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
345 CONFIG_HHP_CRADLE, CONFIG_DNP1110, CONFIG_EP7312,
346 CONFIG_IMPA7, CONFIG_LART, CONFIG_LUBBOCK,
347 CONFIG_SHANNON, CONFIG_SMDK2400, CONFIG_SMDK2410,
351 - CPU Module Type: (if CONFIG_COGENT is defined)
352 Define exactly one of
354 --- FIXME --- not tested yet:
355 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
356 CONFIG_CMA287_23, CONFIG_CMA287_50
358 - Motherboard Type: (if CONFIG_COGENT is defined)
359 Define exactly one of
360 CONFIG_CMA101, CONFIG_CMA102
362 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
363 Define one or more of
366 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
367 Define one or more of
368 CONFIG_LCD_HEARTBEAT - update a character position on
369 the lcd display every second with
372 - MPC824X Family Member (if CONFIG_MPC824X is defined)
373 Define exactly one of
374 CONFIG_MPC8240, CONFIG_MPC8245
376 - 8xx CPU Options: (if using an 8xx cpu)
377 Define one or more of
378 CONFIG_8xx_GCLK_FREQ - if get_gclk_freq() can not work e.g.
379 no 32KHz reference PIT/RTC clock
384 U-Boot stores all clock information in Hz
385 internally. For binary compatibility with older Linux
386 kernels (which expect the clocks passed in the
387 bd_info data to be in MHz) the environment variable
388 "clocks_in_mhz" can be defined so that U-Boot
389 converts clock data to MHZ before passing it to the
392 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
393 "clocks_in_mhz=1" is automatically included in the
397 Depending on board, define exactly one serial port
398 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
399 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
400 console by defining CONFIG_8xx_CONS_NONE
402 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
403 port routines must be defined elsewhere
404 (i.e. serial_init(), serial_getc(), ...)
407 Enables console device for a color framebuffer. Needs following
408 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
409 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
411 VIDEO_HW_RECTFILL graphic chip supports
414 VIDEO_HW_BITBLT graphic chip supports
415 bit-blit (cf. smiLynxEM)
416 VIDEO_VISIBLE_COLS visible pixel columns
418 VIDEO_VISIBLE_ROWS visible pixel rows
419 VIDEO_PIXEL_SIZE bytes per pixel
420 VIDEO_DATA_FORMAT graphic data format
421 (0-5, cf. cfb_console.c)
422 VIDEO_FB_ADRS framebuffer address
423 VIDEO_KBD_INIT_FCT keyboard int fct
424 (i.e. i8042_kbd_init())
425 VIDEO_TSTC_FCT test char fct
427 VIDEO_GETC_FCT get char fct
429 CONFIG_CONSOLE_CURSOR cursor drawing on/off
430 (requires blink timer
432 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
433 CONFIG_CONSOLE_TIME display time/date info in
435 (requires CFG_CMD_DATE)
436 CONFIG_VIDEO_LOGO display Linux logo in
438 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
439 linux_logo.h for logo.
440 Requires CONFIG_VIDEO_LOGO
441 CONFIG_CONSOLE_EXTRA_INFO
442 addional board info beside
445 When CONFIG_CFB_CONSOLE is defined, video console is
446 default i/o. Serial console can be forced with
447 environment 'console=serial'.
450 CONFIG_BAUDRATE - in bps
451 Select one of the baudrates listed in
452 CFG_BAUDRATE_TABLE, see below.
454 - Interrupt driven serial port input:
455 CONFIG_SERIAL_SOFTWARE_FIFO
458 Use an interrupt handler for receiving data on the
459 serial port. It also enables using hardware handshake
460 (RTS/CTS) and UART's built-in FIFO. Set the number of
461 bytes the interrupt driven input buffer should have.
463 Set to 0 to disable this feature (this is the default).
464 This will also disable hardware handshake.
466 - Boot Delay: CONFIG_BOOTDELAY - in seconds
467 Delay before automatically booting the default image;
468 set to -1 to disable autoboot.
470 See doc/README.autoboot for these options that
471 work with CONFIG_BOOTDELAY. None are required.
472 CONFIG_BOOT_RETRY_TIME
473 CONFIG_BOOT_RETRY_MIN
474 CONFIG_AUTOBOOT_KEYED
475 CONFIG_AUTOBOOT_PROMPT
476 CONFIG_AUTOBOOT_DELAY_STR
477 CONFIG_AUTOBOOT_STOP_STR
478 CONFIG_AUTOBOOT_DELAY_STR2
479 CONFIG_AUTOBOOT_STOP_STR2
480 CONFIG_ZERO_BOOTDELAY_CHECK
481 CONFIG_RESET_TO_RETRY
485 Only needed when CONFIG_BOOTDELAY is enabled;
486 define a command string that is automatically executed
487 when no character is read on the console interface
488 within "Boot Delay" after reset.
491 This can be used to pass arguments to the bootm
492 command. The value of CONFIG_BOOTARGS goes into the
493 environment value "bootargs".
495 CONFIG_RAMBOOT and CONFIG_NFSBOOT
496 The value of these goes into the environment as
497 "ramboot" and "nfsboot" respectively, and can be used
498 as a convenience, when switching between booting from
504 When this option is #defined, the existence of the
505 environment variable "preboot" will be checked
506 immediately before starting the CONFIG_BOOTDELAY
507 countdown and/or running the auto-boot command resp.
508 entering interactive mode.
510 This feature is especially useful when "preboot" is
511 automatically generated or modified. For an example
512 see the LWMON board specific code: here "preboot" is
513 modified when the user holds down a certain
514 combination of keys on the (special) keyboard when
517 - Serial Download Echo Mode:
519 If defined to 1, all characters received during a
520 serial download (using the "loads" command) are
521 echoed back. This might be needed by some terminal
522 emulations (like "cu"), but may as well just take
523 time on others. This setting #define's the initial
524 value of the "loads_echo" environment variable.
526 - Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
528 Select one of the baudrates listed in
529 CFG_BAUDRATE_TABLE, see below.
533 Most monitor functions can be selected (or
534 de-selected) by adjusting the definition of
535 CONFIG_COMMANDS; to select individual functions,
536 #define CONFIG_COMMANDS by "OR"ing any of the
539 #define enables commands:
540 -------------------------
541 CFG_CMD_ASKENV * ask for env variable
543 CFG_CMD_BEDBUG Include BedBug Debugger
545 CFG_CMD_CACHE icache, dcache
546 CFG_CMD_CONSOLE coninfo
547 CFG_CMD_DATE * support for RTC, date/time...
548 CFG_CMD_DHCP DHCP support
549 CFG_CMD_ECHO * echo arguments
550 CFG_CMD_EEPROM * EEPROM read/write support
551 CFG_CMD_ELF bootelf, bootvx
553 CFG_CMD_FDC * Floppy Disk Support
554 CFG_CMD_FDOS * Dos diskette Support
555 CFG_CMD_FLASH flinfo, erase, protect
556 CFG_CMD_FPGA FPGA device initialization support
557 CFG_CMD_I2C * I2C serial bus support
558 CFG_CMD_IDE * IDE harddisk support
560 CFG_CMD_IMMAP * IMMR dump support
561 CFG_CMD_IRQ * irqinfo
565 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
567 CFG_CMD_MII MII utility commands
568 CFG_CMD_NET bootp, tftpboot, rarpboot
569 CFG_CMD_PCI * pciinfo
570 CFG_CMD_PCMCIA * PCMCIA support
571 CFG_CMD_REGINFO * Register dump
572 CFG_CMD_RUN run command in env variable
573 CFG_CMD_SCSI * SCSI Support
574 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
575 CFG_CMD_SPI * SPI serial bus support
576 CFG_CMD_USB * USB support
577 CFG_CMD_BSP * Board SPecific functions
578 -----------------------------------------------
581 CFG_CMD_DFL Default configuration; at the moment
582 this is includes all commands, except
583 the ones marked with "*" in the list
586 If you don't define CONFIG_COMMANDS it defaults to
587 CFG_CMD_DFL in include/cmd_confdefs.h. A board can
588 override the default settings in the respective
591 EXAMPLE: If you want all functions except of network
592 support you can write:
594 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
597 Note: Don't enable the "icache" and "dcache" commands
598 (configuration option CFG_CMD_CACHE) unless you know
599 what you (and your U-Boot users) are doing. Data
600 cache cannot be enabled on systems like the 8xx or
601 8260 (where accesses to the IMMR region must be
602 uncached), and it cannot be disabled on all other
603 systems where we (mis-) use the data cache to hold an
604 initial stack and some data.
607 XXX - this list needs to get updated!
611 If this variable is defined, it enables watchdog
612 support. There must support in the platform specific
613 code for a watchdog. For the 8xx and 8260 CPUs, the
614 SIU Watchdog feature is enabled in the SYPCR
619 When CFG_CMD_DATE is selected, the type of the RTC
620 has to be selected, too. Define exactly one of the
623 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
624 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
625 CONFIG_RTC_MC146818 - use MC146818 RTC
626 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
630 When CONFIG_TIMESTAMP is selected, the timestamp
631 (date and time) of an image is printed by image
632 commands like bootm or iminfo. This option is
633 automatically enabled when you select CFG_CMD_DATE .
636 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
637 and/or CONFIG_ISO_PARTITION
639 If IDE or SCSI support is enabled (CFG_CMD_IDE or
640 CFG_CMD_SCSI) you must configure support for at least
641 one partition type as well.
644 CONFIG_IDE_RESET_ROUTINE
646 Set this to define that instead of a reset Pin, the
647 routine ide_set_reset(int idereset) will be used.
652 Set this to enable ATAPI support.
655 At the moment only there is only support for the
656 SYM53C8XX SCSI controller; define
657 CONFIG_SCSI_SYM53C8XX to enable it.
659 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
660 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
661 CFG_SCSI_MAX_LUN] can be adjusted to define the
662 maximum numbers of LUNs, SCSI ID's and target
664 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
666 - NETWORK Support (PCI):
668 Support for Intel 82557/82559/82559ER chips.
669 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
670 write routine for first time initialisation.
673 Support for Digital 2114x chips.
674 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
675 modem chip initialisation (KS8761/QS6611).
678 Support for National dp83815 chips.
681 Support for National dp8382[01] gigabit chips.
684 At the moment only the UHCI host controller is
685 supported (PIP405, MIP405); define
686 CONFIG_USB_UHCI to enable it.
687 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
688 end define CONFIG_USB_STORAGE to enable the USB
691 Supported are USB Keyboards and USB Floppy drives
697 Define this to enable standard (PC-Style) keyboard
701 Standard PC keyboard driver with US (is default) and
702 GERMAN key layout (switch via environment 'keymap=de') support.
703 Export function i8042_kbd_init, i8042_tstc and i8042_getc
704 for cfb_console. Supports cursor blinking.
709 Define this to enable video support (for output to
714 Enable Chips & Technologies 69000 Video chip
716 CONFIG_VIDEO_SMI_LYNXEM
717 Enable Silicon Motion SMI 712/710/810 Video chip
718 Videomode are selected via environment 'videomode' with
719 standard LiLo mode numbers.
720 Following modes are supported (* is default):
722 800x600 1024x768 1280x1024
723 256 (8bit) 303* 305 307
724 65536 (16bit) 314 317 31a
725 16,7 Mill (24bit) 315 318 31b
726 (i.e. setenv videomode 317; saveenv; reset;)
728 CONFIG_VIDEO_SED13806
729 Enable Epson SED13806 driver. This driver supports 8bpp
730 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
731 or CONFIG_VIDEO_SED13806_16BPP
734 - LCD Support: CONFIG_LCD
736 Define this to enable LCD support (for output to LCD
737 display); also select one of the supported displays
738 by defining one of these:
740 CONFIG_NEC_NL6648AC33:
742 NEC NL6648AC33-18. Active, color, single scan.
744 CONFIG_NEC_NL6648BC20
746 NEC NL6648BC20-08. 6.5", 640x480.
747 Active, color, single scan.
751 Sharp 320x240. Active, color, single scan.
752 It isn't 16x9, and I am not sure what it is.
754 CONFIG_SHARP_LQ64D341
756 Sharp LQ64D341 display, 640x480.
757 Active, color, single scan.
761 HLD1045 display, 640x480.
762 Active, color, single scan.
766 Optrex CBL50840-2 NF-FW 99 22 M5
768 Hitachi LMG6912RPFC-00T
772 320x240. Black & white.
774 Normally display is black on white background; define
775 CFG_WHITE_ON_BLACK to get it inverted.
782 Define a default value for ethernet address to use
783 for the respective ethernet interface, in case this
784 is not determined automatically.
789 Define a default value for the IP address to use for
790 the default ethernet interface, in case this is not
791 determined through e.g. bootp.
796 Defines a default value for theIP address of a TFTP
797 server to contact when using the "tftboot" command.
799 - BOOTP Recovery Mode:
800 CONFIG_BOOTP_RANDOM_DELAY
802 If you have many targets in a network that try to
803 boot using BOOTP, you may want to avoid that all
804 systems send out BOOTP requests at precisely the same
805 moment (which would happen for instance at recovery
806 from a power failure, when all systems will try to
807 boot, thus flooding the BOOTP server. Defining
808 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
809 inserted before sending out BOOTP requests. The
810 following delays are insterted then:
812 1st BOOTP request: delay 0 ... 1 sec
813 2nd BOOTP request: delay 0 ... 2 sec
814 3rd BOOTP request: delay 0 ... 4 sec
816 BOOTP requests: delay 0 ... 8 sec
818 - Status LED: CONFIG_STATUS_LED
820 Several configurations allow to display the current
821 status using a LED. For instance, the LED will blink
822 fast while running U-Boot code, stop blinking as
823 soon as a reply to a BOOTP request was received, and
824 start blinking slow once the Linux kernel is running
825 (supported by a status LED driver in the Linux
826 kernel). Defining CONFIG_STATUS_LED enables this
829 - CAN Support: CONFIG_CAN_DRIVER
831 Defining CONFIG_CAN_DRIVER enables CAN driver support
832 on those systems that support this (optional)
833 feature, like the TQM8xxL modules.
835 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
837 Enables I2C serial bus commands. If this is selected,
838 either CONFIG_HARD_I2C or CONFIG_SOFT_I2C must be defined
839 to include the appropriate I2C driver.
841 See also: common/cmd_i2c.c for a description of the
842 command line interface.
847 Selects the CPM hardware driver for I2C.
851 Use software (aka bit-banging) driver instead of CPM
852 or similar hardware support for I2C. This is configured
853 via the following defines.
857 (Optional). Any commands necessary to enable I2C
858 controller or configure ports.
862 (Only for MPC8260 CPU). The I/O port to use (the code
863 assumes both bits are on the same port). Valid values
864 are 0..3 for ports A..D.
868 The code necessary to make the I2C data line active
869 (driven). If the data line is open collector, this
874 The code necessary to make the I2C data line tri-stated
875 (inactive). If the data line is open collector, this
880 Code that returns TRUE if the I2C data line is high,
885 If <bit> is TRUE, sets the I2C data line high. If it
886 is FALSE, it clears it (low).
890 If <bit> is TRUE, sets the I2C clock line high. If it
891 is FALSE, it clears it (low).
895 This delay is invoked four times per clock cycle so this
896 controls the rate of data transfer. The data rate thus
897 is 1 / (I2C_DELAY * 4).
899 - SPI Support: CONFIG_SPI
901 Enables SPI driver (so far only tested with
902 SPI EEPROM, also an instance works with Crystal A/D and
903 D/As on the SACSng board)
907 Enables extended (16-bit) SPI EEPROM addressing.
908 (symmetrical to CONFIG_I2C_X)
912 Enables a software (bit-bang) SPI driver rather than
913 using hardware support. This is a general purpose
914 driver that only requires three general I/O port pins
915 (two outputs, one input) to function. If this is
916 defined, the board configuration must define several
917 SPI configuration items (port pins to use, etc). For
918 an example, see include/configs/sacsng.h.
920 - FPGA Support: CONFIG_FPGA_COUNT
922 Specify the number of FPGA devices to support.
926 Used to specify the types of FPGA devices. For
928 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
930 CFG_FPGA_PROG_FEEDBACK
932 Enable printing of hash marks during FPGA
937 Enable checks on FPGA configuration interface busy
938 status by the configuration function. This option
939 will require a board or device specific function to
944 If defined, a function that provides delays in the
945 FPGA configuration driver.
949 Allow Control-C to interrupt FPGA configuration
953 Check for configuration errors during FPGA bitfile
954 loading. For example, abort during Virtex II
955 configuration if the INIT_B line goes low (which
956 indicated a CRC error).
960 Maximum time to wait for the INIT_B line to deassert
961 after PROB_B has been deasserted during a Virtex II
962 FPGA configuration sequence. The default time is 500 mS.
966 Maximum time to wait for BUSY to deassert during
967 Virtex II FPGA configuration. The default is 5 mS.
971 Time to wait after FPGA configuration. The default is
974 - FPGA Support: CONFIG_FPGA_COUNT
976 Specify the number of FPGA devices to support.
980 Used to specify the types of FPGA devices. For example,
981 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
983 CFG_FPGA_PROG_FEEDBACK
985 Enable printing of hash marks during FPGA configuration.
989 Enable checks on FPGA configuration interface busy
990 status by the configuration function. This option
991 will require a board or device specific function to
996 If defined, a function that provides delays in the FPGA
997 configuration driver.
1000 Allow Control-C to interrupt FPGA configuration
1002 CFG_FPGA_CHECK_ERROR
1004 Check for configuration errors during FPGA bitfile
1005 loading. For example, abort during Virtex II
1006 configuration if the INIT_B line goes low (which
1007 indicated a CRC error).
1011 Maximum time to wait for the INIT_B line to deassert
1012 after PROB_B has been deasserted during a Virtex II
1013 FPGA configuration sequence. The default time is 500
1018 Maximum time to wait for BUSY to deassert during
1019 Virtex II FPGA configuration. The default is 5 mS.
1021 CFG_FPGA_WAIT_CONFIG
1023 Time to wait after FPGA configuration. The default is
1026 - Configuration Management:
1029 If defined, this string will be added to the U-Boot
1030 version information (U_BOOT_VERSION)
1032 - Vendor Parameter Protection:
1034 U-Boot considers the values of the environment
1035 variables "serial#" (Board Serial Number) and
1036 "ethaddr" (Ethernet Address) to bb parameters that
1037 are set once by the board vendor / manufacturer, and
1038 protects these variables from casual modification by
1039 the user. Once set, these variables are read-only,
1040 and write or delete attempts are rejected. You can
1041 change this behviour:
1043 If CONFIG_ENV_OVERWRITE is #defined in your config
1044 file, the write protection for vendor parameters is
1045 completely disabled. Anybody can change or delte
1048 Alternatively, if you #define _both_ CONFIG_ETHADDR
1049 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1050 ethernet address is installed in the environment,
1051 which can be changed exactly ONCE by the user. [The
1052 serial# is unaffected by this, i. e. it remains
1058 Define this variable to enable the reservation of
1059 "protected RAM", i. e. RAM which is not overwritten
1060 by U-Boot. Define CONFIG_PRAM to hold the number of
1061 kB you want to reserve for pRAM. You can overwrite
1062 this default value by defining an environment
1063 variable "pram" to the number of kB you want to
1064 reserve. Note that the board info structure will
1065 still show the full amount of RAM. If pRAM is
1066 reserved, a new environment variable "mem" will
1067 automatically be defined to hold the amount of
1068 remaining RAM in a form that can be passed as boot
1069 argument to Linux, for instance like that:
1071 setenv bootargs ... mem=\$(mem)
1074 This way you can tell Linux not to use this memory,
1075 either, which results in a memory region that will
1076 not be affected by reboots.
1078 *WARNING* If your board configuration uses automatic
1079 detection of the RAM size, you must make sure that
1080 this memory test is non-destructive. So far, the
1081 following board configurations are known to be
1084 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1085 HERMES, IP860, RPXlite, LWMON, LANTEC,
1086 PCU_E, FLAGADM, TQM8260
1091 Define this variable to stop the system in case of a
1092 fatal error, so that you have to reset it manually.
1093 This is probably NOT a good idea for an embedded
1094 system where you want to system to reboot
1095 automatically as fast as possible, but it may be
1096 useful during development since you can try to debug
1097 the conditions that lead to the situation.
1099 CONFIG_NET_RETRY_COUNT
1101 This variable defines the number of retries for
1102 network operations like ARP, RARP, TFTP, or BOOTP
1103 before giving up the operation. If not defined, a
1104 default value of 5 is used.
1106 - Command Interpreter:
1109 Define this variable to enable the "hush" shell (from
1110 Busybox) as command line interpreter, thus enabling
1111 powerful command line syntax like
1112 if...then...else...fi conditionals or `&&' and '||'
1113 constructs ("shell scripts").
1115 If undefined, you get the old, much simpler behaviour
1116 with a somewhat smaller memory footprint.
1121 This defines the secondary prompt string, which is
1122 printed when the command interpreter needs more input
1123 to complete a command. Usually "> ".
1127 In the current implementation, the local variables
1128 space and global environment variables space are
1129 separated. Local variables are those you define by
1130 simply typing like `name=value'. To access a local
1131 variable later on, you have write `$name' or
1132 `${name}'; variable directly by typing say `$name' at
1135 Global environment variables are those you use
1136 setenv/printenv to work with. To run a command stored
1137 in such a variable, you need to use the run command,
1138 and you must not use the '$' sign to access them.
1140 To store commands and special characters in a
1141 variable, please use double quotation marks
1142 surrounding the whole text of the variable, instead
1143 of the backslashes before semicolons and special
1146 - Default Environment
1147 CONFIG_EXTRA_ENV_SETTINGS
1149 Define this to contain any number of null terminated
1150 strings (variable = value pairs) that will be part of
1151 the default enviroment compiled into the boot image.
1153 For example, place something like this in your
1154 board's config file:
1156 #define CONFIG_EXTRA_ENV_SETTINGS \
1160 Warning: This method is based on knowledge about the
1161 internal format how the environment is stored by the
1162 U-Boot code. This is NOT an official, exported
1163 interface! Although it is unlikely that this format
1164 will change soon, but there is no guarantee either.
1165 You better know what you are doing here.
1167 Note: overly (ab)use of the default environment is
1168 discouraged. Make sure to check other ways to preset
1169 the environment like the autoscript function or the
1172 - Show boot progress
1173 CONFIG_SHOW_BOOT_PROGRESS
1175 Defining this option allows to add some board-
1176 specific code (calling a user-provided function
1177 "show_boot_progress(int)") that enables you to show
1178 the system's boot progress on some display (for
1179 example, some LED's) on your board. At the moment,
1180 the following checkpoints are implemented:
1183 1 common/cmd_bootm.c before attempting to boot an image
1184 -1 common/cmd_bootm.c Image header has bad magic number
1185 2 common/cmd_bootm.c Image header has correct magic number
1186 -2 common/cmd_bootm.c Image header has bad checksum
1187 3 common/cmd_bootm.c Image header has correct checksum
1188 -3 common/cmd_bootm.c Image data has bad checksum
1189 4 common/cmd_bootm.c Image data has correct checksum
1190 -4 common/cmd_bootm.c Image is for unsupported architecture
1191 5 common/cmd_bootm.c Architecture check OK
1192 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1193 6 common/cmd_bootm.c Image Type check OK
1194 -6 common/cmd_bootm.c gunzip uncompression error
1195 -7 common/cmd_bootm.c Unimplemented compression type
1196 7 common/cmd_bootm.c Uncompression OK
1197 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1198 8 common/cmd_bootm.c Image Type check OK
1199 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1200 9 common/cmd_bootm.c Start initial ramdisk verification
1201 -10 common/cmd_bootm.c Ramdisk header has bad magic number
1202 -11 common/cmd_bootm.c Ramdisk header has bad checksum
1203 10 common/cmd_bootm.c Ramdisk header is OK
1204 -12 common/cmd_bootm.c Ramdisk data has bad checksum
1205 11 common/cmd_bootm.c Ramdisk data has correct checksum
1206 12 common/cmd_bootm.c Ramdisk verification complete, start loading
1207 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk)
1208 13 common/cmd_bootm.c Start multifile image verification
1209 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue.
1210 15 common/cmd_bootm.c All preparation done, transferring control to OS
1212 -1 common/cmd_doc.c Bad usage of "doc" command
1213 -1 common/cmd_doc.c No boot device
1214 -1 common/cmd_doc.c Unknown Chip ID on boot device
1215 -1 common/cmd_doc.c Read Error on boot device
1216 -1 common/cmd_doc.c Image header has bad magic number
1218 -1 common/cmd_ide.c Bad usage of "ide" command
1219 -1 common/cmd_ide.c No boot device
1220 -1 common/cmd_ide.c Unknown boot device
1221 -1 common/cmd_ide.c Unknown partition table
1222 -1 common/cmd_ide.c Invalid partition type
1223 -1 common/cmd_ide.c Read Error on boot device
1224 -1 common/cmd_ide.c Image header has bad magic number
1226 -1 common/cmd_nvedit.c Environment not changable, but has bad CRC
1232 [so far only for SMDK2400 board]
1234 - Modem support endable:
1235 CONFIG_MODEM_SUPPORT
1237 - RTS/CTS Flow control enable:
1240 - Modem debug support:
1241 CONFIG_MODEM_SUPPORT_DEBUG
1243 Enables debugging stuff (char screen[1024], dbg())
1244 for modem support. Useful only with BDI2000.
1248 In the target system modem support is enabled when a
1249 specific key (key combination) is pressed during
1250 power-on. Otherwise U-Boot will boot normally
1251 (autoboot). The key_pressed() fuction is called from
1252 board_init(). Currently key_pressed() is a dummy
1253 function, returning 1 and thus enabling modem
1256 If there are no modem init strings in the
1257 environment, U-Boot proceed to autoboot; the
1258 previous output (banner, info printfs) will be
1261 See also: doc/README.Modem
1266 Configuration Settings:
1267 -----------------------
1269 - CFG_LONGHELP: Defined when you want long help messages included;
1270 undefine this when you're short of memory.
1272 - CFG_PROMPT: This is what U-Boot prints on the console to
1273 prompt for user input.
1275 - CFG_CBSIZE: Buffer size for input from the Console
1277 - CFG_PBSIZE: Buffer size for Console output
1279 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1281 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1282 the application (usually a Linux kernel) when it is
1285 - CFG_BAUDRATE_TABLE:
1286 List of legal baudrate settings for this board.
1288 - CFG_CONSOLE_INFO_QUIET
1289 Suppress display of console information at boot.
1291 - CFG_CONSOLE_IS_IN_ENV
1292 If the board specific function
1293 extern int overwrite_console (void);
1294 returns 1, the stdin, stderr and stdout are switched to the
1295 serial port, else the settings in the environment are used.
1297 - CFG_CONSOLE_OVERWRITE_ROUTINE
1298 Enable the call to overwrite_console().
1300 - CFG_CONSOLE_ENV_OVERWRITE
1301 Enable overwrite of previous console environment settings.
1303 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1304 Begin and End addresses of the area used by the
1308 Enable an alternate, more extensive memory test.
1310 - CFG_TFTP_LOADADDR:
1311 Default load address for network file downloads
1313 - CFG_LOADS_BAUD_CHANGE:
1314 Enable temporary baudrate change while serial download
1317 Physical start address of SDRAM. _Must_ be 0 here.
1320 Physical start address of Motherboard I/O (if using a
1324 Physical start address of Flash memory.
1327 Physical start address of boot monitor code (set by
1328 make config files to be same as the text base address
1329 (TEXT_BASE) used when linking) - same as
1330 CFG_FLASH_BASE when booting from flash.
1333 Size of memory reserved for monitor code
1336 Size of DRAM reserved for malloc() use.
1339 Maximum size of memory mapped by the startup code of
1340 the Linux kernel; all data that must be processed by
1341 the Linux kernel (bd_info, boot arguments, eventually
1342 initrd image) must be put below this limit.
1344 - CFG_MAX_FLASH_BANKS:
1345 Max number of Flash memory banks
1347 - CFG_MAX_FLASH_SECT:
1348 Max number of sectors on a Flash chip
1350 - CFG_FLASH_ERASE_TOUT:
1351 Timeout for Flash erase operations (in ms)
1353 - CFG_FLASH_WRITE_TOUT:
1354 Timeout for Flash write operations (in ms)
1356 - CFG_DIRECT_FLASH_TFTP:
1358 Enable TFTP transfers directly to flash memory;
1359 without this option such a download has to be
1360 performed in two steps: (1) download to RAM, and (2)
1361 copy from RAM to flash.
1363 The two-step approach is usually more reliable, since
1364 you can check if the download worked before you erase
1365 the flash, but in some situations (when sytem RAM is
1366 too limited to allow for a tempory copy of the
1367 downloaded image) this option may be very useful.
1370 Define if the flash driver uses extra elements in the
1371 common flash structure for storing flash geometry
1373 The following definitions that deal with the placement and management
1374 of environment data (variable area); in general, we support the
1375 following configurations:
1377 - CFG_ENV_IS_IN_FLASH:
1379 Define this if the environment is in flash memory.
1381 a) The environment occupies one whole flash sector, which is
1382 "embedded" in the text segment with the U-Boot code. This
1383 happens usually with "bottom boot sector" or "top boot
1384 sector" type flash chips, which have several smaller
1385 sectors at the start or the end. For instance, such a
1386 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
1387 such a case you would place the environment in one of the
1388 4 kB sectors - with U-Boot code before and after it. With
1389 "top boot sector" type flash chips, you would put the
1390 environment in one of the last sectors, leaving a gap
1391 between U-Boot and the environment.
1395 Offset of environment data (variable area) to the
1396 beginning of flash memory; for instance, with bottom boot
1397 type flash chips the second sector can be used: the offset
1398 for this sector is given here.
1400 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
1404 This is just another way to specify the start address of
1405 the flash sector containing the environment (instead of
1408 - CFG_ENV_SECT_SIZE:
1410 Size of the sector containing the environment.
1413 b) Sometimes flash chips have few, equal sized, BIG sectors.
1414 In such a case you don't want to spend a whole sector for
1419 If you use this in combination with CFG_ENV_IS_IN_FLASH
1420 and CFG_ENV_SECT_SIZE, you can specify to use only a part
1421 of this flash sector for the environment. This saves
1422 memory for the RAM copy of the environment.
1424 It may also save flash memory if you decide to use this
1425 when your environment is "embedded" within U-Boot code,
1426 since then the remainder of the flash sector could be used
1427 for U-Boot code. It should be pointed out that this is
1428 STRONGLY DISCOURAGED from a robustness point of view:
1429 updating the environment in flash makes it always
1430 necessary to erase the WHOLE sector. If something goes
1431 wrong before the contents has been restored from a copy in
1432 RAM, your target system will be dead.
1434 - CFG_ENV_ADDR_REDUND
1437 These settings describe a second storage area used to hold
1438 a redundand copy of the environment data, so that there is
1439 a valid backup copy in case there is a power failur during
1440 a "saveenv" operation.
1442 BE CAREFUL! Any changes to the flash layout, and some changes to the
1443 source code will make it necessary to adapt <board>/u-boot.lds*
1447 - CFG_ENV_IS_IN_NVRAM:
1449 Define this if you have some non-volatile memory device
1450 (NVRAM, battery buffered SRAM) which you want to use for the
1456 These two #defines are used to determin the memory area you
1457 want to use for environment. It is assumed that this memory
1458 can just be read and written to, without any special
1461 BE CAREFUL! The first access to the environment happens quite early
1462 in U-Boot initalization (when we try to get the setting of for the
1463 console baudrate). You *MUST* have mappend your NVRAM area then, or
1466 Please note that even with NVRAM we still use a copy of the
1467 environment in RAM: we could work on NVRAM directly, but we want to
1468 keep settings there always unmodified except somebody uses "saveenv"
1469 to save the current settings.
1472 - CFG_ENV_IS_IN_EEPROM:
1474 Use this if you have an EEPROM or similar serial access
1475 device and a driver for it.
1480 These two #defines specify the offset and size of the
1481 environment area within the total memory of your EEPROM.
1483 - CFG_I2C_EEPROM_ADDR:
1484 If defined, specified the chip address of the EEPROM device.
1485 The default address is zero.
1487 - CFG_EEPROM_PAGE_WRITE_BITS:
1488 If defined, the number of bits used to address bytes in a
1489 single page in the EEPROM device. A 64 byte page, for example
1490 would require six bits.
1492 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1493 If defined, the number of milliseconds to delay between
1494 page writes. The default is zero milliseconds.
1496 - CFG_I2C_EEPROM_ADDR_LEN:
1497 The length in bytes of the EEPROM memory array address. Note
1498 that this is NOT the chip address length!
1501 The size in bytes of the EEPROM device.
1503 - CFG_I2C_EEPROM_ADDR:
1504 If defined, specified the chip address of the EEPROM device.
1505 The default address is zero.
1507 - CFG_EEPROM_PAGE_WRITE_BITS:
1508 If defined, the number of bits used to address bytes in a
1509 single page in the EEPROM device. A 64 byte page, for example
1510 would require six bits.
1512 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1513 If defined, the number of milliseconds to delay between
1514 page writes. The default is zero milliseconds.
1516 - CFG_I2C_EEPROM_ADDR_LEN:
1517 The length in bytes of the EEPROM memory array address. Note
1518 that this is NOT the chip address length!
1521 The size in bytes of the EEPROM device.
1523 - CFG_SPI_INIT_OFFSET
1525 Defines offset to the initial SPI buffer area in DPRAM. The
1526 area is used at an early stage (ROM part) if the environment
1527 is configured to reside in the SPI EEPROM: We need a 520 byte
1528 scratch DPRAM area. It is used between the two initialization
1529 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
1530 to be a good choice since it makes it far enough from the
1531 start of the data area as well as from the stack pointer.
1533 Please note that the environment is read-only as long as the monitor
1534 has been relocated to RAM and a RAM copy of the environment has been
1535 created; also, when using EEPROM you will have to use getenv_r()
1536 until then to read environment variables.
1538 The environment is now protected by a CRC32 checksum. Before the
1539 monitor is relocated into RAM, as a result of a bad CRC you will be
1540 working with the compiled-in default environment - *silently*!!!
1541 [This is necessary, because the first environment variable we need is
1542 the "baudrate" setting for the console - if we have a bad CRC, we
1543 don't have any device yet where we could complain.]
1545 Note: once the monitor has been relocated, then it will complain if
1546 the default environment is used; a new CRC is computed as soon as you
1547 use the "setenv" command to modify / delete / add any environment
1548 variable [even when you try to delete a non-existing variable!].
1550 Note2: you must edit your u-boot.lds file to reflect this
1554 Low Level (hardware related) configuration options:
1556 - CFG_CACHELINE_SIZE:
1557 Cache Line Size of the CPU.
1560 Default address of the IMMR after system reset.
1561 Needed on some 8260 systems (MPC8260ADS and RPXsuper)
1562 to be able to adjust the position of the IMMR
1563 register after a reset.
1565 - Floppy Disk Support:
1566 CFG_FDC_DRIVE_NUMBER
1568 the default drive number (default value 0)
1572 defines the spacing between fdc chipset registers
1577 defines the offset of register from address. It
1578 depends on which part of the data bus is connected to
1579 the fdc chipset. (default value 0)
1581 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
1582 CFG_FDC_DRIVE_NUMBER are undefined, they take their
1585 if CFG_FDC_HW_INIT is defined, then the function
1586 fdc_hw_init() is called at the beginning of the FDC
1587 setup. fdc_hw_init() must be provided by the board
1588 source code. It is used to make hardware dependant
1591 - CFG_IMMR: Physical address of the Internal Memory Mapped
1592 Register; DO NOT CHANGE! (11-4)
1593 [MPC8xx systems only]
1595 - CFG_INIT_RAM_ADDR:
1597 Start address of memory area tha can be used for
1598 initial data and stack; please note that this must be
1599 writable memory that is working WITHOUT special
1600 initialization, i. e. you CANNOT use normal RAM which
1601 will become available only after programming the
1602 memory controller and running certain initialization
1605 U-Boot uses the following memory types:
1606 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
1607 - MPC824X: data cache
1608 - PPC4xx: data cache
1610 - CFG_INIT_DATA_OFFSET:
1612 Offset of the initial data structure in the memory
1613 area defined by CFG_INIT_RAM_ADDR. Usually
1614 CFG_INIT_DATA_OFFSET is chosen such that the initial
1615 data is located at the end of the available space
1616 (sometimes written as (CFG_INIT_RAM_END -
1617 CFG_INIT_DATA_SIZE), and the initial stack is just
1618 below that area (growing from (CFG_INIT_RAM_ADDR +
1619 CFG_INIT_DATA_OFFSET) downward.
1622 On the MPC824X (or other systems that use the data
1623 cache for initial memory) the address chosen for
1624 CFG_INIT_RAM_ADDR is basically arbitrary - it must
1625 point to an otherwise UNUSED address space between
1626 the top of RAM and the start of the PCI space.
1628 - CFG_SIUMCR: SIU Module Configuration (11-6)
1630 - CFG_SYPCR: System Protection Control (11-9)
1632 - CFG_TBSCR: Time Base Status and Control (11-26)
1634 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
1636 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
1638 - CFG_SCCR: System Clock and reset Control Register (15-27)
1640 - CFG_OR_TIMING_SDRAM:
1644 periodic timer for refresh
1646 - CFG_DER: Debug Event Register (37-47)
1648 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
1649 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
1650 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
1652 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
1654 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
1655 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
1656 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
1657 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
1659 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
1660 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
1661 Machine Mode Register and Memory Periodic Timer
1662 Prescaler definitions (SDRAM timing)
1664 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
1665 enable I2C microcode relocation patch (MPC8xx);
1666 define relocation offset in DPRAM [DSP2]
1668 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
1669 enable SPI microcode relocation patch (MPC8xx);
1670 define relocation offset in DPRAM [SCC4]
1673 Use OSCM clock mode on MBX8xx board. Be careful,
1674 wrong setting might damage your board. Read
1675 doc/README.MBX before setting this variable!
1677 - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
1678 Offset of the bootmode word in DPRAM used by post
1679 (Power On Self Tests). This definition overrides
1680 #define'd default value in commproc.h resp.
1683 Building the Software:
1684 ======================
1686 Building U-Boot has been tested in native PPC environments (on a
1687 PowerBook G3 running LinuxPPC 2000) and in cross environments
1688 (running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
1691 If you are not using a native PPC environment, it is assumed that you
1692 have the GNU cross compiling tools available in your path and named
1693 with a prefix of "powerpc-linux-". If this is not the case, (e.g. if
1694 you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
1695 the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
1698 CROSS_COMPILE = ppc_4xx-
1701 U-Boot is intended to be simple to build. After installing the
1702 sources you must configure U-Boot for one specific board type. This
1707 where "NAME_config" is the name of one of the existing
1708 configurations; the following names are supported:
1710 ADCIOP_config GTH_config TQM850L_config
1711 ADS860_config IP860_config TQM855L_config
1712 AR405_config IVML24_config TQM860L_config
1713 CANBT_config IVMS8_config WALNUT405_config
1714 CPCI405_config LANTEC_config cogent_common_config
1715 CPCIISER4_config MBX_config cogent_mpc8260_config
1716 CU824_config MBX860T_config cogent_mpc8xx_config
1717 ESTEEM192E_config RPXlite_config hermes_config
1718 ETX094_config RPXsuper_config hymod_config
1719 FADS823_config SM850_config lwmon_config
1720 FADS850SAR_config SPD823TS_config pcu_e_config
1721 FADS860T_config SXNI855T_config rsdproto_config
1722 FPS850L_config Sandpoint8240_config sbc8260_config
1723 GENIETV_config TQM823L_config PIP405_config
1724 GEN860T_config EBONY_config FPS860L_config
1726 Note: for some board special configuration names may exist; check if
1727 additional information is available from the board vendor; for
1728 instance, the TQM8xxL systems run normally at 50 MHz and use a
1729 SCC for 10baseT ethernet; there are also systems with 80 MHz
1730 CPU clock, and an optional Fast Ethernet module is available
1731 for CPU's with FEC. You can select such additional "features"
1732 when chosing the configuration, i. e.
1735 - will configure for a plain TQM860L, i. e. 50MHz, no FEC
1737 make TQM860L_FEC_config
1738 - will configure for a TQM860L at 50MHz with FEC for ethernet
1740 make TQM860L_80MHz_config
1741 - will configure for a TQM860L at 80 MHz, with normal 10baseT
1744 make TQM860L_FEC_80MHz_config
1745 - will configure for a TQM860L at 80 MHz with FEC for ethernet
1747 make TQM823L_LCD_config
1748 - will configure for a TQM823L with U-Boot console on LCD
1750 make TQM823L_LCD_80MHz_config
1751 - will configure for a TQM823L at 80 MHz with U-Boot console on LCD
1757 Finally, type "make all", and you should get some working U-Boot
1758 images ready for downlod to / installation on your system:
1760 - "u-boot.bin" is a raw binary image
1761 - "u-boot" is an image in ELF binary format
1762 - "u-boot.srec" is in Motorola S-Record format
1765 Please be aware that the Makefiles assume you are using GNU make, so
1766 for instance on NetBSD you might need to use "gmake" instead of
1770 If the system board that you have is not listed, then you will need
1771 to port U-Boot to your hardware platform. To do this, follow these
1774 1. Add a new configuration option for your board to the toplevel
1775 "Makefile", using the existing entries as examples.
1776 2. Create a new directory to hold your board specific code. Add any
1778 3. If you're porting U-Boot to a new CPU, then also create a new
1779 directory to hold your CPU specific code. Add any files you need.
1780 4. Run "make config_name" with your new name.
1781 5. Type "make", and you should get a working "u-boot.srec" file
1782 to be installed on your target system.
1783 [Of course, this last step is much harder than it sounds.]
1786 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
1787 ==============================================================
1789 If you have modified U-Boot sources (for instance added a new board
1790 or support for new devices, a new CPU, etc.) you are expected to
1791 provide feedback to the other developers. The feedback normally takes
1792 the form of a "patch", i. e. a context diff against a certain (latest
1793 official or latest in CVS) version of U-Boot sources.
1795 But before you submit such a patch, please verify that your modifi-
1796 cation did not break existing code. At least make sure that *ALL* of
1797 the supported boards compile WITHOUT ANY compiler warnings. To do so,
1798 just run the "MAKEALL" script, which will configure and build U-Boot
1799 for ALL supported system. Be warned, this will take a while. You can
1800 select which (cross) compiler to use py passing a `CROSS_COMPILE'
1801 environment variable to the script, i. e. to use the cross tools from
1802 MontaVista's Hard Hat Linux you can type
1804 CROSS_COMPILE=ppc_8xx- MAKEALL
1806 or to build on a native PowerPC system you can type
1808 CROSS_COMPILE=' ' MAKEALL
1810 See also "U-Boot Porting Guide" below.
1814 Monitor Commands - Overview:
1815 ============================
1817 go - start application at address 'addr'
1818 run - run commands in an environment variable
1819 bootm - boot application image from memory
1820 bootp - boot image via network using BootP/TFTP protocol
1821 tftpboot- boot image via network using TFTP protocol
1822 and env variables "ipaddr" and "serverip"
1823 (and eventually "gatewayip")
1824 rarpboot- boot image via network using RARP/TFTP protocol
1825 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
1826 loads - load S-Record file over serial line
1827 loadb - load binary file over serial line (kermit mode)
1829 mm - memory modify (auto-incrementing)
1830 nm - memory modify (constant address)
1831 mw - memory write (fill)
1833 cmp - memory compare
1834 crc32 - checksum calculation
1835 imd - i2c memory display
1836 imm - i2c memory modify (auto-incrementing)
1837 inm - i2c memory modify (constant address)
1838 imw - i2c memory write (fill)
1839 icrc32 - i2c checksum calculation
1840 iprobe - probe to discover valid I2C chip addresses
1841 iloop - infinite loop on address range
1842 isdram - print SDRAM configuration information
1843 sspi - SPI utility commands
1844 base - print or set address offset
1845 printenv- print environment variables
1846 setenv - set environment variables
1847 saveenv - save environment variables to persistent storage
1848 protect - enable or disable FLASH write protection
1849 erase - erase FLASH memory
1850 flinfo - print FLASH memory information
1851 bdinfo - print Board Info structure
1852 iminfo - print header information for application image
1853 coninfo - print console devices and informations
1854 ide - IDE sub-system
1855 loop - infinite loop on address range
1856 mtest - simple RAM test
1857 icache - enable or disable instruction cache
1858 dcache - enable or disable data cache
1859 reset - Perform RESET of the CPU
1860 echo - echo args to console
1861 version - print monitor version
1862 help - print online help
1863 ? - alias for 'help'
1866 Monitor Commands - Detailed Description:
1867 ========================================
1871 For now: just type "help <command>".
1874 Environment Variables:
1875 ======================
1877 U-Boot supports user configuration using Environment Variables which
1878 can be made persistent by saving to Flash memory.
1880 Environment Variables are set using "setenv", printed using
1881 "printenv", and saved to Flash using "saveenv". Using "setenv"
1882 without a value can be used to delete a variable from the
1883 environment. As long as you don't save the environment you are
1884 working with an in-memory copy. In case the Flash area containing the
1885 environment is erased by accident, a default environment is provided.
1887 Some configuration options can be set using Environment Variables:
1889 baudrate - see CONFIG_BAUDRATE
1891 bootdelay - see CONFIG_BOOTDELAY
1893 bootcmd - see CONFIG_BOOTCOMMAND
1895 bootargs - Boot arguments when booting an RTOS image
1897 bootfile - Name of the image to load with TFTP
1899 autoload - if set to "no" (any string beginning with 'n'),
1900 "bootp" will just load perform a lookup of the
1901 configuration from the BOOTP server, but not try to
1902 load any image using TFTP
1904 autostart - if set to "yes", an image loaded using the "bootp",
1905 "rarpboot", "tftpboot" or "diskboot" commands will
1906 be automatically started (by internally calling
1909 initrd_high - restrict positioning of initrd images:
1910 If this variable is not set, initrd images will be
1911 copied to the highest possible address in RAM; this
1912 is usually what you want since it allows for
1913 maximum initrd size. If for some reason you want to
1914 make sure that the initrd image is loaded below the
1915 CFG_BOOTMAPSZ limit, you can set this environment
1916 variable to a value of "no" or "off" or "0".
1917 Alternatively, you can set it to a maximum upper
1918 address to use (U-Boot will still check that it
1919 does not overwrite the U-Boot stack and data).
1921 For instance, when you have a system with 16 MB
1922 RAM, and want to reseve 4 MB from use by Linux,
1923 you can do this by adding "mem=12M" to the value of
1924 the "bootargs" variable. However, now you must make
1925 sure, that the initrd image is placed in the first
1926 12 MB as well - this can be done with
1928 setenv initrd_high 00c00000
1930 ipaddr - IP address; needed for tftpboot command
1932 loadaddr - Default load address for commands like "bootp",
1933 "rarpboot", "tftpboot" or "diskboot"
1935 loads_echo - see CONFIG_LOADS_ECHO
1937 serverip - TFTP server IP address; needed for tftpboot command
1939 bootretry - see CONFIG_BOOT_RETRY_TIME
1941 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
1943 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
1946 The following environment variables may be used and automatically
1947 updated by the network boot commands ("bootp" and "rarpboot"),
1948 depending the information provided by your boot server:
1950 bootfile - see above
1951 dnsip - IP address of your Domain Name Server
1952 gatewayip - IP address of the Gateway (Router) to use
1953 hostname - Target hostname
1955 netmask - Subnet Mask
1956 rootpath - Pathname of the root filesystem on the NFS server
1957 serverip - see above
1960 There are two special Environment Variables:
1962 serial# - contains hardware identification information such
1963 as type string and/or serial number
1964 ethaddr - Ethernet address
1966 These variables can be set only once (usually during manufacturing of
1967 the board). U-Boot refuses to delete or overwrite these variables
1968 once they have been set once.
1971 Please note that changes to some configuration parameters may take
1972 only effect after the next boot (yes, that's just like Windoze :-).
1975 Note for Redundant Ethernet Interfaces:
1976 =======================================
1978 Some boards come with redundand ethernet interfaces; U-Boot supports
1979 such configurations and is capable of automatic selection of a
1980 "working" interface when needed. MAC assignemnt works as follows:
1982 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
1983 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
1984 "eth1addr" (=>eth1), "eth2addr", ...
1986 If the network interface stores some valid MAC address (for instance
1987 in SROM), this is used as default address if there is NO correspon-
1988 ding setting in the environment; if the corresponding environment
1989 variable is set, this overrides the settings in the card; that means:
1991 o If the SROM has a valid MAC address, and there is no address in the
1992 environment, the SROM's address is used.
1994 o If there is no valid address in the SROM, and a definition in the
1995 environment exists, then the value from the environment variable is
1998 o If both the SROM and the environment contain a MAC address, and
1999 both addresses are the same, this MAC address is used.
2001 o If both the SROM and the environment contain a MAC address, and the
2002 addresses differ, the value from the environment is used and a
2005 o If neither SROM nor the environment contain a MAC address, an error
2013 The "boot" commands of this monitor operate on "image" files which
2014 can be basicly anything, preceeded by a special header; see the
2015 definitions in include/image.h for details; basicly, the header
2016 defines the following image properties:
2018 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2019 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2021 Currently supported: Linux, NetBSD, VxWorks, QNX).
2022 * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
2023 IA64, MIPS, MIPS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2024 Currently supported: PowerPC).
2025 * Compression Type (Provisions for uncompressed, gzip, bzip2;
2026 Currently supported: uncompressed, gzip).
2032 The header is marked by a special Magic Number, and both the header
2033 and the data portions of the image are secured against corruption by
2040 Although U-Boot should support any OS or standalone application
2041 easily, Linux has always been in the focus during the design of
2044 U-Boot includes many features that so far have been part of some
2045 special "boot loader" code within the Linux kernel. Also, any
2046 "initrd" images to be used are no longer part of one big Linux image;
2047 instead, kernel and "initrd" are separate images. This implementation
2048 serves serveral purposes:
2050 - the same features can be used for other OS or standalone
2051 applications (for instance: using compressed images to reduce the
2052 Flash memory footprint)
2054 - it becomes much easier to port new Linux kernel versions because
2055 lots of low-level, hardware dependend stuff are done by U-Boot
2057 - the same Linux kernel image can now be used with different "initrd"
2058 images; of course this also means that different kernel images can
2059 be run with the same "initrd". This makes testing easier (you don't
2060 have to build a new "zImage.initrd" Linux image when you just
2061 change a file in your "initrd"). Also, a field-upgrade of the
2062 software is easier now.
2068 Porting Linux to U-Boot based systems:
2069 ---------------------------------------
2071 U-Boot cannot save you from doing all the necessary modifications to
2072 configure the Linux device drivers for use with your target hardware
2073 (no, we don't intend to provide a full virtual machine interface to
2076 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
2078 Just make sure your machine specific header file (for instance
2079 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
2080 Information structure as we define in include/u-boot.h, and make
2081 sure that your definition of IMAP_ADDR uses the same value as your
2082 U-Boot configuration in CFG_IMMR.
2085 Configuring the Linux kernel:
2086 -----------------------------
2088 No specific requirements for U-Boot. Make sure you have some root
2089 device (initial ramdisk, NFS) for your target system.
2092 Building a Linux Image:
2093 -----------------------
2095 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2096 not used. If you use recent kernel source, a new build target
2097 "uImage" will exist which automatically builds an image usable by
2098 U-Boot. Most older kernels also have support for a "pImage" target,
2099 which was introduced for our predecessor project PPCBoot and uses a
2100 100% compatible format.
2109 The "uImage" build target uses a special tool (in 'tools/mkimage') to
2110 encapsulate a compressed Linux kernel image with header information,
2111 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
2113 * build a standard "vmlinux" kernel image (in ELF binary format):
2115 * convert the kernel into a raw binary image:
2117 ${CROSS_COMPILE}-objcopy -O binary \
2118 -R .note -R .comment \
2119 -S vmlinux linux.bin
2121 * compress the binary image:
2125 * package compressed binary image for U-Boot:
2127 mkimage -A ppc -O linux -T kernel -C gzip \
2128 -a 0 -e 0 -n "Linux Kernel Image" \
2129 -d linux.bin.gz uImage
2132 The "mkimage" tool can also be used to create ramdisk images for use
2133 with U-Boot, either separated from the Linux kernel image, or
2134 combined into one file. "mkimage" encapsulates the images with a 64
2135 byte header containing information about target architecture,
2136 operating system, image type, compression method, entry points, time
2137 stamp, CRC32 checksums, etc.
2139 "mkimage" can be called in two ways: to verify existing images and
2140 print the header information, or to build new images.
2142 In the first form (with "-l" option) mkimage lists the information
2143 contained in the header of an existing U-Boot image; this includes
2144 checksum verification:
2146 tools/mkimage -l image
2147 -l ==> list image header information
2149 The second form (with "-d" option) is used to build a U-Boot image
2150 from a "data file" which is used as image payload:
2152 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2153 -n name -d data_file image
2154 -A ==> set architecture to 'arch'
2155 -O ==> set operating system to 'os'
2156 -T ==> set image type to 'type'
2157 -C ==> set compression type 'comp'
2158 -a ==> set load address to 'addr' (hex)
2159 -e ==> set entry point to 'ep' (hex)
2160 -n ==> set image name to 'name'
2161 -d ==> use image data from 'datafile'
2163 Right now, all Linux kernels use the same load address (0x00000000),
2164 but the entry point address depends on the kernel version:
2166 - 2.2.x kernels have the entry point at 0x0000000C,
2167 - 2.3.x and later kernels have the entry point at 0x00000000.
2169 So a typical call to build a U-Boot image would read:
2171 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2172 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
2173 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
2174 > examples/uImage.TQM850L
2175 Image Name: 2.4.4 kernel for TQM850L
2176 Created: Wed Jul 19 02:34:59 2000
2177 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2178 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2179 Load Address: 0x00000000
2180 Entry Point: 0x00000000
2182 To verify the contents of the image (or check for corruption):
2184 -> tools/mkimage -l examples/uImage.TQM850L
2185 Image Name: 2.4.4 kernel for TQM850L
2186 Created: Wed Jul 19 02:34:59 2000
2187 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2188 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2189 Load Address: 0x00000000
2190 Entry Point: 0x00000000
2192 NOTE: for embedded systems where boot time is critical you can trade
2193 speed for memory and install an UNCOMPRESSED image instead: this
2194 needs more space in Flash, but boots much faster since it does not
2195 need to be uncompressed:
2197 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
2198 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2199 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
2200 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
2201 > examples/uImage.TQM850L-uncompressed
2202 Image Name: 2.4.4 kernel for TQM850L
2203 Created: Wed Jul 19 02:34:59 2000
2204 Image Type: PowerPC Linux Kernel Image (uncompressed)
2205 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
2206 Load Address: 0x00000000
2207 Entry Point: 0x00000000
2210 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2211 when your kernel is intended to use an initial ramdisk:
2213 -> tools/mkimage -n 'Simple Ramdisk Image' \
2214 > -A ppc -O linux -T ramdisk -C gzip \
2215 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2216 Image Name: Simple Ramdisk Image
2217 Created: Wed Jan 12 14:01:50 2000
2218 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2219 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
2220 Load Address: 0x00000000
2221 Entry Point: 0x00000000
2224 Installing a Linux Image:
2225 -------------------------
2227 To downloading a U-Boot image over the serial (console) interface,
2228 you must convert the image to S-Record format:
2230 objcopy -I binary -O srec examples/image examples/image.srec
2232 The 'objcopy' does not understand the information in the U-Boot
2233 image header, so the resulting S-Record file will be relative to
2234 address 0x00000000. To load it to a given address, you need to
2235 specify the target address as 'offset' parameter with the 'loads'
2238 Example: install the image to address 0x40100000 (which on the
2239 TQM8xxL is in the first Flash bank):
2241 => erase 40100000 401FFFFF
2247 ## Ready for S-Record download ...
2248 ~>examples/image.srec
2249 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2251 15989 15990 15991 15992
2252 [file transfer complete]
2254 ## Start Addr = 0x00000000
2257 You can check the success of the download using the 'iminfo' command;
2258 this includes a checksum verification so you can be sure no data
2259 corruption happened:
2263 ## Checking Image at 40100000 ...
2264 Image Name: 2.2.13 for initrd on TQM850L
2265 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2266 Data Size: 335725 Bytes = 327 kB = 0 MB
2267 Load Address: 00000000
2268 Entry Point: 0000000c
2269 Verifying Checksum ... OK
2276 The "bootm" command is used to boot an application that is stored in
2277 memory (RAM or Flash). In case of a Linux kernel image, the contents
2278 of the "bootargs" environment variable is passed to the kernel as
2279 parameters. You can check and modify this variable using the
2280 "printenv" and "setenv" commands:
2283 => printenv bootargs
2284 bootargs=root=/dev/ram
2286 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2288 => printenv bootargs
2289 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2292 ## Booting Linux kernel at 40020000 ...
2293 Image Name: 2.2.13 for NFS on TQM850L
2294 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2295 Data Size: 381681 Bytes = 372 kB = 0 MB
2296 Load Address: 00000000
2297 Entry Point: 0000000c
2298 Verifying Checksum ... OK
2299 Uncompressing Kernel Image ... OK
2300 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
2301 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2302 time_init: decrementer frequency = 187500000/60
2303 Calibrating delay loop... 49.77 BogoMIPS
2304 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2307 If you want to boot a Linux kernel with initial ram disk, you pass
2308 the memory addreses of both the kernel and the initrd image (PPBCOOT
2309 format!) to the "bootm" command:
2311 => imi 40100000 40200000
2313 ## Checking Image at 40100000 ...
2314 Image Name: 2.2.13 for initrd on TQM850L
2315 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2316 Data Size: 335725 Bytes = 327 kB = 0 MB
2317 Load Address: 00000000
2318 Entry Point: 0000000c
2319 Verifying Checksum ... OK
2321 ## Checking Image at 40200000 ...
2322 Image Name: Simple Ramdisk Image
2323 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2324 Data Size: 566530 Bytes = 553 kB = 0 MB
2325 Load Address: 00000000
2326 Entry Point: 00000000
2327 Verifying Checksum ... OK
2329 => bootm 40100000 40200000
2330 ## Booting Linux kernel at 40100000 ...
2331 Image Name: 2.2.13 for initrd on TQM850L
2332 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2333 Data Size: 335725 Bytes = 327 kB = 0 MB
2334 Load Address: 00000000
2335 Entry Point: 0000000c
2336 Verifying Checksum ... OK
2337 Uncompressing Kernel Image ... OK
2338 ## Loading RAMDisk Image at 40200000 ...
2339 Image Name: Simple Ramdisk Image
2340 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2341 Data Size: 566530 Bytes = 553 kB = 0 MB
2342 Load Address: 00000000
2343 Entry Point: 00000000
2344 Verifying Checksum ... OK
2345 Loading Ramdisk ... OK
2346 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
2347 Boot arguments: root=/dev/ram
2348 time_init: decrementer frequency = 187500000/60
2349 Calibrating delay loop... 49.77 BogoMIPS
2351 RAMDISK: Compressed image found at block 0
2352 VFS: Mounted root (ext2 filesystem).
2360 One of the features of U-Boot is that you can dynamically load and
2361 run "standalone" applications, which can use some resources of
2362 U-Boot like console I/O functions or interrupt services.
2364 Two simple examples are included with the sources:
2369 'examples/hello_world.c' contains a small "Hello World" Demo
2370 application; it is automatically compiled when you build U-Boot.
2371 It's configured to run at address 0x00040004, so you can play with it
2375 ## Ready for S-Record download ...
2376 ~>examples/hello_world.srec
2377 1 2 3 4 5 6 7 8 9 10 11 ...
2378 [file transfer complete]
2380 ## Start Addr = 0x00040004
2382 => go 40004 Hello World! This is a test.
2383 ## Starting application at 0x00040004 ...
2394 Hit any key to exit ...
2396 ## Application terminated, rc = 0x0
2398 Another example, which demonstrates how to register a CPM interrupt
2399 handler with the U-Boot code, can be found in 'examples/timer.c'.
2400 Here, a CPM timer is set up to generate an interrupt every second.
2401 The interrupt service routine is trivial, just printing a '.'
2402 character, but this is just a demo program. The application can be
2403 controlled by the following keys:
2405 ? - print current values og the CPM Timer registers
2406 b - enable interrupts and start timer
2407 e - stop timer and disable interrupts
2408 q - quit application
2411 ## Ready for S-Record download ...
2412 ~>examples/timer.srec
2413 1 2 3 4 5 6 7 8 9 10 11 ...
2414 [file transfer complete]
2416 ## Start Addr = 0x00040004
2419 ## Starting application at 0x00040004 ...
2422 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
2425 [q, b, e, ?] Set interval 1000000 us
2428 [q, b, e, ?] ........
2429 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
2432 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
2435 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
2438 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
2440 [q, b, e, ?] ...Stopping timer
2442 [q, b, e, ?] ## Application terminated, rc = 0x0
2448 Starting at version 0.9.2, U-Boot supports NetBSD both as host
2449 (build U-Boot) and target system (boots NetBSD/mpc8xx).
2451 Building requires a cross environment; it is known to work on
2452 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
2453 need gmake since the Makefiles are not compatible with BSD make).
2454 Note that the cross-powerpc package does not install include files;
2455 attempting to build U-Boot will fail because <machine/ansi.h> is
2456 missing. This file has to be installed and patched manually:
2458 # cd /usr/pkg/cross/powerpc-netbsd/include
2460 # ln -s powerpc machine
2461 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
2462 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
2464 Native builds *don't* work due to incompatibilities between native
2465 and U-Boot include files.
2467 Booting assumes that (the first part of) the image booted is a
2468 stage-2 loader which in turn loads and then invokes the kernel
2469 proper. Loader sources will eventually appear in the NetBSD source
2470 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
2471 meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for
2475 Implementation Internals:
2476 =========================
2478 The following is not intended to be a complete description of every
2479 implementation detail. However, it should help to understand the
2480 inner workings of U-Boot and make it easier to port it to custom
2484 Initial Stack, Global Data:
2485 ---------------------------
2487 The implementation of U-Boot is complicated by the fact that U-Boot
2488 starts running out of ROM (flash memory), usually without access to
2489 system RAM (because the memory controller is not initialized yet).
2490 This means that we don't have writable Data or BSS segments, and BSS
2491 is not initialized as zero. To be able to get a C environment working
2492 at all, we have to allocate at least a minimal stack. Implementation
2493 options for this are defined and restricted by the CPU used: Some CPU
2494 models provide on-chip memory (like the IMMR area on MPC8xx and
2495 MPC826x processors), on others (parts of) the data cache can be
2496 locked as (mis-) used as memory, etc.
2498 It is essential to remember this, since it has some impact on the C
2499 code for the initialization procedures:
2501 * Initialized global data (data segment) is read-only. Do not attempt
2504 * Do not use any unitialized global data (or implicitely initialized
2505 as zero data - BSS segment) at all - this is undefined, initiali-
2506 zation is performed later (when relocationg to RAM).
2508 * Stack space is very limited. Avoid big data buffers or things like
2511 Having only the stack as writable memory limits means we cannot use
2512 normal global data to share information beween the code. But it
2513 turned out that the implementation of U-Boot can be greatly
2514 simplified by making a global data structure (gd_t) available to all
2515 functions. We could pass a pointer to this data as argument to _all_
2516 functions, but this would bloat the code. Instead we use a feature of
2517 the GCC compiler (Global Register Variables) to share the data: we
2518 place a pointer (gd) to the global data into a register which we
2519 reserve for this purpose.
2521 When chosing a register for such a purpose we are restricted by the
2522 relevant (E)ABI specifications for the current architecture, and by
2523 GCC's implementation.
2525 For PowerPC, the following registers have specific use:
2528 R3-R4: parameter passing and return values
2529 R5-R10: parameter passing
2530 R13: small data area pointer
2534 (U-Boot also uses R14 as internal GOT pointer.)
2536 ==> U-Boot will use R29 to hold a pointer to the global data
2538 Note: on PPC, we could use a static initializer (since the
2539 address of the global data structure is known at compile time),
2540 but it turned out that reserving a register results in somewhat
2541 smaller code - although the code savings are not that big (on
2542 average for all boards 752 bytes for the whole U-Boot image,
2543 624 text + 127 data).
2545 On ARM, the following registers are used:
2547 R0: function argument word/integer result
2548 R1-R3: function argument word
2550 R10: stack limit (used only if stack checking if enabled)
2551 R11: argument (frame) pointer
2552 R12: temporary workspace
2555 R15: program counter
2557 ==> U-Boot will use R8 to hold a pointer to the global data
2564 U-Boot runs in system state and uses physical addresses, i.e. the
2565 MMU is not used either for address mapping nor for memory protection.
2567 The available memory is mapped to fixed addresses using the memory
2568 controller. In this process, a contiguous block is formed for each
2569 memory type (Flash, SDRAM, SRAM), even when it consists of several
2570 physical memory banks.
2572 U-Boot is installed in the first 128 kB of the first Flash bank (on
2573 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
2574 booting and sizing and initializing DRAM, the code relocates itself
2575 to the upper end of DRAM. Immediately below the U-Boot code some
2576 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
2577 configuration setting]. Below that, a structure with global Board
2578 Info data is placed, followed by the stack (growing downward).
2580 Additionally, some exception handler code is copied to the low 8 kB
2581 of DRAM (0x00000000 ... 0x00001FFF).
2583 So a typical memory configuration with 16 MB of DRAM could look like
2586 0x0000 0000 Exception Vector code
2589 0x0000 2000 Free for Application Use
2595 0x00FB FF20 Monitor Stack (Growing downward)
2596 0x00FB FFAC Board Info Data and permanent copy of global data
2597 0x00FC 0000 Malloc Arena
2600 0x00FE 0000 RAM Copy of Monitor Code
2601 ... eventually: LCD or video framebuffer
2602 ... eventually: pRAM (Protected RAM - unchanged by reset)
2603 0x00FF FFFF [End of RAM]
2606 System Initialization:
2607 ----------------------
2609 In the reset configuration, U-Boot starts at the reset entry point
2610 (on most PowerPC systens at address 0x00000100). Because of the reset
2611 configuration for CS0# this is a mirror of the onboard Flash memory.
2612 To be able to re-map memory U-Boot then jumps to it's link address.
2613 To be able to implement the initialization code in C, a (small!)
2614 initial stack is set up in the internal Dual Ported RAM (in case CPUs
2615 which provide such a feature like MPC8xx or MPC8260), or in a locked
2616 part of the data cache. After that, U-Boot initializes the CPU core,
2617 the caches and the SIU.
2619 Next, all (potentially) available memory banks are mapped using a
2620 preliminary mapping. For example, we put them on 512 MB boundaries
2621 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
2622 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
2623 programmed for SDRAM access. Using the temporary configuration, a
2624 simple memory test is run that determines the size of the SDRAM
2627 When there is more than one SDRAM bank, and the banks are of
2628 different size, the larger is mapped first. For equal size, the first
2629 bank (CS2#) is mapped first. The first mapping is always for address
2630 0x00000000, with any additional banks following immediately to create
2631 contiguous memory starting from 0.
2633 Then, the monitor installs itself at the upper end of the SDRAM area
2634 and allocates memory for use by malloc() and for the global Board
2635 Info data; also, the exception vector code is copied to the low RAM
2636 pages, and the final stack is set up.
2638 Only after this relocation will you have a "normal" C environment;
2639 until that you are restricted in several ways, mostly because you are
2640 running from ROM, and because the code will have to be relocated to a
2644 U-Boot Porting Guide:
2645 ----------------------
2647 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
2651 int main (int argc, char *argv[])
2653 sighandler_t no_more_time;
2655 signal (SIGALRM, no_more_time);
2656 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
2658 if (available_money > available_manpower) {
2659 pay consultant to port U-Boot;
2663 Download latest U-Boot source;
2665 Subscribe to u-boot-users mailing list;
2668 email ("Hi, I am new to U-Boot, how do I get started?");
2672 Read the README file in the top level directory;
2673 Read http://www.denx.de/re/DPLG.html
2674 Read the source, Luke;
2677 if (available_money > toLocalCurrency ($2500)) {
2680 Add a lot of aggravation and time;
2683 Create your own board support subdirectory;
2685 Create your own board config file;
2689 Add / modify source code;
2693 email ("Hi, I am having problems...");
2695 Send patch file to Wolfgang;
2700 void no_more_time (int sig)
2710 All contributions to U-Boot should conform to the Linux kernel
2711 coding style; see the file "Documentation/CodingStyle" in your Linux
2712 kernel source directory.
2714 Please note that U-Boot is implemented in C (and to some small parts
2715 in Assembler); no C++ is used, so please do not use C++ style
2716 comments (//) in your code.
2718 Submissions which do not conform to the standards may be returned
2719 with a request to reformat the changes.
2725 Since the number of patches for U-Boot is growing, we need to
2726 establish some rules. Submissions which do not conform to these rules
2727 may be rejected, even when they contain important and valuable stuff.
2730 When you send a patch, please include the following information with
2733 * For bug fixes: a description of the bug and how your patch fixes
2734 this bug. Please try to include a way of demonstrating that the
2735 patch actually fixes something.
2737 * For new features: a description of the feature and your
2740 * A CHANGELOG entry as plaintext (separate from the patch)
2742 * For major contributions, your entry to the CREDITS file
2744 * When you add support for a new board, don't forget to add this
2745 board to the MAKEALL script, too.
2747 * If your patch adds new configuration options, don't forget to
2748 document these in the README file.
2750 * The patch itself. If you are accessing the CVS repository use "cvs
2751 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
2752 version of diff does not support these options, then get the latest
2753 version of GNU diff.
2755 We accept patches as plain text, MIME attachments or as uuencoded
2760 * Before sending the patch, run the MAKEALL script on your patched
2761 source tree and make sure that no errors or warnings are reported
2762 for any of the boards.
2764 * Keep your modifications to the necessary minimum: A patch
2765 containing several unrelated changes or arbitrary reformats will be
2766 returned with a request to re-formatting / split it.
2768 * If you modify existing code, make sure that your new code does not
2769 add to the memory footprint of the code ;-) Small is beautiful!
2770 When adding new features, these should compile conditionally only
2771 (using #ifdef), and the resulting code with the new feature
2772 disabled must not need more memory than the old code without your
projects / platform / kernel / u-boot.git / blob