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_OSK_OMAP5912, CONFIG_SHANNON,
298 CONFIG_P2_OMAP730, CONFIG_SMDK2400, CONFIG_SMDK2410,
299 CONFIG_TRAB, CONFIG_VCMA9
301 MicroBlaze based boards:
302 ------------------------
307 - CPU Module Type: (if CONFIG_COGENT is defined)
308 Define exactly one of
310 --- FIXME --- not tested yet:
311 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
312 CONFIG_CMA287_23, CONFIG_CMA287_50
314 - Motherboard Type: (if CONFIG_COGENT is defined)
315 Define exactly one of
316 CONFIG_CMA101, CONFIG_CMA102
318 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
319 Define one or more of
322 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
323 Define one or more of
324 CONFIG_LCD_HEARTBEAT - update a character position on
325 the lcd display every second with
328 - Board flavour: (if CONFIG_MPC8260ADS is defined)
331 CFG_8260ADS - original MPC8260ADS
332 CFG_8266ADS - MPC8266ADS
333 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
334 CFG_8272ADS - MPC8272ADS
336 - MPC824X Family Member (if CONFIG_MPC824X is defined)
337 Define exactly one of
338 CONFIG_MPC8240, CONFIG_MPC8245
340 - 8xx CPU Options: (if using an MPC8xx cpu)
341 Define one or more of
342 CONFIG_8xx_GCLK_FREQ - if get_gclk_freq() cannot work
343 e.g. if there is no 32KHz
344 reference PIT/RTC clock
346 - 859/866 CPU options: (if using a MPC859 or MPC866 CPU):
350 CFG_866_CPUCLK_DEFAULT
351 See doc/README.MPC866
355 Define this to measure the actual CPU clock instead
356 of relying on the correctness of the configured
357 values. Mostly useful for board bringup to make sure
358 the PLL is locked at the intended frequency. Note
359 that this requires a (stable) reference clock (32 kHz
362 - Linux Kernel Interface:
365 U-Boot stores all clock information in Hz
366 internally. For binary compatibility with older Linux
367 kernels (which expect the clocks passed in the
368 bd_info data to be in MHz) the environment variable
369 "clocks_in_mhz" can be defined so that U-Boot
370 converts clock data to MHZ before passing it to the
372 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
373 "clocks_in_mhz=1" is automatically included in the
376 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
378 When transfering memsize parameter to linux, some versions
379 expect it to be in bytes, others in MB.
380 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
383 Depending on board, define exactly one serial port
384 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
385 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
386 console by defining CONFIG_8xx_CONS_NONE
388 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
389 port routines must be defined elsewhere
390 (i.e. serial_init(), serial_getc(), ...)
393 Enables console device for a color framebuffer. Needs following
394 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
395 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
397 VIDEO_HW_RECTFILL graphic chip supports
400 VIDEO_HW_BITBLT graphic chip supports
401 bit-blit (cf. smiLynxEM)
402 VIDEO_VISIBLE_COLS visible pixel columns
404 VIDEO_VISIBLE_ROWS visible pixel rows
405 VIDEO_PIXEL_SIZE bytes per pixel
406 VIDEO_DATA_FORMAT graphic data format
407 (0-5, cf. cfb_console.c)
408 VIDEO_FB_ADRS framebuffer address
409 VIDEO_KBD_INIT_FCT keyboard int fct
410 (i.e. i8042_kbd_init())
411 VIDEO_TSTC_FCT test char fct
413 VIDEO_GETC_FCT get char fct
415 CONFIG_CONSOLE_CURSOR cursor drawing on/off
416 (requires blink timer
418 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
419 CONFIG_CONSOLE_TIME display time/date info in
421 (requires CFG_CMD_DATE)
422 CONFIG_VIDEO_LOGO display Linux logo in
424 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
425 linux_logo.h for logo.
426 Requires CONFIG_VIDEO_LOGO
427 CONFIG_CONSOLE_EXTRA_INFO
428 addional board info beside
431 When CONFIG_CFB_CONSOLE is defined, video console is
432 default i/o. Serial console can be forced with
433 environment 'console=serial'.
435 When CONFIG_SILENT_CONSOLE is defined, all console
436 messages (by U-Boot and Linux!) can be silenced with
437 the "silent" environment variable. See
438 doc/README.silent for more information.
441 CONFIG_BAUDRATE - in bps
442 Select one of the baudrates listed in
443 CFG_BAUDRATE_TABLE, see below.
444 CFG_BRGCLK_PRESCALE, baudrate prescale
446 - Interrupt driven serial port input:
447 CONFIG_SERIAL_SOFTWARE_FIFO
450 Use an interrupt handler for receiving data on the
451 serial port. It also enables using hardware handshake
452 (RTS/CTS) and UART's built-in FIFO. Set the number of
453 bytes the interrupt driven input buffer should have.
455 Leave undefined to disable this feature, including
456 disable the buffer and hardware handshake.
458 - Console UART Number:
462 If defined internal UART1 (and not UART0) is used
463 as default U-Boot console.
465 - Boot Delay: CONFIG_BOOTDELAY - in seconds
466 Delay before automatically booting the default image;
467 set to -1 to disable autoboot.
469 See doc/README.autoboot for these options that
470 work with CONFIG_BOOTDELAY. None are required.
471 CONFIG_BOOT_RETRY_TIME
472 CONFIG_BOOT_RETRY_MIN
473 CONFIG_AUTOBOOT_KEYED
474 CONFIG_AUTOBOOT_PROMPT
475 CONFIG_AUTOBOOT_DELAY_STR
476 CONFIG_AUTOBOOT_STOP_STR
477 CONFIG_AUTOBOOT_DELAY_STR2
478 CONFIG_AUTOBOOT_STOP_STR2
479 CONFIG_ZERO_BOOTDELAY_CHECK
480 CONFIG_RESET_TO_RETRY
484 Only needed when CONFIG_BOOTDELAY is enabled;
485 define a command string that is automatically executed
486 when no character is read on the console interface
487 within "Boot Delay" after reset.
490 This can be used to pass arguments to the bootm
491 command. The value of CONFIG_BOOTARGS goes into the
492 environment value "bootargs".
494 CONFIG_RAMBOOT and CONFIG_NFSBOOT
495 The value of these goes into the environment as
496 "ramboot" and "nfsboot" respectively, and can be used
497 as a convenience, when switching between booting from
503 When this option is #defined, the existence of the
504 environment variable "preboot" will be checked
505 immediately before starting the CONFIG_BOOTDELAY
506 countdown and/or running the auto-boot command resp.
507 entering interactive mode.
509 This feature is especially useful when "preboot" is
510 automatically generated or modified. For an example
511 see the LWMON board specific code: here "preboot" is
512 modified when the user holds down a certain
513 combination of keys on the (special) keyboard when
516 - Serial Download Echo Mode:
518 If defined to 1, all characters received during a
519 serial download (using the "loads" command) are
520 echoed back. This might be needed by some terminal
521 emulations (like "cu"), but may as well just take
522 time on others. This setting #define's the initial
523 value of the "loads_echo" environment variable.
525 - Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
527 Select one of the baudrates listed in
528 CFG_BAUDRATE_TABLE, see below.
532 Most monitor functions can be selected (or
533 de-selected) by adjusting the definition of
534 CONFIG_COMMANDS; to select individual functions,
535 #define CONFIG_COMMANDS by "OR"ing any of the
538 #define enables commands:
539 -------------------------
540 CFG_CMD_ASKENV * ask for env variable
541 CFG_CMD_AUTOSCRIPT Autoscript Support
543 CFG_CMD_BEDBUG Include BedBug Debugger
544 CFG_CMD_BMP * BMP support
546 CFG_CMD_CACHE icache, dcache
547 CFG_CMD_CONSOLE coninfo
548 CFG_CMD_DATE * support for RTC, date/time...
549 CFG_CMD_DHCP DHCP support
550 CFG_CMD_DIAG * Diagnostics
551 CFG_CMD_DOC * Disk-On-Chip Support
552 CFG_CMD_DTT Digital Therm and Thermostat
553 CFG_CMD_ECHO * echo arguments
554 CFG_CMD_EEPROM * EEPROM read/write support
555 CFG_CMD_ELF bootelf, bootvx
557 CFG_CMD_FDC * Floppy Disk Support
558 CFG_CMD_FAT FAT partition support
559 CFG_CMD_FDOS * Dos diskette Support
560 CFG_CMD_FLASH flinfo, erase, protect
561 CFG_CMD_FPGA FPGA device initialization support
562 CFG_CMD_HWFLOW * RTS/CTS hw flow control
563 CFG_CMD_I2C * I2C serial bus support
564 CFG_CMD_IDE * IDE harddisk support
566 CFG_CMD_IMLS List all found images
567 CFG_CMD_IMMAP * IMMR dump support
568 CFG_CMD_IRQ * irqinfo
569 CFG_CMD_ITEST * Integer/string test of 2 values
570 CFG_CMD_JFFS2 * JFFS2 Support
574 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
576 CFG_CMD_MISC Misc functions like sleep etc
577 CFG_CMD_MMC MMC memory mapped support
578 CFG_CMD_MII MII utility commands
579 CFG_CMD_NAND * NAND support
580 CFG_CMD_NET bootp, tftpboot, rarpboot
581 CFG_CMD_PCI * pciinfo
582 CFG_CMD_PCMCIA * PCMCIA support
583 CFG_CMD_PING * send ICMP ECHO_REQUEST to network host
584 CFG_CMD_PORTIO * Port I/O
585 CFG_CMD_REGINFO * Register dump
586 CFG_CMD_RUN run command in env variable
587 CFG_CMD_SAVES save S record dump
588 CFG_CMD_SCSI * SCSI Support
589 CFG_CMD_SDRAM * print SDRAM configuration information
590 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
591 CFG_CMD_SPI * SPI serial bus support
592 CFG_CMD_USB * USB support
593 CFG_CMD_VFD * VFD support (TRAB)
594 CFG_CMD_BSP * Board SPecific functions
595 CFG_CMD_CDP * Cisco Discover Protocol support
596 -----------------------------------------------
599 CFG_CMD_DFL Default configuration; at the moment
600 this is includes all commands, except
601 the ones marked with "*" in the list
604 If you don't define CONFIG_COMMANDS it defaults to
605 CFG_CMD_DFL in include/cmd_confdefs.h. A board can
606 override the default settings in the respective
609 EXAMPLE: If you want all functions except of network
610 support you can write:
612 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
615 Note: Don't enable the "icache" and "dcache" commands
616 (configuration option CFG_CMD_CACHE) unless you know
617 what you (and your U-Boot users) are doing. Data
618 cache cannot be enabled on systems like the 8xx or
619 8260 (where accesses to the IMMR region must be
620 uncached), and it cannot be disabled on all other
621 systems where we (mis-) use the data cache to hold an
622 initial stack and some data.
625 XXX - this list needs to get updated!
629 If this variable is defined, it enables watchdog
630 support. There must be support in the platform specific
631 code for a watchdog. For the 8xx and 8260 CPUs, the
632 SIU Watchdog feature is enabled in the SYPCR
636 CONFIG_VERSION_VARIABLE
637 If this variable is defined, an environment variable
638 named "ver" is created by U-Boot showing the U-Boot
639 version as printed by the "version" command.
640 This variable is readonly.
644 When CFG_CMD_DATE is selected, the type of the RTC
645 has to be selected, too. Define exactly one of the
648 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
649 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
650 CONFIG_RTC_MC146818 - use MC146818 RTC
651 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
652 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
653 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
654 CONFIG_RTC_DS164x - use Dallas DS164x RTC
656 Note that if the RTC uses I2C, then the I2C interface
657 must also be configured. See I2C Support, below.
661 When CONFIG_TIMESTAMP is selected, the timestamp
662 (date and time) of an image is printed by image
663 commands like bootm or iminfo. This option is
664 automatically enabled when you select CFG_CMD_DATE .
667 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
668 and/or CONFIG_ISO_PARTITION
670 If IDE or SCSI support is enabled (CFG_CMD_IDE or
671 CFG_CMD_SCSI) you must configure support for at least
672 one partition type as well.
675 CONFIG_IDE_RESET_ROUTINE - this is defined in several
676 board configurations files but used nowhere!
678 CONFIG_IDE_RESET - is this is defined, IDE Reset will
679 be performed by calling the function
680 ide_set_reset(int reset)
681 which has to be defined in a board specific file
686 Set this to enable ATAPI support.
691 Set this to enable support for disks larger than 137GB
692 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL
693 Whithout these , LBA48 support uses 32bit variables and will 'only'
694 support disks up to 2.1TB.
697 When enabled, makes the IDE subsystem use 64bit sector addresses.
701 At the moment only there is only support for the
702 SYM53C8XX SCSI controller; define
703 CONFIG_SCSI_SYM53C8XX to enable it.
705 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
706 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
707 CFG_SCSI_MAX_LUN] can be adjusted to define the
708 maximum numbers of LUNs, SCSI ID's and target
710 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
712 - NETWORK Support (PCI):
714 Support for Intel 8254x gigabit chips.
717 Support for Intel 82557/82559/82559ER chips.
718 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
719 write routine for first time initialisation.
722 Support for Digital 2114x chips.
723 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
724 modem chip initialisation (KS8761/QS6611).
727 Support for National dp83815 chips.
730 Support for National dp8382[01] gigabit chips.
732 - NETWORK Support (other):
734 CONFIG_DRIVER_LAN91C96
735 Support for SMSC's LAN91C96 chips.
738 Define this to hold the physical address
739 of the LAN91C96's I/O space
741 CONFIG_LAN91C96_USE_32_BIT
742 Define this to enable 32 bit addressing
745 At the moment only the UHCI host controller is
746 supported (PIP405, MIP405, MPC5200); define
747 CONFIG_USB_UHCI to enable it.
748 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
749 end define CONFIG_USB_STORAGE to enable the USB
752 Supported are USB Keyboards and USB Floppy drives
754 MPC5200 USB requires additional defines:
756 for 528 MHz Clock: 0x0001bbbb
758 for differential drivers: 0x00001000
759 for single ended drivers: 0x00005000
763 The MMC controller on the Intel PXA is supported. To
764 enable this define CONFIG_MMC. The MMC can be
765 accessed from the boot prompt by mapping the device
766 to physical memory similar to flash. Command line is
767 enabled with CFG_CMD_MMC. The MMC driver also works with
768 the FAT fs. This is enabled with CFG_CMD_FAT.
773 Define this to enable standard (PC-Style) keyboard
777 Standard PC keyboard driver with US (is default) and
778 GERMAN key layout (switch via environment 'keymap=de') support.
779 Export function i8042_kbd_init, i8042_tstc and i8042_getc
780 for cfb_console. Supports cursor blinking.
785 Define this to enable video support (for output to
790 Enable Chips & Technologies 69000 Video chip
792 CONFIG_VIDEO_SMI_LYNXEM
793 Enable Silicon Motion SMI 712/710/810 Video chip. The
794 video output is selected via environment 'videoout'
795 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
798 For the CT69000 and SMI_LYNXEM drivers, videomode is
799 selected via environment 'videomode'. Two diferent ways
801 - "videomode=num" 'num' is a standard LiLo mode numbers.
802 Following standard modes are supported (* is default):
804 Colors 640x480 800x600 1024x768 1152x864 1280x1024
805 -------------+---------------------------------------------
806 8 bits | 0x301* 0x303 0x305 0x161 0x307
807 15 bits | 0x310 0x313 0x316 0x162 0x319
808 16 bits | 0x311 0x314 0x317 0x163 0x31A
809 24 bits | 0x312 0x315 0x318 ? 0x31B
810 -------------+---------------------------------------------
811 (i.e. setenv videomode 317; saveenv; reset;)
813 - "videomode=bootargs" all the video parameters are parsed
814 from the bootargs. (See drivers/videomodes.c)
817 CONFIG_VIDEO_SED13806
818 Enable Epson SED13806 driver. This driver supports 8bpp
819 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
820 or CONFIG_VIDEO_SED13806_16BPP
825 Define this to enable a custom keyboard support.
826 This simply calls drv_keyboard_init() which must be
827 defined in your board-specific files.
828 The only board using this so far is RBC823.
830 - LCD Support: CONFIG_LCD
832 Define this to enable LCD support (for output to LCD
833 display); also select one of the supported displays
834 by defining one of these:
836 CONFIG_NEC_NL6448AC33:
838 NEC NL6448AC33-18. Active, color, single scan.
840 CONFIG_NEC_NL6448BC20
842 NEC NL6448BC20-08. 6.5", 640x480.
843 Active, color, single scan.
845 CONFIG_NEC_NL6448BC33_54
847 NEC NL6448BC33-54. 10.4", 640x480.
848 Active, color, single scan.
852 Sharp 320x240. Active, color, single scan.
853 It isn't 16x9, and I am not sure what it is.
855 CONFIG_SHARP_LQ64D341
857 Sharp LQ64D341 display, 640x480.
858 Active, color, single scan.
862 HLD1045 display, 640x480.
863 Active, color, single scan.
867 Optrex CBL50840-2 NF-FW 99 22 M5
869 Hitachi LMG6912RPFC-00T
873 320x240. Black & white.
875 Normally display is black on white background; define
876 CFG_WHITE_ON_BLACK to get it inverted.
878 - Splash Screen Support: CONFIG_SPLASH_SCREEN
880 If this option is set, the environment is checked for
881 a variable "splashimage". If found, the usual display
882 of logo, copyright and system information on the LCD
883 is supressed and the BMP image at the address
884 specified in "splashimage" is loaded instead. The
885 console is redirected to the "nulldev", too. This
886 allows for a "silent" boot where a splash screen is
887 loaded very quickly after power-on.
889 - Compression support:
892 If this option is set, support for bzip2 compressed
893 images is included. If not, only uncompressed and gzip
894 compressed images are supported.
896 NOTE: the bzip2 algorithm requires a lot of RAM, so
897 the malloc area (as defined by CFG_MALLOC_LEN) should
903 The address of PHY on MII bus.
905 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
907 The clock frequency of the MII bus
911 If this option is set, support for speed/duplex
912 detection of Gigabit PHY is included.
914 CONFIG_PHY_RESET_DELAY
916 Some PHY like Intel LXT971A need extra delay after
917 reset before any MII register access is possible.
918 For such PHY, set this option to the usec delay
919 required. (minimum 300usec for LXT971A)
921 CONFIG_PHY_CMD_DELAY (ppc4xx)
923 Some PHY like Intel LXT971A need extra delay after
924 command issued before MII status register can be read
931 Define a default value for ethernet address to use
932 for the respective ethernet interface, in case this
933 is not determined automatically.
938 Define a default value for the IP address to use for
939 the default ethernet interface, in case this is not
940 determined through e.g. bootp.
945 Defines a default value for theIP address of a TFTP
946 server to contact when using the "tftboot" command.
948 - BOOTP Recovery Mode:
949 CONFIG_BOOTP_RANDOM_DELAY
951 If you have many targets in a network that try to
952 boot using BOOTP, you may want to avoid that all
953 systems send out BOOTP requests at precisely the same
954 moment (which would happen for instance at recovery
955 from a power failure, when all systems will try to
956 boot, thus flooding the BOOTP server. Defining
957 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
958 inserted before sending out BOOTP requests. The
959 following delays are insterted then:
961 1st BOOTP request: delay 0 ... 1 sec
962 2nd BOOTP request: delay 0 ... 2 sec
963 3rd BOOTP request: delay 0 ... 4 sec
965 BOOTP requests: delay 0 ... 8 sec
967 - DHCP Advanced Options:
970 You can fine tune the DHCP functionality by adding
971 these flags to the CONFIG_BOOTP_MASK define:
973 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
974 serverip from a DHCP server, it is possible that more
975 than one DNS serverip is offered to the client.
976 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
977 serverip will be stored in the additional environment
978 variable "dnsip2". The first DNS serverip is always
979 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
980 is added to the CONFIG_BOOTP_MASK.
982 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
983 to do a dynamic update of a DNS server. To do this, they
984 need the hostname of the DHCP requester.
985 If CONFIG_BOOP_SEND_HOSTNAME is added to the
986 CONFIG_BOOTP_MASK, the content of the "hostname"
987 environment variable is passed as option 12 to
993 The device id used in CDP trigger frames.
995 CONFIG_CDP_DEVICE_ID_PREFIX
997 A two character string which is prefixed to the MAC address
1002 A printf format string which contains the ascii name of
1003 the port. Normally is set to "eth%d" which sets
1004 eth0 for the first ethernet, eth1 for the second etc.
1006 CONFIG_CDP_CAPABILITIES
1008 A 32bit integer which indicates the device capabilities;
1009 0x00000010 for a normal host which does not forwards.
1013 An ascii string containing the version of the software.
1017 An ascii string containing the name of the platform.
1021 A 32bit integer sent on the trigger.
1023 CONFIG_CDP_POWER_CONSUMPTION
1025 A 16bit integer containing the power consumption of the
1026 device in .1 of milliwatts.
1028 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1030 A byte containing the id of the VLAN.
1032 - Status LED: CONFIG_STATUS_LED
1034 Several configurations allow to display the current
1035 status using a LED. For instance, the LED will blink
1036 fast while running U-Boot code, stop blinking as
1037 soon as a reply to a BOOTP request was received, and
1038 start blinking slow once the Linux kernel is running
1039 (supported by a status LED driver in the Linux
1040 kernel). Defining CONFIG_STATUS_LED enables this
1043 - CAN Support: CONFIG_CAN_DRIVER
1045 Defining CONFIG_CAN_DRIVER enables CAN driver support
1046 on those systems that support this (optional)
1047 feature, like the TQM8xxL modules.
1049 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1051 These enable I2C serial bus commands. Defining either of
1052 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1053 include the appropriate I2C driver for the selected cpu.
1055 This will allow you to use i2c commands at the u-boot
1056 command line (as long as you set CFG_CMD_I2C in
1057 CONFIG_COMMANDS) and communicate with i2c based realtime
1058 clock chips. See common/cmd_i2c.c for a description of the
1059 command line interface.
1061 CONFIG_HARD_I2C selects the CPM hardware driver for I2C.
1063 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1064 bit-banging) driver instead of CPM or similar hardware
1067 There are several other quantities that must also be
1068 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1070 In both cases you will need to define CFG_I2C_SPEED
1071 to be the frequency (in Hz) at which you wish your i2c bus
1072 to run and CFG_I2C_SLAVE to be the address of this node (ie
1073 the cpu's i2c node address).
1075 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1076 sets the cpu up as a master node and so its address should
1077 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1078 p.16-473). So, set CFG_I2C_SLAVE to 0.
1080 That's all that's required for CONFIG_HARD_I2C.
1082 If you use the software i2c interface (CONFIG_SOFT_I2C)
1083 then the following macros need to be defined (examples are
1084 from include/configs/lwmon.h):
1088 (Optional). Any commands necessary to enable the I2C
1089 controller or configure ports.
1091 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1095 (Only for MPC8260 CPU). The I/O port to use (the code
1096 assumes both bits are on the same port). Valid values
1097 are 0..3 for ports A..D.
1101 The code necessary to make the I2C data line active
1102 (driven). If the data line is open collector, this
1105 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1109 The code necessary to make the I2C data line tri-stated
1110 (inactive). If the data line is open collector, this
1113 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1117 Code that returns TRUE if the I2C data line is high,
1120 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1124 If <bit> is TRUE, sets the I2C data line high. If it
1125 is FALSE, it clears it (low).
1127 eg: #define I2C_SDA(bit) \
1128 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1129 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1133 If <bit> is TRUE, sets the I2C clock line high. If it
1134 is FALSE, it clears it (low).
1136 eg: #define I2C_SCL(bit) \
1137 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1138 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1142 This delay is invoked four times per clock cycle so this
1143 controls the rate of data transfer. The data rate thus
1144 is 1 / (I2C_DELAY * 4). Often defined to be something
1147 #define I2C_DELAY udelay(2)
1151 When a board is reset during an i2c bus transfer
1152 chips might think that the current transfer is still
1153 in progress. On some boards it is possible to access
1154 the i2c SCLK line directly, either by using the
1155 processor pin as a GPIO or by having a second pin
1156 connected to the bus. If this option is defined a
1157 custom i2c_init_board() routine in boards/xxx/board.c
1158 is run early in the boot sequence.
1160 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1162 This option enables configuration of bi_iic_fast[] flags
1163 in u-boot bd_info structure based on u-boot environment
1164 variable "i2cfast". (see also i2cfast)
1166 - SPI Support: CONFIG_SPI
1168 Enables SPI driver (so far only tested with
1169 SPI EEPROM, also an instance works with Crystal A/D and
1170 D/As on the SACSng board)
1174 Enables extended (16-bit) SPI EEPROM addressing.
1175 (symmetrical to CONFIG_I2C_X)
1179 Enables a software (bit-bang) SPI driver rather than
1180 using hardware support. This is a general purpose
1181 driver that only requires three general I/O port pins
1182 (two outputs, one input) to function. If this is
1183 defined, the board configuration must define several
1184 SPI configuration items (port pins to use, etc). For
1185 an example, see include/configs/sacsng.h.
1187 - FPGA Support: CONFIG_FPGA_COUNT
1189 Specify the number of FPGA devices to support.
1193 Used to specify the types of FPGA devices. For example,
1194 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
1196 CFG_FPGA_PROG_FEEDBACK
1198 Enable printing of hash marks during FPGA configuration.
1202 Enable checks on FPGA configuration interface busy
1203 status by the configuration function. This option
1204 will require a board or device specific function to
1209 If defined, a function that provides delays in the FPGA
1210 configuration driver.
1212 CFG_FPGA_CHECK_CTRLC
1213 Allow Control-C to interrupt FPGA configuration
1215 CFG_FPGA_CHECK_ERROR
1217 Check for configuration errors during FPGA bitfile
1218 loading. For example, abort during Virtex II
1219 configuration if the INIT_B line goes low (which
1220 indicated a CRC error).
1224 Maximum time to wait for the INIT_B line to deassert
1225 after PROB_B has been deasserted during a Virtex II
1226 FPGA configuration sequence. The default time is 500
1231 Maximum time to wait for BUSY to deassert during
1232 Virtex II FPGA configuration. The default is 5 mS.
1234 CFG_FPGA_WAIT_CONFIG
1236 Time to wait after FPGA configuration. The default is
1239 - Configuration Management:
1242 If defined, this string will be added to the U-Boot
1243 version information (U_BOOT_VERSION)
1245 - Vendor Parameter Protection:
1247 U-Boot considers the values of the environment
1248 variables "serial#" (Board Serial Number) and
1249 "ethaddr" (Ethernet Address) to be parameters that
1250 are set once by the board vendor / manufacturer, and
1251 protects these variables from casual modification by
1252 the user. Once set, these variables are read-only,
1253 and write or delete attempts are rejected. You can
1254 change this behviour:
1256 If CONFIG_ENV_OVERWRITE is #defined in your config
1257 file, the write protection for vendor parameters is
1258 completely disabled. Anybody can change or delete
1261 Alternatively, if you #define _both_ CONFIG_ETHADDR
1262 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1263 ethernet address is installed in the environment,
1264 which can be changed exactly ONCE by the user. [The
1265 serial# is unaffected by this, i. e. it remains
1271 Define this variable to enable the reservation of
1272 "protected RAM", i. e. RAM which is not overwritten
1273 by U-Boot. Define CONFIG_PRAM to hold the number of
1274 kB you want to reserve for pRAM. You can overwrite
1275 this default value by defining an environment
1276 variable "pram" to the number of kB you want to
1277 reserve. Note that the board info structure will
1278 still show the full amount of RAM. If pRAM is
1279 reserved, a new environment variable "mem" will
1280 automatically be defined to hold the amount of
1281 remaining RAM in a form that can be passed as boot
1282 argument to Linux, for instance like that:
1284 setenv bootargs ... mem=\$(mem)
1287 This way you can tell Linux not to use this memory,
1288 either, which results in a memory region that will
1289 not be affected by reboots.
1291 *WARNING* If your board configuration uses automatic
1292 detection of the RAM size, you must make sure that
1293 this memory test is non-destructive. So far, the
1294 following board configurations are known to be
1297 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1298 HERMES, IP860, RPXlite, LWMON, LANTEC,
1299 PCU_E, FLAGADM, TQM8260
1304 Define this variable to stop the system in case of a
1305 fatal error, so that you have to reset it manually.
1306 This is probably NOT a good idea for an embedded
1307 system where you want to system to reboot
1308 automatically as fast as possible, but it may be
1309 useful during development since you can try to debug
1310 the conditions that lead to the situation.
1312 CONFIG_NET_RETRY_COUNT
1314 This variable defines the number of retries for
1315 network operations like ARP, RARP, TFTP, or BOOTP
1316 before giving up the operation. If not defined, a
1317 default value of 5 is used.
1319 - Command Interpreter:
1322 Enable auto completion of commands using TAB.
1326 Define this variable to enable the "hush" shell (from
1327 Busybox) as command line interpreter, thus enabling
1328 powerful command line syntax like
1329 if...then...else...fi conditionals or `&&' and '||'
1330 constructs ("shell scripts").
1332 If undefined, you get the old, much simpler behaviour
1333 with a somewhat smaller memory footprint.
1338 This defines the secondary prompt string, which is
1339 printed when the command interpreter needs more input
1340 to complete a command. Usually "> ".
1344 In the current implementation, the local variables
1345 space and global environment variables space are
1346 separated. Local variables are those you define by
1347 simply typing `name=value'. To access a local
1348 variable later on, you have write `$name' or
1349 `${name}'; to execute the contents of a variable
1350 directly type `$name' at the command prompt.
1352 Global environment variables are those you use
1353 setenv/printenv to work with. To run a command stored
1354 in such a variable, you need to use the run command,
1355 and you must not use the '$' sign to access them.
1357 To store commands and special characters in a
1358 variable, please use double quotation marks
1359 surrounding the whole text of the variable, instead
1360 of the backslashes before semicolons and special
1363 - Default Environment:
1364 CONFIG_EXTRA_ENV_SETTINGS
1366 Define this to contain any number of null terminated
1367 strings (variable = value pairs) that will be part of
1368 the default environment compiled into the boot image.
1370 For example, place something like this in your
1371 board's config file:
1373 #define CONFIG_EXTRA_ENV_SETTINGS \
1377 Warning: This method is based on knowledge about the
1378 internal format how the environment is stored by the
1379 U-Boot code. This is NOT an official, exported
1380 interface! Although it is unlikely that this format
1381 will change soon, there is no guarantee either.
1382 You better know what you are doing here.
1384 Note: overly (ab)use of the default environment is
1385 discouraged. Make sure to check other ways to preset
1386 the environment like the autoscript function or the
1389 - DataFlash Support:
1390 CONFIG_HAS_DATAFLASH
1392 Defining this option enables DataFlash features and
1393 allows to read/write in Dataflash via the standard
1396 - SystemACE Support:
1399 Adding this option adds support for Xilinx SystemACE
1400 chips attached via some sort of local bus. The address
1401 of the chip must alsh be defined in the
1402 CFG_SYSTEMACE_BASE macro. For example:
1404 #define CONFIG_SYSTEMACE
1405 #define CFG_SYSTEMACE_BASE 0xf0000000
1407 When SystemACE support is added, the "ace" device type
1408 becomes available to the fat commands, i.e. fatls.
1410 - Show boot progress:
1411 CONFIG_SHOW_BOOT_PROGRESS
1413 Defining this option allows to add some board-
1414 specific code (calling a user-provided function
1415 "show_boot_progress(int)") that enables you to show
1416 the system's boot progress on some display (for
1417 example, some LED's) on your board. At the moment,
1418 the following checkpoints are implemented:
1421 1 common/cmd_bootm.c before attempting to boot an image
1422 -1 common/cmd_bootm.c Image header has bad magic number
1423 2 common/cmd_bootm.c Image header has correct magic number
1424 -2 common/cmd_bootm.c Image header has bad checksum
1425 3 common/cmd_bootm.c Image header has correct checksum
1426 -3 common/cmd_bootm.c Image data has bad checksum
1427 4 common/cmd_bootm.c Image data has correct checksum
1428 -4 common/cmd_bootm.c Image is for unsupported architecture
1429 5 common/cmd_bootm.c Architecture check OK
1430 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1431 6 common/cmd_bootm.c Image Type check OK
1432 -6 common/cmd_bootm.c gunzip uncompression error
1433 -7 common/cmd_bootm.c Unimplemented compression type
1434 7 common/cmd_bootm.c Uncompression OK
1435 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1436 8 common/cmd_bootm.c Image Type check OK
1437 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1438 9 common/cmd_bootm.c Start initial ramdisk verification
1439 -10 common/cmd_bootm.c Ramdisk header has bad magic number
1440 -11 common/cmd_bootm.c Ramdisk header has bad checksum
1441 10 common/cmd_bootm.c Ramdisk header is OK
1442 -12 common/cmd_bootm.c Ramdisk data has bad checksum
1443 11 common/cmd_bootm.c Ramdisk data has correct checksum
1444 12 common/cmd_bootm.c Ramdisk verification complete, start loading
1445 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk)
1446 13 common/cmd_bootm.c Start multifile image verification
1447 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue.
1448 15 common/cmd_bootm.c All preparation done, transferring control to OS
1450 -30 lib_ppc/board.c Fatal error, hang the system
1451 -31 post/post.c POST test failed, detected by post_output_backlog()
1452 -32 post/post.c POST test failed, detected by post_run_single()
1454 -1 common/cmd_doc.c Bad usage of "doc" command
1455 -1 common/cmd_doc.c No boot device
1456 -1 common/cmd_doc.c Unknown Chip ID on boot device
1457 -1 common/cmd_doc.c Read Error on boot device
1458 -1 common/cmd_doc.c Image header has bad magic number
1460 -1 common/cmd_ide.c Bad usage of "ide" command
1461 -1 common/cmd_ide.c No boot device
1462 -1 common/cmd_ide.c Unknown boot device
1463 -1 common/cmd_ide.c Unknown partition table
1464 -1 common/cmd_ide.c Invalid partition type
1465 -1 common/cmd_ide.c Read Error on boot device
1466 -1 common/cmd_ide.c Image header has bad magic number
1468 -1 common/cmd_nand.c Bad usage of "nand" command
1469 -1 common/cmd_nand.c No boot device
1470 -1 common/cmd_nand.c Unknown Chip ID on boot device
1471 -1 common/cmd_nand.c Read Error on boot device
1472 -1 common/cmd_nand.c Image header has bad magic number
1474 -1 common/env_common.c Environment has a bad CRC, using default
1480 [so far only for SMDK2400 and TRAB boards]
1482 - Modem support endable:
1483 CONFIG_MODEM_SUPPORT
1485 - RTS/CTS Flow control enable:
1488 - Modem debug support:
1489 CONFIG_MODEM_SUPPORT_DEBUG
1491 Enables debugging stuff (char screen[1024], dbg())
1492 for modem support. Useful only with BDI2000.
1494 - Interrupt support (PPC):
1496 There are common interrupt_init() and timer_interrupt()
1497 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
1498 for cpu specific initialization. interrupt_init_cpu()
1499 should set decrementer_count to appropriate value. If
1500 cpu resets decrementer automatically after interrupt
1501 (ppc4xx) it should set decrementer_count to zero.
1502 timer_interrupt() calls timer_interrupt_cpu() for cpu
1503 specific handling. If board has watchdog / status_led
1504 / other_activity_monitor it works automatically from
1505 general timer_interrupt().
1509 In the target system modem support is enabled when a
1510 specific key (key combination) is pressed during
1511 power-on. Otherwise U-Boot will boot normally
1512 (autoboot). The key_pressed() fuction is called from
1513 board_init(). Currently key_pressed() is a dummy
1514 function, returning 1 and thus enabling modem
1517 If there are no modem init strings in the
1518 environment, U-Boot proceed to autoboot; the
1519 previous output (banner, info printfs) will be
1522 See also: doc/README.Modem
1525 Configuration Settings:
1526 -----------------------
1528 - CFG_LONGHELP: Defined when you want long help messages included;
1529 undefine this when you're short of memory.
1531 - CFG_PROMPT: This is what U-Boot prints on the console to
1532 prompt for user input.
1534 - CFG_CBSIZE: Buffer size for input from the Console
1536 - CFG_PBSIZE: Buffer size for Console output
1538 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1540 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1541 the application (usually a Linux kernel) when it is
1544 - CFG_BAUDRATE_TABLE:
1545 List of legal baudrate settings for this board.
1547 - CFG_CONSOLE_INFO_QUIET
1548 Suppress display of console information at boot.
1550 - CFG_CONSOLE_IS_IN_ENV
1551 If the board specific function
1552 extern int overwrite_console (void);
1553 returns 1, the stdin, stderr and stdout are switched to the
1554 serial port, else the settings in the environment are used.
1556 - CFG_CONSOLE_OVERWRITE_ROUTINE
1557 Enable the call to overwrite_console().
1559 - CFG_CONSOLE_ENV_OVERWRITE
1560 Enable overwrite of previous console environment settings.
1562 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1563 Begin and End addresses of the area used by the
1567 Enable an alternate, more extensive memory test.
1569 - CFG_MEMTEST_SCRATCH:
1570 Scratch address used by the alternate memory test
1571 You only need to set this if address zero isn't writeable
1573 - CFG_TFTP_LOADADDR:
1574 Default load address for network file downloads
1576 - CFG_LOADS_BAUD_CHANGE:
1577 Enable temporary baudrate change while serial download
1580 Physical start address of SDRAM. _Must_ be 0 here.
1583 Physical start address of Motherboard I/O (if using a
1587 Physical start address of Flash memory.
1590 Physical start address of boot monitor code (set by
1591 make config files to be same as the text base address
1592 (TEXT_BASE) used when linking) - same as
1593 CFG_FLASH_BASE when booting from flash.
1596 Size of memory reserved for monitor code, used to
1597 determine _at_compile_time_ (!) if the environment is
1598 embedded within the U-Boot image, or in a separate
1602 Size of DRAM reserved for malloc() use.
1605 Maximum size of memory mapped by the startup code of
1606 the Linux kernel; all data that must be processed by
1607 the Linux kernel (bd_info, boot arguments, eventually
1608 initrd image) must be put below this limit.
1610 - CFG_MAX_FLASH_BANKS:
1611 Max number of Flash memory banks
1613 - CFG_MAX_FLASH_SECT:
1614 Max number of sectors on a Flash chip
1616 - CFG_FLASH_ERASE_TOUT:
1617 Timeout for Flash erase operations (in ms)
1619 - CFG_FLASH_WRITE_TOUT:
1620 Timeout for Flash write operations (in ms)
1622 - CFG_FLASH_LOCK_TOUT
1623 Timeout for Flash set sector lock bit operation (in ms)
1625 - CFG_FLASH_UNLOCK_TOUT
1626 Timeout for Flash clear lock bits operation (in ms)
1628 - CFG_FLASH_PROTECTION
1629 If defined, hardware flash sectors protection is used
1630 instead of U-Boot software protection.
1632 - CFG_DIRECT_FLASH_TFTP:
1634 Enable TFTP transfers directly to flash memory;
1635 without this option such a download has to be
1636 performed in two steps: (1) download to RAM, and (2)
1637 copy from RAM to flash.
1639 The two-step approach is usually more reliable, since
1640 you can check if the download worked before you erase
1641 the flash, but in some situations (when sytem RAM is
1642 too limited to allow for a tempory copy of the
1643 downloaded image) this option may be very useful.
1646 Define if the flash driver uses extra elements in the
1647 common flash structure for storing flash geometry.
1649 - CFG_FLASH_CFI_DRIVER
1650 This option also enables the building of the cfi_flash driver
1651 in the drivers directory
1653 - CFG_RX_ETH_BUFFER:
1654 Defines the number of ethernet receive buffers. On some
1655 ethernet controllers it is recommended to set this value
1656 to 8 or even higher (EEPRO100 or 405 EMAC), since all
1657 buffers can be full shortly after enabling the interface
1658 on high ethernet traffic.
1659 Defaults to 4 if not defined.
1661 The following definitions that deal with the placement and management
1662 of environment data (variable area); in general, we support the
1663 following configurations:
1665 - CFG_ENV_IS_IN_FLASH:
1667 Define this if the environment is in flash memory.
1669 a) The environment occupies one whole flash sector, which is
1670 "embedded" in the text segment with the U-Boot code. This
1671 happens usually with "bottom boot sector" or "top boot
1672 sector" type flash chips, which have several smaller
1673 sectors at the start or the end. For instance, such a
1674 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
1675 such a case you would place the environment in one of the
1676 4 kB sectors - with U-Boot code before and after it. With
1677 "top boot sector" type flash chips, you would put the
1678 environment in one of the last sectors, leaving a gap
1679 between U-Boot and the environment.
1683 Offset of environment data (variable area) to the
1684 beginning of flash memory; for instance, with bottom boot
1685 type flash chips the second sector can be used: the offset
1686 for this sector is given here.
1688 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
1692 This is just another way to specify the start address of
1693 the flash sector containing the environment (instead of
1696 - CFG_ENV_SECT_SIZE:
1698 Size of the sector containing the environment.
1701 b) Sometimes flash chips have few, equal sized, BIG sectors.
1702 In such a case you don't want to spend a whole sector for
1707 If you use this in combination with CFG_ENV_IS_IN_FLASH
1708 and CFG_ENV_SECT_SIZE, you can specify to use only a part
1709 of this flash sector for the environment. This saves
1710 memory for the RAM copy of the environment.
1712 It may also save flash memory if you decide to use this
1713 when your environment is "embedded" within U-Boot code,
1714 since then the remainder of the flash sector could be used
1715 for U-Boot code. It should be pointed out that this is
1716 STRONGLY DISCOURAGED from a robustness point of view:
1717 updating the environment in flash makes it always
1718 necessary to erase the WHOLE sector. If something goes
1719 wrong before the contents has been restored from a copy in
1720 RAM, your target system will be dead.
1722 - CFG_ENV_ADDR_REDUND
1725 These settings describe a second storage area used to hold
1726 a redundand copy of the environment data, so that there is
1727 a valid backup copy in case there is a power failure during
1728 a "saveenv" operation.
1730 BE CAREFUL! Any changes to the flash layout, and some changes to the
1731 source code will make it necessary to adapt <board>/u-boot.lds*
1735 - CFG_ENV_IS_IN_NVRAM:
1737 Define this if you have some non-volatile memory device
1738 (NVRAM, battery buffered SRAM) which you want to use for the
1744 These two #defines are used to determin the memory area you
1745 want to use for environment. It is assumed that this memory
1746 can just be read and written to, without any special
1749 BE CAREFUL! The first access to the environment happens quite early
1750 in U-Boot initalization (when we try to get the setting of for the
1751 console baudrate). You *MUST* have mappend your NVRAM area then, or
1754 Please note that even with NVRAM we still use a copy of the
1755 environment in RAM: we could work on NVRAM directly, but we want to
1756 keep settings there always unmodified except somebody uses "saveenv"
1757 to save the current settings.
1760 - CFG_ENV_IS_IN_EEPROM:
1762 Use this if you have an EEPROM or similar serial access
1763 device and a driver for it.
1768 These two #defines specify the offset and size of the
1769 environment area within the total memory of your EEPROM.
1771 - CFG_I2C_EEPROM_ADDR:
1772 If defined, specified the chip address of the EEPROM device.
1773 The default address is zero.
1775 - CFG_EEPROM_PAGE_WRITE_BITS:
1776 If defined, the number of bits used to address bytes in a
1777 single page in the EEPROM device. A 64 byte page, for example
1778 would require six bits.
1780 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1781 If defined, the number of milliseconds to delay between
1782 page writes. The default is zero milliseconds.
1784 - CFG_I2C_EEPROM_ADDR_LEN:
1785 The length in bytes of the EEPROM memory array address. Note
1786 that this is NOT the chip address length!
1788 - CFG_I2C_EEPROM_ADDR_OVERFLOW:
1789 EEPROM chips that implement "address overflow" are ones
1790 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
1791 address and the extra bits end up in the "chip address" bit
1792 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
1795 Note that we consider the length of the address field to
1796 still be one byte because the extra address bits are hidden
1797 in the chip address.
1800 The size in bytes of the EEPROM device.
1803 - CFG_ENV_IS_IN_DATAFLASH:
1805 Define this if you have a DataFlash memory device which you
1806 want to use for the environment.
1812 These three #defines specify the offset and size of the
1813 environment area within the total memory of your DataFlash placed
1814 at the specified address.
1817 - CFG_SPI_INIT_OFFSET
1819 Defines offset to the initial SPI buffer area in DPRAM. The
1820 area is used at an early stage (ROM part) if the environment
1821 is configured to reside in the SPI EEPROM: We need a 520 byte
1822 scratch DPRAM area. It is used between the two initialization
1823 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
1824 to be a good choice since it makes it far enough from the
1825 start of the data area as well as from the stack pointer.
1827 Please note that the environment is read-only as long as the monitor
1828 has been relocated to RAM and a RAM copy of the environment has been
1829 created; also, when using EEPROM you will have to use getenv_r()
1830 until then to read environment variables.
1832 The environment is protected by a CRC32 checksum. Before the monitor
1833 is relocated into RAM, as a result of a bad CRC you will be working
1834 with the compiled-in default environment - *silently*!!! [This is
1835 necessary, because the first environment variable we need is the
1836 "baudrate" setting for the console - if we have a bad CRC, we don't
1837 have any device yet where we could complain.]
1839 Note: once the monitor has been relocated, then it will complain if
1840 the default environment is used; a new CRC is computed as soon as you
1841 use the "saveenv" command to store a valid environment.
1843 - CFG_FAULT_ECHO_LINK_DOWN:
1844 Echo the inverted Ethernet link state to the fault LED.
1846 Note: If this option is active, then CFG_FAULT_MII_ADDR
1847 also needs to be defined.
1849 - CFG_FAULT_MII_ADDR:
1850 MII address of the PHY to check for the Ethernet link state.
1852 - CFG_64BIT_VSPRINTF:
1853 Makes vsprintf (and all *printf functions) support printing
1854 of 64bit values by using the L quantifier
1856 - CFG_64BIT_STRTOUL:
1857 Adds simple_strtoull that returns a 64bit value
1859 Low Level (hardware related) configuration options:
1860 ---------------------------------------------------
1862 - CFG_CACHELINE_SIZE:
1863 Cache Line Size of the CPU.
1866 Default address of the IMMR after system reset.
1868 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
1869 and RPXsuper) to be able to adjust the position of
1870 the IMMR register after a reset.
1872 - Floppy Disk Support:
1873 CFG_FDC_DRIVE_NUMBER
1875 the default drive number (default value 0)
1879 defines the spacing between fdc chipset registers
1884 defines the offset of register from address. It
1885 depends on which part of the data bus is connected to
1886 the fdc chipset. (default value 0)
1888 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
1889 CFG_FDC_DRIVE_NUMBER are undefined, they take their
1892 if CFG_FDC_HW_INIT is defined, then the function
1893 fdc_hw_init() is called at the beginning of the FDC
1894 setup. fdc_hw_init() must be provided by the board
1895 source code. It is used to make hardware dependant
1898 - CFG_IMMR: Physical address of the Internal Memory Mapped
1899 Register; DO NOT CHANGE! (11-4)
1900 [MPC8xx systems only]
1902 - CFG_INIT_RAM_ADDR:
1904 Start address of memory area that can be used for
1905 initial data and stack; please note that this must be
1906 writable memory that is working WITHOUT special
1907 initialization, i. e. you CANNOT use normal RAM which
1908 will become available only after programming the
1909 memory controller and running certain initialization
1912 U-Boot uses the following memory types:
1913 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
1914 - MPC824X: data cache
1915 - PPC4xx: data cache
1917 - CFG_GBL_DATA_OFFSET:
1919 Offset of the initial data structure in the memory
1920 area defined by CFG_INIT_RAM_ADDR. Usually
1921 CFG_GBL_DATA_OFFSET is chosen such that the initial
1922 data is located at the end of the available space
1923 (sometimes written as (CFG_INIT_RAM_END -
1924 CFG_INIT_DATA_SIZE), and the initial stack is just
1925 below that area (growing from (CFG_INIT_RAM_ADDR +
1926 CFG_GBL_DATA_OFFSET) downward.
1929 On the MPC824X (or other systems that use the data
1930 cache for initial memory) the address chosen for
1931 CFG_INIT_RAM_ADDR is basically arbitrary - it must
1932 point to an otherwise UNUSED address space between
1933 the top of RAM and the start of the PCI space.
1935 - CFG_SIUMCR: SIU Module Configuration (11-6)
1937 - CFG_SYPCR: System Protection Control (11-9)
1939 - CFG_TBSCR: Time Base Status and Control (11-26)
1941 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
1943 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
1945 - CFG_SCCR: System Clock and reset Control Register (15-27)
1947 - CFG_OR_TIMING_SDRAM:
1951 periodic timer for refresh
1953 - CFG_DER: Debug Event Register (37-47)
1955 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
1956 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
1957 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
1959 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
1961 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
1962 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
1963 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
1964 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
1966 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
1967 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
1968 Machine Mode Register and Memory Periodic Timer
1969 Prescaler definitions (SDRAM timing)
1971 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
1972 enable I2C microcode relocation patch (MPC8xx);
1973 define relocation offset in DPRAM [DSP2]
1975 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
1976 enable SPI microcode relocation patch (MPC8xx);
1977 define relocation offset in DPRAM [SCC4]
1980 Use OSCM clock mode on MBX8xx board. Be careful,
1981 wrong setting might damage your board. Read
1982 doc/README.MBX before setting this variable!
1984 - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
1985 Offset of the bootmode word in DPRAM used by post
1986 (Power On Self Tests). This definition overrides
1987 #define'd default value in commproc.h resp.
1990 - CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
1991 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
1992 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
1993 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
1994 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
1995 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
1996 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
1997 CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
1998 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2000 - CONFIG_ETHER_ON_FEC[12]
2001 Define to enable FEC[12] on a 8xx series processor.
2003 - CONFIG_FEC[12]_PHY
2004 Define to the hardcoded PHY address which corresponds
2005 to the given FEC; i. e.
2006 #define CONFIG_FEC1_PHY 4
2007 means that the PHY with address 4 is connected to FEC1
2009 When set to -1, means to probe for first available.
2011 - CONFIG_FEC[12]_PHY_NORXERR
2012 The PHY does not have a RXERR line (RMII only).
2013 (so program the FEC to ignore it).
2016 Enable RMII mode for all FECs.
2017 Note that this is a global option, we can't
2018 have one FEC in standard MII mode and another in RMII mode.
2020 - CONFIG_CRC32_VERIFY
2021 Add a verify option to the crc32 command.
2024 => crc32 -v <address> <count> <crc32>
2026 Where address/count indicate a memory area
2027 and crc32 is the correct crc32 which the
2030 Building the Software:
2031 ======================
2033 Building U-Boot has been tested in native PPC environments (on a
2034 PowerBook G3 running LinuxPPC 2000) and in cross environments
2035 (running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
2038 If you are not using a native PPC environment, it is assumed that you
2039 have the GNU cross compiling tools available in your path and named
2040 with a prefix of "powerpc-linux-". If this is not the case, (e.g. if
2041 you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
2042 the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
2045 CROSS_COMPILE = ppc_4xx-
2048 U-Boot is intended to be simple to build. After installing the
2049 sources you must configure U-Boot for one specific board type. This
2054 where "NAME_config" is the name of one of the existing
2055 configurations; the following names are supported:
2057 ADCIOP_config FPS860L_config omap730p2_config
2058 ADS860_config GEN860T_config pcu_e_config
2059 AR405_config GENIETV_config PIP405_config
2060 at91rm9200dk_config GTH_config QS823_config
2061 CANBT_config hermes_config QS850_config
2062 cmi_mpc5xx_config hymod_config QS860T_config
2063 cogent_common_config IP860_config RPXlite_config
2064 cogent_mpc8260_config IVML24_config RPXsuper_config
2065 cogent_mpc8xx_config IVMS8_config rsdproto_config
2066 CPCI405_config JSE_config Sandpoint8240_config
2067 CPCIISER4_config LANTEC_config sbc8260_config
2068 csb272_config lwmon_config SM850_config
2069 CU824_config MBX860T_config SPD823TS_config
2070 DUET_ADS_config MBX_config stxgp3_config
2071 EBONY_config MPC8260ADS_config SXNI855T_config
2072 ELPT860_config MPC8540ADS_config TQM823L_config
2073 ESTEEM192E_config MPC8560ADS_config TQM850L_config
2074 ETX094_config NETVIA_config TQM855L_config
2075 FADS823_config omap1510inn_config TQM860L_config
2076 FADS850SAR_config omap1610h2_config WALNUT405_config
2077 FADS860T_config omap1610inn_config ZPC1900_config
2078 FPS850L_config omap5912osk_config
2080 Note: for some board special configuration names may exist; check if
2081 additional information is available from the board vendor; for
2082 instance, the TQM823L systems are available without (standard)
2083 or with LCD support. You can select such additional "features"
2084 when chosing the configuration, i. e.
2087 - will configure for a plain TQM823L, i. e. no LCD support
2089 make TQM823L_LCD_config
2090 - will configure for a TQM823L with U-Boot console on LCD
2095 Finally, type "make all", and you should get some working U-Boot
2096 images ready for download to / installation on your system:
2098 - "u-boot.bin" is a raw binary image
2099 - "u-boot" is an image in ELF binary format
2100 - "u-boot.srec" is in Motorola S-Record format
2103 Please be aware that the Makefiles assume you are using GNU make, so
2104 for instance on NetBSD you might need to use "gmake" instead of
2108 If the system board that you have is not listed, then you will need
2109 to port U-Boot to your hardware platform. To do this, follow these
2112 1. Add a new configuration option for your board to the toplevel
2113 "Makefile" and to the "MAKEALL" script, using the existing
2114 entries as examples. Note that here and at many other places
2115 boards and other names are listed in alphabetical sort order. Please
2117 2. Create a new directory to hold your board specific code. Add any
2118 files you need. In your board directory, you will need at least
2119 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2120 3. Create a new configuration file "include/configs/<board>.h" for
2122 3. If you're porting U-Boot to a new CPU, then also create a new
2123 directory to hold your CPU specific code. Add any files you need.
2124 4. Run "make <board>_config" with your new name.
2125 5. Type "make", and you should get a working "u-boot.srec" file
2126 to be installed on your target system.
2127 6. Debug and solve any problems that might arise.
2128 [Of course, this last step is much harder than it sounds.]
2131 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2132 ==============================================================
2134 If you have modified U-Boot sources (for instance added a new board
2135 or support for new devices, a new CPU, etc.) you are expected to
2136 provide feedback to the other developers. The feedback normally takes
2137 the form of a "patch", i. e. a context diff against a certain (latest
2138 official or latest in CVS) version of U-Boot sources.
2140 But before you submit such a patch, please verify that your modifi-
2141 cation did not break existing code. At least make sure that *ALL* of
2142 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2143 just run the "MAKEALL" script, which will configure and build U-Boot
2144 for ALL supported system. Be warned, this will take a while. You can
2145 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2146 environment variable to the script, i. e. to use the cross tools from
2147 MontaVista's Hard Hat Linux you can type
2149 CROSS_COMPILE=ppc_8xx- MAKEALL
2151 or to build on a native PowerPC system you can type
2153 CROSS_COMPILE=' ' MAKEALL
2155 See also "U-Boot Porting Guide" below.
2158 Monitor Commands - Overview:
2159 ============================
2161 go - start application at address 'addr'
2162 run - run commands in an environment variable
2163 bootm - boot application image from memory
2164 bootp - boot image via network using BootP/TFTP protocol
2165 tftpboot- boot image via network using TFTP protocol
2166 and env variables "ipaddr" and "serverip"
2167 (and eventually "gatewayip")
2168 rarpboot- boot image via network using RARP/TFTP protocol
2169 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2170 loads - load S-Record file over serial line
2171 loadb - load binary file over serial line (kermit mode)
2173 mm - memory modify (auto-incrementing)
2174 nm - memory modify (constant address)
2175 mw - memory write (fill)
2177 cmp - memory compare
2178 crc32 - checksum calculation
2179 imd - i2c memory display
2180 imm - i2c memory modify (auto-incrementing)
2181 inm - i2c memory modify (constant address)
2182 imw - i2c memory write (fill)
2183 icrc32 - i2c checksum calculation
2184 iprobe - probe to discover valid I2C chip addresses
2185 iloop - infinite loop on address range
2186 isdram - print SDRAM configuration information
2187 sspi - SPI utility commands
2188 base - print or set address offset
2189 printenv- print environment variables
2190 setenv - set environment variables
2191 saveenv - save environment variables to persistent storage
2192 protect - enable or disable FLASH write protection
2193 erase - erase FLASH memory
2194 flinfo - print FLASH memory information
2195 bdinfo - print Board Info structure
2196 iminfo - print header information for application image
2197 coninfo - print console devices and informations
2198 ide - IDE sub-system
2199 loop - infinite loop on address range
2200 mtest - simple RAM test
2201 icache - enable or disable instruction cache
2202 dcache - enable or disable data cache
2203 reset - Perform RESET of the CPU
2204 echo - echo args to console
2205 version - print monitor version
2206 help - print online help
2207 ? - alias for 'help'
2210 Monitor Commands - Detailed Description:
2211 ========================================
2215 For now: just type "help <command>".
2218 Environment Variables:
2219 ======================
2221 U-Boot supports user configuration using Environment Variables which
2222 can be made persistent by saving to Flash memory.
2224 Environment Variables are set using "setenv", printed using
2225 "printenv", and saved to Flash using "saveenv". Using "setenv"
2226 without a value can be used to delete a variable from the
2227 environment. As long as you don't save the environment you are
2228 working with an in-memory copy. In case the Flash area containing the
2229 environment is erased by accident, a default environment is provided.
2231 Some configuration options can be set using Environment Variables:
2233 baudrate - see CONFIG_BAUDRATE
2235 bootdelay - see CONFIG_BOOTDELAY
2237 bootcmd - see CONFIG_BOOTCOMMAND
2239 bootargs - Boot arguments when booting an RTOS image
2241 bootfile - Name of the image to load with TFTP
2243 autoload - if set to "no" (any string beginning with 'n'),
2244 "bootp" will just load perform a lookup of the
2245 configuration from the BOOTP server, but not try to
2246 load any image using TFTP
2248 autostart - if set to "yes", an image loaded using the "bootp",
2249 "rarpboot", "tftpboot" or "diskboot" commands will
2250 be automatically started (by internally calling
2253 If set to "no", a standalone image passed to the
2254 "bootm" command will be copied to the load address
2255 (and eventually uncompressed), but NOT be started.
2256 This can be used to load and uncompress arbitrary
2259 i2cfast - (PPC405GP|PPC405EP only)
2260 if set to 'y' configures Linux I2C driver for fast
2261 mode (400kHZ). This environment variable is used in
2262 initialization code. So, for changes to be effective
2263 it must be saved and board must be reset.
2265 initrd_high - restrict positioning of initrd images:
2266 If this variable is not set, initrd images will be
2267 copied to the highest possible address in RAM; this
2268 is usually what you want since it allows for
2269 maximum initrd size. If for some reason you want to
2270 make sure that the initrd image is loaded below the
2271 CFG_BOOTMAPSZ limit, you can set this environment
2272 variable to a value of "no" or "off" or "0".
2273 Alternatively, you can set it to a maximum upper
2274 address to use (U-Boot will still check that it
2275 does not overwrite the U-Boot stack and data).
2277 For instance, when you have a system with 16 MB
2278 RAM, and want to reserve 4 MB from use by Linux,
2279 you can do this by adding "mem=12M" to the value of
2280 the "bootargs" variable. However, now you must make
2281 sure that the initrd image is placed in the first
2282 12 MB as well - this can be done with
2284 setenv initrd_high 00c00000
2286 If you set initrd_high to 0xFFFFFFFF, this is an
2287 indication to U-Boot that all addresses are legal
2288 for the Linux kernel, including addresses in flash
2289 memory. In this case U-Boot will NOT COPY the
2290 ramdisk at all. This may be useful to reduce the
2291 boot time on your system, but requires that this
2292 feature is supported by your Linux kernel.
2294 ipaddr - IP address; needed for tftpboot command
2296 loadaddr - Default load address for commands like "bootp",
2297 "rarpboot", "tftpboot", "loadb" or "diskboot"
2299 loads_echo - see CONFIG_LOADS_ECHO
2301 serverip - TFTP server IP address; needed for tftpboot command
2303 bootretry - see CONFIG_BOOT_RETRY_TIME
2305 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
2307 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
2309 ethprime - When CONFIG_NET_MULTI is enabled controls which
2310 interface is used first.
2312 ethact - When CONFIG_NET_MULTI is enabled controls which
2313 interface is currently active. For example you
2314 can do the following
2316 => setenv ethact FEC ETHERNET
2317 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
2318 => setenv ethact SCC ETHERNET
2319 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
2321 netretry - When set to "no" each network operation will
2322 either succeed or fail without retrying.
2323 When set to "once" the network operation will
2324 fail when all the available network interfaces
2325 are tried once without success.
2326 Useful on scripts which control the retry operation
2329 vlan - When set to a value < 4095 the traffic over
2330 ethernet is encapsulated/received over 802.1q
2333 The following environment variables may be used and automatically
2334 updated by the network boot commands ("bootp" and "rarpboot"),
2335 depending the information provided by your boot server:
2337 bootfile - see above
2338 dnsip - IP address of your Domain Name Server
2339 dnsip2 - IP address of your secondary Domain Name Server
2340 gatewayip - IP address of the Gateway (Router) to use
2341 hostname - Target hostname
2343 netmask - Subnet Mask
2344 rootpath - Pathname of the root filesystem on the NFS server
2345 serverip - see above
2348 There are two special Environment Variables:
2350 serial# - contains hardware identification information such
2351 as type string and/or serial number
2352 ethaddr - Ethernet address
2354 These variables can be set only once (usually during manufacturing of
2355 the board). U-Boot refuses to delete or overwrite these variables
2356 once they have been set once.
2359 Further special Environment Variables:
2361 ver - Contains the U-Boot version string as printed
2362 with the "version" command. This variable is
2363 readonly (see CONFIG_VERSION_VARIABLE).
2366 Please note that changes to some configuration parameters may take
2367 only effect after the next boot (yes, that's just like Windoze :-).
2370 Command Line Parsing:
2371 =====================
2373 There are two different command line parsers available with U-Boot:
2374 the old "simple" one, and the much more powerful "hush" shell:
2376 Old, simple command line parser:
2377 --------------------------------
2379 - supports environment variables (through setenv / saveenv commands)
2380 - several commands on one line, separated by ';'
2381 - variable substitution using "... $(name) ..." syntax
2382 - special characters ('$', ';') can be escaped by prefixing with '\',
2384 setenv bootcmd bootm \$(address)
2385 - You can also escape text by enclosing in single apostrophes, for example:
2386 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2391 - similar to Bourne shell, with control structures like
2392 if...then...else...fi, for...do...done; while...do...done,
2393 until...do...done, ...
2394 - supports environment ("global") variables (through setenv / saveenv
2395 commands) and local shell variables (through standard shell syntax
2396 "name=value"); only environment variables can be used with "run"
2402 (1) If a command line (or an environment variable executed by a "run"
2403 command) contains several commands separated by semicolon, and
2404 one of these commands fails, then the remaining commands will be
2407 (2) If you execute several variables with one call to run (i. e.
2408 calling run with a list af variables as arguments), any failing
2409 command will cause "run" to terminate, i. e. the remaining
2410 variables are not executed.
2412 Note for Redundant Ethernet Interfaces:
2413 =======================================
2415 Some boards come with redundant ethernet interfaces; U-Boot supports
2416 such configurations and is capable of automatic selection of a
2417 "working" interface when needed. MAC assignment works as follows:
2419 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2420 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2421 "eth1addr" (=>eth1), "eth2addr", ...
2423 If the network interface stores some valid MAC address (for instance
2424 in SROM), this is used as default address if there is NO correspon-
2425 ding setting in the environment; if the corresponding environment
2426 variable is set, this overrides the settings in the card; that means:
2428 o If the SROM has a valid MAC address, and there is no address in the
2429 environment, the SROM's address is used.
2431 o If there is no valid address in the SROM, and a definition in the
2432 environment exists, then the value from the environment variable is
2435 o If both the SROM and the environment contain a MAC address, and
2436 both addresses are the same, this MAC address is used.
2438 o If both the SROM and the environment contain a MAC address, and the
2439 addresses differ, the value from the environment is used and a
2442 o If neither SROM nor the environment contain a MAC address, an error
2449 The "boot" commands of this monitor operate on "image" files which
2450 can be basicly anything, preceeded by a special header; see the
2451 definitions in include/image.h for details; basicly, the header
2452 defines the following image properties:
2454 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2455 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2456 LynxOS, pSOS, QNX, RTEMS, ARTOS;
2457 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
2458 * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
2459 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2460 Currently supported: ARM, Intel x86, MIPS, NIOS, PowerPC).
2461 * Compression Type (uncompressed, gzip, bzip2)
2467 The header is marked by a special Magic Number, and both the header
2468 and the data portions of the image are secured against corruption by
2475 Although U-Boot should support any OS or standalone application
2476 easily, the main focus has always been on Linux during the design of
2479 U-Boot includes many features that so far have been part of some
2480 special "boot loader" code within the Linux kernel. Also, any
2481 "initrd" images to be used are no longer part of one big Linux image;
2482 instead, kernel and "initrd" are separate images. This implementation
2483 serves several purposes:
2485 - the same features can be used for other OS or standalone
2486 applications (for instance: using compressed images to reduce the
2487 Flash memory footprint)
2489 - it becomes much easier to port new Linux kernel versions because
2490 lots of low-level, hardware dependent stuff are done by U-Boot
2492 - the same Linux kernel image can now be used with different "initrd"
2493 images; of course this also means that different kernel images can
2494 be run with the same "initrd". This makes testing easier (you don't
2495 have to build a new "zImage.initrd" Linux image when you just
2496 change a file in your "initrd"). Also, a field-upgrade of the
2497 software is easier now.
2503 Porting Linux to U-Boot based systems:
2504 ---------------------------------------
2506 U-Boot cannot save you from doing all the necessary modifications to
2507 configure the Linux device drivers for use with your target hardware
2508 (no, we don't intend to provide a full virtual machine interface to
2511 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
2513 Just make sure your machine specific header file (for instance
2514 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
2515 Information structure as we define in include/u-boot.h, and make
2516 sure that your definition of IMAP_ADDR uses the same value as your
2517 U-Boot configuration in CFG_IMMR.
2520 Configuring the Linux kernel:
2521 -----------------------------
2523 No specific requirements for U-Boot. Make sure you have some root
2524 device (initial ramdisk, NFS) for your target system.
2527 Building a Linux Image:
2528 -----------------------
2530 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2531 not used. If you use recent kernel source, a new build target
2532 "uImage" will exist which automatically builds an image usable by
2533 U-Boot. Most older kernels also have support for a "pImage" target,
2534 which was introduced for our predecessor project PPCBoot and uses a
2535 100% compatible format.
2544 The "uImage" build target uses a special tool (in 'tools/mkimage') to
2545 encapsulate a compressed Linux kernel image with header information,
2546 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
2548 * build a standard "vmlinux" kernel image (in ELF binary format):
2550 * convert the kernel into a raw binary image:
2552 ${CROSS_COMPILE}-objcopy -O binary \
2553 -R .note -R .comment \
2554 -S vmlinux linux.bin
2556 * compress the binary image:
2560 * package compressed binary image for U-Boot:
2562 mkimage -A ppc -O linux -T kernel -C gzip \
2563 -a 0 -e 0 -n "Linux Kernel Image" \
2564 -d linux.bin.gz uImage
2567 The "mkimage" tool can also be used to create ramdisk images for use
2568 with U-Boot, either separated from the Linux kernel image, or
2569 combined into one file. "mkimage" encapsulates the images with a 64
2570 byte header containing information about target architecture,
2571 operating system, image type, compression method, entry points, time
2572 stamp, CRC32 checksums, etc.
2574 "mkimage" can be called in two ways: to verify existing images and
2575 print the header information, or to build new images.
2577 In the first form (with "-l" option) mkimage lists the information
2578 contained in the header of an existing U-Boot image; this includes
2579 checksum verification:
2581 tools/mkimage -l image
2582 -l ==> list image header information
2584 The second form (with "-d" option) is used to build a U-Boot image
2585 from a "data file" which is used as image payload:
2587 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2588 -n name -d data_file image
2589 -A ==> set architecture to 'arch'
2590 -O ==> set operating system to 'os'
2591 -T ==> set image type to 'type'
2592 -C ==> set compression type 'comp'
2593 -a ==> set load address to 'addr' (hex)
2594 -e ==> set entry point to 'ep' (hex)
2595 -n ==> set image name to 'name'
2596 -d ==> use image data from 'datafile'
2598 Right now, all Linux kernels for PowerPC systems use the same load
2599 address (0x00000000), but the entry point address depends on the
2602 - 2.2.x kernels have the entry point at 0x0000000C,
2603 - 2.3.x and later kernels have the entry point at 0x00000000.
2605 So a typical call to build a U-Boot image would read:
2607 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2608 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
2609 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
2610 > examples/uImage.TQM850L
2611 Image Name: 2.4.4 kernel for TQM850L
2612 Created: Wed Jul 19 02:34:59 2000
2613 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2614 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2615 Load Address: 0x00000000
2616 Entry Point: 0x00000000
2618 To verify the contents of the image (or check for corruption):
2620 -> tools/mkimage -l examples/uImage.TQM850L
2621 Image Name: 2.4.4 kernel for TQM850L
2622 Created: Wed Jul 19 02:34:59 2000
2623 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2624 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2625 Load Address: 0x00000000
2626 Entry Point: 0x00000000
2628 NOTE: for embedded systems where boot time is critical you can trade
2629 speed for memory and install an UNCOMPRESSED image instead: this
2630 needs more space in Flash, but boots much faster since it does not
2631 need to be uncompressed:
2633 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
2634 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2635 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
2636 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
2637 > examples/uImage.TQM850L-uncompressed
2638 Image Name: 2.4.4 kernel for TQM850L
2639 Created: Wed Jul 19 02:34:59 2000
2640 Image Type: PowerPC Linux Kernel Image (uncompressed)
2641 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
2642 Load Address: 0x00000000
2643 Entry Point: 0x00000000
2646 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2647 when your kernel is intended to use an initial ramdisk:
2649 -> tools/mkimage -n 'Simple Ramdisk Image' \
2650 > -A ppc -O linux -T ramdisk -C gzip \
2651 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2652 Image Name: Simple Ramdisk Image
2653 Created: Wed Jan 12 14:01:50 2000
2654 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2655 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
2656 Load Address: 0x00000000
2657 Entry Point: 0x00000000
2660 Installing a Linux Image:
2661 -------------------------
2663 To downloading a U-Boot image over the serial (console) interface,
2664 you must convert the image to S-Record format:
2666 objcopy -I binary -O srec examples/image examples/image.srec
2668 The 'objcopy' does not understand the information in the U-Boot
2669 image header, so the resulting S-Record file will be relative to
2670 address 0x00000000. To load it to a given address, you need to
2671 specify the target address as 'offset' parameter with the 'loads'
2674 Example: install the image to address 0x40100000 (which on the
2675 TQM8xxL is in the first Flash bank):
2677 => erase 40100000 401FFFFF
2683 ## Ready for S-Record download ...
2684 ~>examples/image.srec
2685 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2687 15989 15990 15991 15992
2688 [file transfer complete]
2690 ## Start Addr = 0x00000000
2693 You can check the success of the download using the 'iminfo' command;
2694 this includes a checksum verification so you can be sure no data
2695 corruption happened:
2699 ## Checking Image at 40100000 ...
2700 Image Name: 2.2.13 for initrd on TQM850L
2701 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2702 Data Size: 335725 Bytes = 327 kB = 0 MB
2703 Load Address: 00000000
2704 Entry Point: 0000000c
2705 Verifying Checksum ... OK
2711 The "bootm" command is used to boot an application that is stored in
2712 memory (RAM or Flash). In case of a Linux kernel image, the contents
2713 of the "bootargs" environment variable is passed to the kernel as
2714 parameters. You can check and modify this variable using the
2715 "printenv" and "setenv" commands:
2718 => printenv bootargs
2719 bootargs=root=/dev/ram
2721 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2723 => printenv bootargs
2724 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2727 ## Booting Linux kernel at 40020000 ...
2728 Image Name: 2.2.13 for NFS on TQM850L
2729 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2730 Data Size: 381681 Bytes = 372 kB = 0 MB
2731 Load Address: 00000000
2732 Entry Point: 0000000c
2733 Verifying Checksum ... OK
2734 Uncompressing Kernel Image ... OK
2735 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
2736 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2737 time_init: decrementer frequency = 187500000/60
2738 Calibrating delay loop... 49.77 BogoMIPS
2739 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2742 If you want to boot a Linux kernel with initial ram disk, you pass
2743 the memory addresses of both the kernel and the initrd image (PPBCOOT
2744 format!) to the "bootm" command:
2746 => imi 40100000 40200000
2748 ## Checking Image at 40100000 ...
2749 Image Name: 2.2.13 for initrd on TQM850L
2750 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2751 Data Size: 335725 Bytes = 327 kB = 0 MB
2752 Load Address: 00000000
2753 Entry Point: 0000000c
2754 Verifying Checksum ... OK
2756 ## Checking Image at 40200000 ...
2757 Image Name: Simple Ramdisk Image
2758 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2759 Data Size: 566530 Bytes = 553 kB = 0 MB
2760 Load Address: 00000000
2761 Entry Point: 00000000
2762 Verifying Checksum ... OK
2764 => bootm 40100000 40200000
2765 ## Booting Linux kernel at 40100000 ...
2766 Image Name: 2.2.13 for initrd on TQM850L
2767 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2768 Data Size: 335725 Bytes = 327 kB = 0 MB
2769 Load Address: 00000000
2770 Entry Point: 0000000c
2771 Verifying Checksum ... OK
2772 Uncompressing Kernel Image ... OK
2773 ## Loading RAMDisk Image at 40200000 ...
2774 Image Name: Simple Ramdisk Image
2775 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2776 Data Size: 566530 Bytes = 553 kB = 0 MB
2777 Load Address: 00000000
2778 Entry Point: 00000000
2779 Verifying Checksum ... OK
2780 Loading Ramdisk ... OK
2781 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
2782 Boot arguments: root=/dev/ram
2783 time_init: decrementer frequency = 187500000/60
2784 Calibrating delay loop... 49.77 BogoMIPS
2786 RAMDISK: Compressed image found at block 0
2787 VFS: Mounted root (ext2 filesystem).
2791 More About U-Boot Image Types:
2792 ------------------------------
2794 U-Boot supports the following image types:
2796 "Standalone Programs" are directly runnable in the environment
2797 provided by U-Boot; it is expected that (if they behave
2798 well) you can continue to work in U-Boot after return from
2799 the Standalone Program.
2800 "OS Kernel Images" are usually images of some Embedded OS which
2801 will take over control completely. Usually these programs
2802 will install their own set of exception handlers, device
2803 drivers, set up the MMU, etc. - this means, that you cannot
2804 expect to re-enter U-Boot except by resetting the CPU.
2805 "RAMDisk Images" are more or less just data blocks, and their
2806 parameters (address, size) are passed to an OS kernel that is
2808 "Multi-File Images" contain several images, typically an OS
2809 (Linux) kernel image and one or more data images like
2810 RAMDisks. This construct is useful for instance when you want
2811 to boot over the network using BOOTP etc., where the boot
2812 server provides just a single image file, but you want to get
2813 for instance an OS kernel and a RAMDisk image.
2815 "Multi-File Images" start with a list of image sizes, each
2816 image size (in bytes) specified by an "uint32_t" in network
2817 byte order. This list is terminated by an "(uint32_t)0".
2818 Immediately after the terminating 0 follow the images, one by
2819 one, all aligned on "uint32_t" boundaries (size rounded up to
2820 a multiple of 4 bytes).
2822 "Firmware Images" are binary images containing firmware (like
2823 U-Boot or FPGA images) which usually will be programmed to
2826 "Script files" are command sequences that will be executed by
2827 U-Boot's command interpreter; this feature is especially
2828 useful when you configure U-Boot to use a real shell (hush)
2829 as command interpreter.
2835 One of the features of U-Boot is that you can dynamically load and
2836 run "standalone" applications, which can use some resources of
2837 U-Boot like console I/O functions or interrupt services.
2839 Two simple examples are included with the sources:
2844 'examples/hello_world.c' contains a small "Hello World" Demo
2845 application; it is automatically compiled when you build U-Boot.
2846 It's configured to run at address 0x00040004, so you can play with it
2850 ## Ready for S-Record download ...
2851 ~>examples/hello_world.srec
2852 1 2 3 4 5 6 7 8 9 10 11 ...
2853 [file transfer complete]
2855 ## Start Addr = 0x00040004
2857 => go 40004 Hello World! This is a test.
2858 ## Starting application at 0x00040004 ...
2869 Hit any key to exit ...
2871 ## Application terminated, rc = 0x0
2873 Another example, which demonstrates how to register a CPM interrupt
2874 handler with the U-Boot code, can be found in 'examples/timer.c'.
2875 Here, a CPM timer is set up to generate an interrupt every second.
2876 The interrupt service routine is trivial, just printing a '.'
2877 character, but this is just a demo program. The application can be
2878 controlled by the following keys:
2880 ? - print current values og the CPM Timer registers
2881 b - enable interrupts and start timer
2882 e - stop timer and disable interrupts
2883 q - quit application
2886 ## Ready for S-Record download ...
2887 ~>examples/timer.srec
2888 1 2 3 4 5 6 7 8 9 10 11 ...
2889 [file transfer complete]
2891 ## Start Addr = 0x00040004
2894 ## Starting application at 0x00040004 ...
2897 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
2900 [q, b, e, ?] Set interval 1000000 us
2903 [q, b, e, ?] ........
2904 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
2907 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
2910 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
2913 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
2915 [q, b, e, ?] ...Stopping timer
2917 [q, b, e, ?] ## Application terminated, rc = 0x0
2923 Over time, many people have reported problems when trying to use the
2924 "minicom" terminal emulation program for serial download. I (wd)
2925 consider minicom to be broken, and recommend not to use it. Under
2926 Unix, I recommend to use C-Kermit for general purpose use (and
2927 especially for kermit binary protocol download ("loadb" command), and
2928 use "cu" for S-Record download ("loads" command).
2930 Nevertheless, if you absolutely want to use it try adding this
2931 configuration to your "File transfer protocols" section:
2933 Name Program Name U/D FullScr IO-Red. Multi
2934 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
2935 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
2941 Starting at version 0.9.2, U-Boot supports NetBSD both as host
2942 (build U-Boot) and target system (boots NetBSD/mpc8xx).
2944 Building requires a cross environment; it is known to work on
2945 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
2946 need gmake since the Makefiles are not compatible with BSD make).
2947 Note that the cross-powerpc package does not install include files;
2948 attempting to build U-Boot will fail because <machine/ansi.h> is
2949 missing. This file has to be installed and patched manually:
2951 # cd /usr/pkg/cross/powerpc-netbsd/include
2953 # ln -s powerpc machine
2954 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
2955 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
2957 Native builds *don't* work due to incompatibilities between native
2958 and U-Boot include files.
2960 Booting assumes that (the first part of) the image booted is a
2961 stage-2 loader which in turn loads and then invokes the kernel
2962 proper. Loader sources will eventually appear in the NetBSD source
2963 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
2964 meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for
2968 Implementation Internals:
2969 =========================
2971 The following is not intended to be a complete description of every
2972 implementation detail. However, it should help to understand the
2973 inner workings of U-Boot and make it easier to port it to custom
2977 Initial Stack, Global Data:
2978 ---------------------------
2980 The implementation of U-Boot is complicated by the fact that U-Boot
2981 starts running out of ROM (flash memory), usually without access to
2982 system RAM (because the memory controller is not initialized yet).
2983 This means that we don't have writable Data or BSS segments, and BSS
2984 is not initialized as zero. To be able to get a C environment working
2985 at all, we have to allocate at least a minimal stack. Implementation
2986 options for this are defined and restricted by the CPU used: Some CPU
2987 models provide on-chip memory (like the IMMR area on MPC8xx and
2988 MPC826x processors), on others (parts of) the data cache can be
2989 locked as (mis-) used as memory, etc.
2991 Chris Hallinan posted a good summary of these issues to the
2992 u-boot-users mailing list:
2994 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
2995 From: "Chris Hallinan" <clh@net1plus.com>
2996 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
2999 Correct me if I'm wrong, folks, but the way I understand it
3000 is this: Using DCACHE as initial RAM for Stack, etc, does not
3001 require any physical RAM backing up the cache. The cleverness
3002 is that the cache is being used as a temporary supply of
3003 necessary storage before the SDRAM controller is setup. It's
3004 beyond the scope of this list to expain the details, but you
3005 can see how this works by studying the cache architecture and
3006 operation in the architecture and processor-specific manuals.
3008 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3009 is another option for the system designer to use as an
3010 initial stack/ram area prior to SDRAM being available. Either
3011 option should work for you. Using CS 4 should be fine if your
3012 board designers haven't used it for something that would
3013 cause you grief during the initial boot! It is frequently not
3016 CFG_INIT_RAM_ADDR should be somewhere that won't interfere
3017 with your processor/board/system design. The default value
3018 you will find in any recent u-boot distribution in
3019 Walnut405.h should work for you. I'd set it to a value larger
3020 than your SDRAM module. If you have a 64MB SDRAM module, set
3021 it above 400_0000. Just make sure your board has no resources
3022 that are supposed to respond to that address! That code in
3023 start.S has been around a while and should work as is when
3024 you get the config right.
3029 It is essential to remember this, since it has some impact on the C
3030 code for the initialization procedures:
3032 * Initialized global data (data segment) is read-only. Do not attempt
3035 * Do not use any unitialized global data (or implicitely initialized
3036 as zero data - BSS segment) at all - this is undefined, initiali-
3037 zation is performed later (when relocating to RAM).
3039 * Stack space is very limited. Avoid big data buffers or things like
3042 Having only the stack as writable memory limits means we cannot use
3043 normal global data to share information beween the code. But it
3044 turned out that the implementation of U-Boot can be greatly
3045 simplified by making a global data structure (gd_t) available to all
3046 functions. We could pass a pointer to this data as argument to _all_
3047 functions, but this would bloat the code. Instead we use a feature of
3048 the GCC compiler (Global Register Variables) to share the data: we
3049 place a pointer (gd) to the global data into a register which we
3050 reserve for this purpose.
3052 When choosing a register for such a purpose we are restricted by the
3053 relevant (E)ABI specifications for the current architecture, and by
3054 GCC's implementation.
3056 For PowerPC, the following registers have specific use:
3059 R3-R4: parameter passing and return values
3060 R5-R10: parameter passing
3061 R13: small data area pointer
3065 (U-Boot also uses R14 as internal GOT pointer.)
3067 ==> U-Boot will use R29 to hold a pointer to the global data
3069 Note: on PPC, we could use a static initializer (since the
3070 address of the global data structure is known at compile time),
3071 but it turned out that reserving a register results in somewhat
3072 smaller code - although the code savings are not that big (on
3073 average for all boards 752 bytes for the whole U-Boot image,
3074 624 text + 127 data).
3076 On ARM, the following registers are used:
3078 R0: function argument word/integer result
3079 R1-R3: function argument word
3081 R10: stack limit (used only if stack checking if enabled)
3082 R11: argument (frame) pointer
3083 R12: temporary workspace
3086 R15: program counter
3088 ==> U-Boot will use R8 to hold a pointer to the global data
3094 U-Boot runs in system state and uses physical addresses, i.e. the
3095 MMU is not used either for address mapping nor for memory protection.
3097 The available memory is mapped to fixed addresses using the memory
3098 controller. In this process, a contiguous block is formed for each
3099 memory type (Flash, SDRAM, SRAM), even when it consists of several
3100 physical memory banks.
3102 U-Boot is installed in the first 128 kB of the first Flash bank (on
3103 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3104 booting and sizing and initializing DRAM, the code relocates itself
3105 to the upper end of DRAM. Immediately below the U-Boot code some
3106 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
3107 configuration setting]. Below that, a structure with global Board
3108 Info data is placed, followed by the stack (growing downward).
3110 Additionally, some exception handler code is copied to the low 8 kB
3111 of DRAM (0x00000000 ... 0x00001FFF).
3113 So a typical memory configuration with 16 MB of DRAM could look like
3116 0x0000 0000 Exception Vector code
3119 0x0000 2000 Free for Application Use
3125 0x00FB FF20 Monitor Stack (Growing downward)
3126 0x00FB FFAC Board Info Data and permanent copy of global data
3127 0x00FC 0000 Malloc Arena
3130 0x00FE 0000 RAM Copy of Monitor Code
3131 ... eventually: LCD or video framebuffer
3132 ... eventually: pRAM (Protected RAM - unchanged by reset)
3133 0x00FF FFFF [End of RAM]
3136 System Initialization:
3137 ----------------------
3139 In the reset configuration, U-Boot starts at the reset entry point
3140 (on most PowerPC systens at address 0x00000100). Because of the reset
3141 configuration for CS0# this is a mirror of the onboard Flash memory.
3142 To be able to re-map memory U-Boot then jumps to its link address.
3143 To be able to implement the initialization code in C, a (small!)
3144 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3145 which provide such a feature like MPC8xx or MPC8260), or in a locked
3146 part of the data cache. After that, U-Boot initializes the CPU core,
3147 the caches and the SIU.
3149 Next, all (potentially) available memory banks are mapped using a
3150 preliminary mapping. For example, we put them on 512 MB boundaries
3151 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3152 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3153 programmed for SDRAM access. Using the temporary configuration, a
3154 simple memory test is run that determines the size of the SDRAM
3157 When there is more than one SDRAM bank, and the banks are of
3158 different size, the largest is mapped first. For equal size, the first
3159 bank (CS2#) is mapped first. The first mapping is always for address
3160 0x00000000, with any additional banks following immediately to create
3161 contiguous memory starting from 0.
3163 Then, the monitor installs itself at the upper end of the SDRAM area
3164 and allocates memory for use by malloc() and for the global Board
3165 Info data; also, the exception vector code is copied to the low RAM
3166 pages, and the final stack is set up.
3168 Only after this relocation will you have a "normal" C environment;
3169 until that you are restricted in several ways, mostly because you are
3170 running from ROM, and because the code will have to be relocated to a
3174 U-Boot Porting Guide:
3175 ----------------------
3177 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3181 int main (int argc, char *argv[])
3183 sighandler_t no_more_time;
3185 signal (SIGALRM, no_more_time);
3186 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3188 if (available_money > available_manpower) {
3189 pay consultant to port U-Boot;
3193 Download latest U-Boot source;
3195 Subscribe to u-boot-users mailing list;
3198 email ("Hi, I am new to U-Boot, how do I get started?");
3202 Read the README file in the top level directory;
3203 Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
3204 Read the source, Luke;
3207 if (available_money > toLocalCurrency ($2500)) {
3210 Add a lot of aggravation and time;
3213 Create your own board support subdirectory;
3215 Create your own board config file;
3219 Add / modify source code;
3223 email ("Hi, I am having problems...");
3225 Send patch file to Wolfgang;
3230 void no_more_time (int sig)
3239 All contributions to U-Boot should conform to the Linux kernel
3240 coding style; see the file "Documentation/CodingStyle" in your Linux
3241 kernel source directory.
3243 Please note that U-Boot is implemented in C (and to some small parts
3244 in Assembler); no C++ is used, so please do not use C++ style
3245 comments (//) in your code.
3247 Please also stick to the following formatting rules:
3248 - remove any trailing white space
3249 - use TAB characters for indentation, not spaces
3250 - make sure NOT to use DOS '\r\n' line feeds
3251 - do not add more than 2 empty lines to source files
3252 - do not add trailing empty lines to source files
3254 Submissions which do not conform to the standards may be returned
3255 with a request to reformat the changes.
3261 Since the number of patches for U-Boot is growing, we need to
3262 establish some rules. Submissions which do not conform to these rules
3263 may be rejected, even when they contain important and valuable stuff.
3266 When you send a patch, please include the following information with
3269 * For bug fixes: a description of the bug and how your patch fixes
3270 this bug. Please try to include a way of demonstrating that the
3271 patch actually fixes something.
3273 * For new features: a description of the feature and your
3276 * A CHANGELOG entry as plaintext (separate from the patch)
3278 * For major contributions, your entry to the CREDITS file
3280 * When you add support for a new board, don't forget to add this
3281 board to the MAKEALL script, too.
3283 * If your patch adds new configuration options, don't forget to
3284 document these in the README file.
3286 * The patch itself. If you are accessing the CVS repository use "cvs
3287 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
3288 version of diff does not support these options, then get the latest
3289 version of GNU diff.
3291 The current directory when running this command shall be the top
3292 level directory of the U-Boot source tree, or it's parent directory
3293 (i. e. please make sure that your patch includes sufficient
3294 directory information for the affected files).
3296 We accept patches as plain text, MIME attachments or as uuencoded
3299 * If one logical set of modifications affects or creates several
3300 files, all these changes shall be submitted in a SINGLE patch file.
3302 * Changesets that contain different, unrelated modifications shall be
3303 submitted as SEPARATE patches, one patch per changeset.
3308 * Before sending the patch, run the MAKEALL script on your patched
3309 source tree and make sure that no errors or warnings are reported
3310 for any of the boards.
3312 * Keep your modifications to the necessary minimum: A patch
3313 containing several unrelated changes or arbitrary reformats will be
3314 returned with a request to re-formatting / split it.
3316 * If you modify existing code, make sure that your new code does not
3317 add to the memory footprint of the code ;-) Small is beautiful!
3318 When adding new features, these should compile conditionally only
3319 (using #ifdef), and the resulting code with the new feature
3320 disabled must not need more memory than the old code without your
projects / platform / kernel / u-boot.git / blob