2 # (C) Copyright 2000 - 2008
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, ARM, MIPS and several other
29 processors, which can be installed in a boot ROM and used to
30 initialize and test the hardware or to download and run application
33 The development of U-Boot is closely related to Linux: some parts of
34 the source code originate in the Linux source tree, we have some
35 header files in common, and special provision has been made to
36 support booting of Linux images.
38 Some attention has been paid to make this software easily
39 configurable and extendable. For instance, all monitor commands are
40 implemented with the same call interface, so that it's very easy to
41 add new commands. Also, instead of permanently adding rarely used
42 code (for instance hardware test utilities) to the monitor, you can
43 load and run it dynamically.
49 In general, all boards for which a configuration option exists in the
50 Makefile have been tested to some extent and can be considered
51 "working". In fact, many of them are used in production systems.
53 In case of problems see the CHANGELOG and CREDITS files to find out
54 who contributed the specific port. The MAINTAINERS file lists board
61 In case you have questions about, problems with or contributions for
62 U-Boot you should send a message to the U-Boot mailing list at
63 <u-boot-users@lists.sourceforge.net>. There is also an archive of
64 previous traffic on the mailing list - please search the archive
65 before asking FAQ's. Please see
66 http://lists.sourceforge.net/lists/listinfo/u-boot-users/
69 Where to get source code:
70 =========================
72 The U-Boot source code is maintained in the git repository at
73 git://www.denx.de/git/u-boot.git ; you can browse it online at
74 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
76 The "snapshot" links on this page allow you to download tarballs of
77 any version you might be interested in. Ofifcial releases are also
78 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
81 Pre-built (and tested) images are available from
82 ftp://ftp.denx.de/pub/u-boot/images/
88 - start from 8xxrom sources
89 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
91 - make it easier to add custom boards
92 - make it possible to add other [PowerPC] CPUs
93 - extend functions, especially:
94 * Provide extended interface to Linux boot loader
97 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot
98 - create ARMBoot project (http://sourceforge.net/projects/armboot)
99 - add other CPU families (starting with ARM)
100 - create U-Boot project (http://sourceforge.net/projects/u-boot)
101 - current project page: see http://www.denx.de/wiki/UBoot
107 The "official" name of this project is "Das U-Boot". The spelling
108 "U-Boot" shall be used in all written text (documentation, comments
109 in source files etc.). Example:
111 This is the README file for the U-Boot project.
113 File names etc. shall be based on the string "u-boot". Examples:
115 include/asm-ppc/u-boot.h
117 #include <asm/u-boot.h>
119 Variable names, preprocessor constants etc. shall be either based on
120 the string "u_boot" or on "U_BOOT". Example:
122 U_BOOT_VERSION u_boot_logo
123 IH_OS_U_BOOT u_boot_hush_start
129 U-Boot uses a 3 level version number containing a version, a
130 sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2",
131 sub-version "34", and patchlevel "4".
133 The patchlevel is used to indicate certain stages of development
134 between released versions, i. e. officially released versions of
135 U-Boot will always have a patchlevel of "0".
141 - board Board dependent files
142 - common Misc architecture independent functions
143 - cpu CPU specific files
144 - 74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
145 - arm720t Files specific to ARM 720 CPUs
146 - arm920t Files specific to ARM 920 CPUs
147 - at91rm9200 Files specific to Atmel AT91RM9200 CPU
148 - imx Files specific to Freescale MC9328 i.MX CPUs
149 - s3c24x0 Files specific to Samsung S3C24X0 CPUs
150 - arm925t Files specific to ARM 925 CPUs
151 - arm926ejs Files specific to ARM 926 CPUs
152 - arm1136 Files specific to ARM 1136 CPUs
153 - at32ap Files specific to Atmel AVR32 AP CPUs
154 - i386 Files specific to i386 CPUs
155 - ixp Files specific to Intel XScale IXP CPUs
156 - mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
157 - mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
158 - mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
159 - mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
160 - mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
161 - mips Files specific to MIPS CPUs
162 - mpc5xx Files specific to Freescale MPC5xx CPUs
163 - mpc5xxx Files specific to Freescale MPC5xxx CPUs
164 - mpc8xx Files specific to Freescale MPC8xx CPUs
165 - mpc8220 Files specific to Freescale MPC8220 CPUs
166 - mpc824x Files specific to Freescale MPC824x CPUs
167 - mpc8260 Files specific to Freescale MPC8260 CPUs
168 - mpc85xx Files specific to Freescale MPC85xx CPUs
169 - nios Files specific to Altera NIOS CPUs
170 - nios2 Files specific to Altera Nios-II CPUs
171 - ppc4xx Files specific to AMCC PowerPC 4xx CPUs
172 - pxa Files specific to Intel XScale PXA CPUs
173 - s3c44b0 Files specific to Samsung S3C44B0 CPUs
174 - sa1100 Files specific to Intel StrongARM SA1100 CPUs
175 - disk Code for disk drive partition handling
176 - doc Documentation (don't expect too much)
177 - drivers Commonly used device drivers
178 - dtt Digital Thermometer and Thermostat drivers
179 - examples Example code for standalone applications, etc.
180 - include Header Files
181 - lib_arm Files generic to ARM architecture
182 - lib_avr32 Files generic to AVR32 architecture
183 - lib_generic Files generic to all architectures
184 - lib_i386 Files generic to i386 architecture
185 - lib_m68k Files generic to m68k architecture
186 - lib_mips Files generic to MIPS architecture
187 - lib_nios Files generic to NIOS architecture
188 - lib_ppc Files generic to PowerPC architecture
189 - libfdt Library files to support flattened device trees
190 - net Networking code
191 - post Power On Self Test
192 - rtc Real Time Clock drivers
193 - tools Tools to build S-Record or U-Boot images, etc.
195 Software Configuration:
196 =======================
198 Configuration is usually done using C preprocessor defines; the
199 rationale behind that is to avoid dead code whenever possible.
201 There are two classes of configuration variables:
203 * Configuration _OPTIONS_:
204 These are selectable by the user and have names beginning with
207 * Configuration _SETTINGS_:
208 These depend on the hardware etc. and should not be meddled with if
209 you don't know what you're doing; they have names beginning with
212 Later we will add a configuration tool - probably similar to or even
213 identical to what's used for the Linux kernel. Right now, we have to
214 do the configuration by hand, which means creating some symbolic
215 links and editing some configuration files. We use the TQM8xxL boards
219 Selection of Processor Architecture and Board Type:
220 ---------------------------------------------------
222 For all supported boards there are ready-to-use default
223 configurations available; just type "make <board_name>_config".
225 Example: For a TQM823L module type:
230 For the Cogent platform, you need to specify the cpu type as well;
231 e.g. "make cogent_mpc8xx_config". And also configure the cogent
232 directory according to the instructions in cogent/README.
235 Configuration Options:
236 ----------------------
238 Configuration depends on the combination of board and CPU type; all
239 such information is kept in a configuration file
240 "include/configs/<board_name>.h".
242 Example: For a TQM823L module, all configuration settings are in
243 "include/configs/TQM823L.h".
246 Many of the options are named exactly as the corresponding Linux
247 kernel configuration options. The intention is to make it easier to
248 build a config tool - later.
251 The following options need to be configured:
253 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
255 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
257 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
258 Define exactly one, e.g. CONFIG_ATSTK1002
260 - CPU Module Type: (if CONFIG_COGENT is defined)
261 Define exactly one of
263 --- FIXME --- not tested yet:
264 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
265 CONFIG_CMA287_23, CONFIG_CMA287_50
267 - Motherboard Type: (if CONFIG_COGENT is defined)
268 Define exactly one of
269 CONFIG_CMA101, CONFIG_CMA102
271 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
272 Define one or more of
275 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
276 Define one or more of
277 CONFIG_LCD_HEARTBEAT - update a character position on
278 the lcd display every second with
281 - Board flavour: (if CONFIG_MPC8260ADS is defined)
284 CFG_8260ADS - original MPC8260ADS
285 CFG_8266ADS - MPC8266ADS
286 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
287 CFG_8272ADS - MPC8272ADS
289 - MPC824X Family Member (if CONFIG_MPC824X is defined)
290 Define exactly one of
291 CONFIG_MPC8240, CONFIG_MPC8245
293 - 8xx CPU Options: (if using an MPC8xx cpu)
294 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
295 get_gclk_freq() cannot work
296 e.g. if there is no 32KHz
297 reference PIT/RTC clock
298 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
301 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
304 CONFIG_8xx_CPUCLK_DEFAULT
305 See doc/README.MPC866
309 Define this to measure the actual CPU clock instead
310 of relying on the correctness of the configured
311 values. Mostly useful for board bringup to make sure
312 the PLL is locked at the intended frequency. Note
313 that this requires a (stable) reference clock (32 kHz
314 RTC clock or CFG_8XX_XIN)
316 - Intel Monahans options:
317 CFG_MONAHANS_RUN_MODE_OSC_RATIO
319 Defines the Monahans run mode to oscillator
320 ratio. Valid values are 8, 16, 24, 31. The core
321 frequency is this value multiplied by 13 MHz.
323 CFG_MONAHANS_TURBO_RUN_MODE_RATIO
325 Defines the Monahans turbo mode to oscillator
326 ratio. Valid values are 1 (default if undefined) and
327 2. The core frequency as calculated above is multiplied
330 - Linux Kernel Interface:
333 U-Boot stores all clock information in Hz
334 internally. For binary compatibility with older Linux
335 kernels (which expect the clocks passed in the
336 bd_info data to be in MHz) the environment variable
337 "clocks_in_mhz" can be defined so that U-Boot
338 converts clock data to MHZ before passing it to the
340 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
341 "clocks_in_mhz=1" is automatically included in the
344 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
346 When transfering memsize parameter to linux, some versions
347 expect it to be in bytes, others in MB.
348 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
350 CONFIG_OF_LIBFDT / CONFIG_OF_FLAT_TREE
352 New kernel versions are expecting firmware settings to be
353 passed using flattened device trees (based on open firmware
357 * New libfdt-based support
358 * Adds the "fdt" command
359 * The bootm command automatically updates the fdt
362 * Deprecated, see CONFIG_OF_LIBFDT
363 * Original ft_build.c-based support
364 * Automatically modifies the dft as part of the bootm command
365 * The environment variable "disable_of", when set,
366 disables this functionality.
368 OF_CPU - The proper name of the cpus node.
369 OF_SOC - The proper name of the soc node.
370 OF_TBCLK - The timebase frequency.
371 OF_STDOUT_PATH - The path to the console device
373 boards with QUICC Engines require OF_QE to set UCC mac addresses
375 CONFIG_OF_BOARD_SETUP
377 Board code has addition modification that it wants to make
378 to the flat device tree before handing it off to the kernel
382 This define fills in the correct boot cpu in the boot
383 param header, the default value is zero if undefined.
388 Define this if you want support for Amba PrimeCell PL010 UARTs.
392 Define this if you want support for Amba PrimeCell PL011 UARTs.
396 If you have Amba PrimeCell PL011 UARTs, set this variable to
397 the clock speed of the UARTs.
401 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
402 define this to a list of base addresses for each (supported)
403 port. See e.g. include/configs/versatile.h
407 Depending on board, define exactly one serial port
408 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
409 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
410 console by defining CONFIG_8xx_CONS_NONE
412 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
413 port routines must be defined elsewhere
414 (i.e. serial_init(), serial_getc(), ...)
417 Enables console device for a color framebuffer. Needs following
418 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
419 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
421 VIDEO_HW_RECTFILL graphic chip supports
424 VIDEO_HW_BITBLT graphic chip supports
425 bit-blit (cf. smiLynxEM)
426 VIDEO_VISIBLE_COLS visible pixel columns
428 VIDEO_VISIBLE_ROWS visible pixel rows
429 VIDEO_PIXEL_SIZE bytes per pixel
430 VIDEO_DATA_FORMAT graphic data format
431 (0-5, cf. cfb_console.c)
432 VIDEO_FB_ADRS framebuffer address
433 VIDEO_KBD_INIT_FCT keyboard int fct
434 (i.e. i8042_kbd_init())
435 VIDEO_TSTC_FCT test char fct
437 VIDEO_GETC_FCT get char fct
439 CONFIG_CONSOLE_CURSOR cursor drawing on/off
440 (requires blink timer
442 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
443 CONFIG_CONSOLE_TIME display time/date info in
445 (requires CONFIG_CMD_DATE)
446 CONFIG_VIDEO_LOGO display Linux logo in
448 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
449 linux_logo.h for logo.
450 Requires CONFIG_VIDEO_LOGO
451 CONFIG_CONSOLE_EXTRA_INFO
452 addional board info beside
455 When CONFIG_CFB_CONSOLE is defined, video console is
456 default i/o. Serial console can be forced with
457 environment 'console=serial'.
459 When CONFIG_SILENT_CONSOLE is defined, all console
460 messages (by U-Boot and Linux!) can be silenced with
461 the "silent" environment variable. See
462 doc/README.silent for more information.
465 CONFIG_BAUDRATE - in bps
466 Select one of the baudrates listed in
467 CFG_BAUDRATE_TABLE, see below.
468 CFG_BRGCLK_PRESCALE, baudrate prescale
470 - Interrupt driven serial port input:
471 CONFIG_SERIAL_SOFTWARE_FIFO
474 Use an interrupt handler for receiving data on the
475 serial port. It also enables using hardware handshake
476 (RTS/CTS) and UART's built-in FIFO. Set the number of
477 bytes the interrupt driven input buffer should have.
479 Leave undefined to disable this feature, including
480 disable the buffer and hardware handshake.
482 - Console UART Number:
486 If defined internal UART1 (and not UART0) is used
487 as default U-Boot console.
489 - Boot Delay: CONFIG_BOOTDELAY - in seconds
490 Delay before automatically booting the default image;
491 set to -1 to disable autoboot.
493 See doc/README.autoboot for these options that
494 work with CONFIG_BOOTDELAY. None are required.
495 CONFIG_BOOT_RETRY_TIME
496 CONFIG_BOOT_RETRY_MIN
497 CONFIG_AUTOBOOT_KEYED
498 CONFIG_AUTOBOOT_PROMPT
499 CONFIG_AUTOBOOT_DELAY_STR
500 CONFIG_AUTOBOOT_STOP_STR
501 CONFIG_AUTOBOOT_DELAY_STR2
502 CONFIG_AUTOBOOT_STOP_STR2
503 CONFIG_ZERO_BOOTDELAY_CHECK
504 CONFIG_RESET_TO_RETRY
508 Only needed when CONFIG_BOOTDELAY is enabled;
509 define a command string that is automatically executed
510 when no character is read on the console interface
511 within "Boot Delay" after reset.
514 This can be used to pass arguments to the bootm
515 command. The value of CONFIG_BOOTARGS goes into the
516 environment value "bootargs".
518 CONFIG_RAMBOOT and CONFIG_NFSBOOT
519 The value of these goes into the environment as
520 "ramboot" and "nfsboot" respectively, and can be used
521 as a convenience, when switching between booting from
527 When this option is #defined, the existence of the
528 environment variable "preboot" will be checked
529 immediately before starting the CONFIG_BOOTDELAY
530 countdown and/or running the auto-boot command resp.
531 entering interactive mode.
533 This feature is especially useful when "preboot" is
534 automatically generated or modified. For an example
535 see the LWMON board specific code: here "preboot" is
536 modified when the user holds down a certain
537 combination of keys on the (special) keyboard when
540 - Serial Download Echo Mode:
542 If defined to 1, all characters received during a
543 serial download (using the "loads" command) are
544 echoed back. This might be needed by some terminal
545 emulations (like "cu"), but may as well just take
546 time on others. This setting #define's the initial
547 value of the "loads_echo" environment variable.
549 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
551 Select one of the baudrates listed in
552 CFG_BAUDRATE_TABLE, see below.
555 Monitor commands can be included or excluded
556 from the build by using the #include files
557 "config_cmd_all.h" and #undef'ing unwanted
558 commands, or using "config_cmd_default.h"
559 and augmenting with additional #define's
562 The default command configuration includes all commands
563 except those marked below with a "*".
565 CONFIG_CMD_ASKENV * ask for env variable
566 CONFIG_CMD_AUTOSCRIPT Autoscript Support
567 CONFIG_CMD_BDI bdinfo
568 CONFIG_CMD_BEDBUG * Include BedBug Debugger
569 CONFIG_CMD_BMP * BMP support
570 CONFIG_CMD_BSP * Board specific commands
571 CONFIG_CMD_BOOTD bootd
572 CONFIG_CMD_CACHE * icache, dcache
573 CONFIG_CMD_CONSOLE coninfo
574 CONFIG_CMD_DATE * support for RTC, date/time...
575 CONFIG_CMD_DHCP * DHCP support
576 CONFIG_CMD_DIAG * Diagnostics
577 CONFIG_CMD_DOC * Disk-On-Chip Support
578 CONFIG_CMD_DTT * Digital Therm and Thermostat
579 CONFIG_CMD_ECHO echo arguments
580 CONFIG_CMD_EEPROM * EEPROM read/write support
581 CONFIG_CMD_ELF * bootelf, bootvx
582 CONFIG_CMD_ENV saveenv
583 CONFIG_CMD_FDC * Floppy Disk Support
584 CONFIG_CMD_FAT * FAT partition support
585 CONFIG_CMD_FDOS * Dos diskette Support
586 CONFIG_CMD_FLASH flinfo, erase, protect
587 CONFIG_CMD_FPGA FPGA device initialization support
588 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
589 CONFIG_CMD_I2C * I2C serial bus support
590 CONFIG_CMD_IDE * IDE harddisk support
591 CONFIG_CMD_IMI iminfo
592 CONFIG_CMD_IMLS List all found images
593 CONFIG_CMD_IMMAP * IMMR dump support
594 CONFIG_CMD_IRQ * irqinfo
595 CONFIG_CMD_ITEST Integer/string test of 2 values
596 CONFIG_CMD_JFFS2 * JFFS2 Support
597 CONFIG_CMD_KGDB * kgdb
598 CONFIG_CMD_LOADB loadb
599 CONFIG_CMD_LOADS loads
600 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
602 CONFIG_CMD_MISC Misc functions like sleep etc
603 CONFIG_CMD_MMC * MMC memory mapped support
604 CONFIG_CMD_MII * MII utility commands
605 CONFIG_CMD_NAND * NAND support
606 CONFIG_CMD_NET bootp, tftpboot, rarpboot
607 CONFIG_CMD_PCI * pciinfo
608 CONFIG_CMD_PCMCIA * PCMCIA support
609 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
611 CONFIG_CMD_PORTIO * Port I/O
612 CONFIG_CMD_REGINFO * Register dump
613 CONFIG_CMD_RUN run command in env variable
614 CONFIG_CMD_SAVES * save S record dump
615 CONFIG_CMD_SCSI * SCSI Support
616 CONFIG_CMD_SDRAM * print SDRAM configuration information
617 (requires CONFIG_CMD_I2C)
618 CONFIG_CMD_SETGETDCR Support for DCR Register access
620 CONFIG_CMD_SPI * SPI serial bus support
621 CONFIG_CMD_USB * USB support
622 CONFIG_CMD_VFD * VFD support (TRAB)
623 CONFIG_CMD_BSP * Board SPecific functions
624 CONFIG_CMD_CDP * Cisco Discover Protocol support
625 CONFIG_CMD_FSL * Microblaze FSL support
628 EXAMPLE: If you want all functions except of network
629 support you can write:
631 #include "config_cmd_all.h"
632 #undef CONFIG_CMD_NET
635 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
637 Note: Don't enable the "icache" and "dcache" commands
638 (configuration option CONFIG_CMD_CACHE) unless you know
639 what you (and your U-Boot users) are doing. Data
640 cache cannot be enabled on systems like the 8xx or
641 8260 (where accesses to the IMMR region must be
642 uncached), and it cannot be disabled on all other
643 systems where we (mis-) use the data cache to hold an
644 initial stack and some data.
647 XXX - this list needs to get updated!
651 If this variable is defined, it enables watchdog
652 support. There must be support in the platform specific
653 code for a watchdog. For the 8xx and 8260 CPUs, the
654 SIU Watchdog feature is enabled in the SYPCR
658 CONFIG_VERSION_VARIABLE
659 If this variable is defined, an environment variable
660 named "ver" is created by U-Boot showing the U-Boot
661 version as printed by the "version" command.
662 This variable is readonly.
666 When CONFIG_CMD_DATE is selected, the type of the RTC
667 has to be selected, too. Define exactly one of the
670 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
671 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
672 CONFIG_RTC_MC146818 - use MC146818 RTC
673 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
674 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
675 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
676 CONFIG_RTC_DS164x - use Dallas DS164x RTC
677 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
678 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
679 CFG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
681 Note that if the RTC uses I2C, then the I2C interface
682 must also be configured. See I2C Support, below.
686 When CONFIG_TIMESTAMP is selected, the timestamp
687 (date and time) of an image is printed by image
688 commands like bootm or iminfo. This option is
689 automatically enabled when you select CONFIG_CMD_DATE .
692 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
693 and/or CONFIG_ISO_PARTITION
695 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
696 CONFIG_CMD_SCSI) you must configure support for at
697 least one partition type as well.
700 CONFIG_IDE_RESET_ROUTINE - this is defined in several
701 board configurations files but used nowhere!
703 CONFIG_IDE_RESET - is this is defined, IDE Reset will
704 be performed by calling the function
705 ide_set_reset(int reset)
706 which has to be defined in a board specific file
711 Set this to enable ATAPI support.
716 Set this to enable support for disks larger than 137GB
717 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL
718 Whithout these , LBA48 support uses 32bit variables and will 'only'
719 support disks up to 2.1TB.
722 When enabled, makes the IDE subsystem use 64bit sector addresses.
726 At the moment only there is only support for the
727 SYM53C8XX SCSI controller; define
728 CONFIG_SCSI_SYM53C8XX to enable it.
730 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
731 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
732 CFG_SCSI_MAX_LUN] can be adjusted to define the
733 maximum numbers of LUNs, SCSI ID's and target
735 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
737 - NETWORK Support (PCI):
739 Support for Intel 8254x gigabit chips.
741 CONFIG_E1000_FALLBACK_MAC
742 default MAC for empty eeprom after production.
745 Support for Intel 82557/82559/82559ER chips.
746 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
747 write routine for first time initialisation.
750 Support for Digital 2114x chips.
751 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
752 modem chip initialisation (KS8761/QS6611).
755 Support for National dp83815 chips.
758 Support for National dp8382[01] gigabit chips.
760 - NETWORK Support (other):
762 CONFIG_DRIVER_LAN91C96
763 Support for SMSC's LAN91C96 chips.
766 Define this to hold the physical address
767 of the LAN91C96's I/O space
769 CONFIG_LAN91C96_USE_32_BIT
770 Define this to enable 32 bit addressing
772 CONFIG_DRIVER_SMC91111
773 Support for SMSC's LAN91C111 chip
776 Define this to hold the physical address
777 of the device (I/O space)
779 CONFIG_SMC_USE_32_BIT
780 Define this if data bus is 32 bits
782 CONFIG_SMC_USE_IOFUNCS
783 Define this to use i/o functions instead of macros
784 (some hardware wont work with macros)
787 At the moment only the UHCI host controller is
788 supported (PIP405, MIP405, MPC5200); define
789 CONFIG_USB_UHCI to enable it.
790 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
791 and define CONFIG_USB_STORAGE to enable the USB
794 Supported are USB Keyboards and USB Floppy drives
796 MPC5200 USB requires additional defines:
798 for 528 MHz Clock: 0x0001bbbb
800 for differential drivers: 0x00001000
801 for single ended drivers: 0x00005000
803 May be defined to allow interrupt polling
804 instead of using asynchronous interrupts
807 Define the below if you wish to use the USB console.
808 Once firmware is rebuilt from a serial console issue the
809 command "setenv stdin usbtty; setenv stdout usbtty" and
810 attach your usb cable. The Unix command "dmesg" should print
811 it has found a new device. The environment variable usbtty
812 can be set to gserial or cdc_acm to enable your device to
813 appear to a USB host as a Linux gserial device or a
814 Common Device Class Abstract Control Model serial device.
815 If you select usbtty = gserial you should be able to enumerate
817 # modprobe usbserial vendor=0xVendorID product=0xProductID
818 else if using cdc_acm, simply setting the environment
819 variable usbtty to be cdc_acm should suffice. The following
820 might be defined in YourBoardName.h
823 Define this to build a UDC device
826 Define this to have a tty type of device available to
827 talk to the UDC device
829 CFG_CONSOLE_IS_IN_ENV
830 Define this if you want stdin, stdout &/or stderr to
834 CFG_USB_EXTC_CLK 0xBLAH
835 Derive USB clock from external clock "blah"
836 - CFG_USB_EXTC_CLK 0x02
838 CFG_USB_BRG_CLK 0xBLAH
839 Derive USB clock from brgclk
840 - CFG_USB_BRG_CLK 0x04
842 If you have a USB-IF assigned VendorID then you may wish to
843 define your own vendor specific values either in BoardName.h
844 or directly in usbd_vendor_info.h. If you don't define
845 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
846 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
847 should pretend to be a Linux device to it's target host.
849 CONFIG_USBD_MANUFACTURER
850 Define this string as the name of your company for
851 - CONFIG_USBD_MANUFACTURER "my company"
853 CONFIG_USBD_PRODUCT_NAME
854 Define this string as the name of your product
855 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
858 Define this as your assigned Vendor ID from the USB
859 Implementors Forum. This *must* be a genuine Vendor ID
860 to avoid polluting the USB namespace.
861 - CONFIG_USBD_VENDORID 0xFFFF
863 CONFIG_USBD_PRODUCTID
864 Define this as the unique Product ID
866 - CONFIG_USBD_PRODUCTID 0xFFFF
870 The MMC controller on the Intel PXA is supported. To
871 enable this define CONFIG_MMC. The MMC can be
872 accessed from the boot prompt by mapping the device
873 to physical memory similar to flash. Command line is
874 enabled with CONFIG_CMD_MMC. The MMC driver also works with
875 the FAT fs. This is enabled with CONFIG_CMD_FAT.
877 - Journaling Flash filesystem support:
878 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
879 CONFIG_JFFS2_NAND_DEV
880 Define these for a default partition on a NAND device
882 CFG_JFFS2_FIRST_SECTOR,
883 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS
884 Define these for a default partition on a NOR device
887 Define this to create an own partition. You have to provide a
888 function struct part_info* jffs2_part_info(int part_num)
890 If you define only one JFFS2 partition you may also want to
891 #define CFG_JFFS_SINGLE_PART 1
892 to disable the command chpart. This is the default when you
893 have not defined a custom partition
898 Define this to enable standard (PC-Style) keyboard
902 Standard PC keyboard driver with US (is default) and
903 GERMAN key layout (switch via environment 'keymap=de') support.
904 Export function i8042_kbd_init, i8042_tstc and i8042_getc
905 for cfb_console. Supports cursor blinking.
910 Define this to enable video support (for output to
915 Enable Chips & Technologies 69000 Video chip
917 CONFIG_VIDEO_SMI_LYNXEM
918 Enable Silicon Motion SMI 712/710/810 Video chip. The
919 video output is selected via environment 'videoout'
920 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
923 For the CT69000 and SMI_LYNXEM drivers, videomode is
924 selected via environment 'videomode'. Two diferent ways
926 - "videomode=num" 'num' is a standard LiLo mode numbers.
927 Following standard modes are supported (* is default):
929 Colors 640x480 800x600 1024x768 1152x864 1280x1024
930 -------------+---------------------------------------------
931 8 bits | 0x301* 0x303 0x305 0x161 0x307
932 15 bits | 0x310 0x313 0x316 0x162 0x319
933 16 bits | 0x311 0x314 0x317 0x163 0x31A
934 24 bits | 0x312 0x315 0x318 ? 0x31B
935 -------------+---------------------------------------------
936 (i.e. setenv videomode 317; saveenv; reset;)
938 - "videomode=bootargs" all the video parameters are parsed
939 from the bootargs. (See drivers/video/videomodes.c)
942 CONFIG_VIDEO_SED13806
943 Enable Epson SED13806 driver. This driver supports 8bpp
944 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
945 or CONFIG_VIDEO_SED13806_16BPP
950 Define this to enable a custom keyboard support.
951 This simply calls drv_keyboard_init() which must be
952 defined in your board-specific files.
953 The only board using this so far is RBC823.
955 - LCD Support: CONFIG_LCD
957 Define this to enable LCD support (for output to LCD
958 display); also select one of the supported displays
959 by defining one of these:
961 CONFIG_NEC_NL6448AC33:
963 NEC NL6448AC33-18. Active, color, single scan.
965 CONFIG_NEC_NL6448BC20
967 NEC NL6448BC20-08. 6.5", 640x480.
968 Active, color, single scan.
970 CONFIG_NEC_NL6448BC33_54
972 NEC NL6448BC33-54. 10.4", 640x480.
973 Active, color, single scan.
977 Sharp 320x240. Active, color, single scan.
978 It isn't 16x9, and I am not sure what it is.
980 CONFIG_SHARP_LQ64D341
982 Sharp LQ64D341 display, 640x480.
983 Active, color, single scan.
987 HLD1045 display, 640x480.
988 Active, color, single scan.
992 Optrex CBL50840-2 NF-FW 99 22 M5
994 Hitachi LMG6912RPFC-00T
998 320x240. Black & white.
1000 Normally display is black on white background; define
1001 CFG_WHITE_ON_BLACK to get it inverted.
1003 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1005 If this option is set, the environment is checked for
1006 a variable "splashimage". If found, the usual display
1007 of logo, copyright and system information on the LCD
1008 is suppressed and the BMP image at the address
1009 specified in "splashimage" is loaded instead. The
1010 console is redirected to the "nulldev", too. This
1011 allows for a "silent" boot where a splash screen is
1012 loaded very quickly after power-on.
1014 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1016 If this option is set, additionally to standard BMP
1017 images, gzipped BMP images can be displayed via the
1018 splashscreen support or the bmp command.
1020 - Compression support:
1023 If this option is set, support for bzip2 compressed
1024 images is included. If not, only uncompressed and gzip
1025 compressed images are supported.
1027 NOTE: the bzip2 algorithm requires a lot of RAM, so
1028 the malloc area (as defined by CFG_MALLOC_LEN) should
1034 The address of PHY on MII bus.
1036 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1038 The clock frequency of the MII bus
1042 If this option is set, support for speed/duplex
1043 detection of Gigabit PHY is included.
1045 CONFIG_PHY_RESET_DELAY
1047 Some PHY like Intel LXT971A need extra delay after
1048 reset before any MII register access is possible.
1049 For such PHY, set this option to the usec delay
1050 required. (minimum 300usec for LXT971A)
1052 CONFIG_PHY_CMD_DELAY (ppc4xx)
1054 Some PHY like Intel LXT971A need extra delay after
1055 command issued before MII status register can be read
1062 Define a default value for ethernet address to use
1063 for the respective ethernet interface, in case this
1064 is not determined automatically.
1069 Define a default value for the IP address to use for
1070 the default ethernet interface, in case this is not
1071 determined through e.g. bootp.
1073 - Server IP address:
1076 Defines a default value for theIP address of a TFTP
1077 server to contact when using the "tftboot" command.
1079 - Multicast TFTP Mode:
1082 Defines whether you want to support multicast TFTP as per
1083 rfc-2090; for example to work with atftp. Lets lots of targets
1084 tftp down the same boot image concurrently. Note: the ethernet
1085 driver in use must provide a function: mcast() to join/leave a
1088 CONFIG_BOOTP_RANDOM_DELAY
1089 - BOOTP Recovery Mode:
1090 CONFIG_BOOTP_RANDOM_DELAY
1092 If you have many targets in a network that try to
1093 boot using BOOTP, you may want to avoid that all
1094 systems send out BOOTP requests at precisely the same
1095 moment (which would happen for instance at recovery
1096 from a power failure, when all systems will try to
1097 boot, thus flooding the BOOTP server. Defining
1098 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1099 inserted before sending out BOOTP requests. The
1100 following delays are inserted then:
1102 1st BOOTP request: delay 0 ... 1 sec
1103 2nd BOOTP request: delay 0 ... 2 sec
1104 3rd BOOTP request: delay 0 ... 4 sec
1106 BOOTP requests: delay 0 ... 8 sec
1108 - DHCP Advanced Options:
1109 You can fine tune the DHCP functionality by defining
1110 CONFIG_BOOTP_* symbols:
1112 CONFIG_BOOTP_SUBNETMASK
1113 CONFIG_BOOTP_GATEWAY
1114 CONFIG_BOOTP_HOSTNAME
1115 CONFIG_BOOTP_NISDOMAIN
1116 CONFIG_BOOTP_BOOTPATH
1117 CONFIG_BOOTP_BOOTFILESIZE
1120 CONFIG_BOOTP_SEND_HOSTNAME
1121 CONFIG_BOOTP_NTPSERVER
1122 CONFIG_BOOTP_TIMEOFFSET
1123 CONFIG_BOOTP_VENDOREX
1125 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1126 environment variable, not the BOOTP server.
1128 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1129 serverip from a DHCP server, it is possible that more
1130 than one DNS serverip is offered to the client.
1131 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1132 serverip will be stored in the additional environment
1133 variable "dnsip2". The first DNS serverip is always
1134 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1137 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1138 to do a dynamic update of a DNS server. To do this, they
1139 need the hostname of the DHCP requester.
1140 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1141 of the "hostname" environment variable is passed as
1142 option 12 to the DHCP server.
1144 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1146 A 32bit value in microseconds for a delay between
1147 receiving a "DHCP Offer" and sending the "DHCP Request".
1148 This fixes a problem with certain DHCP servers that don't
1149 respond 100% of the time to a "DHCP request". E.g. On an
1150 AT91RM9200 processor running at 180MHz, this delay needed
1151 to be *at least* 15,000 usec before a Windows Server 2003
1152 DHCP server would reply 100% of the time. I recommend at
1153 least 50,000 usec to be safe. The alternative is to hope
1154 that one of the retries will be successful but note that
1155 the DHCP timeout and retry process takes a longer than
1159 CONFIG_CDP_DEVICE_ID
1161 The device id used in CDP trigger frames.
1163 CONFIG_CDP_DEVICE_ID_PREFIX
1165 A two character string which is prefixed to the MAC address
1170 A printf format string which contains the ascii name of
1171 the port. Normally is set to "eth%d" which sets
1172 eth0 for the first ethernet, eth1 for the second etc.
1174 CONFIG_CDP_CAPABILITIES
1176 A 32bit integer which indicates the device capabilities;
1177 0x00000010 for a normal host which does not forwards.
1181 An ascii string containing the version of the software.
1185 An ascii string containing the name of the platform.
1189 A 32bit integer sent on the trigger.
1191 CONFIG_CDP_POWER_CONSUMPTION
1193 A 16bit integer containing the power consumption of the
1194 device in .1 of milliwatts.
1196 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1198 A byte containing the id of the VLAN.
1200 - Status LED: CONFIG_STATUS_LED
1202 Several configurations allow to display the current
1203 status using a LED. For instance, the LED will blink
1204 fast while running U-Boot code, stop blinking as
1205 soon as a reply to a BOOTP request was received, and
1206 start blinking slow once the Linux kernel is running
1207 (supported by a status LED driver in the Linux
1208 kernel). Defining CONFIG_STATUS_LED enables this
1211 - CAN Support: CONFIG_CAN_DRIVER
1213 Defining CONFIG_CAN_DRIVER enables CAN driver support
1214 on those systems that support this (optional)
1215 feature, like the TQM8xxL modules.
1217 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1219 These enable I2C serial bus commands. Defining either of
1220 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1221 include the appropriate I2C driver for the selected cpu.
1223 This will allow you to use i2c commands at the u-boot
1224 command line (as long as you set CONFIG_CMD_I2C in
1225 CONFIG_COMMANDS) and communicate with i2c based realtime
1226 clock chips. See common/cmd_i2c.c for a description of the
1227 command line interface.
1229 CONFIG_I2C_CMD_TREE is a recommended option that places
1230 all I2C commands under a single 'i2c' root command. The
1231 older 'imm', 'imd', 'iprobe' etc. commands are considered
1232 deprecated and may disappear in the future.
1234 CONFIG_HARD_I2C selects a hardware I2C controller.
1236 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1237 bit-banging) driver instead of CPM or similar hardware
1240 There are several other quantities that must also be
1241 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1243 In both cases you will need to define CFG_I2C_SPEED
1244 to be the frequency (in Hz) at which you wish your i2c bus
1245 to run and CFG_I2C_SLAVE to be the address of this node (ie
1246 the cpu's i2c node address).
1248 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1249 sets the cpu up as a master node and so its address should
1250 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1251 p.16-473). So, set CFG_I2C_SLAVE to 0.
1253 That's all that's required for CONFIG_HARD_I2C.
1255 If you use the software i2c interface (CONFIG_SOFT_I2C)
1256 then the following macros need to be defined (examples are
1257 from include/configs/lwmon.h):
1261 (Optional). Any commands necessary to enable the I2C
1262 controller or configure ports.
1264 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1268 (Only for MPC8260 CPU). The I/O port to use (the code
1269 assumes both bits are on the same port). Valid values
1270 are 0..3 for ports A..D.
1274 The code necessary to make the I2C data line active
1275 (driven). If the data line is open collector, this
1278 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1282 The code necessary to make the I2C data line tri-stated
1283 (inactive). If the data line is open collector, this
1286 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1290 Code that returns TRUE if the I2C data line is high,
1293 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1297 If <bit> is TRUE, sets the I2C data line high. If it
1298 is FALSE, it clears it (low).
1300 eg: #define I2C_SDA(bit) \
1301 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1302 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1306 If <bit> is TRUE, sets the I2C clock line high. If it
1307 is FALSE, it clears it (low).
1309 eg: #define I2C_SCL(bit) \
1310 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1311 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1315 This delay is invoked four times per clock cycle so this
1316 controls the rate of data transfer. The data rate thus
1317 is 1 / (I2C_DELAY * 4). Often defined to be something
1320 #define I2C_DELAY udelay(2)
1324 When a board is reset during an i2c bus transfer
1325 chips might think that the current transfer is still
1326 in progress. On some boards it is possible to access
1327 the i2c SCLK line directly, either by using the
1328 processor pin as a GPIO or by having a second pin
1329 connected to the bus. If this option is defined a
1330 custom i2c_init_board() routine in boards/xxx/board.c
1331 is run early in the boot sequence.
1333 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1335 This option enables configuration of bi_iic_fast[] flags
1336 in u-boot bd_info structure based on u-boot environment
1337 variable "i2cfast". (see also i2cfast)
1339 CONFIG_I2C_MULTI_BUS
1341 This option allows the use of multiple I2C buses, each of which
1342 must have a controller. At any point in time, only one bus is
1343 active. To switch to a different bus, use the 'i2c dev' command.
1344 Note that bus numbering is zero-based.
1348 This option specifies a list of I2C devices that will be skipped
1349 when the 'i2c probe' command is issued (or 'iprobe' using the legacy
1350 command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device
1351 pairs. Otherwise, specify a 1D array of device addresses
1354 #undef CONFIG_I2C_MULTI_BUS
1355 #define CFG_I2C_NOPROBES {0x50,0x68}
1357 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1359 #define CONFIG_I2C_MULTI_BUS
1360 #define CFG_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1362 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1366 If defined, then this indicates the I2C bus number for DDR SPD.
1367 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1371 If defined, then this indicates the I2C bus number for the RTC.
1372 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1376 If defined, then this indicates the I2C bus number for the DTT.
1377 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1381 Define this option if you want to use Freescale's I2C driver in
1382 drivers/i2c/fsl_i2c.c.
1385 - SPI Support: CONFIG_SPI
1387 Enables SPI driver (so far only tested with
1388 SPI EEPROM, also an instance works with Crystal A/D and
1389 D/As on the SACSng board)
1393 Enables extended (16-bit) SPI EEPROM addressing.
1394 (symmetrical to CONFIG_I2C_X)
1398 Enables a software (bit-bang) SPI driver rather than
1399 using hardware support. This is a general purpose
1400 driver that only requires three general I/O port pins
1401 (two outputs, one input) to function. If this is
1402 defined, the board configuration must define several
1403 SPI configuration items (port pins to use, etc). For
1404 an example, see include/configs/sacsng.h.
1408 Enables a hardware SPI driver for general-purpose reads
1409 and writes. As with CONFIG_SOFT_SPI, the board configuration
1410 must define a list of chip-select function pointers.
1411 Currently supported on some MPC8xxx processors. For an
1412 example, see include/configs/mpc8349emds.h.
1414 - FPGA Support: CONFIG_FPGA
1416 Enables FPGA subsystem.
1418 CONFIG_FPGA_<vendor>
1420 Enables support for specific chip vendors.
1423 CONFIG_FPGA_<family>
1425 Enables support for FPGA family.
1426 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1430 Specify the number of FPGA devices to support.
1432 CFG_FPGA_PROG_FEEDBACK
1434 Enable printing of hash marks during FPGA configuration.
1438 Enable checks on FPGA configuration interface busy
1439 status by the configuration function. This option
1440 will require a board or device specific function to
1445 If defined, a function that provides delays in the FPGA
1446 configuration driver.
1448 CFG_FPGA_CHECK_CTRLC
1449 Allow Control-C to interrupt FPGA configuration
1451 CFG_FPGA_CHECK_ERROR
1453 Check for configuration errors during FPGA bitfile
1454 loading. For example, abort during Virtex II
1455 configuration if the INIT_B line goes low (which
1456 indicated a CRC error).
1460 Maximum time to wait for the INIT_B line to deassert
1461 after PROB_B has been deasserted during a Virtex II
1462 FPGA configuration sequence. The default time is 500
1467 Maximum time to wait for BUSY to deassert during
1468 Virtex II FPGA configuration. The default is 5 mS.
1470 CFG_FPGA_WAIT_CONFIG
1472 Time to wait after FPGA configuration. The default is
1475 - Configuration Management:
1478 If defined, this string will be added to the U-Boot
1479 version information (U_BOOT_VERSION)
1481 - Vendor Parameter Protection:
1483 U-Boot considers the values of the environment
1484 variables "serial#" (Board Serial Number) and
1485 "ethaddr" (Ethernet Address) to be parameters that
1486 are set once by the board vendor / manufacturer, and
1487 protects these variables from casual modification by
1488 the user. Once set, these variables are read-only,
1489 and write or delete attempts are rejected. You can
1490 change this behviour:
1492 If CONFIG_ENV_OVERWRITE is #defined in your config
1493 file, the write protection for vendor parameters is
1494 completely disabled. Anybody can change or delete
1497 Alternatively, if you #define _both_ CONFIG_ETHADDR
1498 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1499 ethernet address is installed in the environment,
1500 which can be changed exactly ONCE by the user. [The
1501 serial# is unaffected by this, i. e. it remains
1507 Define this variable to enable the reservation of
1508 "protected RAM", i. e. RAM which is not overwritten
1509 by U-Boot. Define CONFIG_PRAM to hold the number of
1510 kB you want to reserve for pRAM. You can overwrite
1511 this default value by defining an environment
1512 variable "pram" to the number of kB you want to
1513 reserve. Note that the board info structure will
1514 still show the full amount of RAM. If pRAM is
1515 reserved, a new environment variable "mem" will
1516 automatically be defined to hold the amount of
1517 remaining RAM in a form that can be passed as boot
1518 argument to Linux, for instance like that:
1520 setenv bootargs ... mem=\${mem}
1523 This way you can tell Linux not to use this memory,
1524 either, which results in a memory region that will
1525 not be affected by reboots.
1527 *WARNING* If your board configuration uses automatic
1528 detection of the RAM size, you must make sure that
1529 this memory test is non-destructive. So far, the
1530 following board configurations are known to be
1533 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1534 HERMES, IP860, RPXlite, LWMON, LANTEC,
1535 PCU_E, FLAGADM, TQM8260
1540 Define this variable to stop the system in case of a
1541 fatal error, so that you have to reset it manually.
1542 This is probably NOT a good idea for an embedded
1543 system where you want to system to reboot
1544 automatically as fast as possible, but it may be
1545 useful during development since you can try to debug
1546 the conditions that lead to the situation.
1548 CONFIG_NET_RETRY_COUNT
1550 This variable defines the number of retries for
1551 network operations like ARP, RARP, TFTP, or BOOTP
1552 before giving up the operation. If not defined, a
1553 default value of 5 is used.
1555 - Command Interpreter:
1556 CONFIG_AUTO_COMPLETE
1558 Enable auto completion of commands using TAB.
1560 Note that this feature has NOT been implemented yet
1561 for the "hush" shell.
1566 Define this variable to enable the "hush" shell (from
1567 Busybox) as command line interpreter, thus enabling
1568 powerful command line syntax like
1569 if...then...else...fi conditionals or `&&' and '||'
1570 constructs ("shell scripts").
1572 If undefined, you get the old, much simpler behaviour
1573 with a somewhat smaller memory footprint.
1578 This defines the secondary prompt string, which is
1579 printed when the command interpreter needs more input
1580 to complete a command. Usually "> ".
1584 In the current implementation, the local variables
1585 space and global environment variables space are
1586 separated. Local variables are those you define by
1587 simply typing `name=value'. To access a local
1588 variable later on, you have write `$name' or
1589 `${name}'; to execute the contents of a variable
1590 directly type `$name' at the command prompt.
1592 Global environment variables are those you use
1593 setenv/printenv to work with. To run a command stored
1594 in such a variable, you need to use the run command,
1595 and you must not use the '$' sign to access them.
1597 To store commands and special characters in a
1598 variable, please use double quotation marks
1599 surrounding the whole text of the variable, instead
1600 of the backslashes before semicolons and special
1603 - Commandline Editing and History:
1604 CONFIG_CMDLINE_EDITING
1606 Enable editiong and History functions for interactive
1607 commandline input operations
1609 - Default Environment:
1610 CONFIG_EXTRA_ENV_SETTINGS
1612 Define this to contain any number of null terminated
1613 strings (variable = value pairs) that will be part of
1614 the default environment compiled into the boot image.
1616 For example, place something like this in your
1617 board's config file:
1619 #define CONFIG_EXTRA_ENV_SETTINGS \
1623 Warning: This method is based on knowledge about the
1624 internal format how the environment is stored by the
1625 U-Boot code. This is NOT an official, exported
1626 interface! Although it is unlikely that this format
1627 will change soon, there is no guarantee either.
1628 You better know what you are doing here.
1630 Note: overly (ab)use of the default environment is
1631 discouraged. Make sure to check other ways to preset
1632 the environment like the autoscript function or the
1635 - DataFlash Support:
1636 CONFIG_HAS_DATAFLASH
1638 Defining this option enables DataFlash features and
1639 allows to read/write in Dataflash via the standard
1642 - SystemACE Support:
1645 Adding this option adds support for Xilinx SystemACE
1646 chips attached via some sort of local bus. The address
1647 of the chip must alsh be defined in the
1648 CFG_SYSTEMACE_BASE macro. For example:
1650 #define CONFIG_SYSTEMACE
1651 #define CFG_SYSTEMACE_BASE 0xf0000000
1653 When SystemACE support is added, the "ace" device type
1654 becomes available to the fat commands, i.e. fatls.
1656 - TFTP Fixed UDP Port:
1659 If this is defined, the environment variable tftpsrcp
1660 is used to supply the TFTP UDP source port value.
1661 If tftpsrcp isn't defined, the normal pseudo-random port
1662 number generator is used.
1664 Also, the environment variable tftpdstp is used to supply
1665 the TFTP UDP destination port value. If tftpdstp isn't
1666 defined, the normal port 69 is used.
1668 The purpose for tftpsrcp is to allow a TFTP server to
1669 blindly start the TFTP transfer using the pre-configured
1670 target IP address and UDP port. This has the effect of
1671 "punching through" the (Windows XP) firewall, allowing
1672 the remainder of the TFTP transfer to proceed normally.
1673 A better solution is to properly configure the firewall,
1674 but sometimes that is not allowed.
1676 - Show boot progress:
1677 CONFIG_SHOW_BOOT_PROGRESS
1679 Defining this option allows to add some board-
1680 specific code (calling a user-provided function
1681 "show_boot_progress(int)") that enables you to show
1682 the system's boot progress on some display (for
1683 example, some LED's) on your board. At the moment,
1684 the following checkpoints are implemented:
1686 Legacy uImage format:
1689 1 common/cmd_bootm.c before attempting to boot an image
1690 -1 common/cmd_bootm.c Image header has bad magic number
1691 2 common/cmd_bootm.c Image header has correct magic number
1692 -2 common/cmd_bootm.c Image header has bad checksum
1693 3 common/cmd_bootm.c Image header has correct checksum
1694 -3 common/cmd_bootm.c Image data has bad checksum
1695 4 common/cmd_bootm.c Image data has correct checksum
1696 -4 common/cmd_bootm.c Image is for unsupported architecture
1697 5 common/cmd_bootm.c Architecture check OK
1698 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
1699 6 common/cmd_bootm.c Image Type check OK
1700 -6 common/cmd_bootm.c gunzip uncompression error
1701 -7 common/cmd_bootm.c Unimplemented compression type
1702 7 common/cmd_bootm.c Uncompression OK
1703 8 common/cmd_bootm.c No uncompress/copy overwrite error
1704 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1706 9 common/image.c Start initial ramdisk verification
1707 -10 common/image.c Ramdisk header has bad magic number
1708 -11 common/image.c Ramdisk header has bad checksum
1709 10 common/image.c Ramdisk header is OK
1710 -12 common/image.c Ramdisk data has bad checksum
1711 11 common/image.c Ramdisk data has correct checksum
1712 12 common/image.c Ramdisk verification complete, start loading
1713 -13 common/image.c Wrong Image Type (not PPC Linux Ramdisk)
1714 13 common/image.c Start multifile image verification
1715 14 common/image.c No initial ramdisk, no multifile, continue.
1717 15 lib_<arch>/bootm.c All preparation done, transferring control to OS
1719 -30 lib_ppc/board.c Fatal error, hang the system
1720 -31 post/post.c POST test failed, detected by post_output_backlog()
1721 -32 post/post.c POST test failed, detected by post_run_single()
1723 34 common/cmd_doc.c before loading a Image from a DOC device
1724 -35 common/cmd_doc.c Bad usage of "doc" command
1725 35 common/cmd_doc.c correct usage of "doc" command
1726 -36 common/cmd_doc.c No boot device
1727 36 common/cmd_doc.c correct boot device
1728 -37 common/cmd_doc.c Unknown Chip ID on boot device
1729 37 common/cmd_doc.c correct chip ID found, device available
1730 -38 common/cmd_doc.c Read Error on boot device
1731 38 common/cmd_doc.c reading Image header from DOC device OK
1732 -39 common/cmd_doc.c Image header has bad magic number
1733 39 common/cmd_doc.c Image header has correct magic number
1734 -40 common/cmd_doc.c Error reading Image from DOC device
1735 40 common/cmd_doc.c Image header has correct magic number
1736 41 common/cmd_ide.c before loading a Image from a IDE device
1737 -42 common/cmd_ide.c Bad usage of "ide" command
1738 42 common/cmd_ide.c correct usage of "ide" command
1739 -43 common/cmd_ide.c No boot device
1740 43 common/cmd_ide.c boot device found
1741 -44 common/cmd_ide.c Device not available
1742 44 common/cmd_ide.c Device available
1743 -45 common/cmd_ide.c wrong partition selected
1744 45 common/cmd_ide.c partition selected
1745 -46 common/cmd_ide.c Unknown partition table
1746 46 common/cmd_ide.c valid partition table found
1747 -47 common/cmd_ide.c Invalid partition type
1748 47 common/cmd_ide.c correct partition type
1749 -48 common/cmd_ide.c Error reading Image Header on boot device
1750 48 common/cmd_ide.c reading Image Header from IDE device OK
1751 -49 common/cmd_ide.c Image header has bad magic number
1752 49 common/cmd_ide.c Image header has correct magic number
1753 -50 common/cmd_ide.c Image header has bad checksum
1754 50 common/cmd_ide.c Image header has correct checksum
1755 -51 common/cmd_ide.c Error reading Image from IDE device
1756 51 common/cmd_ide.c reading Image from IDE device OK
1757 52 common/cmd_nand.c before loading a Image from a NAND device
1758 -53 common/cmd_nand.c Bad usage of "nand" command
1759 53 common/cmd_nand.c correct usage of "nand" command
1760 -54 common/cmd_nand.c No boot device
1761 54 common/cmd_nand.c boot device found
1762 -55 common/cmd_nand.c Unknown Chip ID on boot device
1763 55 common/cmd_nand.c correct chip ID found, device available
1764 -56 common/cmd_nand.c Error reading Image Header on boot device
1765 56 common/cmd_nand.c reading Image Header from NAND device OK
1766 -57 common/cmd_nand.c Image header has bad magic number
1767 57 common/cmd_nand.c Image header has correct magic number
1768 -58 common/cmd_nand.c Error reading Image from NAND device
1769 58 common/cmd_nand.c reading Image from NAND device OK
1771 -60 common/env_common.c Environment has a bad CRC, using default
1773 64 net/eth.c starting with Ethernetconfiguration.
1774 -64 net/eth.c no Ethernet found.
1775 65 net/eth.c Ethernet found.
1777 -80 common/cmd_net.c usage wrong
1778 80 common/cmd_net.c before calling NetLoop()
1779 -81 common/cmd_net.c some error in NetLoop() occured
1780 81 common/cmd_net.c NetLoop() back without error
1781 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
1782 82 common/cmd_net.c trying automatic boot
1783 83 common/cmd_net.c running autoscript
1784 -83 common/cmd_net.c some error in automatic boot or autoscript
1785 84 common/cmd_net.c end without errors
1790 100 common/cmd_bootm.c Kernel FIT Image has correct format
1791 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
1792 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
1793 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
1794 102 common/cmd_bootm.c Kernel unit name specified
1795 -103 common/cmd_bootm.c Can't get kernel subimage node offset
1796 103 common/cmd_bootm.c Found configuration node
1797 104 common/cmd_bootm.c Got kernel subimage node offset
1798 -104 common/cmd_bootm.c Kernel subimage hash verification failed
1799 105 common/cmd_bootm.c Kernel subimage hash verification OK
1800 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
1801 106 common/cmd_bootm.c Architecture check OK
1802 -106 common/cmd_bootm.c Kernel subimage has wrong typea
1803 107 common/cmd_bootm.c Kernel subimge type OK
1804 -107 common/cmd_bootm.c Can't get kernel subimage data/size
1805 108 common/cmd_bootm.c Got kernel subimage data/size
1806 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
1807 -109 common/cmd_bootm.c Can't get kernel subimage type
1808 -110 common/cmd_bootm.c Can't get kernel subimage comp
1809 -111 common/cmd_bootm.c Can't get kernel subimage os
1810 -112 common/cmd_bootm.c Can't get kernel subimage load address
1811 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
1813 120 common/image.c Start initial ramdisk verification
1814 -120 common/image.c Ramdisk FIT image has incorrect format
1815 121 common/image.c Ramdisk FIT image has correct format
1816 122 common/image.c No Ramdisk subimage unit name, using configuration
1817 -122 common/image.c Can't get configuration for ramdisk subimage
1818 123 common/image.c Ramdisk unit name specified
1819 -124 common/image.c Can't get ramdisk subimage node offset
1820 125 common/image.c Got ramdisk subimage node offset
1821 -125 common/image.c Ramdisk subimage hash verification failed
1822 126 common/image.c Ramdisk subimage hash verification OK
1823 -126 common/image.c Ramdisk subimage for unsupported architecture
1824 127 common/image.c Architecture check OK
1825 -127 common/image.c Can't get ramdisk subimage data/size
1826 128 common/image.c Got ramdisk subimage data/size
1827 129 common/image.c Can't get ramdisk load address
1828 -129 common/image.c Got ramdisk load address
1830 -130 common/cmd_doc.c Icorrect FIT image format
1831 131 common/cmd_doc.c FIT image format OK
1833 -140 common/cmd_ide.c Icorrect FIT image format
1834 141 common/cmd_ide.c FIT image format OK
1836 -150 common/cmd_nand.c Icorrect FIT image format
1837 151 common/cmd_nand.c FIT image format OK
1843 [so far only for SMDK2400 and TRAB boards]
1845 - Modem support endable:
1846 CONFIG_MODEM_SUPPORT
1848 - RTS/CTS Flow control enable:
1851 - Modem debug support:
1852 CONFIG_MODEM_SUPPORT_DEBUG
1854 Enables debugging stuff (char screen[1024], dbg())
1855 for modem support. Useful only with BDI2000.
1857 - Interrupt support (PPC):
1859 There are common interrupt_init() and timer_interrupt()
1860 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
1861 for cpu specific initialization. interrupt_init_cpu()
1862 should set decrementer_count to appropriate value. If
1863 cpu resets decrementer automatically after interrupt
1864 (ppc4xx) it should set decrementer_count to zero.
1865 timer_interrupt() calls timer_interrupt_cpu() for cpu
1866 specific handling. If board has watchdog / status_led
1867 / other_activity_monitor it works automatically from
1868 general timer_interrupt().
1872 In the target system modem support is enabled when a
1873 specific key (key combination) is pressed during
1874 power-on. Otherwise U-Boot will boot normally
1875 (autoboot). The key_pressed() fuction is called from
1876 board_init(). Currently key_pressed() is a dummy
1877 function, returning 1 and thus enabling modem
1880 If there are no modem init strings in the
1881 environment, U-Boot proceed to autoboot; the
1882 previous output (banner, info printfs) will be
1885 See also: doc/README.Modem
1888 Configuration Settings:
1889 -----------------------
1891 - CFG_LONGHELP: Defined when you want long help messages included;
1892 undefine this when you're short of memory.
1894 - CFG_PROMPT: This is what U-Boot prints on the console to
1895 prompt for user input.
1897 - CFG_CBSIZE: Buffer size for input from the Console
1899 - CFG_PBSIZE: Buffer size for Console output
1901 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1903 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1904 the application (usually a Linux kernel) when it is
1907 - CFG_BAUDRATE_TABLE:
1908 List of legal baudrate settings for this board.
1910 - CFG_CONSOLE_INFO_QUIET
1911 Suppress display of console information at boot.
1913 - CFG_CONSOLE_IS_IN_ENV
1914 If the board specific function
1915 extern int overwrite_console (void);
1916 returns 1, the stdin, stderr and stdout are switched to the
1917 serial port, else the settings in the environment are used.
1919 - CFG_CONSOLE_OVERWRITE_ROUTINE
1920 Enable the call to overwrite_console().
1922 - CFG_CONSOLE_ENV_OVERWRITE
1923 Enable overwrite of previous console environment settings.
1925 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1926 Begin and End addresses of the area used by the
1930 Enable an alternate, more extensive memory test.
1932 - CFG_MEMTEST_SCRATCH:
1933 Scratch address used by the alternate memory test
1934 You only need to set this if address zero isn't writeable
1936 - CFG_MEM_TOP_HIDE (PPC only):
1937 If CFG_MEM_TOP_HIDE is defined in the board config header,
1938 this specified memory area will get subtracted from the top
1939 (end) of ram and won't get "touched" at all by U-Boot. By
1940 fixing up gd->ram_size the Linux kernel should gets passed
1941 the now "corrected" memory size and won't touch it either.
1942 This should work for arch/ppc and arch/powerpc. Only Linux
1943 board ports in arch/powerpc with bootwrapper support that
1944 recalculate the memory size from the SDRAM controller setup
1945 will have to get fixed in Linux additionally.
1947 This option can be used as a workaround for the 440EPx/GRx
1948 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
1951 WARNING: Please make sure that this value is a multiple of
1952 the Linux page size (normally 4k). If this is not the case,
1953 then the end address of the Linux memory will be located at a
1954 non page size aligned address and this could cause major
1957 - CFG_TFTP_LOADADDR:
1958 Default load address for network file downloads
1960 - CFG_LOADS_BAUD_CHANGE:
1961 Enable temporary baudrate change while serial download
1964 Physical start address of SDRAM. _Must_ be 0 here.
1967 Physical start address of Motherboard I/O (if using a
1971 Physical start address of Flash memory.
1974 Physical start address of boot monitor code (set by
1975 make config files to be same as the text base address
1976 (TEXT_BASE) used when linking) - same as
1977 CFG_FLASH_BASE when booting from flash.
1980 Size of memory reserved for monitor code, used to
1981 determine _at_compile_time_ (!) if the environment is
1982 embedded within the U-Boot image, or in a separate
1986 Size of DRAM reserved for malloc() use.
1989 Normally compressed uImages are limited to an
1990 uncompressed size of 8 MBytes. If this is not enough,
1991 you can define CFG_BOOTM_LEN in your board config file
1992 to adjust this setting to your needs.
1995 Maximum size of memory mapped by the startup code of
1996 the Linux kernel; all data that must be processed by
1997 the Linux kernel (bd_info, boot arguments, eventually
1998 initrd image) must be put below this limit.
2000 - CFG_MAX_FLASH_BANKS:
2001 Max number of Flash memory banks
2003 - CFG_MAX_FLASH_SECT:
2004 Max number of sectors on a Flash chip
2006 - CFG_FLASH_ERASE_TOUT:
2007 Timeout for Flash erase operations (in ms)
2009 - CFG_FLASH_WRITE_TOUT:
2010 Timeout for Flash write operations (in ms)
2012 - CFG_FLASH_LOCK_TOUT
2013 Timeout for Flash set sector lock bit operation (in ms)
2015 - CFG_FLASH_UNLOCK_TOUT
2016 Timeout for Flash clear lock bits operation (in ms)
2018 - CFG_FLASH_PROTECTION
2019 If defined, hardware flash sectors protection is used
2020 instead of U-Boot software protection.
2022 - CFG_DIRECT_FLASH_TFTP:
2024 Enable TFTP transfers directly to flash memory;
2025 without this option such a download has to be
2026 performed in two steps: (1) download to RAM, and (2)
2027 copy from RAM to flash.
2029 The two-step approach is usually more reliable, since
2030 you can check if the download worked before you erase
2031 the flash, but in some situations (when sytem RAM is
2032 too limited to allow for a tempory copy of the
2033 downloaded image) this option may be very useful.
2036 Define if the flash driver uses extra elements in the
2037 common flash structure for storing flash geometry.
2039 - CFG_FLASH_CFI_DRIVER
2040 This option also enables the building of the cfi_flash driver
2041 in the drivers directory
2043 - CFG_FLASH_USE_BUFFER_WRITE
2044 Use buffered writes to flash.
2046 - CONFIG_FLASH_SPANSION_S29WS_N
2047 s29ws-n MirrorBit flash has non-standard addresses for buffered
2050 - CFG_FLASH_QUIET_TEST
2051 If this option is defined, the common CFI flash doesn't
2052 print it's warning upon not recognized FLASH banks. This
2053 is useful, if some of the configured banks are only
2054 optionally available.
2056 - CONFIG_FLASH_SHOW_PROGRESS
2057 If defined (must be an integer), print out countdown
2058 digits and dots. Recommended value: 45 (9..1) for 80
2059 column displays, 15 (3..1) for 40 column displays.
2061 - CFG_RX_ETH_BUFFER:
2062 Defines the number of ethernet receive buffers. On some
2063 ethernet controllers it is recommended to set this value
2064 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2065 buffers can be full shortly after enabling the interface
2066 on high ethernet traffic.
2067 Defaults to 4 if not defined.
2069 The following definitions that deal with the placement and management
2070 of environment data (variable area); in general, we support the
2071 following configurations:
2073 - CFG_ENV_IS_IN_FLASH:
2075 Define this if the environment is in flash memory.
2077 a) The environment occupies one whole flash sector, which is
2078 "embedded" in the text segment with the U-Boot code. This
2079 happens usually with "bottom boot sector" or "top boot
2080 sector" type flash chips, which have several smaller
2081 sectors at the start or the end. For instance, such a
2082 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2083 such a case you would place the environment in one of the
2084 4 kB sectors - with U-Boot code before and after it. With
2085 "top boot sector" type flash chips, you would put the
2086 environment in one of the last sectors, leaving a gap
2087 between U-Boot and the environment.
2091 Offset of environment data (variable area) to the
2092 beginning of flash memory; for instance, with bottom boot
2093 type flash chips the second sector can be used: the offset
2094 for this sector is given here.
2096 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
2100 This is just another way to specify the start address of
2101 the flash sector containing the environment (instead of
2104 - CFG_ENV_SECT_SIZE:
2106 Size of the sector containing the environment.
2109 b) Sometimes flash chips have few, equal sized, BIG sectors.
2110 In such a case you don't want to spend a whole sector for
2115 If you use this in combination with CFG_ENV_IS_IN_FLASH
2116 and CFG_ENV_SECT_SIZE, you can specify to use only a part
2117 of this flash sector for the environment. This saves
2118 memory for the RAM copy of the environment.
2120 It may also save flash memory if you decide to use this
2121 when your environment is "embedded" within U-Boot code,
2122 since then the remainder of the flash sector could be used
2123 for U-Boot code. It should be pointed out that this is
2124 STRONGLY DISCOURAGED from a robustness point of view:
2125 updating the environment in flash makes it always
2126 necessary to erase the WHOLE sector. If something goes
2127 wrong before the contents has been restored from a copy in
2128 RAM, your target system will be dead.
2130 - CFG_ENV_ADDR_REDUND
2133 These settings describe a second storage area used to hold
2134 a redundand copy of the environment data, so that there is
2135 a valid backup copy in case there is a power failure during
2136 a "saveenv" operation.
2138 BE CAREFUL! Any changes to the flash layout, and some changes to the
2139 source code will make it necessary to adapt <board>/u-boot.lds*
2143 - CFG_ENV_IS_IN_NVRAM:
2145 Define this if you have some non-volatile memory device
2146 (NVRAM, battery buffered SRAM) which you want to use for the
2152 These two #defines are used to determin the memory area you
2153 want to use for environment. It is assumed that this memory
2154 can just be read and written to, without any special
2157 BE CAREFUL! The first access to the environment happens quite early
2158 in U-Boot initalization (when we try to get the setting of for the
2159 console baudrate). You *MUST* have mappend your NVRAM area then, or
2162 Please note that even with NVRAM we still use a copy of the
2163 environment in RAM: we could work on NVRAM directly, but we want to
2164 keep settings there always unmodified except somebody uses "saveenv"
2165 to save the current settings.
2168 - CFG_ENV_IS_IN_EEPROM:
2170 Use this if you have an EEPROM or similar serial access
2171 device and a driver for it.
2176 These two #defines specify the offset and size of the
2177 environment area within the total memory of your EEPROM.
2179 - CFG_I2C_EEPROM_ADDR:
2180 If defined, specified the chip address of the EEPROM device.
2181 The default address is zero.
2183 - CFG_EEPROM_PAGE_WRITE_BITS:
2184 If defined, the number of bits used to address bytes in a
2185 single page in the EEPROM device. A 64 byte page, for example
2186 would require six bits.
2188 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
2189 If defined, the number of milliseconds to delay between
2190 page writes. The default is zero milliseconds.
2192 - CFG_I2C_EEPROM_ADDR_LEN:
2193 The length in bytes of the EEPROM memory array address. Note
2194 that this is NOT the chip address length!
2196 - CFG_I2C_EEPROM_ADDR_OVERFLOW:
2197 EEPROM chips that implement "address overflow" are ones
2198 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2199 address and the extra bits end up in the "chip address" bit
2200 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2203 Note that we consider the length of the address field to
2204 still be one byte because the extra address bits are hidden
2205 in the chip address.
2208 The size in bytes of the EEPROM device.
2211 - CFG_ENV_IS_IN_DATAFLASH:
2213 Define this if you have a DataFlash memory device which you
2214 want to use for the environment.
2220 These three #defines specify the offset and size of the
2221 environment area within the total memory of your DataFlash placed
2222 at the specified address.
2224 - CFG_ENV_IS_IN_NAND:
2226 Define this if you have a NAND device which you want to use
2227 for the environment.
2232 These two #defines specify the offset and size of the environment
2233 area within the first NAND device.
2235 - CFG_ENV_OFFSET_REDUND
2237 This setting describes a second storage area of CFG_ENV_SIZE
2238 size used to hold a redundant copy of the environment data,
2239 so that there is a valid backup copy in case there is a
2240 power failure during a "saveenv" operation.
2242 Note: CFG_ENV_OFFSET and CFG_ENV_OFFSET_REDUND must be aligned
2243 to a block boundary, and CFG_ENV_SIZE must be a multiple of
2244 the NAND devices block size.
2246 - CFG_SPI_INIT_OFFSET
2248 Defines offset to the initial SPI buffer area in DPRAM. The
2249 area is used at an early stage (ROM part) if the environment
2250 is configured to reside in the SPI EEPROM: We need a 520 byte
2251 scratch DPRAM area. It is used between the two initialization
2252 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2253 to be a good choice since it makes it far enough from the
2254 start of the data area as well as from the stack pointer.
2256 Please note that the environment is read-only until the monitor
2257 has been relocated to RAM and a RAM copy of the environment has been
2258 created; also, when using EEPROM you will have to use getenv_r()
2259 until then to read environment variables.
2261 The environment is protected by a CRC32 checksum. Before the monitor
2262 is relocated into RAM, as a result of a bad CRC you will be working
2263 with the compiled-in default environment - *silently*!!! [This is
2264 necessary, because the first environment variable we need is the
2265 "baudrate" setting for the console - if we have a bad CRC, we don't
2266 have any device yet where we could complain.]
2268 Note: once the monitor has been relocated, then it will complain if
2269 the default environment is used; a new CRC is computed as soon as you
2270 use the "saveenv" command to store a valid environment.
2272 - CFG_FAULT_ECHO_LINK_DOWN:
2273 Echo the inverted Ethernet link state to the fault LED.
2275 Note: If this option is active, then CFG_FAULT_MII_ADDR
2276 also needs to be defined.
2278 - CFG_FAULT_MII_ADDR:
2279 MII address of the PHY to check for the Ethernet link state.
2281 - CFG_64BIT_VSPRINTF:
2282 Makes vsprintf (and all *printf functions) support printing
2283 of 64bit values by using the L quantifier
2285 - CFG_64BIT_STRTOUL:
2286 Adds simple_strtoull that returns a 64bit value
2288 Low Level (hardware related) configuration options:
2289 ---------------------------------------------------
2291 - CFG_CACHELINE_SIZE:
2292 Cache Line Size of the CPU.
2295 Default address of the IMMR after system reset.
2297 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2298 and RPXsuper) to be able to adjust the position of
2299 the IMMR register after a reset.
2301 - Floppy Disk Support:
2302 CFG_FDC_DRIVE_NUMBER
2304 the default drive number (default value 0)
2308 defines the spacing between fdc chipset registers
2313 defines the offset of register from address. It
2314 depends on which part of the data bus is connected to
2315 the fdc chipset. (default value 0)
2317 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
2318 CFG_FDC_DRIVE_NUMBER are undefined, they take their
2321 if CFG_FDC_HW_INIT is defined, then the function
2322 fdc_hw_init() is called at the beginning of the FDC
2323 setup. fdc_hw_init() must be provided by the board
2324 source code. It is used to make hardware dependant
2327 - CFG_IMMR: Physical address of the Internal Memory.
2328 DO NOT CHANGE unless you know exactly what you're
2329 doing! (11-4) [MPC8xx/82xx systems only]
2331 - CFG_INIT_RAM_ADDR:
2333 Start address of memory area that can be used for
2334 initial data and stack; please note that this must be
2335 writable memory that is working WITHOUT special
2336 initialization, i. e. you CANNOT use normal RAM which
2337 will become available only after programming the
2338 memory controller and running certain initialization
2341 U-Boot uses the following memory types:
2342 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2343 - MPC824X: data cache
2344 - PPC4xx: data cache
2346 - CFG_GBL_DATA_OFFSET:
2348 Offset of the initial data structure in the memory
2349 area defined by CFG_INIT_RAM_ADDR. Usually
2350 CFG_GBL_DATA_OFFSET is chosen such that the initial
2351 data is located at the end of the available space
2352 (sometimes written as (CFG_INIT_RAM_END -
2353 CFG_INIT_DATA_SIZE), and the initial stack is just
2354 below that area (growing from (CFG_INIT_RAM_ADDR +
2355 CFG_GBL_DATA_OFFSET) downward.
2358 On the MPC824X (or other systems that use the data
2359 cache for initial memory) the address chosen for
2360 CFG_INIT_RAM_ADDR is basically arbitrary - it must
2361 point to an otherwise UNUSED address space between
2362 the top of RAM and the start of the PCI space.
2364 - CFG_SIUMCR: SIU Module Configuration (11-6)
2366 - CFG_SYPCR: System Protection Control (11-9)
2368 - CFG_TBSCR: Time Base Status and Control (11-26)
2370 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
2372 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2374 - CFG_SCCR: System Clock and reset Control Register (15-27)
2376 - CFG_OR_TIMING_SDRAM:
2380 periodic timer for refresh
2382 - CFG_DER: Debug Event Register (37-47)
2384 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
2385 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
2386 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
2388 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2390 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2391 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
2392 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
2393 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2395 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
2396 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
2397 Machine Mode Register and Memory Periodic Timer
2398 Prescaler definitions (SDRAM timing)
2400 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
2401 enable I2C microcode relocation patch (MPC8xx);
2402 define relocation offset in DPRAM [DSP2]
2404 - CFG_SMC_UCODE_PATCH, CFG_SMC_DPMEM_OFFSET [0x1FC0]:
2405 enable SMC microcode relocation patch (MPC8xx);
2406 define relocation offset in DPRAM [SMC1]
2408 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
2409 enable SPI microcode relocation patch (MPC8xx);
2410 define relocation offset in DPRAM [SCC4]
2413 Use OSCM clock mode on MBX8xx board. Be careful,
2414 wrong setting might damage your board. Read
2415 doc/README.MBX before setting this variable!
2417 - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2418 Offset of the bootmode word in DPRAM used by post
2419 (Power On Self Tests). This definition overrides
2420 #define'd default value in commproc.h resp.
2423 - CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
2424 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
2425 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
2426 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
2427 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2428 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
2429 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
2430 CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
2431 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2434 Get DDR timing information from an I2C EEPROM. Common
2435 with pluggable memory modules such as SODIMMs
2438 I2C address of the SPD EEPROM
2441 If SPD EEPROM is on an I2C bus other than the first
2442 one, specify here. Note that the value must resolve
2443 to something your driver can deal with.
2445 - CFG_83XX_DDR_USES_CS0
2446 Only for 83xx systems. If specified, then DDR should
2447 be configured using CS0 and CS1 instead of CS2 and CS3.
2449 - CFG_83XX_DDR_USES_CS0
2450 Only for 83xx systems. If specified, then DDR should
2451 be configured using CS0 and CS1 instead of CS2 and CS3.
2453 - CONFIG_ETHER_ON_FEC[12]
2454 Define to enable FEC[12] on a 8xx series processor.
2456 - CONFIG_FEC[12]_PHY
2457 Define to the hardcoded PHY address which corresponds
2458 to the given FEC; i. e.
2459 #define CONFIG_FEC1_PHY 4
2460 means that the PHY with address 4 is connected to FEC1
2462 When set to -1, means to probe for first available.
2464 - CONFIG_FEC[12]_PHY_NORXERR
2465 The PHY does not have a RXERR line (RMII only).
2466 (so program the FEC to ignore it).
2469 Enable RMII mode for all FECs.
2470 Note that this is a global option, we can't
2471 have one FEC in standard MII mode and another in RMII mode.
2473 - CONFIG_CRC32_VERIFY
2474 Add a verify option to the crc32 command.
2477 => crc32 -v <address> <count> <crc32>
2479 Where address/count indicate a memory area
2480 and crc32 is the correct crc32 which the
2484 Add the "loopw" memory command. This only takes effect if
2485 the memory commands are activated globally (CONFIG_CMD_MEM).
2488 Add the "mdc" and "mwc" memory commands. These are cyclic
2493 This command will print 4 bytes (10,11,12,13) each 500 ms.
2495 => mwc.l 100 12345678 10
2496 This command will write 12345678 to address 100 all 10 ms.
2498 This only takes effect if the memory commands are activated
2499 globally (CONFIG_CMD_MEM).
2501 - CONFIG_SKIP_LOWLEVEL_INIT
2502 - CONFIG_SKIP_RELOCATE_UBOOT
2504 [ARM only] If these variables are defined, then
2505 certain low level initializations (like setting up
2506 the memory controller) are omitted and/or U-Boot does
2507 not relocate itself into RAM.
2508 Normally these variables MUST NOT be defined. The
2509 only exception is when U-Boot is loaded (to RAM) by
2510 some other boot loader or by a debugger which
2511 performs these intializations itself.
2514 Building the Software:
2515 ======================
2517 Building U-Boot has been tested in several native build environments
2518 and in many different cross environments. Of course we cannot support
2519 all possibly existing versions of cross development tools in all
2520 (potentially obsolete) versions. In case of tool chain problems we
2521 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2522 which is extensively used to build and test U-Boot.
2524 If you are not using a native environment, it is assumed that you
2525 have GNU cross compiling tools available in your path. In this case,
2526 you must set the environment variable CROSS_COMPILE in your shell.
2527 Note that no changes to the Makefile or any other source files are
2528 necessary. For example using the ELDK on a 4xx CPU, please enter:
2530 $ CROSS_COMPILE=ppc_4xx-
2531 $ export CROSS_COMPILE
2533 U-Boot is intended to be simple to build. After installing the
2534 sources you must configure U-Boot for one specific board type. This
2539 where "NAME_config" is the name of one of the existing configu-
2540 rations; see the main Makefile for supported names.
2542 Note: for some board special configuration names may exist; check if
2543 additional information is available from the board vendor; for
2544 instance, the TQM823L systems are available without (standard)
2545 or with LCD support. You can select such additional "features"
2546 when chosing the configuration, i. e.
2549 - will configure for a plain TQM823L, i. e. no LCD support
2551 make TQM823L_LCD_config
2552 - will configure for a TQM823L with U-Boot console on LCD
2557 Finally, type "make all", and you should get some working U-Boot
2558 images ready for download to / installation on your system:
2560 - "u-boot.bin" is a raw binary image
2561 - "u-boot" is an image in ELF binary format
2562 - "u-boot.srec" is in Motorola S-Record format
2564 By default the build is performed locally and the objects are saved
2565 in the source directory. One of the two methods can be used to change
2566 this behavior and build U-Boot to some external directory:
2568 1. Add O= to the make command line invocations:
2570 make O=/tmp/build distclean
2571 make O=/tmp/build NAME_config
2572 make O=/tmp/build all
2574 2. Set environment variable BUILD_DIR to point to the desired location:
2576 export BUILD_DIR=/tmp/build
2581 Note that the command line "O=" setting overrides the BUILD_DIR environment
2585 Please be aware that the Makefiles assume you are using GNU make, so
2586 for instance on NetBSD you might need to use "gmake" instead of
2590 If the system board that you have is not listed, then you will need
2591 to port U-Boot to your hardware platform. To do this, follow these
2594 1. Add a new configuration option for your board to the toplevel
2595 "Makefile" and to the "MAKEALL" script, using the existing
2596 entries as examples. Note that here and at many other places
2597 boards and other names are listed in alphabetical sort order. Please
2599 2. Create a new directory to hold your board specific code. Add any
2600 files you need. In your board directory, you will need at least
2601 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2602 3. Create a new configuration file "include/configs/<board>.h" for
2604 3. If you're porting U-Boot to a new CPU, then also create a new
2605 directory to hold your CPU specific code. Add any files you need.
2606 4. Run "make <board>_config" with your new name.
2607 5. Type "make", and you should get a working "u-boot.srec" file
2608 to be installed on your target system.
2609 6. Debug and solve any problems that might arise.
2610 [Of course, this last step is much harder than it sounds.]
2613 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2614 ==============================================================
2616 If you have modified U-Boot sources (for instance added a new board
2617 or support for new devices, a new CPU, etc.) you are expected to
2618 provide feedback to the other developers. The feedback normally takes
2619 the form of a "patch", i. e. a context diff against a certain (latest
2620 official or latest in the git repository) version of U-Boot sources.
2622 But before you submit such a patch, please verify that your modifi-
2623 cation did not break existing code. At least make sure that *ALL* of
2624 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2625 just run the "MAKEALL" script, which will configure and build U-Boot
2626 for ALL supported system. Be warned, this will take a while. You can
2627 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2628 environment variable to the script, i. e. to use the ELDK cross tools
2631 CROSS_COMPILE=ppc_8xx- MAKEALL
2633 or to build on a native PowerPC system you can type
2635 CROSS_COMPILE=' ' MAKEALL
2637 When using the MAKEALL script, the default behaviour is to build
2638 U-Boot in the source directory. This location can be changed by
2639 setting the BUILD_DIR environment variable. Also, for each target
2640 built, the MAKEALL script saves two log files (<target>.ERR and
2641 <target>.MAKEALL) in the <source dir>/LOG directory. This default
2642 location can be changed by setting the MAKEALL_LOGDIR environment
2643 variable. For example:
2645 export BUILD_DIR=/tmp/build
2646 export MAKEALL_LOGDIR=/tmp/log
2647 CROSS_COMPILE=ppc_8xx- MAKEALL
2649 With the above settings build objects are saved in the /tmp/build,
2650 log files are saved in the /tmp/log and the source tree remains clean
2651 during the whole build process.
2654 See also "U-Boot Porting Guide" below.
2657 Monitor Commands - Overview:
2658 ============================
2660 go - start application at address 'addr'
2661 run - run commands in an environment variable
2662 bootm - boot application image from memory
2663 bootp - boot image via network using BootP/TFTP protocol
2664 tftpboot- boot image via network using TFTP protocol
2665 and env variables "ipaddr" and "serverip"
2666 (and eventually "gatewayip")
2667 rarpboot- boot image via network using RARP/TFTP protocol
2668 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2669 loads - load S-Record file over serial line
2670 loadb - load binary file over serial line (kermit mode)
2672 mm - memory modify (auto-incrementing)
2673 nm - memory modify (constant address)
2674 mw - memory write (fill)
2676 cmp - memory compare
2677 crc32 - checksum calculation
2678 imd - i2c memory display
2679 imm - i2c memory modify (auto-incrementing)
2680 inm - i2c memory modify (constant address)
2681 imw - i2c memory write (fill)
2682 icrc32 - i2c checksum calculation
2683 iprobe - probe to discover valid I2C chip addresses
2684 iloop - infinite loop on address range
2685 isdram - print SDRAM configuration information
2686 sspi - SPI utility commands
2687 base - print or set address offset
2688 printenv- print environment variables
2689 setenv - set environment variables
2690 saveenv - save environment variables to persistent storage
2691 protect - enable or disable FLASH write protection
2692 erase - erase FLASH memory
2693 flinfo - print FLASH memory information
2694 bdinfo - print Board Info structure
2695 iminfo - print header information for application image
2696 coninfo - print console devices and informations
2697 ide - IDE sub-system
2698 loop - infinite loop on address range
2699 loopw - infinite write loop on address range
2700 mtest - simple RAM test
2701 icache - enable or disable instruction cache
2702 dcache - enable or disable data cache
2703 reset - Perform RESET of the CPU
2704 echo - echo args to console
2705 version - print monitor version
2706 help - print online help
2707 ? - alias for 'help'
2710 Monitor Commands - Detailed Description:
2711 ========================================
2715 For now: just type "help <command>".
2718 Environment Variables:
2719 ======================
2721 U-Boot supports user configuration using Environment Variables which
2722 can be made persistent by saving to Flash memory.
2724 Environment Variables are set using "setenv", printed using
2725 "printenv", and saved to Flash using "saveenv". Using "setenv"
2726 without a value can be used to delete a variable from the
2727 environment. As long as you don't save the environment you are
2728 working with an in-memory copy. In case the Flash area containing the
2729 environment is erased by accident, a default environment is provided.
2731 Some configuration options can be set using Environment Variables:
2733 baudrate - see CONFIG_BAUDRATE
2735 bootdelay - see CONFIG_BOOTDELAY
2737 bootcmd - see CONFIG_BOOTCOMMAND
2739 bootargs - Boot arguments when booting an RTOS image
2741 bootfile - Name of the image to load with TFTP
2743 autoload - if set to "no" (any string beginning with 'n'),
2744 "bootp" will just load perform a lookup of the
2745 configuration from the BOOTP server, but not try to
2746 load any image using TFTP
2748 autoscript - if set to "yes" commands like "loadb", "loady",
2749 "bootp", "tftpb", "rarpboot" and "nfs" will attempt
2750 to automatically run script images (by internally
2751 calling "autoscript").
2753 autoscript_uname - if script image is in a format (FIT) this
2754 variable is used to get script subimage unit name.
2756 autostart - if set to "yes", an image loaded using the "bootp",
2757 "rarpboot", "tftpboot" or "diskboot" commands will
2758 be automatically started (by internally calling
2761 If set to "no", a standalone image passed to the
2762 "bootm" command will be copied to the load address
2763 (and eventually uncompressed), but NOT be started.
2764 This can be used to load and uncompress arbitrary
2767 i2cfast - (PPC405GP|PPC405EP only)
2768 if set to 'y' configures Linux I2C driver for fast
2769 mode (400kHZ). This environment variable is used in
2770 initialization code. So, for changes to be effective
2771 it must be saved and board must be reset.
2773 initrd_high - restrict positioning of initrd images:
2774 If this variable is not set, initrd images will be
2775 copied to the highest possible address in RAM; this
2776 is usually what you want since it allows for
2777 maximum initrd size. If for some reason you want to
2778 make sure that the initrd image is loaded below the
2779 CFG_BOOTMAPSZ limit, you can set this environment
2780 variable to a value of "no" or "off" or "0".
2781 Alternatively, you can set it to a maximum upper
2782 address to use (U-Boot will still check that it
2783 does not overwrite the U-Boot stack and data).
2785 For instance, when you have a system with 16 MB
2786 RAM, and want to reserve 4 MB from use by Linux,
2787 you can do this by adding "mem=12M" to the value of
2788 the "bootargs" variable. However, now you must make
2789 sure that the initrd image is placed in the first
2790 12 MB as well - this can be done with
2792 setenv initrd_high 00c00000
2794 If you set initrd_high to 0xFFFFFFFF, this is an
2795 indication to U-Boot that all addresses are legal
2796 for the Linux kernel, including addresses in flash
2797 memory. In this case U-Boot will NOT COPY the
2798 ramdisk at all. This may be useful to reduce the
2799 boot time on your system, but requires that this
2800 feature is supported by your Linux kernel.
2802 ipaddr - IP address; needed for tftpboot command
2804 loadaddr - Default load address for commands like "bootp",
2805 "rarpboot", "tftpboot", "loadb" or "diskboot"
2807 loads_echo - see CONFIG_LOADS_ECHO
2809 serverip - TFTP server IP address; needed for tftpboot command
2811 bootretry - see CONFIG_BOOT_RETRY_TIME
2813 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
2815 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
2817 ethprime - When CONFIG_NET_MULTI is enabled controls which
2818 interface is used first.
2820 ethact - When CONFIG_NET_MULTI is enabled controls which
2821 interface is currently active. For example you
2822 can do the following
2824 => setenv ethact FEC ETHERNET
2825 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
2826 => setenv ethact SCC ETHERNET
2827 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
2829 ethrotate - When set to "no" U-Boot does not go through all
2830 available network interfaces.
2831 It just stays at the currently selected interface.
2833 netretry - When set to "no" each network operation will
2834 either succeed or fail without retrying.
2835 When set to "once" the network operation will
2836 fail when all the available network interfaces
2837 are tried once without success.
2838 Useful on scripts which control the retry operation
2841 npe_ucode - see CONFIG_IXP4XX_NPE_EXT_UCOD
2842 if set load address for the npe microcode
2844 tftpsrcport - If this is set, the value is used for TFTP's
2847 tftpdstport - If this is set, the value is used for TFTP's UDP
2848 destination port instead of the Well Know Port 69.
2850 vlan - When set to a value < 4095 the traffic over
2851 ethernet is encapsulated/received over 802.1q
2854 The following environment variables may be used and automatically
2855 updated by the network boot commands ("bootp" and "rarpboot"),
2856 depending the information provided by your boot server:
2858 bootfile - see above
2859 dnsip - IP address of your Domain Name Server
2860 dnsip2 - IP address of your secondary Domain Name Server
2861 gatewayip - IP address of the Gateway (Router) to use
2862 hostname - Target hostname
2864 netmask - Subnet Mask
2865 rootpath - Pathname of the root filesystem on the NFS server
2866 serverip - see above
2869 There are two special Environment Variables:
2871 serial# - contains hardware identification information such
2872 as type string and/or serial number
2873 ethaddr - Ethernet address
2875 These variables can be set only once (usually during manufacturing of
2876 the board). U-Boot refuses to delete or overwrite these variables
2877 once they have been set once.
2880 Further special Environment Variables:
2882 ver - Contains the U-Boot version string as printed
2883 with the "version" command. This variable is
2884 readonly (see CONFIG_VERSION_VARIABLE).
2887 Please note that changes to some configuration parameters may take
2888 only effect after the next boot (yes, that's just like Windoze :-).
2891 Command Line Parsing:
2892 =====================
2894 There are two different command line parsers available with U-Boot:
2895 the old "simple" one, and the much more powerful "hush" shell:
2897 Old, simple command line parser:
2898 --------------------------------
2900 - supports environment variables (through setenv / saveenv commands)
2901 - several commands on one line, separated by ';'
2902 - variable substitution using "... ${name} ..." syntax
2903 - special characters ('$', ';') can be escaped by prefixing with '\',
2905 setenv bootcmd bootm \${address}
2906 - You can also escape text by enclosing in single apostrophes, for example:
2907 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2912 - similar to Bourne shell, with control structures like
2913 if...then...else...fi, for...do...done; while...do...done,
2914 until...do...done, ...
2915 - supports environment ("global") variables (through setenv / saveenv
2916 commands) and local shell variables (through standard shell syntax
2917 "name=value"); only environment variables can be used with "run"
2923 (1) If a command line (or an environment variable executed by a "run"
2924 command) contains several commands separated by semicolon, and
2925 one of these commands fails, then the remaining commands will be
2928 (2) If you execute several variables with one call to run (i. e.
2929 calling run with a list af variables as arguments), any failing
2930 command will cause "run" to terminate, i. e. the remaining
2931 variables are not executed.
2933 Note for Redundant Ethernet Interfaces:
2934 =======================================
2936 Some boards come with redundant ethernet interfaces; U-Boot supports
2937 such configurations and is capable of automatic selection of a
2938 "working" interface when needed. MAC assignment works as follows:
2940 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2941 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2942 "eth1addr" (=>eth1), "eth2addr", ...
2944 If the network interface stores some valid MAC address (for instance
2945 in SROM), this is used as default address if there is NO correspon-
2946 ding setting in the environment; if the corresponding environment
2947 variable is set, this overrides the settings in the card; that means:
2949 o If the SROM has a valid MAC address, and there is no address in the
2950 environment, the SROM's address is used.
2952 o If there is no valid address in the SROM, and a definition in the
2953 environment exists, then the value from the environment variable is
2956 o If both the SROM and the environment contain a MAC address, and
2957 both addresses are the same, this MAC address is used.
2959 o If both the SROM and the environment contain a MAC address, and the
2960 addresses differ, the value from the environment is used and a
2963 o If neither SROM nor the environment contain a MAC address, an error
2970 U-Boot is capable of booting (and performing other auxiliary operations on)
2971 images in two formats:
2973 New uImage format (FIT)
2974 -----------------------
2976 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
2977 to Flattened Device Tree). It allows the use of images with multiple
2978 components (several kernels, ramdisks, etc.), with contents protected by
2979 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
2985 Old image format is based on binary files which can be basically anything,
2986 preceded by a special header; see the definitions in include/image.h for
2987 details; basically, the header defines the following image properties:
2989 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2990 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2991 LynxOS, pSOS, QNX, RTEMS, ARTOS;
2992 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
2993 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
2994 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2995 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
2996 * Compression Type (uncompressed, gzip, bzip2)
3002 The header is marked by a special Magic Number, and both the header
3003 and the data portions of the image are secured against corruption by
3010 Although U-Boot should support any OS or standalone application
3011 easily, the main focus has always been on Linux during the design of
3014 U-Boot includes many features that so far have been part of some
3015 special "boot loader" code within the Linux kernel. Also, any
3016 "initrd" images to be used are no longer part of one big Linux image;
3017 instead, kernel and "initrd" are separate images. This implementation
3018 serves several purposes:
3020 - the same features can be used for other OS or standalone
3021 applications (for instance: using compressed images to reduce the
3022 Flash memory footprint)
3024 - it becomes much easier to port new Linux kernel versions because
3025 lots of low-level, hardware dependent stuff are done by U-Boot
3027 - the same Linux kernel image can now be used with different "initrd"
3028 images; of course this also means that different kernel images can
3029 be run with the same "initrd". This makes testing easier (you don't
3030 have to build a new "zImage.initrd" Linux image when you just
3031 change a file in your "initrd"). Also, a field-upgrade of the
3032 software is easier now.
3038 Porting Linux to U-Boot based systems:
3039 ---------------------------------------
3041 U-Boot cannot save you from doing all the necessary modifications to
3042 configure the Linux device drivers for use with your target hardware
3043 (no, we don't intend to provide a full virtual machine interface to
3046 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
3048 Just make sure your machine specific header file (for instance
3049 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3050 Information structure as we define in include/u-boot.h, and make
3051 sure that your definition of IMAP_ADDR uses the same value as your
3052 U-Boot configuration in CFG_IMMR.
3055 Configuring the Linux kernel:
3056 -----------------------------
3058 No specific requirements for U-Boot. Make sure you have some root
3059 device (initial ramdisk, NFS) for your target system.
3062 Building a Linux Image:
3063 -----------------------
3065 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3066 not used. If you use recent kernel source, a new build target
3067 "uImage" will exist which automatically builds an image usable by
3068 U-Boot. Most older kernels also have support for a "pImage" target,
3069 which was introduced for our predecessor project PPCBoot and uses a
3070 100% compatible format.
3079 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3080 encapsulate a compressed Linux kernel image with header information,
3081 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3083 * build a standard "vmlinux" kernel image (in ELF binary format):
3085 * convert the kernel into a raw binary image:
3087 ${CROSS_COMPILE}-objcopy -O binary \
3088 -R .note -R .comment \
3089 -S vmlinux linux.bin
3091 * compress the binary image:
3095 * package compressed binary image for U-Boot:
3097 mkimage -A ppc -O linux -T kernel -C gzip \
3098 -a 0 -e 0 -n "Linux Kernel Image" \
3099 -d linux.bin.gz uImage
3102 The "mkimage" tool can also be used to create ramdisk images for use
3103 with U-Boot, either separated from the Linux kernel image, or
3104 combined into one file. "mkimage" encapsulates the images with a 64
3105 byte header containing information about target architecture,
3106 operating system, image type, compression method, entry points, time
3107 stamp, CRC32 checksums, etc.
3109 "mkimage" can be called in two ways: to verify existing images and
3110 print the header information, or to build new images.
3112 In the first form (with "-l" option) mkimage lists the information
3113 contained in the header of an existing U-Boot image; this includes
3114 checksum verification:
3116 tools/mkimage -l image
3117 -l ==> list image header information
3119 The second form (with "-d" option) is used to build a U-Boot image
3120 from a "data file" which is used as image payload:
3122 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3123 -n name -d data_file image
3124 -A ==> set architecture to 'arch'
3125 -O ==> set operating system to 'os'
3126 -T ==> set image type to 'type'
3127 -C ==> set compression type 'comp'
3128 -a ==> set load address to 'addr' (hex)
3129 -e ==> set entry point to 'ep' (hex)
3130 -n ==> set image name to 'name'
3131 -d ==> use image data from 'datafile'
3133 Right now, all Linux kernels for PowerPC systems use the same load
3134 address (0x00000000), but the entry point address depends on the
3137 - 2.2.x kernels have the entry point at 0x0000000C,
3138 - 2.3.x and later kernels have the entry point at 0x00000000.
3140 So a typical call to build a U-Boot image would read:
3142 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3143 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3144 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
3145 > examples/uImage.TQM850L
3146 Image Name: 2.4.4 kernel for TQM850L
3147 Created: Wed Jul 19 02:34:59 2000
3148 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3149 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3150 Load Address: 0x00000000
3151 Entry Point: 0x00000000
3153 To verify the contents of the image (or check for corruption):
3155 -> tools/mkimage -l examples/uImage.TQM850L
3156 Image Name: 2.4.4 kernel for TQM850L
3157 Created: Wed Jul 19 02:34:59 2000
3158 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3159 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3160 Load Address: 0x00000000
3161 Entry Point: 0x00000000
3163 NOTE: for embedded systems where boot time is critical you can trade
3164 speed for memory and install an UNCOMPRESSED image instead: this
3165 needs more space in Flash, but boots much faster since it does not
3166 need to be uncompressed:
3168 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
3169 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3170 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3171 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
3172 > examples/uImage.TQM850L-uncompressed
3173 Image Name: 2.4.4 kernel for TQM850L
3174 Created: Wed Jul 19 02:34:59 2000
3175 Image Type: PowerPC Linux Kernel Image (uncompressed)
3176 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3177 Load Address: 0x00000000
3178 Entry Point: 0x00000000
3181 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3182 when your kernel is intended to use an initial ramdisk:
3184 -> tools/mkimage -n 'Simple Ramdisk Image' \
3185 > -A ppc -O linux -T ramdisk -C gzip \
3186 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3187 Image Name: Simple Ramdisk Image
3188 Created: Wed Jan 12 14:01:50 2000
3189 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3190 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3191 Load Address: 0x00000000
3192 Entry Point: 0x00000000
3195 Installing a Linux Image:
3196 -------------------------
3198 To downloading a U-Boot image over the serial (console) interface,
3199 you must convert the image to S-Record format:
3201 objcopy -I binary -O srec examples/image examples/image.srec
3203 The 'objcopy' does not understand the information in the U-Boot
3204 image header, so the resulting S-Record file will be relative to
3205 address 0x00000000. To load it to a given address, you need to
3206 specify the target address as 'offset' parameter with the 'loads'
3209 Example: install the image to address 0x40100000 (which on the
3210 TQM8xxL is in the first Flash bank):
3212 => erase 40100000 401FFFFF
3218 ## Ready for S-Record download ...
3219 ~>examples/image.srec
3220 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3222 15989 15990 15991 15992
3223 [file transfer complete]
3225 ## Start Addr = 0x00000000
3228 You can check the success of the download using the 'iminfo' command;
3229 this includes a checksum verification so you can be sure no data
3230 corruption happened:
3234 ## Checking Image at 40100000 ...
3235 Image Name: 2.2.13 for initrd on TQM850L
3236 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3237 Data Size: 335725 Bytes = 327 kB = 0 MB
3238 Load Address: 00000000
3239 Entry Point: 0000000c
3240 Verifying Checksum ... OK
3246 The "bootm" command is used to boot an application that is stored in
3247 memory (RAM or Flash). In case of a Linux kernel image, the contents
3248 of the "bootargs" environment variable is passed to the kernel as
3249 parameters. You can check and modify this variable using the
3250 "printenv" and "setenv" commands:
3253 => printenv bootargs
3254 bootargs=root=/dev/ram
3256 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3258 => printenv bootargs
3259 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3262 ## Booting Linux kernel at 40020000 ...
3263 Image Name: 2.2.13 for NFS on TQM850L
3264 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3265 Data Size: 381681 Bytes = 372 kB = 0 MB
3266 Load Address: 00000000
3267 Entry Point: 0000000c
3268 Verifying Checksum ... OK
3269 Uncompressing Kernel Image ... OK
3270 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
3271 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3272 time_init: decrementer frequency = 187500000/60
3273 Calibrating delay loop... 49.77 BogoMIPS
3274 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3277 If you want to boot a Linux kernel with initial ram disk, you pass
3278 the memory addresses of both the kernel and the initrd image (PPBCOOT
3279 format!) to the "bootm" command:
3281 => imi 40100000 40200000
3283 ## Checking Image at 40100000 ...
3284 Image Name: 2.2.13 for initrd on TQM850L
3285 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3286 Data Size: 335725 Bytes = 327 kB = 0 MB
3287 Load Address: 00000000
3288 Entry Point: 0000000c
3289 Verifying Checksum ... OK
3291 ## Checking Image at 40200000 ...
3292 Image Name: Simple Ramdisk Image
3293 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3294 Data Size: 566530 Bytes = 553 kB = 0 MB
3295 Load Address: 00000000
3296 Entry Point: 00000000
3297 Verifying Checksum ... OK
3299 => bootm 40100000 40200000
3300 ## Booting Linux kernel at 40100000 ...
3301 Image Name: 2.2.13 for initrd on TQM850L
3302 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3303 Data Size: 335725 Bytes = 327 kB = 0 MB
3304 Load Address: 00000000
3305 Entry Point: 0000000c
3306 Verifying Checksum ... OK
3307 Uncompressing Kernel Image ... OK
3308 ## Loading RAMDisk Image at 40200000 ...
3309 Image Name: Simple Ramdisk Image
3310 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3311 Data Size: 566530 Bytes = 553 kB = 0 MB
3312 Load Address: 00000000
3313 Entry Point: 00000000
3314 Verifying Checksum ... OK
3315 Loading Ramdisk ... OK
3316 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
3317 Boot arguments: root=/dev/ram
3318 time_init: decrementer frequency = 187500000/60
3319 Calibrating delay loop... 49.77 BogoMIPS
3321 RAMDISK: Compressed image found at block 0
3322 VFS: Mounted root (ext2 filesystem).
3326 Boot Linux and pass a flat device tree:
3329 First, U-Boot must be compiled with the appropriate defines. See the section
3330 titled "Linux Kernel Interface" above for a more in depth explanation. The
3331 following is an example of how to start a kernel and pass an updated
3337 oft=oftrees/mpc8540ads.dtb
3338 => tftp $oftaddr $oft
3339 Speed: 1000, full duplex
3341 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3342 Filename 'oftrees/mpc8540ads.dtb'.
3343 Load address: 0x300000
3346 Bytes transferred = 4106 (100a hex)
3347 => tftp $loadaddr $bootfile
3348 Speed: 1000, full duplex
3350 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3352 Load address: 0x200000
3353 Loading:############
3355 Bytes transferred = 1029407 (fb51f hex)
3360 => bootm $loadaddr - $oftaddr
3361 ## Booting image at 00200000 ...
3362 Image Name: Linux-2.6.17-dirty
3363 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3364 Data Size: 1029343 Bytes = 1005.2 kB
3365 Load Address: 00000000
3366 Entry Point: 00000000
3367 Verifying Checksum ... OK
3368 Uncompressing Kernel Image ... OK
3369 Booting using flat device tree at 0x300000
3370 Using MPC85xx ADS machine description
3371 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3375 More About U-Boot Image Types:
3376 ------------------------------
3378 U-Boot supports the following image types:
3380 "Standalone Programs" are directly runnable in the environment
3381 provided by U-Boot; it is expected that (if they behave
3382 well) you can continue to work in U-Boot after return from
3383 the Standalone Program.
3384 "OS Kernel Images" are usually images of some Embedded OS which
3385 will take over control completely. Usually these programs
3386 will install their own set of exception handlers, device
3387 drivers, set up the MMU, etc. - this means, that you cannot
3388 expect to re-enter U-Boot except by resetting the CPU.
3389 "RAMDisk Images" are more or less just data blocks, and their
3390 parameters (address, size) are passed to an OS kernel that is
3392 "Multi-File Images" contain several images, typically an OS
3393 (Linux) kernel image and one or more data images like
3394 RAMDisks. This construct is useful for instance when you want
3395 to boot over the network using BOOTP etc., where the boot
3396 server provides just a single image file, but you want to get
3397 for instance an OS kernel and a RAMDisk image.
3399 "Multi-File Images" start with a list of image sizes, each
3400 image size (in bytes) specified by an "uint32_t" in network
3401 byte order. This list is terminated by an "(uint32_t)0".
3402 Immediately after the terminating 0 follow the images, one by
3403 one, all aligned on "uint32_t" boundaries (size rounded up to
3404 a multiple of 4 bytes).
3406 "Firmware Images" are binary images containing firmware (like
3407 U-Boot or FPGA images) which usually will be programmed to
3410 "Script files" are command sequences that will be executed by
3411 U-Boot's command interpreter; this feature is especially
3412 useful when you configure U-Boot to use a real shell (hush)
3413 as command interpreter.
3419 One of the features of U-Boot is that you can dynamically load and
3420 run "standalone" applications, which can use some resources of
3421 U-Boot like console I/O functions or interrupt services.
3423 Two simple examples are included with the sources:
3428 'examples/hello_world.c' contains a small "Hello World" Demo
3429 application; it is automatically compiled when you build U-Boot.
3430 It's configured to run at address 0x00040004, so you can play with it
3434 ## Ready for S-Record download ...
3435 ~>examples/hello_world.srec
3436 1 2 3 4 5 6 7 8 9 10 11 ...
3437 [file transfer complete]
3439 ## Start Addr = 0x00040004
3441 => go 40004 Hello World! This is a test.
3442 ## Starting application at 0x00040004 ...
3453 Hit any key to exit ...
3455 ## Application terminated, rc = 0x0
3457 Another example, which demonstrates how to register a CPM interrupt
3458 handler with the U-Boot code, can be found in 'examples/timer.c'.
3459 Here, a CPM timer is set up to generate an interrupt every second.
3460 The interrupt service routine is trivial, just printing a '.'
3461 character, but this is just a demo program. The application can be
3462 controlled by the following keys:
3464 ? - print current values og the CPM Timer registers
3465 b - enable interrupts and start timer
3466 e - stop timer and disable interrupts
3467 q - quit application
3470 ## Ready for S-Record download ...
3471 ~>examples/timer.srec
3472 1 2 3 4 5 6 7 8 9 10 11 ...
3473 [file transfer complete]
3475 ## Start Addr = 0x00040004
3478 ## Starting application at 0x00040004 ...
3481 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3484 [q, b, e, ?] Set interval 1000000 us
3487 [q, b, e, ?] ........
3488 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3491 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3494 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3497 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3499 [q, b, e, ?] ...Stopping timer
3501 [q, b, e, ?] ## Application terminated, rc = 0x0
3507 Over time, many people have reported problems when trying to use the
3508 "minicom" terminal emulation program for serial download. I (wd)
3509 consider minicom to be broken, and recommend not to use it. Under
3510 Unix, I recommend to use C-Kermit for general purpose use (and
3511 especially for kermit binary protocol download ("loadb" command), and
3512 use "cu" for S-Record download ("loads" command).
3514 Nevertheless, if you absolutely want to use it try adding this
3515 configuration to your "File transfer protocols" section:
3517 Name Program Name U/D FullScr IO-Red. Multi
3518 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3519 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3525 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3526 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3528 Building requires a cross environment; it is known to work on
3529 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3530 need gmake since the Makefiles are not compatible with BSD make).
3531 Note that the cross-powerpc package does not install include files;
3532 attempting to build U-Boot will fail because <machine/ansi.h> is
3533 missing. This file has to be installed and patched manually:
3535 # cd /usr/pkg/cross/powerpc-netbsd/include
3537 # ln -s powerpc machine
3538 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3539 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3541 Native builds *don't* work due to incompatibilities between native
3542 and U-Boot include files.
3544 Booting assumes that (the first part of) the image booted is a
3545 stage-2 loader which in turn loads and then invokes the kernel
3546 proper. Loader sources will eventually appear in the NetBSD source
3547 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3548 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3551 Implementation Internals:
3552 =========================
3554 The following is not intended to be a complete description of every
3555 implementation detail. However, it should help to understand the
3556 inner workings of U-Boot and make it easier to port it to custom
3560 Initial Stack, Global Data:
3561 ---------------------------
3563 The implementation of U-Boot is complicated by the fact that U-Boot
3564 starts running out of ROM (flash memory), usually without access to
3565 system RAM (because the memory controller is not initialized yet).
3566 This means that we don't have writable Data or BSS segments, and BSS
3567 is not initialized as zero. To be able to get a C environment working
3568 at all, we have to allocate at least a minimal stack. Implementation
3569 options for this are defined and restricted by the CPU used: Some CPU
3570 models provide on-chip memory (like the IMMR area on MPC8xx and
3571 MPC826x processors), on others (parts of) the data cache can be
3572 locked as (mis-) used as memory, etc.
3574 Chris Hallinan posted a good summary of these issues to the
3575 u-boot-users mailing list:
3577 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3578 From: "Chris Hallinan" <clh@net1plus.com>
3579 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3582 Correct me if I'm wrong, folks, but the way I understand it
3583 is this: Using DCACHE as initial RAM for Stack, etc, does not
3584 require any physical RAM backing up the cache. The cleverness
3585 is that the cache is being used as a temporary supply of
3586 necessary storage before the SDRAM controller is setup. It's
3587 beyond the scope of this list to expain the details, but you
3588 can see how this works by studying the cache architecture and
3589 operation in the architecture and processor-specific manuals.
3591 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3592 is another option for the system designer to use as an
3593 initial stack/ram area prior to SDRAM being available. Either
3594 option should work for you. Using CS 4 should be fine if your
3595 board designers haven't used it for something that would
3596 cause you grief during the initial boot! It is frequently not
3599 CFG_INIT_RAM_ADDR should be somewhere that won't interfere
3600 with your processor/board/system design. The default value
3601 you will find in any recent u-boot distribution in
3602 walnut.h should work for you. I'd set it to a value larger
3603 than your SDRAM module. If you have a 64MB SDRAM module, set
3604 it above 400_0000. Just make sure your board has no resources
3605 that are supposed to respond to that address! That code in
3606 start.S has been around a while and should work as is when
3607 you get the config right.
3612 It is essential to remember this, since it has some impact on the C
3613 code for the initialization procedures:
3615 * Initialized global data (data segment) is read-only. Do not attempt
3618 * Do not use any unitialized global data (or implicitely initialized
3619 as zero data - BSS segment) at all - this is undefined, initiali-
3620 zation is performed later (when relocating to RAM).
3622 * Stack space is very limited. Avoid big data buffers or things like
3625 Having only the stack as writable memory limits means we cannot use
3626 normal global data to share information beween the code. But it
3627 turned out that the implementation of U-Boot can be greatly
3628 simplified by making a global data structure (gd_t) available to all
3629 functions. We could pass a pointer to this data as argument to _all_
3630 functions, but this would bloat the code. Instead we use a feature of
3631 the GCC compiler (Global Register Variables) to share the data: we
3632 place a pointer (gd) to the global data into a register which we
3633 reserve for this purpose.
3635 When choosing a register for such a purpose we are restricted by the
3636 relevant (E)ABI specifications for the current architecture, and by
3637 GCC's implementation.
3639 For PowerPC, the following registers have specific use:
3641 R2: reserved for system use
3642 R3-R4: parameter passing and return values
3643 R5-R10: parameter passing
3644 R13: small data area pointer
3648 (U-Boot also uses R14 as internal GOT pointer.)
3650 ==> U-Boot will use R2 to hold a pointer to the global data
3652 Note: on PPC, we could use a static initializer (since the
3653 address of the global data structure is known at compile time),
3654 but it turned out that reserving a register results in somewhat
3655 smaller code - although the code savings are not that big (on
3656 average for all boards 752 bytes for the whole U-Boot image,
3657 624 text + 127 data).
3659 On Blackfin, the normal C ABI (except for P5) is followed as documented here:
3660 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
3662 ==> U-Boot will use P5 to hold a pointer to the global data
3664 On ARM, the following registers are used:
3666 R0: function argument word/integer result
3667 R1-R3: function argument word
3669 R10: stack limit (used only if stack checking if enabled)
3670 R11: argument (frame) pointer
3671 R12: temporary workspace
3674 R15: program counter
3676 ==> U-Boot will use R8 to hold a pointer to the global data
3678 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3679 or current versions of GCC may "optimize" the code too much.
3684 U-Boot runs in system state and uses physical addresses, i.e. the
3685 MMU is not used either for address mapping nor for memory protection.
3687 The available memory is mapped to fixed addresses using the memory
3688 controller. In this process, a contiguous block is formed for each
3689 memory type (Flash, SDRAM, SRAM), even when it consists of several
3690 physical memory banks.
3692 U-Boot is installed in the first 128 kB of the first Flash bank (on
3693 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3694 booting and sizing and initializing DRAM, the code relocates itself
3695 to the upper end of DRAM. Immediately below the U-Boot code some
3696 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
3697 configuration setting]. Below that, a structure with global Board
3698 Info data is placed, followed by the stack (growing downward).
3700 Additionally, some exception handler code is copied to the low 8 kB
3701 of DRAM (0x00000000 ... 0x00001FFF).
3703 So a typical memory configuration with 16 MB of DRAM could look like
3706 0x0000 0000 Exception Vector code
3709 0x0000 2000 Free for Application Use
3715 0x00FB FF20 Monitor Stack (Growing downward)
3716 0x00FB FFAC Board Info Data and permanent copy of global data
3717 0x00FC 0000 Malloc Arena
3720 0x00FE 0000 RAM Copy of Monitor Code
3721 ... eventually: LCD or video framebuffer
3722 ... eventually: pRAM (Protected RAM - unchanged by reset)
3723 0x00FF FFFF [End of RAM]
3726 System Initialization:
3727 ----------------------
3729 In the reset configuration, U-Boot starts at the reset entry point
3730 (on most PowerPC systens at address 0x00000100). Because of the reset
3731 configuration for CS0# this is a mirror of the onboard Flash memory.
3732 To be able to re-map memory U-Boot then jumps to its link address.
3733 To be able to implement the initialization code in C, a (small!)
3734 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3735 which provide such a feature like MPC8xx or MPC8260), or in a locked
3736 part of the data cache. After that, U-Boot initializes the CPU core,
3737 the caches and the SIU.
3739 Next, all (potentially) available memory banks are mapped using a
3740 preliminary mapping. For example, we put them on 512 MB boundaries
3741 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3742 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3743 programmed for SDRAM access. Using the temporary configuration, a
3744 simple memory test is run that determines the size of the SDRAM
3747 When there is more than one SDRAM bank, and the banks are of
3748 different size, the largest is mapped first. For equal size, the first
3749 bank (CS2#) is mapped first. The first mapping is always for address
3750 0x00000000, with any additional banks following immediately to create
3751 contiguous memory starting from 0.
3753 Then, the monitor installs itself at the upper end of the SDRAM area
3754 and allocates memory for use by malloc() and for the global Board
3755 Info data; also, the exception vector code is copied to the low RAM
3756 pages, and the final stack is set up.
3758 Only after this relocation will you have a "normal" C environment;
3759 until that you are restricted in several ways, mostly because you are
3760 running from ROM, and because the code will have to be relocated to a
3764 U-Boot Porting Guide:
3765 ----------------------
3767 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3771 int main (int argc, char *argv[])
3773 sighandler_t no_more_time;
3775 signal (SIGALRM, no_more_time);
3776 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3778 if (available_money > available_manpower) {
3779 pay consultant to port U-Boot;
3783 Download latest U-Boot source;
3785 Subscribe to u-boot-users mailing list;
3788 email ("Hi, I am new to U-Boot, how do I get started?");
3792 Read the README file in the top level directory;
3793 Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
3794 Read the source, Luke;
3797 if (available_money > toLocalCurrency ($2500)) {
3800 Add a lot of aggravation and time;
3803 Create your own board support subdirectory;
3805 Create your own board config file;
3809 Add / modify source code;
3813 email ("Hi, I am having problems...");
3815 Send patch file to Wolfgang;
3820 void no_more_time (int sig)
3829 All contributions to U-Boot should conform to the Linux kernel
3830 coding style; see the file "Documentation/CodingStyle" and the script
3831 "scripts/Lindent" in your Linux kernel source directory. In sources
3832 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
3833 spaces before parameters to function calls) is actually used.
3835 Source files originating from a different project (for example the
3836 MTD subsystem) are generally exempt from these guidelines and are not
3837 reformated to ease subsequent migration to newer versions of those
3840 Please note that U-Boot is implemented in C (and to some small parts in
3841 Assembler); no C++ is used, so please do not use C++ style comments (//)
3844 Please also stick to the following formatting rules:
3845 - remove any trailing white space
3846 - use TAB characters for indentation, not spaces
3847 - make sure NOT to use DOS '\r\n' line feeds
3848 - do not add more than 2 empty lines to source files
3849 - do not add trailing empty lines to source files
3851 Submissions which do not conform to the standards may be returned
3852 with a request to reformat the changes.
3858 Since the number of patches for U-Boot is growing, we need to
3859 establish some rules. Submissions which do not conform to these rules
3860 may be rejected, even when they contain important and valuable stuff.
3862 Patches shall be sent to the u-boot-users mailing list.
3864 Please see http://www.denx.de/wiki/UBoot/Patches for details.
3866 When you send a patch, please include the following information with
3869 * For bug fixes: a description of the bug and how your patch fixes
3870 this bug. Please try to include a way of demonstrating that the
3871 patch actually fixes something.
3873 * For new features: a description of the feature and your
3876 * A CHANGELOG entry as plaintext (separate from the patch)
3878 * For major contributions, your entry to the CREDITS file
3880 * When you add support for a new board, don't forget to add this
3881 board to the MAKEALL script, too.
3883 * If your patch adds new configuration options, don't forget to
3884 document these in the README file.
3886 * The patch itself. If you are using git (which is *strongly*
3887 recommended) you can easily generate the patch using the
3888 "git-format-patch". If you then use "git-send-email" to send it to
3889 the U-Boot mailing list, you will avoid most of the common problems
3890 with some other mail clients.
3892 If you cannot use git, use "diff -purN OLD NEW". If your version of
3893 diff does not support these options, then get the latest version of
3896 The current directory when running this command shall be the parent
3897 directory of the U-Boot source tree (i. e. please make sure that
3898 your patch includes sufficient directory information for the
3901 We prefer patches as plain text. MIME attachments are discouraged,
3902 and compressed attachments must not be used.
3904 * If one logical set of modifications affects or creates several
3905 files, all these changes shall be submitted in a SINGLE patch file.
3907 * Changesets that contain different, unrelated modifications shall be
3908 submitted as SEPARATE patches, one patch per changeset.
3913 * Before sending the patch, run the MAKEALL script on your patched
3914 source tree and make sure that no errors or warnings are reported
3915 for any of the boards.
3917 * Keep your modifications to the necessary minimum: A patch
3918 containing several unrelated changes or arbitrary reformats will be
3919 returned with a request to re-formatting / split it.
3921 * If you modify existing code, make sure that your new code does not
3922 add to the memory footprint of the code ;-) Small is beautiful!
3923 When adding new features, these should compile conditionally only
3924 (using #ifdef), and the resulting code with the new feature
3925 disabled must not need more memory than the old code without your
3928 * Remember that there is a size limit of 40 kB per message on the
3929 u-boot-users mailing list. Bigger patches will be moderated. If
3930 they are reasonable and not bigger than 100 kB, they will be
3931 acknowledged. Even bigger patches should be avoided.
projects / people / ms / u-boot.git / blob