2 # (C) Copyright 2000 - 2004
5 # See file CREDITS for list of people who contributed to this
8 # This program is free software; you can redistribute it and/or
9 # modify it under the terms of the GNU General Public License as
10 # published by the Free Software Foundation; either version 2 of
11 # the License, or (at your option) any later version.
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with this program; if not, write to the Free Software
20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27 This directory contains the source code for U-Boot, a boot loader for
28 Embedded boards based on PowerPC and ARM processors, which can be
29 installed in a boot ROM and used to initialize and test the hardware
30 or to download and run application code.
32 The development of U-Boot is closely related to Linux: some parts of
33 the source code originate in the Linux source tree, we have some
34 header files in common, and special provision has been made to
35 support booting of Linux images.
37 Some attention has been paid to make this software easily
38 configurable and extendable. For instance, all monitor commands are
39 implemented with the same call interface, so that it's very easy to
40 add new commands. Also, instead of permanently adding rarely used
41 code (for instance hardware test utilities) to the monitor, you can
42 load and run it dynamically.
48 In general, all boards for which a configuration option exists in the
49 Makefile have been tested to some extent and can be considered
50 "working". In fact, many of them are used in production systems.
52 In case of problems see the CHANGELOG and CREDITS files to find out
53 who contributed the specific port.
59 In case you have questions about, problems with or contributions for
60 U-Boot you should send a message to the U-Boot mailing list at
62 previous traffic on the mailing list - please search the archive
63 before asking FAQ's. Please see
64 http://lists.sourceforge.net/lists/listinfo/u-boot-users/
70 - start from 8xxrom sources
71 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
73 - make it easier to add custom boards
74 - make it possible to add other [PowerPC] CPUs
75 - extend functions, especially:
76 * Provide extended interface to Linux boot loader
79 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot
80 - create ARMBoot project (http://sourceforge.net/projects/armboot)
81 - add other CPU families (starting with ARM)
82 - create U-Boot project (http://sourceforge.net/projects/u-boot)
88 The "official" name of this project is "Das U-Boot". The spelling
89 "U-Boot" shall be used in all written text (documentation, comments
90 in source files etc.). Example:
92 This is the README file for the U-Boot project.
94 File names etc. shall be based on the string "u-boot". Examples:
96 include/asm-ppc/u-boot.h
98 #include <asm/u-boot.h>
100 Variable names, preprocessor constants etc. shall be either based on
101 the string "u_boot" or on "U_BOOT". Example:
103 U_BOOT_VERSION u_boot_logo
104 IH_OS_U_BOOT u_boot_hush_start
110 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_ICU862 CONFIG_RPXsuper,
250 CONFIG_ADS860, CONFIG_IP860, CONFIG_SM850,
251 CONFIG_AMX860, CONFIG_IPHASE4539, CONFIG_SPD823TS,
252 CONFIG_AR405, CONFIG_IVML24, CONFIG_SXNI855T,
253 CONFIG_BAB7xx, CONFIG_IVML24_128, CONFIG_Sandpoint8240,
254 CONFIG_CANBT, CONFIG_IVML24_256, CONFIG_Sandpoint8245,
255 CONFIG_CCM, CONFIG_IVMS8, CONFIG_TQM823L,
256 CONFIG_CPCI405, CONFIG_IVMS8_128, CONFIG_TQM850L,
257 CONFIG_CPCI4052, CONFIG_IVMS8_256, CONFIG_TQM855L,
258 CONFIG_CPCIISER4, CONFIG_LANTEC, CONFIG_TQM860L,
259 CONFIG_CPU86, CONFIG_MBX, CONFIG_TQM8260,
260 CONFIG_CRAYL1, CONFIG_MBX860T, CONFIG_TTTech,
261 CONFIG_CU824, CONFIG_MHPC, CONFIG_UTX8245,
262 CONFIG_DASA_SIM, CONFIG_MIP405, CONFIG_W7OLMC,
263 CONFIG_DU405, CONFIG_MOUSSE, CONFIG_W7OLMG,
264 CONFIG_ELPPC, CONFIG_MPC8260ADS, CONFIG_WALNUT405,
265 CONFIG_ERIC, CONFIG_MUSENKI, CONFIG_ZUMA,
266 CONFIG_ESTEEM192E, CONFIG_MVS1, CONFIG_c2mon,
267 CONFIG_ETX094, CONFIG_NX823, CONFIG_cogent_mpc8260,
268 CONFIG_EVB64260, CONFIG_OCRTC, CONFIG_cogent_mpc8xx,
269 CONFIG_FADS823, CONFIG_ORSG, CONFIG_ep8260,
270 CONFIG_FADS850SAR, CONFIG_OXC, CONFIG_gw8260,
271 CONFIG_FADS860T, CONFIG_PCI405, CONFIG_hermes,
272 CONFIG_FLAGADM, CONFIG_PCIPPC2, CONFIG_hymod,
273 CONFIG_FPS850L, CONFIG_PCIPPC6, CONFIG_lwmon,
274 CONFIG_GEN860T, CONFIG_PIP405, CONFIG_pcu_e,
275 CONFIG_GENIETV, CONFIG_PM826, CONFIG_ppmc8260,
276 CONFIG_GTH, CONFIG_RPXClassic, CONFIG_rsdproto,
277 CONFIG_IAD210, CONFIG_RPXlite, CONFIG_sbc8260,
278 CONFIG_EBONY, CONFIG_sacsng, CONFIG_FPS860L,
279 CONFIG_V37, CONFIG_ELPT860, CONFIG_CMI,
280 CONFIG_NETVIA, CONFIG_RBC823, CONFIG_ZPC1900,
281 CONFIG_MPC8540ADS, CONFIG_MPC8560ADS, CONFIG_QS850,
282 CONFIG_QS823, CONFIG_QS860T, CONFIG_DB64360,
283 CONFIG_DB64460, CONFIG_DUET_ADS
288 CONFIG_HHP_CRADLE, CONFIG_DNP1110, CONFIG_EP7312,
289 CONFIG_IMPA7, CONFIG_LART, CONFIG_LUBBOCK,
290 CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610,
291 CONFIG_H2_OMAP1610, CONFIG_SHANNON, CONFIG_SMDK2400,
292 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
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 -----------------------------------------------
587 CFG_CMD_DFL Default configuration; at the moment
588 this is includes all commands, except
589 the ones marked with "*" in the list
592 If you don't define CONFIG_COMMANDS it defaults to
593 CFG_CMD_DFL in include/cmd_confdefs.h. A board can
594 override the default settings in the respective
597 EXAMPLE: If you want all functions except of network
598 support you can write:
600 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
603 Note: Don't enable the "icache" and "dcache" commands
604 (configuration option CFG_CMD_CACHE) unless you know
605 what you (and your U-Boot users) are doing. Data
606 cache cannot be enabled on systems like the 8xx or
607 8260 (where accesses to the IMMR region must be
608 uncached), and it cannot be disabled on all other
609 systems where we (mis-) use the data cache to hold an
610 initial stack and some data.
613 XXX - this list needs to get updated!
617 If this variable is defined, it enables watchdog
618 support. There must be support in the platform specific
619 code for a watchdog. For the 8xx and 8260 CPUs, the
620 SIU Watchdog feature is enabled in the SYPCR
624 CONFIG_VERSION_VARIABLE
625 If this variable is defined, an environment variable
626 named "ver" is created by U-Boot showing the U-Boot
627 version as printed by the "version" command.
628 This variable is readonly.
632 When CFG_CMD_DATE is selected, the type of the RTC
633 has to be selected, too. Define exactly one of the
636 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
637 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
638 CONFIG_RTC_MC146818 - use MC146818 RTC
639 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
640 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
641 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
642 CONFIG_RTC_DS164x - use Dallas DS164x RTC
644 Note that if the RTC uses I2C, then the I2C interface
645 must also be configured. See I2C Support, below.
649 When CONFIG_TIMESTAMP is selected, the timestamp
650 (date and time) of an image is printed by image
651 commands like bootm or iminfo. This option is
652 automatically enabled when you select CFG_CMD_DATE .
655 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
656 and/or CONFIG_ISO_PARTITION
658 If IDE or SCSI support is enabled (CFG_CMD_IDE or
659 CFG_CMD_SCSI) you must configure support for at least
660 one partition type as well.
663 CONFIG_IDE_RESET_ROUTINE - this is defined in several
664 board configurations files but used nowhere!
666 CONFIG_IDE_RESET - is this is defined, IDE Reset will
667 be performed by calling the function
668 ide_set_reset(int reset)
669 which has to be defined in a board specific file
674 Set this to enable ATAPI support.
679 Set this to enable support for disks larger than 137GB
680 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL
681 Whithout these , LBA48 support uses 32bit variables and will 'only'
682 support disks up to 2.1TB.
685 When enabled, makes the IDE subsystem use 64bit sector addresses.
689 At the moment only there is only support for the
690 SYM53C8XX SCSI controller; define
691 CONFIG_SCSI_SYM53C8XX to enable it.
693 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
694 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
695 CFG_SCSI_MAX_LUN] can be adjusted to define the
696 maximum numbers of LUNs, SCSI ID's and target
698 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
700 - NETWORK Support (PCI):
702 Support for Intel 8254x gigabit chips.
705 Support for Intel 82557/82559/82559ER chips.
706 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
707 write routine for first time initialisation.
710 Support for Digital 2114x chips.
711 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
712 modem chip initialisation (KS8761/QS6611).
715 Support for National dp83815 chips.
718 Support for National dp8382[01] gigabit chips.
720 - NETWORK Support (other):
722 CONFIG_DRIVER_LAN91C96
723 Support for SMSC's LAN91C96 chips.
726 Define this to hold the physical address
727 of the LAN91C96's I/O space
729 CONFIG_LAN91C96_USE_32_BIT
730 Define this to enable 32 bit addressing
733 At the moment only the UHCI host controller is
734 supported (PIP405, MIP405, MPC5200); define
735 CONFIG_USB_UHCI to enable it.
736 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
737 end define CONFIG_USB_STORAGE to enable the USB
740 Supported are USB Keyboards and USB Floppy drives
742 MPC5200 USB requires additional defines:
744 for 528 MHz Clock: 0x0001bbbb
746 for differential drivers: 0x00001000
747 for single ended drivers: 0x00005000
751 The MMC controller on the Intel PXA is supported. To
752 enable this define CONFIG_MMC. The MMC can be
753 accessed from the boot prompt by mapping the device
754 to physical memory similar to flash. Command line is
755 enabled with CFG_CMD_MMC. The MMC driver also works with
756 the FAT fs. This is enabled with CFG_CMD_FAT.
761 Define this to enable standard (PC-Style) keyboard
765 Standard PC keyboard driver with US (is default) and
766 GERMAN key layout (switch via environment 'keymap=de') support.
767 Export function i8042_kbd_init, i8042_tstc and i8042_getc
768 for cfb_console. Supports cursor blinking.
773 Define this to enable video support (for output to
778 Enable Chips & Technologies 69000 Video chip
780 CONFIG_VIDEO_SMI_LYNXEM
781 Enable Silicon Motion SMI 712/710/810 Video chip. The
782 video output is selected via environment 'videoout'
783 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
786 For the CT69000 and SMI_LYNXEM drivers, videomode is
787 selected via environment 'videomode'. Two diferent ways
789 - "videomode=num" 'num' is a standard LiLo mode numbers.
790 Following standard modes are supported (* is default):
792 Colors 640x480 800x600 1024x768 1152x864 1280x1024
793 -------------+---------------------------------------------
794 8 bits | 0x301* 0x303 0x305 0x161 0x307
795 15 bits | 0x310 0x313 0x316 0x162 0x319
796 16 bits | 0x311 0x314 0x317 0x163 0x31A
797 24 bits | 0x312 0x315 0x318 ? 0x31B
798 -------------+---------------------------------------------
799 (i.e. setenv videomode 317; saveenv; reset;)
801 - "videomode=bootargs" all the video parameters are parsed
802 from the bootargs. (See drivers/videomodes.c)
805 CONFIG_VIDEO_SED13806
806 Enable Epson SED13806 driver. This driver supports 8bpp
807 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
808 or CONFIG_VIDEO_SED13806_16BPP
813 Define this to enable a custom keyboard support.
814 This simply calls drv_keyboard_init() which must be
815 defined in your board-specific files.
816 The only board using this so far is RBC823.
818 - LCD Support: CONFIG_LCD
820 Define this to enable LCD support (for output to LCD
821 display); also select one of the supported displays
822 by defining one of these:
824 CONFIG_NEC_NL6448AC33:
826 NEC NL6448AC33-18. Active, color, single scan.
828 CONFIG_NEC_NL6448BC20
830 NEC NL6448BC20-08. 6.5", 640x480.
831 Active, color, single scan.
833 CONFIG_NEC_NL6448BC33_54
835 NEC NL6448BC33-54. 10.4", 640x480.
836 Active, color, single scan.
840 Sharp 320x240. Active, color, single scan.
841 It isn't 16x9, and I am not sure what it is.
843 CONFIG_SHARP_LQ64D341
845 Sharp LQ64D341 display, 640x480.
846 Active, color, single scan.
850 HLD1045 display, 640x480.
851 Active, color, single scan.
855 Optrex CBL50840-2 NF-FW 99 22 M5
857 Hitachi LMG6912RPFC-00T
861 320x240. Black & white.
863 Normally display is black on white background; define
864 CFG_WHITE_ON_BLACK to get it inverted.
866 - Splash Screen Support: CONFIG_SPLASH_SCREEN
868 If this option is set, the environment is checked for
869 a variable "splashimage". If found, the usual display
870 of logo, copyright and system information on the LCD
871 is supressed and the BMP image at the address
872 specified in "splashimage" is loaded instead. The
873 console is redirected to the "nulldev", too. This
874 allows for a "silent" boot where a splash screen is
875 loaded very quickly after power-on.
877 - Compression support:
880 If this option is set, support for bzip2 compressed
881 images is included. If not, only uncompressed and gzip
882 compressed images are supported.
884 NOTE: the bzip2 algorithm requires a lot of RAM, so
885 the malloc area (as defined by CFG_MALLOC_LEN) should
893 Define a default value for ethernet address to use
894 for the respective ethernet interface, in case this
895 is not determined automatically.
900 Define a default value for the IP address to use for
901 the default ethernet interface, in case this is not
902 determined through e.g. bootp.
907 Defines a default value for theIP address of a TFTP
908 server to contact when using the "tftboot" command.
910 - BOOTP Recovery Mode:
911 CONFIG_BOOTP_RANDOM_DELAY
913 If you have many targets in a network that try to
914 boot using BOOTP, you may want to avoid that all
915 systems send out BOOTP requests at precisely the same
916 moment (which would happen for instance at recovery
917 from a power failure, when all systems will try to
918 boot, thus flooding the BOOTP server. Defining
919 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
920 inserted before sending out BOOTP requests. The
921 following delays are insterted then:
923 1st BOOTP request: delay 0 ... 1 sec
924 2nd BOOTP request: delay 0 ... 2 sec
925 3rd BOOTP request: delay 0 ... 4 sec
927 BOOTP requests: delay 0 ... 8 sec
929 - DHCP Advanced Options:
932 You can fine tune the DHCP functionality by adding
933 these flags to the CONFIG_BOOTP_MASK define:
935 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
936 serverip from a DHCP server, it is possible that more
937 than one DNS serverip is offered to the client.
938 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
939 serverip will be stored in the additional environment
940 variable "dnsip2". The first DNS serverip is always
941 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
942 is added to the CONFIG_BOOTP_MASK.
944 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
945 to do a dynamic update of a DNS server. To do this, they
946 need the hostname of the DHCP requester.
947 If CONFIG_BOOP_SEND_HOSTNAME is added to the
948 CONFIG_BOOTP_MASK, the content of the "hostname"
949 environment variable is passed as option 12 to
952 - Status LED: CONFIG_STATUS_LED
954 Several configurations allow to display the current
955 status using a LED. For instance, the LED will blink
956 fast while running U-Boot code, stop blinking as
957 soon as a reply to a BOOTP request was received, and
958 start blinking slow once the Linux kernel is running
959 (supported by a status LED driver in the Linux
960 kernel). Defining CONFIG_STATUS_LED enables this
963 - CAN Support: CONFIG_CAN_DRIVER
965 Defining CONFIG_CAN_DRIVER enables CAN driver support
966 on those systems that support this (optional)
967 feature, like the TQM8xxL modules.
969 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
971 These enable I2C serial bus commands. Defining either of
972 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
973 include the appropriate I2C driver for the selected cpu.
975 This will allow you to use i2c commands at the u-boot
976 command line (as long as you set CFG_CMD_I2C in
977 CONFIG_COMMANDS) and communicate with i2c based realtime
978 clock chips. See common/cmd_i2c.c for a description of the
979 command line interface.
981 CONFIG_HARD_I2C selects the CPM hardware driver for I2C.
983 CONFIG_SOFT_I2C configures u-boot to use a software (aka
984 bit-banging) driver instead of CPM or similar hardware
987 There are several other quantities that must also be
988 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
990 In both cases you will need to define CFG_I2C_SPEED
991 to be the frequency (in Hz) at which you wish your i2c bus
992 to run and CFG_I2C_SLAVE to be the address of this node (ie
993 the cpu's i2c node address).
995 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
996 sets the cpu up as a master node and so its address should
997 therefore be cleared to 0 (See, eg, MPC823e User's Manual
998 p.16-473). So, set CFG_I2C_SLAVE to 0.
1000 That's all that's required for CONFIG_HARD_I2C.
1002 If you use the software i2c interface (CONFIG_SOFT_I2C)
1003 then the following macros need to be defined (examples are
1004 from include/configs/lwmon.h):
1008 (Optional). Any commands necessary to enable the I2C
1009 controller or configure ports.
1011 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1015 (Only for MPC8260 CPU). The I/O port to use (the code
1016 assumes both bits are on the same port). Valid values
1017 are 0..3 for ports A..D.
1021 The code necessary to make the I2C data line active
1022 (driven). If the data line is open collector, this
1025 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1029 The code necessary to make the I2C data line tri-stated
1030 (inactive). If the data line is open collector, this
1033 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1037 Code that returns TRUE if the I2C data line is high,
1040 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1044 If <bit> is TRUE, sets the I2C data line high. If it
1045 is FALSE, it clears it (low).
1047 eg: #define I2C_SDA(bit) \
1048 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1049 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1053 If <bit> is TRUE, sets the I2C clock line high. If it
1054 is FALSE, it clears it (low).
1056 eg: #define I2C_SCL(bit) \
1057 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1058 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1062 This delay is invoked four times per clock cycle so this
1063 controls the rate of data transfer. The data rate thus
1064 is 1 / (I2C_DELAY * 4). Often defined to be something
1067 #define I2C_DELAY udelay(2)
1071 When a board is reset during an i2c bus transfer
1072 chips might think that the current transfer is still
1073 in progress. On some boards it is possible to access
1074 the i2c SCLK line directly, either by using the
1075 processor pin as a GPIO or by having a second pin
1076 connected to the bus. If this option is defined a
1077 custom i2c_init_board() routine in boards/xxx/board.c
1078 is run early in the boot sequence.
1080 - SPI Support: CONFIG_SPI
1082 Enables SPI driver (so far only tested with
1083 SPI EEPROM, also an instance works with Crystal A/D and
1084 D/As on the SACSng board)
1088 Enables extended (16-bit) SPI EEPROM addressing.
1089 (symmetrical to CONFIG_I2C_X)
1093 Enables a software (bit-bang) SPI driver rather than
1094 using hardware support. This is a general purpose
1095 driver that only requires three general I/O port pins
1096 (two outputs, one input) to function. If this is
1097 defined, the board configuration must define several
1098 SPI configuration items (port pins to use, etc). For
1099 an example, see include/configs/sacsng.h.
1101 - FPGA Support: CONFIG_FPGA_COUNT
1103 Specify the number of FPGA devices to support.
1107 Used to specify the types of FPGA devices. For example,
1108 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
1110 CFG_FPGA_PROG_FEEDBACK
1112 Enable printing of hash marks during FPGA configuration.
1116 Enable checks on FPGA configuration interface busy
1117 status by the configuration function. This option
1118 will require a board or device specific function to
1123 If defined, a function that provides delays in the FPGA
1124 configuration driver.
1126 CFG_FPGA_CHECK_CTRLC
1127 Allow Control-C to interrupt FPGA configuration
1129 CFG_FPGA_CHECK_ERROR
1131 Check for configuration errors during FPGA bitfile
1132 loading. For example, abort during Virtex II
1133 configuration if the INIT_B line goes low (which
1134 indicated a CRC error).
1138 Maximum time to wait for the INIT_B line to deassert
1139 after PROB_B has been deasserted during a Virtex II
1140 FPGA configuration sequence. The default time is 500
1145 Maximum time to wait for BUSY to deassert during
1146 Virtex II FPGA configuration. The default is 5 mS.
1148 CFG_FPGA_WAIT_CONFIG
1150 Time to wait after FPGA configuration. The default is
1153 - Configuration Management:
1156 If defined, this string will be added to the U-Boot
1157 version information (U_BOOT_VERSION)
1159 - Vendor Parameter Protection:
1161 U-Boot considers the values of the environment
1162 variables "serial#" (Board Serial Number) and
1163 "ethaddr" (Ethernet Address) to be parameters that
1164 are set once by the board vendor / manufacturer, and
1165 protects these variables from casual modification by
1166 the user. Once set, these variables are read-only,
1167 and write or delete attempts are rejected. You can
1168 change this behviour:
1170 If CONFIG_ENV_OVERWRITE is #defined in your config
1171 file, the write protection for vendor parameters is
1172 completely disabled. Anybody can change or delete
1175 Alternatively, if you #define _both_ CONFIG_ETHADDR
1176 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1177 ethernet address is installed in the environment,
1178 which can be changed exactly ONCE by the user. [The
1179 serial# is unaffected by this, i. e. it remains
1185 Define this variable to enable the reservation of
1186 "protected RAM", i. e. RAM which is not overwritten
1187 by U-Boot. Define CONFIG_PRAM to hold the number of
1188 kB you want to reserve for pRAM. You can overwrite
1189 this default value by defining an environment
1190 variable "pram" to the number of kB you want to
1191 reserve. Note that the board info structure will
1192 still show the full amount of RAM. If pRAM is
1193 reserved, a new environment variable "mem" will
1194 automatically be defined to hold the amount of
1195 remaining RAM in a form that can be passed as boot
1196 argument to Linux, for instance like that:
1198 setenv bootargs ... mem=\$(mem)
1201 This way you can tell Linux not to use this memory,
1202 either, which results in a memory region that will
1203 not be affected by reboots.
1205 *WARNING* If your board configuration uses automatic
1206 detection of the RAM size, you must make sure that
1207 this memory test is non-destructive. So far, the
1208 following board configurations are known to be
1211 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1212 HERMES, IP860, RPXlite, LWMON, LANTEC,
1213 PCU_E, FLAGADM, TQM8260
1218 Define this variable to stop the system in case of a
1219 fatal error, so that you have to reset it manually.
1220 This is probably NOT a good idea for an embedded
1221 system where you want to system to reboot
1222 automatically as fast as possible, but it may be
1223 useful during development since you can try to debug
1224 the conditions that lead to the situation.
1226 CONFIG_NET_RETRY_COUNT
1228 This variable defines the number of retries for
1229 network operations like ARP, RARP, TFTP, or BOOTP
1230 before giving up the operation. If not defined, a
1231 default value of 5 is used.
1233 - Command Interpreter:
1236 Define this variable to enable the "hush" shell (from
1237 Busybox) as command line interpreter, thus enabling
1238 powerful command line syntax like
1239 if...then...else...fi conditionals or `&&' and '||'
1240 constructs ("shell scripts").
1242 If undefined, you get the old, much simpler behaviour
1243 with a somewhat smaller memory footprint.
1248 This defines the secondary prompt string, which is
1249 printed when the command interpreter needs more input
1250 to complete a command. Usually "> ".
1254 In the current implementation, the local variables
1255 space and global environment variables space are
1256 separated. Local variables are those you define by
1257 simply typing `name=value'. To access a local
1258 variable later on, you have write `$name' or
1259 `${name}'; to execute the contents of a variable
1260 directly type `$name' at the command prompt.
1262 Global environment variables are those you use
1263 setenv/printenv to work with. To run a command stored
1264 in such a variable, you need to use the run command,
1265 and you must not use the '$' sign to access them.
1267 To store commands and special characters in a
1268 variable, please use double quotation marks
1269 surrounding the whole text of the variable, instead
1270 of the backslashes before semicolons and special
1273 - Default Environment:
1274 CONFIG_EXTRA_ENV_SETTINGS
1276 Define this to contain any number of null terminated
1277 strings (variable = value pairs) that will be part of
1278 the default environment compiled into the boot image.
1280 For example, place something like this in your
1281 board's config file:
1283 #define CONFIG_EXTRA_ENV_SETTINGS \
1287 Warning: This method is based on knowledge about the
1288 internal format how the environment is stored by the
1289 U-Boot code. This is NOT an official, exported
1290 interface! Although it is unlikely that this format
1291 will change soon, there is no guarantee either.
1292 You better know what you are doing here.
1294 Note: overly (ab)use of the default environment is
1295 discouraged. Make sure to check other ways to preset
1296 the environment like the autoscript function or the
1299 - DataFlash Support:
1300 CONFIG_HAS_DATAFLASH
1302 Defining this option enables DataFlash features and
1303 allows to read/write in Dataflash via the standard
1306 - SystemACE Support:
1309 Adding this option adds support for Xilinx SystemACE
1310 chips attached via some sort of local bus. The address
1311 of the chip must alsh be defined in the
1312 CFG_SYSTEMACE_BASE macro. For example:
1314 #define CONFIG_SYSTEMACE
1315 #define CFG_SYSTEMACE_BASE 0xf0000000
1317 When SystemACE support is added, the "ace" device type
1318 becomes available to the fat commands, i.e. fatls.
1320 - Show boot progress:
1321 CONFIG_SHOW_BOOT_PROGRESS
1323 Defining this option allows to add some board-
1324 specific code (calling a user-provided function
1325 "show_boot_progress(int)") that enables you to show
1326 the system's boot progress on some display (for
1327 example, some LED's) on your board. At the moment,
1328 the following checkpoints are implemented:
1331 1 common/cmd_bootm.c before attempting to boot an image
1332 -1 common/cmd_bootm.c Image header has bad magic number
1333 2 common/cmd_bootm.c Image header has correct magic number
1334 -2 common/cmd_bootm.c Image header has bad checksum
1335 3 common/cmd_bootm.c Image header has correct checksum
1336 -3 common/cmd_bootm.c Image data has bad checksum
1337 4 common/cmd_bootm.c Image data has correct checksum
1338 -4 common/cmd_bootm.c Image is for unsupported architecture
1339 5 common/cmd_bootm.c Architecture check OK
1340 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1341 6 common/cmd_bootm.c Image Type check OK
1342 -6 common/cmd_bootm.c gunzip uncompression error
1343 -7 common/cmd_bootm.c Unimplemented compression type
1344 7 common/cmd_bootm.c Uncompression OK
1345 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1346 8 common/cmd_bootm.c Image Type check OK
1347 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1348 9 common/cmd_bootm.c Start initial ramdisk verification
1349 -10 common/cmd_bootm.c Ramdisk header has bad magic number
1350 -11 common/cmd_bootm.c Ramdisk header has bad checksum
1351 10 common/cmd_bootm.c Ramdisk header is OK
1352 -12 common/cmd_bootm.c Ramdisk data has bad checksum
1353 11 common/cmd_bootm.c Ramdisk data has correct checksum
1354 12 common/cmd_bootm.c Ramdisk verification complete, start loading
1355 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk)
1356 13 common/cmd_bootm.c Start multifile image verification
1357 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue.
1358 15 common/cmd_bootm.c All preparation done, transferring control to OS
1360 -30 lib_ppc/board.c Fatal error, hang the system
1361 -31 post/post.c POST test failed, detected by post_output_backlog()
1362 -32 post/post.c POST test failed, detected by post_run_single()
1364 -1 common/cmd_doc.c Bad usage of "doc" command
1365 -1 common/cmd_doc.c No boot device
1366 -1 common/cmd_doc.c Unknown Chip ID on boot device
1367 -1 common/cmd_doc.c Read Error on boot device
1368 -1 common/cmd_doc.c Image header has bad magic number
1370 -1 common/cmd_ide.c Bad usage of "ide" command
1371 -1 common/cmd_ide.c No boot device
1372 -1 common/cmd_ide.c Unknown boot device
1373 -1 common/cmd_ide.c Unknown partition table
1374 -1 common/cmd_ide.c Invalid partition type
1375 -1 common/cmd_ide.c Read Error on boot device
1376 -1 common/cmd_ide.c Image header has bad magic number
1378 -1 common/cmd_nand.c Bad usage of "nand" command
1379 -1 common/cmd_nand.c No boot device
1380 -1 common/cmd_nand.c Unknown Chip ID on boot device
1381 -1 common/cmd_nand.c Read Error on boot device
1382 -1 common/cmd_nand.c Image header has bad magic number
1384 -1 common/env_common.c Environment has a bad CRC, using default
1390 [so far only for SMDK2400 and TRAB boards]
1392 - Modem support endable:
1393 CONFIG_MODEM_SUPPORT
1395 - RTS/CTS Flow control enable:
1398 - Modem debug support:
1399 CONFIG_MODEM_SUPPORT_DEBUG
1401 Enables debugging stuff (char screen[1024], dbg())
1402 for modem support. Useful only with BDI2000.
1404 - Interrupt support (PPC):
1406 There are common interrupt_init() and timer_interrupt()
1407 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
1408 for cpu specific initialization. interrupt_init_cpu()
1409 should set decrementer_count to appropriate value. If
1410 cpu resets decrementer automatically after interrupt
1411 (ppc4xx) it should set decrementer_count to zero.
1412 timer_interrupt() calls timer_interrupt_cpu() for cpu
1413 specific handling. If board has watchdog / status_led
1414 / other_activity_monitor it works automatically from
1415 general timer_interrupt().
1419 In the target system modem support is enabled when a
1420 specific key (key combination) is pressed during
1421 power-on. Otherwise U-Boot will boot normally
1422 (autoboot). The key_pressed() fuction is called from
1423 board_init(). Currently key_pressed() is a dummy
1424 function, returning 1 and thus enabling modem
1427 If there are no modem init strings in the
1428 environment, U-Boot proceed to autoboot; the
1429 previous output (banner, info printfs) will be
1432 See also: doc/README.Modem
1435 Configuration Settings:
1436 -----------------------
1438 - CFG_LONGHELP: Defined when you want long help messages included;
1439 undefine this when you're short of memory.
1441 - CFG_PROMPT: This is what U-Boot prints on the console to
1442 prompt for user input.
1444 - CFG_CBSIZE: Buffer size for input from the Console
1446 - CFG_PBSIZE: Buffer size for Console output
1448 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1450 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1451 the application (usually a Linux kernel) when it is
1454 - CFG_BAUDRATE_TABLE:
1455 List of legal baudrate settings for this board.
1457 - CFG_CONSOLE_INFO_QUIET
1458 Suppress display of console information at boot.
1460 - CFG_CONSOLE_IS_IN_ENV
1461 If the board specific function
1462 extern int overwrite_console (void);
1463 returns 1, the stdin, stderr and stdout are switched to the
1464 serial port, else the settings in the environment are used.
1466 - CFG_CONSOLE_OVERWRITE_ROUTINE
1467 Enable the call to overwrite_console().
1469 - CFG_CONSOLE_ENV_OVERWRITE
1470 Enable overwrite of previous console environment settings.
1472 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1473 Begin and End addresses of the area used by the
1477 Enable an alternate, more extensive memory test.
1479 - CFG_MEMTEST_SCRATCH:
1480 Scratch address used by the alternate memory test
1481 You only need to set this if address zero isn't writeable
1483 - CFG_TFTP_LOADADDR:
1484 Default load address for network file downloads
1486 - CFG_LOADS_BAUD_CHANGE:
1487 Enable temporary baudrate change while serial download
1490 Physical start address of SDRAM. _Must_ be 0 here.
1493 Physical start address of Motherboard I/O (if using a
1497 Physical start address of Flash memory.
1500 Physical start address of boot monitor code (set by
1501 make config files to be same as the text base address
1502 (TEXT_BASE) used when linking) - same as
1503 CFG_FLASH_BASE when booting from flash.
1506 Size of memory reserved for monitor code, used to
1507 determine _at_compile_time_ (!) if the environment is
1508 embedded within the U-Boot image, or in a separate
1512 Size of DRAM reserved for malloc() use.
1515 Maximum size of memory mapped by the startup code of
1516 the Linux kernel; all data that must be processed by
1517 the Linux kernel (bd_info, boot arguments, eventually
1518 initrd image) must be put below this limit.
1520 - CFG_MAX_FLASH_BANKS:
1521 Max number of Flash memory banks
1523 - CFG_MAX_FLASH_SECT:
1524 Max number of sectors on a Flash chip
1526 - CFG_FLASH_ERASE_TOUT:
1527 Timeout for Flash erase operations (in ms)
1529 - CFG_FLASH_WRITE_TOUT:
1530 Timeout for Flash write operations (in ms)
1532 - CFG_FLASH_LOCK_TOUT
1533 Timeout for Flash set sector lock bit operation (in ms)
1535 - CFG_FLASH_UNLOCK_TOUT
1536 Timeout for Flash clear lock bits operation (in ms)
1538 - CFG_FLASH_PROTECTION
1539 If defined, hardware flash sectors protection is used
1540 instead of U-Boot software protection.
1542 - CFG_DIRECT_FLASH_TFTP:
1544 Enable TFTP transfers directly to flash memory;
1545 without this option such a download has to be
1546 performed in two steps: (1) download to RAM, and (2)
1547 copy from RAM to flash.
1549 The two-step approach is usually more reliable, since
1550 you can check if the download worked before you erase
1551 the flash, but in some situations (when sytem RAM is
1552 too limited to allow for a tempory copy of the
1553 downloaded image) this option may be very useful.
1556 Define if the flash driver uses extra elements in the
1557 common flash structure for storing flash geometry.
1559 - CFG_FLASH_CFI_DRIVER
1560 This option also enables the building of the cfi_flash driver
1561 in the drivers directory
1563 - CFG_RX_ETH_BUFFER:
1564 Defines the number of ethernet receive buffers. On some
1565 ethernet controllers it is recommended to set this value
1566 to 8 or even higher (EEPRO100 or 405 EMAC), since all
1567 buffers can be full shortly after enabling the interface
1568 on high ethernet traffic.
1569 Defaults to 4 if not defined.
1571 The following definitions that deal with the placement and management
1572 of environment data (variable area); in general, we support the
1573 following configurations:
1575 - CFG_ENV_IS_IN_FLASH:
1577 Define this if the environment is in flash memory.
1579 a) The environment occupies one whole flash sector, which is
1580 "embedded" in the text segment with the U-Boot code. This
1581 happens usually with "bottom boot sector" or "top boot
1582 sector" type flash chips, which have several smaller
1583 sectors at the start or the end. For instance, such a
1584 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
1585 such a case you would place the environment in one of the
1586 4 kB sectors - with U-Boot code before and after it. With
1587 "top boot sector" type flash chips, you would put the
1588 environment in one of the last sectors, leaving a gap
1589 between U-Boot and the environment.
1593 Offset of environment data (variable area) to the
1594 beginning of flash memory; for instance, with bottom boot
1595 type flash chips the second sector can be used: the offset
1596 for this sector is given here.
1598 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
1602 This is just another way to specify the start address of
1603 the flash sector containing the environment (instead of
1606 - CFG_ENV_SECT_SIZE:
1608 Size of the sector containing the environment.
1611 b) Sometimes flash chips have few, equal sized, BIG sectors.
1612 In such a case you don't want to spend a whole sector for
1617 If you use this in combination with CFG_ENV_IS_IN_FLASH
1618 and CFG_ENV_SECT_SIZE, you can specify to use only a part
1619 of this flash sector for the environment. This saves
1620 memory for the RAM copy of the environment.
1622 It may also save flash memory if you decide to use this
1623 when your environment is "embedded" within U-Boot code,
1624 since then the remainder of the flash sector could be used
1625 for U-Boot code. It should be pointed out that this is
1626 STRONGLY DISCOURAGED from a robustness point of view:
1627 updating the environment in flash makes it always
1628 necessary to erase the WHOLE sector. If something goes
1629 wrong before the contents has been restored from a copy in
1630 RAM, your target system will be dead.
1632 - CFG_ENV_ADDR_REDUND
1635 These settings describe a second storage area used to hold
1636 a redundand copy of the environment data, so that there is
1637 a valid backup copy in case there is a power failure during
1638 a "saveenv" operation.
1640 BE CAREFUL! Any changes to the flash layout, and some changes to the
1641 source code will make it necessary to adapt <board>/u-boot.lds*
1645 - CFG_ENV_IS_IN_NVRAM:
1647 Define this if you have some non-volatile memory device
1648 (NVRAM, battery buffered SRAM) which you want to use for the
1654 These two #defines are used to determin the memory area you
1655 want to use for environment. It is assumed that this memory
1656 can just be read and written to, without any special
1659 BE CAREFUL! The first access to the environment happens quite early
1660 in U-Boot initalization (when we try to get the setting of for the
1661 console baudrate). You *MUST* have mappend your NVRAM area then, or
1664 Please note that even with NVRAM we still use a copy of the
1665 environment in RAM: we could work on NVRAM directly, but we want to
1666 keep settings there always unmodified except somebody uses "saveenv"
1667 to save the current settings.
1670 - CFG_ENV_IS_IN_EEPROM:
1672 Use this if you have an EEPROM or similar serial access
1673 device and a driver for it.
1678 These two #defines specify the offset and size of the
1679 environment area within the total memory of your EEPROM.
1681 - CFG_I2C_EEPROM_ADDR:
1682 If defined, specified the chip address of the EEPROM device.
1683 The default address is zero.
1685 - CFG_EEPROM_PAGE_WRITE_BITS:
1686 If defined, the number of bits used to address bytes in a
1687 single page in the EEPROM device. A 64 byte page, for example
1688 would require six bits.
1690 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1691 If defined, the number of milliseconds to delay between
1692 page writes. The default is zero milliseconds.
1694 - CFG_I2C_EEPROM_ADDR_LEN:
1695 The length in bytes of the EEPROM memory array address. Note
1696 that this is NOT the chip address length!
1699 The size in bytes of the EEPROM device.
1702 - CFG_ENV_IS_IN_DATAFLASH:
1704 Define this if you have a DataFlash memory device which you
1705 want to use for the environment.
1711 These three #defines specify the offset and size of the
1712 environment area within the total memory of your DataFlash placed
1713 at the specified address.
1716 - CFG_SPI_INIT_OFFSET
1718 Defines offset to the initial SPI buffer area in DPRAM. The
1719 area is used at an early stage (ROM part) if the environment
1720 is configured to reside in the SPI EEPROM: We need a 520 byte
1721 scratch DPRAM area. It is used between the two initialization
1722 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
1723 to be a good choice since it makes it far enough from the
1724 start of the data area as well as from the stack pointer.
1726 Please note that the environment is read-only as long as the monitor
1727 has been relocated to RAM and a RAM copy of the environment has been
1728 created; also, when using EEPROM you will have to use getenv_r()
1729 until then to read environment variables.
1731 The environment is protected by a CRC32 checksum. Before the monitor
1732 is relocated into RAM, as a result of a bad CRC you will be working
1733 with the compiled-in default environment - *silently*!!! [This is
1734 necessary, because the first environment variable we need is the
1735 "baudrate" setting for the console - if we have a bad CRC, we don't
1736 have any device yet where we could complain.]
1738 Note: once the monitor has been relocated, then it will complain if
1739 the default environment is used; a new CRC is computed as soon as you
1740 use the "saveenv" command to store a valid environment.
1742 - CFG_FAULT_ECHO_LINK_DOWN:
1743 Echo the inverted Ethernet link state to the fault LED.
1745 Note: If this option is active, then CFG_FAULT_MII_ADDR
1746 also needs to be defined.
1748 - CFG_FAULT_MII_ADDR:
1749 MII address of the PHY to check for the Ethernet link state.
1751 - CFG_64BIT_VSPRINTF:
1752 Makes vsprintf (and all *printf functions) support printing
1753 of 64bit values by using the L quantifier
1755 - CFG_64BIT_STRTOUL:
1756 Adds simple_strtoull that returns a 64bit value
1758 Low Level (hardware related) configuration options:
1759 ---------------------------------------------------
1761 - CFG_CACHELINE_SIZE:
1762 Cache Line Size of the CPU.
1765 Default address of the IMMR after system reset.
1767 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
1768 and RPXsuper) to be able to adjust the position of
1769 the IMMR register after a reset.
1771 - Floppy Disk Support:
1772 CFG_FDC_DRIVE_NUMBER
1774 the default drive number (default value 0)
1778 defines the spacing between fdc chipset registers
1783 defines the offset of register from address. It
1784 depends on which part of the data bus is connected to
1785 the fdc chipset. (default value 0)
1787 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
1788 CFG_FDC_DRIVE_NUMBER are undefined, they take their
1791 if CFG_FDC_HW_INIT is defined, then the function
1792 fdc_hw_init() is called at the beginning of the FDC
1793 setup. fdc_hw_init() must be provided by the board
1794 source code. It is used to make hardware dependant
1797 - CFG_IMMR: Physical address of the Internal Memory Mapped
1798 Register; DO NOT CHANGE! (11-4)
1799 [MPC8xx systems only]
1801 - CFG_INIT_RAM_ADDR:
1803 Start address of memory area that can be used for
1804 initial data and stack; please note that this must be
1805 writable memory that is working WITHOUT special
1806 initialization, i. e. you CANNOT use normal RAM which
1807 will become available only after programming the
1808 memory controller and running certain initialization
1811 U-Boot uses the following memory types:
1812 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
1813 - MPC824X: data cache
1814 - PPC4xx: data cache
1816 - CFG_GBL_DATA_OFFSET:
1818 Offset of the initial data structure in the memory
1819 area defined by CFG_INIT_RAM_ADDR. Usually
1820 CFG_GBL_DATA_OFFSET is chosen such that the initial
1821 data is located at the end of the available space
1822 (sometimes written as (CFG_INIT_RAM_END -
1823 CFG_INIT_DATA_SIZE), and the initial stack is just
1824 below that area (growing from (CFG_INIT_RAM_ADDR +
1825 CFG_GBL_DATA_OFFSET) downward.
1828 On the MPC824X (or other systems that use the data
1829 cache for initial memory) the address chosen for
1830 CFG_INIT_RAM_ADDR is basically arbitrary - it must
1831 point to an otherwise UNUSED address space between
1832 the top of RAM and the start of the PCI space.
1834 - CFG_SIUMCR: SIU Module Configuration (11-6)
1836 - CFG_SYPCR: System Protection Control (11-9)
1838 - CFG_TBSCR: Time Base Status and Control (11-26)
1840 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
1842 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
1844 - CFG_SCCR: System Clock and reset Control Register (15-27)
1846 - CFG_OR_TIMING_SDRAM:
1850 periodic timer for refresh
1852 - CFG_DER: Debug Event Register (37-47)
1854 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
1855 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
1856 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
1858 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
1860 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
1861 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
1862 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
1863 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
1865 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
1866 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
1867 Machine Mode Register and Memory Periodic Timer
1868 Prescaler definitions (SDRAM timing)
1870 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
1871 enable I2C microcode relocation patch (MPC8xx);
1872 define relocation offset in DPRAM [DSP2]
1874 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
1875 enable SPI microcode relocation patch (MPC8xx);
1876 define relocation offset in DPRAM [SCC4]
1879 Use OSCM clock mode on MBX8xx board. Be careful,
1880 wrong setting might damage your board. Read
1881 doc/README.MBX before setting this variable!
1883 - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
1884 Offset of the bootmode word in DPRAM used by post
1885 (Power On Self Tests). This definition overrides
1886 #define'd default value in commproc.h resp.
1889 - CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
1890 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
1891 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
1892 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
1893 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
1894 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
1895 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
1896 CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
1897 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
1899 Building the Software:
1900 ======================
1902 Building U-Boot has been tested in native PPC environments (on a
1903 PowerBook G3 running LinuxPPC 2000) and in cross environments
1904 (running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
1907 If you are not using a native PPC environment, it is assumed that you
1908 have the GNU cross compiling tools available in your path and named
1909 with a prefix of "powerpc-linux-". If this is not the case, (e.g. if
1910 you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
1911 the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
1914 CROSS_COMPILE = ppc_4xx-
1917 U-Boot is intended to be simple to build. After installing the
1918 sources you must configure U-Boot for one specific board type. This
1923 where "NAME_config" is the name of one of the existing
1924 configurations; the following names are supported:
1926 ADCIOP_config GTH_config TQM850L_config
1927 ADS860_config IP860_config TQM855L_config
1928 AR405_config IVML24_config TQM860L_config
1929 CANBT_config IVMS8_config WALNUT405_config
1930 CPCI405_config LANTEC_config cogent_common_config
1931 CPCIISER4_config MBX_config cogent_mpc8260_config
1932 CU824_config MBX860T_config cogent_mpc8xx_config
1933 ESTEEM192E_config RPXlite_config hermes_config
1934 ETX094_config RPXsuper_config hymod_config
1935 FADS823_config SM850_config lwmon_config
1936 FADS850SAR_config SPD823TS_config pcu_e_config
1937 FADS860T_config SXNI855T_config rsdproto_config
1938 FPS850L_config Sandpoint8240_config sbc8260_config
1939 GENIETV_config TQM823L_config PIP405_config
1940 GEN860T_config EBONY_config FPS860L_config
1941 ELPT860_config cmi_mpc5xx_config NETVIA_config
1942 at91rm9200dk_config omap1510inn_config MPC8260ADS_config
1943 omap1610inn_config ZPC1900_config MPC8540ADS_config
1944 MPC8560ADS_config QS850_config QS823_config
1945 QS860T_config DUET_ADS_config omap1610h2_config
1947 Note: for some board special configuration names may exist; check if
1948 additional information is available from the board vendor; for
1949 instance, the TQM8xxL systems run normally at 50 MHz and use a
1950 SCC for 10baseT ethernet; there are also systems with 80 MHz
1951 CPU clock, and an optional Fast Ethernet module is available
1952 for CPU's with FEC. You can select such additional "features"
1953 when chosing the configuration, i. e.
1956 - will configure for a plain TQM860L, i. e. 50MHz, no FEC
1958 make TQM860L_FEC_config
1959 - will configure for a TQM860L at 50MHz with FEC for ethernet
1961 make TQM860L_80MHz_config
1962 - will configure for a TQM860L at 80 MHz, with normal 10baseT
1965 make TQM860L_FEC_80MHz_config
1966 - will configure for a TQM860L at 80 MHz with FEC for ethernet
1968 make TQM823L_LCD_config
1969 - will configure for a TQM823L with U-Boot console on LCD
1971 make TQM823L_LCD_80MHz_config
1972 - will configure for a TQM823L at 80 MHz with U-Boot console on LCD
1977 Finally, type "make all", and you should get some working U-Boot
1978 images ready for download to / installation on your system:
1980 - "u-boot.bin" is a raw binary image
1981 - "u-boot" is an image in ELF binary format
1982 - "u-boot.srec" is in Motorola S-Record format
1985 Please be aware that the Makefiles assume you are using GNU make, so
1986 for instance on NetBSD you might need to use "gmake" instead of
1990 If the system board that you have is not listed, then you will need
1991 to port U-Boot to your hardware platform. To do this, follow these
1994 1. Add a new configuration option for your board to the toplevel
1995 "Makefile" and to the "MAKEALL" script, using the existing
1996 entries as examples. Note that here and at many other places
1997 boards and other names are listed in alphabetical sort order. Please
1999 2. Create a new directory to hold your board specific code. Add any
2000 files you need. In your board directory, you will need at least
2001 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2002 3. Create a new configuration file "include/configs/<board>.h" for
2004 3. If you're porting U-Boot to a new CPU, then also create a new
2005 directory to hold your CPU specific code. Add any files you need.
2006 4. Run "make <board>_config" with your new name.
2007 5. Type "make", and you should get a working "u-boot.srec" file
2008 to be installed on your target system.
2009 6. Debug and solve any problems that might arise.
2010 [Of course, this last step is much harder than it sounds.]
2013 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2014 ==============================================================
2016 If you have modified U-Boot sources (for instance added a new board
2017 or support for new devices, a new CPU, etc.) you are expected to
2018 provide feedback to the other developers. The feedback normally takes
2019 the form of a "patch", i. e. a context diff against a certain (latest
2020 official or latest in CVS) version of U-Boot sources.
2022 But before you submit such a patch, please verify that your modifi-
2023 cation did not break existing code. At least make sure that *ALL* of
2024 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2025 just run the "MAKEALL" script, which will configure and build U-Boot
2026 for ALL supported system. Be warned, this will take a while. You can
2027 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2028 environment variable to the script, i. e. to use the cross tools from
2029 MontaVista's Hard Hat Linux you can type
2031 CROSS_COMPILE=ppc_8xx- MAKEALL
2033 or to build on a native PowerPC system you can type
2035 CROSS_COMPILE=' ' MAKEALL
2037 See also "U-Boot Porting Guide" below.
2040 Monitor Commands - Overview:
2041 ============================
2043 go - start application at address 'addr'
2044 run - run commands in an environment variable
2045 bootm - boot application image from memory
2046 bootp - boot image via network using BootP/TFTP protocol
2047 tftpboot- boot image via network using TFTP protocol
2048 and env variables "ipaddr" and "serverip"
2049 (and eventually "gatewayip")
2050 rarpboot- boot image via network using RARP/TFTP protocol
2051 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2052 loads - load S-Record file over serial line
2053 loadb - load binary file over serial line (kermit mode)
2055 mm - memory modify (auto-incrementing)
2056 nm - memory modify (constant address)
2057 mw - memory write (fill)
2059 cmp - memory compare
2060 crc32 - checksum calculation
2061 imd - i2c memory display
2062 imm - i2c memory modify (auto-incrementing)
2063 inm - i2c memory modify (constant address)
2064 imw - i2c memory write (fill)
2065 icrc32 - i2c checksum calculation
2066 iprobe - probe to discover valid I2C chip addresses
2067 iloop - infinite loop on address range
2068 isdram - print SDRAM configuration information
2069 sspi - SPI utility commands
2070 base - print or set address offset
2071 printenv- print environment variables
2072 setenv - set environment variables
2073 saveenv - save environment variables to persistent storage
2074 protect - enable or disable FLASH write protection
2075 erase - erase FLASH memory
2076 flinfo - print FLASH memory information
2077 bdinfo - print Board Info structure
2078 iminfo - print header information for application image
2079 coninfo - print console devices and informations
2080 ide - IDE sub-system
2081 loop - infinite loop on address range
2082 mtest - simple RAM test
2083 icache - enable or disable instruction cache
2084 dcache - enable or disable data cache
2085 reset - Perform RESET of the CPU
2086 echo - echo args to console
2087 version - print monitor version
2088 help - print online help
2089 ? - alias for 'help'
2092 Monitor Commands - Detailed Description:
2093 ========================================
2097 For now: just type "help <command>".
2100 Environment Variables:
2101 ======================
2103 U-Boot supports user configuration using Environment Variables which
2104 can be made persistent by saving to Flash memory.
2106 Environment Variables are set using "setenv", printed using
2107 "printenv", and saved to Flash using "saveenv". Using "setenv"
2108 without a value can be used to delete a variable from the
2109 environment. As long as you don't save the environment you are
2110 working with an in-memory copy. In case the Flash area containing the
2111 environment is erased by accident, a default environment is provided.
2113 Some configuration options can be set using Environment Variables:
2115 baudrate - see CONFIG_BAUDRATE
2117 bootdelay - see CONFIG_BOOTDELAY
2119 bootcmd - see CONFIG_BOOTCOMMAND
2121 bootargs - Boot arguments when booting an RTOS image
2123 bootfile - Name of the image to load with TFTP
2125 autoload - if set to "no" (any string beginning with 'n'),
2126 "bootp" will just load perform a lookup of the
2127 configuration from the BOOTP server, but not try to
2128 load any image using TFTP
2130 autostart - if set to "yes", an image loaded using the "bootp",
2131 "rarpboot", "tftpboot" or "diskboot" commands will
2132 be automatically started (by internally calling
2135 If set to "no", a standalone image passed to the
2136 "bootm" command will be copied to the load address
2137 (and eventually uncompressed), but NOT be started.
2138 This can be used to load and uncompress arbitrary
2141 initrd_high - restrict positioning of initrd images:
2142 If this variable is not set, initrd images will be
2143 copied to the highest possible address in RAM; this
2144 is usually what you want since it allows for
2145 maximum initrd size. If for some reason you want to
2146 make sure that the initrd image is loaded below the
2147 CFG_BOOTMAPSZ limit, you can set this environment
2148 variable to a value of "no" or "off" or "0".
2149 Alternatively, you can set it to a maximum upper
2150 address to use (U-Boot will still check that it
2151 does not overwrite the U-Boot stack and data).
2153 For instance, when you have a system with 16 MB
2154 RAM, and want to reserve 4 MB from use by Linux,
2155 you can do this by adding "mem=12M" to the value of
2156 the "bootargs" variable. However, now you must make
2157 sure that the initrd image is placed in the first
2158 12 MB as well - this can be done with
2160 setenv initrd_high 00c00000
2162 If you set initrd_high to 0xFFFFFFFF, this is an
2163 indication to U-Boot that all addresses are legal
2164 for the Linux kernel, including addresses in flash
2165 memory. In this case U-Boot will NOT COPY the
2166 ramdisk at all. This may be useful to reduce the
2167 boot time on your system, but requires that this
2168 feature is supported by your Linux kernel.
2170 ipaddr - IP address; needed for tftpboot command
2172 loadaddr - Default load address for commands like "bootp",
2173 "rarpboot", "tftpboot", "loadb" or "diskboot"
2175 loads_echo - see CONFIG_LOADS_ECHO
2177 serverip - TFTP server IP address; needed for tftpboot command
2179 bootretry - see CONFIG_BOOT_RETRY_TIME
2181 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
2183 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
2186 The following environment variables may be used and automatically
2187 updated by the network boot commands ("bootp" and "rarpboot"),
2188 depending the information provided by your boot server:
2190 bootfile - see above
2191 dnsip - IP address of your Domain Name Server
2192 dnsip2 - IP address of your secondary Domain Name Server
2193 gatewayip - IP address of the Gateway (Router) to use
2194 hostname - Target hostname
2196 netmask - Subnet Mask
2197 rootpath - Pathname of the root filesystem on the NFS server
2198 serverip - see above
2201 There are two special Environment Variables:
2203 serial# - contains hardware identification information such
2204 as type string and/or serial number
2205 ethaddr - Ethernet address
2207 These variables can be set only once (usually during manufacturing of
2208 the board). U-Boot refuses to delete or overwrite these variables
2209 once they have been set once.
2212 Further special Environment Variables:
2214 ver - Contains the U-Boot version string as printed
2215 with the "version" command. This variable is
2216 readonly (see CONFIG_VERSION_VARIABLE).
2219 Please note that changes to some configuration parameters may take
2220 only effect after the next boot (yes, that's just like Windoze :-).
2223 Command Line Parsing:
2224 =====================
2226 There are two different command line parsers available with U-Boot:
2227 the old "simple" one, and the much more powerful "hush" shell:
2229 Old, simple command line parser:
2230 --------------------------------
2232 - supports environment variables (through setenv / saveenv commands)
2233 - several commands on one line, separated by ';'
2234 - variable substitution using "... $(name) ..." syntax
2235 - special characters ('$', ';') can be escaped by prefixing with '\',
2237 setenv bootcmd bootm \$(address)
2238 - You can also escape text by enclosing in single apostrophes, for example:
2239 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2244 - similar to Bourne shell, with control structures like
2245 if...then...else...fi, for...do...done; while...do...done,
2246 until...do...done, ...
2247 - supports environment ("global") variables (through setenv / saveenv
2248 commands) and local shell variables (through standard shell syntax
2249 "name=value"); only environment variables can be used with "run"
2255 (1) If a command line (or an environment variable executed by a "run"
2256 command) contains several commands separated by semicolon, and
2257 one of these commands fails, then the remaining commands will be
2260 (2) If you execute several variables with one call to run (i. e.
2261 calling run with a list af variables as arguments), any failing
2262 command will cause "run" to terminate, i. e. the remaining
2263 variables are not executed.
2265 Note for Redundant Ethernet Interfaces:
2266 =======================================
2268 Some boards come with redundant ethernet interfaces; U-Boot supports
2269 such configurations and is capable of automatic selection of a
2270 "working" interface when needed. MAC assignment works as follows:
2272 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2273 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2274 "eth1addr" (=>eth1), "eth2addr", ...
2276 If the network interface stores some valid MAC address (for instance
2277 in SROM), this is used as default address if there is NO correspon-
2278 ding setting in the environment; if the corresponding environment
2279 variable is set, this overrides the settings in the card; that means:
2281 o If the SROM has a valid MAC address, and there is no address in the
2282 environment, the SROM's address is used.
2284 o If there is no valid address in the SROM, and a definition in the
2285 environment exists, then the value from the environment variable is
2288 o If both the SROM and the environment contain a MAC address, and
2289 both addresses are the same, this MAC address is used.
2291 o If both the SROM and the environment contain a MAC address, and the
2292 addresses differ, the value from the environment is used and a
2295 o If neither SROM nor the environment contain a MAC address, an error
2302 The "boot" commands of this monitor operate on "image" files which
2303 can be basicly anything, preceeded by a special header; see the
2304 definitions in include/image.h for details; basicly, the header
2305 defines the following image properties:
2307 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2308 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2309 LynxOS, pSOS, QNX, RTEMS, ARTOS;
2310 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
2311 * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
2312 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2313 Currently supported: ARM, Intel x86, MIPS, NIOS, PowerPC).
2314 * Compression Type (uncompressed, gzip, bzip2)
2320 The header is marked by a special Magic Number, and both the header
2321 and the data portions of the image are secured against corruption by
2328 Although U-Boot should support any OS or standalone application
2329 easily, the main focus has always been on Linux during the design of
2332 U-Boot includes many features that so far have been part of some
2333 special "boot loader" code within the Linux kernel. Also, any
2334 "initrd" images to be used are no longer part of one big Linux image;
2335 instead, kernel and "initrd" are separate images. This implementation
2336 serves several purposes:
2338 - the same features can be used for other OS or standalone
2339 applications (for instance: using compressed images to reduce the
2340 Flash memory footprint)
2342 - it becomes much easier to port new Linux kernel versions because
2343 lots of low-level, hardware dependent stuff are done by U-Boot
2345 - the same Linux kernel image can now be used with different "initrd"
2346 images; of course this also means that different kernel images can
2347 be run with the same "initrd". This makes testing easier (you don't
2348 have to build a new "zImage.initrd" Linux image when you just
2349 change a file in your "initrd"). Also, a field-upgrade of the
2350 software is easier now.
2356 Porting Linux to U-Boot based systems:
2357 ---------------------------------------
2359 U-Boot cannot save you from doing all the necessary modifications to
2360 configure the Linux device drivers for use with your target hardware
2361 (no, we don't intend to provide a full virtual machine interface to
2364 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
2366 Just make sure your machine specific header file (for instance
2367 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
2368 Information structure as we define in include/u-boot.h, and make
2369 sure that your definition of IMAP_ADDR uses the same value as your
2370 U-Boot configuration in CFG_IMMR.
2373 Configuring the Linux kernel:
2374 -----------------------------
2376 No specific requirements for U-Boot. Make sure you have some root
2377 device (initial ramdisk, NFS) for your target system.
2380 Building a Linux Image:
2381 -----------------------
2383 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2384 not used. If you use recent kernel source, a new build target
2385 "uImage" will exist which automatically builds an image usable by
2386 U-Boot. Most older kernels also have support for a "pImage" target,
2387 which was introduced for our predecessor project PPCBoot and uses a
2388 100% compatible format.
2397 The "uImage" build target uses a special tool (in 'tools/mkimage') to
2398 encapsulate a compressed Linux kernel image with header information,
2399 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
2401 * build a standard "vmlinux" kernel image (in ELF binary format):
2403 * convert the kernel into a raw binary image:
2405 ${CROSS_COMPILE}-objcopy -O binary \
2406 -R .note -R .comment \
2407 -S vmlinux linux.bin
2409 * compress the binary image:
2413 * package compressed binary image for U-Boot:
2415 mkimage -A ppc -O linux -T kernel -C gzip \
2416 -a 0 -e 0 -n "Linux Kernel Image" \
2417 -d linux.bin.gz uImage
2420 The "mkimage" tool can also be used to create ramdisk images for use
2421 with U-Boot, either separated from the Linux kernel image, or
2422 combined into one file. "mkimage" encapsulates the images with a 64
2423 byte header containing information about target architecture,
2424 operating system, image type, compression method, entry points, time
2425 stamp, CRC32 checksums, etc.
2427 "mkimage" can be called in two ways: to verify existing images and
2428 print the header information, or to build new images.
2430 In the first form (with "-l" option) mkimage lists the information
2431 contained in the header of an existing U-Boot image; this includes
2432 checksum verification:
2434 tools/mkimage -l image
2435 -l ==> list image header information
2437 The second form (with "-d" option) is used to build a U-Boot image
2438 from a "data file" which is used as image payload:
2440 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2441 -n name -d data_file image
2442 -A ==> set architecture to 'arch'
2443 -O ==> set operating system to 'os'
2444 -T ==> set image type to 'type'
2445 -C ==> set compression type 'comp'
2446 -a ==> set load address to 'addr' (hex)
2447 -e ==> set entry point to 'ep' (hex)
2448 -n ==> set image name to 'name'
2449 -d ==> use image data from 'datafile'
2451 Right now, all Linux kernels use the same load address (0x00000000),
2452 but the entry point address depends on the kernel version:
2454 - 2.2.x kernels have the entry point at 0x0000000C,
2455 - 2.3.x and later kernels have the entry point at 0x00000000.
2457 So a typical call to build a U-Boot image would read:
2459 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2460 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
2461 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
2462 > examples/uImage.TQM850L
2463 Image Name: 2.4.4 kernel for TQM850L
2464 Created: Wed Jul 19 02:34:59 2000
2465 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2466 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2467 Load Address: 0x00000000
2468 Entry Point: 0x00000000
2470 To verify the contents of the image (or check for corruption):
2472 -> tools/mkimage -l examples/uImage.TQM850L
2473 Image Name: 2.4.4 kernel for TQM850L
2474 Created: Wed Jul 19 02:34:59 2000
2475 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2476 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2477 Load Address: 0x00000000
2478 Entry Point: 0x00000000
2480 NOTE: for embedded systems where boot time is critical you can trade
2481 speed for memory and install an UNCOMPRESSED image instead: this
2482 needs more space in Flash, but boots much faster since it does not
2483 need to be uncompressed:
2485 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
2486 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2487 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
2488 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
2489 > examples/uImage.TQM850L-uncompressed
2490 Image Name: 2.4.4 kernel for TQM850L
2491 Created: Wed Jul 19 02:34:59 2000
2492 Image Type: PowerPC Linux Kernel Image (uncompressed)
2493 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
2494 Load Address: 0x00000000
2495 Entry Point: 0x00000000
2498 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2499 when your kernel is intended to use an initial ramdisk:
2501 -> tools/mkimage -n 'Simple Ramdisk Image' \
2502 > -A ppc -O linux -T ramdisk -C gzip \
2503 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2504 Image Name: Simple Ramdisk Image
2505 Created: Wed Jan 12 14:01:50 2000
2506 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2507 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
2508 Load Address: 0x00000000
2509 Entry Point: 0x00000000
2512 Installing a Linux Image:
2513 -------------------------
2515 To downloading a U-Boot image over the serial (console) interface,
2516 you must convert the image to S-Record format:
2518 objcopy -I binary -O srec examples/image examples/image.srec
2520 The 'objcopy' does not understand the information in the U-Boot
2521 image header, so the resulting S-Record file will be relative to
2522 address 0x00000000. To load it to a given address, you need to
2523 specify the target address as 'offset' parameter with the 'loads'
2526 Example: install the image to address 0x40100000 (which on the
2527 TQM8xxL is in the first Flash bank):
2529 => erase 40100000 401FFFFF
2535 ## Ready for S-Record download ...
2536 ~>examples/image.srec
2537 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2539 15989 15990 15991 15992
2540 [file transfer complete]
2542 ## Start Addr = 0x00000000
2545 You can check the success of the download using the 'iminfo' command;
2546 this includes a checksum verification so you can be sure no data
2547 corruption happened:
2551 ## Checking Image at 40100000 ...
2552 Image Name: 2.2.13 for initrd on TQM850L
2553 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2554 Data Size: 335725 Bytes = 327 kB = 0 MB
2555 Load Address: 00000000
2556 Entry Point: 0000000c
2557 Verifying Checksum ... OK
2563 The "bootm" command is used to boot an application that is stored in
2564 memory (RAM or Flash). In case of a Linux kernel image, the contents
2565 of the "bootargs" environment variable is passed to the kernel as
2566 parameters. You can check and modify this variable using the
2567 "printenv" and "setenv" commands:
2570 => printenv bootargs
2571 bootargs=root=/dev/ram
2573 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2575 => printenv bootargs
2576 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2579 ## Booting Linux kernel at 40020000 ...
2580 Image Name: 2.2.13 for NFS on TQM850L
2581 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2582 Data Size: 381681 Bytes = 372 kB = 0 MB
2583 Load Address: 00000000
2584 Entry Point: 0000000c
2585 Verifying Checksum ... OK
2586 Uncompressing Kernel Image ... OK
2587 Linux version 2.2.13 (
[email protected]) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
2588 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2589 time_init: decrementer frequency = 187500000/60
2590 Calibrating delay loop... 49.77 BogoMIPS
2591 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2594 If you want to boot a Linux kernel with initial ram disk, you pass
2595 the memory addresses of both the kernel and the initrd image (PPBCOOT
2596 format!) to the "bootm" command:
2598 => imi 40100000 40200000
2600 ## Checking Image at 40100000 ...
2601 Image Name: 2.2.13 for initrd on TQM850L
2602 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2603 Data Size: 335725 Bytes = 327 kB = 0 MB
2604 Load Address: 00000000
2605 Entry Point: 0000000c
2606 Verifying Checksum ... OK
2608 ## Checking Image at 40200000 ...
2609 Image Name: Simple Ramdisk Image
2610 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2611 Data Size: 566530 Bytes = 553 kB = 0 MB
2612 Load Address: 00000000
2613 Entry Point: 00000000
2614 Verifying Checksum ... OK
2616 => bootm 40100000 40200000
2617 ## Booting Linux kernel at 40100000 ...
2618 Image Name: 2.2.13 for initrd on TQM850L
2619 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2620 Data Size: 335725 Bytes = 327 kB = 0 MB
2621 Load Address: 00000000
2622 Entry Point: 0000000c
2623 Verifying Checksum ... OK
2624 Uncompressing Kernel Image ... OK
2625 ## Loading RAMDisk Image at 40200000 ...
2626 Image Name: Simple Ramdisk Image
2627 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2628 Data Size: 566530 Bytes = 553 kB = 0 MB
2629 Load Address: 00000000
2630 Entry Point: 00000000
2631 Verifying Checksum ... OK
2632 Loading Ramdisk ... OK
2633 Linux version 2.2.13 (
[email protected]) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
2634 Boot arguments: root=/dev/ram
2635 time_init: decrementer frequency = 187500000/60
2636 Calibrating delay loop... 49.77 BogoMIPS
2638 RAMDISK: Compressed image found at block 0
2639 VFS: Mounted root (ext2 filesystem).
2643 More About U-Boot Image Types:
2644 ------------------------------
2646 U-Boot supports the following image types:
2648 "Standalone Programs" are directly runnable in the environment
2649 provided by U-Boot; it is expected that (if they behave
2650 well) you can continue to work in U-Boot after return from
2651 the Standalone Program.
2652 "OS Kernel Images" are usually images of some Embedded OS which
2653 will take over control completely. Usually these programs
2654 will install their own set of exception handlers, device
2655 drivers, set up the MMU, etc. - this means, that you cannot
2656 expect to re-enter U-Boot except by resetting the CPU.
2657 "RAMDisk Images" are more or less just data blocks, and their
2658 parameters (address, size) are passed to an OS kernel that is
2660 "Multi-File Images" contain several images, typically an OS
2661 (Linux) kernel image and one or more data images like
2662 RAMDisks. This construct is useful for instance when you want
2663 to boot over the network using BOOTP etc., where the boot
2664 server provides just a single image file, but you want to get
2665 for instance an OS kernel and a RAMDisk image.
2667 "Multi-File Images" start with a list of image sizes, each
2668 image size (in bytes) specified by an "uint32_t" in network
2669 byte order. This list is terminated by an "(uint32_t)0".
2670 Immediately after the terminating 0 follow the images, one by
2671 one, all aligned on "uint32_t" boundaries (size rounded up to
2672 a multiple of 4 bytes).
2674 "Firmware Images" are binary images containing firmware (like
2675 U-Boot or FPGA images) which usually will be programmed to
2678 "Script files" are command sequences that will be executed by
2679 U-Boot's command interpreter; this feature is especially
2680 useful when you configure U-Boot to use a real shell (hush)
2681 as command interpreter.
2687 One of the features of U-Boot is that you can dynamically load and
2688 run "standalone" applications, which can use some resources of
2689 U-Boot like console I/O functions or interrupt services.
2691 Two simple examples are included with the sources:
2696 'examples/hello_world.c' contains a small "Hello World" Demo
2697 application; it is automatically compiled when you build U-Boot.
2698 It's configured to run at address 0x00040004, so you can play with it
2702 ## Ready for S-Record download ...
2703 ~>examples/hello_world.srec
2704 1 2 3 4 5 6 7 8 9 10 11 ...
2705 [file transfer complete]
2707 ## Start Addr = 0x00040004
2709 => go 40004 Hello World! This is a test.
2710 ## Starting application at 0x00040004 ...
2721 Hit any key to exit ...
2723 ## Application terminated, rc = 0x0
2725 Another example, which demonstrates how to register a CPM interrupt
2726 handler with the U-Boot code, can be found in 'examples/timer.c'.
2727 Here, a CPM timer is set up to generate an interrupt every second.
2728 The interrupt service routine is trivial, just printing a '.'
2729 character, but this is just a demo program. The application can be
2730 controlled by the following keys:
2732 ? - print current values og the CPM Timer registers
2733 b - enable interrupts and start timer
2734 e - stop timer and disable interrupts
2735 q - quit application
2738 ## Ready for S-Record download ...
2739 ~>examples/timer.srec
2740 1 2 3 4 5 6 7 8 9 10 11 ...
2741 [file transfer complete]
2743 ## Start Addr = 0x00040004
2746 ## Starting application at 0x00040004 ...
2749 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
2752 [q, b, e, ?] Set interval 1000000 us
2755 [q, b, e, ?] ........
2756 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
2759 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
2762 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
2765 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
2767 [q, b, e, ?] ...Stopping timer
2769 [q, b, e, ?] ## Application terminated, rc = 0x0
2775 Over time, many people have reported problems when trying to use the
2776 "minicom" terminal emulation program for serial download. I (wd)
2777 consider minicom to be broken, and recommend not to use it. Under
2778 Unix, I recommend to use C-Kermit for general purpose use (and
2779 especially for kermit binary protocol download ("loadb" command), and
2780 use "cu" for S-Record download ("loads" command).
2782 Nevertheless, if you absolutely want to use it try adding this
2783 configuration to your "File transfer protocols" section:
2785 Name Program Name U/D FullScr IO-Red. Multi
2786 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
2787 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
2793 Starting at version 0.9.2, U-Boot supports NetBSD both as host
2794 (build U-Boot) and target system (boots NetBSD/mpc8xx).
2796 Building requires a cross environment; it is known to work on
2797 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
2798 need gmake since the Makefiles are not compatible with BSD make).
2799 Note that the cross-powerpc package does not install include files;
2800 attempting to build U-Boot will fail because <machine/ansi.h> is
2801 missing. This file has to be installed and patched manually:
2803 # cd /usr/pkg/cross/powerpc-netbsd/include
2805 # ln -s powerpc machine
2806 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
2807 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
2809 Native builds *don't* work due to incompatibilities between native
2810 and U-Boot include files.
2812 Booting assumes that (the first part of) the image booted is a
2813 stage-2 loader which in turn loads and then invokes the kernel
2814 proper. Loader sources will eventually appear in the NetBSD source
2815 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
2820 Implementation Internals:
2821 =========================
2823 The following is not intended to be a complete description of every
2824 implementation detail. However, it should help to understand the
2825 inner workings of U-Boot and make it easier to port it to custom
2829 Initial Stack, Global Data:
2830 ---------------------------
2832 The implementation of U-Boot is complicated by the fact that U-Boot
2833 starts running out of ROM (flash memory), usually without access to
2834 system RAM (because the memory controller is not initialized yet).
2835 This means that we don't have writable Data or BSS segments, and BSS
2836 is not initialized as zero. To be able to get a C environment working
2837 at all, we have to allocate at least a minimal stack. Implementation
2838 options for this are defined and restricted by the CPU used: Some CPU
2839 models provide on-chip memory (like the IMMR area on MPC8xx and
2840 MPC826x processors), on others (parts of) the data cache can be
2841 locked as (mis-) used as memory, etc.
2843 Chris Hallinan posted a good summary of these issues to the
2844 u-boot-users mailing list:
2846 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
2848 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
2851 Correct me if I'm wrong, folks, but the way I understand it
2852 is this: Using DCACHE as initial RAM for Stack, etc, does not
2853 require any physical RAM backing up the cache. The cleverness
2854 is that the cache is being used as a temporary supply of
2855 necessary storage before the SDRAM controller is setup. It's
2856 beyond the scope of this list to expain the details, but you
2857 can see how this works by studying the cache architecture and
2858 operation in the architecture and processor-specific manuals.
2860 OCM is On Chip Memory, which I believe the 405GP has 4K. It
2861 is another option for the system designer to use as an
2862 initial stack/ram area prior to SDRAM being available. Either
2863 option should work for you. Using CS 4 should be fine if your
2864 board designers haven't used it for something that would
2865 cause you grief during the initial boot! It is frequently not
2868 CFG_INIT_RAM_ADDR should be somewhere that won't interfere
2869 with your processor/board/system design. The default value
2870 you will find in any recent u-boot distribution in
2871 Walnut405.h should work for you. I'd set it to a value larger
2872 than your SDRAM module. If you have a 64MB SDRAM module, set
2873 it above 400_0000. Just make sure your board has no resources
2874 that are supposed to respond to that address! That code in
2875 start.S has been around a while and should work as is when
2876 you get the config right.
2881 It is essential to remember this, since it has some impact on the C
2882 code for the initialization procedures:
2884 * Initialized global data (data segment) is read-only. Do not attempt
2887 * Do not use any unitialized global data (or implicitely initialized
2888 as zero data - BSS segment) at all - this is undefined, initiali-
2889 zation is performed later (when relocating to RAM).
2891 * Stack space is very limited. Avoid big data buffers or things like
2894 Having only the stack as writable memory limits means we cannot use
2895 normal global data to share information beween the code. But it
2896 turned out that the implementation of U-Boot can be greatly
2897 simplified by making a global data structure (gd_t) available to all
2898 functions. We could pass a pointer to this data as argument to _all_
2899 functions, but this would bloat the code. Instead we use a feature of
2900 the GCC compiler (Global Register Variables) to share the data: we
2901 place a pointer (gd) to the global data into a register which we
2902 reserve for this purpose.
2904 When choosing a register for such a purpose we are restricted by the
2905 relevant (E)ABI specifications for the current architecture, and by
2906 GCC's implementation.
2908 For PowerPC, the following registers have specific use:
2911 R3-R4: parameter passing and return values
2912 R5-R10: parameter passing
2913 R13: small data area pointer
2917 (U-Boot also uses R14 as internal GOT pointer.)
2919 ==> U-Boot will use R29 to hold a pointer to the global data
2921 Note: on PPC, we could use a static initializer (since the
2922 address of the global data structure is known at compile time),
2923 but it turned out that reserving a register results in somewhat
2924 smaller code - although the code savings are not that big (on
2925 average for all boards 752 bytes for the whole U-Boot image,
2926 624 text + 127 data).
2928 On ARM, the following registers are used:
2930 R0: function argument word/integer result
2931 R1-R3: function argument word
2933 R10: stack limit (used only if stack checking if enabled)
2934 R11: argument (frame) pointer
2935 R12: temporary workspace
2938 R15: program counter
2940 ==> U-Boot will use R8 to hold a pointer to the global data
2946 U-Boot runs in system state and uses physical addresses, i.e. the
2947 MMU is not used either for address mapping nor for memory protection.
2949 The available memory is mapped to fixed addresses using the memory
2950 controller. In this process, a contiguous block is formed for each
2951 memory type (Flash, SDRAM, SRAM), even when it consists of several
2952 physical memory banks.
2954 U-Boot is installed in the first 128 kB of the first Flash bank (on
2955 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
2956 booting and sizing and initializing DRAM, the code relocates itself
2957 to the upper end of DRAM. Immediately below the U-Boot code some
2958 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
2959 configuration setting]. Below that, a structure with global Board
2960 Info data is placed, followed by the stack (growing downward).
2962 Additionally, some exception handler code is copied to the low 8 kB
2963 of DRAM (0x00000000 ... 0x00001FFF).
2965 So a typical memory configuration with 16 MB of DRAM could look like
2968 0x0000 0000 Exception Vector code
2971 0x0000 2000 Free for Application Use
2977 0x00FB FF20 Monitor Stack (Growing downward)
2978 0x00FB FFAC Board Info Data and permanent copy of global data
2979 0x00FC 0000 Malloc Arena
2982 0x00FE 0000 RAM Copy of Monitor Code
2983 ... eventually: LCD or video framebuffer
2984 ... eventually: pRAM (Protected RAM - unchanged by reset)
2985 0x00FF FFFF [End of RAM]
2988 System Initialization:
2989 ----------------------
2991 In the reset configuration, U-Boot starts at the reset entry point
2992 (on most PowerPC systens at address 0x00000100). Because of the reset
2993 configuration for CS0# this is a mirror of the onboard Flash memory.
2994 To be able to re-map memory U-Boot then jumps to its link address.
2995 To be able to implement the initialization code in C, a (small!)
2996 initial stack is set up in the internal Dual Ported RAM (in case CPUs
2997 which provide such a feature like MPC8xx or MPC8260), or in a locked
2998 part of the data cache. After that, U-Boot initializes the CPU core,
2999 the caches and the SIU.
3001 Next, all (potentially) available memory banks are mapped using a
3002 preliminary mapping. For example, we put them on 512 MB boundaries
3003 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3004 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3005 programmed for SDRAM access. Using the temporary configuration, a
3006 simple memory test is run that determines the size of the SDRAM
3009 When there is more than one SDRAM bank, and the banks are of
3010 different size, the largest is mapped first. For equal size, the first
3011 bank (CS2#) is mapped first. The first mapping is always for address
3012 0x00000000, with any additional banks following immediately to create
3013 contiguous memory starting from 0.
3015 Then, the monitor installs itself at the upper end of the SDRAM area
3016 and allocates memory for use by malloc() and for the global Board
3017 Info data; also, the exception vector code is copied to the low RAM
3018 pages, and the final stack is set up.
3020 Only after this relocation will you have a "normal" C environment;
3021 until that you are restricted in several ways, mostly because you are
3022 running from ROM, and because the code will have to be relocated to a
3026 U-Boot Porting Guide:
3027 ----------------------
3029 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3033 int main (int argc, char *argv[])
3035 sighandler_t no_more_time;
3037 signal (SIGALRM, no_more_time);
3038 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3040 if (available_money > available_manpower) {
3041 pay consultant to port U-Boot;
3045 Download latest U-Boot source;
3047 Subscribe to u-boot-users mailing list;
3050 email ("Hi, I am new to U-Boot, how do I get started?");
3054 Read the README file in the top level directory;
3055 Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
3056 Read the source, Luke;
3059 if (available_money > toLocalCurrency ($2500)) {
3062 Add a lot of aggravation and time;
3065 Create your own board support subdirectory;
3067 Create your own board config file;
3071 Add / modify source code;
3075 email ("Hi, I am having problems...");
3077 Send patch file to Wolfgang;
3082 void no_more_time (int sig)
3091 All contributions to U-Boot should conform to the Linux kernel
3092 coding style; see the file "Documentation/CodingStyle" in your Linux
3093 kernel source directory.
3095 Please note that U-Boot is implemented in C (and to some small parts
3096 in Assembler); no C++ is used, so please do not use C++ style
3097 comments (//) in your code.
3099 Please also stick to the following formatting rules:
3100 - remove any trailing white space
3101 - use TAB characters for indentation, not spaces
3102 - make sure NOT to use DOS '\r\n' line feeds
3103 - do not add more than 2 empty lines to source files
3104 - do not add trailing empty lines to source files
3106 Submissions which do not conform to the standards may be returned
3107 with a request to reformat the changes.
3113 Since the number of patches for U-Boot is growing, we need to
3114 establish some rules. Submissions which do not conform to these rules
3115 may be rejected, even when they contain important and valuable stuff.
3118 When you send a patch, please include the following information with
3121 * For bug fixes: a description of the bug and how your patch fixes
3122 this bug. Please try to include a way of demonstrating that the
3123 patch actually fixes something.
3125 * For new features: a description of the feature and your
3128 * A CHANGELOG entry as plaintext (separate from the patch)
3130 * For major contributions, your entry to the CREDITS file
3132 * When you add support for a new board, don't forget to add this
3133 board to the MAKEALL script, too.
3135 * If your patch adds new configuration options, don't forget to
3136 document these in the README file.
3138 * The patch itself. If you are accessing the CVS repository use "cvs
3139 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
3140 version of diff does not support these options, then get the latest
3141 version of GNU diff.
3143 The current directory when running this command shall be the top
3144 level directory of the U-Boot source tree, or it's parent directory
3145 (i. e. please make sure that your patch includes sufficient
3146 directory information for the affected files).
3148 We accept patches as plain text, MIME attachments or as uuencoded
3151 * If one logical set of modifications affects or creates several
3152 files, all these changes shall be submitted in a SINGLE patch file.
3154 * Changesets that contain different, unrelated modifications shall be
3155 submitted as SEPARATE patches, one patch per changeset.
3160 * Before sending the patch, run the MAKEALL script on your patched
3161 source tree and make sure that no errors or warnings are reported
3162 for any of the boards.
3164 * Keep your modifications to the necessary minimum: A patch
3165 containing several unrelated changes or arbitrary reformats will be
3166 returned with a request to re-formatting / split it.
3168 * If you modify existing code, make sure that your new code does not
3169 add to the memory footprint of the code ;-) Small is beautiful!
3170 When adding new features, these should compile conditionally only
3171 (using #ifdef), and the resulting code with the new feature
3172 disabled must not need more memory than the old code without your
projects / J-u-boot.git / blob