2 # (C) Copyright 2000 - 2002
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
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 - board Board dependend files
111 - common Misc architecture independend functions
112 - cpu CPU specific files
113 - disk Code for disk drive partition handling
114 - doc Documentation (don't expect too much)
115 - drivers Common used device drivers
116 - dtt Digital Thermometer and Thermostat drivers
117 - examples Example code for standalone applications, etc.
118 - include Header Files
119 - disk Harddisk interface code
120 - net Networking code
121 - ppc Files generic to PowerPC architecture
122 - post Power On Self Test
123 - post/arch Symlink to architecture specific Power On Self Test
124 - post/arch-ppc PowerPC architecture specific Power On Self Test
125 - post/cpu/mpc8260 MPC8260 CPU specific Power On Self Test
126 - post/cpu/mpc8xx MPC8xx CPU specific Power On Self Test
127 - rtc Real Time Clock drivers
128 - tools Tools to build S-Record or U-Boot images, etc.
130 - cpu/74xx_7xx Files specific to Motorola MPC74xx and 7xx CPUs
131 - cpu/mpc8xx Files specific to Motorola MPC8xx CPUs
132 - cpu/mpc824x Files specific to Motorola MPC824x CPUs
133 - cpu/mpc8260 Files specific to Motorola MPC8260 CPU
134 - cpu/ppc4xx Files specific to IBM 4xx CPUs
137 Files specific to RPXClassic boards
138 - board/RPXlite Files specific to RPXlite boards
139 - board/c2mon Files specific to c2mon boards
140 - board/cogent Files specific to Cogent boards
141 (need further configuration)
142 Files specific to CPCIISER4 boards
143 - board/cpu86 Files specific to CPU86 boards
144 - board/cray/ Files specific to boards manufactured by Cray
145 - board/cray/L1 Files specific to L1 boards
146 - board/cu824 Files specific to CU824 boards
147 - board/ebony Files specific to IBM Ebony board
148 - board/eric Files specific to ERIC boards
149 - board/esd/ Files specific to boards manufactured by ESD
150 - board/esd/adciop Files specific to ADCIOP boards
151 - board/esd/ar405 Files specific to AR405 boards
152 - board/esd/canbt Files specific to CANBT boards
153 - board/esd/cpci405 Files specific to CPCI405 boards
154 - board/esd/cpciiser4 Files specific to CPCIISER4 boards
155 - board/esd/common Common files for ESD boards
156 - board/esd/dasa_sim Files specific to DASA_SIM boards
157 - board/esd/du405 Files specific to DU405 boards
158 - board/esd/ocrtc Files specific to OCRTC boards
159 - board/esd/pci405 Files specific to PCI405 boards
161 Files specific to ESTEEM192E boards
162 - board/etx094 Files specific to ETX_094 boards
164 Files specific to EVB64260 boards
165 - board/fads Files specific to FADS boards
166 - board/flagadm Files specific to FLAGADM boards
167 - board/gen860t Files specific to GEN860T boards
168 - board/genietv Files specific to GENIETV boards
169 - board/gth Files specific to GTH boards
170 - board/hermes Files specific to HERMES boards
171 - board/hymod Files specific to HYMOD boards
172 - board/icu862 Files specific to ICU862 boards
173 - board/ip860 Files specific to IP860 boards
175 Files specific to Interphase4539 boards
176 - board/ivm Files specific to IVMS8/IVML24 boards
177 - board/lantec Files specific to LANTEC boards
178 - board/lwmon Files specific to LWMON boards
179 - board/mbx8xx Files specific to MBX boards
181 Files specific to MMPC8260ADS boards
182 - board/mpl/ Files specific to boards manufactured by MPL
183 - board/mpl/common Common files for MPL boards
184 - board/mpl/pip405 Files specific to PIP405 boards
185 - board/mpl/mip405 Files specific to MIP405 boards
186 - board/musenki Files specific to MUSEKNI boards
187 - board/mvs1 Files specific to MVS1 boards
188 - board/nx823 Files specific to NX823 boards
189 - board/oxc Files specific to OXC boards
190 - board/pcippc2 Files specific to PCIPPC2/PCIPPC6 boards
191 - board/pm826 Files specific to PM826 boards
193 Files specific to PPMC8260 boards
195 Files specific to RPXsuper boards
197 Files specific to RSDproto boards
199 Files specific to Sandpoint boards
200 - board/sbc8260 Files specific to SBC8260 boards
201 - board/sacsng Files specific to SACSng boards
202 - board/siemens Files specific to boards manufactured by Siemens AG
203 - board/siemens/CCM Files specific to CCM boards
204 - board/siemens/IAD210 Files specific to IAD210 boards
205 - board/siemens/SCM Files specific to SCM boards
206 - board/siemens/pcu_e Files specific to PCU_E boards
207 - board/sixnet Files specific to SIXNET boards
208 - board/spd8xx Files specific to SPD8xxTS boards
209 - board/tqm8260 Files specific to TQM8260 boards
210 - board/tqm8xx Files specific to TQM8xxL boards
211 - board/w7o Files specific to W7O boards
213 Files specific to Walnut405 boards
214 - board/westel/ Files specific to boards manufactured by Westel Wireless
215 - board/westel/amx860 Files specific to AMX860 boards
216 - board/utx8245 Files specific to UTX8245 boards
218 Software Configuration:
219 =======================
221 Configuration is usually done using C preprocessor defines; the
222 rationale behind that is to avoid dead code whenever possible.
224 There are two classes of configuration variables:
226 * Configuration _OPTIONS_:
227 These are selectable by the user and have names beginning with
230 * Configuration _SETTINGS_:
231 These depend on the hardware etc. and should not be meddled with if
232 you don't know what you're doing; they have names beginning with
235 Later we will add a configuration tool - probably similar to or even
236 identical to what's used for the Linux kernel. Right now, we have to
237 do the configuration by hand, which means creating some symbolic
238 links and editing some configuration files. We use the TQM8xxL boards
242 Selection of Processor Architecture and Board Type:
243 ---------------------------------------------------
245 For all supported boards there are ready-to-use default
246 configurations available; just type "make <board_name>_config".
248 Example: For a TQM823L module type:
253 For the Cogent platform, you need to specify the cpu type as well;
254 e.g. "make cogent_mpc8xx_config". And also configure the cogent
255 directory according to the instructions in cogent/README.
258 Configuration Options:
259 ----------------------
261 Configuration depends on the combination of board and CPU type; all
262 such information is kept in a configuration file
263 "include/configs/<board_name>.h".
265 Example: For a TQM823L module, all configuration settings are in
266 "include/configs/TQM823L.h".
269 Many of the options are named exactly as the corresponding Linux
270 kernel configuration options. The intention is to make it easier to
271 build a config tool - later.
274 The following options need to be configured:
276 - CPU Type: Define exactly one of
280 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860
281 or CONFIG_MPC824X, CONFIG_MPC8260
294 - Board Type: Define exactly one of
296 PowerPC based boards:
297 ---------------------
299 CONFIG_ADCIOP, CONFIG_ICU862 CONFIG_RPXsuper,
300 CONFIG_ADS860, CONFIG_IP860, CONFIG_SM850,
301 CONFIG_AMX860, CONFIG_IPHASE4539, CONFIG_SPD823TS,
302 CONFIG_AR405, CONFIG_IVML24, CONFIG_SXNI855T,
303 CONFIG_BAB7xx, CONFIG_IVML24_128, CONFIG_Sandpoint8240,
304 CONFIG_CANBT, CONFIG_IVML24_256, CONFIG_Sandpoint8245,
305 CONFIG_CCM, CONFIG_IVMS8, CONFIG_TQM823L,
306 CONFIG_CPCI405, CONFIG_IVMS8_128, CONFIG_TQM850L,
307 CONFIG_CPCI4052, CONFIG_IVMS8_256, CONFIG_TQM855L,
308 CONFIG_CPCIISER4, CONFIG_LANTEC, CONFIG_TQM860L,
309 CONFIG_CPU86, CONFIG_MBX, CONFIG_TQM8260,
310 CONFIG_CRAYL1, CONFIG_MBX860T, CONFIG_TTTech,
311 CONFIG_CU824, CONFIG_MHPC, CONFIG_UTX8245,
312 CONFIG_DASA_SIM, CONFIG_MIP405, CONFIG_W7OLMC,
313 CONFIG_DU405, CONFIG_MOUSSE, CONFIG_W7OLMG,
314 CONFIG_ELPPC, CONFIG_MPC8260ADS, CONFIG_WALNUT405,
315 CONFIG_ERIC, CONFIG_MUSENKI, CONFIG_ZUMA,
316 CONFIG_ESTEEM192E, CONFIG_MVS1, CONFIG_c2mon,
317 CONFIG_ETX094, CONFIG_NX823, CONFIG_cogent_mpc8260,
318 CONFIG_EVB64260, CONFIG_OCRTC, CONFIG_cogent_mpc8xx,
319 CONFIG_FADS823, CONFIG_ORSG, CONFIG_ep8260,
320 CONFIG_FADS850SAR, CONFIG_OXC, CONFIG_gw8260,
321 CONFIG_FADS860T, CONFIG_PCI405, CONFIG_hermes,
322 CONFIG_FLAGADM, CONFIG_PCIPPC2, CONFIG_hymod,
323 CONFIG_FPS850L, CONFIG_PCIPPC6, CONFIG_lwmon,
324 CONFIG_GEN860T, CONFIG_PIP405, CONFIG_pcu_e,
325 CONFIG_GENIETV, CONFIG_PM826, CONFIG_ppmc8260,
326 CONFIG_GTH, CONFIG_RPXClassic, CONFIG_rsdproto,
327 CONFIG_IAD210, CONFIG_RPXlite, CONFIG_sbc8260,
328 CONFIG_EBONY, CONFIG_sacsng, CONFIG_FPS860L
333 CONFIG_HHP_CRADLE, CONFIG_DNP1110, CONFIG_EP7312,
334 CONFIG_IMPA7, CONFIG_LART, CONFIG_LUBBOCK,
335 CONFIG_SHANNON, CONFIG_SMDK2400, CONFIG_SMDK2410,
339 - CPU Module Type: (if CONFIG_COGENT is defined)
340 Define exactly one of
342 --- FIXME --- not tested yet:
343 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
344 CONFIG_CMA287_23, CONFIG_CMA287_50
346 - Motherboard Type: (if CONFIG_COGENT is defined)
347 Define exactly one of
348 CONFIG_CMA101, CONFIG_CMA102
350 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
351 Define one or more of
354 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
355 Define one or more of
356 CONFIG_LCD_HEARTBEAT - update a character position on
357 the lcd display every second with
360 - MPC824X Family Member (if CONFIG_MPC824X is defined)
361 Define exactly one of
362 CONFIG_MPC8240, CONFIG_MPC8245
364 - 8xx CPU Options: (if using an 8xx cpu)
365 Define one or more of
366 CONFIG_8xx_GCLK_FREQ - if get_gclk_freq() can not work e.g.
367 no 32KHz reference PIT/RTC clock
372 U-Boot stores all clock information in Hz
373 internally. For binary compatibility with older Linux
374 kernels (which expect the clocks passed in the
375 bd_info data to be in MHz) the environment variable
376 "clocks_in_mhz" can be defined so that U-Boot
377 converts clock data to MHZ before passing it to the
380 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
381 "clocks_in_mhz=1" is automatically included in the
385 Depending on board, define exactly one serial port
386 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
387 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
388 console by defining CONFIG_8xx_CONS_NONE
390 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
391 port routines must be defined elsewhere
392 (i.e. serial_init(), serial_getc(), ...)
395 Enables console device for a color framebuffer. Needs following
396 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
397 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
399 VIDEO_HW_RECTFILL graphic chip supports
402 VIDEO_HW_BITBLT graphic chip supports
403 bit-blit (cf. smiLynxEM)
404 VIDEO_VISIBLE_COLS visible pixel columns
406 VIDEO_VISIBLE_ROWS visible pixel rows
407 VIDEO_PIXEL_SIZE bytes per pixel
408 VIDEO_DATA_FORMAT graphic data format
409 (0-5, cf. cfb_console.c)
410 VIDEO_FB_ADRS framebuffer address
411 VIDEO_KBD_INIT_FCT keyboard int fct
412 (i.e. i8042_kbd_init())
413 VIDEO_TSTC_FCT test char fct
415 VIDEO_GETC_FCT get char fct
417 CONFIG_CONSOLE_CURSOR cursor drawing on/off
418 (requires blink timer
420 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
421 CONFIG_CONSOLE_TIME display time/date info in
423 (requires CFG_CMD_DATE)
424 CONFIG_VIDEO_LOGO display Linux logo in
426 CONFIG_CONSOLE_EXTRA_INFO
427 addional board info beside
430 When CONFIG_CFB_CONSOLE is defined, video console is
431 default i/o. Serial console can be forced with
432 environment 'console=serial'.
435 CONFIG_BAUDRATE - in bps
436 Select one of the baudrates listed in
437 CFG_BAUDRATE_TABLE, see below.
439 - Interrupt driven serial port input:
440 CONFIG_SERIAL_SOFTWARE_FIFO
443 Use an interrupt handler for receiving data on the
444 serial port. It also enables using hardware handshake
445 (RTS/CTS) and UART's built-in FIFO. Set the number of
446 bytes the interrupt driven input buffer should have.
448 Set to 0 to disable this feature (this is the default).
449 This will also disable hardware handshake.
451 - Boot Delay: CONFIG_BOOTDELAY - in seconds
452 Delay before automatically booting the default image;
453 set to -1 to disable autoboot.
455 See doc/README.autoboot for these options that
456 work with CONFIG_BOOTDELAY. None are required.
457 CONFIG_BOOT_RETRY_TIME
458 CONFIG_BOOT_RETRY_MIN
459 CONFIG_AUTOBOOT_KEYED
460 CONFIG_AUTOBOOT_PROMPT
461 CONFIG_AUTOBOOT_DELAY_STR
462 CONFIG_AUTOBOOT_STOP_STR
463 CONFIG_AUTOBOOT_DELAY_STR2
464 CONFIG_AUTOBOOT_STOP_STR2
465 CONFIG_ZERO_BOOTDELAY_CHECK
466 CONFIG_RESET_TO_RETRY
470 Only needed when CONFIG_BOOTDELAY is enabled;
471 define a command string that is automatically executed
472 when no character is read on the console interface
473 within "Boot Delay" after reset.
476 This can be used to pass arguments to the bootm
477 command. The value of CONFIG_BOOTARGS goes into the
478 environment value "bootargs".
480 CONFIG_RAMBOOT and CONFIG_NFSBOOT
481 The value of these goes into the environment as
482 "ramboot" and "nfsboot" respectively, and can be used
483 as a convenience, when switching between booting from
489 When this option is #defined, the existence of the
490 environment variable "preboot" will be checked
491 immediately before starting the CONFIG_BOOTDELAY
492 countdown and/or running the auto-boot command resp.
493 entering interactive mode.
495 This feature is especially useful when "preboot" is
496 automatically generated or modified. For an example
497 see the LWMON board specific code: here "preboot" is
498 modified when the user holds down a certain
499 combination of keys on the (special) keyboard when
502 - Serial Download Echo Mode:
504 If defined to 1, all characters received during a
505 serial download (using the "loads" command) are
506 echoed back. This might be needed by some terminal
507 emulations (like "cu"), but may as well just take
508 time on others. This setting #define's the initial
509 value of the "loads_echo" environment variable.
511 - Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
513 Select one of the baudrates listed in
514 CFG_BAUDRATE_TABLE, see below.
518 Most monitor functions can be selected (or
519 de-selected) by adjusting the definition of
520 CONFIG_COMMANDS; to select individual functions,
521 #define CONFIG_COMMANDS by "OR"ing any of the
524 #define enables commands:
525 -------------------------
526 CFG_CMD_ASKENV * ask for env variable
528 CFG_CMD_BEDBUG Include BedBug Debugger
530 CFG_CMD_CACHE icache, dcache
531 CFG_CMD_CONSOLE coninfo
532 CFG_CMD_DATE * support for RTC, date/time...
533 CFG_CMD_DHCP DHCP support
534 CFG_CMD_ECHO * echo arguments
535 CFG_CMD_EEPROM * EEPROM read/write support
536 CFG_CMD_ELF bootelf, bootvx
538 CFG_CMD_FDC * Floppy Disk Support
539 CFG_CMD_FDOS * Dos diskette Support
540 CFG_CMD_FLASH flinfo, erase, protect
541 CFG_CMD_FPGA FPGA device initialization support
542 CFG_CMD_I2C * I2C serial bus support
543 CFG_CMD_IDE * IDE harddisk support
545 CFG_CMD_IMMAP * IMMR dump support
546 CFG_CMD_IRQ * irqinfo
550 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
552 CFG_CMD_MII MII utility commands
553 CFG_CMD_NET bootp, tftpboot, rarpboot
554 CFG_CMD_PCI * pciinfo
555 CFG_CMD_PCMCIA * PCMCIA support
556 CFG_CMD_REGINFO * Register dump
557 CFG_CMD_RUN run command in env variable
558 CFG_CMD_SCSI * SCSI Support
559 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
560 CFG_CMD_SPI * SPI serial bus support
561 CFG_CMD_USB * USB support
562 CFG_CMD_BSP * Board SPecific functions
563 -----------------------------------------------
566 CFG_CMD_DFL Default configuration; at the moment
567 this is includes all commands, except
568 the ones marked with "*" in the list
571 If you don't define CONFIG_COMMANDS it defaults to
572 CFG_CMD_DFL in include/cmd_confdefs.h. A board can
573 override the default settings in the respective
576 EXAMPLE: If you want all functions except of network
577 support you can write:
579 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
582 Note: Don't enable the "icache" and "dcache" commands
583 (configuration option CFG_CMD_CACHE) unless you know
584 what you (and your U-Boot users) are doing. Data
585 cache cannot be enabled on systems like the 8xx or
586 8260 (where accesses to the IMMR region must be
587 uncached), and it cannot be disabled on all other
588 systems where we (mis-) use the data cache to hold an
589 initial stack and some data.
592 XXX - this list needs to get updated!
596 If this variable is defined, it enables watchdog
597 support. There must support in the platform specific
598 code for a watchdog. For the 8xx and 8260 CPUs, the
599 SIU Watchdog feature is enabled in the SYPCR
604 When CFG_CMD_DATE is selected, the type of the RTC
605 has to be selected, too. Define exactly one of the
608 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
609 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
610 CONFIG_RTC_MC146818 - use MC146818 RTC
611 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
615 When CONFIG_TIMESTAMP is selected, the timestamp
616 (date and time) of an image is printed by image
617 commands like bootm or iminfo. This option is
618 automatically enabled when you select CFG_CMD_DATE .
621 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
622 and/or CONFIG_ISO_PARTITION
624 If IDE or SCSI support is enabled (CFG_CMD_IDE or
625 CFG_CMD_SCSI) you must configure support for at least
626 one partition type as well.
629 CONFIG_IDE_RESET_ROUTINE
631 Set this to define that instead of a reset Pin, the
632 routine ide_set_reset(int idereset) will be used.
637 Set this to enable ATAPI support.
640 At the moment only there is only support for the
641 SYM53C8XX SCSI controller; define
642 CONFIG_SCSI_SYM53C8XX to enable it.
644 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
645 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
646 CFG_SCSI_MAX_LUN] can be adjusted to define the
647 maximum numbers of LUNs, SCSI ID's and target
649 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
651 - NETWORK Support (PCI):
653 Support for Intel 82557/82559/82559ER chips.
654 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
655 write routine for first time initialisation.
658 Support for Digital 2114x chips.
659 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
660 modem chip initialisation (KS8761/QS6611).
663 Support for National dp83815 chips.
666 Support for National dp8382[01] gigabit chips.
669 At the moment only the UHCI host controller is
670 supported (PIP405, MIP405); define
671 CONFIG_USB_UHCI to enable it.
672 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
673 end define CONFIG_USB_STORAGE to enable the USB
676 Supported are USB Keyboards and USB Floppy drives
682 Define this to enable standard (PC-Style) keyboard
686 Standard PC keyboard driver with US (is default) and
687 GERMAN key layout (switch via environment 'keymap=de') support.
688 Export function i8042_kbd_init, i8042_tstc and i8042_getc
689 for cfb_console. Supports cursor blinking.
694 Define this to enable video support (for output to
699 Enable Chips & Technologies 69000 Video chip
701 CONFIG_VIDEO_SMI_LYNXEM
702 Enable Silicon Motion SMI 712/710/810 Video chip
703 Videomode are selected via environment 'videomode' with
704 standard LiLo mode numbers.
705 Following modes are supported (* is default):
707 800x600 1024x768 1280x1024
708 256 (8bit) 303* 305 307
709 65536 (16bit) 314 317 31a
710 16,7 Mill (24bit) 315 318 31b
711 (i.e. setenv videomode 317; saveenv; reset;)
713 - LCD Support: CONFIG_LCD
715 Define this to enable LCD support (for output to LCD
716 display); also select one of the supported displays
717 by defining one of these:
719 CONFIG_NEC_NL6648AC33:
721 NEC NL6648AC33-18. Active, color, single scan.
723 CONFIG_NEC_NL6648BC20
725 NEC NL6648BC20-08. 6.5", 640x480.
726 Active, color, single scan.
730 Sharp 320x240. Active, color, single scan.
731 It isn't 16x9, and I am not sure what it is.
733 CONFIG_SHARP_LQ64D341
735 Sharp LQ64D341 display, 640x480.
736 Active, color, single scan.
740 HLD1045 display, 640x480.
741 Active, color, single scan.
745 Optrex CBL50840-2 NF-FW 99 22 M5
747 Hitachi LMG6912RPFC-00T
751 320x240. Black & white.
753 Normally display is black on white background; define
754 CFG_WHITE_ON_BLACK to get it inverted.
761 Define a default value for ethernet address to use
762 for the respective ethernet interface, in case this
763 is not determined automatically.
768 Define a default value for the IP address to use for
769 the default ethernet interface, in case this is not
770 determined through e.g. bootp.
775 Defines a default value for theIP address of a TFTP
776 server to contact when using the "tftboot" command.
778 - BOOTP Recovery Mode:
779 CONFIG_BOOTP_RANDOM_DELAY
781 If you have many targets in a network that try to
782 boot using BOOTP, you may want to avoid that all
783 systems send out BOOTP requests at precisely the same
784 moment (which would happen for instance at recovery
785 from a power failure, when all systems will try to
786 boot, thus flooding the BOOTP server. Defining
787 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
788 inserted before sending out BOOTP requests. The
789 following delays are insterted then:
791 1st BOOTP request: delay 0 ... 1 sec
792 2nd BOOTP request: delay 0 ... 2 sec
793 3rd BOOTP request: delay 0 ... 4 sec
795 BOOTP requests: delay 0 ... 8 sec
797 - Status LED: CONFIG_STATUS_LED
799 Several configurations allow to display the current
800 status using a LED. For instance, the LED will blink
801 fast while running U-Boot code, stop blinking as
802 soon as a reply to a BOOTP request was received, and
803 start blinking slow once the Linux kernel is running
804 (supported by a status LED driver in the Linux
805 kernel). Defining CONFIG_STATUS_LED enables this
808 - CAN Support: CONFIG_CAN_DRIVER
810 Defining CONFIG_CAN_DRIVER enables CAN driver support
811 on those systems that support this (optional)
812 feature, like the TQM8xxL modules.
814 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
816 Enables I2C serial bus commands. If this is selected,
817 either CONFIG_HARD_I2C or CONFIG_SOFT_I2C must be defined
818 to include the appropriate I2C driver.
820 See also: common/cmd_i2c.c for a description of the
821 command line interface.
826 Selects the CPM hardware driver for I2C.
830 Use software (aka bit-banging) driver instead of CPM
831 or similar hardware support for I2C. This is configured
832 via the following defines.
836 (Optional). Any commands necessary to enable I2C
837 controller or configure ports.
841 (Only for MPC8260 CPU). The I/O port to use (the code
842 assumes both bits are on the same port). Valid values
843 are 0..3 for ports A..D.
847 The code necessary to make the I2C data line active
848 (driven). If the data line is open collector, this
853 The code necessary to make the I2C data line tri-stated
854 (inactive). If the data line is open collector, this
859 Code that returns TRUE if the I2C data line is high,
864 If <bit> is TRUE, sets the I2C data line high. If it
865 is FALSE, it clears it (low).
869 If <bit> is TRUE, sets the I2C clock line high. If it
870 is FALSE, it clears it (low).
874 This delay is invoked four times per clock cycle so this
875 controls the rate of data transfer. The data rate thus
876 is 1 / (I2C_DELAY * 4).
878 - SPI Support: CONFIG_SPI
880 Enables SPI driver (so far only tested with
881 SPI EEPROM, also an instance works with Crystal A/D and
882 D/As on the SACSng board)
886 Enables extended (16-bit) SPI EEPROM addressing.
887 (symmetrical to CONFIG_I2C_X)
891 Enables a software (bit-bang) SPI driver rather than
892 using hardware support. This is a general purpose
893 driver that only requires three general I/O port pins
894 (two outputs, one input) to function. If this is
895 defined, the board configuration must define several
896 SPI configuration items (port pins to use, etc). For
897 an example, see include/configs/sacsng.h.
899 - FPGA Support: CONFIG_FPGA_COUNT
901 Specify the number of FPGA devices to support.
905 Used to specify the types of FPGA devices. For
907 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
909 CFG_FPGA_PROG_FEEDBACK
911 Enable printing of hash marks during FPGA
916 Enable checks on FPGA configuration interface busy
917 status by the configuration function. This option
918 will require a board or device specific function to
923 If defined, a function that provides delays in the
924 FPGA configuration driver.
928 Allow Control-C to interrupt FPGA configuration
932 Check for configuration errors during FPGA bitfile
933 loading. For example, abort during Virtex II
934 configuration if the INIT_B line goes low (which
935 indicated a CRC error).
939 Maximum time to wait for the INIT_B line to deassert
940 after PROB_B has been deasserted during a Virtex II
941 FPGA configuration sequence. The default time is 500 mS.
945 Maximum time to wait for BUSY to deassert during
946 Virtex II FPGA configuration. The default is 5 mS.
950 Time to wait after FPGA configuration. The default is
953 - FPGA Support: CONFIG_FPGA_COUNT
955 Specify the number of FPGA devices to support.
959 Used to specify the types of FPGA devices. For example,
960 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
962 CFG_FPGA_PROG_FEEDBACK
964 Enable printing of hash marks during FPGA configuration.
968 Enable checks on FPGA configuration interface busy
969 status by the configuration function. This option
970 will require a board or device specific function to
975 If defined, a function that provides delays in the FPGA
976 configuration driver.
979 Allow Control-C to interrupt FPGA configuration
983 Check for configuration errors during FPGA bitfile
984 loading. For example, abort during Virtex II
985 configuration if the INIT_B line goes low (which
986 indicated a CRC error).
990 Maximum time to wait for the INIT_B line to deassert
991 after PROB_B has been deasserted during a Virtex II
992 FPGA configuration sequence. The default time is 500
997 Maximum time to wait for BUSY to deassert during
998 Virtex II FPGA configuration. The default is 5 mS.
1000 CFG_FPGA_WAIT_CONFIG
1002 Time to wait after FPGA configuration. The default is
1005 - Configuration Management:
1008 If defined, this string will be added to the U-Boot
1009 version information (U_BOOT_VERSION)
1011 - Vendor Parameter Protection:
1013 U-Boot considers the values of the environment
1014 variables "serial#" (Board Serial Number) and
1015 "ethaddr" (Ethernet Address) to bb parameters that
1016 are set once by the board vendor / manufacturer, and
1017 protects these variables from casual modification by
1018 the user. Once set, these variables are read-only,
1019 and write or delete attempts are rejected. You can
1020 change this behviour:
1022 If CONFIG_ENV_OVERWRITE is #defined in your config
1023 file, the write protection for vendor parameters is
1024 completely disabled. Anybody can change or delte
1027 Alternatively, if you #define _both_ CONFIG_ETHADDR
1028 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1029 ethernet address is installed in the environment,
1030 which can be changed exactly ONCE by the user. [The
1031 serial# is unaffected by this, i. e. it remains
1037 Define this variable to enable the reservation of
1038 "protected RAM", i. e. RAM which is not overwritten
1039 by U-Boot. Define CONFIG_PRAM to hold the number of
1040 kB you want to reserve for pRAM. You can overwrite
1041 this default value by defining an environment
1042 variable "pram" to the number of kB you want to
1043 reserve. Note that the board info structure will
1044 still show the full amount of RAM. If pRAM is
1045 reserved, a new environment variable "mem" will
1046 automatically be defined to hold the amount of
1047 remaining RAM in a form that can be passed as boot
1048 argument to Linux, for instance like that:
1050 setenv bootargs ... mem=\$(mem)
1053 This way you can tell Linux not to use this memory,
1054 either, which results in a memory region that will
1055 not be affected by reboots.
1057 *WARNING* If your board configuration uses automatic
1058 detection of the RAM size, you must make sure that
1059 this memory test is non-destructive. So far, the
1060 following board configurations are known to be
1063 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1064 HERMES, IP860, RPXlite, LWMON, LANTEC,
1065 PCU_E, FLAGADM, TQM8260
1070 Define this variable to stop the system in case of a
1071 fatal error, so that you have to reset it manually.
1072 This is probably NOT a good idea for an embedded
1073 system where you want to system to reboot
1074 automatically as fast as possible, but it may be
1075 useful during development since you can try to debug
1076 the conditions that lead to the situation.
1078 CONFIG_NET_RETRY_COUNT
1080 This variable defines the number of retries for
1081 network operations like ARP, RARP, TFTP, or BOOTP
1082 before giving up the operation. If not defined, a
1083 default value of 5 is used.
1085 - Command Interpreter:
1088 Define this variable to enable the "hush" shell (from
1089 Busybox) as command line interpreter, thus enabling
1090 powerful command line syntax like
1091 if...then...else...fi conditionals or `&&' and '||'
1092 constructs ("shell scripts").
1094 If undefined, you get the old, much simpler behaviour
1095 with a somewhat smaller memory footprint.
1100 This defines the secondary prompt string, which is
1101 printed when the command interpreter needs more input
1102 to complete a command. Usually "> ".
1106 In the current implementation, the local variables
1107 space and global environment variables space are
1108 separated. Local variables are those you define by
1109 simply typing like `name=value'. To access a local
1110 variable later on, you have write `$name' or
1111 `${name}'; variable directly by typing say `$name' at
1114 Global environment variables are those you use
1115 setenv/printenv to work with. To run a command stored
1116 in such a variable, you need to use the run command,
1117 and you must not use the '$' sign to access them.
1119 To store commands and special characters in a
1120 variable, please use double quotation marks
1121 surrounding the whole text of the variable, instead
1122 of the backslashes before semicolons and special
1125 - Default Environment
1126 CONFIG_EXTRA_ENV_SETTINGS
1128 Define this to contain any number of null terminated
1129 strings (variable = value pairs) that will be part of
1130 the default enviroment compiled into the boot image.
1132 For example, place something like this in your
1133 board's config file:
1135 #define CONFIG_EXTRA_ENV_SETTINGS \
1139 Warning: This method is based on knowledge about the
1140 internal format how the environment is stored by the
1141 U-Boot code. This is NOT an official, exported
1142 interface! Although it is unlikely that this format
1143 will change soon, but there is no guarantee either.
1144 You better know what you are doing here.
1146 Note: overly (ab)use of the default environment is
1147 discouraged. Make sure to check other ways to preset
1148 the environment like the autoscript function or the
1151 - Show boot progress
1152 CONFIG_SHOW_BOOT_PROGRESS
1154 Defining this option allows to add some board-
1155 specific code (calling a user-provided function
1156 "show_boot_progress(int)") that enables you to show
1157 the system's boot progress on some display (for
1158 example, some LED's) on your board. At the moment,
1159 the following checkpoints are implemented:
1162 1 common/cmd_bootm.c before attempting to boot an image
1163 -1 common/cmd_bootm.c Image header has bad magic number
1164 2 common/cmd_bootm.c Image header has correct magic number
1165 -2 common/cmd_bootm.c Image header has bad checksum
1166 3 common/cmd_bootm.c Image header has correct checksum
1167 -3 common/cmd_bootm.c Image data has bad checksum
1168 4 common/cmd_bootm.c Image data has correct checksum
1169 -4 common/cmd_bootm.c Image is for unsupported architecture
1170 5 common/cmd_bootm.c Architecture check OK
1171 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1172 6 common/cmd_bootm.c Image Type check OK
1173 -6 common/cmd_bootm.c gunzip uncompression error
1174 -7 common/cmd_bootm.c Unimplemented compression type
1175 7 common/cmd_bootm.c Uncompression OK
1176 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1177 8 common/cmd_bootm.c Image Type check OK
1178 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1179 9 common/cmd_bootm.c Start initial ramdisk verification
1180 -10 common/cmd_bootm.c Ramdisk header has bad magic number
1181 -11 common/cmd_bootm.c Ramdisk header has bad checksum
1182 10 common/cmd_bootm.c Ramdisk header is OK
1183 -12 common/cmd_bootm.c Ramdisk data has bad checksum
1184 11 common/cmd_bootm.c Ramdisk data has correct checksum
1185 12 common/cmd_bootm.c Ramdisk verification complete, start loading
1186 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk)
1187 13 common/cmd_bootm.c Start multifile image verification
1188 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue.
1189 15 common/cmd_bootm.c All preparation done, transferring control to OS
1191 -1 common/cmd_doc.c Bad usage of "doc" command
1192 -1 common/cmd_doc.c No boot device
1193 -1 common/cmd_doc.c Unknown Chip ID on boot device
1194 -1 common/cmd_doc.c Read Error on boot device
1195 -1 common/cmd_doc.c Image header has bad magic number
1197 -1 common/cmd_ide.c Bad usage of "ide" command
1198 -1 common/cmd_ide.c No boot device
1199 -1 common/cmd_ide.c Unknown boot device
1200 -1 common/cmd_ide.c Unknown partition table
1201 -1 common/cmd_ide.c Invalid partition type
1202 -1 common/cmd_ide.c Read Error on boot device
1203 -1 common/cmd_ide.c Image header has bad magic number
1205 -1 common/cmd_nvedit.c Environment not changable, but has bad CRC
1211 [so far only for SMDK2400 board]
1213 - Modem support endable:
1214 CONFIG_MODEM_SUPPORT
1216 - RTS/CTS Flow control enable:
1219 - Modem debug support:
1220 CONFIG_MODEM_SUPPORT_DEBUG
1222 Enables debugging stuff (char screen[1024], dbg())
1223 for modem support. Useful only with BDI2000.
1227 In the target system modem support is enabled when a
1228 specific key (key combination) is pressed during
1229 power-on. Otherwise U-Boot will boot normally
1230 (autoboot). The key_pressed() fuction is called from
1231 board_init(). Currently key_pressed() is a dummy
1232 function, returning 1 and thus enabling modem
1235 If there are no modem init strings in the
1236 environment, U-Boot proceed to autoboot; the
1237 previous output (banner, info printfs) will be
1240 See also: doc/README.Modem
1245 Configuration Settings:
1246 -----------------------
1248 - CFG_LONGHELP: Defined when you want long help messages included;
1249 undefine this when you're short of memory.
1251 - CFG_PROMPT: This is what U-Boot prints on the console to
1252 prompt for user input.
1254 - CFG_CBSIZE: Buffer size for input from the Console
1256 - CFG_PBSIZE: Buffer size for Console output
1258 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1260 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1261 the application (usually a Linux kernel) when it is
1264 - CFG_BAUDRATE_TABLE:
1265 List of legal baudrate settings for this board.
1267 - CFG_CONSOLE_INFO_QUIET
1268 Suppress display of console information at boot.
1270 - CFG_CONSOLE_IS_IN_ENV
1271 If the board specific function
1272 extern int overwrite_console (void);
1273 returns 1, the stdin, stderr and stdout are switched to the
1274 serial port, else the settings in the environment are used.
1276 - CFG_CONSOLE_OVERWRITE_ROUTINE
1277 Enable the call to overwrite_console().
1279 - CFG_CONSOLE_ENV_OVERWRITE
1280 Enable overwrite of previous console environment settings.
1282 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1283 Begin and End addresses of the area used by the
1287 Enable an alternate, more extensive memory test.
1289 - CFG_TFTP_LOADADDR:
1290 Default load address for network file downloads
1292 - CFG_LOADS_BAUD_CHANGE:
1293 Enable temporary baudrate change while serial download
1296 Physical start address of SDRAM. _Must_ be 0 here.
1299 Physical start address of Motherboard I/O (if using a
1303 Physical start address of Flash memory.
1306 Physical start address of boot monitor code (set by
1307 make config files to be same as the text base address
1308 (TEXT_BASE) used when linking) - same as
1309 CFG_FLASH_BASE when booting from flash.
1312 Size of memory reserved for monitor code
1315 Size of DRAM reserved for malloc() use.
1318 Maximum size of memory mapped by the startup code of
1319 the Linux kernel; all data that must be processed by
1320 the Linux kernel (bd_info, boot arguments, eventually
1321 initrd image) must be put below this limit.
1323 - CFG_MAX_FLASH_BANKS:
1324 Max number of Flash memory banks
1326 - CFG_MAX_FLASH_SECT:
1327 Max number of sectors on a Flash chip
1329 - CFG_FLASH_ERASE_TOUT:
1330 Timeout for Flash erase operations (in ms)
1332 - CFG_FLASH_WRITE_TOUT:
1333 Timeout for Flash write operations (in ms)
1335 - CFG_DIRECT_FLASH_TFTP:
1337 Enable TFTP transfers directly to flash memory;
1338 without this option such a download has to be
1339 performed in two steps: (1) download to RAM, and (2)
1340 copy from RAM to flash.
1342 The two-step approach is usually more reliable, since
1343 you can check if the download worked before you erase
1344 the flash, but in some situations (when sytem RAM is
1345 too limited to allow for a tempory copy of the
1346 downloaded image) this option may be very useful.
1349 Define if the flash driver uses extra elements in the
1350 common flash structure for storing flash geometry
1352 The following definitions that deal with the placement and management
1353 of environment data (variable area); in general, we support the
1354 following configurations:
1356 - CFG_ENV_IS_IN_FLASH:
1358 Define this if the environment is in flash memory.
1360 a) The environment occupies one whole flash sector, which is
1361 "embedded" in the text segment with the U-Boot code. This
1362 happens usually with "bottom boot sector" or "top boot
1363 sector" type flash chips, which have several smaller
1364 sectors at the start or the end. For instance, such a
1365 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
1366 such a case you would place the environment in one of the
1367 4 kB sectors - with U-Boot code before and after it. With
1368 "top boot sector" type flash chips, you would put the
1369 environment in one of the last sectors, leaving a gap
1370 between U-Boot and the environment.
1374 Offset of environment data (variable area) to the
1375 beginning of flash memory; for instance, with bottom boot
1376 type flash chips the second sector can be used: the offset
1377 for this sector is given here.
1379 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
1383 This is just another way to specify the start address of
1384 the flash sector containing the environment (instead of
1387 - CFG_ENV_SECT_SIZE:
1389 Size of the sector containing the environment.
1392 b) Sometimes flash chips have few, equal sized, BIG sectors.
1393 In such a case you don't want to spend a whole sector for
1398 If you use this in combination with CFG_ENV_IS_IN_FLASH
1399 and CFG_ENV_SECT_SIZE, you can specify to use only a part
1400 of this flash sector for the environment. This saves
1401 memory for the RAM copy of the environment.
1403 It may also save flash memory if you decide to use this
1404 when your environment is "embedded" within U-Boot code,
1405 since then the remainder of the flash sector could be used
1406 for U-Boot code. It should be pointed out that this is
1407 STRONGLY DISCOURAGED from a robustness point of view:
1408 updating the environment in flash makes it always
1409 necessary to erase the WHOLE sector. If something goes
1410 wrong before the contents has been restored from a copy in
1411 RAM, your target system will be dead.
1413 - CFG_ENV_ADDR_REDUND
1416 These settings describe a second storage area used to hold
1417 a redundand copy of the environment data, so that there is
1418 a valid backup copy in case there is a power failur during
1419 a "saveenv" operation.
1421 BE CAREFUL! Any changes to the flash layout, and some changes to the
1422 source code will make it necessary to adapt <board>/u-boot.lds*
1426 - CFG_ENV_IS_IN_NVRAM:
1428 Define this if you have some non-volatile memory device
1429 (NVRAM, battery buffered SRAM) which you want to use for the
1435 These two #defines are used to determin the memory area you
1436 want to use for environment. It is assumed that this memory
1437 can just be read and written to, without any special
1440 BE CAREFUL! The first access to the environment happens quite early
1441 in U-Boot initalization (when we try to get the setting of for the
1442 console baudrate). You *MUST* have mappend your NVRAM area then, or
1445 Please note that even with NVRAM we still use a copy of the
1446 environment in RAM: we could work on NVRAM directly, but we want to
1447 keep settings there always unmodified except somebody uses "saveenv"
1448 to save the current settings.
1451 - CFG_ENV_IS_IN_EEPROM:
1453 Use this if you have an EEPROM or similar serial access
1454 device and a driver for it.
1459 These two #defines specify the offset and size of the
1460 environment area within the total memory of your EEPROM.
1462 - CFG_I2C_EEPROM_ADDR:
1463 If defined, specified the chip address of the EEPROM device.
1464 The default address is zero.
1466 - CFG_EEPROM_PAGE_WRITE_BITS:
1467 If defined, the number of bits used to address bytes in a
1468 single page in the EEPROM device. A 64 byte page, for example
1469 would require six bits.
1471 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1472 If defined, the number of milliseconds to delay between
1473 page writes. The default is zero milliseconds.
1475 - CFG_I2C_EEPROM_ADDR_LEN:
1476 The length in bytes of the EEPROM memory array address. Note
1477 that this is NOT the chip address length!
1480 The size in bytes of the EEPROM device.
1482 - CFG_I2C_EEPROM_ADDR:
1483 If defined, specified the chip address of the EEPROM device.
1484 The default address is zero.
1486 - CFG_EEPROM_PAGE_WRITE_BITS:
1487 If defined, the number of bits used to address bytes in a
1488 single page in the EEPROM device. A 64 byte page, for example
1489 would require six bits.
1491 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1492 If defined, the number of milliseconds to delay between
1493 page writes. The default is zero milliseconds.
1495 - CFG_I2C_EEPROM_ADDR_LEN:
1496 The length in bytes of the EEPROM memory array address. Note
1497 that this is NOT the chip address length!
1500 The size in bytes of the EEPROM device.
1502 - CFG_SPI_INIT_OFFSET
1504 Defines offset to the initial SPI buffer area in DPRAM. The
1505 area is used at an early stage (ROM part) if the environment
1506 is configured to reside in the SPI EEPROM: We need a 520 byte
1507 scratch DPRAM area. It is used between the two initialization
1508 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
1509 to be a good choice since it makes it far enough from the
1510 start of the data area as well as from the stack pointer.
1512 Please note that the environment is read-only as long as the monitor
1513 has been relocated to RAM and a RAM copy of the environment has been
1514 created; also, when using EEPROM you will have to use getenv_r()
1515 until then to read environment variables.
1517 The environment is now protected by a CRC32 checksum. Before the
1518 monitor is relocated into RAM, as a result of a bad CRC you will be
1519 working with the compiled-in default environment - *silently*!!!
1520 [This is necessary, because the first environment variable we need is
1521 the "baudrate" setting for the console - if we have a bad CRC, we
1522 don't have any device yet where we could complain.]
1524 Note: once the monitor has been relocated, then it will complain if
1525 the default environment is used; a new CRC is computed as soon as you
1526 use the "setenv" command to modify / delete / add any environment
1527 variable [even when you try to delete a non-existing variable!].
1529 Note2: you must edit your u-boot.lds file to reflect this
1533 Low Level (hardware related) configuration options:
1535 - CFG_CACHELINE_SIZE:
1536 Cache Line Size of the CPU.
1539 Default address of the IMMR after system reset.
1540 Needed on some 8260 systems (MPC8260ADS and RPXsuper)
1541 to be able to adjust the position of the IMMR
1542 register after a reset.
1544 - Floppy Disk Support:
1545 CFG_FDC_DRIVE_NUMBER
1547 the default drive number (default value 0)
1551 defines the spacing between fdc chipset registers
1556 defines the offset of register from address. It
1557 depends on which part of the data bus is connected to
1558 the fdc chipset. (default value 0)
1560 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
1561 CFG_FDC_DRIVE_NUMBER are undefined, they take their
1564 if CFG_FDC_HW_INIT is defined, then the function
1565 fdc_hw_init() is called at the beginning of the FDC
1566 setup. fdc_hw_init() must be provided by the board
1567 source code. It is used to make hardware dependant
1570 - CFG_IMMR: Physical address of the Internal Memory Mapped
1571 Register; DO NOT CHANGE! (11-4)
1572 [MPC8xx systems only]
1574 - CFG_INIT_RAM_ADDR:
1576 Start address of memory area tha can be used for
1577 initial data and stack; please note that this must be
1578 writable memory that is working WITHOUT special
1579 initialization, i. e. you CANNOT use normal RAM which
1580 will become available only after programming the
1581 memory controller and running certain initialization
1584 U-Boot uses the following memory types:
1585 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
1586 - MPC824X: data cache
1587 - PPC4xx: data cache
1589 - CFG_INIT_DATA_OFFSET:
1591 Offset of the initial data structure in the memory
1592 area defined by CFG_INIT_RAM_ADDR. Usually
1593 CFG_INIT_DATA_OFFSET is chosen such that the initial
1594 data is located at the end of the available space
1595 (sometimes written as (CFG_INIT_RAM_END -
1596 CFG_INIT_DATA_SIZE), and the initial stack is just
1597 below that area (growing from (CFG_INIT_RAM_ADDR +
1598 CFG_INIT_DATA_OFFSET) downward.
1601 On the MPC824X (or other systems that use the data
1602 cache for initial memory) the address chosen for
1603 CFG_INIT_RAM_ADDR is basically arbitrary - it must
1604 point to an otherwise UNUSED address space between
1605 the top of RAM and the start of the PCI space.
1607 - CFG_SIUMCR: SIU Module Configuration (11-6)
1609 - CFG_SYPCR: System Protection Control (11-9)
1611 - CFG_TBSCR: Time Base Status and Control (11-26)
1613 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
1615 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
1617 - CFG_SCCR: System Clock and reset Control Register (15-27)
1619 - CFG_OR_TIMING_SDRAM:
1623 periodic timer for refresh
1625 - CFG_DER: Debug Event Register (37-47)
1627 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
1628 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
1629 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
1631 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
1633 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
1634 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
1635 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
1636 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
1638 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
1639 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
1640 Machine Mode Register and Memory Periodic Timer
1641 Prescaler definitions (SDRAM timing)
1643 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
1644 enable I2C microcode relocation patch (MPC8xx);
1645 define relocation offset in DPRAM [DSP2]
1647 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
1648 enable SPI microcode relocation patch (MPC8xx);
1649 define relocation offset in DPRAM [SCC4]
1652 Use OSCM clock mode on MBX8xx board. Be careful,
1653 wrong setting might damage your board. Read
1654 doc/README.MBX before setting this variable!
1656 Building the Software:
1657 ======================
1659 Building U-Boot has been tested in native PPC environments (on a
1660 PowerBook G3 running LinuxPPC 2000) and in cross environments
1661 (running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
1664 If you are not using a native PPC environment, it is assumed that you
1665 have the GNU cross compiling tools available in your path and named
1666 with a prefix of "powerpc-linux-". If this is not the case, (e.g. if
1667 you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
1668 the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
1671 CROSS_COMPILE = ppc_4xx-
1674 U-Boot is intended to be simple to build. After installing the
1675 sources you must configure U-Boot for one specific board type. This
1680 where "NAME_config" is the name of one of the existing
1681 configurations; the following names are supported:
1683 ADCIOP_config GTH_config TQM850L_config
1684 ADS860_config IP860_config TQM855L_config
1685 AR405_config IVML24_config TQM860L_config
1686 CANBT_config IVMS8_config WALNUT405_config
1687 CPCI405_config LANTEC_config cogent_common_config
1688 CPCIISER4_config MBX_config cogent_mpc8260_config
1689 CU824_config MBX860T_config cogent_mpc8xx_config
1690 ESTEEM192E_config RPXlite_config hermes_config
1691 ETX094_config RPXsuper_config hymod_config
1692 FADS823_config SM850_config lwmon_config
1693 FADS850SAR_config SPD823TS_config pcu_e_config
1694 FADS860T_config SXNI855T_config rsdproto_config
1695 FPS850L_config Sandpoint8240_config sbc8260_config
1696 GENIETV_config TQM823L_config PIP405_config
1697 GEN860T_config EBONY_config FPS860L_config
1699 Note: for some board special configuration names may exist; check if
1700 additional information is available from the board vendor; for
1701 instance, the TQM8xxL systems run normally at 50 MHz and use a
1702 SCC for 10baseT ethernet; there are also systems with 80 MHz
1703 CPU clock, and an optional Fast Ethernet module is available
1704 for CPU's with FEC. You can select such additional "features"
1705 when chosing the configuration, i. e.
1708 - will configure for a plain TQM860L, i. e. 50MHz, no FEC
1710 make TQM860L_FEC_config
1711 - will configure for a TQM860L at 50MHz with FEC for ethernet
1713 make TQM860L_80MHz_config
1714 - will configure for a TQM860L at 80 MHz, with normal 10baseT
1717 make TQM860L_FEC_80MHz_config
1718 - will configure for a TQM860L at 80 MHz with FEC for ethernet
1720 make TQM823L_LCD_config
1721 - will configure for a TQM823L with U-Boot console on LCD
1723 make TQM823L_LCD_80MHz_config
1724 - will configure for a TQM823L at 80 MHz with U-Boot console on LCD
1730 Finally, type "make all", and you should get some working U-Boot
1731 images ready for downlod to / installation on your system:
1733 - "u-boot.bin" is a raw binary image
1734 - "u-boot" is an image in ELF binary format
1735 - "u-boot.srec" is in Motorola S-Record format
1738 Please be aware that the Makefiles assume you are using GNU make, so
1739 for instance on NetBSD you might need to use "gmake" instead of
1743 If the system board that you have is not listed, then you will need
1744 to port U-Boot to your hardware platform. To do this, follow these
1747 1. Add a new configuration option for your board to the toplevel
1748 "Makefile", using the existing entries as examples.
1749 2. Create a new directory to hold your board specific code. Add any
1751 3. If you're porting U-Boot to a new CPU, then also create a new
1752 directory to hold your CPU specific code. Add any files you need.
1753 4. Run "make config_name" with your new name.
1754 5. Type "make", and you should get a working "u-boot.srec" file
1755 to be installed on your target system.
1756 [Of course, this last step is much harder than it sounds.]
1759 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
1760 ==============================================================
1762 If you have modified U-Boot sources (for instance added a new board
1763 or support for new devices, a new CPU, etc.) you are expected to
1764 provide feedback to the other developers. The feedback normally takes
1765 the form of a "patch", i. e. a context diff against a certain (latest
1766 official or latest in CVS) version of U-Boot sources.
1768 But before you submit such a patch, please verify that your modifi-
1769 cation did not break existing code. At least make sure that *ALL* of
1770 the supported boards compile WITHOUT ANY compiler warnings. To do so,
1771 just run the "MAKEALL" script, which will configure and build U-Boot
1772 for ALL supported system. Be warned, this will take a while. You can
1773 select which (cross) compiler to use py passing a `CROSS_COMPILE'
1774 environment variable to the script, i. e. to use the cross tools from
1775 MontaVista's Hard Hat Linux you can type
1777 CROSS_COMPILE=ppc_8xx- MAKEALL
1779 or to build on a native PowerPC system you can type
1781 CROSS_COMPILE=' ' MAKEALL
1783 See also "U-Boot Porting Guide" below.
1787 Monitor Commands - Overview:
1788 ============================
1790 go - start application at address 'addr'
1791 run - run commands in an environment variable
1792 bootm - boot application image from memory
1793 bootp - boot image via network using BootP/TFTP protocol
1794 tftpboot- boot image via network using TFTP protocol
1795 and env variables "ipaddr" and "serverip"
1796 (and eventually "gatewayip")
1797 rarpboot- boot image via network using RARP/TFTP protocol
1798 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
1799 loads - load S-Record file over serial line
1800 loadb - load binary file over serial line (kermit mode)
1802 mm - memory modify (auto-incrementing)
1803 nm - memory modify (constant address)
1804 mw - memory write (fill)
1806 cmp - memory compare
1807 crc32 - checksum calculation
1808 imd - i2c memory display
1809 imm - i2c memory modify (auto-incrementing)
1810 inm - i2c memory modify (constant address)
1811 imw - i2c memory write (fill)
1812 icrc32 - i2c checksum calculation
1813 iprobe - probe to discover valid I2C chip addresses
1814 iloop - infinite loop on address range
1815 isdram - print SDRAM configuration information
1816 sspi - SPI utility commands
1817 base - print or set address offset
1818 printenv- print environment variables
1819 setenv - set environment variables
1820 saveenv - save environment variables to persistent storage
1821 protect - enable or disable FLASH write protection
1822 erase - erase FLASH memory
1823 flinfo - print FLASH memory information
1824 bdinfo - print Board Info structure
1825 iminfo - print header information for application image
1826 coninfo - print console devices and informations
1827 ide - IDE sub-system
1828 loop - infinite loop on address range
1829 mtest - simple RAM test
1830 icache - enable or disable instruction cache
1831 dcache - enable or disable data cache
1832 reset - Perform RESET of the CPU
1833 echo - echo args to console
1834 version - print monitor version
1835 help - print online help
1836 ? - alias for 'help'
1839 Monitor Commands - Detailed Description:
1840 ========================================
1844 For now: just type "help <command>".
1847 Environment Variables:
1848 ======================
1850 U-Boot supports user configuration using Environment Variables which
1851 can be made persistent by saving to Flash memory.
1853 Environment Variables are set using "setenv", printed using
1854 "printenv", and saved to Flash using "saveenv". Using "setenv"
1855 without a value can be used to delete a variable from the
1856 environment. As long as you don't save the environment you are
1857 working with an in-memory copy. In case the Flash area containing the
1858 environment is erased by accident, a default environment is provided.
1860 Some configuration options can be set using Environment Variables:
1862 baudrate - see CONFIG_BAUDRATE
1864 bootdelay - see CONFIG_BOOTDELAY
1866 bootcmd - see CONFIG_BOOTCOMMAND
1868 bootargs - Boot arguments when booting an RTOS image
1870 bootfile - Name of the image to load with TFTP
1872 autoload - if set to "no" (any string beginning with 'n'),
1873 "bootp" will just load perform a lookup of the
1874 configuration from the BOOTP server, but not try to
1875 load any image using TFTP
1877 autostart - if set to "yes", an image loaded using the "bootp",
1878 "rarpboot", "tftpboot" or "diskboot" commands will
1879 be automatically started (by internally calling
1882 initrd_high - restrict positioning of initrd images:
1883 If this variable is not set, initrd images will be
1884 copied to the highest possible address in RAM; this
1885 is usually what you want since it allows for
1886 maximum initrd size. If for some reason you want to
1887 make sure that the initrd image is loaded below the
1888 CFG_BOOTMAPSZ limit, you can set this environment
1889 variable to a value of "no" or "off" or "0".
1890 Alternatively, you can set it to a maximum upper
1891 address to use (U-Boot will still check that it
1892 does not overwrite the U-Boot stack and data).
1894 For instance, when you have a system with 16 MB
1895 RAM, and want to reseve 4 MB from use by Linux,
1896 you can do this by adding "mem=12M" to the value of
1897 the "bootargs" variable. However, now you must make
1898 sure, that the initrd image is placed in the first
1899 12 MB as well - this can be done with
1901 setenv initrd_high 00c00000
1903 ipaddr - IP address; needed for tftpboot command
1905 loadaddr - Default load address for commands like "bootp",
1906 "rarpboot", "tftpboot" or "diskboot"
1908 loads_echo - see CONFIG_LOADS_ECHO
1910 serverip - TFTP server IP address; needed for tftpboot command
1912 bootretry - see CONFIG_BOOT_RETRY_TIME
1914 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
1916 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
1919 The following environment variables may be used and automatically
1920 updated by the network boot commands ("bootp" and "rarpboot"),
1921 depending the information provided by your boot server:
1923 bootfile - see above
1924 dnsip - IP address of your Domain Name Server
1925 gatewayip - IP address of the Gateway (Router) to use
1926 hostname - Target hostname
1928 netmask - Subnet Mask
1929 rootpath - Pathname of the root filesystem on the NFS server
1930 serverip - see above
1933 There are two special Environment Variables:
1935 serial# - contains hardware identification information such
1936 as type string and/or serial number
1937 ethaddr - Ethernet address
1939 These variables can be set only once (usually during manufacturing of
1940 the board). U-Boot refuses to delete or overwrite these variables
1941 once they have been set once.
1944 Please note that changes to some configuration parameters may take
1945 only effect after the next boot (yes, that's just like Windoze :-).
1948 Note for Redundant Ethernet Interfaces:
1949 =======================================
1951 Some boards come with redundand ethernet interfaces; U-Boot supports
1952 such configurations and is capable of automatic selection of a
1953 "working" interface when needed. MAC assignemnt works as follows:
1955 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
1956 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
1957 "eth1addr" (=>eth1), "eth2addr", ...
1959 If the network interface stores some valid MAC address (for instance
1960 in SROM), this is used as default address if there is NO correspon-
1961 ding setting in the environment; if the corresponding environment
1962 variable is set, this overrides the settings in the card; that means:
1964 o If the SROM has a valid MAC address, and there is no address in the
1965 environment, the SROM's address is used.
1967 o If there is no valid address in the SROM, and a definition in the
1968 environment exists, then the value from the environment variable is
1971 o If both the SROM and the environment contain a MAC address, and
1972 both addresses are the same, this MAC address is used.
1974 o If both the SROM and the environment contain a MAC address, and the
1975 addresses differ, the value from the environment is used and a
1978 o If neither SROM nor the environment contain a MAC address, an error
1986 The "boot" commands of this monitor operate on "image" files which
1987 can be basicly anything, preceeded by a special header; see the
1988 definitions in include/image.h for details; basicly, the header
1989 defines the following image properties:
1991 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
1992 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
1994 Currently supported: Linux, NetBSD, VxWorks, QNX).
1995 * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
1996 IA64, MIPS, MIPS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
1997 Currently supported: PowerPC).
1998 * Compression Type (Provisions for uncompressed, gzip, bzip2;
1999 Currently supported: uncompressed, gzip).
2005 The header is marked by a special Magic Number, and both the header
2006 and the data portions of the image are secured against corruption by
2013 Although U-Boot should support any OS or standalone application
2014 easily, Linux has always been in the focus during the design of
2017 U-Boot includes many features that so far have been part of some
2018 special "boot loader" code within the Linux kernel. Also, any
2019 "initrd" images to be used are no longer part of one big Linux image;
2020 instead, kernel and "initrd" are separate images. This implementation
2021 serves serveral purposes:
2023 - the same features can be used for other OS or standalone
2024 applications (for instance: using compressed images to reduce the
2025 Flash memory footprint)
2027 - it becomes much easier to port new Linux kernel versions because
2028 lots of low-level, hardware dependend stuff are done by U-Boot
2030 - the same Linux kernel image can now be used with different "initrd"
2031 images; of course this also means that different kernel images can
2032 be run with the same "initrd". This makes testing easier (you don't
2033 have to build a new "zImage.initrd" Linux image when you just
2034 change a file in your "initrd"). Also, a field-upgrade of the
2035 software is easier now.
2041 Porting Linux to U-Boot based systems:
2042 ---------------------------------------
2044 U-Boot cannot save you from doing all the necessary modifications to
2045 configure the Linux device drivers for use with your target hardware
2046 (no, we don't intend to provide a full virtual machine interface to
2049 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
2051 Just make sure your machine specific header file (for instance
2052 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
2053 Information structure as we define in include/u-boot.h, and make
2054 sure that your definition of IMAP_ADDR uses the same value as your
2055 U-Boot configuration in CFG_IMMR.
2058 Configuring the Linux kernel:
2059 -----------------------------
2061 No specific requirements for U-Boot. Make sure you have some root
2062 device (initial ramdisk, NFS) for your target system.
2065 Building a Linux Image:
2066 -----------------------
2068 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2069 not used. If you use recent kernel source, a new build target
2070 "uImage" will exist which automatically builds an image usable by
2071 U-Boot. Most older kernels also have support for a "pImage" target,
2072 which was introduced for our predecessor project PPCBoot and uses a
2073 100% compatible format.
2082 The "uImage" build target uses a special tool (in 'tools/mkimage') to
2083 encapsulate a compressed Linux kernel image with header information,
2084 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
2086 * build a standard "vmlinux" kernel image (in ELF binary format):
2088 * convert the kernel into a raw binary image:
2090 ${CROSS_COMPILE}-objcopy -O binary \
2091 -R .note -R .comment \
2092 -S vmlinux linux.bin
2094 * compress the binary image:
2098 * package compressed binary image for U-Boot:
2100 mkimage -A ppc -O linux -T kernel -C gzip \
2101 -a 0 -e 0 -n "Linux Kernel Image" \
2102 -d linux.bin.gz uImage
2105 The "mkimage" tool can also be used to create ramdisk images for use
2106 with U-Boot, either separated from the Linux kernel image, or
2107 combined into one file. "mkimage" encapsulates the images with a 64
2108 byte header containing information about target architecture,
2109 operating system, image type, compression method, entry points, time
2110 stamp, CRC32 checksums, etc.
2112 "mkimage" can be called in two ways: to verify existing images and
2113 print the header information, or to build new images.
2115 In the first form (with "-l" option) mkimage lists the information
2116 contained in the header of an existing U-Boot image; this includes
2117 checksum verification:
2119 tools/mkimage -l image
2120 -l ==> list image header information
2122 The second form (with "-d" option) is used to build a U-Boot image
2123 from a "data file" which is used as image payload:
2125 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2126 -n name -d data_file image
2127 -A ==> set architecture to 'arch'
2128 -O ==> set operating system to 'os'
2129 -T ==> set image type to 'type'
2130 -C ==> set compression type 'comp'
2131 -a ==> set load address to 'addr' (hex)
2132 -e ==> set entry point to 'ep' (hex)
2133 -n ==> set image name to 'name'
2134 -d ==> use image data from 'datafile'
2136 Right now, all Linux kernels use the same load address (0x00000000),
2137 but the entry point address depends on the kernel version:
2139 - 2.2.x kernels have the entry point at 0x0000000C,
2140 - 2.3.x and later kernels have the entry point at 0x00000000.
2142 So a typical call to build a U-Boot image would read:
2144 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2145 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
2146 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
2147 > examples/uImage.TQM850L
2148 Image Name: 2.4.4 kernel for TQM850L
2149 Created: Wed Jul 19 02:34:59 2000
2150 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2151 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2152 Load Address: 0x00000000
2153 Entry Point: 0x00000000
2155 To verify the contents of the image (or check for corruption):
2157 -> tools/mkimage -l examples/uImage.TQM850L
2158 Image Name: 2.4.4 kernel for TQM850L
2159 Created: Wed Jul 19 02:34:59 2000
2160 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2161 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2162 Load Address: 0x00000000
2163 Entry Point: 0x00000000
2165 NOTE: for embedded systems where boot time is critical you can trade
2166 speed for memory and install an UNCOMPRESSED image instead: this
2167 needs more space in Flash, but boots much faster since it does not
2168 need to be uncompressed:
2170 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
2171 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2172 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
2173 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
2174 > examples/uImage.TQM850L-uncompressed
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 (uncompressed)
2178 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
2179 Load Address: 0x00000000
2180 Entry Point: 0x00000000
2183 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2184 when your kernel is intended to use an initial ramdisk:
2186 -> tools/mkimage -n 'Simple Ramdisk Image' \
2187 > -A ppc -O linux -T ramdisk -C gzip \
2188 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2189 Image Name: Simple Ramdisk Image
2190 Created: Wed Jan 12 14:01:50 2000
2191 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2192 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
2193 Load Address: 0x00000000
2194 Entry Point: 0x00000000
2197 Installing a Linux Image:
2198 -------------------------
2200 To downloading a U-Boot image over the serial (console) interface,
2201 you must convert the image to S-Record format:
2203 objcopy -I binary -O srec examples/image examples/image.srec
2205 The 'objcopy' does not understand the information in the U-Boot
2206 image header, so the resulting S-Record file will be relative to
2207 address 0x00000000. To load it to a given address, you need to
2208 specify the target address as 'offset' parameter with the 'loads'
2211 Example: install the image to address 0x40100000 (which on the
2212 TQM8xxL is in the first Flash bank):
2214 => erase 40100000 401FFFFF
2220 ## Ready for S-Record download ...
2221 ~>examples/image.srec
2222 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2224 15989 15990 15991 15992
2225 [file transfer complete]
2227 ## Start Addr = 0x00000000
2230 You can check the success of the download using the 'iminfo' command;
2231 this includes a checksum verification so you can be sure no data
2232 corruption happened:
2236 ## Checking Image at 40100000 ...
2237 Image Name: 2.2.13 for initrd on TQM850L
2238 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2239 Data Size: 335725 Bytes = 327 kB = 0 MB
2240 Load Address: 00000000
2241 Entry Point: 0000000c
2242 Verifying Checksum ... OK
2249 The "bootm" command is used to boot an application that is stored in
2250 memory (RAM or Flash). In case of a Linux kernel image, the contents
2251 of the "bootargs" environment variable is passed to the kernel as
2252 parameters. You can check and modify this variable using the
2253 "printenv" and "setenv" commands:
2256 => printenv bootargs
2257 bootargs=root=/dev/ram
2259 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2261 => printenv bootargs
2262 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2265 ## Booting Linux kernel at 40020000 ...
2266 Image Name: 2.2.13 for NFS on TQM850L
2267 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2268 Data Size: 381681 Bytes = 372 kB = 0 MB
2269 Load Address: 00000000
2270 Entry Point: 0000000c
2271 Verifying Checksum ... OK
2272 Uncompressing Kernel Image ... OK
2273 Linux version 2.2.13 (
[email protected]) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
2274 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2275 time_init: decrementer frequency = 187500000/60
2276 Calibrating delay loop... 49.77 BogoMIPS
2277 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2280 If you want to boot a Linux kernel with initial ram disk, you pass
2281 the memory addreses of both the kernel and the initrd image (PPBCOOT
2282 format!) to the "bootm" command:
2284 => imi 40100000 40200000
2286 ## Checking Image at 40100000 ...
2287 Image Name: 2.2.13 for initrd on TQM850L
2288 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2289 Data Size: 335725 Bytes = 327 kB = 0 MB
2290 Load Address: 00000000
2291 Entry Point: 0000000c
2292 Verifying Checksum ... OK
2294 ## Checking Image at 40200000 ...
2295 Image Name: Simple Ramdisk Image
2296 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2297 Data Size: 566530 Bytes = 553 kB = 0 MB
2298 Load Address: 00000000
2299 Entry Point: 00000000
2300 Verifying Checksum ... OK
2302 => bootm 40100000 40200000
2303 ## Booting Linux kernel at 40100000 ...
2304 Image Name: 2.2.13 for initrd on TQM850L
2305 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2306 Data Size: 335725 Bytes = 327 kB = 0 MB
2307 Load Address: 00000000
2308 Entry Point: 0000000c
2309 Verifying Checksum ... OK
2310 Uncompressing Kernel Image ... OK
2311 ## Loading RAMDisk Image at 40200000 ...
2312 Image Name: Simple Ramdisk Image
2313 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2314 Data Size: 566530 Bytes = 553 kB = 0 MB
2315 Load Address: 00000000
2316 Entry Point: 00000000
2317 Verifying Checksum ... OK
2318 Loading Ramdisk ... OK
2319 Linux version 2.2.13 (
[email protected]) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
2320 Boot arguments: root=/dev/ram
2321 time_init: decrementer frequency = 187500000/60
2322 Calibrating delay loop... 49.77 BogoMIPS
2324 RAMDISK: Compressed image found at block 0
2325 VFS: Mounted root (ext2 filesystem).
2333 One of the features of U-Boot is that you can dynamically load and
2334 run "standalone" applications, which can use some resources of
2335 U-Boot like console I/O functions or interrupt services.
2337 Two simple examples are included with the sources:
2342 'examples/hello_world.c' contains a small "Hello World" Demo
2343 application; it is automatically compiled when you build U-Boot.
2344 It's configured to run at address 0x00040004, so you can play with it
2348 ## Ready for S-Record download ...
2349 ~>examples/hello_world.srec
2350 1 2 3 4 5 6 7 8 9 10 11 ...
2351 [file transfer complete]
2353 ## Start Addr = 0x00040004
2355 => go 40004 Hello World! This is a test.
2356 ## Starting application at 0x00040004 ...
2367 Hit any key to exit ...
2369 ## Application terminated, rc = 0x0
2371 Another example, which demonstrates how to register a CPM interrupt
2372 handler with the U-Boot code, can be found in 'examples/timer.c'.
2373 Here, a CPM timer is set up to generate an interrupt every second.
2374 The interrupt service routine is trivial, just printing a '.'
2375 character, but this is just a demo program. The application can be
2376 controlled by the following keys:
2378 ? - print current values og the CPM Timer registers
2379 b - enable interrupts and start timer
2380 e - stop timer and disable interrupts
2381 q - quit application
2384 ## Ready for S-Record download ...
2385 ~>examples/timer.srec
2386 1 2 3 4 5 6 7 8 9 10 11 ...
2387 [file transfer complete]
2389 ## Start Addr = 0x00040004
2392 ## Starting application at 0x00040004 ...
2395 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
2398 [q, b, e, ?] Set interval 1000000 us
2401 [q, b, e, ?] ........
2402 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
2405 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
2408 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
2411 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
2413 [q, b, e, ?] ...Stopping timer
2415 [q, b, e, ?] ## Application terminated, rc = 0x0
2421 Starting at version 0.9.2, U-Boot supports NetBSD both as host
2422 (build U-Boot) and target system (boots NetBSD/mpc8xx).
2424 Building requires a cross environment; it is known to work on
2425 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
2426 need gmake since the Makefiles are not compatible with BSD make).
2427 Note that the cross-powerpc package does not install include files;
2428 attempting to build U-Boot will fail because <machine/ansi.h> is
2429 missing. This file has to be installed and patched manually:
2431 # cd /usr/pkg/cross/powerpc-netbsd/include
2433 # ln -s powerpc machine
2434 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
2435 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
2437 Native builds *don't* work due to incompatibilities between native
2438 and U-Boot include files.
2440 Booting assumes that (the first part of) the image booted is a
2441 stage-2 loader which in turn loads and then invokes the kernel
2442 proper. Loader sources will eventually appear in the NetBSD source
2443 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
2448 Implementation Internals:
2449 =========================
2451 The following is not intended to be a complete description of every
2452 implementation detail. However, it should help to understand the
2453 inner workings of U-Boot and make it easier to port it to custom
2457 Initial Stack, Global Data:
2458 ---------------------------
2460 The implementation of U-Boot is complicated by the fact that U-Boot
2461 starts running out of ROM (flash memory), usually without access to
2462 system RAM (because the memory controller is not initialized yet).
2463 This means that we don't have writable Data or BSS segments, and BSS
2464 is not initialized as zero. To be able to get a C environment working
2465 at all, we have to allocate at least a minimal stack. Implementation
2466 options for this are defined and restricted by the CPU used: Some CPU
2467 models provide on-chip memory (like the IMMR area on MPC8xx and
2468 MPC826x processors), on others (parts of) the data cache can be
2469 locked as (mis-) used as memory, etc.
2471 It is essential to remember this, since it has some impact on the C
2472 code for the initialization procedures:
2474 * Initialized global data (data segment) is read-only. Do not attempt
2477 * Do not use any unitialized global data (or implicitely initialized
2478 as zero data - BSS segment) at all - this is undefined, initiali-
2479 zation is performed later (when relocationg to RAM).
2481 * Stack space is very limited. Avoid big data buffers or things like
2484 Having only the stack as writable memory limits means we cannot use
2485 normal global data to share information beween the code. But it
2486 turned out that the implementation of U-Boot can be greatly
2487 simplified by making a global data structure (gd_t) available to all
2488 functions. We could pass a pointer to this data as argument to _all_
2489 functions, but this would bloat the code. Instead we use a feature of
2490 the GCC compiler (Global Register Variables) to share the data: we
2491 place a pointer (gd) to the global data into a register which we
2492 reserve for this purpose.
2494 When chosing a register for such a purpose we are restricted by the
2495 relevant (E)ABI specifications for the current architecture, and by
2496 GCC's implementation.
2498 For PowerPC, the following registers have specific use:
2501 R3-R4: parameter passing and return values
2502 R5-R10: parameter passing
2503 R13: small data area pointer
2507 (U-Boot also uses R14 as internal GOT pointer.)
2509 ==> U-Boot will use R29 to hold a pointer to the global data
2511 Note: on PPC, we could use a static initializer (since the
2512 address of the global data structure is known at compile time),
2513 but it turned out that reserving a register results in somewhat
2514 smaller code - although the code savings are not that big (on
2515 average for all boards 752 bytes for the whole U-Boot image,
2516 624 text + 127 data).
2518 On ARM, the following registers are used:
2520 R0: function argument word/integer result
2521 R1-R3: function argument word
2523 R10: stack limit (used only if stack checking if enabled)
2524 R11: argument (frame) pointer
2525 R12: temporary workspace
2528 R15: program counter
2530 ==> U-Boot will use R8 to hold a pointer to the global data
2537 U-Boot runs in system state and uses physical addresses, i.e. the
2538 MMU is not used either for address mapping nor for memory protection.
2540 The available memory is mapped to fixed addresses using the memory
2541 controller. In this process, a contiguous block is formed for each
2542 memory type (Flash, SDRAM, SRAM), even when it consists of several
2543 physical memory banks.
2545 U-Boot is installed in the first 128 kB of the first Flash bank (on
2546 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
2547 booting and sizing and initializing DRAM, the code relocates itself
2548 to the upper end of DRAM. Immediately below the U-Boot code some
2549 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
2550 configuration setting]. Below that, a structure with global Board
2551 Info data is placed, followed by the stack (growing downward).
2553 Additionally, some exception handler code is copied to the low 8 kB
2554 of DRAM (0x00000000 ... 0x00001FFF).
2556 So a typical memory configuration with 16 MB of DRAM could look like
2559 0x0000 0000 Exception Vector code
2562 0x0000 2000 Free for Application Use
2568 0x00FB FF20 Monitor Stack (Growing downward)
2569 0x00FB FFAC Board Info Data and permanent copy of global data
2570 0x00FC 0000 Malloc Arena
2573 0x00FE 0000 RAM Copy of Monitor Code
2574 ... eventually: LCD or video framebuffer
2575 ... eventually: pRAM (Protected RAM - unchanged by reset)
2576 0x00FF FFFF [End of RAM]
2579 System Initialization:
2580 ----------------------
2582 In the reset configuration, U-Boot starts at the reset entry point
2583 (on most PowerPC systens at address 0x00000100). Because of the reset
2584 configuration for CS0# this is a mirror of the onboard Flash memory.
2585 To be able to re-map memory U-Boot then jumps to it's link address.
2586 To be able to implement the initialization code in C, a (small!)
2587 initial stack is set up in the internal Dual Ported RAM (in case CPUs
2588 which provide such a feature like MPC8xx or MPC8260), or in a locked
2589 part of the data cache. After that, U-Boot initializes the CPU core,
2590 the caches and the SIU.
2592 Next, all (potentially) available memory banks are mapped using a
2593 preliminary mapping. For example, we put them on 512 MB boundaries
2594 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
2595 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
2596 programmed for SDRAM access. Using the temporary configuration, a
2597 simple memory test is run that determines the size of the SDRAM
2600 When there is more than one SDRAM bank, and the banks are of
2601 different size, the larger is mapped first. For equal size, the first
2602 bank (CS2#) is mapped first. The first mapping is always for address
2603 0x00000000, with any additional banks following immediately to create
2604 contiguous memory starting from 0.
2606 Then, the monitor installs itself at the upper end of the SDRAM area
2607 and allocates memory for use by malloc() and for the global Board
2608 Info data; also, the exception vector code is copied to the low RAM
2609 pages, and the final stack is set up.
2611 Only after this relocation will you have a "normal" C environment;
2612 until that you are restricted in several ways, mostly because you are
2613 running from ROM, and because the code will have to be relocated to a
2617 U-Boot Porting Guide:
2618 ----------------------
2620 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
2624 int main (int argc, char *argv[])
2626 sighandler_t no_more_time;
2628 signal (SIGALRM, no_more_time);
2629 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
2631 if (available_money > available_manpower) {
2632 pay consultant to port U-Boot;
2636 Download latest U-Boot source;
2639 email ("Hi, I am new to U-Boot, how do I get started?");
2643 Read the README file in the top level directory;
2644 Read http://www.denx.de/re/DPLG.html
2645 Read the source, Luke;
2648 if (available_money > toLocalCurrency ($2500)) {
2651 Add a lot of aggravation and time;
2654 Create your own board support subdirectory;
2658 Add / modify source code;
2662 email ("Hi, I am having problems...");
2664 Send patch file to Wolfgang;
2669 void no_more_time (int sig)
2679 All contributions to U-Boot should conform to the Linux kernel
2680 coding style; see the file "Documentation/CodingStyle" in your Linux
2681 kernel source directory.
2683 Please note that U-Boot is implemented in C (and to some small parts
2684 in Assembler); no C++ is used, so please do not use C++ style
2685 comments (//) in your code.
2687 Submissions which do not conform to the standards may be returned
2688 with a request to reformat the changes.
2694 Since the number of patches for U-Boot is growing, we need to
2695 establish some rules. Submissions which do not conform to these rules
2696 may be rejected, even when they contain important and valuable stuff.
2699 When you send a patch, please include the following information with
2702 * For bug fixes: a description of the bug and how your patch fixes
2703 this bug. Please try to include a way of demonstrating that the
2704 patch actually fixes something.
2706 * For new features: a description of the feature and your
2709 * A CHANGELOG entry as plaintext (separate from the patch)
2711 * For major contributions, your entry to the CREDITS file
2713 * When you add support for a new board, don't forget to add this
2714 board to the MAKEALL script, too.
2716 * If your patch adds new configuration options, don't forget to
2717 document these in the README file.
2719 * The patch itself. If you are accessing the CVS repository use "cvs
2720 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
2721 version of diff does not support these options, then get the latest
2722 version of GNU diff.
2724 We accept patches as plain text, MIME attachments or as uuencoded
2729 * Before sending the patch, run the MAKEALL script on your patched
2730 source tree and make sure that no errors or warnings are reported
2731 for any of the boards.
2733 * Keep your modifications to the necessary minimum: A patch
2734 containing several unrelated changes or arbitrary reformats will be
2735 returned with a request to re-formatting / split it.
2737 * If you modify existing code, make sure that your new code does not
2738 add to the memory footprint of the code ;-) Small is beautiful!
2739 When adding new features, these should compile conditionally only
2740 (using #ifdef), and the resulting code with the new feature
2741 disabled must not need more memory than the old code without your
projects / J-u-boot.git / blob