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 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_FLASH flinfo, erase, protect
540 CFG_CMD_FPGA FPGA device initialization support
541 CFG_CMD_I2C * I2C serial bus support
542 CFG_CMD_IDE * IDE harddisk support
544 CFG_CMD_IMMAP * IMMR dump support
545 CFG_CMD_IRQ * irqinfo
549 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
551 CFG_CMD_MII MII utility commands
552 CFG_CMD_NET bootp, tftpboot, rarpboot
553 CFG_CMD_PCI * pciinfo
554 CFG_CMD_PCMCIA * PCMCIA support
555 CFG_CMD_REGINFO * Register dump
556 CFG_CMD_RUN run command in env variable
557 CFG_CMD_SCSI * SCSI Support
558 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
559 CFG_CMD_SPI * SPI serial bus support
560 CFG_CMD_USB * USB support
561 CFG_CMD_BSP * Board SPecific functions
562 -----------------------------------------------
565 CFG_CMD_DFL Default configuration; at the moment
566 this is includes all commands, except
567 the ones marked with "*" in the list
570 If you don't define CONFIG_COMMANDS it defaults to
571 CFG_CMD_DFL in include/cmd_confdefs.h. A board can
572 override the default settings in the respective
575 EXAMPLE: If you want all functions except of network
576 support you can write:
578 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
581 Note: Don't enable the "icache" and "dcache" commands
582 (configuration option CFG_CMD_CACHE) unless you know
583 what you (and your U-Boot users) are doing. Data
584 cache cannot be enabled on systems like the 8xx or
585 8260 (where accesses to the IMMR region must be
586 uncached), and it cannot be disabled on all other
587 systems where we (mis-) use the data cache to hold an
588 initial stack and some data.
591 XXX - this list needs to get updated!
595 If this variable is defined, it enables watchdog
596 support. There must support in the platform specific
597 code for a watchdog. For the 8xx and 8260 CPUs, the
598 SIU Watchdog feature is enabled in the SYPCR
603 When CFG_CMD_DATE is selected, the type of the RTC
604 has to be selected, too. Define exactly one of the
607 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
608 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
609 CONFIG_RTC_MC146818 - use MC146818 RTC
610 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
614 When CONFIG_TIMESTAMP is selected, the timestamp
615 (date and time) of an image is printed by image
616 commands like bootm or iminfo. This option is
617 automatically enabled when you select CFG_CMD_DATE .
620 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
621 and/or CONFIG_ISO_PARTITION
623 If IDE or SCSI support is enabled (CFG_CMD_IDE or
624 CFG_CMD_SCSI) you must configure support for at least
625 one partition type as well.
628 CONFIG_IDE_RESET_ROUTINE
630 Set this to define that instead of a reset Pin, the
631 routine ide_set_reset(int idereset) will be used.
636 Set this to enable ATAPI support.
639 At the moment only there is only support for the
640 SYM53C8XX SCSI controller; define
641 CONFIG_SCSI_SYM53C8XX to enable it.
643 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
644 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
645 CFG_SCSI_MAX_LUN] can be adjusted to define the
646 maximum numbers of LUNs, SCSI ID's and target
648 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
650 - NETWORK Support (PCI):
652 Support for Intel 82557/82559/82559ER chips.
653 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
654 write routine for first time initialisation.
657 Support for Digital 2114x chips.
658 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
659 modem chip initialisation (KS8761/QS6611).
662 Support for National dp83815 chips.
665 Support for National dp8382[01] gigabit chips.
668 At the moment only the UHCI host controller is
669 supported (PIP405, MIP405); define
670 CONFIG_USB_UHCI to enable it.
671 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
672 end define CONFIG_USB_STORAGE to enable the USB
675 Supported are USB Keyboards and USB Floppy drives
681 Define this to enable standard (PC-Style) keyboard
685 Standard PC keyboard driver with US (is default) and
686 GERMAN key layout (switch via environment 'keymap=de') support.
687 Export function i8042_kbd_init, i8042_tstc and i8042_getc
688 for cfb_console. Supports cursor blinking.
693 Define this to enable video support (for output to
698 Enable Chips & Technologies 69000 Video chip
700 CONFIG_VIDEO_SMI_LYNXEM
701 Enable Silicon Motion SMI 712/710/810 Video chip
702 Videomode are selected via environment 'videomode' with
703 standard LiLo mode numbers.
704 Following modes are supported (* is default):
706 800x600 1024x768 1280x1024
707 256 (8bit) 303* 305 307
708 65536 (16bit) 314 317 31a
709 16,7 Mill (24bit) 315 318 31b
710 (i.e. setenv videomode 317; saveenv; reset;)
712 - LCD Support: CONFIG_LCD
714 Define this to enable LCD support (for output to LCD
715 display); also select one of the supported displays
716 by defining one of these:
718 CONFIG_NEC_NL6648AC33:
720 NEC NL6648AC33-18. Active, color, single scan.
722 CONFIG_NEC_NL6648BC20
724 NEC NL6648BC20-08. 6.5", 640x480.
725 Active, color, single scan.
729 Sharp 320x240. Active, color, single scan.
730 It isn't 16x9, and I am not sure what it is.
732 CONFIG_SHARP_LQ64D341
734 Sharp LQ64D341 display, 640x480.
735 Active, color, single scan.
739 HLD1045 display, 640x480.
740 Active, color, single scan.
744 Optrex CBL50840-2 NF-FW 99 22 M5
746 Hitachi LMG6912RPFC-00T
750 320x240. Black & white.
752 Normally display is black on white background; define
753 CFG_WHITE_ON_BLACK to get it inverted.
760 Define a default value for ethernet address to use
761 for the respective ethernet interface, in case this
762 is not determined automatically.
767 Define a default value for the IP address to use for
768 the default ethernet interface, in case this is not
769 determined through e.g. bootp.
774 Defines a default value for theIP address of a TFTP
775 server to contact when using the "tftboot" command.
777 - BOOTP Recovery Mode:
778 CONFIG_BOOTP_RANDOM_DELAY
780 If you have many targets in a network that try to
781 boot using BOOTP, you may want to avoid that all
782 systems send out BOOTP requests at precisely the same
783 moment (which would happen for instance at recovery
784 from a power failure, when all systems will try to
785 boot, thus flooding the BOOTP server. Defining
786 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
787 inserted before sending out BOOTP requests. The
788 following delays are insterted then:
790 1st BOOTP request: delay 0 ... 1 sec
791 2nd BOOTP request: delay 0 ... 2 sec
792 3rd BOOTP request: delay 0 ... 4 sec
794 BOOTP requests: delay 0 ... 8 sec
796 - Status LED: CONFIG_STATUS_LED
798 Several configurations allow to display the current
799 status using a LED. For instance, the LED will blink
800 fast while running U-Boot code, stop blinking as
801 soon as a reply to a BOOTP request was received, and
802 start blinking slow once the Linux kernel is running
803 (supported by a status LED driver in the Linux
804 kernel). Defining CONFIG_STATUS_LED enables this
807 - CAN Support: CONFIG_CAN_DRIVER
809 Defining CONFIG_CAN_DRIVER enables CAN driver support
810 on those systems that support this (optional)
811 feature, like the TQM8xxL modules.
813 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
815 Enables I2C serial bus commands. If this is selected,
816 either CONFIG_HARD_I2C or CONFIG_SOFT_I2C must be defined
817 to include the appropriate I2C driver.
819 See also: common/cmd_i2c.c for a description of the
820 command line interface.
825 Selects the CPM hardware driver for I2C.
829 Use software (aka bit-banging) driver instead of CPM
830 or similar hardware support for I2C. This is configured
831 via the following defines.
835 (Optional). Any commands necessary to enable I2C
836 controller or configure ports.
840 (Only for MPC8260 CPU). The I/O port to use (the code
841 assumes both bits are on the same port). Valid values
842 are 0..3 for ports A..D.
846 The code necessary to make the I2C data line active
847 (driven). If the data line is open collector, this
852 The code necessary to make the I2C data line tri-stated
853 (inactive). If the data line is open collector, this
858 Code that returns TRUE if the I2C data line is high,
863 If <bit> is TRUE, sets the I2C data line high. If it
864 is FALSE, it clears it (low).
868 If <bit> is TRUE, sets the I2C clock line high. If it
869 is FALSE, it clears it (low).
873 This delay is invoked four times per clock cycle so this
874 controls the rate of data transfer. The data rate thus
875 is 1 / (I2C_DELAY * 4).
877 - SPI Support: CONFIG_SPI
879 Enables SPI driver (so far only tested with
880 SPI EEPROM, also an instance works with Crystal A/D and
881 D/As on the SACSng board)
885 Enables extended (16-bit) SPI EEPROM addressing.
886 (symmetrical to CONFIG_I2C_X)
890 Enables a software (bit-bang) SPI driver rather than
891 using hardware support. This is a general purpose
892 driver that only requires three general I/O port pins
893 (two outputs, one input) to function. If this is
894 defined, the board configuration must define several
895 SPI configuration items (port pins to use, etc). For
896 an example, see include/configs/sacsng.h.
898 - FPGA Support: CONFIG_FPGA_COUNT
900 Specify the number of FPGA devices to support.
904 Used to specify the types of FPGA devices. For
906 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
908 CFG_FPGA_PROG_FEEDBACK
910 Enable printing of hash marks during FPGA
915 Enable checks on FPGA configuration interface busy
916 status by the configuration function. This option
917 will require a board or device specific function to
922 If defined, a function that provides delays in the
923 FPGA configuration driver.
927 Allow Control-C to interrupt FPGA configuration
931 Check for configuration errors during FPGA bitfile
932 loading. For example, abort during Virtex II
933 configuration if the INIT_B line goes low (which
934 indicated a CRC error).
938 Maximum time to wait for the INIT_B line to deassert
939 after PROB_B has been deasserted during a Virtex II
940 FPGA configuration sequence. The default time is 500 mS.
944 Maximum time to wait for BUSY to deassert during
945 Virtex II FPGA configuration. The default is 5 mS.
949 Time to wait after FPGA configuration. The default is
952 - FPGA Support: CONFIG_FPGA_COUNT
954 Specify the number of FPGA devices to support.
958 Used to specify the types of FPGA devices. For example,
959 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
961 CFG_FPGA_PROG_FEEDBACK
963 Enable printing of hash marks during FPGA configuration.
967 Enable checks on FPGA configuration interface busy
968 status by the configuration function. This option
969 will require a board or device specific function to
974 If defined, a function that provides delays in the FPGA
975 configuration driver.
978 Allow Control-C to interrupt FPGA configuration
982 Check for configuration errors during FPGA bitfile
983 loading. For example, abort during Virtex II
984 configuration if the INIT_B line goes low (which
985 indicated a CRC error).
989 Maximum time to wait for the INIT_B line to deassert
990 after PROB_B has been deasserted during a Virtex II
991 FPGA configuration sequence. The default time is 500
996 Maximum time to wait for BUSY to deassert during
997 Virtex II FPGA configuration. The default is 5 mS.
1001 Time to wait after FPGA configuration. The default is
1004 - Configuration Management:
1007 If defined, this string will be added to the U-Boot
1008 version information (U_BOOT_VERSION)
1010 - Vendor Parameter Protection:
1012 U-Boot considers the values of the environment
1013 variables "serial#" (Board Serial Number) and
1014 "ethaddr" (Ethernet Address) to bb parameters that
1015 are set once by the board vendor / manufacturer, and
1016 protects these variables from casual modification by
1017 the user. Once set, these variables are read-only,
1018 and write or delete attempts are rejected. You can
1019 change this behviour:
1021 If CONFIG_ENV_OVERWRITE is #defined in your config
1022 file, the write protection for vendor parameters is
1023 completely disabled. Anybody can change or delte
1026 Alternatively, if you #define _both_ CONFIG_ETHADDR
1027 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1028 ethernet address is installed in the environment,
1029 which can be changed exactly ONCE by the user. [The
1030 serial# is unaffected by this, i. e. it remains
1036 Define this variable to enable the reservation of
1037 "protected RAM", i. e. RAM which is not overwritten
1038 by U-Boot. Define CONFIG_PRAM to hold the number of
1039 kB you want to reserve for pRAM. You can overwrite
1040 this default value by defining an environment
1041 variable "pram" to the number of kB you want to
1042 reserve. Note that the board info structure will
1043 still show the full amount of RAM. If pRAM is
1044 reserved, a new environment variable "mem" will
1045 automatically be defined to hold the amount of
1046 remaining RAM in a form that can be passed as boot
1047 argument to Linux, for instance like that:
1049 setenv bootargs ... mem=\$(mem)
1052 This way you can tell Linux not to use this memory,
1053 either, which results in a memory region that will
1054 not be affected by reboots.
1056 *WARNING* If your board configuration uses automatic
1057 detection of the RAM size, you must make sure that
1058 this memory test is non-destructive. So far, the
1059 following board configurations are known to be
1062 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1063 HERMES, IP860, RPXlite, LWMON, LANTEC,
1064 PCU_E, FLAGADM, TQM8260
1069 Define this variable to stop the system in case of a
1070 fatal error, so that you have to reset it manually.
1071 This is probably NOT a good idea for an embedded
1072 system where you want to system to reboot
1073 automatically as fast as possible, but it may be
1074 useful during development since you can try to debug
1075 the conditions that lead to the situation.
1077 CONFIG_NET_RETRY_COUNT
1079 This variable defines the number of retries for
1080 network operations like ARP, RARP, TFTP, or BOOTP
1081 before giving up the operation. If not defined, a
1082 default value of 5 is used.
1084 - Command Interpreter:
1087 Define this variable to enable the "hush" shell (from
1088 Busybox) as command line interpreter, thus enabling
1089 powerful command line syntax like
1090 if...then...else...fi conditionals or `&&' and '||'
1091 constructs ("shell scripts").
1093 If undefined, you get the old, much simpler behaviour
1094 with a somewhat smaller memory footprint.
1099 This defines the secondary prompt string, which is
1100 printed when the command interpreter needs more input
1101 to complete a command. Usually "> ".
1105 In the current implementation, the local variables
1106 space and global environment variables space are
1107 separated. Local variables are those you define by
1108 simply typing like `name=value'. To access a local
1109 variable later on, you have write `$name' or
1110 `${name}'; variable directly by typing say `$name' at
1113 Global environment variables are those you use
1114 setenv/printenv to work with. To run a command stored
1115 in such a variable, you need to use the run command,
1116 and you must not use the '$' sign to access them.
1118 To store commands and special characters in a
1119 variable, please use double quotation marks
1120 surrounding the whole text of the variable, instead
1121 of the backslashes before semicolons and special
1124 - Default Environment
1125 CONFIG_EXTRA_ENV_SETTINGS
1127 Define this to contain any number of null terminated
1128 strings (variable = value pairs) that will be part of
1129 the default enviroment compiled into the boot image.
1130 For example, place something like this in your
1131 board's config file:
1133 #define CONFIG_EXTRA_ENV_SETTINGS \
1137 Warning: This method is based on knowledge about the
1138 internal format how the environment is stored by the
1139 U-Boot code. This is NOT an official, expoerted
1140 interface! Although it is unlikely that this format
1141 will change soon, there is no guarantee either.
1142 You better know what you are doing here.
1144 Note: overly (ab)use of the default environment is
1145 discouraged. Make sure to check other ways to preset
1146 the environment like the autoscript function or the
1149 - Show boot progress
1150 CONFIG_SHOW_BOOT_PROGRESS
1152 Defining this option allows to add some board-
1153 specific code (calling a user-provided function
1154 "show_boot_progress(int)") that enables you to show
1155 the system's boot progress on some display (for
1156 example, some LED's) on your board. At the moment,
1157 the following checkpoints are implemented:
1160 1 common/cmd_bootm.c before attempting to boot an image
1161 -1 common/cmd_bootm.c Image header has bad magic number
1162 2 common/cmd_bootm.c Image header has correct magic number
1163 -2 common/cmd_bootm.c Image header has bad checksum
1164 3 common/cmd_bootm.c Image header has correct checksum
1165 -3 common/cmd_bootm.c Image data has bad checksum
1166 4 common/cmd_bootm.c Image data has correct checksum
1167 -4 common/cmd_bootm.c Image is for unsupported architecture
1168 5 common/cmd_bootm.c Architecture check OK
1169 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1170 6 common/cmd_bootm.c Image Type check OK
1171 -6 common/cmd_bootm.c gunzip uncompression error
1172 -7 common/cmd_bootm.c Unimplemented compression type
1173 7 common/cmd_bootm.c Uncompression OK
1174 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1175 8 common/cmd_bootm.c Image Type check OK
1176 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1177 9 common/cmd_bootm.c Start initial ramdisk verification
1178 -10 common/cmd_bootm.c Ramdisk header has bad magic number
1179 -11 common/cmd_bootm.c Ramdisk header has bad checksum
1180 10 common/cmd_bootm.c Ramdisk header is OK
1181 -12 common/cmd_bootm.c Ramdisk data has bad checksum
1182 11 common/cmd_bootm.c Ramdisk data has correct checksum
1183 12 common/cmd_bootm.c Ramdisk verification complete, start loading
1184 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk)
1185 13 common/cmd_bootm.c Start multifile image verification
1186 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue.
1187 15 common/cmd_bootm.c All preparation done, transferring control to OS
1189 -1 common/cmd_doc.c Bad usage of "doc" command
1190 -1 common/cmd_doc.c No boot device
1191 -1 common/cmd_doc.c Unknown Chip ID on boot device
1192 -1 common/cmd_doc.c Read Error on boot device
1193 -1 common/cmd_doc.c Image header has bad magic number
1195 -1 common/cmd_ide.c Bad usage of "ide" command
1196 -1 common/cmd_ide.c No boot device
1197 -1 common/cmd_ide.c Unknown boot device
1198 -1 common/cmd_ide.c Unknown partition table
1199 -1 common/cmd_ide.c Invalid partition type
1200 -1 common/cmd_ide.c Read Error on boot device
1201 -1 common/cmd_ide.c Image header has bad magic number
1203 -1 common/cmd_nvedit.c Environment not changable, but has bad CRC
1209 [so far only for SMDK2400 board]
1211 - Modem support endable:
1212 CONFIG_MODEM_SUPPORT
1214 - RTS/CTS Flow control enable:
1217 - Modem debug support:
1218 CONFIG_MODEM_SUPPORT_DEBUG
1220 Enables debugging stuff (char screen[1024], dbg())
1221 for modem support. Useful only with BDI2000.
1225 In the target system modem support is enabled when a
1226 specific key (key combination) is pressed during
1227 power-on. Otherwise U-Boot will boot normally
1228 (autoboot). The key_pressed() fuction is called from
1229 board_init(). Currently key_pressed() is a dummy
1230 function, returning 1 and thus enabling modem
1233 If there are no modem init strings in the
1234 environment, U-Boot proceed to autoboot; the
1235 previous output (banner, info printfs) will be
1238 See also: doc/README.Modem
1243 Configuration Settings:
1244 -----------------------
1246 - CFG_LONGHELP: Defined when you want long help messages included;
1247 undefine this when you're short of memory.
1249 - CFG_PROMPT: This is what U-Boot prints on the console to
1250 prompt for user input.
1252 - CFG_CBSIZE: Buffer size for input from the Console
1254 - CFG_PBSIZE: Buffer size for Console output
1256 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1258 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1259 the application (usually a Linux kernel) when it is
1262 - CFG_BAUDRATE_TABLE:
1263 List of legal baudrate settings for this board.
1265 - CFG_CONSOLE_INFO_QUIET
1266 Suppress display of console information at boot.
1268 - CFG_CONSOLE_IS_IN_ENV
1269 If the board specific function
1270 extern int overwrite_console (void);
1271 returns 1, the stdin, stderr and stdout are switched to the
1272 serial port, else the settings in the environment are used.
1274 - CFG_CONSOLE_OVERWRITE_ROUTINE
1275 Enable the call to overwrite_console().
1277 - CFG_CONSOLE_ENV_OVERWRITE
1278 Enable overwrite of previous console environment settings.
1280 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1281 Begin and End addresses of the area used by the
1285 Enable an alternate, more extensive memory test.
1287 - CFG_TFTP_LOADADDR:
1288 Default load address for network file downloads
1290 - CFG_LOADS_BAUD_CHANGE:
1291 Enable temporary baudrate change while serial download
1294 Physical start address of SDRAM. _Must_ be 0 here.
1297 Physical start address of Motherboard I/O (if using a
1301 Physical start address of Flash memory.
1304 Physical start address of boot monitor code (set by
1305 make config files to be same as the text base address
1306 (TEXT_BASE) used when linking) - same as
1307 CFG_FLASH_BASE when booting from flash.
1310 Size of memory reserved for monitor code
1313 Size of DRAM reserved for malloc() use.
1316 Maximum size of memory mapped by the startup code of
1317 the Linux kernel; all data that must be processed by
1318 the Linux kernel (bd_info, boot arguments, eventually
1319 initrd image) must be put below this limit.
1321 - CFG_MAX_FLASH_BANKS:
1322 Max number of Flash memory banks
1324 - CFG_MAX_FLASH_SECT:
1325 Max number of sectors on a Flash chip
1327 - CFG_FLASH_ERASE_TOUT:
1328 Timeout for Flash erase operations (in ms)
1330 - CFG_FLASH_WRITE_TOUT:
1331 Timeout for Flash write operations (in ms)
1333 - CFG_DIRECT_FLASH_TFTP:
1335 Enable TFTP transfers directly to flash memory;
1336 without this option such a download has to be
1337 performed in two steps: (1) download to RAM, and (2)
1338 copy from RAM to flash.
1340 The two-step approach is usually more reliable, since
1341 you can check if the download worked before you erase
1342 the flash, but in some situations (when sytem RAM is
1343 too limited to allow for a tempory copy of the
1344 downloaded image) this option may be very useful.
1347 Define if the flash driver uses extra elements in the
1348 common flash structure for storing flash geometry
1350 The following definitions that deal with the placement and management
1351 of environment data (variable area); in general, we support the
1352 following configurations:
1354 - CFG_ENV_IS_IN_FLASH:
1356 Define this if the environment is in flash memory.
1358 a) The environment occupies one whole flash sector, which is
1359 "embedded" in the text segment with the U-Boot code. This
1360 happens usually with "bottom boot sector" or "top boot
1361 sector" type flash chips, which have several smaller
1362 sectors at the start or the end. For instance, such a
1363 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
1364 such a case you would place the environment in one of the
1365 4 kB sectors - with U-Boot code before and after it. With
1366 "top boot sector" type flash chips, you would put the
1367 environment in one of the last sectors, leaving a gap
1368 between U-Boot and the environment.
1372 Offset of environment data (variable area) to the
1373 beginning of flash memory; for instance, with bottom boot
1374 type flash chips the second sector can be used: the offset
1375 for this sector is given here.
1377 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
1381 This is just another way to specify the start address of
1382 the flash sector containing the environment (instead of
1385 - CFG_ENV_SECT_SIZE:
1387 Size of the sector containing the environment.
1390 b) Sometimes flash chips have few, equal sized, BIG sectors.
1391 In such a case you don't want to spend a whole sector for
1396 If you use this in combination with CFG_ENV_IS_IN_FLASH
1397 and CFG_ENV_SECT_SIZE, you can specify to use only a part
1398 of this flash sector for the environment. This saves
1399 memory for the RAM copy of the environment.
1401 It may also save flash memory if you decide to use this
1402 when your environment is "embedded" within U-Boot code,
1403 since then the remainder of the flash sector could be used
1404 for U-Boot code. It should be pointed out that this is
1405 STRONGLY DISCOURAGED from a robustness point of view:
1406 updating the environment in flash makes it always
1407 necessary to erase the WHOLE sector. If something goes
1408 wrong before the contents has been restored from a copy in
1409 RAM, your target system will be dead.
1411 - CFG_ENV_ADDR_REDUND
1414 These settings describe a second storage area used to hold
1415 a redundand copy of the environment data, so that there is
1416 a valid backup copy in case there is a power failur during
1417 a "saveenv" operation.
1419 BE CAREFUL! Any changes to the flash layout, and some changes to the
1420 source code will make it necessary to adapt <board>/u-boot.lds*
1424 - CFG_ENV_IS_IN_NVRAM:
1426 Define this if you have some non-volatile memory device
1427 (NVRAM, battery buffered SRAM) which you want to use for the
1433 These two #defines are used to determin the memory area you
1434 want to use for environment. It is assumed that this memory
1435 can just be read and written to, without any special
1438 BE CAREFUL! The first access to the environment happens quite early
1439 in U-Boot initalization (when we try to get the setting of for the
1440 console baudrate). You *MUST* have mappend your NVRAM area then, or
1443 Please note that even with NVRAM we still use a copy of the
1444 environment in RAM: we could work on NVRAM directly, but we want to
1445 keep settings there always unmodified except somebody uses "saveenv"
1446 to save the current settings.
1449 - CFG_ENV_IS_IN_EEPROM:
1451 Use this if you have an EEPROM or similar serial access
1452 device and a driver for it.
1457 These two #defines specify the offset and size of the
1458 environment area within the total memory of your EEPROM.
1460 - CFG_I2C_EEPROM_ADDR:
1461 If defined, specified the chip address of the EEPROM device.
1462 The default address is zero.
1464 - CFG_EEPROM_PAGE_WRITE_BITS:
1465 If defined, the number of bits used to address bytes in a
1466 single page in the EEPROM device. A 64 byte page, for example
1467 would require six bits.
1469 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1470 If defined, the number of milliseconds to delay between
1471 page writes. The default is zero milliseconds.
1473 - CFG_I2C_EEPROM_ADDR_LEN:
1474 The length in bytes of the EEPROM memory array address. Note
1475 that this is NOT the chip address length!
1478 The size in bytes of the EEPROM device.
1480 - CFG_I2C_EEPROM_ADDR:
1481 If defined, specified the chip address of the EEPROM device.
1482 The default address is zero.
1484 - CFG_EEPROM_PAGE_WRITE_BITS:
1485 If defined, the number of bits used to address bytes in a
1486 single page in the EEPROM device. A 64 byte page, for example
1487 would require six bits.
1489 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1490 If defined, the number of milliseconds to delay between
1491 page writes. The default is zero milliseconds.
1493 - CFG_I2C_EEPROM_ADDR_LEN:
1494 The length in bytes of the EEPROM memory array address. Note
1495 that this is NOT the chip address length!
1498 The size in bytes of the EEPROM device.
1500 - CFG_SPI_INIT_OFFSET
1502 Defines offset to the initial SPI buffer area in DPRAM. The
1503 area is used at an early stage (ROM part) if the environment
1504 is configured to reside in the SPI EEPROM: We need a 520 byte
1505 scratch DPRAM area. It is used between the two initialization
1506 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
1507 to be a good choice since it makes it far enough from the
1508 start of the data area as well as from the stack pointer.
1510 Please note that the environment is read-only as long as the monitor
1511 has been relocated to RAM and a RAM copy of the environment has been
1512 created; also, when using EEPROM you will have to use getenv_r()
1513 until then to read environment variables.
1515 The environment is now protected by a CRC32 checksum. Before the
1516 monitor is relocated into RAM, as a result of a bad CRC you will be
1517 working with the compiled-in default environment - *silently*!!!
1518 [This is necessary, because the first environment variable we need is
1519 the "baudrate" setting for the console - if we have a bad CRC, we
1520 don't have any device yet where we could complain.]
1522 Note: once the monitor has been relocated, then it will complain if
1523 the default environment is used; a new CRC is computed as soon as you
1524 use the "setenv" command to modify / delete / add any environment
1525 variable [even when you try to delete a non-existing variable!].
1527 Note2: you must edit your u-boot.lds file to reflect this
1531 Low Level (hardware related) configuration options:
1533 - CFG_CACHELINE_SIZE:
1534 Cache Line Size of the CPU.
1537 Default address of the IMMR after system reset.
1538 Needed on some 8260 systems (MPC8260ADS and RPXsuper)
1539 to be able to adjust the position of the IMMR
1540 register after a reset.
1542 - Floppy Disk Support:
1543 CFG_FDC_DRIVE_NUMBER
1545 the default drive number (default value 0)
1549 defines the spacing between fdc chipset registers
1554 defines the offset of register from address. It
1555 depends on which part of the data bus is connected to
1556 the fdc chipset. (default value 0)
1558 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
1559 CFG_FDC_DRIVE_NUMBER are undefined, they take their
1562 if CFG_FDC_HW_INIT is defined, then the function
1563 fdc_hw_init() is called at the beginning of the FDC
1564 setup. fdc_hw_init() must be provided by the board
1565 source code. It is used to make hardware dependant
1568 - CFG_IMMR: Physical address of the Internal Memory Mapped
1569 Register; DO NOT CHANGE! (11-4)
1570 [MPC8xx systems only]
1572 - CFG_INIT_RAM_ADDR:
1574 Start address of memory area tha can be used for
1575 initial data and stack; please note that this must be
1576 writable memory that is working WITHOUT special
1577 initialization, i. e. you CANNOT use normal RAM which
1578 will become available only after programming the
1579 memory controller and running certain initialization
1582 U-Boot uses the following memory types:
1583 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
1584 - MPC824X: data cache
1585 - PPC4xx: data cache
1587 - CFG_INIT_DATA_OFFSET:
1589 Offset of the initial data structure in the memory
1590 area defined by CFG_INIT_RAM_ADDR. Usually
1591 CFG_INIT_DATA_OFFSET is chosen such that the initial
1592 data is located at the end of the available space
1593 (sometimes written as (CFG_INIT_RAM_END -
1594 CFG_INIT_DATA_SIZE), and the initial stack is just
1595 below that area (growing from (CFG_INIT_RAM_ADDR +
1596 CFG_INIT_DATA_OFFSET) downward.
1599 On the MPC824X (or other systems that use the data
1600 cache for initial memory) the address chosen for
1601 CFG_INIT_RAM_ADDR is basically arbitrary - it must
1602 point to an otherwise UNUSED address space between
1603 the top of RAM and the start of the PCI space.
1605 - CFG_SIUMCR: SIU Module Configuration (11-6)
1607 - CFG_SYPCR: System Protection Control (11-9)
1609 - CFG_TBSCR: Time Base Status and Control (11-26)
1611 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
1613 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
1615 - CFG_SCCR: System Clock and reset Control Register (15-27)
1617 - CFG_OR_TIMING_SDRAM:
1621 periodic timer for refresh
1623 - CFG_DER: Debug Event Register (37-47)
1625 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
1626 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
1627 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
1629 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
1631 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
1632 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
1633 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
1634 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
1636 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
1637 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
1638 Machine Mode Register and Memory Periodic Timer
1639 Prescaler definitions (SDRAM timing)
1641 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
1642 enable I2C microcode relocation patch (MPC8xx);
1643 define relocation offset in DPRAM [DSP2]
1645 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
1646 enable SPI microcode relocation patch (MPC8xx);
1647 define relocation offset in DPRAM [SCC4]
1650 Use OSCM clock mode on MBX8xx board. Be careful,
1651 wrong setting might damage your board. Read
1652 doc/README.MBX before setting this variable!
1654 Building the Software:
1655 ======================
1657 Building U-Boot has been tested in native PPC environments (on a
1658 PowerBook G3 running LinuxPPC 2000) and in cross environments
1659 (running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
1662 If you are not using a native PPC environment, it is assumed that you
1663 have the GNU cross compiling tools available in your path and named
1664 with a prefix of "powerpc-linux-". If this is not the case, (e.g. if
1665 you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
1666 the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
1669 CROSS_COMPILE = ppc_4xx-
1672 U-Boot is intended to be simple to build. After installing the
1673 sources you must configure U-Boot for one specific board type. This
1678 where "NAME_config" is the name of one of the existing
1679 configurations; the following names are supported:
1681 ADCIOP_config GTH_config TQM850L_config
1682 ADS860_config IP860_config TQM855L_config
1683 AR405_config IVML24_config TQM860L_config
1684 CANBT_config IVMS8_config WALNUT405_config
1685 CPCI405_config LANTEC_config cogent_common_config
1686 CPCIISER4_config MBX_config cogent_mpc8260_config
1687 CU824_config MBX860T_config cogent_mpc8xx_config
1688 ESTEEM192E_config RPXlite_config hermes_config
1689 ETX094_config RPXsuper_config hymod_config
1690 FADS823_config SM850_config lwmon_config
1691 FADS850SAR_config SPD823TS_config pcu_e_config
1692 FADS860T_config SXNI855T_config rsdproto_config
1693 FPS850L_config Sandpoint8240_config sbc8260_config
1694 GENIETV_config TQM823L_config PIP405_config
1695 GEN860T_config EBONY_config FPS860L_config
1697 Note: for some board special configuration names may exist; check if
1698 additional information is available from the board vendor; for
1699 instance, the TQM8xxL systems run normally at 50 MHz and use a
1700 SCC for 10baseT ethernet; there are also systems with 80 MHz
1701 CPU clock, and an optional Fast Ethernet module is available
1702 for CPU's with FEC. You can select such additional "features"
1703 when chosing the configuration, i. e.
1706 - will configure for a plain TQM860L, i. e. 50MHz, no FEC
1708 make TQM860L_FEC_config
1709 - will configure for a TQM860L at 50MHz with FEC for ethernet
1711 make TQM860L_80MHz_config
1712 - will configure for a TQM860L at 80 MHz, with normal 10baseT
1715 make TQM860L_FEC_80MHz_config
1716 - will configure for a TQM860L at 80 MHz with FEC for ethernet
1718 make TQM823L_LCD_config
1719 - will configure for a TQM823L with U-Boot console on LCD
1721 make TQM823L_LCD_80MHz_config
1722 - will configure for a TQM823L at 80 MHz with U-Boot console on LCD
1728 Finally, type "make all", and you should get some working U-Boot
1729 images ready for downlod to / installation on your system:
1731 - "u-boot.bin" is a raw binary image
1732 - "u-boot" is an image in ELF binary format
1733 - "u-boot.srec" is in Motorola S-Record format
1736 Please be aware that the Makefiles assume you are using GNU make, so
1737 for instance on NetBSD you might need to use "gmake" instead of
1741 If the system board that you have is not listed, then you will need
1742 to port U-Boot to your hardware platform. To do this, follow these
1745 1. Add a new configuration option for your board to the toplevel
1746 "Makefile", using the existing entries as examples.
1747 2. Create a new directory to hold your board specific code. Add any
1749 3. If you're porting U-Boot to a new CPU, then also create a new
1750 directory to hold your CPU specific code. Add any files you need.
1751 4. Run "make config_name" with your new name.
1752 5. Type "make", and you should get a working "u-boot.srec" file
1753 to be installed on your target system.
1754 [Of course, this last step is much harder than it sounds.]
1757 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
1758 ==============================================================
1760 If you have modified U-Boot sources (for instance added a new board
1761 or support for new devices, a new CPU, etc.) you are expected to
1762 provide feedback to the other developers. The feedback normally takes
1763 the form of a "patch", i. e. a context diff against a certain (latest
1764 official or latest in CVS) version of U-Boot sources.
1766 But before you submit such a patch, please verify that your modifi-
1767 cation did not break existing code. At least make sure that *ALL* of
1768 the supported boards compile WITHOUT ANY compiler warnings. To do so,
1769 just run the "MAKEALL" script, which will configure and build U-Boot
1770 for ALL supported system. Be warned, this will take a while. You can
1771 select which (cross) compiler to use py passing a `CROSS_COMPILE'
1772 environment variable to the script, i. e. to use the cross tools from
1773 MontaVista's Hard Hat Linux you can type
1775 CROSS_COMPILE=ppc_8xx- MAKEALL
1777 or to build on a native PowerPC system you can type
1779 CROSS_COMPILE=' ' MAKEALL
1781 See also "U-Boot Porting Guide" below.
1785 Monitor Commands - Overview:
1786 ============================
1788 go - start application at address 'addr'
1789 run - run commands in an environment variable
1790 bootm - boot application image from memory
1791 bootp - boot image via network using BootP/TFTP protocol
1792 tftpboot- boot image via network using TFTP protocol
1793 and env variables "ipaddr" and "serverip"
1794 (and eventually "gatewayip")
1795 rarpboot- boot image via network using RARP/TFTP protocol
1796 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
1797 loads - load S-Record file over serial line
1798 loadb - load binary file over serial line (kermit mode)
1800 mm - memory modify (auto-incrementing)
1801 nm - memory modify (constant address)
1802 mw - memory write (fill)
1804 cmp - memory compare
1805 crc32 - checksum calculation
1806 imd - i2c memory display
1807 imm - i2c memory modify (auto-incrementing)
1808 inm - i2c memory modify (constant address)
1809 imw - i2c memory write (fill)
1810 icrc32 - i2c checksum calculation
1811 iprobe - probe to discover valid I2C chip addresses
1812 iloop - infinite loop on address range
1813 isdram - print SDRAM configuration information
1814 sspi - SPI utility commands
1815 base - print or set address offset
1816 printenv- print environment variables
1817 setenv - set environment variables
1818 saveenv - save environment variables to persistent storage
1819 protect - enable or disable FLASH write protection
1820 erase - erase FLASH memory
1821 flinfo - print FLASH memory information
1822 bdinfo - print Board Info structure
1823 iminfo - print header information for application image
1824 coninfo - print console devices and informations
1825 ide - IDE sub-system
1826 loop - infinite loop on address range
1827 mtest - simple RAM test
1828 icache - enable or disable instruction cache
1829 dcache - enable or disable data cache
1830 reset - Perform RESET of the CPU
1831 echo - echo args to console
1832 version - print monitor version
1833 help - print online help
1834 ? - alias for 'help'
1837 Monitor Commands - Detailed Description:
1838 ========================================
1842 For now: just type "help <command>".
1845 Environment Variables:
1846 ======================
1848 U-Boot supports user configuration using Environment Variables which
1849 can be made persistent by saving to Flash memory.
1851 Environment Variables are set using "setenv", printed using
1852 "printenv", and saved to Flash using "saveenv". Using "setenv"
1853 without a value can be used to delete a variable from the
1854 environment. As long as you don't save the environment you are
1855 working with an in-memory copy. In case the Flash area containing the
1856 environment is erased by accident, a default environment is provided.
1858 Some configuration options can be set using Environment Variables:
1860 baudrate - see CONFIG_BAUDRATE
1862 bootdelay - see CONFIG_BOOTDELAY
1864 bootcmd - see CONFIG_BOOTCOMMAND
1866 bootargs - Boot arguments when booting an RTOS image
1868 bootfile - Name of the image to load with TFTP
1870 autoload - if set to "no" (any string beginning with 'n'),
1871 "bootp" will just load perform a lookup of the
1872 configuration from the BOOTP server, but not try to
1873 load any image using TFTP
1875 autostart - if set to "yes", an image loaded using the "bootp",
1876 "rarpboot", "tftpboot" or "diskboot" commands will
1877 be automatically started (by internally calling
1880 initrd_high - restrict positioning of initrd images:
1881 If this variable is not set, initrd images will be
1882 copied to the highest possible address in RAM; this
1883 is usually what you want since it allows for
1884 maximum initrd size. If for some reason you want to
1885 make sure that the initrd image is loaded below the
1886 CFG_BOOTMAPSZ limit, you can set this environment
1887 variable to a value of "no" or "off" or "0".
1888 Alternatively, you can set it to a maximum upper
1889 address to use (U-Boot will still check that it
1890 does not overwrite the U-Boot stack and data).
1892 For instance, when you have a system with 16 MB
1893 RAM, and want to reseve 4 MB from use by Linux,
1894 you can do this by adding "mem=12M" to the value of
1895 the "bootargs" variable. However, now you must make
1896 sure, that the initrd image is placed in the first
1897 12 MB as well - this can be done with
1899 setenv initrd_high 00c00000
1901 ipaddr - IP address; needed for tftpboot command
1903 loadaddr - Default load address for commands like "bootp",
1904 "rarpboot", "tftpboot" or "diskboot"
1906 loads_echo - see CONFIG_LOADS_ECHO
1908 serverip - TFTP server IP address; needed for tftpboot command
1910 bootretry - see CONFIG_BOOT_RETRY_TIME
1912 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
1914 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
1917 The following environment variables may be used and automatically
1918 updated by the network boot commands ("bootp" and "rarpboot"),
1919 depending the information provided by your boot server:
1921 bootfile - see above
1922 dnsip - IP address of your Domain Name Server
1923 gatewayip - IP address of the Gateway (Router) to use
1924 hostname - Target hostname
1926 netmask - Subnet Mask
1927 rootpath - Pathname of the root filesystem on the NFS server
1928 serverip - see above
1931 There are two special Environment Variables:
1933 serial# - contains hardware identification information such
1934 as type string and/or serial number
1935 ethaddr - Ethernet address
1937 These variables can be set only once (usually during manufacturing of
1938 the board). U-Boot refuses to delete or overwrite these variables
1939 once they have been set once.
1942 Please note that changes to some configuration parameters may take
1943 only effect after the next boot (yes, that's just like Windoze :-).
1946 Note for Redundant Ethernet Interfaces:
1947 =======================================
1949 Some boards come with redundand ethernet interfaces; U-Boot supports
1950 such configurations and is capable of automatic selection of a
1951 "working" interface when needed. MAC assignemnt works as follows:
1953 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
1954 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
1955 "eth1addr" (=>eth1), "eth2addr", ...
1957 If the network interface stores some valid MAC address (for instance
1958 in SROM), this is used as default address if there is NO correspon-
1959 ding setting in the environment; if the corresponding environment
1960 variable is set, this overrides the settings in the card; that means:
1962 o If the SROM has a valid MAC address, and there is no address in the
1963 environment, the SROM's address is used.
1965 o If there is no valid address in the SROM, and a definition in the
1966 environment exists, then the value from the environment variable is
1969 o If both the SROM and the environment contain a MAC address, and
1970 both addresses are the same, this MAC address is used.
1972 o If both the SROM and the environment contain a MAC address, and the
1973 addresses differ, the value from the environment is used and a
1976 o If neither SROM nor the environment contain a MAC address, an error
1984 The "boot" commands of this monitor operate on "image" files which
1985 can be basicly anything, preceeded by a special header; see the
1986 definitions in include/image.h for details; basicly, the header
1987 defines the following image properties:
1989 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
1990 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
1992 Currently supported: Linux, NetBSD, VxWorks, QNX).
1993 * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
1994 IA64, MIPS, MIPS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
1995 Currently supported: PowerPC).
1996 * Compression Type (Provisions for uncompressed, gzip, bzip2;
1997 Currently supported: uncompressed, gzip).
2003 The header is marked by a special Magic Number, and both the header
2004 and the data portions of the image are secured against corruption by
2011 Although U-Boot should support any OS or standalone application
2012 easily, Linux has always been in the focus during the design of
2015 U-Boot includes many features that so far have been part of some
2016 special "boot loader" code within the Linux kernel. Also, any
2017 "initrd" images to be used are no longer part of one big Linux image;
2018 instead, kernel and "initrd" are separate images. This implementation
2019 serves serveral purposes:
2021 - the same features can be used for other OS or standalone
2022 applications (for instance: using compressed images to reduce the
2023 Flash memory footprint)
2025 - it becomes much easier to port new Linux kernel versions because
2026 lots of low-level, hardware dependend stuff are done by U-Boot
2028 - the same Linux kernel image can now be used with different "initrd"
2029 images; of course this also means that different kernel images can
2030 be run with the same "initrd". This makes testing easier (you don't
2031 have to build a new "zImage.initrd" Linux image when you just
2032 change a file in your "initrd"). Also, a field-upgrade of the
2033 software is easier now.
2039 Porting Linux to U-Boot based systems:
2040 ---------------------------------------
2042 U-Boot cannot save you from doing all the necessary modifications to
2043 configure the Linux device drivers for use with your target hardware
2044 (no, we don't intend to provide a full virtual machine interface to
2047 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
2049 Just make sure your machine specific header file (for instance
2050 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
2051 Information structure as we define in include/u-boot.h, and make
2052 sure that your definition of IMAP_ADDR uses the same value as your
2053 U-Boot configuration in CFG_IMMR.
2056 Configuring the Linux kernel:
2057 -----------------------------
2059 No specific requirements for U-Boot. Make sure you have some root
2060 device (initial ramdisk, NFS) for your target system.
2063 Building a Linux Image:
2064 -----------------------
2066 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2067 not used. If you use recent kernel source, a new build target
2068 "uImage" will exist which automatically builds an image usable by
2069 U-Boot. Most older kernels also have support for a "pImage" target,
2070 which was introduced for our predecessor project PPCBoot and uses a
2071 100% compatible format.
2080 The "uImage" build target uses a special tool (in 'tools/mkimage') to
2081 encapsulate a compressed Linux kernel image with header information,
2082 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
2084 * build a standard "vmlinux" kernel image (in ELF binary format):
2086 * convert the kernel into a raw binary image:
2088 ${CROSS_COMPILE}-objcopy -O binary \
2089 -R .note -R .comment \
2090 -S vmlinux linux.bin
2092 * compress the binary image:
2096 * package compressed binary image for U-Boot:
2098 mkimage -A ppc -O linux -T kernel -C gzip \
2099 -a 0 -e 0 -n "Linux Kernel Image" \
2100 -d linux.bin.gz uImage
2103 The "mkimage" tool can also be used to create ramdisk images for use
2104 with U-Boot, either separated from the Linux kernel image, or
2105 combined into one file. "mkimage" encapsulates the images with a 64
2106 byte header containing information about target architecture,
2107 operating system, image type, compression method, entry points, time
2108 stamp, CRC32 checksums, etc.
2110 "mkimage" can be called in two ways: to verify existing images and
2111 print the header information, or to build new images.
2113 In the first form (with "-l" option) mkimage lists the information
2114 contained in the header of an existing U-Boot image; this includes
2115 checksum verification:
2117 tools/mkimage -l image
2118 -l ==> list image header information
2120 The second form (with "-d" option) is used to build a U-Boot image
2121 from a "data file" which is used as image payload:
2123 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2124 -n name -d data_file image
2125 -A ==> set architecture to 'arch'
2126 -O ==> set operating system to 'os'
2127 -T ==> set image type to 'type'
2128 -C ==> set compression type 'comp'
2129 -a ==> set load address to 'addr' (hex)
2130 -e ==> set entry point to 'ep' (hex)
2131 -n ==> set image name to 'name'
2132 -d ==> use image data from 'datafile'
2134 Right now, all Linux kernels use the same load address (0x00000000),
2135 but the entry point address depends on the kernel version:
2137 - 2.2.x kernels have the entry point at 0x0000000C,
2138 - 2.3.x and later kernels have the entry point at 0x00000000.
2140 So a typical call to build a U-Boot image would read:
2142 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2143 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
2144 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
2145 > examples/uImage.TQM850L
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 (gzip compressed)
2149 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2150 Load Address: 0x00000000
2151 Entry Point: 0x00000000
2153 To verify the contents of the image (or check for corruption):
2155 -> tools/mkimage -l examples/uImage.TQM850L
2156 Image Name: 2.4.4 kernel for TQM850L
2157 Created: Wed Jul 19 02:34:59 2000
2158 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2159 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2160 Load Address: 0x00000000
2161 Entry Point: 0x00000000
2163 NOTE: for embedded systems where boot time is critical you can trade
2164 speed for memory and install an UNCOMPRESSED image instead: this
2165 needs more space in Flash, but boots much faster since it does not
2166 need to be uncompressed:
2168 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
2169 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2170 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
2171 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
2172 > examples/uImage.TQM850L-uncompressed
2173 Image Name: 2.4.4 kernel for TQM850L
2174 Created: Wed Jul 19 02:34:59 2000
2175 Image Type: PowerPC Linux Kernel Image (uncompressed)
2176 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
2177 Load Address: 0x00000000
2178 Entry Point: 0x00000000
2181 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2182 when your kernel is intended to use an initial ramdisk:
2184 -> tools/mkimage -n 'Simple Ramdisk Image' \
2185 > -A ppc -O linux -T ramdisk -C gzip \
2186 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2187 Image Name: Simple Ramdisk Image
2188 Created: Wed Jan 12 14:01:50 2000
2189 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2190 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
2191 Load Address: 0x00000000
2192 Entry Point: 0x00000000
2195 Installing a Linux Image:
2196 -------------------------
2198 To downloading a U-Boot image over the serial (console) interface,
2199 you must convert the image to S-Record format:
2201 objcopy -I binary -O srec examples/image examples/image.srec
2203 The 'objcopy' does not understand the information in the U-Boot
2204 image header, so the resulting S-Record file will be relative to
2205 address 0x00000000. To load it to a given address, you need to
2206 specify the target address as 'offset' parameter with the 'loads'
2209 Example: install the image to address 0x40100000 (which on the
2210 TQM8xxL is in the first Flash bank):
2212 => erase 40100000 401FFFFF
2218 ## Ready for S-Record download ...
2219 ~>examples/image.srec
2220 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2222 15989 15990 15991 15992
2223 [file transfer complete]
2225 ## Start Addr = 0x00000000
2228 You can check the success of the download using the 'iminfo' command;
2229 this includes a checksum verification so you can be sure no data
2230 corruption happened:
2234 ## Checking Image at 40100000 ...
2235 Image Name: 2.2.13 for initrd on TQM850L
2236 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2237 Data Size: 335725 Bytes = 327 kB = 0 MB
2238 Load Address: 00000000
2239 Entry Point: 0000000c
2240 Verifying Checksum ... OK
2247 The "bootm" command is used to boot an application that is stored in
2248 memory (RAM or Flash). In case of a Linux kernel image, the contents
2249 of the "bootargs" environment variable is passed to the kernel as
2250 parameters. You can check and modify this variable using the
2251 "printenv" and "setenv" commands:
2254 => printenv bootargs
2255 bootargs=root=/dev/ram
2257 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2259 => printenv bootargs
2260 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2263 ## Booting Linux kernel at 40020000 ...
2264 Image Name: 2.2.13 for NFS on TQM850L
2265 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2266 Data Size: 381681 Bytes = 372 kB = 0 MB
2267 Load Address: 00000000
2268 Entry Point: 0000000c
2269 Verifying Checksum ... OK
2270 Uncompressing Kernel Image ... OK
2271 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
2272 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2273 time_init: decrementer frequency = 187500000/60
2274 Calibrating delay loop... 49.77 BogoMIPS
2275 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2278 If you want to boot a Linux kernel with initial ram disk, you pass
2279 the memory addreses of both the kernel and the initrd image (PPBCOOT
2280 format!) to the "bootm" command:
2282 => imi 40100000 40200000
2284 ## Checking Image at 40100000 ...
2285 Image Name: 2.2.13 for initrd on TQM850L
2286 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2287 Data Size: 335725 Bytes = 327 kB = 0 MB
2288 Load Address: 00000000
2289 Entry Point: 0000000c
2290 Verifying Checksum ... OK
2292 ## Checking Image at 40200000 ...
2293 Image Name: Simple Ramdisk Image
2294 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2295 Data Size: 566530 Bytes = 553 kB = 0 MB
2296 Load Address: 00000000
2297 Entry Point: 00000000
2298 Verifying Checksum ... OK
2300 => bootm 40100000 40200000
2301 ## Booting Linux kernel at 40100000 ...
2302 Image Name: 2.2.13 for initrd on TQM850L
2303 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2304 Data Size: 335725 Bytes = 327 kB = 0 MB
2305 Load Address: 00000000
2306 Entry Point: 0000000c
2307 Verifying Checksum ... OK
2308 Uncompressing Kernel Image ... OK
2309 ## Loading RAMDisk Image at 40200000 ...
2310 Image Name: Simple Ramdisk Image
2311 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2312 Data Size: 566530 Bytes = 553 kB = 0 MB
2313 Load Address: 00000000
2314 Entry Point: 00000000
2315 Verifying Checksum ... OK
2316 Loading Ramdisk ... OK
2317 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
2318 Boot arguments: root=/dev/ram
2319 time_init: decrementer frequency = 187500000/60
2320 Calibrating delay loop... 49.77 BogoMIPS
2322 RAMDISK: Compressed image found at block 0
2323 VFS: Mounted root (ext2 filesystem).
2331 One of the features of U-Boot is that you can dynamically load and
2332 run "standalone" applications, which can use some resources of
2333 U-Boot like console I/O functions or interrupt services.
2335 Two simple examples are included with the sources:
2340 'examples/hello_world.c' contains a small "Hello World" Demo
2341 application; it is automatically compiled when you build U-Boot.
2342 It's configured to run at address 0x00040004, so you can play with it
2346 ## Ready for S-Record download ...
2347 ~>examples/hello_world.srec
2348 1 2 3 4 5 6 7 8 9 10 11 ...
2349 [file transfer complete]
2351 ## Start Addr = 0x00040004
2353 => go 40004 Hello World! This is a test.
2354 ## Starting application at 0x00040004 ...
2365 Hit any key to exit ...
2367 ## Application terminated, rc = 0x0
2369 Another example, which demonstrates how to register a CPM interrupt
2370 handler with the U-Boot code, can be found in 'examples/timer.c'.
2371 Here, a CPM timer is set up to generate an interrupt every second.
2372 The interrupt service routine is trivial, just printing a '.'
2373 character, but this is just a demo program. The application can be
2374 controlled by the following keys:
2376 ? - print current values og the CPM Timer registers
2377 b - enable interrupts and start timer
2378 e - stop timer and disable interrupts
2379 q - quit application
2382 ## Ready for S-Record download ...
2383 ~>examples/timer.srec
2384 1 2 3 4 5 6 7 8 9 10 11 ...
2385 [file transfer complete]
2387 ## Start Addr = 0x00040004
2390 ## Starting application at 0x00040004 ...
2393 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
2396 [q, b, e, ?] Set interval 1000000 us
2399 [q, b, e, ?] ........
2400 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
2403 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
2406 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
2409 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
2411 [q, b, e, ?] ...Stopping timer
2413 [q, b, e, ?] ## Application terminated, rc = 0x0
2419 Starting at version 0.9.2, U-Boot supports NetBSD both as host
2420 (build U-Boot) and target system (boots NetBSD/mpc8xx).
2422 Building requires a cross environment; it is known to work on
2423 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
2424 need gmake since the Makefiles are not compatible with BSD make).
2425 Note that the cross-powerpc package does not install include files;
2426 attempting to build U-Boot will fail because <machine/ansi.h> is
2427 missing. This file has to be installed and patched manually:
2429 # cd /usr/pkg/cross/powerpc-netbsd/include
2431 # ln -s powerpc machine
2432 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
2433 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
2435 Native builds *don't* work due to incompatibilities between native
2436 and U-Boot include files.
2438 Booting assumes that (the first part of) the image booted is a
2439 stage-2 loader which in turn loads and then invokes the kernel
2440 proper. Loader sources will eventually appear in the NetBSD source
2441 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
2442 meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for
2446 Implementation Internals:
2447 =========================
2449 The following is not intended to be a complete description of every
2450 implementation detail. However, it should help to understand the
2451 inner workings of U-Boot and make it easier to port it to custom
2455 Initial Stack, Global Data:
2456 ---------------------------
2458 The implementation of U-Boot is complicated by the fact that U-Boot
2459 starts running out of ROM (flash memory), usually without access to
2460 system RAM (because the memory controller is not initialized yet).
2461 This means that we don't have writable Data or BSS segments, and BSS
2462 is not initialized as zero. To be able to get a C environment working
2463 at all, we have to allocate at least a minimal stack. Implementation
2464 options for this are defined and restricted by the CPU used: Some CPU
2465 models provide on-chip memory (like the IMMR area on MPC8xx and
2466 MPC826x processors), on others (parts of) the data cache can be
2467 locked as (mis-) used as memory, etc.
2469 It is essential to remember this, since it has some impact on the C
2470 code for the initialization procedures:
2472 * Initialized global data (data segment) is read-only. Do not attempt
2475 * Do not use any unitialized global data (or implicitely initialized
2476 as zero data - BSS segment) at all - this is undefined, initiali-
2477 zation is performed later (when relocationg to RAM).
2479 * Stack space is very limited. Avoid big data buffers or things like
2482 Having only the stack as writable memory limits means we cannot use
2483 normal global data to share information beween the code. But it
2484 turned out that the implementation of U-Boot can be greatly
2485 simplified by making a global data structure (gd_t) available to all
2486 functions. We could pass a pointer to this data as argument to _all_
2487 functions, but this would bloat the code. Instead we use a feature of
2488 the GCC compiler (Global Register Variables) to share the data: we
2489 place a pointer (gd) to the global data into a register which we
2490 reserve for this purpose.
2492 When chosing a register for such a purpose we are restricted by the
2493 relevant (E)ABI specifications for the current architecture, and by
2494 GCC's implementation.
2496 For PowerPC, the following registers have specific use:
2499 R3-R4: parameter passing and return values
2500 R5-R10: parameter passing
2501 R13: small data area pointer
2505 (U-Boot also uses R14 as internal GOT pointer.)
2507 ==> U-Boot will use R29 to hold a pointer to the global data
2509 Note: on PPC, we could use a static initializer (since the
2510 address of the global data structure is known at compile time),
2511 but it turned out that reserving a register results in somewhat
2512 smaller code - although the code savings are not that big (on
2513 average for all boards 752 bytes for the whole U-Boot image,
2514 624 text + 127 data).
2516 On ARM, the following registers are used:
2518 R0: function argument word/integer result
2519 R1-R3: function argument word
2521 R10: stack limit (used only if stack checking if enabled)
2522 R11: argument (frame) pointer
2523 R12: temporary workspace
2526 R15: program counter
2528 ==> U-Boot will use R8 to hold a pointer to the global data
2535 U-Boot runs in system state and uses physical addresses, i.e. the
2536 MMU is not used either for address mapping nor for memory protection.
2538 The available memory is mapped to fixed addresses using the memory
2539 controller. In this process, a contiguous block is formed for each
2540 memory type (Flash, SDRAM, SRAM), even when it consists of several
2541 physical memory banks.
2543 U-Boot is installed in the first 128 kB of the first Flash bank (on
2544 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
2545 booting and sizing and initializing DRAM, the code relocates itself
2546 to the upper end of DRAM. Immediately below the U-Boot code some
2547 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
2548 configuration setting]. Below that, a structure with global Board
2549 Info data is placed, followed by the stack (growing downward).
2551 Additionally, some exception handler code is copied to the low 8 kB
2552 of DRAM (0x00000000 ... 0x00001FFF).
2554 So a typical memory configuration with 16 MB of DRAM could look like
2557 0x0000 0000 Exception Vector code
2560 0x0000 2000 Free for Application Use
2566 0x00FB FF20 Monitor Stack (Growing downward)
2567 0x00FB FFAC Board Info Data and permanent copy of global data
2568 0x00FC 0000 Malloc Arena
2571 0x00FE 0000 RAM Copy of Monitor Code
2572 ... eventually: LCD or video framebuffer
2573 ... eventually: pRAM (Protected RAM - unchanged by reset)
2574 0x00FF FFFF [End of RAM]
2577 System Initialization:
2578 ----------------------
2580 In the reset configuration, U-Boot starts at the reset entry point
2581 (on most PowerPC systens at address 0x00000100). Because of the reset
2582 configuration for CS0# this is a mirror of the onboard Flash memory.
2583 To be able to re-map memory U-Boot then jumps to it's link address.
2584 To be able to implement the initialization code in C, a (small!)
2585 initial stack is set up in the internal Dual Ported RAM (in case CPUs
2586 which provide such a feature like MPC8xx or MPC8260), or in a locked
2587 part of the data cache. After that, U-Boot initializes the CPU core,
2588 the caches and the SIU.
2590 Next, all (potentially) available memory banks are mapped using a
2591 preliminary mapping. For example, we put them on 512 MB boundaries
2592 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
2593 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
2594 programmed for SDRAM access. Using the temporary configuration, a
2595 simple memory test is run that determines the size of the SDRAM
2598 When there is more than one SDRAM bank, and the banks are of
2599 different size, the larger is mapped first. For equal size, the first
2600 bank (CS2#) is mapped first. The first mapping is always for address
2601 0x00000000, with any additional banks following immediately to create
2602 contiguous memory starting from 0.
2604 Then, the monitor installs itself at the upper end of the SDRAM area
2605 and allocates memory for use by malloc() and for the global Board
2606 Info data; also, the exception vector code is copied to the low RAM
2607 pages, and the final stack is set up.
2609 Only after this relocation will you have a "normal" C environment;
2610 until that you are restricted in several ways, mostly because you are
2611 running from ROM, and because the code will have to be relocated to a
2615 U-Boot Porting Guide:
2616 ----------------------
2618 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
2622 int main (int argc, char *argv[])
2624 sighandler_t no_more_time;
2626 signal (SIGALRM, no_more_time);
2627 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
2629 if (available_money > available_manpower) {
2630 pay consultant to port U-Boot;
2634 Download latest U-Boot source;
2637 email ("Hi, I am new to U-Boot, how do I get started?");
2641 Read the README file in the top level directory;
2642 Read http://www.denx.de/re/DPLG.html
2643 Read the source, Luke;
2646 if (available_money > toLocalCurrency ($2500)) {
2649 Add a lot of aggravation and time;
2652 Create your own board support subdirectory;
2656 Add / modify source code;
2660 email ("Hi, I am having problems...");
2662 Send patch file to Wolfgang;
2667 void no_more_time (int sig)
2677 All contributions to U-Boot should conform to the Linux kernel
2678 coding style; see the file "Documentation/CodingStyle" in your Linux
2679 kernel source directory.
2681 Please note that U-Boot is implemented in C (and to some small parts
2682 in Assembler); no C++ is used, so please do not use C++ style
2683 comments (//) in your code.
2685 Submissions which do not conform to the standards may be returned
2686 with a request to reformat the changes.
2692 Since the number of patches for U-Boot is growing, we need to
2693 establish some rules. Submissions which do not conform to these rules
2694 may be rejected, even when they contain important and valuable stuff.
2697 When you send a patch, please include the following information with
2700 * For bug fixes: a description of the bug and how your patch fixes
2701 this bug. Please try to include a way of demonstrating that the
2702 patch actually fixes something.
2704 * For new features: a description of the feature and your
2707 * A CHANGELOG entry as plaintext (separate from the patch)
2709 * For major contributions, your entry to the CREDITS file
2711 * When you add support for a new board, don't forget to add this
2712 board to the MAKEALL script, too.
2714 * If your patch adds new configuration options, don't forget to
2715 document these in the README file.
2717 * The patch itself. If you are accessing the CVS repository use "cvs
2718 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
2719 version of diff does not support these options, then get the latest
2720 version of GNU diff.
2722 We accept patches as plain text, MIME attachments or as uuencoded
2727 * Before sending the patch, run the MAKEALL script on your patched
2728 source tree and make sure that no errors or warnings are reported
2729 for any of the boards.
2731 * Keep your modifications to the necessary minimum: A patch
2732 containing several unrelated changes or arbitrary reformats will be
2733 returned with a request to re-formatting / split it.
2735 * If you modify existing code, make sure that your new code does not
2736 add to the memory footprint of the code ;-) Small is beautiful!
2737 When adding new features, these should compile conditionally only
2738 (using #ifdef), and the resulting code with the new feature
2739 disabled must not need more memory than the old code without your
projects / karo-tx-uboot.git / blob