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 - Intel Monahans options:
322 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
324 Defines the Monahans run mode to oscillator
325 ratio. Valid values are 8, 16, 24, 31. The core
326 frequency is this value multiplied by 13 MHz.
328 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
330 Defines the Monahans turbo mode to oscillator
331 ratio. Valid values are 1 (default if undefined) and
332 2. The core frequency as calculated above is multiplied
335 - Linux Kernel Interface:
338 U-Boot stores all clock information in Hz
339 internally. For binary compatibility with older Linux
340 kernels (which expect the clocks passed in the
341 bd_info data to be in MHz) the environment variable
342 "clocks_in_mhz" can be defined so that U-Boot
343 converts clock data to MHZ before passing it to the
345 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
346 "clocks_in_mhz=1" is automatically included in the
349 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
351 When transferring memsize parameter to linux, some versions
352 expect it to be in bytes, others in MB.
353 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
357 New kernel versions are expecting firmware settings to be
358 passed using flattened device trees (based on open firmware
362 * New libfdt-based support
363 * Adds the "fdt" command
364 * The bootm command automatically updates the fdt
366 OF_CPU - The proper name of the cpus node.
367 OF_SOC - The proper name of the soc node.
368 OF_TBCLK - The timebase frequency.
369 OF_STDOUT_PATH - The path to the console device
371 boards with QUICC Engines require OF_QE to set UCC MAC
374 CONFIG_OF_BOARD_SETUP
376 Board code has addition modification that it wants to make
377 to the flat device tree before handing it off to the kernel
381 This define fills in the correct boot CPU in the boot
382 param header, the default value is zero if undefined.
384 - vxWorks boot parameters:
386 bootvx constructs a valid bootline using the following
387 environments variables: bootfile, ipaddr, serverip, hostname.
388 It loads the vxWorks image pointed bootfile.
390 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
391 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
392 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
393 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
395 CONFIG_SYS_VXWORKS_ADD_PARAMS
397 Add it at the end of the bootline. E.g "u=username pw=secret"
399 Note: If a "bootargs" environment is defined, it will overwride
400 the defaults discussed just above.
405 Define this if you want support for Amba PrimeCell PL010 UARTs.
409 Define this if you want support for Amba PrimeCell PL011 UARTs.
413 If you have Amba PrimeCell PL011 UARTs, set this variable to
414 the clock speed of the UARTs.
418 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
419 define this to a list of base addresses for each (supported)
420 port. See e.g. include/configs/versatile.h
424 Depending on board, define exactly one serial port
425 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
426 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
427 console by defining CONFIG_8xx_CONS_NONE
429 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
430 port routines must be defined elsewhere
431 (i.e. serial_init(), serial_getc(), ...)
434 Enables console device for a color framebuffer. Needs following
435 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
436 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
438 VIDEO_HW_RECTFILL graphic chip supports
441 VIDEO_HW_BITBLT graphic chip supports
442 bit-blit (cf. smiLynxEM)
443 VIDEO_VISIBLE_COLS visible pixel columns
445 VIDEO_VISIBLE_ROWS visible pixel rows
446 VIDEO_PIXEL_SIZE bytes per pixel
447 VIDEO_DATA_FORMAT graphic data format
448 (0-5, cf. cfb_console.c)
449 VIDEO_FB_ADRS framebuffer address
450 VIDEO_KBD_INIT_FCT keyboard int fct
451 (i.e. i8042_kbd_init())
452 VIDEO_TSTC_FCT test char fct
454 VIDEO_GETC_FCT get char fct
456 CONFIG_CONSOLE_CURSOR cursor drawing on/off
457 (requires blink timer
459 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
460 CONFIG_CONSOLE_TIME display time/date info in
462 (requires CONFIG_CMD_DATE)
463 CONFIG_VIDEO_LOGO display Linux logo in
465 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
466 linux_logo.h for logo.
467 Requires CONFIG_VIDEO_LOGO
468 CONFIG_CONSOLE_EXTRA_INFO
469 additional board info beside
472 When CONFIG_CFB_CONSOLE is defined, video console is
473 default i/o. Serial console can be forced with
474 environment 'console=serial'.
476 When CONFIG_SILENT_CONSOLE is defined, all console
477 messages (by U-Boot and Linux!) can be silenced with
478 the "silent" environment variable. See
479 doc/README.silent for more information.
482 CONFIG_BAUDRATE - in bps
483 Select one of the baudrates listed in
484 CONFIG_SYS_BAUDRATE_TABLE, see below.
485 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
487 - Console Rx buffer length
488 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
489 the maximum receive buffer length for the SMC.
490 This option is actual only for 82xx and 8xx possible.
491 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
492 must be defined, to setup the maximum idle timeout for
495 - Interrupt driven serial port input:
496 CONFIG_SERIAL_SOFTWARE_FIFO
499 Use an interrupt handler for receiving data on the
500 serial port. It also enables using hardware handshake
501 (RTS/CTS) and UART's built-in FIFO. Set the number of
502 bytes the interrupt driven input buffer should have.
504 Leave undefined to disable this feature, including
505 disable the buffer and hardware handshake.
507 - Console UART Number:
511 If defined internal UART1 (and not UART0) is used
512 as default U-Boot console.
514 - Boot Delay: CONFIG_BOOTDELAY - in seconds
515 Delay before automatically booting the default image;
516 set to -1 to disable autoboot.
518 See doc/README.autoboot for these options that
519 work with CONFIG_BOOTDELAY. None are required.
520 CONFIG_BOOT_RETRY_TIME
521 CONFIG_BOOT_RETRY_MIN
522 CONFIG_AUTOBOOT_KEYED
523 CONFIG_AUTOBOOT_PROMPT
524 CONFIG_AUTOBOOT_DELAY_STR
525 CONFIG_AUTOBOOT_STOP_STR
526 CONFIG_AUTOBOOT_DELAY_STR2
527 CONFIG_AUTOBOOT_STOP_STR2
528 CONFIG_ZERO_BOOTDELAY_CHECK
529 CONFIG_RESET_TO_RETRY
533 Only needed when CONFIG_BOOTDELAY is enabled;
534 define a command string that is automatically executed
535 when no character is read on the console interface
536 within "Boot Delay" after reset.
539 This can be used to pass arguments to the bootm
540 command. The value of CONFIG_BOOTARGS goes into the
541 environment value "bootargs".
543 CONFIG_RAMBOOT and CONFIG_NFSBOOT
544 The value of these goes into the environment as
545 "ramboot" and "nfsboot" respectively, and can be used
546 as a convenience, when switching between booting from
552 When this option is #defined, the existence of the
553 environment variable "preboot" will be checked
554 immediately before starting the CONFIG_BOOTDELAY
555 countdown and/or running the auto-boot command resp.
556 entering interactive mode.
558 This feature is especially useful when "preboot" is
559 automatically generated or modified. For an example
560 see the LWMON board specific code: here "preboot" is
561 modified when the user holds down a certain
562 combination of keys on the (special) keyboard when
565 - Serial Download Echo Mode:
567 If defined to 1, all characters received during a
568 serial download (using the "loads" command) are
569 echoed back. This might be needed by some terminal
570 emulations (like "cu"), but may as well just take
571 time on others. This setting #define's the initial
572 value of the "loads_echo" environment variable.
574 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
576 Select one of the baudrates listed in
577 CONFIG_SYS_BAUDRATE_TABLE, see below.
580 Monitor commands can be included or excluded
581 from the build by using the #include files
582 "config_cmd_all.h" and #undef'ing unwanted
583 commands, or using "config_cmd_default.h"
584 and augmenting with additional #define's
587 The default command configuration includes all commands
588 except those marked below with a "*".
590 CONFIG_CMD_ASKENV * ask for env variable
591 CONFIG_CMD_AUTOSCRIPT Autoscript Support
592 CONFIG_CMD_BDI bdinfo
593 CONFIG_CMD_BEDBUG * Include BedBug Debugger
594 CONFIG_CMD_BMP * BMP support
595 CONFIG_CMD_BSP * Board specific commands
596 CONFIG_CMD_BOOTD bootd
597 CONFIG_CMD_CACHE * icache, dcache
598 CONFIG_CMD_CONSOLE coninfo
599 CONFIG_CMD_DATE * support for RTC, date/time...
600 CONFIG_CMD_DHCP * DHCP support
601 CONFIG_CMD_DIAG * Diagnostics
602 CONFIG_CMD_DOC * Disk-On-Chip Support
603 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
604 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
605 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
606 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
607 CONFIG_CMD_DTT * Digital Therm and Thermostat
608 CONFIG_CMD_ECHO echo arguments
609 CONFIG_CMD_EEPROM * EEPROM read/write support
610 CONFIG_CMD_ELF * bootelf, bootvx
611 CONFIG_CMD_SAVEENV saveenv
612 CONFIG_CMD_FDC * Floppy Disk Support
613 CONFIG_CMD_FAT * FAT partition support
614 CONFIG_CMD_FDOS * Dos diskette Support
615 CONFIG_CMD_FLASH flinfo, erase, protect
616 CONFIG_CMD_FPGA FPGA device initialization support
617 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
618 CONFIG_CMD_I2C * I2C serial bus support
619 CONFIG_CMD_IDE * IDE harddisk support
620 CONFIG_CMD_IMI iminfo
621 CONFIG_CMD_IMLS List all found images
622 CONFIG_CMD_IMMAP * IMMR dump support
623 CONFIG_CMD_IRQ * irqinfo
624 CONFIG_CMD_ITEST Integer/string test of 2 values
625 CONFIG_CMD_JFFS2 * JFFS2 Support
626 CONFIG_CMD_KGDB * kgdb
627 CONFIG_CMD_LOADB loadb
628 CONFIG_CMD_LOADS loads
629 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
631 CONFIG_CMD_MISC Misc functions like sleep etc
632 CONFIG_CMD_MMC * MMC memory mapped support
633 CONFIG_CMD_MII * MII utility commands
634 CONFIG_CMD_NAND * NAND support
635 CONFIG_CMD_NET bootp, tftpboot, rarpboot
636 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
637 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
638 CONFIG_CMD_PCI * pciinfo
639 CONFIG_CMD_PCMCIA * PCMCIA support
640 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
642 CONFIG_CMD_PORTIO * Port I/O
643 CONFIG_CMD_REGINFO * Register dump
644 CONFIG_CMD_RUN run command in env variable
645 CONFIG_CMD_SAVES * save S record dump
646 CONFIG_CMD_SCSI * SCSI Support
647 CONFIG_CMD_SDRAM * print SDRAM configuration information
648 (requires CONFIG_CMD_I2C)
649 CONFIG_CMD_SETGETDCR Support for DCR Register access
651 CONFIG_CMD_SPI * SPI serial bus support
652 CONFIG_CMD_USB * USB support
653 CONFIG_CMD_VFD * VFD support (TRAB)
654 CONFIG_CMD_CDP * Cisco Discover Protocol support
655 CONFIG_CMD_FSL * Microblaze FSL support
658 EXAMPLE: If you want all functions except of network
659 support you can write:
661 #include "config_cmd_all.h"
662 #undef CONFIG_CMD_NET
665 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
667 Note: Don't enable the "icache" and "dcache" commands
668 (configuration option CONFIG_CMD_CACHE) unless you know
669 what you (and your U-Boot users) are doing. Data
670 cache cannot be enabled on systems like the 8xx or
671 8260 (where accesses to the IMMR region must be
672 uncached), and it cannot be disabled on all other
673 systems where we (mis-) use the data cache to hold an
674 initial stack and some data.
677 XXX - this list needs to get updated!
681 If this variable is defined, it enables watchdog
682 support. There must be support in the platform specific
683 code for a watchdog. For the 8xx and 8260 CPUs, the
684 SIU Watchdog feature is enabled in the SYPCR
688 CONFIG_VERSION_VARIABLE
689 If this variable is defined, an environment variable
690 named "ver" is created by U-Boot showing the U-Boot
691 version as printed by the "version" command.
692 This variable is readonly.
696 When CONFIG_CMD_DATE is selected, the type of the RTC
697 has to be selected, too. Define exactly one of the
700 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
701 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
702 CONFIG_RTC_MC13783 - use MC13783 RTC
703 CONFIG_RTC_MC146818 - use MC146818 RTC
704 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
705 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
706 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
707 CONFIG_RTC_DS164x - use Dallas DS164x RTC
708 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
709 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
710 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
712 Note that if the RTC uses I2C, then the I2C interface
713 must also be configured. See I2C Support, below.
716 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
717 CONFIG_PCA953X_INFO - enable pca953x info command
719 Note that if the GPIO device uses I2C, then the I2C interface
720 must also be configured. See I2C Support, below.
724 When CONFIG_TIMESTAMP is selected, the timestamp
725 (date and time) of an image is printed by image
726 commands like bootm or iminfo. This option is
727 automatically enabled when you select CONFIG_CMD_DATE .
730 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
731 and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION
733 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
734 CONFIG_CMD_SCSI) you must configure support for at
735 least one partition type as well.
738 CONFIG_IDE_RESET_ROUTINE - this is defined in several
739 board configurations files but used nowhere!
741 CONFIG_IDE_RESET - is this is defined, IDE Reset will
742 be performed by calling the function
743 ide_set_reset(int reset)
744 which has to be defined in a board specific file
749 Set this to enable ATAPI support.
754 Set this to enable support for disks larger than 137GB
755 Also look at CONFIG_SYS_64BIT_LBA ,CONFIG_SYS_64BIT_VSPRINTF and CONFIG_SYS_64BIT_STRTOUL
756 Whithout these , LBA48 support uses 32bit variables and will 'only'
757 support disks up to 2.1TB.
759 CONFIG_SYS_64BIT_LBA:
760 When enabled, makes the IDE subsystem use 64bit sector addresses.
764 At the moment only there is only support for the
765 SYM53C8XX SCSI controller; define
766 CONFIG_SCSI_SYM53C8XX to enable it.
768 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
769 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
770 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
771 maximum numbers of LUNs, SCSI ID's and target
773 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
775 - NETWORK Support (PCI):
777 Support for Intel 8254x gigabit chips.
779 CONFIG_E1000_FALLBACK_MAC
780 default MAC for empty EEPROM after production.
783 Support for Intel 82557/82559/82559ER chips.
784 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
785 write routine for first time initialisation.
788 Support for Digital 2114x chips.
789 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
790 modem chip initialisation (KS8761/QS6611).
793 Support for National dp83815 chips.
796 Support for National dp8382[01] gigabit chips.
798 - NETWORK Support (other):
800 CONFIG_DRIVER_LAN91C96
801 Support for SMSC's LAN91C96 chips.
804 Define this to hold the physical address
805 of the LAN91C96's I/O space
807 CONFIG_LAN91C96_USE_32_BIT
808 Define this to enable 32 bit addressing
810 CONFIG_DRIVER_SMC91111
811 Support for SMSC's LAN91C111 chip
814 Define this to hold the physical address
815 of the device (I/O space)
817 CONFIG_SMC_USE_32_BIT
818 Define this if data bus is 32 bits
820 CONFIG_SMC_USE_IOFUNCS
821 Define this to use i/o functions instead of macros
822 (some hardware wont work with macros)
824 CONFIG_DRIVER_SMC911X
825 Support for SMSC's LAN911x and LAN921x chips
827 CONFIG_DRIVER_SMC911X_BASE
828 Define this to hold the physical address
829 of the device (I/O space)
831 CONFIG_DRIVER_SMC911X_32_BIT
832 Define this if data bus is 32 bits
834 CONFIG_DRIVER_SMC911X_16_BIT
835 Define this if data bus is 16 bits. If your processor
836 automatically converts one 32 bit word to two 16 bit
837 words you may also try CONFIG_DRIVER_SMC911X_32_BIT.
840 At the moment only the UHCI host controller is
841 supported (PIP405, MIP405, MPC5200); define
842 CONFIG_USB_UHCI to enable it.
843 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
844 and define CONFIG_USB_STORAGE to enable the USB
847 Supported are USB Keyboards and USB Floppy drives
849 MPC5200 USB requires additional defines:
851 for 528 MHz Clock: 0x0001bbbb
853 for differential drivers: 0x00001000
854 for single ended drivers: 0x00005000
855 CONFIG_SYS_USB_EVENT_POLL
856 May be defined to allow interrupt polling
857 instead of using asynchronous interrupts
860 Define the below if you wish to use the USB console.
861 Once firmware is rebuilt from a serial console issue the
862 command "setenv stdin usbtty; setenv stdout usbtty" and
863 attach your USB cable. The Unix command "dmesg" should print
864 it has found a new device. The environment variable usbtty
865 can be set to gserial or cdc_acm to enable your device to
866 appear to a USB host as a Linux gserial device or a
867 Common Device Class Abstract Control Model serial device.
868 If you select usbtty = gserial you should be able to enumerate
870 # modprobe usbserial vendor=0xVendorID product=0xProductID
871 else if using cdc_acm, simply setting the environment
872 variable usbtty to be cdc_acm should suffice. The following
873 might be defined in YourBoardName.h
876 Define this to build a UDC device
879 Define this to have a tty type of device available to
880 talk to the UDC device
882 CONFIG_SYS_CONSOLE_IS_IN_ENV
883 Define this if you want stdin, stdout &/or stderr to
887 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
888 Derive USB clock from external clock "blah"
889 - CONFIG_SYS_USB_EXTC_CLK 0x02
891 CONFIG_SYS_USB_BRG_CLK 0xBLAH
892 Derive USB clock from brgclk
893 - CONFIG_SYS_USB_BRG_CLK 0x04
895 If you have a USB-IF assigned VendorID then you may wish to
896 define your own vendor specific values either in BoardName.h
897 or directly in usbd_vendor_info.h. If you don't define
898 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
899 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
900 should pretend to be a Linux device to it's target host.
902 CONFIG_USBD_MANUFACTURER
903 Define this string as the name of your company for
904 - CONFIG_USBD_MANUFACTURER "my company"
906 CONFIG_USBD_PRODUCT_NAME
907 Define this string as the name of your product
908 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
911 Define this as your assigned Vendor ID from the USB
912 Implementors Forum. This *must* be a genuine Vendor ID
913 to avoid polluting the USB namespace.
914 - CONFIG_USBD_VENDORID 0xFFFF
916 CONFIG_USBD_PRODUCTID
917 Define this as the unique Product ID
919 - CONFIG_USBD_PRODUCTID 0xFFFF
923 The MMC controller on the Intel PXA is supported. To
924 enable this define CONFIG_MMC. The MMC can be
925 accessed from the boot prompt by mapping the device
926 to physical memory similar to flash. Command line is
927 enabled with CONFIG_CMD_MMC. The MMC driver also works with
928 the FAT fs. This is enabled with CONFIG_CMD_FAT.
930 - Journaling Flash filesystem support:
931 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
932 CONFIG_JFFS2_NAND_DEV
933 Define these for a default partition on a NAND device
935 CONFIG_SYS_JFFS2_FIRST_SECTOR,
936 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
937 Define these for a default partition on a NOR device
939 CONFIG_SYS_JFFS_CUSTOM_PART
940 Define this to create an own partition. You have to provide a
941 function struct part_info* jffs2_part_info(int part_num)
943 If you define only one JFFS2 partition you may also want to
944 #define CONFIG_SYS_JFFS_SINGLE_PART 1
945 to disable the command chpart. This is the default when you
946 have not defined a custom partition
951 Define this to enable standard (PC-Style) keyboard
955 Standard PC keyboard driver with US (is default) and
956 GERMAN key layout (switch via environment 'keymap=de') support.
957 Export function i8042_kbd_init, i8042_tstc and i8042_getc
958 for cfb_console. Supports cursor blinking.
963 Define this to enable video support (for output to
968 Enable Chips & Technologies 69000 Video chip
970 CONFIG_VIDEO_SMI_LYNXEM
971 Enable Silicon Motion SMI 712/710/810 Video chip. The
972 video output is selected via environment 'videoout'
973 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
976 For the CT69000 and SMI_LYNXEM drivers, videomode is
977 selected via environment 'videomode'. Two different ways
979 - "videomode=num" 'num' is a standard LiLo mode numbers.
980 Following standard modes are supported (* is default):
982 Colors 640x480 800x600 1024x768 1152x864 1280x1024
983 -------------+---------------------------------------------
984 8 bits | 0x301* 0x303 0x305 0x161 0x307
985 15 bits | 0x310 0x313 0x316 0x162 0x319
986 16 bits | 0x311 0x314 0x317 0x163 0x31A
987 24 bits | 0x312 0x315 0x318 ? 0x31B
988 -------------+---------------------------------------------
989 (i.e. setenv videomode 317; saveenv; reset;)
991 - "videomode=bootargs" all the video parameters are parsed
992 from the bootargs. (See drivers/video/videomodes.c)
995 CONFIG_VIDEO_SED13806
996 Enable Epson SED13806 driver. This driver supports 8bpp
997 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
998 or CONFIG_VIDEO_SED13806_16BPP
1003 Define this to enable a custom keyboard support.
1004 This simply calls drv_keyboard_init() which must be
1005 defined in your board-specific files.
1006 The only board using this so far is RBC823.
1008 - LCD Support: CONFIG_LCD
1010 Define this to enable LCD support (for output to LCD
1011 display); also select one of the supported displays
1012 by defining one of these:
1016 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1018 CONFIG_NEC_NL6448AC33:
1020 NEC NL6448AC33-18. Active, color, single scan.
1022 CONFIG_NEC_NL6448BC20
1024 NEC NL6448BC20-08. 6.5", 640x480.
1025 Active, color, single scan.
1027 CONFIG_NEC_NL6448BC33_54
1029 NEC NL6448BC33-54. 10.4", 640x480.
1030 Active, color, single scan.
1034 Sharp 320x240. Active, color, single scan.
1035 It isn't 16x9, and I am not sure what it is.
1037 CONFIG_SHARP_LQ64D341
1039 Sharp LQ64D341 display, 640x480.
1040 Active, color, single scan.
1044 HLD1045 display, 640x480.
1045 Active, color, single scan.
1049 Optrex CBL50840-2 NF-FW 99 22 M5
1051 Hitachi LMG6912RPFC-00T
1055 320x240. Black & white.
1057 Normally display is black on white background; define
1058 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1060 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1062 If this option is set, the environment is checked for
1063 a variable "splashimage". If found, the usual display
1064 of logo, copyright and system information on the LCD
1065 is suppressed and the BMP image at the address
1066 specified in "splashimage" is loaded instead. The
1067 console is redirected to the "nulldev", too. This
1068 allows for a "silent" boot where a splash screen is
1069 loaded very quickly after power-on.
1071 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1073 If this option is set, additionally to standard BMP
1074 images, gzipped BMP images can be displayed via the
1075 splashscreen support or the bmp command.
1077 - Compression support:
1080 If this option is set, support for bzip2 compressed
1081 images is included. If not, only uncompressed and gzip
1082 compressed images are supported.
1084 NOTE: the bzip2 algorithm requires a lot of RAM, so
1085 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1090 If this option is set, support for lzma compressed
1093 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1094 requires an amount of dynamic memory that is given by the
1097 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1099 Where lc and lp stand for, respectively, Literal context bits
1100 and Literal pos bits.
1102 This value is upper-bounded by 14MB in the worst case. Anyway,
1103 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1104 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1105 a very small buffer.
1107 Use the lzmainfo tool to determinate the lc and lp values and
1108 then calculate the amount of needed dynamic memory (ensuring
1109 the appropriate CONFIG_SYS_MALLOC_LEN value).
1114 The address of PHY on MII bus.
1116 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1118 The clock frequency of the MII bus
1122 If this option is set, support for speed/duplex
1123 detection of gigabit PHY is included.
1125 CONFIG_PHY_RESET_DELAY
1127 Some PHY like Intel LXT971A need extra delay after
1128 reset before any MII register access is possible.
1129 For such PHY, set this option to the usec delay
1130 required. (minimum 300usec for LXT971A)
1132 CONFIG_PHY_CMD_DELAY (ppc4xx)
1134 Some PHY like Intel LXT971A need extra delay after
1135 command issued before MII status register can be read
1145 Define a default value for Ethernet address to use
1146 for the respective Ethernet interface, in case this
1147 is not determined automatically.
1152 Define a default value for the IP address to use for
1153 the default Ethernet interface, in case this is not
1154 determined through e.g. bootp.
1156 - Server IP address:
1159 Defines a default value for the IP address of a TFTP
1160 server to contact when using the "tftboot" command.
1162 - Multicast TFTP Mode:
1165 Defines whether you want to support multicast TFTP as per
1166 rfc-2090; for example to work with atftp. Lets lots of targets
1167 tftp down the same boot image concurrently. Note: the Ethernet
1168 driver in use must provide a function: mcast() to join/leave a
1171 CONFIG_BOOTP_RANDOM_DELAY
1172 - BOOTP Recovery Mode:
1173 CONFIG_BOOTP_RANDOM_DELAY
1175 If you have many targets in a network that try to
1176 boot using BOOTP, you may want to avoid that all
1177 systems send out BOOTP requests at precisely the same
1178 moment (which would happen for instance at recovery
1179 from a power failure, when all systems will try to
1180 boot, thus flooding the BOOTP server. Defining
1181 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1182 inserted before sending out BOOTP requests. The
1183 following delays are inserted then:
1185 1st BOOTP request: delay 0 ... 1 sec
1186 2nd BOOTP request: delay 0 ... 2 sec
1187 3rd BOOTP request: delay 0 ... 4 sec
1189 BOOTP requests: delay 0 ... 8 sec
1191 - DHCP Advanced Options:
1192 You can fine tune the DHCP functionality by defining
1193 CONFIG_BOOTP_* symbols:
1195 CONFIG_BOOTP_SUBNETMASK
1196 CONFIG_BOOTP_GATEWAY
1197 CONFIG_BOOTP_HOSTNAME
1198 CONFIG_BOOTP_NISDOMAIN
1199 CONFIG_BOOTP_BOOTPATH
1200 CONFIG_BOOTP_BOOTFILESIZE
1203 CONFIG_BOOTP_SEND_HOSTNAME
1204 CONFIG_BOOTP_NTPSERVER
1205 CONFIG_BOOTP_TIMEOFFSET
1206 CONFIG_BOOTP_VENDOREX
1208 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1209 environment variable, not the BOOTP server.
1211 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1212 serverip from a DHCP server, it is possible that more
1213 than one DNS serverip is offered to the client.
1214 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1215 serverip will be stored in the additional environment
1216 variable "dnsip2". The first DNS serverip is always
1217 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1220 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1221 to do a dynamic update of a DNS server. To do this, they
1222 need the hostname of the DHCP requester.
1223 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1224 of the "hostname" environment variable is passed as
1225 option 12 to the DHCP server.
1227 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1229 A 32bit value in microseconds for a delay between
1230 receiving a "DHCP Offer" and sending the "DHCP Request".
1231 This fixes a problem with certain DHCP servers that don't
1232 respond 100% of the time to a "DHCP request". E.g. On an
1233 AT91RM9200 processor running at 180MHz, this delay needed
1234 to be *at least* 15,000 usec before a Windows Server 2003
1235 DHCP server would reply 100% of the time. I recommend at
1236 least 50,000 usec to be safe. The alternative is to hope
1237 that one of the retries will be successful but note that
1238 the DHCP timeout and retry process takes a longer than
1242 CONFIG_CDP_DEVICE_ID
1244 The device id used in CDP trigger frames.
1246 CONFIG_CDP_DEVICE_ID_PREFIX
1248 A two character string which is prefixed to the MAC address
1253 A printf format string which contains the ascii name of
1254 the port. Normally is set to "eth%d" which sets
1255 eth0 for the first Ethernet, eth1 for the second etc.
1257 CONFIG_CDP_CAPABILITIES
1259 A 32bit integer which indicates the device capabilities;
1260 0x00000010 for a normal host which does not forwards.
1264 An ascii string containing the version of the software.
1268 An ascii string containing the name of the platform.
1272 A 32bit integer sent on the trigger.
1274 CONFIG_CDP_POWER_CONSUMPTION
1276 A 16bit integer containing the power consumption of the
1277 device in .1 of milliwatts.
1279 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1281 A byte containing the id of the VLAN.
1283 - Status LED: CONFIG_STATUS_LED
1285 Several configurations allow to display the current
1286 status using a LED. For instance, the LED will blink
1287 fast while running U-Boot code, stop blinking as
1288 soon as a reply to a BOOTP request was received, and
1289 start blinking slow once the Linux kernel is running
1290 (supported by a status LED driver in the Linux
1291 kernel). Defining CONFIG_STATUS_LED enables this
1294 - CAN Support: CONFIG_CAN_DRIVER
1296 Defining CONFIG_CAN_DRIVER enables CAN driver support
1297 on those systems that support this (optional)
1298 feature, like the TQM8xxL modules.
1300 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1302 These enable I2C serial bus commands. Defining either of
1303 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1304 include the appropriate I2C driver for the selected CPU.
1306 This will allow you to use i2c commands at the u-boot
1307 command line (as long as you set CONFIG_CMD_I2C in
1308 CONFIG_COMMANDS) and communicate with i2c based realtime
1309 clock chips. See common/cmd_i2c.c for a description of the
1310 command line interface.
1312 CONFIG_I2C_CMD_TREE is a recommended option that places
1313 all I2C commands under a single 'i2c' root command. The
1314 older 'imm', 'imd', 'iprobe' etc. commands are considered
1315 deprecated and may disappear in the future.
1317 CONFIG_HARD_I2C selects a hardware I2C controller.
1319 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1320 bit-banging) driver instead of CPM or similar hardware
1323 There are several other quantities that must also be
1324 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1326 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1327 to be the frequency (in Hz) at which you wish your i2c bus
1328 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1329 the CPU's i2c node address).
1331 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1332 sets the CPU up as a master node and so its address should
1333 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1334 p.16-473). So, set CONFIG_SYS_I2C_SLAVE to 0.
1336 That's all that's required for CONFIG_HARD_I2C.
1338 If you use the software i2c interface (CONFIG_SOFT_I2C)
1339 then the following macros need to be defined (examples are
1340 from include/configs/lwmon.h):
1344 (Optional). Any commands necessary to enable the I2C
1345 controller or configure ports.
1347 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1351 (Only for MPC8260 CPU). The I/O port to use (the code
1352 assumes both bits are on the same port). Valid values
1353 are 0..3 for ports A..D.
1357 The code necessary to make the I2C data line active
1358 (driven). If the data line is open collector, this
1361 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1365 The code necessary to make the I2C data line tri-stated
1366 (inactive). If the data line is open collector, this
1369 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1373 Code that returns TRUE if the I2C data line is high,
1376 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1380 If <bit> is TRUE, sets the I2C data line high. If it
1381 is FALSE, it clears it (low).
1383 eg: #define I2C_SDA(bit) \
1384 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1385 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1389 If <bit> is TRUE, sets the I2C clock line high. If it
1390 is FALSE, it clears it (low).
1392 eg: #define I2C_SCL(bit) \
1393 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1394 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1398 This delay is invoked four times per clock cycle so this
1399 controls the rate of data transfer. The data rate thus
1400 is 1 / (I2C_DELAY * 4). Often defined to be something
1403 #define I2C_DELAY udelay(2)
1405 CONFIG_SYS_I2C_INIT_BOARD
1407 When a board is reset during an i2c bus transfer
1408 chips might think that the current transfer is still
1409 in progress. On some boards it is possible to access
1410 the i2c SCLK line directly, either by using the
1411 processor pin as a GPIO or by having a second pin
1412 connected to the bus. If this option is defined a
1413 custom i2c_init_board() routine in boards/xxx/board.c
1414 is run early in the boot sequence.
1416 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1418 This option enables configuration of bi_iic_fast[] flags
1419 in u-boot bd_info structure based on u-boot environment
1420 variable "i2cfast". (see also i2cfast)
1422 CONFIG_I2C_MULTI_BUS
1424 This option allows the use of multiple I2C buses, each of which
1425 must have a controller. At any point in time, only one bus is
1426 active. To switch to a different bus, use the 'i2c dev' command.
1427 Note that bus numbering is zero-based.
1429 CONFIG_SYS_I2C_NOPROBES
1431 This option specifies a list of I2C devices that will be skipped
1432 when the 'i2c probe' command is issued (or 'iprobe' using the legacy
1433 command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device
1434 pairs. Otherwise, specify a 1D array of device addresses
1437 #undef CONFIG_I2C_MULTI_BUS
1438 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1440 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1442 #define CONFIG_I2C_MULTI_BUS
1443 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1445 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1447 CONFIG_SYS_SPD_BUS_NUM
1449 If defined, then this indicates the I2C bus number for DDR SPD.
1450 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1452 CONFIG_SYS_RTC_BUS_NUM
1454 If defined, then this indicates the I2C bus number for the RTC.
1455 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1457 CONFIG_SYS_DTT_BUS_NUM
1459 If defined, then this indicates the I2C bus number for the DTT.
1460 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1462 CONFIG_SYS_I2C_DTT_ADDR:
1464 If defined, specifies the I2C address of the DTT device.
1465 If not defined, then U-Boot uses predefined value for
1466 specified DTT device.
1470 Define this option if you want to use Freescale's I2C driver in
1471 drivers/i2c/fsl_i2c.c.
1475 Define this option if you have I2C devices reached over 1 .. n
1476 I2C Muxes like the pca9544a. This option addes a new I2C
1477 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1478 new I2C Bus to the existing I2C Busses. If you select the
1479 new Bus with "i2c dev", u-bbot sends first the commandos for
1480 the muxes to activate this new "bus".
1482 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1486 Adding a new I2C Bus reached over 2 pca9544a muxes
1487 The First mux with address 70 and channel 6
1488 The Second mux with address 71 and channel 4
1490 => i2c bus pca9544a:70:6:pca9544a:71:4
1492 Use the "i2c bus" command without parameter, to get a list
1493 of I2C Busses with muxes:
1496 Busses reached over muxes:
1498 reached over Mux(es):
1501 reached over Mux(es):
1506 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1507 u-boot sends First the Commando to the mux@70 to enable
1508 channel 6, and then the Commando to the mux@71 to enable
1511 After that, you can use the "normal" i2c commands as
1512 usual, to communicate with your I2C devices behind
1515 This option is actually implemented for the bitbanging
1516 algorithm in common/soft_i2c.c and for the Hardware I2C
1517 Bus on the MPC8260. But it should be not so difficult
1518 to add this option to other architectures.
1520 CONFIG_SOFT_I2C_READ_REPEATED_START
1522 defining this will force the i2c_read() function in
1523 the soft_i2c driver to perform an I2C repeated start
1524 between writing the address pointer and reading the
1525 data. If this define is omitted the default behaviour
1526 of doing a stop-start sequence will be used. Most I2C
1527 devices can use either method, but some require one or
1530 - SPI Support: CONFIG_SPI
1532 Enables SPI driver (so far only tested with
1533 SPI EEPROM, also an instance works with Crystal A/D and
1534 D/As on the SACSng board)
1538 Enables extended (16-bit) SPI EEPROM addressing.
1539 (symmetrical to CONFIG_I2C_X)
1543 Enables a software (bit-bang) SPI driver rather than
1544 using hardware support. This is a general purpose
1545 driver that only requires three general I/O port pins
1546 (two outputs, one input) to function. If this is
1547 defined, the board configuration must define several
1548 SPI configuration items (port pins to use, etc). For
1549 an example, see include/configs/sacsng.h.
1553 Enables a hardware SPI driver for general-purpose reads
1554 and writes. As with CONFIG_SOFT_SPI, the board configuration
1555 must define a list of chip-select function pointers.
1556 Currently supported on some MPC8xxx processors. For an
1557 example, see include/configs/mpc8349emds.h.
1561 Enables the driver for the SPI controllers on i.MX and MXC
1562 SoCs. Currently only i.MX31 is supported.
1564 - FPGA Support: CONFIG_FPGA
1566 Enables FPGA subsystem.
1568 CONFIG_FPGA_<vendor>
1570 Enables support for specific chip vendors.
1573 CONFIG_FPGA_<family>
1575 Enables support for FPGA family.
1576 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1580 Specify the number of FPGA devices to support.
1582 CONFIG_SYS_FPGA_PROG_FEEDBACK
1584 Enable printing of hash marks during FPGA configuration.
1586 CONFIG_SYS_FPGA_CHECK_BUSY
1588 Enable checks on FPGA configuration interface busy
1589 status by the configuration function. This option
1590 will require a board or device specific function to
1595 If defined, a function that provides delays in the FPGA
1596 configuration driver.
1598 CONFIG_SYS_FPGA_CHECK_CTRLC
1599 Allow Control-C to interrupt FPGA configuration
1601 CONFIG_SYS_FPGA_CHECK_ERROR
1603 Check for configuration errors during FPGA bitfile
1604 loading. For example, abort during Virtex II
1605 configuration if the INIT_B line goes low (which
1606 indicated a CRC error).
1608 CONFIG_SYS_FPGA_WAIT_INIT
1610 Maximum time to wait for the INIT_B line to deassert
1611 after PROB_B has been deasserted during a Virtex II
1612 FPGA configuration sequence. The default time is 500
1615 CONFIG_SYS_FPGA_WAIT_BUSY
1617 Maximum time to wait for BUSY to deassert during
1618 Virtex II FPGA configuration. The default is 5 ms.
1620 CONFIG_SYS_FPGA_WAIT_CONFIG
1622 Time to wait after FPGA configuration. The default is
1625 - Configuration Management:
1628 If defined, this string will be added to the U-Boot
1629 version information (U_BOOT_VERSION)
1631 - Vendor Parameter Protection:
1633 U-Boot considers the values of the environment
1634 variables "serial#" (Board Serial Number) and
1635 "ethaddr" (Ethernet Address) to be parameters that
1636 are set once by the board vendor / manufacturer, and
1637 protects these variables from casual modification by
1638 the user. Once set, these variables are read-only,
1639 and write or delete attempts are rejected. You can
1640 change this behaviour:
1642 If CONFIG_ENV_OVERWRITE is #defined in your config
1643 file, the write protection for vendor parameters is
1644 completely disabled. Anybody can change or delete
1647 Alternatively, if you #define _both_ CONFIG_ETHADDR
1648 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1649 Ethernet address is installed in the environment,
1650 which can be changed exactly ONCE by the user. [The
1651 serial# is unaffected by this, i. e. it remains
1657 Define this variable to enable the reservation of
1658 "protected RAM", i. e. RAM which is not overwritten
1659 by U-Boot. Define CONFIG_PRAM to hold the number of
1660 kB you want to reserve for pRAM. You can overwrite
1661 this default value by defining an environment
1662 variable "pram" to the number of kB you want to
1663 reserve. Note that the board info structure will
1664 still show the full amount of RAM. If pRAM is
1665 reserved, a new environment variable "mem" will
1666 automatically be defined to hold the amount of
1667 remaining RAM in a form that can be passed as boot
1668 argument to Linux, for instance like that:
1670 setenv bootargs ... mem=\${mem}
1673 This way you can tell Linux not to use this memory,
1674 either, which results in a memory region that will
1675 not be affected by reboots.
1677 *WARNING* If your board configuration uses automatic
1678 detection of the RAM size, you must make sure that
1679 this memory test is non-destructive. So far, the
1680 following board configurations are known to be
1683 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1684 HERMES, IP860, RPXlite, LWMON, LANTEC,
1685 PCU_E, FLAGADM, TQM8260
1690 Define this variable to stop the system in case of a
1691 fatal error, so that you have to reset it manually.
1692 This is probably NOT a good idea for an embedded
1693 system where you want the system to reboot
1694 automatically as fast as possible, but it may be
1695 useful during development since you can try to debug
1696 the conditions that lead to the situation.
1698 CONFIG_NET_RETRY_COUNT
1700 This variable defines the number of retries for
1701 network operations like ARP, RARP, TFTP, or BOOTP
1702 before giving up the operation. If not defined, a
1703 default value of 5 is used.
1707 Timeout waiting for an ARP reply in milliseconds.
1709 - Command Interpreter:
1710 CONFIG_AUTO_COMPLETE
1712 Enable auto completion of commands using TAB.
1714 Note that this feature has NOT been implemented yet
1715 for the "hush" shell.
1718 CONFIG_SYS_HUSH_PARSER
1720 Define this variable to enable the "hush" shell (from
1721 Busybox) as command line interpreter, thus enabling
1722 powerful command line syntax like
1723 if...then...else...fi conditionals or `&&' and '||'
1724 constructs ("shell scripts").
1726 If undefined, you get the old, much simpler behaviour
1727 with a somewhat smaller memory footprint.
1730 CONFIG_SYS_PROMPT_HUSH_PS2
1732 This defines the secondary prompt string, which is
1733 printed when the command interpreter needs more input
1734 to complete a command. Usually "> ".
1738 In the current implementation, the local variables
1739 space and global environment variables space are
1740 separated. Local variables are those you define by
1741 simply typing `name=value'. To access a local
1742 variable later on, you have write `$name' or
1743 `${name}'; to execute the contents of a variable
1744 directly type `$name' at the command prompt.
1746 Global environment variables are those you use
1747 setenv/printenv to work with. To run a command stored
1748 in such a variable, you need to use the run command,
1749 and you must not use the '$' sign to access them.
1751 To store commands and special characters in a
1752 variable, please use double quotation marks
1753 surrounding the whole text of the variable, instead
1754 of the backslashes before semicolons and special
1757 - Commandline Editing and History:
1758 CONFIG_CMDLINE_EDITING
1760 Enable editing and History functions for interactive
1761 commandline input operations
1763 - Default Environment:
1764 CONFIG_EXTRA_ENV_SETTINGS
1766 Define this to contain any number of null terminated
1767 strings (variable = value pairs) that will be part of
1768 the default environment compiled into the boot image.
1770 For example, place something like this in your
1771 board's config file:
1773 #define CONFIG_EXTRA_ENV_SETTINGS \
1777 Warning: This method is based on knowledge about the
1778 internal format how the environment is stored by the
1779 U-Boot code. This is NOT an official, exported
1780 interface! Although it is unlikely that this format
1781 will change soon, there is no guarantee either.
1782 You better know what you are doing here.
1784 Note: overly (ab)use of the default environment is
1785 discouraged. Make sure to check other ways to preset
1786 the environment like the autoscript function or the
1789 - DataFlash Support:
1790 CONFIG_HAS_DATAFLASH
1792 Defining this option enables DataFlash features and
1793 allows to read/write in Dataflash via the standard
1796 - SystemACE Support:
1799 Adding this option adds support for Xilinx SystemACE
1800 chips attached via some sort of local bus. The address
1801 of the chip must also be defined in the
1802 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
1804 #define CONFIG_SYSTEMACE
1805 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
1807 When SystemACE support is added, the "ace" device type
1808 becomes available to the fat commands, i.e. fatls.
1810 - TFTP Fixed UDP Port:
1813 If this is defined, the environment variable tftpsrcp
1814 is used to supply the TFTP UDP source port value.
1815 If tftpsrcp isn't defined, the normal pseudo-random port
1816 number generator is used.
1818 Also, the environment variable tftpdstp is used to supply
1819 the TFTP UDP destination port value. If tftpdstp isn't
1820 defined, the normal port 69 is used.
1822 The purpose for tftpsrcp is to allow a TFTP server to
1823 blindly start the TFTP transfer using the pre-configured
1824 target IP address and UDP port. This has the effect of
1825 "punching through" the (Windows XP) firewall, allowing
1826 the remainder of the TFTP transfer to proceed normally.
1827 A better solution is to properly configure the firewall,
1828 but sometimes that is not allowed.
1830 - Show boot progress:
1831 CONFIG_SHOW_BOOT_PROGRESS
1833 Defining this option allows to add some board-
1834 specific code (calling a user-provided function
1835 "show_boot_progress(int)") that enables you to show
1836 the system's boot progress on some display (for
1837 example, some LED's) on your board. At the moment,
1838 the following checkpoints are implemented:
1840 - Automatic software updates via TFTP server
1842 CONFIG_UPDATE_TFTP_CNT_MAX
1843 CONFIG_UPDATE_TFTP_MSEC_MAX
1845 These options enable and control the auto-update feature;
1846 for a more detailed description refer to doc/README.update.
1848 Legacy uImage format:
1851 1 common/cmd_bootm.c before attempting to boot an image
1852 -1 common/cmd_bootm.c Image header has bad magic number
1853 2 common/cmd_bootm.c Image header has correct magic number
1854 -2 common/cmd_bootm.c Image header has bad checksum
1855 3 common/cmd_bootm.c Image header has correct checksum
1856 -3 common/cmd_bootm.c Image data has bad checksum
1857 4 common/cmd_bootm.c Image data has correct checksum
1858 -4 common/cmd_bootm.c Image is for unsupported architecture
1859 5 common/cmd_bootm.c Architecture check OK
1860 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
1861 6 common/cmd_bootm.c Image Type check OK
1862 -6 common/cmd_bootm.c gunzip uncompression error
1863 -7 common/cmd_bootm.c Unimplemented compression type
1864 7 common/cmd_bootm.c Uncompression OK
1865 8 common/cmd_bootm.c No uncompress/copy overwrite error
1866 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1868 9 common/image.c Start initial ramdisk verification
1869 -10 common/image.c Ramdisk header has bad magic number
1870 -11 common/image.c Ramdisk header has bad checksum
1871 10 common/image.c Ramdisk header is OK
1872 -12 common/image.c Ramdisk data has bad checksum
1873 11 common/image.c Ramdisk data has correct checksum
1874 12 common/image.c Ramdisk verification complete, start loading
1875 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
1876 13 common/image.c Start multifile image verification
1877 14 common/image.c No initial ramdisk, no multifile, continue.
1879 15 lib_<arch>/bootm.c All preparation done, transferring control to OS
1881 -30 lib_ppc/board.c Fatal error, hang the system
1882 -31 post/post.c POST test failed, detected by post_output_backlog()
1883 -32 post/post.c POST test failed, detected by post_run_single()
1885 34 common/cmd_doc.c before loading a Image from a DOC device
1886 -35 common/cmd_doc.c Bad usage of "doc" command
1887 35 common/cmd_doc.c correct usage of "doc" command
1888 -36 common/cmd_doc.c No boot device
1889 36 common/cmd_doc.c correct boot device
1890 -37 common/cmd_doc.c Unknown Chip ID on boot device
1891 37 common/cmd_doc.c correct chip ID found, device available
1892 -38 common/cmd_doc.c Read Error on boot device
1893 38 common/cmd_doc.c reading Image header from DOC device OK
1894 -39 common/cmd_doc.c Image header has bad magic number
1895 39 common/cmd_doc.c Image header has correct magic number
1896 -40 common/cmd_doc.c Error reading Image from DOC device
1897 40 common/cmd_doc.c Image header has correct magic number
1898 41 common/cmd_ide.c before loading a Image from a IDE device
1899 -42 common/cmd_ide.c Bad usage of "ide" command
1900 42 common/cmd_ide.c correct usage of "ide" command
1901 -43 common/cmd_ide.c No boot device
1902 43 common/cmd_ide.c boot device found
1903 -44 common/cmd_ide.c Device not available
1904 44 common/cmd_ide.c Device available
1905 -45 common/cmd_ide.c wrong partition selected
1906 45 common/cmd_ide.c partition selected
1907 -46 common/cmd_ide.c Unknown partition table
1908 46 common/cmd_ide.c valid partition table found
1909 -47 common/cmd_ide.c Invalid partition type
1910 47 common/cmd_ide.c correct partition type
1911 -48 common/cmd_ide.c Error reading Image Header on boot device
1912 48 common/cmd_ide.c reading Image Header from IDE device OK
1913 -49 common/cmd_ide.c Image header has bad magic number
1914 49 common/cmd_ide.c Image header has correct magic number
1915 -50 common/cmd_ide.c Image header has bad checksum
1916 50 common/cmd_ide.c Image header has correct checksum
1917 -51 common/cmd_ide.c Error reading Image from IDE device
1918 51 common/cmd_ide.c reading Image from IDE device OK
1919 52 common/cmd_nand.c before loading a Image from a NAND device
1920 -53 common/cmd_nand.c Bad usage of "nand" command
1921 53 common/cmd_nand.c correct usage of "nand" command
1922 -54 common/cmd_nand.c No boot device
1923 54 common/cmd_nand.c boot device found
1924 -55 common/cmd_nand.c Unknown Chip ID on boot device
1925 55 common/cmd_nand.c correct chip ID found, device available
1926 -56 common/cmd_nand.c Error reading Image Header on boot device
1927 56 common/cmd_nand.c reading Image Header from NAND device OK
1928 -57 common/cmd_nand.c Image header has bad magic number
1929 57 common/cmd_nand.c Image header has correct magic number
1930 -58 common/cmd_nand.c Error reading Image from NAND device
1931 58 common/cmd_nand.c reading Image from NAND device OK
1933 -60 common/env_common.c Environment has a bad CRC, using default
1935 64 net/eth.c starting with Ethernet configuration.
1936 -64 net/eth.c no Ethernet found.
1937 65 net/eth.c Ethernet found.
1939 -80 common/cmd_net.c usage wrong
1940 80 common/cmd_net.c before calling NetLoop()
1941 -81 common/cmd_net.c some error in NetLoop() occurred
1942 81 common/cmd_net.c NetLoop() back without error
1943 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
1944 82 common/cmd_net.c trying automatic boot
1945 83 common/cmd_net.c running autoscript
1946 -83 common/cmd_net.c some error in automatic boot or autoscript
1947 84 common/cmd_net.c end without errors
1952 100 common/cmd_bootm.c Kernel FIT Image has correct format
1953 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
1954 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
1955 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
1956 102 common/cmd_bootm.c Kernel unit name specified
1957 -103 common/cmd_bootm.c Can't get kernel subimage node offset
1958 103 common/cmd_bootm.c Found configuration node
1959 104 common/cmd_bootm.c Got kernel subimage node offset
1960 -104 common/cmd_bootm.c Kernel subimage hash verification failed
1961 105 common/cmd_bootm.c Kernel subimage hash verification OK
1962 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
1963 106 common/cmd_bootm.c Architecture check OK
1964 -106 common/cmd_bootm.c Kernel subimage has wrong type
1965 107 common/cmd_bootm.c Kernel subimage type OK
1966 -107 common/cmd_bootm.c Can't get kernel subimage data/size
1967 108 common/cmd_bootm.c Got kernel subimage data/size
1968 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
1969 -109 common/cmd_bootm.c Can't get kernel subimage type
1970 -110 common/cmd_bootm.c Can't get kernel subimage comp
1971 -111 common/cmd_bootm.c Can't get kernel subimage os
1972 -112 common/cmd_bootm.c Can't get kernel subimage load address
1973 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
1975 120 common/image.c Start initial ramdisk verification
1976 -120 common/image.c Ramdisk FIT image has incorrect format
1977 121 common/image.c Ramdisk FIT image has correct format
1978 122 common/image.c No ramdisk subimage unit name, using configuration
1979 -122 common/image.c Can't get configuration for ramdisk subimage
1980 123 common/image.c Ramdisk unit name specified
1981 -124 common/image.c Can't get ramdisk subimage node offset
1982 125 common/image.c Got ramdisk subimage node offset
1983 -125 common/image.c Ramdisk subimage hash verification failed
1984 126 common/image.c Ramdisk subimage hash verification OK
1985 -126 common/image.c Ramdisk subimage for unsupported architecture
1986 127 common/image.c Architecture check OK
1987 -127 common/image.c Can't get ramdisk subimage data/size
1988 128 common/image.c Got ramdisk subimage data/size
1989 129 common/image.c Can't get ramdisk load address
1990 -129 common/image.c Got ramdisk load address
1992 -130 common/cmd_doc.c Incorrect FIT image format
1993 131 common/cmd_doc.c FIT image format OK
1995 -140 common/cmd_ide.c Incorrect FIT image format
1996 141 common/cmd_ide.c FIT image format OK
1998 -150 common/cmd_nand.c Incorrect FIT image format
1999 151 common/cmd_nand.c FIT image format OK
2005 [so far only for SMDK2400 and TRAB boards]
2007 - Modem support enable:
2008 CONFIG_MODEM_SUPPORT
2010 - RTS/CTS Flow control enable:
2013 - Modem debug support:
2014 CONFIG_MODEM_SUPPORT_DEBUG
2016 Enables debugging stuff (char screen[1024], dbg())
2017 for modem support. Useful only with BDI2000.
2019 - Interrupt support (PPC):
2021 There are common interrupt_init() and timer_interrupt()
2022 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2023 for CPU specific initialization. interrupt_init_cpu()
2024 should set decrementer_count to appropriate value. If
2025 CPU resets decrementer automatically after interrupt
2026 (ppc4xx) it should set decrementer_count to zero.
2027 timer_interrupt() calls timer_interrupt_cpu() for CPU
2028 specific handling. If board has watchdog / status_led
2029 / other_activity_monitor it works automatically from
2030 general timer_interrupt().
2034 In the target system modem support is enabled when a
2035 specific key (key combination) is pressed during
2036 power-on. Otherwise U-Boot will boot normally
2037 (autoboot). The key_pressed() function is called from
2038 board_init(). Currently key_pressed() is a dummy
2039 function, returning 1 and thus enabling modem
2042 If there are no modem init strings in the
2043 environment, U-Boot proceed to autoboot; the
2044 previous output (banner, info printfs) will be
2047 See also: doc/README.Modem
2050 Configuration Settings:
2051 -----------------------
2053 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2054 undefine this when you're short of memory.
2056 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2057 width of the commands listed in the 'help' command output.
2059 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2060 prompt for user input.
2062 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2064 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2066 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2068 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2069 the application (usually a Linux kernel) when it is
2072 - CONFIG_SYS_BAUDRATE_TABLE:
2073 List of legal baudrate settings for this board.
2075 - CONFIG_SYS_CONSOLE_INFO_QUIET
2076 Suppress display of console information at boot.
2078 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2079 If the board specific function
2080 extern int overwrite_console (void);
2081 returns 1, the stdin, stderr and stdout are switched to the
2082 serial port, else the settings in the environment are used.
2084 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2085 Enable the call to overwrite_console().
2087 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2088 Enable overwrite of previous console environment settings.
2090 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2091 Begin and End addresses of the area used by the
2094 - CONFIG_SYS_ALT_MEMTEST:
2095 Enable an alternate, more extensive memory test.
2097 - CONFIG_SYS_MEMTEST_SCRATCH:
2098 Scratch address used by the alternate memory test
2099 You only need to set this if address zero isn't writeable
2101 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2102 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2103 this specified memory area will get subtracted from the top
2104 (end) of RAM and won't get "touched" at all by U-Boot. By
2105 fixing up gd->ram_size the Linux kernel should gets passed
2106 the now "corrected" memory size and won't touch it either.
2107 This should work for arch/ppc and arch/powerpc. Only Linux
2108 board ports in arch/powerpc with bootwrapper support that
2109 recalculate the memory size from the SDRAM controller setup
2110 will have to get fixed in Linux additionally.
2112 This option can be used as a workaround for the 440EPx/GRx
2113 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2116 WARNING: Please make sure that this value is a multiple of
2117 the Linux page size (normally 4k). If this is not the case,
2118 then the end address of the Linux memory will be located at a
2119 non page size aligned address and this could cause major
2122 - CONFIG_SYS_TFTP_LOADADDR:
2123 Default load address for network file downloads
2125 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2126 Enable temporary baudrate change while serial download
2128 - CONFIG_SYS_SDRAM_BASE:
2129 Physical start address of SDRAM. _Must_ be 0 here.
2131 - CONFIG_SYS_MBIO_BASE:
2132 Physical start address of Motherboard I/O (if using a
2135 - CONFIG_SYS_FLASH_BASE:
2136 Physical start address of Flash memory.
2138 - CONFIG_SYS_MONITOR_BASE:
2139 Physical start address of boot monitor code (set by
2140 make config files to be same as the text base address
2141 (TEXT_BASE) used when linking) - same as
2142 CONFIG_SYS_FLASH_BASE when booting from flash.
2144 - CONFIG_SYS_MONITOR_LEN:
2145 Size of memory reserved for monitor code, used to
2146 determine _at_compile_time_ (!) if the environment is
2147 embedded within the U-Boot image, or in a separate
2150 - CONFIG_SYS_MALLOC_LEN:
2151 Size of DRAM reserved for malloc() use.
2153 - CONFIG_SYS_BOOTM_LEN:
2154 Normally compressed uImages are limited to an
2155 uncompressed size of 8 MBytes. If this is not enough,
2156 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2157 to adjust this setting to your needs.
2159 - CONFIG_SYS_BOOTMAPSZ:
2160 Maximum size of memory mapped by the startup code of
2161 the Linux kernel; all data that must be processed by
2162 the Linux kernel (bd_info, boot arguments, FDT blob if
2163 used) must be put below this limit, unless "bootm_low"
2164 enviroment variable is defined and non-zero. In such case
2165 all data for the Linux kernel must be between "bootm_low"
2166 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ.
2168 - CONFIG_SYS_MAX_FLASH_BANKS:
2169 Max number of Flash memory banks
2171 - CONFIG_SYS_MAX_FLASH_SECT:
2172 Max number of sectors on a Flash chip
2174 - CONFIG_SYS_FLASH_ERASE_TOUT:
2175 Timeout for Flash erase operations (in ms)
2177 - CONFIG_SYS_FLASH_WRITE_TOUT:
2178 Timeout for Flash write operations (in ms)
2180 - CONFIG_SYS_FLASH_LOCK_TOUT
2181 Timeout for Flash set sector lock bit operation (in ms)
2183 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2184 Timeout for Flash clear lock bits operation (in ms)
2186 - CONFIG_SYS_FLASH_PROTECTION
2187 If defined, hardware flash sectors protection is used
2188 instead of U-Boot software protection.
2190 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2192 Enable TFTP transfers directly to flash memory;
2193 without this option such a download has to be
2194 performed in two steps: (1) download to RAM, and (2)
2195 copy from RAM to flash.
2197 The two-step approach is usually more reliable, since
2198 you can check if the download worked before you erase
2199 the flash, but in some situations (when system RAM is
2200 too limited to allow for a temporary copy of the
2201 downloaded image) this option may be very useful.
2203 - CONFIG_SYS_FLASH_CFI:
2204 Define if the flash driver uses extra elements in the
2205 common flash structure for storing flash geometry.
2207 - CONFIG_FLASH_CFI_DRIVER
2208 This option also enables the building of the cfi_flash driver
2209 in the drivers directory
2211 - CONFIG_FLASH_CFI_MTD
2212 This option enables the building of the cfi_mtd driver
2213 in the drivers directory. The driver exports CFI flash
2216 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2217 Use buffered writes to flash.
2219 - CONFIG_FLASH_SPANSION_S29WS_N
2220 s29ws-n MirrorBit flash has non-standard addresses for buffered
2223 - CONFIG_SYS_FLASH_QUIET_TEST
2224 If this option is defined, the common CFI flash doesn't
2225 print it's warning upon not recognized FLASH banks. This
2226 is useful, if some of the configured banks are only
2227 optionally available.
2229 - CONFIG_FLASH_SHOW_PROGRESS
2230 If defined (must be an integer), print out countdown
2231 digits and dots. Recommended value: 45 (9..1) for 80
2232 column displays, 15 (3..1) for 40 column displays.
2234 - CONFIG_SYS_RX_ETH_BUFFER:
2235 Defines the number of Ethernet receive buffers. On some
2236 Ethernet controllers it is recommended to set this value
2237 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2238 buffers can be full shortly after enabling the interface
2239 on high Ethernet traffic.
2240 Defaults to 4 if not defined.
2242 The following definitions that deal with the placement and management
2243 of environment data (variable area); in general, we support the
2244 following configurations:
2246 - CONFIG_ENV_IS_IN_FLASH:
2248 Define this if the environment is in flash memory.
2250 a) The environment occupies one whole flash sector, which is
2251 "embedded" in the text segment with the U-Boot code. This
2252 happens usually with "bottom boot sector" or "top boot
2253 sector" type flash chips, which have several smaller
2254 sectors at the start or the end. For instance, such a
2255 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2256 such a case you would place the environment in one of the
2257 4 kB sectors - with U-Boot code before and after it. With
2258 "top boot sector" type flash chips, you would put the
2259 environment in one of the last sectors, leaving a gap
2260 between U-Boot and the environment.
2262 - CONFIG_ENV_OFFSET:
2264 Offset of environment data (variable area) to the
2265 beginning of flash memory; for instance, with bottom boot
2266 type flash chips the second sector can be used: the offset
2267 for this sector is given here.
2269 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2273 This is just another way to specify the start address of
2274 the flash sector containing the environment (instead of
2277 - CONFIG_ENV_SECT_SIZE:
2279 Size of the sector containing the environment.
2282 b) Sometimes flash chips have few, equal sized, BIG sectors.
2283 In such a case you don't want to spend a whole sector for
2288 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2289 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2290 of this flash sector for the environment. This saves
2291 memory for the RAM copy of the environment.
2293 It may also save flash memory if you decide to use this
2294 when your environment is "embedded" within U-Boot code,
2295 since then the remainder of the flash sector could be used
2296 for U-Boot code. It should be pointed out that this is
2297 STRONGLY DISCOURAGED from a robustness point of view:
2298 updating the environment in flash makes it always
2299 necessary to erase the WHOLE sector. If something goes
2300 wrong before the contents has been restored from a copy in
2301 RAM, your target system will be dead.
2303 - CONFIG_ENV_ADDR_REDUND
2304 CONFIG_ENV_SIZE_REDUND
2306 These settings describe a second storage area used to hold
2307 a redundant copy of the environment data, so that there is
2308 a valid backup copy in case there is a power failure during
2309 a "saveenv" operation.
2311 BE CAREFUL! Any changes to the flash layout, and some changes to the
2312 source code will make it necessary to adapt <board>/u-boot.lds*
2316 - CONFIG_ENV_IS_IN_NVRAM:
2318 Define this if you have some non-volatile memory device
2319 (NVRAM, battery buffered SRAM) which you want to use for the
2325 These two #defines are used to determine the memory area you
2326 want to use for environment. It is assumed that this memory
2327 can just be read and written to, without any special
2330 BE CAREFUL! The first access to the environment happens quite early
2331 in U-Boot initalization (when we try to get the setting of for the
2332 console baudrate). You *MUST* have mapped your NVRAM area then, or
2335 Please note that even with NVRAM we still use a copy of the
2336 environment in RAM: we could work on NVRAM directly, but we want to
2337 keep settings there always unmodified except somebody uses "saveenv"
2338 to save the current settings.
2341 - CONFIG_ENV_IS_IN_EEPROM:
2343 Use this if you have an EEPROM or similar serial access
2344 device and a driver for it.
2346 - CONFIG_ENV_OFFSET:
2349 These two #defines specify the offset and size of the
2350 environment area within the total memory of your EEPROM.
2352 - CONFIG_SYS_I2C_EEPROM_ADDR:
2353 If defined, specified the chip address of the EEPROM device.
2354 The default address is zero.
2356 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2357 If defined, the number of bits used to address bytes in a
2358 single page in the EEPROM device. A 64 byte page, for example
2359 would require six bits.
2361 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2362 If defined, the number of milliseconds to delay between
2363 page writes. The default is zero milliseconds.
2365 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2366 The length in bytes of the EEPROM memory array address. Note
2367 that this is NOT the chip address length!
2369 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2370 EEPROM chips that implement "address overflow" are ones
2371 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2372 address and the extra bits end up in the "chip address" bit
2373 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2376 Note that we consider the length of the address field to
2377 still be one byte because the extra address bits are hidden
2378 in the chip address.
2380 - CONFIG_SYS_EEPROM_SIZE:
2381 The size in bytes of the EEPROM device.
2384 - CONFIG_ENV_IS_IN_DATAFLASH:
2386 Define this if you have a DataFlash memory device which you
2387 want to use for the environment.
2389 - CONFIG_ENV_OFFSET:
2393 These three #defines specify the offset and size of the
2394 environment area within the total memory of your DataFlash placed
2395 at the specified address.
2397 - CONFIG_ENV_IS_IN_NAND:
2399 Define this if you have a NAND device which you want to use
2400 for the environment.
2402 - CONFIG_ENV_OFFSET:
2405 These two #defines specify the offset and size of the environment
2406 area within the first NAND device.
2408 - CONFIG_ENV_OFFSET_REDUND
2410 This setting describes a second storage area of CONFIG_ENV_SIZE
2411 size used to hold a redundant copy of the environment data,
2412 so that there is a valid backup copy in case there is a
2413 power failure during a "saveenv" operation.
2415 Note: CONFIG_ENV_OFFSET and CONFIG_ENV_OFFSET_REDUND must be aligned
2416 to a block boundary, and CONFIG_ENV_SIZE must be a multiple of
2417 the NAND devices block size.
2419 - CONFIG_SYS_SPI_INIT_OFFSET
2421 Defines offset to the initial SPI buffer area in DPRAM. The
2422 area is used at an early stage (ROM part) if the environment
2423 is configured to reside in the SPI EEPROM: We need a 520 byte
2424 scratch DPRAM area. It is used between the two initialization
2425 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2426 to be a good choice since it makes it far enough from the
2427 start of the data area as well as from the stack pointer.
2429 Please note that the environment is read-only until the monitor
2430 has been relocated to RAM and a RAM copy of the environment has been
2431 created; also, when using EEPROM you will have to use getenv_r()
2432 until then to read environment variables.
2434 The environment is protected by a CRC32 checksum. Before the monitor
2435 is relocated into RAM, as a result of a bad CRC you will be working
2436 with the compiled-in default environment - *silently*!!! [This is
2437 necessary, because the first environment variable we need is the
2438 "baudrate" setting for the console - if we have a bad CRC, we don't
2439 have any device yet where we could complain.]
2441 Note: once the monitor has been relocated, then it will complain if
2442 the default environment is used; a new CRC is computed as soon as you
2443 use the "saveenv" command to store a valid environment.
2445 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2446 Echo the inverted Ethernet link state to the fault LED.
2448 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2449 also needs to be defined.
2451 - CONFIG_SYS_FAULT_MII_ADDR:
2452 MII address of the PHY to check for the Ethernet link state.
2454 - CONFIG_SYS_64BIT_VSPRINTF:
2455 Makes vsprintf (and all *printf functions) support printing
2456 of 64bit values by using the L quantifier
2458 - CONFIG_SYS_64BIT_STRTOUL:
2459 Adds simple_strtoull that returns a 64bit value
2461 - CONFIG_NS16550_MIN_FUNCTIONS:
2462 Define this if you desire to only have use of the NS16550_init
2463 and NS16550_putc functions for the serial driver located at
2464 drivers/serial/ns16550.c. This option is useful for saving
2465 space for already greatly restricted images, including but not
2466 limited to NAND_SPL configurations.
2468 Low Level (hardware related) configuration options:
2469 ---------------------------------------------------
2471 - CONFIG_SYS_CACHELINE_SIZE:
2472 Cache Line Size of the CPU.
2474 - CONFIG_SYS_DEFAULT_IMMR:
2475 Default address of the IMMR after system reset.
2477 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2478 and RPXsuper) to be able to adjust the position of
2479 the IMMR register after a reset.
2481 - Floppy Disk Support:
2482 CONFIG_SYS_FDC_DRIVE_NUMBER
2484 the default drive number (default value 0)
2486 CONFIG_SYS_ISA_IO_STRIDE
2488 defines the spacing between FDC chipset registers
2491 CONFIG_SYS_ISA_IO_OFFSET
2493 defines the offset of register from address. It
2494 depends on which part of the data bus is connected to
2495 the FDC chipset. (default value 0)
2497 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
2498 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
2501 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
2502 fdc_hw_init() is called at the beginning of the FDC
2503 setup. fdc_hw_init() must be provided by the board
2504 source code. It is used to make hardware dependant
2507 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
2508 DO NOT CHANGE unless you know exactly what you're
2509 doing! (11-4) [MPC8xx/82xx systems only]
2511 - CONFIG_SYS_INIT_RAM_ADDR:
2513 Start address of memory area that can be used for
2514 initial data and stack; please note that this must be
2515 writable memory that is working WITHOUT special
2516 initialization, i. e. you CANNOT use normal RAM which
2517 will become available only after programming the
2518 memory controller and running certain initialization
2521 U-Boot uses the following memory types:
2522 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2523 - MPC824X: data cache
2524 - PPC4xx: data cache
2526 - CONFIG_SYS_GBL_DATA_OFFSET:
2528 Offset of the initial data structure in the memory
2529 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2530 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
2531 data is located at the end of the available space
2532 (sometimes written as (CONFIG_SYS_INIT_RAM_END -
2533 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
2534 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2535 CONFIG_SYS_GBL_DATA_OFFSET) downward.
2538 On the MPC824X (or other systems that use the data
2539 cache for initial memory) the address chosen for
2540 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
2541 point to an otherwise UNUSED address space between
2542 the top of RAM and the start of the PCI space.
2544 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
2546 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
2548 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
2550 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
2552 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2554 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
2556 - CONFIG_SYS_OR_TIMING_SDRAM:
2559 - CONFIG_SYS_MAMR_PTA:
2560 periodic timer for refresh
2562 - CONFIG_SYS_DER: Debug Event Register (37-47)
2564 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2565 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2566 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2567 CONFIG_SYS_BR1_PRELIM:
2568 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2570 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2571 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2572 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
2573 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2575 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
2576 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
2577 Machine Mode Register and Memory Periodic Timer
2578 Prescaler definitions (SDRAM timing)
2580 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
2581 enable I2C microcode relocation patch (MPC8xx);
2582 define relocation offset in DPRAM [DSP2]
2584 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
2585 enable SMC microcode relocation patch (MPC8xx);
2586 define relocation offset in DPRAM [SMC1]
2588 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
2589 enable SPI microcode relocation patch (MPC8xx);
2590 define relocation offset in DPRAM [SCC4]
2592 - CONFIG_SYS_USE_OSCCLK:
2593 Use OSCM clock mode on MBX8xx board. Be careful,
2594 wrong setting might damage your board. Read
2595 doc/README.MBX before setting this variable!
2597 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2598 Offset of the bootmode word in DPRAM used by post
2599 (Power On Self Tests). This definition overrides
2600 #define'd default value in commproc.h resp.
2603 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
2604 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
2605 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
2606 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
2607 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2608 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
2609 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
2610 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
2611 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2613 - CONFIG_PCI_DISABLE_PCIE:
2614 Disable PCI-Express on systems where it is supported but not
2618 Get DDR timing information from an I2C EEPROM. Common
2619 with pluggable memory modules such as SODIMMs
2622 I2C address of the SPD EEPROM
2624 - CONFIG_SYS_SPD_BUS_NUM
2625 If SPD EEPROM is on an I2C bus other than the first
2626 one, specify here. Note that the value must resolve
2627 to something your driver can deal with.
2629 - CONFIG_SYS_83XX_DDR_USES_CS0
2630 Only for 83xx systems. If specified, then DDR should
2631 be configured using CS0 and CS1 instead of CS2 and CS3.
2633 - CONFIG_ETHER_ON_FEC[12]
2634 Define to enable FEC[12] on a 8xx series processor.
2636 - CONFIG_FEC[12]_PHY
2637 Define to the hardcoded PHY address which corresponds
2638 to the given FEC; i. e.
2639 #define CONFIG_FEC1_PHY 4
2640 means that the PHY with address 4 is connected to FEC1
2642 When set to -1, means to probe for first available.
2644 - CONFIG_FEC[12]_PHY_NORXERR
2645 The PHY does not have a RXERR line (RMII only).
2646 (so program the FEC to ignore it).
2649 Enable RMII mode for all FECs.
2650 Note that this is a global option, we can't
2651 have one FEC in standard MII mode and another in RMII mode.
2653 - CONFIG_CRC32_VERIFY
2654 Add a verify option to the crc32 command.
2657 => crc32 -v <address> <count> <crc32>
2659 Where address/count indicate a memory area
2660 and crc32 is the correct crc32 which the
2664 Add the "loopw" memory command. This only takes effect if
2665 the memory commands are activated globally (CONFIG_CMD_MEM).
2668 Add the "mdc" and "mwc" memory commands. These are cyclic
2673 This command will print 4 bytes (10,11,12,13) each 500 ms.
2675 => mwc.l 100 12345678 10
2676 This command will write 12345678 to address 100 all 10 ms.
2678 This only takes effect if the memory commands are activated
2679 globally (CONFIG_CMD_MEM).
2681 - CONFIG_SKIP_LOWLEVEL_INIT
2682 - CONFIG_SKIP_RELOCATE_UBOOT
2684 [ARM only] If these variables are defined, then
2685 certain low level initializations (like setting up
2686 the memory controller) are omitted and/or U-Boot does
2687 not relocate itself into RAM.
2688 Normally these variables MUST NOT be defined. The
2689 only exception is when U-Boot is loaded (to RAM) by
2690 some other boot loader or by a debugger which
2691 performs these initializations itself.
2694 Building the Software:
2695 ======================
2697 Building U-Boot has been tested in several native build environments
2698 and in many different cross environments. Of course we cannot support
2699 all possibly existing versions of cross development tools in all
2700 (potentially obsolete) versions. In case of tool chain problems we
2701 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2702 which is extensively used to build and test U-Boot.
2704 If you are not using a native environment, it is assumed that you
2705 have GNU cross compiling tools available in your path. In this case,
2706 you must set the environment variable CROSS_COMPILE in your shell.
2707 Note that no changes to the Makefile or any other source files are
2708 necessary. For example using the ELDK on a 4xx CPU, please enter:
2710 $ CROSS_COMPILE=ppc_4xx-
2711 $ export CROSS_COMPILE
2713 U-Boot is intended to be simple to build. After installing the
2714 sources you must configure U-Boot for one specific board type. This
2719 where "NAME_config" is the name of one of the existing configu-
2720 rations; see the main Makefile for supported names.
2722 Note: for some board special configuration names may exist; check if
2723 additional information is available from the board vendor; for
2724 instance, the TQM823L systems are available without (standard)
2725 or with LCD support. You can select such additional "features"
2726 when choosing the configuration, i. e.
2729 - will configure for a plain TQM823L, i. e. no LCD support
2731 make TQM823L_LCD_config
2732 - will configure for a TQM823L with U-Boot console on LCD
2737 Finally, type "make all", and you should get some working U-Boot
2738 images ready for download to / installation on your system:
2740 - "u-boot.bin" is a raw binary image
2741 - "u-boot" is an image in ELF binary format
2742 - "u-boot.srec" is in Motorola S-Record format
2744 By default the build is performed locally and the objects are saved
2745 in the source directory. One of the two methods can be used to change
2746 this behavior and build U-Boot to some external directory:
2748 1. Add O= to the make command line invocations:
2750 make O=/tmp/build distclean
2751 make O=/tmp/build NAME_config
2752 make O=/tmp/build all
2754 2. Set environment variable BUILD_DIR to point to the desired location:
2756 export BUILD_DIR=/tmp/build
2761 Note that the command line "O=" setting overrides the BUILD_DIR environment
2765 Please be aware that the Makefiles assume you are using GNU make, so
2766 for instance on NetBSD you might need to use "gmake" instead of
2770 If the system board that you have is not listed, then you will need
2771 to port U-Boot to your hardware platform. To do this, follow these
2774 1. Add a new configuration option for your board to the toplevel
2775 "Makefile" and to the "MAKEALL" script, using the existing
2776 entries as examples. Note that here and at many other places
2777 boards and other names are listed in alphabetical sort order. Please
2779 2. Create a new directory to hold your board specific code. Add any
2780 files you need. In your board directory, you will need at least
2781 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2782 3. Create a new configuration file "include/configs/<board>.h" for
2784 3. If you're porting U-Boot to a new CPU, then also create a new
2785 directory to hold your CPU specific code. Add any files you need.
2786 4. Run "make <board>_config" with your new name.
2787 5. Type "make", and you should get a working "u-boot.srec" file
2788 to be installed on your target system.
2789 6. Debug and solve any problems that might arise.
2790 [Of course, this last step is much harder than it sounds.]
2793 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2794 ==============================================================
2796 If you have modified U-Boot sources (for instance added a new board
2797 or support for new devices, a new CPU, etc.) you are expected to
2798 provide feedback to the other developers. The feedback normally takes
2799 the form of a "patch", i. e. a context diff against a certain (latest
2800 official or latest in the git repository) version of U-Boot sources.
2802 But before you submit such a patch, please verify that your modifi-
2803 cation did not break existing code. At least make sure that *ALL* of
2804 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2805 just run the "MAKEALL" script, which will configure and build U-Boot
2806 for ALL supported system. Be warned, this will take a while. You can
2807 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2808 environment variable to the script, i. e. to use the ELDK cross tools
2811 CROSS_COMPILE=ppc_8xx- MAKEALL
2813 or to build on a native PowerPC system you can type
2815 CROSS_COMPILE=' ' MAKEALL
2817 When using the MAKEALL script, the default behaviour is to build
2818 U-Boot in the source directory. This location can be changed by
2819 setting the BUILD_DIR environment variable. Also, for each target
2820 built, the MAKEALL script saves two log files (<target>.ERR and
2821 <target>.MAKEALL) in the <source dir>/LOG directory. This default
2822 location can be changed by setting the MAKEALL_LOGDIR environment
2823 variable. For example:
2825 export BUILD_DIR=/tmp/build
2826 export MAKEALL_LOGDIR=/tmp/log
2827 CROSS_COMPILE=ppc_8xx- MAKEALL
2829 With the above settings build objects are saved in the /tmp/build,
2830 log files are saved in the /tmp/log and the source tree remains clean
2831 during the whole build process.
2834 See also "U-Boot Porting Guide" below.
2837 Monitor Commands - Overview:
2838 ============================
2840 go - start application at address 'addr'
2841 run - run commands in an environment variable
2842 bootm - boot application image from memory
2843 bootp - boot image via network using BootP/TFTP protocol
2844 tftpboot- boot image via network using TFTP protocol
2845 and env variables "ipaddr" and "serverip"
2846 (and eventually "gatewayip")
2847 rarpboot- boot image via network using RARP/TFTP protocol
2848 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2849 loads - load S-Record file over serial line
2850 loadb - load binary file over serial line (kermit mode)
2852 mm - memory modify (auto-incrementing)
2853 nm - memory modify (constant address)
2854 mw - memory write (fill)
2856 cmp - memory compare
2857 crc32 - checksum calculation
2858 imd - i2c memory display
2859 imm - i2c memory modify (auto-incrementing)
2860 inm - i2c memory modify (constant address)
2861 imw - i2c memory write (fill)
2862 icrc32 - i2c checksum calculation
2863 iprobe - probe to discover valid I2C chip addresses
2864 iloop - infinite loop on address range
2865 isdram - print SDRAM configuration information
2866 sspi - SPI utility commands
2867 base - print or set address offset
2868 printenv- print environment variables
2869 setenv - set environment variables
2870 saveenv - save environment variables to persistent storage
2871 protect - enable or disable FLASH write protection
2872 erase - erase FLASH memory
2873 flinfo - print FLASH memory information
2874 bdinfo - print Board Info structure
2875 iminfo - print header information for application image
2876 coninfo - print console devices and informations
2877 ide - IDE sub-system
2878 loop - infinite loop on address range
2879 loopw - infinite write loop on address range
2880 mtest - simple RAM test
2881 icache - enable or disable instruction cache
2882 dcache - enable or disable data cache
2883 reset - Perform RESET of the CPU
2884 echo - echo args to console
2885 version - print monitor version
2886 help - print online help
2887 ? - alias for 'help'
2890 Monitor Commands - Detailed Description:
2891 ========================================
2895 For now: just type "help <command>".
2898 Environment Variables:
2899 ======================
2901 U-Boot supports user configuration using Environment Variables which
2902 can be made persistent by saving to Flash memory.
2904 Environment Variables are set using "setenv", printed using
2905 "printenv", and saved to Flash using "saveenv". Using "setenv"
2906 without a value can be used to delete a variable from the
2907 environment. As long as you don't save the environment you are
2908 working with an in-memory copy. In case the Flash area containing the
2909 environment is erased by accident, a default environment is provided.
2911 Some configuration options can be set using Environment Variables:
2913 baudrate - see CONFIG_BAUDRATE
2915 bootdelay - see CONFIG_BOOTDELAY
2917 bootcmd - see CONFIG_BOOTCOMMAND
2919 bootargs - Boot arguments when booting an RTOS image
2921 bootfile - Name of the image to load with TFTP
2923 bootm_low - Memory range available for image processing in the bootm
2924 command can be restricted. This variable is given as
2925 a hexadecimal number and defines lowest address allowed
2926 for use by the bootm command. See also "bootm_size"
2927 environment variable. Address defined by "bootm_low" is
2928 also the base of the initial memory mapping for the Linux
2929 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ.
2931 bootm_size - Memory range available for image processing in the bootm
2932 command can be restricted. This variable is given as
2933 a hexadecimal number and defines the size of the region
2934 allowed for use by the bootm command. See also "bootm_low"
2935 environment variable.
2937 updatefile - Location of the software update file on a TFTP server, used
2938 by the automatic software update feature. Please refer to
2939 documentation in doc/README.update for more details.
2941 autoload - if set to "no" (any string beginning with 'n'),
2942 "bootp" will just load perform a lookup of the
2943 configuration from the BOOTP server, but not try to
2944 load any image using TFTP
2946 autoscript - if set to "yes" commands like "loadb", "loady",
2947 "bootp", "tftpb", "rarpboot" and "nfs" will attempt
2948 to automatically run script images (by internally
2949 calling "autoscript").
2951 autoscript_uname - if script image is in a format (FIT) this
2952 variable is used to get script subimage unit name.
2954 autostart - if set to "yes", an image loaded using the "bootp",
2955 "rarpboot", "tftpboot" or "diskboot" commands will
2956 be automatically started (by internally calling
2959 If set to "no", a standalone image passed to the
2960 "bootm" command will be copied to the load address
2961 (and eventually uncompressed), but NOT be started.
2962 This can be used to load and uncompress arbitrary
2965 i2cfast - (PPC405GP|PPC405EP only)
2966 if set to 'y' configures Linux I2C driver for fast
2967 mode (400kHZ). This environment variable is used in
2968 initialization code. So, for changes to be effective
2969 it must be saved and board must be reset.
2971 initrd_high - restrict positioning of initrd images:
2972 If this variable is not set, initrd images will be
2973 copied to the highest possible address in RAM; this
2974 is usually what you want since it allows for
2975 maximum initrd size. If for some reason you want to
2976 make sure that the initrd image is loaded below the
2977 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
2978 variable to a value of "no" or "off" or "0".
2979 Alternatively, you can set it to a maximum upper
2980 address to use (U-Boot will still check that it
2981 does not overwrite the U-Boot stack and data).
2983 For instance, when you have a system with 16 MB
2984 RAM, and want to reserve 4 MB from use by Linux,
2985 you can do this by adding "mem=12M" to the value of
2986 the "bootargs" variable. However, now you must make
2987 sure that the initrd image is placed in the first
2988 12 MB as well - this can be done with
2990 setenv initrd_high 00c00000
2992 If you set initrd_high to 0xFFFFFFFF, this is an
2993 indication to U-Boot that all addresses are legal
2994 for the Linux kernel, including addresses in flash
2995 memory. In this case U-Boot will NOT COPY the
2996 ramdisk at all. This may be useful to reduce the
2997 boot time on your system, but requires that this
2998 feature is supported by your Linux kernel.
3000 ipaddr - IP address; needed for tftpboot command
3002 loadaddr - Default load address for commands like "bootp",
3003 "rarpboot", "tftpboot", "loadb" or "diskboot"
3005 loads_echo - see CONFIG_LOADS_ECHO
3007 serverip - TFTP server IP address; needed for tftpboot command
3009 bootretry - see CONFIG_BOOT_RETRY_TIME
3011 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3013 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3015 ethprime - When CONFIG_NET_MULTI is enabled controls which
3016 interface is used first.
3018 ethact - When CONFIG_NET_MULTI is enabled controls which
3019 interface is currently active. For example you
3020 can do the following
3022 => setenv ethact FEC ETHERNET
3023 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
3024 => setenv ethact SCC ETHERNET
3025 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
3027 ethrotate - When set to "no" U-Boot does not go through all
3028 available network interfaces.
3029 It just stays at the currently selected interface.
3031 netretry - When set to "no" each network operation will
3032 either succeed or fail without retrying.
3033 When set to "once" the network operation will
3034 fail when all the available network interfaces
3035 are tried once without success.
3036 Useful on scripts which control the retry operation
3039 npe_ucode - set load address for the NPE microcode
3041 tftpsrcport - If this is set, the value is used for TFTP's
3044 tftpdstport - If this is set, the value is used for TFTP's UDP
3045 destination port instead of the Well Know Port 69.
3047 vlan - When set to a value < 4095 the traffic over
3048 Ethernet is encapsulated/received over 802.1q
3051 The following environment variables may be used and automatically
3052 updated by the network boot commands ("bootp" and "rarpboot"),
3053 depending the information provided by your boot server:
3055 bootfile - see above
3056 dnsip - IP address of your Domain Name Server
3057 dnsip2 - IP address of your secondary Domain Name Server
3058 gatewayip - IP address of the Gateway (Router) to use
3059 hostname - Target hostname
3061 netmask - Subnet Mask
3062 rootpath - Pathname of the root filesystem on the NFS server
3063 serverip - see above
3066 There are two special Environment Variables:
3068 serial# - contains hardware identification information such
3069 as type string and/or serial number
3070 ethaddr - Ethernet address
3072 These variables can be set only once (usually during manufacturing of
3073 the board). U-Boot refuses to delete or overwrite these variables
3074 once they have been set once.
3077 Further special Environment Variables:
3079 ver - Contains the U-Boot version string as printed
3080 with the "version" command. This variable is
3081 readonly (see CONFIG_VERSION_VARIABLE).
3084 Please note that changes to some configuration parameters may take
3085 only effect after the next boot (yes, that's just like Windoze :-).
3088 Command Line Parsing:
3089 =====================
3091 There are two different command line parsers available with U-Boot:
3092 the old "simple" one, and the much more powerful "hush" shell:
3094 Old, simple command line parser:
3095 --------------------------------
3097 - supports environment variables (through setenv / saveenv commands)
3098 - several commands on one line, separated by ';'
3099 - variable substitution using "... ${name} ..." syntax
3100 - special characters ('$', ';') can be escaped by prefixing with '\',
3102 setenv bootcmd bootm \${address}
3103 - You can also escape text by enclosing in single apostrophes, for example:
3104 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3109 - similar to Bourne shell, with control structures like
3110 if...then...else...fi, for...do...done; while...do...done,
3111 until...do...done, ...
3112 - supports environment ("global") variables (through setenv / saveenv
3113 commands) and local shell variables (through standard shell syntax
3114 "name=value"); only environment variables can be used with "run"
3120 (1) If a command line (or an environment variable executed by a "run"
3121 command) contains several commands separated by semicolon, and
3122 one of these commands fails, then the remaining commands will be
3125 (2) If you execute several variables with one call to run (i. e.
3126 calling run with a list of variables as arguments), any failing
3127 command will cause "run" to terminate, i. e. the remaining
3128 variables are not executed.
3130 Note for Redundant Ethernet Interfaces:
3131 =======================================
3133 Some boards come with redundant Ethernet interfaces; U-Boot supports
3134 such configurations and is capable of automatic selection of a
3135 "working" interface when needed. MAC assignment works as follows:
3137 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3138 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3139 "eth1addr" (=>eth1), "eth2addr", ...
3141 If the network interface stores some valid MAC address (for instance
3142 in SROM), this is used as default address if there is NO correspon-
3143 ding setting in the environment; if the corresponding environment
3144 variable is set, this overrides the settings in the card; that means:
3146 o If the SROM has a valid MAC address, and there is no address in the
3147 environment, the SROM's address is used.
3149 o If there is no valid address in the SROM, and a definition in the
3150 environment exists, then the value from the environment variable is
3153 o If both the SROM and the environment contain a MAC address, and
3154 both addresses are the same, this MAC address is used.
3156 o If both the SROM and the environment contain a MAC address, and the
3157 addresses differ, the value from the environment is used and a
3160 o If neither SROM nor the environment contain a MAC address, an error
3167 U-Boot is capable of booting (and performing other auxiliary operations on)
3168 images in two formats:
3170 New uImage format (FIT)
3171 -----------------------
3173 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3174 to Flattened Device Tree). It allows the use of images with multiple
3175 components (several kernels, ramdisks, etc.), with contents protected by
3176 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3182 Old image format is based on binary files which can be basically anything,
3183 preceded by a special header; see the definitions in include/image.h for
3184 details; basically, the header defines the following image properties:
3186 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3187 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3188 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3189 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3191 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3192 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3193 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
3194 * Compression Type (uncompressed, gzip, bzip2)
3200 The header is marked by a special Magic Number, and both the header
3201 and the data portions of the image are secured against corruption by
3208 Although U-Boot should support any OS or standalone application
3209 easily, the main focus has always been on Linux during the design of
3212 U-Boot includes many features that so far have been part of some
3213 special "boot loader" code within the Linux kernel. Also, any
3214 "initrd" images to be used are no longer part of one big Linux image;
3215 instead, kernel and "initrd" are separate images. This implementation
3216 serves several purposes:
3218 - the same features can be used for other OS or standalone
3219 applications (for instance: using compressed images to reduce the
3220 Flash memory footprint)
3222 - it becomes much easier to port new Linux kernel versions because
3223 lots of low-level, hardware dependent stuff are done by U-Boot
3225 - the same Linux kernel image can now be used with different "initrd"
3226 images; of course this also means that different kernel images can
3227 be run with the same "initrd". This makes testing easier (you don't
3228 have to build a new "zImage.initrd" Linux image when you just
3229 change a file in your "initrd"). Also, a field-upgrade of the
3230 software is easier now.
3236 Porting Linux to U-Boot based systems:
3237 ---------------------------------------
3239 U-Boot cannot save you from doing all the necessary modifications to
3240 configure the Linux device drivers for use with your target hardware
3241 (no, we don't intend to provide a full virtual machine interface to
3244 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
3246 Just make sure your machine specific header file (for instance
3247 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3248 Information structure as we define in include/asm-<arch>/u-boot.h,
3249 and make sure that your definition of IMAP_ADDR uses the same value
3250 as your U-Boot configuration in CONFIG_SYS_IMMR.
3253 Configuring the Linux kernel:
3254 -----------------------------
3256 No specific requirements for U-Boot. Make sure you have some root
3257 device (initial ramdisk, NFS) for your target system.
3260 Building a Linux Image:
3261 -----------------------
3263 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3264 not used. If you use recent kernel source, a new build target
3265 "uImage" will exist which automatically builds an image usable by
3266 U-Boot. Most older kernels also have support for a "pImage" target,
3267 which was introduced for our predecessor project PPCBoot and uses a
3268 100% compatible format.
3277 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3278 encapsulate a compressed Linux kernel image with header information,
3279 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3281 * build a standard "vmlinux" kernel image (in ELF binary format):
3283 * convert the kernel into a raw binary image:
3285 ${CROSS_COMPILE}-objcopy -O binary \
3286 -R .note -R .comment \
3287 -S vmlinux linux.bin
3289 * compress the binary image:
3293 * package compressed binary image for U-Boot:
3295 mkimage -A ppc -O linux -T kernel -C gzip \
3296 -a 0 -e 0 -n "Linux Kernel Image" \
3297 -d linux.bin.gz uImage
3300 The "mkimage" tool can also be used to create ramdisk images for use
3301 with U-Boot, either separated from the Linux kernel image, or
3302 combined into one file. "mkimage" encapsulates the images with a 64
3303 byte header containing information about target architecture,
3304 operating system, image type, compression method, entry points, time
3305 stamp, CRC32 checksums, etc.
3307 "mkimage" can be called in two ways: to verify existing images and
3308 print the header information, or to build new images.
3310 In the first form (with "-l" option) mkimage lists the information
3311 contained in the header of an existing U-Boot image; this includes
3312 checksum verification:
3314 tools/mkimage -l image
3315 -l ==> list image header information
3317 The second form (with "-d" option) is used to build a U-Boot image
3318 from a "data file" which is used as image payload:
3320 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3321 -n name -d data_file image
3322 -A ==> set architecture to 'arch'
3323 -O ==> set operating system to 'os'
3324 -T ==> set image type to 'type'
3325 -C ==> set compression type 'comp'
3326 -a ==> set load address to 'addr' (hex)
3327 -e ==> set entry point to 'ep' (hex)
3328 -n ==> set image name to 'name'
3329 -d ==> use image data from 'datafile'
3331 Right now, all Linux kernels for PowerPC systems use the same load
3332 address (0x00000000), but the entry point address depends on the
3335 - 2.2.x kernels have the entry point at 0x0000000C,
3336 - 2.3.x and later kernels have the entry point at 0x00000000.
3338 So a typical call to build a U-Boot image would read:
3340 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3341 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3342 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
3343 > examples/uImage.TQM850L
3344 Image Name: 2.4.4 kernel for TQM850L
3345 Created: Wed Jul 19 02:34:59 2000
3346 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3347 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3348 Load Address: 0x00000000
3349 Entry Point: 0x00000000
3351 To verify the contents of the image (or check for corruption):
3353 -> tools/mkimage -l examples/uImage.TQM850L
3354 Image Name: 2.4.4 kernel for TQM850L
3355 Created: Wed Jul 19 02:34:59 2000
3356 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3357 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3358 Load Address: 0x00000000
3359 Entry Point: 0x00000000
3361 NOTE: for embedded systems where boot time is critical you can trade
3362 speed for memory and install an UNCOMPRESSED image instead: this
3363 needs more space in Flash, but boots much faster since it does not
3364 need to be uncompressed:
3366 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
3367 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3368 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3369 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
3370 > examples/uImage.TQM850L-uncompressed
3371 Image Name: 2.4.4 kernel for TQM850L
3372 Created: Wed Jul 19 02:34:59 2000
3373 Image Type: PowerPC Linux Kernel Image (uncompressed)
3374 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3375 Load Address: 0x00000000
3376 Entry Point: 0x00000000
3379 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3380 when your kernel is intended to use an initial ramdisk:
3382 -> tools/mkimage -n 'Simple Ramdisk Image' \
3383 > -A ppc -O linux -T ramdisk -C gzip \
3384 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3385 Image Name: Simple Ramdisk Image
3386 Created: Wed Jan 12 14:01:50 2000
3387 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3388 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3389 Load Address: 0x00000000
3390 Entry Point: 0x00000000
3393 Installing a Linux Image:
3394 -------------------------
3396 To downloading a U-Boot image over the serial (console) interface,
3397 you must convert the image to S-Record format:
3399 objcopy -I binary -O srec examples/image examples/image.srec
3401 The 'objcopy' does not understand the information in the U-Boot
3402 image header, so the resulting S-Record file will be relative to
3403 address 0x00000000. To load it to a given address, you need to
3404 specify the target address as 'offset' parameter with the 'loads'
3407 Example: install the image to address 0x40100000 (which on the
3408 TQM8xxL is in the first Flash bank):
3410 => erase 40100000 401FFFFF
3416 ## Ready for S-Record download ...
3417 ~>examples/image.srec
3418 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3420 15989 15990 15991 15992
3421 [file transfer complete]
3423 ## Start Addr = 0x00000000
3426 You can check the success of the download using the 'iminfo' command;
3427 this includes a checksum verification so you can be sure no data
3428 corruption happened:
3432 ## Checking Image at 40100000 ...
3433 Image Name: 2.2.13 for initrd on TQM850L
3434 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3435 Data Size: 335725 Bytes = 327 kB = 0 MB
3436 Load Address: 00000000
3437 Entry Point: 0000000c
3438 Verifying Checksum ... OK
3444 The "bootm" command is used to boot an application that is stored in
3445 memory (RAM or Flash). In case of a Linux kernel image, the contents
3446 of the "bootargs" environment variable is passed to the kernel as
3447 parameters. You can check and modify this variable using the
3448 "printenv" and "setenv" commands:
3451 => printenv bootargs
3452 bootargs=root=/dev/ram
3454 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3456 => printenv bootargs
3457 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3460 ## Booting Linux kernel at 40020000 ...
3461 Image Name: 2.2.13 for NFS on TQM850L
3462 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3463 Data Size: 381681 Bytes = 372 kB = 0 MB
3464 Load Address: 00000000
3465 Entry Point: 0000000c
3466 Verifying Checksum ... OK
3467 Uncompressing Kernel Image ... OK
3468 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
3469 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3470 time_init: decrementer frequency = 187500000/60
3471 Calibrating delay loop... 49.77 BogoMIPS
3472 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3475 If you want to boot a Linux kernel with initial RAM disk, you pass
3476 the memory addresses of both the kernel and the initrd image (PPBCOOT
3477 format!) to the "bootm" command:
3479 => imi 40100000 40200000
3481 ## Checking Image at 40100000 ...
3482 Image Name: 2.2.13 for initrd on TQM850L
3483 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3484 Data Size: 335725 Bytes = 327 kB = 0 MB
3485 Load Address: 00000000
3486 Entry Point: 0000000c
3487 Verifying Checksum ... OK
3489 ## Checking Image at 40200000 ...
3490 Image Name: Simple Ramdisk Image
3491 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3492 Data Size: 566530 Bytes = 553 kB = 0 MB
3493 Load Address: 00000000
3494 Entry Point: 00000000
3495 Verifying Checksum ... OK
3497 => bootm 40100000 40200000
3498 ## Booting Linux kernel at 40100000 ...
3499 Image Name: 2.2.13 for initrd on TQM850L
3500 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3501 Data Size: 335725 Bytes = 327 kB = 0 MB
3502 Load Address: 00000000
3503 Entry Point: 0000000c
3504 Verifying Checksum ... OK
3505 Uncompressing Kernel Image ... OK
3506 ## Loading RAMDisk Image at 40200000 ...
3507 Image Name: Simple Ramdisk Image
3508 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3509 Data Size: 566530 Bytes = 553 kB = 0 MB
3510 Load Address: 00000000
3511 Entry Point: 00000000
3512 Verifying Checksum ... OK
3513 Loading Ramdisk ... OK
3514 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
3515 Boot arguments: root=/dev/ram
3516 time_init: decrementer frequency = 187500000/60
3517 Calibrating delay loop... 49.77 BogoMIPS
3519 RAMDISK: Compressed image found at block 0
3520 VFS: Mounted root (ext2 filesystem).
3524 Boot Linux and pass a flat device tree:
3527 First, U-Boot must be compiled with the appropriate defines. See the section
3528 titled "Linux Kernel Interface" above for a more in depth explanation. The
3529 following is an example of how to start a kernel and pass an updated
3535 oft=oftrees/mpc8540ads.dtb
3536 => tftp $oftaddr $oft
3537 Speed: 1000, full duplex
3539 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3540 Filename 'oftrees/mpc8540ads.dtb'.
3541 Load address: 0x300000
3544 Bytes transferred = 4106 (100a hex)
3545 => tftp $loadaddr $bootfile
3546 Speed: 1000, full duplex
3548 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3550 Load address: 0x200000
3551 Loading:############
3553 Bytes transferred = 1029407 (fb51f hex)
3558 => bootm $loadaddr - $oftaddr
3559 ## Booting image at 00200000 ...
3560 Image Name: Linux-2.6.17-dirty
3561 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3562 Data Size: 1029343 Bytes = 1005.2 kB
3563 Load Address: 00000000
3564 Entry Point: 00000000
3565 Verifying Checksum ... OK
3566 Uncompressing Kernel Image ... OK
3567 Booting using flat device tree at 0x300000
3568 Using MPC85xx ADS machine description
3569 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3573 More About U-Boot Image Types:
3574 ------------------------------
3576 U-Boot supports the following image types:
3578 "Standalone Programs" are directly runnable in the environment
3579 provided by U-Boot; it is expected that (if they behave
3580 well) you can continue to work in U-Boot after return from
3581 the Standalone Program.
3582 "OS Kernel Images" are usually images of some Embedded OS which
3583 will take over control completely. Usually these programs
3584 will install their own set of exception handlers, device
3585 drivers, set up the MMU, etc. - this means, that you cannot
3586 expect to re-enter U-Boot except by resetting the CPU.
3587 "RAMDisk Images" are more or less just data blocks, and their
3588 parameters (address, size) are passed to an OS kernel that is
3590 "Multi-File Images" contain several images, typically an OS
3591 (Linux) kernel image and one or more data images like
3592 RAMDisks. This construct is useful for instance when you want
3593 to boot over the network using BOOTP etc., where the boot
3594 server provides just a single image file, but you want to get
3595 for instance an OS kernel and a RAMDisk image.
3597 "Multi-File Images" start with a list of image sizes, each
3598 image size (in bytes) specified by an "uint32_t" in network
3599 byte order. This list is terminated by an "(uint32_t)0".
3600 Immediately after the terminating 0 follow the images, one by
3601 one, all aligned on "uint32_t" boundaries (size rounded up to
3602 a multiple of 4 bytes).
3604 "Firmware Images" are binary images containing firmware (like
3605 U-Boot or FPGA images) which usually will be programmed to
3608 "Script files" are command sequences that will be executed by
3609 U-Boot's command interpreter; this feature is especially
3610 useful when you configure U-Boot to use a real shell (hush)
3611 as command interpreter.
3617 One of the features of U-Boot is that you can dynamically load and
3618 run "standalone" applications, which can use some resources of
3619 U-Boot like console I/O functions or interrupt services.
3621 Two simple examples are included with the sources:
3626 'examples/hello_world.c' contains a small "Hello World" Demo
3627 application; it is automatically compiled when you build U-Boot.
3628 It's configured to run at address 0x00040004, so you can play with it
3632 ## Ready for S-Record download ...
3633 ~>examples/hello_world.srec
3634 1 2 3 4 5 6 7 8 9 10 11 ...
3635 [file transfer complete]
3637 ## Start Addr = 0x00040004
3639 => go 40004 Hello World! This is a test.
3640 ## Starting application at 0x00040004 ...
3651 Hit any key to exit ...
3653 ## Application terminated, rc = 0x0
3655 Another example, which demonstrates how to register a CPM interrupt
3656 handler with the U-Boot code, can be found in 'examples/timer.c'.
3657 Here, a CPM timer is set up to generate an interrupt every second.
3658 The interrupt service routine is trivial, just printing a '.'
3659 character, but this is just a demo program. The application can be
3660 controlled by the following keys:
3662 ? - print current values og the CPM Timer registers
3663 b - enable interrupts and start timer
3664 e - stop timer and disable interrupts
3665 q - quit application
3668 ## Ready for S-Record download ...
3669 ~>examples/timer.srec
3670 1 2 3 4 5 6 7 8 9 10 11 ...
3671 [file transfer complete]
3673 ## Start Addr = 0x00040004
3676 ## Starting application at 0x00040004 ...
3679 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3682 [q, b, e, ?] Set interval 1000000 us
3685 [q, b, e, ?] ........
3686 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3689 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3692 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3695 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3697 [q, b, e, ?] ...Stopping timer
3699 [q, b, e, ?] ## Application terminated, rc = 0x0
3705 Over time, many people have reported problems when trying to use the
3706 "minicom" terminal emulation program for serial download. I (wd)
3707 consider minicom to be broken, and recommend not to use it. Under
3708 Unix, I recommend to use C-Kermit for general purpose use (and
3709 especially for kermit binary protocol download ("loadb" command), and
3710 use "cu" for S-Record download ("loads" command).
3712 Nevertheless, if you absolutely want to use it try adding this
3713 configuration to your "File transfer protocols" section:
3715 Name Program Name U/D FullScr IO-Red. Multi
3716 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3717 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3723 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3724 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3726 Building requires a cross environment; it is known to work on
3727 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3728 need gmake since the Makefiles are not compatible with BSD make).
3729 Note that the cross-powerpc package does not install include files;
3730 attempting to build U-Boot will fail because <machine/ansi.h> is
3731 missing. This file has to be installed and patched manually:
3733 # cd /usr/pkg/cross/powerpc-netbsd/include
3735 # ln -s powerpc machine
3736 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3737 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3739 Native builds *don't* work due to incompatibilities between native
3740 and U-Boot include files.
3742 Booting assumes that (the first part of) the image booted is a
3743 stage-2 loader which in turn loads and then invokes the kernel
3744 proper. Loader sources will eventually appear in the NetBSD source
3745 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3746 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3749 Implementation Internals:
3750 =========================
3752 The following is not intended to be a complete description of every
3753 implementation detail. However, it should help to understand the
3754 inner workings of U-Boot and make it easier to port it to custom
3758 Initial Stack, Global Data:
3759 ---------------------------
3761 The implementation of U-Boot is complicated by the fact that U-Boot
3762 starts running out of ROM (flash memory), usually without access to
3763 system RAM (because the memory controller is not initialized yet).
3764 This means that we don't have writable Data or BSS segments, and BSS
3765 is not initialized as zero. To be able to get a C environment working
3766 at all, we have to allocate at least a minimal stack. Implementation
3767 options for this are defined and restricted by the CPU used: Some CPU
3768 models provide on-chip memory (like the IMMR area on MPC8xx and
3769 MPC826x processors), on others (parts of) the data cache can be
3770 locked as (mis-) used as memory, etc.
3772 Chris Hallinan posted a good summary of these issues to the
3773 U-Boot mailing list:
3775 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3776 From: "Chris Hallinan" <clh@net1plus.com>
3777 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3780 Correct me if I'm wrong, folks, but the way I understand it
3781 is this: Using DCACHE as initial RAM for Stack, etc, does not
3782 require any physical RAM backing up the cache. The cleverness
3783 is that the cache is being used as a temporary supply of
3784 necessary storage before the SDRAM controller is setup. It's
3785 beyond the scope of this list to explain the details, but you
3786 can see how this works by studying the cache architecture and
3787 operation in the architecture and processor-specific manuals.
3789 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3790 is another option for the system designer to use as an
3791 initial stack/RAM area prior to SDRAM being available. Either
3792 option should work for you. Using CS 4 should be fine if your
3793 board designers haven't used it for something that would
3794 cause you grief during the initial boot! It is frequently not
3797 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
3798 with your processor/board/system design. The default value
3799 you will find in any recent u-boot distribution in
3800 walnut.h should work for you. I'd set it to a value larger
3801 than your SDRAM module. If you have a 64MB SDRAM module, set
3802 it above 400_0000. Just make sure your board has no resources
3803 that are supposed to respond to that address! That code in
3804 start.S has been around a while and should work as is when
3805 you get the config right.
3810 It is essential to remember this, since it has some impact on the C
3811 code for the initialization procedures:
3813 * Initialized global data (data segment) is read-only. Do not attempt
3816 * Do not use any uninitialized global data (or implicitely initialized
3817 as zero data - BSS segment) at all - this is undefined, initiali-
3818 zation is performed later (when relocating to RAM).
3820 * Stack space is very limited. Avoid big data buffers or things like
3823 Having only the stack as writable memory limits means we cannot use
3824 normal global data to share information beween the code. But it
3825 turned out that the implementation of U-Boot can be greatly
3826 simplified by making a global data structure (gd_t) available to all
3827 functions. We could pass a pointer to this data as argument to _all_
3828 functions, but this would bloat the code. Instead we use a feature of
3829 the GCC compiler (Global Register Variables) to share the data: we
3830 place a pointer (gd) to the global data into a register which we
3831 reserve for this purpose.
3833 When choosing a register for such a purpose we are restricted by the
3834 relevant (E)ABI specifications for the current architecture, and by
3835 GCC's implementation.
3837 For PowerPC, the following registers have specific use:
3839 R2: reserved for system use
3840 R3-R4: parameter passing and return values
3841 R5-R10: parameter passing
3842 R13: small data area pointer
3846 (U-Boot also uses R14 as internal GOT pointer.)
3848 ==> U-Boot will use R2 to hold a pointer to the global data
3850 Note: on PPC, we could use a static initializer (since the
3851 address of the global data structure is known at compile time),
3852 but it turned out that reserving a register results in somewhat
3853 smaller code - although the code savings are not that big (on
3854 average for all boards 752 bytes for the whole U-Boot image,
3855 624 text + 127 data).
3857 On Blackfin, the normal C ABI (except for P5) is followed as documented here:
3858 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
3860 ==> U-Boot will use P5 to hold a pointer to the global data
3862 On ARM, the following registers are used:
3864 R0: function argument word/integer result
3865 R1-R3: function argument word
3867 R10: stack limit (used only if stack checking if enabled)
3868 R11: argument (frame) pointer
3869 R12: temporary workspace
3872 R15: program counter
3874 ==> U-Boot will use R8 to hold a pointer to the global data
3876 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3877 or current versions of GCC may "optimize" the code too much.
3882 U-Boot runs in system state and uses physical addresses, i.e. the
3883 MMU is not used either for address mapping nor for memory protection.
3885 The available memory is mapped to fixed addresses using the memory
3886 controller. In this process, a contiguous block is formed for each
3887 memory type (Flash, SDRAM, SRAM), even when it consists of several
3888 physical memory banks.
3890 U-Boot is installed in the first 128 kB of the first Flash bank (on
3891 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3892 booting and sizing and initializing DRAM, the code relocates itself
3893 to the upper end of DRAM. Immediately below the U-Boot code some
3894 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
3895 configuration setting]. Below that, a structure with global Board
3896 Info data is placed, followed by the stack (growing downward).
3898 Additionally, some exception handler code is copied to the low 8 kB
3899 of DRAM (0x00000000 ... 0x00001FFF).
3901 So a typical memory configuration with 16 MB of DRAM could look like
3904 0x0000 0000 Exception Vector code
3907 0x0000 2000 Free for Application Use
3913 0x00FB FF20 Monitor Stack (Growing downward)
3914 0x00FB FFAC Board Info Data and permanent copy of global data
3915 0x00FC 0000 Malloc Arena
3918 0x00FE 0000 RAM Copy of Monitor Code
3919 ... eventually: LCD or video framebuffer
3920 ... eventually: pRAM (Protected RAM - unchanged by reset)
3921 0x00FF FFFF [End of RAM]
3924 System Initialization:
3925 ----------------------
3927 In the reset configuration, U-Boot starts at the reset entry point
3928 (on most PowerPC systems at address 0x00000100). Because of the reset
3929 configuration for CS0# this is a mirror of the onboard Flash memory.
3930 To be able to re-map memory U-Boot then jumps to its link address.
3931 To be able to implement the initialization code in C, a (small!)
3932 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3933 which provide such a feature like MPC8xx or MPC8260), or in a locked
3934 part of the data cache. After that, U-Boot initializes the CPU core,
3935 the caches and the SIU.
3937 Next, all (potentially) available memory banks are mapped using a
3938 preliminary mapping. For example, we put them on 512 MB boundaries
3939 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3940 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3941 programmed for SDRAM access. Using the temporary configuration, a
3942 simple memory test is run that determines the size of the SDRAM
3945 When there is more than one SDRAM bank, and the banks are of
3946 different size, the largest is mapped first. For equal size, the first
3947 bank (CS2#) is mapped first. The first mapping is always for address
3948 0x00000000, with any additional banks following immediately to create
3949 contiguous memory starting from 0.
3951 Then, the monitor installs itself at the upper end of the SDRAM area
3952 and allocates memory for use by malloc() and for the global Board
3953 Info data; also, the exception vector code is copied to the low RAM
3954 pages, and the final stack is set up.
3956 Only after this relocation will you have a "normal" C environment;
3957 until that you are restricted in several ways, mostly because you are
3958 running from ROM, and because the code will have to be relocated to a
3962 U-Boot Porting Guide:
3963 ----------------------
3965 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3969 int main (int argc, char *argv[])
3971 sighandler_t no_more_time;
3973 signal (SIGALRM, no_more_time);
3974 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3976 if (available_money > available_manpower) {
3977 pay consultant to port U-Boot;
3981 Download latest U-Boot source;
3983 Subscribe to u-boot mailing list;
3986 email ("Hi, I am new to U-Boot, how do I get started?");
3990 Read the README file in the top level directory;
3991 Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
3992 Read the source, Luke;
3995 if (available_money > toLocalCurrency ($2500)) {
3998 Add a lot of aggravation and time;
4001 Create your own board support subdirectory;
4003 Create your own board config file;
4007 Add / modify source code;
4011 email ("Hi, I am having problems...");
4013 Send patch file to Wolfgang;
4018 void no_more_time (int sig)
4027 All contributions to U-Boot should conform to the Linux kernel
4028 coding style; see the file "Documentation/CodingStyle" and the script
4029 "scripts/Lindent" in your Linux kernel source directory. In sources
4030 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
4031 spaces before parameters to function calls) is actually used.
4033 Source files originating from a different project (for example the
4034 MTD subsystem) are generally exempt from these guidelines and are not
4035 reformated to ease subsequent migration to newer versions of those
4038 Please note that U-Boot is implemented in C (and to some small parts in
4039 Assembler); no C++ is used, so please do not use C++ style comments (//)
4042 Please also stick to the following formatting rules:
4043 - remove any trailing white space
4044 - use TAB characters for indentation, not spaces
4045 - make sure NOT to use DOS '\r\n' line feeds
4046 - do not add more than 2 empty lines to source files
4047 - do not add trailing empty lines to source files
4049 Submissions which do not conform to the standards may be returned
4050 with a request to reformat the changes.
4056 Since the number of patches for U-Boot is growing, we need to
4057 establish some rules. Submissions which do not conform to these rules
4058 may be rejected, even when they contain important and valuable stuff.
4060 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4062 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4063 see http://lists.denx.de/mailman/listinfo/u-boot
4065 When you send a patch, please include the following information with
4068 * For bug fixes: a description of the bug and how your patch fixes
4069 this bug. Please try to include a way of demonstrating that the
4070 patch actually fixes something.
4072 * For new features: a description of the feature and your
4075 * A CHANGELOG entry as plaintext (separate from the patch)
4077 * For major contributions, your entry to the CREDITS file
4079 * When you add support for a new board, don't forget to add this
4080 board to the MAKEALL script, too.
4082 * If your patch adds new configuration options, don't forget to
4083 document these in the README file.
4085 * The patch itself. If you are using git (which is *strongly*
4086 recommended) you can easily generate the patch using the
4087 "git-format-patch". If you then use "git-send-email" to send it to
4088 the U-Boot mailing list, you will avoid most of the common problems
4089 with some other mail clients.
4091 If you cannot use git, use "diff -purN OLD NEW". If your version of
4092 diff does not support these options, then get the latest version of
4095 The current directory when running this command shall be the parent
4096 directory of the U-Boot source tree (i. e. please make sure that
4097 your patch includes sufficient directory information for the
4100 We prefer patches as plain text. MIME attachments are discouraged,
4101 and compressed attachments must not be used.
4103 * If one logical set of modifications affects or creates several
4104 files, all these changes shall be submitted in a SINGLE patch file.
4106 * Changesets that contain different, unrelated modifications shall be
4107 submitted as SEPARATE patches, one patch per changeset.
4112 * Before sending the patch, run the MAKEALL script on your patched
4113 source tree and make sure that no errors or warnings are reported
4114 for any of the boards.
4116 * Keep your modifications to the necessary minimum: A patch
4117 containing several unrelated changes or arbitrary reformats will be
4118 returned with a request to re-formatting / split it.
4120 * If you modify existing code, make sure that your new code does not
4121 add to the memory footprint of the code ;-) Small is beautiful!
4122 When adding new features, these should compile conditionally only
4123 (using #ifdef), and the resulting code with the new feature
4124 disabled must not need more memory than the old code without your
4127 * Remember that there is a size limit of 100 kB per message on the
4128 u-boot mailing list. Bigger patches will be moderated. If they are
4129 reasonable and not too big, they will be acknowledged. But patches
4130 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob