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 - leon3 Files specific to Gaisler LEON3 SPARC CPU
157 - mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
158 - mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
159 - mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
160 - mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
161 - mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
162 - mips Files specific to MIPS CPUs
163 - mpc5xx Files specific to Freescale MPC5xx CPUs
164 - mpc5xxx Files specific to Freescale MPC5xxx CPUs
165 - mpc8xx Files specific to Freescale MPC8xx CPUs
166 - mpc8220 Files specific to Freescale MPC8220 CPUs
167 - mpc824x Files specific to Freescale MPC824x CPUs
168 - mpc8260 Files specific to Freescale MPC8260 CPUs
169 - mpc85xx Files specific to Freescale MPC85xx CPUs
170 - nios Files specific to Altera NIOS CPUs
171 - nios2 Files specific to Altera Nios-II CPUs
172 - ppc4xx Files specific to AMCC PowerPC 4xx CPUs
173 - pxa Files specific to Intel XScale PXA CPUs
174 - s3c44b0 Files specific to Samsung S3C44B0 CPUs
175 - sa1100 Files specific to Intel StrongARM SA1100 CPUs
176 - disk Code for disk drive partition handling
177 - doc Documentation (don't expect too much)
178 - drivers Commonly used device drivers
179 - dtt Digital Thermometer and Thermostat drivers
180 - examples Example code for standalone applications, etc.
181 - include Header Files
182 - lib_arm Files generic to ARM architecture
183 - lib_avr32 Files generic to AVR32 architecture
184 - lib_generic Files generic to all architectures
185 - lib_i386 Files generic to i386 architecture
186 - lib_m68k Files generic to m68k architecture
187 - lib_mips Files generic to MIPS architecture
188 - lib_nios Files generic to NIOS architecture
189 - lib_ppc Files generic to PowerPC architecture
190 - lib_sparc Files generic to SPARC architecture
191 - libfdt Library files to support flattened device trees
192 - net Networking code
193 - post Power On Self Test
194 - rtc Real Time Clock drivers
195 - tools Tools to build S-Record or U-Boot images, etc.
197 Software Configuration:
198 =======================
200 Configuration is usually done using C preprocessor defines; the
201 rationale behind that is to avoid dead code whenever possible.
203 There are two classes of configuration variables:
205 * Configuration _OPTIONS_:
206 These are selectable by the user and have names beginning with
209 * Configuration _SETTINGS_:
210 These depend on the hardware etc. and should not be meddled with if
211 you don't know what you're doing; they have names beginning with
214 Later we will add a configuration tool - probably similar to or even
215 identical to what's used for the Linux kernel. Right now, we have to
216 do the configuration by hand, which means creating some symbolic
217 links and editing some configuration files. We use the TQM8xxL boards
221 Selection of Processor Architecture and Board Type:
222 ---------------------------------------------------
224 For all supported boards there are ready-to-use default
225 configurations available; just type "make <board_name>_config".
227 Example: For a TQM823L module type:
232 For the Cogent platform, you need to specify the cpu type as well;
233 e.g. "make cogent_mpc8xx_config". And also configure the cogent
234 directory according to the instructions in cogent/README.
237 Configuration Options:
238 ----------------------
240 Configuration depends on the combination of board and CPU type; all
241 such information is kept in a configuration file
242 "include/configs/<board_name>.h".
244 Example: For a TQM823L module, all configuration settings are in
245 "include/configs/TQM823L.h".
248 Many of the options are named exactly as the corresponding Linux
249 kernel configuration options. The intention is to make it easier to
250 build a config tool - later.
253 The following options need to be configured:
255 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
257 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
259 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
260 Define exactly one, e.g. CONFIG_ATSTK1002
262 - CPU Module Type: (if CONFIG_COGENT is defined)
263 Define exactly one of
265 --- FIXME --- not tested yet:
266 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
267 CONFIG_CMA287_23, CONFIG_CMA287_50
269 - Motherboard Type: (if CONFIG_COGENT is defined)
270 Define exactly one of
271 CONFIG_CMA101, CONFIG_CMA102
273 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
274 Define one or more of
277 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
278 Define one or more of
279 CONFIG_LCD_HEARTBEAT - update a character position on
280 the lcd display every second with
283 - Board flavour: (if CONFIG_MPC8260ADS is defined)
286 CFG_8260ADS - original MPC8260ADS
287 CFG_8266ADS - MPC8266ADS
288 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
289 CFG_8272ADS - MPC8272ADS
291 - MPC824X Family Member (if CONFIG_MPC824X is defined)
292 Define exactly one of
293 CONFIG_MPC8240, CONFIG_MPC8245
295 - 8xx CPU Options: (if using an MPC8xx cpu)
296 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
297 get_gclk_freq() cannot work
298 e.g. if there is no 32KHz
299 reference PIT/RTC clock
300 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
303 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
306 CONFIG_8xx_CPUCLK_DEFAULT
307 See doc/README.MPC866
311 Define this to measure the actual CPU clock instead
312 of relying on the correctness of the configured
313 values. Mostly useful for board bringup to make sure
314 the PLL is locked at the intended frequency. Note
315 that this requires a (stable) reference clock (32 kHz
316 RTC clock or CFG_8XX_XIN)
318 - Intel Monahans options:
319 CFG_MONAHANS_RUN_MODE_OSC_RATIO
321 Defines the Monahans run mode to oscillator
322 ratio. Valid values are 8, 16, 24, 31. The core
323 frequency is this value multiplied by 13 MHz.
325 CFG_MONAHANS_TURBO_RUN_MODE_RATIO
327 Defines the Monahans turbo mode to oscillator
328 ratio. Valid values are 1 (default if undefined) and
329 2. The core frequency as calculated above is multiplied
332 - Linux Kernel Interface:
335 U-Boot stores all clock information in Hz
336 internally. For binary compatibility with older Linux
337 kernels (which expect the clocks passed in the
338 bd_info data to be in MHz) the environment variable
339 "clocks_in_mhz" can be defined so that U-Boot
340 converts clock data to MHZ before passing it to the
342 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
343 "clocks_in_mhz=1" is automatically included in the
346 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
348 When transfering memsize parameter to linux, some versions
349 expect it to be in bytes, others in MB.
350 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
352 CONFIG_OF_LIBFDT / CONFIG_OF_FLAT_TREE
354 New kernel versions are expecting firmware settings to be
355 passed using flattened device trees (based on open firmware
359 * New libfdt-based support
360 * Adds the "fdt" command
361 * The bootm command automatically updates the fdt
364 * Deprecated, see CONFIG_OF_LIBFDT
365 * Original ft_build.c-based support
366 * Automatically modifies the dft as part of the bootm command
367 * The environment variable "disable_of", when set,
368 disables this functionality.
370 OF_CPU - The proper name of the cpus node.
371 OF_SOC - The proper name of the soc node.
372 OF_TBCLK - The timebase frequency.
373 OF_STDOUT_PATH - The path to the console device
375 boards with QUICC Engines require OF_QE to set UCC mac addresses
377 CONFIG_OF_BOARD_SETUP
379 Board code has addition modification that it wants to make
380 to the flat device tree before handing it off to the kernel
384 This define fills in the correct boot cpu in the boot
385 param header, the default value is zero if undefined.
390 Define this if you want support for Amba PrimeCell PL010 UARTs.
394 Define this if you want support for Amba PrimeCell PL011 UARTs.
398 If you have Amba PrimeCell PL011 UARTs, set this variable to
399 the clock speed of the UARTs.
403 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
404 define this to a list of base addresses for each (supported)
405 port. See e.g. include/configs/versatile.h
409 Depending on board, define exactly one serial port
410 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
411 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
412 console by defining CONFIG_8xx_CONS_NONE
414 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
415 port routines must be defined elsewhere
416 (i.e. serial_init(), serial_getc(), ...)
419 Enables console device for a color framebuffer. Needs following
420 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
421 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
423 VIDEO_HW_RECTFILL graphic chip supports
426 VIDEO_HW_BITBLT graphic chip supports
427 bit-blit (cf. smiLynxEM)
428 VIDEO_VISIBLE_COLS visible pixel columns
430 VIDEO_VISIBLE_ROWS visible pixel rows
431 VIDEO_PIXEL_SIZE bytes per pixel
432 VIDEO_DATA_FORMAT graphic data format
433 (0-5, cf. cfb_console.c)
434 VIDEO_FB_ADRS framebuffer address
435 VIDEO_KBD_INIT_FCT keyboard int fct
436 (i.e. i8042_kbd_init())
437 VIDEO_TSTC_FCT test char fct
439 VIDEO_GETC_FCT get char fct
441 CONFIG_CONSOLE_CURSOR cursor drawing on/off
442 (requires blink timer
444 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
445 CONFIG_CONSOLE_TIME display time/date info in
447 (requires CONFIG_CMD_DATE)
448 CONFIG_VIDEO_LOGO display Linux logo in
450 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
451 linux_logo.h for logo.
452 Requires CONFIG_VIDEO_LOGO
453 CONFIG_CONSOLE_EXTRA_INFO
454 addional board info beside
457 When CONFIG_CFB_CONSOLE is defined, video console is
458 default i/o. Serial console can be forced with
459 environment 'console=serial'.
461 When CONFIG_SILENT_CONSOLE is defined, all console
462 messages (by U-Boot and Linux!) can be silenced with
463 the "silent" environment variable. See
464 doc/README.silent for more information.
467 CONFIG_BAUDRATE - in bps
468 Select one of the baudrates listed in
469 CFG_BAUDRATE_TABLE, see below.
470 CFG_BRGCLK_PRESCALE, baudrate prescale
472 - Interrupt driven serial port input:
473 CONFIG_SERIAL_SOFTWARE_FIFO
476 Use an interrupt handler for receiving data on the
477 serial port. It also enables using hardware handshake
478 (RTS/CTS) and UART's built-in FIFO. Set the number of
479 bytes the interrupt driven input buffer should have.
481 Leave undefined to disable this feature, including
482 disable the buffer and hardware handshake.
484 - Console UART Number:
488 If defined internal UART1 (and not UART0) is used
489 as default U-Boot console.
491 - Boot Delay: CONFIG_BOOTDELAY - in seconds
492 Delay before automatically booting the default image;
493 set to -1 to disable autoboot.
495 See doc/README.autoboot for these options that
496 work with CONFIG_BOOTDELAY. None are required.
497 CONFIG_BOOT_RETRY_TIME
498 CONFIG_BOOT_RETRY_MIN
499 CONFIG_AUTOBOOT_KEYED
500 CONFIG_AUTOBOOT_PROMPT
501 CONFIG_AUTOBOOT_DELAY_STR
502 CONFIG_AUTOBOOT_STOP_STR
503 CONFIG_AUTOBOOT_DELAY_STR2
504 CONFIG_AUTOBOOT_STOP_STR2
505 CONFIG_ZERO_BOOTDELAY_CHECK
506 CONFIG_RESET_TO_RETRY
510 Only needed when CONFIG_BOOTDELAY is enabled;
511 define a command string that is automatically executed
512 when no character is read on the console interface
513 within "Boot Delay" after reset.
516 This can be used to pass arguments to the bootm
517 command. The value of CONFIG_BOOTARGS goes into the
518 environment value "bootargs".
520 CONFIG_RAMBOOT and CONFIG_NFSBOOT
521 The value of these goes into the environment as
522 "ramboot" and "nfsboot" respectively, and can be used
523 as a convenience, when switching between booting from
529 When this option is #defined, the existence of the
530 environment variable "preboot" will be checked
531 immediately before starting the CONFIG_BOOTDELAY
532 countdown and/or running the auto-boot command resp.
533 entering interactive mode.
535 This feature is especially useful when "preboot" is
536 automatically generated or modified. For an example
537 see the LWMON board specific code: here "preboot" is
538 modified when the user holds down a certain
539 combination of keys on the (special) keyboard when
542 - Serial Download Echo Mode:
544 If defined to 1, all characters received during a
545 serial download (using the "loads" command) are
546 echoed back. This might be needed by some terminal
547 emulations (like "cu"), but may as well just take
548 time on others. This setting #define's the initial
549 value of the "loads_echo" environment variable.
551 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
553 Select one of the baudrates listed in
554 CFG_BAUDRATE_TABLE, see below.
557 Monitor commands can be included or excluded
558 from the build by using the #include files
559 "config_cmd_all.h" and #undef'ing unwanted
560 commands, or using "config_cmd_default.h"
561 and augmenting with additional #define's
564 The default command configuration includes all commands
565 except those marked below with a "*".
567 CONFIG_CMD_ASKENV * ask for env variable
568 CONFIG_CMD_AUTOSCRIPT Autoscript Support
569 CONFIG_CMD_BDI bdinfo
570 CONFIG_CMD_BEDBUG * Include BedBug Debugger
571 CONFIG_CMD_BMP * BMP support
572 CONFIG_CMD_BSP * Board specific commands
573 CONFIG_CMD_BOOTD bootd
574 CONFIG_CMD_CACHE * icache, dcache
575 CONFIG_CMD_CONSOLE coninfo
576 CONFIG_CMD_DATE * support for RTC, date/time...
577 CONFIG_CMD_DHCP * DHCP support
578 CONFIG_CMD_DIAG * Diagnostics
579 CONFIG_CMD_DOC * Disk-On-Chip Support
580 CONFIG_CMD_DTT * Digital Therm and Thermostat
581 CONFIG_CMD_ECHO echo arguments
582 CONFIG_CMD_EEPROM * EEPROM read/write support
583 CONFIG_CMD_ELF * bootelf, bootvx
584 CONFIG_CMD_ENV saveenv
585 CONFIG_CMD_FDC * Floppy Disk Support
586 CONFIG_CMD_FAT * FAT partition support
587 CONFIG_CMD_FDOS * Dos diskette Support
588 CONFIG_CMD_FLASH flinfo, erase, protect
589 CONFIG_CMD_FPGA FPGA device initialization support
590 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
591 CONFIG_CMD_I2C * I2C serial bus support
592 CONFIG_CMD_IDE * IDE harddisk support
593 CONFIG_CMD_IMI iminfo
594 CONFIG_CMD_IMLS List all found images
595 CONFIG_CMD_IMMAP * IMMR dump support
596 CONFIG_CMD_IRQ * irqinfo
597 CONFIG_CMD_ITEST Integer/string test of 2 values
598 CONFIG_CMD_JFFS2 * JFFS2 Support
599 CONFIG_CMD_KGDB * kgdb
600 CONFIG_CMD_LOADB loadb
601 CONFIG_CMD_LOADS loads
602 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
604 CONFIG_CMD_MISC Misc functions like sleep etc
605 CONFIG_CMD_MMC * MMC memory mapped support
606 CONFIG_CMD_MII * MII utility commands
607 CONFIG_CMD_NAND * NAND support
608 CONFIG_CMD_NET bootp, tftpboot, rarpboot
609 CONFIG_CMD_PCI * pciinfo
610 CONFIG_CMD_PCMCIA * PCMCIA support
611 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
613 CONFIG_CMD_PORTIO * Port I/O
614 CONFIG_CMD_REGINFO * Register dump
615 CONFIG_CMD_RUN run command in env variable
616 CONFIG_CMD_SAVES * save S record dump
617 CONFIG_CMD_SCSI * SCSI Support
618 CONFIG_CMD_SDRAM * print SDRAM configuration information
619 (requires CONFIG_CMD_I2C)
620 CONFIG_CMD_SETGETDCR Support for DCR Register access
622 CONFIG_CMD_SPI * SPI serial bus support
623 CONFIG_CMD_USB * USB support
624 CONFIG_CMD_VFD * VFD support (TRAB)
625 CONFIG_CMD_BSP * Board SPecific functions
626 CONFIG_CMD_CDP * Cisco Discover Protocol support
627 CONFIG_CMD_FSL * Microblaze FSL support
630 EXAMPLE: If you want all functions except of network
631 support you can write:
633 #include "config_cmd_all.h"
634 #undef CONFIG_CMD_NET
637 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
639 Note: Don't enable the "icache" and "dcache" commands
640 (configuration option CONFIG_CMD_CACHE) unless you know
641 what you (and your U-Boot users) are doing. Data
642 cache cannot be enabled on systems like the 8xx or
643 8260 (where accesses to the IMMR region must be
644 uncached), and it cannot be disabled on all other
645 systems where we (mis-) use the data cache to hold an
646 initial stack and some data.
649 XXX - this list needs to get updated!
653 If this variable is defined, it enables watchdog
654 support. There must be support in the platform specific
655 code for a watchdog. For the 8xx and 8260 CPUs, the
656 SIU Watchdog feature is enabled in the SYPCR
660 CONFIG_VERSION_VARIABLE
661 If this variable is defined, an environment variable
662 named "ver" is created by U-Boot showing the U-Boot
663 version as printed by the "version" command.
664 This variable is readonly.
668 When CONFIG_CMD_DATE is selected, the type of the RTC
669 has to be selected, too. Define exactly one of the
672 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
673 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
674 CONFIG_RTC_MC146818 - use MC146818 RTC
675 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
676 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
677 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
678 CONFIG_RTC_DS164x - use Dallas DS164x RTC
679 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
680 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
681 CFG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
683 Note that if the RTC uses I2C, then the I2C interface
684 must also be configured. See I2C Support, below.
688 When CONFIG_TIMESTAMP is selected, the timestamp
689 (date and time) of an image is printed by image
690 commands like bootm or iminfo. This option is
691 automatically enabled when you select CONFIG_CMD_DATE .
694 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
695 and/or CONFIG_ISO_PARTITION
697 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
698 CONFIG_CMD_SCSI) you must configure support for at
699 least one partition type as well.
702 CONFIG_IDE_RESET_ROUTINE - this is defined in several
703 board configurations files but used nowhere!
705 CONFIG_IDE_RESET - is this is defined, IDE Reset will
706 be performed by calling the function
707 ide_set_reset(int reset)
708 which has to be defined in a board specific file
713 Set this to enable ATAPI support.
718 Set this to enable support for disks larger than 137GB
719 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL
720 Whithout these , LBA48 support uses 32bit variables and will 'only'
721 support disks up to 2.1TB.
724 When enabled, makes the IDE subsystem use 64bit sector addresses.
728 At the moment only there is only support for the
729 SYM53C8XX SCSI controller; define
730 CONFIG_SCSI_SYM53C8XX to enable it.
732 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
733 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
734 CFG_SCSI_MAX_LUN] can be adjusted to define the
735 maximum numbers of LUNs, SCSI ID's and target
737 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
739 - NETWORK Support (PCI):
741 Support for Intel 8254x gigabit chips.
743 CONFIG_E1000_FALLBACK_MAC
744 default MAC for empty eeprom after production.
747 Support for Intel 82557/82559/82559ER chips.
748 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
749 write routine for first time initialisation.
752 Support for Digital 2114x chips.
753 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
754 modem chip initialisation (KS8761/QS6611).
757 Support for National dp83815 chips.
760 Support for National dp8382[01] gigabit chips.
762 - NETWORK Support (other):
764 CONFIG_DRIVER_LAN91C96
765 Support for SMSC's LAN91C96 chips.
768 Define this to hold the physical address
769 of the LAN91C96's I/O space
771 CONFIG_LAN91C96_USE_32_BIT
772 Define this to enable 32 bit addressing
774 CONFIG_DRIVER_SMC91111
775 Support for SMSC's LAN91C111 chip
778 Define this to hold the physical address
779 of the device (I/O space)
781 CONFIG_SMC_USE_32_BIT
782 Define this if data bus is 32 bits
784 CONFIG_SMC_USE_IOFUNCS
785 Define this to use i/o functions instead of macros
786 (some hardware wont work with macros)
789 At the moment only the UHCI host controller is
790 supported (PIP405, MIP405, MPC5200); define
791 CONFIG_USB_UHCI to enable it.
792 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
793 and define CONFIG_USB_STORAGE to enable the USB
796 Supported are USB Keyboards and USB Floppy drives
798 MPC5200 USB requires additional defines:
800 for 528 MHz Clock: 0x0001bbbb
802 for differential drivers: 0x00001000
803 for single ended drivers: 0x00005000
805 May be defined to allow interrupt polling
806 instead of using asynchronous interrupts
809 Define the below if you wish to use the USB console.
810 Once firmware is rebuilt from a serial console issue the
811 command "setenv stdin usbtty; setenv stdout usbtty" and
812 attach your usb cable. The Unix command "dmesg" should print
813 it has found a new device. The environment variable usbtty
814 can be set to gserial or cdc_acm to enable your device to
815 appear to a USB host as a Linux gserial device or a
816 Common Device Class Abstract Control Model serial device.
817 If you select usbtty = gserial you should be able to enumerate
819 # modprobe usbserial vendor=0xVendorID product=0xProductID
820 else if using cdc_acm, simply setting the environment
821 variable usbtty to be cdc_acm should suffice. The following
822 might be defined in YourBoardName.h
825 Define this to build a UDC device
828 Define this to have a tty type of device available to
829 talk to the UDC device
831 CFG_CONSOLE_IS_IN_ENV
832 Define this if you want stdin, stdout &/or stderr to
836 CFG_USB_EXTC_CLK 0xBLAH
837 Derive USB clock from external clock "blah"
838 - CFG_USB_EXTC_CLK 0x02
840 CFG_USB_BRG_CLK 0xBLAH
841 Derive USB clock from brgclk
842 - CFG_USB_BRG_CLK 0x04
844 If you have a USB-IF assigned VendorID then you may wish to
845 define your own vendor specific values either in BoardName.h
846 or directly in usbd_vendor_info.h. If you don't define
847 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
848 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
849 should pretend to be a Linux device to it's target host.
851 CONFIG_USBD_MANUFACTURER
852 Define this string as the name of your company for
853 - CONFIG_USBD_MANUFACTURER "my company"
855 CONFIG_USBD_PRODUCT_NAME
856 Define this string as the name of your product
857 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
860 Define this as your assigned Vendor ID from the USB
861 Implementors Forum. This *must* be a genuine Vendor ID
862 to avoid polluting the USB namespace.
863 - CONFIG_USBD_VENDORID 0xFFFF
865 CONFIG_USBD_PRODUCTID
866 Define this as the unique Product ID
868 - CONFIG_USBD_PRODUCTID 0xFFFF
872 The MMC controller on the Intel PXA is supported. To
873 enable this define CONFIG_MMC. The MMC can be
874 accessed from the boot prompt by mapping the device
875 to physical memory similar to flash. Command line is
876 enabled with CONFIG_CMD_MMC. The MMC driver also works with
877 the FAT fs. This is enabled with CONFIG_CMD_FAT.
879 - Journaling Flash filesystem support:
880 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
881 CONFIG_JFFS2_NAND_DEV
882 Define these for a default partition on a NAND device
884 CFG_JFFS2_FIRST_SECTOR,
885 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS
886 Define these for a default partition on a NOR device
889 Define this to create an own partition. You have to provide a
890 function struct part_info* jffs2_part_info(int part_num)
892 If you define only one JFFS2 partition you may also want to
893 #define CFG_JFFS_SINGLE_PART 1
894 to disable the command chpart. This is the default when you
895 have not defined a custom partition
900 Define this to enable standard (PC-Style) keyboard
904 Standard PC keyboard driver with US (is default) and
905 GERMAN key layout (switch via environment 'keymap=de') support.
906 Export function i8042_kbd_init, i8042_tstc and i8042_getc
907 for cfb_console. Supports cursor blinking.
912 Define this to enable video support (for output to
917 Enable Chips & Technologies 69000 Video chip
919 CONFIG_VIDEO_SMI_LYNXEM
920 Enable Silicon Motion SMI 712/710/810 Video chip. The
921 video output is selected via environment 'videoout'
922 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
925 For the CT69000 and SMI_LYNXEM drivers, videomode is
926 selected via environment 'videomode'. Two diferent ways
928 - "videomode=num" 'num' is a standard LiLo mode numbers.
929 Following standard modes are supported (* is default):
931 Colors 640x480 800x600 1024x768 1152x864 1280x1024
932 -------------+---------------------------------------------
933 8 bits | 0x301* 0x303 0x305 0x161 0x307
934 15 bits | 0x310 0x313 0x316 0x162 0x319
935 16 bits | 0x311 0x314 0x317 0x163 0x31A
936 24 bits | 0x312 0x315 0x318 ? 0x31B
937 -------------+---------------------------------------------
938 (i.e. setenv videomode 317; saveenv; reset;)
940 - "videomode=bootargs" all the video parameters are parsed
941 from the bootargs. (See drivers/video/videomodes.c)
944 CONFIG_VIDEO_SED13806
945 Enable Epson SED13806 driver. This driver supports 8bpp
946 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
947 or CONFIG_VIDEO_SED13806_16BPP
952 Define this to enable a custom keyboard support.
953 This simply calls drv_keyboard_init() which must be
954 defined in your board-specific files.
955 The only board using this so far is RBC823.
957 - LCD Support: CONFIG_LCD
959 Define this to enable LCD support (for output to LCD
960 display); also select one of the supported displays
961 by defining one of these:
963 CONFIG_NEC_NL6448AC33:
965 NEC NL6448AC33-18. Active, color, single scan.
967 CONFIG_NEC_NL6448BC20
969 NEC NL6448BC20-08. 6.5", 640x480.
970 Active, color, single scan.
972 CONFIG_NEC_NL6448BC33_54
974 NEC NL6448BC33-54. 10.4", 640x480.
975 Active, color, single scan.
979 Sharp 320x240. Active, color, single scan.
980 It isn't 16x9, and I am not sure what it is.
982 CONFIG_SHARP_LQ64D341
984 Sharp LQ64D341 display, 640x480.
985 Active, color, single scan.
989 HLD1045 display, 640x480.
990 Active, color, single scan.
994 Optrex CBL50840-2 NF-FW 99 22 M5
996 Hitachi LMG6912RPFC-00T
1000 320x240. Black & white.
1002 Normally display is black on white background; define
1003 CFG_WHITE_ON_BLACK to get it inverted.
1005 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1007 If this option is set, the environment is checked for
1008 a variable "splashimage". If found, the usual display
1009 of logo, copyright and system information on the LCD
1010 is suppressed and the BMP image at the address
1011 specified in "splashimage" is loaded instead. The
1012 console is redirected to the "nulldev", too. This
1013 allows for a "silent" boot where a splash screen is
1014 loaded very quickly after power-on.
1016 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1018 If this option is set, additionally to standard BMP
1019 images, gzipped BMP images can be displayed via the
1020 splashscreen support or the bmp command.
1022 - Compression support:
1025 If this option is set, support for bzip2 compressed
1026 images is included. If not, only uncompressed and gzip
1027 compressed images are supported.
1029 NOTE: the bzip2 algorithm requires a lot of RAM, so
1030 the malloc area (as defined by CFG_MALLOC_LEN) should
1036 The address of PHY on MII bus.
1038 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1040 The clock frequency of the MII bus
1044 If this option is set, support for speed/duplex
1045 detection of Gigabit PHY is included.
1047 CONFIG_PHY_RESET_DELAY
1049 Some PHY like Intel LXT971A need extra delay after
1050 reset before any MII register access is possible.
1051 For such PHY, set this option to the usec delay
1052 required. (minimum 300usec for LXT971A)
1054 CONFIG_PHY_CMD_DELAY (ppc4xx)
1056 Some PHY like Intel LXT971A need extra delay after
1057 command issued before MII status register can be read
1064 Define a default value for ethernet address to use
1065 for the respective ethernet interface, in case this
1066 is not determined automatically.
1071 Define a default value for the IP address to use for
1072 the default ethernet interface, in case this is not
1073 determined through e.g. bootp.
1075 - Server IP address:
1078 Defines a default value for theIP address of a TFTP
1079 server to contact when using the "tftboot" command.
1081 - Multicast TFTP Mode:
1084 Defines whether you want to support multicast TFTP as per
1085 rfc-2090; for example to work with atftp. Lets lots of targets
1086 tftp down the same boot image concurrently. Note: the ethernet
1087 driver in use must provide a function: mcast() to join/leave a
1090 CONFIG_BOOTP_RANDOM_DELAY
1091 - BOOTP Recovery Mode:
1092 CONFIG_BOOTP_RANDOM_DELAY
1094 If you have many targets in a network that try to
1095 boot using BOOTP, you may want to avoid that all
1096 systems send out BOOTP requests at precisely the same
1097 moment (which would happen for instance at recovery
1098 from a power failure, when all systems will try to
1099 boot, thus flooding the BOOTP server. Defining
1100 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1101 inserted before sending out BOOTP requests. The
1102 following delays are inserted then:
1104 1st BOOTP request: delay 0 ... 1 sec
1105 2nd BOOTP request: delay 0 ... 2 sec
1106 3rd BOOTP request: delay 0 ... 4 sec
1108 BOOTP requests: delay 0 ... 8 sec
1110 - DHCP Advanced Options:
1111 You can fine tune the DHCP functionality by defining
1112 CONFIG_BOOTP_* symbols:
1114 CONFIG_BOOTP_SUBNETMASK
1115 CONFIG_BOOTP_GATEWAY
1116 CONFIG_BOOTP_HOSTNAME
1117 CONFIG_BOOTP_NISDOMAIN
1118 CONFIG_BOOTP_BOOTPATH
1119 CONFIG_BOOTP_BOOTFILESIZE
1122 CONFIG_BOOTP_SEND_HOSTNAME
1123 CONFIG_BOOTP_NTPSERVER
1124 CONFIG_BOOTP_TIMEOFFSET
1125 CONFIG_BOOTP_VENDOREX
1127 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1128 environment variable, not the BOOTP server.
1130 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1131 serverip from a DHCP server, it is possible that more
1132 than one DNS serverip is offered to the client.
1133 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1134 serverip will be stored in the additional environment
1135 variable "dnsip2". The first DNS serverip is always
1136 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1139 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1140 to do a dynamic update of a DNS server. To do this, they
1141 need the hostname of the DHCP requester.
1142 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1143 of the "hostname" environment variable is passed as
1144 option 12 to the DHCP server.
1146 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1148 A 32bit value in microseconds for a delay between
1149 receiving a "DHCP Offer" and sending the "DHCP Request".
1150 This fixes a problem with certain DHCP servers that don't
1151 respond 100% of the time to a "DHCP request". E.g. On an
1152 AT91RM9200 processor running at 180MHz, this delay needed
1153 to be *at least* 15,000 usec before a Windows Server 2003
1154 DHCP server would reply 100% of the time. I recommend at
1155 least 50,000 usec to be safe. The alternative is to hope
1156 that one of the retries will be successful but note that
1157 the DHCP timeout and retry process takes a longer than
1161 CONFIG_CDP_DEVICE_ID
1163 The device id used in CDP trigger frames.
1165 CONFIG_CDP_DEVICE_ID_PREFIX
1167 A two character string which is prefixed to the MAC address
1172 A printf format string which contains the ascii name of
1173 the port. Normally is set to "eth%d" which sets
1174 eth0 for the first ethernet, eth1 for the second etc.
1176 CONFIG_CDP_CAPABILITIES
1178 A 32bit integer which indicates the device capabilities;
1179 0x00000010 for a normal host which does not forwards.
1183 An ascii string containing the version of the software.
1187 An ascii string containing the name of the platform.
1191 A 32bit integer sent on the trigger.
1193 CONFIG_CDP_POWER_CONSUMPTION
1195 A 16bit integer containing the power consumption of the
1196 device in .1 of milliwatts.
1198 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1200 A byte containing the id of the VLAN.
1202 - Status LED: CONFIG_STATUS_LED
1204 Several configurations allow to display the current
1205 status using a LED. For instance, the LED will blink
1206 fast while running U-Boot code, stop blinking as
1207 soon as a reply to a BOOTP request was received, and
1208 start blinking slow once the Linux kernel is running
1209 (supported by a status LED driver in the Linux
1210 kernel). Defining CONFIG_STATUS_LED enables this
1213 - CAN Support: CONFIG_CAN_DRIVER
1215 Defining CONFIG_CAN_DRIVER enables CAN driver support
1216 on those systems that support this (optional)
1217 feature, like the TQM8xxL modules.
1219 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1221 These enable I2C serial bus commands. Defining either of
1222 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1223 include the appropriate I2C driver for the selected cpu.
1225 This will allow you to use i2c commands at the u-boot
1226 command line (as long as you set CONFIG_CMD_I2C in
1227 CONFIG_COMMANDS) and communicate with i2c based realtime
1228 clock chips. See common/cmd_i2c.c for a description of the
1229 command line interface.
1231 CONFIG_I2C_CMD_TREE is a recommended option that places
1232 all I2C commands under a single 'i2c' root command. The
1233 older 'imm', 'imd', 'iprobe' etc. commands are considered
1234 deprecated and may disappear in the future.
1236 CONFIG_HARD_I2C selects a hardware I2C controller.
1238 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1239 bit-banging) driver instead of CPM or similar hardware
1242 There are several other quantities that must also be
1243 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1245 In both cases you will need to define CFG_I2C_SPEED
1246 to be the frequency (in Hz) at which you wish your i2c bus
1247 to run and CFG_I2C_SLAVE to be the address of this node (ie
1248 the cpu's i2c node address).
1250 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1251 sets the cpu up as a master node and so its address should
1252 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1253 p.16-473). So, set CFG_I2C_SLAVE to 0.
1255 That's all that's required for CONFIG_HARD_I2C.
1257 If you use the software i2c interface (CONFIG_SOFT_I2C)
1258 then the following macros need to be defined (examples are
1259 from include/configs/lwmon.h):
1263 (Optional). Any commands necessary to enable the I2C
1264 controller or configure ports.
1266 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1270 (Only for MPC8260 CPU). The I/O port to use (the code
1271 assumes both bits are on the same port). Valid values
1272 are 0..3 for ports A..D.
1276 The code necessary to make the I2C data line active
1277 (driven). If the data line is open collector, this
1280 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1284 The code necessary to make the I2C data line tri-stated
1285 (inactive). If the data line is open collector, this
1288 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1292 Code that returns TRUE if the I2C data line is high,
1295 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1299 If <bit> is TRUE, sets the I2C data line high. If it
1300 is FALSE, it clears it (low).
1302 eg: #define I2C_SDA(bit) \
1303 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1304 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1308 If <bit> is TRUE, sets the I2C clock line high. If it
1309 is FALSE, it clears it (low).
1311 eg: #define I2C_SCL(bit) \
1312 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1313 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1317 This delay is invoked four times per clock cycle so this
1318 controls the rate of data transfer. The data rate thus
1319 is 1 / (I2C_DELAY * 4). Often defined to be something
1322 #define I2C_DELAY udelay(2)
1326 When a board is reset during an i2c bus transfer
1327 chips might think that the current transfer is still
1328 in progress. On some boards it is possible to access
1329 the i2c SCLK line directly, either by using the
1330 processor pin as a GPIO or by having a second pin
1331 connected to the bus. If this option is defined a
1332 custom i2c_init_board() routine in boards/xxx/board.c
1333 is run early in the boot sequence.
1335 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1337 This option enables configuration of bi_iic_fast[] flags
1338 in u-boot bd_info structure based on u-boot environment
1339 variable "i2cfast". (see also i2cfast)
1341 CONFIG_I2C_MULTI_BUS
1343 This option allows the use of multiple I2C buses, each of which
1344 must have a controller. At any point in time, only one bus is
1345 active. To switch to a different bus, use the 'i2c dev' command.
1346 Note that bus numbering is zero-based.
1350 This option specifies a list of I2C devices that will be skipped
1351 when the 'i2c probe' command is issued (or 'iprobe' using the legacy
1352 command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device
1353 pairs. Otherwise, specify a 1D array of device addresses
1356 #undef CONFIG_I2C_MULTI_BUS
1357 #define CFG_I2C_NOPROBES {0x50,0x68}
1359 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1361 #define CONFIG_I2C_MULTI_BUS
1362 #define CFG_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1364 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1368 If defined, then this indicates the I2C bus number for DDR SPD.
1369 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1373 If defined, then this indicates the I2C bus number for the RTC.
1374 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1378 If defined, then this indicates the I2C bus number for the DTT.
1379 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1383 Define this option if you want to use Freescale's I2C driver in
1384 drivers/i2c/fsl_i2c.c.
1387 - SPI Support: CONFIG_SPI
1389 Enables SPI driver (so far only tested with
1390 SPI EEPROM, also an instance works with Crystal A/D and
1391 D/As on the SACSng board)
1395 Enables extended (16-bit) SPI EEPROM addressing.
1396 (symmetrical to CONFIG_I2C_X)
1400 Enables a software (bit-bang) SPI driver rather than
1401 using hardware support. This is a general purpose
1402 driver that only requires three general I/O port pins
1403 (two outputs, one input) to function. If this is
1404 defined, the board configuration must define several
1405 SPI configuration items (port pins to use, etc). For
1406 an example, see include/configs/sacsng.h.
1410 Enables a hardware SPI driver for general-purpose reads
1411 and writes. As with CONFIG_SOFT_SPI, the board configuration
1412 must define a list of chip-select function pointers.
1413 Currently supported on some MPC8xxx processors. For an
1414 example, see include/configs/mpc8349emds.h.
1416 - FPGA Support: CONFIG_FPGA
1418 Enables FPGA subsystem.
1420 CONFIG_FPGA_<vendor>
1422 Enables support for specific chip vendors.
1425 CONFIG_FPGA_<family>
1427 Enables support for FPGA family.
1428 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1432 Specify the number of FPGA devices to support.
1434 CFG_FPGA_PROG_FEEDBACK
1436 Enable printing of hash marks during FPGA configuration.
1440 Enable checks on FPGA configuration interface busy
1441 status by the configuration function. This option
1442 will require a board or device specific function to
1447 If defined, a function that provides delays in the FPGA
1448 configuration driver.
1450 CFG_FPGA_CHECK_CTRLC
1451 Allow Control-C to interrupt FPGA configuration
1453 CFG_FPGA_CHECK_ERROR
1455 Check for configuration errors during FPGA bitfile
1456 loading. For example, abort during Virtex II
1457 configuration if the INIT_B line goes low (which
1458 indicated a CRC error).
1462 Maximum time to wait for the INIT_B line to deassert
1463 after PROB_B has been deasserted during a Virtex II
1464 FPGA configuration sequence. The default time is 500
1469 Maximum time to wait for BUSY to deassert during
1470 Virtex II FPGA configuration. The default is 5 mS.
1472 CFG_FPGA_WAIT_CONFIG
1474 Time to wait after FPGA configuration. The default is
1477 - Configuration Management:
1480 If defined, this string will be added to the U-Boot
1481 version information (U_BOOT_VERSION)
1483 - Vendor Parameter Protection:
1485 U-Boot considers the values of the environment
1486 variables "serial#" (Board Serial Number) and
1487 "ethaddr" (Ethernet Address) to be parameters that
1488 are set once by the board vendor / manufacturer, and
1489 protects these variables from casual modification by
1490 the user. Once set, these variables are read-only,
1491 and write or delete attempts are rejected. You can
1492 change this behviour:
1494 If CONFIG_ENV_OVERWRITE is #defined in your config
1495 file, the write protection for vendor parameters is
1496 completely disabled. Anybody can change or delete
1499 Alternatively, if you #define _both_ CONFIG_ETHADDR
1500 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1501 ethernet address is installed in the environment,
1502 which can be changed exactly ONCE by the user. [The
1503 serial# is unaffected by this, i. e. it remains
1509 Define this variable to enable the reservation of
1510 "protected RAM", i. e. RAM which is not overwritten
1511 by U-Boot. Define CONFIG_PRAM to hold the number of
1512 kB you want to reserve for pRAM. You can overwrite
1513 this default value by defining an environment
1514 variable "pram" to the number of kB you want to
1515 reserve. Note that the board info structure will
1516 still show the full amount of RAM. If pRAM is
1517 reserved, a new environment variable "mem" will
1518 automatically be defined to hold the amount of
1519 remaining RAM in a form that can be passed as boot
1520 argument to Linux, for instance like that:
1522 setenv bootargs ... mem=\${mem}
1525 This way you can tell Linux not to use this memory,
1526 either, which results in a memory region that will
1527 not be affected by reboots.
1529 *WARNING* If your board configuration uses automatic
1530 detection of the RAM size, you must make sure that
1531 this memory test is non-destructive. So far, the
1532 following board configurations are known to be
1535 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1536 HERMES, IP860, RPXlite, LWMON, LANTEC,
1537 PCU_E, FLAGADM, TQM8260
1542 Define this variable to stop the system in case of a
1543 fatal error, so that you have to reset it manually.
1544 This is probably NOT a good idea for an embedded
1545 system where you want to system to reboot
1546 automatically as fast as possible, but it may be
1547 useful during development since you can try to debug
1548 the conditions that lead to the situation.
1550 CONFIG_NET_RETRY_COUNT
1552 This variable defines the number of retries for
1553 network operations like ARP, RARP, TFTP, or BOOTP
1554 before giving up the operation. If not defined, a
1555 default value of 5 is used.
1557 - Command Interpreter:
1558 CONFIG_AUTO_COMPLETE
1560 Enable auto completion of commands using TAB.
1562 Note that this feature has NOT been implemented yet
1563 for the "hush" shell.
1568 Define this variable to enable the "hush" shell (from
1569 Busybox) as command line interpreter, thus enabling
1570 powerful command line syntax like
1571 if...then...else...fi conditionals or `&&' and '||'
1572 constructs ("shell scripts").
1574 If undefined, you get the old, much simpler behaviour
1575 with a somewhat smaller memory footprint.
1580 This defines the secondary prompt string, which is
1581 printed when the command interpreter needs more input
1582 to complete a command. Usually "> ".
1586 In the current implementation, the local variables
1587 space and global environment variables space are
1588 separated. Local variables are those you define by
1589 simply typing `name=value'. To access a local
1590 variable later on, you have write `$name' or
1591 `${name}'; to execute the contents of a variable
1592 directly type `$name' at the command prompt.
1594 Global environment variables are those you use
1595 setenv/printenv to work with. To run a command stored
1596 in such a variable, you need to use the run command,
1597 and you must not use the '$' sign to access them.
1599 To store commands and special characters in a
1600 variable, please use double quotation marks
1601 surrounding the whole text of the variable, instead
1602 of the backslashes before semicolons and special
1605 - Commandline Editing and History:
1606 CONFIG_CMDLINE_EDITING
1608 Enable editiong and History functions for interactive
1609 commandline input operations
1611 - Default Environment:
1612 CONFIG_EXTRA_ENV_SETTINGS
1614 Define this to contain any number of null terminated
1615 strings (variable = value pairs) that will be part of
1616 the default environment compiled into the boot image.
1618 For example, place something like this in your
1619 board's config file:
1621 #define CONFIG_EXTRA_ENV_SETTINGS \
1625 Warning: This method is based on knowledge about the
1626 internal format how the environment is stored by the
1627 U-Boot code. This is NOT an official, exported
1628 interface! Although it is unlikely that this format
1629 will change soon, there is no guarantee either.
1630 You better know what you are doing here.
1632 Note: overly (ab)use of the default environment is
1633 discouraged. Make sure to check other ways to preset
1634 the environment like the autoscript function or the
1637 - DataFlash Support:
1638 CONFIG_HAS_DATAFLASH
1640 Defining this option enables DataFlash features and
1641 allows to read/write in Dataflash via the standard
1644 - SystemACE Support:
1647 Adding this option adds support for Xilinx SystemACE
1648 chips attached via some sort of local bus. The address
1649 of the chip must alsh be defined in the
1650 CFG_SYSTEMACE_BASE macro. For example:
1652 #define CONFIG_SYSTEMACE
1653 #define CFG_SYSTEMACE_BASE 0xf0000000
1655 When SystemACE support is added, the "ace" device type
1656 becomes available to the fat commands, i.e. fatls.
1658 - TFTP Fixed UDP Port:
1661 If this is defined, the environment variable tftpsrcp
1662 is used to supply the TFTP UDP source port value.
1663 If tftpsrcp isn't defined, the normal pseudo-random port
1664 number generator is used.
1666 Also, the environment variable tftpdstp is used to supply
1667 the TFTP UDP destination port value. If tftpdstp isn't
1668 defined, the normal port 69 is used.
1670 The purpose for tftpsrcp is to allow a TFTP server to
1671 blindly start the TFTP transfer using the pre-configured
1672 target IP address and UDP port. This has the effect of
1673 "punching through" the (Windows XP) firewall, allowing
1674 the remainder of the TFTP transfer to proceed normally.
1675 A better solution is to properly configure the firewall,
1676 but sometimes that is not allowed.
1678 - Show boot progress:
1679 CONFIG_SHOW_BOOT_PROGRESS
1681 Defining this option allows to add some board-
1682 specific code (calling a user-provided function
1683 "show_boot_progress(int)") that enables you to show
1684 the system's boot progress on some display (for
1685 example, some LED's) on your board. At the moment,
1686 the following checkpoints are implemented:
1688 Legacy uImage format:
1691 1 common/cmd_bootm.c before attempting to boot an image
1692 -1 common/cmd_bootm.c Image header has bad magic number
1693 2 common/cmd_bootm.c Image header has correct magic number
1694 -2 common/cmd_bootm.c Image header has bad checksum
1695 3 common/cmd_bootm.c Image header has correct checksum
1696 -3 common/cmd_bootm.c Image data has bad checksum
1697 4 common/cmd_bootm.c Image data has correct checksum
1698 -4 common/cmd_bootm.c Image is for unsupported architecture
1699 5 common/cmd_bootm.c Architecture check OK
1700 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
1701 6 common/cmd_bootm.c Image Type check OK
1702 -6 common/cmd_bootm.c gunzip uncompression error
1703 -7 common/cmd_bootm.c Unimplemented compression type
1704 7 common/cmd_bootm.c Uncompression OK
1705 8 common/cmd_bootm.c No uncompress/copy overwrite error
1706 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1708 9 common/image.c Start initial ramdisk verification
1709 -10 common/image.c Ramdisk header has bad magic number
1710 -11 common/image.c Ramdisk header has bad checksum
1711 10 common/image.c Ramdisk header is OK
1712 -12 common/image.c Ramdisk data has bad checksum
1713 11 common/image.c Ramdisk data has correct checksum
1714 12 common/image.c Ramdisk verification complete, start loading
1715 -13 common/image.c Wrong Image Type (not PPC Linux Ramdisk)
1716 13 common/image.c Start multifile image verification
1717 14 common/image.c No initial ramdisk, no multifile, continue.
1719 15 lib_<arch>/bootm.c All preparation done, transferring control to OS
1721 -30 lib_ppc/board.c Fatal error, hang the system
1722 -31 post/post.c POST test failed, detected by post_output_backlog()
1723 -32 post/post.c POST test failed, detected by post_run_single()
1725 34 common/cmd_doc.c before loading a Image from a DOC device
1726 -35 common/cmd_doc.c Bad usage of "doc" command
1727 35 common/cmd_doc.c correct usage of "doc" command
1728 -36 common/cmd_doc.c No boot device
1729 36 common/cmd_doc.c correct boot device
1730 -37 common/cmd_doc.c Unknown Chip ID on boot device
1731 37 common/cmd_doc.c correct chip ID found, device available
1732 -38 common/cmd_doc.c Read Error on boot device
1733 38 common/cmd_doc.c reading Image header from DOC device OK
1734 -39 common/cmd_doc.c Image header has bad magic number
1735 39 common/cmd_doc.c Image header has correct magic number
1736 -40 common/cmd_doc.c Error reading Image from DOC device
1737 40 common/cmd_doc.c Image header has correct magic number
1738 41 common/cmd_ide.c before loading a Image from a IDE device
1739 -42 common/cmd_ide.c Bad usage of "ide" command
1740 42 common/cmd_ide.c correct usage of "ide" command
1741 -43 common/cmd_ide.c No boot device
1742 43 common/cmd_ide.c boot device found
1743 -44 common/cmd_ide.c Device not available
1744 44 common/cmd_ide.c Device available
1745 -45 common/cmd_ide.c wrong partition selected
1746 45 common/cmd_ide.c partition selected
1747 -46 common/cmd_ide.c Unknown partition table
1748 46 common/cmd_ide.c valid partition table found
1749 -47 common/cmd_ide.c Invalid partition type
1750 47 common/cmd_ide.c correct partition type
1751 -48 common/cmd_ide.c Error reading Image Header on boot device
1752 48 common/cmd_ide.c reading Image Header from IDE device OK
1753 -49 common/cmd_ide.c Image header has bad magic number
1754 49 common/cmd_ide.c Image header has correct magic number
1755 -50 common/cmd_ide.c Image header has bad checksum
1756 50 common/cmd_ide.c Image header has correct checksum
1757 -51 common/cmd_ide.c Error reading Image from IDE device
1758 51 common/cmd_ide.c reading Image from IDE device OK
1759 52 common/cmd_nand.c before loading a Image from a NAND device
1760 -53 common/cmd_nand.c Bad usage of "nand" command
1761 53 common/cmd_nand.c correct usage of "nand" command
1762 -54 common/cmd_nand.c No boot device
1763 54 common/cmd_nand.c boot device found
1764 -55 common/cmd_nand.c Unknown Chip ID on boot device
1765 55 common/cmd_nand.c correct chip ID found, device available
1766 -56 common/cmd_nand.c Error reading Image Header on boot device
1767 56 common/cmd_nand.c reading Image Header from NAND device OK
1768 -57 common/cmd_nand.c Image header has bad magic number
1769 57 common/cmd_nand.c Image header has correct magic number
1770 -58 common/cmd_nand.c Error reading Image from NAND device
1771 58 common/cmd_nand.c reading Image from NAND device OK
1773 -60 common/env_common.c Environment has a bad CRC, using default
1775 64 net/eth.c starting with Ethernetconfiguration.
1776 -64 net/eth.c no Ethernet found.
1777 65 net/eth.c Ethernet found.
1779 -80 common/cmd_net.c usage wrong
1780 80 common/cmd_net.c before calling NetLoop()
1781 -81 common/cmd_net.c some error in NetLoop() occured
1782 81 common/cmd_net.c NetLoop() back without error
1783 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
1784 82 common/cmd_net.c trying automatic boot
1785 83 common/cmd_net.c running autoscript
1786 -83 common/cmd_net.c some error in automatic boot or autoscript
1787 84 common/cmd_net.c end without errors
1792 100 common/cmd_bootm.c Kernel FIT Image has correct format
1793 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
1794 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
1795 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
1796 102 common/cmd_bootm.c Kernel unit name specified
1797 -103 common/cmd_bootm.c Can't get kernel subimage node offset
1798 103 common/cmd_bootm.c Found configuration node
1799 104 common/cmd_bootm.c Got kernel subimage node offset
1800 -104 common/cmd_bootm.c Kernel subimage hash verification failed
1801 105 common/cmd_bootm.c Kernel subimage hash verification OK
1802 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
1803 106 common/cmd_bootm.c Architecture check OK
1804 -106 common/cmd_bootm.c Kernel subimage has wrong typea
1805 107 common/cmd_bootm.c Kernel subimge type OK
1806 -107 common/cmd_bootm.c Can't get kernel subimage data/size
1807 108 common/cmd_bootm.c Got kernel subimage data/size
1808 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
1809 -109 common/cmd_bootm.c Can't get kernel subimage type
1810 -110 common/cmd_bootm.c Can't get kernel subimage comp
1811 -111 common/cmd_bootm.c Can't get kernel subimage os
1812 -112 common/cmd_bootm.c Can't get kernel subimage load address
1813 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
1815 120 common/image.c Start initial ramdisk verification
1816 -120 common/image.c Ramdisk FIT image has incorrect format
1817 121 common/image.c Ramdisk FIT image has correct format
1818 122 common/image.c No Ramdisk subimage unit name, using configuration
1819 -122 common/image.c Can't get configuration for ramdisk subimage
1820 123 common/image.c Ramdisk unit name specified
1821 -124 common/image.c Can't get ramdisk subimage node offset
1822 125 common/image.c Got ramdisk subimage node offset
1823 -125 common/image.c Ramdisk subimage hash verification failed
1824 126 common/image.c Ramdisk subimage hash verification OK
1825 -126 common/image.c Ramdisk subimage for unsupported architecture
1826 127 common/image.c Architecture check OK
1827 -127 common/image.c Can't get ramdisk subimage data/size
1828 128 common/image.c Got ramdisk subimage data/size
1829 129 common/image.c Can't get ramdisk load address
1830 -129 common/image.c Got ramdisk load address
1832 -130 common/cmd_doc.c Icorrect FIT image format
1833 131 common/cmd_doc.c FIT image format OK
1835 -140 common/cmd_ide.c Icorrect FIT image format
1836 141 common/cmd_ide.c FIT image format OK
1838 -150 common/cmd_nand.c Icorrect FIT image format
1839 151 common/cmd_nand.c FIT image format OK
1845 [so far only for SMDK2400 and TRAB boards]
1847 - Modem support endable:
1848 CONFIG_MODEM_SUPPORT
1850 - RTS/CTS Flow control enable:
1853 - Modem debug support:
1854 CONFIG_MODEM_SUPPORT_DEBUG
1856 Enables debugging stuff (char screen[1024], dbg())
1857 for modem support. Useful only with BDI2000.
1859 - Interrupt support (PPC):
1861 There are common interrupt_init() and timer_interrupt()
1862 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
1863 for cpu specific initialization. interrupt_init_cpu()
1864 should set decrementer_count to appropriate value. If
1865 cpu resets decrementer automatically after interrupt
1866 (ppc4xx) it should set decrementer_count to zero.
1867 timer_interrupt() calls timer_interrupt_cpu() for cpu
1868 specific handling. If board has watchdog / status_led
1869 / other_activity_monitor it works automatically from
1870 general timer_interrupt().
1874 In the target system modem support is enabled when a
1875 specific key (key combination) is pressed during
1876 power-on. Otherwise U-Boot will boot normally
1877 (autoboot). The key_pressed() fuction is called from
1878 board_init(). Currently key_pressed() is a dummy
1879 function, returning 1 and thus enabling modem
1882 If there are no modem init strings in the
1883 environment, U-Boot proceed to autoboot; the
1884 previous output (banner, info printfs) will be
1887 See also: doc/README.Modem
1890 Configuration Settings:
1891 -----------------------
1893 - CFG_LONGHELP: Defined when you want long help messages included;
1894 undefine this when you're short of memory.
1896 - CFG_PROMPT: This is what U-Boot prints on the console to
1897 prompt for user input.
1899 - CFG_CBSIZE: Buffer size for input from the Console
1901 - CFG_PBSIZE: Buffer size for Console output
1903 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1905 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1906 the application (usually a Linux kernel) when it is
1909 - CFG_BAUDRATE_TABLE:
1910 List of legal baudrate settings for this board.
1912 - CFG_CONSOLE_INFO_QUIET
1913 Suppress display of console information at boot.
1915 - CFG_CONSOLE_IS_IN_ENV
1916 If the board specific function
1917 extern int overwrite_console (void);
1918 returns 1, the stdin, stderr and stdout are switched to the
1919 serial port, else the settings in the environment are used.
1921 - CFG_CONSOLE_OVERWRITE_ROUTINE
1922 Enable the call to overwrite_console().
1924 - CFG_CONSOLE_ENV_OVERWRITE
1925 Enable overwrite of previous console environment settings.
1927 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1928 Begin and End addresses of the area used by the
1932 Enable an alternate, more extensive memory test.
1934 - CFG_MEMTEST_SCRATCH:
1935 Scratch address used by the alternate memory test
1936 You only need to set this if address zero isn't writeable
1938 - CFG_MEM_TOP_HIDE (PPC only):
1939 If CFG_MEM_TOP_HIDE is defined in the board config header,
1940 this specified memory area will get subtracted from the top
1941 (end) of ram and won't get "touched" at all by U-Boot. By
1942 fixing up gd->ram_size the Linux kernel should gets passed
1943 the now "corrected" memory size and won't touch it either.
1944 This should work for arch/ppc and arch/powerpc. Only Linux
1945 board ports in arch/powerpc with bootwrapper support that
1946 recalculate the memory size from the SDRAM controller setup
1947 will have to get fixed in Linux additionally.
1949 This option can be used as a workaround for the 440EPx/GRx
1950 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
1953 WARNING: Please make sure that this value is a multiple of
1954 the Linux page size (normally 4k). If this is not the case,
1955 then the end address of the Linux memory will be located at a
1956 non page size aligned address and this could cause major
1959 - CFG_TFTP_LOADADDR:
1960 Default load address for network file downloads
1962 - CFG_LOADS_BAUD_CHANGE:
1963 Enable temporary baudrate change while serial download
1966 Physical start address of SDRAM. _Must_ be 0 here.
1969 Physical start address of Motherboard I/O (if using a
1973 Physical start address of Flash memory.
1976 Physical start address of boot monitor code (set by
1977 make config files to be same as the text base address
1978 (TEXT_BASE) used when linking) - same as
1979 CFG_FLASH_BASE when booting from flash.
1982 Size of memory reserved for monitor code, used to
1983 determine _at_compile_time_ (!) if the environment is
1984 embedded within the U-Boot image, or in a separate
1988 Size of DRAM reserved for malloc() use.
1991 Normally compressed uImages are limited to an
1992 uncompressed size of 8 MBytes. If this is not enough,
1993 you can define CFG_BOOTM_LEN in your board config file
1994 to adjust this setting to your needs.
1997 Maximum size of memory mapped by the startup code of
1998 the Linux kernel; all data that must be processed by
1999 the Linux kernel (bd_info, boot arguments, eventually
2000 initrd image) must be put below this limit.
2002 - CFG_MAX_FLASH_BANKS:
2003 Max number of Flash memory banks
2005 - CFG_MAX_FLASH_SECT:
2006 Max number of sectors on a Flash chip
2008 - CFG_FLASH_ERASE_TOUT:
2009 Timeout for Flash erase operations (in ms)
2011 - CFG_FLASH_WRITE_TOUT:
2012 Timeout for Flash write operations (in ms)
2014 - CFG_FLASH_LOCK_TOUT
2015 Timeout for Flash set sector lock bit operation (in ms)
2017 - CFG_FLASH_UNLOCK_TOUT
2018 Timeout for Flash clear lock bits operation (in ms)
2020 - CFG_FLASH_PROTECTION
2021 If defined, hardware flash sectors protection is used
2022 instead of U-Boot software protection.
2024 - CFG_DIRECT_FLASH_TFTP:
2026 Enable TFTP transfers directly to flash memory;
2027 without this option such a download has to be
2028 performed in two steps: (1) download to RAM, and (2)
2029 copy from RAM to flash.
2031 The two-step approach is usually more reliable, since
2032 you can check if the download worked before you erase
2033 the flash, but in some situations (when sytem RAM is
2034 too limited to allow for a tempory copy of the
2035 downloaded image) this option may be very useful.
2038 Define if the flash driver uses extra elements in the
2039 common flash structure for storing flash geometry.
2041 - CFG_FLASH_CFI_DRIVER
2042 This option also enables the building of the cfi_flash driver
2043 in the drivers directory
2045 - CFG_FLASH_QUIET_TEST
2046 If this option is defined, the common CFI flash doesn't
2047 print it's warning upon not recognized FLASH banks. This
2048 is useful, if some of the configured banks are only
2049 optionally available.
2051 - CONFIG_FLASH_SHOW_PROGRESS
2052 If defined (must be an integer), print out countdown
2053 digits and dots. Recommended value: 45 (9..1) for 80
2054 column displays, 15 (3..1) for 40 column displays.
2056 - CFG_RX_ETH_BUFFER:
2057 Defines the number of ethernet receive buffers. On some
2058 ethernet controllers it is recommended to set this value
2059 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2060 buffers can be full shortly after enabling the interface
2061 on high ethernet traffic.
2062 Defaults to 4 if not defined.
2064 The following definitions that deal with the placement and management
2065 of environment data (variable area); in general, we support the
2066 following configurations:
2068 - CFG_ENV_IS_IN_FLASH:
2070 Define this if the environment is in flash memory.
2072 a) The environment occupies one whole flash sector, which is
2073 "embedded" in the text segment with the U-Boot code. This
2074 happens usually with "bottom boot sector" or "top boot
2075 sector" type flash chips, which have several smaller
2076 sectors at the start or the end. For instance, such a
2077 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2078 such a case you would place the environment in one of the
2079 4 kB sectors - with U-Boot code before and after it. With
2080 "top boot sector" type flash chips, you would put the
2081 environment in one of the last sectors, leaving a gap
2082 between U-Boot and the environment.
2086 Offset of environment data (variable area) to the
2087 beginning of flash memory; for instance, with bottom boot
2088 type flash chips the second sector can be used: the offset
2089 for this sector is given here.
2091 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
2095 This is just another way to specify the start address of
2096 the flash sector containing the environment (instead of
2099 - CFG_ENV_SECT_SIZE:
2101 Size of the sector containing the environment.
2104 b) Sometimes flash chips have few, equal sized, BIG sectors.
2105 In such a case you don't want to spend a whole sector for
2110 If you use this in combination with CFG_ENV_IS_IN_FLASH
2111 and CFG_ENV_SECT_SIZE, you can specify to use only a part
2112 of this flash sector for the environment. This saves
2113 memory for the RAM copy of the environment.
2115 It may also save flash memory if you decide to use this
2116 when your environment is "embedded" within U-Boot code,
2117 since then the remainder of the flash sector could be used
2118 for U-Boot code. It should be pointed out that this is
2119 STRONGLY DISCOURAGED from a robustness point of view:
2120 updating the environment in flash makes it always
2121 necessary to erase the WHOLE sector. If something goes
2122 wrong before the contents has been restored from a copy in
2123 RAM, your target system will be dead.
2125 - CFG_ENV_ADDR_REDUND
2128 These settings describe a second storage area used to hold
2129 a redundand copy of the environment data, so that there is
2130 a valid backup copy in case there is a power failure during
2131 a "saveenv" operation.
2133 BE CAREFUL! Any changes to the flash layout, and some changes to the
2134 source code will make it necessary to adapt <board>/u-boot.lds*
2138 - CFG_ENV_IS_IN_NVRAM:
2140 Define this if you have some non-volatile memory device
2141 (NVRAM, battery buffered SRAM) which you want to use for the
2147 These two #defines are used to determin the memory area you
2148 want to use for environment. It is assumed that this memory
2149 can just be read and written to, without any special
2152 BE CAREFUL! The first access to the environment happens quite early
2153 in U-Boot initalization (when we try to get the setting of for the
2154 console baudrate). You *MUST* have mappend your NVRAM area then, or
2157 Please note that even with NVRAM we still use a copy of the
2158 environment in RAM: we could work on NVRAM directly, but we want to
2159 keep settings there always unmodified except somebody uses "saveenv"
2160 to save the current settings.
2163 - CFG_ENV_IS_IN_EEPROM:
2165 Use this if you have an EEPROM or similar serial access
2166 device and a driver for it.
2171 These two #defines specify the offset and size of the
2172 environment area within the total memory of your EEPROM.
2174 - CFG_I2C_EEPROM_ADDR:
2175 If defined, specified the chip address of the EEPROM device.
2176 The default address is zero.
2178 - CFG_EEPROM_PAGE_WRITE_BITS:
2179 If defined, the number of bits used to address bytes in a
2180 single page in the EEPROM device. A 64 byte page, for example
2181 would require six bits.
2183 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
2184 If defined, the number of milliseconds to delay between
2185 page writes. The default is zero milliseconds.
2187 - CFG_I2C_EEPROM_ADDR_LEN:
2188 The length in bytes of the EEPROM memory array address. Note
2189 that this is NOT the chip address length!
2191 - CFG_I2C_EEPROM_ADDR_OVERFLOW:
2192 EEPROM chips that implement "address overflow" are ones
2193 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2194 address and the extra bits end up in the "chip address" bit
2195 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2198 Note that we consider the length of the address field to
2199 still be one byte because the extra address bits are hidden
2200 in the chip address.
2203 The size in bytes of the EEPROM device.
2206 - CFG_ENV_IS_IN_DATAFLASH:
2208 Define this if you have a DataFlash memory device which you
2209 want to use for the environment.
2215 These three #defines specify the offset and size of the
2216 environment area within the total memory of your DataFlash placed
2217 at the specified address.
2219 - CFG_ENV_IS_IN_NAND:
2221 Define this if you have a NAND device which you want to use
2222 for the environment.
2227 These two #defines specify the offset and size of the environment
2228 area within the first NAND device.
2230 - CFG_ENV_OFFSET_REDUND
2232 This setting describes a second storage area of CFG_ENV_SIZE
2233 size used to hold a redundant copy of the environment data,
2234 so that there is a valid backup copy in case there is a
2235 power failure during a "saveenv" operation.
2237 Note: CFG_ENV_OFFSET and CFG_ENV_OFFSET_REDUND must be aligned
2238 to a block boundary, and CFG_ENV_SIZE must be a multiple of
2239 the NAND devices block size.
2241 - CFG_SPI_INIT_OFFSET
2243 Defines offset to the initial SPI buffer area in DPRAM. The
2244 area is used at an early stage (ROM part) if the environment
2245 is configured to reside in the SPI EEPROM: We need a 520 byte
2246 scratch DPRAM area. It is used between the two initialization
2247 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2248 to be a good choice since it makes it far enough from the
2249 start of the data area as well as from the stack pointer.
2251 Please note that the environment is read-only until the monitor
2252 has been relocated to RAM and a RAM copy of the environment has been
2253 created; also, when using EEPROM you will have to use getenv_r()
2254 until then to read environment variables.
2256 The environment is protected by a CRC32 checksum. Before the monitor
2257 is relocated into RAM, as a result of a bad CRC you will be working
2258 with the compiled-in default environment - *silently*!!! [This is
2259 necessary, because the first environment variable we need is the
2260 "baudrate" setting for the console - if we have a bad CRC, we don't
2261 have any device yet where we could complain.]
2263 Note: once the monitor has been relocated, then it will complain if
2264 the default environment is used; a new CRC is computed as soon as you
2265 use the "saveenv" command to store a valid environment.
2267 - CFG_FAULT_ECHO_LINK_DOWN:
2268 Echo the inverted Ethernet link state to the fault LED.
2270 Note: If this option is active, then CFG_FAULT_MII_ADDR
2271 also needs to be defined.
2273 - CFG_FAULT_MII_ADDR:
2274 MII address of the PHY to check for the Ethernet link state.
2276 - CFG_64BIT_VSPRINTF:
2277 Makes vsprintf (and all *printf functions) support printing
2278 of 64bit values by using the L quantifier
2280 - CFG_64BIT_STRTOUL:
2281 Adds simple_strtoull that returns a 64bit value
2283 Low Level (hardware related) configuration options:
2284 ---------------------------------------------------
2286 - CFG_CACHELINE_SIZE:
2287 Cache Line Size of the CPU.
2290 Default address of the IMMR after system reset.
2292 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2293 and RPXsuper) to be able to adjust the position of
2294 the IMMR register after a reset.
2296 - Floppy Disk Support:
2297 CFG_FDC_DRIVE_NUMBER
2299 the default drive number (default value 0)
2303 defines the spacing between fdc chipset registers
2308 defines the offset of register from address. It
2309 depends on which part of the data bus is connected to
2310 the fdc chipset. (default value 0)
2312 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
2313 CFG_FDC_DRIVE_NUMBER are undefined, they take their
2316 if CFG_FDC_HW_INIT is defined, then the function
2317 fdc_hw_init() is called at the beginning of the FDC
2318 setup. fdc_hw_init() must be provided by the board
2319 source code. It is used to make hardware dependant
2322 - CFG_IMMR: Physical address of the Internal Memory.
2323 DO NOT CHANGE unless you know exactly what you're
2324 doing! (11-4) [MPC8xx/82xx systems only]
2326 - CFG_INIT_RAM_ADDR:
2328 Start address of memory area that can be used for
2329 initial data and stack; please note that this must be
2330 writable memory that is working WITHOUT special
2331 initialization, i. e. you CANNOT use normal RAM which
2332 will become available only after programming the
2333 memory controller and running certain initialization
2336 U-Boot uses the following memory types:
2337 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2338 - MPC824X: data cache
2339 - PPC4xx: data cache
2341 - CFG_GBL_DATA_OFFSET:
2343 Offset of the initial data structure in the memory
2344 area defined by CFG_INIT_RAM_ADDR. Usually
2345 CFG_GBL_DATA_OFFSET is chosen such that the initial
2346 data is located at the end of the available space
2347 (sometimes written as (CFG_INIT_RAM_END -
2348 CFG_INIT_DATA_SIZE), and the initial stack is just
2349 below that area (growing from (CFG_INIT_RAM_ADDR +
2350 CFG_GBL_DATA_OFFSET) downward.
2353 On the MPC824X (or other systems that use the data
2354 cache for initial memory) the address chosen for
2355 CFG_INIT_RAM_ADDR is basically arbitrary - it must
2356 point to an otherwise UNUSED address space between
2357 the top of RAM and the start of the PCI space.
2359 - CFG_SIUMCR: SIU Module Configuration (11-6)
2361 - CFG_SYPCR: System Protection Control (11-9)
2363 - CFG_TBSCR: Time Base Status and Control (11-26)
2365 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
2367 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2369 - CFG_SCCR: System Clock and reset Control Register (15-27)
2371 - CFG_OR_TIMING_SDRAM:
2375 periodic timer for refresh
2377 - CFG_DER: Debug Event Register (37-47)
2379 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
2380 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
2381 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
2383 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2385 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2386 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
2387 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
2388 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2390 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
2391 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
2392 Machine Mode Register and Memory Periodic Timer
2393 Prescaler definitions (SDRAM timing)
2395 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
2396 enable I2C microcode relocation patch (MPC8xx);
2397 define relocation offset in DPRAM [DSP2]
2399 - CFG_SMC_UCODE_PATCH, CFG_SMC_DPMEM_OFFSET [0x1FC0]:
2400 enable SMC microcode relocation patch (MPC8xx);
2401 define relocation offset in DPRAM [SMC1]
2403 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
2404 enable SPI microcode relocation patch (MPC8xx);
2405 define relocation offset in DPRAM [SCC4]
2408 Use OSCM clock mode on MBX8xx board. Be careful,
2409 wrong setting might damage your board. Read
2410 doc/README.MBX before setting this variable!
2412 - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2413 Offset of the bootmode word in DPRAM used by post
2414 (Power On Self Tests). This definition overrides
2415 #define'd default value in commproc.h resp.
2418 - CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
2419 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
2420 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
2421 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
2422 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2423 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
2424 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
2425 CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
2426 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2429 Get DDR timing information from an I2C EEPROM. Common
2430 with pluggable memory modules such as SODIMMs
2433 I2C address of the SPD EEPROM
2436 If SPD EEPROM is on an I2C bus other than the first
2437 one, specify here. Note that the value must resolve
2438 to something your driver can deal with.
2440 - CFG_83XX_DDR_USES_CS0
2441 Only for 83xx systems. If specified, then DDR should
2442 be configured using CS0 and CS1 instead of CS2 and CS3.
2444 - CFG_83XX_DDR_USES_CS0
2445 Only for 83xx systems. If specified, then DDR should
2446 be configured using CS0 and CS1 instead of CS2 and CS3.
2448 - CONFIG_ETHER_ON_FEC[12]
2449 Define to enable FEC[12] on a 8xx series processor.
2451 - CONFIG_FEC[12]_PHY
2452 Define to the hardcoded PHY address which corresponds
2453 to the given FEC; i. e.
2454 #define CONFIG_FEC1_PHY 4
2455 means that the PHY with address 4 is connected to FEC1
2457 When set to -1, means to probe for first available.
2459 - CONFIG_FEC[12]_PHY_NORXERR
2460 The PHY does not have a RXERR line (RMII only).
2461 (so program the FEC to ignore it).
2464 Enable RMII mode for all FECs.
2465 Note that this is a global option, we can't
2466 have one FEC in standard MII mode and another in RMII mode.
2468 - CONFIG_CRC32_VERIFY
2469 Add a verify option to the crc32 command.
2472 => crc32 -v <address> <count> <crc32>
2474 Where address/count indicate a memory area
2475 and crc32 is the correct crc32 which the
2479 Add the "loopw" memory command. This only takes effect if
2480 the memory commands are activated globally (CONFIG_CMD_MEM).
2483 Add the "mdc" and "mwc" memory commands. These are cyclic
2488 This command will print 4 bytes (10,11,12,13) each 500 ms.
2490 => mwc.l 100 12345678 10
2491 This command will write 12345678 to address 100 all 10 ms.
2493 This only takes effect if the memory commands are activated
2494 globally (CONFIG_CMD_MEM).
2496 - CONFIG_SKIP_LOWLEVEL_INIT
2497 - CONFIG_SKIP_RELOCATE_UBOOT
2499 [ARM only] If these variables are defined, then
2500 certain low level initializations (like setting up
2501 the memory controller) are omitted and/or U-Boot does
2502 not relocate itself into RAM.
2503 Normally these variables MUST NOT be defined. The
2504 only exception is when U-Boot is loaded (to RAM) by
2505 some other boot loader or by a debugger which
2506 performs these intializations itself.
2509 Building the Software:
2510 ======================
2512 Building U-Boot has been tested in several native build environments
2513 and in many different cross environments. Of course we cannot support
2514 all possibly existing versions of cross development tools in all
2515 (potentially obsolete) versions. In case of tool chain problems we
2516 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2517 which is extensively used to build and test U-Boot.
2519 If you are not using a native environment, it is assumed that you
2520 have GNU cross compiling tools available in your path. In this case,
2521 you must set the environment variable CROSS_COMPILE in your shell.
2522 Note that no changes to the Makefile or any other source files are
2523 necessary. For example using the ELDK on a 4xx CPU, please enter:
2525 $ CROSS_COMPILE=ppc_4xx-
2526 $ export CROSS_COMPILE
2528 U-Boot is intended to be simple to build. After installing the
2529 sources you must configure U-Boot for one specific board type. This
2534 where "NAME_config" is the name of one of the existing configu-
2535 rations; see the main Makefile for supported names.
2537 Note: for some board special configuration names may exist; check if
2538 additional information is available from the board vendor; for
2539 instance, the TQM823L systems are available without (standard)
2540 or with LCD support. You can select such additional "features"
2541 when chosing the configuration, i. e.
2544 - will configure for a plain TQM823L, i. e. no LCD support
2546 make TQM823L_LCD_config
2547 - will configure for a TQM823L with U-Boot console on LCD
2552 Finally, type "make all", and you should get some working U-Boot
2553 images ready for download to / installation on your system:
2555 - "u-boot.bin" is a raw binary image
2556 - "u-boot" is an image in ELF binary format
2557 - "u-boot.srec" is in Motorola S-Record format
2559 By default the build is performed locally and the objects are saved
2560 in the source directory. One of the two methods can be used to change
2561 this behavior and build U-Boot to some external directory:
2563 1. Add O= to the make command line invocations:
2565 make O=/tmp/build distclean
2566 make O=/tmp/build NAME_config
2567 make O=/tmp/build all
2569 2. Set environment variable BUILD_DIR to point to the desired location:
2571 export BUILD_DIR=/tmp/build
2576 Note that the command line "O=" setting overrides the BUILD_DIR environment
2580 Please be aware that the Makefiles assume you are using GNU make, so
2581 for instance on NetBSD you might need to use "gmake" instead of
2585 If the system board that you have is not listed, then you will need
2586 to port U-Boot to your hardware platform. To do this, follow these
2589 1. Add a new configuration option for your board to the toplevel
2590 "Makefile" and to the "MAKEALL" script, using the existing
2591 entries as examples. Note that here and at many other places
2592 boards and other names are listed in alphabetical sort order. Please
2594 2. Create a new directory to hold your board specific code. Add any
2595 files you need. In your board directory, you will need at least
2596 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2597 3. Create a new configuration file "include/configs/<board>.h" for
2599 3. If you're porting U-Boot to a new CPU, then also create a new
2600 directory to hold your CPU specific code. Add any files you need.
2601 4. Run "make <board>_config" with your new name.
2602 5. Type "make", and you should get a working "u-boot.srec" file
2603 to be installed on your target system.
2604 6. Debug and solve any problems that might arise.
2605 [Of course, this last step is much harder than it sounds.]
2608 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2609 ==============================================================
2611 If you have modified U-Boot sources (for instance added a new board
2612 or support for new devices, a new CPU, etc.) you are expected to
2613 provide feedback to the other developers. The feedback normally takes
2614 the form of a "patch", i. e. a context diff against a certain (latest
2615 official or latest in the git repository) version of U-Boot sources.
2617 But before you submit such a patch, please verify that your modifi-
2618 cation did not break existing code. At least make sure that *ALL* of
2619 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2620 just run the "MAKEALL" script, which will configure and build U-Boot
2621 for ALL supported system. Be warned, this will take a while. You can
2622 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2623 environment variable to the script, i. e. to use the ELDK cross tools
2626 CROSS_COMPILE=ppc_8xx- MAKEALL
2628 or to build on a native PowerPC system you can type
2630 CROSS_COMPILE=' ' MAKEALL
2632 When using the MAKEALL script, the default behaviour is to build
2633 U-Boot in the source directory. This location can be changed by
2634 setting the BUILD_DIR environment variable. Also, for each target
2635 built, the MAKEALL script saves two log files (<target>.ERR and
2636 <target>.MAKEALL) in the <source dir>/LOG directory. This default
2637 location can be changed by setting the MAKEALL_LOGDIR environment
2638 variable. For example:
2640 export BUILD_DIR=/tmp/build
2641 export MAKEALL_LOGDIR=/tmp/log
2642 CROSS_COMPILE=ppc_8xx- MAKEALL
2644 With the above settings build objects are saved in the /tmp/build,
2645 log files are saved in the /tmp/log and the source tree remains clean
2646 during the whole build process.
2649 See also "U-Boot Porting Guide" below.
2652 Monitor Commands - Overview:
2653 ============================
2655 go - start application at address 'addr'
2656 run - run commands in an environment variable
2657 bootm - boot application image from memory
2658 bootp - boot image via network using BootP/TFTP protocol
2659 tftpboot- boot image via network using TFTP protocol
2660 and env variables "ipaddr" and "serverip"
2661 (and eventually "gatewayip")
2662 rarpboot- boot image via network using RARP/TFTP protocol
2663 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2664 loads - load S-Record file over serial line
2665 loadb - load binary file over serial line (kermit mode)
2667 mm - memory modify (auto-incrementing)
2668 nm - memory modify (constant address)
2669 mw - memory write (fill)
2671 cmp - memory compare
2672 crc32 - checksum calculation
2673 imd - i2c memory display
2674 imm - i2c memory modify (auto-incrementing)
2675 inm - i2c memory modify (constant address)
2676 imw - i2c memory write (fill)
2677 icrc32 - i2c checksum calculation
2678 iprobe - probe to discover valid I2C chip addresses
2679 iloop - infinite loop on address range
2680 isdram - print SDRAM configuration information
2681 sspi - SPI utility commands
2682 base - print or set address offset
2683 printenv- print environment variables
2684 setenv - set environment variables
2685 saveenv - save environment variables to persistent storage
2686 protect - enable or disable FLASH write protection
2687 erase - erase FLASH memory
2688 flinfo - print FLASH memory information
2689 bdinfo - print Board Info structure
2690 iminfo - print header information for application image
2691 coninfo - print console devices and informations
2692 ide - IDE sub-system
2693 loop - infinite loop on address range
2694 loopw - infinite write loop on address range
2695 mtest - simple RAM test
2696 icache - enable or disable instruction cache
2697 dcache - enable or disable data cache
2698 reset - Perform RESET of the CPU
2699 echo - echo args to console
2700 version - print monitor version
2701 help - print online help
2702 ? - alias for 'help'
2705 Monitor Commands - Detailed Description:
2706 ========================================
2710 For now: just type "help <command>".
2713 Environment Variables:
2714 ======================
2716 U-Boot supports user configuration using Environment Variables which
2717 can be made persistent by saving to Flash memory.
2719 Environment Variables are set using "setenv", printed using
2720 "printenv", and saved to Flash using "saveenv". Using "setenv"
2721 without a value can be used to delete a variable from the
2722 environment. As long as you don't save the environment you are
2723 working with an in-memory copy. In case the Flash area containing the
2724 environment is erased by accident, a default environment is provided.
2726 Some configuration options can be set using Environment Variables:
2728 baudrate - see CONFIG_BAUDRATE
2730 bootdelay - see CONFIG_BOOTDELAY
2732 bootcmd - see CONFIG_BOOTCOMMAND
2734 bootargs - Boot arguments when booting an RTOS image
2736 bootfile - Name of the image to load with TFTP
2738 autoload - if set to "no" (any string beginning with 'n'),
2739 "bootp" will just load perform a lookup of the
2740 configuration from the BOOTP server, but not try to
2741 load any image using TFTP
2743 autoscript - if set to "yes" commands like "loadb", "loady",
2744 "bootp", "tftpb", "rarpboot" and "nfs" will attempt
2745 to automatically run script images (by internally
2746 calling "autoscript").
2748 autoscript_uname - if script image is in a format (FIT) this
2749 variable is used to get script subimage unit name.
2751 autostart - if set to "yes", an image loaded using the "bootp",
2752 "rarpboot", "tftpboot" or "diskboot" commands will
2753 be automatically started (by internally calling
2756 If set to "no", a standalone image passed to the
2757 "bootm" command will be copied to the load address
2758 (and eventually uncompressed), but NOT be started.
2759 This can be used to load and uncompress arbitrary
2762 i2cfast - (PPC405GP|PPC405EP only)
2763 if set to 'y' configures Linux I2C driver for fast
2764 mode (400kHZ). This environment variable is used in
2765 initialization code. So, for changes to be effective
2766 it must be saved and board must be reset.
2768 initrd_high - restrict positioning of initrd images:
2769 If this variable is not set, initrd images will be
2770 copied to the highest possible address in RAM; this
2771 is usually what you want since it allows for
2772 maximum initrd size. If for some reason you want to
2773 make sure that the initrd image is loaded below the
2774 CFG_BOOTMAPSZ limit, you can set this environment
2775 variable to a value of "no" or "off" or "0".
2776 Alternatively, you can set it to a maximum upper
2777 address to use (U-Boot will still check that it
2778 does not overwrite the U-Boot stack and data).
2780 For instance, when you have a system with 16 MB
2781 RAM, and want to reserve 4 MB from use by Linux,
2782 you can do this by adding "mem=12M" to the value of
2783 the "bootargs" variable. However, now you must make
2784 sure that the initrd image is placed in the first
2785 12 MB as well - this can be done with
2787 setenv initrd_high 00c00000
2789 If you set initrd_high to 0xFFFFFFFF, this is an
2790 indication to U-Boot that all addresses are legal
2791 for the Linux kernel, including addresses in flash
2792 memory. In this case U-Boot will NOT COPY the
2793 ramdisk at all. This may be useful to reduce the
2794 boot time on your system, but requires that this
2795 feature is supported by your Linux kernel.
2797 ipaddr - IP address; needed for tftpboot command
2799 loadaddr - Default load address for commands like "bootp",
2800 "rarpboot", "tftpboot", "loadb" or "diskboot"
2802 loads_echo - see CONFIG_LOADS_ECHO
2804 serverip - TFTP server IP address; needed for tftpboot command
2806 bootretry - see CONFIG_BOOT_RETRY_TIME
2808 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
2810 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
2812 ethprime - When CONFIG_NET_MULTI is enabled controls which
2813 interface is used first.
2815 ethact - When CONFIG_NET_MULTI is enabled controls which
2816 interface is currently active. For example you
2817 can do the following
2819 => setenv ethact FEC ETHERNET
2820 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
2821 => setenv ethact SCC ETHERNET
2822 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
2824 ethrotate - When set to "no" U-Boot does not go through all
2825 available network interfaces.
2826 It just stays at the currently selected interface.
2828 netretry - When set to "no" each network operation will
2829 either succeed or fail without retrying.
2830 When set to "once" the network operation will
2831 fail when all the available network interfaces
2832 are tried once without success.
2833 Useful on scripts which control the retry operation
2836 npe_ucode - see CONFIG_IXP4XX_NPE_EXT_UCOD
2837 if set load address for the npe microcode
2839 tftpsrcport - If this is set, the value is used for TFTP's
2842 tftpdstport - If this is set, the value is used for TFTP's UDP
2843 destination port instead of the Well Know Port 69.
2845 vlan - When set to a value < 4095 the traffic over
2846 ethernet is encapsulated/received over 802.1q
2849 The following environment variables may be used and automatically
2850 updated by the network boot commands ("bootp" and "rarpboot"),
2851 depending the information provided by your boot server:
2853 bootfile - see above
2854 dnsip - IP address of your Domain Name Server
2855 dnsip2 - IP address of your secondary Domain Name Server
2856 gatewayip - IP address of the Gateway (Router) to use
2857 hostname - Target hostname
2859 netmask - Subnet Mask
2860 rootpath - Pathname of the root filesystem on the NFS server
2861 serverip - see above
2864 There are two special Environment Variables:
2866 serial# - contains hardware identification information such
2867 as type string and/or serial number
2868 ethaddr - Ethernet address
2870 These variables can be set only once (usually during manufacturing of
2871 the board). U-Boot refuses to delete or overwrite these variables
2872 once they have been set once.
2875 Further special Environment Variables:
2877 ver - Contains the U-Boot version string as printed
2878 with the "version" command. This variable is
2879 readonly (see CONFIG_VERSION_VARIABLE).
2882 Please note that changes to some configuration parameters may take
2883 only effect after the next boot (yes, that's just like Windoze :-).
2886 Command Line Parsing:
2887 =====================
2889 There are two different command line parsers available with U-Boot:
2890 the old "simple" one, and the much more powerful "hush" shell:
2892 Old, simple command line parser:
2893 --------------------------------
2895 - supports environment variables (through setenv / saveenv commands)
2896 - several commands on one line, separated by ';'
2897 - variable substitution using "... ${name} ..." syntax
2898 - special characters ('$', ';') can be escaped by prefixing with '\',
2900 setenv bootcmd bootm \${address}
2901 - You can also escape text by enclosing in single apostrophes, for example:
2902 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2907 - similar to Bourne shell, with control structures like
2908 if...then...else...fi, for...do...done; while...do...done,
2909 until...do...done, ...
2910 - supports environment ("global") variables (through setenv / saveenv
2911 commands) and local shell variables (through standard shell syntax
2912 "name=value"); only environment variables can be used with "run"
2918 (1) If a command line (or an environment variable executed by a "run"
2919 command) contains several commands separated by semicolon, and
2920 one of these commands fails, then the remaining commands will be
2923 (2) If you execute several variables with one call to run (i. e.
2924 calling run with a list af variables as arguments), any failing
2925 command will cause "run" to terminate, i. e. the remaining
2926 variables are not executed.
2928 Note for Redundant Ethernet Interfaces:
2929 =======================================
2931 Some boards come with redundant ethernet interfaces; U-Boot supports
2932 such configurations and is capable of automatic selection of a
2933 "working" interface when needed. MAC assignment works as follows:
2935 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2936 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2937 "eth1addr" (=>eth1), "eth2addr", ...
2939 If the network interface stores some valid MAC address (for instance
2940 in SROM), this is used as default address if there is NO correspon-
2941 ding setting in the environment; if the corresponding environment
2942 variable is set, this overrides the settings in the card; that means:
2944 o If the SROM has a valid MAC address, and there is no address in the
2945 environment, the SROM's address is used.
2947 o If there is no valid address in the SROM, and a definition in the
2948 environment exists, then the value from the environment variable is
2951 o If both the SROM and the environment contain a MAC address, and
2952 both addresses are the same, this MAC address is used.
2954 o If both the SROM and the environment contain a MAC address, and the
2955 addresses differ, the value from the environment is used and a
2958 o If neither SROM nor the environment contain a MAC address, an error
2965 U-Boot is capable of booting (and performing other auxiliary operations on)
2966 images in two formats:
2968 New uImage format (FIT)
2969 -----------------------
2971 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
2972 to Flattened Device Tree). It allows the use of images with multiple
2973 components (several kernels, ramdisks, etc.), with contents protected by
2974 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
2980 Old image format is based on binary files which can be basically anything,
2981 preceded by a special header; see the definitions in include/image.h for
2982 details; basically, the header defines the following image properties:
2984 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2985 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2986 LynxOS, pSOS, QNX, RTEMS, ARTOS;
2987 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
2988 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
2989 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2990 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
2991 * Compression Type (uncompressed, gzip, bzip2)
2997 The header is marked by a special Magic Number, and both the header
2998 and the data portions of the image are secured against corruption by
3005 Although U-Boot should support any OS or standalone application
3006 easily, the main focus has always been on Linux during the design of
3009 U-Boot includes many features that so far have been part of some
3010 special "boot loader" code within the Linux kernel. Also, any
3011 "initrd" images to be used are no longer part of one big Linux image;
3012 instead, kernel and "initrd" are separate images. This implementation
3013 serves several purposes:
3015 - the same features can be used for other OS or standalone
3016 applications (for instance: using compressed images to reduce the
3017 Flash memory footprint)
3019 - it becomes much easier to port new Linux kernel versions because
3020 lots of low-level, hardware dependent stuff are done by U-Boot
3022 - the same Linux kernel image can now be used with different "initrd"
3023 images; of course this also means that different kernel images can
3024 be run with the same "initrd". This makes testing easier (you don't
3025 have to build a new "zImage.initrd" Linux image when you just
3026 change a file in your "initrd"). Also, a field-upgrade of the
3027 software is easier now.
3033 Porting Linux to U-Boot based systems:
3034 ---------------------------------------
3036 U-Boot cannot save you from doing all the necessary modifications to
3037 configure the Linux device drivers for use with your target hardware
3038 (no, we don't intend to provide a full virtual machine interface to
3041 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
3043 Just make sure your machine specific header file (for instance
3044 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3045 Information structure as we define in include/u-boot.h, and make
3046 sure that your definition of IMAP_ADDR uses the same value as your
3047 U-Boot configuration in CFG_IMMR.
3050 Configuring the Linux kernel:
3051 -----------------------------
3053 No specific requirements for U-Boot. Make sure you have some root
3054 device (initial ramdisk, NFS) for your target system.
3057 Building a Linux Image:
3058 -----------------------
3060 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3061 not used. If you use recent kernel source, a new build target
3062 "uImage" will exist which automatically builds an image usable by
3063 U-Boot. Most older kernels also have support for a "pImage" target,
3064 which was introduced for our predecessor project PPCBoot and uses a
3065 100% compatible format.
3074 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3075 encapsulate a compressed Linux kernel image with header information,
3076 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3078 * build a standard "vmlinux" kernel image (in ELF binary format):
3080 * convert the kernel into a raw binary image:
3082 ${CROSS_COMPILE}-objcopy -O binary \
3083 -R .note -R .comment \
3084 -S vmlinux linux.bin
3086 * compress the binary image:
3090 * package compressed binary image for U-Boot:
3092 mkimage -A ppc -O linux -T kernel -C gzip \
3093 -a 0 -e 0 -n "Linux Kernel Image" \
3094 -d linux.bin.gz uImage
3097 The "mkimage" tool can also be used to create ramdisk images for use
3098 with U-Boot, either separated from the Linux kernel image, or
3099 combined into one file. "mkimage" encapsulates the images with a 64
3100 byte header containing information about target architecture,
3101 operating system, image type, compression method, entry points, time
3102 stamp, CRC32 checksums, etc.
3104 "mkimage" can be called in two ways: to verify existing images and
3105 print the header information, or to build new images.
3107 In the first form (with "-l" option) mkimage lists the information
3108 contained in the header of an existing U-Boot image; this includes
3109 checksum verification:
3111 tools/mkimage -l image
3112 -l ==> list image header information
3114 The second form (with "-d" option) is used to build a U-Boot image
3115 from a "data file" which is used as image payload:
3117 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3118 -n name -d data_file image
3119 -A ==> set architecture to 'arch'
3120 -O ==> set operating system to 'os'
3121 -T ==> set image type to 'type'
3122 -C ==> set compression type 'comp'
3123 -a ==> set load address to 'addr' (hex)
3124 -e ==> set entry point to 'ep' (hex)
3125 -n ==> set image name to 'name'
3126 -d ==> use image data from 'datafile'
3128 Right now, all Linux kernels for PowerPC systems use the same load
3129 address (0x00000000), but the entry point address depends on the
3132 - 2.2.x kernels have the entry point at 0x0000000C,
3133 - 2.3.x and later kernels have the entry point at 0x00000000.
3135 So a typical call to build a U-Boot image would read:
3137 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3138 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3139 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
3140 > examples/uImage.TQM850L
3141 Image Name: 2.4.4 kernel for TQM850L
3142 Created: Wed Jul 19 02:34:59 2000
3143 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3144 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3145 Load Address: 0x00000000
3146 Entry Point: 0x00000000
3148 To verify the contents of the image (or check for corruption):
3150 -> tools/mkimage -l examples/uImage.TQM850L
3151 Image Name: 2.4.4 kernel for TQM850L
3152 Created: Wed Jul 19 02:34:59 2000
3153 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3154 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3155 Load Address: 0x00000000
3156 Entry Point: 0x00000000
3158 NOTE: for embedded systems where boot time is critical you can trade
3159 speed for memory and install an UNCOMPRESSED image instead: this
3160 needs more space in Flash, but boots much faster since it does not
3161 need to be uncompressed:
3163 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
3164 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3165 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3166 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
3167 > examples/uImage.TQM850L-uncompressed
3168 Image Name: 2.4.4 kernel for TQM850L
3169 Created: Wed Jul 19 02:34:59 2000
3170 Image Type: PowerPC Linux Kernel Image (uncompressed)
3171 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3172 Load Address: 0x00000000
3173 Entry Point: 0x00000000
3176 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3177 when your kernel is intended to use an initial ramdisk:
3179 -> tools/mkimage -n 'Simple Ramdisk Image' \
3180 > -A ppc -O linux -T ramdisk -C gzip \
3181 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3182 Image Name: Simple Ramdisk Image
3183 Created: Wed Jan 12 14:01:50 2000
3184 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3185 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3186 Load Address: 0x00000000
3187 Entry Point: 0x00000000
3190 Installing a Linux Image:
3191 -------------------------
3193 To downloading a U-Boot image over the serial (console) interface,
3194 you must convert the image to S-Record format:
3196 objcopy -I binary -O srec examples/image examples/image.srec
3198 The 'objcopy' does not understand the information in the U-Boot
3199 image header, so the resulting S-Record file will be relative to
3200 address 0x00000000. To load it to a given address, you need to
3201 specify the target address as 'offset' parameter with the 'loads'
3204 Example: install the image to address 0x40100000 (which on the
3205 TQM8xxL is in the first Flash bank):
3207 => erase 40100000 401FFFFF
3213 ## Ready for S-Record download ...
3214 ~>examples/image.srec
3215 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3217 15989 15990 15991 15992
3218 [file transfer complete]
3220 ## Start Addr = 0x00000000
3223 You can check the success of the download using the 'iminfo' command;
3224 this includes a checksum verification so you can be sure no data
3225 corruption happened:
3229 ## Checking Image at 40100000 ...
3230 Image Name: 2.2.13 for initrd on TQM850L
3231 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3232 Data Size: 335725 Bytes = 327 kB = 0 MB
3233 Load Address: 00000000
3234 Entry Point: 0000000c
3235 Verifying Checksum ... OK
3241 The "bootm" command is used to boot an application that is stored in
3242 memory (RAM or Flash). In case of a Linux kernel image, the contents
3243 of the "bootargs" environment variable is passed to the kernel as
3244 parameters. You can check and modify this variable using the
3245 "printenv" and "setenv" commands:
3248 => printenv bootargs
3249 bootargs=root=/dev/ram
3251 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3253 => printenv bootargs
3254 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3257 ## Booting Linux kernel at 40020000 ...
3258 Image Name: 2.2.13 for NFS on TQM850L
3259 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3260 Data Size: 381681 Bytes = 372 kB = 0 MB
3261 Load Address: 00000000
3262 Entry Point: 0000000c
3263 Verifying Checksum ... OK
3264 Uncompressing Kernel Image ... OK
3265 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
3266 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3267 time_init: decrementer frequency = 187500000/60
3268 Calibrating delay loop... 49.77 BogoMIPS
3269 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3272 If you want to boot a Linux kernel with initial ram disk, you pass
3273 the memory addresses of both the kernel and the initrd image (PPBCOOT
3274 format!) to the "bootm" command:
3276 => imi 40100000 40200000
3278 ## Checking Image at 40100000 ...
3279 Image Name: 2.2.13 for initrd on TQM850L
3280 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3281 Data Size: 335725 Bytes = 327 kB = 0 MB
3282 Load Address: 00000000
3283 Entry Point: 0000000c
3284 Verifying Checksum ... OK
3286 ## Checking Image at 40200000 ...
3287 Image Name: Simple Ramdisk Image
3288 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3289 Data Size: 566530 Bytes = 553 kB = 0 MB
3290 Load Address: 00000000
3291 Entry Point: 00000000
3292 Verifying Checksum ... OK
3294 => bootm 40100000 40200000
3295 ## Booting Linux kernel at 40100000 ...
3296 Image Name: 2.2.13 for initrd on TQM850L
3297 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3298 Data Size: 335725 Bytes = 327 kB = 0 MB
3299 Load Address: 00000000
3300 Entry Point: 0000000c
3301 Verifying Checksum ... OK
3302 Uncompressing Kernel Image ... OK
3303 ## Loading RAMDisk Image at 40200000 ...
3304 Image Name: Simple Ramdisk Image
3305 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3306 Data Size: 566530 Bytes = 553 kB = 0 MB
3307 Load Address: 00000000
3308 Entry Point: 00000000
3309 Verifying Checksum ... OK
3310 Loading Ramdisk ... OK
3311 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
3312 Boot arguments: root=/dev/ram
3313 time_init: decrementer frequency = 187500000/60
3314 Calibrating delay loop... 49.77 BogoMIPS
3316 RAMDISK: Compressed image found at block 0
3317 VFS: Mounted root (ext2 filesystem).
3321 Boot Linux and pass a flat device tree:
3324 First, U-Boot must be compiled with the appropriate defines. See the section
3325 titled "Linux Kernel Interface" above for a more in depth explanation. The
3326 following is an example of how to start a kernel and pass an updated
3332 oft=oftrees/mpc8540ads.dtb
3333 => tftp $oftaddr $oft
3334 Speed: 1000, full duplex
3336 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3337 Filename 'oftrees/mpc8540ads.dtb'.
3338 Load address: 0x300000
3341 Bytes transferred = 4106 (100a hex)
3342 => tftp $loadaddr $bootfile
3343 Speed: 1000, full duplex
3345 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3347 Load address: 0x200000
3348 Loading:############
3350 Bytes transferred = 1029407 (fb51f hex)
3355 => bootm $loadaddr - $oftaddr
3356 ## Booting image at 00200000 ...
3357 Image Name: Linux-2.6.17-dirty
3358 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3359 Data Size: 1029343 Bytes = 1005.2 kB
3360 Load Address: 00000000
3361 Entry Point: 00000000
3362 Verifying Checksum ... OK
3363 Uncompressing Kernel Image ... OK
3364 Booting using flat device tree at 0x300000
3365 Using MPC85xx ADS machine description
3366 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3370 More About U-Boot Image Types:
3371 ------------------------------
3373 U-Boot supports the following image types:
3375 "Standalone Programs" are directly runnable in the environment
3376 provided by U-Boot; it is expected that (if they behave
3377 well) you can continue to work in U-Boot after return from
3378 the Standalone Program.
3379 "OS Kernel Images" are usually images of some Embedded OS which
3380 will take over control completely. Usually these programs
3381 will install their own set of exception handlers, device
3382 drivers, set up the MMU, etc. - this means, that you cannot
3383 expect to re-enter U-Boot except by resetting the CPU.
3384 "RAMDisk Images" are more or less just data blocks, and their
3385 parameters (address, size) are passed to an OS kernel that is
3387 "Multi-File Images" contain several images, typically an OS
3388 (Linux) kernel image and one or more data images like
3389 RAMDisks. This construct is useful for instance when you want
3390 to boot over the network using BOOTP etc., where the boot
3391 server provides just a single image file, but you want to get
3392 for instance an OS kernel and a RAMDisk image.
3394 "Multi-File Images" start with a list of image sizes, each
3395 image size (in bytes) specified by an "uint32_t" in network
3396 byte order. This list is terminated by an "(uint32_t)0".
3397 Immediately after the terminating 0 follow the images, one by
3398 one, all aligned on "uint32_t" boundaries (size rounded up to
3399 a multiple of 4 bytes).
3401 "Firmware Images" are binary images containing firmware (like
3402 U-Boot or FPGA images) which usually will be programmed to
3405 "Script files" are command sequences that will be executed by
3406 U-Boot's command interpreter; this feature is especially
3407 useful when you configure U-Boot to use a real shell (hush)
3408 as command interpreter.
3414 One of the features of U-Boot is that you can dynamically load and
3415 run "standalone" applications, which can use some resources of
3416 U-Boot like console I/O functions or interrupt services.
3418 Two simple examples are included with the sources:
3423 'examples/hello_world.c' contains a small "Hello World" Demo
3424 application; it is automatically compiled when you build U-Boot.
3425 It's configured to run at address 0x00040004, so you can play with it
3429 ## Ready for S-Record download ...
3430 ~>examples/hello_world.srec
3431 1 2 3 4 5 6 7 8 9 10 11 ...
3432 [file transfer complete]
3434 ## Start Addr = 0x00040004
3436 => go 40004 Hello World! This is a test.
3437 ## Starting application at 0x00040004 ...
3448 Hit any key to exit ...
3450 ## Application terminated, rc = 0x0
3452 Another example, which demonstrates how to register a CPM interrupt
3453 handler with the U-Boot code, can be found in 'examples/timer.c'.
3454 Here, a CPM timer is set up to generate an interrupt every second.
3455 The interrupt service routine is trivial, just printing a '.'
3456 character, but this is just a demo program. The application can be
3457 controlled by the following keys:
3459 ? - print current values og the CPM Timer registers
3460 b - enable interrupts and start timer
3461 e - stop timer and disable interrupts
3462 q - quit application
3465 ## Ready for S-Record download ...
3466 ~>examples/timer.srec
3467 1 2 3 4 5 6 7 8 9 10 11 ...
3468 [file transfer complete]
3470 ## Start Addr = 0x00040004
3473 ## Starting application at 0x00040004 ...
3476 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3479 [q, b, e, ?] Set interval 1000000 us
3482 [q, b, e, ?] ........
3483 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3486 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3489 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3492 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3494 [q, b, e, ?] ...Stopping timer
3496 [q, b, e, ?] ## Application terminated, rc = 0x0
3502 Over time, many people have reported problems when trying to use the
3503 "minicom" terminal emulation program for serial download. I (wd)
3504 consider minicom to be broken, and recommend not to use it. Under
3505 Unix, I recommend to use C-Kermit for general purpose use (and
3506 especially for kermit binary protocol download ("loadb" command), and
3507 use "cu" for S-Record download ("loads" command).
3509 Nevertheless, if you absolutely want to use it try adding this
3510 configuration to your "File transfer protocols" section:
3512 Name Program Name U/D FullScr IO-Red. Multi
3513 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3514 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3520 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3521 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3523 Building requires a cross environment; it is known to work on
3524 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3525 need gmake since the Makefiles are not compatible with BSD make).
3526 Note that the cross-powerpc package does not install include files;
3527 attempting to build U-Boot will fail because <machine/ansi.h> is
3528 missing. This file has to be installed and patched manually:
3530 # cd /usr/pkg/cross/powerpc-netbsd/include
3532 # ln -s powerpc machine
3533 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3534 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3536 Native builds *don't* work due to incompatibilities between native
3537 and U-Boot include files.
3539 Booting assumes that (the first part of) the image booted is a
3540 stage-2 loader which in turn loads and then invokes the kernel
3541 proper. Loader sources will eventually appear in the NetBSD source
3542 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3543 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3546 Implementation Internals:
3547 =========================
3549 The following is not intended to be a complete description of every
3550 implementation detail. However, it should help to understand the
3551 inner workings of U-Boot and make it easier to port it to custom
3555 Initial Stack, Global Data:
3556 ---------------------------
3558 The implementation of U-Boot is complicated by the fact that U-Boot
3559 starts running out of ROM (flash memory), usually without access to
3560 system RAM (because the memory controller is not initialized yet).
3561 This means that we don't have writable Data or BSS segments, and BSS
3562 is not initialized as zero. To be able to get a C environment working
3563 at all, we have to allocate at least a minimal stack. Implementation
3564 options for this are defined and restricted by the CPU used: Some CPU
3565 models provide on-chip memory (like the IMMR area on MPC8xx and
3566 MPC826x processors), on others (parts of) the data cache can be
3567 locked as (mis-) used as memory, etc.
3569 Chris Hallinan posted a good summary of these issues to the
3570 u-boot-users mailing list:
3572 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3573 From: "Chris Hallinan" <clh@net1plus.com>
3574 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3577 Correct me if I'm wrong, folks, but the way I understand it
3578 is this: Using DCACHE as initial RAM for Stack, etc, does not
3579 require any physical RAM backing up the cache. The cleverness
3580 is that the cache is being used as a temporary supply of
3581 necessary storage before the SDRAM controller is setup. It's
3582 beyond the scope of this list to expain the details, but you
3583 can see how this works by studying the cache architecture and
3584 operation in the architecture and processor-specific manuals.
3586 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3587 is another option for the system designer to use as an
3588 initial stack/ram area prior to SDRAM being available. Either
3589 option should work for you. Using CS 4 should be fine if your
3590 board designers haven't used it for something that would
3591 cause you grief during the initial boot! It is frequently not
3594 CFG_INIT_RAM_ADDR should be somewhere that won't interfere
3595 with your processor/board/system design. The default value
3596 you will find in any recent u-boot distribution in
3597 walnut.h should work for you. I'd set it to a value larger
3598 than your SDRAM module. If you have a 64MB SDRAM module, set
3599 it above 400_0000. Just make sure your board has no resources
3600 that are supposed to respond to that address! That code in
3601 start.S has been around a while and should work as is when
3602 you get the config right.
3607 It is essential to remember this, since it has some impact on the C
3608 code for the initialization procedures:
3610 * Initialized global data (data segment) is read-only. Do not attempt
3613 * Do not use any unitialized global data (or implicitely initialized
3614 as zero data - BSS segment) at all - this is undefined, initiali-
3615 zation is performed later (when relocating to RAM).
3617 * Stack space is very limited. Avoid big data buffers or things like
3620 Having only the stack as writable memory limits means we cannot use
3621 normal global data to share information beween the code. But it
3622 turned out that the implementation of U-Boot can be greatly
3623 simplified by making a global data structure (gd_t) available to all
3624 functions. We could pass a pointer to this data as argument to _all_
3625 functions, but this would bloat the code. Instead we use a feature of
3626 the GCC compiler (Global Register Variables) to share the data: we
3627 place a pointer (gd) to the global data into a register which we
3628 reserve for this purpose.
3630 When choosing a register for such a purpose we are restricted by the
3631 relevant (E)ABI specifications for the current architecture, and by
3632 GCC's implementation.
3634 For PowerPC, the following registers have specific use:
3636 R2: reserved for system use
3637 R3-R4: parameter passing and return values
3638 R5-R10: parameter passing
3639 R13: small data area pointer
3643 (U-Boot also uses R14 as internal GOT pointer.)
3645 ==> U-Boot will use R2 to hold a pointer to the global data
3647 Note: on PPC, we could use a static initializer (since the
3648 address of the global data structure is known at compile time),
3649 but it turned out that reserving a register results in somewhat
3650 smaller code - although the code savings are not that big (on
3651 average for all boards 752 bytes for the whole U-Boot image,
3652 624 text + 127 data).
3654 On Blackfin, the normal C ABI (except for P5) is followed as documented here:
3655 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
3657 ==> U-Boot will use P5 to hold a pointer to the global data
3659 On ARM, the following registers are used:
3661 R0: function argument word/integer result
3662 R1-R3: function argument word
3664 R10: stack limit (used only if stack checking if enabled)
3665 R11: argument (frame) pointer
3666 R12: temporary workspace
3669 R15: program counter
3671 ==> U-Boot will use R8 to hold a pointer to the global data
3673 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3674 or current versions of GCC may "optimize" the code too much.
3679 U-Boot runs in system state and uses physical addresses, i.e. the
3680 MMU is not used either for address mapping nor for memory protection.
3682 The available memory is mapped to fixed addresses using the memory
3683 controller. In this process, a contiguous block is formed for each
3684 memory type (Flash, SDRAM, SRAM), even when it consists of several
3685 physical memory banks.
3687 U-Boot is installed in the first 128 kB of the first Flash bank (on
3688 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3689 booting and sizing and initializing DRAM, the code relocates itself
3690 to the upper end of DRAM. Immediately below the U-Boot code some
3691 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
3692 configuration setting]. Below that, a structure with global Board
3693 Info data is placed, followed by the stack (growing downward).
3695 Additionally, some exception handler code is copied to the low 8 kB
3696 of DRAM (0x00000000 ... 0x00001FFF).
3698 So a typical memory configuration with 16 MB of DRAM could look like
3701 0x0000 0000 Exception Vector code
3704 0x0000 2000 Free for Application Use
3710 0x00FB FF20 Monitor Stack (Growing downward)
3711 0x00FB FFAC Board Info Data and permanent copy of global data
3712 0x00FC 0000 Malloc Arena
3715 0x00FE 0000 RAM Copy of Monitor Code
3716 ... eventually: LCD or video framebuffer
3717 ... eventually: pRAM (Protected RAM - unchanged by reset)
3718 0x00FF FFFF [End of RAM]
3721 System Initialization:
3722 ----------------------
3724 In the reset configuration, U-Boot starts at the reset entry point
3725 (on most PowerPC systens at address 0x00000100). Because of the reset
3726 configuration for CS0# this is a mirror of the onboard Flash memory.
3727 To be able to re-map memory U-Boot then jumps to its link address.
3728 To be able to implement the initialization code in C, a (small!)
3729 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3730 which provide such a feature like MPC8xx or MPC8260), or in a locked
3731 part of the data cache. After that, U-Boot initializes the CPU core,
3732 the caches and the SIU.
3734 Next, all (potentially) available memory banks are mapped using a
3735 preliminary mapping. For example, we put them on 512 MB boundaries
3736 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3737 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3738 programmed for SDRAM access. Using the temporary configuration, a
3739 simple memory test is run that determines the size of the SDRAM
3742 When there is more than one SDRAM bank, and the banks are of
3743 different size, the largest is mapped first. For equal size, the first
3744 bank (CS2#) is mapped first. The first mapping is always for address
3745 0x00000000, with any additional banks following immediately to create
3746 contiguous memory starting from 0.
3748 Then, the monitor installs itself at the upper end of the SDRAM area
3749 and allocates memory for use by malloc() and for the global Board
3750 Info data; also, the exception vector code is copied to the low RAM
3751 pages, and the final stack is set up.
3753 Only after this relocation will you have a "normal" C environment;
3754 until that you are restricted in several ways, mostly because you are
3755 running from ROM, and because the code will have to be relocated to a
3759 U-Boot Porting Guide:
3760 ----------------------
3762 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3766 int main (int argc, char *argv[])
3768 sighandler_t no_more_time;
3770 signal (SIGALRM, no_more_time);
3771 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3773 if (available_money > available_manpower) {
3774 pay consultant to port U-Boot;
3778 Download latest U-Boot source;
3780 Subscribe to u-boot-users mailing list;
3783 email ("Hi, I am new to U-Boot, how do I get started?");
3787 Read the README file in the top level directory;
3788 Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
3789 Read the source, Luke;
3792 if (available_money > toLocalCurrency ($2500)) {
3795 Add a lot of aggravation and time;
3798 Create your own board support subdirectory;
3800 Create your own board config file;
3804 Add / modify source code;
3808 email ("Hi, I am having problems...");
3810 Send patch file to Wolfgang;
3815 void no_more_time (int sig)
3824 All contributions to U-Boot should conform to the Linux kernel
3825 coding style; see the file "Documentation/CodingStyle" and the script
3826 "scripts/Lindent" in your Linux kernel source directory. In sources
3827 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
3828 spaces before parameters to function calls) is actually used.
3830 Source files originating from a different project (for example the
3831 MTD subsystem) are generally exempt from these guidelines and are not
3832 reformated to ease subsequent migration to newer versions of those
3835 Please note that U-Boot is implemented in C (and to some small parts in
3836 Assembler); no C++ is used, so please do not use C++ style comments (//)
3839 Please also stick to the following formatting rules:
3840 - remove any trailing white space
3841 - use TAB characters for indentation, not spaces
3842 - make sure NOT to use DOS '\r\n' line feeds
3843 - do not add more than 2 empty lines to source files
3844 - do not add trailing empty lines to source files
3846 Submissions which do not conform to the standards may be returned
3847 with a request to reformat the changes.
3853 Since the number of patches for U-Boot is growing, we need to
3854 establish some rules. Submissions which do not conform to these rules
3855 may be rejected, even when they contain important and valuable stuff.
3857 Patches shall be sent to the u-boot-users mailing list.
3859 Please see http://www.denx.de/wiki/UBoot/Patches for details.
3861 When you send a patch, please include the following information with
3864 * For bug fixes: a description of the bug and how your patch fixes
3865 this bug. Please try to include a way of demonstrating that the
3866 patch actually fixes something.
3868 * For new features: a description of the feature and your
3871 * A CHANGELOG entry as plaintext (separate from the patch)
3873 * For major contributions, your entry to the CREDITS file
3875 * When you add support for a new board, don't forget to add this
3876 board to the MAKEALL script, too.
3878 * If your patch adds new configuration options, don't forget to
3879 document these in the README file.
3881 * The patch itself. If you are using git (which is *strongly*
3882 recommended) you can easily generate the patch using the
3883 "git-format-patch". If you then use "git-send-email" to send it to
3884 the U-Boot mailing list, you will avoid most of the common problems
3885 with some other mail clients.
3887 If you cannot use git, use "diff -purN OLD NEW". If your version of
3888 diff does not support these options, then get the latest version of
3891 The current directory when running this command shall be the parent
3892 directory of the U-Boot source tree (i. e. please make sure that
3893 your patch includes sufficient directory information for the
3896 We prefer patches as plain text. MIME attachments are discouraged,
3897 and compressed attachments must not be used.
3899 * If one logical set of modifications affects or creates several
3900 files, all these changes shall be submitted in a SINGLE patch file.
3902 * Changesets that contain different, unrelated modifications shall be
3903 submitted as SEPARATE patches, one patch per changeset.
3908 * Before sending the patch, run the MAKEALL script on your patched
3909 source tree and make sure that no errors or warnings are reported
3910 for any of the boards.
3912 * Keep your modifications to the necessary minimum: A patch
3913 containing several unrelated changes or arbitrary reformats will be
3914 returned with a request to re-formatting / split it.
3916 * If you modify existing code, make sure that your new code does not
3917 add to the memory footprint of the code ;-) Small is beautiful!
3918 When adding new features, these should compile conditionally only
3919 (using #ifdef), and the resulting code with the new feature
3920 disabled must not need more memory than the old code without your
3923 * Remember that there is a size limit of 40 kB per message on the
3924 u-boot-users mailing list. Bigger patches will be moderated. If
3925 they are reasonable and not bigger than 100 kB, they will be
3926 acknowledged. Even bigger patches should be avoided.
projects / u-boot / blob