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_DOC * Disk-On-Chip Support
607 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
608 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
609 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
610 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
611 CONFIG_CMD_DTT * Digital Therm and Thermostat
612 CONFIG_CMD_ECHO echo arguments
613 CONFIG_CMD_EEPROM * EEPROM read/write support
614 CONFIG_CMD_ELF * bootelf, bootvx
615 CONFIG_CMD_SAVEENV saveenv
616 CONFIG_CMD_FDC * Floppy Disk Support
617 CONFIG_CMD_FAT * FAT partition support
618 CONFIG_CMD_FDOS * Dos diskette Support
619 CONFIG_CMD_FLASH flinfo, erase, protect
620 CONFIG_CMD_FPGA FPGA device initialization support
621 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
622 CONFIG_CMD_I2C * I2C serial bus support
623 CONFIG_CMD_IDE * IDE harddisk support
624 CONFIG_CMD_IMI iminfo
625 CONFIG_CMD_IMLS List all found images
626 CONFIG_CMD_IMMAP * IMMR dump support
627 CONFIG_CMD_IRQ * irqinfo
628 CONFIG_CMD_ITEST Integer/string test of 2 values
629 CONFIG_CMD_JFFS2 * JFFS2 Support
630 CONFIG_CMD_KGDB * kgdb
631 CONFIG_CMD_LOADB loadb
632 CONFIG_CMD_LOADS loads
633 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
635 CONFIG_CMD_MISC Misc functions like sleep etc
636 CONFIG_CMD_MMC * MMC memory mapped support
637 CONFIG_CMD_MII * MII utility commands
638 CONFIG_CMD_MTDPARTS * MTD partition support
639 CONFIG_CMD_NAND * NAND support
640 CONFIG_CMD_NET bootp, tftpboot, rarpboot
641 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
642 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
643 CONFIG_CMD_PCI * pciinfo
644 CONFIG_CMD_PCMCIA * PCMCIA support
645 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
647 CONFIG_CMD_PORTIO * Port I/O
648 CONFIG_CMD_REGINFO * Register dump
649 CONFIG_CMD_RUN run command in env variable
650 CONFIG_CMD_SAVES * save S record dump
651 CONFIG_CMD_SCSI * SCSI Support
652 CONFIG_CMD_SDRAM * print SDRAM configuration information
653 (requires CONFIG_CMD_I2C)
654 CONFIG_CMD_SETGETDCR Support for DCR Register access
656 CONFIG_CMD_SOURCE "source" command Support
657 CONFIG_CMD_SPI * SPI serial bus support
658 CONFIG_CMD_USB * USB support
659 CONFIG_CMD_VFD * VFD support (TRAB)
660 CONFIG_CMD_CDP * Cisco Discover Protocol support
661 CONFIG_CMD_FSL * Microblaze FSL support
664 EXAMPLE: If you want all functions except of network
665 support you can write:
667 #include "config_cmd_all.h"
668 #undef CONFIG_CMD_NET
671 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
673 Note: Don't enable the "icache" and "dcache" commands
674 (configuration option CONFIG_CMD_CACHE) unless you know
675 what you (and your U-Boot users) are doing. Data
676 cache cannot be enabled on systems like the 8xx or
677 8260 (where accesses to the IMMR region must be
678 uncached), and it cannot be disabled on all other
679 systems where we (mis-) use the data cache to hold an
680 initial stack and some data.
683 XXX - this list needs to get updated!
687 If this variable is defined, it enables watchdog
688 support. There must be support in the platform specific
689 code for a watchdog. For the 8xx and 8260 CPUs, the
690 SIU Watchdog feature is enabled in the SYPCR
694 CONFIG_VERSION_VARIABLE
695 If this variable is defined, an environment variable
696 named "ver" is created by U-Boot showing the U-Boot
697 version as printed by the "version" command.
698 This variable is readonly.
702 When CONFIG_CMD_DATE is selected, the type of the RTC
703 has to be selected, too. Define exactly one of the
706 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
707 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
708 CONFIG_RTC_MC13783 - use MC13783 RTC
709 CONFIG_RTC_MC146818 - use MC146818 RTC
710 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
711 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
712 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
713 CONFIG_RTC_DS164x - use Dallas DS164x RTC
714 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
715 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
716 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
718 Note that if the RTC uses I2C, then the I2C interface
719 must also be configured. See I2C Support, below.
722 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
723 CONFIG_PCA953X_INFO - enable pca953x info command
725 Note that if the GPIO device uses I2C, then the I2C interface
726 must also be configured. See I2C Support, below.
730 When CONFIG_TIMESTAMP is selected, the timestamp
731 (date and time) of an image is printed by image
732 commands like bootm or iminfo. This option is
733 automatically enabled when you select CONFIG_CMD_DATE .
736 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
737 and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION
739 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
740 CONFIG_CMD_SCSI) you must configure support for at
741 least one partition type as well.
744 CONFIG_IDE_RESET_ROUTINE - this is defined in several
745 board configurations files but used nowhere!
747 CONFIG_IDE_RESET - is this is defined, IDE Reset will
748 be performed by calling the function
749 ide_set_reset(int reset)
750 which has to be defined in a board specific file
755 Set this to enable ATAPI support.
760 Set this to enable support for disks larger than 137GB
761 Also look at CONFIG_SYS_64BIT_LBA ,CONFIG_SYS_64BIT_VSPRINTF and CONFIG_SYS_64BIT_STRTOUL
762 Whithout these , LBA48 support uses 32bit variables and will 'only'
763 support disks up to 2.1TB.
765 CONFIG_SYS_64BIT_LBA:
766 When enabled, makes the IDE subsystem use 64bit sector addresses.
770 At the moment only there is only support for the
771 SYM53C8XX SCSI controller; define
772 CONFIG_SCSI_SYM53C8XX to enable it.
774 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
775 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
776 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
777 maximum numbers of LUNs, SCSI ID's and target
779 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
781 - NETWORK Support (PCI):
783 Support for Intel 8254x gigabit chips.
785 CONFIG_E1000_FALLBACK_MAC
786 default MAC for empty EEPROM after production.
789 Support for Intel 82557/82559/82559ER chips.
790 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
791 write routine for first time initialisation.
794 Support for Digital 2114x chips.
795 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
796 modem chip initialisation (KS8761/QS6611).
799 Support for National dp83815 chips.
802 Support for National dp8382[01] gigabit chips.
804 - NETWORK Support (other):
806 CONFIG_DRIVER_LAN91C96
807 Support for SMSC's LAN91C96 chips.
810 Define this to hold the physical address
811 of the LAN91C96's I/O space
813 CONFIG_LAN91C96_USE_32_BIT
814 Define this to enable 32 bit addressing
816 CONFIG_DRIVER_SMC91111
817 Support for SMSC's LAN91C111 chip
820 Define this to hold the physical address
821 of the device (I/O space)
823 CONFIG_SMC_USE_32_BIT
824 Define this if data bus is 32 bits
826 CONFIG_SMC_USE_IOFUNCS
827 Define this to use i/o functions instead of macros
828 (some hardware wont work with macros)
830 CONFIG_DRIVER_SMC911X
831 Support for SMSC's LAN911x and LAN921x chips
833 CONFIG_DRIVER_SMC911X_BASE
834 Define this to hold the physical address
835 of the device (I/O space)
837 CONFIG_DRIVER_SMC911X_32_BIT
838 Define this if data bus is 32 bits
840 CONFIG_DRIVER_SMC911X_16_BIT
841 Define this if data bus is 16 bits. If your processor
842 automatically converts one 32 bit word to two 16 bit
843 words you may also try CONFIG_DRIVER_SMC911X_32_BIT.
846 At the moment only the UHCI host controller is
847 supported (PIP405, MIP405, MPC5200); define
848 CONFIG_USB_UHCI to enable it.
849 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
850 and define CONFIG_USB_STORAGE to enable the USB
853 Supported are USB Keyboards and USB Floppy drives
855 MPC5200 USB requires additional defines:
857 for 528 MHz Clock: 0x0001bbbb
859 for differential drivers: 0x00001000
860 for single ended drivers: 0x00005000
861 CONFIG_SYS_USB_EVENT_POLL
862 May be defined to allow interrupt polling
863 instead of using asynchronous interrupts
866 Define the below if you wish to use the USB console.
867 Once firmware is rebuilt from a serial console issue the
868 command "setenv stdin usbtty; setenv stdout usbtty" and
869 attach your USB cable. The Unix command "dmesg" should print
870 it has found a new device. The environment variable usbtty
871 can be set to gserial or cdc_acm to enable your device to
872 appear to a USB host as a Linux gserial device or a
873 Common Device Class Abstract Control Model serial device.
874 If you select usbtty = gserial you should be able to enumerate
876 # modprobe usbserial vendor=0xVendorID product=0xProductID
877 else if using cdc_acm, simply setting the environment
878 variable usbtty to be cdc_acm should suffice. The following
879 might be defined in YourBoardName.h
882 Define this to build a UDC device
885 Define this to have a tty type of device available to
886 talk to the UDC device
888 CONFIG_SYS_CONSOLE_IS_IN_ENV
889 Define this if you want stdin, stdout &/or stderr to
893 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
894 Derive USB clock from external clock "blah"
895 - CONFIG_SYS_USB_EXTC_CLK 0x02
897 CONFIG_SYS_USB_BRG_CLK 0xBLAH
898 Derive USB clock from brgclk
899 - CONFIG_SYS_USB_BRG_CLK 0x04
901 If you have a USB-IF assigned VendorID then you may wish to
902 define your own vendor specific values either in BoardName.h
903 or directly in usbd_vendor_info.h. If you don't define
904 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
905 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
906 should pretend to be a Linux device to it's target host.
908 CONFIG_USBD_MANUFACTURER
909 Define this string as the name of your company for
910 - CONFIG_USBD_MANUFACTURER "my company"
912 CONFIG_USBD_PRODUCT_NAME
913 Define this string as the name of your product
914 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
917 Define this as your assigned Vendor ID from the USB
918 Implementors Forum. This *must* be a genuine Vendor ID
919 to avoid polluting the USB namespace.
920 - CONFIG_USBD_VENDORID 0xFFFF
922 CONFIG_USBD_PRODUCTID
923 Define this as the unique Product ID
925 - CONFIG_USBD_PRODUCTID 0xFFFF
929 The MMC controller on the Intel PXA is supported. To
930 enable this define CONFIG_MMC. The MMC can be
931 accessed from the boot prompt by mapping the device
932 to physical memory similar to flash. Command line is
933 enabled with CONFIG_CMD_MMC. The MMC driver also works with
934 the FAT fs. This is enabled with CONFIG_CMD_FAT.
936 - Journaling Flash filesystem support:
937 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
938 CONFIG_JFFS2_NAND_DEV
939 Define these for a default partition on a NAND device
941 CONFIG_SYS_JFFS2_FIRST_SECTOR,
942 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
943 Define these for a default partition on a NOR device
945 CONFIG_SYS_JFFS_CUSTOM_PART
946 Define this to create an own partition. You have to provide a
947 function struct part_info* jffs2_part_info(int part_num)
949 If you define only one JFFS2 partition you may also want to
950 #define CONFIG_SYS_JFFS_SINGLE_PART 1
951 to disable the command chpart. This is the default when you
952 have not defined a custom partition
957 Define this to enable standard (PC-Style) keyboard
961 Standard PC keyboard driver with US (is default) and
962 GERMAN key layout (switch via environment 'keymap=de') support.
963 Export function i8042_kbd_init, i8042_tstc and i8042_getc
964 for cfb_console. Supports cursor blinking.
969 Define this to enable video support (for output to
974 Enable Chips & Technologies 69000 Video chip
976 CONFIG_VIDEO_SMI_LYNXEM
977 Enable Silicon Motion SMI 712/710/810 Video chip. The
978 video output is selected via environment 'videoout'
979 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
982 For the CT69000 and SMI_LYNXEM drivers, videomode is
983 selected via environment 'videomode'. Two different ways
985 - "videomode=num" 'num' is a standard LiLo mode numbers.
986 Following standard modes are supported (* is default):
988 Colors 640x480 800x600 1024x768 1152x864 1280x1024
989 -------------+---------------------------------------------
990 8 bits | 0x301* 0x303 0x305 0x161 0x307
991 15 bits | 0x310 0x313 0x316 0x162 0x319
992 16 bits | 0x311 0x314 0x317 0x163 0x31A
993 24 bits | 0x312 0x315 0x318 ? 0x31B
994 -------------+---------------------------------------------
995 (i.e. setenv videomode 317; saveenv; reset;)
997 - "videomode=bootargs" all the video parameters are parsed
998 from the bootargs. (See drivers/video/videomodes.c)
1001 CONFIG_VIDEO_SED13806
1002 Enable Epson SED13806 driver. This driver supports 8bpp
1003 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1004 or CONFIG_VIDEO_SED13806_16BPP
1009 Define this to enable a custom keyboard support.
1010 This simply calls drv_keyboard_init() which must be
1011 defined in your board-specific files.
1012 The only board using this so far is RBC823.
1014 - LCD Support: CONFIG_LCD
1016 Define this to enable LCD support (for output to LCD
1017 display); also select one of the supported displays
1018 by defining one of these:
1022 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1024 CONFIG_NEC_NL6448AC33:
1026 NEC NL6448AC33-18. Active, color, single scan.
1028 CONFIG_NEC_NL6448BC20
1030 NEC NL6448BC20-08. 6.5", 640x480.
1031 Active, color, single scan.
1033 CONFIG_NEC_NL6448BC33_54
1035 NEC NL6448BC33-54. 10.4", 640x480.
1036 Active, color, single scan.
1040 Sharp 320x240. Active, color, single scan.
1041 It isn't 16x9, and I am not sure what it is.
1043 CONFIG_SHARP_LQ64D341
1045 Sharp LQ64D341 display, 640x480.
1046 Active, color, single scan.
1050 HLD1045 display, 640x480.
1051 Active, color, single scan.
1055 Optrex CBL50840-2 NF-FW 99 22 M5
1057 Hitachi LMG6912RPFC-00T
1061 320x240. Black & white.
1063 Normally display is black on white background; define
1064 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1066 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1068 If this option is set, the environment is checked for
1069 a variable "splashimage". If found, the usual display
1070 of logo, copyright and system information on the LCD
1071 is suppressed and the BMP image at the address
1072 specified in "splashimage" is loaded instead. The
1073 console is redirected to the "nulldev", too. This
1074 allows for a "silent" boot where a splash screen is
1075 loaded very quickly after power-on.
1077 CONFIG_SPLASH_SCREEN_ALIGN
1079 If this option is set the splash image can be freely positioned
1080 on the screen. Environment variable "splashpos" specifies the
1081 position as "x,y". If a positive number is given it is used as
1082 number of pixel from left/top. If a negative number is given it
1083 is used as number of pixel from right/bottom. You can also
1084 specify 'm' for centering the image.
1087 setenv splashpos m,m
1088 => image at center of screen
1090 setenv splashpos 30,20
1091 => image at x = 30 and y = 20
1093 setenv splashpos -10,m
1094 => vertically centered image
1095 at x = dspWidth - bmpWidth - 9
1097 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1099 If this option is set, additionally to standard BMP
1100 images, gzipped BMP images can be displayed via the
1101 splashscreen support or the bmp command.
1103 - Compression support:
1106 If this option is set, support for bzip2 compressed
1107 images is included. If not, only uncompressed and gzip
1108 compressed images are supported.
1110 NOTE: the bzip2 algorithm requires a lot of RAM, so
1111 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1116 If this option is set, support for lzma compressed
1119 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1120 requires an amount of dynamic memory that is given by the
1123 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1125 Where lc and lp stand for, respectively, Literal context bits
1126 and Literal pos bits.
1128 This value is upper-bounded by 14MB in the worst case. Anyway,
1129 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1130 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1131 a very small buffer.
1133 Use the lzmainfo tool to determinate the lc and lp values and
1134 then calculate the amount of needed dynamic memory (ensuring
1135 the appropriate CONFIG_SYS_MALLOC_LEN value).
1140 The address of PHY on MII bus.
1142 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1144 The clock frequency of the MII bus
1148 If this option is set, support for speed/duplex
1149 detection of gigabit PHY is included.
1151 CONFIG_PHY_RESET_DELAY
1153 Some PHY like Intel LXT971A need extra delay after
1154 reset before any MII register access is possible.
1155 For such PHY, set this option to the usec delay
1156 required. (minimum 300usec for LXT971A)
1158 CONFIG_PHY_CMD_DELAY (ppc4xx)
1160 Some PHY like Intel LXT971A need extra delay after
1161 command issued before MII status register can be read
1171 Define a default value for Ethernet address to use
1172 for the respective Ethernet interface, in case this
1173 is not determined automatically.
1178 Define a default value for the IP address to use for
1179 the default Ethernet interface, in case this is not
1180 determined through e.g. bootp.
1182 - Server IP address:
1185 Defines a default value for the IP address of a TFTP
1186 server to contact when using the "tftboot" command.
1188 - Multicast TFTP Mode:
1191 Defines whether you want to support multicast TFTP as per
1192 rfc-2090; for example to work with atftp. Lets lots of targets
1193 tftp down the same boot image concurrently. Note: the Ethernet
1194 driver in use must provide a function: mcast() to join/leave a
1197 CONFIG_BOOTP_RANDOM_DELAY
1198 - BOOTP Recovery Mode:
1199 CONFIG_BOOTP_RANDOM_DELAY
1201 If you have many targets in a network that try to
1202 boot using BOOTP, you may want to avoid that all
1203 systems send out BOOTP requests at precisely the same
1204 moment (which would happen for instance at recovery
1205 from a power failure, when all systems will try to
1206 boot, thus flooding the BOOTP server. Defining
1207 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1208 inserted before sending out BOOTP requests. The
1209 following delays are inserted then:
1211 1st BOOTP request: delay 0 ... 1 sec
1212 2nd BOOTP request: delay 0 ... 2 sec
1213 3rd BOOTP request: delay 0 ... 4 sec
1215 BOOTP requests: delay 0 ... 8 sec
1217 - DHCP Advanced Options:
1218 You can fine tune the DHCP functionality by defining
1219 CONFIG_BOOTP_* symbols:
1221 CONFIG_BOOTP_SUBNETMASK
1222 CONFIG_BOOTP_GATEWAY
1223 CONFIG_BOOTP_HOSTNAME
1224 CONFIG_BOOTP_NISDOMAIN
1225 CONFIG_BOOTP_BOOTPATH
1226 CONFIG_BOOTP_BOOTFILESIZE
1229 CONFIG_BOOTP_SEND_HOSTNAME
1230 CONFIG_BOOTP_NTPSERVER
1231 CONFIG_BOOTP_TIMEOFFSET
1232 CONFIG_BOOTP_VENDOREX
1234 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1235 environment variable, not the BOOTP server.
1237 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1238 serverip from a DHCP server, it is possible that more
1239 than one DNS serverip is offered to the client.
1240 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1241 serverip will be stored in the additional environment
1242 variable "dnsip2". The first DNS serverip is always
1243 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1246 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1247 to do a dynamic update of a DNS server. To do this, they
1248 need the hostname of the DHCP requester.
1249 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1250 of the "hostname" environment variable is passed as
1251 option 12 to the DHCP server.
1253 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1255 A 32bit value in microseconds for a delay between
1256 receiving a "DHCP Offer" and sending the "DHCP Request".
1257 This fixes a problem with certain DHCP servers that don't
1258 respond 100% of the time to a "DHCP request". E.g. On an
1259 AT91RM9200 processor running at 180MHz, this delay needed
1260 to be *at least* 15,000 usec before a Windows Server 2003
1261 DHCP server would reply 100% of the time. I recommend at
1262 least 50,000 usec to be safe. The alternative is to hope
1263 that one of the retries will be successful but note that
1264 the DHCP timeout and retry process takes a longer than
1268 CONFIG_CDP_DEVICE_ID
1270 The device id used in CDP trigger frames.
1272 CONFIG_CDP_DEVICE_ID_PREFIX
1274 A two character string which is prefixed to the MAC address
1279 A printf format string which contains the ascii name of
1280 the port. Normally is set to "eth%d" which sets
1281 eth0 for the first Ethernet, eth1 for the second etc.
1283 CONFIG_CDP_CAPABILITIES
1285 A 32bit integer which indicates the device capabilities;
1286 0x00000010 for a normal host which does not forwards.
1290 An ascii string containing the version of the software.
1294 An ascii string containing the name of the platform.
1298 A 32bit integer sent on the trigger.
1300 CONFIG_CDP_POWER_CONSUMPTION
1302 A 16bit integer containing the power consumption of the
1303 device in .1 of milliwatts.
1305 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1307 A byte containing the id of the VLAN.
1309 - Status LED: CONFIG_STATUS_LED
1311 Several configurations allow to display the current
1312 status using a LED. For instance, the LED will blink
1313 fast while running U-Boot code, stop blinking as
1314 soon as a reply to a BOOTP request was received, and
1315 start blinking slow once the Linux kernel is running
1316 (supported by a status LED driver in the Linux
1317 kernel). Defining CONFIG_STATUS_LED enables this
1320 - CAN Support: CONFIG_CAN_DRIVER
1322 Defining CONFIG_CAN_DRIVER enables CAN driver support
1323 on those systems that support this (optional)
1324 feature, like the TQM8xxL modules.
1326 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1328 These enable I2C serial bus commands. Defining either of
1329 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1330 include the appropriate I2C driver for the selected CPU.
1332 This will allow you to use i2c commands at the u-boot
1333 command line (as long as you set CONFIG_CMD_I2C in
1334 CONFIG_COMMANDS) and communicate with i2c based realtime
1335 clock chips. See common/cmd_i2c.c for a description of the
1336 command line interface.
1338 CONFIG_HARD_I2C selects a hardware I2C controller.
1340 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1341 bit-banging) driver instead of CPM or similar hardware
1344 There are several other quantities that must also be
1345 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1347 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1348 to be the frequency (in Hz) at which you wish your i2c bus
1349 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1350 the CPU's i2c node address).
1352 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1353 sets the CPU up as a master node and so its address should
1354 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1355 p.16-473). So, set CONFIG_SYS_I2C_SLAVE to 0.
1357 That's all that's required for CONFIG_HARD_I2C.
1359 If you use the software i2c interface (CONFIG_SOFT_I2C)
1360 then the following macros need to be defined (examples are
1361 from include/configs/lwmon.h):
1365 (Optional). Any commands necessary to enable the I2C
1366 controller or configure ports.
1368 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1372 (Only for MPC8260 CPU). The I/O port to use (the code
1373 assumes both bits are on the same port). Valid values
1374 are 0..3 for ports A..D.
1378 The code necessary to make the I2C data line active
1379 (driven). If the data line is open collector, this
1382 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1386 The code necessary to make the I2C data line tri-stated
1387 (inactive). If the data line is open collector, this
1390 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1394 Code that returns TRUE if the I2C data line is high,
1397 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1401 If <bit> is TRUE, sets the I2C data line high. If it
1402 is FALSE, it clears it (low).
1404 eg: #define I2C_SDA(bit) \
1405 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1406 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1410 If <bit> is TRUE, sets the I2C clock line high. If it
1411 is FALSE, it clears it (low).
1413 eg: #define I2C_SCL(bit) \
1414 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1415 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1419 This delay is invoked four times per clock cycle so this
1420 controls the rate of data transfer. The data rate thus
1421 is 1 / (I2C_DELAY * 4). Often defined to be something
1424 #define I2C_DELAY udelay(2)
1426 CONFIG_SYS_I2C_INIT_BOARD
1428 When a board is reset during an i2c bus transfer
1429 chips might think that the current transfer is still
1430 in progress. On some boards it is possible to access
1431 the i2c SCLK line directly, either by using the
1432 processor pin as a GPIO or by having a second pin
1433 connected to the bus. If this option is defined a
1434 custom i2c_init_board() routine in boards/xxx/board.c
1435 is run early in the boot sequence.
1437 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1439 This option enables configuration of bi_iic_fast[] flags
1440 in u-boot bd_info structure based on u-boot environment
1441 variable "i2cfast". (see also i2cfast)
1443 CONFIG_I2C_MULTI_BUS
1445 This option allows the use of multiple I2C buses, each of which
1446 must have a controller. At any point in time, only one bus is
1447 active. To switch to a different bus, use the 'i2c dev' command.
1448 Note that bus numbering is zero-based.
1450 CONFIG_SYS_I2C_NOPROBES
1452 This option specifies a list of I2C devices that will be skipped
1453 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1454 is set, specify a list of bus-device pairs. Otherwise, specify
1455 a 1D array of device addresses
1458 #undef CONFIG_I2C_MULTI_BUS
1459 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1461 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1463 #define CONFIG_I2C_MULTI_BUS
1464 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1466 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1468 CONFIG_SYS_SPD_BUS_NUM
1470 If defined, then this indicates the I2C bus number for DDR SPD.
1471 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1473 CONFIG_SYS_RTC_BUS_NUM
1475 If defined, then this indicates the I2C bus number for the RTC.
1476 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1478 CONFIG_SYS_DTT_BUS_NUM
1480 If defined, then this indicates the I2C bus number for the DTT.
1481 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1483 CONFIG_SYS_I2C_DTT_ADDR:
1485 If defined, specifies the I2C address of the DTT device.
1486 If not defined, then U-Boot uses predefined value for
1487 specified DTT device.
1491 Define this option if you want to use Freescale's I2C driver in
1492 drivers/i2c/fsl_i2c.c.
1496 Define this option if you have I2C devices reached over 1 .. n
1497 I2C Muxes like the pca9544a. This option addes a new I2C
1498 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1499 new I2C Bus to the existing I2C Busses. If you select the
1500 new Bus with "i2c dev", u-bbot sends first the commandos for
1501 the muxes to activate this new "bus".
1503 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1507 Adding a new I2C Bus reached over 2 pca9544a muxes
1508 The First mux with address 70 and channel 6
1509 The Second mux with address 71 and channel 4
1511 => i2c bus pca9544a:70:6:pca9544a:71:4
1513 Use the "i2c bus" command without parameter, to get a list
1514 of I2C Busses with muxes:
1517 Busses reached over muxes:
1519 reached over Mux(es):
1522 reached over Mux(es):
1527 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1528 u-boot sends First the Commando to the mux@70 to enable
1529 channel 6, and then the Commando to the mux@71 to enable
1532 After that, you can use the "normal" i2c commands as
1533 usual, to communicate with your I2C devices behind
1536 This option is actually implemented for the bitbanging
1537 algorithm in common/soft_i2c.c and for the Hardware I2C
1538 Bus on the MPC8260. But it should be not so difficult
1539 to add this option to other architectures.
1541 CONFIG_SOFT_I2C_READ_REPEATED_START
1543 defining this will force the i2c_read() function in
1544 the soft_i2c driver to perform an I2C repeated start
1545 between writing the address pointer and reading the
1546 data. If this define is omitted the default behaviour
1547 of doing a stop-start sequence will be used. Most I2C
1548 devices can use either method, but some require one or
1551 - SPI Support: CONFIG_SPI
1553 Enables SPI driver (so far only tested with
1554 SPI EEPROM, also an instance works with Crystal A/D and
1555 D/As on the SACSng board)
1559 Enables extended (16-bit) SPI EEPROM addressing.
1560 (symmetrical to CONFIG_I2C_X)
1564 Enables a software (bit-bang) SPI driver rather than
1565 using hardware support. This is a general purpose
1566 driver that only requires three general I/O port pins
1567 (two outputs, one input) to function. If this is
1568 defined, the board configuration must define several
1569 SPI configuration items (port pins to use, etc). For
1570 an example, see include/configs/sacsng.h.
1574 Enables a hardware SPI driver for general-purpose reads
1575 and writes. As with CONFIG_SOFT_SPI, the board configuration
1576 must define a list of chip-select function pointers.
1577 Currently supported on some MPC8xxx processors. For an
1578 example, see include/configs/mpc8349emds.h.
1582 Enables the driver for the SPI controllers on i.MX and MXC
1583 SoCs. Currently only i.MX31 is supported.
1585 - FPGA Support: CONFIG_FPGA
1587 Enables FPGA subsystem.
1589 CONFIG_FPGA_<vendor>
1591 Enables support for specific chip vendors.
1594 CONFIG_FPGA_<family>
1596 Enables support for FPGA family.
1597 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1601 Specify the number of FPGA devices to support.
1603 CONFIG_SYS_FPGA_PROG_FEEDBACK
1605 Enable printing of hash marks during FPGA configuration.
1607 CONFIG_SYS_FPGA_CHECK_BUSY
1609 Enable checks on FPGA configuration interface busy
1610 status by the configuration function. This option
1611 will require a board or device specific function to
1616 If defined, a function that provides delays in the FPGA
1617 configuration driver.
1619 CONFIG_SYS_FPGA_CHECK_CTRLC
1620 Allow Control-C to interrupt FPGA configuration
1622 CONFIG_SYS_FPGA_CHECK_ERROR
1624 Check for configuration errors during FPGA bitfile
1625 loading. For example, abort during Virtex II
1626 configuration if the INIT_B line goes low (which
1627 indicated a CRC error).
1629 CONFIG_SYS_FPGA_WAIT_INIT
1631 Maximum time to wait for the INIT_B line to deassert
1632 after PROB_B has been deasserted during a Virtex II
1633 FPGA configuration sequence. The default time is 500
1636 CONFIG_SYS_FPGA_WAIT_BUSY
1638 Maximum time to wait for BUSY to deassert during
1639 Virtex II FPGA configuration. The default is 5 ms.
1641 CONFIG_SYS_FPGA_WAIT_CONFIG
1643 Time to wait after FPGA configuration. The default is
1646 - Configuration Management:
1649 If defined, this string will be added to the U-Boot
1650 version information (U_BOOT_VERSION)
1652 - Vendor Parameter Protection:
1654 U-Boot considers the values of the environment
1655 variables "serial#" (Board Serial Number) and
1656 "ethaddr" (Ethernet Address) to be parameters that
1657 are set once by the board vendor / manufacturer, and
1658 protects these variables from casual modification by
1659 the user. Once set, these variables are read-only,
1660 and write or delete attempts are rejected. You can
1661 change this behaviour:
1663 If CONFIG_ENV_OVERWRITE is #defined in your config
1664 file, the write protection for vendor parameters is
1665 completely disabled. Anybody can change or delete
1668 Alternatively, if you #define _both_ CONFIG_ETHADDR
1669 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1670 Ethernet address is installed in the environment,
1671 which can be changed exactly ONCE by the user. [The
1672 serial# is unaffected by this, i. e. it remains
1678 Define this variable to enable the reservation of
1679 "protected RAM", i. e. RAM which is not overwritten
1680 by U-Boot. Define CONFIG_PRAM to hold the number of
1681 kB you want to reserve for pRAM. You can overwrite
1682 this default value by defining an environment
1683 variable "pram" to the number of kB you want to
1684 reserve. Note that the board info structure will
1685 still show the full amount of RAM. If pRAM is
1686 reserved, a new environment variable "mem" will
1687 automatically be defined to hold the amount of
1688 remaining RAM in a form that can be passed as boot
1689 argument to Linux, for instance like that:
1691 setenv bootargs ... mem=\${mem}
1694 This way you can tell Linux not to use this memory,
1695 either, which results in a memory region that will
1696 not be affected by reboots.
1698 *WARNING* If your board configuration uses automatic
1699 detection of the RAM size, you must make sure that
1700 this memory test is non-destructive. So far, the
1701 following board configurations are known to be
1704 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1705 HERMES, IP860, RPXlite, LWMON, LANTEC,
1706 PCU_E, FLAGADM, TQM8260
1711 Define this variable to stop the system in case of a
1712 fatal error, so that you have to reset it manually.
1713 This is probably NOT a good idea for an embedded
1714 system where you want the system to reboot
1715 automatically as fast as possible, but it may be
1716 useful during development since you can try to debug
1717 the conditions that lead to the situation.
1719 CONFIG_NET_RETRY_COUNT
1721 This variable defines the number of retries for
1722 network operations like ARP, RARP, TFTP, or BOOTP
1723 before giving up the operation. If not defined, a
1724 default value of 5 is used.
1728 Timeout waiting for an ARP reply in milliseconds.
1730 - Command Interpreter:
1731 CONFIG_AUTO_COMPLETE
1733 Enable auto completion of commands using TAB.
1735 Note that this feature has NOT been implemented yet
1736 for the "hush" shell.
1739 CONFIG_SYS_HUSH_PARSER
1741 Define this variable to enable the "hush" shell (from
1742 Busybox) as command line interpreter, thus enabling
1743 powerful command line syntax like
1744 if...then...else...fi conditionals or `&&' and '||'
1745 constructs ("shell scripts").
1747 If undefined, you get the old, much simpler behaviour
1748 with a somewhat smaller memory footprint.
1751 CONFIG_SYS_PROMPT_HUSH_PS2
1753 This defines the secondary prompt string, which is
1754 printed when the command interpreter needs more input
1755 to complete a command. Usually "> ".
1759 In the current implementation, the local variables
1760 space and global environment variables space are
1761 separated. Local variables are those you define by
1762 simply typing `name=value'. To access a local
1763 variable later on, you have write `$name' or
1764 `${name}'; to execute the contents of a variable
1765 directly type `$name' at the command prompt.
1767 Global environment variables are those you use
1768 setenv/printenv to work with. To run a command stored
1769 in such a variable, you need to use the run command,
1770 and you must not use the '$' sign to access them.
1772 To store commands and special characters in a
1773 variable, please use double quotation marks
1774 surrounding the whole text of the variable, instead
1775 of the backslashes before semicolons and special
1778 - Commandline Editing and History:
1779 CONFIG_CMDLINE_EDITING
1781 Enable editing and History functions for interactive
1782 commandline input operations
1784 - Default Environment:
1785 CONFIG_EXTRA_ENV_SETTINGS
1787 Define this to contain any number of null terminated
1788 strings (variable = value pairs) that will be part of
1789 the default environment compiled into the boot image.
1791 For example, place something like this in your
1792 board's config file:
1794 #define CONFIG_EXTRA_ENV_SETTINGS \
1798 Warning: This method is based on knowledge about the
1799 internal format how the environment is stored by the
1800 U-Boot code. This is NOT an official, exported
1801 interface! Although it is unlikely that this format
1802 will change soon, there is no guarantee either.
1803 You better know what you are doing here.
1805 Note: overly (ab)use of the default environment is
1806 discouraged. Make sure to check other ways to preset
1807 the environment like the "source" command or the
1810 - DataFlash Support:
1811 CONFIG_HAS_DATAFLASH
1813 Defining this option enables DataFlash features and
1814 allows to read/write in Dataflash via the standard
1817 - SystemACE Support:
1820 Adding this option adds support for Xilinx SystemACE
1821 chips attached via some sort of local bus. The address
1822 of the chip must also be defined in the
1823 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
1825 #define CONFIG_SYSTEMACE
1826 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
1828 When SystemACE support is added, the "ace" device type
1829 becomes available to the fat commands, i.e. fatls.
1831 - TFTP Fixed UDP Port:
1834 If this is defined, the environment variable tftpsrcp
1835 is used to supply the TFTP UDP source port value.
1836 If tftpsrcp isn't defined, the normal pseudo-random port
1837 number generator is used.
1839 Also, the environment variable tftpdstp is used to supply
1840 the TFTP UDP destination port value. If tftpdstp isn't
1841 defined, the normal port 69 is used.
1843 The purpose for tftpsrcp is to allow a TFTP server to
1844 blindly start the TFTP transfer using the pre-configured
1845 target IP address and UDP port. This has the effect of
1846 "punching through" the (Windows XP) firewall, allowing
1847 the remainder of the TFTP transfer to proceed normally.
1848 A better solution is to properly configure the firewall,
1849 but sometimes that is not allowed.
1851 - Show boot progress:
1852 CONFIG_SHOW_BOOT_PROGRESS
1854 Defining this option allows to add some board-
1855 specific code (calling a user-provided function
1856 "show_boot_progress(int)") that enables you to show
1857 the system's boot progress on some display (for
1858 example, some LED's) on your board. At the moment,
1859 the following checkpoints are implemented:
1861 - Automatic software updates via TFTP server
1863 CONFIG_UPDATE_TFTP_CNT_MAX
1864 CONFIG_UPDATE_TFTP_MSEC_MAX
1866 These options enable and control the auto-update feature;
1867 for a more detailed description refer to doc/README.update.
1869 - MTD Support (mtdparts command, UBI support)
1872 Adds the MTD device infrastructure from the Linux kernel.
1873 Needed for mtdparts command support.
1875 CONFIG_MTD_PARTITIONS
1877 Adds the MTD partitioning infrastructure from the Linux
1878 kernel. Needed for UBI support.
1880 Legacy uImage format:
1883 1 common/cmd_bootm.c before attempting to boot an image
1884 -1 common/cmd_bootm.c Image header has bad magic number
1885 2 common/cmd_bootm.c Image header has correct magic number
1886 -2 common/cmd_bootm.c Image header has bad checksum
1887 3 common/cmd_bootm.c Image header has correct checksum
1888 -3 common/cmd_bootm.c Image data has bad checksum
1889 4 common/cmd_bootm.c Image data has correct checksum
1890 -4 common/cmd_bootm.c Image is for unsupported architecture
1891 5 common/cmd_bootm.c Architecture check OK
1892 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
1893 6 common/cmd_bootm.c Image Type check OK
1894 -6 common/cmd_bootm.c gunzip uncompression error
1895 -7 common/cmd_bootm.c Unimplemented compression type
1896 7 common/cmd_bootm.c Uncompression OK
1897 8 common/cmd_bootm.c No uncompress/copy overwrite error
1898 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1900 9 common/image.c Start initial ramdisk verification
1901 -10 common/image.c Ramdisk header has bad magic number
1902 -11 common/image.c Ramdisk header has bad checksum
1903 10 common/image.c Ramdisk header is OK
1904 -12 common/image.c Ramdisk data has bad checksum
1905 11 common/image.c Ramdisk data has correct checksum
1906 12 common/image.c Ramdisk verification complete, start loading
1907 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
1908 13 common/image.c Start multifile image verification
1909 14 common/image.c No initial ramdisk, no multifile, continue.
1911 15 lib_<arch>/bootm.c All preparation done, transferring control to OS
1913 -30 lib_ppc/board.c Fatal error, hang the system
1914 -31 post/post.c POST test failed, detected by post_output_backlog()
1915 -32 post/post.c POST test failed, detected by post_run_single()
1917 34 common/cmd_doc.c before loading a Image from a DOC device
1918 -35 common/cmd_doc.c Bad usage of "doc" command
1919 35 common/cmd_doc.c correct usage of "doc" command
1920 -36 common/cmd_doc.c No boot device
1921 36 common/cmd_doc.c correct boot device
1922 -37 common/cmd_doc.c Unknown Chip ID on boot device
1923 37 common/cmd_doc.c correct chip ID found, device available
1924 -38 common/cmd_doc.c Read Error on boot device
1925 38 common/cmd_doc.c reading Image header from DOC device OK
1926 -39 common/cmd_doc.c Image header has bad magic number
1927 39 common/cmd_doc.c Image header has correct magic number
1928 -40 common/cmd_doc.c Error reading Image from DOC device
1929 40 common/cmd_doc.c Image header has correct magic number
1930 41 common/cmd_ide.c before loading a Image from a IDE device
1931 -42 common/cmd_ide.c Bad usage of "ide" command
1932 42 common/cmd_ide.c correct usage of "ide" command
1933 -43 common/cmd_ide.c No boot device
1934 43 common/cmd_ide.c boot device found
1935 -44 common/cmd_ide.c Device not available
1936 44 common/cmd_ide.c Device available
1937 -45 common/cmd_ide.c wrong partition selected
1938 45 common/cmd_ide.c partition selected
1939 -46 common/cmd_ide.c Unknown partition table
1940 46 common/cmd_ide.c valid partition table found
1941 -47 common/cmd_ide.c Invalid partition type
1942 47 common/cmd_ide.c correct partition type
1943 -48 common/cmd_ide.c Error reading Image Header on boot device
1944 48 common/cmd_ide.c reading Image Header from IDE device OK
1945 -49 common/cmd_ide.c Image header has bad magic number
1946 49 common/cmd_ide.c Image header has correct magic number
1947 -50 common/cmd_ide.c Image header has bad checksum
1948 50 common/cmd_ide.c Image header has correct checksum
1949 -51 common/cmd_ide.c Error reading Image from IDE device
1950 51 common/cmd_ide.c reading Image from IDE device OK
1951 52 common/cmd_nand.c before loading a Image from a NAND device
1952 -53 common/cmd_nand.c Bad usage of "nand" command
1953 53 common/cmd_nand.c correct usage of "nand" command
1954 -54 common/cmd_nand.c No boot device
1955 54 common/cmd_nand.c boot device found
1956 -55 common/cmd_nand.c Unknown Chip ID on boot device
1957 55 common/cmd_nand.c correct chip ID found, device available
1958 -56 common/cmd_nand.c Error reading Image Header on boot device
1959 56 common/cmd_nand.c reading Image Header from NAND device OK
1960 -57 common/cmd_nand.c Image header has bad magic number
1961 57 common/cmd_nand.c Image header has correct magic number
1962 -58 common/cmd_nand.c Error reading Image from NAND device
1963 58 common/cmd_nand.c reading Image from NAND device OK
1965 -60 common/env_common.c Environment has a bad CRC, using default
1967 64 net/eth.c starting with Ethernet configuration.
1968 -64 net/eth.c no Ethernet found.
1969 65 net/eth.c Ethernet found.
1971 -80 common/cmd_net.c usage wrong
1972 80 common/cmd_net.c before calling NetLoop()
1973 -81 common/cmd_net.c some error in NetLoop() occurred
1974 81 common/cmd_net.c NetLoop() back without error
1975 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
1976 82 common/cmd_net.c trying automatic boot
1977 83 common/cmd_net.c running "source" command
1978 -83 common/cmd_net.c some error in automatic boot or "source" command
1979 84 common/cmd_net.c end without errors
1984 100 common/cmd_bootm.c Kernel FIT Image has correct format
1985 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
1986 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
1987 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
1988 102 common/cmd_bootm.c Kernel unit name specified
1989 -103 common/cmd_bootm.c Can't get kernel subimage node offset
1990 103 common/cmd_bootm.c Found configuration node
1991 104 common/cmd_bootm.c Got kernel subimage node offset
1992 -104 common/cmd_bootm.c Kernel subimage hash verification failed
1993 105 common/cmd_bootm.c Kernel subimage hash verification OK
1994 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
1995 106 common/cmd_bootm.c Architecture check OK
1996 -106 common/cmd_bootm.c Kernel subimage has wrong type
1997 107 common/cmd_bootm.c Kernel subimage type OK
1998 -107 common/cmd_bootm.c Can't get kernel subimage data/size
1999 108 common/cmd_bootm.c Got kernel subimage data/size
2000 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2001 -109 common/cmd_bootm.c Can't get kernel subimage type
2002 -110 common/cmd_bootm.c Can't get kernel subimage comp
2003 -111 common/cmd_bootm.c Can't get kernel subimage os
2004 -112 common/cmd_bootm.c Can't get kernel subimage load address
2005 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2007 120 common/image.c Start initial ramdisk verification
2008 -120 common/image.c Ramdisk FIT image has incorrect format
2009 121 common/image.c Ramdisk FIT image has correct format
2010 122 common/image.c No ramdisk subimage unit name, using configuration
2011 -122 common/image.c Can't get configuration for ramdisk subimage
2012 123 common/image.c Ramdisk unit name specified
2013 -124 common/image.c Can't get ramdisk subimage node offset
2014 125 common/image.c Got ramdisk subimage node offset
2015 -125 common/image.c Ramdisk subimage hash verification failed
2016 126 common/image.c Ramdisk subimage hash verification OK
2017 -126 common/image.c Ramdisk subimage for unsupported architecture
2018 127 common/image.c Architecture check OK
2019 -127 common/image.c Can't get ramdisk subimage data/size
2020 128 common/image.c Got ramdisk subimage data/size
2021 129 common/image.c Can't get ramdisk load address
2022 -129 common/image.c Got ramdisk load address
2024 -130 common/cmd_doc.c Incorrect FIT image format
2025 131 common/cmd_doc.c FIT image format OK
2027 -140 common/cmd_ide.c Incorrect FIT image format
2028 141 common/cmd_ide.c FIT image format OK
2030 -150 common/cmd_nand.c Incorrect FIT image format
2031 151 common/cmd_nand.c FIT image format OK
2037 [so far only for SMDK2400 and TRAB boards]
2039 - Modem support enable:
2040 CONFIG_MODEM_SUPPORT
2042 - RTS/CTS Flow control enable:
2045 - Modem debug support:
2046 CONFIG_MODEM_SUPPORT_DEBUG
2048 Enables debugging stuff (char screen[1024], dbg())
2049 for modem support. Useful only with BDI2000.
2051 - Interrupt support (PPC):
2053 There are common interrupt_init() and timer_interrupt()
2054 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2055 for CPU specific initialization. interrupt_init_cpu()
2056 should set decrementer_count to appropriate value. If
2057 CPU resets decrementer automatically after interrupt
2058 (ppc4xx) it should set decrementer_count to zero.
2059 timer_interrupt() calls timer_interrupt_cpu() for CPU
2060 specific handling. If board has watchdog / status_led
2061 / other_activity_monitor it works automatically from
2062 general timer_interrupt().
2066 In the target system modem support is enabled when a
2067 specific key (key combination) is pressed during
2068 power-on. Otherwise U-Boot will boot normally
2069 (autoboot). The key_pressed() function is called from
2070 board_init(). Currently key_pressed() is a dummy
2071 function, returning 1 and thus enabling modem
2074 If there are no modem init strings in the
2075 environment, U-Boot proceed to autoboot; the
2076 previous output (banner, info printfs) will be
2079 See also: doc/README.Modem
2082 Configuration Settings:
2083 -----------------------
2085 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2086 undefine this when you're short of memory.
2088 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2089 width of the commands listed in the 'help' command output.
2091 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2092 prompt for user input.
2094 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2096 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2098 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2100 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2101 the application (usually a Linux kernel) when it is
2104 - CONFIG_SYS_BAUDRATE_TABLE:
2105 List of legal baudrate settings for this board.
2107 - CONFIG_SYS_CONSOLE_INFO_QUIET
2108 Suppress display of console information at boot.
2110 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2111 If the board specific function
2112 extern int overwrite_console (void);
2113 returns 1, the stdin, stderr and stdout are switched to the
2114 serial port, else the settings in the environment are used.
2116 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2117 Enable the call to overwrite_console().
2119 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2120 Enable overwrite of previous console environment settings.
2122 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2123 Begin and End addresses of the area used by the
2126 - CONFIG_SYS_ALT_MEMTEST:
2127 Enable an alternate, more extensive memory test.
2129 - CONFIG_SYS_MEMTEST_SCRATCH:
2130 Scratch address used by the alternate memory test
2131 You only need to set this if address zero isn't writeable
2133 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2134 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2135 this specified memory area will get subtracted from the top
2136 (end) of RAM and won't get "touched" at all by U-Boot. By
2137 fixing up gd->ram_size the Linux kernel should gets passed
2138 the now "corrected" memory size and won't touch it either.
2139 This should work for arch/ppc and arch/powerpc. Only Linux
2140 board ports in arch/powerpc with bootwrapper support that
2141 recalculate the memory size from the SDRAM controller setup
2142 will have to get fixed in Linux additionally.
2144 This option can be used as a workaround for the 440EPx/GRx
2145 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2148 WARNING: Please make sure that this value is a multiple of
2149 the Linux page size (normally 4k). If this is not the case,
2150 then the end address of the Linux memory will be located at a
2151 non page size aligned address and this could cause major
2154 - CONFIG_SYS_TFTP_LOADADDR:
2155 Default load address for network file downloads
2157 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2158 Enable temporary baudrate change while serial download
2160 - CONFIG_SYS_SDRAM_BASE:
2161 Physical start address of SDRAM. _Must_ be 0 here.
2163 - CONFIG_SYS_MBIO_BASE:
2164 Physical start address of Motherboard I/O (if using a
2167 - CONFIG_SYS_FLASH_BASE:
2168 Physical start address of Flash memory.
2170 - CONFIG_SYS_MONITOR_BASE:
2171 Physical start address of boot monitor code (set by
2172 make config files to be same as the text base address
2173 (TEXT_BASE) used when linking) - same as
2174 CONFIG_SYS_FLASH_BASE when booting from flash.
2176 - CONFIG_SYS_MONITOR_LEN:
2177 Size of memory reserved for monitor code, used to
2178 determine _at_compile_time_ (!) if the environment is
2179 embedded within the U-Boot image, or in a separate
2182 - CONFIG_SYS_MALLOC_LEN:
2183 Size of DRAM reserved for malloc() use.
2185 - CONFIG_SYS_BOOTM_LEN:
2186 Normally compressed uImages are limited to an
2187 uncompressed size of 8 MBytes. If this is not enough,
2188 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2189 to adjust this setting to your needs.
2191 - CONFIG_SYS_BOOTMAPSZ:
2192 Maximum size of memory mapped by the startup code of
2193 the Linux kernel; all data that must be processed by
2194 the Linux kernel (bd_info, boot arguments, FDT blob if
2195 used) must be put below this limit, unless "bootm_low"
2196 enviroment variable is defined and non-zero. In such case
2197 all data for the Linux kernel must be between "bootm_low"
2198 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ.
2200 - CONFIG_SYS_MAX_FLASH_BANKS:
2201 Max number of Flash memory banks
2203 - CONFIG_SYS_MAX_FLASH_SECT:
2204 Max number of sectors on a Flash chip
2206 - CONFIG_SYS_FLASH_ERASE_TOUT:
2207 Timeout for Flash erase operations (in ms)
2209 - CONFIG_SYS_FLASH_WRITE_TOUT:
2210 Timeout for Flash write operations (in ms)
2212 - CONFIG_SYS_FLASH_LOCK_TOUT
2213 Timeout for Flash set sector lock bit operation (in ms)
2215 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2216 Timeout for Flash clear lock bits operation (in ms)
2218 - CONFIG_SYS_FLASH_PROTECTION
2219 If defined, hardware flash sectors protection is used
2220 instead of U-Boot software protection.
2222 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2224 Enable TFTP transfers directly to flash memory;
2225 without this option such a download has to be
2226 performed in two steps: (1) download to RAM, and (2)
2227 copy from RAM to flash.
2229 The two-step approach is usually more reliable, since
2230 you can check if the download worked before you erase
2231 the flash, but in some situations (when system RAM is
2232 too limited to allow for a temporary copy of the
2233 downloaded image) this option may be very useful.
2235 - CONFIG_SYS_FLASH_CFI:
2236 Define if the flash driver uses extra elements in the
2237 common flash structure for storing flash geometry.
2239 - CONFIG_FLASH_CFI_DRIVER
2240 This option also enables the building of the cfi_flash driver
2241 in the drivers directory
2243 - CONFIG_FLASH_CFI_MTD
2244 This option enables the building of the cfi_mtd driver
2245 in the drivers directory. The driver exports CFI flash
2248 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2249 Use buffered writes to flash.
2251 - CONFIG_FLASH_SPANSION_S29WS_N
2252 s29ws-n MirrorBit flash has non-standard addresses for buffered
2255 - CONFIG_SYS_FLASH_QUIET_TEST
2256 If this option is defined, the common CFI flash doesn't
2257 print it's warning upon not recognized FLASH banks. This
2258 is useful, if some of the configured banks are only
2259 optionally available.
2261 - CONFIG_FLASH_SHOW_PROGRESS
2262 If defined (must be an integer), print out countdown
2263 digits and dots. Recommended value: 45 (9..1) for 80
2264 column displays, 15 (3..1) for 40 column displays.
2266 - CONFIG_SYS_RX_ETH_BUFFER:
2267 Defines the number of Ethernet receive buffers. On some
2268 Ethernet controllers it is recommended to set this value
2269 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2270 buffers can be full shortly after enabling the interface
2271 on high Ethernet traffic.
2272 Defaults to 4 if not defined.
2274 The following definitions that deal with the placement and management
2275 of environment data (variable area); in general, we support the
2276 following configurations:
2278 - CONFIG_ENV_IS_IN_FLASH:
2280 Define this if the environment is in flash memory.
2282 a) The environment occupies one whole flash sector, which is
2283 "embedded" in the text segment with the U-Boot code. This
2284 happens usually with "bottom boot sector" or "top boot
2285 sector" type flash chips, which have several smaller
2286 sectors at the start or the end. For instance, such a
2287 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2288 such a case you would place the environment in one of the
2289 4 kB sectors - with U-Boot code before and after it. With
2290 "top boot sector" type flash chips, you would put the
2291 environment in one of the last sectors, leaving a gap
2292 between U-Boot and the environment.
2294 - CONFIG_ENV_OFFSET:
2296 Offset of environment data (variable area) to the
2297 beginning of flash memory; for instance, with bottom boot
2298 type flash chips the second sector can be used: the offset
2299 for this sector is given here.
2301 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2305 This is just another way to specify the start address of
2306 the flash sector containing the environment (instead of
2309 - CONFIG_ENV_SECT_SIZE:
2311 Size of the sector containing the environment.
2314 b) Sometimes flash chips have few, equal sized, BIG sectors.
2315 In such a case you don't want to spend a whole sector for
2320 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2321 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2322 of this flash sector for the environment. This saves
2323 memory for the RAM copy of the environment.
2325 It may also save flash memory if you decide to use this
2326 when your environment is "embedded" within U-Boot code,
2327 since then the remainder of the flash sector could be used
2328 for U-Boot code. It should be pointed out that this is
2329 STRONGLY DISCOURAGED from a robustness point of view:
2330 updating the environment in flash makes it always
2331 necessary to erase the WHOLE sector. If something goes
2332 wrong before the contents has been restored from a copy in
2333 RAM, your target system will be dead.
2335 - CONFIG_ENV_ADDR_REDUND
2336 CONFIG_ENV_SIZE_REDUND
2338 These settings describe a second storage area used to hold
2339 a redundant copy of the environment data, so that there is
2340 a valid backup copy in case there is a power failure during
2341 a "saveenv" operation.
2343 BE CAREFUL! Any changes to the flash layout, and some changes to the
2344 source code will make it necessary to adapt <board>/u-boot.lds*
2348 - CONFIG_ENV_IS_IN_NVRAM:
2350 Define this if you have some non-volatile memory device
2351 (NVRAM, battery buffered SRAM) which you want to use for the
2357 These two #defines are used to determine the memory area you
2358 want to use for environment. It is assumed that this memory
2359 can just be read and written to, without any special
2362 BE CAREFUL! The first access to the environment happens quite early
2363 in U-Boot initalization (when we try to get the setting of for the
2364 console baudrate). You *MUST* have mapped your NVRAM area then, or
2367 Please note that even with NVRAM we still use a copy of the
2368 environment in RAM: we could work on NVRAM directly, but we want to
2369 keep settings there always unmodified except somebody uses "saveenv"
2370 to save the current settings.
2373 - CONFIG_ENV_IS_IN_EEPROM:
2375 Use this if you have an EEPROM or similar serial access
2376 device and a driver for it.
2378 - CONFIG_ENV_OFFSET:
2381 These two #defines specify the offset and size of the
2382 environment area within the total memory of your EEPROM.
2384 - CONFIG_SYS_I2C_EEPROM_ADDR:
2385 If defined, specified the chip address of the EEPROM device.
2386 The default address is zero.
2388 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2389 If defined, the number of bits used to address bytes in a
2390 single page in the EEPROM device. A 64 byte page, for example
2391 would require six bits.
2393 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2394 If defined, the number of milliseconds to delay between
2395 page writes. The default is zero milliseconds.
2397 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2398 The length in bytes of the EEPROM memory array address. Note
2399 that this is NOT the chip address length!
2401 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2402 EEPROM chips that implement "address overflow" are ones
2403 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2404 address and the extra bits end up in the "chip address" bit
2405 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2408 Note that we consider the length of the address field to
2409 still be one byte because the extra address bits are hidden
2410 in the chip address.
2412 - CONFIG_SYS_EEPROM_SIZE:
2413 The size in bytes of the EEPROM device.
2416 - CONFIG_ENV_IS_IN_DATAFLASH:
2418 Define this if you have a DataFlash memory device which you
2419 want to use for the environment.
2421 - CONFIG_ENV_OFFSET:
2425 These three #defines specify the offset and size of the
2426 environment area within the total memory of your DataFlash placed
2427 at the specified address.
2429 - CONFIG_ENV_IS_IN_NAND:
2431 Define this if you have a NAND device which you want to use
2432 for the environment.
2434 - CONFIG_ENV_OFFSET:
2437 These two #defines specify the offset and size of the environment
2438 area within the first NAND device.
2440 - CONFIG_ENV_OFFSET_REDUND
2442 This setting describes a second storage area of CONFIG_ENV_SIZE
2443 size used to hold a redundant copy of the environment data,
2444 so that there is a valid backup copy in case there is a
2445 power failure during a "saveenv" operation.
2447 Note: CONFIG_ENV_OFFSET and CONFIG_ENV_OFFSET_REDUND must be aligned
2448 to a block boundary, and CONFIG_ENV_SIZE must be a multiple of
2449 the NAND devices block size.
2451 - CONFIG_NAND_ENV_DST
2453 Defines address in RAM to which the nand_spl code should copy the
2454 environment. If redundant environment is used, it will be copied to
2455 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2457 - CONFIG_SYS_SPI_INIT_OFFSET
2459 Defines offset to the initial SPI buffer area in DPRAM. The
2460 area is used at an early stage (ROM part) if the environment
2461 is configured to reside in the SPI EEPROM: We need a 520 byte
2462 scratch DPRAM area. It is used between the two initialization
2463 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2464 to be a good choice since it makes it far enough from the
2465 start of the data area as well as from the stack pointer.
2467 Please note that the environment is read-only until the monitor
2468 has been relocated to RAM and a RAM copy of the environment has been
2469 created; also, when using EEPROM you will have to use getenv_r()
2470 until then to read environment variables.
2472 The environment is protected by a CRC32 checksum. Before the monitor
2473 is relocated into RAM, as a result of a bad CRC you will be working
2474 with the compiled-in default environment - *silently*!!! [This is
2475 necessary, because the first environment variable we need is the
2476 "baudrate" setting for the console - if we have a bad CRC, we don't
2477 have any device yet where we could complain.]
2479 Note: once the monitor has been relocated, then it will complain if
2480 the default environment is used; a new CRC is computed as soon as you
2481 use the "saveenv" command to store a valid environment.
2483 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2484 Echo the inverted Ethernet link state to the fault LED.
2486 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2487 also needs to be defined.
2489 - CONFIG_SYS_FAULT_MII_ADDR:
2490 MII address of the PHY to check for the Ethernet link state.
2492 - CONFIG_SYS_64BIT_VSPRINTF:
2493 Makes vsprintf (and all *printf functions) support printing
2494 of 64bit values by using the L quantifier
2496 - CONFIG_SYS_64BIT_STRTOUL:
2497 Adds simple_strtoull that returns a 64bit value
2499 - CONFIG_NS16550_MIN_FUNCTIONS:
2500 Define this if you desire to only have use of the NS16550_init
2501 and NS16550_putc functions for the serial driver located at
2502 drivers/serial/ns16550.c. This option is useful for saving
2503 space for already greatly restricted images, including but not
2504 limited to NAND_SPL configurations.
2506 Low Level (hardware related) configuration options:
2507 ---------------------------------------------------
2509 - CONFIG_SYS_CACHELINE_SIZE:
2510 Cache Line Size of the CPU.
2512 - CONFIG_SYS_DEFAULT_IMMR:
2513 Default address of the IMMR after system reset.
2515 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2516 and RPXsuper) to be able to adjust the position of
2517 the IMMR register after a reset.
2519 - Floppy Disk Support:
2520 CONFIG_SYS_FDC_DRIVE_NUMBER
2522 the default drive number (default value 0)
2524 CONFIG_SYS_ISA_IO_STRIDE
2526 defines the spacing between FDC chipset registers
2529 CONFIG_SYS_ISA_IO_OFFSET
2531 defines the offset of register from address. It
2532 depends on which part of the data bus is connected to
2533 the FDC chipset. (default value 0)
2535 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
2536 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
2539 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
2540 fdc_hw_init() is called at the beginning of the FDC
2541 setup. fdc_hw_init() must be provided by the board
2542 source code. It is used to make hardware dependant
2545 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
2546 DO NOT CHANGE unless you know exactly what you're
2547 doing! (11-4) [MPC8xx/82xx systems only]
2549 - CONFIG_SYS_INIT_RAM_ADDR:
2551 Start address of memory area that can be used for
2552 initial data and stack; please note that this must be
2553 writable memory that is working WITHOUT special
2554 initialization, i. e. you CANNOT use normal RAM which
2555 will become available only after programming the
2556 memory controller and running certain initialization
2559 U-Boot uses the following memory types:
2560 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2561 - MPC824X: data cache
2562 - PPC4xx: data cache
2564 - CONFIG_SYS_GBL_DATA_OFFSET:
2566 Offset of the initial data structure in the memory
2567 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2568 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
2569 data is located at the end of the available space
2570 (sometimes written as (CONFIG_SYS_INIT_RAM_END -
2571 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
2572 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2573 CONFIG_SYS_GBL_DATA_OFFSET) downward.
2576 On the MPC824X (or other systems that use the data
2577 cache for initial memory) the address chosen for
2578 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
2579 point to an otherwise UNUSED address space between
2580 the top of RAM and the start of the PCI space.
2582 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
2584 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
2586 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
2588 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
2590 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2592 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
2594 - CONFIG_SYS_OR_TIMING_SDRAM:
2597 - CONFIG_SYS_MAMR_PTA:
2598 periodic timer for refresh
2600 - CONFIG_SYS_DER: Debug Event Register (37-47)
2602 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2603 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2604 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2605 CONFIG_SYS_BR1_PRELIM:
2606 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2608 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2609 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2610 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
2611 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2613 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
2614 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
2615 Machine Mode Register and Memory Periodic Timer
2616 Prescaler definitions (SDRAM timing)
2618 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
2619 enable I2C microcode relocation patch (MPC8xx);
2620 define relocation offset in DPRAM [DSP2]
2622 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
2623 enable SMC microcode relocation patch (MPC8xx);
2624 define relocation offset in DPRAM [SMC1]
2626 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
2627 enable SPI microcode relocation patch (MPC8xx);
2628 define relocation offset in DPRAM [SCC4]
2630 - CONFIG_SYS_USE_OSCCLK:
2631 Use OSCM clock mode on MBX8xx board. Be careful,
2632 wrong setting might damage your board. Read
2633 doc/README.MBX before setting this variable!
2635 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2636 Offset of the bootmode word in DPRAM used by post
2637 (Power On Self Tests). This definition overrides
2638 #define'd default value in commproc.h resp.
2641 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
2642 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
2643 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
2644 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
2645 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2646 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
2647 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
2648 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
2649 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2651 - CONFIG_PCI_DISABLE_PCIE:
2652 Disable PCI-Express on systems where it is supported but not
2656 Get DDR timing information from an I2C EEPROM. Common
2657 with pluggable memory modules such as SODIMMs
2660 I2C address of the SPD EEPROM
2662 - CONFIG_SYS_SPD_BUS_NUM
2663 If SPD EEPROM is on an I2C bus other than the first
2664 one, specify here. Note that the value must resolve
2665 to something your driver can deal with.
2667 - CONFIG_SYS_83XX_DDR_USES_CS0
2668 Only for 83xx systems. If specified, then DDR should
2669 be configured using CS0 and CS1 instead of CS2 and CS3.
2671 - CONFIG_ETHER_ON_FEC[12]
2672 Define to enable FEC[12] on a 8xx series processor.
2674 - CONFIG_FEC[12]_PHY
2675 Define to the hardcoded PHY address which corresponds
2676 to the given FEC; i. e.
2677 #define CONFIG_FEC1_PHY 4
2678 means that the PHY with address 4 is connected to FEC1
2680 When set to -1, means to probe for first available.
2682 - CONFIG_FEC[12]_PHY_NORXERR
2683 The PHY does not have a RXERR line (RMII only).
2684 (so program the FEC to ignore it).
2687 Enable RMII mode for all FECs.
2688 Note that this is a global option, we can't
2689 have one FEC in standard MII mode and another in RMII mode.
2691 - CONFIG_CRC32_VERIFY
2692 Add a verify option to the crc32 command.
2695 => crc32 -v <address> <count> <crc32>
2697 Where address/count indicate a memory area
2698 and crc32 is the correct crc32 which the
2702 Add the "loopw" memory command. This only takes effect if
2703 the memory commands are activated globally (CONFIG_CMD_MEM).
2706 Add the "mdc" and "mwc" memory commands. These are cyclic
2711 This command will print 4 bytes (10,11,12,13) each 500 ms.
2713 => mwc.l 100 12345678 10
2714 This command will write 12345678 to address 100 all 10 ms.
2716 This only takes effect if the memory commands are activated
2717 globally (CONFIG_CMD_MEM).
2719 - CONFIG_SKIP_LOWLEVEL_INIT
2720 - CONFIG_SKIP_RELOCATE_UBOOT
2722 [ARM only] If these variables are defined, then
2723 certain low level initializations (like setting up
2724 the memory controller) are omitted and/or U-Boot does
2725 not relocate itself into RAM.
2726 Normally these variables MUST NOT be defined. The
2727 only exception is when U-Boot is loaded (to RAM) by
2728 some other boot loader or by a debugger which
2729 performs these initializations itself.
2733 Modifies the behaviour of start.S when compiling a loader
2734 that is executed before the actual U-Boot. E.g. when
2735 compiling a NAND SPL.
2737 Building the Software:
2738 ======================
2740 Building U-Boot has been tested in several native build environments
2741 and in many different cross environments. Of course we cannot support
2742 all possibly existing versions of cross development tools in all
2743 (potentially obsolete) versions. In case of tool chain problems we
2744 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2745 which is extensively used to build and test U-Boot.
2747 If you are not using a native environment, it is assumed that you
2748 have GNU cross compiling tools available in your path. In this case,
2749 you must set the environment variable CROSS_COMPILE in your shell.
2750 Note that no changes to the Makefile or any other source files are
2751 necessary. For example using the ELDK on a 4xx CPU, please enter:
2753 $ CROSS_COMPILE=ppc_4xx-
2754 $ export CROSS_COMPILE
2756 Note: If you wish to generate Windows versions of the utilities in
2757 the tools directory you can use the MinGW toolchain
2758 (http://www.mingw.org). Set your HOST tools to the MinGW
2759 toolchain and execute 'make tools'. For example:
2761 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
2763 Binaries such as tools/mkimage.exe will be created which can
2764 be executed on computers running Windows.
2766 U-Boot is intended to be simple to build. After installing the
2767 sources you must configure U-Boot for one specific board type. This
2772 where "NAME_config" is the name of one of the existing configu-
2773 rations; see the main Makefile for supported names.
2775 Note: for some board special configuration names may exist; check if
2776 additional information is available from the board vendor; for
2777 instance, the TQM823L systems are available without (standard)
2778 or with LCD support. You can select such additional "features"
2779 when choosing the configuration, i. e.
2782 - will configure for a plain TQM823L, i. e. no LCD support
2784 make TQM823L_LCD_config
2785 - will configure for a TQM823L with U-Boot console on LCD
2790 Finally, type "make all", and you should get some working U-Boot
2791 images ready for download to / installation on your system:
2793 - "u-boot.bin" is a raw binary image
2794 - "u-boot" is an image in ELF binary format
2795 - "u-boot.srec" is in Motorola S-Record format
2797 By default the build is performed locally and the objects are saved
2798 in the source directory. One of the two methods can be used to change
2799 this behavior and build U-Boot to some external directory:
2801 1. Add O= to the make command line invocations:
2803 make O=/tmp/build distclean
2804 make O=/tmp/build NAME_config
2805 make O=/tmp/build all
2807 2. Set environment variable BUILD_DIR to point to the desired location:
2809 export BUILD_DIR=/tmp/build
2814 Note that the command line "O=" setting overrides the BUILD_DIR environment
2818 Please be aware that the Makefiles assume you are using GNU make, so
2819 for instance on NetBSD you might need to use "gmake" instead of
2823 If the system board that you have is not listed, then you will need
2824 to port U-Boot to your hardware platform. To do this, follow these
2827 1. Add a new configuration option for your board to the toplevel
2828 "Makefile" and to the "MAKEALL" script, using the existing
2829 entries as examples. Note that here and at many other places
2830 boards and other names are listed in alphabetical sort order. Please
2832 2. Create a new directory to hold your board specific code. Add any
2833 files you need. In your board directory, you will need at least
2834 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2835 3. Create a new configuration file "include/configs/<board>.h" for
2837 3. If you're porting U-Boot to a new CPU, then also create a new
2838 directory to hold your CPU specific code. Add any files you need.
2839 4. Run "make <board>_config" with your new name.
2840 5. Type "make", and you should get a working "u-boot.srec" file
2841 to be installed on your target system.
2842 6. Debug and solve any problems that might arise.
2843 [Of course, this last step is much harder than it sounds.]
2846 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2847 ==============================================================
2849 If you have modified U-Boot sources (for instance added a new board
2850 or support for new devices, a new CPU, etc.) you are expected to
2851 provide feedback to the other developers. The feedback normally takes
2852 the form of a "patch", i. e. a context diff against a certain (latest
2853 official or latest in the git repository) version of U-Boot sources.
2855 But before you submit such a patch, please verify that your modifi-
2856 cation did not break existing code. At least make sure that *ALL* of
2857 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2858 just run the "MAKEALL" script, which will configure and build U-Boot
2859 for ALL supported system. Be warned, this will take a while. You can
2860 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2861 environment variable to the script, i. e. to use the ELDK cross tools
2864 CROSS_COMPILE=ppc_8xx- MAKEALL
2866 or to build on a native PowerPC system you can type
2868 CROSS_COMPILE=' ' MAKEALL
2870 When using the MAKEALL script, the default behaviour is to build
2871 U-Boot in the source directory. This location can be changed by
2872 setting the BUILD_DIR environment variable. Also, for each target
2873 built, the MAKEALL script saves two log files (<target>.ERR and
2874 <target>.MAKEALL) in the <source dir>/LOG directory. This default
2875 location can be changed by setting the MAKEALL_LOGDIR environment
2876 variable. For example:
2878 export BUILD_DIR=/tmp/build
2879 export MAKEALL_LOGDIR=/tmp/log
2880 CROSS_COMPILE=ppc_8xx- MAKEALL
2882 With the above settings build objects are saved in the /tmp/build,
2883 log files are saved in the /tmp/log and the source tree remains clean
2884 during the whole build process.
2887 See also "U-Boot Porting Guide" below.
2890 Monitor Commands - Overview:
2891 ============================
2893 go - start application at address 'addr'
2894 run - run commands in an environment variable
2895 bootm - boot application image from memory
2896 bootp - boot image via network using BootP/TFTP protocol
2897 tftpboot- boot image via network using TFTP protocol
2898 and env variables "ipaddr" and "serverip"
2899 (and eventually "gatewayip")
2900 rarpboot- boot image via network using RARP/TFTP protocol
2901 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2902 loads - load S-Record file over serial line
2903 loadb - load binary file over serial line (kermit mode)
2905 mm - memory modify (auto-incrementing)
2906 nm - memory modify (constant address)
2907 mw - memory write (fill)
2909 cmp - memory compare
2910 crc32 - checksum calculation
2911 i2c - I2C sub-system
2912 sspi - SPI utility commands
2913 base - print or set address offset
2914 printenv- print environment variables
2915 setenv - set environment variables
2916 saveenv - save environment variables to persistent storage
2917 protect - enable or disable FLASH write protection
2918 erase - erase FLASH memory
2919 flinfo - print FLASH memory information
2920 bdinfo - print Board Info structure
2921 iminfo - print header information for application image
2922 coninfo - print console devices and informations
2923 ide - IDE sub-system
2924 loop - infinite loop on address range
2925 loopw - infinite write loop on address range
2926 mtest - simple RAM test
2927 icache - enable or disable instruction cache
2928 dcache - enable or disable data cache
2929 reset - Perform RESET of the CPU
2930 echo - echo args to console
2931 version - print monitor version
2932 help - print online help
2933 ? - alias for 'help'
2936 Monitor Commands - Detailed Description:
2937 ========================================
2941 For now: just type "help <command>".
2944 Environment Variables:
2945 ======================
2947 U-Boot supports user configuration using Environment Variables which
2948 can be made persistent by saving to Flash memory.
2950 Environment Variables are set using "setenv", printed using
2951 "printenv", and saved to Flash using "saveenv". Using "setenv"
2952 without a value can be used to delete a variable from the
2953 environment. As long as you don't save the environment you are
2954 working with an in-memory copy. In case the Flash area containing the
2955 environment is erased by accident, a default environment is provided.
2957 Some configuration options can be set using Environment Variables:
2959 baudrate - see CONFIG_BAUDRATE
2961 bootdelay - see CONFIG_BOOTDELAY
2963 bootcmd - see CONFIG_BOOTCOMMAND
2965 bootargs - Boot arguments when booting an RTOS image
2967 bootfile - Name of the image to load with TFTP
2969 bootm_low - Memory range available for image processing in the bootm
2970 command can be restricted. This variable is given as
2971 a hexadecimal number and defines lowest address allowed
2972 for use by the bootm command. See also "bootm_size"
2973 environment variable. Address defined by "bootm_low" is
2974 also the base of the initial memory mapping for the Linux
2975 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ.
2977 bootm_size - Memory range available for image processing in the bootm
2978 command can be restricted. This variable is given as
2979 a hexadecimal number and defines the size of the region
2980 allowed for use by the bootm command. See also "bootm_low"
2981 environment variable.
2983 updatefile - Location of the software update file on a TFTP server, used
2984 by the automatic software update feature. Please refer to
2985 documentation in doc/README.update for more details.
2987 autoload - if set to "no" (any string beginning with 'n'),
2988 "bootp" will just load perform a lookup of the
2989 configuration from the BOOTP server, but not try to
2990 load any image using TFTP
2992 autoscript - if set to "yes" commands like "loadb", "loady",
2993 "bootp", "tftpb", "rarpboot" and "nfs" will attempt
2994 to automatically run script images (by internally
2997 autoscript_uname - if script image is in a format (FIT) this
2998 variable is used to get script subimage unit name.
3000 autostart - if set to "yes", an image loaded using the "bootp",
3001 "rarpboot", "tftpboot" or "diskboot" commands will
3002 be automatically started (by internally calling
3005 If set to "no", a standalone image passed to the
3006 "bootm" command will be copied to the load address
3007 (and eventually uncompressed), but NOT be started.
3008 This can be used to load and uncompress arbitrary
3011 i2cfast - (PPC405GP|PPC405EP only)
3012 if set to 'y' configures Linux I2C driver for fast
3013 mode (400kHZ). This environment variable is used in
3014 initialization code. So, for changes to be effective
3015 it must be saved and board must be reset.
3017 initrd_high - restrict positioning of initrd images:
3018 If this variable is not set, initrd images will be
3019 copied to the highest possible address in RAM; this
3020 is usually what you want since it allows for
3021 maximum initrd size. If for some reason you want to
3022 make sure that the initrd image is loaded below the
3023 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3024 variable to a value of "no" or "off" or "0".
3025 Alternatively, you can set it to a maximum upper
3026 address to use (U-Boot will still check that it
3027 does not overwrite the U-Boot stack and data).
3029 For instance, when you have a system with 16 MB
3030 RAM, and want to reserve 4 MB from use by Linux,
3031 you can do this by adding "mem=12M" to the value of
3032 the "bootargs" variable. However, now you must make
3033 sure that the initrd image is placed in the first
3034 12 MB as well - this can be done with
3036 setenv initrd_high 00c00000
3038 If you set initrd_high to 0xFFFFFFFF, this is an
3039 indication to U-Boot that all addresses are legal
3040 for the Linux kernel, including addresses in flash
3041 memory. In this case U-Boot will NOT COPY the
3042 ramdisk at all. This may be useful to reduce the
3043 boot time on your system, but requires that this
3044 feature is supported by your Linux kernel.
3046 ipaddr - IP address; needed for tftpboot command
3048 loadaddr - Default load address for commands like "bootp",
3049 "rarpboot", "tftpboot", "loadb" or "diskboot"
3051 loads_echo - see CONFIG_LOADS_ECHO
3053 serverip - TFTP server IP address; needed for tftpboot command
3055 bootretry - see CONFIG_BOOT_RETRY_TIME
3057 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3059 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3061 ethprime - When CONFIG_NET_MULTI is enabled controls which
3062 interface is used first.
3064 ethact - When CONFIG_NET_MULTI is enabled controls which
3065 interface is currently active. For example you
3066 can do the following
3068 => setenv ethact FEC ETHERNET
3069 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
3070 => setenv ethact SCC ETHERNET
3071 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
3073 ethrotate - When set to "no" U-Boot does not go through all
3074 available network interfaces.
3075 It just stays at the currently selected interface.
3077 netretry - When set to "no" each network operation will
3078 either succeed or fail without retrying.
3079 When set to "once" the network operation will
3080 fail when all the available network interfaces
3081 are tried once without success.
3082 Useful on scripts which control the retry operation
3085 npe_ucode - set load address for the NPE microcode
3087 tftpsrcport - If this is set, the value is used for TFTP's
3090 tftpdstport - If this is set, the value is used for TFTP's UDP
3091 destination port instead of the Well Know Port 69.
3093 vlan - When set to a value < 4095 the traffic over
3094 Ethernet is encapsulated/received over 802.1q
3097 The following environment variables may be used and automatically
3098 updated by the network boot commands ("bootp" and "rarpboot"),
3099 depending the information provided by your boot server:
3101 bootfile - see above
3102 dnsip - IP address of your Domain Name Server
3103 dnsip2 - IP address of your secondary Domain Name Server
3104 gatewayip - IP address of the Gateway (Router) to use
3105 hostname - Target hostname
3107 netmask - Subnet Mask
3108 rootpath - Pathname of the root filesystem on the NFS server
3109 serverip - see above
3112 There are two special Environment Variables:
3114 serial# - contains hardware identification information such
3115 as type string and/or serial number
3116 ethaddr - Ethernet address
3118 These variables can be set only once (usually during manufacturing of
3119 the board). U-Boot refuses to delete or overwrite these variables
3120 once they have been set once.
3123 Further special Environment Variables:
3125 ver - Contains the U-Boot version string as printed
3126 with the "version" command. This variable is
3127 readonly (see CONFIG_VERSION_VARIABLE).
3130 Please note that changes to some configuration parameters may take
3131 only effect after the next boot (yes, that's just like Windoze :-).
3134 Command Line Parsing:
3135 =====================
3137 There are two different command line parsers available with U-Boot:
3138 the old "simple" one, and the much more powerful "hush" shell:
3140 Old, simple command line parser:
3141 --------------------------------
3143 - supports environment variables (through setenv / saveenv commands)
3144 - several commands on one line, separated by ';'
3145 - variable substitution using "... ${name} ..." syntax
3146 - special characters ('$', ';') can be escaped by prefixing with '\',
3148 setenv bootcmd bootm \${address}
3149 - You can also escape text by enclosing in single apostrophes, for example:
3150 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3155 - similar to Bourne shell, with control structures like
3156 if...then...else...fi, for...do...done; while...do...done,
3157 until...do...done, ...
3158 - supports environment ("global") variables (through setenv / saveenv
3159 commands) and local shell variables (through standard shell syntax
3160 "name=value"); only environment variables can be used with "run"
3166 (1) If a command line (or an environment variable executed by a "run"
3167 command) contains several commands separated by semicolon, and
3168 one of these commands fails, then the remaining commands will be
3171 (2) If you execute several variables with one call to run (i. e.
3172 calling run with a list of variables as arguments), any failing
3173 command will cause "run" to terminate, i. e. the remaining
3174 variables are not executed.
3176 Note for Redundant Ethernet Interfaces:
3177 =======================================
3179 Some boards come with redundant Ethernet interfaces; U-Boot supports
3180 such configurations and is capable of automatic selection of a
3181 "working" interface when needed. MAC assignment works as follows:
3183 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3184 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3185 "eth1addr" (=>eth1), "eth2addr", ...
3187 If the network interface stores some valid MAC address (for instance
3188 in SROM), this is used as default address if there is NO correspon-
3189 ding setting in the environment; if the corresponding environment
3190 variable is set, this overrides the settings in the card; that means:
3192 o If the SROM has a valid MAC address, and there is no address in the
3193 environment, the SROM's address is used.
3195 o If there is no valid address in the SROM, and a definition in the
3196 environment exists, then the value from the environment variable is
3199 o If both the SROM and the environment contain a MAC address, and
3200 both addresses are the same, this MAC address is used.
3202 o If both the SROM and the environment contain a MAC address, and the
3203 addresses differ, the value from the environment is used and a
3206 o If neither SROM nor the environment contain a MAC address, an error
3213 U-Boot is capable of booting (and performing other auxiliary operations on)
3214 images in two formats:
3216 New uImage format (FIT)
3217 -----------------------
3219 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3220 to Flattened Device Tree). It allows the use of images with multiple
3221 components (several kernels, ramdisks, etc.), with contents protected by
3222 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3228 Old image format is based on binary files which can be basically anything,
3229 preceded by a special header; see the definitions in include/image.h for
3230 details; basically, the header defines the following image properties:
3232 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3233 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3234 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3235 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3237 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3238 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3239 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
3240 * Compression Type (uncompressed, gzip, bzip2)
3246 The header is marked by a special Magic Number, and both the header
3247 and the data portions of the image are secured against corruption by
3254 Although U-Boot should support any OS or standalone application
3255 easily, the main focus has always been on Linux during the design of
3258 U-Boot includes many features that so far have been part of some
3259 special "boot loader" code within the Linux kernel. Also, any
3260 "initrd" images to be used are no longer part of one big Linux image;
3261 instead, kernel and "initrd" are separate images. This implementation
3262 serves several purposes:
3264 - the same features can be used for other OS or standalone
3265 applications (for instance: using compressed images to reduce the
3266 Flash memory footprint)
3268 - it becomes much easier to port new Linux kernel versions because
3269 lots of low-level, hardware dependent stuff are done by U-Boot
3271 - the same Linux kernel image can now be used with different "initrd"
3272 images; of course this also means that different kernel images can
3273 be run with the same "initrd". This makes testing easier (you don't
3274 have to build a new "zImage.initrd" Linux image when you just
3275 change a file in your "initrd"). Also, a field-upgrade of the
3276 software is easier now.
3282 Porting Linux to U-Boot based systems:
3283 ---------------------------------------
3285 U-Boot cannot save you from doing all the necessary modifications to
3286 configure the Linux device drivers for use with your target hardware
3287 (no, we don't intend to provide a full virtual machine interface to
3290 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
3292 Just make sure your machine specific header file (for instance
3293 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3294 Information structure as we define in include/asm-<arch>/u-boot.h,
3295 and make sure that your definition of IMAP_ADDR uses the same value
3296 as your U-Boot configuration in CONFIG_SYS_IMMR.
3299 Configuring the Linux kernel:
3300 -----------------------------
3302 No specific requirements for U-Boot. Make sure you have some root
3303 device (initial ramdisk, NFS) for your target system.
3306 Building a Linux Image:
3307 -----------------------
3309 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3310 not used. If you use recent kernel source, a new build target
3311 "uImage" will exist which automatically builds an image usable by
3312 U-Boot. Most older kernels also have support for a "pImage" target,
3313 which was introduced for our predecessor project PPCBoot and uses a
3314 100% compatible format.
3323 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3324 encapsulate a compressed Linux kernel image with header information,
3325 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3327 * build a standard "vmlinux" kernel image (in ELF binary format):
3329 * convert the kernel into a raw binary image:
3331 ${CROSS_COMPILE}-objcopy -O binary \
3332 -R .note -R .comment \
3333 -S vmlinux linux.bin
3335 * compress the binary image:
3339 * package compressed binary image for U-Boot:
3341 mkimage -A ppc -O linux -T kernel -C gzip \
3342 -a 0 -e 0 -n "Linux Kernel Image" \
3343 -d linux.bin.gz uImage
3346 The "mkimage" tool can also be used to create ramdisk images for use
3347 with U-Boot, either separated from the Linux kernel image, or
3348 combined into one file. "mkimage" encapsulates the images with a 64
3349 byte header containing information about target architecture,
3350 operating system, image type, compression method, entry points, time
3351 stamp, CRC32 checksums, etc.
3353 "mkimage" can be called in two ways: to verify existing images and
3354 print the header information, or to build new images.
3356 In the first form (with "-l" option) mkimage lists the information
3357 contained in the header of an existing U-Boot image; this includes
3358 checksum verification:
3360 tools/mkimage -l image
3361 -l ==> list image header information
3363 The second form (with "-d" option) is used to build a U-Boot image
3364 from a "data file" which is used as image payload:
3366 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3367 -n name -d data_file image
3368 -A ==> set architecture to 'arch'
3369 -O ==> set operating system to 'os'
3370 -T ==> set image type to 'type'
3371 -C ==> set compression type 'comp'
3372 -a ==> set load address to 'addr' (hex)
3373 -e ==> set entry point to 'ep' (hex)
3374 -n ==> set image name to 'name'
3375 -d ==> use image data from 'datafile'
3377 Right now, all Linux kernels for PowerPC systems use the same load
3378 address (0x00000000), but the entry point address depends on the
3381 - 2.2.x kernels have the entry point at 0x0000000C,
3382 - 2.3.x and later kernels have the entry point at 0x00000000.
3384 So a typical call to build a U-Boot image would read:
3386 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3387 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3388 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
3389 > examples/uImage.TQM850L
3390 Image Name: 2.4.4 kernel for TQM850L
3391 Created: Wed Jul 19 02:34:59 2000
3392 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3393 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3394 Load Address: 0x00000000
3395 Entry Point: 0x00000000
3397 To verify the contents of the image (or check for corruption):
3399 -> tools/mkimage -l examples/uImage.TQM850L
3400 Image Name: 2.4.4 kernel for TQM850L
3401 Created: Wed Jul 19 02:34:59 2000
3402 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3403 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3404 Load Address: 0x00000000
3405 Entry Point: 0x00000000
3407 NOTE: for embedded systems where boot time is critical you can trade
3408 speed for memory and install an UNCOMPRESSED image instead: this
3409 needs more space in Flash, but boots much faster since it does not
3410 need to be uncompressed:
3412 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
3413 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3414 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3415 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
3416 > examples/uImage.TQM850L-uncompressed
3417 Image Name: 2.4.4 kernel for TQM850L
3418 Created: Wed Jul 19 02:34:59 2000
3419 Image Type: PowerPC Linux Kernel Image (uncompressed)
3420 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3421 Load Address: 0x00000000
3422 Entry Point: 0x00000000
3425 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3426 when your kernel is intended to use an initial ramdisk:
3428 -> tools/mkimage -n 'Simple Ramdisk Image' \
3429 > -A ppc -O linux -T ramdisk -C gzip \
3430 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3431 Image Name: Simple Ramdisk Image
3432 Created: Wed Jan 12 14:01:50 2000
3433 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3434 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3435 Load Address: 0x00000000
3436 Entry Point: 0x00000000
3439 Installing a Linux Image:
3440 -------------------------
3442 To downloading a U-Boot image over the serial (console) interface,
3443 you must convert the image to S-Record format:
3445 objcopy -I binary -O srec examples/image examples/image.srec
3447 The 'objcopy' does not understand the information in the U-Boot
3448 image header, so the resulting S-Record file will be relative to
3449 address 0x00000000. To load it to a given address, you need to
3450 specify the target address as 'offset' parameter with the 'loads'
3453 Example: install the image to address 0x40100000 (which on the
3454 TQM8xxL is in the first Flash bank):
3456 => erase 40100000 401FFFFF
3462 ## Ready for S-Record download ...
3463 ~>examples/image.srec
3464 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3466 15989 15990 15991 15992
3467 [file transfer complete]
3469 ## Start Addr = 0x00000000
3472 You can check the success of the download using the 'iminfo' command;
3473 this includes a checksum verification so you can be sure no data
3474 corruption happened:
3478 ## Checking Image at 40100000 ...
3479 Image Name: 2.2.13 for initrd on TQM850L
3480 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3481 Data Size: 335725 Bytes = 327 kB = 0 MB
3482 Load Address: 00000000
3483 Entry Point: 0000000c
3484 Verifying Checksum ... OK
3490 The "bootm" command is used to boot an application that is stored in
3491 memory (RAM or Flash). In case of a Linux kernel image, the contents
3492 of the "bootargs" environment variable is passed to the kernel as
3493 parameters. You can check and modify this variable using the
3494 "printenv" and "setenv" commands:
3497 => printenv bootargs
3498 bootargs=root=/dev/ram
3500 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3502 => printenv bootargs
3503 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3506 ## Booting Linux kernel at 40020000 ...
3507 Image Name: 2.2.13 for NFS on TQM850L
3508 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3509 Data Size: 381681 Bytes = 372 kB = 0 MB
3510 Load Address: 00000000
3511 Entry Point: 0000000c
3512 Verifying Checksum ... OK
3513 Uncompressing Kernel Image ... OK
3514 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
3515 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3516 time_init: decrementer frequency = 187500000/60
3517 Calibrating delay loop... 49.77 BogoMIPS
3518 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3521 If you want to boot a Linux kernel with initial RAM disk, you pass
3522 the memory addresses of both the kernel and the initrd image (PPBCOOT
3523 format!) to the "bootm" command:
3525 => imi 40100000 40200000
3527 ## Checking Image at 40100000 ...
3528 Image Name: 2.2.13 for initrd on TQM850L
3529 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3530 Data Size: 335725 Bytes = 327 kB = 0 MB
3531 Load Address: 00000000
3532 Entry Point: 0000000c
3533 Verifying Checksum ... OK
3535 ## Checking Image at 40200000 ...
3536 Image Name: Simple Ramdisk Image
3537 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3538 Data Size: 566530 Bytes = 553 kB = 0 MB
3539 Load Address: 00000000
3540 Entry Point: 00000000
3541 Verifying Checksum ... OK
3543 => bootm 40100000 40200000
3544 ## Booting Linux kernel at 40100000 ...
3545 Image Name: 2.2.13 for initrd on TQM850L
3546 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3547 Data Size: 335725 Bytes = 327 kB = 0 MB
3548 Load Address: 00000000
3549 Entry Point: 0000000c
3550 Verifying Checksum ... OK
3551 Uncompressing Kernel Image ... OK
3552 ## Loading RAMDisk Image at 40200000 ...
3553 Image Name: Simple Ramdisk Image
3554 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3555 Data Size: 566530 Bytes = 553 kB = 0 MB
3556 Load Address: 00000000
3557 Entry Point: 00000000
3558 Verifying Checksum ... OK
3559 Loading Ramdisk ... OK
3560 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
3561 Boot arguments: root=/dev/ram
3562 time_init: decrementer frequency = 187500000/60
3563 Calibrating delay loop... 49.77 BogoMIPS
3565 RAMDISK: Compressed image found at block 0
3566 VFS: Mounted root (ext2 filesystem).
3570 Boot Linux and pass a flat device tree:
3573 First, U-Boot must be compiled with the appropriate defines. See the section
3574 titled "Linux Kernel Interface" above for a more in depth explanation. The
3575 following is an example of how to start a kernel and pass an updated
3581 oft=oftrees/mpc8540ads.dtb
3582 => tftp $oftaddr $oft
3583 Speed: 1000, full duplex
3585 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3586 Filename 'oftrees/mpc8540ads.dtb'.
3587 Load address: 0x300000
3590 Bytes transferred = 4106 (100a hex)
3591 => tftp $loadaddr $bootfile
3592 Speed: 1000, full duplex
3594 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3596 Load address: 0x200000
3597 Loading:############
3599 Bytes transferred = 1029407 (fb51f hex)
3604 => bootm $loadaddr - $oftaddr
3605 ## Booting image at 00200000 ...
3606 Image Name: Linux-2.6.17-dirty
3607 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3608 Data Size: 1029343 Bytes = 1005.2 kB
3609 Load Address: 00000000
3610 Entry Point: 00000000
3611 Verifying Checksum ... OK
3612 Uncompressing Kernel Image ... OK
3613 Booting using flat device tree at 0x300000
3614 Using MPC85xx ADS machine description
3615 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3619 More About U-Boot Image Types:
3620 ------------------------------
3622 U-Boot supports the following image types:
3624 "Standalone Programs" are directly runnable in the environment
3625 provided by U-Boot; it is expected that (if they behave
3626 well) you can continue to work in U-Boot after return from
3627 the Standalone Program.
3628 "OS Kernel Images" are usually images of some Embedded OS which
3629 will take over control completely. Usually these programs
3630 will install their own set of exception handlers, device
3631 drivers, set up the MMU, etc. - this means, that you cannot
3632 expect to re-enter U-Boot except by resetting the CPU.
3633 "RAMDisk Images" are more or less just data blocks, and their
3634 parameters (address, size) are passed to an OS kernel that is
3636 "Multi-File Images" contain several images, typically an OS
3637 (Linux) kernel image and one or more data images like
3638 RAMDisks. This construct is useful for instance when you want
3639 to boot over the network using BOOTP etc., where the boot
3640 server provides just a single image file, but you want to get
3641 for instance an OS kernel and a RAMDisk image.
3643 "Multi-File Images" start with a list of image sizes, each
3644 image size (in bytes) specified by an "uint32_t" in network
3645 byte order. This list is terminated by an "(uint32_t)0".
3646 Immediately after the terminating 0 follow the images, one by
3647 one, all aligned on "uint32_t" boundaries (size rounded up to
3648 a multiple of 4 bytes).
3650 "Firmware Images" are binary images containing firmware (like
3651 U-Boot or FPGA images) which usually will be programmed to
3654 "Script files" are command sequences that will be executed by
3655 U-Boot's command interpreter; this feature is especially
3656 useful when you configure U-Boot to use a real shell (hush)
3657 as command interpreter.
3663 One of the features of U-Boot is that you can dynamically load and
3664 run "standalone" applications, which can use some resources of
3665 U-Boot like console I/O functions or interrupt services.
3667 Two simple examples are included with the sources:
3672 'examples/hello_world.c' contains a small "Hello World" Demo
3673 application; it is automatically compiled when you build U-Boot.
3674 It's configured to run at address 0x00040004, so you can play with it
3678 ## Ready for S-Record download ...
3679 ~>examples/hello_world.srec
3680 1 2 3 4 5 6 7 8 9 10 11 ...
3681 [file transfer complete]
3683 ## Start Addr = 0x00040004
3685 => go 40004 Hello World! This is a test.
3686 ## Starting application at 0x00040004 ...
3697 Hit any key to exit ...
3699 ## Application terminated, rc = 0x0
3701 Another example, which demonstrates how to register a CPM interrupt
3702 handler with the U-Boot code, can be found in 'examples/timer.c'.
3703 Here, a CPM timer is set up to generate an interrupt every second.
3704 The interrupt service routine is trivial, just printing a '.'
3705 character, but this is just a demo program. The application can be
3706 controlled by the following keys:
3708 ? - print current values og the CPM Timer registers
3709 b - enable interrupts and start timer
3710 e - stop timer and disable interrupts
3711 q - quit application
3714 ## Ready for S-Record download ...
3715 ~>examples/timer.srec
3716 1 2 3 4 5 6 7 8 9 10 11 ...
3717 [file transfer complete]
3719 ## Start Addr = 0x00040004
3722 ## Starting application at 0x00040004 ...
3725 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3728 [q, b, e, ?] Set interval 1000000 us
3731 [q, b, e, ?] ........
3732 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3735 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3738 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3741 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3743 [q, b, e, ?] ...Stopping timer
3745 [q, b, e, ?] ## Application terminated, rc = 0x0
3751 Over time, many people have reported problems when trying to use the
3752 "minicom" terminal emulation program for serial download. I (wd)
3753 consider minicom to be broken, and recommend not to use it. Under
3754 Unix, I recommend to use C-Kermit for general purpose use (and
3755 especially for kermit binary protocol download ("loadb" command), and
3756 use "cu" for S-Record download ("loads" command).
3758 Nevertheless, if you absolutely want to use it try adding this
3759 configuration to your "File transfer protocols" section:
3761 Name Program Name U/D FullScr IO-Red. Multi
3762 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3763 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3769 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3770 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3772 Building requires a cross environment; it is known to work on
3773 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3774 need gmake since the Makefiles are not compatible with BSD make).
3775 Note that the cross-powerpc package does not install include files;
3776 attempting to build U-Boot will fail because <machine/ansi.h> is
3777 missing. This file has to be installed and patched manually:
3779 # cd /usr/pkg/cross/powerpc-netbsd/include
3781 # ln -s powerpc machine
3782 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3783 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3785 Native builds *don't* work due to incompatibilities between native
3786 and U-Boot include files.
3788 Booting assumes that (the first part of) the image booted is a
3789 stage-2 loader which in turn loads and then invokes the kernel
3790 proper. Loader sources will eventually appear in the NetBSD source
3791 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3792 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3795 Implementation Internals:
3796 =========================
3798 The following is not intended to be a complete description of every
3799 implementation detail. However, it should help to understand the
3800 inner workings of U-Boot and make it easier to port it to custom
3804 Initial Stack, Global Data:
3805 ---------------------------
3807 The implementation of U-Boot is complicated by the fact that U-Boot
3808 starts running out of ROM (flash memory), usually without access to
3809 system RAM (because the memory controller is not initialized yet).
3810 This means that we don't have writable Data or BSS segments, and BSS
3811 is not initialized as zero. To be able to get a C environment working
3812 at all, we have to allocate at least a minimal stack. Implementation
3813 options for this are defined and restricted by the CPU used: Some CPU
3814 models provide on-chip memory (like the IMMR area on MPC8xx and
3815 MPC826x processors), on others (parts of) the data cache can be
3816 locked as (mis-) used as memory, etc.
3818 Chris Hallinan posted a good summary of these issues to the
3819 U-Boot mailing list:
3821 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3822 From: "Chris Hallinan" <clh@net1plus.com>
3823 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3826 Correct me if I'm wrong, folks, but the way I understand it
3827 is this: Using DCACHE as initial RAM for Stack, etc, does not
3828 require any physical RAM backing up the cache. The cleverness
3829 is that the cache is being used as a temporary supply of
3830 necessary storage before the SDRAM controller is setup. It's
3831 beyond the scope of this list to explain the details, but you
3832 can see how this works by studying the cache architecture and
3833 operation in the architecture and processor-specific manuals.
3835 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3836 is another option for the system designer to use as an
3837 initial stack/RAM area prior to SDRAM being available. Either
3838 option should work for you. Using CS 4 should be fine if your
3839 board designers haven't used it for something that would
3840 cause you grief during the initial boot! It is frequently not
3843 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
3844 with your processor/board/system design. The default value
3845 you will find in any recent u-boot distribution in
3846 walnut.h should work for you. I'd set it to a value larger
3847 than your SDRAM module. If you have a 64MB SDRAM module, set
3848 it above 400_0000. Just make sure your board has no resources
3849 that are supposed to respond to that address! That code in
3850 start.S has been around a while and should work as is when
3851 you get the config right.
3856 It is essential to remember this, since it has some impact on the C
3857 code for the initialization procedures:
3859 * Initialized global data (data segment) is read-only. Do not attempt
3862 * Do not use any uninitialized global data (or implicitely initialized
3863 as zero data - BSS segment) at all - this is undefined, initiali-
3864 zation is performed later (when relocating to RAM).
3866 * Stack space is very limited. Avoid big data buffers or things like
3869 Having only the stack as writable memory limits means we cannot use
3870 normal global data to share information beween the code. But it
3871 turned out that the implementation of U-Boot can be greatly
3872 simplified by making a global data structure (gd_t) available to all
3873 functions. We could pass a pointer to this data as argument to _all_
3874 functions, but this would bloat the code. Instead we use a feature of
3875 the GCC compiler (Global Register Variables) to share the data: we
3876 place a pointer (gd) to the global data into a register which we
3877 reserve for this purpose.
3879 When choosing a register for such a purpose we are restricted by the
3880 relevant (E)ABI specifications for the current architecture, and by
3881 GCC's implementation.
3883 For PowerPC, the following registers have specific use:
3885 R2: reserved for system use
3886 R3-R4: parameter passing and return values
3887 R5-R10: parameter passing
3888 R13: small data area pointer
3892 (U-Boot also uses R14 as internal GOT pointer.)
3894 ==> U-Boot will use R2 to hold a pointer to the global data
3896 Note: on PPC, we could use a static initializer (since the
3897 address of the global data structure is known at compile time),
3898 but it turned out that reserving a register results in somewhat
3899 smaller code - although the code savings are not that big (on
3900 average for all boards 752 bytes for the whole U-Boot image,
3901 624 text + 127 data).
3903 On Blackfin, the normal C ABI (except for P5) is followed as documented here:
3904 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
3906 ==> U-Boot will use P5 to hold a pointer to the global data
3908 On ARM, the following registers are used:
3910 R0: function argument word/integer result
3911 R1-R3: function argument word
3913 R10: stack limit (used only if stack checking if enabled)
3914 R11: argument (frame) pointer
3915 R12: temporary workspace
3918 R15: program counter
3920 ==> U-Boot will use R8 to hold a pointer to the global data
3922 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3923 or current versions of GCC may "optimize" the code too much.
3928 U-Boot runs in system state and uses physical addresses, i.e. the
3929 MMU is not used either for address mapping nor for memory protection.
3931 The available memory is mapped to fixed addresses using the memory
3932 controller. In this process, a contiguous block is formed for each
3933 memory type (Flash, SDRAM, SRAM), even when it consists of several
3934 physical memory banks.
3936 U-Boot is installed in the first 128 kB of the first Flash bank (on
3937 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3938 booting and sizing and initializing DRAM, the code relocates itself
3939 to the upper end of DRAM. Immediately below the U-Boot code some
3940 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
3941 configuration setting]. Below that, a structure with global Board
3942 Info data is placed, followed by the stack (growing downward).
3944 Additionally, some exception handler code is copied to the low 8 kB
3945 of DRAM (0x00000000 ... 0x00001FFF).
3947 So a typical memory configuration with 16 MB of DRAM could look like
3950 0x0000 0000 Exception Vector code
3953 0x0000 2000 Free for Application Use
3959 0x00FB FF20 Monitor Stack (Growing downward)
3960 0x00FB FFAC Board Info Data and permanent copy of global data
3961 0x00FC 0000 Malloc Arena
3964 0x00FE 0000 RAM Copy of Monitor Code
3965 ... eventually: LCD or video framebuffer
3966 ... eventually: pRAM (Protected RAM - unchanged by reset)
3967 0x00FF FFFF [End of RAM]
3970 System Initialization:
3971 ----------------------
3973 In the reset configuration, U-Boot starts at the reset entry point
3974 (on most PowerPC systems at address 0x00000100). Because of the reset
3975 configuration for CS0# this is a mirror of the onboard Flash memory.
3976 To be able to re-map memory U-Boot then jumps to its link address.
3977 To be able to implement the initialization code in C, a (small!)
3978 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3979 which provide such a feature like MPC8xx or MPC8260), or in a locked
3980 part of the data cache. After that, U-Boot initializes the CPU core,
3981 the caches and the SIU.
3983 Next, all (potentially) available memory banks are mapped using a
3984 preliminary mapping. For example, we put them on 512 MB boundaries
3985 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3986 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3987 programmed for SDRAM access. Using the temporary configuration, a
3988 simple memory test is run that determines the size of the SDRAM
3991 When there is more than one SDRAM bank, and the banks are of
3992 different size, the largest is mapped first. For equal size, the first
3993 bank (CS2#) is mapped first. The first mapping is always for address
3994 0x00000000, with any additional banks following immediately to create
3995 contiguous memory starting from 0.
3997 Then, the monitor installs itself at the upper end of the SDRAM area
3998 and allocates memory for use by malloc() and for the global Board
3999 Info data; also, the exception vector code is copied to the low RAM
4000 pages, and the final stack is set up.
4002 Only after this relocation will you have a "normal" C environment;
4003 until that you are restricted in several ways, mostly because you are
4004 running from ROM, and because the code will have to be relocated to a
4008 U-Boot Porting Guide:
4009 ----------------------
4011 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4015 int main(int argc, char *argv[])
4017 sighandler_t no_more_time;
4019 signal(SIGALRM, no_more_time);
4020 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4022 if (available_money > available_manpower) {
4023 Pay consultant to port U-Boot;
4027 Download latest U-Boot source;
4029 Subscribe to u-boot mailing list;
4032 email("Hi, I am new to U-Boot, how do I get started?");
4035 Read the README file in the top level directory;
4036 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4037 Read applicable doc/*.README;
4038 Read the source, Luke;
4039 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4042 if (available_money > toLocalCurrency ($2500))
4045 Add a lot of aggravation and time;
4047 if (a similar board exists) { /* hopefully... */
4048 cp -a board/<similar> board/<myboard>
4049 cp include/configs/<similar>.h include/configs/<myboard>.h
4051 Create your own board support subdirectory;
4052 Create your own board include/configs/<myboard>.h file;
4054 Edit new board/<myboard> files
4055 Edit new include/configs/<myboard>.h
4060 Add / modify source code;
4064 email("Hi, I am having problems...");
4066 Send patch file to the U-Boot email list;
4067 if (reasonable critiques)
4068 Incorporate improvements from email list code review;
4070 Defend code as written;
4076 void no_more_time (int sig)
4085 All contributions to U-Boot should conform to the Linux kernel
4086 coding style; see the file "Documentation/CodingStyle" and the script
4087 "scripts/Lindent" in your Linux kernel source directory. In sources
4088 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
4089 spaces before parameters to function calls) is actually used.
4091 Source files originating from a different project (for example the
4092 MTD subsystem) are generally exempt from these guidelines and are not
4093 reformated to ease subsequent migration to newer versions of those
4096 Please note that U-Boot is implemented in C (and to some small parts in
4097 Assembler); no C++ is used, so please do not use C++ style comments (//)
4100 Please also stick to the following formatting rules:
4101 - remove any trailing white space
4102 - use TAB characters for indentation, not spaces
4103 - make sure NOT to use DOS '\r\n' line feeds
4104 - do not add more than 2 empty lines to source files
4105 - do not add trailing empty lines to source files
4107 Submissions which do not conform to the standards may be returned
4108 with a request to reformat the changes.
4114 Since the number of patches for U-Boot is growing, we need to
4115 establish some rules. Submissions which do not conform to these rules
4116 may be rejected, even when they contain important and valuable stuff.
4118 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4120 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4121 see http://lists.denx.de/mailman/listinfo/u-boot
4123 When you send a patch, please include the following information with
4126 * For bug fixes: a description of the bug and how your patch fixes
4127 this bug. Please try to include a way of demonstrating that the
4128 patch actually fixes something.
4130 * For new features: a description of the feature and your
4133 * A CHANGELOG entry as plaintext (separate from the patch)
4135 * For major contributions, your entry to the CREDITS file
4137 * When you add support for a new board, don't forget to add this
4138 board to the MAKEALL script, too.
4140 * If your patch adds new configuration options, don't forget to
4141 document these in the README file.
4143 * The patch itself. If you are using git (which is *strongly*
4144 recommended) you can easily generate the patch using the
4145 "git-format-patch". If you then use "git-send-email" to send it to
4146 the U-Boot mailing list, you will avoid most of the common problems
4147 with some other mail clients.
4149 If you cannot use git, use "diff -purN OLD NEW". If your version of
4150 diff does not support these options, then get the latest version of
4153 The current directory when running this command shall be the parent
4154 directory of the U-Boot source tree (i. e. please make sure that
4155 your patch includes sufficient directory information for the
4158 We prefer patches as plain text. MIME attachments are discouraged,
4159 and compressed attachments must not be used.
4161 * If one logical set of modifications affects or creates several
4162 files, all these changes shall be submitted in a SINGLE patch file.
4164 * Changesets that contain different, unrelated modifications shall be
4165 submitted as SEPARATE patches, one patch per changeset.
4170 * Before sending the patch, run the MAKEALL script on your patched
4171 source tree and make sure that no errors or warnings are reported
4172 for any of the boards.
4174 * Keep your modifications to the necessary minimum: A patch
4175 containing several unrelated changes or arbitrary reformats will be
4176 returned with a request to re-formatting / split it.
4178 * If you modify existing code, make sure that your new code does not
4179 add to the memory footprint of the code ;-) Small is beautiful!
4180 When adding new features, these should compile conditionally only
4181 (using #ifdef), and the resulting code with the new feature
4182 disabled must not need more memory than the old code without your
4185 * Remember that there is a size limit of 100 kB per message on the
4186 u-boot mailing list. Bigger patches will be moderated. If they are
4187 reasonable and not too big, they will be acknowledged. But patches
4188 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob