2 # (C) Copyright 2000 - 2004
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # See file CREDITS for list of people who contributed to this
8 # This program is free software; you can redistribute it and/or
9 # modify it under the terms of the GNU General Public License as
10 # published by the Free Software Foundation; either version 2 of
11 # the License, or (at your option) any later version.
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with this program; if not, write to the Free Software
20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27 This directory contains the source code for U-Boot, a boot loader for
28 Embedded boards based on PowerPC and ARM processors, which can be
29 installed in a boot ROM and used to initialize and test the hardware
30 or to download and run application code.
32 The development of U-Boot is closely related to Linux: some parts of
33 the source code originate in the Linux source tree, we have some
34 header files in common, and special provision has been made to
35 support booting of Linux images.
37 Some attention has been paid to make this software easily
38 configurable and extendable. For instance, all monitor commands are
39 implemented with the same call interface, so that it's very easy to
40 add new commands. Also, instead of permanently adding rarely used
41 code (for instance hardware test utilities) to the monitor, you can
42 load and run it dynamically.
48 In general, all boards for which a configuration option exists in the
49 Makefile have been tested to some extent and can be considered
50 "working". In fact, many of them are used in production systems.
52 In case of problems see the CHANGELOG and CREDITS files to find out
53 who contributed the specific port.
59 In case you have questions about, problems with or contributions for
60 U-Boot you should send a message to the U-Boot mailing list at
61 <u-boot-users@lists.sourceforge.net>. There is also an archive of
62 previous traffic on the mailing list - please search the archive
63 before asking FAQ's. Please see
64 http://lists.sourceforge.net/lists/listinfo/u-boot-users/
70 - start from 8xxrom sources
71 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
73 - make it easier to add custom boards
74 - make it possible to add other [PowerPC] CPUs
75 - extend functions, especially:
76 * Provide extended interface to Linux boot loader
79 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot
80 - create ARMBoot project (http://sourceforge.net/projects/armboot)
81 - add other CPU families (starting with ARM)
82 - create U-Boot project (http://sourceforge.net/projects/u-boot)
88 The "official" name of this project is "Das U-Boot". The spelling
89 "U-Boot" shall be used in all written text (documentation, comments
90 in source files etc.). Example:
92 This is the README file for the U-Boot project.
94 File names etc. shall be based on the string "u-boot". Examples:
96 include/asm-ppc/u-boot.h
98 #include <asm/u-boot.h>
100 Variable names, preprocessor constants etc. shall be either based on
101 the string "u_boot" or on "U_BOOT". Example:
103 U_BOOT_VERSION u_boot_logo
104 IH_OS_U_BOOT u_boot_hush_start
110 U-Boot uses a 3 level version number containing a version, a
111 sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2",
112 sub-version "34", and patchlevel "4".
114 The patchlevel is used to indicate certain stages of development
115 between released versions, i. e. officially released versions of
116 U-Boot will always have a patchlevel of "0".
122 - board Board dependent files
123 - common Misc architecture independent functions
124 - cpu CPU specific files
125 - 74xx_7xx Files specific to Motorola MPC74xx and 7xx CPUs
126 - arm720t Files specific to ARM 720 CPUs
127 - arm920t Files specific to ARM 920 CPUs
128 - arm925t Files specific to ARM 925 CPUs
129 - arm926ejs Files specific to ARM 926 CPUs
130 - at91rm9200 Files specific to Atmel AT91RM9200 CPUs
131 - i386 Files specific to i386 CPUs
132 - ixp Files specific to Intel XScale IXP CPUs
133 - mcf52x2 Files specific to Motorola ColdFire MCF52x2 CPUs
134 - mips Files specific to MIPS CPUs
135 - mpc5xx Files specific to Motorola MPC5xx CPUs
136 - mpc5xxx Files specific to Motorola MPC5xxx CPUs
137 - mpc8xx Files specific to Motorola MPC8xx CPUs
138 - mpc824x Files specific to Motorola MPC824x CPUs
139 - mpc8260 Files specific to Motorola MPC8260 CPUs
140 - mpc85xx Files specific to Motorola MPC85xx CPUs
141 - nios Files specific to Altera NIOS CPUs
142 - ppc4xx Files specific to IBM PowerPC 4xx CPUs
143 - pxa Files specific to Intel XScale PXA CPUs
144 - s3c44b0 Files specific to Samsung S3C44B0 CPUs
145 - sa1100 Files specific to Intel StrongARM SA1100 CPUs
146 - disk Code for disk drive partition handling
147 - doc Documentation (don't expect too much)
148 - drivers Commonly used device drivers
149 - dtt Digital Thermometer and Thermostat drivers
150 - examples Example code for standalone applications, etc.
151 - include Header Files
152 - lib_arm Files generic to ARM architecture
153 - lib_generic Files generic to all architectures
154 - lib_i386 Files generic to i386 architecture
155 - lib_m68k Files generic to m68k architecture
156 - lib_mips Files generic to MIPS architecture
157 - lib_nios Files generic to NIOS architecture
158 - lib_ppc Files generic to PowerPC architecture
159 - net Networking code
160 - post Power On Self Test
161 - rtc Real Time Clock drivers
162 - tools Tools to build S-Record or U-Boot images, etc.
164 Software Configuration:
165 =======================
167 Configuration is usually done using C preprocessor defines; the
168 rationale behind that is to avoid dead code whenever possible.
170 There are two classes of configuration variables:
172 * Configuration _OPTIONS_:
173 These are selectable by the user and have names beginning with
176 * Configuration _SETTINGS_:
177 These depend on the hardware etc. and should not be meddled with if
178 you don't know what you're doing; they have names beginning with
181 Later we will add a configuration tool - probably similar to or even
182 identical to what's used for the Linux kernel. Right now, we have to
183 do the configuration by hand, which means creating some symbolic
184 links and editing some configuration files. We use the TQM8xxL boards
188 Selection of Processor Architecture and Board Type:
189 ---------------------------------------------------
191 For all supported boards there are ready-to-use default
192 configurations available; just type "make <board_name>_config".
194 Example: For a TQM823L module type:
199 For the Cogent platform, you need to specify the cpu type as well;
200 e.g. "make cogent_mpc8xx_config". And also configure the cogent
201 directory according to the instructions in cogent/README.
204 Configuration Options:
205 ----------------------
207 Configuration depends on the combination of board and CPU type; all
208 such information is kept in a configuration file
209 "include/configs/<board_name>.h".
211 Example: For a TQM823L module, all configuration settings are in
212 "include/configs/TQM823L.h".
215 Many of the options are named exactly as the corresponding Linux
216 kernel configuration options. The intention is to make it easier to
217 build a config tool - later.
220 The following options need to be configured:
222 - CPU Type: Define exactly one of
226 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860
228 or CONFIG_MPC824X, CONFIG_MPC8260
244 - Board Type: Define exactly one of
246 PowerPC based boards:
247 ---------------------
249 CONFIG_ADCIOP, CONFIG_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 CONFIG_NETTA
289 CONFIG_HHP_CRADLE, CONFIG_DNP1110, CONFIG_EP7312,
290 CONFIG_IMPA7, CONFIG_LART, CONFIG_LUBBOCK,
291 CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610,
292 CONFIG_H2_OMAP1610, CONFIG_SHANNON, CONFIG_SMDK2400,
293 CONFIG_SMDK2410, CONFIG_TRAB, CONFIG_VCMA9,
297 - CPU Module Type: (if CONFIG_COGENT is defined)
298 Define exactly one of
300 --- FIXME --- not tested yet:
301 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
302 CONFIG_CMA287_23, CONFIG_CMA287_50
304 - Motherboard Type: (if CONFIG_COGENT is defined)
305 Define exactly one of
306 CONFIG_CMA101, CONFIG_CMA102
308 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
309 Define one or more of
312 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
313 Define one or more of
314 CONFIG_LCD_HEARTBEAT - update a character position on
315 the lcd display every second with
318 - Board flavour: (if CONFIG_MPC8260ADS is defined)
321 CFG_8260ADS - original MPC8260ADS
322 CFG_8266ADS - MPC8266ADS
323 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
324 CFG_8272ADS - MPC8272ADS
326 - MPC824X Family Member (if CONFIG_MPC824X is defined)
327 Define exactly one of
328 CONFIG_MPC8240, CONFIG_MPC8245
330 - 8xx CPU Options: (if using an MPC8xx cpu)
331 Define one or more of
332 CONFIG_8xx_GCLK_FREQ - if get_gclk_freq() cannot work
333 e.g. if there is no 32KHz
334 reference PIT/RTC clock
336 - 859/866 CPU options: (if using a MPC859 or MPC866 CPU):
340 CFG_866_CPUCLK_DEFAULT
341 See doc/README.MPC866
345 Define this to measure the actual CPU clock instead
346 of relying on the correctness of the configured
347 values. Mostly useful for board bringup to make sure
348 the PLL is locked at the intended frequency. Note
349 that this requires a (stable) reference clock (32 kHz
352 - Linux Kernel Interface:
355 U-Boot stores all clock information in Hz
356 internally. For binary compatibility with older Linux
357 kernels (which expect the clocks passed in the
358 bd_info data to be in MHz) the environment variable
359 "clocks_in_mhz" can be defined so that U-Boot
360 converts clock data to MHZ before passing it to the
362 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
363 "clocks_in_mhz=1" is automatically included in the
366 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
368 When transfering memsize parameter to linux, some versions
369 expect it to be in bytes, others in MB.
370 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
373 Depending on board, define exactly one serial port
374 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
375 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
376 console by defining CONFIG_8xx_CONS_NONE
378 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
379 port routines must be defined elsewhere
380 (i.e. serial_init(), serial_getc(), ...)
383 Enables console device for a color framebuffer. Needs following
384 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
385 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
387 VIDEO_HW_RECTFILL graphic chip supports
390 VIDEO_HW_BITBLT graphic chip supports
391 bit-blit (cf. smiLynxEM)
392 VIDEO_VISIBLE_COLS visible pixel columns
394 VIDEO_VISIBLE_ROWS visible pixel rows
395 VIDEO_PIXEL_SIZE bytes per pixel
396 VIDEO_DATA_FORMAT graphic data format
397 (0-5, cf. cfb_console.c)
398 VIDEO_FB_ADRS framebuffer address
399 VIDEO_KBD_INIT_FCT keyboard int fct
400 (i.e. i8042_kbd_init())
401 VIDEO_TSTC_FCT test char fct
403 VIDEO_GETC_FCT get char fct
405 CONFIG_CONSOLE_CURSOR cursor drawing on/off
406 (requires blink timer
408 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
409 CONFIG_CONSOLE_TIME display time/date info in
411 (requires CFG_CMD_DATE)
412 CONFIG_VIDEO_LOGO display Linux logo in
414 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
415 linux_logo.h for logo.
416 Requires CONFIG_VIDEO_LOGO
417 CONFIG_CONSOLE_EXTRA_INFO
418 addional board info beside
421 When CONFIG_CFB_CONSOLE is defined, video console is
422 default i/o. Serial console can be forced with
423 environment 'console=serial'.
425 When CONFIG_SILENT_CONSOLE is defined, all console
426 messages (by U-Boot and Linux!) can be silenced with
427 the "silent" environment variable. See
428 doc/README.silent for more information.
431 CONFIG_BAUDRATE - in bps
432 Select one of the baudrates listed in
433 CFG_BAUDRATE_TABLE, see below.
434 CFG_BRGCLK_PRESCALE, baudrate prescale
436 - Interrupt driven serial port input:
437 CONFIG_SERIAL_SOFTWARE_FIFO
440 Use an interrupt handler for receiving data on the
441 serial port. It also enables using hardware handshake
442 (RTS/CTS) and UART's built-in FIFO. Set the number of
443 bytes the interrupt driven input buffer should have.
445 Leave undefined to disable this feature, including
446 disable the buffer and hardware handshake.
448 - Console UART Number:
452 If defined internal UART1 (and not UART0) is used
453 as default U-Boot console.
455 - Boot Delay: CONFIG_BOOTDELAY - in seconds
456 Delay before automatically booting the default image;
457 set to -1 to disable autoboot.
459 See doc/README.autoboot for these options that
460 work with CONFIG_BOOTDELAY. None are required.
461 CONFIG_BOOT_RETRY_TIME
462 CONFIG_BOOT_RETRY_MIN
463 CONFIG_AUTOBOOT_KEYED
464 CONFIG_AUTOBOOT_PROMPT
465 CONFIG_AUTOBOOT_DELAY_STR
466 CONFIG_AUTOBOOT_STOP_STR
467 CONFIG_AUTOBOOT_DELAY_STR2
468 CONFIG_AUTOBOOT_STOP_STR2
469 CONFIG_ZERO_BOOTDELAY_CHECK
470 CONFIG_RESET_TO_RETRY
474 Only needed when CONFIG_BOOTDELAY is enabled;
475 define a command string that is automatically executed
476 when no character is read on the console interface
477 within "Boot Delay" after reset.
480 This can be used to pass arguments to the bootm
481 command. The value of CONFIG_BOOTARGS goes into the
482 environment value "bootargs".
484 CONFIG_RAMBOOT and CONFIG_NFSBOOT
485 The value of these goes into the environment as
486 "ramboot" and "nfsboot" respectively, and can be used
487 as a convenience, when switching between booting from
493 When this option is #defined, the existence of the
494 environment variable "preboot" will be checked
495 immediately before starting the CONFIG_BOOTDELAY
496 countdown and/or running the auto-boot command resp.
497 entering interactive mode.
499 This feature is especially useful when "preboot" is
500 automatically generated or modified. For an example
501 see the LWMON board specific code: here "preboot" is
502 modified when the user holds down a certain
503 combination of keys on the (special) keyboard when
506 - Serial Download Echo Mode:
508 If defined to 1, all characters received during a
509 serial download (using the "loads" command) are
510 echoed back. This might be needed by some terminal
511 emulations (like "cu"), but may as well just take
512 time on others. This setting #define's the initial
513 value of the "loads_echo" environment variable.
515 - Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
517 Select one of the baudrates listed in
518 CFG_BAUDRATE_TABLE, see below.
522 Most monitor functions can be selected (or
523 de-selected) by adjusting the definition of
524 CONFIG_COMMANDS; to select individual functions,
525 #define CONFIG_COMMANDS by "OR"ing any of the
528 #define enables commands:
529 -------------------------
530 CFG_CMD_ASKENV * ask for env variable
531 CFG_CMD_AUTOSCRIPT Autoscript Support
533 CFG_CMD_BEDBUG Include BedBug Debugger
534 CFG_CMD_BMP * BMP support
536 CFG_CMD_CACHE icache, dcache
537 CFG_CMD_CONSOLE coninfo
538 CFG_CMD_DATE * support for RTC, date/time...
539 CFG_CMD_DHCP DHCP support
540 CFG_CMD_DIAG * Diagnostics
541 CFG_CMD_DOC * Disk-On-Chip Support
542 CFG_CMD_DTT Digital Therm and Thermostat
543 CFG_CMD_ECHO * echo arguments
544 CFG_CMD_EEPROM * EEPROM read/write support
545 CFG_CMD_ELF bootelf, bootvx
547 CFG_CMD_FDC * Floppy Disk Support
548 CFG_CMD_FAT FAT partition support
549 CFG_CMD_FDOS * Dos diskette Support
550 CFG_CMD_FLASH flinfo, erase, protect
551 CFG_CMD_FPGA FPGA device initialization support
552 CFG_CMD_HWFLOW * RTS/CTS hw flow control
553 CFG_CMD_I2C * I2C serial bus support
554 CFG_CMD_IDE * IDE harddisk support
556 CFG_CMD_IMLS List all found images
557 CFG_CMD_IMMAP * IMMR dump support
558 CFG_CMD_IRQ * irqinfo
559 CFG_CMD_ITEST * Integer/string test of 2 values
560 CFG_CMD_JFFS2 * JFFS2 Support
564 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
566 CFG_CMD_MISC Misc functions like sleep etc
567 CFG_CMD_MMC MMC memory mapped support
568 CFG_CMD_MII MII utility commands
569 CFG_CMD_NAND * NAND support
570 CFG_CMD_NET bootp, tftpboot, rarpboot
571 CFG_CMD_PCI * pciinfo
572 CFG_CMD_PCMCIA * PCMCIA support
573 CFG_CMD_PING * send ICMP ECHO_REQUEST to network host
574 CFG_CMD_PORTIO * Port I/O
575 CFG_CMD_REGINFO * Register dump
576 CFG_CMD_RUN run command in env variable
577 CFG_CMD_SAVES save S record dump
578 CFG_CMD_SCSI * SCSI Support
579 CFG_CMD_SDRAM * print SDRAM configuration information
580 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
581 CFG_CMD_SPI * SPI serial bus support
582 CFG_CMD_USB * USB support
583 CFG_CMD_VFD * VFD support (TRAB)
584 CFG_CMD_BSP * Board SPecific functions
585 CFG_CMD_CDP * Cisco Discover Protocol support
586 -----------------------------------------------
589 CFG_CMD_DFL Default configuration; at the moment
590 this is includes all commands, except
591 the ones marked with "*" in the list
594 If you don't define CONFIG_COMMANDS it defaults to
595 CFG_CMD_DFL in include/cmd_confdefs.h. A board can
596 override the default settings in the respective
599 EXAMPLE: If you want all functions except of network
600 support you can write:
602 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
605 Note: Don't enable the "icache" and "dcache" commands
606 (configuration option CFG_CMD_CACHE) unless you know
607 what you (and your U-Boot users) are doing. Data
608 cache cannot be enabled on systems like the 8xx or
609 8260 (where accesses to the IMMR region must be
610 uncached), and it cannot be disabled on all other
611 systems where we (mis-) use the data cache to hold an
612 initial stack and some data.
615 XXX - this list needs to get updated!
619 If this variable is defined, it enables watchdog
620 support. There must be support in the platform specific
621 code for a watchdog. For the 8xx and 8260 CPUs, the
622 SIU Watchdog feature is enabled in the SYPCR
626 CONFIG_VERSION_VARIABLE
627 If this variable is defined, an environment variable
628 named "ver" is created by U-Boot showing the U-Boot
629 version as printed by the "version" command.
630 This variable is readonly.
634 When CFG_CMD_DATE is selected, the type of the RTC
635 has to be selected, too. Define exactly one of the
638 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
639 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
640 CONFIG_RTC_MC146818 - use MC146818 RTC
641 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
642 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
643 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
644 CONFIG_RTC_DS164x - use Dallas DS164x RTC
646 Note that if the RTC uses I2C, then the I2C interface
647 must also be configured. See I2C Support, below.
651 When CONFIG_TIMESTAMP is selected, the timestamp
652 (date and time) of an image is printed by image
653 commands like bootm or iminfo. This option is
654 automatically enabled when you select CFG_CMD_DATE .
657 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
658 and/or CONFIG_ISO_PARTITION
660 If IDE or SCSI support is enabled (CFG_CMD_IDE or
661 CFG_CMD_SCSI) you must configure support for at least
662 one partition type as well.
665 CONFIG_IDE_RESET_ROUTINE - this is defined in several
666 board configurations files but used nowhere!
668 CONFIG_IDE_RESET - is this is defined, IDE Reset will
669 be performed by calling the function
670 ide_set_reset(int reset)
671 which has to be defined in a board specific file
676 Set this to enable ATAPI support.
681 Set this to enable support for disks larger than 137GB
682 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL
683 Whithout these , LBA48 support uses 32bit variables and will 'only'
684 support disks up to 2.1TB.
687 When enabled, makes the IDE subsystem use 64bit sector addresses.
691 At the moment only there is only support for the
692 SYM53C8XX SCSI controller; define
693 CONFIG_SCSI_SYM53C8XX to enable it.
695 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
696 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
697 CFG_SCSI_MAX_LUN] can be adjusted to define the
698 maximum numbers of LUNs, SCSI ID's and target
700 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
702 - NETWORK Support (PCI):
704 Support for Intel 8254x gigabit chips.
707 Support for Intel 82557/82559/82559ER chips.
708 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
709 write routine for first time initialisation.
712 Support for Digital 2114x chips.
713 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
714 modem chip initialisation (KS8761/QS6611).
717 Support for National dp83815 chips.
720 Support for National dp8382[01] gigabit chips.
722 - NETWORK Support (other):
724 CONFIG_DRIVER_LAN91C96
725 Support for SMSC's LAN91C96 chips.
728 Define this to hold the physical address
729 of the LAN91C96's I/O space
731 CONFIG_LAN91C96_USE_32_BIT
732 Define this to enable 32 bit addressing
735 At the moment only the UHCI host controller is
736 supported (PIP405, MIP405, MPC5200); define
737 CONFIG_USB_UHCI to enable it.
738 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
739 end define CONFIG_USB_STORAGE to enable the USB
742 Supported are USB Keyboards and USB Floppy drives
744 MPC5200 USB requires additional defines:
746 for 528 MHz Clock: 0x0001bbbb
748 for differential drivers: 0x00001000
749 for single ended drivers: 0x00005000
753 The MMC controller on the Intel PXA is supported. To
754 enable this define CONFIG_MMC. The MMC can be
755 accessed from the boot prompt by mapping the device
756 to physical memory similar to flash. Command line is
757 enabled with CFG_CMD_MMC. The MMC driver also works with
758 the FAT fs. This is enabled with CFG_CMD_FAT.
763 Define this to enable standard (PC-Style) keyboard
767 Standard PC keyboard driver with US (is default) and
768 GERMAN key layout (switch via environment 'keymap=de') support.
769 Export function i8042_kbd_init, i8042_tstc and i8042_getc
770 for cfb_console. Supports cursor blinking.
775 Define this to enable video support (for output to
780 Enable Chips & Technologies 69000 Video chip
782 CONFIG_VIDEO_SMI_LYNXEM
783 Enable Silicon Motion SMI 712/710/810 Video chip. The
784 video output is selected via environment 'videoout'
785 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
788 For the CT69000 and SMI_LYNXEM drivers, videomode is
789 selected via environment 'videomode'. Two diferent ways
791 - "videomode=num" 'num' is a standard LiLo mode numbers.
792 Following standard modes are supported (* is default):
794 Colors 640x480 800x600 1024x768 1152x864 1280x1024
795 -------------+---------------------------------------------
796 8 bits | 0x301* 0x303 0x305 0x161 0x307
797 15 bits | 0x310 0x313 0x316 0x162 0x319
798 16 bits | 0x311 0x314 0x317 0x163 0x31A
799 24 bits | 0x312 0x315 0x318 ? 0x31B
800 -------------+---------------------------------------------
801 (i.e. setenv videomode 317; saveenv; reset;)
803 - "videomode=bootargs" all the video parameters are parsed
804 from the bootargs. (See drivers/videomodes.c)
807 CONFIG_VIDEO_SED13806
808 Enable Epson SED13806 driver. This driver supports 8bpp
809 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
810 or CONFIG_VIDEO_SED13806_16BPP
815 Define this to enable a custom keyboard support.
816 This simply calls drv_keyboard_init() which must be
817 defined in your board-specific files.
818 The only board using this so far is RBC823.
820 - LCD Support: CONFIG_LCD
822 Define this to enable LCD support (for output to LCD
823 display); also select one of the supported displays
824 by defining one of these:
826 CONFIG_NEC_NL6448AC33:
828 NEC NL6448AC33-18. Active, color, single scan.
830 CONFIG_NEC_NL6448BC20
832 NEC NL6448BC20-08. 6.5", 640x480.
833 Active, color, single scan.
835 CONFIG_NEC_NL6448BC33_54
837 NEC NL6448BC33-54. 10.4", 640x480.
838 Active, color, single scan.
842 Sharp 320x240. Active, color, single scan.
843 It isn't 16x9, and I am not sure what it is.
845 CONFIG_SHARP_LQ64D341
847 Sharp LQ64D341 display, 640x480.
848 Active, color, single scan.
852 HLD1045 display, 640x480.
853 Active, color, single scan.
857 Optrex CBL50840-2 NF-FW 99 22 M5
859 Hitachi LMG6912RPFC-00T
863 320x240. Black & white.
865 Normally display is black on white background; define
866 CFG_WHITE_ON_BLACK to get it inverted.
868 - Splash Screen Support: CONFIG_SPLASH_SCREEN
870 If this option is set, the environment is checked for
871 a variable "splashimage". If found, the usual display
872 of logo, copyright and system information on the LCD
873 is supressed and the BMP image at the address
874 specified in "splashimage" is loaded instead. The
875 console is redirected to the "nulldev", too. This
876 allows for a "silent" boot where a splash screen is
877 loaded very quickly after power-on.
879 - Compression support:
882 If this option is set, support for bzip2 compressed
883 images is included. If not, only uncompressed and gzip
884 compressed images are supported.
886 NOTE: the bzip2 algorithm requires a lot of RAM, so
887 the malloc area (as defined by CFG_MALLOC_LEN) should
895 Define a default value for ethernet address to use
896 for the respective ethernet interface, in case this
897 is not determined automatically.
902 Define a default value for the IP address to use for
903 the default ethernet interface, in case this is not
904 determined through e.g. bootp.
909 Defines a default value for theIP address of a TFTP
910 server to contact when using the "tftboot" command.
912 - BOOTP Recovery Mode:
913 CONFIG_BOOTP_RANDOM_DELAY
915 If you have many targets in a network that try to
916 boot using BOOTP, you may want to avoid that all
917 systems send out BOOTP requests at precisely the same
918 moment (which would happen for instance at recovery
919 from a power failure, when all systems will try to
920 boot, thus flooding the BOOTP server. Defining
921 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
922 inserted before sending out BOOTP requests. The
923 following delays are insterted then:
925 1st BOOTP request: delay 0 ... 1 sec
926 2nd BOOTP request: delay 0 ... 2 sec
927 3rd BOOTP request: delay 0 ... 4 sec
929 BOOTP requests: delay 0 ... 8 sec
931 - DHCP Advanced Options:
934 You can fine tune the DHCP functionality by adding
935 these flags to the CONFIG_BOOTP_MASK define:
937 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
938 serverip from a DHCP server, it is possible that more
939 than one DNS serverip is offered to the client.
940 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
941 serverip will be stored in the additional environment
942 variable "dnsip2". The first DNS serverip is always
943 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
944 is added to the CONFIG_BOOTP_MASK.
946 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
947 to do a dynamic update of a DNS server. To do this, they
948 need the hostname of the DHCP requester.
949 If CONFIG_BOOP_SEND_HOSTNAME is added to the
950 CONFIG_BOOTP_MASK, the content of the "hostname"
951 environment variable is passed as option 12 to
957 The device id used in CDP trigger frames.
959 CONFIG_CDP_DEVICE_ID_PREFIX
961 A two character string which is prefixed to the MAC address
966 A printf format string which contains the ascii name of
967 the port. Normally is set to "eth%d" which sets
968 eth0 for the first ethernet, eth1 for the second etc.
970 CONFIG_CDP_CAPABILITIES
972 A 32bit integer which indicates the device capabilities;
973 0x00000010 for a normal host which does not forwards.
977 An ascii string containing the version of the software.
981 An ascii string containing the name of the platform.
985 A 32bit integer sent on the trigger.
987 CONFIG_CDP_POWER_CONSUMPTION
989 A 16bit integer containing the power consumption of the
990 device in .1 of milliwatts.
992 CONFIG_CDP_APPLIANCE_VLAN_TYPE
994 A byte containing the id of the VLAN.
996 - Status LED: CONFIG_STATUS_LED
998 Several configurations allow to display the current
999 status using a LED. For instance, the LED will blink
1000 fast while running U-Boot code, stop blinking as
1001 soon as a reply to a BOOTP request was received, and
1002 start blinking slow once the Linux kernel is running
1003 (supported by a status LED driver in the Linux
1004 kernel). Defining CONFIG_STATUS_LED enables this
1007 - CAN Support: CONFIG_CAN_DRIVER
1009 Defining CONFIG_CAN_DRIVER enables CAN driver support
1010 on those systems that support this (optional)
1011 feature, like the TQM8xxL modules.
1013 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1015 These enable I2C serial bus commands. Defining either of
1016 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1017 include the appropriate I2C driver for the selected cpu.
1019 This will allow you to use i2c commands at the u-boot
1020 command line (as long as you set CFG_CMD_I2C in
1021 CONFIG_COMMANDS) and communicate with i2c based realtime
1022 clock chips. See common/cmd_i2c.c for a description of the
1023 command line interface.
1025 CONFIG_HARD_I2C selects the CPM hardware driver for I2C.
1027 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1028 bit-banging) driver instead of CPM or similar hardware
1031 There are several other quantities that must also be
1032 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1034 In both cases you will need to define CFG_I2C_SPEED
1035 to be the frequency (in Hz) at which you wish your i2c bus
1036 to run and CFG_I2C_SLAVE to be the address of this node (ie
1037 the cpu's i2c node address).
1039 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1040 sets the cpu up as a master node and so its address should
1041 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1042 p.16-473). So, set CFG_I2C_SLAVE to 0.
1044 That's all that's required for CONFIG_HARD_I2C.
1046 If you use the software i2c interface (CONFIG_SOFT_I2C)
1047 then the following macros need to be defined (examples are
1048 from include/configs/lwmon.h):
1052 (Optional). Any commands necessary to enable the I2C
1053 controller or configure ports.
1055 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1059 (Only for MPC8260 CPU). The I/O port to use (the code
1060 assumes both bits are on the same port). Valid values
1061 are 0..3 for ports A..D.
1065 The code necessary to make the I2C data line active
1066 (driven). If the data line is open collector, this
1069 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1073 The code necessary to make the I2C data line tri-stated
1074 (inactive). If the data line is open collector, this
1077 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1081 Code that returns TRUE if the I2C data line is high,
1084 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1088 If <bit> is TRUE, sets the I2C data line high. If it
1089 is FALSE, it clears it (low).
1091 eg: #define I2C_SDA(bit) \
1092 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1093 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1097 If <bit> is TRUE, sets the I2C clock line high. If it
1098 is FALSE, it clears it (low).
1100 eg: #define I2C_SCL(bit) \
1101 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1102 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1106 This delay is invoked four times per clock cycle so this
1107 controls the rate of data transfer. The data rate thus
1108 is 1 / (I2C_DELAY * 4). Often defined to be something
1111 #define I2C_DELAY udelay(2)
1115 When a board is reset during an i2c bus transfer
1116 chips might think that the current transfer is still
1117 in progress. On some boards it is possible to access
1118 the i2c SCLK line directly, either by using the
1119 processor pin as a GPIO or by having a second pin
1120 connected to the bus. If this option is defined a
1121 custom i2c_init_board() routine in boards/xxx/board.c
1122 is run early in the boot sequence.
1124 - SPI Support: CONFIG_SPI
1126 Enables SPI driver (so far only tested with
1127 SPI EEPROM, also an instance works with Crystal A/D and
1128 D/As on the SACSng board)
1132 Enables extended (16-bit) SPI EEPROM addressing.
1133 (symmetrical to CONFIG_I2C_X)
1137 Enables a software (bit-bang) SPI driver rather than
1138 using hardware support. This is a general purpose
1139 driver that only requires three general I/O port pins
1140 (two outputs, one input) to function. If this is
1141 defined, the board configuration must define several
1142 SPI configuration items (port pins to use, etc). For
1143 an example, see include/configs/sacsng.h.
1145 - FPGA Support: CONFIG_FPGA_COUNT
1147 Specify the number of FPGA devices to support.
1151 Used to specify the types of FPGA devices. For example,
1152 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
1154 CFG_FPGA_PROG_FEEDBACK
1156 Enable printing of hash marks during FPGA configuration.
1160 Enable checks on FPGA configuration interface busy
1161 status by the configuration function. This option
1162 will require a board or device specific function to
1167 If defined, a function that provides delays in the FPGA
1168 configuration driver.
1170 CFG_FPGA_CHECK_CTRLC
1171 Allow Control-C to interrupt FPGA configuration
1173 CFG_FPGA_CHECK_ERROR
1175 Check for configuration errors during FPGA bitfile
1176 loading. For example, abort during Virtex II
1177 configuration if the INIT_B line goes low (which
1178 indicated a CRC error).
1182 Maximum time to wait for the INIT_B line to deassert
1183 after PROB_B has been deasserted during a Virtex II
1184 FPGA configuration sequence. The default time is 500
1189 Maximum time to wait for BUSY to deassert during
1190 Virtex II FPGA configuration. The default is 5 mS.
1192 CFG_FPGA_WAIT_CONFIG
1194 Time to wait after FPGA configuration. The default is
1197 - Configuration Management:
1200 If defined, this string will be added to the U-Boot
1201 version information (U_BOOT_VERSION)
1203 - Vendor Parameter Protection:
1205 U-Boot considers the values of the environment
1206 variables "serial#" (Board Serial Number) and
1207 "ethaddr" (Ethernet Address) to be parameters that
1208 are set once by the board vendor / manufacturer, and
1209 protects these variables from casual modification by
1210 the user. Once set, these variables are read-only,
1211 and write or delete attempts are rejected. You can
1212 change this behviour:
1214 If CONFIG_ENV_OVERWRITE is #defined in your config
1215 file, the write protection for vendor parameters is
1216 completely disabled. Anybody can change or delete
1219 Alternatively, if you #define _both_ CONFIG_ETHADDR
1220 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1221 ethernet address is installed in the environment,
1222 which can be changed exactly ONCE by the user. [The
1223 serial# is unaffected by this, i. e. it remains
1229 Define this variable to enable the reservation of
1230 "protected RAM", i. e. RAM which is not overwritten
1231 by U-Boot. Define CONFIG_PRAM to hold the number of
1232 kB you want to reserve for pRAM. You can overwrite
1233 this default value by defining an environment
1234 variable "pram" to the number of kB you want to
1235 reserve. Note that the board info structure will
1236 still show the full amount of RAM. If pRAM is
1237 reserved, a new environment variable "mem" will
1238 automatically be defined to hold the amount of
1239 remaining RAM in a form that can be passed as boot
1240 argument to Linux, for instance like that:
1242 setenv bootargs ... mem=\$(mem)
1245 This way you can tell Linux not to use this memory,
1246 either, which results in a memory region that will
1247 not be affected by reboots.
1249 *WARNING* If your board configuration uses automatic
1250 detection of the RAM size, you must make sure that
1251 this memory test is non-destructive. So far, the
1252 following board configurations are known to be
1255 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1256 HERMES, IP860, RPXlite, LWMON, LANTEC,
1257 PCU_E, FLAGADM, TQM8260
1262 Define this variable to stop the system in case of a
1263 fatal error, so that you have to reset it manually.
1264 This is probably NOT a good idea for an embedded
1265 system where you want to system to reboot
1266 automatically as fast as possible, but it may be
1267 useful during development since you can try to debug
1268 the conditions that lead to the situation.
1270 CONFIG_NET_RETRY_COUNT
1272 This variable defines the number of retries for
1273 network operations like ARP, RARP, TFTP, or BOOTP
1274 before giving up the operation. If not defined, a
1275 default value of 5 is used.
1277 - Command Interpreter:
1280 Enable auto completion of commands using TAB.
1284 Define this variable to enable the "hush" shell (from
1285 Busybox) as command line interpreter, thus enabling
1286 powerful command line syntax like
1287 if...then...else...fi conditionals or `&&' and '||'
1288 constructs ("shell scripts").
1290 If undefined, you get the old, much simpler behaviour
1291 with a somewhat smaller memory footprint.
1296 This defines the secondary prompt string, which is
1297 printed when the command interpreter needs more input
1298 to complete a command. Usually "> ".
1302 In the current implementation, the local variables
1303 space and global environment variables space are
1304 separated. Local variables are those you define by
1305 simply typing `name=value'. To access a local
1306 variable later on, you have write `$name' or
1307 `${name}'; to execute the contents of a variable
1308 directly type `$name' at the command prompt.
1310 Global environment variables are those you use
1311 setenv/printenv to work with. To run a command stored
1312 in such a variable, you need to use the run command,
1313 and you must not use the '$' sign to access them.
1315 To store commands and special characters in a
1316 variable, please use double quotation marks
1317 surrounding the whole text of the variable, instead
1318 of the backslashes before semicolons and special
1321 - Default Environment:
1322 CONFIG_EXTRA_ENV_SETTINGS
1324 Define this to contain any number of null terminated
1325 strings (variable = value pairs) that will be part of
1326 the default environment compiled into the boot image.
1328 For example, place something like this in your
1329 board's config file:
1331 #define CONFIG_EXTRA_ENV_SETTINGS \
1335 Warning: This method is based on knowledge about the
1336 internal format how the environment is stored by the
1337 U-Boot code. This is NOT an official, exported
1338 interface! Although it is unlikely that this format
1339 will change soon, there is no guarantee either.
1340 You better know what you are doing here.
1342 Note: overly (ab)use of the default environment is
1343 discouraged. Make sure to check other ways to preset
1344 the environment like the autoscript function or the
1347 - DataFlash Support:
1348 CONFIG_HAS_DATAFLASH
1350 Defining this option enables DataFlash features and
1351 allows to read/write in Dataflash via the standard
1354 - SystemACE Support:
1357 Adding this option adds support for Xilinx SystemACE
1358 chips attached via some sort of local bus. The address
1359 of the chip must alsh be defined in the
1360 CFG_SYSTEMACE_BASE macro. For example:
1362 #define CONFIG_SYSTEMACE
1363 #define CFG_SYSTEMACE_BASE 0xf0000000
1365 When SystemACE support is added, the "ace" device type
1366 becomes available to the fat commands, i.e. fatls.
1368 - Show boot progress:
1369 CONFIG_SHOW_BOOT_PROGRESS
1371 Defining this option allows to add some board-
1372 specific code (calling a user-provided function
1373 "show_boot_progress(int)") that enables you to show
1374 the system's boot progress on some display (for
1375 example, some LED's) on your board. At the moment,
1376 the following checkpoints are implemented:
1379 1 common/cmd_bootm.c before attempting to boot an image
1380 -1 common/cmd_bootm.c Image header has bad magic number
1381 2 common/cmd_bootm.c Image header has correct magic number
1382 -2 common/cmd_bootm.c Image header has bad checksum
1383 3 common/cmd_bootm.c Image header has correct checksum
1384 -3 common/cmd_bootm.c Image data has bad checksum
1385 4 common/cmd_bootm.c Image data has correct checksum
1386 -4 common/cmd_bootm.c Image is for unsupported architecture
1387 5 common/cmd_bootm.c Architecture check OK
1388 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1389 6 common/cmd_bootm.c Image Type check OK
1390 -6 common/cmd_bootm.c gunzip uncompression error
1391 -7 common/cmd_bootm.c Unimplemented compression type
1392 7 common/cmd_bootm.c Uncompression OK
1393 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1394 8 common/cmd_bootm.c Image Type check OK
1395 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1396 9 common/cmd_bootm.c Start initial ramdisk verification
1397 -10 common/cmd_bootm.c Ramdisk header has bad magic number
1398 -11 common/cmd_bootm.c Ramdisk header has bad checksum
1399 10 common/cmd_bootm.c Ramdisk header is OK
1400 -12 common/cmd_bootm.c Ramdisk data has bad checksum
1401 11 common/cmd_bootm.c Ramdisk data has correct checksum
1402 12 common/cmd_bootm.c Ramdisk verification complete, start loading
1403 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk)
1404 13 common/cmd_bootm.c Start multifile image verification
1405 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue.
1406 15 common/cmd_bootm.c All preparation done, transferring control to OS
1408 -30 lib_ppc/board.c Fatal error, hang the system
1409 -31 post/post.c POST test failed, detected by post_output_backlog()
1410 -32 post/post.c POST test failed, detected by post_run_single()
1412 -1 common/cmd_doc.c Bad usage of "doc" command
1413 -1 common/cmd_doc.c No boot device
1414 -1 common/cmd_doc.c Unknown Chip ID on boot device
1415 -1 common/cmd_doc.c Read Error on boot device
1416 -1 common/cmd_doc.c Image header has bad magic number
1418 -1 common/cmd_ide.c Bad usage of "ide" command
1419 -1 common/cmd_ide.c No boot device
1420 -1 common/cmd_ide.c Unknown boot device
1421 -1 common/cmd_ide.c Unknown partition table
1422 -1 common/cmd_ide.c Invalid partition type
1423 -1 common/cmd_ide.c Read Error on boot device
1424 -1 common/cmd_ide.c Image header has bad magic number
1426 -1 common/cmd_nand.c Bad usage of "nand" command
1427 -1 common/cmd_nand.c No boot device
1428 -1 common/cmd_nand.c Unknown Chip ID on boot device
1429 -1 common/cmd_nand.c Read Error on boot device
1430 -1 common/cmd_nand.c Image header has bad magic number
1432 -1 common/env_common.c Environment has a bad CRC, using default
1438 [so far only for SMDK2400 and TRAB boards]
1440 - Modem support endable:
1441 CONFIG_MODEM_SUPPORT
1443 - RTS/CTS Flow control enable:
1446 - Modem debug support:
1447 CONFIG_MODEM_SUPPORT_DEBUG
1449 Enables debugging stuff (char screen[1024], dbg())
1450 for modem support. Useful only with BDI2000.
1452 - Interrupt support (PPC):
1454 There are common interrupt_init() and timer_interrupt()
1455 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
1456 for cpu specific initialization. interrupt_init_cpu()
1457 should set decrementer_count to appropriate value. If
1458 cpu resets decrementer automatically after interrupt
1459 (ppc4xx) it should set decrementer_count to zero.
1460 timer_interrupt() calls timer_interrupt_cpu() for cpu
1461 specific handling. If board has watchdog / status_led
1462 / other_activity_monitor it works automatically from
1463 general timer_interrupt().
1467 In the target system modem support is enabled when a
1468 specific key (key combination) is pressed during
1469 power-on. Otherwise U-Boot will boot normally
1470 (autoboot). The key_pressed() fuction is called from
1471 board_init(). Currently key_pressed() is a dummy
1472 function, returning 1 and thus enabling modem
1475 If there are no modem init strings in the
1476 environment, U-Boot proceed to autoboot; the
1477 previous output (banner, info printfs) will be
1480 See also: doc/README.Modem
1483 Configuration Settings:
1484 -----------------------
1486 - CFG_LONGHELP: Defined when you want long help messages included;
1487 undefine this when you're short of memory.
1489 - CFG_PROMPT: This is what U-Boot prints on the console to
1490 prompt for user input.
1492 - CFG_CBSIZE: Buffer size for input from the Console
1494 - CFG_PBSIZE: Buffer size for Console output
1496 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1498 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1499 the application (usually a Linux kernel) when it is
1502 - CFG_BAUDRATE_TABLE:
1503 List of legal baudrate settings for this board.
1505 - CFG_CONSOLE_INFO_QUIET
1506 Suppress display of console information at boot.
1508 - CFG_CONSOLE_IS_IN_ENV
1509 If the board specific function
1510 extern int overwrite_console (void);
1511 returns 1, the stdin, stderr and stdout are switched to the
1512 serial port, else the settings in the environment are used.
1514 - CFG_CONSOLE_OVERWRITE_ROUTINE
1515 Enable the call to overwrite_console().
1517 - CFG_CONSOLE_ENV_OVERWRITE
1518 Enable overwrite of previous console environment settings.
1520 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1521 Begin and End addresses of the area used by the
1525 Enable an alternate, more extensive memory test.
1527 - CFG_MEMTEST_SCRATCH:
1528 Scratch address used by the alternate memory test
1529 You only need to set this if address zero isn't writeable
1531 - CFG_TFTP_LOADADDR:
1532 Default load address for network file downloads
1534 - CFG_LOADS_BAUD_CHANGE:
1535 Enable temporary baudrate change while serial download
1538 Physical start address of SDRAM. _Must_ be 0 here.
1541 Physical start address of Motherboard I/O (if using a
1545 Physical start address of Flash memory.
1548 Physical start address of boot monitor code (set by
1549 make config files to be same as the text base address
1550 (TEXT_BASE) used when linking) - same as
1551 CFG_FLASH_BASE when booting from flash.
1554 Size of memory reserved for monitor code, used to
1555 determine _at_compile_time_ (!) if the environment is
1556 embedded within the U-Boot image, or in a separate
1560 Size of DRAM reserved for malloc() use.
1563 Maximum size of memory mapped by the startup code of
1564 the Linux kernel; all data that must be processed by
1565 the Linux kernel (bd_info, boot arguments, eventually
1566 initrd image) must be put below this limit.
1568 - CFG_MAX_FLASH_BANKS:
1569 Max number of Flash memory banks
1571 - CFG_MAX_FLASH_SECT:
1572 Max number of sectors on a Flash chip
1574 - CFG_FLASH_ERASE_TOUT:
1575 Timeout for Flash erase operations (in ms)
1577 - CFG_FLASH_WRITE_TOUT:
1578 Timeout for Flash write operations (in ms)
1580 - CFG_FLASH_LOCK_TOUT
1581 Timeout for Flash set sector lock bit operation (in ms)
1583 - CFG_FLASH_UNLOCK_TOUT
1584 Timeout for Flash clear lock bits operation (in ms)
1586 - CFG_FLASH_PROTECTION
1587 If defined, hardware flash sectors protection is used
1588 instead of U-Boot software protection.
1590 - CFG_DIRECT_FLASH_TFTP:
1592 Enable TFTP transfers directly to flash memory;
1593 without this option such a download has to be
1594 performed in two steps: (1) download to RAM, and (2)
1595 copy from RAM to flash.
1597 The two-step approach is usually more reliable, since
1598 you can check if the download worked before you erase
1599 the flash, but in some situations (when sytem RAM is
1600 too limited to allow for a tempory copy of the
1601 downloaded image) this option may be very useful.
1604 Define if the flash driver uses extra elements in the
1605 common flash structure for storing flash geometry.
1607 - CFG_FLASH_CFI_DRIVER
1608 This option also enables the building of the cfi_flash driver
1609 in the drivers directory
1611 - CFG_RX_ETH_BUFFER:
1612 Defines the number of ethernet receive buffers. On some
1613 ethernet controllers it is recommended to set this value
1614 to 8 or even higher (EEPRO100 or 405 EMAC), since all
1615 buffers can be full shortly after enabling the interface
1616 on high ethernet traffic.
1617 Defaults to 4 if not defined.
1619 The following definitions that deal with the placement and management
1620 of environment data (variable area); in general, we support the
1621 following configurations:
1623 - CFG_ENV_IS_IN_FLASH:
1625 Define this if the environment is in flash memory.
1627 a) The environment occupies one whole flash sector, which is
1628 "embedded" in the text segment with the U-Boot code. This
1629 happens usually with "bottom boot sector" or "top boot
1630 sector" type flash chips, which have several smaller
1631 sectors at the start or the end. For instance, such a
1632 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
1633 such a case you would place the environment in one of the
1634 4 kB sectors - with U-Boot code before and after it. With
1635 "top boot sector" type flash chips, you would put the
1636 environment in one of the last sectors, leaving a gap
1637 between U-Boot and the environment.
1641 Offset of environment data (variable area) to the
1642 beginning of flash memory; for instance, with bottom boot
1643 type flash chips the second sector can be used: the offset
1644 for this sector is given here.
1646 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
1650 This is just another way to specify the start address of
1651 the flash sector containing the environment (instead of
1654 - CFG_ENV_SECT_SIZE:
1656 Size of the sector containing the environment.
1659 b) Sometimes flash chips have few, equal sized, BIG sectors.
1660 In such a case you don't want to spend a whole sector for
1665 If you use this in combination with CFG_ENV_IS_IN_FLASH
1666 and CFG_ENV_SECT_SIZE, you can specify to use only a part
1667 of this flash sector for the environment. This saves
1668 memory for the RAM copy of the environment.
1670 It may also save flash memory if you decide to use this
1671 when your environment is "embedded" within U-Boot code,
1672 since then the remainder of the flash sector could be used
1673 for U-Boot code. It should be pointed out that this is
1674 STRONGLY DISCOURAGED from a robustness point of view:
1675 updating the environment in flash makes it always
1676 necessary to erase the WHOLE sector. If something goes
1677 wrong before the contents has been restored from a copy in
1678 RAM, your target system will be dead.
1680 - CFG_ENV_ADDR_REDUND
1683 These settings describe a second storage area used to hold
1684 a redundand copy of the environment data, so that there is
1685 a valid backup copy in case there is a power failure during
1686 a "saveenv" operation.
1688 BE CAREFUL! Any changes to the flash layout, and some changes to the
1689 source code will make it necessary to adapt <board>/u-boot.lds*
1693 - CFG_ENV_IS_IN_NVRAM:
1695 Define this if you have some non-volatile memory device
1696 (NVRAM, battery buffered SRAM) which you want to use for the
1702 These two #defines are used to determin the memory area you
1703 want to use for environment. It is assumed that this memory
1704 can just be read and written to, without any special
1707 BE CAREFUL! The first access to the environment happens quite early
1708 in U-Boot initalization (when we try to get the setting of for the
1709 console baudrate). You *MUST* have mappend your NVRAM area then, or
1712 Please note that even with NVRAM we still use a copy of the
1713 environment in RAM: we could work on NVRAM directly, but we want to
1714 keep settings there always unmodified except somebody uses "saveenv"
1715 to save the current settings.
1718 - CFG_ENV_IS_IN_EEPROM:
1720 Use this if you have an EEPROM or similar serial access
1721 device and a driver for it.
1726 These two #defines specify the offset and size of the
1727 environment area within the total memory of your EEPROM.
1729 - CFG_I2C_EEPROM_ADDR:
1730 If defined, specified the chip address of the EEPROM device.
1731 The default address is zero.
1733 - CFG_EEPROM_PAGE_WRITE_BITS:
1734 If defined, the number of bits used to address bytes in a
1735 single page in the EEPROM device. A 64 byte page, for example
1736 would require six bits.
1738 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1739 If defined, the number of milliseconds to delay between
1740 page writes. The default is zero milliseconds.
1742 - CFG_I2C_EEPROM_ADDR_LEN:
1743 The length in bytes of the EEPROM memory array address. Note
1744 that this is NOT the chip address length!
1747 The size in bytes of the EEPROM device.
1750 - CFG_ENV_IS_IN_DATAFLASH:
1752 Define this if you have a DataFlash memory device which you
1753 want to use for the environment.
1759 These three #defines specify the offset and size of the
1760 environment area within the total memory of your DataFlash placed
1761 at the specified address.
1764 - CFG_SPI_INIT_OFFSET
1766 Defines offset to the initial SPI buffer area in DPRAM. The
1767 area is used at an early stage (ROM part) if the environment
1768 is configured to reside in the SPI EEPROM: We need a 520 byte
1769 scratch DPRAM area. It is used between the two initialization
1770 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
1771 to be a good choice since it makes it far enough from the
1772 start of the data area as well as from the stack pointer.
1774 Please note that the environment is read-only as long as the monitor
1775 has been relocated to RAM and a RAM copy of the environment has been
1776 created; also, when using EEPROM you will have to use getenv_r()
1777 until then to read environment variables.
1779 The environment is protected by a CRC32 checksum. Before the monitor
1780 is relocated into RAM, as a result of a bad CRC you will be working
1781 with the compiled-in default environment - *silently*!!! [This is
1782 necessary, because the first environment variable we need is the
1783 "baudrate" setting for the console - if we have a bad CRC, we don't
1784 have any device yet where we could complain.]
1786 Note: once the monitor has been relocated, then it will complain if
1787 the default environment is used; a new CRC is computed as soon as you
1788 use the "saveenv" command to store a valid environment.
1790 - CFG_FAULT_ECHO_LINK_DOWN:
1791 Echo the inverted Ethernet link state to the fault LED.
1793 Note: If this option is active, then CFG_FAULT_MII_ADDR
1794 also needs to be defined.
1796 - CFG_FAULT_MII_ADDR:
1797 MII address of the PHY to check for the Ethernet link state.
1799 - CFG_64BIT_VSPRINTF:
1800 Makes vsprintf (and all *printf functions) support printing
1801 of 64bit values by using the L quantifier
1803 - CFG_64BIT_STRTOUL:
1804 Adds simple_strtoull that returns a 64bit value
1806 Low Level (hardware related) configuration options:
1807 ---------------------------------------------------
1809 - CFG_CACHELINE_SIZE:
1810 Cache Line Size of the CPU.
1813 Default address of the IMMR after system reset.
1815 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
1816 and RPXsuper) to be able to adjust the position of
1817 the IMMR register after a reset.
1819 - Floppy Disk Support:
1820 CFG_FDC_DRIVE_NUMBER
1822 the default drive number (default value 0)
1826 defines the spacing between fdc chipset registers
1831 defines the offset of register from address. It
1832 depends on which part of the data bus is connected to
1833 the fdc chipset. (default value 0)
1835 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
1836 CFG_FDC_DRIVE_NUMBER are undefined, they take their
1839 if CFG_FDC_HW_INIT is defined, then the function
1840 fdc_hw_init() is called at the beginning of the FDC
1841 setup. fdc_hw_init() must be provided by the board
1842 source code. It is used to make hardware dependant
1845 - CFG_IMMR: Physical address of the Internal Memory Mapped
1846 Register; DO NOT CHANGE! (11-4)
1847 [MPC8xx systems only]
1849 - CFG_INIT_RAM_ADDR:
1851 Start address of memory area that can be used for
1852 initial data and stack; please note that this must be
1853 writable memory that is working WITHOUT special
1854 initialization, i. e. you CANNOT use normal RAM which
1855 will become available only after programming the
1856 memory controller and running certain initialization
1859 U-Boot uses the following memory types:
1860 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
1861 - MPC824X: data cache
1862 - PPC4xx: data cache
1864 - CFG_GBL_DATA_OFFSET:
1866 Offset of the initial data structure in the memory
1867 area defined by CFG_INIT_RAM_ADDR. Usually
1868 CFG_GBL_DATA_OFFSET is chosen such that the initial
1869 data is located at the end of the available space
1870 (sometimes written as (CFG_INIT_RAM_END -
1871 CFG_INIT_DATA_SIZE), and the initial stack is just
1872 below that area (growing from (CFG_INIT_RAM_ADDR +
1873 CFG_GBL_DATA_OFFSET) downward.
1876 On the MPC824X (or other systems that use the data
1877 cache for initial memory) the address chosen for
1878 CFG_INIT_RAM_ADDR is basically arbitrary - it must
1879 point to an otherwise UNUSED address space between
1880 the top of RAM and the start of the PCI space.
1882 - CFG_SIUMCR: SIU Module Configuration (11-6)
1884 - CFG_SYPCR: System Protection Control (11-9)
1886 - CFG_TBSCR: Time Base Status and Control (11-26)
1888 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
1890 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
1892 - CFG_SCCR: System Clock and reset Control Register (15-27)
1894 - CFG_OR_TIMING_SDRAM:
1898 periodic timer for refresh
1900 - CFG_DER: Debug Event Register (37-47)
1902 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
1903 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
1904 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
1906 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
1908 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
1909 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
1910 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
1911 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
1913 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
1914 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
1915 Machine Mode Register and Memory Periodic Timer
1916 Prescaler definitions (SDRAM timing)
1918 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
1919 enable I2C microcode relocation patch (MPC8xx);
1920 define relocation offset in DPRAM [DSP2]
1922 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
1923 enable SPI microcode relocation patch (MPC8xx);
1924 define relocation offset in DPRAM [SCC4]
1927 Use OSCM clock mode on MBX8xx board. Be careful,
1928 wrong setting might damage your board. Read
1929 doc/README.MBX before setting this variable!
1931 - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
1932 Offset of the bootmode word in DPRAM used by post
1933 (Power On Self Tests). This definition overrides
1934 #define'd default value in commproc.h resp.
1937 - CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
1938 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
1939 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
1940 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
1941 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
1942 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
1943 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
1944 CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
1945 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
1947 Building the Software:
1948 ======================
1950 Building U-Boot has been tested in native PPC environments (on a
1951 PowerBook G3 running LinuxPPC 2000) and in cross environments
1952 (running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
1955 If you are not using a native PPC environment, it is assumed that you
1956 have the GNU cross compiling tools available in your path and named
1957 with a prefix of "powerpc-linux-". If this is not the case, (e.g. if
1958 you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
1959 the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
1962 CROSS_COMPILE = ppc_4xx-
1965 U-Boot is intended to be simple to build. After installing the
1966 sources you must configure U-Boot for one specific board type. This
1971 where "NAME_config" is the name of one of the existing
1972 configurations; the following names are supported:
1974 ADCIOP_config GTH_config TQM850L_config
1975 ADS860_config IP860_config TQM855L_config
1976 AR405_config IVML24_config TQM860L_config
1977 CANBT_config IVMS8_config WALNUT405_config
1978 CPCI405_config LANTEC_config cogent_common_config
1979 CPCIISER4_config MBX_config cogent_mpc8260_config
1980 CU824_config MBX860T_config cogent_mpc8xx_config
1981 ESTEEM192E_config RPXlite_config hermes_config
1982 ETX094_config RPXsuper_config hymod_config
1983 FADS823_config SM850_config lwmon_config
1984 FADS850SAR_config SPD823TS_config pcu_e_config
1985 FADS860T_config SXNI855T_config rsdproto_config
1986 FPS850L_config Sandpoint8240_config sbc8260_config
1987 GENIETV_config TQM823L_config PIP405_config
1988 GEN860T_config EBONY_config FPS860L_config
1989 ELPT860_config cmi_mpc5xx_config NETVIA_config
1990 at91rm9200dk_config omap1510inn_config MPC8260ADS_config
1991 omap1610inn_config ZPC1900_config MPC8540ADS_config
1992 MPC8560ADS_config QS850_config QS823_config
1993 QS860T_config DUET_ADS_config omap1610h2_config
1995 Note: for some board special configuration names may exist; check if
1996 additional information is available from the board vendor; for
1997 instance, the TQM8xxL systems run normally at 50 MHz and use a
1998 SCC for 10baseT ethernet; there are also systems with 80 MHz
1999 CPU clock, and an optional Fast Ethernet module is available
2000 for CPU's with FEC. You can select such additional "features"
2001 when chosing the configuration, i. e.
2004 - will configure for a plain TQM860L, i. e. 50MHz, no FEC
2006 make TQM860L_FEC_config
2007 - will configure for a TQM860L at 50MHz with FEC for ethernet
2009 make TQM860L_80MHz_config
2010 - will configure for a TQM860L at 80 MHz, with normal 10baseT
2013 make TQM860L_FEC_80MHz_config
2014 - will configure for a TQM860L at 80 MHz with FEC for ethernet
2016 make TQM823L_LCD_config
2017 - will configure for a TQM823L with U-Boot console on LCD
2019 make TQM823L_LCD_80MHz_config
2020 - will configure for a TQM823L at 80 MHz with U-Boot console on LCD
2025 Finally, type "make all", and you should get some working U-Boot
2026 images ready for download to / installation on your system:
2028 - "u-boot.bin" is a raw binary image
2029 - "u-boot" is an image in ELF binary format
2030 - "u-boot.srec" is in Motorola S-Record format
2033 Please be aware that the Makefiles assume you are using GNU make, so
2034 for instance on NetBSD you might need to use "gmake" instead of
2038 If the system board that you have is not listed, then you will need
2039 to port U-Boot to your hardware platform. To do this, follow these
2042 1. Add a new configuration option for your board to the toplevel
2043 "Makefile" and to the "MAKEALL" script, using the existing
2044 entries as examples. Note that here and at many other places
2045 boards and other names are listed in alphabetical sort order. Please
2047 2. Create a new directory to hold your board specific code. Add any
2048 files you need. In your board directory, you will need at least
2049 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2050 3. Create a new configuration file "include/configs/<board>.h" for
2052 3. If you're porting U-Boot to a new CPU, then also create a new
2053 directory to hold your CPU specific code. Add any files you need.
2054 4. Run "make <board>_config" with your new name.
2055 5. Type "make", and you should get a working "u-boot.srec" file
2056 to be installed on your target system.
2057 6. Debug and solve any problems that might arise.
2058 [Of course, this last step is much harder than it sounds.]
2061 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2062 ==============================================================
2064 If you have modified U-Boot sources (for instance added a new board
2065 or support for new devices, a new CPU, etc.) you are expected to
2066 provide feedback to the other developers. The feedback normally takes
2067 the form of a "patch", i. e. a context diff against a certain (latest
2068 official or latest in CVS) version of U-Boot sources.
2070 But before you submit such a patch, please verify that your modifi-
2071 cation did not break existing code. At least make sure that *ALL* of
2072 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2073 just run the "MAKEALL" script, which will configure and build U-Boot
2074 for ALL supported system. Be warned, this will take a while. You can
2075 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2076 environment variable to the script, i. e. to use the cross tools from
2077 MontaVista's Hard Hat Linux you can type
2079 CROSS_COMPILE=ppc_8xx- MAKEALL
2081 or to build on a native PowerPC system you can type
2083 CROSS_COMPILE=' ' MAKEALL
2085 See also "U-Boot Porting Guide" below.
2088 Monitor Commands - Overview:
2089 ============================
2091 go - start application at address 'addr'
2092 run - run commands in an environment variable
2093 bootm - boot application image from memory
2094 bootp - boot image via network using BootP/TFTP protocol
2095 tftpboot- boot image via network using TFTP protocol
2096 and env variables "ipaddr" and "serverip"
2097 (and eventually "gatewayip")
2098 rarpboot- boot image via network using RARP/TFTP protocol
2099 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2100 loads - load S-Record file over serial line
2101 loadb - load binary file over serial line (kermit mode)
2103 mm - memory modify (auto-incrementing)
2104 nm - memory modify (constant address)
2105 mw - memory write (fill)
2107 cmp - memory compare
2108 crc32 - checksum calculation
2109 imd - i2c memory display
2110 imm - i2c memory modify (auto-incrementing)
2111 inm - i2c memory modify (constant address)
2112 imw - i2c memory write (fill)
2113 icrc32 - i2c checksum calculation
2114 iprobe - probe to discover valid I2C chip addresses
2115 iloop - infinite loop on address range
2116 isdram - print SDRAM configuration information
2117 sspi - SPI utility commands
2118 base - print or set address offset
2119 printenv- print environment variables
2120 setenv - set environment variables
2121 saveenv - save environment variables to persistent storage
2122 protect - enable or disable FLASH write protection
2123 erase - erase FLASH memory
2124 flinfo - print FLASH memory information
2125 bdinfo - print Board Info structure
2126 iminfo - print header information for application image
2127 coninfo - print console devices and informations
2128 ide - IDE sub-system
2129 loop - infinite loop on address range
2130 mtest - simple RAM test
2131 icache - enable or disable instruction cache
2132 dcache - enable or disable data cache
2133 reset - Perform RESET of the CPU
2134 echo - echo args to console
2135 version - print monitor version
2136 help - print online help
2137 ? - alias for 'help'
2140 Monitor Commands - Detailed Description:
2141 ========================================
2145 For now: just type "help <command>".
2148 Environment Variables:
2149 ======================
2151 U-Boot supports user configuration using Environment Variables which
2152 can be made persistent by saving to Flash memory.
2154 Environment Variables are set using "setenv", printed using
2155 "printenv", and saved to Flash using "saveenv". Using "setenv"
2156 without a value can be used to delete a variable from the
2157 environment. As long as you don't save the environment you are
2158 working with an in-memory copy. In case the Flash area containing the
2159 environment is erased by accident, a default environment is provided.
2161 Some configuration options can be set using Environment Variables:
2163 baudrate - see CONFIG_BAUDRATE
2165 bootdelay - see CONFIG_BOOTDELAY
2167 bootcmd - see CONFIG_BOOTCOMMAND
2169 bootargs - Boot arguments when booting an RTOS image
2171 bootfile - Name of the image to load with TFTP
2173 autoload - if set to "no" (any string beginning with 'n'),
2174 "bootp" will just load perform a lookup of the
2175 configuration from the BOOTP server, but not try to
2176 load any image using TFTP
2178 autostart - if set to "yes", an image loaded using the "bootp",
2179 "rarpboot", "tftpboot" or "diskboot" commands will
2180 be automatically started (by internally calling
2183 If set to "no", a standalone image passed to the
2184 "bootm" command will be copied to the load address
2185 (and eventually uncompressed), but NOT be started.
2186 This can be used to load and uncompress arbitrary
2189 initrd_high - restrict positioning of initrd images:
2190 If this variable is not set, initrd images will be
2191 copied to the highest possible address in RAM; this
2192 is usually what you want since it allows for
2193 maximum initrd size. If for some reason you want to
2194 make sure that the initrd image is loaded below the
2195 CFG_BOOTMAPSZ limit, you can set this environment
2196 variable to a value of "no" or "off" or "0".
2197 Alternatively, you can set it to a maximum upper
2198 address to use (U-Boot will still check that it
2199 does not overwrite the U-Boot stack and data).
2201 For instance, when you have a system with 16 MB
2202 RAM, and want to reserve 4 MB from use by Linux,
2203 you can do this by adding "mem=12M" to the value of
2204 the "bootargs" variable. However, now you must make
2205 sure that the initrd image is placed in the first
2206 12 MB as well - this can be done with
2208 setenv initrd_high 00c00000
2210 If you set initrd_high to 0xFFFFFFFF, this is an
2211 indication to U-Boot that all addresses are legal
2212 for the Linux kernel, including addresses in flash
2213 memory. In this case U-Boot will NOT COPY the
2214 ramdisk at all. This may be useful to reduce the
2215 boot time on your system, but requires that this
2216 feature is supported by your Linux kernel.
2218 ipaddr - IP address; needed for tftpboot command
2220 loadaddr - Default load address for commands like "bootp",
2221 "rarpboot", "tftpboot", "loadb" or "diskboot"
2223 loads_echo - see CONFIG_LOADS_ECHO
2225 serverip - TFTP server IP address; needed for tftpboot command
2227 bootretry - see CONFIG_BOOT_RETRY_TIME
2229 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
2231 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
2233 ethprime - When CONFIG_NET_MULTI is enabled controls which
2234 interface is used first.
2236 ethact - When CONFIG_NET_MULTI is enabled controls which
2237 interface is currently active. For example you
2238 can do the following
2240 => setenv ethact FEC ETHERNET
2241 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
2242 => setenv ethact SCC ETHERNET
2243 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
2245 netretry - When set to "no" each network operation will
2246 either succeed or fail without retrying.
2247 Useful on scripts which control the retry operation
2250 vlan - When set to a value < 4095 the traffic over
2251 ethernet is encapsulated/received over 802.1q
2254 The following environment variables may be used and automatically
2255 updated by the network boot commands ("bootp" and "rarpboot"),
2256 depending the information provided by your boot server:
2258 bootfile - see above
2259 dnsip - IP address of your Domain Name Server
2260 dnsip2 - IP address of your secondary Domain Name Server
2261 gatewayip - IP address of the Gateway (Router) to use
2262 hostname - Target hostname
2264 netmask - Subnet Mask
2265 rootpath - Pathname of the root filesystem on the NFS server
2266 serverip - see above
2269 There are two special Environment Variables:
2271 serial# - contains hardware identification information such
2272 as type string and/or serial number
2273 ethaddr - Ethernet address
2275 These variables can be set only once (usually during manufacturing of
2276 the board). U-Boot refuses to delete or overwrite these variables
2277 once they have been set once.
2280 Further special Environment Variables:
2282 ver - Contains the U-Boot version string as printed
2283 with the "version" command. This variable is
2284 readonly (see CONFIG_VERSION_VARIABLE).
2287 Please note that changes to some configuration parameters may take
2288 only effect after the next boot (yes, that's just like Windoze :-).
2291 Command Line Parsing:
2292 =====================
2294 There are two different command line parsers available with U-Boot:
2295 the old "simple" one, and the much more powerful "hush" shell:
2297 Old, simple command line parser:
2298 --------------------------------
2300 - supports environment variables (through setenv / saveenv commands)
2301 - several commands on one line, separated by ';'
2302 - variable substitution using "... $(name) ..." syntax
2303 - special characters ('$', ';') can be escaped by prefixing with '\',
2305 setenv bootcmd bootm \$(address)
2306 - You can also escape text by enclosing in single apostrophes, for example:
2307 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2312 - similar to Bourne shell, with control structures like
2313 if...then...else...fi, for...do...done; while...do...done,
2314 until...do...done, ...
2315 - supports environment ("global") variables (through setenv / saveenv
2316 commands) and local shell variables (through standard shell syntax
2317 "name=value"); only environment variables can be used with "run"
2323 (1) If a command line (or an environment variable executed by a "run"
2324 command) contains several commands separated by semicolon, and
2325 one of these commands fails, then the remaining commands will be
2328 (2) If you execute several variables with one call to run (i. e.
2329 calling run with a list af variables as arguments), any failing
2330 command will cause "run" to terminate, i. e. the remaining
2331 variables are not executed.
2333 Note for Redundant Ethernet Interfaces:
2334 =======================================
2336 Some boards come with redundant ethernet interfaces; U-Boot supports
2337 such configurations and is capable of automatic selection of a
2338 "working" interface when needed. MAC assignment works as follows:
2340 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2341 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2342 "eth1addr" (=>eth1), "eth2addr", ...
2344 If the network interface stores some valid MAC address (for instance
2345 in SROM), this is used as default address if there is NO correspon-
2346 ding setting in the environment; if the corresponding environment
2347 variable is set, this overrides the settings in the card; that means:
2349 o If the SROM has a valid MAC address, and there is no address in the
2350 environment, the SROM's address is used.
2352 o If there is no valid address in the SROM, and a definition in the
2353 environment exists, then the value from the environment variable is
2356 o If both the SROM and the environment contain a MAC address, and
2357 both addresses are the same, this MAC address is used.
2359 o If both the SROM and the environment contain a MAC address, and the
2360 addresses differ, the value from the environment is used and a
2363 o If neither SROM nor the environment contain a MAC address, an error
2370 The "boot" commands of this monitor operate on "image" files which
2371 can be basicly anything, preceeded by a special header; see the
2372 definitions in include/image.h for details; basicly, the header
2373 defines the following image properties:
2375 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2376 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2377 LynxOS, pSOS, QNX, RTEMS, ARTOS;
2378 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
2379 * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
2380 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2381 Currently supported: ARM, Intel x86, MIPS, NIOS, PowerPC).
2382 * Compression Type (uncompressed, gzip, bzip2)
2388 The header is marked by a special Magic Number, and both the header
2389 and the data portions of the image are secured against corruption by
2396 Although U-Boot should support any OS or standalone application
2397 easily, the main focus has always been on Linux during the design of
2400 U-Boot includes many features that so far have been part of some
2401 special "boot loader" code within the Linux kernel. Also, any
2402 "initrd" images to be used are no longer part of one big Linux image;
2403 instead, kernel and "initrd" are separate images. This implementation
2404 serves several purposes:
2406 - the same features can be used for other OS or standalone
2407 applications (for instance: using compressed images to reduce the
2408 Flash memory footprint)
2410 - it becomes much easier to port new Linux kernel versions because
2411 lots of low-level, hardware dependent stuff are done by U-Boot
2413 - the same Linux kernel image can now be used with different "initrd"
2414 images; of course this also means that different kernel images can
2415 be run with the same "initrd". This makes testing easier (you don't
2416 have to build a new "zImage.initrd" Linux image when you just
2417 change a file in your "initrd"). Also, a field-upgrade of the
2418 software is easier now.
2424 Porting Linux to U-Boot based systems:
2425 ---------------------------------------
2427 U-Boot cannot save you from doing all the necessary modifications to
2428 configure the Linux device drivers for use with your target hardware
2429 (no, we don't intend to provide a full virtual machine interface to
2432 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
2434 Just make sure your machine specific header file (for instance
2435 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
2436 Information structure as we define in include/u-boot.h, and make
2437 sure that your definition of IMAP_ADDR uses the same value as your
2438 U-Boot configuration in CFG_IMMR.
2441 Configuring the Linux kernel:
2442 -----------------------------
2444 No specific requirements for U-Boot. Make sure you have some root
2445 device (initial ramdisk, NFS) for your target system.
2448 Building a Linux Image:
2449 -----------------------
2451 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2452 not used. If you use recent kernel source, a new build target
2453 "uImage" will exist which automatically builds an image usable by
2454 U-Boot. Most older kernels also have support for a "pImage" target,
2455 which was introduced for our predecessor project PPCBoot and uses a
2456 100% compatible format.
2465 The "uImage" build target uses a special tool (in 'tools/mkimage') to
2466 encapsulate a compressed Linux kernel image with header information,
2467 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
2469 * build a standard "vmlinux" kernel image (in ELF binary format):
2471 * convert the kernel into a raw binary image:
2473 ${CROSS_COMPILE}-objcopy -O binary \
2474 -R .note -R .comment \
2475 -S vmlinux linux.bin
2477 * compress the binary image:
2481 * package compressed binary image for U-Boot:
2483 mkimage -A ppc -O linux -T kernel -C gzip \
2484 -a 0 -e 0 -n "Linux Kernel Image" \
2485 -d linux.bin.gz uImage
2488 The "mkimage" tool can also be used to create ramdisk images for use
2489 with U-Boot, either separated from the Linux kernel image, or
2490 combined into one file. "mkimage" encapsulates the images with a 64
2491 byte header containing information about target architecture,
2492 operating system, image type, compression method, entry points, time
2493 stamp, CRC32 checksums, etc.
2495 "mkimage" can be called in two ways: to verify existing images and
2496 print the header information, or to build new images.
2498 In the first form (with "-l" option) mkimage lists the information
2499 contained in the header of an existing U-Boot image; this includes
2500 checksum verification:
2502 tools/mkimage -l image
2503 -l ==> list image header information
2505 The second form (with "-d" option) is used to build a U-Boot image
2506 from a "data file" which is used as image payload:
2508 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2509 -n name -d data_file image
2510 -A ==> set architecture to 'arch'
2511 -O ==> set operating system to 'os'
2512 -T ==> set image type to 'type'
2513 -C ==> set compression type 'comp'
2514 -a ==> set load address to 'addr' (hex)
2515 -e ==> set entry point to 'ep' (hex)
2516 -n ==> set image name to 'name'
2517 -d ==> use image data from 'datafile'
2519 Right now, all Linux kernels use the same load address (0x00000000),
2520 but the entry point address depends on the kernel version:
2522 - 2.2.x kernels have the entry point at 0x0000000C,
2523 - 2.3.x and later kernels have the entry point at 0x00000000.
2525 So a typical call to build a U-Boot image would read:
2527 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2528 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
2529 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
2530 > examples/uImage.TQM850L
2531 Image Name: 2.4.4 kernel for TQM850L
2532 Created: Wed Jul 19 02:34:59 2000
2533 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2534 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2535 Load Address: 0x00000000
2536 Entry Point: 0x00000000
2538 To verify the contents of the image (or check for corruption):
2540 -> tools/mkimage -l examples/uImage.TQM850L
2541 Image Name: 2.4.4 kernel for TQM850L
2542 Created: Wed Jul 19 02:34:59 2000
2543 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2544 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2545 Load Address: 0x00000000
2546 Entry Point: 0x00000000
2548 NOTE: for embedded systems where boot time is critical you can trade
2549 speed for memory and install an UNCOMPRESSED image instead: this
2550 needs more space in Flash, but boots much faster since it does not
2551 need to be uncompressed:
2553 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
2554 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2555 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
2556 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
2557 > examples/uImage.TQM850L-uncompressed
2558 Image Name: 2.4.4 kernel for TQM850L
2559 Created: Wed Jul 19 02:34:59 2000
2560 Image Type: PowerPC Linux Kernel Image (uncompressed)
2561 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
2562 Load Address: 0x00000000
2563 Entry Point: 0x00000000
2566 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2567 when your kernel is intended to use an initial ramdisk:
2569 -> tools/mkimage -n 'Simple Ramdisk Image' \
2570 > -A ppc -O linux -T ramdisk -C gzip \
2571 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2572 Image Name: Simple Ramdisk Image
2573 Created: Wed Jan 12 14:01:50 2000
2574 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2575 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
2576 Load Address: 0x00000000
2577 Entry Point: 0x00000000
2580 Installing a Linux Image:
2581 -------------------------
2583 To downloading a U-Boot image over the serial (console) interface,
2584 you must convert the image to S-Record format:
2586 objcopy -I binary -O srec examples/image examples/image.srec
2588 The 'objcopy' does not understand the information in the U-Boot
2589 image header, so the resulting S-Record file will be relative to
2590 address 0x00000000. To load it to a given address, you need to
2591 specify the target address as 'offset' parameter with the 'loads'
2594 Example: install the image to address 0x40100000 (which on the
2595 TQM8xxL is in the first Flash bank):
2597 => erase 40100000 401FFFFF
2603 ## Ready for S-Record download ...
2604 ~>examples/image.srec
2605 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2607 15989 15990 15991 15992
2608 [file transfer complete]
2610 ## Start Addr = 0x00000000
2613 You can check the success of the download using the 'iminfo' command;
2614 this includes a checksum verification so you can be sure no data
2615 corruption happened:
2619 ## Checking Image at 40100000 ...
2620 Image Name: 2.2.13 for initrd on TQM850L
2621 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2622 Data Size: 335725 Bytes = 327 kB = 0 MB
2623 Load Address: 00000000
2624 Entry Point: 0000000c
2625 Verifying Checksum ... OK
2631 The "bootm" command is used to boot an application that is stored in
2632 memory (RAM or Flash). In case of a Linux kernel image, the contents
2633 of the "bootargs" environment variable is passed to the kernel as
2634 parameters. You can check and modify this variable using the
2635 "printenv" and "setenv" commands:
2638 => printenv bootargs
2639 bootargs=root=/dev/ram
2641 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2643 => printenv bootargs
2644 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2647 ## Booting Linux kernel at 40020000 ...
2648 Image Name: 2.2.13 for NFS on TQM850L
2649 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2650 Data Size: 381681 Bytes = 372 kB = 0 MB
2651 Load Address: 00000000
2652 Entry Point: 0000000c
2653 Verifying Checksum ... OK
2654 Uncompressing Kernel Image ... OK
2655 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
2656 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2657 time_init: decrementer frequency = 187500000/60
2658 Calibrating delay loop... 49.77 BogoMIPS
2659 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2662 If you want to boot a Linux kernel with initial ram disk, you pass
2663 the memory addresses of both the kernel and the initrd image (PPBCOOT
2664 format!) to the "bootm" command:
2666 => imi 40100000 40200000
2668 ## Checking Image at 40100000 ...
2669 Image Name: 2.2.13 for initrd on TQM850L
2670 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2671 Data Size: 335725 Bytes = 327 kB = 0 MB
2672 Load Address: 00000000
2673 Entry Point: 0000000c
2674 Verifying Checksum ... OK
2676 ## Checking Image at 40200000 ...
2677 Image Name: Simple Ramdisk Image
2678 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2679 Data Size: 566530 Bytes = 553 kB = 0 MB
2680 Load Address: 00000000
2681 Entry Point: 00000000
2682 Verifying Checksum ... OK
2684 => bootm 40100000 40200000
2685 ## Booting Linux kernel at 40100000 ...
2686 Image Name: 2.2.13 for initrd on TQM850L
2687 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2688 Data Size: 335725 Bytes = 327 kB = 0 MB
2689 Load Address: 00000000
2690 Entry Point: 0000000c
2691 Verifying Checksum ... OK
2692 Uncompressing Kernel Image ... OK
2693 ## Loading RAMDisk Image at 40200000 ...
2694 Image Name: Simple Ramdisk Image
2695 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2696 Data Size: 566530 Bytes = 553 kB = 0 MB
2697 Load Address: 00000000
2698 Entry Point: 00000000
2699 Verifying Checksum ... OK
2700 Loading Ramdisk ... OK
2701 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
2702 Boot arguments: root=/dev/ram
2703 time_init: decrementer frequency = 187500000/60
2704 Calibrating delay loop... 49.77 BogoMIPS
2706 RAMDISK: Compressed image found at block 0
2707 VFS: Mounted root (ext2 filesystem).
2711 More About U-Boot Image Types:
2712 ------------------------------
2714 U-Boot supports the following image types:
2716 "Standalone Programs" are directly runnable in the environment
2717 provided by U-Boot; it is expected that (if they behave
2718 well) you can continue to work in U-Boot after return from
2719 the Standalone Program.
2720 "OS Kernel Images" are usually images of some Embedded OS which
2721 will take over control completely. Usually these programs
2722 will install their own set of exception handlers, device
2723 drivers, set up the MMU, etc. - this means, that you cannot
2724 expect to re-enter U-Boot except by resetting the CPU.
2725 "RAMDisk Images" are more or less just data blocks, and their
2726 parameters (address, size) are passed to an OS kernel that is
2728 "Multi-File Images" contain several images, typically an OS
2729 (Linux) kernel image and one or more data images like
2730 RAMDisks. This construct is useful for instance when you want
2731 to boot over the network using BOOTP etc., where the boot
2732 server provides just a single image file, but you want to get
2733 for instance an OS kernel and a RAMDisk image.
2735 "Multi-File Images" start with a list of image sizes, each
2736 image size (in bytes) specified by an "uint32_t" in network
2737 byte order. This list is terminated by an "(uint32_t)0".
2738 Immediately after the terminating 0 follow the images, one by
2739 one, all aligned on "uint32_t" boundaries (size rounded up to
2740 a multiple of 4 bytes).
2742 "Firmware Images" are binary images containing firmware (like
2743 U-Boot or FPGA images) which usually will be programmed to
2746 "Script files" are command sequences that will be executed by
2747 U-Boot's command interpreter; this feature is especially
2748 useful when you configure U-Boot to use a real shell (hush)
2749 as command interpreter.
2755 One of the features of U-Boot is that you can dynamically load and
2756 run "standalone" applications, which can use some resources of
2757 U-Boot like console I/O functions or interrupt services.
2759 Two simple examples are included with the sources:
2764 'examples/hello_world.c' contains a small "Hello World" Demo
2765 application; it is automatically compiled when you build U-Boot.
2766 It's configured to run at address 0x00040004, so you can play with it
2770 ## Ready for S-Record download ...
2771 ~>examples/hello_world.srec
2772 1 2 3 4 5 6 7 8 9 10 11 ...
2773 [file transfer complete]
2775 ## Start Addr = 0x00040004
2777 => go 40004 Hello World! This is a test.
2778 ## Starting application at 0x00040004 ...
2789 Hit any key to exit ...
2791 ## Application terminated, rc = 0x0
2793 Another example, which demonstrates how to register a CPM interrupt
2794 handler with the U-Boot code, can be found in 'examples/timer.c'.
2795 Here, a CPM timer is set up to generate an interrupt every second.
2796 The interrupt service routine is trivial, just printing a '.'
2797 character, but this is just a demo program. The application can be
2798 controlled by the following keys:
2800 ? - print current values og the CPM Timer registers
2801 b - enable interrupts and start timer
2802 e - stop timer and disable interrupts
2803 q - quit application
2806 ## Ready for S-Record download ...
2807 ~>examples/timer.srec
2808 1 2 3 4 5 6 7 8 9 10 11 ...
2809 [file transfer complete]
2811 ## Start Addr = 0x00040004
2814 ## Starting application at 0x00040004 ...
2817 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
2820 [q, b, e, ?] Set interval 1000000 us
2823 [q, b, e, ?] ........
2824 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
2827 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
2830 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
2833 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
2835 [q, b, e, ?] ...Stopping timer
2837 [q, b, e, ?] ## Application terminated, rc = 0x0
2843 Over time, many people have reported problems when trying to use the
2844 "minicom" terminal emulation program for serial download. I (wd)
2845 consider minicom to be broken, and recommend not to use it. Under
2846 Unix, I recommend to use C-Kermit for general purpose use (and
2847 especially for kermit binary protocol download ("loadb" command), and
2848 use "cu" for S-Record download ("loads" command).
2850 Nevertheless, if you absolutely want to use it try adding this
2851 configuration to your "File transfer protocols" section:
2853 Name Program Name U/D FullScr IO-Red. Multi
2854 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
2855 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
2861 Starting at version 0.9.2, U-Boot supports NetBSD both as host
2862 (build U-Boot) and target system (boots NetBSD/mpc8xx).
2864 Building requires a cross environment; it is known to work on
2865 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
2866 need gmake since the Makefiles are not compatible with BSD make).
2867 Note that the cross-powerpc package does not install include files;
2868 attempting to build U-Boot will fail because <machine/ansi.h> is
2869 missing. This file has to be installed and patched manually:
2871 # cd /usr/pkg/cross/powerpc-netbsd/include
2873 # ln -s powerpc machine
2874 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
2875 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
2877 Native builds *don't* work due to incompatibilities between native
2878 and U-Boot include files.
2880 Booting assumes that (the first part of) the image booted is a
2881 stage-2 loader which in turn loads and then invokes the kernel
2882 proper. Loader sources will eventually appear in the NetBSD source
2883 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
2884 meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for
2888 Implementation Internals:
2889 =========================
2891 The following is not intended to be a complete description of every
2892 implementation detail. However, it should help to understand the
2893 inner workings of U-Boot and make it easier to port it to custom
2897 Initial Stack, Global Data:
2898 ---------------------------
2900 The implementation of U-Boot is complicated by the fact that U-Boot
2901 starts running out of ROM (flash memory), usually without access to
2902 system RAM (because the memory controller is not initialized yet).
2903 This means that we don't have writable Data or BSS segments, and BSS
2904 is not initialized as zero. To be able to get a C environment working
2905 at all, we have to allocate at least a minimal stack. Implementation
2906 options for this are defined and restricted by the CPU used: Some CPU
2907 models provide on-chip memory (like the IMMR area on MPC8xx and
2908 MPC826x processors), on others (parts of) the data cache can be
2909 locked as (mis-) used as memory, etc.
2911 Chris Hallinan posted a good summary of these issues to the
2912 u-boot-users mailing list:
2914 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
2915 From: "Chris Hallinan" <clh@net1plus.com>
2916 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
2919 Correct me if I'm wrong, folks, but the way I understand it
2920 is this: Using DCACHE as initial RAM for Stack, etc, does not
2921 require any physical RAM backing up the cache. The cleverness
2922 is that the cache is being used as a temporary supply of
2923 necessary storage before the SDRAM controller is setup. It's
2924 beyond the scope of this list to expain the details, but you
2925 can see how this works by studying the cache architecture and
2926 operation in the architecture and processor-specific manuals.
2928 OCM is On Chip Memory, which I believe the 405GP has 4K. It
2929 is another option for the system designer to use as an
2930 initial stack/ram area prior to SDRAM being available. Either
2931 option should work for you. Using CS 4 should be fine if your
2932 board designers haven't used it for something that would
2933 cause you grief during the initial boot! It is frequently not
2936 CFG_INIT_RAM_ADDR should be somewhere that won't interfere
2937 with your processor/board/system design. The default value
2938 you will find in any recent u-boot distribution in
2939 Walnut405.h should work for you. I'd set it to a value larger
2940 than your SDRAM module. If you have a 64MB SDRAM module, set
2941 it above 400_0000. Just make sure your board has no resources
2942 that are supposed to respond to that address! That code in
2943 start.S has been around a while and should work as is when
2944 you get the config right.
2949 It is essential to remember this, since it has some impact on the C
2950 code for the initialization procedures:
2952 * Initialized global data (data segment) is read-only. Do not attempt
2955 * Do not use any unitialized global data (or implicitely initialized
2956 as zero data - BSS segment) at all - this is undefined, initiali-
2957 zation is performed later (when relocating to RAM).
2959 * Stack space is very limited. Avoid big data buffers or things like
2962 Having only the stack as writable memory limits means we cannot use
2963 normal global data to share information beween the code. But it
2964 turned out that the implementation of U-Boot can be greatly
2965 simplified by making a global data structure (gd_t) available to all
2966 functions. We could pass a pointer to this data as argument to _all_
2967 functions, but this would bloat the code. Instead we use a feature of
2968 the GCC compiler (Global Register Variables) to share the data: we
2969 place a pointer (gd) to the global data into a register which we
2970 reserve for this purpose.
2972 When choosing a register for such a purpose we are restricted by the
2973 relevant (E)ABI specifications for the current architecture, and by
2974 GCC's implementation.
2976 For PowerPC, the following registers have specific use:
2979 R3-R4: parameter passing and return values
2980 R5-R10: parameter passing
2981 R13: small data area pointer
2985 (U-Boot also uses R14 as internal GOT pointer.)
2987 ==> U-Boot will use R29 to hold a pointer to the global data
2989 Note: on PPC, we could use a static initializer (since the
2990 address of the global data structure is known at compile time),
2991 but it turned out that reserving a register results in somewhat
2992 smaller code - although the code savings are not that big (on
2993 average for all boards 752 bytes for the whole U-Boot image,
2994 624 text + 127 data).
2996 On ARM, the following registers are used:
2998 R0: function argument word/integer result
2999 R1-R3: function argument word
3001 R10: stack limit (used only if stack checking if enabled)
3002 R11: argument (frame) pointer
3003 R12: temporary workspace
3006 R15: program counter
3008 ==> U-Boot will use R8 to hold a pointer to the global data
3014 U-Boot runs in system state and uses physical addresses, i.e. the
3015 MMU is not used either for address mapping nor for memory protection.
3017 The available memory is mapped to fixed addresses using the memory
3018 controller. In this process, a contiguous block is formed for each
3019 memory type (Flash, SDRAM, SRAM), even when it consists of several
3020 physical memory banks.
3022 U-Boot is installed in the first 128 kB of the first Flash bank (on
3023 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3024 booting and sizing and initializing DRAM, the code relocates itself
3025 to the upper end of DRAM. Immediately below the U-Boot code some
3026 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
3027 configuration setting]. Below that, a structure with global Board
3028 Info data is placed, followed by the stack (growing downward).
3030 Additionally, some exception handler code is copied to the low 8 kB
3031 of DRAM (0x00000000 ... 0x00001FFF).
3033 So a typical memory configuration with 16 MB of DRAM could look like
3036 0x0000 0000 Exception Vector code
3039 0x0000 2000 Free for Application Use
3045 0x00FB FF20 Monitor Stack (Growing downward)
3046 0x00FB FFAC Board Info Data and permanent copy of global data
3047 0x00FC 0000 Malloc Arena
3050 0x00FE 0000 RAM Copy of Monitor Code
3051 ... eventually: LCD or video framebuffer
3052 ... eventually: pRAM (Protected RAM - unchanged by reset)
3053 0x00FF FFFF [End of RAM]
3056 System Initialization:
3057 ----------------------
3059 In the reset configuration, U-Boot starts at the reset entry point
3060 (on most PowerPC systens at address 0x00000100). Because of the reset
3061 configuration for CS0# this is a mirror of the onboard Flash memory.
3062 To be able to re-map memory U-Boot then jumps to its link address.
3063 To be able to implement the initialization code in C, a (small!)
3064 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3065 which provide such a feature like MPC8xx or MPC8260), or in a locked
3066 part of the data cache. After that, U-Boot initializes the CPU core,
3067 the caches and the SIU.
3069 Next, all (potentially) available memory banks are mapped using a
3070 preliminary mapping. For example, we put them on 512 MB boundaries
3071 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3072 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3073 programmed for SDRAM access. Using the temporary configuration, a
3074 simple memory test is run that determines the size of the SDRAM
3077 When there is more than one SDRAM bank, and the banks are of
3078 different size, the largest is mapped first. For equal size, the first
3079 bank (CS2#) is mapped first. The first mapping is always for address
3080 0x00000000, with any additional banks following immediately to create
3081 contiguous memory starting from 0.
3083 Then, the monitor installs itself at the upper end of the SDRAM area
3084 and allocates memory for use by malloc() and for the global Board
3085 Info data; also, the exception vector code is copied to the low RAM
3086 pages, and the final stack is set up.
3088 Only after this relocation will you have a "normal" C environment;
3089 until that you are restricted in several ways, mostly because you are
3090 running from ROM, and because the code will have to be relocated to a
3094 U-Boot Porting Guide:
3095 ----------------------
3097 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3101 int main (int argc, char *argv[])
3103 sighandler_t no_more_time;
3105 signal (SIGALRM, no_more_time);
3106 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3108 if (available_money > available_manpower) {
3109 pay consultant to port U-Boot;
3113 Download latest U-Boot source;
3115 Subscribe to u-boot-users mailing list;
3118 email ("Hi, I am new to U-Boot, how do I get started?");
3122 Read the README file in the top level directory;
3123 Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
3124 Read the source, Luke;
3127 if (available_money > toLocalCurrency ($2500)) {
3130 Add a lot of aggravation and time;
3133 Create your own board support subdirectory;
3135 Create your own board config file;
3139 Add / modify source code;
3143 email ("Hi, I am having problems...");
3145 Send patch file to Wolfgang;
3150 void no_more_time (int sig)
3159 All contributions to U-Boot should conform to the Linux kernel
3160 coding style; see the file "Documentation/CodingStyle" in your Linux
3161 kernel source directory.
3163 Please note that U-Boot is implemented in C (and to some small parts
3164 in Assembler); no C++ is used, so please do not use C++ style
3165 comments (//) in your code.
3167 Please also stick to the following formatting rules:
3168 - remove any trailing white space
3169 - use TAB characters for indentation, not spaces
3170 - make sure NOT to use DOS '\r\n' line feeds
3171 - do not add more than 2 empty lines to source files
3172 - do not add trailing empty lines to source files
3174 Submissions which do not conform to the standards may be returned
3175 with a request to reformat the changes.
3181 Since the number of patches for U-Boot is growing, we need to
3182 establish some rules. Submissions which do not conform to these rules
3183 may be rejected, even when they contain important and valuable stuff.
3186 When you send a patch, please include the following information with
3189 * For bug fixes: a description of the bug and how your patch fixes
3190 this bug. Please try to include a way of demonstrating that the
3191 patch actually fixes something.
3193 * For new features: a description of the feature and your
3196 * A CHANGELOG entry as plaintext (separate from the patch)
3198 * For major contributions, your entry to the CREDITS file
3200 * When you add support for a new board, don't forget to add this
3201 board to the MAKEALL script, too.
3203 * If your patch adds new configuration options, don't forget to
3204 document these in the README file.
3206 * The patch itself. If you are accessing the CVS repository use "cvs
3207 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
3208 version of diff does not support these options, then get the latest
3209 version of GNU diff.
3211 The current directory when running this command shall be the top
3212 level directory of the U-Boot source tree, or it's parent directory
3213 (i. e. please make sure that your patch includes sufficient
3214 directory information for the affected files).
3216 We accept patches as plain text, MIME attachments or as uuencoded
3219 * If one logical set of modifications affects or creates several
3220 files, all these changes shall be submitted in a SINGLE patch file.
3222 * Changesets that contain different, unrelated modifications shall be
3223 submitted as SEPARATE patches, one patch per changeset.
3228 * Before sending the patch, run the MAKEALL script on your patched
3229 source tree and make sure that no errors or warnings are reported
3230 for any of the boards.
3232 * Keep your modifications to the necessary minimum: A patch
3233 containing several unrelated changes or arbitrary reformats will be
3234 returned with a request to re-formatting / split it.
3236 * If you modify existing code, make sure that your new code does not
3237 add to the memory footprint of the code ;-) Small is beautiful!
3238 When adding new features, these should compile conditionally only
3239 (using #ifdef), and the resulting code with the new feature
3240 disabled must not need more memory than the old code without your
projects / platform / kernel / u-boot.git / blob