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 - 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 The following options need to be configured:
271 - CPU Type: Define exactly one of
275 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860
276 or CONFIG_MPC824X, CONFIG_MPC8260
289 - Board Type: Define exactly one of
291 PowerPC based boards:
292 ---------------------
294 CONFIG_ADCIOP, CONFIG_ICU862 CONFIG_RPXsuper,
295 CONFIG_ADS860, CONFIG_IP860, CONFIG_SM850,
296 CONFIG_AMX860, CONFIG_IPHASE4539, CONFIG_SPD823TS,
297 CONFIG_AR405, CONFIG_IVML24, CONFIG_SXNI855T,
298 CONFIG_BAB7xx, CONFIG_IVML24_128, CONFIG_Sandpoint8240,
299 CONFIG_CANBT, CONFIG_IVML24_256, CONFIG_Sandpoint8245,
300 CONFIG_CCM, CONFIG_IVMS8, CONFIG_TQM823L,
301 CONFIG_CPCI405, CONFIG_IVMS8_128, CONFIG_TQM850L,
302 CONFIG_CPCI4052, CONFIG_IVMS8_256, CONFIG_TQM855L,
303 CONFIG_CPCIISER4, CONFIG_LANTEC, CONFIG_TQM860L,
304 CONFIG_CPU86, CONFIG_MBX, CONFIG_TQM8260,
305 CONFIG_CRAYL1, CONFIG_MBX860T, CONFIG_TTTech,
306 CONFIG_CU824, CONFIG_MHPC, CONFIG_UTX8245,
307 CONFIG_DASA_SIM, CONFIG_MIP405, CONFIG_W7OLMC,
308 CONFIG_DU405, CONFIG_MOUSSE, CONFIG_W7OLMG,
309 CONFIG_ELPPC, CONFIG_MPC8260ADS, CONFIG_WALNUT405,
310 CONFIG_ERIC, CONFIG_MUSENKI, CONFIG_ZUMA,
311 CONFIG_ESTEEM192E, CONFIG_MVS1, CONFIG_c2mon,
312 CONFIG_ETX094, CONFIG_NX823, CONFIG_cogent_mpc8260,
313 CONFIG_EVB64260, CONFIG_OCRTC, CONFIG_cogent_mpc8xx,
314 CONFIG_FADS823, CONFIG_ORSG, CONFIG_ep8260,
315 CONFIG_FADS850SAR, CONFIG_OXC, CONFIG_gw8260,
316 CONFIG_FADS860T, CONFIG_PCI405, CONFIG_hermes,
317 CONFIG_FLAGADM, CONFIG_PCIPPC2, CONFIG_hymod,
318 CONFIG_FPS850L, CONFIG_PCIPPC6, CONFIG_lwmon,
319 CONFIG_GEN860T, CONFIG_PIP405, CONFIG_pcu_e,
320 CONFIG_GENIETV, CONFIG_PM826, CONFIG_ppmc8260,
321 CONFIG_GTH, CONFIG_RPXClassic, CONFIG_rsdproto,
322 CONFIG_IAD210, CONFIG_RPXlite, CONFIG_sbc8260,
323 CONFIG_EBONY, CONFIG_sacsng
328 CONFIG_HHP_CRADLE, CONFIG_DNP1110, CONFIG_EP7312,
329 CONFIG_IMPA7, CONFIG_LART, CONFIG_LUBBOCK,
330 CONFIG_SHANNON, CONFIG_SMDK2400, CONFIG_SMDK2410,
334 - CPU Module Type: (if CONFIG_COGENT is defined)
335 Define exactly one of
337 --- FIXME --- not tested yet:
338 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
339 CONFIG_CMA287_23, CONFIG_CMA287_50
341 - Motherboard Type: (if CONFIG_COGENT is defined)
342 Define exactly one of
343 CONFIG_CMA101, CONFIG_CMA102
345 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
346 Define one or more of
349 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
350 Define one or more of
351 CONFIG_LCD_HEARTBEAT - update a character position on
352 the lcd display every second with
355 - MPC824X Family Member (if CONFIG_MPC824X is defined)
356 Define exactly one of
357 CONFIG_MPC8240, CONFIG_MPC8245
359 - 8xx CPU Options: (if using an 8xx cpu)
360 Define one or more of
361 CONFIG_8xx_GCLK_FREQ - if get_gclk_freq() can not work e.g.
362 no 32KHz reference PIT/RTC clock
367 U-Boot stores all clock information in Hz
368 internally. For binary compatibility with older Linux
369 kernels (which expect the clocks passed in the
370 bd_info data to be in MHz) the environment variable
371 "clocks_in_mhz" can be defined so that U-Boot
372 converts clock data to MHZ before passing it to the
375 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
376 "clocks_in_mhz=1" is automatically included in the
380 Depending on board, define exactly one serial port
381 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
382 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
383 console by defining CONFIG_8xx_CONS_NONE
385 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
386 port routines must be defined elsewhere
387 (i.e. serial_init(), serial_getc(), ...)
390 Enables console device for a color framebuffer. Needs following
391 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
392 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
394 VIDEO_HW_RECTFILL graphic chip supports
397 VIDEO_HW_BITBLT graphic chip supports
398 bit-blit (cf. smiLynxEM)
399 VIDEO_VISIBLE_COLS visible pixel columns
401 VIDEO_VISIBLE_ROWS visible pixel rows
402 VIDEO_PIXEL_SIZE bytes per pixel
403 VIDEO_DATA_FORMAT graphic data format
404 (0-5, cf. cfb_console.c)
405 VIDEO_FB_ADRS framebuffer address
406 VIDEO_KBD_INIT_FCT keyboard int fct
407 (i.e. i8042_kbd_init())
408 VIDEO_TSTC_FCT test char fct
410 VIDEO_GETC_FCT get char fct
412 CONFIG_CONSOLE_CURSOR cursor drawing on/off
413 (requires blink timer
415 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
416 CONFIG_CONSOLE_TIME display time/date info in
418 (requires CFG_CMD_DATE)
419 CONFIG_VIDEO_LOGO display Linux logo in
421 CONFIG_CONSOLE_EXTRA_INFO
422 addional board info beside
425 When CONFIG_CFB_CONSOLE is defined, video console is
426 default i/o. Serial console can be forced with
427 environment 'console=serial'.
430 CONFIG_BAUDRATE - in bps
431 Select one of the baudrates listed in
432 CFG_BAUDRATE_TABLE, see below.
434 - Interrupt driven serial port input:
435 CONFIG_SERIAL_SOFTWARE_FIFO
438 Use an interrupt handler for receiving data on the
439 serial port. It also enables using hardware handshake
440 (RTS/CTS) and UART's built-in FIFO. Set the number of
441 bytes the interrupt driven input buffer should have.
443 Set to 0 to disable this feature (this is the default).
444 This will also disable hardware handshake.
446 - Boot Delay: CONFIG_BOOTDELAY - in seconds
447 Delay before automatically booting the default image;
448 set to -1 to disable autoboot.
450 See doc/README.autoboot for these options that
451 work with CONFIG_BOOTDELAY. None are required.
452 CONFIG_BOOT_RETRY_TIME
453 CONFIG_BOOT_RETRY_MIN
454 CONFIG_AUTOBOOT_KEYED
455 CONFIG_AUTOBOOT_PROMPT
456 CONFIG_AUTOBOOT_DELAY_STR
457 CONFIG_AUTOBOOT_STOP_STR
458 CONFIG_AUTOBOOT_DELAY_STR2
459 CONFIG_AUTOBOOT_STOP_STR2
460 CONFIG_ZERO_BOOTDELAY_CHECK
461 CONFIG_RESET_TO_RETRY
465 Only needed when CONFIG_BOOTDELAY is enabled;
466 define a command string that is automatically executed
467 when no character is read on the console interface
468 within "Boot Delay" after reset.
471 This can be used to pass arguments to the bootm
472 command. The value of CONFIG_BOOTARGS goes into the
473 environment value "bootargs".
475 CONFIG_RAMBOOT and CONFIG_NFSBOOT
476 The value of these goes into the environment as
477 "ramboot" and "nfsboot" respectively, and can be used
478 as a convenience, when switching between booting from
484 When this option is #defined, the existence of the
485 environment variable "preboot" will be checked
486 immediately before starting the CONFIG_BOOTDELAY
487 countdown and/or running the auto-boot command resp.
488 entering interactive mode.
490 This feature is especially useful when "preboot" is
491 automatically generated or modified. For an example
492 see the LWMON board specific code: here "preboot" is
493 modified when the user holds down a certain
494 combination of keys on the (special) keyboard when
497 - Serial Download Echo Mode:
499 If defined to 1, all characters received during a
500 serial download (using the "loads" command) are
501 echoed back. This might be needed by some terminal
502 emulations (like "cu"), but may as well just take
503 time on others. This setting #define's the initial
504 value of the "loads_echo" environment variable.
506 - Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
508 Select one of the baudrates listed in
509 CFG_BAUDRATE_TABLE, see below.
513 Most monitor functions can be selected (or
514 de-selected) by adjusting the definition of
515 CONFIG_COMMANDS; to select individual functions,
516 #define CONFIG_COMMANDS by "OR"ing any of the
519 #define enables commands:
520 -------------------------
521 CFG_CMD_ASKENV * ask for env variable
523 CFG_CMD_BEDBUG Include BedBug Debugger
525 CFG_CMD_CACHE icache, dcache
526 CFG_CMD_CONSOLE coninfo
527 CFG_CMD_DATE * support for RTC, date/time...
528 CFG_CMD_DHCP DHCP support
529 CFG_CMD_ECHO * echo arguments
530 CFG_CMD_EEPROM * EEPROM read/write support
531 CFG_CMD_ELF bootelf, bootvx
533 CFG_CMD_FDC * Floppy Disk Support
534 CFG_CMD_FLASH flinfo, erase, protect
535 CFG_CMD_FPGA FPGA device initialization support
536 CFG_CMD_I2C * I2C serial bus support
537 CFG_CMD_IDE * IDE harddisk support
539 CFG_CMD_IMMAP * IMMR dump support
540 CFG_CMD_IRQ * irqinfo
544 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
546 CFG_CMD_MII MII utility commands
547 CFG_CMD_NET bootp, tftpboot, rarpboot
548 CFG_CMD_PCI * pciinfo
549 CFG_CMD_PCMCIA * PCMCIA support
550 CFG_CMD_REGINFO * Register dump
551 CFG_CMD_RUN run command in env variable
552 CFG_CMD_SCSI * SCSI Support
553 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
554 CFG_CMD_SPI * SPI serial bus support
555 CFG_CMD_USB * USB support
556 CFG_CMD_BSP * Board SPecific functions
557 -----------------------------------------------
560 CFG_CMD_DFL Default configuration; at the moment
561 this is includes all commands, except
562 the ones marked with "*" in the list
565 If you don't define CONFIG_COMMANDS it defaults to
566 CFG_CMD_DFL in include/cmd_confdefs.h. A board can
567 override the default settings in the respective
570 EXAMPLE: If you want all functions except of network
571 support you can write:
573 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
576 Note: Don't enable the "icache" and "dcache" commands
577 (configuration option CFG_CMD_CACHE) unless you know
578 what you (and your U-Boot users) are doing. Data
579 cache cannot be enabled on systems like the 8xx or
580 8260 (where accesses to the IMMR region must be
581 uncached), and it cannot be disabled on all other
582 systems where we (mis-) use the data cache to hold an
583 initial stack and some data.
586 XXX - this list needs to get updated!
590 If this variable is defined, it enables watchdog
591 support. There must support in the platform specific
592 code for a watchdog. For the 8xx and 8260 CPUs, the
593 SIU Watchdog feature is enabled in the SYPCR
598 When CFG_CMD_DATE is selected, the type of the RTC
599 has to be selected, too. Define exactly one of the
602 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
603 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
604 CONFIG_RTC_MC146818 - use MC146818 RTC
605 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
609 When CONFIG_TIMESTAMP is selected, the timestamp
610 (date and time) of an image is printed by image
611 commands like bootm or iminfo. This option is
612 automatically enabled when you select CFG_CMD_DATE .
615 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
616 and/or CONFIG_ISO_PARTITION
618 If IDE or SCSI support is enabled (CFG_CMD_IDE or
619 CFG_CMD_SCSI) you must configure support for at least
620 one partition type as well.
623 CONFIG_IDE_RESET_ROUTINE
625 Set this to define that instead of a reset Pin, the
626 routine ide_set_reset(int idereset) will be used.
631 Set this to enable ATAPI support.
634 At the moment only there is only support for the
635 SYM53C8XX SCSI controller; define
636 CONFIG_SCSI_SYM53C8XX to enable it.
638 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
639 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
640 CFG_SCSI_MAX_LUN] can be adjusted to define the
641 maximum numbers of LUNs, SCSI ID's and target
643 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
645 - NETWORK Support (PCI):
647 Support for Intel 82557/82559/82559ER chips.
648 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
649 write routine for first time initialisation.
652 Support for Digital 2114x chips.
653 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
654 modem chip initialisation (KS8761/QS6611).
657 Support for National dp83815 chips.
660 Support for National dp8382[01] gigabit chips.
663 At the moment only the UHCI host controller is
664 supported (PIP405, MIP405); define
665 CONFIG_USB_UHCI to enable it.
666 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
667 end define CONFIG_USB_STORAGE to enable the USB
670 Supported are USB Keyboards and USB Floppy drives
676 Define this to enable standard (PC-Style) keyboard
680 Standard PC keyboard driver with US (is default) and
681 GERMAN key layout (switch via environment 'keymap=de') support.
682 Export function i8042_kbd_init, i8042_tstc and i8042_getc
683 for cfb_console. Supports cursor blinking.
688 Define this to enable video support (for output to
693 Enable Chips & Technologies 69000 Video chip
695 CONFIG_VIDEO_SMI_LYNXEM
696 Enable Silicon Motion SMI 712/710/810 Video chip
697 Videomode are selected via environment 'videomode' with
698 standard LiLo mode numbers.
699 Following modes are supported (* is default):
701 800x600 1024x768 1280x1024
702 256 (8bit) 303* 305 307
703 65536 (16bit) 314 317 31a
704 16,7 Mill (24bit) 315 318 31b
705 (i.e. setenv videomode 317; saveenv; reset;)
707 - LCD Support: CONFIG_LCD
709 Define this to enable LCD support (for output to LCD
710 display); also select one of the supported displays
711 by defining one of these:
713 CONFIG_NEC_NL6648AC33:
715 NEC NL6648AC33-18. Active, color, single scan.
717 CONFIG_NEC_NL6648BC20
719 NEC NL6648BC20-08. 6.5", 640x480.
720 Active, color, single scan.
724 Sharp 320x240. Active, color, single scan.
725 It isn't 16x9, and I am not sure what it is.
727 CONFIG_SHARP_LQ64D341
729 Sharp LQ64D341 display, 640x480.
730 Active, color, single scan.
734 HLD1045 display, 640x480.
735 Active, color, single scan.
739 Optrex CBL50840-2 NF-FW 99 22 M5
741 Hitachi LMG6912RPFC-00T
745 320x240. Black & white.
747 Normally display is black on white background; define
748 CFG_WHITE_ON_BLACK to get it inverted.
755 Define a default value for ethernet address to use
756 for the respective ethernet interface, in case this
757 is not determined automatically.
762 Define a default value for the IP address to use for
763 the default ethernet interface, in case this is not
764 determined through e.g. bootp.
769 Defines a default value for theIP address of a TFTP
770 server to contact when using the "tftboot" command.
772 - BOOTP Recovery Mode:
773 CONFIG_BOOTP_RANDOM_DELAY
775 If you have many targets in a network that try to
776 boot using BOOTP, you may want to avoid that all
777 systems send out BOOTP requests at precisely the same
778 moment (which would happen for instance at recovery
779 from a power failure, when all systems will try to
780 boot, thus flooding the BOOTP server. Defining
781 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
782 inserted before sending out BOOTP requests. The
783 following delays are insterted then:
785 1st BOOTP request: delay 0 ... 1 sec
786 2nd BOOTP request: delay 0 ... 2 sec
787 3rd BOOTP request: delay 0 ... 4 sec
789 BOOTP requests: delay 0 ... 8 sec
791 - Status LED: CONFIG_STATUS_LED
793 Several configurations allow to display the current
794 status using a LED. For instance, the LED will blink
795 fast while running U-Boot code, stop blinking as
796 soon as a reply to a BOOTP request was received, and
797 start blinking slow once the Linux kernel is running
798 (supported by a status LED driver in the Linux
799 kernel). Defining CONFIG_STATUS_LED enables this
802 - CAN Support: CONFIG_CAN_DRIVER
804 Defining CONFIG_CAN_DRIVER enables CAN driver support
805 on those systems that support this (optional)
806 feature, like the TQM8xxL modules.
808 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
810 Enables I2C serial bus commands. If this is selected,
811 either CONFIG_HARD_I2C or CONFIG_SOFT_I2C must be defined
812 to include the appropriate I2C driver.
814 See also: common/cmd_i2c.c for a description of the
815 command line interface.
820 Selects the CPM hardware driver for I2C.
824 Use software (aka bit-banging) driver instead of CPM
825 or similar hardware support for I2C. This is configured
826 via the following defines.
830 (Optional). Any commands necessary to enable I2C
831 controller or configure ports.
835 (Only for MPC8260 CPU). The I/O port to use (the code
836 assumes both bits are on the same port). Valid values
837 are 0..3 for ports A..D.
841 The code necessary to make the I2C data line active
842 (driven). If the data line is open collector, this
847 The code necessary to make the I2C data line tri-stated
848 (inactive). If the data line is open collector, this
853 Code that returns TRUE if the I2C data line is high,
858 If <bit> is TRUE, sets the I2C data line high. If it
859 is FALSE, it clears it (low).
863 If <bit> is TRUE, sets the I2C clock line high. If it
864 is FALSE, it clears it (low).
868 This delay is invoked four times per clock cycle so this
869 controls the rate of data transfer. The data rate thus
870 is 1 / (I2C_DELAY * 4).
872 - SPI Support: CONFIG_SPI
874 Enables SPI driver (so far only tested with
875 SPI EEPROM, also an instance works with Crystal A/D and
876 D/As on the SACSng board)
880 Enables extended (16-bit) SPI EEPROM addressing.
881 (symmetrical to CONFIG_I2C_X)
885 Enables a software (bit-bang) SPI driver rather than
886 using hardware support. This is a general purpose
887 driver that only requires three general I/O port pins
888 (two outputs, one input) to function. If this is
889 defined, the board configuration must define several
890 SPI configuration items (port pins to use, etc). For
891 an example, see include/configs/sacsng.h.
893 - FPGA Support: CONFIG_FPGA_COUNT
895 Specify the number of FPGA devices to support.
899 Used to specify the types of FPGA devices. For
901 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
903 CFG_FPGA_PROG_FEEDBACK
905 Enable printing of hash marks during FPGA
910 Enable checks on FPGA configuration interface busy
911 status by the configuration function. This option
912 will require a board or device specific function to
917 If defined, a function that provides delays in the
918 FPGA configuration driver.
922 Allow Control-C to interrupt FPGA configuration
926 Check for configuration errors during FPGA bitfile
927 loading. For example, abort during Virtex II
928 configuration if the INIT_B line goes low (which
929 indicated a CRC error).
933 Maximum time to wait for the INIT_B line to deassert
934 after PROB_B has been deasserted during a Virtex II
935 FPGA configuration sequence. The default time is 500 mS.
939 Maximum time to wait for BUSY to deassert during
940 Virtex II FPGA configuration. The default is 5 mS.
944 Time to wait after FPGA configuration. The default is
947 - FPGA Support: CONFIG_FPGA_COUNT
949 Specify the number of FPGA devices to support.
953 Used to specify the types of FPGA devices. For example,
954 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
956 CFG_FPGA_PROG_FEEDBACK
958 Enable printing of hash marks during FPGA configuration.
962 Enable checks on FPGA configuration interface busy
963 status by the configuration function. This option
964 will require a board or device specific function to
969 If defined, a function that provides delays in the FPGA
970 configuration driver.
973 Allow Control-C to interrupt FPGA configuration
977 Check for configuration errors during FPGA bitfile
978 loading. For example, abort during Virtex II
979 configuration if the INIT_B line goes low (which
980 indicated a CRC error).
984 Maximum time to wait for the INIT_B line to deassert
985 after PROB_B has been deasserted during a Virtex II
986 FPGA configuration sequence. The default time is 500
991 Maximum time to wait for BUSY to deassert during
992 Virtex II FPGA configuration. The default is 5 mS.
996 Time to wait after FPGA configuration. The default is
999 - Configuration Management:
1002 If defined, this string will be added to the U-Boot
1003 version information (U_BOOT_VERSION)
1005 - Vendor Parameter Protection:
1007 U-Boot considers the values of the environment
1008 variables "serial#" (Board Serial Number) and
1009 "ethaddr" (Ethernet Address) to bb parameters that
1010 are set once by the board vendor / manufacturer, and
1011 protects these variables from casual modification by
1012 the user. Once set, these variables are read-only,
1013 and write or delete attempts are rejected. You can
1014 change this behviour:
1016 If CONFIG_ENV_OVERWRITE is #defined in your config
1017 file, the write protection for vendor parameters is
1018 completely disabled. Anybody can change or delte
1021 Alternatively, if you #define _both_ CONFIG_ETHADDR
1022 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1023 ethernet address is installed in the environment,
1024 which can be changed exactly ONCE by the user. [The
1025 serial# is unaffected by this, i. e. it remains
1031 Define this variable to enable the reservation of
1032 "protected RAM", i. e. RAM which is not overwritten
1033 by U-Boot. Define CONFIG_PRAM to hold the number of
1034 kB you want to reserve for pRAM. You can overwrite
1035 this default value by defining an environment
1036 variable "pram" to the number of kB you want to
1037 reserve. Note that the board info structure will
1038 still show the full amount of RAM. If pRAM is
1039 reserved, a new environment variable "mem" will
1040 automatically be defined to hold the amount of
1041 remaining RAM in a form that can be passed as boot
1042 argument to Linux, for instance like that:
1044 setenv bootargs ... mem=\$(mem)
1047 This way you can tell Linux not to use this memory,
1048 either, which results in a memory region that will
1049 not be affected by reboots.
1051 *WARNING* If your board configuration uses automatic
1052 detection of the RAM size, you must make sure that
1053 this memory test is non-destructive. So far, the
1054 following board configurations are known to be
1057 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1058 HERMES, IP860, RPXlite, LWMON, LANTEC,
1059 PCU_E, FLAGADM, TQM8260
1064 Define this variable to stop the system in case of a
1065 fatal error, so that you have to reset it manually.
1066 This is probably NOT a good idea for an embedded
1067 system where you want to system to reboot
1068 automatically as fast as possible, but it may be
1069 useful during development since you can try to debug
1070 the conditions that lead to the situation.
1072 CONFIG_NET_RETRY_COUNT
1074 This variable defines the number of retries for
1075 network operations like ARP, RARP, TFTP, or BOOTP
1076 before giving up the operation. If not defined, a
1077 default value of 5 is used.
1079 - Command Interpreter:
1082 Define this variable to enable the "hush" shell (from
1083 Busybox) as command line interpreter, thus enabling
1084 powerful command line syntax like
1085 if...then...else...fi conditionals or `&&' and '||'
1086 constructs ("shell scripts").
1088 If undefined, you get the old, much simpler behaviour
1089 with a somewhat smaller memory footprint.
1094 This defines the secondary prompt string, which is
1095 printed when the command interpreter needs more input
1096 to complete a command. Usually "> ".
1100 In the current implementation, the local variables
1101 space and global environment variables space are
1102 separated. Local variables are those you define by
1103 simply typing like `name=value'. To access a local
1104 variable later on, you have write `$name' or
1105 `${name}'; variable directly by typing say `$name' at
1108 Global environment variables are those you use
1109 setenv/printenv to work with. To run a command stored
1110 in such a variable, you need to use the run command,
1111 and you must not use the '$' sign to access them.
1113 To store commands and special characters in a
1114 variable, please use double quotation marks
1115 surrounding the whole text of the variable, instead
1116 of the backslashes before semicolons and special
1119 - Default Environment
1120 CONFIG_EXTRA_ENV_SETTINGS
1122 Define this to contain any number of null terminated
1123 strings (variable = value pairs) that will be part of
1124 the default enviroment compiled into the boot image.
1125 For example, place something like this in your
1126 board's config file:
1128 #define CONFIG_EXTRA_ENV_SETTINGS \
1132 Warning: This method is based on knowledge about the
1133 internal format how the environment is stored by the
1134 U-Boot code. This is NOT an official, expoerted
1135 interface! Although it is unlikely that this format
1136 will change soon, there is no guarantee either.
1137 You better know what you are doing here.
1139 Note: overly (ab)use of the default environment is
1140 discouraged. Make sure to check other ways to preset
1141 the environment like the autoscript function or the
1144 - Show boot progress
1145 CONFIG_SHOW_BOOT_PROGRESS
1147 Defining this option allows to add some board-
1148 specific code (calling a user-provided function
1149 "show_boot_progress(int)") that enables you to show
1150 the system's boot progress on some display (for
1151 example, some LED's) on your board. At the moment,
1152 the following checkpoints are implemented:
1155 1 common/cmd_bootm.c before attempting to boot an image
1156 -1 common/cmd_bootm.c Image header has bad magic number
1157 2 common/cmd_bootm.c Image header has correct magic number
1158 -2 common/cmd_bootm.c Image header has bad checksum
1159 3 common/cmd_bootm.c Image header has correct checksum
1160 -3 common/cmd_bootm.c Image data has bad checksum
1161 4 common/cmd_bootm.c Image data has correct checksum
1162 -4 common/cmd_bootm.c Image is for unsupported architecture
1163 5 common/cmd_bootm.c Architecture check OK
1164 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1165 6 common/cmd_bootm.c Image Type check OK
1166 -6 common/cmd_bootm.c gunzip uncompression error
1167 -7 common/cmd_bootm.c Unimplemented compression type
1168 7 common/cmd_bootm.c Uncompression OK
1169 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1170 8 common/cmd_bootm.c Image Type check OK
1171 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1172 9 common/cmd_bootm.c Start initial ramdisk verification
1173 -10 common/cmd_bootm.c Ramdisk header has bad magic number
1174 -11 common/cmd_bootm.c Ramdisk header has bad checksum
1175 10 common/cmd_bootm.c Ramdisk header is OK
1176 -12 common/cmd_bootm.c Ramdisk data has bad checksum
1177 11 common/cmd_bootm.c Ramdisk data has correct checksum
1178 12 common/cmd_bootm.c Ramdisk verification complete, start loading
1179 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk)
1180 13 common/cmd_bootm.c Start multifile image verification
1181 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue.
1182 15 common/cmd_bootm.c All preparation done, transferring control to OS
1184 -1 common/cmd_doc.c Bad usage of "doc" command
1185 -1 common/cmd_doc.c No boot device
1186 -1 common/cmd_doc.c Unknown Chip ID on boot device
1187 -1 common/cmd_doc.c Read Error on boot device
1188 -1 common/cmd_doc.c Image header has bad magic number
1190 -1 common/cmd_ide.c Bad usage of "ide" command
1191 -1 common/cmd_ide.c No boot device
1192 -1 common/cmd_ide.c Unknown boot device
1193 -1 common/cmd_ide.c Unknown partition table
1194 -1 common/cmd_ide.c Invalid partition type
1195 -1 common/cmd_ide.c Read Error on boot device
1196 -1 common/cmd_ide.c Image header has bad magic number
1198 -1 common/cmd_nvedit.c Environment not changable, but has bad CRC
1204 [so far only for SMDK2400 board]
1206 - Modem support endable:
1207 CONFIG_MODEM_SUPPORT
1209 - RTS/CTS Flow control enable:
1212 - Modem debug support:
1213 CONFIG_MODEM_SUPPORT_DEBUG
1215 Enables debugging stuff (char screen[1024], dbg())
1216 for modem support. Useful only with BDI2000.
1220 In the target system modem support is enabled when a
1221 specific key (key combination) is pressed during
1222 power-on. Otherwise U-Boot will boot normally
1223 (autoboot). The key_pressed() fuction is called from
1224 board_init(). Currently key_pressed() is a dummy
1225 function, returning 1 and thus enabling modem
1228 If there are no modem init strings in the
1229 environment, U-Boot proceed to autoboot; the
1230 previous output (banner, info printfs) will be
1233 See also: doc/README.Modem
1238 Configuration Settings:
1239 -----------------------
1241 - CFG_LONGHELP: Defined when you want long help messages included;
1242 undefine this when you're short of memory.
1244 - CFG_PROMPT: This is what U-Boot prints on the console to
1245 prompt for user input.
1247 - CFG_CBSIZE: Buffer size for input from the Console
1249 - CFG_PBSIZE: Buffer size for Console output
1251 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1253 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1254 the application (usually a Linux kernel) when it is
1257 - CFG_BAUDRATE_TABLE:
1258 List of legal baudrate settings for this board.
1260 - CFG_CONSOLE_INFO_QUIET
1261 Suppress display of console information at boot.
1263 - CFG_CONSOLE_IS_IN_ENV
1264 If the board specific function
1265 extern int overwrite_console (void);
1266 returns 1, the stdin, stderr and stdout are switched to the
1267 serial port, else the settings in the environment are used.
1269 - CFG_CONSOLE_OVERWRITE_ROUTINE
1270 Enable the call to overwrite_console().
1272 - CFG_CONSOLE_ENV_OVERWRITE
1273 Enable overwrite of previous console environment settings.
1275 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1276 Begin and End addresses of the area used by the
1280 Enable an alternate, more extensive memory test.
1282 - CFG_TFTP_LOADADDR:
1283 Default load address for network file downloads
1285 - CFG_LOADS_BAUD_CHANGE:
1286 Enable temporary baudrate change while serial download
1289 Physical start address of SDRAM. _Must_ be 0 here.
1292 Physical start address of Motherboard I/O (if using a
1296 Physical start address of Flash memory.
1299 Physical start address of boot monitor code (set by
1300 make config files to be same as the text base address
1301 (TEXT_BASE) used when linking) - same as
1302 CFG_FLASH_BASE when booting from flash.
1305 Size of memory reserved for monitor code
1308 Size of DRAM reserved for malloc() use.
1311 Maximum size of memory mapped by the startup code of
1312 the Linux kernel; all data that must be processed by
1313 the Linux kernel (bd_info, boot arguments, eventually
1314 initrd image) must be put below this limit.
1316 - CFG_MAX_FLASH_BANKS:
1317 Max number of Flash memory banks
1319 - CFG_MAX_FLASH_SECT:
1320 Max number of sectors on a Flash chip
1322 - CFG_FLASH_ERASE_TOUT:
1323 Timeout for Flash erase operations (in ms)
1325 - CFG_FLASH_WRITE_TOUT:
1326 Timeout for Flash write operations (in ms)
1328 - CFG_DIRECT_FLASH_TFTP:
1330 Enable TFTP transfers directly to flash memory;
1331 without this option such a download has to be
1332 performed in two steps: (1) download to RAM, and (2)
1333 copy from RAM to flash.
1335 The two-step approach is usually more reliable, since
1336 you can check if the download worked before you erase
1337 the flash, but in some situations (when sytem RAM is
1338 too limited to allow for a tempory copy of the
1339 downloaded image) this option may be very useful.
1342 Define if the flash driver uses extra elements in the
1343 common flash structure for storing flash geometry
1345 The following definitions that deal with the placement and management
1346 of environment data (variable area); in general, we support the
1347 following configurations:
1349 - CFG_ENV_IS_IN_FLASH:
1351 Define this if the environment is in flash memory.
1353 a) The environment occupies one whole flash sector, which is
1354 "embedded" in the text segment with the U-Boot code. This
1355 happens usually with "bottom boot sector" or "top boot
1356 sector" type flash chips, which have several smaller
1357 sectors at the start or the end. For instance, such a
1358 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
1359 such a case you would place the environment in one of the
1360 4 kB sectors - with U-Boot code before and after it. With
1361 "top boot sector" type flash chips, you would put the
1362 environment in one of the last sectors, leaving a gap
1363 between U-Boot and the environment.
1367 Offset of environment data (variable area) to the
1368 beginning of flash memory; for instance, with bottom boot
1369 type flash chips the second sector can be used: the offset
1370 for this sector is given here.
1372 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
1376 This is just another way to specify the start address of
1377 the flash sector containing the environment (instead of
1380 - CFG_ENV_SECT_SIZE:
1382 Size of the sector containing the environment.
1385 b) Sometimes flash chips have few, equal sized, BIG sectors.
1386 In such a case you don't want to spend a whole sector for
1391 If you use this in combination with CFG_ENV_IS_IN_FLASH
1392 and CFG_ENV_SECT_SIZE, you can specify to use only a part
1393 of this flash sector for the environment. This saves
1394 memory for the RAM copy of the environment.
1396 It may also save flash memory if you decide to use this
1397 when your environment is "embedded" within U-Boot code,
1398 since then the remainder of the flash sector could be used
1399 for U-Boot code. It should be pointed out that this is
1400 STRONGLY DISCOURAGED from a robustness point of view:
1401 updating the environment in flash makes it always
1402 necessary to erase the WHOLE sector. If something goes
1403 wrong before the contents has been restored from a copy in
1404 RAM, your target system will be dead.
1406 - CFG_ENV_ADDR_REDUND
1409 These settings describe a second storage area used to hold
1410 a redundand copy of the environment data, so that there is
1411 a valid backup copy in case there is a power failur during
1412 a "saveenv" operation.
1414 BE CAREFUL! Any changes to the flash layout, and some changes to the
1415 source code will make it necessary to adapt <board>/u-boot.lds*
1419 - CFG_ENV_IS_IN_NVRAM:
1421 Define this if you have some non-volatile memory device
1422 (NVRAM, battery buffered SRAM) which you want to use for the
1428 These two #defines are used to determin the memory area you
1429 want to use for environment. It is assumed that this memory
1430 can just be read and written to, without any special
1433 BE CAREFUL! The first access to the environment happens quite early
1434 in U-Boot initalization (when we try to get the setting of for the
1435 console baudrate). You *MUST* have mappend your NVRAM area then, or
1438 Please note that even with NVRAM we still use a copy of the
1439 environment in RAM: we could work on NVRAM directly, but we want to
1440 keep settings there always unmodified except somebody uses "saveenv"
1441 to save the current settings.
1444 - CFG_ENV_IS_IN_EEPROM:
1446 Use this if you have an EEPROM or similar serial access
1447 device and a driver for it.
1452 These two #defines specify the offset and size of the
1453 environment area within the total memory of your EEPROM.
1455 - CFG_I2C_EEPROM_ADDR:
1456 If defined, specified the chip address of the EEPROM device.
1457 The default address is zero.
1459 - CFG_EEPROM_PAGE_WRITE_BITS:
1460 If defined, the number of bits used to address bytes in a
1461 single page in the EEPROM device. A 64 byte page, for example
1462 would require six bits.
1464 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1465 If defined, the number of milliseconds to delay between
1466 page writes. The default is zero milliseconds.
1468 - CFG_I2C_EEPROM_ADDR_LEN:
1469 The length in bytes of the EEPROM memory array address. Note
1470 that this is NOT the chip address length!
1473 The size in bytes of the EEPROM device.
1475 - CFG_I2C_EEPROM_ADDR:
1476 If defined, specified the chip address of the EEPROM device.
1477 The default address is zero.
1479 - CFG_EEPROM_PAGE_WRITE_BITS:
1480 If defined, the number of bits used to address bytes in a
1481 single page in the EEPROM device. A 64 byte page, for example
1482 would require six bits.
1484 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1485 If defined, the number of milliseconds to delay between
1486 page writes. The default is zero milliseconds.
1488 - CFG_I2C_EEPROM_ADDR_LEN:
1489 The length in bytes of the EEPROM memory array address. Note
1490 that this is NOT the chip address length!
1493 The size in bytes of the EEPROM device.
1495 - CFG_SPI_INIT_OFFSET
1497 Defines offset to the initial SPI buffer area in DPRAM. The
1498 area is used at an early stage (ROM part) if the environment
1499 is configured to reside in the SPI EEPROM: We need a 520 byte
1500 scratch DPRAM area. It is used between the two initialization
1501 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
1502 to be a good choice since it makes it far enough from the
1503 start of the data area as well as from the stack pointer.
1505 Please note that the environment is read-only as long as the monitor
1506 has been relocated to RAM and a RAM copy of the environment has been
1507 created; also, when using EEPROM you will have to use getenv_r()
1508 until then to read environment variables.
1510 The environment is now protected by a CRC32 checksum. Before the
1511 monitor is relocated into RAM, as a result of a bad CRC you will be
1512 working with the compiled-in default environment - *silently*!!!
1513 [This is necessary, because the first environment variable we need is
1514 the "baudrate" setting for the console - if we have a bad CRC, we
1515 don't have any device yet where we could complain.]
1517 Note: once the monitor has been relocated, then it will complain if
1518 the default environment is used; a new CRC is computed as soon as you
1519 use the "setenv" command to modify / delete / add any environment
1520 variable [even when you try to delete a non-existing variable!].
1522 Note2: you must edit your u-boot.lds file to reflect this
1526 Many of the options are named exactly as the corresponding Linux
1527 kernel configuration options. The intention is to make it easier to
1528 build a config tool - later.
1530 Low Level (hardware related) configuration options:
1532 - CFG_CACHELINE_SIZE:
1533 Cache Line Size of the CPU.
1536 Default address of the IMMR after system reset.
1537 Needed on some 8260 systems (MPC8260ADS and RPXsuper)
1538 to be able to adjust the position of the IMMR
1539 register after a reset.
1541 - CFG_IMMR: Physical address of the Internal Memory Mapped
1542 Register; DO NOT CHANGE! (11-4)
1543 [MPC8xx systems only]
1545 - CFG_INIT_RAM_ADDR:
1547 Start address of memory area tha can be used for
1548 initial data and stack; please note that this must be
1549 writable memory that is working WITHOUT special
1550 initialization, i. e. you CANNOT use normal RAM which
1551 will become available only after programming the
1552 memory controller and running certain initialization
1555 U-Boot uses the following memory types:
1556 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
1557 - MPC824X: data cache
1558 - PPC4xx: data cache
1560 - CFG_INIT_DATA_OFFSET:
1562 Offset of the initial data structure in the memory
1563 area defined by CFG_INIT_RAM_ADDR. Usually
1564 CFG_INIT_DATA_OFFSET is chosen such that the initial
1565 data is located at the end of the available space
1566 (sometimes written as (CFG_INIT_RAM_END -
1567 CFG_INIT_DATA_SIZE), and the initial stack is just
1568 below that area (growing from (CFG_INIT_RAM_ADDR +
1569 CFG_INIT_DATA_OFFSET) downward.
1572 On the MPC824X (or other systems that use the data
1573 cache for initial memory) the address chosen for
1574 CFG_INIT_RAM_ADDR is basically arbitrary - it must
1575 point to an otherwise UNUSED address space between
1576 the top of RAM and the start of the PCI space.
1578 - CFG_SIUMCR: SIU Module Configuration (11-6)
1580 - CFG_SYPCR: System Protection Control (11-9)
1582 - CFG_TBSCR: Time Base Status and Control (11-26)
1584 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
1586 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
1588 - CFG_SCCR: System Clock and reset Control Register (15-27)
1590 - CFG_OR_TIMING_SDRAM:
1594 periodic timer for refresh
1596 - CFG_DER: Debug Event Register (37-47)
1598 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
1599 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
1600 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
1602 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
1604 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
1605 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
1606 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
1607 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
1609 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
1610 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
1611 Machine Mode Register and Memory Periodic Timer
1612 Prescaler definitions (SDRAM timing)
1614 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
1615 enable I2C microcode relocation patch (MPC8xx);
1616 define relocation offset in DPRAM [DSP2]
1618 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
1619 enable SPI microcode relocation patch (MPC8xx);
1620 define relocation offset in DPRAM [SCC4]
1623 Use OSCM clock mode on MBX8xx board. Be careful,
1624 wrong setting might damage your board. Read
1625 doc/README.MBX before setting this variable!
1627 Building the Software:
1628 ======================
1630 Building U-Boot has been tested in native PPC environments (on a
1631 PowerBook G3 running LinuxPPC 2000) and in cross environments
1632 (running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
1635 If you are not using a native PPC environment, it is assumed that you
1636 have the GNU cross compiling tools available in your path and named
1637 with a prefix of "powerpc-linux-". If this is not the case, (e.g. if
1638 you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
1639 the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
1642 CROSS_COMPILE = ppc_4xx-
1645 U-Boot is intended to be simple to build. After installing the
1646 sources you must configure U-Boot for one specific board type. This
1651 where "NAME_config" is the name of one of the existing
1652 configurations; the following names are supported:
1654 ADCIOP_config GTH_config TQM850L_config
1655 ADS860_config IP860_config TQM855L_config
1656 AR405_config IVML24_config TQM860L_config
1657 CANBT_config IVMS8_config WALNUT405_config
1658 CPCI405_config LANTEC_config cogent_common_config
1659 CPCIISER4_config MBX_config cogent_mpc8260_config
1660 CU824_config MBX860T_config cogent_mpc8xx_config
1661 ESTEEM192E_config RPXlite_config hermes_config
1662 ETX094_config RPXsuper_config hymod_config
1663 FADS823_config SM850_config lwmon_config
1664 FADS850SAR_config SPD823TS_config pcu_e_config
1665 FADS860T_config SXNI855T_config rsdproto_config
1666 FPS850L_config Sandpoint8240_config sbc8260_config
1667 GENIETV_config TQM823L_config PIP405_config
1668 GEN860T_config EBONY_config
1670 Note: for some board special configuration names may exist; check if
1671 additional information is available from the board vendor; for
1672 instance, the TQM8xxL systems run normally at 50 MHz and use a
1673 SCC for 10baseT ethernet; there are also systems with 80 MHz
1674 CPU clock, and an optional Fast Ethernet module is available
1675 for CPU's with FEC. You can select such additional "features"
1676 when chosing the configuration, i. e.
1679 - will configure for a plain TQM860L, i. e. 50MHz, no FEC
1681 make TQM860L_FEC_config
1682 - will configure for a TQM860L at 50MHz with FEC for ethernet
1684 make TQM860L_80MHz_config
1685 - will configure for a TQM860L at 80 MHz, with normal 10baseT
1688 make TQM860L_FEC_80MHz_config
1689 - will configure for a TQM860L at 80 MHz with FEC for ethernet
1691 make TQM823L_LCD_config
1692 - will configure for a TQM823L with U-Boot console on LCD
1694 make TQM823L_LCD_80MHz_config
1695 - will configure for a TQM823L at 80 MHz with U-Boot console on LCD
1701 Finally, type "make all", and you should get some working U-Boot
1702 images ready for downlod to / installation on your system:
1704 - "u-boot.bin" is a raw binary image
1705 - "u-boot" is an image in ELF binary format
1706 - "u-boot.srec" is in Motorola S-Record format
1709 Please be aware that the Makefiles assume you are using GNU make, so
1710 for instance on NetBSD you might need to use "gmake" instead of
1714 If the system board that you have is not listed, then you will need
1715 to port U-Boot to your hardware platform. To do this, follow these
1718 1. Add a new configuration option for your board to the toplevel
1719 "Makefile", using the existing entries as examples.
1720 2. Create a new directory to hold your board specific code. Add any
1722 3. If you're porting U-Boot to a new CPU, then also create a new
1723 directory to hold your CPU specific code. Add any files you need.
1724 4. Run "make config_name" with your new name.
1725 5. Type "make", and you should get a working "u-boot.srec" file
1726 to be installed on your target system.
1727 [Of course, this last step is much harder than it sounds.]
1730 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
1731 ==============================================================
1733 If you have modified U-Boot sources (for instance added a new board
1734 or support for new devices, a new CPU, etc.) you are expected to
1735 provide feedback to the other developers. The feedback normally takes
1736 the form of a "patch", i. e. a context diff against a certain (latest
1737 official or latest in CVS) version of U-Boot sources.
1739 But before you submit such a patch, please verify that your modifi-
1740 cation did not break existing code. At least make sure that *ALL* of
1741 the supported boards compile WITHOUT ANY compiler warnings. To do so,
1742 just run the "MAKEALL" script, which will configure and build U-Boot
1743 for ALL supported system. Be warned, this will take a while. You can
1744 select which (cross) compiler to use py passing a `CROSS_COMPILE'
1745 environment variable to the script, i. e. to use the cross tools from
1746 MontaVista's Hard Hat Linux you can type
1748 CROSS_COMPILE=ppc_8xx- MAKEALL
1750 or to build on a native PowerPC system you can type
1752 CROSS_COMPILE=' ' MAKEALL
1754 See also "U-Boot Porting Guide" below.
1758 Monitor Commands - Overview:
1759 ============================
1761 go - start application at address 'addr'
1762 run - run commands in an environment variable
1763 bootm - boot application image from memory
1764 bootp - boot image via network using BootP/TFTP protocol
1765 tftpboot- boot image via network using TFTP protocol
1766 and env variables "ipaddr" and "serverip"
1767 (and eventually "gatewayip")
1768 rarpboot- boot image via network using RARP/TFTP protocol
1769 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
1770 loads - load S-Record file over serial line
1771 loadb - load binary file over serial line (kermit mode)
1773 mm - memory modify (auto-incrementing)
1774 nm - memory modify (constant address)
1775 mw - memory write (fill)
1777 cmp - memory compare
1778 crc32 - checksum calculation
1779 imd - i2c memory display
1780 imm - i2c memory modify (auto-incrementing)
1781 inm - i2c memory modify (constant address)
1782 imw - i2c memory write (fill)
1783 icrc32 - i2c checksum calculation
1784 iprobe - probe to discover valid I2C chip addresses
1785 iloop - infinite loop on address range
1786 isdram - print SDRAM configuration information
1787 sspi - SPI utility commands
1788 base - print or set address offset
1789 printenv- print environment variables
1790 setenv - set environment variables
1791 saveenv - save environment variables to persistent storage
1792 protect - enable or disable FLASH write protection
1793 erase - erase FLASH memory
1794 flinfo - print FLASH memory information
1795 bdinfo - print Board Info structure
1796 iminfo - print header information for application image
1797 coninfo - print console devices and informations
1798 ide - IDE sub-system
1799 loop - infinite loop on address range
1800 mtest - simple RAM test
1801 icache - enable or disable instruction cache
1802 dcache - enable or disable data cache
1803 reset - Perform RESET of the CPU
1804 echo - echo args to console
1805 version - print monitor version
1806 help - print online help
1807 ? - alias for 'help'
1810 Monitor Commands - Detailed Description:
1811 ========================================
1815 For now: just type "help <command>".
1818 Environment Variables:
1819 ======================
1821 U-Boot supports user configuration using Environment Variables which
1822 can be made persistent by saving to Flash memory.
1824 Environment Variables are set using "setenv", printed using
1825 "printenv", and saved to Flash using "saveenv". Using "setenv"
1826 without a value can be used to delete a variable from the
1827 environment. As long as you don't save the environment you are
1828 working with an in-memory copy. In case the Flash area containing the
1829 environment is erased by accident, a default environment is provided.
1831 Some configuration options can be set using Environment Variables:
1833 baudrate - see CONFIG_BAUDRATE
1835 bootdelay - see CONFIG_BOOTDELAY
1837 bootcmd - see CONFIG_BOOTCOMMAND
1839 bootargs - Boot arguments when booting an RTOS image
1841 bootfile - Name of the image to load with TFTP
1843 autoload - if set to "no" (any string beginning with 'n'),
1844 "bootp" will just load perform a lookup of the
1845 configuration from the BOOTP server, but not try to
1846 load any image using TFTP
1848 autostart - if set to "yes", an image loaded using the "bootp",
1849 "rarpboot", "tftpboot" or "diskboot" commands will
1850 be automatically started (by internally calling
1853 initrd_high - restrict positioning of initrd images:
1854 If this variable is not set, initrd images will be
1855 copied to the highest possible address in RAM; this
1856 is usually what you want since it allows for
1857 maximum initrd size. If for some reason you want to
1858 make sure that the initrd image is loaded below the
1859 CFG_BOOTMAPSZ limit, you can set this environment
1860 variable to a value of "no" or "off" or "0".
1861 Alternatively, you can set it to a maximum upper
1862 address to use (U-Boot will still check that it
1863 does not overwrite the U-Boot stack and data).
1865 For instance, when you have a system with 16 MB
1866 RAM, and want to reseve 4 MB from use by Linux,
1867 you can do this by adding "mem=12M" to the value of
1868 the "bootargs" variable. However, now you must make
1869 sure, that the initrd image is placed in the first
1870 12 MB as well - this can be done with
1872 setenv initrd_high 00c00000
1874 ipaddr - IP address; needed for tftpboot command
1876 loadaddr - Default load address for commands like "bootp",
1877 "rarpboot", "tftpboot" or "diskboot"
1879 loads_echo - see CONFIG_LOADS_ECHO
1881 serverip - TFTP server IP address; needed for tftpboot command
1883 bootretry - see CONFIG_BOOT_RETRY_TIME
1885 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
1887 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
1890 The following environment variables may be used and automatically
1891 updated by the network boot commands ("bootp" and "rarpboot"),
1892 depending the information provided by your boot server:
1894 bootfile - see above
1895 dnsip - IP address of your Domain Name Server
1896 gatewayip - IP address of the Gateway (Router) to use
1897 hostname - Target hostname
1899 netmask - Subnet Mask
1900 rootpath - Pathname of the root filesystem on the NFS server
1901 serverip - see above
1904 There are two special Environment Variables:
1906 serial# - contains hardware identification information such
1907 as type string and/or serial number
1908 ethaddr - Ethernet address
1910 These variables can be set only once (usually during manufacturing of
1911 the board). U-Boot refuses to delete or overwrite these variables
1912 once they have been set once.
1915 Please note that changes to some configuration parameters may take
1916 only effect after the next boot (yes, that's just like Windoze :-).
1919 Note for Redundant Ethernet Interfaces:
1920 =======================================
1922 Some boards come with redundand ethernet interfaces; U-Boot supports
1923 such configurations and is capable of automatic selection of a
1924 "working" interface when needed. MAC assignemnt works as follows:
1926 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
1927 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
1928 "eth1addr" (=>eth1), "eth2addr", ...
1930 If the network interface stores some valid MAC address (for instance
1931 in SROM), this is used as default address if there is NO correspon-
1932 ding setting in the environment; if the corresponding environment
1933 variable is set, this overrides the settings in the card; that means:
1935 o If the SROM has a valid MAC address, and there is no address in the
1936 environment, the SROM's address is used.
1938 o If there is no valid address in the SROM, and a definition in the
1939 environment exists, then the value from the environment variable is
1942 o If both the SROM and the environment contain a MAC address, and
1943 both addresses are the same, this MAC address is used.
1945 o If both the SROM and the environment contain a MAC address, and the
1946 addresses differ, the value from the environment is used and a
1949 o If neither SROM nor the environment contain a MAC address, an error
1957 The "boot" commands of this monitor operate on "image" files which
1958 can be basicly anything, preceeded by a special header; see the
1959 definitions in include/image.h for details; basicly, the header
1960 defines the following image properties:
1962 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
1963 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
1965 Currently supported: Linux, NetBSD, VxWorks, QNX).
1966 * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
1967 IA64, MIPS, MIPS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
1968 Currently supported: PowerPC).
1969 * Compression Type (Provisions for uncompressed, gzip, bzip2;
1970 Currently supported: uncompressed, gzip).
1976 The header is marked by a special Magic Number, and both the header
1977 and the data portions of the image are secured against corruption by
1984 Although U-Boot should support any OS or standalone application
1985 easily, Linux has always been in the focus during the design of
1988 U-Boot includes many features that so far have been part of some
1989 special "boot loader" code within the Linux kernel. Also, any
1990 "initrd" images to be used are no longer part of one big Linux image;
1991 instead, kernel and "initrd" are separate images. This implementation
1992 serves serveral purposes:
1994 - the same features can be used for other OS or standalone
1995 applications (for instance: using compressed images to reduce the
1996 Flash memory footprint)
1998 - it becomes much easier to port new Linux kernel versions because
1999 lots of low-level, hardware dependend stuff are done by U-Boot
2001 - the same Linux kernel image can now be used with different "initrd"
2002 images; of course this also means that different kernel images can
2003 be run with the same "initrd". This makes testing easier (you don't
2004 have to build a new "zImage.initrd" Linux image when you just
2005 change a file in your "initrd"). Also, a field-upgrade of the
2006 software is easier now.
2012 Porting Linux to U-Boot based systems:
2013 ---------------------------------------
2015 U-Boot cannot save you from doing all the necessary modifications to
2016 configure the Linux device drivers for use with your target hardware
2017 (no, we don't intend to provide a full virtual machine interface to
2020 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
2022 Just make sure your machine specific header file (for instance
2023 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
2024 Information structure as we define in include/u-boot.h, and make
2025 sure that your definition of IMAP_ADDR uses the same value as your
2026 U-Boot configuration in CFG_IMMR.
2029 Configuring the Linux kernel:
2030 -----------------------------
2032 No specific requirements for U-Boot. Make sure you have some root
2033 device (initial ramdisk, NFS) for your target system.
2036 Building a Linux Image:
2037 -----------------------
2039 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2040 not used. If you use recent kernel source, a new build target
2041 "uImage" will exist which automatically builds an image usable by
2042 U-Boot. Most older kernels also have support for a "pImage" target,
2043 which was introduced for our predecessor project PPCBoot and uses a
2044 100% compatible format.
2053 The "uImage" build target uses a special tool (in 'tools/mkimage') to
2054 encapsulate a compressed Linux kernel image with header information,
2055 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
2057 * build a standard "vmlinux" kernel image (in ELF binary format):
2059 * convert the kernel into a raw binary image:
2061 ${CROSS_COMPILE}-objcopy -O binary \
2062 -R .note -R .comment \
2063 -S vmlinux linux.bin
2065 * compress the binary image:
2069 * package compressed binary image for U-Boot:
2071 mkimage -A ppc -O linux -T kernel -C gzip \
2072 -a 0 -e 0 -n "Linux Kernel Image" \
2073 -d linux.bin.gz uImage
2076 The "mkimage" tool can also be used to create ramdisk images for use
2077 with U-Boot, either separated from the Linux kernel image, or
2078 combined into one file. "mkimage" encapsulates the images with a 64
2079 byte header containing information about target architecture,
2080 operating system, image type, compression method, entry points, time
2081 stamp, CRC32 checksums, etc.
2083 "mkimage" can be called in two ways: to verify existing images and
2084 print the header information, or to build new images.
2086 In the first form (with "-l" option) mkimage lists the information
2087 contained in the header of an existing U-Boot image; this includes
2088 checksum verification:
2090 tools/mkimage -l image
2091 -l ==> list image header information
2093 The second form (with "-d" option) is used to build a U-Boot image
2094 from a "data file" which is used as image payload:
2096 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2097 -n name -d data_file image
2098 -A ==> set architecture to 'arch'
2099 -O ==> set operating system to 'os'
2100 -T ==> set image type to 'type'
2101 -C ==> set compression type 'comp'
2102 -a ==> set load address to 'addr' (hex)
2103 -e ==> set entry point to 'ep' (hex)
2104 -n ==> set image name to 'name'
2105 -d ==> use image data from 'datafile'
2107 Right now, all Linux kernels use the same load address (0x00000000),
2108 but the entry point address depends on the kernel version:
2110 - 2.2.x kernels have the entry point at 0x0000000C,
2111 - 2.3.x and later kernels have the entry point at 0x00000000.
2113 So a typical call to build a U-Boot image would read:
2115 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2116 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
2117 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
2118 > examples/uImage.TQM850L
2119 Image Name: 2.4.4 kernel for TQM850L
2120 Created: Wed Jul 19 02:34:59 2000
2121 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2122 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2123 Load Address: 0x00000000
2124 Entry Point: 0x00000000
2126 To verify the contents of the image (or check for corruption):
2128 -> tools/mkimage -l examples/uImage.TQM850L
2129 Image Name: 2.4.4 kernel for TQM850L
2130 Created: Wed Jul 19 02:34:59 2000
2131 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2132 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2133 Load Address: 0x00000000
2134 Entry Point: 0x00000000
2136 NOTE: for embedded systems where boot time is critical you can trade
2137 speed for memory and install an UNCOMPRESSED image instead: this
2138 needs more space in Flash, but boots much faster since it does not
2139 need to be uncompressed:
2141 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
2142 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2143 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
2144 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
2145 > examples/uImage.TQM850L-uncompressed
2146 Image Name: 2.4.4 kernel for TQM850L
2147 Created: Wed Jul 19 02:34:59 2000
2148 Image Type: PowerPC Linux Kernel Image (uncompressed)
2149 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
2150 Load Address: 0x00000000
2151 Entry Point: 0x00000000
2154 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2155 when your kernel is intended to use an initial ramdisk:
2157 -> tools/mkimage -n 'Simple Ramdisk Image' \
2158 > -A ppc -O linux -T ramdisk -C gzip \
2159 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2160 Image Name: Simple Ramdisk Image
2161 Created: Wed Jan 12 14:01:50 2000
2162 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2163 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
2164 Load Address: 0x00000000
2165 Entry Point: 0x00000000
2168 Installing a Linux Image:
2169 -------------------------
2171 To downloading a U-Boot image over the serial (console) interface,
2172 you must convert the image to S-Record format:
2174 objcopy -I binary -O srec examples/image examples/image.srec
2176 The 'objcopy' does not understand the information in the U-Boot
2177 image header, so the resulting S-Record file will be relative to
2178 address 0x00000000. To load it to a given address, you need to
2179 specify the target address as 'offset' parameter with the 'loads'
2182 Example: install the image to address 0x40100000 (which on the
2183 TQM8xxL is in the first Flash bank):
2185 => erase 40100000 401FFFFF
2191 ## Ready for S-Record download ...
2192 ~>examples/image.srec
2193 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2195 15989 15990 15991 15992
2196 [file transfer complete]
2198 ## Start Addr = 0x00000000
2201 You can check the success of the download using the 'iminfo' command;
2202 this includes a checksum verification so you can be sure no data
2203 corruption happened:
2207 ## Checking Image at 40100000 ...
2208 Image Name: 2.2.13 for initrd on TQM850L
2209 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2210 Data Size: 335725 Bytes = 327 kB = 0 MB
2211 Load Address: 00000000
2212 Entry Point: 0000000c
2213 Verifying Checksum ... OK
2220 The "bootm" command is used to boot an application that is stored in
2221 memory (RAM or Flash). In case of a Linux kernel image, the contents
2222 of the "bootargs" environment variable is passed to the kernel as
2223 parameters. You can check and modify this variable using the
2224 "printenv" and "setenv" commands:
2227 => printenv bootargs
2228 bootargs=root=/dev/ram
2230 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2232 => printenv bootargs
2233 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2236 ## Booting Linux kernel at 40020000 ...
2237 Image Name: 2.2.13 for NFS on TQM850L
2238 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2239 Data Size: 381681 Bytes = 372 kB = 0 MB
2240 Load Address: 00000000
2241 Entry Point: 0000000c
2242 Verifying Checksum ... OK
2243 Uncompressing Kernel Image ... OK
2244 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
2245 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2246 time_init: decrementer frequency = 187500000/60
2247 Calibrating delay loop... 49.77 BogoMIPS
2248 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2251 If you want to boot a Linux kernel with initial ram disk, you pass
2252 the memory addreses of both the kernel and the initrd image (PPBCOOT
2253 format!) to the "bootm" command:
2255 => imi 40100000 40200000
2257 ## Checking Image at 40100000 ...
2258 Image Name: 2.2.13 for initrd on TQM850L
2259 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2260 Data Size: 335725 Bytes = 327 kB = 0 MB
2261 Load Address: 00000000
2262 Entry Point: 0000000c
2263 Verifying Checksum ... OK
2265 ## Checking Image at 40200000 ...
2266 Image Name: Simple Ramdisk Image
2267 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2268 Data Size: 566530 Bytes = 553 kB = 0 MB
2269 Load Address: 00000000
2270 Entry Point: 00000000
2271 Verifying Checksum ... OK
2273 => bootm 40100000 40200000
2274 ## Booting Linux kernel at 40100000 ...
2275 Image Name: 2.2.13 for initrd on TQM850L
2276 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2277 Data Size: 335725 Bytes = 327 kB = 0 MB
2278 Load Address: 00000000
2279 Entry Point: 0000000c
2280 Verifying Checksum ... OK
2281 Uncompressing Kernel Image ... OK
2282 ## Loading RAMDisk Image at 40200000 ...
2283 Image Name: Simple Ramdisk Image
2284 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2285 Data Size: 566530 Bytes = 553 kB = 0 MB
2286 Load Address: 00000000
2287 Entry Point: 00000000
2288 Verifying Checksum ... OK
2289 Loading Ramdisk ... OK
2290 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
2291 Boot arguments: root=/dev/ram
2292 time_init: decrementer frequency = 187500000/60
2293 Calibrating delay loop... 49.77 BogoMIPS
2295 RAMDISK: Compressed image found at block 0
2296 VFS: Mounted root (ext2 filesystem).
2304 One of the features of U-Boot is that you can dynamically load and
2305 run "standalone" applications, which can use some resources of
2306 U-Boot like console I/O functions or interrupt services.
2308 Two simple examples are included with the sources:
2313 'examples/hello_world.c' contains a small "Hello World" Demo
2314 application; it is automatically compiled when you build U-Boot.
2315 It's configured to run at address 0x00040004, so you can play with it
2319 ## Ready for S-Record download ...
2320 ~>examples/hello_world.srec
2321 1 2 3 4 5 6 7 8 9 10 11 ...
2322 [file transfer complete]
2324 ## Start Addr = 0x00040004
2326 => go 40004 Hello World! This is a test.
2327 ## Starting application at 0x00040004 ...
2338 Hit any key to exit ...
2340 ## Application terminated, rc = 0x0
2342 Another example, which demonstrates how to register a CPM interrupt
2343 handler with the U-Boot code, can be found in 'examples/timer.c'.
2344 Here, a CPM timer is set up to generate an interrupt every second.
2345 The interrupt service routine is trivial, just printing a '.'
2346 character, but this is just a demo program. The application can be
2347 controlled by the following keys:
2349 ? - print current values og the CPM Timer registers
2350 b - enable interrupts and start timer
2351 e - stop timer and disable interrupts
2352 q - quit application
2355 ## Ready for S-Record download ...
2356 ~>examples/timer.srec
2357 1 2 3 4 5 6 7 8 9 10 11 ...
2358 [file transfer complete]
2360 ## Start Addr = 0x00040004
2363 ## Starting application at 0x00040004 ...
2366 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
2369 [q, b, e, ?] Set interval 1000000 us
2372 [q, b, e, ?] ........
2373 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
2376 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
2379 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
2382 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
2384 [q, b, e, ?] ...Stopping timer
2386 [q, b, e, ?] ## Application terminated, rc = 0x0
2392 Starting at version 0.9.2, U-Boot supports NetBSD both as host
2393 (build U-Boot) and target system (boots NetBSD/mpc8xx).
2395 Building requires a cross environment; it is known to work on
2396 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
2397 need gmake since the Makefiles are not compatible with BSD make).
2398 Note that the cross-powerpc package does not install include files;
2399 attempting to build U-Boot will fail because <machine/ansi.h> is
2400 missing. This file has to be installed and patched manually:
2402 # cd /usr/pkg/cross/powerpc-netbsd/include
2404 # ln -s powerpc machine
2405 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
2406 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
2408 Native builds *don't* work due to incompatibilities between native
2409 and U-Boot include files.
2411 Booting assumes that (the first part of) the image booted is a
2412 stage-2 loader which in turn loads and then invokes the kernel
2413 proper. Loader sources will eventually appear in the NetBSD source
2414 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
2415 meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for
2419 Implementation Internals:
2420 =========================
2422 The following is not intended to be a complete description of every
2423 implementation detail. However, it should help to understand the
2424 inner workings of U-Boot and make it easier to port it to custom
2428 Initial Stack, Global Data:
2429 ---------------------------
2431 The implementation of U-Boot is complicated by the fact that U-Boot
2432 starts running out of ROM (flash memory), usually without access to
2433 system RAM (because the memory controller is not initialized yet).
2434 This means that we don't have writable Data or BSS segments, and BSS
2435 is not initialized as zero. To be able to get a C environment working
2436 at all, we have to allocate at least a minimal stack. Implementation
2437 options for this are defined and restricted by the CPU used: Some CPU
2438 models provide on-chip memory (like the IMMR area on MPC8xx and
2439 MPC826x processors), on others (parts of) the data cache can be
2440 locked as (mis-) used as memory, etc.
2442 It is essential to remember this, since it has some impact on the C
2443 code for the initialization procedures:
2445 * Initialized global data (data segment) is read-only. Do not attempt
2448 * Do not use any unitialized global data (or implicitely initialized
2449 as zero data - BSS segment) at all - this is undefined, initiali-
2450 zation is performed later (when relocationg to RAM).
2452 * Stack space is very limited. Avoid big data buffers or things like
2455 Having only the stack as writable memory limits means we cannot use
2456 normal global data to share information beween the code. But it
2457 turned out that the implementation of U-Boot can be greatly
2458 simplified by making a global data structure (gd_t) available to all
2459 functions. We could pass a pointer to this data as argument to _all_
2460 functions, but this would bloat the code. Instead we use a feature of
2461 the GCC compiler (Global Register Variables) to share the data: we
2462 place a pointer (gd) to the global data into a register which we
2463 reserve for this purpose.
2465 When chosing a register for such a purpose we are restricted by the
2466 relevant (E)ABI specifications for the current architecture, and by
2467 GCC's implementation.
2469 For PowerPC, the following registers have specific use:
2472 R3-R4: parameter passing and return values
2473 R5-R10: parameter passing
2474 R13: small data area pointer
2478 (U-Boot also uses R14 as internal GOT pointer.)
2480 ==> U-Boot will use R29 to hold a pointer to the global data
2482 Note: on PPC, we could use a static initializer (since the
2483 address of the global data structure is known at compile time),
2484 but it turned out that reserving a register results in somewhat
2485 smaller code - although the code savings are not that big (on
2486 average for all boards 752 bytes for the whole U-Boot image,
2487 624 text + 127 data).
2489 On ARM, the following registers are used:
2491 R0: function argument word/integer result
2492 R1-R3: function argument word
2494 R10: stack limit (used only if stack checking if enabled)
2495 R11: argument (frame) pointer
2496 R12: temporary workspace
2499 R15: program counter
2501 ==> U-Boot will use R8 to hold a pointer to the global data
2508 U-Boot runs in system state and uses physical addresses, i.e. the
2509 MMU is not used either for address mapping nor for memory protection.
2511 The available memory is mapped to fixed addresses using the memory
2512 controller. In this process, a contiguous block is formed for each
2513 memory type (Flash, SDRAM, SRAM), even when it consists of several
2514 physical memory banks.
2516 U-Boot is installed in the first 128 kB of the first Flash bank (on
2517 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
2518 booting and sizing and initializing DRAM, the code relocates itself
2519 to the upper end of DRAM. Immediately below the U-Boot code some
2520 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
2521 configuration setting]. Below that, a structure with global Board
2522 Info data is placed, followed by the stack (growing downward).
2524 Additionally, some exception handler code is copied to the low 8 kB
2525 of DRAM (0x00000000 ... 0x00001FFF).
2527 So a typical memory configuration with 16 MB of DRAM could look like
2530 0x0000 0000 Exception Vector code
2533 0x0000 2000 Free for Application Use
2539 0x00FB FF20 Monitor Stack (Growing downward)
2540 0x00FB FFAC Board Info Data and permanent copy of global data
2541 0x00FC 0000 Malloc Arena
2544 0x00FE 0000 RAM Copy of Monitor Code
2545 ... eventually: LCD or video framebuffer
2546 ... eventually: pRAM (Protected RAM - unchanged by reset)
2547 0x00FF FFFF [End of RAM]
2550 System Initialization:
2551 ----------------------
2553 In the reset configuration, U-Boot starts at the reset entry point
2554 (on most PowerPC systens at address 0x00000100). Because of the reset
2555 configuration for CS0# this is a mirror of the onboard Flash memory.
2556 To be able to re-map memory U-Boot then jumps to it's link address.
2557 To be able to implement the initialization code in C, a (small!)
2558 initial stack is set up in the internal Dual Ported RAM (in case CPUs
2559 which provide such a feature like MPC8xx or MPC8260), or in a locked
2560 part of the data cache. After that, U-Boot initializes the CPU core,
2561 the caches and the SIU.
2563 Next, all (potentially) available memory banks are mapped using a
2564 preliminary mapping. For example, we put them on 512 MB boundaries
2565 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
2566 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
2567 programmed for SDRAM access. Using the temporary configuration, a
2568 simple memory test is run that determines the size of the SDRAM
2571 When there is more than one SDRAM bank, and the banks are of
2572 different size, the larger is mapped first. For equal size, the first
2573 bank (CS2#) is mapped first. The first mapping is always for address
2574 0x00000000, with any additional banks following immediately to create
2575 contiguous memory starting from 0.
2577 Then, the monitor installs itself at the upper end of the SDRAM area
2578 and allocates memory for use by malloc() and for the global Board
2579 Info data; also, the exception vector code is copied to the low RAM
2580 pages, and the final stack is set up.
2582 Only after this relocation will you have a "normal" C environment;
2583 until that you are restricted in several ways, mostly because you are
2584 running from ROM, and because the code will have to be relocated to a
2588 U-Boot Porting Guide:
2589 ----------------------
2591 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
2595 int main (int argc, char *argv[])
2597 sighandler_t no_more_time;
2599 signal (SIGALRM, no_more_time);
2600 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
2602 if (available_money > available_manpower) {
2603 pay consultant to port U-Boot;
2607 Download latest U-Boot source;
2610 email ("Hi, I am new to U-Boot, how do I get started?");
2614 Read the README file in the top level directory;
2615 Read http://www.denx.de/re/DPLG.html
2616 Read the source, Luke;
2619 if (available_money > toLocalCurrency ($2500)) {
2622 Add a lot of aggravation and time;
2625 Create your own board support subdirectory;
2629 Add / modify source code;
2633 email ("Hi, I am having problems...");
2635 Send patch file to Wolfgang;
2640 void no_more_time (int sig)
2650 All contributions to U-Boot should conform to the Linux kernel
2651 coding style; see the file "Documentation/CodingStyle" in your Linux
2652 kernel source directory.
2654 Please note that U-Boot is implemented in C (and to some small parts
2655 in Assembler); no C++ is used, so please do not use C++ style
2656 comments (//) in your code.
2658 Submissions which do not conform to the standards may be returned
2659 with a request to reformat the changes.
2665 Since the number of patches for U-Boot is growing, we need to
2666 establish some rules. Submissions which do not conform to these rules
2667 may be rejected, even when they contain important and valuable stuff.
2670 When you send a patch, please include the following information with
2673 * For bug fixes: a description of the bug and how your patch fixes
2674 this bug. Please try to include a way of demonstrating that the
2675 patch actually fixes something.
2677 * For new features: a description of the feature and your
2680 * A CHANGELOG entry as plaintext (separate from the patch)
2682 * For major contributions, your entry to the CREDITS file
2684 * When you add support for a new board, don't forget to add this
2685 board to the MAKEALL script, too.
2687 * If your patch adds new configuration options, don't forget to
2688 document these in the README file.
2690 * The patch itself. If you are accessing the CVS repository use "cvs
2691 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
2692 version of diff does not support these options, then get the latest
2693 version of GNU diff.
2695 We accept patches as plain text, MIME attachments or as uuencoded
2700 * Before sending the patch, run the MAKEALL script on your patched
2701 source tree and make sure that no errors or warnings are reported
2702 for any of the boards.
2704 * Keep your modifications to the necessary minimum: A patch
2705 containing several unrelated changes or arbitrary reformats will be
2706 returned with a request to re-formatting / split it.
2708 * If you modify existing code, make sure that your new code does not
2709 add to the memory footprint of the code ;-) Small is beautiful!
2710 When adding new features, these should compile conditionally only
2711 (using #ifdef), and the resulting code with the new feature
2712 disabled must not need more memory than the old code without your
projects / karo-tx-uboot.git / blob