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@lists.denx.de>. There is also an archive of previous traffic
64 on the mailing list - please search the archive before asking FAQ's.
65 Please see http://lists.denx.de/pipermail/u-boot and
66 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
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. Official 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/U-Boot
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 - blackfin Files specific to Analog Devices Blackfin CPUs
155 - i386 Files specific to i386 CPUs
156 - ixp Files specific to Intel XScale IXP CPUs
157 - leon2 Files specific to Gaisler LEON2 SPARC CPU
158 - leon3 Files specific to Gaisler LEON3 SPARC CPU
159 - mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 - mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 - mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 - mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 - mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 - mips Files specific to MIPS CPUs
165 - mpc5xx Files specific to Freescale MPC5xx CPUs
166 - mpc5xxx Files specific to Freescale MPC5xxx CPUs
167 - mpc8xx Files specific to Freescale MPC8xx CPUs
168 - mpc8220 Files specific to Freescale MPC8220 CPUs
169 - mpc824x Files specific to Freescale MPC824x CPUs
170 - mpc8260 Files specific to Freescale MPC8260 CPUs
171 - mpc85xx Files specific to Freescale MPC85xx CPUs
172 - nios Files specific to Altera NIOS CPUs
173 - nios2 Files specific to Altera Nios-II CPUs
174 - ppc4xx Files specific to AMCC PowerPC 4xx CPUs
175 - pxa Files specific to Intel XScale PXA CPUs
176 - s3c44b0 Files specific to Samsung S3C44B0 CPUs
177 - sa1100 Files specific to Intel StrongARM SA1100 CPUs
178 - disk Code for disk drive partition handling
179 - doc Documentation (don't expect too much)
180 - drivers Commonly used device drivers
181 - dtt Digital Thermometer and Thermostat drivers
182 - examples Example code for standalone applications, etc.
183 - include Header Files
184 - lib_arm Files generic to ARM architecture
185 - lib_avr32 Files generic to AVR32 architecture
186 - lib_blackfin Files generic to Blackfin architecture
187 - lib_generic Files generic to all architectures
188 - lib_i386 Files generic to i386 architecture
189 - lib_m68k Files generic to m68k architecture
190 - lib_mips Files generic to MIPS architecture
191 - lib_nios Files generic to NIOS architecture
192 - lib_ppc Files generic to PowerPC architecture
193 - lib_sparc Files generic to SPARC architecture
194 - libfdt Library files to support flattened device trees
195 - net Networking code
196 - post Power On Self Test
197 - rtc Real Time Clock drivers
198 - tools Tools to build S-Record or U-Boot images, etc.
200 Software Configuration:
201 =======================
203 Configuration is usually done using C preprocessor defines; the
204 rationale behind that is to avoid dead code whenever possible.
206 There are two classes of configuration variables:
208 * Configuration _OPTIONS_:
209 These are selectable by the user and have names beginning with
212 * Configuration _SETTINGS_:
213 These depend on the hardware etc. and should not be meddled with if
214 you don't know what you're doing; they have names beginning with
217 Later we will add a configuration tool - probably similar to or even
218 identical to what's used for the Linux kernel. Right now, we have to
219 do the configuration by hand, which means creating some symbolic
220 links and editing some configuration files. We use the TQM8xxL boards
224 Selection of Processor Architecture and Board Type:
225 ---------------------------------------------------
227 For all supported boards there are ready-to-use default
228 configurations available; just type "make <board_name>_config".
230 Example: For a TQM823L module type:
235 For the Cogent platform, you need to specify the CPU type as well;
236 e.g. "make cogent_mpc8xx_config". And also configure the cogent
237 directory according to the instructions in cogent/README.
240 Configuration Options:
241 ----------------------
243 Configuration depends on the combination of board and CPU type; all
244 such information is kept in a configuration file
245 "include/configs/<board_name>.h".
247 Example: For a TQM823L module, all configuration settings are in
248 "include/configs/TQM823L.h".
251 Many of the options are named exactly as the corresponding Linux
252 kernel configuration options. The intention is to make it easier to
253 build a config tool - later.
256 The following options need to be configured:
258 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
260 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
262 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
263 Define exactly one, e.g. CONFIG_ATSTK1002
265 - CPU Module Type: (if CONFIG_COGENT is defined)
266 Define exactly one of
268 --- FIXME --- not tested yet:
269 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
270 CONFIG_CMA287_23, CONFIG_CMA287_50
272 - Motherboard Type: (if CONFIG_COGENT is defined)
273 Define exactly one of
274 CONFIG_CMA101, CONFIG_CMA102
276 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
277 Define one or more of
280 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
281 Define one or more of
282 CONFIG_LCD_HEARTBEAT - update a character position on
283 the LCD display every second with
286 - Board flavour: (if CONFIG_MPC8260ADS is defined)
289 CONFIG_SYS_8260ADS - original MPC8260ADS
290 CONFIG_SYS_8266ADS - MPC8266ADS
291 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
292 CONFIG_SYS_8272ADS - MPC8272ADS
294 - MPC824X Family Member (if CONFIG_MPC824X is defined)
295 Define exactly one of
296 CONFIG_MPC8240, CONFIG_MPC8245
298 - 8xx CPU Options: (if using an MPC8xx CPU)
299 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
300 get_gclk_freq() cannot work
301 e.g. if there is no 32KHz
302 reference PIT/RTC clock
303 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
306 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
307 CONFIG_SYS_8xx_CPUCLK_MIN
308 CONFIG_SYS_8xx_CPUCLK_MAX
309 CONFIG_8xx_CPUCLK_DEFAULT
310 See doc/README.MPC866
312 CONFIG_SYS_MEASURE_CPUCLK
314 Define this to measure the actual CPU clock instead
315 of relying on the correctness of the configured
316 values. Mostly useful for board bringup to make sure
317 the PLL is locked at the intended frequency. Note
318 that this requires a (stable) reference clock (32 kHz
319 RTC clock or CONFIG_SYS_8XX_XIN)
321 CONFIG_SYS_DELAYED_ICACHE
323 Define this option if you want to enable the
324 ICache only when Code runs from RAM.
326 - Intel Monahans options:
327 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
329 Defines the Monahans run mode to oscillator
330 ratio. Valid values are 8, 16, 24, 31. The core
331 frequency is this value multiplied by 13 MHz.
333 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
335 Defines the Monahans turbo mode to oscillator
336 ratio. Valid values are 1 (default if undefined) and
337 2. The core frequency as calculated above is multiplied
340 - Linux Kernel Interface:
343 U-Boot stores all clock information in Hz
344 internally. For binary compatibility with older Linux
345 kernels (which expect the clocks passed in the
346 bd_info data to be in MHz) the environment variable
347 "clocks_in_mhz" can be defined so that U-Boot
348 converts clock data to MHZ before passing it to the
350 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
351 "clocks_in_mhz=1" is automatically included in the
354 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
356 When transferring memsize parameter to linux, some versions
357 expect it to be in bytes, others in MB.
358 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
362 New kernel versions are expecting firmware settings to be
363 passed using flattened device trees (based on open firmware
367 * New libfdt-based support
368 * Adds the "fdt" command
369 * The bootm command automatically updates the fdt
371 OF_CPU - The proper name of the cpus node.
372 OF_SOC - The proper name of the soc node.
373 OF_TBCLK - The timebase frequency.
374 OF_STDOUT_PATH - The path to the console device
376 boards with QUICC Engines require OF_QE to set UCC MAC
379 CONFIG_OF_BOARD_SETUP
381 Board code has addition modification that it wants to make
382 to the flat device tree before handing it off to the kernel
386 This define fills in the correct boot CPU in the boot
387 param header, the default value is zero if undefined.
389 - vxWorks boot parameters:
391 bootvx constructs a valid bootline using the following
392 environments variables: bootfile, ipaddr, serverip, hostname.
393 It loads the vxWorks image pointed bootfile.
395 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
396 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
397 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
398 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
400 CONFIG_SYS_VXWORKS_ADD_PARAMS
402 Add it at the end of the bootline. E.g "u=username pw=secret"
404 Note: If a "bootargs" environment is defined, it will overwride
405 the defaults discussed just above.
410 Define this if you want support for Amba PrimeCell PL010 UARTs.
414 Define this if you want support for Amba PrimeCell PL011 UARTs.
418 If you have Amba PrimeCell PL011 UARTs, set this variable to
419 the clock speed of the UARTs.
423 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
424 define this to a list of base addresses for each (supported)
425 port. See e.g. include/configs/versatile.h
429 Depending on board, define exactly one serial port
430 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
431 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
432 console by defining CONFIG_8xx_CONS_NONE
434 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
435 port routines must be defined elsewhere
436 (i.e. serial_init(), serial_getc(), ...)
439 Enables console device for a color framebuffer. Needs following
440 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
441 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
443 VIDEO_HW_RECTFILL graphic chip supports
446 VIDEO_HW_BITBLT graphic chip supports
447 bit-blit (cf. smiLynxEM)
448 VIDEO_VISIBLE_COLS visible pixel columns
450 VIDEO_VISIBLE_ROWS visible pixel rows
451 VIDEO_PIXEL_SIZE bytes per pixel
452 VIDEO_DATA_FORMAT graphic data format
453 (0-5, cf. cfb_console.c)
454 VIDEO_FB_ADRS framebuffer address
455 VIDEO_KBD_INIT_FCT keyboard int fct
456 (i.e. i8042_kbd_init())
457 VIDEO_TSTC_FCT test char fct
459 VIDEO_GETC_FCT get char fct
461 CONFIG_CONSOLE_CURSOR cursor drawing on/off
462 (requires blink timer
464 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
465 CONFIG_CONSOLE_TIME display time/date info in
467 (requires CONFIG_CMD_DATE)
468 CONFIG_VIDEO_LOGO display Linux logo in
470 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
471 linux_logo.h for logo.
472 Requires CONFIG_VIDEO_LOGO
473 CONFIG_CONSOLE_EXTRA_INFO
474 additional board info beside
477 When CONFIG_CFB_CONSOLE is defined, video console is
478 default i/o. Serial console can be forced with
479 environment 'console=serial'.
481 When CONFIG_SILENT_CONSOLE is defined, all console
482 messages (by U-Boot and Linux!) can be silenced with
483 the "silent" environment variable. See
484 doc/README.silent for more information.
487 CONFIG_BAUDRATE - in bps
488 Select one of the baudrates listed in
489 CONFIG_SYS_BAUDRATE_TABLE, see below.
490 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
492 - Console Rx buffer length
493 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
494 the maximum receive buffer length for the SMC.
495 This option is actual only for 82xx and 8xx possible.
496 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
497 must be defined, to setup the maximum idle timeout for
500 - Interrupt driven serial port input:
501 CONFIG_SERIAL_SOFTWARE_FIFO
504 Use an interrupt handler for receiving data on the
505 serial port. It also enables using hardware handshake
506 (RTS/CTS) and UART's built-in FIFO. Set the number of
507 bytes the interrupt driven input buffer should have.
509 Leave undefined to disable this feature, including
510 disable the buffer and hardware handshake.
512 - Console UART Number:
516 If defined internal UART1 (and not UART0) is used
517 as default U-Boot console.
519 - Boot Delay: CONFIG_BOOTDELAY - in seconds
520 Delay before automatically booting the default image;
521 set to -1 to disable autoboot.
523 See doc/README.autoboot for these options that
524 work with CONFIG_BOOTDELAY. None are required.
525 CONFIG_BOOT_RETRY_TIME
526 CONFIG_BOOT_RETRY_MIN
527 CONFIG_AUTOBOOT_KEYED
528 CONFIG_AUTOBOOT_PROMPT
529 CONFIG_AUTOBOOT_DELAY_STR
530 CONFIG_AUTOBOOT_STOP_STR
531 CONFIG_AUTOBOOT_DELAY_STR2
532 CONFIG_AUTOBOOT_STOP_STR2
533 CONFIG_ZERO_BOOTDELAY_CHECK
534 CONFIG_RESET_TO_RETRY
538 Only needed when CONFIG_BOOTDELAY is enabled;
539 define a command string that is automatically executed
540 when no character is read on the console interface
541 within "Boot Delay" after reset.
544 This can be used to pass arguments to the bootm
545 command. The value of CONFIG_BOOTARGS goes into the
546 environment value "bootargs".
548 CONFIG_RAMBOOT and CONFIG_NFSBOOT
549 The value of these goes into the environment as
550 "ramboot" and "nfsboot" respectively, and can be used
551 as a convenience, when switching between booting from
557 When this option is #defined, the existence of the
558 environment variable "preboot" will be checked
559 immediately before starting the CONFIG_BOOTDELAY
560 countdown and/or running the auto-boot command resp.
561 entering interactive mode.
563 This feature is especially useful when "preboot" is
564 automatically generated or modified. For an example
565 see the LWMON board specific code: here "preboot" is
566 modified when the user holds down a certain
567 combination of keys on the (special) keyboard when
570 - Serial Download Echo Mode:
572 If defined to 1, all characters received during a
573 serial download (using the "loads" command) are
574 echoed back. This might be needed by some terminal
575 emulations (like "cu"), but may as well just take
576 time on others. This setting #define's the initial
577 value of the "loads_echo" environment variable.
579 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
581 Select one of the baudrates listed in
582 CONFIG_SYS_BAUDRATE_TABLE, see below.
585 Monitor commands can be included or excluded
586 from the build by using the #include files
587 "config_cmd_all.h" and #undef'ing unwanted
588 commands, or using "config_cmd_default.h"
589 and augmenting with additional #define's
592 The default command configuration includes all commands
593 except those marked below with a "*".
595 CONFIG_CMD_ASKENV * ask for env variable
596 CONFIG_CMD_BDI bdinfo
597 CONFIG_CMD_BEDBUG * Include BedBug Debugger
598 CONFIG_CMD_BMP * BMP support
599 CONFIG_CMD_BSP * Board specific commands
600 CONFIG_CMD_BOOTD bootd
601 CONFIG_CMD_CACHE * icache, dcache
602 CONFIG_CMD_CONSOLE coninfo
603 CONFIG_CMD_DATE * support for RTC, date/time...
604 CONFIG_CMD_DHCP * DHCP support
605 CONFIG_CMD_DIAG * Diagnostics
606 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
607 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
608 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
609 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
610 CONFIG_CMD_DTT * Digital Therm and Thermostat
611 CONFIG_CMD_ECHO echo arguments
612 CONFIG_CMD_EEPROM * EEPROM read/write support
613 CONFIG_CMD_ELF * bootelf, bootvx
614 CONFIG_CMD_SAVEENV saveenv
615 CONFIG_CMD_FDC * Floppy Disk Support
616 CONFIG_CMD_FAT * FAT partition support
617 CONFIG_CMD_FDOS * Dos diskette Support
618 CONFIG_CMD_FLASH flinfo, erase, protect
619 CONFIG_CMD_FPGA FPGA device initialization support
620 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
621 CONFIG_CMD_I2C * I2C serial bus support
622 CONFIG_CMD_IDE * IDE harddisk support
623 CONFIG_CMD_IMI iminfo
624 CONFIG_CMD_IMLS List all found images
625 CONFIG_CMD_IMMAP * IMMR dump support
626 CONFIG_CMD_IRQ * irqinfo
627 CONFIG_CMD_ITEST Integer/string test of 2 values
628 CONFIG_CMD_JFFS2 * JFFS2 Support
629 CONFIG_CMD_KGDB * kgdb
630 CONFIG_CMD_LOADB loadb
631 CONFIG_CMD_LOADS loads
632 CONFIG_CMD_MD5SUM print md5 message digest
633 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
634 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
636 CONFIG_CMD_MISC Misc functions like sleep etc
637 CONFIG_CMD_MMC * MMC memory mapped support
638 CONFIG_CMD_MII * MII utility commands
639 CONFIG_CMD_MTDPARTS * MTD partition support
640 CONFIG_CMD_NAND * NAND support
641 CONFIG_CMD_NET bootp, tftpboot, rarpboot
642 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
643 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
644 CONFIG_CMD_PCI * pciinfo
645 CONFIG_CMD_PCMCIA * PCMCIA support
646 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
648 CONFIG_CMD_PORTIO * Port I/O
649 CONFIG_CMD_REGINFO * Register dump
650 CONFIG_CMD_RUN run command in env variable
651 CONFIG_CMD_SAVES * save S record dump
652 CONFIG_CMD_SCSI * SCSI Support
653 CONFIG_CMD_SDRAM * print SDRAM configuration information
654 (requires CONFIG_CMD_I2C)
655 CONFIG_CMD_SETGETDCR Support for DCR Register access
657 CONFIG_CMD_SHA1 print sha1 memory digest
658 (requires CONFIG_CMD_MEMORY)
659 CONFIG_CMD_SOURCE "source" command Support
660 CONFIG_CMD_SPI * SPI serial bus support
661 CONFIG_CMD_USB * USB support
662 CONFIG_CMD_VFD * VFD support (TRAB)
663 CONFIG_CMD_CDP * Cisco Discover Protocol support
664 CONFIG_CMD_FSL * Microblaze FSL support
667 EXAMPLE: If you want all functions except of network
668 support you can write:
670 #include "config_cmd_all.h"
671 #undef CONFIG_CMD_NET
674 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
676 Note: Don't enable the "icache" and "dcache" commands
677 (configuration option CONFIG_CMD_CACHE) unless you know
678 what you (and your U-Boot users) are doing. Data
679 cache cannot be enabled on systems like the 8xx or
680 8260 (where accesses to the IMMR region must be
681 uncached), and it cannot be disabled on all other
682 systems where we (mis-) use the data cache to hold an
683 initial stack and some data.
686 XXX - this list needs to get updated!
690 If this variable is defined, it enables watchdog
691 support. There must be support in the platform specific
692 code for a watchdog. For the 8xx and 8260 CPUs, the
693 SIU Watchdog feature is enabled in the SYPCR
697 CONFIG_VERSION_VARIABLE
698 If this variable is defined, an environment variable
699 named "ver" is created by U-Boot showing the U-Boot
700 version as printed by the "version" command.
701 This variable is readonly.
705 When CONFIG_CMD_DATE is selected, the type of the RTC
706 has to be selected, too. Define exactly one of the
709 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
710 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
711 CONFIG_RTC_MC13783 - use MC13783 RTC
712 CONFIG_RTC_MC146818 - use MC146818 RTC
713 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
714 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
715 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
716 CONFIG_RTC_DS164x - use Dallas DS164x RTC
717 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
718 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
719 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
721 Note that if the RTC uses I2C, then the I2C interface
722 must also be configured. See I2C Support, below.
725 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
726 CONFIG_PCA953X_INFO - enable pca953x info command
728 Note that if the GPIO device uses I2C, then the I2C interface
729 must also be configured. See I2C Support, below.
733 When CONFIG_TIMESTAMP is selected, the timestamp
734 (date and time) of an image is printed by image
735 commands like bootm or iminfo. This option is
736 automatically enabled when you select CONFIG_CMD_DATE .
739 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
740 and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION
742 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
743 CONFIG_CMD_SCSI) you must configure support for at
744 least one partition type as well.
747 CONFIG_IDE_RESET_ROUTINE - this is defined in several
748 board configurations files but used nowhere!
750 CONFIG_IDE_RESET - is this is defined, IDE Reset will
751 be performed by calling the function
752 ide_set_reset(int reset)
753 which has to be defined in a board specific file
758 Set this to enable ATAPI support.
763 Set this to enable support for disks larger than 137GB
764 Also look at CONFIG_SYS_64BIT_LBA ,CONFIG_SYS_64BIT_VSPRINTF and CONFIG_SYS_64BIT_STRTOUL
765 Whithout these , LBA48 support uses 32bit variables and will 'only'
766 support disks up to 2.1TB.
768 CONFIG_SYS_64BIT_LBA:
769 When enabled, makes the IDE subsystem use 64bit sector addresses.
773 At the moment only there is only support for the
774 SYM53C8XX SCSI controller; define
775 CONFIG_SCSI_SYM53C8XX to enable it.
777 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
778 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
779 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
780 maximum numbers of LUNs, SCSI ID's and target
782 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
784 - NETWORK Support (PCI):
786 Support for Intel 8254x gigabit chips.
788 CONFIG_E1000_FALLBACK_MAC
789 default MAC for empty EEPROM after production.
792 Support for Intel 82557/82559/82559ER chips.
793 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
794 write routine for first time initialisation.
797 Support for Digital 2114x chips.
798 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
799 modem chip initialisation (KS8761/QS6611).
802 Support for National dp83815 chips.
805 Support for National dp8382[01] gigabit chips.
807 - NETWORK Support (other):
809 CONFIG_DRIVER_LAN91C96
810 Support for SMSC's LAN91C96 chips.
813 Define this to hold the physical address
814 of the LAN91C96's I/O space
816 CONFIG_LAN91C96_USE_32_BIT
817 Define this to enable 32 bit addressing
819 CONFIG_DRIVER_SMC91111
820 Support for SMSC's LAN91C111 chip
823 Define this to hold the physical address
824 of the device (I/O space)
826 CONFIG_SMC_USE_32_BIT
827 Define this if data bus is 32 bits
829 CONFIG_SMC_USE_IOFUNCS
830 Define this to use i/o functions instead of macros
831 (some hardware wont work with macros)
833 CONFIG_DRIVER_SMC911X
834 Support for SMSC's LAN911x and LAN921x chips
836 CONFIG_DRIVER_SMC911X_BASE
837 Define this to hold the physical address
838 of the device (I/O space)
840 CONFIG_DRIVER_SMC911X_32_BIT
841 Define this if data bus is 32 bits
843 CONFIG_DRIVER_SMC911X_16_BIT
844 Define this if data bus is 16 bits. If your processor
845 automatically converts one 32 bit word to two 16 bit
846 words you may also try CONFIG_DRIVER_SMC911X_32_BIT.
849 At the moment only the UHCI host controller is
850 supported (PIP405, MIP405, MPC5200); define
851 CONFIG_USB_UHCI to enable it.
852 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
853 and define CONFIG_USB_STORAGE to enable the USB
856 Supported are USB Keyboards and USB Floppy drives
858 MPC5200 USB requires additional defines:
860 for 528 MHz Clock: 0x0001bbbb
864 for differential drivers: 0x00001000
865 for single ended drivers: 0x00005000
866 for differential drivers on PSC3: 0x00000100
867 for single ended drivers on PSC3: 0x00004100
868 CONFIG_SYS_USB_EVENT_POLL
869 May be defined to allow interrupt polling
870 instead of using asynchronous interrupts
873 Define the below if you wish to use the USB console.
874 Once firmware is rebuilt from a serial console issue the
875 command "setenv stdin usbtty; setenv stdout usbtty" and
876 attach your USB cable. The Unix command "dmesg" should print
877 it has found a new device. The environment variable usbtty
878 can be set to gserial or cdc_acm to enable your device to
879 appear to a USB host as a Linux gserial device or a
880 Common Device Class Abstract Control Model serial device.
881 If you select usbtty = gserial you should be able to enumerate
883 # modprobe usbserial vendor=0xVendorID product=0xProductID
884 else if using cdc_acm, simply setting the environment
885 variable usbtty to be cdc_acm should suffice. The following
886 might be defined in YourBoardName.h
889 Define this to build a UDC device
892 Define this to have a tty type of device available to
893 talk to the UDC device
895 CONFIG_SYS_CONSOLE_IS_IN_ENV
896 Define this if you want stdin, stdout &/or stderr to
900 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
901 Derive USB clock from external clock "blah"
902 - CONFIG_SYS_USB_EXTC_CLK 0x02
904 CONFIG_SYS_USB_BRG_CLK 0xBLAH
905 Derive USB clock from brgclk
906 - CONFIG_SYS_USB_BRG_CLK 0x04
908 If you have a USB-IF assigned VendorID then you may wish to
909 define your own vendor specific values either in BoardName.h
910 or directly in usbd_vendor_info.h. If you don't define
911 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
912 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
913 should pretend to be a Linux device to it's target host.
915 CONFIG_USBD_MANUFACTURER
916 Define this string as the name of your company for
917 - CONFIG_USBD_MANUFACTURER "my company"
919 CONFIG_USBD_PRODUCT_NAME
920 Define this string as the name of your product
921 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
924 Define this as your assigned Vendor ID from the USB
925 Implementors Forum. This *must* be a genuine Vendor ID
926 to avoid polluting the USB namespace.
927 - CONFIG_USBD_VENDORID 0xFFFF
929 CONFIG_USBD_PRODUCTID
930 Define this as the unique Product ID
932 - CONFIG_USBD_PRODUCTID 0xFFFF
936 The MMC controller on the Intel PXA is supported. To
937 enable this define CONFIG_MMC. The MMC can be
938 accessed from the boot prompt by mapping the device
939 to physical memory similar to flash. Command line is
940 enabled with CONFIG_CMD_MMC. The MMC driver also works with
941 the FAT fs. This is enabled with CONFIG_CMD_FAT.
943 - Journaling Flash filesystem support:
944 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
945 CONFIG_JFFS2_NAND_DEV
946 Define these for a default partition on a NAND device
948 CONFIG_SYS_JFFS2_FIRST_SECTOR,
949 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
950 Define these for a default partition on a NOR device
952 CONFIG_SYS_JFFS_CUSTOM_PART
953 Define this to create an own partition. You have to provide a
954 function struct part_info* jffs2_part_info(int part_num)
956 If you define only one JFFS2 partition you may also want to
957 #define CONFIG_SYS_JFFS_SINGLE_PART 1
958 to disable the command chpart. This is the default when you
959 have not defined a custom partition
964 Define this to enable standard (PC-Style) keyboard
968 Standard PC keyboard driver with US (is default) and
969 GERMAN key layout (switch via environment 'keymap=de') support.
970 Export function i8042_kbd_init, i8042_tstc and i8042_getc
971 for cfb_console. Supports cursor blinking.
976 Define this to enable video support (for output to
981 Enable Chips & Technologies 69000 Video chip
983 CONFIG_VIDEO_SMI_LYNXEM
984 Enable Silicon Motion SMI 712/710/810 Video chip. The
985 video output is selected via environment 'videoout'
986 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
989 For the CT69000 and SMI_LYNXEM drivers, videomode is
990 selected via environment 'videomode'. Two different ways
992 - "videomode=num" 'num' is a standard LiLo mode numbers.
993 Following standard modes are supported (* is default):
995 Colors 640x480 800x600 1024x768 1152x864 1280x1024
996 -------------+---------------------------------------------
997 8 bits | 0x301* 0x303 0x305 0x161 0x307
998 15 bits | 0x310 0x313 0x316 0x162 0x319
999 16 bits | 0x311 0x314 0x317 0x163 0x31A
1000 24 bits | 0x312 0x315 0x318 ? 0x31B
1001 -------------+---------------------------------------------
1002 (i.e. setenv videomode 317; saveenv; reset;)
1004 - "videomode=bootargs" all the video parameters are parsed
1005 from the bootargs. (See drivers/video/videomodes.c)
1008 CONFIG_VIDEO_SED13806
1009 Enable Epson SED13806 driver. This driver supports 8bpp
1010 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1011 or CONFIG_VIDEO_SED13806_16BPP
1016 Define this to enable a custom keyboard support.
1017 This simply calls drv_keyboard_init() which must be
1018 defined in your board-specific files.
1019 The only board using this so far is RBC823.
1021 - LCD Support: CONFIG_LCD
1023 Define this to enable LCD support (for output to LCD
1024 display); also select one of the supported displays
1025 by defining one of these:
1029 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1031 CONFIG_NEC_NL6448AC33:
1033 NEC NL6448AC33-18. Active, color, single scan.
1035 CONFIG_NEC_NL6448BC20
1037 NEC NL6448BC20-08. 6.5", 640x480.
1038 Active, color, single scan.
1040 CONFIG_NEC_NL6448BC33_54
1042 NEC NL6448BC33-54. 10.4", 640x480.
1043 Active, color, single scan.
1047 Sharp 320x240. Active, color, single scan.
1048 It isn't 16x9, and I am not sure what it is.
1050 CONFIG_SHARP_LQ64D341
1052 Sharp LQ64D341 display, 640x480.
1053 Active, color, single scan.
1057 HLD1045 display, 640x480.
1058 Active, color, single scan.
1062 Optrex CBL50840-2 NF-FW 99 22 M5
1064 Hitachi LMG6912RPFC-00T
1068 320x240. Black & white.
1070 Normally display is black on white background; define
1071 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1073 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1075 If this option is set, the environment is checked for
1076 a variable "splashimage". If found, the usual display
1077 of logo, copyright and system information on the LCD
1078 is suppressed and the BMP image at the address
1079 specified in "splashimage" is loaded instead. The
1080 console is redirected to the "nulldev", too. This
1081 allows for a "silent" boot where a splash screen is
1082 loaded very quickly after power-on.
1084 CONFIG_SPLASH_SCREEN_ALIGN
1086 If this option is set the splash image can be freely positioned
1087 on the screen. Environment variable "splashpos" specifies the
1088 position as "x,y". If a positive number is given it is used as
1089 number of pixel from left/top. If a negative number is given it
1090 is used as number of pixel from right/bottom. You can also
1091 specify 'm' for centering the image.
1094 setenv splashpos m,m
1095 => image at center of screen
1097 setenv splashpos 30,20
1098 => image at x = 30 and y = 20
1100 setenv splashpos -10,m
1101 => vertically centered image
1102 at x = dspWidth - bmpWidth - 9
1104 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1106 If this option is set, additionally to standard BMP
1107 images, gzipped BMP images can be displayed via the
1108 splashscreen support or the bmp command.
1110 - Compression support:
1113 If this option is set, support for bzip2 compressed
1114 images is included. If not, only uncompressed and gzip
1115 compressed images are supported.
1117 NOTE: the bzip2 algorithm requires a lot of RAM, so
1118 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1123 If this option is set, support for lzma compressed
1126 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1127 requires an amount of dynamic memory that is given by the
1130 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1132 Where lc and lp stand for, respectively, Literal context bits
1133 and Literal pos bits.
1135 This value is upper-bounded by 14MB in the worst case. Anyway,
1136 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1137 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1138 a very small buffer.
1140 Use the lzmainfo tool to determinate the lc and lp values and
1141 then calculate the amount of needed dynamic memory (ensuring
1142 the appropriate CONFIG_SYS_MALLOC_LEN value).
1147 The address of PHY on MII bus.
1149 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1151 The clock frequency of the MII bus
1155 If this option is set, support for speed/duplex
1156 detection of gigabit PHY is included.
1158 CONFIG_PHY_RESET_DELAY
1160 Some PHY like Intel LXT971A need extra delay after
1161 reset before any MII register access is possible.
1162 For such PHY, set this option to the usec delay
1163 required. (minimum 300usec for LXT971A)
1165 CONFIG_PHY_CMD_DELAY (ppc4xx)
1167 Some PHY like Intel LXT971A need extra delay after
1168 command issued before MII status register can be read
1178 Define a default value for Ethernet address to use
1179 for the respective Ethernet interface, in case this
1180 is not determined automatically.
1185 Define a default value for the IP address to use for
1186 the default Ethernet interface, in case this is not
1187 determined through e.g. bootp.
1189 - Server IP address:
1192 Defines a default value for the IP address of a TFTP
1193 server to contact when using the "tftboot" command.
1195 CONFIG_KEEP_SERVERADDR
1197 Keeps the server's MAC address, in the env 'serveraddr'
1198 for passing to bootargs (like Linux's netconsole option)
1200 - Multicast TFTP Mode:
1203 Defines whether you want to support multicast TFTP as per
1204 rfc-2090; for example to work with atftp. Lets lots of targets
1205 tftp down the same boot image concurrently. Note: the Ethernet
1206 driver in use must provide a function: mcast() to join/leave a
1209 CONFIG_BOOTP_RANDOM_DELAY
1210 - BOOTP Recovery Mode:
1211 CONFIG_BOOTP_RANDOM_DELAY
1213 If you have many targets in a network that try to
1214 boot using BOOTP, you may want to avoid that all
1215 systems send out BOOTP requests at precisely the same
1216 moment (which would happen for instance at recovery
1217 from a power failure, when all systems will try to
1218 boot, thus flooding the BOOTP server. Defining
1219 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1220 inserted before sending out BOOTP requests. The
1221 following delays are inserted then:
1223 1st BOOTP request: delay 0 ... 1 sec
1224 2nd BOOTP request: delay 0 ... 2 sec
1225 3rd BOOTP request: delay 0 ... 4 sec
1227 BOOTP requests: delay 0 ... 8 sec
1229 - DHCP Advanced Options:
1230 You can fine tune the DHCP functionality by defining
1231 CONFIG_BOOTP_* symbols:
1233 CONFIG_BOOTP_SUBNETMASK
1234 CONFIG_BOOTP_GATEWAY
1235 CONFIG_BOOTP_HOSTNAME
1236 CONFIG_BOOTP_NISDOMAIN
1237 CONFIG_BOOTP_BOOTPATH
1238 CONFIG_BOOTP_BOOTFILESIZE
1241 CONFIG_BOOTP_SEND_HOSTNAME
1242 CONFIG_BOOTP_NTPSERVER
1243 CONFIG_BOOTP_TIMEOFFSET
1244 CONFIG_BOOTP_VENDOREX
1246 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1247 environment variable, not the BOOTP server.
1249 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1250 serverip from a DHCP server, it is possible that more
1251 than one DNS serverip is offered to the client.
1252 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1253 serverip will be stored in the additional environment
1254 variable "dnsip2". The first DNS serverip is always
1255 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1258 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1259 to do a dynamic update of a DNS server. To do this, they
1260 need the hostname of the DHCP requester.
1261 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1262 of the "hostname" environment variable is passed as
1263 option 12 to the DHCP server.
1265 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1267 A 32bit value in microseconds for a delay between
1268 receiving a "DHCP Offer" and sending the "DHCP Request".
1269 This fixes a problem with certain DHCP servers that don't
1270 respond 100% of the time to a "DHCP request". E.g. On an
1271 AT91RM9200 processor running at 180MHz, this delay needed
1272 to be *at least* 15,000 usec before a Windows Server 2003
1273 DHCP server would reply 100% of the time. I recommend at
1274 least 50,000 usec to be safe. The alternative is to hope
1275 that one of the retries will be successful but note that
1276 the DHCP timeout and retry process takes a longer than
1280 CONFIG_CDP_DEVICE_ID
1282 The device id used in CDP trigger frames.
1284 CONFIG_CDP_DEVICE_ID_PREFIX
1286 A two character string which is prefixed to the MAC address
1291 A printf format string which contains the ascii name of
1292 the port. Normally is set to "eth%d" which sets
1293 eth0 for the first Ethernet, eth1 for the second etc.
1295 CONFIG_CDP_CAPABILITIES
1297 A 32bit integer which indicates the device capabilities;
1298 0x00000010 for a normal host which does not forwards.
1302 An ascii string containing the version of the software.
1306 An ascii string containing the name of the platform.
1310 A 32bit integer sent on the trigger.
1312 CONFIG_CDP_POWER_CONSUMPTION
1314 A 16bit integer containing the power consumption of the
1315 device in .1 of milliwatts.
1317 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1319 A byte containing the id of the VLAN.
1321 - Status LED: CONFIG_STATUS_LED
1323 Several configurations allow to display the current
1324 status using a LED. For instance, the LED will blink
1325 fast while running U-Boot code, stop blinking as
1326 soon as a reply to a BOOTP request was received, and
1327 start blinking slow once the Linux kernel is running
1328 (supported by a status LED driver in the Linux
1329 kernel). Defining CONFIG_STATUS_LED enables this
1332 - CAN Support: CONFIG_CAN_DRIVER
1334 Defining CONFIG_CAN_DRIVER enables CAN driver support
1335 on those systems that support this (optional)
1336 feature, like the TQM8xxL modules.
1338 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1340 These enable I2C serial bus commands. Defining either of
1341 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1342 include the appropriate I2C driver for the selected CPU.
1344 This will allow you to use i2c commands at the u-boot
1345 command line (as long as you set CONFIG_CMD_I2C in
1346 CONFIG_COMMANDS) and communicate with i2c based realtime
1347 clock chips. See common/cmd_i2c.c for a description of the
1348 command line interface.
1350 CONFIG_HARD_I2C selects a hardware I2C controller.
1352 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1353 bit-banging) driver instead of CPM or similar hardware
1356 There are several other quantities that must also be
1357 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1359 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1360 to be the frequency (in Hz) at which you wish your i2c bus
1361 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1362 the CPU's i2c node address).
1364 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1365 sets the CPU up as a master node and so its address should
1366 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1367 p.16-473). So, set CONFIG_SYS_I2C_SLAVE to 0.
1369 CONFIG_SYS_I2C_INIT_MPC5XXX
1371 When a board is reset during an i2c bus transfer
1372 chips might think that the current transfer is still
1373 in progress. Reset the slave devices by sending start
1374 commands until the slave device responds.
1376 That's all that's required for CONFIG_HARD_I2C.
1378 If you use the software i2c interface (CONFIG_SOFT_I2C)
1379 then the following macros need to be defined (examples are
1380 from include/configs/lwmon.h):
1384 (Optional). Any commands necessary to enable the I2C
1385 controller or configure ports.
1387 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1391 (Only for MPC8260 CPU). The I/O port to use (the code
1392 assumes both bits are on the same port). Valid values
1393 are 0..3 for ports A..D.
1397 The code necessary to make the I2C data line active
1398 (driven). If the data line is open collector, this
1401 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1405 The code necessary to make the I2C data line tri-stated
1406 (inactive). If the data line is open collector, this
1409 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1413 Code that returns TRUE if the I2C data line is high,
1416 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1420 If <bit> is TRUE, sets the I2C data line high. If it
1421 is FALSE, it clears it (low).
1423 eg: #define I2C_SDA(bit) \
1424 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1425 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1429 If <bit> is TRUE, sets the I2C clock line high. If it
1430 is FALSE, it clears it (low).
1432 eg: #define I2C_SCL(bit) \
1433 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1434 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1438 This delay is invoked four times per clock cycle so this
1439 controls the rate of data transfer. The data rate thus
1440 is 1 / (I2C_DELAY * 4). Often defined to be something
1443 #define I2C_DELAY udelay(2)
1445 CONFIG_SYS_I2C_INIT_BOARD
1447 When a board is reset during an i2c bus transfer
1448 chips might think that the current transfer is still
1449 in progress. On some boards it is possible to access
1450 the i2c SCLK line directly, either by using the
1451 processor pin as a GPIO or by having a second pin
1452 connected to the bus. If this option is defined a
1453 custom i2c_init_board() routine in boards/xxx/board.c
1454 is run early in the boot sequence.
1456 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1458 This option enables configuration of bi_iic_fast[] flags
1459 in u-boot bd_info structure based on u-boot environment
1460 variable "i2cfast". (see also i2cfast)
1462 CONFIG_I2C_MULTI_BUS
1464 This option allows the use of multiple I2C buses, each of which
1465 must have a controller. At any point in time, only one bus is
1466 active. To switch to a different bus, use the 'i2c dev' command.
1467 Note that bus numbering is zero-based.
1469 CONFIG_SYS_I2C_NOPROBES
1471 This option specifies a list of I2C devices that will be skipped
1472 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1473 is set, specify a list of bus-device pairs. Otherwise, specify
1474 a 1D array of device addresses
1477 #undef CONFIG_I2C_MULTI_BUS
1478 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1480 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1482 #define CONFIG_I2C_MULTI_BUS
1483 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1485 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1487 CONFIG_SYS_SPD_BUS_NUM
1489 If defined, then this indicates the I2C bus number for DDR SPD.
1490 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1492 CONFIG_SYS_RTC_BUS_NUM
1494 If defined, then this indicates the I2C bus number for the RTC.
1495 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1497 CONFIG_SYS_DTT_BUS_NUM
1499 If defined, then this indicates the I2C bus number for the DTT.
1500 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1502 CONFIG_SYS_I2C_DTT_ADDR:
1504 If defined, specifies the I2C address of the DTT device.
1505 If not defined, then U-Boot uses predefined value for
1506 specified DTT device.
1510 Define this option if you want to use Freescale's I2C driver in
1511 drivers/i2c/fsl_i2c.c.
1515 Define this option if you have I2C devices reached over 1 .. n
1516 I2C Muxes like the pca9544a. This option addes a new I2C
1517 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1518 new I2C Bus to the existing I2C Busses. If you select the
1519 new Bus with "i2c dev", u-bbot sends first the commandos for
1520 the muxes to activate this new "bus".
1522 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1526 Adding a new I2C Bus reached over 2 pca9544a muxes
1527 The First mux with address 70 and channel 6
1528 The Second mux with address 71 and channel 4
1530 => i2c bus pca9544a:70:6:pca9544a:71:4
1532 Use the "i2c bus" command without parameter, to get a list
1533 of I2C Busses with muxes:
1536 Busses reached over muxes:
1538 reached over Mux(es):
1541 reached over Mux(es):
1546 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1547 u-boot sends First the Commando to the mux@70 to enable
1548 channel 6, and then the Commando to the mux@71 to enable
1551 After that, you can use the "normal" i2c commands as
1552 usual, to communicate with your I2C devices behind
1555 This option is actually implemented for the bitbanging
1556 algorithm in common/soft_i2c.c and for the Hardware I2C
1557 Bus on the MPC8260. But it should be not so difficult
1558 to add this option to other architectures.
1560 CONFIG_SOFT_I2C_READ_REPEATED_START
1562 defining this will force the i2c_read() function in
1563 the soft_i2c driver to perform an I2C repeated start
1564 between writing the address pointer and reading the
1565 data. If this define is omitted the default behaviour
1566 of doing a stop-start sequence will be used. Most I2C
1567 devices can use either method, but some require one or
1570 - SPI Support: CONFIG_SPI
1572 Enables SPI driver (so far only tested with
1573 SPI EEPROM, also an instance works with Crystal A/D and
1574 D/As on the SACSng board)
1578 Enables extended (16-bit) SPI EEPROM addressing.
1579 (symmetrical to CONFIG_I2C_X)
1583 Enables a software (bit-bang) SPI driver rather than
1584 using hardware support. This is a general purpose
1585 driver that only requires three general I/O port pins
1586 (two outputs, one input) to function. If this is
1587 defined, the board configuration must define several
1588 SPI configuration items (port pins to use, etc). For
1589 an example, see include/configs/sacsng.h.
1593 Enables a hardware SPI driver for general-purpose reads
1594 and writes. As with CONFIG_SOFT_SPI, the board configuration
1595 must define a list of chip-select function pointers.
1596 Currently supported on some MPC8xxx processors. For an
1597 example, see include/configs/mpc8349emds.h.
1601 Enables the driver for the SPI controllers on i.MX and MXC
1602 SoCs. Currently only i.MX31 is supported.
1604 - FPGA Support: CONFIG_FPGA
1606 Enables FPGA subsystem.
1608 CONFIG_FPGA_<vendor>
1610 Enables support for specific chip vendors.
1613 CONFIG_FPGA_<family>
1615 Enables support for FPGA family.
1616 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1620 Specify the number of FPGA devices to support.
1622 CONFIG_SYS_FPGA_PROG_FEEDBACK
1624 Enable printing of hash marks during FPGA configuration.
1626 CONFIG_SYS_FPGA_CHECK_BUSY
1628 Enable checks on FPGA configuration interface busy
1629 status by the configuration function. This option
1630 will require a board or device specific function to
1635 If defined, a function that provides delays in the FPGA
1636 configuration driver.
1638 CONFIG_SYS_FPGA_CHECK_CTRLC
1639 Allow Control-C to interrupt FPGA configuration
1641 CONFIG_SYS_FPGA_CHECK_ERROR
1643 Check for configuration errors during FPGA bitfile
1644 loading. For example, abort during Virtex II
1645 configuration if the INIT_B line goes low (which
1646 indicated a CRC error).
1648 CONFIG_SYS_FPGA_WAIT_INIT
1650 Maximum time to wait for the INIT_B line to deassert
1651 after PROB_B has been deasserted during a Virtex II
1652 FPGA configuration sequence. The default time is 500
1655 CONFIG_SYS_FPGA_WAIT_BUSY
1657 Maximum time to wait for BUSY to deassert during
1658 Virtex II FPGA configuration. The default is 5 ms.
1660 CONFIG_SYS_FPGA_WAIT_CONFIG
1662 Time to wait after FPGA configuration. The default is
1665 - Configuration Management:
1668 If defined, this string will be added to the U-Boot
1669 version information (U_BOOT_VERSION)
1671 - Vendor Parameter Protection:
1673 U-Boot considers the values of the environment
1674 variables "serial#" (Board Serial Number) and
1675 "ethaddr" (Ethernet Address) to be parameters that
1676 are set once by the board vendor / manufacturer, and
1677 protects these variables from casual modification by
1678 the user. Once set, these variables are read-only,
1679 and write or delete attempts are rejected. You can
1680 change this behaviour:
1682 If CONFIG_ENV_OVERWRITE is #defined in your config
1683 file, the write protection for vendor parameters is
1684 completely disabled. Anybody can change or delete
1687 Alternatively, if you #define _both_ CONFIG_ETHADDR
1688 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1689 Ethernet address is installed in the environment,
1690 which can be changed exactly ONCE by the user. [The
1691 serial# is unaffected by this, i. e. it remains
1697 Define this variable to enable the reservation of
1698 "protected RAM", i. e. RAM which is not overwritten
1699 by U-Boot. Define CONFIG_PRAM to hold the number of
1700 kB you want to reserve for pRAM. You can overwrite
1701 this default value by defining an environment
1702 variable "pram" to the number of kB you want to
1703 reserve. Note that the board info structure will
1704 still show the full amount of RAM. If pRAM is
1705 reserved, a new environment variable "mem" will
1706 automatically be defined to hold the amount of
1707 remaining RAM in a form that can be passed as boot
1708 argument to Linux, for instance like that:
1710 setenv bootargs ... mem=\${mem}
1713 This way you can tell Linux not to use this memory,
1714 either, which results in a memory region that will
1715 not be affected by reboots.
1717 *WARNING* If your board configuration uses automatic
1718 detection of the RAM size, you must make sure that
1719 this memory test is non-destructive. So far, the
1720 following board configurations are known to be
1723 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1724 HERMES, IP860, RPXlite, LWMON, LANTEC,
1725 PCU_E, FLAGADM, TQM8260
1730 Define this variable to stop the system in case of a
1731 fatal error, so that you have to reset it manually.
1732 This is probably NOT a good idea for an embedded
1733 system where you want the system to reboot
1734 automatically as fast as possible, but it may be
1735 useful during development since you can try to debug
1736 the conditions that lead to the situation.
1738 CONFIG_NET_RETRY_COUNT
1740 This variable defines the number of retries for
1741 network operations like ARP, RARP, TFTP, or BOOTP
1742 before giving up the operation. If not defined, a
1743 default value of 5 is used.
1747 Timeout waiting for an ARP reply in milliseconds.
1749 - Command Interpreter:
1750 CONFIG_AUTO_COMPLETE
1752 Enable auto completion of commands using TAB.
1754 Note that this feature has NOT been implemented yet
1755 for the "hush" shell.
1758 CONFIG_SYS_HUSH_PARSER
1760 Define this variable to enable the "hush" shell (from
1761 Busybox) as command line interpreter, thus enabling
1762 powerful command line syntax like
1763 if...then...else...fi conditionals or `&&' and '||'
1764 constructs ("shell scripts").
1766 If undefined, you get the old, much simpler behaviour
1767 with a somewhat smaller memory footprint.
1770 CONFIG_SYS_PROMPT_HUSH_PS2
1772 This defines the secondary prompt string, which is
1773 printed when the command interpreter needs more input
1774 to complete a command. Usually "> ".
1778 In the current implementation, the local variables
1779 space and global environment variables space are
1780 separated. Local variables are those you define by
1781 simply typing `name=value'. To access a local
1782 variable later on, you have write `$name' or
1783 `${name}'; to execute the contents of a variable
1784 directly type `$name' at the command prompt.
1786 Global environment variables are those you use
1787 setenv/printenv to work with. To run a command stored
1788 in such a variable, you need to use the run command,
1789 and you must not use the '$' sign to access them.
1791 To store commands and special characters in a
1792 variable, please use double quotation marks
1793 surrounding the whole text of the variable, instead
1794 of the backslashes before semicolons and special
1797 - Commandline Editing and History:
1798 CONFIG_CMDLINE_EDITING
1800 Enable editing and History functions for interactive
1801 commandline input operations
1803 - Default Environment:
1804 CONFIG_EXTRA_ENV_SETTINGS
1806 Define this to contain any number of null terminated
1807 strings (variable = value pairs) that will be part of
1808 the default environment compiled into the boot image.
1810 For example, place something like this in your
1811 board's config file:
1813 #define CONFIG_EXTRA_ENV_SETTINGS \
1817 Warning: This method is based on knowledge about the
1818 internal format how the environment is stored by the
1819 U-Boot code. This is NOT an official, exported
1820 interface! Although it is unlikely that this format
1821 will change soon, there is no guarantee either.
1822 You better know what you are doing here.
1824 Note: overly (ab)use of the default environment is
1825 discouraged. Make sure to check other ways to preset
1826 the environment like the "source" command or the
1829 - DataFlash Support:
1830 CONFIG_HAS_DATAFLASH
1832 Defining this option enables DataFlash features and
1833 allows to read/write in Dataflash via the standard
1836 - SystemACE Support:
1839 Adding this option adds support for Xilinx SystemACE
1840 chips attached via some sort of local bus. The address
1841 of the chip must also be defined in the
1842 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
1844 #define CONFIG_SYSTEMACE
1845 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
1847 When SystemACE support is added, the "ace" device type
1848 becomes available to the fat commands, i.e. fatls.
1850 - TFTP Fixed UDP Port:
1853 If this is defined, the environment variable tftpsrcp
1854 is used to supply the TFTP UDP source port value.
1855 If tftpsrcp isn't defined, the normal pseudo-random port
1856 number generator is used.
1858 Also, the environment variable tftpdstp is used to supply
1859 the TFTP UDP destination port value. If tftpdstp isn't
1860 defined, the normal port 69 is used.
1862 The purpose for tftpsrcp is to allow a TFTP server to
1863 blindly start the TFTP transfer using the pre-configured
1864 target IP address and UDP port. This has the effect of
1865 "punching through" the (Windows XP) firewall, allowing
1866 the remainder of the TFTP transfer to proceed normally.
1867 A better solution is to properly configure the firewall,
1868 but sometimes that is not allowed.
1870 - Show boot progress:
1871 CONFIG_SHOW_BOOT_PROGRESS
1873 Defining this option allows to add some board-
1874 specific code (calling a user-provided function
1875 "show_boot_progress(int)") that enables you to show
1876 the system's boot progress on some display (for
1877 example, some LED's) on your board. At the moment,
1878 the following checkpoints are implemented:
1880 - Automatic software updates via TFTP server
1882 CONFIG_UPDATE_TFTP_CNT_MAX
1883 CONFIG_UPDATE_TFTP_MSEC_MAX
1885 These options enable and control the auto-update feature;
1886 for a more detailed description refer to doc/README.update.
1888 - MTD Support (mtdparts command, UBI support)
1891 Adds the MTD device infrastructure from the Linux kernel.
1892 Needed for mtdparts command support.
1894 CONFIG_MTD_PARTITIONS
1896 Adds the MTD partitioning infrastructure from the Linux
1897 kernel. Needed for UBI support.
1899 Legacy uImage format:
1902 1 common/cmd_bootm.c before attempting to boot an image
1903 -1 common/cmd_bootm.c Image header has bad magic number
1904 2 common/cmd_bootm.c Image header has correct magic number
1905 -2 common/cmd_bootm.c Image header has bad checksum
1906 3 common/cmd_bootm.c Image header has correct checksum
1907 -3 common/cmd_bootm.c Image data has bad checksum
1908 4 common/cmd_bootm.c Image data has correct checksum
1909 -4 common/cmd_bootm.c Image is for unsupported architecture
1910 5 common/cmd_bootm.c Architecture check OK
1911 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
1912 6 common/cmd_bootm.c Image Type check OK
1913 -6 common/cmd_bootm.c gunzip uncompression error
1914 -7 common/cmd_bootm.c Unimplemented compression type
1915 7 common/cmd_bootm.c Uncompression OK
1916 8 common/cmd_bootm.c No uncompress/copy overwrite error
1917 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1919 9 common/image.c Start initial ramdisk verification
1920 -10 common/image.c Ramdisk header has bad magic number
1921 -11 common/image.c Ramdisk header has bad checksum
1922 10 common/image.c Ramdisk header is OK
1923 -12 common/image.c Ramdisk data has bad checksum
1924 11 common/image.c Ramdisk data has correct checksum
1925 12 common/image.c Ramdisk verification complete, start loading
1926 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
1927 13 common/image.c Start multifile image verification
1928 14 common/image.c No initial ramdisk, no multifile, continue.
1930 15 lib_<arch>/bootm.c All preparation done, transferring control to OS
1932 -30 lib_ppc/board.c Fatal error, hang the system
1933 -31 post/post.c POST test failed, detected by post_output_backlog()
1934 -32 post/post.c POST test failed, detected by post_run_single()
1936 34 common/cmd_doc.c before loading a Image from a DOC device
1937 -35 common/cmd_doc.c Bad usage of "doc" command
1938 35 common/cmd_doc.c correct usage of "doc" command
1939 -36 common/cmd_doc.c No boot device
1940 36 common/cmd_doc.c correct boot device
1941 -37 common/cmd_doc.c Unknown Chip ID on boot device
1942 37 common/cmd_doc.c correct chip ID found, device available
1943 -38 common/cmd_doc.c Read Error on boot device
1944 38 common/cmd_doc.c reading Image header from DOC device OK
1945 -39 common/cmd_doc.c Image header has bad magic number
1946 39 common/cmd_doc.c Image header has correct magic number
1947 -40 common/cmd_doc.c Error reading Image from DOC device
1948 40 common/cmd_doc.c Image header has correct magic number
1949 41 common/cmd_ide.c before loading a Image from a IDE device
1950 -42 common/cmd_ide.c Bad usage of "ide" command
1951 42 common/cmd_ide.c correct usage of "ide" command
1952 -43 common/cmd_ide.c No boot device
1953 43 common/cmd_ide.c boot device found
1954 -44 common/cmd_ide.c Device not available
1955 44 common/cmd_ide.c Device available
1956 -45 common/cmd_ide.c wrong partition selected
1957 45 common/cmd_ide.c partition selected
1958 -46 common/cmd_ide.c Unknown partition table
1959 46 common/cmd_ide.c valid partition table found
1960 -47 common/cmd_ide.c Invalid partition type
1961 47 common/cmd_ide.c correct partition type
1962 -48 common/cmd_ide.c Error reading Image Header on boot device
1963 48 common/cmd_ide.c reading Image Header from IDE device OK
1964 -49 common/cmd_ide.c Image header has bad magic number
1965 49 common/cmd_ide.c Image header has correct magic number
1966 -50 common/cmd_ide.c Image header has bad checksum
1967 50 common/cmd_ide.c Image header has correct checksum
1968 -51 common/cmd_ide.c Error reading Image from IDE device
1969 51 common/cmd_ide.c reading Image from IDE device OK
1970 52 common/cmd_nand.c before loading a Image from a NAND device
1971 -53 common/cmd_nand.c Bad usage of "nand" command
1972 53 common/cmd_nand.c correct usage of "nand" command
1973 -54 common/cmd_nand.c No boot device
1974 54 common/cmd_nand.c boot device found
1975 -55 common/cmd_nand.c Unknown Chip ID on boot device
1976 55 common/cmd_nand.c correct chip ID found, device available
1977 -56 common/cmd_nand.c Error reading Image Header on boot device
1978 56 common/cmd_nand.c reading Image Header from NAND device OK
1979 -57 common/cmd_nand.c Image header has bad magic number
1980 57 common/cmd_nand.c Image header has correct magic number
1981 -58 common/cmd_nand.c Error reading Image from NAND device
1982 58 common/cmd_nand.c reading Image from NAND device OK
1984 -60 common/env_common.c Environment has a bad CRC, using default
1986 64 net/eth.c starting with Ethernet configuration.
1987 -64 net/eth.c no Ethernet found.
1988 65 net/eth.c Ethernet found.
1990 -80 common/cmd_net.c usage wrong
1991 80 common/cmd_net.c before calling NetLoop()
1992 -81 common/cmd_net.c some error in NetLoop() occurred
1993 81 common/cmd_net.c NetLoop() back without error
1994 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
1995 82 common/cmd_net.c trying automatic boot
1996 83 common/cmd_net.c running "source" command
1997 -83 common/cmd_net.c some error in automatic boot or "source" command
1998 84 common/cmd_net.c end without errors
2003 100 common/cmd_bootm.c Kernel FIT Image has correct format
2004 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2005 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2006 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2007 102 common/cmd_bootm.c Kernel unit name specified
2008 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2009 103 common/cmd_bootm.c Found configuration node
2010 104 common/cmd_bootm.c Got kernel subimage node offset
2011 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2012 105 common/cmd_bootm.c Kernel subimage hash verification OK
2013 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2014 106 common/cmd_bootm.c Architecture check OK
2015 -106 common/cmd_bootm.c Kernel subimage has wrong type
2016 107 common/cmd_bootm.c Kernel subimage type OK
2017 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2018 108 common/cmd_bootm.c Got kernel subimage data/size
2019 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2020 -109 common/cmd_bootm.c Can't get kernel subimage type
2021 -110 common/cmd_bootm.c Can't get kernel subimage comp
2022 -111 common/cmd_bootm.c Can't get kernel subimage os
2023 -112 common/cmd_bootm.c Can't get kernel subimage load address
2024 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2026 120 common/image.c Start initial ramdisk verification
2027 -120 common/image.c Ramdisk FIT image has incorrect format
2028 121 common/image.c Ramdisk FIT image has correct format
2029 122 common/image.c No ramdisk subimage unit name, using configuration
2030 -122 common/image.c Can't get configuration for ramdisk subimage
2031 123 common/image.c Ramdisk unit name specified
2032 -124 common/image.c Can't get ramdisk subimage node offset
2033 125 common/image.c Got ramdisk subimage node offset
2034 -125 common/image.c Ramdisk subimage hash verification failed
2035 126 common/image.c Ramdisk subimage hash verification OK
2036 -126 common/image.c Ramdisk subimage for unsupported architecture
2037 127 common/image.c Architecture check OK
2038 -127 common/image.c Can't get ramdisk subimage data/size
2039 128 common/image.c Got ramdisk subimage data/size
2040 129 common/image.c Can't get ramdisk load address
2041 -129 common/image.c Got ramdisk load address
2043 -130 common/cmd_doc.c Incorrect FIT image format
2044 131 common/cmd_doc.c FIT image format OK
2046 -140 common/cmd_ide.c Incorrect FIT image format
2047 141 common/cmd_ide.c FIT image format OK
2049 -150 common/cmd_nand.c Incorrect FIT image format
2050 151 common/cmd_nand.c FIT image format OK
2056 [so far only for SMDK2400 and TRAB boards]
2058 - Modem support enable:
2059 CONFIG_MODEM_SUPPORT
2061 - RTS/CTS Flow control enable:
2064 - Modem debug support:
2065 CONFIG_MODEM_SUPPORT_DEBUG
2067 Enables debugging stuff (char screen[1024], dbg())
2068 for modem support. Useful only with BDI2000.
2070 - Interrupt support (PPC):
2072 There are common interrupt_init() and timer_interrupt()
2073 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2074 for CPU specific initialization. interrupt_init_cpu()
2075 should set decrementer_count to appropriate value. If
2076 CPU resets decrementer automatically after interrupt
2077 (ppc4xx) it should set decrementer_count to zero.
2078 timer_interrupt() calls timer_interrupt_cpu() for CPU
2079 specific handling. If board has watchdog / status_led
2080 / other_activity_monitor it works automatically from
2081 general timer_interrupt().
2085 In the target system modem support is enabled when a
2086 specific key (key combination) is pressed during
2087 power-on. Otherwise U-Boot will boot normally
2088 (autoboot). The key_pressed() function is called from
2089 board_init(). Currently key_pressed() is a dummy
2090 function, returning 1 and thus enabling modem
2093 If there are no modem init strings in the
2094 environment, U-Boot proceed to autoboot; the
2095 previous output (banner, info printfs) will be
2098 See also: doc/README.Modem
2101 Configuration Settings:
2102 -----------------------
2104 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2105 undefine this when you're short of memory.
2107 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2108 width of the commands listed in the 'help' command output.
2110 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2111 prompt for user input.
2113 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2115 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2117 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2119 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2120 the application (usually a Linux kernel) when it is
2123 - CONFIG_SYS_BAUDRATE_TABLE:
2124 List of legal baudrate settings for this board.
2126 - CONFIG_SYS_CONSOLE_INFO_QUIET
2127 Suppress display of console information at boot.
2129 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2130 If the board specific function
2131 extern int overwrite_console (void);
2132 returns 1, the stdin, stderr and stdout are switched to the
2133 serial port, else the settings in the environment are used.
2135 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2136 Enable the call to overwrite_console().
2138 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2139 Enable overwrite of previous console environment settings.
2141 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2142 Begin and End addresses of the area used by the
2145 - CONFIG_SYS_ALT_MEMTEST:
2146 Enable an alternate, more extensive memory test.
2148 - CONFIG_SYS_MEMTEST_SCRATCH:
2149 Scratch address used by the alternate memory test
2150 You only need to set this if address zero isn't writeable
2152 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2153 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2154 this specified memory area will get subtracted from the top
2155 (end) of RAM and won't get "touched" at all by U-Boot. By
2156 fixing up gd->ram_size the Linux kernel should gets passed
2157 the now "corrected" memory size and won't touch it either.
2158 This should work for arch/ppc and arch/powerpc. Only Linux
2159 board ports in arch/powerpc with bootwrapper support that
2160 recalculate the memory size from the SDRAM controller setup
2161 will have to get fixed in Linux additionally.
2163 This option can be used as a workaround for the 440EPx/GRx
2164 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2167 WARNING: Please make sure that this value is a multiple of
2168 the Linux page size (normally 4k). If this is not the case,
2169 then the end address of the Linux memory will be located at a
2170 non page size aligned address and this could cause major
2173 - CONFIG_SYS_TFTP_LOADADDR:
2174 Default load address for network file downloads
2176 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2177 Enable temporary baudrate change while serial download
2179 - CONFIG_SYS_SDRAM_BASE:
2180 Physical start address of SDRAM. _Must_ be 0 here.
2182 - CONFIG_SYS_MBIO_BASE:
2183 Physical start address of Motherboard I/O (if using a
2186 - CONFIG_SYS_FLASH_BASE:
2187 Physical start address of Flash memory.
2189 - CONFIG_SYS_MONITOR_BASE:
2190 Physical start address of boot monitor code (set by
2191 make config files to be same as the text base address
2192 (TEXT_BASE) used when linking) - same as
2193 CONFIG_SYS_FLASH_BASE when booting from flash.
2195 - CONFIG_SYS_MONITOR_LEN:
2196 Size of memory reserved for monitor code, used to
2197 determine _at_compile_time_ (!) if the environment is
2198 embedded within the U-Boot image, or in a separate
2201 - CONFIG_SYS_MALLOC_LEN:
2202 Size of DRAM reserved for malloc() use.
2204 - CONFIG_SYS_BOOTM_LEN:
2205 Normally compressed uImages are limited to an
2206 uncompressed size of 8 MBytes. If this is not enough,
2207 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2208 to adjust this setting to your needs.
2210 - CONFIG_SYS_BOOTMAPSZ:
2211 Maximum size of memory mapped by the startup code of
2212 the Linux kernel; all data that must be processed by
2213 the Linux kernel (bd_info, boot arguments, FDT blob if
2214 used) must be put below this limit, unless "bootm_low"
2215 enviroment variable is defined and non-zero. In such case
2216 all data for the Linux kernel must be between "bootm_low"
2217 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ.
2219 - CONFIG_SYS_MAX_FLASH_BANKS:
2220 Max number of Flash memory banks
2222 - CONFIG_SYS_MAX_FLASH_SECT:
2223 Max number of sectors on a Flash chip
2225 - CONFIG_SYS_FLASH_ERASE_TOUT:
2226 Timeout for Flash erase operations (in ms)
2228 - CONFIG_SYS_FLASH_WRITE_TOUT:
2229 Timeout for Flash write operations (in ms)
2231 - CONFIG_SYS_FLASH_LOCK_TOUT
2232 Timeout for Flash set sector lock bit operation (in ms)
2234 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2235 Timeout for Flash clear lock bits operation (in ms)
2237 - CONFIG_SYS_FLASH_PROTECTION
2238 If defined, hardware flash sectors protection is used
2239 instead of U-Boot software protection.
2241 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2243 Enable TFTP transfers directly to flash memory;
2244 without this option such a download has to be
2245 performed in two steps: (1) download to RAM, and (2)
2246 copy from RAM to flash.
2248 The two-step approach is usually more reliable, since
2249 you can check if the download worked before you erase
2250 the flash, but in some situations (when system RAM is
2251 too limited to allow for a temporary copy of the
2252 downloaded image) this option may be very useful.
2254 - CONFIG_SYS_FLASH_CFI:
2255 Define if the flash driver uses extra elements in the
2256 common flash structure for storing flash geometry.
2258 - CONFIG_FLASH_CFI_DRIVER
2259 This option also enables the building of the cfi_flash driver
2260 in the drivers directory
2262 - CONFIG_FLASH_CFI_MTD
2263 This option enables the building of the cfi_mtd driver
2264 in the drivers directory. The driver exports CFI flash
2267 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2268 Use buffered writes to flash.
2270 - CONFIG_FLASH_SPANSION_S29WS_N
2271 s29ws-n MirrorBit flash has non-standard addresses for buffered
2274 - CONFIG_SYS_FLASH_QUIET_TEST
2275 If this option is defined, the common CFI flash doesn't
2276 print it's warning upon not recognized FLASH banks. This
2277 is useful, if some of the configured banks are only
2278 optionally available.
2280 - CONFIG_FLASH_SHOW_PROGRESS
2281 If defined (must be an integer), print out countdown
2282 digits and dots. Recommended value: 45 (9..1) for 80
2283 column displays, 15 (3..1) for 40 column displays.
2285 - CONFIG_SYS_RX_ETH_BUFFER:
2286 Defines the number of Ethernet receive buffers. On some
2287 Ethernet controllers it is recommended to set this value
2288 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2289 buffers can be full shortly after enabling the interface
2290 on high Ethernet traffic.
2291 Defaults to 4 if not defined.
2293 The following definitions that deal with the placement and management
2294 of environment data (variable area); in general, we support the
2295 following configurations:
2297 - CONFIG_ENV_IS_IN_FLASH:
2299 Define this if the environment is in flash memory.
2301 a) The environment occupies one whole flash sector, which is
2302 "embedded" in the text segment with the U-Boot code. This
2303 happens usually with "bottom boot sector" or "top boot
2304 sector" type flash chips, which have several smaller
2305 sectors at the start or the end. For instance, such a
2306 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2307 such a case you would place the environment in one of the
2308 4 kB sectors - with U-Boot code before and after it. With
2309 "top boot sector" type flash chips, you would put the
2310 environment in one of the last sectors, leaving a gap
2311 between U-Boot and the environment.
2313 - CONFIG_ENV_OFFSET:
2315 Offset of environment data (variable area) to the
2316 beginning of flash memory; for instance, with bottom boot
2317 type flash chips the second sector can be used: the offset
2318 for this sector is given here.
2320 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2324 This is just another way to specify the start address of
2325 the flash sector containing the environment (instead of
2328 - CONFIG_ENV_SECT_SIZE:
2330 Size of the sector containing the environment.
2333 b) Sometimes flash chips have few, equal sized, BIG sectors.
2334 In such a case you don't want to spend a whole sector for
2339 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2340 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2341 of this flash sector for the environment. This saves
2342 memory for the RAM copy of the environment.
2344 It may also save flash memory if you decide to use this
2345 when your environment is "embedded" within U-Boot code,
2346 since then the remainder of the flash sector could be used
2347 for U-Boot code. It should be pointed out that this is
2348 STRONGLY DISCOURAGED from a robustness point of view:
2349 updating the environment in flash makes it always
2350 necessary to erase the WHOLE sector. If something goes
2351 wrong before the contents has been restored from a copy in
2352 RAM, your target system will be dead.
2354 - CONFIG_ENV_ADDR_REDUND
2355 CONFIG_ENV_SIZE_REDUND
2357 These settings describe a second storage area used to hold
2358 a redundant copy of the environment data, so that there is
2359 a valid backup copy in case there is a power failure during
2360 a "saveenv" operation.
2362 BE CAREFUL! Any changes to the flash layout, and some changes to the
2363 source code will make it necessary to adapt <board>/u-boot.lds*
2367 - CONFIG_ENV_IS_IN_NVRAM:
2369 Define this if you have some non-volatile memory device
2370 (NVRAM, battery buffered SRAM) which you want to use for the
2376 These two #defines are used to determine the memory area you
2377 want to use for environment. It is assumed that this memory
2378 can just be read and written to, without any special
2381 BE CAREFUL! The first access to the environment happens quite early
2382 in U-Boot initalization (when we try to get the setting of for the
2383 console baudrate). You *MUST* have mapped your NVRAM area then, or
2386 Please note that even with NVRAM we still use a copy of the
2387 environment in RAM: we could work on NVRAM directly, but we want to
2388 keep settings there always unmodified except somebody uses "saveenv"
2389 to save the current settings.
2392 - CONFIG_ENV_IS_IN_EEPROM:
2394 Use this if you have an EEPROM or similar serial access
2395 device and a driver for it.
2397 - CONFIG_ENV_OFFSET:
2400 These two #defines specify the offset and size of the
2401 environment area within the total memory of your EEPROM.
2403 - CONFIG_SYS_I2C_EEPROM_ADDR:
2404 If defined, specified the chip address of the EEPROM device.
2405 The default address is zero.
2407 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2408 If defined, the number of bits used to address bytes in a
2409 single page in the EEPROM device. A 64 byte page, for example
2410 would require six bits.
2412 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2413 If defined, the number of milliseconds to delay between
2414 page writes. The default is zero milliseconds.
2416 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2417 The length in bytes of the EEPROM memory array address. Note
2418 that this is NOT the chip address length!
2420 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2421 EEPROM chips that implement "address overflow" are ones
2422 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2423 address and the extra bits end up in the "chip address" bit
2424 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2427 Note that we consider the length of the address field to
2428 still be one byte because the extra address bits are hidden
2429 in the chip address.
2431 - CONFIG_SYS_EEPROM_SIZE:
2432 The size in bytes of the EEPROM device.
2435 - CONFIG_ENV_IS_IN_DATAFLASH:
2437 Define this if you have a DataFlash memory device which you
2438 want to use for the environment.
2440 - CONFIG_ENV_OFFSET:
2444 These three #defines specify the offset and size of the
2445 environment area within the total memory of your DataFlash placed
2446 at the specified address.
2448 - CONFIG_ENV_IS_IN_NAND:
2450 Define this if you have a NAND device which you want to use
2451 for the environment.
2453 - CONFIG_ENV_OFFSET:
2456 These two #defines specify the offset and size of the environment
2457 area within the first NAND device.
2459 - CONFIG_ENV_OFFSET_REDUND
2461 This setting describes a second storage area of CONFIG_ENV_SIZE
2462 size used to hold a redundant copy of the environment data,
2463 so that there is a valid backup copy in case there is a
2464 power failure during a "saveenv" operation.
2466 Note: CONFIG_ENV_OFFSET and CONFIG_ENV_OFFSET_REDUND must be aligned
2467 to a block boundary, and CONFIG_ENV_SIZE must be a multiple of
2468 the NAND devices block size.
2470 - CONFIG_NAND_ENV_DST
2472 Defines address in RAM to which the nand_spl code should copy the
2473 environment. If redundant environment is used, it will be copied to
2474 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2476 - CONFIG_SYS_SPI_INIT_OFFSET
2478 Defines offset to the initial SPI buffer area in DPRAM. The
2479 area is used at an early stage (ROM part) if the environment
2480 is configured to reside in the SPI EEPROM: We need a 520 byte
2481 scratch DPRAM area. It is used between the two initialization
2482 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2483 to be a good choice since it makes it far enough from the
2484 start of the data area as well as from the stack pointer.
2486 Please note that the environment is read-only until the monitor
2487 has been relocated to RAM and a RAM copy of the environment has been
2488 created; also, when using EEPROM you will have to use getenv_r()
2489 until then to read environment variables.
2491 The environment is protected by a CRC32 checksum. Before the monitor
2492 is relocated into RAM, as a result of a bad CRC you will be working
2493 with the compiled-in default environment - *silently*!!! [This is
2494 necessary, because the first environment variable we need is the
2495 "baudrate" setting for the console - if we have a bad CRC, we don't
2496 have any device yet where we could complain.]
2498 Note: once the monitor has been relocated, then it will complain if
2499 the default environment is used; a new CRC is computed as soon as you
2500 use the "saveenv" command to store a valid environment.
2502 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2503 Echo the inverted Ethernet link state to the fault LED.
2505 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2506 also needs to be defined.
2508 - CONFIG_SYS_FAULT_MII_ADDR:
2509 MII address of the PHY to check for the Ethernet link state.
2511 - CONFIG_SYS_64BIT_VSPRINTF:
2512 Makes vsprintf (and all *printf functions) support printing
2513 of 64bit values by using the L quantifier
2515 - CONFIG_SYS_64BIT_STRTOUL:
2516 Adds simple_strtoull that returns a 64bit value
2518 - CONFIG_NS16550_MIN_FUNCTIONS:
2519 Define this if you desire to only have use of the NS16550_init
2520 and NS16550_putc functions for the serial driver located at
2521 drivers/serial/ns16550.c. This option is useful for saving
2522 space for already greatly restricted images, including but not
2523 limited to NAND_SPL configurations.
2525 Low Level (hardware related) configuration options:
2526 ---------------------------------------------------
2528 - CONFIG_SYS_CACHELINE_SIZE:
2529 Cache Line Size of the CPU.
2531 - CONFIG_SYS_DEFAULT_IMMR:
2532 Default address of the IMMR after system reset.
2534 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2535 and RPXsuper) to be able to adjust the position of
2536 the IMMR register after a reset.
2538 - Floppy Disk Support:
2539 CONFIG_SYS_FDC_DRIVE_NUMBER
2541 the default drive number (default value 0)
2543 CONFIG_SYS_ISA_IO_STRIDE
2545 defines the spacing between FDC chipset registers
2548 CONFIG_SYS_ISA_IO_OFFSET
2550 defines the offset of register from address. It
2551 depends on which part of the data bus is connected to
2552 the FDC chipset. (default value 0)
2554 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
2555 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
2558 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
2559 fdc_hw_init() is called at the beginning of the FDC
2560 setup. fdc_hw_init() must be provided by the board
2561 source code. It is used to make hardware dependant
2564 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
2565 DO NOT CHANGE unless you know exactly what you're
2566 doing! (11-4) [MPC8xx/82xx systems only]
2568 - CONFIG_SYS_INIT_RAM_ADDR:
2570 Start address of memory area that can be used for
2571 initial data and stack; please note that this must be
2572 writable memory that is working WITHOUT special
2573 initialization, i. e. you CANNOT use normal RAM which
2574 will become available only after programming the
2575 memory controller and running certain initialization
2578 U-Boot uses the following memory types:
2579 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2580 - MPC824X: data cache
2581 - PPC4xx: data cache
2583 - CONFIG_SYS_GBL_DATA_OFFSET:
2585 Offset of the initial data structure in the memory
2586 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2587 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
2588 data is located at the end of the available space
2589 (sometimes written as (CONFIG_SYS_INIT_RAM_END -
2590 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
2591 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2592 CONFIG_SYS_GBL_DATA_OFFSET) downward.
2595 On the MPC824X (or other systems that use the data
2596 cache for initial memory) the address chosen for
2597 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
2598 point to an otherwise UNUSED address space between
2599 the top of RAM and the start of the PCI space.
2601 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
2603 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
2605 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
2607 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
2609 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2611 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
2613 - CONFIG_SYS_OR_TIMING_SDRAM:
2616 - CONFIG_SYS_MAMR_PTA:
2617 periodic timer for refresh
2619 - CONFIG_SYS_DER: Debug Event Register (37-47)
2621 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2622 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2623 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2624 CONFIG_SYS_BR1_PRELIM:
2625 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2627 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2628 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2629 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
2630 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2632 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
2633 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
2634 Machine Mode Register and Memory Periodic Timer
2635 Prescaler definitions (SDRAM timing)
2637 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
2638 enable I2C microcode relocation patch (MPC8xx);
2639 define relocation offset in DPRAM [DSP2]
2641 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
2642 enable SMC microcode relocation patch (MPC8xx);
2643 define relocation offset in DPRAM [SMC1]
2645 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
2646 enable SPI microcode relocation patch (MPC8xx);
2647 define relocation offset in DPRAM [SCC4]
2649 - CONFIG_SYS_USE_OSCCLK:
2650 Use OSCM clock mode on MBX8xx board. Be careful,
2651 wrong setting might damage your board. Read
2652 doc/README.MBX before setting this variable!
2654 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2655 Offset of the bootmode word in DPRAM used by post
2656 (Power On Self Tests). This definition overrides
2657 #define'd default value in commproc.h resp.
2660 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
2661 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
2662 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
2663 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
2664 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2665 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
2666 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
2667 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
2668 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2670 - CONFIG_PCI_DISABLE_PCIE:
2671 Disable PCI-Express on systems where it is supported but not
2675 Get DDR timing information from an I2C EEPROM. Common
2676 with pluggable memory modules such as SODIMMs
2679 I2C address of the SPD EEPROM
2681 - CONFIG_SYS_SPD_BUS_NUM
2682 If SPD EEPROM is on an I2C bus other than the first
2683 one, specify here. Note that the value must resolve
2684 to something your driver can deal with.
2686 - CONFIG_SYS_83XX_DDR_USES_CS0
2687 Only for 83xx systems. If specified, then DDR should
2688 be configured using CS0 and CS1 instead of CS2 and CS3.
2690 - CONFIG_ETHER_ON_FEC[12]
2691 Define to enable FEC[12] on a 8xx series processor.
2693 - CONFIG_FEC[12]_PHY
2694 Define to the hardcoded PHY address which corresponds
2695 to the given FEC; i. e.
2696 #define CONFIG_FEC1_PHY 4
2697 means that the PHY with address 4 is connected to FEC1
2699 When set to -1, means to probe for first available.
2701 - CONFIG_FEC[12]_PHY_NORXERR
2702 The PHY does not have a RXERR line (RMII only).
2703 (so program the FEC to ignore it).
2706 Enable RMII mode for all FECs.
2707 Note that this is a global option, we can't
2708 have one FEC in standard MII mode and another in RMII mode.
2710 - CONFIG_CRC32_VERIFY
2711 Add a verify option to the crc32 command.
2714 => crc32 -v <address> <count> <crc32>
2716 Where address/count indicate a memory area
2717 and crc32 is the correct crc32 which the
2721 Add the "loopw" memory command. This only takes effect if
2722 the memory commands are activated globally (CONFIG_CMD_MEM).
2725 Add the "mdc" and "mwc" memory commands. These are cyclic
2730 This command will print 4 bytes (10,11,12,13) each 500 ms.
2732 => mwc.l 100 12345678 10
2733 This command will write 12345678 to address 100 all 10 ms.
2735 This only takes effect if the memory commands are activated
2736 globally (CONFIG_CMD_MEM).
2738 - CONFIG_SKIP_LOWLEVEL_INIT
2739 - CONFIG_SKIP_RELOCATE_UBOOT
2741 [ARM only] If these variables are defined, then
2742 certain low level initializations (like setting up
2743 the memory controller) are omitted and/or U-Boot does
2744 not relocate itself into RAM.
2745 Normally these variables MUST NOT be defined. The
2746 only exception is when U-Boot is loaded (to RAM) by
2747 some other boot loader or by a debugger which
2748 performs these initializations itself.
2752 Modifies the behaviour of start.S when compiling a loader
2753 that is executed before the actual U-Boot. E.g. when
2754 compiling a NAND SPL.
2756 Building the Software:
2757 ======================
2759 Building U-Boot has been tested in several native build environments
2760 and in many different cross environments. Of course we cannot support
2761 all possibly existing versions of cross development tools in all
2762 (potentially obsolete) versions. In case of tool chain problems we
2763 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2764 which is extensively used to build and test U-Boot.
2766 If you are not using a native environment, it is assumed that you
2767 have GNU cross compiling tools available in your path. In this case,
2768 you must set the environment variable CROSS_COMPILE in your shell.
2769 Note that no changes to the Makefile or any other source files are
2770 necessary. For example using the ELDK on a 4xx CPU, please enter:
2772 $ CROSS_COMPILE=ppc_4xx-
2773 $ export CROSS_COMPILE
2775 Note: If you wish to generate Windows versions of the utilities in
2776 the tools directory you can use the MinGW toolchain
2777 (http://www.mingw.org). Set your HOST tools to the MinGW
2778 toolchain and execute 'make tools'. For example:
2780 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
2782 Binaries such as tools/mkimage.exe will be created which can
2783 be executed on computers running Windows.
2785 U-Boot is intended to be simple to build. After installing the
2786 sources you must configure U-Boot for one specific board type. This
2791 where "NAME_config" is the name of one of the existing configu-
2792 rations; see the main Makefile for supported names.
2794 Note: for some board special configuration names may exist; check if
2795 additional information is available from the board vendor; for
2796 instance, the TQM823L systems are available without (standard)
2797 or with LCD support. You can select such additional "features"
2798 when choosing the configuration, i. e.
2801 - will configure for a plain TQM823L, i. e. no LCD support
2803 make TQM823L_LCD_config
2804 - will configure for a TQM823L with U-Boot console on LCD
2809 Finally, type "make all", and you should get some working U-Boot
2810 images ready for download to / installation on your system:
2812 - "u-boot.bin" is a raw binary image
2813 - "u-boot" is an image in ELF binary format
2814 - "u-boot.srec" is in Motorola S-Record format
2816 By default the build is performed locally and the objects are saved
2817 in the source directory. One of the two methods can be used to change
2818 this behavior and build U-Boot to some external directory:
2820 1. Add O= to the make command line invocations:
2822 make O=/tmp/build distclean
2823 make O=/tmp/build NAME_config
2824 make O=/tmp/build all
2826 2. Set environment variable BUILD_DIR to point to the desired location:
2828 export BUILD_DIR=/tmp/build
2833 Note that the command line "O=" setting overrides the BUILD_DIR environment
2837 Please be aware that the Makefiles assume you are using GNU make, so
2838 for instance on NetBSD you might need to use "gmake" instead of
2842 If the system board that you have is not listed, then you will need
2843 to port U-Boot to your hardware platform. To do this, follow these
2846 1. Add a new configuration option for your board to the toplevel
2847 "Makefile" and to the "MAKEALL" script, using the existing
2848 entries as examples. Note that here and at many other places
2849 boards and other names are listed in alphabetical sort order. Please
2851 2. Create a new directory to hold your board specific code. Add any
2852 files you need. In your board directory, you will need at least
2853 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2854 3. Create a new configuration file "include/configs/<board>.h" for
2856 3. If you're porting U-Boot to a new CPU, then also create a new
2857 directory to hold your CPU specific code. Add any files you need.
2858 4. Run "make <board>_config" with your new name.
2859 5. Type "make", and you should get a working "u-boot.srec" file
2860 to be installed on your target system.
2861 6. Debug and solve any problems that might arise.
2862 [Of course, this last step is much harder than it sounds.]
2865 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2866 ==============================================================
2868 If you have modified U-Boot sources (for instance added a new board
2869 or support for new devices, a new CPU, etc.) you are expected to
2870 provide feedback to the other developers. The feedback normally takes
2871 the form of a "patch", i. e. a context diff against a certain (latest
2872 official or latest in the git repository) version of U-Boot sources.
2874 But before you submit such a patch, please verify that your modifi-
2875 cation did not break existing code. At least make sure that *ALL* of
2876 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2877 just run the "MAKEALL" script, which will configure and build U-Boot
2878 for ALL supported system. Be warned, this will take a while. You can
2879 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2880 environment variable to the script, i. e. to use the ELDK cross tools
2883 CROSS_COMPILE=ppc_8xx- MAKEALL
2885 or to build on a native PowerPC system you can type
2887 CROSS_COMPILE=' ' MAKEALL
2889 When using the MAKEALL script, the default behaviour is to build
2890 U-Boot in the source directory. This location can be changed by
2891 setting the BUILD_DIR environment variable. Also, for each target
2892 built, the MAKEALL script saves two log files (<target>.ERR and
2893 <target>.MAKEALL) in the <source dir>/LOG directory. This default
2894 location can be changed by setting the MAKEALL_LOGDIR environment
2895 variable. For example:
2897 export BUILD_DIR=/tmp/build
2898 export MAKEALL_LOGDIR=/tmp/log
2899 CROSS_COMPILE=ppc_8xx- MAKEALL
2901 With the above settings build objects are saved in the /tmp/build,
2902 log files are saved in the /tmp/log and the source tree remains clean
2903 during the whole build process.
2906 See also "U-Boot Porting Guide" below.
2909 Monitor Commands - Overview:
2910 ============================
2912 go - start application at address 'addr'
2913 run - run commands in an environment variable
2914 bootm - boot application image from memory
2915 bootp - boot image via network using BootP/TFTP protocol
2916 tftpboot- boot image via network using TFTP protocol
2917 and env variables "ipaddr" and "serverip"
2918 (and eventually "gatewayip")
2919 rarpboot- boot image via network using RARP/TFTP protocol
2920 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2921 loads - load S-Record file over serial line
2922 loadb - load binary file over serial line (kermit mode)
2924 mm - memory modify (auto-incrementing)
2925 nm - memory modify (constant address)
2926 mw - memory write (fill)
2928 cmp - memory compare
2929 crc32 - checksum calculation
2930 i2c - I2C sub-system
2931 sspi - SPI utility commands
2932 base - print or set address offset
2933 printenv- print environment variables
2934 setenv - set environment variables
2935 saveenv - save environment variables to persistent storage
2936 protect - enable or disable FLASH write protection
2937 erase - erase FLASH memory
2938 flinfo - print FLASH memory information
2939 bdinfo - print Board Info structure
2940 iminfo - print header information for application image
2941 coninfo - print console devices and informations
2942 ide - IDE sub-system
2943 loop - infinite loop on address range
2944 loopw - infinite write loop on address range
2945 mtest - simple RAM test
2946 icache - enable or disable instruction cache
2947 dcache - enable or disable data cache
2948 reset - Perform RESET of the CPU
2949 echo - echo args to console
2950 version - print monitor version
2951 help - print online help
2952 ? - alias for 'help'
2955 Monitor Commands - Detailed Description:
2956 ========================================
2960 For now: just type "help <command>".
2963 Environment Variables:
2964 ======================
2966 U-Boot supports user configuration using Environment Variables which
2967 can be made persistent by saving to Flash memory.
2969 Environment Variables are set using "setenv", printed using
2970 "printenv", and saved to Flash using "saveenv". Using "setenv"
2971 without a value can be used to delete a variable from the
2972 environment. As long as you don't save the environment you are
2973 working with an in-memory copy. In case the Flash area containing the
2974 environment is erased by accident, a default environment is provided.
2976 Some configuration options can be set using Environment Variables:
2978 baudrate - see CONFIG_BAUDRATE
2980 bootdelay - see CONFIG_BOOTDELAY
2982 bootcmd - see CONFIG_BOOTCOMMAND
2984 bootargs - Boot arguments when booting an RTOS image
2986 bootfile - Name of the image to load with TFTP
2988 bootm_low - Memory range available for image processing in the bootm
2989 command can be restricted. This variable is given as
2990 a hexadecimal number and defines lowest address allowed
2991 for use by the bootm command. See also "bootm_size"
2992 environment variable. Address defined by "bootm_low" is
2993 also the base of the initial memory mapping for the Linux
2994 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ.
2996 bootm_size - Memory range available for image processing in the bootm
2997 command can be restricted. This variable is given as
2998 a hexadecimal number and defines the size of the region
2999 allowed for use by the bootm command. See also "bootm_low"
3000 environment variable.
3002 updatefile - Location of the software update file on a TFTP server, used
3003 by the automatic software update feature. Please refer to
3004 documentation in doc/README.update for more details.
3006 autoload - if set to "no" (any string beginning with 'n'),
3007 "bootp" will just load perform a lookup of the
3008 configuration from the BOOTP server, but not try to
3009 load any image using TFTP
3011 autoscript - if set to "yes" commands like "loadb", "loady",
3012 "bootp", "tftpb", "rarpboot" and "nfs" will attempt
3013 to automatically run script images (by internally
3016 autoscript_uname - if script image is in a format (FIT) this
3017 variable is used to get script subimage unit name.
3019 autostart - if set to "yes", an image loaded using the "bootp",
3020 "rarpboot", "tftpboot" or "diskboot" commands will
3021 be automatically started (by internally calling
3024 If set to "no", a standalone image passed to the
3025 "bootm" command will be copied to the load address
3026 (and eventually uncompressed), but NOT be started.
3027 This can be used to load and uncompress arbitrary
3030 i2cfast - (PPC405GP|PPC405EP only)
3031 if set to 'y' configures Linux I2C driver for fast
3032 mode (400kHZ). This environment variable is used in
3033 initialization code. So, for changes to be effective
3034 it must be saved and board must be reset.
3036 initrd_high - restrict positioning of initrd images:
3037 If this variable is not set, initrd images will be
3038 copied to the highest possible address in RAM; this
3039 is usually what you want since it allows for
3040 maximum initrd size. If for some reason you want to
3041 make sure that the initrd image is loaded below the
3042 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3043 variable to a value of "no" or "off" or "0".
3044 Alternatively, you can set it to a maximum upper
3045 address to use (U-Boot will still check that it
3046 does not overwrite the U-Boot stack and data).
3048 For instance, when you have a system with 16 MB
3049 RAM, and want to reserve 4 MB from use by Linux,
3050 you can do this by adding "mem=12M" to the value of
3051 the "bootargs" variable. However, now you must make
3052 sure that the initrd image is placed in the first
3053 12 MB as well - this can be done with
3055 setenv initrd_high 00c00000
3057 If you set initrd_high to 0xFFFFFFFF, this is an
3058 indication to U-Boot that all addresses are legal
3059 for the Linux kernel, including addresses in flash
3060 memory. In this case U-Boot will NOT COPY the
3061 ramdisk at all. This may be useful to reduce the
3062 boot time on your system, but requires that this
3063 feature is supported by your Linux kernel.
3065 ipaddr - IP address; needed for tftpboot command
3067 loadaddr - Default load address for commands like "bootp",
3068 "rarpboot", "tftpboot", "loadb" or "diskboot"
3070 loads_echo - see CONFIG_LOADS_ECHO
3072 serverip - TFTP server IP address; needed for tftpboot command
3074 bootretry - see CONFIG_BOOT_RETRY_TIME
3076 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3078 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3080 ethprime - When CONFIG_NET_MULTI is enabled controls which
3081 interface is used first.
3083 ethact - When CONFIG_NET_MULTI is enabled controls which
3084 interface is currently active. For example you
3085 can do the following
3087 => setenv ethact FEC ETHERNET
3088 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
3089 => setenv ethact SCC ETHERNET
3090 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
3092 ethrotate - When set to "no" U-Boot does not go through all
3093 available network interfaces.
3094 It just stays at the currently selected interface.
3096 netretry - When set to "no" each network operation will
3097 either succeed or fail without retrying.
3098 When set to "once" the network operation will
3099 fail when all the available network interfaces
3100 are tried once without success.
3101 Useful on scripts which control the retry operation
3104 npe_ucode - set load address for the NPE microcode
3106 tftpsrcport - If this is set, the value is used for TFTP's
3109 tftpdstport - If this is set, the value is used for TFTP's UDP
3110 destination port instead of the Well Know Port 69.
3112 vlan - When set to a value < 4095 the traffic over
3113 Ethernet is encapsulated/received over 802.1q
3116 The following environment variables may be used and automatically
3117 updated by the network boot commands ("bootp" and "rarpboot"),
3118 depending the information provided by your boot server:
3120 bootfile - see above
3121 dnsip - IP address of your Domain Name Server
3122 dnsip2 - IP address of your secondary Domain Name Server
3123 gatewayip - IP address of the Gateway (Router) to use
3124 hostname - Target hostname
3126 netmask - Subnet Mask
3127 rootpath - Pathname of the root filesystem on the NFS server
3128 serverip - see above
3131 There are two special Environment Variables:
3133 serial# - contains hardware identification information such
3134 as type string and/or serial number
3135 ethaddr - Ethernet address
3137 These variables can be set only once (usually during manufacturing of
3138 the board). U-Boot refuses to delete or overwrite these variables
3139 once they have been set once.
3142 Further special Environment Variables:
3144 ver - Contains the U-Boot version string as printed
3145 with the "version" command. This variable is
3146 readonly (see CONFIG_VERSION_VARIABLE).
3149 Please note that changes to some configuration parameters may take
3150 only effect after the next boot (yes, that's just like Windoze :-).
3153 Command Line Parsing:
3154 =====================
3156 There are two different command line parsers available with U-Boot:
3157 the old "simple" one, and the much more powerful "hush" shell:
3159 Old, simple command line parser:
3160 --------------------------------
3162 - supports environment variables (through setenv / saveenv commands)
3163 - several commands on one line, separated by ';'
3164 - variable substitution using "... ${name} ..." syntax
3165 - special characters ('$', ';') can be escaped by prefixing with '\',
3167 setenv bootcmd bootm \${address}
3168 - You can also escape text by enclosing in single apostrophes, for example:
3169 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3174 - similar to Bourne shell, with control structures like
3175 if...then...else...fi, for...do...done; while...do...done,
3176 until...do...done, ...
3177 - supports environment ("global") variables (through setenv / saveenv
3178 commands) and local shell variables (through standard shell syntax
3179 "name=value"); only environment variables can be used with "run"
3185 (1) If a command line (or an environment variable executed by a "run"
3186 command) contains several commands separated by semicolon, and
3187 one of these commands fails, then the remaining commands will be
3190 (2) If you execute several variables with one call to run (i. e.
3191 calling run with a list of variables as arguments), any failing
3192 command will cause "run" to terminate, i. e. the remaining
3193 variables are not executed.
3195 Note for Redundant Ethernet Interfaces:
3196 =======================================
3198 Some boards come with redundant Ethernet interfaces; U-Boot supports
3199 such configurations and is capable of automatic selection of a
3200 "working" interface when needed. MAC assignment works as follows:
3202 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3203 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3204 "eth1addr" (=>eth1), "eth2addr", ...
3206 If the network interface stores some valid MAC address (for instance
3207 in SROM), this is used as default address if there is NO correspon-
3208 ding setting in the environment; if the corresponding environment
3209 variable is set, this overrides the settings in the card; that means:
3211 o If the SROM has a valid MAC address, and there is no address in the
3212 environment, the SROM's address is used.
3214 o If there is no valid address in the SROM, and a definition in the
3215 environment exists, then the value from the environment variable is
3218 o If both the SROM and the environment contain a MAC address, and
3219 both addresses are the same, this MAC address is used.
3221 o If both the SROM and the environment contain a MAC address, and the
3222 addresses differ, the value from the environment is used and a
3225 o If neither SROM nor the environment contain a MAC address, an error
3232 U-Boot is capable of booting (and performing other auxiliary operations on)
3233 images in two formats:
3235 New uImage format (FIT)
3236 -----------------------
3238 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3239 to Flattened Device Tree). It allows the use of images with multiple
3240 components (several kernels, ramdisks, etc.), with contents protected by
3241 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3247 Old image format is based on binary files which can be basically anything,
3248 preceded by a special header; see the definitions in include/image.h for
3249 details; basically, the header defines the following image properties:
3251 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3252 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3253 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3254 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3256 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3257 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3258 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
3259 * Compression Type (uncompressed, gzip, bzip2)
3265 The header is marked by a special Magic Number, and both the header
3266 and the data portions of the image are secured against corruption by
3273 Although U-Boot should support any OS or standalone application
3274 easily, the main focus has always been on Linux during the design of
3277 U-Boot includes many features that so far have been part of some
3278 special "boot loader" code within the Linux kernel. Also, any
3279 "initrd" images to be used are no longer part of one big Linux image;
3280 instead, kernel and "initrd" are separate images. This implementation
3281 serves several purposes:
3283 - the same features can be used for other OS or standalone
3284 applications (for instance: using compressed images to reduce the
3285 Flash memory footprint)
3287 - it becomes much easier to port new Linux kernel versions because
3288 lots of low-level, hardware dependent stuff are done by U-Boot
3290 - the same Linux kernel image can now be used with different "initrd"
3291 images; of course this also means that different kernel images can
3292 be run with the same "initrd". This makes testing easier (you don't
3293 have to build a new "zImage.initrd" Linux image when you just
3294 change a file in your "initrd"). Also, a field-upgrade of the
3295 software is easier now.
3301 Porting Linux to U-Boot based systems:
3302 ---------------------------------------
3304 U-Boot cannot save you from doing all the necessary modifications to
3305 configure the Linux device drivers for use with your target hardware
3306 (no, we don't intend to provide a full virtual machine interface to
3309 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
3311 Just make sure your machine specific header file (for instance
3312 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3313 Information structure as we define in include/asm-<arch>/u-boot.h,
3314 and make sure that your definition of IMAP_ADDR uses the same value
3315 as your U-Boot configuration in CONFIG_SYS_IMMR.
3318 Configuring the Linux kernel:
3319 -----------------------------
3321 No specific requirements for U-Boot. Make sure you have some root
3322 device (initial ramdisk, NFS) for your target system.
3325 Building a Linux Image:
3326 -----------------------
3328 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3329 not used. If you use recent kernel source, a new build target
3330 "uImage" will exist which automatically builds an image usable by
3331 U-Boot. Most older kernels also have support for a "pImage" target,
3332 which was introduced for our predecessor project PPCBoot and uses a
3333 100% compatible format.
3342 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3343 encapsulate a compressed Linux kernel image with header information,
3344 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3346 * build a standard "vmlinux" kernel image (in ELF binary format):
3348 * convert the kernel into a raw binary image:
3350 ${CROSS_COMPILE}-objcopy -O binary \
3351 -R .note -R .comment \
3352 -S vmlinux linux.bin
3354 * compress the binary image:
3358 * package compressed binary image for U-Boot:
3360 mkimage -A ppc -O linux -T kernel -C gzip \
3361 -a 0 -e 0 -n "Linux Kernel Image" \
3362 -d linux.bin.gz uImage
3365 The "mkimage" tool can also be used to create ramdisk images for use
3366 with U-Boot, either separated from the Linux kernel image, or
3367 combined into one file. "mkimage" encapsulates the images with a 64
3368 byte header containing information about target architecture,
3369 operating system, image type, compression method, entry points, time
3370 stamp, CRC32 checksums, etc.
3372 "mkimage" can be called in two ways: to verify existing images and
3373 print the header information, or to build new images.
3375 In the first form (with "-l" option) mkimage lists the information
3376 contained in the header of an existing U-Boot image; this includes
3377 checksum verification:
3379 tools/mkimage -l image
3380 -l ==> list image header information
3382 The second form (with "-d" option) is used to build a U-Boot image
3383 from a "data file" which is used as image payload:
3385 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3386 -n name -d data_file image
3387 -A ==> set architecture to 'arch'
3388 -O ==> set operating system to 'os'
3389 -T ==> set image type to 'type'
3390 -C ==> set compression type 'comp'
3391 -a ==> set load address to 'addr' (hex)
3392 -e ==> set entry point to 'ep' (hex)
3393 -n ==> set image name to 'name'
3394 -d ==> use image data from 'datafile'
3396 Right now, all Linux kernels for PowerPC systems use the same load
3397 address (0x00000000), but the entry point address depends on the
3400 - 2.2.x kernels have the entry point at 0x0000000C,
3401 - 2.3.x and later kernels have the entry point at 0x00000000.
3403 So a typical call to build a U-Boot image would read:
3405 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3406 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3407 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
3408 > examples/uImage.TQM850L
3409 Image Name: 2.4.4 kernel for TQM850L
3410 Created: Wed Jul 19 02:34:59 2000
3411 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3412 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3413 Load Address: 0x00000000
3414 Entry Point: 0x00000000
3416 To verify the contents of the image (or check for corruption):
3418 -> tools/mkimage -l examples/uImage.TQM850L
3419 Image Name: 2.4.4 kernel for TQM850L
3420 Created: Wed Jul 19 02:34:59 2000
3421 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3422 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3423 Load Address: 0x00000000
3424 Entry Point: 0x00000000
3426 NOTE: for embedded systems where boot time is critical you can trade
3427 speed for memory and install an UNCOMPRESSED image instead: this
3428 needs more space in Flash, but boots much faster since it does not
3429 need to be uncompressed:
3431 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
3432 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3433 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3434 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
3435 > examples/uImage.TQM850L-uncompressed
3436 Image Name: 2.4.4 kernel for TQM850L
3437 Created: Wed Jul 19 02:34:59 2000
3438 Image Type: PowerPC Linux Kernel Image (uncompressed)
3439 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3440 Load Address: 0x00000000
3441 Entry Point: 0x00000000
3444 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3445 when your kernel is intended to use an initial ramdisk:
3447 -> tools/mkimage -n 'Simple Ramdisk Image' \
3448 > -A ppc -O linux -T ramdisk -C gzip \
3449 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3450 Image Name: Simple Ramdisk Image
3451 Created: Wed Jan 12 14:01:50 2000
3452 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3453 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3454 Load Address: 0x00000000
3455 Entry Point: 0x00000000
3458 Installing a Linux Image:
3459 -------------------------
3461 To downloading a U-Boot image over the serial (console) interface,
3462 you must convert the image to S-Record format:
3464 objcopy -I binary -O srec examples/image examples/image.srec
3466 The 'objcopy' does not understand the information in the U-Boot
3467 image header, so the resulting S-Record file will be relative to
3468 address 0x00000000. To load it to a given address, you need to
3469 specify the target address as 'offset' parameter with the 'loads'
3472 Example: install the image to address 0x40100000 (which on the
3473 TQM8xxL is in the first Flash bank):
3475 => erase 40100000 401FFFFF
3481 ## Ready for S-Record download ...
3482 ~>examples/image.srec
3483 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3485 15989 15990 15991 15992
3486 [file transfer complete]
3488 ## Start Addr = 0x00000000
3491 You can check the success of the download using the 'iminfo' command;
3492 this includes a checksum verification so you can be sure no data
3493 corruption happened:
3497 ## Checking Image at 40100000 ...
3498 Image Name: 2.2.13 for initrd on TQM850L
3499 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3500 Data Size: 335725 Bytes = 327 kB = 0 MB
3501 Load Address: 00000000
3502 Entry Point: 0000000c
3503 Verifying Checksum ... OK
3509 The "bootm" command is used to boot an application that is stored in
3510 memory (RAM or Flash). In case of a Linux kernel image, the contents
3511 of the "bootargs" environment variable is passed to the kernel as
3512 parameters. You can check and modify this variable using the
3513 "printenv" and "setenv" commands:
3516 => printenv bootargs
3517 bootargs=root=/dev/ram
3519 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3521 => printenv bootargs
3522 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3525 ## Booting Linux kernel at 40020000 ...
3526 Image Name: 2.2.13 for NFS on TQM850L
3527 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3528 Data Size: 381681 Bytes = 372 kB = 0 MB
3529 Load Address: 00000000
3530 Entry Point: 0000000c
3531 Verifying Checksum ... OK
3532 Uncompressing Kernel Image ... OK
3533 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
3534 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3535 time_init: decrementer frequency = 187500000/60
3536 Calibrating delay loop... 49.77 BogoMIPS
3537 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3540 If you want to boot a Linux kernel with initial RAM disk, you pass
3541 the memory addresses of both the kernel and the initrd image (PPBCOOT
3542 format!) to the "bootm" command:
3544 => imi 40100000 40200000
3546 ## Checking Image at 40100000 ...
3547 Image Name: 2.2.13 for initrd on TQM850L
3548 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3549 Data Size: 335725 Bytes = 327 kB = 0 MB
3550 Load Address: 00000000
3551 Entry Point: 0000000c
3552 Verifying Checksum ... OK
3554 ## Checking Image at 40200000 ...
3555 Image Name: Simple Ramdisk Image
3556 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3557 Data Size: 566530 Bytes = 553 kB = 0 MB
3558 Load Address: 00000000
3559 Entry Point: 00000000
3560 Verifying Checksum ... OK
3562 => bootm 40100000 40200000
3563 ## Booting Linux kernel at 40100000 ...
3564 Image Name: 2.2.13 for initrd on TQM850L
3565 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3566 Data Size: 335725 Bytes = 327 kB = 0 MB
3567 Load Address: 00000000
3568 Entry Point: 0000000c
3569 Verifying Checksum ... OK
3570 Uncompressing Kernel Image ... OK
3571 ## Loading RAMDisk Image at 40200000 ...
3572 Image Name: Simple Ramdisk Image
3573 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3574 Data Size: 566530 Bytes = 553 kB = 0 MB
3575 Load Address: 00000000
3576 Entry Point: 00000000
3577 Verifying Checksum ... OK
3578 Loading Ramdisk ... OK
3579 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
3580 Boot arguments: root=/dev/ram
3581 time_init: decrementer frequency = 187500000/60
3582 Calibrating delay loop... 49.77 BogoMIPS
3584 RAMDISK: Compressed image found at block 0
3585 VFS: Mounted root (ext2 filesystem).
3589 Boot Linux and pass a flat device tree:
3592 First, U-Boot must be compiled with the appropriate defines. See the section
3593 titled "Linux Kernel Interface" above for a more in depth explanation. The
3594 following is an example of how to start a kernel and pass an updated
3600 oft=oftrees/mpc8540ads.dtb
3601 => tftp $oftaddr $oft
3602 Speed: 1000, full duplex
3604 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3605 Filename 'oftrees/mpc8540ads.dtb'.
3606 Load address: 0x300000
3609 Bytes transferred = 4106 (100a hex)
3610 => tftp $loadaddr $bootfile
3611 Speed: 1000, full duplex
3613 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3615 Load address: 0x200000
3616 Loading:############
3618 Bytes transferred = 1029407 (fb51f hex)
3623 => bootm $loadaddr - $oftaddr
3624 ## Booting image at 00200000 ...
3625 Image Name: Linux-2.6.17-dirty
3626 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3627 Data Size: 1029343 Bytes = 1005.2 kB
3628 Load Address: 00000000
3629 Entry Point: 00000000
3630 Verifying Checksum ... OK
3631 Uncompressing Kernel Image ... OK
3632 Booting using flat device tree at 0x300000
3633 Using MPC85xx ADS machine description
3634 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3638 More About U-Boot Image Types:
3639 ------------------------------
3641 U-Boot supports the following image types:
3643 "Standalone Programs" are directly runnable in the environment
3644 provided by U-Boot; it is expected that (if they behave
3645 well) you can continue to work in U-Boot after return from
3646 the Standalone Program.
3647 "OS Kernel Images" are usually images of some Embedded OS which
3648 will take over control completely. Usually these programs
3649 will install their own set of exception handlers, device
3650 drivers, set up the MMU, etc. - this means, that you cannot
3651 expect to re-enter U-Boot except by resetting the CPU.
3652 "RAMDisk Images" are more or less just data blocks, and their
3653 parameters (address, size) are passed to an OS kernel that is
3655 "Multi-File Images" contain several images, typically an OS
3656 (Linux) kernel image and one or more data images like
3657 RAMDisks. This construct is useful for instance when you want
3658 to boot over the network using BOOTP etc., where the boot
3659 server provides just a single image file, but you want to get
3660 for instance an OS kernel and a RAMDisk image.
3662 "Multi-File Images" start with a list of image sizes, each
3663 image size (in bytes) specified by an "uint32_t" in network
3664 byte order. This list is terminated by an "(uint32_t)0".
3665 Immediately after the terminating 0 follow the images, one by
3666 one, all aligned on "uint32_t" boundaries (size rounded up to
3667 a multiple of 4 bytes).
3669 "Firmware Images" are binary images containing firmware (like
3670 U-Boot or FPGA images) which usually will be programmed to
3673 "Script files" are command sequences that will be executed by
3674 U-Boot's command interpreter; this feature is especially
3675 useful when you configure U-Boot to use a real shell (hush)
3676 as command interpreter.
3682 One of the features of U-Boot is that you can dynamically load and
3683 run "standalone" applications, which can use some resources of
3684 U-Boot like console I/O functions or interrupt services.
3686 Two simple examples are included with the sources:
3691 'examples/hello_world.c' contains a small "Hello World" Demo
3692 application; it is automatically compiled when you build U-Boot.
3693 It's configured to run at address 0x00040004, so you can play with it
3697 ## Ready for S-Record download ...
3698 ~>examples/hello_world.srec
3699 1 2 3 4 5 6 7 8 9 10 11 ...
3700 [file transfer complete]
3702 ## Start Addr = 0x00040004
3704 => go 40004 Hello World! This is a test.
3705 ## Starting application at 0x00040004 ...
3716 Hit any key to exit ...
3718 ## Application terminated, rc = 0x0
3720 Another example, which demonstrates how to register a CPM interrupt
3721 handler with the U-Boot code, can be found in 'examples/timer.c'.
3722 Here, a CPM timer is set up to generate an interrupt every second.
3723 The interrupt service routine is trivial, just printing a '.'
3724 character, but this is just a demo program. The application can be
3725 controlled by the following keys:
3727 ? - print current values og the CPM Timer registers
3728 b - enable interrupts and start timer
3729 e - stop timer and disable interrupts
3730 q - quit application
3733 ## Ready for S-Record download ...
3734 ~>examples/timer.srec
3735 1 2 3 4 5 6 7 8 9 10 11 ...
3736 [file transfer complete]
3738 ## Start Addr = 0x00040004
3741 ## Starting application at 0x00040004 ...
3744 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3747 [q, b, e, ?] Set interval 1000000 us
3750 [q, b, e, ?] ........
3751 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3754 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3757 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3760 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3762 [q, b, e, ?] ...Stopping timer
3764 [q, b, e, ?] ## Application terminated, rc = 0x0
3770 Over time, many people have reported problems when trying to use the
3771 "minicom" terminal emulation program for serial download. I (wd)
3772 consider minicom to be broken, and recommend not to use it. Under
3773 Unix, I recommend to use C-Kermit for general purpose use (and
3774 especially for kermit binary protocol download ("loadb" command), and
3775 use "cu" for S-Record download ("loads" command).
3777 Nevertheless, if you absolutely want to use it try adding this
3778 configuration to your "File transfer protocols" section:
3780 Name Program Name U/D FullScr IO-Red. Multi
3781 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3782 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3788 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3789 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3791 Building requires a cross environment; it is known to work on
3792 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3793 need gmake since the Makefiles are not compatible with BSD make).
3794 Note that the cross-powerpc package does not install include files;
3795 attempting to build U-Boot will fail because <machine/ansi.h> is
3796 missing. This file has to be installed and patched manually:
3798 # cd /usr/pkg/cross/powerpc-netbsd/include
3800 # ln -s powerpc machine
3801 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3802 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3804 Native builds *don't* work due to incompatibilities between native
3805 and U-Boot include files.
3807 Booting assumes that (the first part of) the image booted is a
3808 stage-2 loader which in turn loads and then invokes the kernel
3809 proper. Loader sources will eventually appear in the NetBSD source
3810 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3811 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3814 Implementation Internals:
3815 =========================
3817 The following is not intended to be a complete description of every
3818 implementation detail. However, it should help to understand the
3819 inner workings of U-Boot and make it easier to port it to custom
3823 Initial Stack, Global Data:
3824 ---------------------------
3826 The implementation of U-Boot is complicated by the fact that U-Boot
3827 starts running out of ROM (flash memory), usually without access to
3828 system RAM (because the memory controller is not initialized yet).
3829 This means that we don't have writable Data or BSS segments, and BSS
3830 is not initialized as zero. To be able to get a C environment working
3831 at all, we have to allocate at least a minimal stack. Implementation
3832 options for this are defined and restricted by the CPU used: Some CPU
3833 models provide on-chip memory (like the IMMR area on MPC8xx and
3834 MPC826x processors), on others (parts of) the data cache can be
3835 locked as (mis-) used as memory, etc.
3837 Chris Hallinan posted a good summary of these issues to the
3838 U-Boot mailing list:
3840 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3841 From: "Chris Hallinan" <clh@net1plus.com>
3842 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3845 Correct me if I'm wrong, folks, but the way I understand it
3846 is this: Using DCACHE as initial RAM for Stack, etc, does not
3847 require any physical RAM backing up the cache. The cleverness
3848 is that the cache is being used as a temporary supply of
3849 necessary storage before the SDRAM controller is setup. It's
3850 beyond the scope of this list to explain the details, but you
3851 can see how this works by studying the cache architecture and
3852 operation in the architecture and processor-specific manuals.
3854 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3855 is another option for the system designer to use as an
3856 initial stack/RAM area prior to SDRAM being available. Either
3857 option should work for you. Using CS 4 should be fine if your
3858 board designers haven't used it for something that would
3859 cause you grief during the initial boot! It is frequently not
3862 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
3863 with your processor/board/system design. The default value
3864 you will find in any recent u-boot distribution in
3865 walnut.h should work for you. I'd set it to a value larger
3866 than your SDRAM module. If you have a 64MB SDRAM module, set
3867 it above 400_0000. Just make sure your board has no resources
3868 that are supposed to respond to that address! That code in
3869 start.S has been around a while and should work as is when
3870 you get the config right.
3875 It is essential to remember this, since it has some impact on the C
3876 code for the initialization procedures:
3878 * Initialized global data (data segment) is read-only. Do not attempt
3881 * Do not use any uninitialized global data (or implicitely initialized
3882 as zero data - BSS segment) at all - this is undefined, initiali-
3883 zation is performed later (when relocating to RAM).
3885 * Stack space is very limited. Avoid big data buffers or things like
3888 Having only the stack as writable memory limits means we cannot use
3889 normal global data to share information beween the code. But it
3890 turned out that the implementation of U-Boot can be greatly
3891 simplified by making a global data structure (gd_t) available to all
3892 functions. We could pass a pointer to this data as argument to _all_
3893 functions, but this would bloat the code. Instead we use a feature of
3894 the GCC compiler (Global Register Variables) to share the data: we
3895 place a pointer (gd) to the global data into a register which we
3896 reserve for this purpose.
3898 When choosing a register for such a purpose we are restricted by the
3899 relevant (E)ABI specifications for the current architecture, and by
3900 GCC's implementation.
3902 For PowerPC, the following registers have specific use:
3904 R2: reserved for system use
3905 R3-R4: parameter passing and return values
3906 R5-R10: parameter passing
3907 R13: small data area pointer
3911 (U-Boot also uses R14 as internal GOT pointer.)
3913 ==> U-Boot will use R2 to hold a pointer to the global data
3915 Note: on PPC, we could use a static initializer (since the
3916 address of the global data structure is known at compile time),
3917 but it turned out that reserving a register results in somewhat
3918 smaller code - although the code savings are not that big (on
3919 average for all boards 752 bytes for the whole U-Boot image,
3920 624 text + 127 data).
3922 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
3923 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
3925 ==> U-Boot will use P3 to hold a pointer to the global data
3927 On ARM, the following registers are used:
3929 R0: function argument word/integer result
3930 R1-R3: function argument word
3932 R10: stack limit (used only if stack checking if enabled)
3933 R11: argument (frame) pointer
3934 R12: temporary workspace
3937 R15: program counter
3939 ==> U-Boot will use R8 to hold a pointer to the global data
3941 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3942 or current versions of GCC may "optimize" the code too much.
3947 U-Boot runs in system state and uses physical addresses, i.e. the
3948 MMU is not used either for address mapping nor for memory protection.
3950 The available memory is mapped to fixed addresses using the memory
3951 controller. In this process, a contiguous block is formed for each
3952 memory type (Flash, SDRAM, SRAM), even when it consists of several
3953 physical memory banks.
3955 U-Boot is installed in the first 128 kB of the first Flash bank (on
3956 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3957 booting and sizing and initializing DRAM, the code relocates itself
3958 to the upper end of DRAM. Immediately below the U-Boot code some
3959 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
3960 configuration setting]. Below that, a structure with global Board
3961 Info data is placed, followed by the stack (growing downward).
3963 Additionally, some exception handler code is copied to the low 8 kB
3964 of DRAM (0x00000000 ... 0x00001FFF).
3966 So a typical memory configuration with 16 MB of DRAM could look like
3969 0x0000 0000 Exception Vector code
3972 0x0000 2000 Free for Application Use
3978 0x00FB FF20 Monitor Stack (Growing downward)
3979 0x00FB FFAC Board Info Data and permanent copy of global data
3980 0x00FC 0000 Malloc Arena
3983 0x00FE 0000 RAM Copy of Monitor Code
3984 ... eventually: LCD or video framebuffer
3985 ... eventually: pRAM (Protected RAM - unchanged by reset)
3986 0x00FF FFFF [End of RAM]
3989 System Initialization:
3990 ----------------------
3992 In the reset configuration, U-Boot starts at the reset entry point
3993 (on most PowerPC systems at address 0x00000100). Because of the reset
3994 configuration for CS0# this is a mirror of the onboard Flash memory.
3995 To be able to re-map memory U-Boot then jumps to its link address.
3996 To be able to implement the initialization code in C, a (small!)
3997 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3998 which provide such a feature like MPC8xx or MPC8260), or in a locked
3999 part of the data cache. After that, U-Boot initializes the CPU core,
4000 the caches and the SIU.
4002 Next, all (potentially) available memory banks are mapped using a
4003 preliminary mapping. For example, we put them on 512 MB boundaries
4004 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4005 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4006 programmed for SDRAM access. Using the temporary configuration, a
4007 simple memory test is run that determines the size of the SDRAM
4010 When there is more than one SDRAM bank, and the banks are of
4011 different size, the largest is mapped first. For equal size, the first
4012 bank (CS2#) is mapped first. The first mapping is always for address
4013 0x00000000, with any additional banks following immediately to create
4014 contiguous memory starting from 0.
4016 Then, the monitor installs itself at the upper end of the SDRAM area
4017 and allocates memory for use by malloc() and for the global Board
4018 Info data; also, the exception vector code is copied to the low RAM
4019 pages, and the final stack is set up.
4021 Only after this relocation will you have a "normal" C environment;
4022 until that you are restricted in several ways, mostly because you are
4023 running from ROM, and because the code will have to be relocated to a
4027 U-Boot Porting Guide:
4028 ----------------------
4030 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4034 int main(int argc, char *argv[])
4036 sighandler_t no_more_time;
4038 signal(SIGALRM, no_more_time);
4039 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4041 if (available_money > available_manpower) {
4042 Pay consultant to port U-Boot;
4046 Download latest U-Boot source;
4048 Subscribe to u-boot mailing list;
4051 email("Hi, I am new to U-Boot, how do I get started?");
4054 Read the README file in the top level directory;
4055 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4056 Read applicable doc/*.README;
4057 Read the source, Luke;
4058 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4061 if (available_money > toLocalCurrency ($2500))
4064 Add a lot of aggravation and time;
4066 if (a similar board exists) { /* hopefully... */
4067 cp -a board/<similar> board/<myboard>
4068 cp include/configs/<similar>.h include/configs/<myboard>.h
4070 Create your own board support subdirectory;
4071 Create your own board include/configs/<myboard>.h file;
4073 Edit new board/<myboard> files
4074 Edit new include/configs/<myboard>.h
4079 Add / modify source code;
4083 email("Hi, I am having problems...");
4085 Send patch file to the U-Boot email list;
4086 if (reasonable critiques)
4087 Incorporate improvements from email list code review;
4089 Defend code as written;
4095 void no_more_time (int sig)
4104 All contributions to U-Boot should conform to the Linux kernel
4105 coding style; see the file "Documentation/CodingStyle" and the script
4106 "scripts/Lindent" in your Linux kernel source directory. In sources
4107 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
4108 spaces before parameters to function calls) is actually used.
4110 Source files originating from a different project (for example the
4111 MTD subsystem) are generally exempt from these guidelines and are not
4112 reformated to ease subsequent migration to newer versions of those
4115 Please note that U-Boot is implemented in C (and to some small parts in
4116 Assembler); no C++ is used, so please do not use C++ style comments (//)
4119 Please also stick to the following formatting rules:
4120 - remove any trailing white space
4121 - use TAB characters for indentation, not spaces
4122 - make sure NOT to use DOS '\r\n' line feeds
4123 - do not add more than 2 empty lines to source files
4124 - do not add trailing empty lines to source files
4126 Submissions which do not conform to the standards may be returned
4127 with a request to reformat the changes.
4133 Since the number of patches for U-Boot is growing, we need to
4134 establish some rules. Submissions which do not conform to these rules
4135 may be rejected, even when they contain important and valuable stuff.
4137 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4139 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4140 see http://lists.denx.de/mailman/listinfo/u-boot
4142 When you send a patch, please include the following information with
4145 * For bug fixes: a description of the bug and how your patch fixes
4146 this bug. Please try to include a way of demonstrating that the
4147 patch actually fixes something.
4149 * For new features: a description of the feature and your
4152 * A CHANGELOG entry as plaintext (separate from the patch)
4154 * For major contributions, your entry to the CREDITS file
4156 * When you add support for a new board, don't forget to add this
4157 board to the MAKEALL script, too.
4159 * If your patch adds new configuration options, don't forget to
4160 document these in the README file.
4162 * The patch itself. If you are using git (which is *strongly*
4163 recommended) you can easily generate the patch using the
4164 "git-format-patch". If you then use "git-send-email" to send it to
4165 the U-Boot mailing list, you will avoid most of the common problems
4166 with some other mail clients.
4168 If you cannot use git, use "diff -purN OLD NEW". If your version of
4169 diff does not support these options, then get the latest version of
4172 The current directory when running this command shall be the parent
4173 directory of the U-Boot source tree (i. e. please make sure that
4174 your patch includes sufficient directory information for the
4177 We prefer patches as plain text. MIME attachments are discouraged,
4178 and compressed attachments must not be used.
4180 * If one logical set of modifications affects or creates several
4181 files, all these changes shall be submitted in a SINGLE patch file.
4183 * Changesets that contain different, unrelated modifications shall be
4184 submitted as SEPARATE patches, one patch per changeset.
4189 * Before sending the patch, run the MAKEALL script on your patched
4190 source tree and make sure that no errors or warnings are reported
4191 for any of the boards.
4193 * Keep your modifications to the necessary minimum: A patch
4194 containing several unrelated changes or arbitrary reformats will be
4195 returned with a request to re-formatting / split it.
4197 * If you modify existing code, make sure that your new code does not
4198 add to the memory footprint of the code ;-) Small is beautiful!
4199 When adding new features, these should compile conditionally only
4200 (using #ifdef), and the resulting code with the new feature
4201 disabled must not need more memory than the old code without your
4204 * Remember that there is a size limit of 100 kB per message on the
4205 u-boot mailing list. Bigger patches will be moderated. If they are
4206 reasonable and not too big, they will be acknowledged. But patches
4207 bigger than the size limit should be avoided.
projects / people / ms / u-boot.git / blob