2 # (C) Copyright 2000 - 2002
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 dependend files
123 - common Misc architecture independend functions
124 - cpu CPU specific files
125 - disk Code for disk drive partition handling
126 - doc Documentation (don't expect too much)
127 - drivers Common used device drivers
128 - dtt Digital Thermometer and Thermostat drivers
129 - examples Example code for standalone applications, etc.
130 - include Header Files
131 - disk Harddisk interface code
132 - net Networking code
133 - ppc Files generic to PowerPC architecture
134 - post Power On Self Test
135 - post/arch Symlink to architecture specific Power On Self Test
136 - post/arch-ppc PowerPC architecture specific Power On Self Test
137 - post/cpu/mpc8260 MPC8260 CPU specific Power On Self Test
138 - post/cpu/mpc8xx MPC8xx CPU specific Power On Self Test
139 - rtc Real Time Clock drivers
140 - tools Tools to build S-Record or U-Boot images, etc.
142 - cpu/74xx_7xx Files specific to Motorola MPC74xx and 7xx CPUs
143 - cpu/mpc8xx Files specific to Motorola MPC8xx CPUs
144 - cpu/mpc824x Files specific to Motorola MPC824x CPUs
145 - cpu/mpc8260 Files specific to Motorola MPC8260 CPU
146 - cpu/ppc4xx Files specific to IBM 4xx CPUs
149 Files specific to RPXClassic boards
150 - board/RPXlite Files specific to RPXlite boards
151 - board/c2mon Files specific to c2mon boards
152 - board/cogent Files specific to Cogent boards
153 (need further configuration)
154 Files specific to CPCIISER4 boards
155 - board/cpu86 Files specific to CPU86 boards
156 - board/cray/ Files specific to boards manufactured by Cray
157 - board/cray/L1 Files specific to L1 boards
158 - board/cu824 Files specific to CU824 boards
159 - board/ebony Files specific to IBM Ebony board
160 - board/eric Files specific to ERIC boards
161 - board/esd/ Files specific to boards manufactured by ESD
162 - board/esd/adciop Files specific to ADCIOP boards
163 - board/esd/ar405 Files specific to AR405 boards
164 - board/esd/canbt Files specific to CANBT boards
165 - board/esd/cpci405 Files specific to CPCI405 boards
166 - board/esd/cpciiser4 Files specific to CPCIISER4 boards
167 - board/esd/common Common files for ESD boards
168 - board/esd/dasa_sim Files specific to DASA_SIM boards
169 - board/esd/du405 Files specific to DU405 boards
170 - board/esd/ocrtc Files specific to OCRTC boards
171 - board/esd/pci405 Files specific to PCI405 boards
173 Files specific to ESTEEM192E boards
174 - board/etx094 Files specific to ETX_094 boards
176 Files specific to EVB64260 boards
177 - board/fads Files specific to FADS boards
178 - board/flagadm Files specific to FLAGADM boards
179 - board/gen860t Files specific to GEN860T boards
180 - board/genietv Files specific to GENIETV boards
181 - board/gth Files specific to GTH boards
182 - board/hermes Files specific to HERMES boards
183 - board/hymod Files specific to HYMOD boards
184 - board/icu862 Files specific to ICU862 boards
185 - board/ip860 Files specific to IP860 boards
187 Files specific to Interphase4539 boards
188 - board/ivm Files specific to IVMS8/IVML24 boards
189 - board/lantec Files specific to LANTEC boards
190 - board/lwmon Files specific to LWMON boards
191 - board/mbx8xx Files specific to MBX boards
193 Files specific to MMPC8260ADS boards
194 - board/mpl/ Files specific to boards manufactured by MPL
195 - board/mpl/common Common files for MPL boards
196 - board/mpl/pip405 Files specific to PIP405 boards
197 - board/mpl/mip405 Files specific to MIP405 boards
198 - board/musenki Files specific to MUSEKNI boards
199 - board/mvs1 Files specific to MVS1 boards
200 - board/nx823 Files specific to NX823 boards
201 - board/oxc Files specific to OXC boards
202 - board/pcippc2 Files specific to PCIPPC2/PCIPPC6 boards
203 - board/pm826 Files specific to PM826 boards
205 Files specific to PPMC8260 boards
207 Files specific to RPXsuper boards
209 Files specific to RSDproto boards
211 Files specific to Sandpoint boards
212 - board/sbc8260 Files specific to SBC8260 boards
213 - board/sacsng Files specific to SACSng boards
214 - board/siemens Files specific to boards manufactured by Siemens AG
215 - board/siemens/CCM Files specific to CCM boards
216 - board/siemens/IAD210 Files specific to IAD210 boards
217 - board/siemens/SCM Files specific to SCM boards
218 - board/siemens/pcu_e Files specific to PCU_E boards
219 - board/sixnet Files specific to SIXNET boards
220 - board/spd8xx Files specific to SPD8xxTS boards
221 - board/tqm8260 Files specific to TQM8260 boards
222 - board/tqm8xx Files specific to TQM8xxL boards
223 - board/w7o Files specific to W7O boards
225 Files specific to Walnut405 boards
226 - board/westel/ Files specific to boards manufactured by Westel Wireless
227 - board/westel/amx860 Files specific to AMX860 boards
228 - board/utx8245 Files specific to UTX8245 boards
230 Software Configuration:
231 =======================
233 Configuration is usually done using C preprocessor defines; the
234 rationale behind that is to avoid dead code whenever possible.
236 There are two classes of configuration variables:
238 * Configuration _OPTIONS_:
239 These are selectable by the user and have names beginning with
242 * Configuration _SETTINGS_:
243 These depend on the hardware etc. and should not be meddled with if
244 you don't know what you're doing; they have names beginning with
247 Later we will add a configuration tool - probably similar to or even
248 identical to what's used for the Linux kernel. Right now, we have to
249 do the configuration by hand, which means creating some symbolic
250 links and editing some configuration files. We use the TQM8xxL boards
254 Selection of Processor Architecture and Board Type:
255 ---------------------------------------------------
257 For all supported boards there are ready-to-use default
258 configurations available; just type "make <board_name>_config".
260 Example: For a TQM823L module type:
265 For the Cogent platform, you need to specify the cpu type as well;
266 e.g. "make cogent_mpc8xx_config". And also configure the cogent
267 directory according to the instructions in cogent/README.
270 Configuration Options:
271 ----------------------
273 Configuration depends on the combination of board and CPU type; all
274 such information is kept in a configuration file
275 "include/configs/<board_name>.h".
277 Example: For a TQM823L module, all configuration settings are in
278 "include/configs/TQM823L.h".
281 Many of the options are named exactly as the corresponding Linux
282 kernel configuration options. The intention is to make it easier to
283 build a config tool - later.
286 The following options need to be configured:
288 - CPU Type: Define exactly one of
292 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860
293 or CONFIG_MPC824X, CONFIG_MPC8260
306 - Board Type: Define exactly one of
308 PowerPC based boards:
309 ---------------------
311 CONFIG_ADCIOP, CONFIG_ICU862 CONFIG_RPXsuper,
312 CONFIG_ADS860, CONFIG_IP860, CONFIG_SM850,
313 CONFIG_AMX860, CONFIG_IPHASE4539, CONFIG_SPD823TS,
314 CONFIG_AR405, CONFIG_IVML24, CONFIG_SXNI855T,
315 CONFIG_BAB7xx, CONFIG_IVML24_128, CONFIG_Sandpoint8240,
316 CONFIG_CANBT, CONFIG_IVML24_256, CONFIG_Sandpoint8245,
317 CONFIG_CCM, CONFIG_IVMS8, CONFIG_TQM823L,
318 CONFIG_CPCI405, CONFIG_IVMS8_128, CONFIG_TQM850L,
319 CONFIG_CPCI4052, CONFIG_IVMS8_256, CONFIG_TQM855L,
320 CONFIG_CPCIISER4, CONFIG_LANTEC, CONFIG_TQM860L,
321 CONFIG_CPU86, CONFIG_MBX, CONFIG_TQM8260,
322 CONFIG_CRAYL1, CONFIG_MBX860T, CONFIG_TTTech,
323 CONFIG_CU824, CONFIG_MHPC, CONFIG_UTX8245,
324 CONFIG_DASA_SIM, CONFIG_MIP405, CONFIG_W7OLMC,
325 CONFIG_DU405, CONFIG_MOUSSE, CONFIG_W7OLMG,
326 CONFIG_ELPPC, CONFIG_MPC8260ADS, CONFIG_WALNUT405,
327 CONFIG_ERIC, CONFIG_MUSENKI, CONFIG_ZUMA,
328 CONFIG_ESTEEM192E, CONFIG_MVS1, CONFIG_c2mon,
329 CONFIG_ETX094, CONFIG_NX823, CONFIG_cogent_mpc8260,
330 CONFIG_EVB64260, CONFIG_OCRTC, CONFIG_cogent_mpc8xx,
331 CONFIG_FADS823, CONFIG_ORSG, CONFIG_ep8260,
332 CONFIG_FADS850SAR, CONFIG_OXC, CONFIG_gw8260,
333 CONFIG_FADS860T, CONFIG_PCI405, CONFIG_hermes,
334 CONFIG_FLAGADM, CONFIG_PCIPPC2, CONFIG_hymod,
335 CONFIG_FPS850L, CONFIG_PCIPPC6, CONFIG_lwmon,
336 CONFIG_GEN860T, CONFIG_PIP405, CONFIG_pcu_e,
337 CONFIG_GENIETV, CONFIG_PM826, CONFIG_ppmc8260,
338 CONFIG_GTH, CONFIG_RPXClassic, CONFIG_rsdproto,
339 CONFIG_IAD210, CONFIG_RPXlite, CONFIG_sbc8260,
340 CONFIG_EBONY, CONFIG_sacsng, CONFIG_FPS860L,
346 CONFIG_HHP_CRADLE, CONFIG_DNP1110, CONFIG_EP7312,
347 CONFIG_IMPA7, CONFIG_LART, CONFIG_LUBBOCK,
348 CONFIG_SHANNON, CONFIG_SMDK2400, CONFIG_SMDK2410,
352 - CPU Module Type: (if CONFIG_COGENT is defined)
353 Define exactly one of
355 --- FIXME --- not tested yet:
356 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
357 CONFIG_CMA287_23, CONFIG_CMA287_50
359 - Motherboard Type: (if CONFIG_COGENT is defined)
360 Define exactly one of
361 CONFIG_CMA101, CONFIG_CMA102
363 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
364 Define one or more of
367 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
368 Define one or more of
369 CONFIG_LCD_HEARTBEAT - update a character position on
370 the lcd display every second with
373 - MPC824X Family Member (if CONFIG_MPC824X is defined)
374 Define exactly one of
375 CONFIG_MPC8240, CONFIG_MPC8245
377 - 8xx CPU Options: (if using an 8xx cpu)
378 Define one or more of
379 CONFIG_8xx_GCLK_FREQ - if get_gclk_freq() can not work e.g.
380 no 32KHz reference PIT/RTC clock
385 U-Boot stores all clock information in Hz
386 internally. For binary compatibility with older Linux
387 kernels (which expect the clocks passed in the
388 bd_info data to be in MHz) the environment variable
389 "clocks_in_mhz" can be defined so that U-Boot
390 converts clock data to MHZ before passing it to the
393 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
394 "clocks_in_mhz=1" is automatically included in the
398 Depending on board, define exactly one serial port
399 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
400 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
401 console by defining CONFIG_8xx_CONS_NONE
403 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
404 port routines must be defined elsewhere
405 (i.e. serial_init(), serial_getc(), ...)
408 Enables console device for a color framebuffer. Needs following
409 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
410 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
412 VIDEO_HW_RECTFILL graphic chip supports
415 VIDEO_HW_BITBLT graphic chip supports
416 bit-blit (cf. smiLynxEM)
417 VIDEO_VISIBLE_COLS visible pixel columns
419 VIDEO_VISIBLE_ROWS visible pixel rows
420 VIDEO_PIXEL_SIZE bytes per pixel
421 VIDEO_DATA_FORMAT graphic data format
422 (0-5, cf. cfb_console.c)
423 VIDEO_FB_ADRS framebuffer address
424 VIDEO_KBD_INIT_FCT keyboard int fct
425 (i.e. i8042_kbd_init())
426 VIDEO_TSTC_FCT test char fct
428 VIDEO_GETC_FCT get char fct
430 CONFIG_CONSOLE_CURSOR cursor drawing on/off
431 (requires blink timer
433 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
434 CONFIG_CONSOLE_TIME display time/date info in
436 (requires CFG_CMD_DATE)
437 CONFIG_VIDEO_LOGO display Linux logo in
439 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
440 linux_logo.h for logo.
441 Requires CONFIG_VIDEO_LOGO
442 CONFIG_CONSOLE_EXTRA_INFO
443 addional board info beside
446 When CONFIG_CFB_CONSOLE is defined, video console is
447 default i/o. Serial console can be forced with
448 environment 'console=serial'.
451 CONFIG_BAUDRATE - in bps
452 Select one of the baudrates listed in
453 CFG_BAUDRATE_TABLE, see below.
455 - Interrupt driven serial port input:
456 CONFIG_SERIAL_SOFTWARE_FIFO
459 Use an interrupt handler for receiving data on the
460 serial port. It also enables using hardware handshake
461 (RTS/CTS) and UART's built-in FIFO. Set the number of
462 bytes the interrupt driven input buffer should have.
464 Set to 0 to disable this feature (this is the default).
465 This will also disable hardware handshake.
467 - Boot Delay: CONFIG_BOOTDELAY - in seconds
468 Delay before automatically booting the default image;
469 set to -1 to disable autoboot.
471 See doc/README.autoboot for these options that
472 work with CONFIG_BOOTDELAY. None are required.
473 CONFIG_BOOT_RETRY_TIME
474 CONFIG_BOOT_RETRY_MIN
475 CONFIG_AUTOBOOT_KEYED
476 CONFIG_AUTOBOOT_PROMPT
477 CONFIG_AUTOBOOT_DELAY_STR
478 CONFIG_AUTOBOOT_STOP_STR
479 CONFIG_AUTOBOOT_DELAY_STR2
480 CONFIG_AUTOBOOT_STOP_STR2
481 CONFIG_ZERO_BOOTDELAY_CHECK
482 CONFIG_RESET_TO_RETRY
486 Only needed when CONFIG_BOOTDELAY is enabled;
487 define a command string that is automatically executed
488 when no character is read on the console interface
489 within "Boot Delay" after reset.
492 This can be used to pass arguments to the bootm
493 command. The value of CONFIG_BOOTARGS goes into the
494 environment value "bootargs".
496 CONFIG_RAMBOOT and CONFIG_NFSBOOT
497 The value of these goes into the environment as
498 "ramboot" and "nfsboot" respectively, and can be used
499 as a convenience, when switching between booting from
505 When this option is #defined, the existence of the
506 environment variable "preboot" will be checked
507 immediately before starting the CONFIG_BOOTDELAY
508 countdown and/or running the auto-boot command resp.
509 entering interactive mode.
511 This feature is especially useful when "preboot" is
512 automatically generated or modified. For an example
513 see the LWMON board specific code: here "preboot" is
514 modified when the user holds down a certain
515 combination of keys on the (special) keyboard when
518 - Serial Download Echo Mode:
520 If defined to 1, all characters received during a
521 serial download (using the "loads" command) are
522 echoed back. This might be needed by some terminal
523 emulations (like "cu"), but may as well just take
524 time on others. This setting #define's the initial
525 value of the "loads_echo" environment variable.
527 - Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
529 Select one of the baudrates listed in
530 CFG_BAUDRATE_TABLE, see below.
534 Most monitor functions can be selected (or
535 de-selected) by adjusting the definition of
536 CONFIG_COMMANDS; to select individual functions,
537 #define CONFIG_COMMANDS by "OR"ing any of the
540 #define enables commands:
541 -------------------------
542 CFG_CMD_ASKENV * ask for env variable
544 CFG_CMD_BEDBUG Include BedBug Debugger
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_ECHO * echo arguments
551 CFG_CMD_EEPROM * EEPROM read/write support
552 CFG_CMD_ELF bootelf, bootvx
554 CFG_CMD_FDC * Floppy Disk Support
555 CFG_CMD_FDOS * Dos diskette Support
556 CFG_CMD_FLASH flinfo, erase, protect
557 CFG_CMD_FPGA FPGA device initialization support
558 CFG_CMD_I2C * I2C serial bus support
559 CFG_CMD_IDE * IDE harddisk support
561 CFG_CMD_IMMAP * IMMR dump support
562 CFG_CMD_IRQ * irqinfo
566 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
568 CFG_CMD_MII MII utility commands
569 CFG_CMD_NET bootp, tftpboot, rarpboot
570 CFG_CMD_PCI * pciinfo
571 CFG_CMD_PCMCIA * PCMCIA support
572 CFG_CMD_REGINFO * Register dump
573 CFG_CMD_RUN run command in env variable
574 CFG_CMD_SCSI * SCSI Support
575 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
576 CFG_CMD_SPI * SPI serial bus support
577 CFG_CMD_USB * USB support
578 CFG_CMD_BSP * Board SPecific functions
579 -----------------------------------------------
582 CFG_CMD_DFL Default configuration; at the moment
583 this is includes all commands, except
584 the ones marked with "*" in the list
587 If you don't define CONFIG_COMMANDS it defaults to
588 CFG_CMD_DFL in include/cmd_confdefs.h. A board can
589 override the default settings in the respective
592 EXAMPLE: If you want all functions except of network
593 support you can write:
595 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
598 Note: Don't enable the "icache" and "dcache" commands
599 (configuration option CFG_CMD_CACHE) unless you know
600 what you (and your U-Boot users) are doing. Data
601 cache cannot be enabled on systems like the 8xx or
602 8260 (where accesses to the IMMR region must be
603 uncached), and it cannot be disabled on all other
604 systems where we (mis-) use the data cache to hold an
605 initial stack and some data.
608 XXX - this list needs to get updated!
612 If this variable is defined, it enables watchdog
613 support. There must support in the platform specific
614 code for a watchdog. For the 8xx and 8260 CPUs, the
615 SIU Watchdog feature is enabled in the SYPCR
620 When CFG_CMD_DATE is selected, the type of the RTC
621 has to be selected, too. Define exactly one of the
624 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
625 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
626 CONFIG_RTC_MC146818 - use MC146818 RTC
627 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
631 When CONFIG_TIMESTAMP is selected, the timestamp
632 (date and time) of an image is printed by image
633 commands like bootm or iminfo. This option is
634 automatically enabled when you select CFG_CMD_DATE .
637 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
638 and/or CONFIG_ISO_PARTITION
640 If IDE or SCSI support is enabled (CFG_CMD_IDE or
641 CFG_CMD_SCSI) you must configure support for at least
642 one partition type as well.
645 CONFIG_IDE_RESET_ROUTINE
647 Set this to define that instead of a reset Pin, the
648 routine ide_set_reset(int idereset) will be used.
653 Set this to enable ATAPI support.
656 At the moment only there is only support for the
657 SYM53C8XX SCSI controller; define
658 CONFIG_SCSI_SYM53C8XX to enable it.
660 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
661 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
662 CFG_SCSI_MAX_LUN] can be adjusted to define the
663 maximum numbers of LUNs, SCSI ID's and target
665 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
667 - NETWORK Support (PCI):
669 Support for Intel 82557/82559/82559ER chips.
670 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
671 write routine for first time initialisation.
674 Support for Digital 2114x chips.
675 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
676 modem chip initialisation (KS8761/QS6611).
679 Support for National dp83815 chips.
682 Support for National dp8382[01] gigabit chips.
685 At the moment only the UHCI host controller is
686 supported (PIP405, MIP405); define
687 CONFIG_USB_UHCI to enable it.
688 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
689 end define CONFIG_USB_STORAGE to enable the USB
692 Supported are USB Keyboards and USB Floppy drives
698 Define this to enable standard (PC-Style) keyboard
702 Standard PC keyboard driver with US (is default) and
703 GERMAN key layout (switch via environment 'keymap=de') support.
704 Export function i8042_kbd_init, i8042_tstc and i8042_getc
705 for cfb_console. Supports cursor blinking.
710 Define this to enable video support (for output to
715 Enable Chips & Technologies 69000 Video chip
717 CONFIG_VIDEO_SMI_LYNXEM
718 Enable Silicon Motion SMI 712/710/810 Video chip
719 Videomode are selected via environment 'videomode' with
720 standard LiLo mode numbers.
721 Following modes are supported (* is default):
723 800x600 1024x768 1280x1024
724 256 (8bit) 303* 305 307
725 65536 (16bit) 314 317 31a
726 16,7 Mill (24bit) 315 318 31b
727 (i.e. setenv videomode 317; saveenv; reset;)
729 CONFIG_VIDEO_SED13806
730 Enable Epson SED13806 driver. This driver supports 8bpp
731 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
732 or CONFIG_VIDEO_SED13806_16BPP
735 - LCD Support: CONFIG_LCD
737 Define this to enable LCD support (for output to LCD
738 display); also select one of the supported displays
739 by defining one of these:
741 CONFIG_NEC_NL6648AC33:
743 NEC NL6648AC33-18. Active, color, single scan.
745 CONFIG_NEC_NL6648BC20
747 NEC NL6648BC20-08. 6.5", 640x480.
748 Active, color, single scan.
752 Sharp 320x240. Active, color, single scan.
753 It isn't 16x9, and I am not sure what it is.
755 CONFIG_SHARP_LQ64D341
757 Sharp LQ64D341 display, 640x480.
758 Active, color, single scan.
762 HLD1045 display, 640x480.
763 Active, color, single scan.
767 Optrex CBL50840-2 NF-FW 99 22 M5
769 Hitachi LMG6912RPFC-00T
773 320x240. Black & white.
775 Normally display is black on white background; define
776 CFG_WHITE_ON_BLACK to get it inverted.
783 Define a default value for ethernet address to use
784 for the respective ethernet interface, in case this
785 is not determined automatically.
790 Define a default value for the IP address to use for
791 the default ethernet interface, in case this is not
792 determined through e.g. bootp.
797 Defines a default value for theIP address of a TFTP
798 server to contact when using the "tftboot" command.
800 - BOOTP Recovery Mode:
801 CONFIG_BOOTP_RANDOM_DELAY
803 If you have many targets in a network that try to
804 boot using BOOTP, you may want to avoid that all
805 systems send out BOOTP requests at precisely the same
806 moment (which would happen for instance at recovery
807 from a power failure, when all systems will try to
808 boot, thus flooding the BOOTP server. Defining
809 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
810 inserted before sending out BOOTP requests. The
811 following delays are insterted then:
813 1st BOOTP request: delay 0 ... 1 sec
814 2nd BOOTP request: delay 0 ... 2 sec
815 3rd BOOTP request: delay 0 ... 4 sec
817 BOOTP requests: delay 0 ... 8 sec
819 - Status LED: CONFIG_STATUS_LED
821 Several configurations allow to display the current
822 status using a LED. For instance, the LED will blink
823 fast while running U-Boot code, stop blinking as
824 soon as a reply to a BOOTP request was received, and
825 start blinking slow once the Linux kernel is running
826 (supported by a status LED driver in the Linux
827 kernel). Defining CONFIG_STATUS_LED enables this
830 - CAN Support: CONFIG_CAN_DRIVER
832 Defining CONFIG_CAN_DRIVER enables CAN driver support
833 on those systems that support this (optional)
834 feature, like the TQM8xxL modules.
836 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
838 Enables I2C serial bus commands. If this is selected,
839 either CONFIG_HARD_I2C or CONFIG_SOFT_I2C must be defined
840 to include the appropriate I2C driver.
842 See also: common/cmd_i2c.c for a description of the
843 command line interface.
848 Selects the CPM hardware driver for I2C.
852 Use software (aka bit-banging) driver instead of CPM
853 or similar hardware support for I2C. This is configured
854 via the following defines.
858 (Optional). Any commands necessary to enable I2C
859 controller or configure ports.
863 (Only for MPC8260 CPU). The I/O port to use (the code
864 assumes both bits are on the same port). Valid values
865 are 0..3 for ports A..D.
869 The code necessary to make the I2C data line active
870 (driven). If the data line is open collector, this
875 The code necessary to make the I2C data line tri-stated
876 (inactive). If the data line is open collector, this
881 Code that returns TRUE if the I2C data line is high,
886 If <bit> is TRUE, sets the I2C data line high. If it
887 is FALSE, it clears it (low).
891 If <bit> is TRUE, sets the I2C clock line high. If it
892 is FALSE, it clears it (low).
896 This delay is invoked four times per clock cycle so this
897 controls the rate of data transfer. The data rate thus
898 is 1 / (I2C_DELAY * 4).
900 - SPI Support: CONFIG_SPI
902 Enables SPI driver (so far only tested with
903 SPI EEPROM, also an instance works with Crystal A/D and
904 D/As on the SACSng board)
908 Enables extended (16-bit) SPI EEPROM addressing.
909 (symmetrical to CONFIG_I2C_X)
913 Enables a software (bit-bang) SPI driver rather than
914 using hardware support. This is a general purpose
915 driver that only requires three general I/O port pins
916 (two outputs, one input) to function. If this is
917 defined, the board configuration must define several
918 SPI configuration items (port pins to use, etc). For
919 an example, see include/configs/sacsng.h.
921 - FPGA Support: CONFIG_FPGA_COUNT
923 Specify the number of FPGA devices to support.
927 Used to specify the types of FPGA devices. For
929 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
931 CFG_FPGA_PROG_FEEDBACK
933 Enable printing of hash marks during FPGA
938 Enable checks on FPGA configuration interface busy
939 status by the configuration function. This option
940 will require a board or device specific function to
945 If defined, a function that provides delays in the
946 FPGA configuration driver.
950 Allow Control-C to interrupt FPGA configuration
954 Check for configuration errors during FPGA bitfile
955 loading. For example, abort during Virtex II
956 configuration if the INIT_B line goes low (which
957 indicated a CRC error).
961 Maximum time to wait for the INIT_B line to deassert
962 after PROB_B has been deasserted during a Virtex II
963 FPGA configuration sequence. The default time is 500 mS.
967 Maximum time to wait for BUSY to deassert during
968 Virtex II FPGA configuration. The default is 5 mS.
972 Time to wait after FPGA configuration. The default is
975 - FPGA Support: CONFIG_FPGA_COUNT
977 Specify the number of FPGA devices to support.
981 Used to specify the types of FPGA devices. For example,
982 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
984 CFG_FPGA_PROG_FEEDBACK
986 Enable printing of hash marks during FPGA configuration.
990 Enable checks on FPGA configuration interface busy
991 status by the configuration function. This option
992 will require a board or device specific function to
997 If defined, a function that provides delays in the FPGA
998 configuration driver.
1000 CFG_FPGA_CHECK_CTRLC
1001 Allow Control-C to interrupt FPGA configuration
1003 CFG_FPGA_CHECK_ERROR
1005 Check for configuration errors during FPGA bitfile
1006 loading. For example, abort during Virtex II
1007 configuration if the INIT_B line goes low (which
1008 indicated a CRC error).
1012 Maximum time to wait for the INIT_B line to deassert
1013 after PROB_B has been deasserted during a Virtex II
1014 FPGA configuration sequence. The default time is 500
1019 Maximum time to wait for BUSY to deassert during
1020 Virtex II FPGA configuration. The default is 5 mS.
1022 CFG_FPGA_WAIT_CONFIG
1024 Time to wait after FPGA configuration. The default is
1027 - Configuration Management:
1030 If defined, this string will be added to the U-Boot
1031 version information (U_BOOT_VERSION)
1033 - Vendor Parameter Protection:
1035 U-Boot considers the values of the environment
1036 variables "serial#" (Board Serial Number) and
1037 "ethaddr" (Ethernet Address) to bb parameters that
1038 are set once by the board vendor / manufacturer, and
1039 protects these variables from casual modification by
1040 the user. Once set, these variables are read-only,
1041 and write or delete attempts are rejected. You can
1042 change this behviour:
1044 If CONFIG_ENV_OVERWRITE is #defined in your config
1045 file, the write protection for vendor parameters is
1046 completely disabled. Anybody can change or delte
1049 Alternatively, if you #define _both_ CONFIG_ETHADDR
1050 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1051 ethernet address is installed in the environment,
1052 which can be changed exactly ONCE by the user. [The
1053 serial# is unaffected by this, i. e. it remains
1059 Define this variable to enable the reservation of
1060 "protected RAM", i. e. RAM which is not overwritten
1061 by U-Boot. Define CONFIG_PRAM to hold the number of
1062 kB you want to reserve for pRAM. You can overwrite
1063 this default value by defining an environment
1064 variable "pram" to the number of kB you want to
1065 reserve. Note that the board info structure will
1066 still show the full amount of RAM. If pRAM is
1067 reserved, a new environment variable "mem" will
1068 automatically be defined to hold the amount of
1069 remaining RAM in a form that can be passed as boot
1070 argument to Linux, for instance like that:
1072 setenv bootargs ... mem=\$(mem)
1075 This way you can tell Linux not to use this memory,
1076 either, which results in a memory region that will
1077 not be affected by reboots.
1079 *WARNING* If your board configuration uses automatic
1080 detection of the RAM size, you must make sure that
1081 this memory test is non-destructive. So far, the
1082 following board configurations are known to be
1085 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1086 HERMES, IP860, RPXlite, LWMON, LANTEC,
1087 PCU_E, FLAGADM, TQM8260
1092 Define this variable to stop the system in case of a
1093 fatal error, so that you have to reset it manually.
1094 This is probably NOT a good idea for an embedded
1095 system where you want to system to reboot
1096 automatically as fast as possible, but it may be
1097 useful during development since you can try to debug
1098 the conditions that lead to the situation.
1100 CONFIG_NET_RETRY_COUNT
1102 This variable defines the number of retries for
1103 network operations like ARP, RARP, TFTP, or BOOTP
1104 before giving up the operation. If not defined, a
1105 default value of 5 is used.
1107 - Command Interpreter:
1110 Define this variable to enable the "hush" shell (from
1111 Busybox) as command line interpreter, thus enabling
1112 powerful command line syntax like
1113 if...then...else...fi conditionals or `&&' and '||'
1114 constructs ("shell scripts").
1116 If undefined, you get the old, much simpler behaviour
1117 with a somewhat smaller memory footprint.
1122 This defines the secondary prompt string, which is
1123 printed when the command interpreter needs more input
1124 to complete a command. Usually "> ".
1128 In the current implementation, the local variables
1129 space and global environment variables space are
1130 separated. Local variables are those you define by
1131 simply typing like `name=value'. To access a local
1132 variable later on, you have write `$name' or
1133 `${name}'; variable directly by typing say `$name' at
1136 Global environment variables are those you use
1137 setenv/printenv to work with. To run a command stored
1138 in such a variable, you need to use the run command,
1139 and you must not use the '$' sign to access them.
1141 To store commands and special characters in a
1142 variable, please use double quotation marks
1143 surrounding the whole text of the variable, instead
1144 of the backslashes before semicolons and special
1147 - Default Environment
1148 CONFIG_EXTRA_ENV_SETTINGS
1150 Define this to contain any number of null terminated
1151 strings (variable = value pairs) that will be part of
1152 the default enviroment compiled into the boot image.
1154 For example, place something like this in your
1155 board's config file:
1157 #define CONFIG_EXTRA_ENV_SETTINGS \
1161 Warning: This method is based on knowledge about the
1162 internal format how the environment is stored by the
1163 U-Boot code. This is NOT an official, exported
1164 interface! Although it is unlikely that this format
1165 will change soon, but there is no guarantee either.
1166 You better know what you are doing here.
1168 Note: overly (ab)use of the default environment is
1169 discouraged. Make sure to check other ways to preset
1170 the environment like the autoscript function or the
1173 - Show boot progress
1174 CONFIG_SHOW_BOOT_PROGRESS
1176 Defining this option allows to add some board-
1177 specific code (calling a user-provided function
1178 "show_boot_progress(int)") that enables you to show
1179 the system's boot progress on some display (for
1180 example, some LED's) on your board. At the moment,
1181 the following checkpoints are implemented:
1184 1 common/cmd_bootm.c before attempting to boot an image
1185 -1 common/cmd_bootm.c Image header has bad magic number
1186 2 common/cmd_bootm.c Image header has correct magic number
1187 -2 common/cmd_bootm.c Image header has bad checksum
1188 3 common/cmd_bootm.c Image header has correct checksum
1189 -3 common/cmd_bootm.c Image data has bad checksum
1190 4 common/cmd_bootm.c Image data has correct checksum
1191 -4 common/cmd_bootm.c Image is for unsupported architecture
1192 5 common/cmd_bootm.c Architecture check OK
1193 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1194 6 common/cmd_bootm.c Image Type check OK
1195 -6 common/cmd_bootm.c gunzip uncompression error
1196 -7 common/cmd_bootm.c Unimplemented compression type
1197 7 common/cmd_bootm.c Uncompression OK
1198 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1199 8 common/cmd_bootm.c Image Type check OK
1200 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1201 9 common/cmd_bootm.c Start initial ramdisk verification
1202 -10 common/cmd_bootm.c Ramdisk header has bad magic number
1203 -11 common/cmd_bootm.c Ramdisk header has bad checksum
1204 10 common/cmd_bootm.c Ramdisk header is OK
1205 -12 common/cmd_bootm.c Ramdisk data has bad checksum
1206 11 common/cmd_bootm.c Ramdisk data has correct checksum
1207 12 common/cmd_bootm.c Ramdisk verification complete, start loading
1208 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk)
1209 13 common/cmd_bootm.c Start multifile image verification
1210 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue.
1211 15 common/cmd_bootm.c All preparation done, transferring control to OS
1213 -1 common/cmd_doc.c Bad usage of "doc" command
1214 -1 common/cmd_doc.c No boot device
1215 -1 common/cmd_doc.c Unknown Chip ID on boot device
1216 -1 common/cmd_doc.c Read Error on boot device
1217 -1 common/cmd_doc.c Image header has bad magic number
1219 -1 common/cmd_ide.c Bad usage of "ide" command
1220 -1 common/cmd_ide.c No boot device
1221 -1 common/cmd_ide.c Unknown boot device
1222 -1 common/cmd_ide.c Unknown partition table
1223 -1 common/cmd_ide.c Invalid partition type
1224 -1 common/cmd_ide.c Read Error on boot device
1225 -1 common/cmd_ide.c Image header has bad magic number
1227 -1 common/cmd_nvedit.c Environment not changable, but has bad CRC
1233 [so far only for SMDK2400 board]
1235 - Modem support endable:
1236 CONFIG_MODEM_SUPPORT
1238 - RTS/CTS Flow control enable:
1241 - Modem debug support:
1242 CONFIG_MODEM_SUPPORT_DEBUG
1244 Enables debugging stuff (char screen[1024], dbg())
1245 for modem support. Useful only with BDI2000.
1249 In the target system modem support is enabled when a
1250 specific key (key combination) is pressed during
1251 power-on. Otherwise U-Boot will boot normally
1252 (autoboot). The key_pressed() fuction is called from
1253 board_init(). Currently key_pressed() is a dummy
1254 function, returning 1 and thus enabling modem
1257 If there are no modem init strings in the
1258 environment, U-Boot proceed to autoboot; the
1259 previous output (banner, info printfs) will be
1262 See also: doc/README.Modem
1267 Configuration Settings:
1268 -----------------------
1270 - CFG_LONGHELP: Defined when you want long help messages included;
1271 undefine this when you're short of memory.
1273 - CFG_PROMPT: This is what U-Boot prints on the console to
1274 prompt for user input.
1276 - CFG_CBSIZE: Buffer size for input from the Console
1278 - CFG_PBSIZE: Buffer size for Console output
1280 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1282 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1283 the application (usually a Linux kernel) when it is
1286 - CFG_BAUDRATE_TABLE:
1287 List of legal baudrate settings for this board.
1289 - CFG_CONSOLE_INFO_QUIET
1290 Suppress display of console information at boot.
1292 - CFG_CONSOLE_IS_IN_ENV
1293 If the board specific function
1294 extern int overwrite_console (void);
1295 returns 1, the stdin, stderr and stdout are switched to the
1296 serial port, else the settings in the environment are used.
1298 - CFG_CONSOLE_OVERWRITE_ROUTINE
1299 Enable the call to overwrite_console().
1301 - CFG_CONSOLE_ENV_OVERWRITE
1302 Enable overwrite of previous console environment settings.
1304 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1305 Begin and End addresses of the area used by the
1309 Enable an alternate, more extensive memory test.
1311 - CFG_TFTP_LOADADDR:
1312 Default load address for network file downloads
1314 - CFG_LOADS_BAUD_CHANGE:
1315 Enable temporary baudrate change while serial download
1318 Physical start address of SDRAM. _Must_ be 0 here.
1321 Physical start address of Motherboard I/O (if using a
1325 Physical start address of Flash memory.
1328 Physical start address of boot monitor code (set by
1329 make config files to be same as the text base address
1330 (TEXT_BASE) used when linking) - same as
1331 CFG_FLASH_BASE when booting from flash.
1334 Size of memory reserved for monitor code
1337 Size of DRAM reserved for malloc() use.
1340 Maximum size of memory mapped by the startup code of
1341 the Linux kernel; all data that must be processed by
1342 the Linux kernel (bd_info, boot arguments, eventually
1343 initrd image) must be put below this limit.
1345 - CFG_MAX_FLASH_BANKS:
1346 Max number of Flash memory banks
1348 - CFG_MAX_FLASH_SECT:
1349 Max number of sectors on a Flash chip
1351 - CFG_FLASH_ERASE_TOUT:
1352 Timeout for Flash erase operations (in ms)
1354 - CFG_FLASH_WRITE_TOUT:
1355 Timeout for Flash write operations (in ms)
1357 - CFG_DIRECT_FLASH_TFTP:
1359 Enable TFTP transfers directly to flash memory;
1360 without this option such a download has to be
1361 performed in two steps: (1) download to RAM, and (2)
1362 copy from RAM to flash.
1364 The two-step approach is usually more reliable, since
1365 you can check if the download worked before you erase
1366 the flash, but in some situations (when sytem RAM is
1367 too limited to allow for a tempory copy of the
1368 downloaded image) this option may be very useful.
1371 Define if the flash driver uses extra elements in the
1372 common flash structure for storing flash geometry
1374 The following definitions that deal with the placement and management
1375 of environment data (variable area); in general, we support the
1376 following configurations:
1378 - CFG_ENV_IS_IN_FLASH:
1380 Define this if the environment is in flash memory.
1382 a) The environment occupies one whole flash sector, which is
1383 "embedded" in the text segment with the U-Boot code. This
1384 happens usually with "bottom boot sector" or "top boot
1385 sector" type flash chips, which have several smaller
1386 sectors at the start or the end. For instance, such a
1387 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
1388 such a case you would place the environment in one of the
1389 4 kB sectors - with U-Boot code before and after it. With
1390 "top boot sector" type flash chips, you would put the
1391 environment in one of the last sectors, leaving a gap
1392 between U-Boot and the environment.
1396 Offset of environment data (variable area) to the
1397 beginning of flash memory; for instance, with bottom boot
1398 type flash chips the second sector can be used: the offset
1399 for this sector is given here.
1401 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
1405 This is just another way to specify the start address of
1406 the flash sector containing the environment (instead of
1409 - CFG_ENV_SECT_SIZE:
1411 Size of the sector containing the environment.
1414 b) Sometimes flash chips have few, equal sized, BIG sectors.
1415 In such a case you don't want to spend a whole sector for
1420 If you use this in combination with CFG_ENV_IS_IN_FLASH
1421 and CFG_ENV_SECT_SIZE, you can specify to use only a part
1422 of this flash sector for the environment. This saves
1423 memory for the RAM copy of the environment.
1425 It may also save flash memory if you decide to use this
1426 when your environment is "embedded" within U-Boot code,
1427 since then the remainder of the flash sector could be used
1428 for U-Boot code. It should be pointed out that this is
1429 STRONGLY DISCOURAGED from a robustness point of view:
1430 updating the environment in flash makes it always
1431 necessary to erase the WHOLE sector. If something goes
1432 wrong before the contents has been restored from a copy in
1433 RAM, your target system will be dead.
1435 - CFG_ENV_ADDR_REDUND
1438 These settings describe a second storage area used to hold
1439 a redundand copy of the environment data, so that there is
1440 a valid backup copy in case there is a power failur during
1441 a "saveenv" operation.
1443 BE CAREFUL! Any changes to the flash layout, and some changes to the
1444 source code will make it necessary to adapt <board>/u-boot.lds*
1448 - CFG_ENV_IS_IN_NVRAM:
1450 Define this if you have some non-volatile memory device
1451 (NVRAM, battery buffered SRAM) which you want to use for the
1457 These two #defines are used to determin the memory area you
1458 want to use for environment. It is assumed that this memory
1459 can just be read and written to, without any special
1462 BE CAREFUL! The first access to the environment happens quite early
1463 in U-Boot initalization (when we try to get the setting of for the
1464 console baudrate). You *MUST* have mappend your NVRAM area then, or
1467 Please note that even with NVRAM we still use a copy of the
1468 environment in RAM: we could work on NVRAM directly, but we want to
1469 keep settings there always unmodified except somebody uses "saveenv"
1470 to save the current settings.
1473 - CFG_ENV_IS_IN_EEPROM:
1475 Use this if you have an EEPROM or similar serial access
1476 device and a driver for it.
1481 These two #defines specify the offset and size of the
1482 environment area within the total memory of your EEPROM.
1484 - CFG_I2C_EEPROM_ADDR:
1485 If defined, specified the chip address of the EEPROM device.
1486 The default address is zero.
1488 - CFG_EEPROM_PAGE_WRITE_BITS:
1489 If defined, the number of bits used to address bytes in a
1490 single page in the EEPROM device. A 64 byte page, for example
1491 would require six bits.
1493 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1494 If defined, the number of milliseconds to delay between
1495 page writes. The default is zero milliseconds.
1497 - CFG_I2C_EEPROM_ADDR_LEN:
1498 The length in bytes of the EEPROM memory array address. Note
1499 that this is NOT the chip address length!
1502 The size in bytes of the EEPROM device.
1504 - CFG_I2C_EEPROM_ADDR:
1505 If defined, specified the chip address of the EEPROM device.
1506 The default address is zero.
1508 - CFG_EEPROM_PAGE_WRITE_BITS:
1509 If defined, the number of bits used to address bytes in a
1510 single page in the EEPROM device. A 64 byte page, for example
1511 would require six bits.
1513 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1514 If defined, the number of milliseconds to delay between
1515 page writes. The default is zero milliseconds.
1517 - CFG_I2C_EEPROM_ADDR_LEN:
1518 The length in bytes of the EEPROM memory array address. Note
1519 that this is NOT the chip address length!
1522 The size in bytes of the EEPROM device.
1524 - CFG_SPI_INIT_OFFSET
1526 Defines offset to the initial SPI buffer area in DPRAM. The
1527 area is used at an early stage (ROM part) if the environment
1528 is configured to reside in the SPI EEPROM: We need a 520 byte
1529 scratch DPRAM area. It is used between the two initialization
1530 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
1531 to be a good choice since it makes it far enough from the
1532 start of the data area as well as from the stack pointer.
1534 Please note that the environment is read-only as long as the monitor
1535 has been relocated to RAM and a RAM copy of the environment has been
1536 created; also, when using EEPROM you will have to use getenv_r()
1537 until then to read environment variables.
1539 The environment is now protected by a CRC32 checksum. Before the
1540 monitor is relocated into RAM, as a result of a bad CRC you will be
1541 working with the compiled-in default environment - *silently*!!!
1542 [This is necessary, because the first environment variable we need is
1543 the "baudrate" setting for the console - if we have a bad CRC, we
1544 don't have any device yet where we could complain.]
1546 Note: once the monitor has been relocated, then it will complain if
1547 the default environment is used; a new CRC is computed as soon as you
1548 use the "setenv" command to modify / delete / add any environment
1549 variable [even when you try to delete a non-existing variable!].
1551 Note2: you must edit your u-boot.lds file to reflect this
1555 Low Level (hardware related) configuration options:
1557 - CFG_CACHELINE_SIZE:
1558 Cache Line Size of the CPU.
1561 Default address of the IMMR after system reset.
1562 Needed on some 8260 systems (MPC8260ADS and RPXsuper)
1563 to be able to adjust the position of the IMMR
1564 register after a reset.
1566 - Floppy Disk Support:
1567 CFG_FDC_DRIVE_NUMBER
1569 the default drive number (default value 0)
1573 defines the spacing between fdc chipset registers
1578 defines the offset of register from address. It
1579 depends on which part of the data bus is connected to
1580 the fdc chipset. (default value 0)
1582 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
1583 CFG_FDC_DRIVE_NUMBER are undefined, they take their
1586 if CFG_FDC_HW_INIT is defined, then the function
1587 fdc_hw_init() is called at the beginning of the FDC
1588 setup. fdc_hw_init() must be provided by the board
1589 source code. It is used to make hardware dependant
1592 - CFG_IMMR: Physical address of the Internal Memory Mapped
1593 Register; DO NOT CHANGE! (11-4)
1594 [MPC8xx systems only]
1596 - CFG_INIT_RAM_ADDR:
1598 Start address of memory area tha can be used for
1599 initial data and stack; please note that this must be
1600 writable memory that is working WITHOUT special
1601 initialization, i. e. you CANNOT use normal RAM which
1602 will become available only after programming the
1603 memory controller and running certain initialization
1606 U-Boot uses the following memory types:
1607 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
1608 - MPC824X: data cache
1609 - PPC4xx: data cache
1611 - CFG_INIT_DATA_OFFSET:
1613 Offset of the initial data structure in the memory
1614 area defined by CFG_INIT_RAM_ADDR. Usually
1615 CFG_INIT_DATA_OFFSET is chosen such that the initial
1616 data is located at the end of the available space
1617 (sometimes written as (CFG_INIT_RAM_END -
1618 CFG_INIT_DATA_SIZE), and the initial stack is just
1619 below that area (growing from (CFG_INIT_RAM_ADDR +
1620 CFG_INIT_DATA_OFFSET) downward.
1623 On the MPC824X (or other systems that use the data
1624 cache for initial memory) the address chosen for
1625 CFG_INIT_RAM_ADDR is basically arbitrary - it must
1626 point to an otherwise UNUSED address space between
1627 the top of RAM and the start of the PCI space.
1629 - CFG_SIUMCR: SIU Module Configuration (11-6)
1631 - CFG_SYPCR: System Protection Control (11-9)
1633 - CFG_TBSCR: Time Base Status and Control (11-26)
1635 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
1637 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
1639 - CFG_SCCR: System Clock and reset Control Register (15-27)
1641 - CFG_OR_TIMING_SDRAM:
1645 periodic timer for refresh
1647 - CFG_DER: Debug Event Register (37-47)
1649 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
1650 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
1651 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
1653 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
1655 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
1656 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
1657 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
1658 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
1660 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
1661 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
1662 Machine Mode Register and Memory Periodic Timer
1663 Prescaler definitions (SDRAM timing)
1665 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
1666 enable I2C microcode relocation patch (MPC8xx);
1667 define relocation offset in DPRAM [DSP2]
1669 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
1670 enable SPI microcode relocation patch (MPC8xx);
1671 define relocation offset in DPRAM [SCC4]
1674 Use OSCM clock mode on MBX8xx board. Be careful,
1675 wrong setting might damage your board. Read
1676 doc/README.MBX before setting this variable!
1678 - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
1679 Offset of the bootmode word in DPRAM used by post
1680 (Power On Self Tests). This definition overrides
1681 #define'd default value in commproc.h resp.
1684 Building the Software:
1685 ======================
1687 Building U-Boot has been tested in native PPC environments (on a
1688 PowerBook G3 running LinuxPPC 2000) and in cross environments
1689 (running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
1692 If you are not using a native PPC environment, it is assumed that you
1693 have the GNU cross compiling tools available in your path and named
1694 with a prefix of "powerpc-linux-". If this is not the case, (e.g. if
1695 you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
1696 the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
1699 CROSS_COMPILE = ppc_4xx-
1702 U-Boot is intended to be simple to build. After installing the
1703 sources you must configure U-Boot for one specific board type. This
1708 where "NAME_config" is the name of one of the existing
1709 configurations; the following names are supported:
1711 ADCIOP_config GTH_config TQM850L_config
1712 ADS860_config IP860_config TQM855L_config
1713 AR405_config IVML24_config TQM860L_config
1714 CANBT_config IVMS8_config WALNUT405_config
1715 CPCI405_config LANTEC_config cogent_common_config
1716 CPCIISER4_config MBX_config cogent_mpc8260_config
1717 CU824_config MBX860T_config cogent_mpc8xx_config
1718 ESTEEM192E_config RPXlite_config hermes_config
1719 ETX094_config RPXsuper_config hymod_config
1720 FADS823_config SM850_config lwmon_config
1721 FADS850SAR_config SPD823TS_config pcu_e_config
1722 FADS860T_config SXNI855T_config rsdproto_config
1723 FPS850L_config Sandpoint8240_config sbc8260_config
1724 GENIETV_config TQM823L_config PIP405_config
1725 GEN860T_config EBONY_config FPS860L_config
1727 Note: for some board special configuration names may exist; check if
1728 additional information is available from the board vendor; for
1729 instance, the TQM8xxL systems run normally at 50 MHz and use a
1730 SCC for 10baseT ethernet; there are also systems with 80 MHz
1731 CPU clock, and an optional Fast Ethernet module is available
1732 for CPU's with FEC. You can select such additional "features"
1733 when chosing the configuration, i. e.
1736 - will configure for a plain TQM860L, i. e. 50MHz, no FEC
1738 make TQM860L_FEC_config
1739 - will configure for a TQM860L at 50MHz with FEC for ethernet
1741 make TQM860L_80MHz_config
1742 - will configure for a TQM860L at 80 MHz, with normal 10baseT
1745 make TQM860L_FEC_80MHz_config
1746 - will configure for a TQM860L at 80 MHz with FEC for ethernet
1748 make TQM823L_LCD_config
1749 - will configure for a TQM823L with U-Boot console on LCD
1751 make TQM823L_LCD_80MHz_config
1752 - will configure for a TQM823L at 80 MHz with U-Boot console on LCD
1758 Finally, type "make all", and you should get some working U-Boot
1759 images ready for downlod to / installation on your system:
1761 - "u-boot.bin" is a raw binary image
1762 - "u-boot" is an image in ELF binary format
1763 - "u-boot.srec" is in Motorola S-Record format
1766 Please be aware that the Makefiles assume you are using GNU make, so
1767 for instance on NetBSD you might need to use "gmake" instead of
1771 If the system board that you have is not listed, then you will need
1772 to port U-Boot to your hardware platform. To do this, follow these
1775 1. Add a new configuration option for your board to the toplevel
1776 "Makefile", using the existing entries as examples.
1777 2. Create a new directory to hold your board specific code. Add any
1779 3. If you're porting U-Boot to a new CPU, then also create a new
1780 directory to hold your CPU specific code. Add any files you need.
1781 4. Run "make config_name" with your new name.
1782 5. Type "make", and you should get a working "u-boot.srec" file
1783 to be installed on your target system.
1784 [Of course, this last step is much harder than it sounds.]
1787 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
1788 ==============================================================
1790 If you have modified U-Boot sources (for instance added a new board
1791 or support for new devices, a new CPU, etc.) you are expected to
1792 provide feedback to the other developers. The feedback normally takes
1793 the form of a "patch", i. e. a context diff against a certain (latest
1794 official or latest in CVS) version of U-Boot sources.
1796 But before you submit such a patch, please verify that your modifi-
1797 cation did not break existing code. At least make sure that *ALL* of
1798 the supported boards compile WITHOUT ANY compiler warnings. To do so,
1799 just run the "MAKEALL" script, which will configure and build U-Boot
1800 for ALL supported system. Be warned, this will take a while. You can
1801 select which (cross) compiler to use py passing a `CROSS_COMPILE'
1802 environment variable to the script, i. e. to use the cross tools from
1803 MontaVista's Hard Hat Linux you can type
1805 CROSS_COMPILE=ppc_8xx- MAKEALL
1807 or to build on a native PowerPC system you can type
1809 CROSS_COMPILE=' ' MAKEALL
1811 See also "U-Boot Porting Guide" below.
1815 Monitor Commands - Overview:
1816 ============================
1818 go - start application at address 'addr'
1819 run - run commands in an environment variable
1820 bootm - boot application image from memory
1821 bootp - boot image via network using BootP/TFTP protocol
1822 tftpboot- boot image via network using TFTP protocol
1823 and env variables "ipaddr" and "serverip"
1824 (and eventually "gatewayip")
1825 rarpboot- boot image via network using RARP/TFTP protocol
1826 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
1827 loads - load S-Record file over serial line
1828 loadb - load binary file over serial line (kermit mode)
1830 mm - memory modify (auto-incrementing)
1831 nm - memory modify (constant address)
1832 mw - memory write (fill)
1834 cmp - memory compare
1835 crc32 - checksum calculation
1836 imd - i2c memory display
1837 imm - i2c memory modify (auto-incrementing)
1838 inm - i2c memory modify (constant address)
1839 imw - i2c memory write (fill)
1840 icrc32 - i2c checksum calculation
1841 iprobe - probe to discover valid I2C chip addresses
1842 iloop - infinite loop on address range
1843 isdram - print SDRAM configuration information
1844 sspi - SPI utility commands
1845 base - print or set address offset
1846 printenv- print environment variables
1847 setenv - set environment variables
1848 saveenv - save environment variables to persistent storage
1849 protect - enable or disable FLASH write protection
1850 erase - erase FLASH memory
1851 flinfo - print FLASH memory information
1852 bdinfo - print Board Info structure
1853 iminfo - print header information for application image
1854 coninfo - print console devices and informations
1855 ide - IDE sub-system
1856 loop - infinite loop on address range
1857 mtest - simple RAM test
1858 icache - enable or disable instruction cache
1859 dcache - enable or disable data cache
1860 reset - Perform RESET of the CPU
1861 echo - echo args to console
1862 version - print monitor version
1863 help - print online help
1864 ? - alias for 'help'
1867 Monitor Commands - Detailed Description:
1868 ========================================
1872 For now: just type "help <command>".
1875 Environment Variables:
1876 ======================
1878 U-Boot supports user configuration using Environment Variables which
1879 can be made persistent by saving to Flash memory.
1881 Environment Variables are set using "setenv", printed using
1882 "printenv", and saved to Flash using "saveenv". Using "setenv"
1883 without a value can be used to delete a variable from the
1884 environment. As long as you don't save the environment you are
1885 working with an in-memory copy. In case the Flash area containing the
1886 environment is erased by accident, a default environment is provided.
1888 Some configuration options can be set using Environment Variables:
1890 baudrate - see CONFIG_BAUDRATE
1892 bootdelay - see CONFIG_BOOTDELAY
1894 bootcmd - see CONFIG_BOOTCOMMAND
1896 bootargs - Boot arguments when booting an RTOS image
1898 bootfile - Name of the image to load with TFTP
1900 autoload - if set to "no" (any string beginning with 'n'),
1901 "bootp" will just load perform a lookup of the
1902 configuration from the BOOTP server, but not try to
1903 load any image using TFTP
1905 autostart - if set to "yes", an image loaded using the "bootp",
1906 "rarpboot", "tftpboot" or "diskboot" commands will
1907 be automatically started (by internally calling
1910 initrd_high - restrict positioning of initrd images:
1911 If this variable is not set, initrd images will be
1912 copied to the highest possible address in RAM; this
1913 is usually what you want since it allows for
1914 maximum initrd size. If for some reason you want to
1915 make sure that the initrd image is loaded below the
1916 CFG_BOOTMAPSZ limit, you can set this environment
1917 variable to a value of "no" or "off" or "0".
1918 Alternatively, you can set it to a maximum upper
1919 address to use (U-Boot will still check that it
1920 does not overwrite the U-Boot stack and data).
1922 For instance, when you have a system with 16 MB
1923 RAM, and want to reseve 4 MB from use by Linux,
1924 you can do this by adding "mem=12M" to the value of
1925 the "bootargs" variable. However, now you must make
1926 sure, that the initrd image is placed in the first
1927 12 MB as well - this can be done with
1929 setenv initrd_high 00c00000
1931 ipaddr - IP address; needed for tftpboot command
1933 loadaddr - Default load address for commands like "bootp",
1934 "rarpboot", "tftpboot" or "diskboot"
1936 loads_echo - see CONFIG_LOADS_ECHO
1938 serverip - TFTP server IP address; needed for tftpboot command
1940 bootretry - see CONFIG_BOOT_RETRY_TIME
1942 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
1944 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
1947 The following environment variables may be used and automatically
1948 updated by the network boot commands ("bootp" and "rarpboot"),
1949 depending the information provided by your boot server:
1951 bootfile - see above
1952 dnsip - IP address of your Domain Name Server
1953 gatewayip - IP address of the Gateway (Router) to use
1954 hostname - Target hostname
1956 netmask - Subnet Mask
1957 rootpath - Pathname of the root filesystem on the NFS server
1958 serverip - see above
1961 There are two special Environment Variables:
1963 serial# - contains hardware identification information such
1964 as type string and/or serial number
1965 ethaddr - Ethernet address
1967 These variables can be set only once (usually during manufacturing of
1968 the board). U-Boot refuses to delete or overwrite these variables
1969 once they have been set once.
1972 Please note that changes to some configuration parameters may take
1973 only effect after the next boot (yes, that's just like Windoze :-).
1976 Note for Redundant Ethernet Interfaces:
1977 =======================================
1979 Some boards come with redundand ethernet interfaces; U-Boot supports
1980 such configurations and is capable of automatic selection of a
1981 "working" interface when needed. MAC assignemnt works as follows:
1983 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
1984 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
1985 "eth1addr" (=>eth1), "eth2addr", ...
1987 If the network interface stores some valid MAC address (for instance
1988 in SROM), this is used as default address if there is NO correspon-
1989 ding setting in the environment; if the corresponding environment
1990 variable is set, this overrides the settings in the card; that means:
1992 o If the SROM has a valid MAC address, and there is no address in the
1993 environment, the SROM's address is used.
1995 o If there is no valid address in the SROM, and a definition in the
1996 environment exists, then the value from the environment variable is
1999 o If both the SROM and the environment contain a MAC address, and
2000 both addresses are the same, this MAC address is used.
2002 o If both the SROM and the environment contain a MAC address, and the
2003 addresses differ, the value from the environment is used and a
2006 o If neither SROM nor the environment contain a MAC address, an error
2014 The "boot" commands of this monitor operate on "image" files which
2015 can be basicly anything, preceeded by a special header; see the
2016 definitions in include/image.h for details; basicly, the header
2017 defines the following image properties:
2019 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2020 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2022 Currently supported: Linux, NetBSD, VxWorks, QNX).
2023 * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
2024 IA64, MIPS, MIPS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2025 Currently supported: PowerPC).
2026 * Compression Type (Provisions for uncompressed, gzip, bzip2;
2027 Currently supported: uncompressed, gzip).
2033 The header is marked by a special Magic Number, and both the header
2034 and the data portions of the image are secured against corruption by
2041 Although U-Boot should support any OS or standalone application
2042 easily, Linux has always been in the focus during the design of
2045 U-Boot includes many features that so far have been part of some
2046 special "boot loader" code within the Linux kernel. Also, any
2047 "initrd" images to be used are no longer part of one big Linux image;
2048 instead, kernel and "initrd" are separate images. This implementation
2049 serves serveral purposes:
2051 - the same features can be used for other OS or standalone
2052 applications (for instance: using compressed images to reduce the
2053 Flash memory footprint)
2055 - it becomes much easier to port new Linux kernel versions because
2056 lots of low-level, hardware dependend stuff are done by U-Boot
2058 - the same Linux kernel image can now be used with different "initrd"
2059 images; of course this also means that different kernel images can
2060 be run with the same "initrd". This makes testing easier (you don't
2061 have to build a new "zImage.initrd" Linux image when you just
2062 change a file in your "initrd"). Also, a field-upgrade of the
2063 software is easier now.
2069 Porting Linux to U-Boot based systems:
2070 ---------------------------------------
2072 U-Boot cannot save you from doing all the necessary modifications to
2073 configure the Linux device drivers for use with your target hardware
2074 (no, we don't intend to provide a full virtual machine interface to
2077 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
2079 Just make sure your machine specific header file (for instance
2080 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
2081 Information structure as we define in include/u-boot.h, and make
2082 sure that your definition of IMAP_ADDR uses the same value as your
2083 U-Boot configuration in CFG_IMMR.
2086 Configuring the Linux kernel:
2087 -----------------------------
2089 No specific requirements for U-Boot. Make sure you have some root
2090 device (initial ramdisk, NFS) for your target system.
2093 Building a Linux Image:
2094 -----------------------
2096 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2097 not used. If you use recent kernel source, a new build target
2098 "uImage" will exist which automatically builds an image usable by
2099 U-Boot. Most older kernels also have support for a "pImage" target,
2100 which was introduced for our predecessor project PPCBoot and uses a
2101 100% compatible format.
2110 The "uImage" build target uses a special tool (in 'tools/mkimage') to
2111 encapsulate a compressed Linux kernel image with header information,
2112 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
2114 * build a standard "vmlinux" kernel image (in ELF binary format):
2116 * convert the kernel into a raw binary image:
2118 ${CROSS_COMPILE}-objcopy -O binary \
2119 -R .note -R .comment \
2120 -S vmlinux linux.bin
2122 * compress the binary image:
2126 * package compressed binary image for U-Boot:
2128 mkimage -A ppc -O linux -T kernel -C gzip \
2129 -a 0 -e 0 -n "Linux Kernel Image" \
2130 -d linux.bin.gz uImage
2133 The "mkimage" tool can also be used to create ramdisk images for use
2134 with U-Boot, either separated from the Linux kernel image, or
2135 combined into one file. "mkimage" encapsulates the images with a 64
2136 byte header containing information about target architecture,
2137 operating system, image type, compression method, entry points, time
2138 stamp, CRC32 checksums, etc.
2140 "mkimage" can be called in two ways: to verify existing images and
2141 print the header information, or to build new images.
2143 In the first form (with "-l" option) mkimage lists the information
2144 contained in the header of an existing U-Boot image; this includes
2145 checksum verification:
2147 tools/mkimage -l image
2148 -l ==> list image header information
2150 The second form (with "-d" option) is used to build a U-Boot image
2151 from a "data file" which is used as image payload:
2153 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2154 -n name -d data_file image
2155 -A ==> set architecture to 'arch'
2156 -O ==> set operating system to 'os'
2157 -T ==> set image type to 'type'
2158 -C ==> set compression type 'comp'
2159 -a ==> set load address to 'addr' (hex)
2160 -e ==> set entry point to 'ep' (hex)
2161 -n ==> set image name to 'name'
2162 -d ==> use image data from 'datafile'
2164 Right now, all Linux kernels use the same load address (0x00000000),
2165 but the entry point address depends on the kernel version:
2167 - 2.2.x kernels have the entry point at 0x0000000C,
2168 - 2.3.x and later kernels have the entry point at 0x00000000.
2170 So a typical call to build a U-Boot image would read:
2172 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2173 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
2174 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
2175 > examples/uImage.TQM850L
2176 Image Name: 2.4.4 kernel for TQM850L
2177 Created: Wed Jul 19 02:34:59 2000
2178 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2179 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2180 Load Address: 0x00000000
2181 Entry Point: 0x00000000
2183 To verify the contents of the image (or check for corruption):
2185 -> tools/mkimage -l examples/uImage.TQM850L
2186 Image Name: 2.4.4 kernel for TQM850L
2187 Created: Wed Jul 19 02:34:59 2000
2188 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2189 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2190 Load Address: 0x00000000
2191 Entry Point: 0x00000000
2193 NOTE: for embedded systems where boot time is critical you can trade
2194 speed for memory and install an UNCOMPRESSED image instead: this
2195 needs more space in Flash, but boots much faster since it does not
2196 need to be uncompressed:
2198 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
2199 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2200 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
2201 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
2202 > examples/uImage.TQM850L-uncompressed
2203 Image Name: 2.4.4 kernel for TQM850L
2204 Created: Wed Jul 19 02:34:59 2000
2205 Image Type: PowerPC Linux Kernel Image (uncompressed)
2206 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
2207 Load Address: 0x00000000
2208 Entry Point: 0x00000000
2211 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2212 when your kernel is intended to use an initial ramdisk:
2214 -> tools/mkimage -n 'Simple Ramdisk Image' \
2215 > -A ppc -O linux -T ramdisk -C gzip \
2216 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2217 Image Name: Simple Ramdisk Image
2218 Created: Wed Jan 12 14:01:50 2000
2219 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2220 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
2221 Load Address: 0x00000000
2222 Entry Point: 0x00000000
2225 Installing a Linux Image:
2226 -------------------------
2228 To downloading a U-Boot image over the serial (console) interface,
2229 you must convert the image to S-Record format:
2231 objcopy -I binary -O srec examples/image examples/image.srec
2233 The 'objcopy' does not understand the information in the U-Boot
2234 image header, so the resulting S-Record file will be relative to
2235 address 0x00000000. To load it to a given address, you need to
2236 specify the target address as 'offset' parameter with the 'loads'
2239 Example: install the image to address 0x40100000 (which on the
2240 TQM8xxL is in the first Flash bank):
2242 => erase 40100000 401FFFFF
2248 ## Ready for S-Record download ...
2249 ~>examples/image.srec
2250 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2252 15989 15990 15991 15992
2253 [file transfer complete]
2255 ## Start Addr = 0x00000000
2258 You can check the success of the download using the 'iminfo' command;
2259 this includes a checksum verification so you can be sure no data
2260 corruption happened:
2264 ## Checking Image at 40100000 ...
2265 Image Name: 2.2.13 for initrd on TQM850L
2266 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2267 Data Size: 335725 Bytes = 327 kB = 0 MB
2268 Load Address: 00000000
2269 Entry Point: 0000000c
2270 Verifying Checksum ... OK
2277 The "bootm" command is used to boot an application that is stored in
2278 memory (RAM or Flash). In case of a Linux kernel image, the contents
2279 of the "bootargs" environment variable is passed to the kernel as
2280 parameters. You can check and modify this variable using the
2281 "printenv" and "setenv" commands:
2284 => printenv bootargs
2285 bootargs=root=/dev/ram
2287 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2289 => printenv bootargs
2290 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2293 ## Booting Linux kernel at 40020000 ...
2294 Image Name: 2.2.13 for NFS on TQM850L
2295 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2296 Data Size: 381681 Bytes = 372 kB = 0 MB
2297 Load Address: 00000000
2298 Entry Point: 0000000c
2299 Verifying Checksum ... OK
2300 Uncompressing Kernel Image ... OK
2301 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
2302 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2303 time_init: decrementer frequency = 187500000/60
2304 Calibrating delay loop... 49.77 BogoMIPS
2305 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2308 If you want to boot a Linux kernel with initial ram disk, you pass
2309 the memory addreses of both the kernel and the initrd image (PPBCOOT
2310 format!) to the "bootm" command:
2312 => imi 40100000 40200000
2314 ## Checking Image at 40100000 ...
2315 Image Name: 2.2.13 for initrd on TQM850L
2316 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2317 Data Size: 335725 Bytes = 327 kB = 0 MB
2318 Load Address: 00000000
2319 Entry Point: 0000000c
2320 Verifying Checksum ... OK
2322 ## Checking Image at 40200000 ...
2323 Image Name: Simple Ramdisk Image
2324 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2325 Data Size: 566530 Bytes = 553 kB = 0 MB
2326 Load Address: 00000000
2327 Entry Point: 00000000
2328 Verifying Checksum ... OK
2330 => bootm 40100000 40200000
2331 ## Booting Linux kernel at 40100000 ...
2332 Image Name: 2.2.13 for initrd on TQM850L
2333 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2334 Data Size: 335725 Bytes = 327 kB = 0 MB
2335 Load Address: 00000000
2336 Entry Point: 0000000c
2337 Verifying Checksum ... OK
2338 Uncompressing Kernel Image ... OK
2339 ## Loading RAMDisk Image at 40200000 ...
2340 Image Name: Simple Ramdisk Image
2341 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2342 Data Size: 566530 Bytes = 553 kB = 0 MB
2343 Load Address: 00000000
2344 Entry Point: 00000000
2345 Verifying Checksum ... OK
2346 Loading Ramdisk ... OK
2347 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
2348 Boot arguments: root=/dev/ram
2349 time_init: decrementer frequency = 187500000/60
2350 Calibrating delay loop... 49.77 BogoMIPS
2352 RAMDISK: Compressed image found at block 0
2353 VFS: Mounted root (ext2 filesystem).
2357 More About U-Boot Image Types:
2358 ------------------------------
2360 U-Boot supports the following image types:
2362 "Standalone Programs" are directly runnable in the environment
2363 provided by U-Boot; it is expected that (if they behave
2364 well) you can continue to work in U-Boot after return from
2365 the Standalone Program.
2366 "OS Kernel Images" are usually images of some Embedded OS which
2367 will take over control completely. Usually these programs
2368 will install their own set of exception handlers, device
2369 drivers, set up the MMU, etc. - this means, that you cannot
2370 expect to re-enter U-Boot except by resetting the CPU.
2371 "RAMDisk Images" are more or less just data blocks, and their
2372 parameters (address, size) are passed to an OS kernel that is
2374 "Multi-File Images" contain several images, typically an OS
2375 (Linux) kernel image and one or more data images like
2376 RAMDisks. This construct is useful for instance when you want
2377 to boot over the network using BOOTP etc., where the boot
2378 server provides just a single image file, but you want to get
2379 for instance an OS kernel and a RAMDisk image.
2381 "Multi-File Images" start with a list of image sizes, each
2382 image size (in bytes) specified by an "uint32_t" in network
2383 byte order. This list is terminated by an "(uint32_t)0".
2384 Immediately after the terminating 0 follow the images, one by
2385 one, all aligned on "uint32_t" boundaries (size rounded up to
2386 a multiple of 4 bytes).
2388 "Firmware Images" are binary images containing firmware (like
2389 U-Boot or FPGA images) which usually will be programmed to
2392 "Script files" are command sequences that will be executed by
2393 U-Boot's command interpreter; this feature is especially
2394 useful when you configure U-Boot to use a real shell (hush)
2395 as command interpreter.
2401 One of the features of U-Boot is that you can dynamically load and
2402 run "standalone" applications, which can use some resources of
2403 U-Boot like console I/O functions or interrupt services.
2405 Two simple examples are included with the sources:
2410 'examples/hello_world.c' contains a small "Hello World" Demo
2411 application; it is automatically compiled when you build U-Boot.
2412 It's configured to run at address 0x00040004, so you can play with it
2416 ## Ready for S-Record download ...
2417 ~>examples/hello_world.srec
2418 1 2 3 4 5 6 7 8 9 10 11 ...
2419 [file transfer complete]
2421 ## Start Addr = 0x00040004
2423 => go 40004 Hello World! This is a test.
2424 ## Starting application at 0x00040004 ...
2435 Hit any key to exit ...
2437 ## Application terminated, rc = 0x0
2439 Another example, which demonstrates how to register a CPM interrupt
2440 handler with the U-Boot code, can be found in 'examples/timer.c'.
2441 Here, a CPM timer is set up to generate an interrupt every second.
2442 The interrupt service routine is trivial, just printing a '.'
2443 character, but this is just a demo program. The application can be
2444 controlled by the following keys:
2446 ? - print current values og the CPM Timer registers
2447 b - enable interrupts and start timer
2448 e - stop timer and disable interrupts
2449 q - quit application
2452 ## Ready for S-Record download ...
2453 ~>examples/timer.srec
2454 1 2 3 4 5 6 7 8 9 10 11 ...
2455 [file transfer complete]
2457 ## Start Addr = 0x00040004
2460 ## Starting application at 0x00040004 ...
2463 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
2466 [q, b, e, ?] Set interval 1000000 us
2469 [q, b, e, ?] ........
2470 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
2473 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
2476 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
2479 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
2481 [q, b, e, ?] ...Stopping timer
2483 [q, b, e, ?] ## Application terminated, rc = 0x0
2489 Starting at version 0.9.2, U-Boot supports NetBSD both as host
2490 (build U-Boot) and target system (boots NetBSD/mpc8xx).
2492 Building requires a cross environment; it is known to work on
2493 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
2494 need gmake since the Makefiles are not compatible with BSD make).
2495 Note that the cross-powerpc package does not install include files;
2496 attempting to build U-Boot will fail because <machine/ansi.h> is
2497 missing. This file has to be installed and patched manually:
2499 # cd /usr/pkg/cross/powerpc-netbsd/include
2501 # ln -s powerpc machine
2502 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
2503 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
2505 Native builds *don't* work due to incompatibilities between native
2506 and U-Boot include files.
2508 Booting assumes that (the first part of) the image booted is a
2509 stage-2 loader which in turn loads and then invokes the kernel
2510 proper. Loader sources will eventually appear in the NetBSD source
2511 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
2512 meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for
2516 Implementation Internals:
2517 =========================
2519 The following is not intended to be a complete description of every
2520 implementation detail. However, it should help to understand the
2521 inner workings of U-Boot and make it easier to port it to custom
2525 Initial Stack, Global Data:
2526 ---------------------------
2528 The implementation of U-Boot is complicated by the fact that U-Boot
2529 starts running out of ROM (flash memory), usually without access to
2530 system RAM (because the memory controller is not initialized yet).
2531 This means that we don't have writable Data or BSS segments, and BSS
2532 is not initialized as zero. To be able to get a C environment working
2533 at all, we have to allocate at least a minimal stack. Implementation
2534 options for this are defined and restricted by the CPU used: Some CPU
2535 models provide on-chip memory (like the IMMR area on MPC8xx and
2536 MPC826x processors), on others (parts of) the data cache can be
2537 locked as (mis-) used as memory, etc.
2539 It is essential to remember this, since it has some impact on the C
2540 code for the initialization procedures:
2542 * Initialized global data (data segment) is read-only. Do not attempt
2545 * Do not use any unitialized global data (or implicitely initialized
2546 as zero data - BSS segment) at all - this is undefined, initiali-
2547 zation is performed later (when relocationg to RAM).
2549 * Stack space is very limited. Avoid big data buffers or things like
2552 Having only the stack as writable memory limits means we cannot use
2553 normal global data to share information beween the code. But it
2554 turned out that the implementation of U-Boot can be greatly
2555 simplified by making a global data structure (gd_t) available to all
2556 functions. We could pass a pointer to this data as argument to _all_
2557 functions, but this would bloat the code. Instead we use a feature of
2558 the GCC compiler (Global Register Variables) to share the data: we
2559 place a pointer (gd) to the global data into a register which we
2560 reserve for this purpose.
2562 When chosing a register for such a purpose we are restricted by the
2563 relevant (E)ABI specifications for the current architecture, and by
2564 GCC's implementation.
2566 For PowerPC, the following registers have specific use:
2569 R3-R4: parameter passing and return values
2570 R5-R10: parameter passing
2571 R13: small data area pointer
2575 (U-Boot also uses R14 as internal GOT pointer.)
2577 ==> U-Boot will use R29 to hold a pointer to the global data
2579 Note: on PPC, we could use a static initializer (since the
2580 address of the global data structure is known at compile time),
2581 but it turned out that reserving a register results in somewhat
2582 smaller code - although the code savings are not that big (on
2583 average for all boards 752 bytes for the whole U-Boot image,
2584 624 text + 127 data).
2586 On ARM, the following registers are used:
2588 R0: function argument word/integer result
2589 R1-R3: function argument word
2591 R10: stack limit (used only if stack checking if enabled)
2592 R11: argument (frame) pointer
2593 R12: temporary workspace
2596 R15: program counter
2598 ==> U-Boot will use R8 to hold a pointer to the global data
2605 U-Boot runs in system state and uses physical addresses, i.e. the
2606 MMU is not used either for address mapping nor for memory protection.
2608 The available memory is mapped to fixed addresses using the memory
2609 controller. In this process, a contiguous block is formed for each
2610 memory type (Flash, SDRAM, SRAM), even when it consists of several
2611 physical memory banks.
2613 U-Boot is installed in the first 128 kB of the first Flash bank (on
2614 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
2615 booting and sizing and initializing DRAM, the code relocates itself
2616 to the upper end of DRAM. Immediately below the U-Boot code some
2617 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
2618 configuration setting]. Below that, a structure with global Board
2619 Info data is placed, followed by the stack (growing downward).
2621 Additionally, some exception handler code is copied to the low 8 kB
2622 of DRAM (0x00000000 ... 0x00001FFF).
2624 So a typical memory configuration with 16 MB of DRAM could look like
2627 0x0000 0000 Exception Vector code
2630 0x0000 2000 Free for Application Use
2636 0x00FB FF20 Monitor Stack (Growing downward)
2637 0x00FB FFAC Board Info Data and permanent copy of global data
2638 0x00FC 0000 Malloc Arena
2641 0x00FE 0000 RAM Copy of Monitor Code
2642 ... eventually: LCD or video framebuffer
2643 ... eventually: pRAM (Protected RAM - unchanged by reset)
2644 0x00FF FFFF [End of RAM]
2647 System Initialization:
2648 ----------------------
2650 In the reset configuration, U-Boot starts at the reset entry point
2651 (on most PowerPC systens at address 0x00000100). Because of the reset
2652 configuration for CS0# this is a mirror of the onboard Flash memory.
2653 To be able to re-map memory U-Boot then jumps to it's link address.
2654 To be able to implement the initialization code in C, a (small!)
2655 initial stack is set up in the internal Dual Ported RAM (in case CPUs
2656 which provide such a feature like MPC8xx or MPC8260), or in a locked
2657 part of the data cache. After that, U-Boot initializes the CPU core,
2658 the caches and the SIU.
2660 Next, all (potentially) available memory banks are mapped using a
2661 preliminary mapping. For example, we put them on 512 MB boundaries
2662 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
2663 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
2664 programmed for SDRAM access. Using the temporary configuration, a
2665 simple memory test is run that determines the size of the SDRAM
2668 When there is more than one SDRAM bank, and the banks are of
2669 different size, the larger is mapped first. For equal size, the first
2670 bank (CS2#) is mapped first. The first mapping is always for address
2671 0x00000000, with any additional banks following immediately to create
2672 contiguous memory starting from 0.
2674 Then, the monitor installs itself at the upper end of the SDRAM area
2675 and allocates memory for use by malloc() and for the global Board
2676 Info data; also, the exception vector code is copied to the low RAM
2677 pages, and the final stack is set up.
2679 Only after this relocation will you have a "normal" C environment;
2680 until that you are restricted in several ways, mostly because you are
2681 running from ROM, and because the code will have to be relocated to a
2685 U-Boot Porting Guide:
2686 ----------------------
2688 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
2692 int main (int argc, char *argv[])
2694 sighandler_t no_more_time;
2696 signal (SIGALRM, no_more_time);
2697 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
2699 if (available_money > available_manpower) {
2700 pay consultant to port U-Boot;
2704 Download latest U-Boot source;
2706 Subscribe to u-boot-users mailing list;
2709 email ("Hi, I am new to U-Boot, how do I get started?");
2713 Read the README file in the top level directory;
2714 Read http://www.denx.de/re/DPLG.html
2715 Read the source, Luke;
2718 if (available_money > toLocalCurrency ($2500)) {
2721 Add a lot of aggravation and time;
2724 Create your own board support subdirectory;
2726 Create your own board config file;
2730 Add / modify source code;
2734 email ("Hi, I am having problems...");
2736 Send patch file to Wolfgang;
2741 void no_more_time (int sig)
2751 All contributions to U-Boot should conform to the Linux kernel
2752 coding style; see the file "Documentation/CodingStyle" in your Linux
2753 kernel source directory.
2755 Please note that U-Boot is implemented in C (and to some small parts
2756 in Assembler); no C++ is used, so please do not use C++ style
2757 comments (//) in your code.
2759 Submissions which do not conform to the standards may be returned
2760 with a request to reformat the changes.
2766 Since the number of patches for U-Boot is growing, we need to
2767 establish some rules. Submissions which do not conform to these rules
2768 may be rejected, even when they contain important and valuable stuff.
2771 When you send a patch, please include the following information with
2774 * For bug fixes: a description of the bug and how your patch fixes
2775 this bug. Please try to include a way of demonstrating that the
2776 patch actually fixes something.
2778 * For new features: a description of the feature and your
2781 * A CHANGELOG entry as plaintext (separate from the patch)
2783 * For major contributions, your entry to the CREDITS file
2785 * When you add support for a new board, don't forget to add this
2786 board to the MAKEALL script, too.
2788 * If your patch adds new configuration options, don't forget to
2789 document these in the README file.
2791 * The patch itself. If you are accessing the CVS repository use "cvs
2792 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
2793 version of diff does not support these options, then get the latest
2794 version of GNU diff.
2796 We accept patches as plain text, MIME attachments or as uuencoded
2801 * Before sending the patch, run the MAKEALL script on your patched
2802 source tree and make sure that no errors or warnings are reported
2803 for any of the boards.
2805 * Keep your modifications to the necessary minimum: A patch
2806 containing several unrelated changes or arbitrary reformats will be
2807 returned with a request to re-formatting / split it.
2809 * If you modify existing code, make sure that your new code does not
2810 add to the memory footprint of the code ;-) Small is beautiful!
2811 When adding new features, these should compile conditionally only
2812 (using #ifdef), and the resulting code with the new feature
2813 disabled must not need more memory than the old code without your
projects / karo-tx-uboot.git / blob