2 # (C) Copyright 2000 - 2004
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 and ARM processors, which can be
29 installed in a boot ROM and used to initialize and test the hardware
30 or to download and run application code.
32 The development of U-Boot is closely related to Linux: some parts of
33 the source code originate in the Linux source tree, we have some
34 header files in common, and special provision has been made to
35 support booting of Linux images.
37 Some attention has been paid to make this software easily
38 configurable and extendable. For instance, all monitor commands are
39 implemented with the same call interface, so that it's very easy to
40 add new commands. Also, instead of permanently adding rarely used
41 code (for instance hardware test utilities) to the monitor, you can
42 load and run it dynamically.
48 In general, all boards for which a configuration option exists in the
49 Makefile have been tested to some extent and can be considered
50 "working". In fact, many of them are used in production systems.
52 In case of problems see the CHANGELOG and CREDITS files to find out
53 who contributed the specific port.
59 In case you have questions about, problems with or contributions for
60 U-Boot you should send a message to the U-Boot mailing list at
61 <u-boot-users@lists.sourceforge.net>. There is also an archive of
62 previous traffic on the mailing list - please search the archive
63 before asking FAQ's. Please see
64 http://lists.sourceforge.net/lists/listinfo/u-boot-users/
70 - start from 8xxrom sources
71 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
73 - make it easier to add custom boards
74 - make it possible to add other [PowerPC] CPUs
75 - extend functions, especially:
76 * Provide extended interface to Linux boot loader
79 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot
80 - create ARMBoot project (http://sourceforge.net/projects/armboot)
81 - add other CPU families (starting with ARM)
82 - create U-Boot project (http://sourceforge.net/projects/u-boot)
88 The "official" name of this project is "Das U-Boot". The spelling
89 "U-Boot" shall be used in all written text (documentation, comments
90 in source files etc.). Example:
92 This is the README file for the U-Boot project.
94 File names etc. shall be based on the string "u-boot". Examples:
96 include/asm-ppc/u-boot.h
98 #include <asm/u-boot.h>
100 Variable names, preprocessor constants etc. shall be either based on
101 the string "u_boot" or on "U_BOOT". Example:
103 U_BOOT_VERSION u_boot_logo
104 IH_OS_U_BOOT u_boot_hush_start
110 U-Boot uses a 3 level version number containing a version, a
111 sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2",
112 sub-version "34", and patchlevel "4".
114 The patchlevel is used to indicate certain stages of development
115 between released versions, i. e. officially released versions of
116 U-Boot will always have a patchlevel of "0".
122 - board Board dependent files
123 - common Misc architecture independent functions
124 - cpu CPU specific files
125 - 74xx_7xx Files specific to Motorola MPC74xx and 7xx CPUs
126 - arm720t Files specific to ARM 720 CPUs
127 - arm920t Files specific to ARM 920 CPUs
128 - arm925t Files specific to ARM 925 CPUs
129 - arm926ejs Files specific to ARM 926 CPUs
130 - at91rm9200 Files specific to Atmel AT91RM9200 CPUs
131 - i386 Files specific to i386 CPUs
132 - ixp Files specific to Intel XScale IXP CPUs
133 - mcf52x2 Files specific to Motorola ColdFire MCF52x2 CPUs
134 - mips Files specific to MIPS CPUs
135 - mpc5xx Files specific to Motorola MPC5xx CPUs
136 - mpc5xxx Files specific to Motorola MPC5xxx CPUs
137 - mpc8xx Files specific to Motorola MPC8xx CPUs
138 - mpc824x Files specific to Motorola MPC824x CPUs
139 - mpc8260 Files specific to Motorola MPC8260 CPUs
140 - mpc85xx Files specific to Motorola MPC85xx CPUs
141 - nios Files specific to Altera NIOS CPUs
142 - ppc4xx Files specific to IBM PowerPC 4xx CPUs
143 - pxa Files specific to Intel XScale PXA CPUs
144 - s3c44b0 Files specific to Samsung S3C44B0 CPUs
145 - sa1100 Files specific to Intel StrongARM SA1100 CPUs
146 - disk Code for disk drive partition handling
147 - doc Documentation (don't expect too much)
148 - drivers Commonly used device drivers
149 - dtt Digital Thermometer and Thermostat drivers
150 - examples Example code for standalone applications, etc.
151 - include Header Files
152 - lib_arm Files generic to ARM architecture
153 - lib_generic Files generic to all architectures
154 - lib_i386 Files generic to i386 architecture
155 - lib_m68k Files generic to m68k architecture
156 - lib_mips Files generic to MIPS architecture
157 - lib_nios Files generic to NIOS architecture
158 - lib_ppc Files generic to PowerPC architecture
159 - net Networking code
160 - post Power On Self Test
161 - rtc Real Time Clock drivers
162 - tools Tools to build S-Record or U-Boot images, etc.
164 Software Configuration:
165 =======================
167 Configuration is usually done using C preprocessor defines; the
168 rationale behind that is to avoid dead code whenever possible.
170 There are two classes of configuration variables:
172 * Configuration _OPTIONS_:
173 These are selectable by the user and have names beginning with
176 * Configuration _SETTINGS_:
177 These depend on the hardware etc. and should not be meddled with if
178 you don't know what you're doing; they have names beginning with
181 Later we will add a configuration tool - probably similar to or even
182 identical to what's used for the Linux kernel. Right now, we have to
183 do the configuration by hand, which means creating some symbolic
184 links and editing some configuration files. We use the TQM8xxL boards
188 Selection of Processor Architecture and Board Type:
189 ---------------------------------------------------
191 For all supported boards there are ready-to-use default
192 configurations available; just type "make <board_name>_config".
194 Example: For a TQM823L module type:
199 For the Cogent platform, you need to specify the cpu type as well;
200 e.g. "make cogent_mpc8xx_config". And also configure the cogent
201 directory according to the instructions in cogent/README.
204 Configuration Options:
205 ----------------------
207 Configuration depends on the combination of board and CPU type; all
208 such information is kept in a configuration file
209 "include/configs/<board_name>.h".
211 Example: For a TQM823L module, all configuration settings are in
212 "include/configs/TQM823L.h".
215 Many of the options are named exactly as the corresponding Linux
216 kernel configuration options. The intention is to make it easier to
217 build a config tool - later.
220 The following options need to be configured:
222 - CPU Type: Define exactly one of
226 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860
228 or CONFIG_MPC824X, CONFIG_MPC8260
243 MicroBlaze based CPUs:
244 ----------------------
248 - Board Type: Define exactly one of
250 PowerPC based boards:
251 ---------------------
253 CONFIG_ADCIOP CONFIG_GEN860T CONFIG_PCI405
254 CONFIG_ADS860 CONFIG_GENIETV CONFIG_PCIPPC2
255 CONFIG_AMX860 CONFIG_GTH CONFIG_PCIPPC6
256 CONFIG_AR405 CONFIG_gw8260 CONFIG_pcu_e
257 CONFIG_BAB7xx CONFIG_hermes CONFIG_PIP405
258 CONFIG_c2mon CONFIG_hymod CONFIG_PM826
259 CONFIG_CANBT CONFIG_IAD210 CONFIG_ppmc8260
260 CONFIG_CCM CONFIG_ICU862 CONFIG_QS823
261 CONFIG_CMI CONFIG_IP860 CONFIG_QS850
262 CONFIG_cogent_mpc8260 CONFIG_IPHASE4539 CONFIG_QS860T
263 CONFIG_cogent_mpc8xx CONFIG_IVML24 CONFIG_RBC823
264 CONFIG_CPCI405 CONFIG_IVML24_128 CONFIG_RPXClassic
265 CONFIG_CPCI4052 CONFIG_IVML24_256 CONFIG_RPXlite
266 CONFIG_CPCIISER4 CONFIG_IVMS8 CONFIG_RPXsuper
267 CONFIG_CPU86 CONFIG_IVMS8_128 CONFIG_rsdproto
268 CONFIG_CRAYL1 CONFIG_IVMS8_256 CONFIG_sacsng
269 CONFIG_CSB272 CONFIG_JSE CONFIG_Sandpoint8240
270 CONFIG_CU824 CONFIG_LANTEC CONFIG_Sandpoint8245
271 CONFIG_DASA_SIM CONFIG_lwmon CONFIG_sbc8260
272 CONFIG_DB64360 CONFIG_MBX CONFIG_SM850
273 CONFIG_DB64460 CONFIG_MBX860T CONFIG_SPD823TS
274 CONFIG_DU405 CONFIG_MHPC CONFIG_STXGP3
275 CONFIG_DUET_ADS CONFIG_MIP405 CONFIG_SXNI855T
276 CONFIG_EBONY CONFIG_MOUSSE CONFIG_TQM823L
277 CONFIG_ELPPC CONFIG_MPC8260ADS CONFIG_TQM8260
278 CONFIG_ELPT860 CONFIG_MPC8540ADS CONFIG_TQM850L
279 CONFIG_ep8260 CONFIG_MPC8560ADS CONFIG_TQM855L
280 CONFIG_ERIC CONFIG_MUSENKI CONFIG_TQM860L
281 CONFIG_ESTEEM192E CONFIG_MVS1 CONFIG_TTTech
282 CONFIG_ETX094 CONFIG_NETPHONE CONFIG_UTX8245
283 CONFIG_EVB64260 CONFIG_NETTA CONFIG_V37
284 CONFIG_FADS823 CONFIG_NETVIA CONFIG_W7OLMC
285 CONFIG_FADS850SAR CONFIG_NX823 CONFIG_W7OLMG
286 CONFIG_FADS860T CONFIG_OCRTC CONFIG_WALNUT405
287 CONFIG_FLAGADM CONFIG_ORSG CONFIG_ZPC1900
288 CONFIG_FPS850L CONFIG_OXC CONFIG_ZUMA
294 CONFIG_AT91RM9200DK, CONFIG_DNP1110, CONFIG_EP7312,
295 CONFIG_H2_OMAP1610, CONFIG_HHP_CRADLE, CONFIG_IMPA7,
296 CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610, CONFIG_LART,
297 CONFIG_LUBBOCK, CONFIG_SHANNON, CONFIG_SMDK2400,
298 CONFIG_SMDK2410, CONFIG_TRAB, CONFIG_VCMA9,
300 MicroBlaze based boards:
301 ------------------------
306 - CPU Module Type: (if CONFIG_COGENT is defined)
307 Define exactly one of
309 --- FIXME --- not tested yet:
310 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
311 CONFIG_CMA287_23, CONFIG_CMA287_50
313 - Motherboard Type: (if CONFIG_COGENT is defined)
314 Define exactly one of
315 CONFIG_CMA101, CONFIG_CMA102
317 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
318 Define one or more of
321 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
322 Define one or more of
323 CONFIG_LCD_HEARTBEAT - update a character position on
324 the lcd display every second with
327 - Board flavour: (if CONFIG_MPC8260ADS is defined)
330 CFG_8260ADS - original MPC8260ADS
331 CFG_8266ADS - MPC8266ADS
332 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
333 CFG_8272ADS - MPC8272ADS
335 - MPC824X Family Member (if CONFIG_MPC824X is defined)
336 Define exactly one of
337 CONFIG_MPC8240, CONFIG_MPC8245
339 - 8xx CPU Options: (if using an MPC8xx cpu)
340 Define one or more of
341 CONFIG_8xx_GCLK_FREQ - if get_gclk_freq() cannot work
342 e.g. if there is no 32KHz
343 reference PIT/RTC clock
345 - 859/866 CPU options: (if using a MPC859 or MPC866 CPU):
349 CFG_866_CPUCLK_DEFAULT
350 See doc/README.MPC866
354 Define this to measure the actual CPU clock instead
355 of relying on the correctness of the configured
356 values. Mostly useful for board bringup to make sure
357 the PLL is locked at the intended frequency. Note
358 that this requires a (stable) reference clock (32 kHz
361 - Linux Kernel Interface:
364 U-Boot stores all clock information in Hz
365 internally. For binary compatibility with older Linux
366 kernels (which expect the clocks passed in the
367 bd_info data to be in MHz) the environment variable
368 "clocks_in_mhz" can be defined so that U-Boot
369 converts clock data to MHZ before passing it to the
371 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
372 "clocks_in_mhz=1" is automatically included in the
375 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
377 When transfering memsize parameter to linux, some versions
378 expect it to be in bytes, others in MB.
379 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
382 Depending on board, define exactly one serial port
383 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
384 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
385 console by defining CONFIG_8xx_CONS_NONE
387 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
388 port routines must be defined elsewhere
389 (i.e. serial_init(), serial_getc(), ...)
392 Enables console device for a color framebuffer. Needs following
393 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
394 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
396 VIDEO_HW_RECTFILL graphic chip supports
399 VIDEO_HW_BITBLT graphic chip supports
400 bit-blit (cf. smiLynxEM)
401 VIDEO_VISIBLE_COLS visible pixel columns
403 VIDEO_VISIBLE_ROWS visible pixel rows
404 VIDEO_PIXEL_SIZE bytes per pixel
405 VIDEO_DATA_FORMAT graphic data format
406 (0-5, cf. cfb_console.c)
407 VIDEO_FB_ADRS framebuffer address
408 VIDEO_KBD_INIT_FCT keyboard int fct
409 (i.e. i8042_kbd_init())
410 VIDEO_TSTC_FCT test char fct
412 VIDEO_GETC_FCT get char fct
414 CONFIG_CONSOLE_CURSOR cursor drawing on/off
415 (requires blink timer
417 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
418 CONFIG_CONSOLE_TIME display time/date info in
420 (requires CFG_CMD_DATE)
421 CONFIG_VIDEO_LOGO display Linux logo in
423 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
424 linux_logo.h for logo.
425 Requires CONFIG_VIDEO_LOGO
426 CONFIG_CONSOLE_EXTRA_INFO
427 addional board info beside
430 When CONFIG_CFB_CONSOLE is defined, video console is
431 default i/o. Serial console can be forced with
432 environment 'console=serial'.
434 When CONFIG_SILENT_CONSOLE is defined, all console
435 messages (by U-Boot and Linux!) can be silenced with
436 the "silent" environment variable. See
437 doc/README.silent for more information.
440 CONFIG_BAUDRATE - in bps
441 Select one of the baudrates listed in
442 CFG_BAUDRATE_TABLE, see below.
443 CFG_BRGCLK_PRESCALE, baudrate prescale
445 - Interrupt driven serial port input:
446 CONFIG_SERIAL_SOFTWARE_FIFO
449 Use an interrupt handler for receiving data on the
450 serial port. It also enables using hardware handshake
451 (RTS/CTS) and UART's built-in FIFO. Set the number of
452 bytes the interrupt driven input buffer should have.
454 Leave undefined to disable this feature, including
455 disable the buffer and hardware handshake.
457 - Console UART Number:
461 If defined internal UART1 (and not UART0) is used
462 as default U-Boot console.
464 - Boot Delay: CONFIG_BOOTDELAY - in seconds
465 Delay before automatically booting the default image;
466 set to -1 to disable autoboot.
468 See doc/README.autoboot for these options that
469 work with CONFIG_BOOTDELAY. None are required.
470 CONFIG_BOOT_RETRY_TIME
471 CONFIG_BOOT_RETRY_MIN
472 CONFIG_AUTOBOOT_KEYED
473 CONFIG_AUTOBOOT_PROMPT
474 CONFIG_AUTOBOOT_DELAY_STR
475 CONFIG_AUTOBOOT_STOP_STR
476 CONFIG_AUTOBOOT_DELAY_STR2
477 CONFIG_AUTOBOOT_STOP_STR2
478 CONFIG_ZERO_BOOTDELAY_CHECK
479 CONFIG_RESET_TO_RETRY
483 Only needed when CONFIG_BOOTDELAY is enabled;
484 define a command string that is automatically executed
485 when no character is read on the console interface
486 within "Boot Delay" after reset.
489 This can be used to pass arguments to the bootm
490 command. The value of CONFIG_BOOTARGS goes into the
491 environment value "bootargs".
493 CONFIG_RAMBOOT and CONFIG_NFSBOOT
494 The value of these goes into the environment as
495 "ramboot" and "nfsboot" respectively, and can be used
496 as a convenience, when switching between booting from
502 When this option is #defined, the existence of the
503 environment variable "preboot" will be checked
504 immediately before starting the CONFIG_BOOTDELAY
505 countdown and/or running the auto-boot command resp.
506 entering interactive mode.
508 This feature is especially useful when "preboot" is
509 automatically generated or modified. For an example
510 see the LWMON board specific code: here "preboot" is
511 modified when the user holds down a certain
512 combination of keys on the (special) keyboard when
515 - Serial Download Echo Mode:
517 If defined to 1, all characters received during a
518 serial download (using the "loads" command) are
519 echoed back. This might be needed by some terminal
520 emulations (like "cu"), but may as well just take
521 time on others. This setting #define's the initial
522 value of the "loads_echo" environment variable.
524 - Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
526 Select one of the baudrates listed in
527 CFG_BAUDRATE_TABLE, see below.
531 Most monitor functions can be selected (or
532 de-selected) by adjusting the definition of
533 CONFIG_COMMANDS; to select individual functions,
534 #define CONFIG_COMMANDS by "OR"ing any of the
537 #define enables commands:
538 -------------------------
539 CFG_CMD_ASKENV * ask for env variable
540 CFG_CMD_AUTOSCRIPT Autoscript Support
542 CFG_CMD_BEDBUG Include BedBug Debugger
543 CFG_CMD_BMP * BMP support
545 CFG_CMD_CACHE icache, dcache
546 CFG_CMD_CONSOLE coninfo
547 CFG_CMD_DATE * support for RTC, date/time...
548 CFG_CMD_DHCP DHCP support
549 CFG_CMD_DIAG * Diagnostics
550 CFG_CMD_DOC * Disk-On-Chip Support
551 CFG_CMD_DTT Digital Therm and Thermostat
552 CFG_CMD_ECHO * echo arguments
553 CFG_CMD_EEPROM * EEPROM read/write support
554 CFG_CMD_ELF bootelf, bootvx
556 CFG_CMD_FDC * Floppy Disk Support
557 CFG_CMD_FAT FAT partition support
558 CFG_CMD_FDOS * Dos diskette Support
559 CFG_CMD_FLASH flinfo, erase, protect
560 CFG_CMD_FPGA FPGA device initialization support
561 CFG_CMD_HWFLOW * RTS/CTS hw flow control
562 CFG_CMD_I2C * I2C serial bus support
563 CFG_CMD_IDE * IDE harddisk support
565 CFG_CMD_IMLS List all found images
566 CFG_CMD_IMMAP * IMMR dump support
567 CFG_CMD_IRQ * irqinfo
568 CFG_CMD_ITEST * Integer/string test of 2 values
569 CFG_CMD_JFFS2 * JFFS2 Support
573 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
575 CFG_CMD_MISC Misc functions like sleep etc
576 CFG_CMD_MMC MMC memory mapped support
577 CFG_CMD_MII MII utility commands
578 CFG_CMD_NAND * NAND support
579 CFG_CMD_NET bootp, tftpboot, rarpboot
580 CFG_CMD_PCI * pciinfo
581 CFG_CMD_PCMCIA * PCMCIA support
582 CFG_CMD_PING * send ICMP ECHO_REQUEST to network host
583 CFG_CMD_PORTIO * Port I/O
584 CFG_CMD_REGINFO * Register dump
585 CFG_CMD_RUN run command in env variable
586 CFG_CMD_SAVES save S record dump
587 CFG_CMD_SCSI * SCSI Support
588 CFG_CMD_SDRAM * print SDRAM configuration information
589 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
590 CFG_CMD_SPI * SPI serial bus support
591 CFG_CMD_USB * USB support
592 CFG_CMD_VFD * VFD support (TRAB)
593 CFG_CMD_BSP * Board SPecific functions
594 CFG_CMD_CDP * Cisco Discover Protocol support
595 -----------------------------------------------
598 CFG_CMD_DFL Default configuration; at the moment
599 this is includes all commands, except
600 the ones marked with "*" in the list
603 If you don't define CONFIG_COMMANDS it defaults to
604 CFG_CMD_DFL in include/cmd_confdefs.h. A board can
605 override the default settings in the respective
608 EXAMPLE: If you want all functions except of network
609 support you can write:
611 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
614 Note: Don't enable the "icache" and "dcache" commands
615 (configuration option CFG_CMD_CACHE) unless you know
616 what you (and your U-Boot users) are doing. Data
617 cache cannot be enabled on systems like the 8xx or
618 8260 (where accesses to the IMMR region must be
619 uncached), and it cannot be disabled on all other
620 systems where we (mis-) use the data cache to hold an
621 initial stack and some data.
624 XXX - this list needs to get updated!
628 If this variable is defined, it enables watchdog
629 support. There must be support in the platform specific
630 code for a watchdog. For the 8xx and 8260 CPUs, the
631 SIU Watchdog feature is enabled in the SYPCR
635 CONFIG_VERSION_VARIABLE
636 If this variable is defined, an environment variable
637 named "ver" is created by U-Boot showing the U-Boot
638 version as printed by the "version" command.
639 This variable is readonly.
643 When CFG_CMD_DATE is selected, the type of the RTC
644 has to be selected, too. Define exactly one of the
647 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
648 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
649 CONFIG_RTC_MC146818 - use MC146818 RTC
650 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
651 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
652 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
653 CONFIG_RTC_DS164x - use Dallas DS164x RTC
655 Note that if the RTC uses I2C, then the I2C interface
656 must also be configured. See I2C Support, below.
660 When CONFIG_TIMESTAMP is selected, the timestamp
661 (date and time) of an image is printed by image
662 commands like bootm or iminfo. This option is
663 automatically enabled when you select CFG_CMD_DATE .
666 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
667 and/or CONFIG_ISO_PARTITION
669 If IDE or SCSI support is enabled (CFG_CMD_IDE or
670 CFG_CMD_SCSI) you must configure support for at least
671 one partition type as well.
674 CONFIG_IDE_RESET_ROUTINE - this is defined in several
675 board configurations files but used nowhere!
677 CONFIG_IDE_RESET - is this is defined, IDE Reset will
678 be performed by calling the function
679 ide_set_reset(int reset)
680 which has to be defined in a board specific file
685 Set this to enable ATAPI support.
690 Set this to enable support for disks larger than 137GB
691 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL
692 Whithout these , LBA48 support uses 32bit variables and will 'only'
693 support disks up to 2.1TB.
696 When enabled, makes the IDE subsystem use 64bit sector addresses.
700 At the moment only there is only support for the
701 SYM53C8XX SCSI controller; define
702 CONFIG_SCSI_SYM53C8XX to enable it.
704 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
705 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
706 CFG_SCSI_MAX_LUN] can be adjusted to define the
707 maximum numbers of LUNs, SCSI ID's and target
709 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
711 - NETWORK Support (PCI):
713 Support for Intel 8254x gigabit chips.
716 Support for Intel 82557/82559/82559ER chips.
717 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
718 write routine for first time initialisation.
721 Support for Digital 2114x chips.
722 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
723 modem chip initialisation (KS8761/QS6611).
726 Support for National dp83815 chips.
729 Support for National dp8382[01] gigabit chips.
731 - NETWORK Support (other):
733 CONFIG_DRIVER_LAN91C96
734 Support for SMSC's LAN91C96 chips.
737 Define this to hold the physical address
738 of the LAN91C96's I/O space
740 CONFIG_LAN91C96_USE_32_BIT
741 Define this to enable 32 bit addressing
744 At the moment only the UHCI host controller is
745 supported (PIP405, MIP405, MPC5200); define
746 CONFIG_USB_UHCI to enable it.
747 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
748 end define CONFIG_USB_STORAGE to enable the USB
751 Supported are USB Keyboards and USB Floppy drives
753 MPC5200 USB requires additional defines:
755 for 528 MHz Clock: 0x0001bbbb
757 for differential drivers: 0x00001000
758 for single ended drivers: 0x00005000
762 The MMC controller on the Intel PXA is supported. To
763 enable this define CONFIG_MMC. The MMC can be
764 accessed from the boot prompt by mapping the device
765 to physical memory similar to flash. Command line is
766 enabled with CFG_CMD_MMC. The MMC driver also works with
767 the FAT fs. This is enabled with CFG_CMD_FAT.
772 Define this to enable standard (PC-Style) keyboard
776 Standard PC keyboard driver with US (is default) and
777 GERMAN key layout (switch via environment 'keymap=de') support.
778 Export function i8042_kbd_init, i8042_tstc and i8042_getc
779 for cfb_console. Supports cursor blinking.
784 Define this to enable video support (for output to
789 Enable Chips & Technologies 69000 Video chip
791 CONFIG_VIDEO_SMI_LYNXEM
792 Enable Silicon Motion SMI 712/710/810 Video chip. The
793 video output is selected via environment 'videoout'
794 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
797 For the CT69000 and SMI_LYNXEM drivers, videomode is
798 selected via environment 'videomode'. Two diferent ways
800 - "videomode=num" 'num' is a standard LiLo mode numbers.
801 Following standard modes are supported (* is default):
803 Colors 640x480 800x600 1024x768 1152x864 1280x1024
804 -------------+---------------------------------------------
805 8 bits | 0x301* 0x303 0x305 0x161 0x307
806 15 bits | 0x310 0x313 0x316 0x162 0x319
807 16 bits | 0x311 0x314 0x317 0x163 0x31A
808 24 bits | 0x312 0x315 0x318 ? 0x31B
809 -------------+---------------------------------------------
810 (i.e. setenv videomode 317; saveenv; reset;)
812 - "videomode=bootargs" all the video parameters are parsed
813 from the bootargs. (See drivers/videomodes.c)
816 CONFIG_VIDEO_SED13806
817 Enable Epson SED13806 driver. This driver supports 8bpp
818 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
819 or CONFIG_VIDEO_SED13806_16BPP
824 Define this to enable a custom keyboard support.
825 This simply calls drv_keyboard_init() which must be
826 defined in your board-specific files.
827 The only board using this so far is RBC823.
829 - LCD Support: CONFIG_LCD
831 Define this to enable LCD support (for output to LCD
832 display); also select one of the supported displays
833 by defining one of these:
835 CONFIG_NEC_NL6448AC33:
837 NEC NL6448AC33-18. Active, color, single scan.
839 CONFIG_NEC_NL6448BC20
841 NEC NL6448BC20-08. 6.5", 640x480.
842 Active, color, single scan.
844 CONFIG_NEC_NL6448BC33_54
846 NEC NL6448BC33-54. 10.4", 640x480.
847 Active, color, single scan.
851 Sharp 320x240. Active, color, single scan.
852 It isn't 16x9, and I am not sure what it is.
854 CONFIG_SHARP_LQ64D341
856 Sharp LQ64D341 display, 640x480.
857 Active, color, single scan.
861 HLD1045 display, 640x480.
862 Active, color, single scan.
866 Optrex CBL50840-2 NF-FW 99 22 M5
868 Hitachi LMG6912RPFC-00T
872 320x240. Black & white.
874 Normally display is black on white background; define
875 CFG_WHITE_ON_BLACK to get it inverted.
877 - Splash Screen Support: CONFIG_SPLASH_SCREEN
879 If this option is set, the environment is checked for
880 a variable "splashimage". If found, the usual display
881 of logo, copyright and system information on the LCD
882 is supressed and the BMP image at the address
883 specified in "splashimage" is loaded instead. The
884 console is redirected to the "nulldev", too. This
885 allows for a "silent" boot where a splash screen is
886 loaded very quickly after power-on.
888 - Compression support:
891 If this option is set, support for bzip2 compressed
892 images is included. If not, only uncompressed and gzip
893 compressed images are supported.
895 NOTE: the bzip2 algorithm requires a lot of RAM, so
896 the malloc area (as defined by CFG_MALLOC_LEN) should
902 The address of PHY on MII bus.
904 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
906 The clock frequency of the MII bus
910 If this option is set, support for speed/duplex
911 detection of Gigabit PHY is included.
913 CONFIG_PHY_RESET_DELAY
915 Some PHY like Intel LXT971A need extra delay after
916 reset before any MII register access is possible.
917 For such PHY, set this option to the usec delay
918 required. (minimum 300usec for LXT971A)
920 CONFIG_PHY_CMD_DELAY (ppc4xx)
922 Some PHY like Intel LXT971A need extra delay after
923 command issued before MII status register can be read
930 Define a default value for ethernet address to use
931 for the respective ethernet interface, in case this
932 is not determined automatically.
937 Define a default value for the IP address to use for
938 the default ethernet interface, in case this is not
939 determined through e.g. bootp.
944 Defines a default value for theIP address of a TFTP
945 server to contact when using the "tftboot" command.
947 - BOOTP Recovery Mode:
948 CONFIG_BOOTP_RANDOM_DELAY
950 If you have many targets in a network that try to
951 boot using BOOTP, you may want to avoid that all
952 systems send out BOOTP requests at precisely the same
953 moment (which would happen for instance at recovery
954 from a power failure, when all systems will try to
955 boot, thus flooding the BOOTP server. Defining
956 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
957 inserted before sending out BOOTP requests. The
958 following delays are insterted then:
960 1st BOOTP request: delay 0 ... 1 sec
961 2nd BOOTP request: delay 0 ... 2 sec
962 3rd BOOTP request: delay 0 ... 4 sec
964 BOOTP requests: delay 0 ... 8 sec
966 - DHCP Advanced Options:
969 You can fine tune the DHCP functionality by adding
970 these flags to the CONFIG_BOOTP_MASK define:
972 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
973 serverip from a DHCP server, it is possible that more
974 than one DNS serverip is offered to the client.
975 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
976 serverip will be stored in the additional environment
977 variable "dnsip2". The first DNS serverip is always
978 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
979 is added to the CONFIG_BOOTP_MASK.
981 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
982 to do a dynamic update of a DNS server. To do this, they
983 need the hostname of the DHCP requester.
984 If CONFIG_BOOP_SEND_HOSTNAME is added to the
985 CONFIG_BOOTP_MASK, the content of the "hostname"
986 environment variable is passed as option 12 to
992 The device id used in CDP trigger frames.
994 CONFIG_CDP_DEVICE_ID_PREFIX
996 A two character string which is prefixed to the MAC address
1001 A printf format string which contains the ascii name of
1002 the port. Normally is set to "eth%d" which sets
1003 eth0 for the first ethernet, eth1 for the second etc.
1005 CONFIG_CDP_CAPABILITIES
1007 A 32bit integer which indicates the device capabilities;
1008 0x00000010 for a normal host which does not forwards.
1012 An ascii string containing the version of the software.
1016 An ascii string containing the name of the platform.
1020 A 32bit integer sent on the trigger.
1022 CONFIG_CDP_POWER_CONSUMPTION
1024 A 16bit integer containing the power consumption of the
1025 device in .1 of milliwatts.
1027 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1029 A byte containing the id of the VLAN.
1031 - Status LED: CONFIG_STATUS_LED
1033 Several configurations allow to display the current
1034 status using a LED. For instance, the LED will blink
1035 fast while running U-Boot code, stop blinking as
1036 soon as a reply to a BOOTP request was received, and
1037 start blinking slow once the Linux kernel is running
1038 (supported by a status LED driver in the Linux
1039 kernel). Defining CONFIG_STATUS_LED enables this
1042 - CAN Support: CONFIG_CAN_DRIVER
1044 Defining CONFIG_CAN_DRIVER enables CAN driver support
1045 on those systems that support this (optional)
1046 feature, like the TQM8xxL modules.
1048 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1050 These enable I2C serial bus commands. Defining either of
1051 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1052 include the appropriate I2C driver for the selected cpu.
1054 This will allow you to use i2c commands at the u-boot
1055 command line (as long as you set CFG_CMD_I2C in
1056 CONFIG_COMMANDS) and communicate with i2c based realtime
1057 clock chips. See common/cmd_i2c.c for a description of the
1058 command line interface.
1060 CONFIG_HARD_I2C selects the CPM hardware driver for I2C.
1062 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1063 bit-banging) driver instead of CPM or similar hardware
1066 There are several other quantities that must also be
1067 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1069 In both cases you will need to define CFG_I2C_SPEED
1070 to be the frequency (in Hz) at which you wish your i2c bus
1071 to run and CFG_I2C_SLAVE to be the address of this node (ie
1072 the cpu's i2c node address).
1074 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1075 sets the cpu up as a master node and so its address should
1076 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1077 p.16-473). So, set CFG_I2C_SLAVE to 0.
1079 That's all that's required for CONFIG_HARD_I2C.
1081 If you use the software i2c interface (CONFIG_SOFT_I2C)
1082 then the following macros need to be defined (examples are
1083 from include/configs/lwmon.h):
1087 (Optional). Any commands necessary to enable the I2C
1088 controller or configure ports.
1090 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1094 (Only for MPC8260 CPU). The I/O port to use (the code
1095 assumes both bits are on the same port). Valid values
1096 are 0..3 for ports A..D.
1100 The code necessary to make the I2C data line active
1101 (driven). If the data line is open collector, this
1104 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1108 The code necessary to make the I2C data line tri-stated
1109 (inactive). If the data line is open collector, this
1112 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1116 Code that returns TRUE if the I2C data line is high,
1119 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1123 If <bit> is TRUE, sets the I2C data line high. If it
1124 is FALSE, it clears it (low).
1126 eg: #define I2C_SDA(bit) \
1127 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1128 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1132 If <bit> is TRUE, sets the I2C clock line high. If it
1133 is FALSE, it clears it (low).
1135 eg: #define I2C_SCL(bit) \
1136 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1137 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1141 This delay is invoked four times per clock cycle so this
1142 controls the rate of data transfer. The data rate thus
1143 is 1 / (I2C_DELAY * 4). Often defined to be something
1146 #define I2C_DELAY udelay(2)
1150 When a board is reset during an i2c bus transfer
1151 chips might think that the current transfer is still
1152 in progress. On some boards it is possible to access
1153 the i2c SCLK line directly, either by using the
1154 processor pin as a GPIO or by having a second pin
1155 connected to the bus. If this option is defined a
1156 custom i2c_init_board() routine in boards/xxx/board.c
1157 is run early in the boot sequence.
1159 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1161 This option enables configuration of bi_iic_fast[] flags
1162 in u-boot bd_info structure based on u-boot environment
1163 variable "i2cfast". (see also i2cfast)
1165 - SPI Support: CONFIG_SPI
1167 Enables SPI driver (so far only tested with
1168 SPI EEPROM, also an instance works with Crystal A/D and
1169 D/As on the SACSng board)
1173 Enables extended (16-bit) SPI EEPROM addressing.
1174 (symmetrical to CONFIG_I2C_X)
1178 Enables a software (bit-bang) SPI driver rather than
1179 using hardware support. This is a general purpose
1180 driver that only requires three general I/O port pins
1181 (two outputs, one input) to function. If this is
1182 defined, the board configuration must define several
1183 SPI configuration items (port pins to use, etc). For
1184 an example, see include/configs/sacsng.h.
1186 - FPGA Support: CONFIG_FPGA_COUNT
1188 Specify the number of FPGA devices to support.
1192 Used to specify the types of FPGA devices. For example,
1193 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
1195 CFG_FPGA_PROG_FEEDBACK
1197 Enable printing of hash marks during FPGA configuration.
1201 Enable checks on FPGA configuration interface busy
1202 status by the configuration function. This option
1203 will require a board or device specific function to
1208 If defined, a function that provides delays in the FPGA
1209 configuration driver.
1211 CFG_FPGA_CHECK_CTRLC
1212 Allow Control-C to interrupt FPGA configuration
1214 CFG_FPGA_CHECK_ERROR
1216 Check for configuration errors during FPGA bitfile
1217 loading. For example, abort during Virtex II
1218 configuration if the INIT_B line goes low (which
1219 indicated a CRC error).
1223 Maximum time to wait for the INIT_B line to deassert
1224 after PROB_B has been deasserted during a Virtex II
1225 FPGA configuration sequence. The default time is 500
1230 Maximum time to wait for BUSY to deassert during
1231 Virtex II FPGA configuration. The default is 5 mS.
1233 CFG_FPGA_WAIT_CONFIG
1235 Time to wait after FPGA configuration. The default is
1238 - Configuration Management:
1241 If defined, this string will be added to the U-Boot
1242 version information (U_BOOT_VERSION)
1244 - Vendor Parameter Protection:
1246 U-Boot considers the values of the environment
1247 variables "serial#" (Board Serial Number) and
1248 "ethaddr" (Ethernet Address) to be parameters that
1249 are set once by the board vendor / manufacturer, and
1250 protects these variables from casual modification by
1251 the user. Once set, these variables are read-only,
1252 and write or delete attempts are rejected. You can
1253 change this behviour:
1255 If CONFIG_ENV_OVERWRITE is #defined in your config
1256 file, the write protection for vendor parameters is
1257 completely disabled. Anybody can change or delete
1260 Alternatively, if you #define _both_ CONFIG_ETHADDR
1261 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1262 ethernet address is installed in the environment,
1263 which can be changed exactly ONCE by the user. [The
1264 serial# is unaffected by this, i. e. it remains
1270 Define this variable to enable the reservation of
1271 "protected RAM", i. e. RAM which is not overwritten
1272 by U-Boot. Define CONFIG_PRAM to hold the number of
1273 kB you want to reserve for pRAM. You can overwrite
1274 this default value by defining an environment
1275 variable "pram" to the number of kB you want to
1276 reserve. Note that the board info structure will
1277 still show the full amount of RAM. If pRAM is
1278 reserved, a new environment variable "mem" will
1279 automatically be defined to hold the amount of
1280 remaining RAM in a form that can be passed as boot
1281 argument to Linux, for instance like that:
1283 setenv bootargs ... mem=\$(mem)
1286 This way you can tell Linux not to use this memory,
1287 either, which results in a memory region that will
1288 not be affected by reboots.
1290 *WARNING* If your board configuration uses automatic
1291 detection of the RAM size, you must make sure that
1292 this memory test is non-destructive. So far, the
1293 following board configurations are known to be
1296 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1297 HERMES, IP860, RPXlite, LWMON, LANTEC,
1298 PCU_E, FLAGADM, TQM8260
1303 Define this variable to stop the system in case of a
1304 fatal error, so that you have to reset it manually.
1305 This is probably NOT a good idea for an embedded
1306 system where you want to system to reboot
1307 automatically as fast as possible, but it may be
1308 useful during development since you can try to debug
1309 the conditions that lead to the situation.
1311 CONFIG_NET_RETRY_COUNT
1313 This variable defines the number of retries for
1314 network operations like ARP, RARP, TFTP, or BOOTP
1315 before giving up the operation. If not defined, a
1316 default value of 5 is used.
1318 - Command Interpreter:
1321 Enable auto completion of commands using TAB.
1325 Define this variable to enable the "hush" shell (from
1326 Busybox) as command line interpreter, thus enabling
1327 powerful command line syntax like
1328 if...then...else...fi conditionals or `&&' and '||'
1329 constructs ("shell scripts").
1331 If undefined, you get the old, much simpler behaviour
1332 with a somewhat smaller memory footprint.
1337 This defines the secondary prompt string, which is
1338 printed when the command interpreter needs more input
1339 to complete a command. Usually "> ".
1343 In the current implementation, the local variables
1344 space and global environment variables space are
1345 separated. Local variables are those you define by
1346 simply typing `name=value'. To access a local
1347 variable later on, you have write `$name' or
1348 `${name}'; to execute the contents of a variable
1349 directly type `$name' at the command prompt.
1351 Global environment variables are those you use
1352 setenv/printenv to work with. To run a command stored
1353 in such a variable, you need to use the run command,
1354 and you must not use the '$' sign to access them.
1356 To store commands and special characters in a
1357 variable, please use double quotation marks
1358 surrounding the whole text of the variable, instead
1359 of the backslashes before semicolons and special
1362 - Default Environment:
1363 CONFIG_EXTRA_ENV_SETTINGS
1365 Define this to contain any number of null terminated
1366 strings (variable = value pairs) that will be part of
1367 the default environment compiled into the boot image.
1369 For example, place something like this in your
1370 board's config file:
1372 #define CONFIG_EXTRA_ENV_SETTINGS \
1376 Warning: This method is based on knowledge about the
1377 internal format how the environment is stored by the
1378 U-Boot code. This is NOT an official, exported
1379 interface! Although it is unlikely that this format
1380 will change soon, there is no guarantee either.
1381 You better know what you are doing here.
1383 Note: overly (ab)use of the default environment is
1384 discouraged. Make sure to check other ways to preset
1385 the environment like the autoscript function or the
1388 - DataFlash Support:
1389 CONFIG_HAS_DATAFLASH
1391 Defining this option enables DataFlash features and
1392 allows to read/write in Dataflash via the standard
1395 - SystemACE Support:
1398 Adding this option adds support for Xilinx SystemACE
1399 chips attached via some sort of local bus. The address
1400 of the chip must alsh be defined in the
1401 CFG_SYSTEMACE_BASE macro. For example:
1403 #define CONFIG_SYSTEMACE
1404 #define CFG_SYSTEMACE_BASE 0xf0000000
1406 When SystemACE support is added, the "ace" device type
1407 becomes available to the fat commands, i.e. fatls.
1409 - Show boot progress:
1410 CONFIG_SHOW_BOOT_PROGRESS
1412 Defining this option allows to add some board-
1413 specific code (calling a user-provided function
1414 "show_boot_progress(int)") that enables you to show
1415 the system's boot progress on some display (for
1416 example, some LED's) on your board. At the moment,
1417 the following checkpoints are implemented:
1420 1 common/cmd_bootm.c before attempting to boot an image
1421 -1 common/cmd_bootm.c Image header has bad magic number
1422 2 common/cmd_bootm.c Image header has correct magic number
1423 -2 common/cmd_bootm.c Image header has bad checksum
1424 3 common/cmd_bootm.c Image header has correct checksum
1425 -3 common/cmd_bootm.c Image data has bad checksum
1426 4 common/cmd_bootm.c Image data has correct checksum
1427 -4 common/cmd_bootm.c Image is for unsupported architecture
1428 5 common/cmd_bootm.c Architecture check OK
1429 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1430 6 common/cmd_bootm.c Image Type check OK
1431 -6 common/cmd_bootm.c gunzip uncompression error
1432 -7 common/cmd_bootm.c Unimplemented compression type
1433 7 common/cmd_bootm.c Uncompression OK
1434 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1435 8 common/cmd_bootm.c Image Type check OK
1436 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1437 9 common/cmd_bootm.c Start initial ramdisk verification
1438 -10 common/cmd_bootm.c Ramdisk header has bad magic number
1439 -11 common/cmd_bootm.c Ramdisk header has bad checksum
1440 10 common/cmd_bootm.c Ramdisk header is OK
1441 -12 common/cmd_bootm.c Ramdisk data has bad checksum
1442 11 common/cmd_bootm.c Ramdisk data has correct checksum
1443 12 common/cmd_bootm.c Ramdisk verification complete, start loading
1444 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk)
1445 13 common/cmd_bootm.c Start multifile image verification
1446 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue.
1447 15 common/cmd_bootm.c All preparation done, transferring control to OS
1449 -30 lib_ppc/board.c Fatal error, hang the system
1450 -31 post/post.c POST test failed, detected by post_output_backlog()
1451 -32 post/post.c POST test failed, detected by post_run_single()
1453 -1 common/cmd_doc.c Bad usage of "doc" command
1454 -1 common/cmd_doc.c No boot device
1455 -1 common/cmd_doc.c Unknown Chip ID on boot device
1456 -1 common/cmd_doc.c Read Error on boot device
1457 -1 common/cmd_doc.c Image header has bad magic number
1459 -1 common/cmd_ide.c Bad usage of "ide" command
1460 -1 common/cmd_ide.c No boot device
1461 -1 common/cmd_ide.c Unknown boot device
1462 -1 common/cmd_ide.c Unknown partition table
1463 -1 common/cmd_ide.c Invalid partition type
1464 -1 common/cmd_ide.c Read Error on boot device
1465 -1 common/cmd_ide.c Image header has bad magic number
1467 -1 common/cmd_nand.c Bad usage of "nand" command
1468 -1 common/cmd_nand.c No boot device
1469 -1 common/cmd_nand.c Unknown Chip ID on boot device
1470 -1 common/cmd_nand.c Read Error on boot device
1471 -1 common/cmd_nand.c Image header has bad magic number
1473 -1 common/env_common.c Environment has a bad CRC, using default
1479 [so far only for SMDK2400 and TRAB boards]
1481 - Modem support endable:
1482 CONFIG_MODEM_SUPPORT
1484 - RTS/CTS Flow control enable:
1487 - Modem debug support:
1488 CONFIG_MODEM_SUPPORT_DEBUG
1490 Enables debugging stuff (char screen[1024], dbg())
1491 for modem support. Useful only with BDI2000.
1493 - Interrupt support (PPC):
1495 There are common interrupt_init() and timer_interrupt()
1496 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
1497 for cpu specific initialization. interrupt_init_cpu()
1498 should set decrementer_count to appropriate value. If
1499 cpu resets decrementer automatically after interrupt
1500 (ppc4xx) it should set decrementer_count to zero.
1501 timer_interrupt() calls timer_interrupt_cpu() for cpu
1502 specific handling. If board has watchdog / status_led
1503 / other_activity_monitor it works automatically from
1504 general timer_interrupt().
1508 In the target system modem support is enabled when a
1509 specific key (key combination) is pressed during
1510 power-on. Otherwise U-Boot will boot normally
1511 (autoboot). The key_pressed() fuction is called from
1512 board_init(). Currently key_pressed() is a dummy
1513 function, returning 1 and thus enabling modem
1516 If there are no modem init strings in the
1517 environment, U-Boot proceed to autoboot; the
1518 previous output (banner, info printfs) will be
1521 See also: doc/README.Modem
1524 Configuration Settings:
1525 -----------------------
1527 - CFG_LONGHELP: Defined when you want long help messages included;
1528 undefine this when you're short of memory.
1530 - CFG_PROMPT: This is what U-Boot prints on the console to
1531 prompt for user input.
1533 - CFG_CBSIZE: Buffer size for input from the Console
1535 - CFG_PBSIZE: Buffer size for Console output
1537 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1539 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1540 the application (usually a Linux kernel) when it is
1543 - CFG_BAUDRATE_TABLE:
1544 List of legal baudrate settings for this board.
1546 - CFG_CONSOLE_INFO_QUIET
1547 Suppress display of console information at boot.
1549 - CFG_CONSOLE_IS_IN_ENV
1550 If the board specific function
1551 extern int overwrite_console (void);
1552 returns 1, the stdin, stderr and stdout are switched to the
1553 serial port, else the settings in the environment are used.
1555 - CFG_CONSOLE_OVERWRITE_ROUTINE
1556 Enable the call to overwrite_console().
1558 - CFG_CONSOLE_ENV_OVERWRITE
1559 Enable overwrite of previous console environment settings.
1561 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1562 Begin and End addresses of the area used by the
1566 Enable an alternate, more extensive memory test.
1568 - CFG_MEMTEST_SCRATCH:
1569 Scratch address used by the alternate memory test
1570 You only need to set this if address zero isn't writeable
1572 - CFG_TFTP_LOADADDR:
1573 Default load address for network file downloads
1575 - CFG_LOADS_BAUD_CHANGE:
1576 Enable temporary baudrate change while serial download
1579 Physical start address of SDRAM. _Must_ be 0 here.
1582 Physical start address of Motherboard I/O (if using a
1586 Physical start address of Flash memory.
1589 Physical start address of boot monitor code (set by
1590 make config files to be same as the text base address
1591 (TEXT_BASE) used when linking) - same as
1592 CFG_FLASH_BASE when booting from flash.
1595 Size of memory reserved for monitor code, used to
1596 determine _at_compile_time_ (!) if the environment is
1597 embedded within the U-Boot image, or in a separate
1601 Size of DRAM reserved for malloc() use.
1604 Maximum size of memory mapped by the startup code of
1605 the Linux kernel; all data that must be processed by
1606 the Linux kernel (bd_info, boot arguments, eventually
1607 initrd image) must be put below this limit.
1609 - CFG_MAX_FLASH_BANKS:
1610 Max number of Flash memory banks
1612 - CFG_MAX_FLASH_SECT:
1613 Max number of sectors on a Flash chip
1615 - CFG_FLASH_ERASE_TOUT:
1616 Timeout for Flash erase operations (in ms)
1618 - CFG_FLASH_WRITE_TOUT:
1619 Timeout for Flash write operations (in ms)
1621 - CFG_FLASH_LOCK_TOUT
1622 Timeout for Flash set sector lock bit operation (in ms)
1624 - CFG_FLASH_UNLOCK_TOUT
1625 Timeout for Flash clear lock bits operation (in ms)
1627 - CFG_FLASH_PROTECTION
1628 If defined, hardware flash sectors protection is used
1629 instead of U-Boot software protection.
1631 - CFG_DIRECT_FLASH_TFTP:
1633 Enable TFTP transfers directly to flash memory;
1634 without this option such a download has to be
1635 performed in two steps: (1) download to RAM, and (2)
1636 copy from RAM to flash.
1638 The two-step approach is usually more reliable, since
1639 you can check if the download worked before you erase
1640 the flash, but in some situations (when sytem RAM is
1641 too limited to allow for a tempory copy of the
1642 downloaded image) this option may be very useful.
1645 Define if the flash driver uses extra elements in the
1646 common flash structure for storing flash geometry.
1648 - CFG_FLASH_CFI_DRIVER
1649 This option also enables the building of the cfi_flash driver
1650 in the drivers directory
1652 - CFG_RX_ETH_BUFFER:
1653 Defines the number of ethernet receive buffers. On some
1654 ethernet controllers it is recommended to set this value
1655 to 8 or even higher (EEPRO100 or 405 EMAC), since all
1656 buffers can be full shortly after enabling the interface
1657 on high ethernet traffic.
1658 Defaults to 4 if not defined.
1660 The following definitions that deal with the placement and management
1661 of environment data (variable area); in general, we support the
1662 following configurations:
1664 - CFG_ENV_IS_IN_FLASH:
1666 Define this if the environment is in flash memory.
1668 a) The environment occupies one whole flash sector, which is
1669 "embedded" in the text segment with the U-Boot code. This
1670 happens usually with "bottom boot sector" or "top boot
1671 sector" type flash chips, which have several smaller
1672 sectors at the start or the end. For instance, such a
1673 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
1674 such a case you would place the environment in one of the
1675 4 kB sectors - with U-Boot code before and after it. With
1676 "top boot sector" type flash chips, you would put the
1677 environment in one of the last sectors, leaving a gap
1678 between U-Boot and the environment.
1682 Offset of environment data (variable area) to the
1683 beginning of flash memory; for instance, with bottom boot
1684 type flash chips the second sector can be used: the offset
1685 for this sector is given here.
1687 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
1691 This is just another way to specify the start address of
1692 the flash sector containing the environment (instead of
1695 - CFG_ENV_SECT_SIZE:
1697 Size of the sector containing the environment.
1700 b) Sometimes flash chips have few, equal sized, BIG sectors.
1701 In such a case you don't want to spend a whole sector for
1706 If you use this in combination with CFG_ENV_IS_IN_FLASH
1707 and CFG_ENV_SECT_SIZE, you can specify to use only a part
1708 of this flash sector for the environment. This saves
1709 memory for the RAM copy of the environment.
1711 It may also save flash memory if you decide to use this
1712 when your environment is "embedded" within U-Boot code,
1713 since then the remainder of the flash sector could be used
1714 for U-Boot code. It should be pointed out that this is
1715 STRONGLY DISCOURAGED from a robustness point of view:
1716 updating the environment in flash makes it always
1717 necessary to erase the WHOLE sector. If something goes
1718 wrong before the contents has been restored from a copy in
1719 RAM, your target system will be dead.
1721 - CFG_ENV_ADDR_REDUND
1724 These settings describe a second storage area used to hold
1725 a redundand copy of the environment data, so that there is
1726 a valid backup copy in case there is a power failure during
1727 a "saveenv" operation.
1729 BE CAREFUL! Any changes to the flash layout, and some changes to the
1730 source code will make it necessary to adapt <board>/u-boot.lds*
1734 - CFG_ENV_IS_IN_NVRAM:
1736 Define this if you have some non-volatile memory device
1737 (NVRAM, battery buffered SRAM) which you want to use for the
1743 These two #defines are used to determin the memory area you
1744 want to use for environment. It is assumed that this memory
1745 can just be read and written to, without any special
1748 BE CAREFUL! The first access to the environment happens quite early
1749 in U-Boot initalization (when we try to get the setting of for the
1750 console baudrate). You *MUST* have mappend your NVRAM area then, or
1753 Please note that even with NVRAM we still use a copy of the
1754 environment in RAM: we could work on NVRAM directly, but we want to
1755 keep settings there always unmodified except somebody uses "saveenv"
1756 to save the current settings.
1759 - CFG_ENV_IS_IN_EEPROM:
1761 Use this if you have an EEPROM or similar serial access
1762 device and a driver for it.
1767 These two #defines specify the offset and size of the
1768 environment area within the total memory of your EEPROM.
1770 - CFG_I2C_EEPROM_ADDR:
1771 If defined, specified the chip address of the EEPROM device.
1772 The default address is zero.
1774 - CFG_EEPROM_PAGE_WRITE_BITS:
1775 If defined, the number of bits used to address bytes in a
1776 single page in the EEPROM device. A 64 byte page, for example
1777 would require six bits.
1779 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1780 If defined, the number of milliseconds to delay between
1781 page writes. The default is zero milliseconds.
1783 - CFG_I2C_EEPROM_ADDR_LEN:
1784 The length in bytes of the EEPROM memory array address. Note
1785 that this is NOT the chip address length!
1787 - CFG_I2C_EEPROM_ADDR_OVERFLOW:
1788 EEPROM chips that implement "address overflow" are ones
1789 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
1790 address and the extra bits end up in the "chip address" bit
1791 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
1794 Note that we consider the length of the address field to
1795 still be one byte because the extra address bits are hidden
1796 in the chip address.
1799 The size in bytes of the EEPROM device.
1802 - CFG_ENV_IS_IN_DATAFLASH:
1804 Define this if you have a DataFlash memory device which you
1805 want to use for the environment.
1811 These three #defines specify the offset and size of the
1812 environment area within the total memory of your DataFlash placed
1813 at the specified address.
1816 - CFG_SPI_INIT_OFFSET
1818 Defines offset to the initial SPI buffer area in DPRAM. The
1819 area is used at an early stage (ROM part) if the environment
1820 is configured to reside in the SPI EEPROM: We need a 520 byte
1821 scratch DPRAM area. It is used between the two initialization
1822 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
1823 to be a good choice since it makes it far enough from the
1824 start of the data area as well as from the stack pointer.
1826 Please note that the environment is read-only as long as the monitor
1827 has been relocated to RAM and a RAM copy of the environment has been
1828 created; also, when using EEPROM you will have to use getenv_r()
1829 until then to read environment variables.
1831 The environment is protected by a CRC32 checksum. Before the monitor
1832 is relocated into RAM, as a result of a bad CRC you will be working
1833 with the compiled-in default environment - *silently*!!! [This is
1834 necessary, because the first environment variable we need is the
1835 "baudrate" setting for the console - if we have a bad CRC, we don't
1836 have any device yet where we could complain.]
1838 Note: once the monitor has been relocated, then it will complain if
1839 the default environment is used; a new CRC is computed as soon as you
1840 use the "saveenv" command to store a valid environment.
1842 - CFG_FAULT_ECHO_LINK_DOWN:
1843 Echo the inverted Ethernet link state to the fault LED.
1845 Note: If this option is active, then CFG_FAULT_MII_ADDR
1846 also needs to be defined.
1848 - CFG_FAULT_MII_ADDR:
1849 MII address of the PHY to check for the Ethernet link state.
1851 - CFG_64BIT_VSPRINTF:
1852 Makes vsprintf (and all *printf functions) support printing
1853 of 64bit values by using the L quantifier
1855 - CFG_64BIT_STRTOUL:
1856 Adds simple_strtoull that returns a 64bit value
1858 Low Level (hardware related) configuration options:
1859 ---------------------------------------------------
1861 - CFG_CACHELINE_SIZE:
1862 Cache Line Size of the CPU.
1865 Default address of the IMMR after system reset.
1867 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
1868 and RPXsuper) to be able to adjust the position of
1869 the IMMR register after a reset.
1871 - Floppy Disk Support:
1872 CFG_FDC_DRIVE_NUMBER
1874 the default drive number (default value 0)
1878 defines the spacing between fdc chipset registers
1883 defines the offset of register from address. It
1884 depends on which part of the data bus is connected to
1885 the fdc chipset. (default value 0)
1887 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
1888 CFG_FDC_DRIVE_NUMBER are undefined, they take their
1891 if CFG_FDC_HW_INIT is defined, then the function
1892 fdc_hw_init() is called at the beginning of the FDC
1893 setup. fdc_hw_init() must be provided by the board
1894 source code. It is used to make hardware dependant
1897 - CFG_IMMR: Physical address of the Internal Memory Mapped
1898 Register; DO NOT CHANGE! (11-4)
1899 [MPC8xx systems only]
1901 - CFG_INIT_RAM_ADDR:
1903 Start address of memory area that can be used for
1904 initial data and stack; please note that this must be
1905 writable memory that is working WITHOUT special
1906 initialization, i. e. you CANNOT use normal RAM which
1907 will become available only after programming the
1908 memory controller and running certain initialization
1911 U-Boot uses the following memory types:
1912 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
1913 - MPC824X: data cache
1914 - PPC4xx: data cache
1916 - CFG_GBL_DATA_OFFSET:
1918 Offset of the initial data structure in the memory
1919 area defined by CFG_INIT_RAM_ADDR. Usually
1920 CFG_GBL_DATA_OFFSET is chosen such that the initial
1921 data is located at the end of the available space
1922 (sometimes written as (CFG_INIT_RAM_END -
1923 CFG_INIT_DATA_SIZE), and the initial stack is just
1924 below that area (growing from (CFG_INIT_RAM_ADDR +
1925 CFG_GBL_DATA_OFFSET) downward.
1928 On the MPC824X (or other systems that use the data
1929 cache for initial memory) the address chosen for
1930 CFG_INIT_RAM_ADDR is basically arbitrary - it must
1931 point to an otherwise UNUSED address space between
1932 the top of RAM and the start of the PCI space.
1934 - CFG_SIUMCR: SIU Module Configuration (11-6)
1936 - CFG_SYPCR: System Protection Control (11-9)
1938 - CFG_TBSCR: Time Base Status and Control (11-26)
1940 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
1942 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
1944 - CFG_SCCR: System Clock and reset Control Register (15-27)
1946 - CFG_OR_TIMING_SDRAM:
1950 periodic timer for refresh
1952 - CFG_DER: Debug Event Register (37-47)
1954 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
1955 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
1956 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
1958 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
1960 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
1961 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
1962 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
1963 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
1965 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
1966 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
1967 Machine Mode Register and Memory Periodic Timer
1968 Prescaler definitions (SDRAM timing)
1970 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
1971 enable I2C microcode relocation patch (MPC8xx);
1972 define relocation offset in DPRAM [DSP2]
1974 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
1975 enable SPI microcode relocation patch (MPC8xx);
1976 define relocation offset in DPRAM [SCC4]
1979 Use OSCM clock mode on MBX8xx board. Be careful,
1980 wrong setting might damage your board. Read
1981 doc/README.MBX before setting this variable!
1983 - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
1984 Offset of the bootmode word in DPRAM used by post
1985 (Power On Self Tests). This definition overrides
1986 #define'd default value in commproc.h resp.
1989 - CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
1990 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
1991 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
1992 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
1993 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
1994 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
1995 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
1996 CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
1997 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
1999 - CONFIG_ETHER_ON_FEC[12]
2000 Define to enable FEC[12] on a 8xx series processor.
2002 - CONFIG_FEC[12]_PHY
2003 Define to the hardcoded PHY address which corresponds
2004 to the given FEC; i. e.
2005 #define CONFIG_FEC1_PHY 4
2006 means that the PHY with address 4 is connected to FEC1
2008 When set to -1, means to probe for first available.
2010 - CONFIG_FEC[12]_PHY_NORXERR
2011 The PHY does not have a RXERR line (RMII only).
2012 (so program the FEC to ignore it).
2015 Enable RMII mode for all FECs.
2016 Note that this is a global option, we can't
2017 have one FEC in standard MII mode and another in RMII mode.
2019 - CONFIG_CRC32_VERIFY
2020 Add a verify option to the crc32 command.
2023 => crc32 -v <address> <count> <crc32>
2025 Where address/count indicate a memory area
2026 and crc32 is the correct crc32 which the
2029 Building the Software:
2030 ======================
2032 Building U-Boot has been tested in native PPC environments (on a
2033 PowerBook G3 running LinuxPPC 2000) and in cross environments
2034 (running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
2037 If you are not using a native PPC environment, it is assumed that you
2038 have the GNU cross compiling tools available in your path and named
2039 with a prefix of "powerpc-linux-". If this is not the case, (e.g. if
2040 you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
2041 the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
2044 CROSS_COMPILE = ppc_4xx-
2047 U-Boot is intended to be simple to build. After installing the
2048 sources you must configure U-Boot for one specific board type. This
2053 where "NAME_config" is the name of one of the existing
2054 configurations; the following names are supported:
2056 ADCIOP_config FPS850L_config omap1610inn_config
2057 ADS860_config FPS860L_config pcu_e_config
2058 AR405_config GEN860T_config PIP405_config
2059 at91rm9200dk_config GENIETV_config QS823_config
2060 CANBT_config GTH_config QS850_config
2061 cmi_mpc5xx_config hermes_config QS860T_config
2062 cogent_common_config hymod_config RPXlite_config
2063 cogent_mpc8260_config IP860_config RPXsuper_config
2064 cogent_mpc8xx_config IVML24_config rsdproto_config
2065 CPCI405_config IVMS8_config Sandpoint8240_config
2066 CPCIISER4_config JSE_config sbc8260_config
2067 csb272_config LANTEC_config SM850_config
2068 CU824_config lwmon_config SPD823TS_config
2069 DUET_ADS_config MBX860T_config stxgp3_config
2070 EBONY_config MBX_config SXNI855T_config
2071 ELPT860_config MPC8260ADS_config TQM823L_config
2072 ESTEEM192E_config MPC8540ADS_config TQM850L_config
2073 ETX094_config MPC8560ADS_config TQM855L_config
2074 FADS823_config NETVIA_config TQM860L_config
2075 FADS850SAR_config omap1510inn_config WALNUT405_config
2076 FADS860T_config omap1610h2_config ZPC1900_config
2078 Note: for some board special configuration names may exist; check if
2079 additional information is available from the board vendor; for
2080 instance, the TQM823L systems are available without (standard)
2081 or with LCD support. You can select such additional "features"
2082 when chosing the configuration, i. e.
2085 - will configure for a plain TQM823L, i. e. no LCD support
2087 make TQM823L_LCD_config
2088 - will configure for a TQM823L with U-Boot console on LCD
2093 Finally, type "make all", and you should get some working U-Boot
2094 images ready for download to / installation on your system:
2096 - "u-boot.bin" is a raw binary image
2097 - "u-boot" is an image in ELF binary format
2098 - "u-boot.srec" is in Motorola S-Record format
2101 Please be aware that the Makefiles assume you are using GNU make, so
2102 for instance on NetBSD you might need to use "gmake" instead of
2106 If the system board that you have is not listed, then you will need
2107 to port U-Boot to your hardware platform. To do this, follow these
2110 1. Add a new configuration option for your board to the toplevel
2111 "Makefile" and to the "MAKEALL" script, using the existing
2112 entries as examples. Note that here and at many other places
2113 boards and other names are listed in alphabetical sort order. Please
2115 2. Create a new directory to hold your board specific code. Add any
2116 files you need. In your board directory, you will need at least
2117 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2118 3. Create a new configuration file "include/configs/<board>.h" for
2120 3. If you're porting U-Boot to a new CPU, then also create a new
2121 directory to hold your CPU specific code. Add any files you need.
2122 4. Run "make <board>_config" with your new name.
2123 5. Type "make", and you should get a working "u-boot.srec" file
2124 to be installed on your target system.
2125 6. Debug and solve any problems that might arise.
2126 [Of course, this last step is much harder than it sounds.]
2129 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2130 ==============================================================
2132 If you have modified U-Boot sources (for instance added a new board
2133 or support for new devices, a new CPU, etc.) you are expected to
2134 provide feedback to the other developers. The feedback normally takes
2135 the form of a "patch", i. e. a context diff against a certain (latest
2136 official or latest in CVS) version of U-Boot sources.
2138 But before you submit such a patch, please verify that your modifi-
2139 cation did not break existing code. At least make sure that *ALL* of
2140 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2141 just run the "MAKEALL" script, which will configure and build U-Boot
2142 for ALL supported system. Be warned, this will take a while. You can
2143 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2144 environment variable to the script, i. e. to use the cross tools from
2145 MontaVista's Hard Hat Linux you can type
2147 CROSS_COMPILE=ppc_8xx- MAKEALL
2149 or to build on a native PowerPC system you can type
2151 CROSS_COMPILE=' ' MAKEALL
2153 See also "U-Boot Porting Guide" below.
2156 Monitor Commands - Overview:
2157 ============================
2159 go - start application at address 'addr'
2160 run - run commands in an environment variable
2161 bootm - boot application image from memory
2162 bootp - boot image via network using BootP/TFTP protocol
2163 tftpboot- boot image via network using TFTP protocol
2164 and env variables "ipaddr" and "serverip"
2165 (and eventually "gatewayip")
2166 rarpboot- boot image via network using RARP/TFTP protocol
2167 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2168 loads - load S-Record file over serial line
2169 loadb - load binary file over serial line (kermit mode)
2171 mm - memory modify (auto-incrementing)
2172 nm - memory modify (constant address)
2173 mw - memory write (fill)
2175 cmp - memory compare
2176 crc32 - checksum calculation
2177 imd - i2c memory display
2178 imm - i2c memory modify (auto-incrementing)
2179 inm - i2c memory modify (constant address)
2180 imw - i2c memory write (fill)
2181 icrc32 - i2c checksum calculation
2182 iprobe - probe to discover valid I2C chip addresses
2183 iloop - infinite loop on address range
2184 isdram - print SDRAM configuration information
2185 sspi - SPI utility commands
2186 base - print or set address offset
2187 printenv- print environment variables
2188 setenv - set environment variables
2189 saveenv - save environment variables to persistent storage
2190 protect - enable or disable FLASH write protection
2191 erase - erase FLASH memory
2192 flinfo - print FLASH memory information
2193 bdinfo - print Board Info structure
2194 iminfo - print header information for application image
2195 coninfo - print console devices and informations
2196 ide - IDE sub-system
2197 loop - infinite loop on address range
2198 mtest - simple RAM test
2199 icache - enable or disable instruction cache
2200 dcache - enable or disable data cache
2201 reset - Perform RESET of the CPU
2202 echo - echo args to console
2203 version - print monitor version
2204 help - print online help
2205 ? - alias for 'help'
2208 Monitor Commands - Detailed Description:
2209 ========================================
2213 For now: just type "help <command>".
2216 Environment Variables:
2217 ======================
2219 U-Boot supports user configuration using Environment Variables which
2220 can be made persistent by saving to Flash memory.
2222 Environment Variables are set using "setenv", printed using
2223 "printenv", and saved to Flash using "saveenv". Using "setenv"
2224 without a value can be used to delete a variable from the
2225 environment. As long as you don't save the environment you are
2226 working with an in-memory copy. In case the Flash area containing the
2227 environment is erased by accident, a default environment is provided.
2229 Some configuration options can be set using Environment Variables:
2231 baudrate - see CONFIG_BAUDRATE
2233 bootdelay - see CONFIG_BOOTDELAY
2235 bootcmd - see CONFIG_BOOTCOMMAND
2237 bootargs - Boot arguments when booting an RTOS image
2239 bootfile - Name of the image to load with TFTP
2241 autoload - if set to "no" (any string beginning with 'n'),
2242 "bootp" will just load perform a lookup of the
2243 configuration from the BOOTP server, but not try to
2244 load any image using TFTP
2246 autostart - if set to "yes", an image loaded using the "bootp",
2247 "rarpboot", "tftpboot" or "diskboot" commands will
2248 be automatically started (by internally calling
2251 If set to "no", a standalone image passed to the
2252 "bootm" command will be copied to the load address
2253 (and eventually uncompressed), but NOT be started.
2254 This can be used to load and uncompress arbitrary
2257 i2cfast - (PPC405GP|PPC405EP only)
2258 if set to 'y' configures Linux I2C driver for fast
2259 mode (400kHZ). This environment variable is used in
2260 initialization code. So, for changes to be effective
2261 it must be saved and board must be reset.
2263 initrd_high - restrict positioning of initrd images:
2264 If this variable is not set, initrd images will be
2265 copied to the highest possible address in RAM; this
2266 is usually what you want since it allows for
2267 maximum initrd size. If for some reason you want to
2268 make sure that the initrd image is loaded below the
2269 CFG_BOOTMAPSZ limit, you can set this environment
2270 variable to a value of "no" or "off" or "0".
2271 Alternatively, you can set it to a maximum upper
2272 address to use (U-Boot will still check that it
2273 does not overwrite the U-Boot stack and data).
2275 For instance, when you have a system with 16 MB
2276 RAM, and want to reserve 4 MB from use by Linux,
2277 you can do this by adding "mem=12M" to the value of
2278 the "bootargs" variable. However, now you must make
2279 sure that the initrd image is placed in the first
2280 12 MB as well - this can be done with
2282 setenv initrd_high 00c00000
2284 If you set initrd_high to 0xFFFFFFFF, this is an
2285 indication to U-Boot that all addresses are legal
2286 for the Linux kernel, including addresses in flash
2287 memory. In this case U-Boot will NOT COPY the
2288 ramdisk at all. This may be useful to reduce the
2289 boot time on your system, but requires that this
2290 feature is supported by your Linux kernel.
2292 ipaddr - IP address; needed for tftpboot command
2294 loadaddr - Default load address for commands like "bootp",
2295 "rarpboot", "tftpboot", "loadb" or "diskboot"
2297 loads_echo - see CONFIG_LOADS_ECHO
2299 serverip - TFTP server IP address; needed for tftpboot command
2301 bootretry - see CONFIG_BOOT_RETRY_TIME
2303 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
2305 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
2307 ethprime - When CONFIG_NET_MULTI is enabled controls which
2308 interface is used first.
2310 ethact - When CONFIG_NET_MULTI is enabled controls which
2311 interface is currently active. For example you
2312 can do the following
2314 => setenv ethact FEC ETHERNET
2315 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
2316 => setenv ethact SCC ETHERNET
2317 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
2319 netretry - When set to "no" each network operation will
2320 either succeed or fail without retrying.
2321 When set to "once" the network operation will
2322 fail when all the available network interfaces
2323 are tried once without success.
2324 Useful on scripts which control the retry operation
2327 vlan - When set to a value < 4095 the traffic over
2328 ethernet is encapsulated/received over 802.1q
2331 The following environment variables may be used and automatically
2332 updated by the network boot commands ("bootp" and "rarpboot"),
2333 depending the information provided by your boot server:
2335 bootfile - see above
2336 dnsip - IP address of your Domain Name Server
2337 dnsip2 - IP address of your secondary Domain Name Server
2338 gatewayip - IP address of the Gateway (Router) to use
2339 hostname - Target hostname
2341 netmask - Subnet Mask
2342 rootpath - Pathname of the root filesystem on the NFS server
2343 serverip - see above
2346 There are two special Environment Variables:
2348 serial# - contains hardware identification information such
2349 as type string and/or serial number
2350 ethaddr - Ethernet address
2352 These variables can be set only once (usually during manufacturing of
2353 the board). U-Boot refuses to delete or overwrite these variables
2354 once they have been set once.
2357 Further special Environment Variables:
2359 ver - Contains the U-Boot version string as printed
2360 with the "version" command. This variable is
2361 readonly (see CONFIG_VERSION_VARIABLE).
2364 Please note that changes to some configuration parameters may take
2365 only effect after the next boot (yes, that's just like Windoze :-).
2368 Command Line Parsing:
2369 =====================
2371 There are two different command line parsers available with U-Boot:
2372 the old "simple" one, and the much more powerful "hush" shell:
2374 Old, simple command line parser:
2375 --------------------------------
2377 - supports environment variables (through setenv / saveenv commands)
2378 - several commands on one line, separated by ';'
2379 - variable substitution using "... $(name) ..." syntax
2380 - special characters ('$', ';') can be escaped by prefixing with '\',
2382 setenv bootcmd bootm \$(address)
2383 - You can also escape text by enclosing in single apostrophes, for example:
2384 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2389 - similar to Bourne shell, with control structures like
2390 if...then...else...fi, for...do...done; while...do...done,
2391 until...do...done, ...
2392 - supports environment ("global") variables (through setenv / saveenv
2393 commands) and local shell variables (through standard shell syntax
2394 "name=value"); only environment variables can be used with "run"
2400 (1) If a command line (or an environment variable executed by a "run"
2401 command) contains several commands separated by semicolon, and
2402 one of these commands fails, then the remaining commands will be
2405 (2) If you execute several variables with one call to run (i. e.
2406 calling run with a list af variables as arguments), any failing
2407 command will cause "run" to terminate, i. e. the remaining
2408 variables are not executed.
2410 Note for Redundant Ethernet Interfaces:
2411 =======================================
2413 Some boards come with redundant ethernet interfaces; U-Boot supports
2414 such configurations and is capable of automatic selection of a
2415 "working" interface when needed. MAC assignment works as follows:
2417 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2418 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2419 "eth1addr" (=>eth1), "eth2addr", ...
2421 If the network interface stores some valid MAC address (for instance
2422 in SROM), this is used as default address if there is NO correspon-
2423 ding setting in the environment; if the corresponding environment
2424 variable is set, this overrides the settings in the card; that means:
2426 o If the SROM has a valid MAC address, and there is no address in the
2427 environment, the SROM's address is used.
2429 o If there is no valid address in the SROM, and a definition in the
2430 environment exists, then the value from the environment variable is
2433 o If both the SROM and the environment contain a MAC address, and
2434 both addresses are the same, this MAC address is used.
2436 o If both the SROM and the environment contain a MAC address, and the
2437 addresses differ, the value from the environment is used and a
2440 o If neither SROM nor the environment contain a MAC address, an error
2447 The "boot" commands of this monitor operate on "image" files which
2448 can be basicly anything, preceeded by a special header; see the
2449 definitions in include/image.h for details; basicly, the header
2450 defines the following image properties:
2452 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2453 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2454 LynxOS, pSOS, QNX, RTEMS, ARTOS;
2455 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
2456 * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
2457 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2458 Currently supported: ARM, Intel x86, MIPS, NIOS, PowerPC).
2459 * Compression Type (uncompressed, gzip, bzip2)
2465 The header is marked by a special Magic Number, and both the header
2466 and the data portions of the image are secured against corruption by
2473 Although U-Boot should support any OS or standalone application
2474 easily, the main focus has always been on Linux during the design of
2477 U-Boot includes many features that so far have been part of some
2478 special "boot loader" code within the Linux kernel. Also, any
2479 "initrd" images to be used are no longer part of one big Linux image;
2480 instead, kernel and "initrd" are separate images. This implementation
2481 serves several purposes:
2483 - the same features can be used for other OS or standalone
2484 applications (for instance: using compressed images to reduce the
2485 Flash memory footprint)
2487 - it becomes much easier to port new Linux kernel versions because
2488 lots of low-level, hardware dependent stuff are done by U-Boot
2490 - the same Linux kernel image can now be used with different "initrd"
2491 images; of course this also means that different kernel images can
2492 be run with the same "initrd". This makes testing easier (you don't
2493 have to build a new "zImage.initrd" Linux image when you just
2494 change a file in your "initrd"). Also, a field-upgrade of the
2495 software is easier now.
2501 Porting Linux to U-Boot based systems:
2502 ---------------------------------------
2504 U-Boot cannot save you from doing all the necessary modifications to
2505 configure the Linux device drivers for use with your target hardware
2506 (no, we don't intend to provide a full virtual machine interface to
2509 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
2511 Just make sure your machine specific header file (for instance
2512 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
2513 Information structure as we define in include/u-boot.h, and make
2514 sure that your definition of IMAP_ADDR uses the same value as your
2515 U-Boot configuration in CFG_IMMR.
2518 Configuring the Linux kernel:
2519 -----------------------------
2521 No specific requirements for U-Boot. Make sure you have some root
2522 device (initial ramdisk, NFS) for your target system.
2525 Building a Linux Image:
2526 -----------------------
2528 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2529 not used. If you use recent kernel source, a new build target
2530 "uImage" will exist which automatically builds an image usable by
2531 U-Boot. Most older kernels also have support for a "pImage" target,
2532 which was introduced for our predecessor project PPCBoot and uses a
2533 100% compatible format.
2542 The "uImage" build target uses a special tool (in 'tools/mkimage') to
2543 encapsulate a compressed Linux kernel image with header information,
2544 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
2546 * build a standard "vmlinux" kernel image (in ELF binary format):
2548 * convert the kernel into a raw binary image:
2550 ${CROSS_COMPILE}-objcopy -O binary \
2551 -R .note -R .comment \
2552 -S vmlinux linux.bin
2554 * compress the binary image:
2558 * package compressed binary image for U-Boot:
2560 mkimage -A ppc -O linux -T kernel -C gzip \
2561 -a 0 -e 0 -n "Linux Kernel Image" \
2562 -d linux.bin.gz uImage
2565 The "mkimage" tool can also be used to create ramdisk images for use
2566 with U-Boot, either separated from the Linux kernel image, or
2567 combined into one file. "mkimage" encapsulates the images with a 64
2568 byte header containing information about target architecture,
2569 operating system, image type, compression method, entry points, time
2570 stamp, CRC32 checksums, etc.
2572 "mkimage" can be called in two ways: to verify existing images and
2573 print the header information, or to build new images.
2575 In the first form (with "-l" option) mkimage lists the information
2576 contained in the header of an existing U-Boot image; this includes
2577 checksum verification:
2579 tools/mkimage -l image
2580 -l ==> list image header information
2582 The second form (with "-d" option) is used to build a U-Boot image
2583 from a "data file" which is used as image payload:
2585 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2586 -n name -d data_file image
2587 -A ==> set architecture to 'arch'
2588 -O ==> set operating system to 'os'
2589 -T ==> set image type to 'type'
2590 -C ==> set compression type 'comp'
2591 -a ==> set load address to 'addr' (hex)
2592 -e ==> set entry point to 'ep' (hex)
2593 -n ==> set image name to 'name'
2594 -d ==> use image data from 'datafile'
2596 Right now, all Linux kernels for PowerPC systems use the same load
2597 address (0x00000000), but the entry point address depends on the
2600 - 2.2.x kernels have the entry point at 0x0000000C,
2601 - 2.3.x and later kernels have the entry point at 0x00000000.
2603 So a typical call to build a U-Boot image would read:
2605 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2606 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
2607 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
2608 > examples/uImage.TQM850L
2609 Image Name: 2.4.4 kernel for TQM850L
2610 Created: Wed Jul 19 02:34:59 2000
2611 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2612 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2613 Load Address: 0x00000000
2614 Entry Point: 0x00000000
2616 To verify the contents of the image (or check for corruption):
2618 -> tools/mkimage -l examples/uImage.TQM850L
2619 Image Name: 2.4.4 kernel for TQM850L
2620 Created: Wed Jul 19 02:34:59 2000
2621 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2622 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2623 Load Address: 0x00000000
2624 Entry Point: 0x00000000
2626 NOTE: for embedded systems where boot time is critical you can trade
2627 speed for memory and install an UNCOMPRESSED image instead: this
2628 needs more space in Flash, but boots much faster since it does not
2629 need to be uncompressed:
2631 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
2632 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2633 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
2634 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
2635 > examples/uImage.TQM850L-uncompressed
2636 Image Name: 2.4.4 kernel for TQM850L
2637 Created: Wed Jul 19 02:34:59 2000
2638 Image Type: PowerPC Linux Kernel Image (uncompressed)
2639 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
2640 Load Address: 0x00000000
2641 Entry Point: 0x00000000
2644 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2645 when your kernel is intended to use an initial ramdisk:
2647 -> tools/mkimage -n 'Simple Ramdisk Image' \
2648 > -A ppc -O linux -T ramdisk -C gzip \
2649 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2650 Image Name: Simple Ramdisk Image
2651 Created: Wed Jan 12 14:01:50 2000
2652 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2653 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
2654 Load Address: 0x00000000
2655 Entry Point: 0x00000000
2658 Installing a Linux Image:
2659 -------------------------
2661 To downloading a U-Boot image over the serial (console) interface,
2662 you must convert the image to S-Record format:
2664 objcopy -I binary -O srec examples/image examples/image.srec
2666 The 'objcopy' does not understand the information in the U-Boot
2667 image header, so the resulting S-Record file will be relative to
2668 address 0x00000000. To load it to a given address, you need to
2669 specify the target address as 'offset' parameter with the 'loads'
2672 Example: install the image to address 0x40100000 (which on the
2673 TQM8xxL is in the first Flash bank):
2675 => erase 40100000 401FFFFF
2681 ## Ready for S-Record download ...
2682 ~>examples/image.srec
2683 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2685 15989 15990 15991 15992
2686 [file transfer complete]
2688 ## Start Addr = 0x00000000
2691 You can check the success of the download using the 'iminfo' command;
2692 this includes a checksum verification so you can be sure no data
2693 corruption happened:
2697 ## Checking Image at 40100000 ...
2698 Image Name: 2.2.13 for initrd on TQM850L
2699 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2700 Data Size: 335725 Bytes = 327 kB = 0 MB
2701 Load Address: 00000000
2702 Entry Point: 0000000c
2703 Verifying Checksum ... OK
2709 The "bootm" command is used to boot an application that is stored in
2710 memory (RAM or Flash). In case of a Linux kernel image, the contents
2711 of the "bootargs" environment variable is passed to the kernel as
2712 parameters. You can check and modify this variable using the
2713 "printenv" and "setenv" commands:
2716 => printenv bootargs
2717 bootargs=root=/dev/ram
2719 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2721 => printenv bootargs
2722 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2725 ## Booting Linux kernel at 40020000 ...
2726 Image Name: 2.2.13 for NFS on TQM850L
2727 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2728 Data Size: 381681 Bytes = 372 kB = 0 MB
2729 Load Address: 00000000
2730 Entry Point: 0000000c
2731 Verifying Checksum ... OK
2732 Uncompressing Kernel Image ... OK
2733 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
2734 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2735 time_init: decrementer frequency = 187500000/60
2736 Calibrating delay loop... 49.77 BogoMIPS
2737 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2740 If you want to boot a Linux kernel with initial ram disk, you pass
2741 the memory addresses of both the kernel and the initrd image (PPBCOOT
2742 format!) to the "bootm" command:
2744 => imi 40100000 40200000
2746 ## Checking Image at 40100000 ...
2747 Image Name: 2.2.13 for initrd on TQM850L
2748 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2749 Data Size: 335725 Bytes = 327 kB = 0 MB
2750 Load Address: 00000000
2751 Entry Point: 0000000c
2752 Verifying Checksum ... OK
2754 ## Checking Image at 40200000 ...
2755 Image Name: Simple Ramdisk Image
2756 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2757 Data Size: 566530 Bytes = 553 kB = 0 MB
2758 Load Address: 00000000
2759 Entry Point: 00000000
2760 Verifying Checksum ... OK
2762 => bootm 40100000 40200000
2763 ## Booting Linux kernel at 40100000 ...
2764 Image Name: 2.2.13 for initrd on TQM850L
2765 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2766 Data Size: 335725 Bytes = 327 kB = 0 MB
2767 Load Address: 00000000
2768 Entry Point: 0000000c
2769 Verifying Checksum ... OK
2770 Uncompressing Kernel Image ... OK
2771 ## Loading RAMDisk Image at 40200000 ...
2772 Image Name: Simple Ramdisk Image
2773 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2774 Data Size: 566530 Bytes = 553 kB = 0 MB
2775 Load Address: 00000000
2776 Entry Point: 00000000
2777 Verifying Checksum ... OK
2778 Loading Ramdisk ... OK
2779 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
2780 Boot arguments: root=/dev/ram
2781 time_init: decrementer frequency = 187500000/60
2782 Calibrating delay loop... 49.77 BogoMIPS
2784 RAMDISK: Compressed image found at block 0
2785 VFS: Mounted root (ext2 filesystem).
2789 More About U-Boot Image Types:
2790 ------------------------------
2792 U-Boot supports the following image types:
2794 "Standalone Programs" are directly runnable in the environment
2795 provided by U-Boot; it is expected that (if they behave
2796 well) you can continue to work in U-Boot after return from
2797 the Standalone Program.
2798 "OS Kernel Images" are usually images of some Embedded OS which
2799 will take over control completely. Usually these programs
2800 will install their own set of exception handlers, device
2801 drivers, set up the MMU, etc. - this means, that you cannot
2802 expect to re-enter U-Boot except by resetting the CPU.
2803 "RAMDisk Images" are more or less just data blocks, and their
2804 parameters (address, size) are passed to an OS kernel that is
2806 "Multi-File Images" contain several images, typically an OS
2807 (Linux) kernel image and one or more data images like
2808 RAMDisks. This construct is useful for instance when you want
2809 to boot over the network using BOOTP etc., where the boot
2810 server provides just a single image file, but you want to get
2811 for instance an OS kernel and a RAMDisk image.
2813 "Multi-File Images" start with a list of image sizes, each
2814 image size (in bytes) specified by an "uint32_t" in network
2815 byte order. This list is terminated by an "(uint32_t)0".
2816 Immediately after the terminating 0 follow the images, one by
2817 one, all aligned on "uint32_t" boundaries (size rounded up to
2818 a multiple of 4 bytes).
2820 "Firmware Images" are binary images containing firmware (like
2821 U-Boot or FPGA images) which usually will be programmed to
2824 "Script files" are command sequences that will be executed by
2825 U-Boot's command interpreter; this feature is especially
2826 useful when you configure U-Boot to use a real shell (hush)
2827 as command interpreter.
2833 One of the features of U-Boot is that you can dynamically load and
2834 run "standalone" applications, which can use some resources of
2835 U-Boot like console I/O functions or interrupt services.
2837 Two simple examples are included with the sources:
2842 'examples/hello_world.c' contains a small "Hello World" Demo
2843 application; it is automatically compiled when you build U-Boot.
2844 It's configured to run at address 0x00040004, so you can play with it
2848 ## Ready for S-Record download ...
2849 ~>examples/hello_world.srec
2850 1 2 3 4 5 6 7 8 9 10 11 ...
2851 [file transfer complete]
2853 ## Start Addr = 0x00040004
2855 => go 40004 Hello World! This is a test.
2856 ## Starting application at 0x00040004 ...
2867 Hit any key to exit ...
2869 ## Application terminated, rc = 0x0
2871 Another example, which demonstrates how to register a CPM interrupt
2872 handler with the U-Boot code, can be found in 'examples/timer.c'.
2873 Here, a CPM timer is set up to generate an interrupt every second.
2874 The interrupt service routine is trivial, just printing a '.'
2875 character, but this is just a demo program. The application can be
2876 controlled by the following keys:
2878 ? - print current values og the CPM Timer registers
2879 b - enable interrupts and start timer
2880 e - stop timer and disable interrupts
2881 q - quit application
2884 ## Ready for S-Record download ...
2885 ~>examples/timer.srec
2886 1 2 3 4 5 6 7 8 9 10 11 ...
2887 [file transfer complete]
2889 ## Start Addr = 0x00040004
2892 ## Starting application at 0x00040004 ...
2895 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
2898 [q, b, e, ?] Set interval 1000000 us
2901 [q, b, e, ?] ........
2902 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
2905 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
2908 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
2911 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
2913 [q, b, e, ?] ...Stopping timer
2915 [q, b, e, ?] ## Application terminated, rc = 0x0
2921 Over time, many people have reported problems when trying to use the
2922 "minicom" terminal emulation program for serial download. I (wd)
2923 consider minicom to be broken, and recommend not to use it. Under
2924 Unix, I recommend to use C-Kermit for general purpose use (and
2925 especially for kermit binary protocol download ("loadb" command), and
2926 use "cu" for S-Record download ("loads" command).
2928 Nevertheless, if you absolutely want to use it try adding this
2929 configuration to your "File transfer protocols" section:
2931 Name Program Name U/D FullScr IO-Red. Multi
2932 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
2933 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
2939 Starting at version 0.9.2, U-Boot supports NetBSD both as host
2940 (build U-Boot) and target system (boots NetBSD/mpc8xx).
2942 Building requires a cross environment; it is known to work on
2943 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
2944 need gmake since the Makefiles are not compatible with BSD make).
2945 Note that the cross-powerpc package does not install include files;
2946 attempting to build U-Boot will fail because <machine/ansi.h> is
2947 missing. This file has to be installed and patched manually:
2949 # cd /usr/pkg/cross/powerpc-netbsd/include
2951 # ln -s powerpc machine
2952 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
2953 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
2955 Native builds *don't* work due to incompatibilities between native
2956 and U-Boot include files.
2958 Booting assumes that (the first part of) the image booted is a
2959 stage-2 loader which in turn loads and then invokes the kernel
2960 proper. Loader sources will eventually appear in the NetBSD source
2961 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
2962 meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for
2966 Implementation Internals:
2967 =========================
2969 The following is not intended to be a complete description of every
2970 implementation detail. However, it should help to understand the
2971 inner workings of U-Boot and make it easier to port it to custom
2975 Initial Stack, Global Data:
2976 ---------------------------
2978 The implementation of U-Boot is complicated by the fact that U-Boot
2979 starts running out of ROM (flash memory), usually without access to
2980 system RAM (because the memory controller is not initialized yet).
2981 This means that we don't have writable Data or BSS segments, and BSS
2982 is not initialized as zero. To be able to get a C environment working
2983 at all, we have to allocate at least a minimal stack. Implementation
2984 options for this are defined and restricted by the CPU used: Some CPU
2985 models provide on-chip memory (like the IMMR area on MPC8xx and
2986 MPC826x processors), on others (parts of) the data cache can be
2987 locked as (mis-) used as memory, etc.
2989 Chris Hallinan posted a good summary of these issues to the
2990 u-boot-users mailing list:
2992 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
2993 From: "Chris Hallinan" <clh@net1plus.com>
2994 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
2997 Correct me if I'm wrong, folks, but the way I understand it
2998 is this: Using DCACHE as initial RAM for Stack, etc, does not
2999 require any physical RAM backing up the cache. The cleverness
3000 is that the cache is being used as a temporary supply of
3001 necessary storage before the SDRAM controller is setup. It's
3002 beyond the scope of this list to expain the details, but you
3003 can see how this works by studying the cache architecture and
3004 operation in the architecture and processor-specific manuals.
3006 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3007 is another option for the system designer to use as an
3008 initial stack/ram area prior to SDRAM being available. Either
3009 option should work for you. Using CS 4 should be fine if your
3010 board designers haven't used it for something that would
3011 cause you grief during the initial boot! It is frequently not
3014 CFG_INIT_RAM_ADDR should be somewhere that won't interfere
3015 with your processor/board/system design. The default value
3016 you will find in any recent u-boot distribution in
3017 Walnut405.h should work for you. I'd set it to a value larger
3018 than your SDRAM module. If you have a 64MB SDRAM module, set
3019 it above 400_0000. Just make sure your board has no resources
3020 that are supposed to respond to that address! That code in
3021 start.S has been around a while and should work as is when
3022 you get the config right.
3027 It is essential to remember this, since it has some impact on the C
3028 code for the initialization procedures:
3030 * Initialized global data (data segment) is read-only. Do not attempt
3033 * Do not use any unitialized global data (or implicitely initialized
3034 as zero data - BSS segment) at all - this is undefined, initiali-
3035 zation is performed later (when relocating to RAM).
3037 * Stack space is very limited. Avoid big data buffers or things like
3040 Having only the stack as writable memory limits means we cannot use
3041 normal global data to share information beween the code. But it
3042 turned out that the implementation of U-Boot can be greatly
3043 simplified by making a global data structure (gd_t) available to all
3044 functions. We could pass a pointer to this data as argument to _all_
3045 functions, but this would bloat the code. Instead we use a feature of
3046 the GCC compiler (Global Register Variables) to share the data: we
3047 place a pointer (gd) to the global data into a register which we
3048 reserve for this purpose.
3050 When choosing a register for such a purpose we are restricted by the
3051 relevant (E)ABI specifications for the current architecture, and by
3052 GCC's implementation.
3054 For PowerPC, the following registers have specific use:
3057 R3-R4: parameter passing and return values
3058 R5-R10: parameter passing
3059 R13: small data area pointer
3063 (U-Boot also uses R14 as internal GOT pointer.)
3065 ==> U-Boot will use R29 to hold a pointer to the global data
3067 Note: on PPC, we could use a static initializer (since the
3068 address of the global data structure is known at compile time),
3069 but it turned out that reserving a register results in somewhat
3070 smaller code - although the code savings are not that big (on
3071 average for all boards 752 bytes for the whole U-Boot image,
3072 624 text + 127 data).
3074 On ARM, the following registers are used:
3076 R0: function argument word/integer result
3077 R1-R3: function argument word
3079 R10: stack limit (used only if stack checking if enabled)
3080 R11: argument (frame) pointer
3081 R12: temporary workspace
3084 R15: program counter
3086 ==> U-Boot will use R8 to hold a pointer to the global data
3092 U-Boot runs in system state and uses physical addresses, i.e. the
3093 MMU is not used either for address mapping nor for memory protection.
3095 The available memory is mapped to fixed addresses using the memory
3096 controller. In this process, a contiguous block is formed for each
3097 memory type (Flash, SDRAM, SRAM), even when it consists of several
3098 physical memory banks.
3100 U-Boot is installed in the first 128 kB of the first Flash bank (on
3101 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3102 booting and sizing and initializing DRAM, the code relocates itself
3103 to the upper end of DRAM. Immediately below the U-Boot code some
3104 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
3105 configuration setting]. Below that, a structure with global Board
3106 Info data is placed, followed by the stack (growing downward).
3108 Additionally, some exception handler code is copied to the low 8 kB
3109 of DRAM (0x00000000 ... 0x00001FFF).
3111 So a typical memory configuration with 16 MB of DRAM could look like
3114 0x0000 0000 Exception Vector code
3117 0x0000 2000 Free for Application Use
3123 0x00FB FF20 Monitor Stack (Growing downward)
3124 0x00FB FFAC Board Info Data and permanent copy of global data
3125 0x00FC 0000 Malloc Arena
3128 0x00FE 0000 RAM Copy of Monitor Code
3129 ... eventually: LCD or video framebuffer
3130 ... eventually: pRAM (Protected RAM - unchanged by reset)
3131 0x00FF FFFF [End of RAM]
3134 System Initialization:
3135 ----------------------
3137 In the reset configuration, U-Boot starts at the reset entry point
3138 (on most PowerPC systens at address 0x00000100). Because of the reset
3139 configuration for CS0# this is a mirror of the onboard Flash memory.
3140 To be able to re-map memory U-Boot then jumps to its link address.
3141 To be able to implement the initialization code in C, a (small!)
3142 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3143 which provide such a feature like MPC8xx or MPC8260), or in a locked
3144 part of the data cache. After that, U-Boot initializes the CPU core,
3145 the caches and the SIU.
3147 Next, all (potentially) available memory banks are mapped using a
3148 preliminary mapping. For example, we put them on 512 MB boundaries
3149 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3150 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3151 programmed for SDRAM access. Using the temporary configuration, a
3152 simple memory test is run that determines the size of the SDRAM
3155 When there is more than one SDRAM bank, and the banks are of
3156 different size, the largest is mapped first. For equal size, the first
3157 bank (CS2#) is mapped first. The first mapping is always for address
3158 0x00000000, with any additional banks following immediately to create
3159 contiguous memory starting from 0.
3161 Then, the monitor installs itself at the upper end of the SDRAM area
3162 and allocates memory for use by malloc() and for the global Board
3163 Info data; also, the exception vector code is copied to the low RAM
3164 pages, and the final stack is set up.
3166 Only after this relocation will you have a "normal" C environment;
3167 until that you are restricted in several ways, mostly because you are
3168 running from ROM, and because the code will have to be relocated to a
3172 U-Boot Porting Guide:
3173 ----------------------
3175 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3179 int main (int argc, char *argv[])
3181 sighandler_t no_more_time;
3183 signal (SIGALRM, no_more_time);
3184 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3186 if (available_money > available_manpower) {
3187 pay consultant to port U-Boot;
3191 Download latest U-Boot source;
3193 Subscribe to u-boot-users mailing list;
3196 email ("Hi, I am new to U-Boot, how do I get started?");
3200 Read the README file in the top level directory;
3201 Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
3202 Read the source, Luke;
3205 if (available_money > toLocalCurrency ($2500)) {
3208 Add a lot of aggravation and time;
3211 Create your own board support subdirectory;
3213 Create your own board config file;
3217 Add / modify source code;
3221 email ("Hi, I am having problems...");
3223 Send patch file to Wolfgang;
3228 void no_more_time (int sig)
3237 All contributions to U-Boot should conform to the Linux kernel
3238 coding style; see the file "Documentation/CodingStyle" in your Linux
3239 kernel source directory.
3241 Please note that U-Boot is implemented in C (and to some small parts
3242 in Assembler); no C++ is used, so please do not use C++ style
3243 comments (//) in your code.
3245 Please also stick to the following formatting rules:
3246 - remove any trailing white space
3247 - use TAB characters for indentation, not spaces
3248 - make sure NOT to use DOS '\r\n' line feeds
3249 - do not add more than 2 empty lines to source files
3250 - do not add trailing empty lines to source files
3252 Submissions which do not conform to the standards may be returned
3253 with a request to reformat the changes.
3259 Since the number of patches for U-Boot is growing, we need to
3260 establish some rules. Submissions which do not conform to these rules
3261 may be rejected, even when they contain important and valuable stuff.
3264 When you send a patch, please include the following information with
3267 * For bug fixes: a description of the bug and how your patch fixes
3268 this bug. Please try to include a way of demonstrating that the
3269 patch actually fixes something.
3271 * For new features: a description of the feature and your
3274 * A CHANGELOG entry as plaintext (separate from the patch)
3276 * For major contributions, your entry to the CREDITS file
3278 * When you add support for a new board, don't forget to add this
3279 board to the MAKEALL script, too.
3281 * If your patch adds new configuration options, don't forget to
3282 document these in the README file.
3284 * The patch itself. If you are accessing the CVS repository use "cvs
3285 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
3286 version of diff does not support these options, then get the latest
3287 version of GNU diff.
3289 The current directory when running this command shall be the top
3290 level directory of the U-Boot source tree, or it's parent directory
3291 (i. e. please make sure that your patch includes sufficient
3292 directory information for the affected files).
3294 We accept patches as plain text, MIME attachments or as uuencoded
3297 * If one logical set of modifications affects or creates several
3298 files, all these changes shall be submitted in a SINGLE patch file.
3300 * Changesets that contain different, unrelated modifications shall be
3301 submitted as SEPARATE patches, one patch per changeset.
3306 * Before sending the patch, run the MAKEALL script on your patched
3307 source tree and make sure that no errors or warnings are reported
3308 for any of the boards.
3310 * Keep your modifications to the necessary minimum: A patch
3311 containing several unrelated changes or arbitrary reformats will be
3312 returned with a request to re-formatting / split it.
3314 * If you modify existing code, make sure that your new code does not
3315 add to the memory footprint of the code ;-) Small is beautiful!
3316 When adding new features, these should compile conditionally only
3317 (using #ifdef), and the resulting code with the new feature
3318 disabled must not need more memory than the old code without your
projects / platform / kernel / u-boot.git / blob