2 # (C) Copyright 2000 - 2004
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # See file CREDITS for list of people who contributed to this
8 # This program is free software; you can redistribute it and/or
9 # modify it under the terms of the GNU General Public License as
10 # published by the Free Software Foundation; either version 2 of
11 # the License, or (at your option) any later version.
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with this program; if not, write to the Free Software
20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27 This directory contains the source code for U-Boot, a boot loader for
28 Embedded boards based on PowerPC and ARM processors, which can be
29 installed in a boot ROM and used to initialize and test the hardware
30 or to download and run application code.
32 The development of U-Boot is closely related to Linux: some parts of
33 the source code originate in the Linux source tree, we have some
34 header files in common, and special provision has been made to
35 support booting of Linux images.
37 Some attention has been paid to make this software easily
38 configurable and extendable. For instance, all monitor commands are
39 implemented with the same call interface, so that it's very easy to
40 add new commands. Also, instead of permanently adding rarely used
41 code (for instance hardware test utilities) to the monitor, you can
42 load and run it dynamically.
48 In general, all boards for which a configuration option exists in the
49 Makefile have been tested to some extent and can be considered
50 "working". In fact, many of them are used in production systems.
52 In case of problems see the CHANGELOG and CREDITS files to find out
53 who contributed the specific port.
59 In case you have questions about, problems with or contributions for
60 U-Boot you should send a message to the U-Boot mailing list at
61 <u-boot-users@lists.sourceforge.net>. There is also an archive of
62 previous traffic on the mailing list - please search the archive
63 before asking FAQ's. Please see
64 http://lists.sourceforge.net/lists/listinfo/u-boot-users/
70 - start from 8xxrom sources
71 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
73 - make it easier to add custom boards
74 - make it possible to add other [PowerPC] CPUs
75 - extend functions, especially:
76 * Provide extended interface to Linux boot loader
79 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot
80 - create ARMBoot project (http://sourceforge.net/projects/armboot)
81 - add other CPU families (starting with ARM)
82 - create U-Boot project (http://sourceforge.net/projects/u-boot)
88 The "official" name of this project is "Das U-Boot". The spelling
89 "U-Boot" shall be used in all written text (documentation, comments
90 in source files etc.). Example:
92 This is the README file for the U-Boot project.
94 File names etc. shall be based on the string "u-boot". Examples:
96 include/asm-ppc/u-boot.h
98 #include <asm/u-boot.h>
100 Variable names, preprocessor constants etc. shall be either based on
101 the string "u_boot" or on "U_BOOT". Example:
103 U_BOOT_VERSION u_boot_logo
104 IH_OS_U_BOOT u_boot_hush_start
110 U-Boot uses a 3 level version number containing a version, a
111 sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2",
112 sub-version "34", and patchlevel "4".
114 The patchlevel is used to indicate certain stages of development
115 between released versions, i. e. officially released versions of
116 U-Boot will always have a patchlevel of "0".
122 - board Board dependent files
123 - common Misc architecture independent functions
124 - cpu CPU specific files
125 - 74xx_7xx Files specific to Motorola MPC74xx and 7xx CPUs
126 - arm720t Files specific to ARM 720 CPUs
127 - arm920t Files specific to ARM 920 CPUs
128 - arm925t Files specific to ARM 925 CPUs
129 - arm926ejs Files specific to ARM 926 CPUs
130 - at91rm9200 Files specific to Atmel AT91RM9200 CPUs
131 - i386 Files specific to i386 CPUs
132 - ixp Files specific to Intel XScale IXP CPUs
133 - mcf52x2 Files specific to Motorola ColdFire MCF52x2 CPUs
134 - mips Files specific to MIPS CPUs
135 - mpc5xx Files specific to Motorola MPC5xx CPUs
136 - mpc5xxx Files specific to Motorola MPC5xxx CPUs
137 - mpc8xx Files specific to Motorola MPC8xx CPUs
138 - mpc824x Files specific to Motorola MPC824x CPUs
139 - mpc8260 Files specific to Motorola MPC8260 CPUs
140 - mpc85xx Files specific to Motorola MPC85xx CPUs
141 - nios Files specific to Altera NIOS CPUs
142 - ppc4xx Files specific to IBM PowerPC 4xx CPUs
143 - pxa Files specific to Intel XScale PXA CPUs
144 - s3c44b0 Files specific to Samsung S3C44B0 CPUs
145 - sa1100 Files specific to Intel StrongARM SA1100 CPUs
146 - disk Code for disk drive partition handling
147 - doc Documentation (don't expect too much)
148 - drivers Commonly used device drivers
149 - dtt Digital Thermometer and Thermostat drivers
150 - examples Example code for standalone applications, etc.
151 - include Header Files
152 - lib_arm Files generic to ARM architecture
153 - lib_generic Files generic to all architectures
154 - lib_i386 Files generic to i386 architecture
155 - lib_m68k Files generic to m68k architecture
156 - lib_mips Files generic to MIPS architecture
157 - lib_nios Files generic to NIOS architecture
158 - lib_ppc Files generic to PowerPC architecture
159 - net Networking code
160 - post Power On Self Test
161 - rtc Real Time Clock drivers
162 - tools Tools to build S-Record or U-Boot images, etc.
164 Software Configuration:
165 =======================
167 Configuration is usually done using C preprocessor defines; the
168 rationale behind that is to avoid dead code whenever possible.
170 There are two classes of configuration variables:
172 * Configuration _OPTIONS_:
173 These are selectable by the user and have names beginning with
176 * Configuration _SETTINGS_:
177 These depend on the hardware etc. and should not be meddled with if
178 you don't know what you're doing; they have names beginning with
181 Later we will add a configuration tool - probably similar to or even
182 identical to what's used for the Linux kernel. Right now, we have to
183 do the configuration by hand, which means creating some symbolic
184 links and editing some configuration files. We use the TQM8xxL boards
188 Selection of Processor Architecture and Board Type:
189 ---------------------------------------------------
191 For all supported boards there are ready-to-use default
192 configurations available; just type "make <board_name>_config".
194 Example: For a TQM823L module type:
199 For the Cogent platform, you need to specify the cpu type as well;
200 e.g. "make cogent_mpc8xx_config". And also configure the cogent
201 directory according to the instructions in cogent/README.
204 Configuration Options:
205 ----------------------
207 Configuration depends on the combination of board and CPU type; all
208 such information is kept in a configuration file
209 "include/configs/<board_name>.h".
211 Example: For a TQM823L module, all configuration settings are in
212 "include/configs/TQM823L.h".
215 Many of the options are named exactly as the corresponding Linux
216 kernel configuration options. The intention is to make it easier to
217 build a config tool - later.
220 The following options need to be configured:
222 - CPU Type: Define exactly one of
226 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860
228 or CONFIG_MPC824X, CONFIG_MPC8260
244 - Board Type: Define exactly one of
246 PowerPC based boards:
247 ---------------------
249 CONFIG_ADCIOP, CONFIG_ADS860, CONFIG_AMX860,
250 CONFIG_AR405, CONFIG_BAB7xx, CONFIG_c2mon,
251 CONFIG_CANBT, CONFIG_CCM, CONFIG_CMI,
252 CONFIG_cogent_mpc8260, CONFIG_cogent_mpc8xx, CONFIG_CPCI405,
253 CONFIG_CPCI4052, CONFIG_CPCIISER4, CONFIG_CPU86,
254 CONFIG_CRAYL1, CONFIG_CU824, CONFIG_DASA_SIM,
255 CONFIG_DB64360, CONFIG_DB64460, CONFIG_DU405,
256 CONFIG_DUET_ADS, CONFIG_EBONY, CONFIG_ELPPC,
257 CONFIG_ELPT860, CONFIG_ep8260, CONFIG_ERIC,
258 CONFIG_ESTEEM192E, CONFIG_ETX094, CONFIG_EVB64260,
259 CONFIG_FADS823, CONFIG_FADS850SAR, CONFIG_FADS860T,
260 CONFIG_FLAGADM, CONFIG_FPS850L, CONFIG_FPS860L,
261 CONFIG_GEN860T, CONFIG_GENIETV, CONFIG_GTH,
262 CONFIG_gw8260, CONFIG_hermes, CONFIG_hymod,
263 CONFIG_IAD210, CONFIG_ICU862, CONFIG_IP860,
264 CONFIG_IPHASE4539, CONFIG_IVML24, CONFIG_IVML24_128,
265 CONFIG_IVML24_256, CONFIG_IVMS8, CONFIG_IVMS8_128,
266 CONFIG_IVMS8_256, CONFIG_JSE, CONFIG_LANTEC,
267 CONFIG_lwmon, CONFIG_MBX, CONFIG_MBX860T,
268 CONFIG_MHPC, CONFIG_MIP405, CONFIG_MOUSSE,
269 CONFIG_MPC8260ADS, CONFIG_MPC8540ADS, CONFIG_MPC8560ADS,
270 CONFIG_MUSENKI, CONFIG_MVS1, CONFIG_NETPHONE,
271 CONFIG_NETTA, CONFIG_NETVIA, CONFIG_NX823,
272 CONFIG_OCRTC, CONFIG_ORSG, CONFIG_OXC,
273 CONFIG_PCI405, CONFIG_PCIPPC2, CONFIG_PCIPPC6,
274 CONFIG_pcu_e, CONFIG_PIP405, CONFIG_PM826,
275 CONFIG_ppmc8260, CONFIG_QS823, CONFIG_QS850,
276 CONFIG_QS860T, CONFIG_RBC823, CONFIG_RPXClassic,
277 CONFIG_RPXlite, CONFIG_RPXsuper, CONFIG_rsdproto,
278 CONFIG_sacsng, CONFIG_Sandpoint8240, CONFIG_Sandpoint8245,
279 CONFIG_sbc8260, CONFIG_SM850, CONFIG_SPD823TS,
280 CONFIG_SXNI855T, CONFIG_TQM823L, CONFIG_TQM8260,
281 CONFIG_TQM850L, CONFIG_TQM855L, CONFIG_TQM860L,
282 CONFIG_TTTech, CONFIG_UTX8245, CONFIG_V37,
283 CONFIG_W7OLMC, CONFIG_W7OLMG, CONFIG_WALNUT405,
284 CONFIG_ZPC1900, CONFIG_ZUMA,
289 CONFIG_AT91RM9200DK, CONFIG_DNP1110, CONFIG_EP7312,
290 CONFIG_H2_OMAP1610, CONFIG_HHP_CRADLE, CONFIG_IMPA7,
291 CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610, CONFIG_LART,
292 CONFIG_LUBBOCK, CONFIG_SHANNON, CONFIG_SMDK2400,
293 CONFIG_SMDK2410, CONFIG_TRAB, CONFIG_VCMA9,
296 - CPU Module Type: (if CONFIG_COGENT is defined)
297 Define exactly one of
299 --- FIXME --- not tested yet:
300 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
301 CONFIG_CMA287_23, CONFIG_CMA287_50
303 - Motherboard Type: (if CONFIG_COGENT is defined)
304 Define exactly one of
305 CONFIG_CMA101, CONFIG_CMA102
307 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
308 Define one or more of
311 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
312 Define one or more of
313 CONFIG_LCD_HEARTBEAT - update a character position on
314 the lcd display every second with
317 - Board flavour: (if CONFIG_MPC8260ADS is defined)
320 CFG_8260ADS - original MPC8260ADS
321 CFG_8266ADS - MPC8266ADS
322 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
323 CFG_8272ADS - MPC8272ADS
325 - MPC824X Family Member (if CONFIG_MPC824X is defined)
326 Define exactly one of
327 CONFIG_MPC8240, CONFIG_MPC8245
329 - 8xx CPU Options: (if using an MPC8xx cpu)
330 Define one or more of
331 CONFIG_8xx_GCLK_FREQ - if get_gclk_freq() cannot work
332 e.g. if there is no 32KHz
333 reference PIT/RTC clock
335 - 859/866 CPU options: (if using a MPC859 or MPC866 CPU):
339 CFG_866_CPUCLK_DEFAULT
340 See doc/README.MPC866
344 Define this to measure the actual CPU clock instead
345 of relying on the correctness of the configured
346 values. Mostly useful for board bringup to make sure
347 the PLL is locked at the intended frequency. Note
348 that this requires a (stable) reference clock (32 kHz
351 - Linux Kernel Interface:
354 U-Boot stores all clock information in Hz
355 internally. For binary compatibility with older Linux
356 kernels (which expect the clocks passed in the
357 bd_info data to be in MHz) the environment variable
358 "clocks_in_mhz" can be defined so that U-Boot
359 converts clock data to MHZ before passing it to the
361 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
362 "clocks_in_mhz=1" is automatically included in the
365 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
367 When transfering memsize parameter to linux, some versions
368 expect it to be in bytes, others in MB.
369 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
372 Depending on board, define exactly one serial port
373 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
374 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
375 console by defining CONFIG_8xx_CONS_NONE
377 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
378 port routines must be defined elsewhere
379 (i.e. serial_init(), serial_getc(), ...)
382 Enables console device for a color framebuffer. Needs following
383 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
384 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
386 VIDEO_HW_RECTFILL graphic chip supports
389 VIDEO_HW_BITBLT graphic chip supports
390 bit-blit (cf. smiLynxEM)
391 VIDEO_VISIBLE_COLS visible pixel columns
393 VIDEO_VISIBLE_ROWS visible pixel rows
394 VIDEO_PIXEL_SIZE bytes per pixel
395 VIDEO_DATA_FORMAT graphic data format
396 (0-5, cf. cfb_console.c)
397 VIDEO_FB_ADRS framebuffer address
398 VIDEO_KBD_INIT_FCT keyboard int fct
399 (i.e. i8042_kbd_init())
400 VIDEO_TSTC_FCT test char fct
402 VIDEO_GETC_FCT get char fct
404 CONFIG_CONSOLE_CURSOR cursor drawing on/off
405 (requires blink timer
407 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
408 CONFIG_CONSOLE_TIME display time/date info in
410 (requires CFG_CMD_DATE)
411 CONFIG_VIDEO_LOGO display Linux logo in
413 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
414 linux_logo.h for logo.
415 Requires CONFIG_VIDEO_LOGO
416 CONFIG_CONSOLE_EXTRA_INFO
417 addional board info beside
420 When CONFIG_CFB_CONSOLE is defined, video console is
421 default i/o. Serial console can be forced with
422 environment 'console=serial'.
424 When CONFIG_SILENT_CONSOLE is defined, all console
425 messages (by U-Boot and Linux!) can be silenced with
426 the "silent" environment variable. See
427 doc/README.silent for more information.
430 CONFIG_BAUDRATE - in bps
431 Select one of the baudrates listed in
432 CFG_BAUDRATE_TABLE, see below.
433 CFG_BRGCLK_PRESCALE, baudrate prescale
435 - Interrupt driven serial port input:
436 CONFIG_SERIAL_SOFTWARE_FIFO
439 Use an interrupt handler for receiving data on the
440 serial port. It also enables using hardware handshake
441 (RTS/CTS) and UART's built-in FIFO. Set the number of
442 bytes the interrupt driven input buffer should have.
444 Leave undefined to disable this feature, including
445 disable the buffer and hardware handshake.
447 - Console UART Number:
451 If defined internal UART1 (and not UART0) is used
452 as default U-Boot console.
454 - Boot Delay: CONFIG_BOOTDELAY - in seconds
455 Delay before automatically booting the default image;
456 set to -1 to disable autoboot.
458 See doc/README.autoboot for these options that
459 work with CONFIG_BOOTDELAY. None are required.
460 CONFIG_BOOT_RETRY_TIME
461 CONFIG_BOOT_RETRY_MIN
462 CONFIG_AUTOBOOT_KEYED
463 CONFIG_AUTOBOOT_PROMPT
464 CONFIG_AUTOBOOT_DELAY_STR
465 CONFIG_AUTOBOOT_STOP_STR
466 CONFIG_AUTOBOOT_DELAY_STR2
467 CONFIG_AUTOBOOT_STOP_STR2
468 CONFIG_ZERO_BOOTDELAY_CHECK
469 CONFIG_RESET_TO_RETRY
473 Only needed when CONFIG_BOOTDELAY is enabled;
474 define a command string that is automatically executed
475 when no character is read on the console interface
476 within "Boot Delay" after reset.
479 This can be used to pass arguments to the bootm
480 command. The value of CONFIG_BOOTARGS goes into the
481 environment value "bootargs".
483 CONFIG_RAMBOOT and CONFIG_NFSBOOT
484 The value of these goes into the environment as
485 "ramboot" and "nfsboot" respectively, and can be used
486 as a convenience, when switching between booting from
492 When this option is #defined, the existence of the
493 environment variable "preboot" will be checked
494 immediately before starting the CONFIG_BOOTDELAY
495 countdown and/or running the auto-boot command resp.
496 entering interactive mode.
498 This feature is especially useful when "preboot" is
499 automatically generated or modified. For an example
500 see the LWMON board specific code: here "preboot" is
501 modified when the user holds down a certain
502 combination of keys on the (special) keyboard when
505 - Serial Download Echo Mode:
507 If defined to 1, all characters received during a
508 serial download (using the "loads" command) are
509 echoed back. This might be needed by some terminal
510 emulations (like "cu"), but may as well just take
511 time on others. This setting #define's the initial
512 value of the "loads_echo" environment variable.
514 - Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
516 Select one of the baudrates listed in
517 CFG_BAUDRATE_TABLE, see below.
521 Most monitor functions can be selected (or
522 de-selected) by adjusting the definition of
523 CONFIG_COMMANDS; to select individual functions,
524 #define CONFIG_COMMANDS by "OR"ing any of the
527 #define enables commands:
528 -------------------------
529 CFG_CMD_ASKENV * ask for env variable
530 CFG_CMD_AUTOSCRIPT Autoscript Support
532 CFG_CMD_BEDBUG Include BedBug Debugger
533 CFG_CMD_BMP * BMP support
535 CFG_CMD_CACHE icache, dcache
536 CFG_CMD_CONSOLE coninfo
537 CFG_CMD_DATE * support for RTC, date/time...
538 CFG_CMD_DHCP DHCP support
539 CFG_CMD_DIAG * Diagnostics
540 CFG_CMD_DOC * Disk-On-Chip Support
541 CFG_CMD_DTT Digital Therm and Thermostat
542 CFG_CMD_ECHO * echo arguments
543 CFG_CMD_EEPROM * EEPROM read/write support
544 CFG_CMD_ELF bootelf, bootvx
546 CFG_CMD_FDC * Floppy Disk Support
547 CFG_CMD_FAT FAT partition support
548 CFG_CMD_FDOS * Dos diskette Support
549 CFG_CMD_FLASH flinfo, erase, protect
550 CFG_CMD_FPGA FPGA device initialization support
551 CFG_CMD_HWFLOW * RTS/CTS hw flow control
552 CFG_CMD_I2C * I2C serial bus support
553 CFG_CMD_IDE * IDE harddisk support
555 CFG_CMD_IMLS List all found images
556 CFG_CMD_IMMAP * IMMR dump support
557 CFG_CMD_IRQ * irqinfo
558 CFG_CMD_ITEST * Integer/string test of 2 values
559 CFG_CMD_JFFS2 * JFFS2 Support
563 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
565 CFG_CMD_MISC Misc functions like sleep etc
566 CFG_CMD_MMC MMC memory mapped support
567 CFG_CMD_MII MII utility commands
568 CFG_CMD_NAND * NAND support
569 CFG_CMD_NET bootp, tftpboot, rarpboot
570 CFG_CMD_PCI * pciinfo
571 CFG_CMD_PCMCIA * PCMCIA support
572 CFG_CMD_PING * send ICMP ECHO_REQUEST to network host
573 CFG_CMD_PORTIO * Port I/O
574 CFG_CMD_REGINFO * Register dump
575 CFG_CMD_RUN run command in env variable
576 CFG_CMD_SAVES save S record dump
577 CFG_CMD_SCSI * SCSI Support
578 CFG_CMD_SDRAM * print SDRAM configuration information
579 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
580 CFG_CMD_SPI * SPI serial bus support
581 CFG_CMD_USB * USB support
582 CFG_CMD_VFD * VFD support (TRAB)
583 CFG_CMD_BSP * Board SPecific functions
584 CFG_CMD_CDP * Cisco Discover Protocol support
585 -----------------------------------------------
588 CFG_CMD_DFL Default configuration; at the moment
589 this is includes all commands, except
590 the ones marked with "*" in the list
593 If you don't define CONFIG_COMMANDS it defaults to
594 CFG_CMD_DFL in include/cmd_confdefs.h. A board can
595 override the default settings in the respective
598 EXAMPLE: If you want all functions except of network
599 support you can write:
601 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
604 Note: Don't enable the "icache" and "dcache" commands
605 (configuration option CFG_CMD_CACHE) unless you know
606 what you (and your U-Boot users) are doing. Data
607 cache cannot be enabled on systems like the 8xx or
608 8260 (where accesses to the IMMR region must be
609 uncached), and it cannot be disabled on all other
610 systems where we (mis-) use the data cache to hold an
611 initial stack and some data.
614 XXX - this list needs to get updated!
618 If this variable is defined, it enables watchdog
619 support. There must be support in the platform specific
620 code for a watchdog. For the 8xx and 8260 CPUs, the
621 SIU Watchdog feature is enabled in the SYPCR
625 CONFIG_VERSION_VARIABLE
626 If this variable is defined, an environment variable
627 named "ver" is created by U-Boot showing the U-Boot
628 version as printed by the "version" command.
629 This variable is readonly.
633 When CFG_CMD_DATE is selected, the type of the RTC
634 has to be selected, too. Define exactly one of the
637 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
638 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
639 CONFIG_RTC_MC146818 - use MC146818 RTC
640 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
641 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
642 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
643 CONFIG_RTC_DS164x - use Dallas DS164x RTC
645 Note that if the RTC uses I2C, then the I2C interface
646 must also be configured. See I2C Support, below.
650 When CONFIG_TIMESTAMP is selected, the timestamp
651 (date and time) of an image is printed by image
652 commands like bootm or iminfo. This option is
653 automatically enabled when you select CFG_CMD_DATE .
656 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
657 and/or CONFIG_ISO_PARTITION
659 If IDE or SCSI support is enabled (CFG_CMD_IDE or
660 CFG_CMD_SCSI) you must configure support for at least
661 one partition type as well.
664 CONFIG_IDE_RESET_ROUTINE - this is defined in several
665 board configurations files but used nowhere!
667 CONFIG_IDE_RESET - is this is defined, IDE Reset will
668 be performed by calling the function
669 ide_set_reset(int reset)
670 which has to be defined in a board specific file
675 Set this to enable ATAPI support.
680 Set this to enable support for disks larger than 137GB
681 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL
682 Whithout these , LBA48 support uses 32bit variables and will 'only'
683 support disks up to 2.1TB.
686 When enabled, makes the IDE subsystem use 64bit sector addresses.
690 At the moment only there is only support for the
691 SYM53C8XX SCSI controller; define
692 CONFIG_SCSI_SYM53C8XX to enable it.
694 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
695 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
696 CFG_SCSI_MAX_LUN] can be adjusted to define the
697 maximum numbers of LUNs, SCSI ID's and target
699 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
701 - NETWORK Support (PCI):
703 Support for Intel 8254x gigabit chips.
706 Support for Intel 82557/82559/82559ER chips.
707 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
708 write routine for first time initialisation.
711 Support for Digital 2114x chips.
712 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
713 modem chip initialisation (KS8761/QS6611).
716 Support for National dp83815 chips.
719 Support for National dp8382[01] gigabit chips.
721 - NETWORK Support (other):
723 CONFIG_DRIVER_LAN91C96
724 Support for SMSC's LAN91C96 chips.
727 Define this to hold the physical address
728 of the LAN91C96's I/O space
730 CONFIG_LAN91C96_USE_32_BIT
731 Define this to enable 32 bit addressing
734 At the moment only the UHCI host controller is
735 supported (PIP405, MIP405, MPC5200); define
736 CONFIG_USB_UHCI to enable it.
737 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
738 end define CONFIG_USB_STORAGE to enable the USB
741 Supported are USB Keyboards and USB Floppy drives
743 MPC5200 USB requires additional defines:
745 for 528 MHz Clock: 0x0001bbbb
747 for differential drivers: 0x00001000
748 for single ended drivers: 0x00005000
752 The MMC controller on the Intel PXA is supported. To
753 enable this define CONFIG_MMC. The MMC can be
754 accessed from the boot prompt by mapping the device
755 to physical memory similar to flash. Command line is
756 enabled with CFG_CMD_MMC. The MMC driver also works with
757 the FAT fs. This is enabled with CFG_CMD_FAT.
762 Define this to enable standard (PC-Style) keyboard
766 Standard PC keyboard driver with US (is default) and
767 GERMAN key layout (switch via environment 'keymap=de') support.
768 Export function i8042_kbd_init, i8042_tstc and i8042_getc
769 for cfb_console. Supports cursor blinking.
774 Define this to enable video support (for output to
779 Enable Chips & Technologies 69000 Video chip
781 CONFIG_VIDEO_SMI_LYNXEM
782 Enable Silicon Motion SMI 712/710/810 Video chip. The
783 video output is selected via environment 'videoout'
784 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
787 For the CT69000 and SMI_LYNXEM drivers, videomode is
788 selected via environment 'videomode'. Two diferent ways
790 - "videomode=num" 'num' is a standard LiLo mode numbers.
791 Following standard modes are supported (* is default):
793 Colors 640x480 800x600 1024x768 1152x864 1280x1024
794 -------------+---------------------------------------------
795 8 bits | 0x301* 0x303 0x305 0x161 0x307
796 15 bits | 0x310 0x313 0x316 0x162 0x319
797 16 bits | 0x311 0x314 0x317 0x163 0x31A
798 24 bits | 0x312 0x315 0x318 ? 0x31B
799 -------------+---------------------------------------------
800 (i.e. setenv videomode 317; saveenv; reset;)
802 - "videomode=bootargs" all the video parameters are parsed
803 from the bootargs. (See drivers/videomodes.c)
806 CONFIG_VIDEO_SED13806
807 Enable Epson SED13806 driver. This driver supports 8bpp
808 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
809 or CONFIG_VIDEO_SED13806_16BPP
814 Define this to enable a custom keyboard support.
815 This simply calls drv_keyboard_init() which must be
816 defined in your board-specific files.
817 The only board using this so far is RBC823.
819 - LCD Support: CONFIG_LCD
821 Define this to enable LCD support (for output to LCD
822 display); also select one of the supported displays
823 by defining one of these:
825 CONFIG_NEC_NL6448AC33:
827 NEC NL6448AC33-18. Active, color, single scan.
829 CONFIG_NEC_NL6448BC20
831 NEC NL6448BC20-08. 6.5", 640x480.
832 Active, color, single scan.
834 CONFIG_NEC_NL6448BC33_54
836 NEC NL6448BC33-54. 10.4", 640x480.
837 Active, color, single scan.
841 Sharp 320x240. Active, color, single scan.
842 It isn't 16x9, and I am not sure what it is.
844 CONFIG_SHARP_LQ64D341
846 Sharp LQ64D341 display, 640x480.
847 Active, color, single scan.
851 HLD1045 display, 640x480.
852 Active, color, single scan.
856 Optrex CBL50840-2 NF-FW 99 22 M5
858 Hitachi LMG6912RPFC-00T
862 320x240. Black & white.
864 Normally display is black on white background; define
865 CFG_WHITE_ON_BLACK to get it inverted.
867 - Splash Screen Support: CONFIG_SPLASH_SCREEN
869 If this option is set, the environment is checked for
870 a variable "splashimage". If found, the usual display
871 of logo, copyright and system information on the LCD
872 is supressed and the BMP image at the address
873 specified in "splashimage" is loaded instead. The
874 console is redirected to the "nulldev", too. This
875 allows for a "silent" boot where a splash screen is
876 loaded very quickly after power-on.
878 - Compression support:
881 If this option is set, support for bzip2 compressed
882 images is included. If not, only uncompressed and gzip
883 compressed images are supported.
885 NOTE: the bzip2 algorithm requires a lot of RAM, so
886 the malloc area (as defined by CFG_MALLOC_LEN) should
894 Define a default value for ethernet address to use
895 for the respective ethernet interface, in case this
896 is not determined automatically.
901 Define a default value for the IP address to use for
902 the default ethernet interface, in case this is not
903 determined through e.g. bootp.
908 Defines a default value for theIP address of a TFTP
909 server to contact when using the "tftboot" command.
911 - BOOTP Recovery Mode:
912 CONFIG_BOOTP_RANDOM_DELAY
914 If you have many targets in a network that try to
915 boot using BOOTP, you may want to avoid that all
916 systems send out BOOTP requests at precisely the same
917 moment (which would happen for instance at recovery
918 from a power failure, when all systems will try to
919 boot, thus flooding the BOOTP server. Defining
920 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
921 inserted before sending out BOOTP requests. The
922 following delays are insterted then:
924 1st BOOTP request: delay 0 ... 1 sec
925 2nd BOOTP request: delay 0 ... 2 sec
926 3rd BOOTP request: delay 0 ... 4 sec
928 BOOTP requests: delay 0 ... 8 sec
930 - DHCP Advanced Options:
933 You can fine tune the DHCP functionality by adding
934 these flags to the CONFIG_BOOTP_MASK define:
936 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
937 serverip from a DHCP server, it is possible that more
938 than one DNS serverip is offered to the client.
939 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
940 serverip will be stored in the additional environment
941 variable "dnsip2". The first DNS serverip is always
942 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
943 is added to the CONFIG_BOOTP_MASK.
945 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
946 to do a dynamic update of a DNS server. To do this, they
947 need the hostname of the DHCP requester.
948 If CONFIG_BOOP_SEND_HOSTNAME is added to the
949 CONFIG_BOOTP_MASK, the content of the "hostname"
950 environment variable is passed as option 12 to
956 The device id used in CDP trigger frames.
958 CONFIG_CDP_DEVICE_ID_PREFIX
960 A two character string which is prefixed to the MAC address
965 A printf format string which contains the ascii name of
966 the port. Normally is set to "eth%d" which sets
967 eth0 for the first ethernet, eth1 for the second etc.
969 CONFIG_CDP_CAPABILITIES
971 A 32bit integer which indicates the device capabilities;
972 0x00000010 for a normal host which does not forwards.
976 An ascii string containing the version of the software.
980 An ascii string containing the name of the platform.
984 A 32bit integer sent on the trigger.
986 CONFIG_CDP_POWER_CONSUMPTION
988 A 16bit integer containing the power consumption of the
989 device in .1 of milliwatts.
991 CONFIG_CDP_APPLIANCE_VLAN_TYPE
993 A byte containing the id of the VLAN.
995 - Status LED: CONFIG_STATUS_LED
997 Several configurations allow to display the current
998 status using a LED. For instance, the LED will blink
999 fast while running U-Boot code, stop blinking as
1000 soon as a reply to a BOOTP request was received, and
1001 start blinking slow once the Linux kernel is running
1002 (supported by a status LED driver in the Linux
1003 kernel). Defining CONFIG_STATUS_LED enables this
1006 - CAN Support: CONFIG_CAN_DRIVER
1008 Defining CONFIG_CAN_DRIVER enables CAN driver support
1009 on those systems that support this (optional)
1010 feature, like the TQM8xxL modules.
1012 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1014 These enable I2C serial bus commands. Defining either of
1015 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1016 include the appropriate I2C driver for the selected cpu.
1018 This will allow you to use i2c commands at the u-boot
1019 command line (as long as you set CFG_CMD_I2C in
1020 CONFIG_COMMANDS) and communicate with i2c based realtime
1021 clock chips. See common/cmd_i2c.c for a description of the
1022 command line interface.
1024 CONFIG_HARD_I2C selects the CPM hardware driver for I2C.
1026 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1027 bit-banging) driver instead of CPM or similar hardware
1030 There are several other quantities that must also be
1031 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1033 In both cases you will need to define CFG_I2C_SPEED
1034 to be the frequency (in Hz) at which you wish your i2c bus
1035 to run and CFG_I2C_SLAVE to be the address of this node (ie
1036 the cpu's i2c node address).
1038 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1039 sets the cpu up as a master node and so its address should
1040 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1041 p.16-473). So, set CFG_I2C_SLAVE to 0.
1043 That's all that's required for CONFIG_HARD_I2C.
1045 If you use the software i2c interface (CONFIG_SOFT_I2C)
1046 then the following macros need to be defined (examples are
1047 from include/configs/lwmon.h):
1051 (Optional). Any commands necessary to enable the I2C
1052 controller or configure ports.
1054 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1058 (Only for MPC8260 CPU). The I/O port to use (the code
1059 assumes both bits are on the same port). Valid values
1060 are 0..3 for ports A..D.
1064 The code necessary to make the I2C data line active
1065 (driven). If the data line is open collector, this
1068 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1072 The code necessary to make the I2C data line tri-stated
1073 (inactive). If the data line is open collector, this
1076 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1080 Code that returns TRUE if the I2C data line is high,
1083 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1087 If <bit> is TRUE, sets the I2C data line high. If it
1088 is FALSE, it clears it (low).
1090 eg: #define I2C_SDA(bit) \
1091 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1092 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1096 If <bit> is TRUE, sets the I2C clock line high. If it
1097 is FALSE, it clears it (low).
1099 eg: #define I2C_SCL(bit) \
1100 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1101 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1105 This delay is invoked four times per clock cycle so this
1106 controls the rate of data transfer. The data rate thus
1107 is 1 / (I2C_DELAY * 4). Often defined to be something
1110 #define I2C_DELAY udelay(2)
1114 When a board is reset during an i2c bus transfer
1115 chips might think that the current transfer is still
1116 in progress. On some boards it is possible to access
1117 the i2c SCLK line directly, either by using the
1118 processor pin as a GPIO or by having a second pin
1119 connected to the bus. If this option is defined a
1120 custom i2c_init_board() routine in boards/xxx/board.c
1121 is run early in the boot sequence.
1123 - SPI Support: CONFIG_SPI
1125 Enables SPI driver (so far only tested with
1126 SPI EEPROM, also an instance works with Crystal A/D and
1127 D/As on the SACSng board)
1131 Enables extended (16-bit) SPI EEPROM addressing.
1132 (symmetrical to CONFIG_I2C_X)
1136 Enables a software (bit-bang) SPI driver rather than
1137 using hardware support. This is a general purpose
1138 driver that only requires three general I/O port pins
1139 (two outputs, one input) to function. If this is
1140 defined, the board configuration must define several
1141 SPI configuration items (port pins to use, etc). For
1142 an example, see include/configs/sacsng.h.
1144 - FPGA Support: CONFIG_FPGA_COUNT
1146 Specify the number of FPGA devices to support.
1150 Used to specify the types of FPGA devices. For example,
1151 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
1153 CFG_FPGA_PROG_FEEDBACK
1155 Enable printing of hash marks during FPGA configuration.
1159 Enable checks on FPGA configuration interface busy
1160 status by the configuration function. This option
1161 will require a board or device specific function to
1166 If defined, a function that provides delays in the FPGA
1167 configuration driver.
1169 CFG_FPGA_CHECK_CTRLC
1170 Allow Control-C to interrupt FPGA configuration
1172 CFG_FPGA_CHECK_ERROR
1174 Check for configuration errors during FPGA bitfile
1175 loading. For example, abort during Virtex II
1176 configuration if the INIT_B line goes low (which
1177 indicated a CRC error).
1181 Maximum time to wait for the INIT_B line to deassert
1182 after PROB_B has been deasserted during a Virtex II
1183 FPGA configuration sequence. The default time is 500
1188 Maximum time to wait for BUSY to deassert during
1189 Virtex II FPGA configuration. The default is 5 mS.
1191 CFG_FPGA_WAIT_CONFIG
1193 Time to wait after FPGA configuration. The default is
1196 - Configuration Management:
1199 If defined, this string will be added to the U-Boot
1200 version information (U_BOOT_VERSION)
1202 - Vendor Parameter Protection:
1204 U-Boot considers the values of the environment
1205 variables "serial#" (Board Serial Number) and
1206 "ethaddr" (Ethernet Address) to be parameters that
1207 are set once by the board vendor / manufacturer, and
1208 protects these variables from casual modification by
1209 the user. Once set, these variables are read-only,
1210 and write or delete attempts are rejected. You can
1211 change this behviour:
1213 If CONFIG_ENV_OVERWRITE is #defined in your config
1214 file, the write protection for vendor parameters is
1215 completely disabled. Anybody can change or delete
1218 Alternatively, if you #define _both_ CONFIG_ETHADDR
1219 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1220 ethernet address is installed in the environment,
1221 which can be changed exactly ONCE by the user. [The
1222 serial# is unaffected by this, i. e. it remains
1228 Define this variable to enable the reservation of
1229 "protected RAM", i. e. RAM which is not overwritten
1230 by U-Boot. Define CONFIG_PRAM to hold the number of
1231 kB you want to reserve for pRAM. You can overwrite
1232 this default value by defining an environment
1233 variable "pram" to the number of kB you want to
1234 reserve. Note that the board info structure will
1235 still show the full amount of RAM. If pRAM is
1236 reserved, a new environment variable "mem" will
1237 automatically be defined to hold the amount of
1238 remaining RAM in a form that can be passed as boot
1239 argument to Linux, for instance like that:
1241 setenv bootargs ... mem=\$(mem)
1244 This way you can tell Linux not to use this memory,
1245 either, which results in a memory region that will
1246 not be affected by reboots.
1248 *WARNING* If your board configuration uses automatic
1249 detection of the RAM size, you must make sure that
1250 this memory test is non-destructive. So far, the
1251 following board configurations are known to be
1254 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1255 HERMES, IP860, RPXlite, LWMON, LANTEC,
1256 PCU_E, FLAGADM, TQM8260
1261 Define this variable to stop the system in case of a
1262 fatal error, so that you have to reset it manually.
1263 This is probably NOT a good idea for an embedded
1264 system where you want to system to reboot
1265 automatically as fast as possible, but it may be
1266 useful during development since you can try to debug
1267 the conditions that lead to the situation.
1269 CONFIG_NET_RETRY_COUNT
1271 This variable defines the number of retries for
1272 network operations like ARP, RARP, TFTP, or BOOTP
1273 before giving up the operation. If not defined, a
1274 default value of 5 is used.
1276 - Command Interpreter:
1279 Enable auto completion of commands using TAB.
1283 Define this variable to enable the "hush" shell (from
1284 Busybox) as command line interpreter, thus enabling
1285 powerful command line syntax like
1286 if...then...else...fi conditionals or `&&' and '||'
1287 constructs ("shell scripts").
1289 If undefined, you get the old, much simpler behaviour
1290 with a somewhat smaller memory footprint.
1295 This defines the secondary prompt string, which is
1296 printed when the command interpreter needs more input
1297 to complete a command. Usually "> ".
1301 In the current implementation, the local variables
1302 space and global environment variables space are
1303 separated. Local variables are those you define by
1304 simply typing `name=value'. To access a local
1305 variable later on, you have write `$name' or
1306 `${name}'; to execute the contents of a variable
1307 directly type `$name' at the command prompt.
1309 Global environment variables are those you use
1310 setenv/printenv to work with. To run a command stored
1311 in such a variable, you need to use the run command,
1312 and you must not use the '$' sign to access them.
1314 To store commands and special characters in a
1315 variable, please use double quotation marks
1316 surrounding the whole text of the variable, instead
1317 of the backslashes before semicolons and special
1320 - Default Environment:
1321 CONFIG_EXTRA_ENV_SETTINGS
1323 Define this to contain any number of null terminated
1324 strings (variable = value pairs) that will be part of
1325 the default environment compiled into the boot image.
1327 For example, place something like this in your
1328 board's config file:
1330 #define CONFIG_EXTRA_ENV_SETTINGS \
1334 Warning: This method is based on knowledge about the
1335 internal format how the environment is stored by the
1336 U-Boot code. This is NOT an official, exported
1337 interface! Although it is unlikely that this format
1338 will change soon, there is no guarantee either.
1339 You better know what you are doing here.
1341 Note: overly (ab)use of the default environment is
1342 discouraged. Make sure to check other ways to preset
1343 the environment like the autoscript function or the
1346 - DataFlash Support:
1347 CONFIG_HAS_DATAFLASH
1349 Defining this option enables DataFlash features and
1350 allows to read/write in Dataflash via the standard
1353 - SystemACE Support:
1356 Adding this option adds support for Xilinx SystemACE
1357 chips attached via some sort of local bus. The address
1358 of the chip must alsh be defined in the
1359 CFG_SYSTEMACE_BASE macro. For example:
1361 #define CONFIG_SYSTEMACE
1362 #define CFG_SYSTEMACE_BASE 0xf0000000
1364 When SystemACE support is added, the "ace" device type
1365 becomes available to the fat commands, i.e. fatls.
1367 - Show boot progress:
1368 CONFIG_SHOW_BOOT_PROGRESS
1370 Defining this option allows to add some board-
1371 specific code (calling a user-provided function
1372 "show_boot_progress(int)") that enables you to show
1373 the system's boot progress on some display (for
1374 example, some LED's) on your board. At the moment,
1375 the following checkpoints are implemented:
1378 1 common/cmd_bootm.c before attempting to boot an image
1379 -1 common/cmd_bootm.c Image header has bad magic number
1380 2 common/cmd_bootm.c Image header has correct magic number
1381 -2 common/cmd_bootm.c Image header has bad checksum
1382 3 common/cmd_bootm.c Image header has correct checksum
1383 -3 common/cmd_bootm.c Image data has bad checksum
1384 4 common/cmd_bootm.c Image data has correct checksum
1385 -4 common/cmd_bootm.c Image is for unsupported architecture
1386 5 common/cmd_bootm.c Architecture check OK
1387 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1388 6 common/cmd_bootm.c Image Type check OK
1389 -6 common/cmd_bootm.c gunzip uncompression error
1390 -7 common/cmd_bootm.c Unimplemented compression type
1391 7 common/cmd_bootm.c Uncompression OK
1392 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1393 8 common/cmd_bootm.c Image Type check OK
1394 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1395 9 common/cmd_bootm.c Start initial ramdisk verification
1396 -10 common/cmd_bootm.c Ramdisk header has bad magic number
1397 -11 common/cmd_bootm.c Ramdisk header has bad checksum
1398 10 common/cmd_bootm.c Ramdisk header is OK
1399 -12 common/cmd_bootm.c Ramdisk data has bad checksum
1400 11 common/cmd_bootm.c Ramdisk data has correct checksum
1401 12 common/cmd_bootm.c Ramdisk verification complete, start loading
1402 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk)
1403 13 common/cmd_bootm.c Start multifile image verification
1404 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue.
1405 15 common/cmd_bootm.c All preparation done, transferring control to OS
1407 -30 lib_ppc/board.c Fatal error, hang the system
1408 -31 post/post.c POST test failed, detected by post_output_backlog()
1409 -32 post/post.c POST test failed, detected by post_run_single()
1411 -1 common/cmd_doc.c Bad usage of "doc" command
1412 -1 common/cmd_doc.c No boot device
1413 -1 common/cmd_doc.c Unknown Chip ID on boot device
1414 -1 common/cmd_doc.c Read Error on boot device
1415 -1 common/cmd_doc.c Image header has bad magic number
1417 -1 common/cmd_ide.c Bad usage of "ide" command
1418 -1 common/cmd_ide.c No boot device
1419 -1 common/cmd_ide.c Unknown boot device
1420 -1 common/cmd_ide.c Unknown partition table
1421 -1 common/cmd_ide.c Invalid partition type
1422 -1 common/cmd_ide.c Read Error on boot device
1423 -1 common/cmd_ide.c Image header has bad magic number
1425 -1 common/cmd_nand.c Bad usage of "nand" command
1426 -1 common/cmd_nand.c No boot device
1427 -1 common/cmd_nand.c Unknown Chip ID on boot device
1428 -1 common/cmd_nand.c Read Error on boot device
1429 -1 common/cmd_nand.c Image header has bad magic number
1431 -1 common/env_common.c Environment has a bad CRC, using default
1437 [so far only for SMDK2400 and TRAB boards]
1439 - Modem support endable:
1440 CONFIG_MODEM_SUPPORT
1442 - RTS/CTS Flow control enable:
1445 - Modem debug support:
1446 CONFIG_MODEM_SUPPORT_DEBUG
1448 Enables debugging stuff (char screen[1024], dbg())
1449 for modem support. Useful only with BDI2000.
1451 - Interrupt support (PPC):
1453 There are common interrupt_init() and timer_interrupt()
1454 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
1455 for cpu specific initialization. interrupt_init_cpu()
1456 should set decrementer_count to appropriate value. If
1457 cpu resets decrementer automatically after interrupt
1458 (ppc4xx) it should set decrementer_count to zero.
1459 timer_interrupt() calls timer_interrupt_cpu() for cpu
1460 specific handling. If board has watchdog / status_led
1461 / other_activity_monitor it works automatically from
1462 general timer_interrupt().
1466 In the target system modem support is enabled when a
1467 specific key (key combination) is pressed during
1468 power-on. Otherwise U-Boot will boot normally
1469 (autoboot). The key_pressed() fuction is called from
1470 board_init(). Currently key_pressed() is a dummy
1471 function, returning 1 and thus enabling modem
1474 If there are no modem init strings in the
1475 environment, U-Boot proceed to autoboot; the
1476 previous output (banner, info printfs) will be
1479 See also: doc/README.Modem
1482 Configuration Settings:
1483 -----------------------
1485 - CFG_LONGHELP: Defined when you want long help messages included;
1486 undefine this when you're short of memory.
1488 - CFG_PROMPT: This is what U-Boot prints on the console to
1489 prompt for user input.
1491 - CFG_CBSIZE: Buffer size for input from the Console
1493 - CFG_PBSIZE: Buffer size for Console output
1495 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1497 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1498 the application (usually a Linux kernel) when it is
1501 - CFG_BAUDRATE_TABLE:
1502 List of legal baudrate settings for this board.
1504 - CFG_CONSOLE_INFO_QUIET
1505 Suppress display of console information at boot.
1507 - CFG_CONSOLE_IS_IN_ENV
1508 If the board specific function
1509 extern int overwrite_console (void);
1510 returns 1, the stdin, stderr and stdout are switched to the
1511 serial port, else the settings in the environment are used.
1513 - CFG_CONSOLE_OVERWRITE_ROUTINE
1514 Enable the call to overwrite_console().
1516 - CFG_CONSOLE_ENV_OVERWRITE
1517 Enable overwrite of previous console environment settings.
1519 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1520 Begin and End addresses of the area used by the
1524 Enable an alternate, more extensive memory test.
1526 - CFG_MEMTEST_SCRATCH:
1527 Scratch address used by the alternate memory test
1528 You only need to set this if address zero isn't writeable
1530 - CFG_TFTP_LOADADDR:
1531 Default load address for network file downloads
1533 - CFG_LOADS_BAUD_CHANGE:
1534 Enable temporary baudrate change while serial download
1537 Physical start address of SDRAM. _Must_ be 0 here.
1540 Physical start address of Motherboard I/O (if using a
1544 Physical start address of Flash memory.
1547 Physical start address of boot monitor code (set by
1548 make config files to be same as the text base address
1549 (TEXT_BASE) used when linking) - same as
1550 CFG_FLASH_BASE when booting from flash.
1553 Size of memory reserved for monitor code, used to
1554 determine _at_compile_time_ (!) if the environment is
1555 embedded within the U-Boot image, or in a separate
1559 Size of DRAM reserved for malloc() use.
1562 Maximum size of memory mapped by the startup code of
1563 the Linux kernel; all data that must be processed by
1564 the Linux kernel (bd_info, boot arguments, eventually
1565 initrd image) must be put below this limit.
1567 - CFG_MAX_FLASH_BANKS:
1568 Max number of Flash memory banks
1570 - CFG_MAX_FLASH_SECT:
1571 Max number of sectors on a Flash chip
1573 - CFG_FLASH_ERASE_TOUT:
1574 Timeout for Flash erase operations (in ms)
1576 - CFG_FLASH_WRITE_TOUT:
1577 Timeout for Flash write operations (in ms)
1579 - CFG_FLASH_LOCK_TOUT
1580 Timeout for Flash set sector lock bit operation (in ms)
1582 - CFG_FLASH_UNLOCK_TOUT
1583 Timeout for Flash clear lock bits operation (in ms)
1585 - CFG_FLASH_PROTECTION
1586 If defined, hardware flash sectors protection is used
1587 instead of U-Boot software protection.
1589 - CFG_DIRECT_FLASH_TFTP:
1591 Enable TFTP transfers directly to flash memory;
1592 without this option such a download has to be
1593 performed in two steps: (1) download to RAM, and (2)
1594 copy from RAM to flash.
1596 The two-step approach is usually more reliable, since
1597 you can check if the download worked before you erase
1598 the flash, but in some situations (when sytem RAM is
1599 too limited to allow for a tempory copy of the
1600 downloaded image) this option may be very useful.
1603 Define if the flash driver uses extra elements in the
1604 common flash structure for storing flash geometry.
1606 - CFG_FLASH_CFI_DRIVER
1607 This option also enables the building of the cfi_flash driver
1608 in the drivers directory
1610 - CFG_RX_ETH_BUFFER:
1611 Defines the number of ethernet receive buffers. On some
1612 ethernet controllers it is recommended to set this value
1613 to 8 or even higher (EEPRO100 or 405 EMAC), since all
1614 buffers can be full shortly after enabling the interface
1615 on high ethernet traffic.
1616 Defaults to 4 if not defined.
1618 The following definitions that deal with the placement and management
1619 of environment data (variable area); in general, we support the
1620 following configurations:
1622 - CFG_ENV_IS_IN_FLASH:
1624 Define this if the environment is in flash memory.
1626 a) The environment occupies one whole flash sector, which is
1627 "embedded" in the text segment with the U-Boot code. This
1628 happens usually with "bottom boot sector" or "top boot
1629 sector" type flash chips, which have several smaller
1630 sectors at the start or the end. For instance, such a
1631 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
1632 such a case you would place the environment in one of the
1633 4 kB sectors - with U-Boot code before and after it. With
1634 "top boot sector" type flash chips, you would put the
1635 environment in one of the last sectors, leaving a gap
1636 between U-Boot and the environment.
1640 Offset of environment data (variable area) to the
1641 beginning of flash memory; for instance, with bottom boot
1642 type flash chips the second sector can be used: the offset
1643 for this sector is given here.
1645 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
1649 This is just another way to specify the start address of
1650 the flash sector containing the environment (instead of
1653 - CFG_ENV_SECT_SIZE:
1655 Size of the sector containing the environment.
1658 b) Sometimes flash chips have few, equal sized, BIG sectors.
1659 In such a case you don't want to spend a whole sector for
1664 If you use this in combination with CFG_ENV_IS_IN_FLASH
1665 and CFG_ENV_SECT_SIZE, you can specify to use only a part
1666 of this flash sector for the environment. This saves
1667 memory for the RAM copy of the environment.
1669 It may also save flash memory if you decide to use this
1670 when your environment is "embedded" within U-Boot code,
1671 since then the remainder of the flash sector could be used
1672 for U-Boot code. It should be pointed out that this is
1673 STRONGLY DISCOURAGED from a robustness point of view:
1674 updating the environment in flash makes it always
1675 necessary to erase the WHOLE sector. If something goes
1676 wrong before the contents has been restored from a copy in
1677 RAM, your target system will be dead.
1679 - CFG_ENV_ADDR_REDUND
1682 These settings describe a second storage area used to hold
1683 a redundand copy of the environment data, so that there is
1684 a valid backup copy in case there is a power failure during
1685 a "saveenv" operation.
1687 BE CAREFUL! Any changes to the flash layout, and some changes to the
1688 source code will make it necessary to adapt <board>/u-boot.lds*
1692 - CFG_ENV_IS_IN_NVRAM:
1694 Define this if you have some non-volatile memory device
1695 (NVRAM, battery buffered SRAM) which you want to use for the
1701 These two #defines are used to determin the memory area you
1702 want to use for environment. It is assumed that this memory
1703 can just be read and written to, without any special
1706 BE CAREFUL! The first access to the environment happens quite early
1707 in U-Boot initalization (when we try to get the setting of for the
1708 console baudrate). You *MUST* have mappend your NVRAM area then, or
1711 Please note that even with NVRAM we still use a copy of the
1712 environment in RAM: we could work on NVRAM directly, but we want to
1713 keep settings there always unmodified except somebody uses "saveenv"
1714 to save the current settings.
1717 - CFG_ENV_IS_IN_EEPROM:
1719 Use this if you have an EEPROM or similar serial access
1720 device and a driver for it.
1725 These two #defines specify the offset and size of the
1726 environment area within the total memory of your EEPROM.
1728 - CFG_I2C_EEPROM_ADDR:
1729 If defined, specified the chip address of the EEPROM device.
1730 The default address is zero.
1732 - CFG_EEPROM_PAGE_WRITE_BITS:
1733 If defined, the number of bits used to address bytes in a
1734 single page in the EEPROM device. A 64 byte page, for example
1735 would require six bits.
1737 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1738 If defined, the number of milliseconds to delay between
1739 page writes. The default is zero milliseconds.
1741 - CFG_I2C_EEPROM_ADDR_LEN:
1742 The length in bytes of the EEPROM memory array address. Note
1743 that this is NOT the chip address length!
1746 The size in bytes of the EEPROM device.
1749 - CFG_ENV_IS_IN_DATAFLASH:
1751 Define this if you have a DataFlash memory device which you
1752 want to use for the environment.
1758 These three #defines specify the offset and size of the
1759 environment area within the total memory of your DataFlash placed
1760 at the specified address.
1763 - CFG_SPI_INIT_OFFSET
1765 Defines offset to the initial SPI buffer area in DPRAM. The
1766 area is used at an early stage (ROM part) if the environment
1767 is configured to reside in the SPI EEPROM: We need a 520 byte
1768 scratch DPRAM area. It is used between the two initialization
1769 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
1770 to be a good choice since it makes it far enough from the
1771 start of the data area as well as from the stack pointer.
1773 Please note that the environment is read-only as long as the monitor
1774 has been relocated to RAM and a RAM copy of the environment has been
1775 created; also, when using EEPROM you will have to use getenv_r()
1776 until then to read environment variables.
1778 The environment is protected by a CRC32 checksum. Before the monitor
1779 is relocated into RAM, as a result of a bad CRC you will be working
1780 with the compiled-in default environment - *silently*!!! [This is
1781 necessary, because the first environment variable we need is the
1782 "baudrate" setting for the console - if we have a bad CRC, we don't
1783 have any device yet where we could complain.]
1785 Note: once the monitor has been relocated, then it will complain if
1786 the default environment is used; a new CRC is computed as soon as you
1787 use the "saveenv" command to store a valid environment.
1789 - CFG_FAULT_ECHO_LINK_DOWN:
1790 Echo the inverted Ethernet link state to the fault LED.
1792 Note: If this option is active, then CFG_FAULT_MII_ADDR
1793 also needs to be defined.
1795 - CFG_FAULT_MII_ADDR:
1796 MII address of the PHY to check for the Ethernet link state.
1798 - CFG_64BIT_VSPRINTF:
1799 Makes vsprintf (and all *printf functions) support printing
1800 of 64bit values by using the L quantifier
1802 - CFG_64BIT_STRTOUL:
1803 Adds simple_strtoull that returns a 64bit value
1805 Low Level (hardware related) configuration options:
1806 ---------------------------------------------------
1808 - CFG_CACHELINE_SIZE:
1809 Cache Line Size of the CPU.
1812 Default address of the IMMR after system reset.
1814 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
1815 and RPXsuper) to be able to adjust the position of
1816 the IMMR register after a reset.
1818 - Floppy Disk Support:
1819 CFG_FDC_DRIVE_NUMBER
1821 the default drive number (default value 0)
1825 defines the spacing between fdc chipset registers
1830 defines the offset of register from address. It
1831 depends on which part of the data bus is connected to
1832 the fdc chipset. (default value 0)
1834 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
1835 CFG_FDC_DRIVE_NUMBER are undefined, they take their
1838 if CFG_FDC_HW_INIT is defined, then the function
1839 fdc_hw_init() is called at the beginning of the FDC
1840 setup. fdc_hw_init() must be provided by the board
1841 source code. It is used to make hardware dependant
1844 - CFG_IMMR: Physical address of the Internal Memory Mapped
1845 Register; DO NOT CHANGE! (11-4)
1846 [MPC8xx systems only]
1848 - CFG_INIT_RAM_ADDR:
1850 Start address of memory area that can be used for
1851 initial data and stack; please note that this must be
1852 writable memory that is working WITHOUT special
1853 initialization, i. e. you CANNOT use normal RAM which
1854 will become available only after programming the
1855 memory controller and running certain initialization
1858 U-Boot uses the following memory types:
1859 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
1860 - MPC824X: data cache
1861 - PPC4xx: data cache
1863 - CFG_GBL_DATA_OFFSET:
1865 Offset of the initial data structure in the memory
1866 area defined by CFG_INIT_RAM_ADDR. Usually
1867 CFG_GBL_DATA_OFFSET is chosen such that the initial
1868 data is located at the end of the available space
1869 (sometimes written as (CFG_INIT_RAM_END -
1870 CFG_INIT_DATA_SIZE), and the initial stack is just
1871 below that area (growing from (CFG_INIT_RAM_ADDR +
1872 CFG_GBL_DATA_OFFSET) downward.
1875 On the MPC824X (or other systems that use the data
1876 cache for initial memory) the address chosen for
1877 CFG_INIT_RAM_ADDR is basically arbitrary - it must
1878 point to an otherwise UNUSED address space between
1879 the top of RAM and the start of the PCI space.
1881 - CFG_SIUMCR: SIU Module Configuration (11-6)
1883 - CFG_SYPCR: System Protection Control (11-9)
1885 - CFG_TBSCR: Time Base Status and Control (11-26)
1887 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
1889 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
1891 - CFG_SCCR: System Clock and reset Control Register (15-27)
1893 - CFG_OR_TIMING_SDRAM:
1897 periodic timer for refresh
1899 - CFG_DER: Debug Event Register (37-47)
1901 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
1902 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
1903 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
1905 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
1907 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
1908 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
1909 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
1910 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
1912 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
1913 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
1914 Machine Mode Register and Memory Periodic Timer
1915 Prescaler definitions (SDRAM timing)
1917 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
1918 enable I2C microcode relocation patch (MPC8xx);
1919 define relocation offset in DPRAM [DSP2]
1921 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
1922 enable SPI microcode relocation patch (MPC8xx);
1923 define relocation offset in DPRAM [SCC4]
1926 Use OSCM clock mode on MBX8xx board. Be careful,
1927 wrong setting might damage your board. Read
1928 doc/README.MBX before setting this variable!
1930 - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
1931 Offset of the bootmode word in DPRAM used by post
1932 (Power On Self Tests). This definition overrides
1933 #define'd default value in commproc.h resp.
1936 - CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
1937 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
1938 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
1939 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
1940 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
1941 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
1942 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
1943 CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
1944 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
1946 - CONFIG_ETHER_ON_FEC[12]
1947 Define to enable FEC[12] on a 8xx series processor.
1949 - CONFIG_FEC[12]_PHY
1950 Define to the hardcoded PHY address which corresponds
1951 to the given FEC; i. e.
1952 #define CONFIG_FEC1_PHY 4
1953 means that the PHY with address 4 is connected to FEC1
1955 When set to -1, means to probe for first available.
1957 - CONFIG_FEC[12]_PHY_NORXERR
1958 The PHY does not have a RXERR line (RMII only).
1959 (so program the FEC to ignore it).
1962 Enable RMII mode for all FECs.
1963 Note that this is a global option, we can't
1964 have one FEC in standard MII mode and another in RMII mode.
1966 Building the Software:
1967 ======================
1969 Building U-Boot has been tested in native PPC environments (on a
1970 PowerBook G3 running LinuxPPC 2000) and in cross environments
1971 (running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
1974 If you are not using a native PPC environment, it is assumed that you
1975 have the GNU cross compiling tools available in your path and named
1976 with a prefix of "powerpc-linux-". If this is not the case, (e.g. if
1977 you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
1978 the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
1981 CROSS_COMPILE = ppc_4xx-
1984 U-Boot is intended to be simple to build. After installing the
1985 sources you must configure U-Boot for one specific board type. This
1990 where "NAME_config" is the name of one of the existing
1991 configurations; the following names are supported:
1993 ADCIOP_config ADS860_config AR405_config
1994 at91rm9200dk_config CANBT_config cmi_mpc5xx_config
1995 cogent_common_config cogent_mpc8260_config cogent_mpc8xx_config
1996 CPCI405_config CPCIISER4_config CU824_config
1997 DUET_ADS_config EBONY_config ELPT860_config
1998 ESTEEM192E_config ETX094_config FADS823_config
1999 FADS850SAR_config FADS860T_config FPS850L_config
2000 FPS860L_config GEN860T_config GENIETV_config
2001 GTH_config hermes_config hymod_config
2002 IP860_config IVML24_config IVMS8_config
2003 JSE_config LANTEC_config lwmon_config
2004 MBX860T_config MBX_config MPC8260ADS_config
2005 MPC8540ADS_config MPC8560ADS_config NETVIA_config
2006 omap1510inn_config omap1610h2_config omap1610inn_config
2007 pcu_e_config PIP405_config QS823_config
2008 QS850_config QS860T_config RPXlite_config
2009 RPXsuper_config rsdproto_config Sandpoint8240_config
2010 sbc8260_config SM850_config SPD823TS_config
2011 SXNI855T_config TQM823L_config TQM850L_config
2012 TQM855L_config TQM860L_config WALNUT405_config
2015 Note: for some board special configuration names may exist; check if
2016 additional information is available from the board vendor; for
2017 instance, the TQM8xxL systems run normally at 50 MHz and use a
2018 SCC for 10baseT ethernet; there are also systems with 80 MHz
2019 CPU clock, and an optional Fast Ethernet module is available
2020 for CPU's with FEC. You can select such additional "features"
2021 when chosing the configuration, i. e.
2024 - will configure for a plain TQM860L, i. e. 50MHz, no FEC
2026 make TQM860L_FEC_config
2027 - will configure for a TQM860L at 50MHz with FEC for ethernet
2029 make TQM860L_80MHz_config
2030 - will configure for a TQM860L at 80 MHz, with normal 10baseT
2033 make TQM860L_FEC_80MHz_config
2034 - will configure for a TQM860L at 80 MHz with FEC for ethernet
2036 make TQM823L_LCD_config
2037 - will configure for a TQM823L with U-Boot console on LCD
2039 make TQM823L_LCD_80MHz_config
2040 - will configure for a TQM823L at 80 MHz with U-Boot console on LCD
2045 Finally, type "make all", and you should get some working U-Boot
2046 images ready for download to / installation on your system:
2048 - "u-boot.bin" is a raw binary image
2049 - "u-boot" is an image in ELF binary format
2050 - "u-boot.srec" is in Motorola S-Record format
2053 Please be aware that the Makefiles assume you are using GNU make, so
2054 for instance on NetBSD you might need to use "gmake" instead of
2058 If the system board that you have is not listed, then you will need
2059 to port U-Boot to your hardware platform. To do this, follow these
2062 1. Add a new configuration option for your board to the toplevel
2063 "Makefile" and to the "MAKEALL" script, using the existing
2064 entries as examples. Note that here and at many other places
2065 boards and other names are listed in alphabetical sort order. Please
2067 2. Create a new directory to hold your board specific code. Add any
2068 files you need. In your board directory, you will need at least
2069 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2070 3. Create a new configuration file "include/configs/<board>.h" for
2072 3. If you're porting U-Boot to a new CPU, then also create a new
2073 directory to hold your CPU specific code. Add any files you need.
2074 4. Run "make <board>_config" with your new name.
2075 5. Type "make", and you should get a working "u-boot.srec" file
2076 to be installed on your target system.
2077 6. Debug and solve any problems that might arise.
2078 [Of course, this last step is much harder than it sounds.]
2081 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2082 ==============================================================
2084 If you have modified U-Boot sources (for instance added a new board
2085 or support for new devices, a new CPU, etc.) you are expected to
2086 provide feedback to the other developers. The feedback normally takes
2087 the form of a "patch", i. e. a context diff against a certain (latest
2088 official or latest in CVS) version of U-Boot sources.
2090 But before you submit such a patch, please verify that your modifi-
2091 cation did not break existing code. At least make sure that *ALL* of
2092 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2093 just run the "MAKEALL" script, which will configure and build U-Boot
2094 for ALL supported system. Be warned, this will take a while. You can
2095 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2096 environment variable to the script, i. e. to use the cross tools from
2097 MontaVista's Hard Hat Linux you can type
2099 CROSS_COMPILE=ppc_8xx- MAKEALL
2101 or to build on a native PowerPC system you can type
2103 CROSS_COMPILE=' ' MAKEALL
2105 See also "U-Boot Porting Guide" below.
2108 Monitor Commands - Overview:
2109 ============================
2111 go - start application at address 'addr'
2112 run - run commands in an environment variable
2113 bootm - boot application image from memory
2114 bootp - boot image via network using BootP/TFTP protocol
2115 tftpboot- boot image via network using TFTP protocol
2116 and env variables "ipaddr" and "serverip"
2117 (and eventually "gatewayip")
2118 rarpboot- boot image via network using RARP/TFTP protocol
2119 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2120 loads - load S-Record file over serial line
2121 loadb - load binary file over serial line (kermit mode)
2123 mm - memory modify (auto-incrementing)
2124 nm - memory modify (constant address)
2125 mw - memory write (fill)
2127 cmp - memory compare
2128 crc32 - checksum calculation
2129 imd - i2c memory display
2130 imm - i2c memory modify (auto-incrementing)
2131 inm - i2c memory modify (constant address)
2132 imw - i2c memory write (fill)
2133 icrc32 - i2c checksum calculation
2134 iprobe - probe to discover valid I2C chip addresses
2135 iloop - infinite loop on address range
2136 isdram - print SDRAM configuration information
2137 sspi - SPI utility commands
2138 base - print or set address offset
2139 printenv- print environment variables
2140 setenv - set environment variables
2141 saveenv - save environment variables to persistent storage
2142 protect - enable or disable FLASH write protection
2143 erase - erase FLASH memory
2144 flinfo - print FLASH memory information
2145 bdinfo - print Board Info structure
2146 iminfo - print header information for application image
2147 coninfo - print console devices and informations
2148 ide - IDE sub-system
2149 loop - infinite loop on address range
2150 mtest - simple RAM test
2151 icache - enable or disable instruction cache
2152 dcache - enable or disable data cache
2153 reset - Perform RESET of the CPU
2154 echo - echo args to console
2155 version - print monitor version
2156 help - print online help
2157 ? - alias for 'help'
2160 Monitor Commands - Detailed Description:
2161 ========================================
2165 For now: just type "help <command>".
2168 Environment Variables:
2169 ======================
2171 U-Boot supports user configuration using Environment Variables which
2172 can be made persistent by saving to Flash memory.
2174 Environment Variables are set using "setenv", printed using
2175 "printenv", and saved to Flash using "saveenv". Using "setenv"
2176 without a value can be used to delete a variable from the
2177 environment. As long as you don't save the environment you are
2178 working with an in-memory copy. In case the Flash area containing the
2179 environment is erased by accident, a default environment is provided.
2181 Some configuration options can be set using Environment Variables:
2183 baudrate - see CONFIG_BAUDRATE
2185 bootdelay - see CONFIG_BOOTDELAY
2187 bootcmd - see CONFIG_BOOTCOMMAND
2189 bootargs - Boot arguments when booting an RTOS image
2191 bootfile - Name of the image to load with TFTP
2193 autoload - if set to "no" (any string beginning with 'n'),
2194 "bootp" will just load perform a lookup of the
2195 configuration from the BOOTP server, but not try to
2196 load any image using TFTP
2198 autostart - if set to "yes", an image loaded using the "bootp",
2199 "rarpboot", "tftpboot" or "diskboot" commands will
2200 be automatically started (by internally calling
2203 If set to "no", a standalone image passed to the
2204 "bootm" command will be copied to the load address
2205 (and eventually uncompressed), but NOT be started.
2206 This can be used to load and uncompress arbitrary
2209 initrd_high - restrict positioning of initrd images:
2210 If this variable is not set, initrd images will be
2211 copied to the highest possible address in RAM; this
2212 is usually what you want since it allows for
2213 maximum initrd size. If for some reason you want to
2214 make sure that the initrd image is loaded below the
2215 CFG_BOOTMAPSZ limit, you can set this environment
2216 variable to a value of "no" or "off" or "0".
2217 Alternatively, you can set it to a maximum upper
2218 address to use (U-Boot will still check that it
2219 does not overwrite the U-Boot stack and data).
2221 For instance, when you have a system with 16 MB
2222 RAM, and want to reserve 4 MB from use by Linux,
2223 you can do this by adding "mem=12M" to the value of
2224 the "bootargs" variable. However, now you must make
2225 sure that the initrd image is placed in the first
2226 12 MB as well - this can be done with
2228 setenv initrd_high 00c00000
2230 If you set initrd_high to 0xFFFFFFFF, this is an
2231 indication to U-Boot that all addresses are legal
2232 for the Linux kernel, including addresses in flash
2233 memory. In this case U-Boot will NOT COPY the
2234 ramdisk at all. This may be useful to reduce the
2235 boot time on your system, but requires that this
2236 feature is supported by your Linux kernel.
2238 ipaddr - IP address; needed for tftpboot command
2240 loadaddr - Default load address for commands like "bootp",
2241 "rarpboot", "tftpboot", "loadb" or "diskboot"
2243 loads_echo - see CONFIG_LOADS_ECHO
2245 serverip - TFTP server IP address; needed for tftpboot command
2247 bootretry - see CONFIG_BOOT_RETRY_TIME
2249 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
2251 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
2253 ethprime - When CONFIG_NET_MULTI is enabled controls which
2254 interface is used first.
2256 ethact - When CONFIG_NET_MULTI is enabled controls which
2257 interface is currently active. For example you
2258 can do the following
2260 => setenv ethact FEC ETHERNET
2261 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
2262 => setenv ethact SCC ETHERNET
2263 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
2265 netretry - When set to "no" each network operation will
2266 either succeed or fail without retrying.
2267 When set to "once" the network operation will
2268 fail when all the available network interfaces
2269 are tried once without success.
2270 Useful on scripts which control the retry operation
2273 vlan - When set to a value < 4095 the traffic over
2274 ethernet is encapsulated/received over 802.1q
2277 The following environment variables may be used and automatically
2278 updated by the network boot commands ("bootp" and "rarpboot"),
2279 depending the information provided by your boot server:
2281 bootfile - see above
2282 dnsip - IP address of your Domain Name Server
2283 dnsip2 - IP address of your secondary Domain Name Server
2284 gatewayip - IP address of the Gateway (Router) to use
2285 hostname - Target hostname
2287 netmask - Subnet Mask
2288 rootpath - Pathname of the root filesystem on the NFS server
2289 serverip - see above
2292 There are two special Environment Variables:
2294 serial# - contains hardware identification information such
2295 as type string and/or serial number
2296 ethaddr - Ethernet address
2298 These variables can be set only once (usually during manufacturing of
2299 the board). U-Boot refuses to delete or overwrite these variables
2300 once they have been set once.
2303 Further special Environment Variables:
2305 ver - Contains the U-Boot version string as printed
2306 with the "version" command. This variable is
2307 readonly (see CONFIG_VERSION_VARIABLE).
2310 Please note that changes to some configuration parameters may take
2311 only effect after the next boot (yes, that's just like Windoze :-).
2314 Command Line Parsing:
2315 =====================
2317 There are two different command line parsers available with U-Boot:
2318 the old "simple" one, and the much more powerful "hush" shell:
2320 Old, simple command line parser:
2321 --------------------------------
2323 - supports environment variables (through setenv / saveenv commands)
2324 - several commands on one line, separated by ';'
2325 - variable substitution using "... $(name) ..." syntax
2326 - special characters ('$', ';') can be escaped by prefixing with '\',
2328 setenv bootcmd bootm \$(address)
2329 - You can also escape text by enclosing in single apostrophes, for example:
2330 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2335 - similar to Bourne shell, with control structures like
2336 if...then...else...fi, for...do...done; while...do...done,
2337 until...do...done, ...
2338 - supports environment ("global") variables (through setenv / saveenv
2339 commands) and local shell variables (through standard shell syntax
2340 "name=value"); only environment variables can be used with "run"
2346 (1) If a command line (or an environment variable executed by a "run"
2347 command) contains several commands separated by semicolon, and
2348 one of these commands fails, then the remaining commands will be
2351 (2) If you execute several variables with one call to run (i. e.
2352 calling run with a list af variables as arguments), any failing
2353 command will cause "run" to terminate, i. e. the remaining
2354 variables are not executed.
2356 Note for Redundant Ethernet Interfaces:
2357 =======================================
2359 Some boards come with redundant ethernet interfaces; U-Boot supports
2360 such configurations and is capable of automatic selection of a
2361 "working" interface when needed. MAC assignment works as follows:
2363 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2364 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2365 "eth1addr" (=>eth1), "eth2addr", ...
2367 If the network interface stores some valid MAC address (for instance
2368 in SROM), this is used as default address if there is NO correspon-
2369 ding setting in the environment; if the corresponding environment
2370 variable is set, this overrides the settings in the card; that means:
2372 o If the SROM has a valid MAC address, and there is no address in the
2373 environment, the SROM's address is used.
2375 o If there is no valid address in the SROM, and a definition in the
2376 environment exists, then the value from the environment variable is
2379 o If both the SROM and the environment contain a MAC address, and
2380 both addresses are the same, this MAC address is used.
2382 o If both the SROM and the environment contain a MAC address, and the
2383 addresses differ, the value from the environment is used and a
2386 o If neither SROM nor the environment contain a MAC address, an error
2393 The "boot" commands of this monitor operate on "image" files which
2394 can be basicly anything, preceeded by a special header; see the
2395 definitions in include/image.h for details; basicly, the header
2396 defines the following image properties:
2398 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2399 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2400 LynxOS, pSOS, QNX, RTEMS, ARTOS;
2401 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
2402 * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
2403 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2404 Currently supported: ARM, Intel x86, MIPS, NIOS, PowerPC).
2405 * Compression Type (uncompressed, gzip, bzip2)
2411 The header is marked by a special Magic Number, and both the header
2412 and the data portions of the image are secured against corruption by
2419 Although U-Boot should support any OS or standalone application
2420 easily, the main focus has always been on Linux during the design of
2423 U-Boot includes many features that so far have been part of some
2424 special "boot loader" code within the Linux kernel. Also, any
2425 "initrd" images to be used are no longer part of one big Linux image;
2426 instead, kernel and "initrd" are separate images. This implementation
2427 serves several purposes:
2429 - the same features can be used for other OS or standalone
2430 applications (for instance: using compressed images to reduce the
2431 Flash memory footprint)
2433 - it becomes much easier to port new Linux kernel versions because
2434 lots of low-level, hardware dependent stuff are done by U-Boot
2436 - the same Linux kernel image can now be used with different "initrd"
2437 images; of course this also means that different kernel images can
2438 be run with the same "initrd". This makes testing easier (you don't
2439 have to build a new "zImage.initrd" Linux image when you just
2440 change a file in your "initrd"). Also, a field-upgrade of the
2441 software is easier now.
2447 Porting Linux to U-Boot based systems:
2448 ---------------------------------------
2450 U-Boot cannot save you from doing all the necessary modifications to
2451 configure the Linux device drivers for use with your target hardware
2452 (no, we don't intend to provide a full virtual machine interface to
2455 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
2457 Just make sure your machine specific header file (for instance
2458 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
2459 Information structure as we define in include/u-boot.h, and make
2460 sure that your definition of IMAP_ADDR uses the same value as your
2461 U-Boot configuration in CFG_IMMR.
2464 Configuring the Linux kernel:
2465 -----------------------------
2467 No specific requirements for U-Boot. Make sure you have some root
2468 device (initial ramdisk, NFS) for your target system.
2471 Building a Linux Image:
2472 -----------------------
2474 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2475 not used. If you use recent kernel source, a new build target
2476 "uImage" will exist which automatically builds an image usable by
2477 U-Boot. Most older kernels also have support for a "pImage" target,
2478 which was introduced for our predecessor project PPCBoot and uses a
2479 100% compatible format.
2488 The "uImage" build target uses a special tool (in 'tools/mkimage') to
2489 encapsulate a compressed Linux kernel image with header information,
2490 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
2492 * build a standard "vmlinux" kernel image (in ELF binary format):
2494 * convert the kernel into a raw binary image:
2496 ${CROSS_COMPILE}-objcopy -O binary \
2497 -R .note -R .comment \
2498 -S vmlinux linux.bin
2500 * compress the binary image:
2504 * package compressed binary image for U-Boot:
2506 mkimage -A ppc -O linux -T kernel -C gzip \
2507 -a 0 -e 0 -n "Linux Kernel Image" \
2508 -d linux.bin.gz uImage
2511 The "mkimage" tool can also be used to create ramdisk images for use
2512 with U-Boot, either separated from the Linux kernel image, or
2513 combined into one file. "mkimage" encapsulates the images with a 64
2514 byte header containing information about target architecture,
2515 operating system, image type, compression method, entry points, time
2516 stamp, CRC32 checksums, etc.
2518 "mkimage" can be called in two ways: to verify existing images and
2519 print the header information, or to build new images.
2521 In the first form (with "-l" option) mkimage lists the information
2522 contained in the header of an existing U-Boot image; this includes
2523 checksum verification:
2525 tools/mkimage -l image
2526 -l ==> list image header information
2528 The second form (with "-d" option) is used to build a U-Boot image
2529 from a "data file" which is used as image payload:
2531 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2532 -n name -d data_file image
2533 -A ==> set architecture to 'arch'
2534 -O ==> set operating system to 'os'
2535 -T ==> set image type to 'type'
2536 -C ==> set compression type 'comp'
2537 -a ==> set load address to 'addr' (hex)
2538 -e ==> set entry point to 'ep' (hex)
2539 -n ==> set image name to 'name'
2540 -d ==> use image data from 'datafile'
2542 Right now, all Linux kernels use the same load address (0x00000000),
2543 but the entry point address depends on the kernel version:
2545 - 2.2.x kernels have the entry point at 0x0000000C,
2546 - 2.3.x and later kernels have the entry point at 0x00000000.
2548 So a typical call to build a U-Boot image would read:
2550 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2551 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
2552 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
2553 > examples/uImage.TQM850L
2554 Image Name: 2.4.4 kernel for TQM850L
2555 Created: Wed Jul 19 02:34:59 2000
2556 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2557 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2558 Load Address: 0x00000000
2559 Entry Point: 0x00000000
2561 To verify the contents of the image (or check for corruption):
2563 -> tools/mkimage -l examples/uImage.TQM850L
2564 Image Name: 2.4.4 kernel for TQM850L
2565 Created: Wed Jul 19 02:34:59 2000
2566 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2567 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2568 Load Address: 0x00000000
2569 Entry Point: 0x00000000
2571 NOTE: for embedded systems where boot time is critical you can trade
2572 speed for memory and install an UNCOMPRESSED image instead: this
2573 needs more space in Flash, but boots much faster since it does not
2574 need to be uncompressed:
2576 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
2577 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2578 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
2579 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
2580 > examples/uImage.TQM850L-uncompressed
2581 Image Name: 2.4.4 kernel for TQM850L
2582 Created: Wed Jul 19 02:34:59 2000
2583 Image Type: PowerPC Linux Kernel Image (uncompressed)
2584 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
2585 Load Address: 0x00000000
2586 Entry Point: 0x00000000
2589 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2590 when your kernel is intended to use an initial ramdisk:
2592 -> tools/mkimage -n 'Simple Ramdisk Image' \
2593 > -A ppc -O linux -T ramdisk -C gzip \
2594 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2595 Image Name: Simple Ramdisk Image
2596 Created: Wed Jan 12 14:01:50 2000
2597 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2598 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
2599 Load Address: 0x00000000
2600 Entry Point: 0x00000000
2603 Installing a Linux Image:
2604 -------------------------
2606 To downloading a U-Boot image over the serial (console) interface,
2607 you must convert the image to S-Record format:
2609 objcopy -I binary -O srec examples/image examples/image.srec
2611 The 'objcopy' does not understand the information in the U-Boot
2612 image header, so the resulting S-Record file will be relative to
2613 address 0x00000000. To load it to a given address, you need to
2614 specify the target address as 'offset' parameter with the 'loads'
2617 Example: install the image to address 0x40100000 (which on the
2618 TQM8xxL is in the first Flash bank):
2620 => erase 40100000 401FFFFF
2626 ## Ready for S-Record download ...
2627 ~>examples/image.srec
2628 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2630 15989 15990 15991 15992
2631 [file transfer complete]
2633 ## Start Addr = 0x00000000
2636 You can check the success of the download using the 'iminfo' command;
2637 this includes a checksum verification so you can be sure no data
2638 corruption happened:
2642 ## Checking Image at 40100000 ...
2643 Image Name: 2.2.13 for initrd on TQM850L
2644 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2645 Data Size: 335725 Bytes = 327 kB = 0 MB
2646 Load Address: 00000000
2647 Entry Point: 0000000c
2648 Verifying Checksum ... OK
2654 The "bootm" command is used to boot an application that is stored in
2655 memory (RAM or Flash). In case of a Linux kernel image, the contents
2656 of the "bootargs" environment variable is passed to the kernel as
2657 parameters. You can check and modify this variable using the
2658 "printenv" and "setenv" commands:
2661 => printenv bootargs
2662 bootargs=root=/dev/ram
2664 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2666 => printenv bootargs
2667 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2670 ## Booting Linux kernel at 40020000 ...
2671 Image Name: 2.2.13 for NFS on TQM850L
2672 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2673 Data Size: 381681 Bytes = 372 kB = 0 MB
2674 Load Address: 00000000
2675 Entry Point: 0000000c
2676 Verifying Checksum ... OK
2677 Uncompressing Kernel Image ... OK
2678 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
2679 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2680 time_init: decrementer frequency = 187500000/60
2681 Calibrating delay loop... 49.77 BogoMIPS
2682 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2685 If you want to boot a Linux kernel with initial ram disk, you pass
2686 the memory addresses of both the kernel and the initrd image (PPBCOOT
2687 format!) to the "bootm" command:
2689 => imi 40100000 40200000
2691 ## Checking Image at 40100000 ...
2692 Image Name: 2.2.13 for initrd on TQM850L
2693 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2694 Data Size: 335725 Bytes = 327 kB = 0 MB
2695 Load Address: 00000000
2696 Entry Point: 0000000c
2697 Verifying Checksum ... OK
2699 ## Checking Image at 40200000 ...
2700 Image Name: Simple Ramdisk Image
2701 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2702 Data Size: 566530 Bytes = 553 kB = 0 MB
2703 Load Address: 00000000
2704 Entry Point: 00000000
2705 Verifying Checksum ... OK
2707 => bootm 40100000 40200000
2708 ## Booting Linux kernel at 40100000 ...
2709 Image Name: 2.2.13 for initrd on TQM850L
2710 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2711 Data Size: 335725 Bytes = 327 kB = 0 MB
2712 Load Address: 00000000
2713 Entry Point: 0000000c
2714 Verifying Checksum ... OK
2715 Uncompressing Kernel Image ... OK
2716 ## Loading RAMDisk Image at 40200000 ...
2717 Image Name: Simple Ramdisk Image
2718 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2719 Data Size: 566530 Bytes = 553 kB = 0 MB
2720 Load Address: 00000000
2721 Entry Point: 00000000
2722 Verifying Checksum ... OK
2723 Loading Ramdisk ... OK
2724 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
2725 Boot arguments: root=/dev/ram
2726 time_init: decrementer frequency = 187500000/60
2727 Calibrating delay loop... 49.77 BogoMIPS
2729 RAMDISK: Compressed image found at block 0
2730 VFS: Mounted root (ext2 filesystem).
2734 More About U-Boot Image Types:
2735 ------------------------------
2737 U-Boot supports the following image types:
2739 "Standalone Programs" are directly runnable in the environment
2740 provided by U-Boot; it is expected that (if they behave
2741 well) you can continue to work in U-Boot after return from
2742 the Standalone Program.
2743 "OS Kernel Images" are usually images of some Embedded OS which
2744 will take over control completely. Usually these programs
2745 will install their own set of exception handlers, device
2746 drivers, set up the MMU, etc. - this means, that you cannot
2747 expect to re-enter U-Boot except by resetting the CPU.
2748 "RAMDisk Images" are more or less just data blocks, and their
2749 parameters (address, size) are passed to an OS kernel that is
2751 "Multi-File Images" contain several images, typically an OS
2752 (Linux) kernel image and one or more data images like
2753 RAMDisks. This construct is useful for instance when you want
2754 to boot over the network using BOOTP etc., where the boot
2755 server provides just a single image file, but you want to get
2756 for instance an OS kernel and a RAMDisk image.
2758 "Multi-File Images" start with a list of image sizes, each
2759 image size (in bytes) specified by an "uint32_t" in network
2760 byte order. This list is terminated by an "(uint32_t)0".
2761 Immediately after the terminating 0 follow the images, one by
2762 one, all aligned on "uint32_t" boundaries (size rounded up to
2763 a multiple of 4 bytes).
2765 "Firmware Images" are binary images containing firmware (like
2766 U-Boot or FPGA images) which usually will be programmed to
2769 "Script files" are command sequences that will be executed by
2770 U-Boot's command interpreter; this feature is especially
2771 useful when you configure U-Boot to use a real shell (hush)
2772 as command interpreter.
2778 One of the features of U-Boot is that you can dynamically load and
2779 run "standalone" applications, which can use some resources of
2780 U-Boot like console I/O functions or interrupt services.
2782 Two simple examples are included with the sources:
2787 'examples/hello_world.c' contains a small "Hello World" Demo
2788 application; it is automatically compiled when you build U-Boot.
2789 It's configured to run at address 0x00040004, so you can play with it
2793 ## Ready for S-Record download ...
2794 ~>examples/hello_world.srec
2795 1 2 3 4 5 6 7 8 9 10 11 ...
2796 [file transfer complete]
2798 ## Start Addr = 0x00040004
2800 => go 40004 Hello World! This is a test.
2801 ## Starting application at 0x00040004 ...
2812 Hit any key to exit ...
2814 ## Application terminated, rc = 0x0
2816 Another example, which demonstrates how to register a CPM interrupt
2817 handler with the U-Boot code, can be found in 'examples/timer.c'.
2818 Here, a CPM timer is set up to generate an interrupt every second.
2819 The interrupt service routine is trivial, just printing a '.'
2820 character, but this is just a demo program. The application can be
2821 controlled by the following keys:
2823 ? - print current values og the CPM Timer registers
2824 b - enable interrupts and start timer
2825 e - stop timer and disable interrupts
2826 q - quit application
2829 ## Ready for S-Record download ...
2830 ~>examples/timer.srec
2831 1 2 3 4 5 6 7 8 9 10 11 ...
2832 [file transfer complete]
2834 ## Start Addr = 0x00040004
2837 ## Starting application at 0x00040004 ...
2840 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
2843 [q, b, e, ?] Set interval 1000000 us
2846 [q, b, e, ?] ........
2847 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
2850 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
2853 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
2856 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
2858 [q, b, e, ?] ...Stopping timer
2860 [q, b, e, ?] ## Application terminated, rc = 0x0
2866 Over time, many people have reported problems when trying to use the
2867 "minicom" terminal emulation program for serial download. I (wd)
2868 consider minicom to be broken, and recommend not to use it. Under
2869 Unix, I recommend to use C-Kermit for general purpose use (and
2870 especially for kermit binary protocol download ("loadb" command), and
2871 use "cu" for S-Record download ("loads" command).
2873 Nevertheless, if you absolutely want to use it try adding this
2874 configuration to your "File transfer protocols" section:
2876 Name Program Name U/D FullScr IO-Red. Multi
2877 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
2878 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
2884 Starting at version 0.9.2, U-Boot supports NetBSD both as host
2885 (build U-Boot) and target system (boots NetBSD/mpc8xx).
2887 Building requires a cross environment; it is known to work on
2888 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
2889 need gmake since the Makefiles are not compatible with BSD make).
2890 Note that the cross-powerpc package does not install include files;
2891 attempting to build U-Boot will fail because <machine/ansi.h> is
2892 missing. This file has to be installed and patched manually:
2894 # cd /usr/pkg/cross/powerpc-netbsd/include
2896 # ln -s powerpc machine
2897 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
2898 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
2900 Native builds *don't* work due to incompatibilities between native
2901 and U-Boot include files.
2903 Booting assumes that (the first part of) the image booted is a
2904 stage-2 loader which in turn loads and then invokes the kernel
2905 proper. Loader sources will eventually appear in the NetBSD source
2906 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
2907 meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for
2911 Implementation Internals:
2912 =========================
2914 The following is not intended to be a complete description of every
2915 implementation detail. However, it should help to understand the
2916 inner workings of U-Boot and make it easier to port it to custom
2920 Initial Stack, Global Data:
2921 ---------------------------
2923 The implementation of U-Boot is complicated by the fact that U-Boot
2924 starts running out of ROM (flash memory), usually without access to
2925 system RAM (because the memory controller is not initialized yet).
2926 This means that we don't have writable Data or BSS segments, and BSS
2927 is not initialized as zero. To be able to get a C environment working
2928 at all, we have to allocate at least a minimal stack. Implementation
2929 options for this are defined and restricted by the CPU used: Some CPU
2930 models provide on-chip memory (like the IMMR area on MPC8xx and
2931 MPC826x processors), on others (parts of) the data cache can be
2932 locked as (mis-) used as memory, etc.
2934 Chris Hallinan posted a good summary of these issues to the
2935 u-boot-users mailing list:
2937 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
2938 From: "Chris Hallinan" <clh@net1plus.com>
2939 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
2942 Correct me if I'm wrong, folks, but the way I understand it
2943 is this: Using DCACHE as initial RAM for Stack, etc, does not
2944 require any physical RAM backing up the cache. The cleverness
2945 is that the cache is being used as a temporary supply of
2946 necessary storage before the SDRAM controller is setup. It's
2947 beyond the scope of this list to expain the details, but you
2948 can see how this works by studying the cache architecture and
2949 operation in the architecture and processor-specific manuals.
2951 OCM is On Chip Memory, which I believe the 405GP has 4K. It
2952 is another option for the system designer to use as an
2953 initial stack/ram area prior to SDRAM being available. Either
2954 option should work for you. Using CS 4 should be fine if your
2955 board designers haven't used it for something that would
2956 cause you grief during the initial boot! It is frequently not
2959 CFG_INIT_RAM_ADDR should be somewhere that won't interfere
2960 with your processor/board/system design. The default value
2961 you will find in any recent u-boot distribution in
2962 Walnut405.h should work for you. I'd set it to a value larger
2963 than your SDRAM module. If you have a 64MB SDRAM module, set
2964 it above 400_0000. Just make sure your board has no resources
2965 that are supposed to respond to that address! That code in
2966 start.S has been around a while and should work as is when
2967 you get the config right.
2972 It is essential to remember this, since it has some impact on the C
2973 code for the initialization procedures:
2975 * Initialized global data (data segment) is read-only. Do not attempt
2978 * Do not use any unitialized global data (or implicitely initialized
2979 as zero data - BSS segment) at all - this is undefined, initiali-
2980 zation is performed later (when relocating to RAM).
2982 * Stack space is very limited. Avoid big data buffers or things like
2985 Having only the stack as writable memory limits means we cannot use
2986 normal global data to share information beween the code. But it
2987 turned out that the implementation of U-Boot can be greatly
2988 simplified by making a global data structure (gd_t) available to all
2989 functions. We could pass a pointer to this data as argument to _all_
2990 functions, but this would bloat the code. Instead we use a feature of
2991 the GCC compiler (Global Register Variables) to share the data: we
2992 place a pointer (gd) to the global data into a register which we
2993 reserve for this purpose.
2995 When choosing a register for such a purpose we are restricted by the
2996 relevant (E)ABI specifications for the current architecture, and by
2997 GCC's implementation.
2999 For PowerPC, the following registers have specific use:
3002 R3-R4: parameter passing and return values
3003 R5-R10: parameter passing
3004 R13: small data area pointer
3008 (U-Boot also uses R14 as internal GOT pointer.)
3010 ==> U-Boot will use R29 to hold a pointer to the global data
3012 Note: on PPC, we could use a static initializer (since the
3013 address of the global data structure is known at compile time),
3014 but it turned out that reserving a register results in somewhat
3015 smaller code - although the code savings are not that big (on
3016 average for all boards 752 bytes for the whole U-Boot image,
3017 624 text + 127 data).
3019 On ARM, the following registers are used:
3021 R0: function argument word/integer result
3022 R1-R3: function argument word
3024 R10: stack limit (used only if stack checking if enabled)
3025 R11: argument (frame) pointer
3026 R12: temporary workspace
3029 R15: program counter
3031 ==> U-Boot will use R8 to hold a pointer to the global data
3037 U-Boot runs in system state and uses physical addresses, i.e. the
3038 MMU is not used either for address mapping nor for memory protection.
3040 The available memory is mapped to fixed addresses using the memory
3041 controller. In this process, a contiguous block is formed for each
3042 memory type (Flash, SDRAM, SRAM), even when it consists of several
3043 physical memory banks.
3045 U-Boot is installed in the first 128 kB of the first Flash bank (on
3046 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3047 booting and sizing and initializing DRAM, the code relocates itself
3048 to the upper end of DRAM. Immediately below the U-Boot code some
3049 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
3050 configuration setting]. Below that, a structure with global Board
3051 Info data is placed, followed by the stack (growing downward).
3053 Additionally, some exception handler code is copied to the low 8 kB
3054 of DRAM (0x00000000 ... 0x00001FFF).
3056 So a typical memory configuration with 16 MB of DRAM could look like
3059 0x0000 0000 Exception Vector code
3062 0x0000 2000 Free for Application Use
3068 0x00FB FF20 Monitor Stack (Growing downward)
3069 0x00FB FFAC Board Info Data and permanent copy of global data
3070 0x00FC 0000 Malloc Arena
3073 0x00FE 0000 RAM Copy of Monitor Code
3074 ... eventually: LCD or video framebuffer
3075 ... eventually: pRAM (Protected RAM - unchanged by reset)
3076 0x00FF FFFF [End of RAM]
3079 System Initialization:
3080 ----------------------
3082 In the reset configuration, U-Boot starts at the reset entry point
3083 (on most PowerPC systens at address 0x00000100). Because of the reset
3084 configuration for CS0# this is a mirror of the onboard Flash memory.
3085 To be able to re-map memory U-Boot then jumps to its link address.
3086 To be able to implement the initialization code in C, a (small!)
3087 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3088 which provide such a feature like MPC8xx or MPC8260), or in a locked
3089 part of the data cache. After that, U-Boot initializes the CPU core,
3090 the caches and the SIU.
3092 Next, all (potentially) available memory banks are mapped using a
3093 preliminary mapping. For example, we put them on 512 MB boundaries
3094 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3095 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3096 programmed for SDRAM access. Using the temporary configuration, a
3097 simple memory test is run that determines the size of the SDRAM
3100 When there is more than one SDRAM bank, and the banks are of
3101 different size, the largest is mapped first. For equal size, the first
3102 bank (CS2#) is mapped first. The first mapping is always for address
3103 0x00000000, with any additional banks following immediately to create
3104 contiguous memory starting from 0.
3106 Then, the monitor installs itself at the upper end of the SDRAM area
3107 and allocates memory for use by malloc() and for the global Board
3108 Info data; also, the exception vector code is copied to the low RAM
3109 pages, and the final stack is set up.
3111 Only after this relocation will you have a "normal" C environment;
3112 until that you are restricted in several ways, mostly because you are
3113 running from ROM, and because the code will have to be relocated to a
3117 U-Boot Porting Guide:
3118 ----------------------
3120 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3124 int main (int argc, char *argv[])
3126 sighandler_t no_more_time;
3128 signal (SIGALRM, no_more_time);
3129 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3131 if (available_money > available_manpower) {
3132 pay consultant to port U-Boot;
3136 Download latest U-Boot source;
3138 Subscribe to u-boot-users mailing list;
3141 email ("Hi, I am new to U-Boot, how do I get started?");
3145 Read the README file in the top level directory;
3146 Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
3147 Read the source, Luke;
3150 if (available_money > toLocalCurrency ($2500)) {
3153 Add a lot of aggravation and time;
3156 Create your own board support subdirectory;
3158 Create your own board config file;
3162 Add / modify source code;
3166 email ("Hi, I am having problems...");
3168 Send patch file to Wolfgang;
3173 void no_more_time (int sig)
3182 All contributions to U-Boot should conform to the Linux kernel
3183 coding style; see the file "Documentation/CodingStyle" in your Linux
3184 kernel source directory.
3186 Please note that U-Boot is implemented in C (and to some small parts
3187 in Assembler); no C++ is used, so please do not use C++ style
3188 comments (//) in your code.
3190 Please also stick to the following formatting rules:
3191 - remove any trailing white space
3192 - use TAB characters for indentation, not spaces
3193 - make sure NOT to use DOS '\r\n' line feeds
3194 - do not add more than 2 empty lines to source files
3195 - do not add trailing empty lines to source files
3197 Submissions which do not conform to the standards may be returned
3198 with a request to reformat the changes.
3204 Since the number of patches for U-Boot is growing, we need to
3205 establish some rules. Submissions which do not conform to these rules
3206 may be rejected, even when they contain important and valuable stuff.
3209 When you send a patch, please include the following information with
3212 * For bug fixes: a description of the bug and how your patch fixes
3213 this bug. Please try to include a way of demonstrating that the
3214 patch actually fixes something.
3216 * For new features: a description of the feature and your
3219 * A CHANGELOG entry as plaintext (separate from the patch)
3221 * For major contributions, your entry to the CREDITS file
3223 * When you add support for a new board, don't forget to add this
3224 board to the MAKEALL script, too.
3226 * If your patch adds new configuration options, don't forget to
3227 document these in the README file.
3229 * The patch itself. If you are accessing the CVS repository use "cvs
3230 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
3231 version of diff does not support these options, then get the latest
3232 version of GNU diff.
3234 The current directory when running this command shall be the top
3235 level directory of the U-Boot source tree, or it's parent directory
3236 (i. e. please make sure that your patch includes sufficient
3237 directory information for the affected files).
3239 We accept patches as plain text, MIME attachments or as uuencoded
3242 * If one logical set of modifications affects or creates several
3243 files, all these changes shall be submitted in a SINGLE patch file.
3245 * Changesets that contain different, unrelated modifications shall be
3246 submitted as SEPARATE patches, one patch per changeset.
3251 * Before sending the patch, run the MAKEALL script on your patched
3252 source tree and make sure that no errors or warnings are reported
3253 for any of the boards.
3255 * Keep your modifications to the necessary minimum: A patch
3256 containing several unrelated changes or arbitrary reformats will be
3257 returned with a request to re-formatting / split it.
3259 * If you modify existing code, make sure that your new code does not
3260 add to the memory footprint of the code ;-) Small is beautiful!
3261 When adding new features, these should compile conditionally only
3262 (using #ifdef), and the resulting code with the new feature
3263 disabled must not need more memory than the old code without your
projects / oweals / u-boot.git / blob