on TQM850L
3151 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3152 Data Size: 381681 Bytes = 372 kB = 0 MB
3153 Load Address: 00000000
3154 Entry Point: 0000000c
3155 Verifying Checksum ... OK
3156 Uncompressing Kernel Image ... OK
3157 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
3158 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3159 time_init: decrementer frequency = 187500000/60
3160 Calibrating delay loop... 49.77 BogoMIPS
3161 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3164 If you want to boot a Linux kernel with initial ram disk, you pass
3165 the memory addresses of both the kernel and the initrd image (PPBCOOT
3166 format!) to the "bootm" command:
3168 => imi 40100000 40200000
3170 ## Checking Image at 40100000 ...
3171 Image Name: 2.2.13 for initrd on TQM850L
3172 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3173 Data Size: 335725 Bytes = 327 kB = 0 MB
3174 Load Address: 00000000
3175 Entry Point: 0000000c
3176 Verifying Checksum ... OK
3178 ## Checking Image at 40200000 ...
3179 Image Name: Simple Ramdisk Image
3180 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3181 Data Size: 566530 Bytes = 553 kB = 0 MB
3182 Load Address: 00000000
3183 Entry Point: 00000000
3184 Verifying Checksum ... OK
3186 => bootm 40100000 40200000
3187 ## Booting Linux kernel at 40100000 ...
3188 Image Name: 2.2.13 for initrd on TQM850L
3189 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3190 Data Size: 335725 Bytes = 327 kB = 0 MB
3191 Load Address: 00000000
3192 Entry Point: 0000000c
3193 Verifying Checksum ... OK
3194 Uncompressing Kernel Image ... OK
3195 ## Loading RAMDisk Image at 40200000 ...
3196 Image Name: Simple Ramdisk Image
3197 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3198 Data Size: 566530 Bytes = 553 kB = 0 MB
3199 Load Address: 00000000
3200 Entry Point: 00000000
3201 Verifying Checksum ... OK
3202 Loading Ramdisk ... OK
3203 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
3204 Boot arguments: root=/dev/ram
3205 time_init: decrementer frequency = 187500000/60
3206 Calibrating delay loop... 49.77 BogoMIPS
3208 RAMDISK: Compressed image found at block 0
3209 VFS: Mounted root (ext2 filesystem).
3213 Boot Linux and pass a flat device tree:
3216 First, U-Boot must be compiled with the appropriate defines. See the section
3217 titled "Linux Kernel Interface" above for a more in depth explanation. The
3218 following is an example of how to start a kernel and pass an updated
3224 oft=oftrees/mpc8540ads.dtb
3225 => tftp $oftaddr $oft
3226 Speed: 1000, full duplex
3228 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3229 Filename 'oftrees/mpc8540ads.dtb'.
3230 Load address: 0x300000
3233 Bytes transferred = 4106 (100a hex)
3234 => tftp $loadaddr $bootfile
3235 Speed: 1000, full duplex
3237 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3239 Load address: 0x200000
3240 Loading:############
3242 Bytes transferred = 1029407 (fb51f hex)
3247 => bootm $loadaddr - $oftaddr
3248 ## Booting image at 00200000 ...
3249 Image Name: Linux-2.6.17-dirty
3250 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3251 Data Size: 1029343 Bytes = 1005.2 kB
3252 Load Address: 00000000
3253 Entry Point: 00000000
3254 Verifying Checksum ... OK
3255 Uncompressing Kernel Image ... OK
3256 Booting using flat device tree at 0x300000
3257 Using MPC85xx ADS machine description
3258 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3262 More About U-Boot Image Types:
3263 ------------------------------
3265 U-Boot supports the following image types:
3267 "Standalone Programs" are directly runnable in the environment
3268 provided by U-Boot; it is expected that (if they behave
3269 well) you can continue to work in U-Boot after return from
3270 the Standalone Program.
3271 "OS Kernel Images" are usually images of some Embedded OS which
3272 will take over control completely. Usually these programs
3273 will install their own set of exception handlers, device
3274 drivers, set up the MMU, etc. - this means, that you cannot
3275 expect to re-enter U-Boot except by resetting the CPU.
3276 "RAMDisk Images" are more or less just data blocks, and their
3277 parameters (address, size) are passed to an OS kernel that is
3279 "Multi-File Images" contain several images, typically an OS
3280 (Linux) kernel image and one or more data images like
3281 RAMDisks. This construct is useful for instance when you want
3282 to boot over the network using BOOTP etc., where the boot
3283 server provides just a single image file, but you want to get
3284 for instance an OS kernel and a RAMDisk image.
3286 "Multi-File Images" start with a list of image sizes, each
3287 image size (in bytes) specified by an "uint32_t" in network
3288 byte order. This list is terminated by an "(uint32_t)0".
3289 Immediately after the terminating 0 follow the images, one by
3290 one, all aligned on "uint32_t" boundaries (size rounded up to
3291 a multiple of 4 bytes).
3293 "Firmware Images" are binary images containing firmware (like
3294 U-Boot or FPGA images) which usually will be programmed to
3297 "Script files" are command sequences that will be executed by
3298 U-Boot's command interpreter; this feature is especially
3299 useful when you configure U-Boot to use a real shell (hush)
3300 as command interpreter.
3306 One of the features of U-Boot is that you can dynamically load and
3307 run "standalone" applications, which can use some resources of
3308 U-Boot like console I/O functions or interrupt services.
3310 Two simple examples are included with the sources:
3315 'examples/hello_world.c' contains a small "Hello World" Demo
3316 application; it is automatically compiled when you build U-Boot.
3317 It's configured to run at address 0x00040004, so you can play with it
3321 ## Ready for S-Record download ...
3322 ~>examples/hello_world.srec
3323 1 2 3 4 5 6 7 8 9 10 11 ...
3324 [file transfer complete]
3326 ## Start Addr = 0x00040004
3328 => go 40004 Hello World! This is a test.
3329 ## Starting application at 0x00040004 ...
3340 Hit any key to exit ...
3342 ## Application terminated, rc = 0x0
3344 Another example, which demonstrates how to register a CPM interrupt
3345 handler with the U-Boot code, can be found in 'examples/timer.c'.
3346 Here, a CPM timer is set up to generate an interrupt every second.
3347 The interrupt service routine is trivial, just printing a '.'
3348 character, but this is just a demo program. The application can be
3349 controlled by the following keys:
3351 ? - print current values og the CPM Timer registers
3352 b - enable interrupts and start timer
3353 e - stop timer and disable interrupts
3354 q - quit application
3357 ## Ready for S-Record download ...
3358 ~>examples/timer.srec
3359 1 2 3 4 5 6 7 8 9 10 11 ...
3360 [file transfer complete]
3362 ## Start Addr = 0x00040004
3365 ## Starting application at 0x00040004 ...
3368 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3371 [q, b, e, ?] Set interval 1000000 us
3374 [q, b, e, ?] ........
3375 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3378 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3381 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3384 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3386 [q, b, e, ?] ...Stopping timer
3388 [q, b, e, ?] ## Application terminated, rc = 0x0
3394 Over time, many people have reported problems when trying to use the
3395 "minicom" terminal emulation program for serial download. I (wd)
3396 consider minicom to be broken, and recommend not to use it. Under
3397 Unix, I recommend to use C-Kermit for general purpose use (and
3398 especially for kermit binary protocol download ("loadb" command), and
3399 use "cu" for S-Record download ("loads" command).
3401 Nevertheless, if you absolutely want to use it try adding this
3402 configuration to your "File transfer protocols" section:
3404 Name Program Name U/D FullScr IO-Red. Multi
3405 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3406 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3412 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3413 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3415 Building requires a cross environment; it is known to work on
3416 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3417 need gmake since the Makefiles are not compatible with BSD make).
3418 Note that the cross-powerpc package does not install include files;
3419 attempting to build U-Boot will fail because <machine/ansi.h> is
3420 missing. This file has to be installed and patched manually:
3422 # cd /usr/pkg/cross/powerpc-netbsd/include
3424 # ln -s powerpc machine
3425 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3426 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3428 Native builds *don't* work due to incompatibilities between native
3429 and U-Boot include files.
3431 Booting assumes that (the first part of) the image booted is a
3432 stage-2 loader which in turn loads and then invokes the kernel
3433 proper. Loader sources will eventually appear in the NetBSD source
3434 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3435 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3438 Implementation Internals:
3439 =========================
3441 The following is not intended to be a complete description of every
3442 implementation detail. However, it should help to understand the
3443 inner workings of U-Boot and make it easier to port it to custom
3447 Initial Stack, Global Data:
3448 ---------------------------
3450 The implementation of U-Boot is complicated by the fact that U-Boot
3451 starts running out of ROM (flash memory), usually without access to
3452 system RAM (because the memory controller is not initialized yet).
3453 This means that we don't have writable Data or BSS segments, and BSS
3454 is not initialized as zero. To be able to get a C environment working
3455 at all, we have to allocate at least a minimal stack. Implementation
3456 options for this are defined and restricted by the CPU used: Some CPU
3457 models provide on-chip memory (like the IMMR area on MPC8xx and
3458 MPC826x processors), on others (parts of) the data cache can be
3459 locked as (mis-) used as memory, etc.
3461 Chris Hallinan posted a good summary of these issues to the
3462 u-boot-users mailing list:
3464 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3465 From: "Chris Hallinan" <clh@net1plus.com>
3466 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3469 Correct me if I'm wrong, folks, but the way I understand it
3470 is this: Using DCACHE as initial RAM for Stack, etc, does not
3471 require any physical RAM backing up the cache. The cleverness
3472 is that the cache is being used as a temporary supply of
3473 necessary storage before the SDRAM controller is setup. It's
3474 beyond the scope of this list to expain the details, but you
3475 can see how this works by studying the cache architecture and
3476 operation in the architecture and processor-specific manuals.
3478 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3479 is another option for the system designer to use as an
3480 initial stack/ram area prior to SDRAM being available. Either
3481 option should work for you. Using CS 4 should be fine if your
3482 board designers haven't used it for something that would
3483 cause you grief during the initial boot! It is frequently not
3486 CFG_INIT_RAM_ADDR should be somewhere that won't interfere
3487 with your processor/board/system design. The default value
3488 you will find in any recent u-boot distribution in
3489 walnut.h should work for you. I'd set it to a value larger
3490 than your SDRAM module. If you have a 64MB SDRAM module, set
3491 it above 400_0000. Just make sure your board has no resources
3492 that are supposed to respond to that address! That code in
3493 start.S has been around a while and should work as is when
3494 you get the config right.
3499 It is essential to remember this, since it has some impact on the C
3500 code for the initialization procedures:
3502 * Initialized global data (data segment) is read-only. Do not attempt
3505 * Do not use any unitialized global data (or implicitely initialized
3506 as zero data - BSS segment) at all - this is undefined, initiali-
3507 zation is performed later (when relocating to RAM).
3509 * Stack space is very limited. Avoid big data buffers or things like
3512 Having only the stack as writable memory limits means we cannot use
3513 normal global data to share information beween the code. But it
3514 turned out that the implementation of U-Boot can be greatly
3515 simplified by making a global data structure (gd_t) available to all
3516 functions. We could pass a pointer to this data as argument to _all_
3517 functions, but this would bloat the code. Instead we use a feature of
3518 the GCC compiler (Global Register Variables) to share the data: we
3519 place a pointer (gd) to the global data into a register which we
3520 reserve for this purpose.
3522 When choosing a register for such a purpose we are restricted by the
3523 relevant (E)ABI specifications for the current architecture, and by
3524 GCC's implementation.
3526 For PowerPC, the following registers have specific use:
3529 R3-R4: parameter passing and return values
3530 R5-R10: parameter passing
3531 R13: small data area pointer
3535 (U-Boot also uses R14 as internal GOT pointer.)
3537 ==> U-Boot will use R29 to hold a pointer to the global data
3539 Note: on PPC, we could use a static initializer (since the
3540 address of the global data structure is known at compile time),
3541 but it turned out that reserving a register results in somewhat
3542 smaller code - although the code savings are not that big (on
3543 average for all boards 752 bytes for the whole U-Boot image,
3544 624 text + 127 data).
3546 On ARM, the following registers are used:
3548 R0: function argument word/integer result
3549 R1-R3: function argument word
3551 R10: stack limit (used only if stack checking if enabled)
3552 R11: argument (frame) pointer
3553 R12: temporary workspace
3556 R15: program counter
3558 ==> U-Boot will use R8 to hold a pointer to the global data
3560 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3561 or current versions of GCC may "optimize" the code too much.
3566 U-Boot runs in system state and uses physical addresses, i.e. the
3567 MMU is not used either for address mapping nor for memory protection.
3569 The available memory is mapped to fixed addresses using the memory
3570 controller. In this process, a contiguous block is formed for each
3571 memory type (Flash, SDRAM, SRAM), even when it consists of several
3572 physical memory banks.
3574 U-Boot is installed in the first 128 kB of the first Flash bank (on
3575 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3576 booting and sizing and initializing DRAM, the code relocates itself
3577 to the upper end of DRAM. Immediately below the U-Boot code some
3578 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
3579 configuration setting]. Below that, a structure with global Board
3580 Info data is placed, followed by the stack (growing downward).
3582 Additionally, some exception handler code is copied to the low 8 kB
3583 of DRAM (0x00000000 ... 0x00001FFF).
3585 So a typical memory configuration with 16 MB of DRAM could look like
3588 0x0000 0000 Exception Vector code
3591 0x0000 2000 Free for Application Use
3597 0x00FB FF20 Monitor Stack (Growing downward)
3598 0x00FB FFAC Board Info Data and permanent copy of global data
3599 0x00FC 0000 Malloc Arena
3602 0x00FE 0000 RAM Copy of Monitor Code
3603 ... eventually: LCD or video framebuffer
3604 ... eventually: pRAM (Protected RAM - unchanged by reset)
3605 0x00FF FFFF [End of RAM]
3608 System Initialization:
3609 ----------------------
3611 In the reset configuration, U-Boot starts at the reset entry point
3612 (on most PowerPC systens at address 0x00000100). Because of the reset
3613 configuration for CS0# this is a mirror of the onboard Flash memory.
3614 To be able to re-map memory U-Boot then jumps to its link address.
3615 To be able to implement the initialization code in C, a (small!)
3616 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3617 which provide such a feature like MPC8xx or MPC8260), or in a locked
3618 part of the data cache. After that, U-Boot initializes the CPU core,
3619 the caches and the SIU.
3621 Next, all (potentially) available memory banks are mapped using a
3622 preliminary mapping. For example, we put them on 512 MB boundaries
3623 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3624 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3625 programmed for SDRAM access. Using the temporary configuration, a
3626 simple memory test is run that determines the size of the SDRAM
3629 When there is more than one SDRAM bank, and the banks are of
3630 different size, the largest is mapped first. For equal size, the first
3631 bank (CS2#) is mapped first. The first mapping is always for address
3632 0x00000000, with any additional banks following immediately to create
3633 contiguous memory starting from 0.
3635 Then, the monitor installs itself at the upper end of the SDRAM area
3636 and allocates memory for use by malloc() and for the global Board
3637 Info data; also, the exception vector code is copied to the low RAM
3638 pages, and the final stack is set up.
3640 Only after this relocation will you have a "normal" C environment;
3641 until that you are restricted in several ways, mostly because you are
3642 running from ROM, and because the code will have to be relocated to a
3646 U-Boot Porting Guide:
3647 ----------------------
3649 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3653 int main (int argc, char *argv[])
3655 sighandler_t no_more_time;
3657 signal (SIGALRM, no_more_time);
3658 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3660 if (available_money > available_manpower) {
3661 pay consultant to port U-Boot;
3665 Download latest U-Boot source;
3667 Subscribe to u-boot-users mailing list;
3670 email ("Hi, I am new to U-Boot, how do I get started?");
3674 Read the README file in the top level directory;
3675 Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
3676 Read the source, Luke;
3679 if (available_money > toLocalCurrency ($2500)) {
3682 Add a lot of aggravation and time;
3685 Create your own board support subdirectory;
3687 Create your own board config file;
3691 Add / modify source code;
3695 email ("Hi, I am having problems...");
3697 Send patch file to Wolfgang;
3702 void no_more_time (int sig)
3711 All contributions to U-Boot should conform to the Linux kernel
3712 coding style; see the file "Documentation/CodingStyle" and the script
3713 "scripts/Lindent" in your Linux kernel source directory. In sources
3714 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
3715 spaces before parameters to function calls) is actually used.
3717 Source files originating from a different project (for example the
3718 MTD subsystem) are generally exempt from these guidelines and are not
3719 reformated to ease subsequent migration to newer versions of those
3722 Please note that U-Boot is implemented in C (and to some small parts in
3723 Assembler); no C++ is used, so please do not use C++ style comments (//)
3726 Please also stick to the following formatting rules:
3727 - remove any trailing white space
3728 - use TAB characters for indentation, not spaces
3729 - make sure NOT to use DOS '\r\n' line feeds
3730 - do not add more than 2 empty lines to source files
3731 - do not add trailing empty lines to source files
3733 Submissions which do not conform to the standards may be returned
3734 with a request to reformat the changes.
3740 Since the number of patches for U-Boot is growing, we need to
3741 establish some rules. Submissions which do not conform to these rules
3742 may be rejected, even when they contain important and valuable stuff.
3744 Patches shall be sent to the u-boot-users mailing list.
3746 When you send a patch, please include the following information with
3749 * For bug fixes: a description of the bug and how your patch fixes
3750 this bug. Please try to include a way of demonstrating that the
3751 patch actually fixes something.
3753 * For new features: a description of the feature and your
3756 * A CHANGELOG entry as plaintext (separate from the patch)
3758 * For major contributions, your entry to the CREDITS file
3760 * When you add support for a new board, don't forget to add this
3761 board to the MAKEALL script, too.
3763 * If your patch adds new configuration options, don't forget to
3764 document these in the README file.
3766 * The patch itself. If you are accessing the CVS repository use "cvs
3767 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
3768 version of diff does not support these options, then get the latest
3769 version of GNU diff.
3771 The current directory when running this command shall be the top
3772 level directory of the U-Boot source tree, or it's parent directory
3773 (i. e. please make sure that your patch includes sufficient
3774 directory information for the affected files).
3776 We accept patches as plain text, MIME attachments or as uuencoded
3779 * If one logical set of modifications affects or creates several
3780 files, all these changes shall be submitted in a SINGLE patch file.
3782 * Changesets that contain different, unrelated modifications shall be
3783 submitted as SEPARATE patches, one patch per changeset.
3788 * Before sending the patch, run the MAKEALL script on your patched
3789 source tree and make sure that no errors or warnings are reported
3790 for any of the boards.
3792 * Keep your modifications to the necessary minimum: A patch
3793 containing several unrelated changes or arbitrary reformats will be
3794 returned with a request to re-formatting / split it.
3796 * If you modify existing code, make sure that your new code does not
3797 add to the memory footprint of the code ;-) Small is beautiful!
3798 When adding new features, these should compile conditionally only
3799 (using #ifdef), and the resulting code with the new feature
3800 disabled must not need more memory than the old code without your
3803 * Remember that there is a size limit of 40 kB per message on the
3804 u-boot-users mailing list. Compression may help.
projects / u-boot / blob