2 # (C) Copyright 2000 - 2008
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # See file CREDITS for list of people who contributed to this
8 # This program is free software; you can redistribute it and/or
9 # modify it under the terms of the GNU General Public License as
10 # published by the Free Software Foundation; either version 2 of
11 # the License, or (at your option) any later version.
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with this program; if not, write to the Free Software
20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27 This directory contains the source code for U-Boot, a boot loader for
28 Embedded boards based on PowerPC, ARM, MIPS and several other
29 processors, which can be installed in a boot ROM and used to
30 initialize and test the hardware or to download and run application
33 The development of U-Boot is closely related to Linux: some parts of
34 the source code originate in the Linux source tree, we have some
35 header files in common, and special provision has been made to
36 support booting of Linux images.
38 Some attention has been paid to make this software easily
39 configurable and extendable. For instance, all monitor commands are
40 implemented with the same call interface, so that it's very easy to
41 add new commands. Also, instead of permanently adding rarely used
42 code (for instance hardware test utilities) to the monitor, you can
43 load and run it dynamically.
49 In general, all boards for which a configuration option exists in the
50 Makefile have been tested to some extent and can be considered
51 "working". In fact, many of them are used in production systems.
53 In case of problems see the CHANGELOG and CREDITS files to find out
54 who contributed the specific port. The MAINTAINERS file lists board
61 In case you have questions about, problems with or contributions for
62 U-Boot you should send a message to the U-Boot mailing list at
63 <u-boot@lists.denx.de>. There is also an archive of previous traffic
64 on the mailing list - please search the archive before asking FAQ's.
65 Please see http://lists.denx.de/pipermail/u-boot and
66 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
69 Where to get source code:
70 =========================
72 The U-Boot source code is maintained in the git repository at
73 git://www.denx.de/git/u-boot.git ; you can browse it online at
74 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
76 The "snapshot" links on this page allow you to download tarballs of
77 any version you might be interested in. Official releases are also
78 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
81 Pre-built (and tested) images are available from
82 ftp://ftp.denx.de/pub/u-boot/images/
88 - start from 8xxrom sources
89 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
91 - make it easier to add custom boards
92 - make it possible to add other [PowerPC] CPUs
93 - extend functions, especially:
94 * Provide extended interface to Linux boot loader
97 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
98 - create ARMBoot project (http://sourceforge.net/projects/armboot)
99 - add other CPU families (starting with ARM)
100 - create U-Boot project (http://sourceforge.net/projects/u-boot)
101 - current project page: see http://www.denx.de/wiki/U-Boot
107 The "official" name of this project is "Das U-Boot". The spelling
108 "U-Boot" shall be used in all written text (documentation, comments
109 in source files etc.). Example:
111 This is the README file for the U-Boot project.
113 File names etc. shall be based on the string "u-boot". Examples:
115 include/asm-ppc/u-boot.h
117 #include <asm/u-boot.h>
119 Variable names, preprocessor constants etc. shall be either based on
120 the string "u_boot" or on "U_BOOT". Example:
122 U_BOOT_VERSION u_boot_logo
123 IH_OS_U_BOOT u_boot_hush_start
129 U-Boot uses a 3 level version number containing a version, a
130 sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2",
131 sub-version "34", and patchlevel "4".
133 The patchlevel is used to indicate certain stages of development
134 between released versions, i. e. officially released versions of
135 U-Boot will always have a patchlevel of "0".
141 - board Board dependent files
142 - common Misc architecture independent functions
143 - cpu CPU specific files
144 - 74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
145 - arm720t Files specific to ARM 720 CPUs
146 - arm920t Files specific to ARM 920 CPUs
147 - at91rm9200 Files specific to Atmel AT91RM9200 CPU
148 - imx Files specific to Freescale MC9328 i.MX CPUs
149 - s3c24x0 Files specific to Samsung S3C24X0 CPUs
150 - arm925t Files specific to ARM 925 CPUs
151 - arm926ejs Files specific to ARM 926 CPUs
152 - arm1136 Files specific to ARM 1136 CPUs
153 - at32ap Files specific to Atmel AVR32 AP CPUs
154 - blackfin Files specific to Analog Devices Blackfin CPUs
155 - i386 Files specific to i386 CPUs
156 - ixp Files specific to Intel XScale IXP CPUs
157 - leon2 Files specific to Gaisler LEON2 SPARC CPU
158 - leon3 Files specific to Gaisler LEON3 SPARC CPU
159 - mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 - mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 - mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 - mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 - mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 - mips Files specific to MIPS CPUs
165 - mpc5xx Files specific to Freescale MPC5xx CPUs
166 - mpc5xxx Files specific to Freescale MPC5xxx CPUs
167 - mpc8xx Files specific to Freescale MPC8xx CPUs
168 - mpc8220 Files specific to Freescale MPC8220 CPUs
169 - mpc824x Files specific to Freescale MPC824x CPUs
170 - mpc8260 Files specific to Freescale MPC8260 CPUs
171 - mpc85xx Files specific to Freescale MPC85xx CPUs
172 - nios Files specific to Altera NIOS CPUs
173 - nios2 Files specific to Altera Nios-II CPUs
174 - ppc4xx Files specific to AMCC PowerPC 4xx CPUs
175 - pxa Files specific to Intel XScale PXA CPUs
176 - s3c44b0 Files specific to Samsung S3C44B0 CPUs
177 - sa1100 Files specific to Intel StrongARM SA1100 CPUs
178 - disk Code for disk drive partition handling
179 - doc Documentation (don't expect too much)
180 - drivers Commonly used device drivers
181 - dtt Digital Thermometer and Thermostat drivers
182 - examples Example code for standalone applications, etc.
183 - include Header Files
184 - lib_arm Files generic to ARM architecture
185 - lib_avr32 Files generic to AVR32 architecture
186 - lib_blackfin Files generic to Blackfin architecture
187 - lib_generic Files generic to all architectures
188 - lib_i386 Files generic to i386 architecture
189 - lib_m68k Files generic to m68k architecture
190 - lib_mips Files generic to MIPS architecture
191 - lib_nios Files generic to NIOS architecture
192 - lib_ppc Files generic to PowerPC architecture
193 - lib_sparc Files generic to SPARC architecture
194 - libfdt Library files to support flattened device trees
195 - net Networking code
196 - post Power On Self Test
197 - rtc Real Time Clock drivers
198 - tools Tools to build S-Record or U-Boot images, etc.
200 Software Configuration:
201 =======================
203 Configuration is usually done using C preprocessor defines; the
204 rationale behind that is to avoid dead code whenever possible.
206 There are two classes of configuration variables:
208 * Configuration _OPTIONS_:
209 These are selectable by the user and have names beginning with
212 * Configuration _SETTINGS_:
213 These depend on the hardware etc. and should not be meddled with if
214 you don't know what you're doing; they have names beginning with
217 Later we will add a configuration tool - probably similar to or even
218 identical to what's used for the Linux kernel. Right now, we have to
219 do the configuration by hand, which means creating some symbolic
220 links and editing some configuration files. We use the TQM8xxL boards
224 Selection of Processor Architecture and Board Type:
225 ---------------------------------------------------
227 For all supported boards there are ready-to-use default
228 configurations available; just type "make <board_name>_config".
230 Example: For a TQM823L module type:
235 For the Cogent platform, you need to specify the CPU type as well;
236 e.g. "make cogent_mpc8xx_config". And also configure the cogent
237 directory according to the instructions in cogent/README.
240 Configuration Options:
241 ----------------------
243 Configuration depends on the combination of board and CPU type; all
244 such information is kept in a configuration file
245 "include/configs/<board_name>.h".
247 Example: For a TQM823L module, all configuration settings are in
248 "include/configs/TQM823L.h".
251 Many of the options are named exactly as the corresponding Linux
252 kernel configuration options. The intention is to make it easier to
253 build a config tool - later.
256 The following options need to be configured:
258 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
260 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
262 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
263 Define exactly one, e.g. CONFIG_ATSTK1002
265 - CPU Module Type: (if CONFIG_COGENT is defined)
266 Define exactly one of
268 --- FIXME --- not tested yet:
269 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
270 CONFIG_CMA287_23, CONFIG_CMA287_50
272 - Motherboard Type: (if CONFIG_COGENT is defined)
273 Define exactly one of
274 CONFIG_CMA101, CONFIG_CMA102
276 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
277 Define one or more of
280 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
281 Define one or more of
282 CONFIG_LCD_HEARTBEAT - update a character position on
283 the LCD display every second with
286 - Board flavour: (if CONFIG_MPC8260ADS is defined)
289 CONFIG_SYS_8260ADS - original MPC8260ADS
290 CONFIG_SYS_8266ADS - MPC8266ADS
291 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
292 CONFIG_SYS_8272ADS - MPC8272ADS
294 - MPC824X Family Member (if CONFIG_MPC824X is defined)
295 Define exactly one of
296 CONFIG_MPC8240, CONFIG_MPC8245
298 - 8xx CPU Options: (if using an MPC8xx CPU)
299 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
300 get_gclk_freq() cannot work
301 e.g. if there is no 32KHz
302 reference PIT/RTC clock
303 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
306 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
307 CONFIG_SYS_8xx_CPUCLK_MIN
308 CONFIG_SYS_8xx_CPUCLK_MAX
309 CONFIG_8xx_CPUCLK_DEFAULT
310 See doc/README.MPC866
312 CONFIG_SYS_MEASURE_CPUCLK
314 Define this to measure the actual CPU clock instead
315 of relying on the correctness of the configured
316 values. Mostly useful for board bringup to make sure
317 the PLL is locked at the intended frequency. Note
318 that this requires a (stable) reference clock (32 kHz
319 RTC clock or CONFIG_SYS_8XX_XIN)
321 CONFIG_SYS_DELAYED_ICACHE
323 Define this option if you want to enable the
324 ICache only when Code runs from RAM.
326 - Intel Monahans options:
327 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
329 Defines the Monahans run mode to oscillator
330 ratio. Valid values are 8, 16, 24, 31. The core
331 frequency is this value multiplied by 13 MHz.
333 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
335 Defines the Monahans turbo mode to oscillator
336 ratio. Valid values are 1 (default if undefined) and
337 2. The core frequency as calculated above is multiplied
340 - Linux Kernel Interface:
343 U-Boot stores all clock information in Hz
344 internally. For binary compatibility with older Linux
345 kernels (which expect the clocks passed in the
346 bd_info data to be in MHz) the environment variable
347 "clocks_in_mhz" can be defined so that U-Boot
348 converts clock data to MHZ before passing it to the
350 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
351 "clocks_in_mhz=1" is automatically included in the
354 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
356 When transferring memsize parameter to linux, some versions
357 expect it to be in bytes, others in MB.
358 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
362 New kernel versions are expecting firmware settings to be
363 passed using flattened device trees (based on open firmware
367 * New libfdt-based support
368 * Adds the "fdt" command
369 * The bootm command automatically updates the fdt
371 OF_CPU - The proper name of the cpus node.
372 OF_SOC - The proper name of the soc node.
373 OF_TBCLK - The timebase frequency.
374 OF_STDOUT_PATH - The path to the console device
376 boards with QUICC Engines require OF_QE to set UCC MAC
379 CONFIG_OF_BOARD_SETUP
381 Board code has addition modification that it wants to make
382 to the flat device tree before handing it off to the kernel
386 This define fills in the correct boot CPU in the boot
387 param header, the default value is zero if undefined.
389 - vxWorks boot parameters:
391 bootvx constructs a valid bootline using the following
392 environments variables: bootfile, ipaddr, serverip, hostname.
393 It loads the vxWorks image pointed bootfile.
395 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
396 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
397 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
398 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
400 CONFIG_SYS_VXWORKS_ADD_PARAMS
402 Add it at the end of the bootline. E.g "u=username pw=secret"
404 Note: If a "bootargs" environment is defined, it will overwride
405 the defaults discussed just above.
410 Define this if you want support for Amba PrimeCell PL010 UARTs.
414 Define this if you want support for Amba PrimeCell PL011 UARTs.
418 If you have Amba PrimeCell PL011 UARTs, set this variable to
419 the clock speed of the UARTs.
423 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
424 define this to a list of base addresses for each (supported)
425 port. See e.g. include/configs/versatile.h
429 Depending on board, define exactly one serial port
430 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
431 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
432 console by defining CONFIG_8xx_CONS_NONE
434 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
435 port routines must be defined elsewhere
436 (i.e. serial_init(), serial_getc(), ...)
439 Enables console device for a color framebuffer. Needs following
440 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
441 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
443 VIDEO_HW_RECTFILL graphic chip supports
446 VIDEO_HW_BITBLT graphic chip supports
447 bit-blit (cf. smiLynxEM)
448 VIDEO_VISIBLE_COLS visible pixel columns
450 VIDEO_VISIBLE_ROWS visible pixel rows
451 VIDEO_PIXEL_SIZE bytes per pixel
452 VIDEO_DATA_FORMAT graphic data format
453 (0-5, cf. cfb_console.c)
454 VIDEO_FB_ADRS framebuffer address
455 VIDEO_KBD_INIT_FCT keyboard int fct
456 (i.e. i8042_kbd_init())
457 VIDEO_TSTC_FCT test char fct
459 VIDEO_GETC_FCT get char fct
461 CONFIG_CONSOLE_CURSOR cursor drawing on/off
462 (requires blink timer
464 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
465 CONFIG_CONSOLE_TIME display time/date info in
467 (requires CONFIG_CMD_DATE)
468 CONFIG_VIDEO_LOGO display Linux logo in
470 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
471 linux_logo.h for logo.
472 Requires CONFIG_VIDEO_LOGO
473 CONFIG_CONSOLE_EXTRA_INFO
474 additional board info beside
477 When CONFIG_CFB_CONSOLE is defined, video console is
478 default i/o. Serial console can be forced with
479 environment 'console=serial'.
481 When CONFIG_SILENT_CONSOLE is defined, all console
482 messages (by U-Boot and Linux!) can be silenced with
483 the "silent" environment variable. See
484 doc/README.silent for more information.
487 CONFIG_BAUDRATE - in bps
488 Select one of the baudrates listed in
489 CONFIG_SYS_BAUDRATE_TABLE, see below.
490 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
492 - Console Rx buffer length
493 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
494 the maximum receive buffer length for the SMC.
495 This option is actual only for 82xx and 8xx possible.
496 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
497 must be defined, to setup the maximum idle timeout for
500 - Interrupt driven serial port input:
501 CONFIG_SERIAL_SOFTWARE_FIFO
504 Use an interrupt handler for receiving data on the
505 serial port. It also enables using hardware handshake
506 (RTS/CTS) and UART's built-in FIFO. Set the number of
507 bytes the interrupt driven input buffer should have.
509 Leave undefined to disable this feature, including
510 disable the buffer and hardware handshake.
512 - Console UART Number:
516 If defined internal UART1 (and not UART0) is used
517 as default U-Boot console.
519 - Boot Delay: CONFIG_BOOTDELAY - in seconds
520 Delay before automatically booting the default image;
521 set to -1 to disable autoboot.
523 See doc/README.autoboot for these options that
524 work with CONFIG_BOOTDELAY. None are required.
525 CONFIG_BOOT_RETRY_TIME
526 CONFIG_BOOT_RETRY_MIN
527 CONFIG_AUTOBOOT_KEYED
528 CONFIG_AUTOBOOT_PROMPT
529 CONFIG_AUTOBOOT_DELAY_STR
530 CONFIG_AUTOBOOT_STOP_STR
531 CONFIG_AUTOBOOT_DELAY_STR2
532 CONFIG_AUTOBOOT_STOP_STR2
533 CONFIG_ZERO_BOOTDELAY_CHECK
534 CONFIG_RESET_TO_RETRY
538 Only needed when CONFIG_BOOTDELAY is enabled;
539 define a command string that is automatically executed
540 when no character is read on the console interface
541 within "Boot Delay" after reset.
544 This can be used to pass arguments to the bootm
545 command. The value of CONFIG_BOOTARGS goes into the
546 environment value "bootargs".
548 CONFIG_RAMBOOT and CONFIG_NFSBOOT
549 The value of these goes into the environment as
550 "ramboot" and "nfsboot" respectively, and can be used
551 as a convenience, when switching between booting from
557 When this option is #defined, the existence of the
558 environment variable "preboot" will be checked
559 immediately before starting the CONFIG_BOOTDELAY
560 countdown and/or running the auto-boot command resp.
561 entering interactive mode.
563 This feature is especially useful when "preboot" is
564 automatically generated or modified. For an example
565 see the LWMON board specific code: here "preboot" is
566 modified when the user holds down a certain
567 combination of keys on the (special) keyboard when
570 - Serial Download Echo Mode:
572 If defined to 1, all characters received during a
573 serial download (using the "loads" command) are
574 echoed back. This might be needed by some terminal
575 emulations (like "cu"), but may as well just take
576 time on others. This setting #define's the initial
577 value of the "loads_echo" environment variable.
579 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
581 Select one of the baudrates listed in
582 CONFIG_SYS_BAUDRATE_TABLE, see below.
585 Monitor commands can be included or excluded
586 from the build by using the #include files
587 "config_cmd_all.h" and #undef'ing unwanted
588 commands, or using "config_cmd_default.h"
589 and augmenting with additional #define's
592 The default command configuration includes all commands
593 except those marked below with a "*".
595 CONFIG_CMD_ASKENV * ask for env variable
596 CONFIG_CMD_AUTOSCRIPT Autoscript Support
597 CONFIG_CMD_BDI bdinfo
598 CONFIG_CMD_BEDBUG * Include BedBug Debugger
599 CONFIG_CMD_BMP * BMP support
600 CONFIG_CMD_BSP * Board specific commands
601 CONFIG_CMD_BOOTD bootd
602 CONFIG_CMD_CACHE * icache, dcache
603 CONFIG_CMD_CONSOLE coninfo
604 CONFIG_CMD_DATE * support for RTC, date/time...
605 CONFIG_CMD_DHCP * DHCP support
606 CONFIG_CMD_DIAG * Diagnostics
607 CONFIG_CMD_DOC * Disk-On-Chip Support
608 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
609 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
610 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
611 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
612 CONFIG_CMD_DTT * Digital Therm and Thermostat
613 CONFIG_CMD_ECHO echo arguments
614 CONFIG_CMD_EEPROM * EEPROM read/write support
615 CONFIG_CMD_ELF * bootelf, bootvx
616 CONFIG_CMD_SAVEENV saveenv
617 CONFIG_CMD_FDC * Floppy Disk Support
618 CONFIG_CMD_FAT * FAT partition support
619 CONFIG_CMD_FDOS * Dos diskette Support
620 CONFIG_CMD_FLASH flinfo, erase, protect
621 CONFIG_CMD_FPGA FPGA device initialization support
622 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
623 CONFIG_CMD_I2C * I2C serial bus support
624 CONFIG_CMD_IDE * IDE harddisk support
625 CONFIG_CMD_IMI iminfo
626 CONFIG_CMD_IMLS List all found images
627 CONFIG_CMD_IMMAP * IMMR dump support
628 CONFIG_CMD_IRQ * irqinfo
629 CONFIG_CMD_ITEST Integer/string test of 2 values
630 CONFIG_CMD_JFFS2 * JFFS2 Support
631 CONFIG_CMD_KGDB * kgdb
632 CONFIG_CMD_LOADB loadb
633 CONFIG_CMD_LOADS loads
634 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
636 CONFIG_CMD_MISC Misc functions like sleep etc
637 CONFIG_CMD_MMC * MMC memory mapped support
638 CONFIG_CMD_MII * MII utility commands
639 CONFIG_CMD_NAND * NAND support
640 CONFIG_CMD_NET bootp, tftpboot, rarpboot
641 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
642 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
643 CONFIG_CMD_PCI * pciinfo
644 CONFIG_CMD_PCMCIA * PCMCIA support
645 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
647 CONFIG_CMD_PORTIO * Port I/O
648 CONFIG_CMD_REGINFO * Register dump
649 CONFIG_CMD_RUN run command in env variable
650 CONFIG_CMD_SAVES * save S record dump
651 CONFIG_CMD_SCSI * SCSI Support
652 CONFIG_CMD_SDRAM * print SDRAM configuration information
653 (requires CONFIG_CMD_I2C)
654 CONFIG_CMD_SETGETDCR Support for DCR Register access
656 CONFIG_CMD_SPI * SPI serial bus support
657 CONFIG_CMD_USB * USB support
658 CONFIG_CMD_VFD * VFD support (TRAB)
659 CONFIG_CMD_CDP * Cisco Discover Protocol support
660 CONFIG_CMD_FSL * Microblaze FSL support
663 EXAMPLE: If you want all functions except of network
664 support you can write:
666 #include "config_cmd_all.h"
667 #undef CONFIG_CMD_NET
670 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
672 Note: Don't enable the "icache" and "dcache" commands
673 (configuration option CONFIG_CMD_CACHE) unless you know
674 what you (and your U-Boot users) are doing. Data
675 cache cannot be enabled on systems like the 8xx or
676 8260 (where accesses to the IMMR region must be
677 uncached), and it cannot be disabled on all other
678 systems where we (mis-) use the data cache to hold an
679 initial stack and some data.
682 XXX - this list needs to get updated!
686 If this variable is defined, it enables watchdog
687 support. There must be support in the platform specific
688 code for a watchdog. For the 8xx and 8260 CPUs, the
689 SIU Watchdog feature is enabled in the SYPCR
693 CONFIG_VERSION_VARIABLE
694 If this variable is defined, an environment variable
695 named "ver" is created by U-Boot showing the U-Boot
696 version as printed by the "version" command.
697 This variable is readonly.
701 When CONFIG_CMD_DATE is selected, the type of the RTC
702 has to be selected, too. Define exactly one of the
705 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
706 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
707 CONFIG_RTC_MC13783 - use MC13783 RTC
708 CONFIG_RTC_MC146818 - use MC146818 RTC
709 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
710 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
711 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
712 CONFIG_RTC_DS164x - use Dallas DS164x RTC
713 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
714 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
715 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
717 Note that if the RTC uses I2C, then the I2C interface
718 must also be configured. See I2C Support, below.
721 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
722 CONFIG_PCA953X_INFO - enable pca953x info command
724 Note that if the GPIO device uses I2C, then the I2C interface
725 must also be configured. See I2C Support, below.
729 When CONFIG_TIMESTAMP is selected, the timestamp
730 (date and time) of an image is printed by image
731 commands like bootm or iminfo. This option is
732 automatically enabled when you select CONFIG_CMD_DATE .
735 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
736 and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION
738 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
739 CONFIG_CMD_SCSI) you must configure support for at
740 least one partition type as well.
743 CONFIG_IDE_RESET_ROUTINE - this is defined in several
744 board configurations files but used nowhere!
746 CONFIG_IDE_RESET - is this is defined, IDE Reset will
747 be performed by calling the function
748 ide_set_reset(int reset)
749 which has to be defined in a board specific file
754 Set this to enable ATAPI support.
759 Set this to enable support for disks larger than 137GB
760 Also look at CONFIG_SYS_64BIT_LBA ,CONFIG_SYS_64BIT_VSPRINTF and CONFIG_SYS_64BIT_STRTOUL
761 Whithout these , LBA48 support uses 32bit variables and will 'only'
762 support disks up to 2.1TB.
764 CONFIG_SYS_64BIT_LBA:
765 When enabled, makes the IDE subsystem use 64bit sector addresses.
769 At the moment only there is only support for the
770 SYM53C8XX SCSI controller; define
771 CONFIG_SCSI_SYM53C8XX to enable it.
773 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
774 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
775 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
776 maximum numbers of LUNs, SCSI ID's and target
778 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
780 - NETWORK Support (PCI):
782 Support for Intel 8254x gigabit chips.
784 CONFIG_E1000_FALLBACK_MAC
785 default MAC for empty EEPROM after production.
788 Support for Intel 82557/82559/82559ER chips.
789 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
790 write routine for first time initialisation.
793 Support for Digital 2114x chips.
794 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
795 modem chip initialisation (KS8761/QS6611).
798 Support for National dp83815 chips.
801 Support for National dp8382[01] gigabit chips.
803 - NETWORK Support (other):
805 CONFIG_DRIVER_LAN91C96
806 Support for SMSC's LAN91C96 chips.
809 Define this to hold the physical address
810 of the LAN91C96's I/O space
812 CONFIG_LAN91C96_USE_32_BIT
813 Define this to enable 32 bit addressing
815 CONFIG_DRIVER_SMC91111
816 Support for SMSC's LAN91C111 chip
819 Define this to hold the physical address
820 of the device (I/O space)
822 CONFIG_SMC_USE_32_BIT
823 Define this if data bus is 32 bits
825 CONFIG_SMC_USE_IOFUNCS
826 Define this to use i/o functions instead of macros
827 (some hardware wont work with macros)
829 CONFIG_DRIVER_SMC911X
830 Support for SMSC's LAN911x and LAN921x chips
832 CONFIG_DRIVER_SMC911X_BASE
833 Define this to hold the physical address
834 of the device (I/O space)
836 CONFIG_DRIVER_SMC911X_32_BIT
837 Define this if data bus is 32 bits
839 CONFIG_DRIVER_SMC911X_16_BIT
840 Define this if data bus is 16 bits. If your processor
841 automatically converts one 32 bit word to two 16 bit
842 words you may also try CONFIG_DRIVER_SMC911X_32_BIT.
845 At the moment only the UHCI host controller is
846 supported (PIP405, MIP405, MPC5200); define
847 CONFIG_USB_UHCI to enable it.
848 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
849 and define CONFIG_USB_STORAGE to enable the USB
852 Supported are USB Keyboards and USB Floppy drives
854 MPC5200 USB requires additional defines:
856 for 528 MHz Clock: 0x0001bbbb
858 for differential drivers: 0x00001000
859 for single ended drivers: 0x00005000
860 CONFIG_SYS_USB_EVENT_POLL
861 May be defined to allow interrupt polling
862 instead of using asynchronous interrupts
865 Define the below if you wish to use the USB console.
866 Once firmware is rebuilt from a serial console issue the
867 command "setenv stdin usbtty; setenv stdout usbtty" and
868 attach your USB cable. The Unix command "dmesg" should print
869 it has found a new device. The environment variable usbtty
870 can be set to gserial or cdc_acm to enable your device to
871 appear to a USB host as a Linux gserial device or a
872 Common Device Class Abstract Control Model serial device.
873 If you select usbtty = gserial you should be able to enumerate
875 # modprobe usbserial vendor=0xVendorID product=0xProductID
876 else if using cdc_acm, simply setting the environment
877 variable usbtty to be cdc_acm should suffice. The following
878 might be defined in YourBoardName.h
881 Define this to build a UDC device
884 Define this to have a tty type of device available to
885 talk to the UDC device
887 CONFIG_SYS_CONSOLE_IS_IN_ENV
888 Define this if you want stdin, stdout &/or stderr to
892 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
893 Derive USB clock from external clock "blah"
894 - CONFIG_SYS_USB_EXTC_CLK 0x02
896 CONFIG_SYS_USB_BRG_CLK 0xBLAH
897 Derive USB clock from brgclk
898 - CONFIG_SYS_USB_BRG_CLK 0x04
900 If you have a USB-IF assigned VendorID then you may wish to
901 define your own vendor specific values either in BoardName.h
902 or directly in usbd_vendor_info.h. If you don't define
903 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
904 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
905 should pretend to be a Linux device to it's target host.
907 CONFIG_USBD_MANUFACTURER
908 Define this string as the name of your company for
909 - CONFIG_USBD_MANUFACTURER "my company"
911 CONFIG_USBD_PRODUCT_NAME
912 Define this string as the name of your product
913 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
916 Define this as your assigned Vendor ID from the USB
917 Implementors Forum. This *must* be a genuine Vendor ID
918 to avoid polluting the USB namespace.
919 - CONFIG_USBD_VENDORID 0xFFFF
921 CONFIG_USBD_PRODUCTID
922 Define this as the unique Product ID
924 - CONFIG_USBD_PRODUCTID 0xFFFF
928 The MMC controller on the Intel PXA is supported. To
929 enable this define CONFIG_MMC. The MMC can be
930 accessed from the boot prompt by mapping the device
931 to physical memory similar to flash. Command line is
932 enabled with CONFIG_CMD_MMC. The MMC driver also works with
933 the FAT fs. This is enabled with CONFIG_CMD_FAT.
935 - Journaling Flash filesystem support:
936 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
937 CONFIG_JFFS2_NAND_DEV
938 Define these for a default partition on a NAND device
940 CONFIG_SYS_JFFS2_FIRST_SECTOR,
941 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
942 Define these for a default partition on a NOR device
944 CONFIG_SYS_JFFS_CUSTOM_PART
945 Define this to create an own partition. You have to provide a
946 function struct part_info* jffs2_part_info(int part_num)
948 If you define only one JFFS2 partition you may also want to
949 #define CONFIG_SYS_JFFS_SINGLE_PART 1
950 to disable the command chpart. This is the default when you
951 have not defined a custom partition
956 Define this to enable standard (PC-Style) keyboard
960 Standard PC keyboard driver with US (is default) and
961 GERMAN key layout (switch via environment 'keymap=de') support.
962 Export function i8042_kbd_init, i8042_tstc and i8042_getc
963 for cfb_console. Supports cursor blinking.
968 Define this to enable video support (for output to
973 Enable Chips & Technologies 69000 Video chip
975 CONFIG_VIDEO_SMI_LYNXEM
976 Enable Silicon Motion SMI 712/710/810 Video chip. The
977 video output is selected via environment 'videoout'
978 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
981 For the CT69000 and SMI_LYNXEM drivers, videomode is
982 selected via environment 'videomode'. Two different ways
984 - "videomode=num" 'num' is a standard LiLo mode numbers.
985 Following standard modes are supported (* is default):
987 Colors 640x480 800x600 1024x768 1152x864 1280x1024
988 -------------+---------------------------------------------
989 8 bits | 0x301* 0x303 0x305 0x161 0x307
990 15 bits | 0x310 0x313 0x316 0x162 0x319
991 16 bits | 0x311 0x314 0x317 0x163 0x31A
992 24 bits | 0x312 0x315 0x318 ? 0x31B
993 -------------+---------------------------------------------
994 (i.e. setenv videomode 317; saveenv; reset;)
996 - "videomode=bootargs" all the video parameters are parsed
997 from the bootargs. (See drivers/video/videomodes.c)
1000 CONFIG_VIDEO_SED13806
1001 Enable Epson SED13806 driver. This driver supports 8bpp
1002 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1003 or CONFIG_VIDEO_SED13806_16BPP
1008 Define this to enable a custom keyboard support.
1009 This simply calls drv_keyboard_init() which must be
1010 defined in your board-specific files.
1011 The only board using this so far is RBC823.
1013 - LCD Support: CONFIG_LCD
1015 Define this to enable LCD support (for output to LCD
1016 display); also select one of the supported displays
1017 by defining one of these:
1021 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1023 CONFIG_NEC_NL6448AC33:
1025 NEC NL6448AC33-18. Active, color, single scan.
1027 CONFIG_NEC_NL6448BC20
1029 NEC NL6448BC20-08. 6.5", 640x480.
1030 Active, color, single scan.
1032 CONFIG_NEC_NL6448BC33_54
1034 NEC NL6448BC33-54. 10.4", 640x480.
1035 Active, color, single scan.
1039 Sharp 320x240. Active, color, single scan.
1040 It isn't 16x9, and I am not sure what it is.
1042 CONFIG_SHARP_LQ64D341
1044 Sharp LQ64D341 display, 640x480.
1045 Active, color, single scan.
1049 HLD1045 display, 640x480.
1050 Active, color, single scan.
1054 Optrex CBL50840-2 NF-FW 99 22 M5
1056 Hitachi LMG6912RPFC-00T
1060 320x240. Black & white.
1062 Normally display is black on white background; define
1063 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1065 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1067 If this option is set, the environment is checked for
1068 a variable "splashimage". If found, the usual display
1069 of logo, copyright and system information on the LCD
1070 is suppressed and the BMP image at the address
1071 specified in "splashimage" is loaded instead. The
1072 console is redirected to the "nulldev", too. This
1073 allows for a "silent" boot where a splash screen is
1074 loaded very quickly after power-on.
1076 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1078 If this option is set, additionally to standard BMP
1079 images, gzipped BMP images can be displayed via the
1080 splashscreen support or the bmp command.
1082 - Compression support:
1085 If this option is set, support for bzip2 compressed
1086 images is included. If not, only uncompressed and gzip
1087 compressed images are supported.
1089 NOTE: the bzip2 algorithm requires a lot of RAM, so
1090 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1095 If this option is set, support for lzma compressed
1098 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1099 requires an amount of dynamic memory that is given by the
1102 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1104 Where lc and lp stand for, respectively, Literal context bits
1105 and Literal pos bits.
1107 This value is upper-bounded by 14MB in the worst case. Anyway,
1108 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1109 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1110 a very small buffer.
1112 Use the lzmainfo tool to determinate the lc and lp values and
1113 then calculate the amount of needed dynamic memory (ensuring
1114 the appropriate CONFIG_SYS_MALLOC_LEN value).
1119 The address of PHY on MII bus.
1121 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1123 The clock frequency of the MII bus
1127 If this option is set, support for speed/duplex
1128 detection of gigabit PHY is included.
1130 CONFIG_PHY_RESET_DELAY
1132 Some PHY like Intel LXT971A need extra delay after
1133 reset before any MII register access is possible.
1134 For such PHY, set this option to the usec delay
1135 required. (minimum 300usec for LXT971A)
1137 CONFIG_PHY_CMD_DELAY (ppc4xx)
1139 Some PHY like Intel LXT971A need extra delay after
1140 command issued before MII status register can be read
1150 Define a default value for Ethernet address to use
1151 for the respective Ethernet interface, in case this
1152 is not determined automatically.
1157 Define a default value for the IP address to use for
1158 the default Ethernet interface, in case this is not
1159 determined through e.g. bootp.
1161 - Server IP address:
1164 Defines a default value for the IP address of a TFTP
1165 server to contact when using the "tftboot" command.
1167 - Multicast TFTP Mode:
1170 Defines whether you want to support multicast TFTP as per
1171 rfc-2090; for example to work with atftp. Lets lots of targets
1172 tftp down the same boot image concurrently. Note: the Ethernet
1173 driver in use must provide a function: mcast() to join/leave a
1176 CONFIG_BOOTP_RANDOM_DELAY
1177 - BOOTP Recovery Mode:
1178 CONFIG_BOOTP_RANDOM_DELAY
1180 If you have many targets in a network that try to
1181 boot using BOOTP, you may want to avoid that all
1182 systems send out BOOTP requests at precisely the same
1183 moment (which would happen for instance at recovery
1184 from a power failure, when all systems will try to
1185 boot, thus flooding the BOOTP server. Defining
1186 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1187 inserted before sending out BOOTP requests. The
1188 following delays are inserted then:
1190 1st BOOTP request: delay 0 ... 1 sec
1191 2nd BOOTP request: delay 0 ... 2 sec
1192 3rd BOOTP request: delay 0 ... 4 sec
1194 BOOTP requests: delay 0 ... 8 sec
1196 - DHCP Advanced Options:
1197 You can fine tune the DHCP functionality by defining
1198 CONFIG_BOOTP_* symbols:
1200 CONFIG_BOOTP_SUBNETMASK
1201 CONFIG_BOOTP_GATEWAY
1202 CONFIG_BOOTP_HOSTNAME
1203 CONFIG_BOOTP_NISDOMAIN
1204 CONFIG_BOOTP_BOOTPATH
1205 CONFIG_BOOTP_BOOTFILESIZE
1208 CONFIG_BOOTP_SEND_HOSTNAME
1209 CONFIG_BOOTP_NTPSERVER
1210 CONFIG_BOOTP_TIMEOFFSET
1211 CONFIG_BOOTP_VENDOREX
1213 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1214 environment variable, not the BOOTP server.
1216 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1217 serverip from a DHCP server, it is possible that more
1218 than one DNS serverip is offered to the client.
1219 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1220 serverip will be stored in the additional environment
1221 variable "dnsip2". The first DNS serverip is always
1222 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1225 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1226 to do a dynamic update of a DNS server. To do this, they
1227 need the hostname of the DHCP requester.
1228 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1229 of the "hostname" environment variable is passed as
1230 option 12 to the DHCP server.
1232 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1234 A 32bit value in microseconds for a delay between
1235 receiving a "DHCP Offer" and sending the "DHCP Request".
1236 This fixes a problem with certain DHCP servers that don't
1237 respond 100% of the time to a "DHCP request". E.g. On an
1238 AT91RM9200 processor running at 180MHz, this delay needed
1239 to be *at least* 15,000 usec before a Windows Server 2003
1240 DHCP server would reply 100% of the time. I recommend at
1241 least 50,000 usec to be safe. The alternative is to hope
1242 that one of the retries will be successful but note that
1243 the DHCP timeout and retry process takes a longer than
1247 CONFIG_CDP_DEVICE_ID
1249 The device id used in CDP trigger frames.
1251 CONFIG_CDP_DEVICE_ID_PREFIX
1253 A two character string which is prefixed to the MAC address
1258 A printf format string which contains the ascii name of
1259 the port. Normally is set to "eth%d" which sets
1260 eth0 for the first Ethernet, eth1 for the second etc.
1262 CONFIG_CDP_CAPABILITIES
1264 A 32bit integer which indicates the device capabilities;
1265 0x00000010 for a normal host which does not forwards.
1269 An ascii string containing the version of the software.
1273 An ascii string containing the name of the platform.
1277 A 32bit integer sent on the trigger.
1279 CONFIG_CDP_POWER_CONSUMPTION
1281 A 16bit integer containing the power consumption of the
1282 device in .1 of milliwatts.
1284 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1286 A byte containing the id of the VLAN.
1288 - Status LED: CONFIG_STATUS_LED
1290 Several configurations allow to display the current
1291 status using a LED. For instance, the LED will blink
1292 fast while running U-Boot code, stop blinking as
1293 soon as a reply to a BOOTP request was received, and
1294 start blinking slow once the Linux kernel is running
1295 (supported by a status LED driver in the Linux
1296 kernel). Defining CONFIG_STATUS_LED enables this
1299 - CAN Support: CONFIG_CAN_DRIVER
1301 Defining CONFIG_CAN_DRIVER enables CAN driver support
1302 on those systems that support this (optional)
1303 feature, like the TQM8xxL modules.
1305 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1307 These enable I2C serial bus commands. Defining either of
1308 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1309 include the appropriate I2C driver for the selected CPU.
1311 This will allow you to use i2c commands at the u-boot
1312 command line (as long as you set CONFIG_CMD_I2C in
1313 CONFIG_COMMANDS) and communicate with i2c based realtime
1314 clock chips. See common/cmd_i2c.c for a description of the
1315 command line interface.
1317 CONFIG_I2C_CMD_TREE is a recommended option that places
1318 all I2C commands under a single 'i2c' root command. The
1319 older 'imm', 'imd', 'iprobe' etc. commands are considered
1320 deprecated and may disappear in the future.
1322 CONFIG_HARD_I2C selects a hardware I2C controller.
1324 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1325 bit-banging) driver instead of CPM or similar hardware
1328 There are several other quantities that must also be
1329 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1331 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1332 to be the frequency (in Hz) at which you wish your i2c bus
1333 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1334 the CPU's i2c node address).
1336 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1337 sets the CPU up as a master node and so its address should
1338 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1339 p.16-473). So, set CONFIG_SYS_I2C_SLAVE to 0.
1341 That's all that's required for CONFIG_HARD_I2C.
1343 If you use the software i2c interface (CONFIG_SOFT_I2C)
1344 then the following macros need to be defined (examples are
1345 from include/configs/lwmon.h):
1349 (Optional). Any commands necessary to enable the I2C
1350 controller or configure ports.
1352 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1356 (Only for MPC8260 CPU). The I/O port to use (the code
1357 assumes both bits are on the same port). Valid values
1358 are 0..3 for ports A..D.
1362 The code necessary to make the I2C data line active
1363 (driven). If the data line is open collector, this
1366 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1370 The code necessary to make the I2C data line tri-stated
1371 (inactive). If the data line is open collector, this
1374 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1378 Code that returns TRUE if the I2C data line is high,
1381 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1385 If <bit> is TRUE, sets the I2C data line high. If it
1386 is FALSE, it clears it (low).
1388 eg: #define I2C_SDA(bit) \
1389 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1390 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1394 If <bit> is TRUE, sets the I2C clock line high. If it
1395 is FALSE, it clears it (low).
1397 eg: #define I2C_SCL(bit) \
1398 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1399 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1403 This delay is invoked four times per clock cycle so this
1404 controls the rate of data transfer. The data rate thus
1405 is 1 / (I2C_DELAY * 4). Often defined to be something
1408 #define I2C_DELAY udelay(2)
1410 CONFIG_SYS_I2C_INIT_BOARD
1412 When a board is reset during an i2c bus transfer
1413 chips might think that the current transfer is still
1414 in progress. On some boards it is possible to access
1415 the i2c SCLK line directly, either by using the
1416 processor pin as a GPIO or by having a second pin
1417 connected to the bus. If this option is defined a
1418 custom i2c_init_board() routine in boards/xxx/board.c
1419 is run early in the boot sequence.
1421 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1423 This option enables configuration of bi_iic_fast[] flags
1424 in u-boot bd_info structure based on u-boot environment
1425 variable "i2cfast". (see also i2cfast)
1427 CONFIG_I2C_MULTI_BUS
1429 This option allows the use of multiple I2C buses, each of which
1430 must have a controller. At any point in time, only one bus is
1431 active. To switch to a different bus, use the 'i2c dev' command.
1432 Note that bus numbering is zero-based.
1434 CONFIG_SYS_I2C_NOPROBES
1436 This option specifies a list of I2C devices that will be skipped
1437 when the 'i2c probe' command is issued (or 'iprobe' using the legacy
1438 command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device
1439 pairs. Otherwise, specify a 1D array of device addresses
1442 #undef CONFIG_I2C_MULTI_BUS
1443 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1445 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1447 #define CONFIG_I2C_MULTI_BUS
1448 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1450 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1452 CONFIG_SYS_SPD_BUS_NUM
1454 If defined, then this indicates the I2C bus number for DDR SPD.
1455 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1457 CONFIG_SYS_RTC_BUS_NUM
1459 If defined, then this indicates the I2C bus number for the RTC.
1460 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1462 CONFIG_SYS_DTT_BUS_NUM
1464 If defined, then this indicates the I2C bus number for the DTT.
1465 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1467 CONFIG_SYS_I2C_DTT_ADDR:
1469 If defined, specifies the I2C address of the DTT device.
1470 If not defined, then U-Boot uses predefined value for
1471 specified DTT device.
1475 Define this option if you want to use Freescale's I2C driver in
1476 drivers/i2c/fsl_i2c.c.
1480 Define this option if you have I2C devices reached over 1 .. n
1481 I2C Muxes like the pca9544a. This option addes a new I2C
1482 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1483 new I2C Bus to the existing I2C Busses. If you select the
1484 new Bus with "i2c dev", u-bbot sends first the commandos for
1485 the muxes to activate this new "bus".
1487 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1491 Adding a new I2C Bus reached over 2 pca9544a muxes
1492 The First mux with address 70 and channel 6
1493 The Second mux with address 71 and channel 4
1495 => i2c bus pca9544a:70:6:pca9544a:71:4
1497 Use the "i2c bus" command without parameter, to get a list
1498 of I2C Busses with muxes:
1501 Busses reached over muxes:
1503 reached over Mux(es):
1506 reached over Mux(es):
1511 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1512 u-boot sends First the Commando to the mux@70 to enable
1513 channel 6, and then the Commando to the mux@71 to enable
1516 After that, you can use the "normal" i2c commands as
1517 usual, to communicate with your I2C devices behind
1520 This option is actually implemented for the bitbanging
1521 algorithm in common/soft_i2c.c and for the Hardware I2C
1522 Bus on the MPC8260. But it should be not so difficult
1523 to add this option to other architectures.
1525 CONFIG_SOFT_I2C_READ_REPEATED_START
1527 defining this will force the i2c_read() function in
1528 the soft_i2c driver to perform an I2C repeated start
1529 between writing the address pointer and reading the
1530 data. If this define is omitted the default behaviour
1531 of doing a stop-start sequence will be used. Most I2C
1532 devices can use either method, but some require one or
1535 - SPI Support: CONFIG_SPI
1537 Enables SPI driver (so far only tested with
1538 SPI EEPROM, also an instance works with Crystal A/D and
1539 D/As on the SACSng board)
1543 Enables extended (16-bit) SPI EEPROM addressing.
1544 (symmetrical to CONFIG_I2C_X)
1548 Enables a software (bit-bang) SPI driver rather than
1549 using hardware support. This is a general purpose
1550 driver that only requires three general I/O port pins
1551 (two outputs, one input) to function. If this is
1552 defined, the board configuration must define several
1553 SPI configuration items (port pins to use, etc). For
1554 an example, see include/configs/sacsng.h.
1558 Enables a hardware SPI driver for general-purpose reads
1559 and writes. As with CONFIG_SOFT_SPI, the board configuration
1560 must define a list of chip-select function pointers.
1561 Currently supported on some MPC8xxx processors. For an
1562 example, see include/configs/mpc8349emds.h.
1566 Enables the driver for the SPI controllers on i.MX and MXC
1567 SoCs. Currently only i.MX31 is supported.
1569 - FPGA Support: CONFIG_FPGA
1571 Enables FPGA subsystem.
1573 CONFIG_FPGA_<vendor>
1575 Enables support for specific chip vendors.
1578 CONFIG_FPGA_<family>
1580 Enables support for FPGA family.
1581 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1585 Specify the number of FPGA devices to support.
1587 CONFIG_SYS_FPGA_PROG_FEEDBACK
1589 Enable printing of hash marks during FPGA configuration.
1591 CONFIG_SYS_FPGA_CHECK_BUSY
1593 Enable checks on FPGA configuration interface busy
1594 status by the configuration function. This option
1595 will require a board or device specific function to
1600 If defined, a function that provides delays in the FPGA
1601 configuration driver.
1603 CONFIG_SYS_FPGA_CHECK_CTRLC
1604 Allow Control-C to interrupt FPGA configuration
1606 CONFIG_SYS_FPGA_CHECK_ERROR
1608 Check for configuration errors during FPGA bitfile
1609 loading. For example, abort during Virtex II
1610 configuration if the INIT_B line goes low (which
1611 indicated a CRC error).
1613 CONFIG_SYS_FPGA_WAIT_INIT
1615 Maximum time to wait for the INIT_B line to deassert
1616 after PROB_B has been deasserted during a Virtex II
1617 FPGA configuration sequence. The default time is 500
1620 CONFIG_SYS_FPGA_WAIT_BUSY
1622 Maximum time to wait for BUSY to deassert during
1623 Virtex II FPGA configuration. The default is 5 ms.
1625 CONFIG_SYS_FPGA_WAIT_CONFIG
1627 Time to wait after FPGA configuration. The default is
1630 - Configuration Management:
1633 If defined, this string will be added to the U-Boot
1634 version information (U_BOOT_VERSION)
1636 - Vendor Parameter Protection:
1638 U-Boot considers the values of the environment
1639 variables "serial#" (Board Serial Number) and
1640 "ethaddr" (Ethernet Address) to be parameters that
1641 are set once by the board vendor / manufacturer, and
1642 protects these variables from casual modification by
1643 the user. Once set, these variables are read-only,
1644 and write or delete attempts are rejected. You can
1645 change this behaviour:
1647 If CONFIG_ENV_OVERWRITE is #defined in your config
1648 file, the write protection for vendor parameters is
1649 completely disabled. Anybody can change or delete
1652 Alternatively, if you #define _both_ CONFIG_ETHADDR
1653 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1654 Ethernet address is installed in the environment,
1655 which can be changed exactly ONCE by the user. [The
1656 serial# is unaffected by this, i. e. it remains
1662 Define this variable to enable the reservation of
1663 "protected RAM", i. e. RAM which is not overwritten
1664 by U-Boot. Define CONFIG_PRAM to hold the number of
1665 kB you want to reserve for pRAM. You can overwrite
1666 this default value by defining an environment
1667 variable "pram" to the number of kB you want to
1668 reserve. Note that the board info structure will
1669 still show the full amount of RAM. If pRAM is
1670 reserved, a new environment variable "mem" will
1671 automatically be defined to hold the amount of
1672 remaining RAM in a form that can be passed as boot
1673 argument to Linux, for instance like that:
1675 setenv bootargs ... mem=\${mem}
1678 This way you can tell Linux not to use this memory,
1679 either, which results in a memory region that will
1680 not be affected by reboots.
1682 *WARNING* If your board configuration uses automatic
1683 detection of the RAM size, you must make sure that
1684 this memory test is non-destructive. So far, the
1685 following board configurations are known to be
1688 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1689 HERMES, IP860, RPXlite, LWMON, LANTEC,
1690 PCU_E, FLAGADM, TQM8260
1695 Define this variable to stop the system in case of a
1696 fatal error, so that you have to reset it manually.
1697 This is probably NOT a good idea for an embedded
1698 system where you want the system to reboot
1699 automatically as fast as possible, but it may be
1700 useful during development since you can try to debug
1701 the conditions that lead to the situation.
1703 CONFIG_NET_RETRY_COUNT
1705 This variable defines the number of retries for
1706 network operations like ARP, RARP, TFTP, or BOOTP
1707 before giving up the operation. If not defined, a
1708 default value of 5 is used.
1712 Timeout waiting for an ARP reply in milliseconds.
1714 - Command Interpreter:
1715 CONFIG_AUTO_COMPLETE
1717 Enable auto completion of commands using TAB.
1719 Note that this feature has NOT been implemented yet
1720 for the "hush" shell.
1723 CONFIG_SYS_HUSH_PARSER
1725 Define this variable to enable the "hush" shell (from
1726 Busybox) as command line interpreter, thus enabling
1727 powerful command line syntax like
1728 if...then...else...fi conditionals or `&&' and '||'
1729 constructs ("shell scripts").
1731 If undefined, you get the old, much simpler behaviour
1732 with a somewhat smaller memory footprint.
1735 CONFIG_SYS_PROMPT_HUSH_PS2
1737 This defines the secondary prompt string, which is
1738 printed when the command interpreter needs more input
1739 to complete a command. Usually "> ".
1743 In the current implementation, the local variables
1744 space and global environment variables space are
1745 separated. Local variables are those you define by
1746 simply typing `name=value'. To access a local
1747 variable later on, you have write `$name' or
1748 `${name}'; to execute the contents of a variable
1749 directly type `$name' at the command prompt.
1751 Global environment variables are those you use
1752 setenv/printenv to work with. To run a command stored
1753 in such a variable, you need to use the run command,
1754 and you must not use the '$' sign to access them.
1756 To store commands and special characters in a
1757 variable, please use double quotation marks
1758 surrounding the whole text of the variable, instead
1759 of the backslashes before semicolons and special
1762 - Commandline Editing and History:
1763 CONFIG_CMDLINE_EDITING
1765 Enable editing and History functions for interactive
1766 commandline input operations
1768 - Default Environment:
1769 CONFIG_EXTRA_ENV_SETTINGS
1771 Define this to contain any number of null terminated
1772 strings (variable = value pairs) that will be part of
1773 the default environment compiled into the boot image.
1775 For example, place something like this in your
1776 board's config file:
1778 #define CONFIG_EXTRA_ENV_SETTINGS \
1782 Warning: This method is based on knowledge about the
1783 internal format how the environment is stored by the
1784 U-Boot code. This is NOT an official, exported
1785 interface! Although it is unlikely that this format
1786 will change soon, there is no guarantee either.
1787 You better know what you are doing here.
1789 Note: overly (ab)use of the default environment is
1790 discouraged. Make sure to check other ways to preset
1791 the environment like the autoscript function or the
1794 - DataFlash Support:
1795 CONFIG_HAS_DATAFLASH
1797 Defining this option enables DataFlash features and
1798 allows to read/write in Dataflash via the standard
1801 - SystemACE Support:
1804 Adding this option adds support for Xilinx SystemACE
1805 chips attached via some sort of local bus. The address
1806 of the chip must also be defined in the
1807 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
1809 #define CONFIG_SYSTEMACE
1810 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
1812 When SystemACE support is added, the "ace" device type
1813 becomes available to the fat commands, i.e. fatls.
1815 - TFTP Fixed UDP Port:
1818 If this is defined, the environment variable tftpsrcp
1819 is used to supply the TFTP UDP source port value.
1820 If tftpsrcp isn't defined, the normal pseudo-random port
1821 number generator is used.
1823 Also, the environment variable tftpdstp is used to supply
1824 the TFTP UDP destination port value. If tftpdstp isn't
1825 defined, the normal port 69 is used.
1827 The purpose for tftpsrcp is to allow a TFTP server to
1828 blindly start the TFTP transfer using the pre-configured
1829 target IP address and UDP port. This has the effect of
1830 "punching through" the (Windows XP) firewall, allowing
1831 the remainder of the TFTP transfer to proceed normally.
1832 A better solution is to properly configure the firewall,
1833 but sometimes that is not allowed.
1835 - Show boot progress:
1836 CONFIG_SHOW_BOOT_PROGRESS
1838 Defining this option allows to add some board-
1839 specific code (calling a user-provided function
1840 "show_boot_progress(int)") that enables you to show
1841 the system's boot progress on some display (for
1842 example, some LED's) on your board. At the moment,
1843 the following checkpoints are implemented:
1845 - Automatic software updates via TFTP server
1847 CONFIG_UPDATE_TFTP_CNT_MAX
1848 CONFIG_UPDATE_TFTP_MSEC_MAX
1850 These options enable and control the auto-update feature;
1851 for a more detailed description refer to doc/README.update.
1853 Legacy uImage format:
1856 1 common/cmd_bootm.c before attempting to boot an image
1857 -1 common/cmd_bootm.c Image header has bad magic number
1858 2 common/cmd_bootm.c Image header has correct magic number
1859 -2 common/cmd_bootm.c Image header has bad checksum
1860 3 common/cmd_bootm.c Image header has correct checksum
1861 -3 common/cmd_bootm.c Image data has bad checksum
1862 4 common/cmd_bootm.c Image data has correct checksum
1863 -4 common/cmd_bootm.c Image is for unsupported architecture
1864 5 common/cmd_bootm.c Architecture check OK
1865 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
1866 6 common/cmd_bootm.c Image Type check OK
1867 -6 common/cmd_bootm.c gunzip uncompression error
1868 -7 common/cmd_bootm.c Unimplemented compression type
1869 7 common/cmd_bootm.c Uncompression OK
1870 8 common/cmd_bootm.c No uncompress/copy overwrite error
1871 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1873 9 common/image.c Start initial ramdisk verification
1874 -10 common/image.c Ramdisk header has bad magic number
1875 -11 common/image.c Ramdisk header has bad checksum
1876 10 common/image.c Ramdisk header is OK
1877 -12 common/image.c Ramdisk data has bad checksum
1878 11 common/image.c Ramdisk data has correct checksum
1879 12 common/image.c Ramdisk verification complete, start loading
1880 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
1881 13 common/image.c Start multifile image verification
1882 14 common/image.c No initial ramdisk, no multifile, continue.
1884 15 lib_<arch>/bootm.c All preparation done, transferring control to OS
1886 -30 lib_ppc/board.c Fatal error, hang the system
1887 -31 post/post.c POST test failed, detected by post_output_backlog()
1888 -32 post/post.c POST test failed, detected by post_run_single()
1890 34 common/cmd_doc.c before loading a Image from a DOC device
1891 -35 common/cmd_doc.c Bad usage of "doc" command
1892 35 common/cmd_doc.c correct usage of "doc" command
1893 -36 common/cmd_doc.c No boot device
1894 36 common/cmd_doc.c correct boot device
1895 -37 common/cmd_doc.c Unknown Chip ID on boot device
1896 37 common/cmd_doc.c correct chip ID found, device available
1897 -38 common/cmd_doc.c Read Error on boot device
1898 38 common/cmd_doc.c reading Image header from DOC device OK
1899 -39 common/cmd_doc.c Image header has bad magic number
1900 39 common/cmd_doc.c Image header has correct magic number
1901 -40 common/cmd_doc.c Error reading Image from DOC device
1902 40 common/cmd_doc.c Image header has correct magic number
1903 41 common/cmd_ide.c before loading a Image from a IDE device
1904 -42 common/cmd_ide.c Bad usage of "ide" command
1905 42 common/cmd_ide.c correct usage of "ide" command
1906 -43 common/cmd_ide.c No boot device
1907 43 common/cmd_ide.c boot device found
1908 -44 common/cmd_ide.c Device not available
1909 44 common/cmd_ide.c Device available
1910 -45 common/cmd_ide.c wrong partition selected
1911 45 common/cmd_ide.c partition selected
1912 -46 common/cmd_ide.c Unknown partition table
1913 46 common/cmd_ide.c valid partition table found
1914 -47 common/cmd_ide.c Invalid partition type
1915 47 common/cmd_ide.c correct partition type
1916 -48 common/cmd_ide.c Error reading Image Header on boot device
1917 48 common/cmd_ide.c reading Image Header from IDE device OK
1918 -49 common/cmd_ide.c Image header has bad magic number
1919 49 common/cmd_ide.c Image header has correct magic number
1920 -50 common/cmd_ide.c Image header has bad checksum
1921 50 common/cmd_ide.c Image header has correct checksum
1922 -51 common/cmd_ide.c Error reading Image from IDE device
1923 51 common/cmd_ide.c reading Image from IDE device OK
1924 52 common/cmd_nand.c before loading a Image from a NAND device
1925 -53 common/cmd_nand.c Bad usage of "nand" command
1926 53 common/cmd_nand.c correct usage of "nand" command
1927 -54 common/cmd_nand.c No boot device
1928 54 common/cmd_nand.c boot device found
1929 -55 common/cmd_nand.c Unknown Chip ID on boot device
1930 55 common/cmd_nand.c correct chip ID found, device available
1931 -56 common/cmd_nand.c Error reading Image Header on boot device
1932 56 common/cmd_nand.c reading Image Header from NAND device OK
1933 -57 common/cmd_nand.c Image header has bad magic number
1934 57 common/cmd_nand.c Image header has correct magic number
1935 -58 common/cmd_nand.c Error reading Image from NAND device
1936 58 common/cmd_nand.c reading Image from NAND device OK
1938 -60 common/env_common.c Environment has a bad CRC, using default
1940 64 net/eth.c starting with Ethernet configuration.
1941 -64 net/eth.c no Ethernet found.
1942 65 net/eth.c Ethernet found.
1944 -80 common/cmd_net.c usage wrong
1945 80 common/cmd_net.c before calling NetLoop()
1946 -81 common/cmd_net.c some error in NetLoop() occurred
1947 81 common/cmd_net.c NetLoop() back without error
1948 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
1949 82 common/cmd_net.c trying automatic boot
1950 83 common/cmd_net.c running autoscript
1951 -83 common/cmd_net.c some error in automatic boot or autoscript
1952 84 common/cmd_net.c end without errors
1957 100 common/cmd_bootm.c Kernel FIT Image has correct format
1958 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
1959 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
1960 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
1961 102 common/cmd_bootm.c Kernel unit name specified
1962 -103 common/cmd_bootm.c Can't get kernel subimage node offset
1963 103 common/cmd_bootm.c Found configuration node
1964 104 common/cmd_bootm.c Got kernel subimage node offset
1965 -104 common/cmd_bootm.c Kernel subimage hash verification failed
1966 105 common/cmd_bootm.c Kernel subimage hash verification OK
1967 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
1968 106 common/cmd_bootm.c Architecture check OK
1969 -106 common/cmd_bootm.c Kernel subimage has wrong type
1970 107 common/cmd_bootm.c Kernel subimage type OK
1971 -107 common/cmd_bootm.c Can't get kernel subimage data/size
1972 108 common/cmd_bootm.c Got kernel subimage data/size
1973 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
1974 -109 common/cmd_bootm.c Can't get kernel subimage type
1975 -110 common/cmd_bootm.c Can't get kernel subimage comp
1976 -111 common/cmd_bootm.c Can't get kernel subimage os
1977 -112 common/cmd_bootm.c Can't get kernel subimage load address
1978 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
1980 120 common/image.c Start initial ramdisk verification
1981 -120 common/image.c Ramdisk FIT image has incorrect format
1982 121 common/image.c Ramdisk FIT image has correct format
1983 122 common/image.c No ramdisk subimage unit name, using configuration
1984 -122 common/image.c Can't get configuration for ramdisk subimage
1985 123 common/image.c Ramdisk unit name specified
1986 -124 common/image.c Can't get ramdisk subimage node offset
1987 125 common/image.c Got ramdisk subimage node offset
1988 -125 common/image.c Ramdisk subimage hash verification failed
1989 126 common/image.c Ramdisk subimage hash verification OK
1990 -126 common/image.c Ramdisk subimage for unsupported architecture
1991 127 common/image.c Architecture check OK
1992 -127 common/image.c Can't get ramdisk subimage data/size
1993 128 common/image.c Got ramdisk subimage data/size
1994 129 common/image.c Can't get ramdisk load address
1995 -129 common/image.c Got ramdisk load address
1997 -130 common/cmd_doc.c Incorrect FIT image format
1998 131 common/cmd_doc.c FIT image format OK
2000 -140 common/cmd_ide.c Incorrect FIT image format
2001 141 common/cmd_ide.c FIT image format OK
2003 -150 common/cmd_nand.c Incorrect FIT image format
2004 151 common/cmd_nand.c FIT image format OK
2010 [so far only for SMDK2400 and TRAB boards]
2012 - Modem support enable:
2013 CONFIG_MODEM_SUPPORT
2015 - RTS/CTS Flow control enable:
2018 - Modem debug support:
2019 CONFIG_MODEM_SUPPORT_DEBUG
2021 Enables debugging stuff (char screen[1024], dbg())
2022 for modem support. Useful only with BDI2000.
2024 - Interrupt support (PPC):
2026 There are common interrupt_init() and timer_interrupt()
2027 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2028 for CPU specific initialization. interrupt_init_cpu()
2029 should set decrementer_count to appropriate value. If
2030 CPU resets decrementer automatically after interrupt
2031 (ppc4xx) it should set decrementer_count to zero.
2032 timer_interrupt() calls timer_interrupt_cpu() for CPU
2033 specific handling. If board has watchdog / status_led
2034 / other_activity_monitor it works automatically from
2035 general timer_interrupt().
2039 In the target system modem support is enabled when a
2040 specific key (key combination) is pressed during
2041 power-on. Otherwise U-Boot will boot normally
2042 (autoboot). The key_pressed() function is called from
2043 board_init(). Currently key_pressed() is a dummy
2044 function, returning 1 and thus enabling modem
2047 If there are no modem init strings in the
2048 environment, U-Boot proceed to autoboot; the
2049 previous output (banner, info printfs) will be
2052 See also: doc/README.Modem
2055 Configuration Settings:
2056 -----------------------
2058 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2059 undefine this when you're short of memory.
2061 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2062 width of the commands listed in the 'help' command output.
2064 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2065 prompt for user input.
2067 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2069 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2071 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2073 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2074 the application (usually a Linux kernel) when it is
2077 - CONFIG_SYS_BAUDRATE_TABLE:
2078 List of legal baudrate settings for this board.
2080 - CONFIG_SYS_CONSOLE_INFO_QUIET
2081 Suppress display of console information at boot.
2083 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2084 If the board specific function
2085 extern int overwrite_console (void);
2086 returns 1, the stdin, stderr and stdout are switched to the
2087 serial port, else the settings in the environment are used.
2089 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2090 Enable the call to overwrite_console().
2092 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2093 Enable overwrite of previous console environment settings.
2095 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2096 Begin and End addresses of the area used by the
2099 - CONFIG_SYS_ALT_MEMTEST:
2100 Enable an alternate, more extensive memory test.
2102 - CONFIG_SYS_MEMTEST_SCRATCH:
2103 Scratch address used by the alternate memory test
2104 You only need to set this if address zero isn't writeable
2106 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2107 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2108 this specified memory area will get subtracted from the top
2109 (end) of RAM and won't get "touched" at all by U-Boot. By
2110 fixing up gd->ram_size the Linux kernel should gets passed
2111 the now "corrected" memory size and won't touch it either.
2112 This should work for arch/ppc and arch/powerpc. Only Linux
2113 board ports in arch/powerpc with bootwrapper support that
2114 recalculate the memory size from the SDRAM controller setup
2115 will have to get fixed in Linux additionally.
2117 This option can be used as a workaround for the 440EPx/GRx
2118 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2121 WARNING: Please make sure that this value is a multiple of
2122 the Linux page size (normally 4k). If this is not the case,
2123 then the end address of the Linux memory will be located at a
2124 non page size aligned address and this could cause major
2127 - CONFIG_SYS_TFTP_LOADADDR:
2128 Default load address for network file downloads
2130 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2131 Enable temporary baudrate change while serial download
2133 - CONFIG_SYS_SDRAM_BASE:
2134 Physical start address of SDRAM. _Must_ be 0 here.
2136 - CONFIG_SYS_MBIO_BASE:
2137 Physical start address of Motherboard I/O (if using a
2140 - CONFIG_SYS_FLASH_BASE:
2141 Physical start address of Flash memory.
2143 - CONFIG_SYS_MONITOR_BASE:
2144 Physical start address of boot monitor code (set by
2145 make config files to be same as the text base address
2146 (TEXT_BASE) used when linking) - same as
2147 CONFIG_SYS_FLASH_BASE when booting from flash.
2149 - CONFIG_SYS_MONITOR_LEN:
2150 Size of memory reserved for monitor code, used to
2151 determine _at_compile_time_ (!) if the environment is
2152 embedded within the U-Boot image, or in a separate
2155 - CONFIG_SYS_MALLOC_LEN:
2156 Size of DRAM reserved for malloc() use.
2158 - CONFIG_SYS_BOOTM_LEN:
2159 Normally compressed uImages are limited to an
2160 uncompressed size of 8 MBytes. If this is not enough,
2161 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2162 to adjust this setting to your needs.
2164 - CONFIG_SYS_BOOTMAPSZ:
2165 Maximum size of memory mapped by the startup code of
2166 the Linux kernel; all data that must be processed by
2167 the Linux kernel (bd_info, boot arguments, FDT blob if
2168 used) must be put below this limit, unless "bootm_low"
2169 enviroment variable is defined and non-zero. In such case
2170 all data for the Linux kernel must be between "bootm_low"
2171 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ.
2173 - CONFIG_SYS_MAX_FLASH_BANKS:
2174 Max number of Flash memory banks
2176 - CONFIG_SYS_MAX_FLASH_SECT:
2177 Max number of sectors on a Flash chip
2179 - CONFIG_SYS_FLASH_ERASE_TOUT:
2180 Timeout for Flash erase operations (in ms)
2182 - CONFIG_SYS_FLASH_WRITE_TOUT:
2183 Timeout for Flash write operations (in ms)
2185 - CONFIG_SYS_FLASH_LOCK_TOUT
2186 Timeout for Flash set sector lock bit operation (in ms)
2188 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2189 Timeout for Flash clear lock bits operation (in ms)
2191 - CONFIG_SYS_FLASH_PROTECTION
2192 If defined, hardware flash sectors protection is used
2193 instead of U-Boot software protection.
2195 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2197 Enable TFTP transfers directly to flash memory;
2198 without this option such a download has to be
2199 performed in two steps: (1) download to RAM, and (2)
2200 copy from RAM to flash.
2202 The two-step approach is usually more reliable, since
2203 you can check if the download worked before you erase
2204 the flash, but in some situations (when system RAM is
2205 too limited to allow for a temporary copy of the
2206 downloaded image) this option may be very useful.
2208 - CONFIG_SYS_FLASH_CFI:
2209 Define if the flash driver uses extra elements in the
2210 common flash structure for storing flash geometry.
2212 - CONFIG_FLASH_CFI_DRIVER
2213 This option also enables the building of the cfi_flash driver
2214 in the drivers directory
2216 - CONFIG_FLASH_CFI_MTD
2217 This option enables the building of the cfi_mtd driver
2218 in the drivers directory. The driver exports CFI flash
2221 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2222 Use buffered writes to flash.
2224 - CONFIG_FLASH_SPANSION_S29WS_N
2225 s29ws-n MirrorBit flash has non-standard addresses for buffered
2228 - CONFIG_SYS_FLASH_QUIET_TEST
2229 If this option is defined, the common CFI flash doesn't
2230 print it's warning upon not recognized FLASH banks. This
2231 is useful, if some of the configured banks are only
2232 optionally available.
2234 - CONFIG_FLASH_SHOW_PROGRESS
2235 If defined (must be an integer), print out countdown
2236 digits and dots. Recommended value: 45 (9..1) for 80
2237 column displays, 15 (3..1) for 40 column displays.
2239 - CONFIG_SYS_RX_ETH_BUFFER:
2240 Defines the number of Ethernet receive buffers. On some
2241 Ethernet controllers it is recommended to set this value
2242 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2243 buffers can be full shortly after enabling the interface
2244 on high Ethernet traffic.
2245 Defaults to 4 if not defined.
2247 The following definitions that deal with the placement and management
2248 of environment data (variable area); in general, we support the
2249 following configurations:
2251 - CONFIG_ENV_IS_IN_FLASH:
2253 Define this if the environment is in flash memory.
2255 a) The environment occupies one whole flash sector, which is
2256 "embedded" in the text segment with the U-Boot code. This
2257 happens usually with "bottom boot sector" or "top boot
2258 sector" type flash chips, which have several smaller
2259 sectors at the start or the end. For instance, such a
2260 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2261 such a case you would place the environment in one of the
2262 4 kB sectors - with U-Boot code before and after it. With
2263 "top boot sector" type flash chips, you would put the
2264 environment in one of the last sectors, leaving a gap
2265 between U-Boot and the environment.
2267 - CONFIG_ENV_OFFSET:
2269 Offset of environment data (variable area) to the
2270 beginning of flash memory; for instance, with bottom boot
2271 type flash chips the second sector can be used: the offset
2272 for this sector is given here.
2274 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2278 This is just another way to specify the start address of
2279 the flash sector containing the environment (instead of
2282 - CONFIG_ENV_SECT_SIZE:
2284 Size of the sector containing the environment.
2287 b) Sometimes flash chips have few, equal sized, BIG sectors.
2288 In such a case you don't want to spend a whole sector for
2293 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2294 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2295 of this flash sector for the environment. This saves
2296 memory for the RAM copy of the environment.
2298 It may also save flash memory if you decide to use this
2299 when your environment is "embedded" within U-Boot code,
2300 since then the remainder of the flash sector could be used
2301 for U-Boot code. It should be pointed out that this is
2302 STRONGLY DISCOURAGED from a robustness point of view:
2303 updating the environment in flash makes it always
2304 necessary to erase the WHOLE sector. If something goes
2305 wrong before the contents has been restored from a copy in
2306 RAM, your target system will be dead.
2308 - CONFIG_ENV_ADDR_REDUND
2309 CONFIG_ENV_SIZE_REDUND
2311 These settings describe a second storage area used to hold
2312 a redundant copy of the environment data, so that there is
2313 a valid backup copy in case there is a power failure during
2314 a "saveenv" operation.
2316 BE CAREFUL! Any changes to the flash layout, and some changes to the
2317 source code will make it necessary to adapt <board>/u-boot.lds*
2321 - CONFIG_ENV_IS_IN_NVRAM:
2323 Define this if you have some non-volatile memory device
2324 (NVRAM, battery buffered SRAM) which you want to use for the
2330 These two #defines are used to determine the memory area you
2331 want to use for environment. It is assumed that this memory
2332 can just be read and written to, without any special
2335 BE CAREFUL! The first access to the environment happens quite early
2336 in U-Boot initalization (when we try to get the setting of for the
2337 console baudrate). You *MUST* have mapped your NVRAM area then, or
2340 Please note that even with NVRAM we still use a copy of the
2341 environment in RAM: we could work on NVRAM directly, but we want to
2342 keep settings there always unmodified except somebody uses "saveenv"
2343 to save the current settings.
2346 - CONFIG_ENV_IS_IN_EEPROM:
2348 Use this if you have an EEPROM or similar serial access
2349 device and a driver for it.
2351 - CONFIG_ENV_OFFSET:
2354 These two #defines specify the offset and size of the
2355 environment area within the total memory of your EEPROM.
2357 - CONFIG_SYS_I2C_EEPROM_ADDR:
2358 If defined, specified the chip address of the EEPROM device.
2359 The default address is zero.
2361 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2362 If defined, the number of bits used to address bytes in a
2363 single page in the EEPROM device. A 64 byte page, for example
2364 would require six bits.
2366 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2367 If defined, the number of milliseconds to delay between
2368 page writes. The default is zero milliseconds.
2370 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2371 The length in bytes of the EEPROM memory array address. Note
2372 that this is NOT the chip address length!
2374 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2375 EEPROM chips that implement "address overflow" are ones
2376 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2377 address and the extra bits end up in the "chip address" bit
2378 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2381 Note that we consider the length of the address field to
2382 still be one byte because the extra address bits are hidden
2383 in the chip address.
2385 - CONFIG_SYS_EEPROM_SIZE:
2386 The size in bytes of the EEPROM device.
2389 - CONFIG_ENV_IS_IN_DATAFLASH:
2391 Define this if you have a DataFlash memory device which you
2392 want to use for the environment.
2394 - CONFIG_ENV_OFFSET:
2398 These three #defines specify the offset and size of the
2399 environment area within the total memory of your DataFlash placed
2400 at the specified address.
2402 - CONFIG_ENV_IS_IN_NAND:
2404 Define this if you have a NAND device which you want to use
2405 for the environment.
2407 - CONFIG_ENV_OFFSET:
2410 These two #defines specify the offset and size of the environment
2411 area within the first NAND device.
2413 - CONFIG_ENV_OFFSET_REDUND
2415 This setting describes a second storage area of CONFIG_ENV_SIZE
2416 size used to hold a redundant copy of the environment data,
2417 so that there is a valid backup copy in case there is a
2418 power failure during a "saveenv" operation.
2420 Note: CONFIG_ENV_OFFSET and CONFIG_ENV_OFFSET_REDUND must be aligned
2421 to a block boundary, and CONFIG_ENV_SIZE must be a multiple of
2422 the NAND devices block size.
2424 - CONFIG_SYS_SPI_INIT_OFFSET
2426 Defines offset to the initial SPI buffer area in DPRAM. The
2427 area is used at an early stage (ROM part) if the environment
2428 is configured to reside in the SPI EEPROM: We need a 520 byte
2429 scratch DPRAM area. It is used between the two initialization
2430 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2431 to be a good choice since it makes it far enough from the
2432 start of the data area as well as from the stack pointer.
2434 Please note that the environment is read-only until the monitor
2435 has been relocated to RAM and a RAM copy of the environment has been
2436 created; also, when using EEPROM you will have to use getenv_r()
2437 until then to read environment variables.
2439 The environment is protected by a CRC32 checksum. Before the monitor
2440 is relocated into RAM, as a result of a bad CRC you will be working
2441 with the compiled-in default environment - *silently*!!! [This is
2442 necessary, because the first environment variable we need is the
2443 "baudrate" setting for the console - if we have a bad CRC, we don't
2444 have any device yet where we could complain.]
2446 Note: once the monitor has been relocated, then it will complain if
2447 the default environment is used; a new CRC is computed as soon as you
2448 use the "saveenv" command to store a valid environment.
2450 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2451 Echo the inverted Ethernet link state to the fault LED.
2453 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2454 also needs to be defined.
2456 - CONFIG_SYS_FAULT_MII_ADDR:
2457 MII address of the PHY to check for the Ethernet link state.
2459 - CONFIG_SYS_64BIT_VSPRINTF:
2460 Makes vsprintf (and all *printf functions) support printing
2461 of 64bit values by using the L quantifier
2463 - CONFIG_SYS_64BIT_STRTOUL:
2464 Adds simple_strtoull that returns a 64bit value
2466 - CONFIG_NS16550_MIN_FUNCTIONS:
2467 Define this if you desire to only have use of the NS16550_init
2468 and NS16550_putc functions for the serial driver located at
2469 drivers/serial/ns16550.c. This option is useful for saving
2470 space for already greatly restricted images, including but not
2471 limited to NAND_SPL configurations.
2473 Low Level (hardware related) configuration options:
2474 ---------------------------------------------------
2476 - CONFIG_SYS_CACHELINE_SIZE:
2477 Cache Line Size of the CPU.
2479 - CONFIG_SYS_DEFAULT_IMMR:
2480 Default address of the IMMR after system reset.
2482 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2483 and RPXsuper) to be able to adjust the position of
2484 the IMMR register after a reset.
2486 - Floppy Disk Support:
2487 CONFIG_SYS_FDC_DRIVE_NUMBER
2489 the default drive number (default value 0)
2491 CONFIG_SYS_ISA_IO_STRIDE
2493 defines the spacing between FDC chipset registers
2496 CONFIG_SYS_ISA_IO_OFFSET
2498 defines the offset of register from address. It
2499 depends on which part of the data bus is connected to
2500 the FDC chipset. (default value 0)
2502 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
2503 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
2506 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
2507 fdc_hw_init() is called at the beginning of the FDC
2508 setup. fdc_hw_init() must be provided by the board
2509 source code. It is used to make hardware dependant
2512 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
2513 DO NOT CHANGE unless you know exactly what you're
2514 doing! (11-4) [MPC8xx/82xx systems only]
2516 - CONFIG_SYS_INIT_RAM_ADDR:
2518 Start address of memory area that can be used for
2519 initial data and stack; please note that this must be
2520 writable memory that is working WITHOUT special
2521 initialization, i. e. you CANNOT use normal RAM which
2522 will become available only after programming the
2523 memory controller and running certain initialization
2526 U-Boot uses the following memory types:
2527 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2528 - MPC824X: data cache
2529 - PPC4xx: data cache
2531 - CONFIG_SYS_GBL_DATA_OFFSET:
2533 Offset of the initial data structure in the memory
2534 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2535 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
2536 data is located at the end of the available space
2537 (sometimes written as (CONFIG_SYS_INIT_RAM_END -
2538 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
2539 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2540 CONFIG_SYS_GBL_DATA_OFFSET) downward.
2543 On the MPC824X (or other systems that use the data
2544 cache for initial memory) the address chosen for
2545 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
2546 point to an otherwise UNUSED address space between
2547 the top of RAM and the start of the PCI space.
2549 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
2551 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
2553 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
2555 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
2557 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2559 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
2561 - CONFIG_SYS_OR_TIMING_SDRAM:
2564 - CONFIG_SYS_MAMR_PTA:
2565 periodic timer for refresh
2567 - CONFIG_SYS_DER: Debug Event Register (37-47)
2569 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2570 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2571 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2572 CONFIG_SYS_BR1_PRELIM:
2573 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2575 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2576 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2577 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
2578 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2580 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
2581 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
2582 Machine Mode Register and Memory Periodic Timer
2583 Prescaler definitions (SDRAM timing)
2585 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
2586 enable I2C microcode relocation patch (MPC8xx);
2587 define relocation offset in DPRAM [DSP2]
2589 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
2590 enable SMC microcode relocation patch (MPC8xx);
2591 define relocation offset in DPRAM [SMC1]
2593 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
2594 enable SPI microcode relocation patch (MPC8xx);
2595 define relocation offset in DPRAM [SCC4]
2597 - CONFIG_SYS_USE_OSCCLK:
2598 Use OSCM clock mode on MBX8xx board. Be careful,
2599 wrong setting might damage your board. Read
2600 doc/README.MBX before setting this variable!
2602 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2603 Offset of the bootmode word in DPRAM used by post
2604 (Power On Self Tests). This definition overrides
2605 #define'd default value in commproc.h resp.
2608 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
2609 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
2610 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
2611 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
2612 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2613 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
2614 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
2615 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
2616 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2618 - CONFIG_PCI_DISABLE_PCIE:
2619 Disable PCI-Express on systems where it is supported but not
2623 Get DDR timing information from an I2C EEPROM. Common
2624 with pluggable memory modules such as SODIMMs
2627 I2C address of the SPD EEPROM
2629 - CONFIG_SYS_SPD_BUS_NUM
2630 If SPD EEPROM is on an I2C bus other than the first
2631 one, specify here. Note that the value must resolve
2632 to something your driver can deal with.
2634 - CONFIG_SYS_83XX_DDR_USES_CS0
2635 Only for 83xx systems. If specified, then DDR should
2636 be configured using CS0 and CS1 instead of CS2 and CS3.
2638 - CONFIG_ETHER_ON_FEC[12]
2639 Define to enable FEC[12] on a 8xx series processor.
2641 - CONFIG_FEC[12]_PHY
2642 Define to the hardcoded PHY address which corresponds
2643 to the given FEC; i. e.
2644 #define CONFIG_FEC1_PHY 4
2645 means that the PHY with address 4 is connected to FEC1
2647 When set to -1, means to probe for first available.
2649 - CONFIG_FEC[12]_PHY_NORXERR
2650 The PHY does not have a RXERR line (RMII only).
2651 (so program the FEC to ignore it).
2654 Enable RMII mode for all FECs.
2655 Note that this is a global option, we can't
2656 have one FEC in standard MII mode and another in RMII mode.
2658 - CONFIG_CRC32_VERIFY
2659 Add a verify option to the crc32 command.
2662 => crc32 -v <address> <count> <crc32>
2664 Where address/count indicate a memory area
2665 and crc32 is the correct crc32 which the
2669 Add the "loopw" memory command. This only takes effect if
2670 the memory commands are activated globally (CONFIG_CMD_MEM).
2673 Add the "mdc" and "mwc" memory commands. These are cyclic
2678 This command will print 4 bytes (10,11,12,13) each 500 ms.
2680 => mwc.l 100 12345678 10
2681 This command will write 12345678 to address 100 all 10 ms.
2683 This only takes effect if the memory commands are activated
2684 globally (CONFIG_CMD_MEM).
2686 - CONFIG_SKIP_LOWLEVEL_INIT
2687 - CONFIG_SKIP_RELOCATE_UBOOT
2689 [ARM only] If these variables are defined, then
2690 certain low level initializations (like setting up
2691 the memory controller) are omitted and/or U-Boot does
2692 not relocate itself into RAM.
2693 Normally these variables MUST NOT be defined. The
2694 only exception is when U-Boot is loaded (to RAM) by
2695 some other boot loader or by a debugger which
2696 performs these initializations itself.
2699 Building the Software:
2700 ======================
2702 Building U-Boot has been tested in several native build environments
2703 and in many different cross environments. Of course we cannot support
2704 all possibly existing versions of cross development tools in all
2705 (potentially obsolete) versions. In case of tool chain problems we
2706 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2707 which is extensively used to build and test U-Boot.
2709 If you are not using a native environment, it is assumed that you
2710 have GNU cross compiling tools available in your path. In this case,
2711 you must set the environment variable CROSS_COMPILE in your shell.
2712 Note that no changes to the Makefile or any other source files are
2713 necessary. For example using the ELDK on a 4xx CPU, please enter:
2715 $ CROSS_COMPILE=ppc_4xx-
2716 $ export CROSS_COMPILE
2718 U-Boot is intended to be simple to build. After installing the
2719 sources you must configure U-Boot for one specific board type. This
2724 where "NAME_config" is the name of one of the existing configu-
2725 rations; see the main Makefile for supported names.
2727 Note: for some board special configuration names may exist; check if
2728 additional information is available from the board vendor; for
2729 instance, the TQM823L systems are available without (standard)
2730 or with LCD support. You can select such additional "features"
2731 when choosing the configuration, i. e.
2734 - will configure for a plain TQM823L, i. e. no LCD support
2736 make TQM823L_LCD_config
2737 - will configure for a TQM823L with U-Boot console on LCD
2742 Finally, type "make all", and you should get some working U-Boot
2743 images ready for download to / installation on your system:
2745 - "u-boot.bin" is a raw binary image
2746 - "u-boot" is an image in ELF binary format
2747 - "u-boot.srec" is in Motorola S-Record format
2749 By default the build is performed locally and the objects are saved
2750 in the source directory. One of the two methods can be used to change
2751 this behavior and build U-Boot to some external directory:
2753 1. Add O= to the make command line invocations:
2755 make O=/tmp/build distclean
2756 make O=/tmp/build NAME_config
2757 make O=/tmp/build all
2759 2. Set environment variable BUILD_DIR to point to the desired location:
2761 export BUILD_DIR=/tmp/build
2766 Note that the command line "O=" setting overrides the BUILD_DIR environment
2770 Please be aware that the Makefiles assume you are using GNU make, so
2771 for instance on NetBSD you might need to use "gmake" instead of
2775 If the system board that you have is not listed, then you will need
2776 to port U-Boot to your hardware platform. To do this, follow these
2779 1. Add a new configuration option for your board to the toplevel
2780 "Makefile" and to the "MAKEALL" script, using the existing
2781 entries as examples. Note that here and at many other places
2782 boards and other names are listed in alphabetical sort order. Please
2784 2. Create a new directory to hold your board specific code. Add any
2785 files you need. In your board directory, you will need at least
2786 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2787 3. Create a new configuration file "include/configs/<board>.h" for
2789 3. If you're porting U-Boot to a new CPU, then also create a new
2790 directory to hold your CPU specific code. Add any files you need.
2791 4. Run "make <board>_config" with your new name.
2792 5. Type "make", and you should get a working "u-boot.srec" file
2793 to be installed on your target system.
2794 6. Debug and solve any problems that might arise.
2795 [Of course, this last step is much harder than it sounds.]
2798 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2799 ==============================================================
2801 If you have modified U-Boot sources (for instance added a new board
2802 or support for new devices, a new CPU, etc.) you are expected to
2803 provide feedback to the other developers. The feedback normally takes
2804 the form of a "patch", i. e. a context diff against a certain (latest
2805 official or latest in the git repository) version of U-Boot sources.
2807 But before you submit such a patch, please verify that your modifi-
2808 cation did not break existing code. At least make sure that *ALL* of
2809 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2810 just run the "MAKEALL" script, which will configure and build U-Boot
2811 for ALL supported system. Be warned, this will take a while. You can
2812 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2813 environment variable to the script, i. e. to use the ELDK cross tools
2816 CROSS_COMPILE=ppc_8xx- MAKEALL
2818 or to build on a native PowerPC system you can type
2820 CROSS_COMPILE=' ' MAKEALL
2822 When using the MAKEALL script, the default behaviour is to build
2823 U-Boot in the source directory. This location can be changed by
2824 setting the BUILD_DIR environment variable. Also, for each target
2825 built, the MAKEALL script saves two log files (<target>.ERR and
2826 <target>.MAKEALL) in the <source dir>/LOG directory. This default
2827 location can be changed by setting the MAKEALL_LOGDIR environment
2828 variable. For example:
2830 export BUILD_DIR=/tmp/build
2831 export MAKEALL_LOGDIR=/tmp/log
2832 CROSS_COMPILE=ppc_8xx- MAKEALL
2834 With the above settings build objects are saved in the /tmp/build,
2835 log files are saved in the /tmp/log and the source tree remains clean
2836 during the whole build process.
2839 See also "U-Boot Porting Guide" below.
2842 Monitor Commands - Overview:
2843 ============================
2845 go - start application at address 'addr'
2846 run - run commands in an environment variable
2847 bootm - boot application image from memory
2848 bootp - boot image via network using BootP/TFTP protocol
2849 tftpboot- boot image via network using TFTP protocol
2850 and env variables "ipaddr" and "serverip"
2851 (and eventually "gatewayip")
2852 rarpboot- boot image via network using RARP/TFTP protocol
2853 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2854 loads - load S-Record file over serial line
2855 loadb - load binary file over serial line (kermit mode)
2857 mm - memory modify (auto-incrementing)
2858 nm - memory modify (constant address)
2859 mw - memory write (fill)
2861 cmp - memory compare
2862 crc32 - checksum calculation
2863 imd - i2c memory display
2864 imm - i2c memory modify (auto-incrementing)
2865 inm - i2c memory modify (constant address)
2866 imw - i2c memory write (fill)
2867 icrc32 - i2c checksum calculation
2868 iprobe - probe to discover valid I2C chip addresses
2869 iloop - infinite loop on address range
2870 isdram - print SDRAM configuration information
2871 sspi - SPI utility commands
2872 base - print or set address offset
2873 printenv- print environment variables
2874 setenv - set environment variables
2875 saveenv - save environment variables to persistent storage
2876 protect - enable or disable FLASH write protection
2877 erase - erase FLASH memory
2878 flinfo - print FLASH memory information
2879 bdinfo - print Board Info structure
2880 iminfo - print header information for application image
2881 coninfo - print console devices and informations
2882 ide - IDE sub-system
2883 loop - infinite loop on address range
2884 loopw - infinite write loop on address range
2885 mtest - simple RAM test
2886 icache - enable or disable instruction cache
2887 dcache - enable or disable data cache
2888 reset - Perform RESET of the CPU
2889 echo - echo args to console
2890 version - print monitor version
2891 help - print online help
2892 ? - alias for 'help'
2895 Monitor Commands - Detailed Description:
2896 ========================================
2900 For now: just type "help <command>".
2903 Environment Variables:
2904 ======================
2906 U-Boot supports user configuration using Environment Variables which
2907 can be made persistent by saving to Flash memory.
2909 Environment Variables are set using "setenv", printed using
2910 "printenv", and saved to Flash using "saveenv". Using "setenv"
2911 without a value can be used to delete a variable from the
2912 environment. As long as you don't save the environment you are
2913 working with an in-memory copy. In case the Flash area containing the
2914 environment is erased by accident, a default environment is provided.
2916 Some configuration options can be set using Environment Variables:
2918 baudrate - see CONFIG_BAUDRATE
2920 bootdelay - see CONFIG_BOOTDELAY
2922 bootcmd - see CONFIG_BOOTCOMMAND
2924 bootargs - Boot arguments when booting an RTOS image
2926 bootfile - Name of the image to load with TFTP
2928 bootm_low - Memory range available for image processing in the bootm
2929 command can be restricted. This variable is given as
2930 a hexadecimal number and defines lowest address allowed
2931 for use by the bootm command. See also "bootm_size"
2932 environment variable. Address defined by "bootm_low" is
2933 also the base of the initial memory mapping for the Linux
2934 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ.
2936 bootm_size - Memory range available for image processing in the bootm
2937 command can be restricted. This variable is given as
2938 a hexadecimal number and defines the size of the region
2939 allowed for use by the bootm command. See also "bootm_low"
2940 environment variable.
2942 updatefile - Location of the software update file on a TFTP server, used
2943 by the automatic software update feature. Please refer to
2944 documentation in doc/README.update for more details.
2946 autoload - if set to "no" (any string beginning with 'n'),
2947 "bootp" will just load perform a lookup of the
2948 configuration from the BOOTP server, but not try to
2949 load any image using TFTP
2951 autoscript - if set to "yes" commands like "loadb", "loady",
2952 "bootp", "tftpb", "rarpboot" and "nfs" will attempt
2953 to automatically run script images (by internally
2954 calling "autoscript").
2956 autoscript_uname - if script image is in a format (FIT) this
2957 variable is used to get script subimage unit name.
2959 autostart - if set to "yes", an image loaded using the "bootp",
2960 "rarpboot", "tftpboot" or "diskboot" commands will
2961 be automatically started (by internally calling
2964 If set to "no", a standalone image passed to the
2965 "bootm" command will be copied to the load address
2966 (and eventually uncompressed), but NOT be started.
2967 This can be used to load and uncompress arbitrary
2970 i2cfast - (PPC405GP|PPC405EP only)
2971 if set to 'y' configures Linux I2C driver for fast
2972 mode (400kHZ). This environment variable is used in
2973 initialization code. So, for changes to be effective
2974 it must be saved and board must be reset.
2976 initrd_high - restrict positioning of initrd images:
2977 If this variable is not set, initrd images will be
2978 copied to the highest possible address in RAM; this
2979 is usually what you want since it allows for
2980 maximum initrd size. If for some reason you want to
2981 make sure that the initrd image is loaded below the
2982 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
2983 variable to a value of "no" or "off" or "0".
2984 Alternatively, you can set it to a maximum upper
2985 address to use (U-Boot will still check that it
2986 does not overwrite the U-Boot stack and data).
2988 For instance, when you have a system with 16 MB
2989 RAM, and want to reserve 4 MB from use by Linux,
2990 you can do this by adding "mem=12M" to the value of
2991 the "bootargs" variable. However, now you must make
2992 sure that the initrd image is placed in the first
2993 12 MB as well - this can be done with
2995 setenv initrd_high 00c00000
2997 If you set initrd_high to 0xFFFFFFFF, this is an
2998 indication to U-Boot that all addresses are legal
2999 for the Linux kernel, including addresses in flash
3000 memory. In this case U-Boot will NOT COPY the
3001 ramdisk at all. This may be useful to reduce the
3002 boot time on your system, but requires that this
3003 feature is supported by your Linux kernel.
3005 ipaddr - IP address; needed for tftpboot command
3007 loadaddr - Default load address for commands like "bootp",
3008 "rarpboot", "tftpboot", "loadb" or "diskboot"
3010 loads_echo - see CONFIG_LOADS_ECHO
3012 serverip - TFTP server IP address; needed for tftpboot command
3014 bootretry - see CONFIG_BOOT_RETRY_TIME
3016 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3018 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3020 ethprime - When CONFIG_NET_MULTI is enabled controls which
3021 interface is used first.
3023 ethact - When CONFIG_NET_MULTI is enabled controls which
3024 interface is currently active. For example you
3025 can do the following
3027 => setenv ethact FEC ETHERNET
3028 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
3029 => setenv ethact SCC ETHERNET
3030 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
3032 ethrotate - When set to "no" U-Boot does not go through all
3033 available network interfaces.
3034 It just stays at the currently selected interface.
3036 netretry - When set to "no" each network operation will
3037 either succeed or fail without retrying.
3038 When set to "once" the network operation will
3039 fail when all the available network interfaces
3040 are tried once without success.
3041 Useful on scripts which control the retry operation
3044 npe_ucode - set load address for the NPE microcode
3046 tftpsrcport - If this is set, the value is used for TFTP's
3049 tftpdstport - If this is set, the value is used for TFTP's UDP
3050 destination port instead of the Well Know Port 69.
3052 vlan - When set to a value < 4095 the traffic over
3053 Ethernet is encapsulated/received over 802.1q
3056 The following environment variables may be used and automatically
3057 updated by the network boot commands ("bootp" and "rarpboot"),
3058 depending the information provided by your boot server:
3060 bootfile - see above
3061 dnsip - IP address of your Domain Name Server
3062 dnsip2 - IP address of your secondary Domain Name Server
3063 gatewayip - IP address of the Gateway (Router) to use
3064 hostname - Target hostname
3066 netmask - Subnet Mask
3067 rootpath - Pathname of the root filesystem on the NFS server
3068 serverip - see above
3071 There are two special Environment Variables:
3073 serial# - contains hardware identification information such
3074 as type string and/or serial number
3075 ethaddr - Ethernet address
3077 These variables can be set only once (usually during manufacturing of
3078 the board). U-Boot refuses to delete or overwrite these variables
3079 once they have been set once.
3082 Further special Environment Variables:
3084 ver - Contains the U-Boot version string as printed
3085 with the "version" command. This variable is
3086 readonly (see CONFIG_VERSION_VARIABLE).
3089 Please note that changes to some configuration parameters may take
3090 only effect after the next boot (yes, that's just like Windoze :-).
3093 Command Line Parsing:
3094 =====================
3096 There are two different command line parsers available with U-Boot:
3097 the old "simple" one, and the much more powerful "hush" shell:
3099 Old, simple command line parser:
3100 --------------------------------
3102 - supports environment variables (through setenv / saveenv commands)
3103 - several commands on one line, separated by ';'
3104 - variable substitution using "... ${name} ..." syntax
3105 - special characters ('$', ';') can be escaped by prefixing with '\',
3107 setenv bootcmd bootm \${address}
3108 - You can also escape text by enclosing in single apostrophes, for example:
3109 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3114 - similar to Bourne shell, with control structures like
3115 if...then...else...fi, for...do...done; while...do...done,
3116 until...do...done, ...
3117 - supports environment ("global") variables (through setenv / saveenv
3118 commands) and local shell variables (through standard shell syntax
3119 "name=value"); only environment variables can be used with "run"
3125 (1) If a command line (or an environment variable executed by a "run"
3126 command) contains several commands separated by semicolon, and
3127 one of these commands fails, then the remaining commands will be
3130 (2) If you execute several variables with one call to run (i. e.
3131 calling run with a list of variables as arguments), any failing
3132 command will cause "run" to terminate, i. e. the remaining
3133 variables are not executed.
3135 Note for Redundant Ethernet Interfaces:
3136 =======================================
3138 Some boards come with redundant Ethernet interfaces; U-Boot supports
3139 such configurations and is capable of automatic selection of a
3140 "working" interface when needed. MAC assignment works as follows:
3142 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3143 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3144 "eth1addr" (=>eth1), "eth2addr", ...
3146 If the network interface stores some valid MAC address (for instance
3147 in SROM), this is used as default address if there is NO correspon-
3148 ding setting in the environment; if the corresponding environment
3149 variable is set, this overrides the settings in the card; that means:
3151 o If the SROM has a valid MAC address, and there is no address in the
3152 environment, the SROM's address is used.
3154 o If there is no valid address in the SROM, and a definition in the
3155 environment exists, then the value from the environment variable is
3158 o If both the SROM and the environment contain a MAC address, and
3159 both addresses are the same, this MAC address is used.
3161 o If both the SROM and the environment contain a MAC address, and the
3162 addresses differ, the value from the environment is used and a
3165 o If neither SROM nor the environment contain a MAC address, an error
3172 U-Boot is capable of booting (and performing other auxiliary operations on)
3173 images in two formats:
3175 New uImage format (FIT)
3176 -----------------------
3178 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3179 to Flattened Device Tree). It allows the use of images with multiple
3180 components (several kernels, ramdisks, etc.), with contents protected by
3181 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3187 Old image format is based on binary files which can be basically anything,
3188 preceded by a special header; see the definitions in include/image.h for
3189 details; basically, the header defines the following image properties:
3191 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3192 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3193 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3194 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3196 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3197 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3198 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
3199 * Compression Type (uncompressed, gzip, bzip2)
3205 The header is marked by a special Magic Number, and both the header
3206 and the data portions of the image are secured against corruption by
3213 Although U-Boot should support any OS or standalone application
3214 easily, the main focus has always been on Linux during the design of
3217 U-Boot includes many features that so far have been part of some
3218 special "boot loader" code within the Linux kernel. Also, any
3219 "initrd" images to be used are no longer part of one big Linux image;
3220 instead, kernel and "initrd" are separate images. This implementation
3221 serves several purposes:
3223 - the same features can be used for other OS or standalone
3224 applications (for instance: using compressed images to reduce the
3225 Flash memory footprint)
3227 - it becomes much easier to port new Linux kernel versions because
3228 lots of low-level, hardware dependent stuff are done by U-Boot
3230 - the same Linux kernel image can now be used with different "initrd"
3231 images; of course this also means that different kernel images can
3232 be run with the same "initrd". This makes testing easier (you don't
3233 have to build a new "zImage.initrd" Linux image when you just
3234 change a file in your "initrd"). Also, a field-upgrade of the
3235 software is easier now.
3241 Porting Linux to U-Boot based systems:
3242 ---------------------------------------
3244 U-Boot cannot save you from doing all the necessary modifications to
3245 configure the Linux device drivers for use with your target hardware
3246 (no, we don't intend to provide a full virtual machine interface to
3249 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
3251 Just make sure your machine specific header file (for instance
3252 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3253 Information structure as we define in include/asm-<arch>/u-boot.h,
3254 and make sure that your definition of IMAP_ADDR uses the same value
3255 as your U-Boot configuration in CONFIG_SYS_IMMR.
3258 Configuring the Linux kernel:
3259 -----------------------------
3261 No specific requirements for U-Boot. Make sure you have some root
3262 device (initial ramdisk, NFS) for your target system.
3265 Building a Linux Image:
3266 -----------------------
3268 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3269 not used. If you use recent kernel source, a new build target
3270 "uImage" will exist which automatically builds an image usable by
3271 U-Boot. Most older kernels also have support for a "pImage" target,
3272 which was introduced for our predecessor project PPCBoot and uses a
3273 100% compatible format.
3282 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3283 encapsulate a compressed Linux kernel image with header information,
3284 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3286 * build a standard "vmlinux" kernel image (in ELF binary format):
3288 * convert the kernel into a raw binary image:
3290 ${CROSS_COMPILE}-objcopy -O binary \
3291 -R .note -R .comment \
3292 -S vmlinux linux.bin
3294 * compress the binary image:
3298 * package compressed binary image for U-Boot:
3300 mkimage -A ppc -O linux -T kernel -C gzip \
3301 -a 0 -e 0 -n "Linux Kernel Image" \
3302 -d linux.bin.gz uImage
3305 The "mkimage" tool can also be used to create ramdisk images for use
3306 with U-Boot, either separated from the Linux kernel image, or
3307 combined into one file. "mkimage" encapsulates the images with a 64
3308 byte header containing information about target architecture,
3309 operating system, image type, compression method, entry points, time
3310 stamp, CRC32 checksums, etc.
3312 "mkimage" can be called in two ways: to verify existing images and
3313 print the header information, or to build new images.
3315 In the first form (with "-l" option) mkimage lists the information
3316 contained in the header of an existing U-Boot image; this includes
3317 checksum verification:
3319 tools/mkimage -l image
3320 -l ==> list image header information
3322 The second form (with "-d" option) is used to build a U-Boot image
3323 from a "data file" which is used as image payload:
3325 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3326 -n name -d data_file image
3327 -A ==> set architecture to 'arch'
3328 -O ==> set operating system to 'os'
3329 -T ==> set image type to 'type'
3330 -C ==> set compression type 'comp'
3331 -a ==> set load address to 'addr' (hex)
3332 -e ==> set entry point to 'ep' (hex)
3333 -n ==> set image name to 'name'
3334 -d ==> use image data from 'datafile'
3336 Right now, all Linux kernels for PowerPC systems use the same load
3337 address (0x00000000), but the entry point address depends on the
3340 - 2.2.x kernels have the entry point at 0x0000000C,
3341 - 2.3.x and later kernels have the entry point at 0x00000000.
3343 So a typical call to build a U-Boot image would read:
3345 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3346 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3347 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
3348 > examples/uImage.TQM850L
3349 Image Name: 2.4.4 kernel for TQM850L
3350 Created: Wed Jul 19 02:34:59 2000
3351 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3352 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3353 Load Address: 0x00000000
3354 Entry Point: 0x00000000
3356 To verify the contents of the image (or check for corruption):
3358 -> tools/mkimage -l examples/uImage.TQM850L
3359 Image Name: 2.4.4 kernel for TQM850L
3360 Created: Wed Jul 19 02:34:59 2000
3361 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3362 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3363 Load Address: 0x00000000
3364 Entry Point: 0x00000000
3366 NOTE: for embedded systems where boot time is critical you can trade
3367 speed for memory and install an UNCOMPRESSED image instead: this
3368 needs more space in Flash, but boots much faster since it does not
3369 need to be uncompressed:
3371 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
3372 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3373 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3374 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
3375 > examples/uImage.TQM850L-uncompressed
3376 Image Name: 2.4.4 kernel for TQM850L
3377 Created: Wed Jul 19 02:34:59 2000
3378 Image Type: PowerPC Linux Kernel Image (uncompressed)
3379 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3380 Load Address: 0x00000000
3381 Entry Point: 0x00000000
3384 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3385 when your kernel is intended to use an initial ramdisk:
3387 -> tools/mkimage -n 'Simple Ramdisk Image' \
3388 > -A ppc -O linux -T ramdisk -C gzip \
3389 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3390 Image Name: Simple Ramdisk Image
3391 Created: Wed Jan 12 14:01:50 2000
3392 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3393 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3394 Load Address: 0x00000000
3395 Entry Point: 0x00000000
3398 Installing a Linux Image:
3399 -------------------------
3401 To downloading a U-Boot image over the serial (console) interface,
3402 you must convert the image to S-Record format:
3404 objcopy -I binary -O srec examples/image examples/image.srec
3406 The 'objcopy' does not understand the information in the U-Boot
3407 image header, so the resulting S-Record file will be relative to
3408 address 0x00000000. To load it to a given address, you need to
3409 specify the target address as 'offset' parameter with the 'loads'
3412 Example: install the image to address 0x40100000 (which on the
3413 TQM8xxL is in the first Flash bank):
3415 => erase 40100000 401FFFFF
3421 ## Ready for S-Record download ...
3422 ~>examples/image.srec
3423 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3425 15989 15990 15991 15992
3426 [file transfer complete]
3428 ## Start Addr = 0x00000000
3431 You can check the success of the download using the 'iminfo' command;
3432 this includes a checksum verification so you can be sure no data
3433 corruption happened:
3437 ## Checking Image at 40100000 ...
3438 Image Name: 2.2.13 for initrd on TQM850L
3439 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3440 Data Size: 335725 Bytes = 327 kB = 0 MB
3441 Load Address: 00000000
3442 Entry Point: 0000000c
3443 Verifying Checksum ... OK
3449 The "bootm" command is used to boot an application that is stored in
3450 memory (RAM or Flash). In case of a Linux kernel image, the contents
3451 of the "bootargs" environment variable is passed to the kernel as
3452 parameters. You can check and modify this variable using the
3453 "printenv" and "setenv" commands:
3456 => printenv bootargs
3457 bootargs=root=/dev/ram
3459 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3461 => printenv bootargs
3462 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3465 ## Booting Linux kernel at 40020000 ...
3466 Image Name: 2.2.13 for NFS on TQM850L
3467 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3468 Data Size: 381681 Bytes = 372 kB = 0 MB
3469 Load Address: 00000000
3470 Entry Point: 0000000c
3471 Verifying Checksum ... OK
3472 Uncompressing Kernel Image ... OK
3473 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
3474 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3475 time_init: decrementer frequency = 187500000/60
3476 Calibrating delay loop... 49.77 BogoMIPS
3477 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3480 If you want to boot a Linux kernel with initial RAM disk, you pass
3481 the memory addresses of both the kernel and the initrd image (PPBCOOT
3482 format!) to the "bootm" command:
3484 => imi 40100000 40200000
3486 ## Checking Image at 40100000 ...
3487 Image Name: 2.2.13 for initrd on TQM850L
3488 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3489 Data Size: 335725 Bytes = 327 kB = 0 MB
3490 Load Address: 00000000
3491 Entry Point: 0000000c
3492 Verifying Checksum ... OK
3494 ## Checking Image at 40200000 ...
3495 Image Name: Simple Ramdisk Image
3496 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3497 Data Size: 566530 Bytes = 553 kB = 0 MB
3498 Load Address: 00000000
3499 Entry Point: 00000000
3500 Verifying Checksum ... OK
3502 => bootm 40100000 40200000
3503 ## Booting Linux kernel at 40100000 ...
3504 Image Name: 2.2.13 for initrd on TQM850L
3505 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3506 Data Size: 335725 Bytes = 327 kB = 0 MB
3507 Load Address: 00000000
3508 Entry Point: 0000000c
3509 Verifying Checksum ... OK
3510 Uncompressing Kernel Image ... OK
3511 ## Loading RAMDisk Image at 40200000 ...
3512 Image Name: Simple Ramdisk Image
3513 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3514 Data Size: 566530 Bytes = 553 kB = 0 MB
3515 Load Address: 00000000
3516 Entry Point: 00000000
3517 Verifying Checksum ... OK
3518 Loading Ramdisk ... OK
3519 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
3520 Boot arguments: root=/dev/ram
3521 time_init: decrementer frequency = 187500000/60
3522 Calibrating delay loop... 49.77 BogoMIPS
3524 RAMDISK: Compressed image found at block 0
3525 VFS: Mounted root (ext2 filesystem).
3529 Boot Linux and pass a flat device tree:
3532 First, U-Boot must be compiled with the appropriate defines. See the section
3533 titled "Linux Kernel Interface" above for a more in depth explanation. The
3534 following is an example of how to start a kernel and pass an updated
3540 oft=oftrees/mpc8540ads.dtb
3541 => tftp $oftaddr $oft
3542 Speed: 1000, full duplex
3544 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3545 Filename 'oftrees/mpc8540ads.dtb'.
3546 Load address: 0x300000
3549 Bytes transferred = 4106 (100a hex)
3550 => tftp $loadaddr $bootfile
3551 Speed: 1000, full duplex
3553 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3555 Load address: 0x200000
3556 Loading:############
3558 Bytes transferred = 1029407 (fb51f hex)
3563 => bootm $loadaddr - $oftaddr
3564 ## Booting image at 00200000 ...
3565 Image Name: Linux-2.6.17-dirty
3566 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3567 Data Size: 1029343 Bytes = 1005.2 kB
3568 Load Address: 00000000
3569 Entry Point: 00000000
3570 Verifying Checksum ... OK
3571 Uncompressing Kernel Image ... OK
3572 Booting using flat device tree at 0x300000
3573 Using MPC85xx ADS machine description
3574 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3578 More About U-Boot Image Types:
3579 ------------------------------
3581 U-Boot supports the following image types:
3583 "Standalone Programs" are directly runnable in the environment
3584 provided by U-Boot; it is expected that (if they behave
3585 well) you can continue to work in U-Boot after return from
3586 the Standalone Program.
3587 "OS Kernel Images" are usually images of some Embedded OS which
3588 will take over control completely. Usually these programs
3589 will install their own set of exception handlers, device
3590 drivers, set up the MMU, etc. - this means, that you cannot
3591 expect to re-enter U-Boot except by resetting the CPU.
3592 "RAMDisk Images" are more or less just data blocks, and their
3593 parameters (address, size) are passed to an OS kernel that is
3595 "Multi-File Images" contain several images, typically an OS
3596 (Linux) kernel image and one or more data images like
3597 RAMDisks. This construct is useful for instance when you want
3598 to boot over the network using BOOTP etc., where the boot
3599 server provides just a single image file, but you want to get
3600 for instance an OS kernel and a RAMDisk image.
3602 "Multi-File Images" start with a list of image sizes, each
3603 image size (in bytes) specified by an "uint32_t" in network
3604 byte order. This list is terminated by an "(uint32_t)0".
3605 Immediately after the terminating 0 follow the images, one by
3606 one, all aligned on "uint32_t" boundaries (size rounded up to
3607 a multiple of 4 bytes).
3609 "Firmware Images" are binary images containing firmware (like
3610 U-Boot or FPGA images) which usually will be programmed to
3613 "Script files" are command sequences that will be executed by
3614 U-Boot's command interpreter; this feature is especially
3615 useful when you configure U-Boot to use a real shell (hush)
3616 as command interpreter.
3622 One of the features of U-Boot is that you can dynamically load and
3623 run "standalone" applications, which can use some resources of
3624 U-Boot like console I/O functions or interrupt services.
3626 Two simple examples are included with the sources:
3631 'examples/hello_world.c' contains a small "Hello World" Demo
3632 application; it is automatically compiled when you build U-Boot.
3633 It's configured to run at address 0x00040004, so you can play with it
3637 ## Ready for S-Record download ...
3638 ~>examples/hello_world.srec
3639 1 2 3 4 5 6 7 8 9 10 11 ...
3640 [file transfer complete]
3642 ## Start Addr = 0x00040004
3644 => go 40004 Hello World! This is a test.
3645 ## Starting application at 0x00040004 ...
3656 Hit any key to exit ...
3658 ## Application terminated, rc = 0x0
3660 Another example, which demonstrates how to register a CPM interrupt
3661 handler with the U-Boot code, can be found in 'examples/timer.c'.
3662 Here, a CPM timer is set up to generate an interrupt every second.
3663 The interrupt service routine is trivial, just printing a '.'
3664 character, but this is just a demo program. The application can be
3665 controlled by the following keys:
3667 ? - print current values og the CPM Timer registers
3668 b - enable interrupts and start timer
3669 e - stop timer and disable interrupts
3670 q - quit application
3673 ## Ready for S-Record download ...
3674 ~>examples/timer.srec
3675 1 2 3 4 5 6 7 8 9 10 11 ...
3676 [file transfer complete]
3678 ## Start Addr = 0x00040004
3681 ## Starting application at 0x00040004 ...
3684 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3687 [q, b, e, ?] Set interval 1000000 us
3690 [q, b, e, ?] ........
3691 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3694 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3697 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3700 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3702 [q, b, e, ?] ...Stopping timer
3704 [q, b, e, ?] ## Application terminated, rc = 0x0
3710 Over time, many people have reported problems when trying to use the
3711 "minicom" terminal emulation program for serial download. I (wd)
3712 consider minicom to be broken, and recommend not to use it. Under
3713 Unix, I recommend to use C-Kermit for general purpose use (and
3714 especially for kermit binary protocol download ("loadb" command), and
3715 use "cu" for S-Record download ("loads" command).
3717 Nevertheless, if you absolutely want to use it try adding this
3718 configuration to your "File transfer protocols" section:
3720 Name Program Name U/D FullScr IO-Red. Multi
3721 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3722 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3728 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3729 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3731 Building requires a cross environment; it is known to work on
3732 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3733 need gmake since the Makefiles are not compatible with BSD make).
3734 Note that the cross-powerpc package does not install include files;
3735 attempting to build U-Boot will fail because <machine/ansi.h> is
3736 missing. This file has to be installed and patched manually:
3738 # cd /usr/pkg/cross/powerpc-netbsd/include
3740 # ln -s powerpc machine
3741 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3742 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3744 Native builds *don't* work due to incompatibilities between native
3745 and U-Boot include files.
3747 Booting assumes that (the first part of) the image booted is a
3748 stage-2 loader which in turn loads and then invokes the kernel
3749 proper. Loader sources will eventually appear in the NetBSD source
3750 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3751 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3754 Implementation Internals:
3755 =========================
3757 The following is not intended to be a complete description of every
3758 implementation detail. However, it should help to understand the
3759 inner workings of U-Boot and make it easier to port it to custom
3763 Initial Stack, Global Data:
3764 ---------------------------
3766 The implementation of U-Boot is complicated by the fact that U-Boot
3767 starts running out of ROM (flash memory), usually without access to
3768 system RAM (because the memory controller is not initialized yet).
3769 This means that we don't have writable Data or BSS segments, and BSS
3770 is not initialized as zero. To be able to get a C environment working
3771 at all, we have to allocate at least a minimal stack. Implementation
3772 options for this are defined and restricted by the CPU used: Some CPU
3773 models provide on-chip memory (like the IMMR area on MPC8xx and
3774 MPC826x processors), on others (parts of) the data cache can be
3775 locked as (mis-) used as memory, etc.
3777 Chris Hallinan posted a good summary of these issues to the
3778 U-Boot mailing list:
3780 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3781 From: "Chris Hallinan" <clh@net1plus.com>
3782 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3785 Correct me if I'm wrong, folks, but the way I understand it
3786 is this: Using DCACHE as initial RAM for Stack, etc, does not
3787 require any physical RAM backing up the cache. The cleverness
3788 is that the cache is being used as a temporary supply of
3789 necessary storage before the SDRAM controller is setup. It's
3790 beyond the scope of this list to explain the details, but you
3791 can see how this works by studying the cache architecture and
3792 operation in the architecture and processor-specific manuals.
3794 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3795 is another option for the system designer to use as an
3796 initial stack/RAM area prior to SDRAM being available. Either
3797 option should work for you. Using CS 4 should be fine if your
3798 board designers haven't used it for something that would
3799 cause you grief during the initial boot! It is frequently not
3802 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
3803 with your processor/board/system design. The default value
3804 you will find in any recent u-boot distribution in
3805 walnut.h should work for you. I'd set it to a value larger
3806 than your SDRAM module. If you have a 64MB SDRAM module, set
3807 it above 400_0000. Just make sure your board has no resources
3808 that are supposed to respond to that address! That code in
3809 start.S has been around a while and should work as is when
3810 you get the config right.
3815 It is essential to remember this, since it has some impact on the C
3816 code for the initialization procedures:
3818 * Initialized global data (data segment) is read-only. Do not attempt
3821 * Do not use any uninitialized global data (or implicitely initialized
3822 as zero data - BSS segment) at all - this is undefined, initiali-
3823 zation is performed later (when relocating to RAM).
3825 * Stack space is very limited. Avoid big data buffers or things like
3828 Having only the stack as writable memory limits means we cannot use
3829 normal global data to share information beween the code. But it
3830 turned out that the implementation of U-Boot can be greatly
3831 simplified by making a global data structure (gd_t) available to all
3832 functions. We could pass a pointer to this data as argument to _all_
3833 functions, but this would bloat the code. Instead we use a feature of
3834 the GCC compiler (Global Register Variables) to share the data: we
3835 place a pointer (gd) to the global data into a register which we
3836 reserve for this purpose.
3838 When choosing a register for such a purpose we are restricted by the
3839 relevant (E)ABI specifications for the current architecture, and by
3840 GCC's implementation.
3842 For PowerPC, the following registers have specific use:
3844 R2: reserved for system use
3845 R3-R4: parameter passing and return values
3846 R5-R10: parameter passing
3847 R13: small data area pointer
3851 (U-Boot also uses R14 as internal GOT pointer.)
3853 ==> U-Boot will use R2 to hold a pointer to the global data
3855 Note: on PPC, we could use a static initializer (since the
3856 address of the global data structure is known at compile time),
3857 but it turned out that reserving a register results in somewhat
3858 smaller code - although the code savings are not that big (on
3859 average for all boards 752 bytes for the whole U-Boot image,
3860 624 text + 127 data).
3862 On Blackfin, the normal C ABI (except for P5) is followed as documented here:
3863 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
3865 ==> U-Boot will use P5 to hold a pointer to the global data
3867 On ARM, the following registers are used:
3869 R0: function argument word/integer result
3870 R1-R3: function argument word
3872 R10: stack limit (used only if stack checking if enabled)
3873 R11: argument (frame) pointer
3874 R12: temporary workspace
3877 R15: program counter
3879 ==> U-Boot will use R8 to hold a pointer to the global data
3881 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3882 or current versions of GCC may "optimize" the code too much.
3887 U-Boot runs in system state and uses physical addresses, i.e. the
3888 MMU is not used either for address mapping nor for memory protection.
3890 The available memory is mapped to fixed addresses using the memory
3891 controller. In this process, a contiguous block is formed for each
3892 memory type (Flash, SDRAM, SRAM), even when it consists of several
3893 physical memory banks.
3895 U-Boot is installed in the first 128 kB of the first Flash bank (on
3896 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3897 booting and sizing and initializing DRAM, the code relocates itself
3898 to the upper end of DRAM. Immediately below the U-Boot code some
3899 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
3900 configuration setting]. Below that, a structure with global Board
3901 Info data is placed, followed by the stack (growing downward).
3903 Additionally, some exception handler code is copied to the low 8 kB
3904 of DRAM (0x00000000 ... 0x00001FFF).
3906 So a typical memory configuration with 16 MB of DRAM could look like
3909 0x0000 0000 Exception Vector code
3912 0x0000 2000 Free for Application Use
3918 0x00FB FF20 Monitor Stack (Growing downward)
3919 0x00FB FFAC Board Info Data and permanent copy of global data
3920 0x00FC 0000 Malloc Arena
3923 0x00FE 0000 RAM Copy of Monitor Code
3924 ... eventually: LCD or video framebuffer
3925 ... eventually: pRAM (Protected RAM - unchanged by reset)
3926 0x00FF FFFF [End of RAM]
3929 System Initialization:
3930 ----------------------
3932 In the reset configuration, U-Boot starts at the reset entry point
3933 (on most PowerPC systems at address 0x00000100). Because of the reset
3934 configuration for CS0# this is a mirror of the onboard Flash memory.
3935 To be able to re-map memory U-Boot then jumps to its link address.
3936 To be able to implement the initialization code in C, a (small!)
3937 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3938 which provide such a feature like MPC8xx or MPC8260), or in a locked
3939 part of the data cache. After that, U-Boot initializes the CPU core,
3940 the caches and the SIU.
3942 Next, all (potentially) available memory banks are mapped using a
3943 preliminary mapping. For example, we put them on 512 MB boundaries
3944 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3945 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3946 programmed for SDRAM access. Using the temporary configuration, a
3947 simple memory test is run that determines the size of the SDRAM
3950 When there is more than one SDRAM bank, and the banks are of
3951 different size, the largest is mapped first. For equal size, the first
3952 bank (CS2#) is mapped first. The first mapping is always for address
3953 0x00000000, with any additional banks following immediately to create
3954 contiguous memory starting from 0.
3956 Then, the monitor installs itself at the upper end of the SDRAM area
3957 and allocates memory for use by malloc() and for the global Board
3958 Info data; also, the exception vector code is copied to the low RAM
3959 pages, and the final stack is set up.
3961 Only after this relocation will you have a "normal" C environment;
3962 until that you are restricted in several ways, mostly because you are
3963 running from ROM, and because the code will have to be relocated to a
3967 U-Boot Porting Guide:
3968 ----------------------
3970 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3974 int main (int argc, char *argv[])
3976 sighandler_t no_more_time;
3978 signal (SIGALRM, no_more_time);
3979 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3981 if (available_money > available_manpower) {
3982 pay consultant to port U-Boot;
3986 Download latest U-Boot source;
3988 Subscribe to u-boot mailing list;
3991 email ("Hi, I am new to U-Boot, how do I get started?");
3995 Read the README file in the top level directory;
3996 Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
3997 Read the source, Luke;
4000 if (available_money > toLocalCurrency ($2500)) {
4003 Add a lot of aggravation and time;
4006 Create your own board support subdirectory;
4008 Create your own board config file;
4012 Add / modify source code;
4016 email ("Hi, I am having problems...");
4018 Send patch file to Wolfgang;
4023 void no_more_time (int sig)
4032 All contributions to U-Boot should conform to the Linux kernel
4033 coding style; see the file "Documentation/CodingStyle" and the script
4034 "scripts/Lindent" in your Linux kernel source directory. In sources
4035 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
4036 spaces before parameters to function calls) is actually used.
4038 Source files originating from a different project (for example the
4039 MTD subsystem) are generally exempt from these guidelines and are not
4040 reformated to ease subsequent migration to newer versions of those
4043 Please note that U-Boot is implemented in C (and to some small parts in
4044 Assembler); no C++ is used, so please do not use C++ style comments (//)
4047 Please also stick to the following formatting rules:
4048 - remove any trailing white space
4049 - use TAB characters for indentation, not spaces
4050 - make sure NOT to use DOS '\r\n' line feeds
4051 - do not add more than 2 empty lines to source files
4052 - do not add trailing empty lines to source files
4054 Submissions which do not conform to the standards may be returned
4055 with a request to reformat the changes.
4061 Since the number of patches for U-Boot is growing, we need to
4062 establish some rules. Submissions which do not conform to these rules
4063 may be rejected, even when they contain important and valuable stuff.
4065 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4067 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4068 see http://lists.denx.de/mailman/listinfo/u-boot
4070 When you send a patch, please include the following information with
4073 * For bug fixes: a description of the bug and how your patch fixes
4074 this bug. Please try to include a way of demonstrating that the
4075 patch actually fixes something.
4077 * For new features: a description of the feature and your
4080 * A CHANGELOG entry as plaintext (separate from the patch)
4082 * For major contributions, your entry to the CREDITS file
4084 * When you add support for a new board, don't forget to add this
4085 board to the MAKEALL script, too.
4087 * If your patch adds new configuration options, don't forget to
4088 document these in the README file.
4090 * The patch itself. If you are using git (which is *strongly*
4091 recommended) you can easily generate the patch using the
4092 "git-format-patch". If you then use "git-send-email" to send it to
4093 the U-Boot mailing list, you will avoid most of the common problems
4094 with some other mail clients.
4096 If you cannot use git, use "diff -purN OLD NEW". If your version of
4097 diff does not support these options, then get the latest version of
4100 The current directory when running this command shall be the parent
4101 directory of the U-Boot source tree (i. e. please make sure that
4102 your patch includes sufficient directory information for the
4105 We prefer patches as plain text. MIME attachments are discouraged,
4106 and compressed attachments must not be used.
4108 * If one logical set of modifications affects or creates several
4109 files, all these changes shall be submitted in a SINGLE patch file.
4111 * Changesets that contain different, unrelated modifications shall be
4112 submitted as SEPARATE patches, one patch per changeset.
4117 * Before sending the patch, run the MAKEALL script on your patched
4118 source tree and make sure that no errors or warnings are reported
4119 for any of the boards.
4121 * Keep your modifications to the necessary minimum: A patch
4122 containing several unrelated changes or arbitrary reformats will be
4123 returned with a request to re-formatting / split it.
4125 * If you modify existing code, make sure that your new code does not
4126 add to the memory footprint of the code ;-) Small is beautiful!
4127 When adding new features, these should compile conditionally only
4128 (using #ifdef), and the resulting code with the new feature
4129 disabled must not need more memory than the old code without your
4132 * Remember that there is a size limit of 100 kB per message on the
4133 u-boot mailing list. Bigger patches will be moderated. If they are
4134 reasonable and not too big, they will be acknowledged. But patches
4135 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob