2 # (C) Copyright 2000 - 2008
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # See file CREDITS for list of people who contributed to this
8 # This program is free software; you can redistribute it and/or
9 # modify it under the terms of the GNU General Public License as
10 # published by the Free Software Foundation; either version 2 of
11 # the License, or (at your option) any later version.
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with this program; if not, write to the Free Software
20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27 This directory contains the source code for U-Boot, a boot loader for
28 Embedded boards based on PowerPC, ARM, MIPS and several other
29 processors, which can be installed in a boot ROM and used to
30 initialize and test the hardware or to download and run application
33 The development of U-Boot is closely related to Linux: some parts of
34 the source code originate in the Linux source tree, we have some
35 header files in common, and special provision has been made to
36 support booting of Linux images.
38 Some attention has been paid to make this software easily
39 configurable and extendable. For instance, all monitor commands are
40 implemented with the same call interface, so that it's very easy to
41 add new commands. Also, instead of permanently adding rarely used
42 code (for instance hardware test utilities) to the monitor, you can
43 load and run it dynamically.
49 In general, all boards for which a configuration option exists in the
50 Makefile have been tested to some extent and can be considered
51 "working". In fact, many of them are used in production systems.
53 In case of problems see the CHANGELOG and CREDITS files to find out
54 who contributed the specific port. The MAINTAINERS file lists board
61 In case you have questions about, problems with or contributions for
62 U-Boot you should send a message to the U-Boot mailing list at
63 <u-boot@lists.denx.de>. There is also an archive of previous traffic
64 on the mailing list - please search the archive before asking FAQ's.
65 Please see http://lists.denx.de/pipermail/u-boot and
66 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
69 Where to get source code:
70 =========================
72 The U-Boot source code is maintained in the git repository at
73 git://www.denx.de/git/u-boot.git ; you can browse it online at
74 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
76 The "snapshot" links on this page allow you to download tarballs of
77 any version you might be interested in. Official releases are also
78 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
81 Pre-built (and tested) images are available from
82 ftp://ftp.denx.de/pub/u-boot/images/
88 - start from 8xxrom sources
89 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
91 - make it easier to add custom boards
92 - make it possible to add other [PowerPC] CPUs
93 - extend functions, especially:
94 * Provide extended interface to Linux boot loader
97 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
98 - create ARMBoot project (http://sourceforge.net/projects/armboot)
99 - add other CPU families (starting with ARM)
100 - create U-Boot project (http://sourceforge.net/projects/u-boot)
101 - current project page: see http://www.denx.de/wiki/U-Boot
107 The "official" name of this project is "Das U-Boot". The spelling
108 "U-Boot" shall be used in all written text (documentation, comments
109 in source files etc.). Example:
111 This is the README file for the U-Boot project.
113 File names etc. shall be based on the string "u-boot". Examples:
115 include/asm-ppc/u-boot.h
117 #include <asm/u-boot.h>
119 Variable names, preprocessor constants etc. shall be either based on
120 the string "u_boot" or on "U_BOOT". Example:
122 U_BOOT_VERSION u_boot_logo
123 IH_OS_U_BOOT u_boot_hush_start
129 U-Boot uses a 3 level version number containing a version, a
130 sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2",
131 sub-version "34", and patchlevel "4".
133 The patchlevel is used to indicate certain stages of development
134 between released versions, i. e. officially released versions of
135 U-Boot will always have a patchlevel of "0".
141 - board Board dependent files
142 - common Misc architecture independent functions
143 - cpu CPU specific files
144 - 74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
145 - arm720t Files specific to ARM 720 CPUs
146 - arm920t Files specific to ARM 920 CPUs
147 - at91rm9200 Files specific to Atmel AT91RM9200 CPU
148 - imx Files specific to Freescale MC9328 i.MX CPUs
149 - s3c24x0 Files specific to Samsung S3C24X0 CPUs
150 - arm925t Files specific to ARM 925 CPUs
151 - arm926ejs Files specific to ARM 926 CPUs
152 - arm1136 Files specific to ARM 1136 CPUs
153 - at32ap Files specific to Atmel AVR32 AP CPUs
154 - blackfin Files specific to Analog Devices Blackfin CPUs
155 - i386 Files specific to i386 CPUs
156 - ixp Files specific to Intel XScale IXP CPUs
157 - leon2 Files specific to Gaisler LEON2 SPARC CPU
158 - leon3 Files specific to Gaisler LEON3 SPARC CPU
159 - mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 - mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 - mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 - mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 - mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 - mips Files specific to MIPS CPUs
165 - mpc5xx Files specific to Freescale MPC5xx CPUs
166 - mpc5xxx Files specific to Freescale MPC5xxx CPUs
167 - mpc8xx Files specific to Freescale MPC8xx CPUs
168 - mpc8220 Files specific to Freescale MPC8220 CPUs
169 - mpc824x Files specific to Freescale MPC824x CPUs
170 - mpc8260 Files specific to Freescale MPC8260 CPUs
171 - mpc85xx Files specific to Freescale MPC85xx CPUs
172 - nios Files specific to Altera NIOS CPUs
173 - nios2 Files specific to Altera Nios-II CPUs
174 - ppc4xx Files specific to AMCC PowerPC 4xx CPUs
175 - pxa Files specific to Intel XScale PXA CPUs
176 - s3c44b0 Files specific to Samsung S3C44B0 CPUs
177 - sa1100 Files specific to Intel StrongARM SA1100 CPUs
178 - disk Code for disk drive partition handling
179 - doc Documentation (don't expect too much)
180 - drivers Commonly used device drivers
181 - dtt Digital Thermometer and Thermostat drivers
182 - examples Example code for standalone applications, etc.
183 - include Header Files
184 - lib_arm Files generic to ARM architecture
185 - lib_avr32 Files generic to AVR32 architecture
186 - lib_blackfin Files generic to Blackfin architecture
187 - lib_generic Files generic to all architectures
188 - lib_i386 Files generic to i386 architecture
189 - lib_m68k Files generic to m68k architecture
190 - lib_mips Files generic to MIPS architecture
191 - lib_nios Files generic to NIOS architecture
192 - lib_ppc Files generic to PowerPC architecture
193 - lib_sparc Files generic to SPARC architecture
194 - libfdt Library files to support flattened device trees
195 - net Networking code
196 - post Power On Self Test
197 - rtc Real Time Clock drivers
198 - tools Tools to build S-Record or U-Boot images, etc.
200 Software Configuration:
201 =======================
203 Configuration is usually done using C preprocessor defines; the
204 rationale behind that is to avoid dead code whenever possible.
206 There are two classes of configuration variables:
208 * Configuration _OPTIONS_:
209 These are selectable by the user and have names beginning with
212 * Configuration _SETTINGS_:
213 These depend on the hardware etc. and should not be meddled with if
214 you don't know what you're doing; they have names beginning with
217 Later we will add a configuration tool - probably similar to or even
218 identical to what's used for the Linux kernel. Right now, we have to
219 do the configuration by hand, which means creating some symbolic
220 links and editing some configuration files. We use the TQM8xxL boards
224 Selection of Processor Architecture and Board Type:
225 ---------------------------------------------------
227 For all supported boards there are ready-to-use default
228 configurations available; just type "make <board_name>_config".
230 Example: For a TQM823L module type:
235 For the Cogent platform, you need to specify the CPU type as well;
236 e.g. "make cogent_mpc8xx_config". And also configure the cogent
237 directory according to the instructions in cogent/README.
240 Configuration Options:
241 ----------------------
243 Configuration depends on the combination of board and CPU type; all
244 such information is kept in a configuration file
245 "include/configs/<board_name>.h".
247 Example: For a TQM823L module, all configuration settings are in
248 "include/configs/TQM823L.h".
251 Many of the options are named exactly as the corresponding Linux
252 kernel configuration options. The intention is to make it easier to
253 build a config tool - later.
256 The following options need to be configured:
258 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
260 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
262 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
263 Define exactly one, e.g. CONFIG_ATSTK1002
265 - CPU Module Type: (if CONFIG_COGENT is defined)
266 Define exactly one of
268 --- FIXME --- not tested yet:
269 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
270 CONFIG_CMA287_23, CONFIG_CMA287_50
272 - Motherboard Type: (if CONFIG_COGENT is defined)
273 Define exactly one of
274 CONFIG_CMA101, CONFIG_CMA102
276 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
277 Define one or more of
280 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
281 Define one or more of
282 CONFIG_LCD_HEARTBEAT - update a character position on
283 the LCD display every second with
286 - Board flavour: (if CONFIG_MPC8260ADS is defined)
289 CONFIG_SYS_8260ADS - original MPC8260ADS
290 CONFIG_SYS_8266ADS - MPC8266ADS
291 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
292 CONFIG_SYS_8272ADS - MPC8272ADS
294 - MPC824X Family Member (if CONFIG_MPC824X is defined)
295 Define exactly one of
296 CONFIG_MPC8240, CONFIG_MPC8245
298 - 8xx CPU Options: (if using an MPC8xx CPU)
299 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
300 get_gclk_freq() cannot work
301 e.g. if there is no 32KHz
302 reference PIT/RTC clock
303 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
306 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
307 CONFIG_SYS_8xx_CPUCLK_MIN
308 CONFIG_SYS_8xx_CPUCLK_MAX
309 CONFIG_8xx_CPUCLK_DEFAULT
310 See doc/README.MPC866
312 CONFIG_SYS_MEASURE_CPUCLK
314 Define this to measure the actual CPU clock instead
315 of relying on the correctness of the configured
316 values. Mostly useful for board bringup to make sure
317 the PLL is locked at the intended frequency. Note
318 that this requires a (stable) reference clock (32 kHz
319 RTC clock or CONFIG_SYS_8XX_XIN)
321 CONFIG_SYS_DELAYED_ICACHE
323 Define this option if you want to enable the
324 ICache only when Code runs from RAM.
326 - Intel Monahans options:
327 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
329 Defines the Monahans run mode to oscillator
330 ratio. Valid values are 8, 16, 24, 31. The core
331 frequency is this value multiplied by 13 MHz.
333 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
335 Defines the Monahans turbo mode to oscillator
336 ratio. Valid values are 1 (default if undefined) and
337 2. The core frequency as calculated above is multiplied
340 - Linux Kernel Interface:
343 U-Boot stores all clock information in Hz
344 internally. For binary compatibility with older Linux
345 kernels (which expect the clocks passed in the
346 bd_info data to be in MHz) the environment variable
347 "clocks_in_mhz" can be defined so that U-Boot
348 converts clock data to MHZ before passing it to the
350 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
351 "clocks_in_mhz=1" is automatically included in the
354 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
356 When transferring memsize parameter to linux, some versions
357 expect it to be in bytes, others in MB.
358 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
362 New kernel versions are expecting firmware settings to be
363 passed using flattened device trees (based on open firmware
367 * New libfdt-based support
368 * Adds the "fdt" command
369 * The bootm command automatically updates the fdt
371 OF_CPU - The proper name of the cpus node.
372 OF_SOC - The proper name of the soc node.
373 OF_TBCLK - The timebase frequency.
374 OF_STDOUT_PATH - The path to the console device
376 boards with QUICC Engines require OF_QE to set UCC MAC
379 CONFIG_OF_BOARD_SETUP
381 Board code has addition modification that it wants to make
382 to the flat device tree before handing it off to the kernel
386 This define fills in the correct boot CPU in the boot
387 param header, the default value is zero if undefined.
389 - vxWorks boot parameters:
391 bootvx constructs a valid bootline using the following
392 environments variables: bootfile, ipaddr, serverip, hostname.
393 It loads the vxWorks image pointed bootfile.
395 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
396 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
397 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
398 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
400 CONFIG_SYS_VXWORKS_ADD_PARAMS
402 Add it at the end of the bootline. E.g "u=username pw=secret"
404 Note: If a "bootargs" environment is defined, it will overwride
405 the defaults discussed just above.
410 Define this if you want support for Amba PrimeCell PL010 UARTs.
414 Define this if you want support for Amba PrimeCell PL011 UARTs.
418 If you have Amba PrimeCell PL011 UARTs, set this variable to
419 the clock speed of the UARTs.
423 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
424 define this to a list of base addresses for each (supported)
425 port. See e.g. include/configs/versatile.h
429 Depending on board, define exactly one serial port
430 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
431 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
432 console by defining CONFIG_8xx_CONS_NONE
434 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
435 port routines must be defined elsewhere
436 (i.e. serial_init(), serial_getc(), ...)
439 Enables console device for a color framebuffer. Needs following
440 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
441 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
443 VIDEO_HW_RECTFILL graphic chip supports
446 VIDEO_HW_BITBLT graphic chip supports
447 bit-blit (cf. smiLynxEM)
448 VIDEO_VISIBLE_COLS visible pixel columns
450 VIDEO_VISIBLE_ROWS visible pixel rows
451 VIDEO_PIXEL_SIZE bytes per pixel
452 VIDEO_DATA_FORMAT graphic data format
453 (0-5, cf. cfb_console.c)
454 VIDEO_FB_ADRS framebuffer address
455 VIDEO_KBD_INIT_FCT keyboard int fct
456 (i.e. i8042_kbd_init())
457 VIDEO_TSTC_FCT test char fct
459 VIDEO_GETC_FCT get char fct
461 CONFIG_CONSOLE_CURSOR cursor drawing on/off
462 (requires blink timer
464 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
465 CONFIG_CONSOLE_TIME display time/date info in
467 (requires CONFIG_CMD_DATE)
468 CONFIG_VIDEO_LOGO display Linux logo in
470 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
471 linux_logo.h for logo.
472 Requires CONFIG_VIDEO_LOGO
473 CONFIG_CONSOLE_EXTRA_INFO
474 additional board info beside
477 When CONFIG_CFB_CONSOLE is defined, video console is
478 default i/o. Serial console can be forced with
479 environment 'console=serial'.
481 When CONFIG_SILENT_CONSOLE is defined, all console
482 messages (by U-Boot and Linux!) can be silenced with
483 the "silent" environment variable. See
484 doc/README.silent for more information.
487 CONFIG_BAUDRATE - in bps
488 Select one of the baudrates listed in
489 CONFIG_SYS_BAUDRATE_TABLE, see below.
490 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
492 - Console Rx buffer length
493 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
494 the maximum receive buffer length for the SMC.
495 This option is actual only for 82xx and 8xx possible.
496 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
497 must be defined, to setup the maximum idle timeout for
500 - Interrupt driven serial port input:
501 CONFIG_SERIAL_SOFTWARE_FIFO
504 Use an interrupt handler for receiving data on the
505 serial port. It also enables using hardware handshake
506 (RTS/CTS) and UART's built-in FIFO. Set the number of
507 bytes the interrupt driven input buffer should have.
509 Leave undefined to disable this feature, including
510 disable the buffer and hardware handshake.
512 - Console UART Number:
516 If defined internal UART1 (and not UART0) is used
517 as default U-Boot console.
519 - Boot Delay: CONFIG_BOOTDELAY - in seconds
520 Delay before automatically booting the default image;
521 set to -1 to disable autoboot.
523 See doc/README.autoboot for these options that
524 work with CONFIG_BOOTDELAY. None are required.
525 CONFIG_BOOT_RETRY_TIME
526 CONFIG_BOOT_RETRY_MIN
527 CONFIG_AUTOBOOT_KEYED
528 CONFIG_AUTOBOOT_PROMPT
529 CONFIG_AUTOBOOT_DELAY_STR
530 CONFIG_AUTOBOOT_STOP_STR
531 CONFIG_AUTOBOOT_DELAY_STR2
532 CONFIG_AUTOBOOT_STOP_STR2
533 CONFIG_ZERO_BOOTDELAY_CHECK
534 CONFIG_RESET_TO_RETRY
538 Only needed when CONFIG_BOOTDELAY is enabled;
539 define a command string that is automatically executed
540 when no character is read on the console interface
541 within "Boot Delay" after reset.
544 This can be used to pass arguments to the bootm
545 command. The value of CONFIG_BOOTARGS goes into the
546 environment value "bootargs".
548 CONFIG_RAMBOOT and CONFIG_NFSBOOT
549 The value of these goes into the environment as
550 "ramboot" and "nfsboot" respectively, and can be used
551 as a convenience, when switching between booting from
557 When this option is #defined, the existence of the
558 environment variable "preboot" will be checked
559 immediately before starting the CONFIG_BOOTDELAY
560 countdown and/or running the auto-boot command resp.
561 entering interactive mode.
563 This feature is especially useful when "preboot" is
564 automatically generated or modified. For an example
565 see the LWMON board specific code: here "preboot" is
566 modified when the user holds down a certain
567 combination of keys on the (special) keyboard when
570 - Serial Download Echo Mode:
572 If defined to 1, all characters received during a
573 serial download (using the "loads" command) are
574 echoed back. This might be needed by some terminal
575 emulations (like "cu"), but may as well just take
576 time on others. This setting #define's the initial
577 value of the "loads_echo" environment variable.
579 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
581 Select one of the baudrates listed in
582 CONFIG_SYS_BAUDRATE_TABLE, see below.
585 Monitor commands can be included or excluded
586 from the build by using the #include files
587 "config_cmd_all.h" and #undef'ing unwanted
588 commands, or using "config_cmd_default.h"
589 and augmenting with additional #define's
592 The default command configuration includes all commands
593 except those marked below with a "*".
595 CONFIG_CMD_ASKENV * ask for env variable
596 CONFIG_CMD_BDI bdinfo
597 CONFIG_CMD_BEDBUG * Include BedBug Debugger
598 CONFIG_CMD_BMP * BMP support
599 CONFIG_CMD_BSP * Board specific commands
600 CONFIG_CMD_BOOTD bootd
601 CONFIG_CMD_CACHE * icache, dcache
602 CONFIG_CMD_CONSOLE coninfo
603 CONFIG_CMD_DATE * support for RTC, date/time...
604 CONFIG_CMD_DHCP * DHCP support
605 CONFIG_CMD_DIAG * Diagnostics
606 CONFIG_CMD_DOC * Disk-On-Chip Support
607 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
608 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
609 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
610 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
611 CONFIG_CMD_DTT * Digital Therm and Thermostat
612 CONFIG_CMD_ECHO echo arguments
613 CONFIG_CMD_EEPROM * EEPROM read/write support
614 CONFIG_CMD_ELF * bootelf, bootvx
615 CONFIG_CMD_SAVEENV saveenv
616 CONFIG_CMD_FDC * Floppy Disk Support
617 CONFIG_CMD_FAT * FAT partition support
618 CONFIG_CMD_FDOS * Dos diskette Support
619 CONFIG_CMD_FLASH flinfo, erase, protect
620 CONFIG_CMD_FPGA FPGA device initialization support
621 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
622 CONFIG_CMD_I2C * I2C serial bus support
623 CONFIG_CMD_IDE * IDE harddisk support
624 CONFIG_CMD_IMI iminfo
625 CONFIG_CMD_IMLS List all found images
626 CONFIG_CMD_IMMAP * IMMR dump support
627 CONFIG_CMD_IRQ * irqinfo
628 CONFIG_CMD_ITEST Integer/string test of 2 values
629 CONFIG_CMD_JFFS2 * JFFS2 Support
630 CONFIG_CMD_KGDB * kgdb
631 CONFIG_CMD_LOADB loadb
632 CONFIG_CMD_LOADS loads
633 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
635 CONFIG_CMD_MISC Misc functions like sleep etc
636 CONFIG_CMD_MMC * MMC memory mapped support
637 CONFIG_CMD_MII * MII utility commands
638 CONFIG_CMD_MTDPARTS * MTD partition support
639 CONFIG_CMD_NAND * NAND support
640 CONFIG_CMD_NET bootp, tftpboot, rarpboot
641 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
642 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
643 CONFIG_CMD_PCI * pciinfo
644 CONFIG_CMD_PCMCIA * PCMCIA support
645 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
647 CONFIG_CMD_PORTIO * Port I/O
648 CONFIG_CMD_REGINFO * Register dump
649 CONFIG_CMD_RUN run command in env variable
650 CONFIG_CMD_SAVES * save S record dump
651 CONFIG_CMD_SCSI * SCSI Support
652 CONFIG_CMD_SDRAM * print SDRAM configuration information
653 (requires CONFIG_CMD_I2C)
654 CONFIG_CMD_SETGETDCR Support for DCR Register access
656 CONFIG_CMD_SOURCE "source" command Support
657 CONFIG_CMD_SPI * SPI serial bus support
658 CONFIG_CMD_USB * USB support
659 CONFIG_CMD_VFD * VFD support (TRAB)
660 CONFIG_CMD_CDP * Cisco Discover Protocol support
661 CONFIG_CMD_FSL * Microblaze FSL support
664 EXAMPLE: If you want all functions except of network
665 support you can write:
667 #include "config_cmd_all.h"
668 #undef CONFIG_CMD_NET
671 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
673 Note: Don't enable the "icache" and "dcache" commands
674 (configuration option CONFIG_CMD_CACHE) unless you know
675 what you (and your U-Boot users) are doing. Data
676 cache cannot be enabled on systems like the 8xx or
677 8260 (where accesses to the IMMR region must be
678 uncached), and it cannot be disabled on all other
679 systems where we (mis-) use the data cache to hold an
680 initial stack and some data.
683 XXX - this list needs to get updated!
687 If this variable is defined, it enables watchdog
688 support. There must be support in the platform specific
689 code for a watchdog. For the 8xx and 8260 CPUs, the
690 SIU Watchdog feature is enabled in the SYPCR
694 CONFIG_VERSION_VARIABLE
695 If this variable is defined, an environment variable
696 named "ver" is created by U-Boot showing the U-Boot
697 version as printed by the "version" command.
698 This variable is readonly.
702 When CONFIG_CMD_DATE is selected, the type of the RTC
703 has to be selected, too. Define exactly one of the
706 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
707 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
708 CONFIG_RTC_MC13783 - use MC13783 RTC
709 CONFIG_RTC_MC146818 - use MC146818 RTC
710 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
711 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
712 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
713 CONFIG_RTC_DS164x - use Dallas DS164x RTC
714 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
715 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
716 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
718 Note that if the RTC uses I2C, then the I2C interface
719 must also be configured. See I2C Support, below.
722 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
723 CONFIG_PCA953X_INFO - enable pca953x info command
725 Note that if the GPIO device uses I2C, then the I2C interface
726 must also be configured. See I2C Support, below.
730 When CONFIG_TIMESTAMP is selected, the timestamp
731 (date and time) of an image is printed by image
732 commands like bootm or iminfo. This option is
733 automatically enabled when you select CONFIG_CMD_DATE .
736 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
737 and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION
739 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
740 CONFIG_CMD_SCSI) you must configure support for at
741 least one partition type as well.
744 CONFIG_IDE_RESET_ROUTINE - this is defined in several
745 board configurations files but used nowhere!
747 CONFIG_IDE_RESET - is this is defined, IDE Reset will
748 be performed by calling the function
749 ide_set_reset(int reset)
750 which has to be defined in a board specific file
755 Set this to enable ATAPI support.
760 Set this to enable support for disks larger than 137GB
761 Also look at CONFIG_SYS_64BIT_LBA ,CONFIG_SYS_64BIT_VSPRINTF and CONFIG_SYS_64BIT_STRTOUL
762 Whithout these , LBA48 support uses 32bit variables and will 'only'
763 support disks up to 2.1TB.
765 CONFIG_SYS_64BIT_LBA:
766 When enabled, makes the IDE subsystem use 64bit sector addresses.
770 At the moment only there is only support for the
771 SYM53C8XX SCSI controller; define
772 CONFIG_SCSI_SYM53C8XX to enable it.
774 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
775 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
776 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
777 maximum numbers of LUNs, SCSI ID's and target
779 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
781 - NETWORK Support (PCI):
783 Support for Intel 8254x gigabit chips.
785 CONFIG_E1000_FALLBACK_MAC
786 default MAC for empty EEPROM after production.
789 Support for Intel 82557/82559/82559ER chips.
790 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
791 write routine for first time initialisation.
794 Support for Digital 2114x chips.
795 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
796 modem chip initialisation (KS8761/QS6611).
799 Support for National dp83815 chips.
802 Support for National dp8382[01] gigabit chips.
804 - NETWORK Support (other):
806 CONFIG_DRIVER_LAN91C96
807 Support for SMSC's LAN91C96 chips.
810 Define this to hold the physical address
811 of the LAN91C96's I/O space
813 CONFIG_LAN91C96_USE_32_BIT
814 Define this to enable 32 bit addressing
816 CONFIG_DRIVER_SMC91111
817 Support for SMSC's LAN91C111 chip
820 Define this to hold the physical address
821 of the device (I/O space)
823 CONFIG_SMC_USE_32_BIT
824 Define this if data bus is 32 bits
826 CONFIG_SMC_USE_IOFUNCS
827 Define this to use i/o functions instead of macros
828 (some hardware wont work with macros)
830 CONFIG_DRIVER_SMC911X
831 Support for SMSC's LAN911x and LAN921x chips
833 CONFIG_DRIVER_SMC911X_BASE
834 Define this to hold the physical address
835 of the device (I/O space)
837 CONFIG_DRIVER_SMC911X_32_BIT
838 Define this if data bus is 32 bits
840 CONFIG_DRIVER_SMC911X_16_BIT
841 Define this if data bus is 16 bits. If your processor
842 automatically converts one 32 bit word to two 16 bit
843 words you may also try CONFIG_DRIVER_SMC911X_32_BIT.
846 At the moment only the UHCI host controller is
847 supported (PIP405, MIP405, MPC5200); define
848 CONFIG_USB_UHCI to enable it.
849 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
850 and define CONFIG_USB_STORAGE to enable the USB
853 Supported are USB Keyboards and USB Floppy drives
855 MPC5200 USB requires additional defines:
857 for 528 MHz Clock: 0x0001bbbb
859 for differential drivers: 0x00001000
860 for single ended drivers: 0x00005000
861 CONFIG_SYS_USB_EVENT_POLL
862 May be defined to allow interrupt polling
863 instead of using asynchronous interrupts
866 Define the below if you wish to use the USB console.
867 Once firmware is rebuilt from a serial console issue the
868 command "setenv stdin usbtty; setenv stdout usbtty" and
869 attach your USB cable. The Unix command "dmesg" should print
870 it has found a new device. The environment variable usbtty
871 can be set to gserial or cdc_acm to enable your device to
872 appear to a USB host as a Linux gserial device or a
873 Common Device Class Abstract Control Model serial device.
874 If you select usbtty = gserial you should be able to enumerate
876 # modprobe usbserial vendor=0xVendorID product=0xProductID
877 else if using cdc_acm, simply setting the environment
878 variable usbtty to be cdc_acm should suffice. The following
879 might be defined in YourBoardName.h
882 Define this to build a UDC device
885 Define this to have a tty type of device available to
886 talk to the UDC device
888 CONFIG_SYS_CONSOLE_IS_IN_ENV
889 Define this if you want stdin, stdout &/or stderr to
893 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
894 Derive USB clock from external clock "blah"
895 - CONFIG_SYS_USB_EXTC_CLK 0x02
897 CONFIG_SYS_USB_BRG_CLK 0xBLAH
898 Derive USB clock from brgclk
899 - CONFIG_SYS_USB_BRG_CLK 0x04
901 If you have a USB-IF assigned VendorID then you may wish to
902 define your own vendor specific values either in BoardName.h
903 or directly in usbd_vendor_info.h. If you don't define
904 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
905 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
906 should pretend to be a Linux device to it's target host.
908 CONFIG_USBD_MANUFACTURER
909 Define this string as the name of your company for
910 - CONFIG_USBD_MANUFACTURER "my company"
912 CONFIG_USBD_PRODUCT_NAME
913 Define this string as the name of your product
914 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
917 Define this as your assigned Vendor ID from the USB
918 Implementors Forum. This *must* be a genuine Vendor ID
919 to avoid polluting the USB namespace.
920 - CONFIG_USBD_VENDORID 0xFFFF
922 CONFIG_USBD_PRODUCTID
923 Define this as the unique Product ID
925 - CONFIG_USBD_PRODUCTID 0xFFFF
929 The MMC controller on the Intel PXA is supported. To
930 enable this define CONFIG_MMC. The MMC can be
931 accessed from the boot prompt by mapping the device
932 to physical memory similar to flash. Command line is
933 enabled with CONFIG_CMD_MMC. The MMC driver also works with
934 the FAT fs. This is enabled with CONFIG_CMD_FAT.
936 - Journaling Flash filesystem support:
937 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
938 CONFIG_JFFS2_NAND_DEV
939 Define these for a default partition on a NAND device
941 CONFIG_SYS_JFFS2_FIRST_SECTOR,
942 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
943 Define these for a default partition on a NOR device
945 CONFIG_SYS_JFFS_CUSTOM_PART
946 Define this to create an own partition. You have to provide a
947 function struct part_info* jffs2_part_info(int part_num)
949 If you define only one JFFS2 partition you may also want to
950 #define CONFIG_SYS_JFFS_SINGLE_PART 1
951 to disable the command chpart. This is the default when you
952 have not defined a custom partition
957 Define this to enable standard (PC-Style) keyboard
961 Standard PC keyboard driver with US (is default) and
962 GERMAN key layout (switch via environment 'keymap=de') support.
963 Export function i8042_kbd_init, i8042_tstc and i8042_getc
964 for cfb_console. Supports cursor blinking.
969 Define this to enable video support (for output to
974 Enable Chips & Technologies 69000 Video chip
976 CONFIG_VIDEO_SMI_LYNXEM
977 Enable Silicon Motion SMI 712/710/810 Video chip. The
978 video output is selected via environment 'videoout'
979 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
982 For the CT69000 and SMI_LYNXEM drivers, videomode is
983 selected via environment 'videomode'. Two different ways
985 - "videomode=num" 'num' is a standard LiLo mode numbers.
986 Following standard modes are supported (* is default):
988 Colors 640x480 800x600 1024x768 1152x864 1280x1024
989 -------------+---------------------------------------------
990 8 bits | 0x301* 0x303 0x305 0x161 0x307
991 15 bits | 0x310 0x313 0x316 0x162 0x319
992 16 bits | 0x311 0x314 0x317 0x163 0x31A
993 24 bits | 0x312 0x315 0x318 ? 0x31B
994 -------------+---------------------------------------------
995 (i.e. setenv videomode 317; saveenv; reset;)
997 - "videomode=bootargs" all the video parameters are parsed
998 from the bootargs. (See drivers/video/videomodes.c)
1001 CONFIG_VIDEO_SED13806
1002 Enable Epson SED13806 driver. This driver supports 8bpp
1003 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1004 or CONFIG_VIDEO_SED13806_16BPP
1009 Define this to enable a custom keyboard support.
1010 This simply calls drv_keyboard_init() which must be
1011 defined in your board-specific files.
1012 The only board using this so far is RBC823.
1014 - LCD Support: CONFIG_LCD
1016 Define this to enable LCD support (for output to LCD
1017 display); also select one of the supported displays
1018 by defining one of these:
1022 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1024 CONFIG_NEC_NL6448AC33:
1026 NEC NL6448AC33-18. Active, color, single scan.
1028 CONFIG_NEC_NL6448BC20
1030 NEC NL6448BC20-08. 6.5", 640x480.
1031 Active, color, single scan.
1033 CONFIG_NEC_NL6448BC33_54
1035 NEC NL6448BC33-54. 10.4", 640x480.
1036 Active, color, single scan.
1040 Sharp 320x240. Active, color, single scan.
1041 It isn't 16x9, and I am not sure what it is.
1043 CONFIG_SHARP_LQ64D341
1045 Sharp LQ64D341 display, 640x480.
1046 Active, color, single scan.
1050 HLD1045 display, 640x480.
1051 Active, color, single scan.
1055 Optrex CBL50840-2 NF-FW 99 22 M5
1057 Hitachi LMG6912RPFC-00T
1061 320x240. Black & white.
1063 Normally display is black on white background; define
1064 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1066 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1068 If this option is set, the environment is checked for
1069 a variable "splashimage". If found, the usual display
1070 of logo, copyright and system information on the LCD
1071 is suppressed and the BMP image at the address
1072 specified in "splashimage" is loaded instead. The
1073 console is redirected to the "nulldev", too. This
1074 allows for a "silent" boot where a splash screen is
1075 loaded very quickly after power-on.
1077 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1079 If this option is set, additionally to standard BMP
1080 images, gzipped BMP images can be displayed via the
1081 splashscreen support or the bmp command.
1083 - Compression support:
1086 If this option is set, support for bzip2 compressed
1087 images is included. If not, only uncompressed and gzip
1088 compressed images are supported.
1090 NOTE: the bzip2 algorithm requires a lot of RAM, so
1091 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1096 If this option is set, support for lzma compressed
1099 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1100 requires an amount of dynamic memory that is given by the
1103 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1105 Where lc and lp stand for, respectively, Literal context bits
1106 and Literal pos bits.
1108 This value is upper-bounded by 14MB in the worst case. Anyway,
1109 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1110 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1111 a very small buffer.
1113 Use the lzmainfo tool to determinate the lc and lp values and
1114 then calculate the amount of needed dynamic memory (ensuring
1115 the appropriate CONFIG_SYS_MALLOC_LEN value).
1120 The address of PHY on MII bus.
1122 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1124 The clock frequency of the MII bus
1128 If this option is set, support for speed/duplex
1129 detection of gigabit PHY is included.
1131 CONFIG_PHY_RESET_DELAY
1133 Some PHY like Intel LXT971A need extra delay after
1134 reset before any MII register access is possible.
1135 For such PHY, set this option to the usec delay
1136 required. (minimum 300usec for LXT971A)
1138 CONFIG_PHY_CMD_DELAY (ppc4xx)
1140 Some PHY like Intel LXT971A need extra delay after
1141 command issued before MII status register can be read
1151 Define a default value for Ethernet address to use
1152 for the respective Ethernet interface, in case this
1153 is not determined automatically.
1158 Define a default value for the IP address to use for
1159 the default Ethernet interface, in case this is not
1160 determined through e.g. bootp.
1162 - Server IP address:
1165 Defines a default value for the IP address of a TFTP
1166 server to contact when using the "tftboot" command.
1168 - Multicast TFTP Mode:
1171 Defines whether you want to support multicast TFTP as per
1172 rfc-2090; for example to work with atftp. Lets lots of targets
1173 tftp down the same boot image concurrently. Note: the Ethernet
1174 driver in use must provide a function: mcast() to join/leave a
1177 CONFIG_BOOTP_RANDOM_DELAY
1178 - BOOTP Recovery Mode:
1179 CONFIG_BOOTP_RANDOM_DELAY
1181 If you have many targets in a network that try to
1182 boot using BOOTP, you may want to avoid that all
1183 systems send out BOOTP requests at precisely the same
1184 moment (which would happen for instance at recovery
1185 from a power failure, when all systems will try to
1186 boot, thus flooding the BOOTP server. Defining
1187 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1188 inserted before sending out BOOTP requests. The
1189 following delays are inserted then:
1191 1st BOOTP request: delay 0 ... 1 sec
1192 2nd BOOTP request: delay 0 ... 2 sec
1193 3rd BOOTP request: delay 0 ... 4 sec
1195 BOOTP requests: delay 0 ... 8 sec
1197 - DHCP Advanced Options:
1198 You can fine tune the DHCP functionality by defining
1199 CONFIG_BOOTP_* symbols:
1201 CONFIG_BOOTP_SUBNETMASK
1202 CONFIG_BOOTP_GATEWAY
1203 CONFIG_BOOTP_HOSTNAME
1204 CONFIG_BOOTP_NISDOMAIN
1205 CONFIG_BOOTP_BOOTPATH
1206 CONFIG_BOOTP_BOOTFILESIZE
1209 CONFIG_BOOTP_SEND_HOSTNAME
1210 CONFIG_BOOTP_NTPSERVER
1211 CONFIG_BOOTP_TIMEOFFSET
1212 CONFIG_BOOTP_VENDOREX
1214 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1215 environment variable, not the BOOTP server.
1217 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1218 serverip from a DHCP server, it is possible that more
1219 than one DNS serverip is offered to the client.
1220 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1221 serverip will be stored in the additional environment
1222 variable "dnsip2". The first DNS serverip is always
1223 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1226 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1227 to do a dynamic update of a DNS server. To do this, they
1228 need the hostname of the DHCP requester.
1229 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1230 of the "hostname" environment variable is passed as
1231 option 12 to the DHCP server.
1233 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1235 A 32bit value in microseconds for a delay between
1236 receiving a "DHCP Offer" and sending the "DHCP Request".
1237 This fixes a problem with certain DHCP servers that don't
1238 respond 100% of the time to a "DHCP request". E.g. On an
1239 AT91RM9200 processor running at 180MHz, this delay needed
1240 to be *at least* 15,000 usec before a Windows Server 2003
1241 DHCP server would reply 100% of the time. I recommend at
1242 least 50,000 usec to be safe. The alternative is to hope
1243 that one of the retries will be successful but note that
1244 the DHCP timeout and retry process takes a longer than
1248 CONFIG_CDP_DEVICE_ID
1250 The device id used in CDP trigger frames.
1252 CONFIG_CDP_DEVICE_ID_PREFIX
1254 A two character string which is prefixed to the MAC address
1259 A printf format string which contains the ascii name of
1260 the port. Normally is set to "eth%d" which sets
1261 eth0 for the first Ethernet, eth1 for the second etc.
1263 CONFIG_CDP_CAPABILITIES
1265 A 32bit integer which indicates the device capabilities;
1266 0x00000010 for a normal host which does not forwards.
1270 An ascii string containing the version of the software.
1274 An ascii string containing the name of the platform.
1278 A 32bit integer sent on the trigger.
1280 CONFIG_CDP_POWER_CONSUMPTION
1282 A 16bit integer containing the power consumption of the
1283 device in .1 of milliwatts.
1285 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1287 A byte containing the id of the VLAN.
1289 - Status LED: CONFIG_STATUS_LED
1291 Several configurations allow to display the current
1292 status using a LED. For instance, the LED will blink
1293 fast while running U-Boot code, stop blinking as
1294 soon as a reply to a BOOTP request was received, and
1295 start blinking slow once the Linux kernel is running
1296 (supported by a status LED driver in the Linux
1297 kernel). Defining CONFIG_STATUS_LED enables this
1300 - CAN Support: CONFIG_CAN_DRIVER
1302 Defining CONFIG_CAN_DRIVER enables CAN driver support
1303 on those systems that support this (optional)
1304 feature, like the TQM8xxL modules.
1306 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1308 These enable I2C serial bus commands. Defining either of
1309 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1310 include the appropriate I2C driver for the selected CPU.
1312 This will allow you to use i2c commands at the u-boot
1313 command line (as long as you set CONFIG_CMD_I2C in
1314 CONFIG_COMMANDS) and communicate with i2c based realtime
1315 clock chips. See common/cmd_i2c.c for a description of the
1316 command line interface.
1318 CONFIG_I2C_CMD_TREE is a recommended option that places
1319 all I2C commands under a single 'i2c' root command. The
1320 older 'imm', 'imd', 'iprobe' etc. commands are considered
1321 deprecated and may disappear in the future.
1323 CONFIG_HARD_I2C selects a hardware I2C controller.
1325 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1326 bit-banging) driver instead of CPM or similar hardware
1329 There are several other quantities that must also be
1330 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1332 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1333 to be the frequency (in Hz) at which you wish your i2c bus
1334 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1335 the CPU's i2c node address).
1337 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1338 sets the CPU up as a master node and so its address should
1339 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1340 p.16-473). So, set CONFIG_SYS_I2C_SLAVE to 0.
1342 That's all that's required for CONFIG_HARD_I2C.
1344 If you use the software i2c interface (CONFIG_SOFT_I2C)
1345 then the following macros need to be defined (examples are
1346 from include/configs/lwmon.h):
1350 (Optional). Any commands necessary to enable the I2C
1351 controller or configure ports.
1353 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1357 (Only for MPC8260 CPU). The I/O port to use (the code
1358 assumes both bits are on the same port). Valid values
1359 are 0..3 for ports A..D.
1363 The code necessary to make the I2C data line active
1364 (driven). If the data line is open collector, this
1367 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1371 The code necessary to make the I2C data line tri-stated
1372 (inactive). If the data line is open collector, this
1375 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1379 Code that returns TRUE if the I2C data line is high,
1382 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1386 If <bit> is TRUE, sets the I2C data line high. If it
1387 is FALSE, it clears it (low).
1389 eg: #define I2C_SDA(bit) \
1390 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1391 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1395 If <bit> is TRUE, sets the I2C clock line high. If it
1396 is FALSE, it clears it (low).
1398 eg: #define I2C_SCL(bit) \
1399 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1400 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1404 This delay is invoked four times per clock cycle so this
1405 controls the rate of data transfer. The data rate thus
1406 is 1 / (I2C_DELAY * 4). Often defined to be something
1409 #define I2C_DELAY udelay(2)
1411 CONFIG_SYS_I2C_INIT_BOARD
1413 When a board is reset during an i2c bus transfer
1414 chips might think that the current transfer is still
1415 in progress. On some boards it is possible to access
1416 the i2c SCLK line directly, either by using the
1417 processor pin as a GPIO or by having a second pin
1418 connected to the bus. If this option is defined a
1419 custom i2c_init_board() routine in boards/xxx/board.c
1420 is run early in the boot sequence.
1422 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1424 This option enables configuration of bi_iic_fast[] flags
1425 in u-boot bd_info structure based on u-boot environment
1426 variable "i2cfast". (see also i2cfast)
1428 CONFIG_I2C_MULTI_BUS
1430 This option allows the use of multiple I2C buses, each of which
1431 must have a controller. At any point in time, only one bus is
1432 active. To switch to a different bus, use the 'i2c dev' command.
1433 Note that bus numbering is zero-based.
1435 CONFIG_SYS_I2C_NOPROBES
1437 This option specifies a list of I2C devices that will be skipped
1438 when the 'i2c probe' command is issued (or 'iprobe' using the legacy
1439 command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device
1440 pairs. Otherwise, specify a 1D array of device addresses
1443 #undef CONFIG_I2C_MULTI_BUS
1444 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1446 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1448 #define CONFIG_I2C_MULTI_BUS
1449 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1451 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1453 CONFIG_SYS_SPD_BUS_NUM
1455 If defined, then this indicates the I2C bus number for DDR SPD.
1456 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1458 CONFIG_SYS_RTC_BUS_NUM
1460 If defined, then this indicates the I2C bus number for the RTC.
1461 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1463 CONFIG_SYS_DTT_BUS_NUM
1465 If defined, then this indicates the I2C bus number for the DTT.
1466 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1468 CONFIG_SYS_I2C_DTT_ADDR:
1470 If defined, specifies the I2C address of the DTT device.
1471 If not defined, then U-Boot uses predefined value for
1472 specified DTT device.
1476 Define this option if you want to use Freescale's I2C driver in
1477 drivers/i2c/fsl_i2c.c.
1481 Define this option if you have I2C devices reached over 1 .. n
1482 I2C Muxes like the pca9544a. This option addes a new I2C
1483 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1484 new I2C Bus to the existing I2C Busses. If you select the
1485 new Bus with "i2c dev", u-bbot sends first the commandos for
1486 the muxes to activate this new "bus".
1488 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1492 Adding a new I2C Bus reached over 2 pca9544a muxes
1493 The First mux with address 70 and channel 6
1494 The Second mux with address 71 and channel 4
1496 => i2c bus pca9544a:70:6:pca9544a:71:4
1498 Use the "i2c bus" command without parameter, to get a list
1499 of I2C Busses with muxes:
1502 Busses reached over muxes:
1504 reached over Mux(es):
1507 reached over Mux(es):
1512 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1513 u-boot sends First the Commando to the mux@70 to enable
1514 channel 6, and then the Commando to the mux@71 to enable
1517 After that, you can use the "normal" i2c commands as
1518 usual, to communicate with your I2C devices behind
1521 This option is actually implemented for the bitbanging
1522 algorithm in common/soft_i2c.c and for the Hardware I2C
1523 Bus on the MPC8260. But it should be not so difficult
1524 to add this option to other architectures.
1526 CONFIG_SOFT_I2C_READ_REPEATED_START
1528 defining this will force the i2c_read() function in
1529 the soft_i2c driver to perform an I2C repeated start
1530 between writing the address pointer and reading the
1531 data. If this define is omitted the default behaviour
1532 of doing a stop-start sequence will be used. Most I2C
1533 devices can use either method, but some require one or
1536 - SPI Support: CONFIG_SPI
1538 Enables SPI driver (so far only tested with
1539 SPI EEPROM, also an instance works with Crystal A/D and
1540 D/As on the SACSng board)
1544 Enables extended (16-bit) SPI EEPROM addressing.
1545 (symmetrical to CONFIG_I2C_X)
1549 Enables a software (bit-bang) SPI driver rather than
1550 using hardware support. This is a general purpose
1551 driver that only requires three general I/O port pins
1552 (two outputs, one input) to function. If this is
1553 defined, the board configuration must define several
1554 SPI configuration items (port pins to use, etc). For
1555 an example, see include/configs/sacsng.h.
1559 Enables a hardware SPI driver for general-purpose reads
1560 and writes. As with CONFIG_SOFT_SPI, the board configuration
1561 must define a list of chip-select function pointers.
1562 Currently supported on some MPC8xxx processors. For an
1563 example, see include/configs/mpc8349emds.h.
1567 Enables the driver for the SPI controllers on i.MX and MXC
1568 SoCs. Currently only i.MX31 is supported.
1570 - FPGA Support: CONFIG_FPGA
1572 Enables FPGA subsystem.
1574 CONFIG_FPGA_<vendor>
1576 Enables support for specific chip vendors.
1579 CONFIG_FPGA_<family>
1581 Enables support for FPGA family.
1582 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1586 Specify the number of FPGA devices to support.
1588 CONFIG_SYS_FPGA_PROG_FEEDBACK
1590 Enable printing of hash marks during FPGA configuration.
1592 CONFIG_SYS_FPGA_CHECK_BUSY
1594 Enable checks on FPGA configuration interface busy
1595 status by the configuration function. This option
1596 will require a board or device specific function to
1601 If defined, a function that provides delays in the FPGA
1602 configuration driver.
1604 CONFIG_SYS_FPGA_CHECK_CTRLC
1605 Allow Control-C to interrupt FPGA configuration
1607 CONFIG_SYS_FPGA_CHECK_ERROR
1609 Check for configuration errors during FPGA bitfile
1610 loading. For example, abort during Virtex II
1611 configuration if the INIT_B line goes low (which
1612 indicated a CRC error).
1614 CONFIG_SYS_FPGA_WAIT_INIT
1616 Maximum time to wait for the INIT_B line to deassert
1617 after PROB_B has been deasserted during a Virtex II
1618 FPGA configuration sequence. The default time is 500
1621 CONFIG_SYS_FPGA_WAIT_BUSY
1623 Maximum time to wait for BUSY to deassert during
1624 Virtex II FPGA configuration. The default is 5 ms.
1626 CONFIG_SYS_FPGA_WAIT_CONFIG
1628 Time to wait after FPGA configuration. The default is
1631 - Configuration Management:
1634 If defined, this string will be added to the U-Boot
1635 version information (U_BOOT_VERSION)
1637 - Vendor Parameter Protection:
1639 U-Boot considers the values of the environment
1640 variables "serial#" (Board Serial Number) and
1641 "ethaddr" (Ethernet Address) to be parameters that
1642 are set once by the board vendor / manufacturer, and
1643 protects these variables from casual modification by
1644 the user. Once set, these variables are read-only,
1645 and write or delete attempts are rejected. You can
1646 change this behaviour:
1648 If CONFIG_ENV_OVERWRITE is #defined in your config
1649 file, the write protection for vendor parameters is
1650 completely disabled. Anybody can change or delete
1653 Alternatively, if you #define _both_ CONFIG_ETHADDR
1654 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1655 Ethernet address is installed in the environment,
1656 which can be changed exactly ONCE by the user. [The
1657 serial# is unaffected by this, i. e. it remains
1663 Define this variable to enable the reservation of
1664 "protected RAM", i. e. RAM which is not overwritten
1665 by U-Boot. Define CONFIG_PRAM to hold the number of
1666 kB you want to reserve for pRAM. You can overwrite
1667 this default value by defining an environment
1668 variable "pram" to the number of kB you want to
1669 reserve. Note that the board info structure will
1670 still show the full amount of RAM. If pRAM is
1671 reserved, a new environment variable "mem" will
1672 automatically be defined to hold the amount of
1673 remaining RAM in a form that can be passed as boot
1674 argument to Linux, for instance like that:
1676 setenv bootargs ... mem=\${mem}
1679 This way you can tell Linux not to use this memory,
1680 either, which results in a memory region that will
1681 not be affected by reboots.
1683 *WARNING* If your board configuration uses automatic
1684 detection of the RAM size, you must make sure that
1685 this memory test is non-destructive. So far, the
1686 following board configurations are known to be
1689 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1690 HERMES, IP860, RPXlite, LWMON, LANTEC,
1691 PCU_E, FLAGADM, TQM8260
1696 Define this variable to stop the system in case of a
1697 fatal error, so that you have to reset it manually.
1698 This is probably NOT a good idea for an embedded
1699 system where you want the system to reboot
1700 automatically as fast as possible, but it may be
1701 useful during development since you can try to debug
1702 the conditions that lead to the situation.
1704 CONFIG_NET_RETRY_COUNT
1706 This variable defines the number of retries for
1707 network operations like ARP, RARP, TFTP, or BOOTP
1708 before giving up the operation. If not defined, a
1709 default value of 5 is used.
1713 Timeout waiting for an ARP reply in milliseconds.
1715 - Command Interpreter:
1716 CONFIG_AUTO_COMPLETE
1718 Enable auto completion of commands using TAB.
1720 Note that this feature has NOT been implemented yet
1721 for the "hush" shell.
1724 CONFIG_SYS_HUSH_PARSER
1726 Define this variable to enable the "hush" shell (from
1727 Busybox) as command line interpreter, thus enabling
1728 powerful command line syntax like
1729 if...then...else...fi conditionals or `&&' and '||'
1730 constructs ("shell scripts").
1732 If undefined, you get the old, much simpler behaviour
1733 with a somewhat smaller memory footprint.
1736 CONFIG_SYS_PROMPT_HUSH_PS2
1738 This defines the secondary prompt string, which is
1739 printed when the command interpreter needs more input
1740 to complete a command. Usually "> ".
1744 In the current implementation, the local variables
1745 space and global environment variables space are
1746 separated. Local variables are those you define by
1747 simply typing `name=value'. To access a local
1748 variable later on, you have write `$name' or
1749 `${name}'; to execute the contents of a variable
1750 directly type `$name' at the command prompt.
1752 Global environment variables are those you use
1753 setenv/printenv to work with. To run a command stored
1754 in such a variable, you need to use the run command,
1755 and you must not use the '$' sign to access them.
1757 To store commands and special characters in a
1758 variable, please use double quotation marks
1759 surrounding the whole text of the variable, instead
1760 of the backslashes before semicolons and special
1763 - Commandline Editing and History:
1764 CONFIG_CMDLINE_EDITING
1766 Enable editing and History functions for interactive
1767 commandline input operations
1769 - Default Environment:
1770 CONFIG_EXTRA_ENV_SETTINGS
1772 Define this to contain any number of null terminated
1773 strings (variable = value pairs) that will be part of
1774 the default environment compiled into the boot image.
1776 For example, place something like this in your
1777 board's config file:
1779 #define CONFIG_EXTRA_ENV_SETTINGS \
1783 Warning: This method is based on knowledge about the
1784 internal format how the environment is stored by the
1785 U-Boot code. This is NOT an official, exported
1786 interface! Although it is unlikely that this format
1787 will change soon, there is no guarantee either.
1788 You better know what you are doing here.
1790 Note: overly (ab)use of the default environment is
1791 discouraged. Make sure to check other ways to preset
1792 the environment like the "source" command or the
1795 - DataFlash Support:
1796 CONFIG_HAS_DATAFLASH
1798 Defining this option enables DataFlash features and
1799 allows to read/write in Dataflash via the standard
1802 - SystemACE Support:
1805 Adding this option adds support for Xilinx SystemACE
1806 chips attached via some sort of local bus. The address
1807 of the chip must also be defined in the
1808 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
1810 #define CONFIG_SYSTEMACE
1811 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
1813 When SystemACE support is added, the "ace" device type
1814 becomes available to the fat commands, i.e. fatls.
1816 - TFTP Fixed UDP Port:
1819 If this is defined, the environment variable tftpsrcp
1820 is used to supply the TFTP UDP source port value.
1821 If tftpsrcp isn't defined, the normal pseudo-random port
1822 number generator is used.
1824 Also, the environment variable tftpdstp is used to supply
1825 the TFTP UDP destination port value. If tftpdstp isn't
1826 defined, the normal port 69 is used.
1828 The purpose for tftpsrcp is to allow a TFTP server to
1829 blindly start the TFTP transfer using the pre-configured
1830 target IP address and UDP port. This has the effect of
1831 "punching through" the (Windows XP) firewall, allowing
1832 the remainder of the TFTP transfer to proceed normally.
1833 A better solution is to properly configure the firewall,
1834 but sometimes that is not allowed.
1836 - Show boot progress:
1837 CONFIG_SHOW_BOOT_PROGRESS
1839 Defining this option allows to add some board-
1840 specific code (calling a user-provided function
1841 "show_boot_progress(int)") that enables you to show
1842 the system's boot progress on some display (for
1843 example, some LED's) on your board. At the moment,
1844 the following checkpoints are implemented:
1846 - Automatic software updates via TFTP server
1848 CONFIG_UPDATE_TFTP_CNT_MAX
1849 CONFIG_UPDATE_TFTP_MSEC_MAX
1851 These options enable and control the auto-update feature;
1852 for a more detailed description refer to doc/README.update.
1854 Legacy uImage format:
1857 1 common/cmd_bootm.c before attempting to boot an image
1858 -1 common/cmd_bootm.c Image header has bad magic number
1859 2 common/cmd_bootm.c Image header has correct magic number
1860 -2 common/cmd_bootm.c Image header has bad checksum
1861 3 common/cmd_bootm.c Image header has correct checksum
1862 -3 common/cmd_bootm.c Image data has bad checksum
1863 4 common/cmd_bootm.c Image data has correct checksum
1864 -4 common/cmd_bootm.c Image is for unsupported architecture
1865 5 common/cmd_bootm.c Architecture check OK
1866 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
1867 6 common/cmd_bootm.c Image Type check OK
1868 -6 common/cmd_bootm.c gunzip uncompression error
1869 -7 common/cmd_bootm.c Unimplemented compression type
1870 7 common/cmd_bootm.c Uncompression OK
1871 8 common/cmd_bootm.c No uncompress/copy overwrite error
1872 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1874 9 common/image.c Start initial ramdisk verification
1875 -10 common/image.c Ramdisk header has bad magic number
1876 -11 common/image.c Ramdisk header has bad checksum
1877 10 common/image.c Ramdisk header is OK
1878 -12 common/image.c Ramdisk data has bad checksum
1879 11 common/image.c Ramdisk data has correct checksum
1880 12 common/image.c Ramdisk verification complete, start loading
1881 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
1882 13 common/image.c Start multifile image verification
1883 14 common/image.c No initial ramdisk, no multifile, continue.
1885 15 lib_<arch>/bootm.c All preparation done, transferring control to OS
1887 -30 lib_ppc/board.c Fatal error, hang the system
1888 -31 post/post.c POST test failed, detected by post_output_backlog()
1889 -32 post/post.c POST test failed, detected by post_run_single()
1891 34 common/cmd_doc.c before loading a Image from a DOC device
1892 -35 common/cmd_doc.c Bad usage of "doc" command
1893 35 common/cmd_doc.c correct usage of "doc" command
1894 -36 common/cmd_doc.c No boot device
1895 36 common/cmd_doc.c correct boot device
1896 -37 common/cmd_doc.c Unknown Chip ID on boot device
1897 37 common/cmd_doc.c correct chip ID found, device available
1898 -38 common/cmd_doc.c Read Error on boot device
1899 38 common/cmd_doc.c reading Image header from DOC device OK
1900 -39 common/cmd_doc.c Image header has bad magic number
1901 39 common/cmd_doc.c Image header has correct magic number
1902 -40 common/cmd_doc.c Error reading Image from DOC device
1903 40 common/cmd_doc.c Image header has correct magic number
1904 41 common/cmd_ide.c before loading a Image from a IDE device
1905 -42 common/cmd_ide.c Bad usage of "ide" command
1906 42 common/cmd_ide.c correct usage of "ide" command
1907 -43 common/cmd_ide.c No boot device
1908 43 common/cmd_ide.c boot device found
1909 -44 common/cmd_ide.c Device not available
1910 44 common/cmd_ide.c Device available
1911 -45 common/cmd_ide.c wrong partition selected
1912 45 common/cmd_ide.c partition selected
1913 -46 common/cmd_ide.c Unknown partition table
1914 46 common/cmd_ide.c valid partition table found
1915 -47 common/cmd_ide.c Invalid partition type
1916 47 common/cmd_ide.c correct partition type
1917 -48 common/cmd_ide.c Error reading Image Header on boot device
1918 48 common/cmd_ide.c reading Image Header from IDE device OK
1919 -49 common/cmd_ide.c Image header has bad magic number
1920 49 common/cmd_ide.c Image header has correct magic number
1921 -50 common/cmd_ide.c Image header has bad checksum
1922 50 common/cmd_ide.c Image header has correct checksum
1923 -51 common/cmd_ide.c Error reading Image from IDE device
1924 51 common/cmd_ide.c reading Image from IDE device OK
1925 52 common/cmd_nand.c before loading a Image from a NAND device
1926 -53 common/cmd_nand.c Bad usage of "nand" command
1927 53 common/cmd_nand.c correct usage of "nand" command
1928 -54 common/cmd_nand.c No boot device
1929 54 common/cmd_nand.c boot device found
1930 -55 common/cmd_nand.c Unknown Chip ID on boot device
1931 55 common/cmd_nand.c correct chip ID found, device available
1932 -56 common/cmd_nand.c Error reading Image Header on boot device
1933 56 common/cmd_nand.c reading Image Header from NAND device OK
1934 -57 common/cmd_nand.c Image header has bad magic number
1935 57 common/cmd_nand.c Image header has correct magic number
1936 -58 common/cmd_nand.c Error reading Image from NAND device
1937 58 common/cmd_nand.c reading Image from NAND device OK
1939 -60 common/env_common.c Environment has a bad CRC, using default
1941 64 net/eth.c starting with Ethernet configuration.
1942 -64 net/eth.c no Ethernet found.
1943 65 net/eth.c Ethernet found.
1945 -80 common/cmd_net.c usage wrong
1946 80 common/cmd_net.c before calling NetLoop()
1947 -81 common/cmd_net.c some error in NetLoop() occurred
1948 81 common/cmd_net.c NetLoop() back without error
1949 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
1950 82 common/cmd_net.c trying automatic boot
1951 83 common/cmd_net.c running "source" command
1952 -83 common/cmd_net.c some error in automatic boot or "source" command
1953 84 common/cmd_net.c end without errors
1958 100 common/cmd_bootm.c Kernel FIT Image has correct format
1959 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
1960 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
1961 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
1962 102 common/cmd_bootm.c Kernel unit name specified
1963 -103 common/cmd_bootm.c Can't get kernel subimage node offset
1964 103 common/cmd_bootm.c Found configuration node
1965 104 common/cmd_bootm.c Got kernel subimage node offset
1966 -104 common/cmd_bootm.c Kernel subimage hash verification failed
1967 105 common/cmd_bootm.c Kernel subimage hash verification OK
1968 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
1969 106 common/cmd_bootm.c Architecture check OK
1970 -106 common/cmd_bootm.c Kernel subimage has wrong type
1971 107 common/cmd_bootm.c Kernel subimage type OK
1972 -107 common/cmd_bootm.c Can't get kernel subimage data/size
1973 108 common/cmd_bootm.c Got kernel subimage data/size
1974 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
1975 -109 common/cmd_bootm.c Can't get kernel subimage type
1976 -110 common/cmd_bootm.c Can't get kernel subimage comp
1977 -111 common/cmd_bootm.c Can't get kernel subimage os
1978 -112 common/cmd_bootm.c Can't get kernel subimage load address
1979 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
1981 120 common/image.c Start initial ramdisk verification
1982 -120 common/image.c Ramdisk FIT image has incorrect format
1983 121 common/image.c Ramdisk FIT image has correct format
1984 122 common/image.c No ramdisk subimage unit name, using configuration
1985 -122 common/image.c Can't get configuration for ramdisk subimage
1986 123 common/image.c Ramdisk unit name specified
1987 -124 common/image.c Can't get ramdisk subimage node offset
1988 125 common/image.c Got ramdisk subimage node offset
1989 -125 common/image.c Ramdisk subimage hash verification failed
1990 126 common/image.c Ramdisk subimage hash verification OK
1991 -126 common/image.c Ramdisk subimage for unsupported architecture
1992 127 common/image.c Architecture check OK
1993 -127 common/image.c Can't get ramdisk subimage data/size
1994 128 common/image.c Got ramdisk subimage data/size
1995 129 common/image.c Can't get ramdisk load address
1996 -129 common/image.c Got ramdisk load address
1998 -130 common/cmd_doc.c Incorrect FIT image format
1999 131 common/cmd_doc.c FIT image format OK
2001 -140 common/cmd_ide.c Incorrect FIT image format
2002 141 common/cmd_ide.c FIT image format OK
2004 -150 common/cmd_nand.c Incorrect FIT image format
2005 151 common/cmd_nand.c FIT image format OK
2011 [so far only for SMDK2400 and TRAB boards]
2013 - Modem support enable:
2014 CONFIG_MODEM_SUPPORT
2016 - RTS/CTS Flow control enable:
2019 - Modem debug support:
2020 CONFIG_MODEM_SUPPORT_DEBUG
2022 Enables debugging stuff (char screen[1024], dbg())
2023 for modem support. Useful only with BDI2000.
2025 - Interrupt support (PPC):
2027 There are common interrupt_init() and timer_interrupt()
2028 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2029 for CPU specific initialization. interrupt_init_cpu()
2030 should set decrementer_count to appropriate value. If
2031 CPU resets decrementer automatically after interrupt
2032 (ppc4xx) it should set decrementer_count to zero.
2033 timer_interrupt() calls timer_interrupt_cpu() for CPU
2034 specific handling. If board has watchdog / status_led
2035 / other_activity_monitor it works automatically from
2036 general timer_interrupt().
2040 In the target system modem support is enabled when a
2041 specific key (key combination) is pressed during
2042 power-on. Otherwise U-Boot will boot normally
2043 (autoboot). The key_pressed() function is called from
2044 board_init(). Currently key_pressed() is a dummy
2045 function, returning 1 and thus enabling modem
2048 If there are no modem init strings in the
2049 environment, U-Boot proceed to autoboot; the
2050 previous output (banner, info printfs) will be
2053 See also: doc/README.Modem
2056 Configuration Settings:
2057 -----------------------
2059 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2060 undefine this when you're short of memory.
2062 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2063 width of the commands listed in the 'help' command output.
2065 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2066 prompt for user input.
2068 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2070 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2072 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2074 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2075 the application (usually a Linux kernel) when it is
2078 - CONFIG_SYS_BAUDRATE_TABLE:
2079 List of legal baudrate settings for this board.
2081 - CONFIG_SYS_CONSOLE_INFO_QUIET
2082 Suppress display of console information at boot.
2084 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2085 If the board specific function
2086 extern int overwrite_console (void);
2087 returns 1, the stdin, stderr and stdout are switched to the
2088 serial port, else the settings in the environment are used.
2090 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2091 Enable the call to overwrite_console().
2093 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2094 Enable overwrite of previous console environment settings.
2096 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2097 Begin and End addresses of the area used by the
2100 - CONFIG_SYS_ALT_MEMTEST:
2101 Enable an alternate, more extensive memory test.
2103 - CONFIG_SYS_MEMTEST_SCRATCH:
2104 Scratch address used by the alternate memory test
2105 You only need to set this if address zero isn't writeable
2107 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2108 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2109 this specified memory area will get subtracted from the top
2110 (end) of RAM and won't get "touched" at all by U-Boot. By
2111 fixing up gd->ram_size the Linux kernel should gets passed
2112 the now "corrected" memory size and won't touch it either.
2113 This should work for arch/ppc and arch/powerpc. Only Linux
2114 board ports in arch/powerpc with bootwrapper support that
2115 recalculate the memory size from the SDRAM controller setup
2116 will have to get fixed in Linux additionally.
2118 This option can be used as a workaround for the 440EPx/GRx
2119 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2122 WARNING: Please make sure that this value is a multiple of
2123 the Linux page size (normally 4k). If this is not the case,
2124 then the end address of the Linux memory will be located at a
2125 non page size aligned address and this could cause major
2128 - CONFIG_SYS_TFTP_LOADADDR:
2129 Default load address for network file downloads
2131 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2132 Enable temporary baudrate change while serial download
2134 - CONFIG_SYS_SDRAM_BASE:
2135 Physical start address of SDRAM. _Must_ be 0 here.
2137 - CONFIG_SYS_MBIO_BASE:
2138 Physical start address of Motherboard I/O (if using a
2141 - CONFIG_SYS_FLASH_BASE:
2142 Physical start address of Flash memory.
2144 - CONFIG_SYS_MONITOR_BASE:
2145 Physical start address of boot monitor code (set by
2146 make config files to be same as the text base address
2147 (TEXT_BASE) used when linking) - same as
2148 CONFIG_SYS_FLASH_BASE when booting from flash.
2150 - CONFIG_SYS_MONITOR_LEN:
2151 Size of memory reserved for monitor code, used to
2152 determine _at_compile_time_ (!) if the environment is
2153 embedded within the U-Boot image, or in a separate
2156 - CONFIG_SYS_MALLOC_LEN:
2157 Size of DRAM reserved for malloc() use.
2159 - CONFIG_SYS_BOOTM_LEN:
2160 Normally compressed uImages are limited to an
2161 uncompressed size of 8 MBytes. If this is not enough,
2162 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2163 to adjust this setting to your needs.
2165 - CONFIG_SYS_BOOTMAPSZ:
2166 Maximum size of memory mapped by the startup code of
2167 the Linux kernel; all data that must be processed by
2168 the Linux kernel (bd_info, boot arguments, FDT blob if
2169 used) must be put below this limit, unless "bootm_low"
2170 enviroment variable is defined and non-zero. In such case
2171 all data for the Linux kernel must be between "bootm_low"
2172 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ.
2174 - CONFIG_SYS_MAX_FLASH_BANKS:
2175 Max number of Flash memory banks
2177 - CONFIG_SYS_MAX_FLASH_SECT:
2178 Max number of sectors on a Flash chip
2180 - CONFIG_SYS_FLASH_ERASE_TOUT:
2181 Timeout for Flash erase operations (in ms)
2183 - CONFIG_SYS_FLASH_WRITE_TOUT:
2184 Timeout for Flash write operations (in ms)
2186 - CONFIG_SYS_FLASH_LOCK_TOUT
2187 Timeout for Flash set sector lock bit operation (in ms)
2189 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2190 Timeout for Flash clear lock bits operation (in ms)
2192 - CONFIG_SYS_FLASH_PROTECTION
2193 If defined, hardware flash sectors protection is used
2194 instead of U-Boot software protection.
2196 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2198 Enable TFTP transfers directly to flash memory;
2199 without this option such a download has to be
2200 performed in two steps: (1) download to RAM, and (2)
2201 copy from RAM to flash.
2203 The two-step approach is usually more reliable, since
2204 you can check if the download worked before you erase
2205 the flash, but in some situations (when system RAM is
2206 too limited to allow for a temporary copy of the
2207 downloaded image) this option may be very useful.
2209 - CONFIG_SYS_FLASH_CFI:
2210 Define if the flash driver uses extra elements in the
2211 common flash structure for storing flash geometry.
2213 - CONFIG_FLASH_CFI_DRIVER
2214 This option also enables the building of the cfi_flash driver
2215 in the drivers directory
2217 - CONFIG_FLASH_CFI_MTD
2218 This option enables the building of the cfi_mtd driver
2219 in the drivers directory. The driver exports CFI flash
2222 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2223 Use buffered writes to flash.
2225 - CONFIG_FLASH_SPANSION_S29WS_N
2226 s29ws-n MirrorBit flash has non-standard addresses for buffered
2229 - CONFIG_SYS_FLASH_QUIET_TEST
2230 If this option is defined, the common CFI flash doesn't
2231 print it's warning upon not recognized FLASH banks. This
2232 is useful, if some of the configured banks are only
2233 optionally available.
2235 - CONFIG_FLASH_SHOW_PROGRESS
2236 If defined (must be an integer), print out countdown
2237 digits and dots. Recommended value: 45 (9..1) for 80
2238 column displays, 15 (3..1) for 40 column displays.
2240 - CONFIG_SYS_RX_ETH_BUFFER:
2241 Defines the number of Ethernet receive buffers. On some
2242 Ethernet controllers it is recommended to set this value
2243 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2244 buffers can be full shortly after enabling the interface
2245 on high Ethernet traffic.
2246 Defaults to 4 if not defined.
2248 The following definitions that deal with the placement and management
2249 of environment data (variable area); in general, we support the
2250 following configurations:
2252 - CONFIG_ENV_IS_IN_FLASH:
2254 Define this if the environment is in flash memory.
2256 a) The environment occupies one whole flash sector, which is
2257 "embedded" in the text segment with the U-Boot code. This
2258 happens usually with "bottom boot sector" or "top boot
2259 sector" type flash chips, which have several smaller
2260 sectors at the start or the end. For instance, such a
2261 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2262 such a case you would place the environment in one of the
2263 4 kB sectors - with U-Boot code before and after it. With
2264 "top boot sector" type flash chips, you would put the
2265 environment in one of the last sectors, leaving a gap
2266 between U-Boot and the environment.
2268 - CONFIG_ENV_OFFSET:
2270 Offset of environment data (variable area) to the
2271 beginning of flash memory; for instance, with bottom boot
2272 type flash chips the second sector can be used: the offset
2273 for this sector is given here.
2275 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2279 This is just another way to specify the start address of
2280 the flash sector containing the environment (instead of
2283 - CONFIG_ENV_SECT_SIZE:
2285 Size of the sector containing the environment.
2288 b) Sometimes flash chips have few, equal sized, BIG sectors.
2289 In such a case you don't want to spend a whole sector for
2294 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2295 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2296 of this flash sector for the environment. This saves
2297 memory for the RAM copy of the environment.
2299 It may also save flash memory if you decide to use this
2300 when your environment is "embedded" within U-Boot code,
2301 since then the remainder of the flash sector could be used
2302 for U-Boot code. It should be pointed out that this is
2303 STRONGLY DISCOURAGED from a robustness point of view:
2304 updating the environment in flash makes it always
2305 necessary to erase the WHOLE sector. If something goes
2306 wrong before the contents has been restored from a copy in
2307 RAM, your target system will be dead.
2309 - CONFIG_ENV_ADDR_REDUND
2310 CONFIG_ENV_SIZE_REDUND
2312 These settings describe a second storage area used to hold
2313 a redundant copy of the environment data, so that there is
2314 a valid backup copy in case there is a power failure during
2315 a "saveenv" operation.
2317 BE CAREFUL! Any changes to the flash layout, and some changes to the
2318 source code will make it necessary to adapt <board>/u-boot.lds*
2322 - CONFIG_ENV_IS_IN_NVRAM:
2324 Define this if you have some non-volatile memory device
2325 (NVRAM, battery buffered SRAM) which you want to use for the
2331 These two #defines are used to determine the memory area you
2332 want to use for environment. It is assumed that this memory
2333 can just be read and written to, without any special
2336 BE CAREFUL! The first access to the environment happens quite early
2337 in U-Boot initalization (when we try to get the setting of for the
2338 console baudrate). You *MUST* have mapped your NVRAM area then, or
2341 Please note that even with NVRAM we still use a copy of the
2342 environment in RAM: we could work on NVRAM directly, but we want to
2343 keep settings there always unmodified except somebody uses "saveenv"
2344 to save the current settings.
2347 - CONFIG_ENV_IS_IN_EEPROM:
2349 Use this if you have an EEPROM or similar serial access
2350 device and a driver for it.
2352 - CONFIG_ENV_OFFSET:
2355 These two #defines specify the offset and size of the
2356 environment area within the total memory of your EEPROM.
2358 - CONFIG_SYS_I2C_EEPROM_ADDR:
2359 If defined, specified the chip address of the EEPROM device.
2360 The default address is zero.
2362 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2363 If defined, the number of bits used to address bytes in a
2364 single page in the EEPROM device. A 64 byte page, for example
2365 would require six bits.
2367 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2368 If defined, the number of milliseconds to delay between
2369 page writes. The default is zero milliseconds.
2371 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2372 The length in bytes of the EEPROM memory array address. Note
2373 that this is NOT the chip address length!
2375 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2376 EEPROM chips that implement "address overflow" are ones
2377 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2378 address and the extra bits end up in the "chip address" bit
2379 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2382 Note that we consider the length of the address field to
2383 still be one byte because the extra address bits are hidden
2384 in the chip address.
2386 - CONFIG_SYS_EEPROM_SIZE:
2387 The size in bytes of the EEPROM device.
2390 - CONFIG_ENV_IS_IN_DATAFLASH:
2392 Define this if you have a DataFlash memory device which you
2393 want to use for the environment.
2395 - CONFIG_ENV_OFFSET:
2399 These three #defines specify the offset and size of the
2400 environment area within the total memory of your DataFlash placed
2401 at the specified address.
2403 - CONFIG_ENV_IS_IN_NAND:
2405 Define this if you have a NAND device which you want to use
2406 for the environment.
2408 - CONFIG_ENV_OFFSET:
2411 These two #defines specify the offset and size of the environment
2412 area within the first NAND device.
2414 - CONFIG_ENV_OFFSET_REDUND
2416 This setting describes a second storage area of CONFIG_ENV_SIZE
2417 size used to hold a redundant copy of the environment data,
2418 so that there is a valid backup copy in case there is a
2419 power failure during a "saveenv" operation.
2421 Note: CONFIG_ENV_OFFSET and CONFIG_ENV_OFFSET_REDUND must be aligned
2422 to a block boundary, and CONFIG_ENV_SIZE must be a multiple of
2423 the NAND devices block size.
2425 - CONFIG_SYS_SPI_INIT_OFFSET
2427 Defines offset to the initial SPI buffer area in DPRAM. The
2428 area is used at an early stage (ROM part) if the environment
2429 is configured to reside in the SPI EEPROM: We need a 520 byte
2430 scratch DPRAM area. It is used between the two initialization
2431 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2432 to be a good choice since it makes it far enough from the
2433 start of the data area as well as from the stack pointer.
2435 Please note that the environment is read-only until the monitor
2436 has been relocated to RAM and a RAM copy of the environment has been
2437 created; also, when using EEPROM you will have to use getenv_r()
2438 until then to read environment variables.
2440 The environment is protected by a CRC32 checksum. Before the monitor
2441 is relocated into RAM, as a result of a bad CRC you will be working
2442 with the compiled-in default environment - *silently*!!! [This is
2443 necessary, because the first environment variable we need is the
2444 "baudrate" setting for the console - if we have a bad CRC, we don't
2445 have any device yet where we could complain.]
2447 Note: once the monitor has been relocated, then it will complain if
2448 the default environment is used; a new CRC is computed as soon as you
2449 use the "saveenv" command to store a valid environment.
2451 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2452 Echo the inverted Ethernet link state to the fault LED.
2454 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2455 also needs to be defined.
2457 - CONFIG_SYS_FAULT_MII_ADDR:
2458 MII address of the PHY to check for the Ethernet link state.
2460 - CONFIG_SYS_64BIT_VSPRINTF:
2461 Makes vsprintf (and all *printf functions) support printing
2462 of 64bit values by using the L quantifier
2464 - CONFIG_SYS_64BIT_STRTOUL:
2465 Adds simple_strtoull that returns a 64bit value
2467 - CONFIG_NS16550_MIN_FUNCTIONS:
2468 Define this if you desire to only have use of the NS16550_init
2469 and NS16550_putc functions for the serial driver located at
2470 drivers/serial/ns16550.c. This option is useful for saving
2471 space for already greatly restricted images, including but not
2472 limited to NAND_SPL configurations.
2474 Low Level (hardware related) configuration options:
2475 ---------------------------------------------------
2477 - CONFIG_SYS_CACHELINE_SIZE:
2478 Cache Line Size of the CPU.
2480 - CONFIG_SYS_DEFAULT_IMMR:
2481 Default address of the IMMR after system reset.
2483 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2484 and RPXsuper) to be able to adjust the position of
2485 the IMMR register after a reset.
2487 - Floppy Disk Support:
2488 CONFIG_SYS_FDC_DRIVE_NUMBER
2490 the default drive number (default value 0)
2492 CONFIG_SYS_ISA_IO_STRIDE
2494 defines the spacing between FDC chipset registers
2497 CONFIG_SYS_ISA_IO_OFFSET
2499 defines the offset of register from address. It
2500 depends on which part of the data bus is connected to
2501 the FDC chipset. (default value 0)
2503 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
2504 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
2507 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
2508 fdc_hw_init() is called at the beginning of the FDC
2509 setup. fdc_hw_init() must be provided by the board
2510 source code. It is used to make hardware dependant
2513 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
2514 DO NOT CHANGE unless you know exactly what you're
2515 doing! (11-4) [MPC8xx/82xx systems only]
2517 - CONFIG_SYS_INIT_RAM_ADDR:
2519 Start address of memory area that can be used for
2520 initial data and stack; please note that this must be
2521 writable memory that is working WITHOUT special
2522 initialization, i. e. you CANNOT use normal RAM which
2523 will become available only after programming the
2524 memory controller and running certain initialization
2527 U-Boot uses the following memory types:
2528 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2529 - MPC824X: data cache
2530 - PPC4xx: data cache
2532 - CONFIG_SYS_GBL_DATA_OFFSET:
2534 Offset of the initial data structure in the memory
2535 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2536 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
2537 data is located at the end of the available space
2538 (sometimes written as (CONFIG_SYS_INIT_RAM_END -
2539 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
2540 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2541 CONFIG_SYS_GBL_DATA_OFFSET) downward.
2544 On the MPC824X (or other systems that use the data
2545 cache for initial memory) the address chosen for
2546 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
2547 point to an otherwise UNUSED address space between
2548 the top of RAM and the start of the PCI space.
2550 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
2552 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
2554 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
2556 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
2558 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2560 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
2562 - CONFIG_SYS_OR_TIMING_SDRAM:
2565 - CONFIG_SYS_MAMR_PTA:
2566 periodic timer for refresh
2568 - CONFIG_SYS_DER: Debug Event Register (37-47)
2570 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2571 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2572 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2573 CONFIG_SYS_BR1_PRELIM:
2574 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2576 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2577 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2578 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
2579 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2581 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
2582 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
2583 Machine Mode Register and Memory Periodic Timer
2584 Prescaler definitions (SDRAM timing)
2586 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
2587 enable I2C microcode relocation patch (MPC8xx);
2588 define relocation offset in DPRAM [DSP2]
2590 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
2591 enable SMC microcode relocation patch (MPC8xx);
2592 define relocation offset in DPRAM [SMC1]
2594 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
2595 enable SPI microcode relocation patch (MPC8xx);
2596 define relocation offset in DPRAM [SCC4]
2598 - CONFIG_SYS_USE_OSCCLK:
2599 Use OSCM clock mode on MBX8xx board. Be careful,
2600 wrong setting might damage your board. Read
2601 doc/README.MBX before setting this variable!
2603 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2604 Offset of the bootmode word in DPRAM used by post
2605 (Power On Self Tests). This definition overrides
2606 #define'd default value in commproc.h resp.
2609 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
2610 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
2611 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
2612 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
2613 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2614 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
2615 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
2616 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
2617 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2619 - CONFIG_PCI_DISABLE_PCIE:
2620 Disable PCI-Express on systems where it is supported but not
2624 Get DDR timing information from an I2C EEPROM. Common
2625 with pluggable memory modules such as SODIMMs
2628 I2C address of the SPD EEPROM
2630 - CONFIG_SYS_SPD_BUS_NUM
2631 If SPD EEPROM is on an I2C bus other than the first
2632 one, specify here. Note that the value must resolve
2633 to something your driver can deal with.
2635 - CONFIG_SYS_83XX_DDR_USES_CS0
2636 Only for 83xx systems. If specified, then DDR should
2637 be configured using CS0 and CS1 instead of CS2 and CS3.
2639 - CONFIG_ETHER_ON_FEC[12]
2640 Define to enable FEC[12] on a 8xx series processor.
2642 - CONFIG_FEC[12]_PHY
2643 Define to the hardcoded PHY address which corresponds
2644 to the given FEC; i. e.
2645 #define CONFIG_FEC1_PHY 4
2646 means that the PHY with address 4 is connected to FEC1
2648 When set to -1, means to probe for first available.
2650 - CONFIG_FEC[12]_PHY_NORXERR
2651 The PHY does not have a RXERR line (RMII only).
2652 (so program the FEC to ignore it).
2655 Enable RMII mode for all FECs.
2656 Note that this is a global option, we can't
2657 have one FEC in standard MII mode and another in RMII mode.
2659 - CONFIG_CRC32_VERIFY
2660 Add a verify option to the crc32 command.
2663 => crc32 -v <address> <count> <crc32>
2665 Where address/count indicate a memory area
2666 and crc32 is the correct crc32 which the
2670 Add the "loopw" memory command. This only takes effect if
2671 the memory commands are activated globally (CONFIG_CMD_MEM).
2674 Add the "mdc" and "mwc" memory commands. These are cyclic
2679 This command will print 4 bytes (10,11,12,13) each 500 ms.
2681 => mwc.l 100 12345678 10
2682 This command will write 12345678 to address 100 all 10 ms.
2684 This only takes effect if the memory commands are activated
2685 globally (CONFIG_CMD_MEM).
2687 - CONFIG_SKIP_LOWLEVEL_INIT
2688 - CONFIG_SKIP_RELOCATE_UBOOT
2690 [ARM only] If these variables are defined, then
2691 certain low level initializations (like setting up
2692 the memory controller) are omitted and/or U-Boot does
2693 not relocate itself into RAM.
2694 Normally these variables MUST NOT be defined. The
2695 only exception is when U-Boot is loaded (to RAM) by
2696 some other boot loader or by a debugger which
2697 performs these initializations itself.
2700 Building the Software:
2701 ======================
2703 Building U-Boot has been tested in several native build environments
2704 and in many different cross environments. Of course we cannot support
2705 all possibly existing versions of cross development tools in all
2706 (potentially obsolete) versions. In case of tool chain problems we
2707 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2708 which is extensively used to build and test U-Boot.
2710 If you are not using a native environment, it is assumed that you
2711 have GNU cross compiling tools available in your path. In this case,
2712 you must set the environment variable CROSS_COMPILE in your shell.
2713 Note that no changes to the Makefile or any other source files are
2714 necessary. For example using the ELDK on a 4xx CPU, please enter:
2716 $ CROSS_COMPILE=ppc_4xx-
2717 $ export CROSS_COMPILE
2719 U-Boot is intended to be simple to build. After installing the
2720 sources you must configure U-Boot for one specific board type. This
2725 where "NAME_config" is the name of one of the existing configu-
2726 rations; see the main Makefile for supported names.
2728 Note: for some board special configuration names may exist; check if
2729 additional information is available from the board vendor; for
2730 instance, the TQM823L systems are available without (standard)
2731 or with LCD support. You can select such additional "features"
2732 when choosing the configuration, i. e.
2735 - will configure for a plain TQM823L, i. e. no LCD support
2737 make TQM823L_LCD_config
2738 - will configure for a TQM823L with U-Boot console on LCD
2743 Finally, type "make all", and you should get some working U-Boot
2744 images ready for download to / installation on your system:
2746 - "u-boot.bin" is a raw binary image
2747 - "u-boot" is an image in ELF binary format
2748 - "u-boot.srec" is in Motorola S-Record format
2750 By default the build is performed locally and the objects are saved
2751 in the source directory. One of the two methods can be used to change
2752 this behavior and build U-Boot to some external directory:
2754 1. Add O= to the make command line invocations:
2756 make O=/tmp/build distclean
2757 make O=/tmp/build NAME_config
2758 make O=/tmp/build all
2760 2. Set environment variable BUILD_DIR to point to the desired location:
2762 export BUILD_DIR=/tmp/build
2767 Note that the command line "O=" setting overrides the BUILD_DIR environment
2771 Please be aware that the Makefiles assume you are using GNU make, so
2772 for instance on NetBSD you might need to use "gmake" instead of
2776 If the system board that you have is not listed, then you will need
2777 to port U-Boot to your hardware platform. To do this, follow these
2780 1. Add a new configuration option for your board to the toplevel
2781 "Makefile" and to the "MAKEALL" script, using the existing
2782 entries as examples. Note that here and at many other places
2783 boards and other names are listed in alphabetical sort order. Please
2785 2. Create a new directory to hold your board specific code. Add any
2786 files you need. In your board directory, you will need at least
2787 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2788 3. Create a new configuration file "include/configs/<board>.h" for
2790 3. If you're porting U-Boot to a new CPU, then also create a new
2791 directory to hold your CPU specific code. Add any files you need.
2792 4. Run "make <board>_config" with your new name.
2793 5. Type "make", and you should get a working "u-boot.srec" file
2794 to be installed on your target system.
2795 6. Debug and solve any problems that might arise.
2796 [Of course, this last step is much harder than it sounds.]
2799 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2800 ==============================================================
2802 If you have modified U-Boot sources (for instance added a new board
2803 or support for new devices, a new CPU, etc.) you are expected to
2804 provide feedback to the other developers. The feedback normally takes
2805 the form of a "patch", i. e. a context diff against a certain (latest
2806 official or latest in the git repository) version of U-Boot sources.
2808 But before you submit such a patch, please verify that your modifi-
2809 cation did not break existing code. At least make sure that *ALL* of
2810 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2811 just run the "MAKEALL" script, which will configure and build U-Boot
2812 for ALL supported system. Be warned, this will take a while. You can
2813 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2814 environment variable to the script, i. e. to use the ELDK cross tools
2817 CROSS_COMPILE=ppc_8xx- MAKEALL
2819 or to build on a native PowerPC system you can type
2821 CROSS_COMPILE=' ' MAKEALL
2823 When using the MAKEALL script, the default behaviour is to build
2824 U-Boot in the source directory. This location can be changed by
2825 setting the BUILD_DIR environment variable. Also, for each target
2826 built, the MAKEALL script saves two log files (<target>.ERR and
2827 <target>.MAKEALL) in the <source dir>/LOG directory. This default
2828 location can be changed by setting the MAKEALL_LOGDIR environment
2829 variable. For example:
2831 export BUILD_DIR=/tmp/build
2832 export MAKEALL_LOGDIR=/tmp/log
2833 CROSS_COMPILE=ppc_8xx- MAKEALL
2835 With the above settings build objects are saved in the /tmp/build,
2836 log files are saved in the /tmp/log and the source tree remains clean
2837 during the whole build process.
2840 See also "U-Boot Porting Guide" below.
2843 Monitor Commands - Overview:
2844 ============================
2846 go - start application at address 'addr'
2847 run - run commands in an environment variable
2848 bootm - boot application image from memory
2849 bootp - boot image via network using BootP/TFTP protocol
2850 tftpboot- boot image via network using TFTP protocol
2851 and env variables "ipaddr" and "serverip"
2852 (and eventually "gatewayip")
2853 rarpboot- boot image via network using RARP/TFTP protocol
2854 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2855 loads - load S-Record file over serial line
2856 loadb - load binary file over serial line (kermit mode)
2858 mm - memory modify (auto-incrementing)
2859 nm - memory modify (constant address)
2860 mw - memory write (fill)
2862 cmp - memory compare
2863 crc32 - checksum calculation
2864 imd - i2c memory display
2865 imm - i2c memory modify (auto-incrementing)
2866 inm - i2c memory modify (constant address)
2867 imw - i2c memory write (fill)
2868 icrc32 - i2c checksum calculation
2869 iprobe - probe to discover valid I2C chip addresses
2870 iloop - infinite loop on address range
2871 isdram - print SDRAM configuration information
2872 sspi - SPI utility commands
2873 base - print or set address offset
2874 printenv- print environment variables
2875 setenv - set environment variables
2876 saveenv - save environment variables to persistent storage
2877 protect - enable or disable FLASH write protection
2878 erase - erase FLASH memory
2879 flinfo - print FLASH memory information
2880 bdinfo - print Board Info structure
2881 iminfo - print header information for application image
2882 coninfo - print console devices and informations
2883 ide - IDE sub-system
2884 loop - infinite loop on address range
2885 loopw - infinite write loop on address range
2886 mtest - simple RAM test
2887 icache - enable or disable instruction cache
2888 dcache - enable or disable data cache
2889 reset - Perform RESET of the CPU
2890 echo - echo args to console
2891 version - print monitor version
2892 help - print online help
2893 ? - alias for 'help'
2896 Monitor Commands - Detailed Description:
2897 ========================================
2901 For now: just type "help <command>".
2904 Environment Variables:
2905 ======================
2907 U-Boot supports user configuration using Environment Variables which
2908 can be made persistent by saving to Flash memory.
2910 Environment Variables are set using "setenv", printed using
2911 "printenv", and saved to Flash using "saveenv". Using "setenv"
2912 without a value can be used to delete a variable from the
2913 environment. As long as you don't save the environment you are
2914 working with an in-memory copy. In case the Flash area containing the
2915 environment is erased by accident, a default environment is provided.
2917 Some configuration options can be set using Environment Variables:
2919 baudrate - see CONFIG_BAUDRATE
2921 bootdelay - see CONFIG_BOOTDELAY
2923 bootcmd - see CONFIG_BOOTCOMMAND
2925 bootargs - Boot arguments when booting an RTOS image
2927 bootfile - Name of the image to load with TFTP
2929 bootm_low - Memory range available for image processing in the bootm
2930 command can be restricted. This variable is given as
2931 a hexadecimal number and defines lowest address allowed
2932 for use by the bootm command. See also "bootm_size"
2933 environment variable. Address defined by "bootm_low" is
2934 also the base of the initial memory mapping for the Linux
2935 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ.
2937 bootm_size - Memory range available for image processing in the bootm
2938 command can be restricted. This variable is given as
2939 a hexadecimal number and defines the size of the region
2940 allowed for use by the bootm command. See also "bootm_low"
2941 environment variable.
2943 updatefile - Location of the software update file on a TFTP server, used
2944 by the automatic software update feature. Please refer to
2945 documentation in doc/README.update for more details.
2947 autoload - if set to "no" (any string beginning with 'n'),
2948 "bootp" will just load perform a lookup of the
2949 configuration from the BOOTP server, but not try to
2950 load any image using TFTP
2952 autoscript - if set to "yes" commands like "loadb", "loady",
2953 "bootp", "tftpb", "rarpboot" and "nfs" will attempt
2954 to automatically run script images (by internally
2957 autoscript_uname - if script image is in a format (FIT) this
2958 variable is used to get script subimage unit name.
2960 autostart - if set to "yes", an image loaded using the "bootp",
2961 "rarpboot", "tftpboot" or "diskboot" commands will
2962 be automatically started (by internally calling
2965 If set to "no", a standalone image passed to the
2966 "bootm" command will be copied to the load address
2967 (and eventually uncompressed), but NOT be started.
2968 This can be used to load and uncompress arbitrary
2971 i2cfast - (PPC405GP|PPC405EP only)
2972 if set to 'y' configures Linux I2C driver for fast
2973 mode (400kHZ). This environment variable is used in
2974 initialization code. So, for changes to be effective
2975 it must be saved and board must be reset.
2977 initrd_high - restrict positioning of initrd images:
2978 If this variable is not set, initrd images will be
2979 copied to the highest possible address in RAM; this
2980 is usually what you want since it allows for
2981 maximum initrd size. If for some reason you want to
2982 make sure that the initrd image is loaded below the
2983 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
2984 variable to a value of "no" or "off" or "0".
2985 Alternatively, you can set it to a maximum upper
2986 address to use (U-Boot will still check that it
2987 does not overwrite the U-Boot stack and data).
2989 For instance, when you have a system with 16 MB
2990 RAM, and want to reserve 4 MB from use by Linux,
2991 you can do this by adding "mem=12M" to the value of
2992 the "bootargs" variable. However, now you must make
2993 sure that the initrd image is placed in the first
2994 12 MB as well - this can be done with
2996 setenv initrd_high 00c00000
2998 If you set initrd_high to 0xFFFFFFFF, this is an
2999 indication to U-Boot that all addresses are legal
3000 for the Linux kernel, including addresses in flash
3001 memory. In this case U-Boot will NOT COPY the
3002 ramdisk at all. This may be useful to reduce the
3003 boot time on your system, but requires that this
3004 feature is supported by your Linux kernel.
3006 ipaddr - IP address; needed for tftpboot command
3008 loadaddr - Default load address for commands like "bootp",
3009 "rarpboot", "tftpboot", "loadb" or "diskboot"
3011 loads_echo - see CONFIG_LOADS_ECHO
3013 serverip - TFTP server IP address; needed for tftpboot command
3015 bootretry - see CONFIG_BOOT_RETRY_TIME
3017 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3019 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3021 ethprime - When CONFIG_NET_MULTI is enabled controls which
3022 interface is used first.
3024 ethact - When CONFIG_NET_MULTI is enabled controls which
3025 interface is currently active. For example you
3026 can do the following
3028 => setenv ethact FEC ETHERNET
3029 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
3030 => setenv ethact SCC ETHERNET
3031 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
3033 ethrotate - When set to "no" U-Boot does not go through all
3034 available network interfaces.
3035 It just stays at the currently selected interface.
3037 netretry - When set to "no" each network operation will
3038 either succeed or fail without retrying.
3039 When set to "once" the network operation will
3040 fail when all the available network interfaces
3041 are tried once without success.
3042 Useful on scripts which control the retry operation
3045 npe_ucode - set load address for the NPE microcode
3047 tftpsrcport - If this is set, the value is used for TFTP's
3050 tftpdstport - If this is set, the value is used for TFTP's UDP
3051 destination port instead of the Well Know Port 69.
3053 vlan - When set to a value < 4095 the traffic over
3054 Ethernet is encapsulated/received over 802.1q
3057 The following environment variables may be used and automatically
3058 updated by the network boot commands ("bootp" and "rarpboot"),
3059 depending the information provided by your boot server:
3061 bootfile - see above
3062 dnsip - IP address of your Domain Name Server
3063 dnsip2 - IP address of your secondary Domain Name Server
3064 gatewayip - IP address of the Gateway (Router) to use
3065 hostname - Target hostname
3067 netmask - Subnet Mask
3068 rootpath - Pathname of the root filesystem on the NFS server
3069 serverip - see above
3072 There are two special Environment Variables:
3074 serial# - contains hardware identification information such
3075 as type string and/or serial number
3076 ethaddr - Ethernet address
3078 These variables can be set only once (usually during manufacturing of
3079 the board). U-Boot refuses to delete or overwrite these variables
3080 once they have been set once.
3083 Further special Environment Variables:
3085 ver - Contains the U-Boot version string as printed
3086 with the "version" command. This variable is
3087 readonly (see CONFIG_VERSION_VARIABLE).
3090 Please note that changes to some configuration parameters may take
3091 only effect after the next boot (yes, that's just like Windoze :-).
3094 Command Line Parsing:
3095 =====================
3097 There are two different command line parsers available with U-Boot:
3098 the old "simple" one, and the much more powerful "hush" shell:
3100 Old, simple command line parser:
3101 --------------------------------
3103 - supports environment variables (through setenv / saveenv commands)
3104 - several commands on one line, separated by ';'
3105 - variable substitution using "... ${name} ..." syntax
3106 - special characters ('$', ';') can be escaped by prefixing with '\',
3108 setenv bootcmd bootm \${address}
3109 - You can also escape text by enclosing in single apostrophes, for example:
3110 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3115 - similar to Bourne shell, with control structures like
3116 if...then...else...fi, for...do...done; while...do...done,
3117 until...do...done, ...
3118 - supports environment ("global") variables (through setenv / saveenv
3119 commands) and local shell variables (through standard shell syntax
3120 "name=value"); only environment variables can be used with "run"
3126 (1) If a command line (or an environment variable executed by a "run"
3127 command) contains several commands separated by semicolon, and
3128 one of these commands fails, then the remaining commands will be
3131 (2) If you execute several variables with one call to run (i. e.
3132 calling run with a list of variables as arguments), any failing
3133 command will cause "run" to terminate, i. e. the remaining
3134 variables are not executed.
3136 Note for Redundant Ethernet Interfaces:
3137 =======================================
3139 Some boards come with redundant Ethernet interfaces; U-Boot supports
3140 such configurations and is capable of automatic selection of a
3141 "working" interface when needed. MAC assignment works as follows:
3143 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3144 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3145 "eth1addr" (=>eth1), "eth2addr", ...
3147 If the network interface stores some valid MAC address (for instance
3148 in SROM), this is used as default address if there is NO correspon-
3149 ding setting in the environment; if the corresponding environment
3150 variable is set, this overrides the settings in the card; that means:
3152 o If the SROM has a valid MAC address, and there is no address in the
3153 environment, the SROM's address is used.
3155 o If there is no valid address in the SROM, and a definition in the
3156 environment exists, then the value from the environment variable is
3159 o If both the SROM and the environment contain a MAC address, and
3160 both addresses are the same, this MAC address is used.
3162 o If both the SROM and the environment contain a MAC address, and the
3163 addresses differ, the value from the environment is used and a
3166 o If neither SROM nor the environment contain a MAC address, an error
3173 U-Boot is capable of booting (and performing other auxiliary operations on)
3174 images in two formats:
3176 New uImage format (FIT)
3177 -----------------------
3179 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3180 to Flattened Device Tree). It allows the use of images with multiple
3181 components (several kernels, ramdisks, etc.), with contents protected by
3182 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3188 Old image format is based on binary files which can be basically anything,
3189 preceded by a special header; see the definitions in include/image.h for
3190 details; basically, the header defines the following image properties:
3192 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3193 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3194 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3195 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3197 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3198 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3199 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
3200 * Compression Type (uncompressed, gzip, bzip2)
3206 The header is marked by a special Magic Number, and both the header
3207 and the data portions of the image are secured against corruption by
3214 Although U-Boot should support any OS or standalone application
3215 easily, the main focus has always been on Linux during the design of
3218 U-Boot includes many features that so far have been part of some
3219 special "boot loader" code within the Linux kernel. Also, any
3220 "initrd" images to be used are no longer part of one big Linux image;
3221 instead, kernel and "initrd" are separate images. This implementation
3222 serves several purposes:
3224 - the same features can be used for other OS or standalone
3225 applications (for instance: using compressed images to reduce the
3226 Flash memory footprint)
3228 - it becomes much easier to port new Linux kernel versions because
3229 lots of low-level, hardware dependent stuff are done by U-Boot
3231 - the same Linux kernel image can now be used with different "initrd"
3232 images; of course this also means that different kernel images can
3233 be run with the same "initrd". This makes testing easier (you don't
3234 have to build a new "zImage.initrd" Linux image when you just
3235 change a file in your "initrd"). Also, a field-upgrade of the
3236 software is easier now.
3242 Porting Linux to U-Boot based systems:
3243 ---------------------------------------
3245 U-Boot cannot save you from doing all the necessary modifications to
3246 configure the Linux device drivers for use with your target hardware
3247 (no, we don't intend to provide a full virtual machine interface to
3250 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
3252 Just make sure your machine specific header file (for instance
3253 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3254 Information structure as we define in include/asm-<arch>/u-boot.h,
3255 and make sure that your definition of IMAP_ADDR uses the same value
3256 as your U-Boot configuration in CONFIG_SYS_IMMR.
3259 Configuring the Linux kernel:
3260 -----------------------------
3262 No specific requirements for U-Boot. Make sure you have some root
3263 device (initial ramdisk, NFS) for your target system.
3266 Building a Linux Image:
3267 -----------------------
3269 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3270 not used. If you use recent kernel source, a new build target
3271 "uImage" will exist which automatically builds an image usable by
3272 U-Boot. Most older kernels also have support for a "pImage" target,
3273 which was introduced for our predecessor project PPCBoot and uses a
3274 100% compatible format.
3283 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3284 encapsulate a compressed Linux kernel image with header information,
3285 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3287 * build a standard "vmlinux" kernel image (in ELF binary format):
3289 * convert the kernel into a raw binary image:
3291 ${CROSS_COMPILE}-objcopy -O binary \
3292 -R .note -R .comment \
3293 -S vmlinux linux.bin
3295 * compress the binary image:
3299 * package compressed binary image for U-Boot:
3301 mkimage -A ppc -O linux -T kernel -C gzip \
3302 -a 0 -e 0 -n "Linux Kernel Image" \
3303 -d linux.bin.gz uImage
3306 The "mkimage" tool can also be used to create ramdisk images for use
3307 with U-Boot, either separated from the Linux kernel image, or
3308 combined into one file. "mkimage" encapsulates the images with a 64
3309 byte header containing information about target architecture,
3310 operating system, image type, compression method, entry points, time
3311 stamp, CRC32 checksums, etc.
3313 "mkimage" can be called in two ways: to verify existing images and
3314 print the header information, or to build new images.
3316 In the first form (with "-l" option) mkimage lists the information
3317 contained in the header of an existing U-Boot image; this includes
3318 checksum verification:
3320 tools/mkimage -l image
3321 -l ==> list image header information
3323 The second form (with "-d" option) is used to build a U-Boot image
3324 from a "data file" which is used as image payload:
3326 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3327 -n name -d data_file image
3328 -A ==> set architecture to 'arch'
3329 -O ==> set operating system to 'os'
3330 -T ==> set image type to 'type'
3331 -C ==> set compression type 'comp'
3332 -a ==> set load address to 'addr' (hex)
3333 -e ==> set entry point to 'ep' (hex)
3334 -n ==> set image name to 'name'
3335 -d ==> use image data from 'datafile'
3337 Right now, all Linux kernels for PowerPC systems use the same load
3338 address (0x00000000), but the entry point address depends on the
3341 - 2.2.x kernels have the entry point at 0x0000000C,
3342 - 2.3.x and later kernels have the entry point at 0x00000000.
3344 So a typical call to build a U-Boot image would read:
3346 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3347 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3348 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
3349 > examples/uImage.TQM850L
3350 Image Name: 2.4.4 kernel for TQM850L
3351 Created: Wed Jul 19 02:34:59 2000
3352 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3353 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3354 Load Address: 0x00000000
3355 Entry Point: 0x00000000
3357 To verify the contents of the image (or check for corruption):
3359 -> tools/mkimage -l examples/uImage.TQM850L
3360 Image Name: 2.4.4 kernel for TQM850L
3361 Created: Wed Jul 19 02:34:59 2000
3362 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3363 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3364 Load Address: 0x00000000
3365 Entry Point: 0x00000000
3367 NOTE: for embedded systems where boot time is critical you can trade
3368 speed for memory and install an UNCOMPRESSED image instead: this
3369 needs more space in Flash, but boots much faster since it does not
3370 need to be uncompressed:
3372 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
3373 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3374 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3375 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
3376 > examples/uImage.TQM850L-uncompressed
3377 Image Name: 2.4.4 kernel for TQM850L
3378 Created: Wed Jul 19 02:34:59 2000
3379 Image Type: PowerPC Linux Kernel Image (uncompressed)
3380 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3381 Load Address: 0x00000000
3382 Entry Point: 0x00000000
3385 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3386 when your kernel is intended to use an initial ramdisk:
3388 -> tools/mkimage -n 'Simple Ramdisk Image' \
3389 > -A ppc -O linux -T ramdisk -C gzip \
3390 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3391 Image Name: Simple Ramdisk Image
3392 Created: Wed Jan 12 14:01:50 2000
3393 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3394 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3395 Load Address: 0x00000000
3396 Entry Point: 0x00000000
3399 Installing a Linux Image:
3400 -------------------------
3402 To downloading a U-Boot image over the serial (console) interface,
3403 you must convert the image to S-Record format:
3405 objcopy -I binary -O srec examples/image examples/image.srec
3407 The 'objcopy' does not understand the information in the U-Boot
3408 image header, so the resulting S-Record file will be relative to
3409 address 0x00000000. To load it to a given address, you need to
3410 specify the target address as 'offset' parameter with the 'loads'
3413 Example: install the image to address 0x40100000 (which on the
3414 TQM8xxL is in the first Flash bank):
3416 => erase 40100000 401FFFFF
3422 ## Ready for S-Record download ...
3423 ~>examples/image.srec
3424 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3426 15989 15990 15991 15992
3427 [file transfer complete]
3429 ## Start Addr = 0x00000000
3432 You can check the success of the download using the 'iminfo' command;
3433 this includes a checksum verification so you can be sure no data
3434 corruption happened:
3438 ## Checking Image at 40100000 ...
3439 Image Name: 2.2.13 for initrd on TQM850L
3440 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3441 Data Size: 335725 Bytes = 327 kB = 0 MB
3442 Load Address: 00000000
3443 Entry Point: 0000000c
3444 Verifying Checksum ... OK
3450 The "bootm" command is used to boot an application that is stored in
3451 memory (RAM or Flash). In case of a Linux kernel image, the contents
3452 of the "bootargs" environment variable is passed to the kernel as
3453 parameters. You can check and modify this variable using the
3454 "printenv" and "setenv" commands:
3457 => printenv bootargs
3458 bootargs=root=/dev/ram
3460 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3462 => printenv bootargs
3463 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3466 ## Booting Linux kernel at 40020000 ...
3467 Image Name: 2.2.13 for NFS on TQM850L
3468 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3469 Data Size: 381681 Bytes = 372 kB = 0 MB
3470 Load Address: 00000000
3471 Entry Point: 0000000c
3472 Verifying Checksum ... OK
3473 Uncompressing Kernel Image ... OK
3474 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
3475 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3476 time_init: decrementer frequency = 187500000/60
3477 Calibrating delay loop... 49.77 BogoMIPS
3478 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3481 If you want to boot a Linux kernel with initial RAM disk, you pass
3482 the memory addresses of both the kernel and the initrd image (PPBCOOT
3483 format!) to the "bootm" command:
3485 => imi 40100000 40200000
3487 ## Checking Image at 40100000 ...
3488 Image Name: 2.2.13 for initrd on TQM850L
3489 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3490 Data Size: 335725 Bytes = 327 kB = 0 MB
3491 Load Address: 00000000
3492 Entry Point: 0000000c
3493 Verifying Checksum ... OK
3495 ## Checking Image at 40200000 ...
3496 Image Name: Simple Ramdisk Image
3497 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3498 Data Size: 566530 Bytes = 553 kB = 0 MB
3499 Load Address: 00000000
3500 Entry Point: 00000000
3501 Verifying Checksum ... OK
3503 => bootm 40100000 40200000
3504 ## Booting Linux kernel at 40100000 ...
3505 Image Name: 2.2.13 for initrd on TQM850L
3506 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3507 Data Size: 335725 Bytes = 327 kB = 0 MB
3508 Load Address: 00000000
3509 Entry Point: 0000000c
3510 Verifying Checksum ... OK
3511 Uncompressing Kernel Image ... OK
3512 ## Loading RAMDisk Image at 40200000 ...
3513 Image Name: Simple Ramdisk Image
3514 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3515 Data Size: 566530 Bytes = 553 kB = 0 MB
3516 Load Address: 00000000
3517 Entry Point: 00000000
3518 Verifying Checksum ... OK
3519 Loading Ramdisk ... OK
3520 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
3521 Boot arguments: root=/dev/ram
3522 time_init: decrementer frequency = 187500000/60
3523 Calibrating delay loop... 49.77 BogoMIPS
3525 RAMDISK: Compressed image found at block 0
3526 VFS: Mounted root (ext2 filesystem).
3530 Boot Linux and pass a flat device tree:
3533 First, U-Boot must be compiled with the appropriate defines. See the section
3534 titled "Linux Kernel Interface" above for a more in depth explanation. The
3535 following is an example of how to start a kernel and pass an updated
3541 oft=oftrees/mpc8540ads.dtb
3542 => tftp $oftaddr $oft
3543 Speed: 1000, full duplex
3545 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3546 Filename 'oftrees/mpc8540ads.dtb'.
3547 Load address: 0x300000
3550 Bytes transferred = 4106 (100a hex)
3551 => tftp $loadaddr $bootfile
3552 Speed: 1000, full duplex
3554 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3556 Load address: 0x200000
3557 Loading:############
3559 Bytes transferred = 1029407 (fb51f hex)
3564 => bootm $loadaddr - $oftaddr
3565 ## Booting image at 00200000 ...
3566 Image Name: Linux-2.6.17-dirty
3567 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3568 Data Size: 1029343 Bytes = 1005.2 kB
3569 Load Address: 00000000
3570 Entry Point: 00000000
3571 Verifying Checksum ... OK
3572 Uncompressing Kernel Image ... OK
3573 Booting using flat device tree at 0x300000
3574 Using MPC85xx ADS machine description
3575 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3579 More About U-Boot Image Types:
3580 ------------------------------
3582 U-Boot supports the following image types:
3584 "Standalone Programs" are directly runnable in the environment
3585 provided by U-Boot; it is expected that (if they behave
3586 well) you can continue to work in U-Boot after return from
3587 the Standalone Program.
3588 "OS Kernel Images" are usually images of some Embedded OS which
3589 will take over control completely. Usually these programs
3590 will install their own set of exception handlers, device
3591 drivers, set up the MMU, etc. - this means, that you cannot
3592 expect to re-enter U-Boot except by resetting the CPU.
3593 "RAMDisk Images" are more or less just data blocks, and their
3594 parameters (address, size) are passed to an OS kernel that is
3596 "Multi-File Images" contain several images, typically an OS
3597 (Linux) kernel image and one or more data images like
3598 RAMDisks. This construct is useful for instance when you want
3599 to boot over the network using BOOTP etc., where the boot
3600 server provides just a single image file, but you want to get
3601 for instance an OS kernel and a RAMDisk image.
3603 "Multi-File Images" start with a list of image sizes, each
3604 image size (in bytes) specified by an "uint32_t" in network
3605 byte order. This list is terminated by an "(uint32_t)0".
3606 Immediately after the terminating 0 follow the images, one by
3607 one, all aligned on "uint32_t" boundaries (size rounded up to
3608 a multiple of 4 bytes).
3610 "Firmware Images" are binary images containing firmware (like
3611 U-Boot or FPGA images) which usually will be programmed to
3614 "Script files" are command sequences that will be executed by
3615 U-Boot's command interpreter; this feature is especially
3616 useful when you configure U-Boot to use a real shell (hush)
3617 as command interpreter.
3623 One of the features of U-Boot is that you can dynamically load and
3624 run "standalone" applications, which can use some resources of
3625 U-Boot like console I/O functions or interrupt services.
3627 Two simple examples are included with the sources:
3632 'examples/hello_world.c' contains a small "Hello World" Demo
3633 application; it is automatically compiled when you build U-Boot.
3634 It's configured to run at address 0x00040004, so you can play with it
3638 ## Ready for S-Record download ...
3639 ~>examples/hello_world.srec
3640 1 2 3 4 5 6 7 8 9 10 11 ...
3641 [file transfer complete]
3643 ## Start Addr = 0x00040004
3645 => go 40004 Hello World! This is a test.
3646 ## Starting application at 0x00040004 ...
3657 Hit any key to exit ...
3659 ## Application terminated, rc = 0x0
3661 Another example, which demonstrates how to register a CPM interrupt
3662 handler with the U-Boot code, can be found in 'examples/timer.c'.
3663 Here, a CPM timer is set up to generate an interrupt every second.
3664 The interrupt service routine is trivial, just printing a '.'
3665 character, but this is just a demo program. The application can be
3666 controlled by the following keys:
3668 ? - print current values og the CPM Timer registers
3669 b - enable interrupts and start timer
3670 e - stop timer and disable interrupts
3671 q - quit application
3674 ## Ready for S-Record download ...
3675 ~>examples/timer.srec
3676 1 2 3 4 5 6 7 8 9 10 11 ...
3677 [file transfer complete]
3679 ## Start Addr = 0x00040004
3682 ## Starting application at 0x00040004 ...
3685 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3688 [q, b, e, ?] Set interval 1000000 us
3691 [q, b, e, ?] ........
3692 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3695 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3698 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3701 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3703 [q, b, e, ?] ...Stopping timer
3705 [q, b, e, ?] ## Application terminated, rc = 0x0
3711 Over time, many people have reported problems when trying to use the
3712 "minicom" terminal emulation program for serial download. I (wd)
3713 consider minicom to be broken, and recommend not to use it. Under
3714 Unix, I recommend to use C-Kermit for general purpose use (and
3715 especially for kermit binary protocol download ("loadb" command), and
3716 use "cu" for S-Record download ("loads" command).
3718 Nevertheless, if you absolutely want to use it try adding this
3719 configuration to your "File transfer protocols" section:
3721 Name Program Name U/D FullScr IO-Red. Multi
3722 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3723 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3729 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3730 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3732 Building requires a cross environment; it is known to work on
3733 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3734 need gmake since the Makefiles are not compatible with BSD make).
3735 Note that the cross-powerpc package does not install include files;
3736 attempting to build U-Boot will fail because <machine/ansi.h> is
3737 missing. This file has to be installed and patched manually:
3739 # cd /usr/pkg/cross/powerpc-netbsd/include
3741 # ln -s powerpc machine
3742 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3743 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3745 Native builds *don't* work due to incompatibilities between native
3746 and U-Boot include files.
3748 Booting assumes that (the first part of) the image booted is a
3749 stage-2 loader which in turn loads and then invokes the kernel
3750 proper. Loader sources will eventually appear in the NetBSD source
3751 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3752 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3755 Implementation Internals:
3756 =========================
3758 The following is not intended to be a complete description of every
3759 implementation detail. However, it should help to understand the
3760 inner workings of U-Boot and make it easier to port it to custom
3764 Initial Stack, Global Data:
3765 ---------------------------
3767 The implementation of U-Boot is complicated by the fact that U-Boot
3768 starts running out of ROM (flash memory), usually without access to
3769 system RAM (because the memory controller is not initialized yet).
3770 This means that we don't have writable Data or BSS segments, and BSS
3771 is not initialized as zero. To be able to get a C environment working
3772 at all, we have to allocate at least a minimal stack. Implementation
3773 options for this are defined and restricted by the CPU used: Some CPU
3774 models provide on-chip memory (like the IMMR area on MPC8xx and
3775 MPC826x processors), on others (parts of) the data cache can be
3776 locked as (mis-) used as memory, etc.
3778 Chris Hallinan posted a good summary of these issues to the
3779 U-Boot mailing list:
3781 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3782 From: "Chris Hallinan" <clh@net1plus.com>
3783 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3786 Correct me if I'm wrong, folks, but the way I understand it
3787 is this: Using DCACHE as initial RAM for Stack, etc, does not
3788 require any physical RAM backing up the cache. The cleverness
3789 is that the cache is being used as a temporary supply of
3790 necessary storage before the SDRAM controller is setup. It's
3791 beyond the scope of this list to explain the details, but you
3792 can see how this works by studying the cache architecture and
3793 operation in the architecture and processor-specific manuals.
3795 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3796 is another option for the system designer to use as an
3797 initial stack/RAM area prior to SDRAM being available. Either
3798 option should work for you. Using CS 4 should be fine if your
3799 board designers haven't used it for something that would
3800 cause you grief during the initial boot! It is frequently not
3803 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
3804 with your processor/board/system design. The default value
3805 you will find in any recent u-boot distribution in
3806 walnut.h should work for you. I'd set it to a value larger
3807 than your SDRAM module. If you have a 64MB SDRAM module, set
3808 it above 400_0000. Just make sure your board has no resources
3809 that are supposed to respond to that address! That code in
3810 start.S has been around a while and should work as is when
3811 you get the config right.
3816 It is essential to remember this, since it has some impact on the C
3817 code for the initialization procedures:
3819 * Initialized global data (data segment) is read-only. Do not attempt
3822 * Do not use any uninitialized global data (or implicitely initialized
3823 as zero data - BSS segment) at all - this is undefined, initiali-
3824 zation is performed later (when relocating to RAM).
3826 * Stack space is very limited. Avoid big data buffers or things like
3829 Having only the stack as writable memory limits means we cannot use
3830 normal global data to share information beween the code. But it
3831 turned out that the implementation of U-Boot can be greatly
3832 simplified by making a global data structure (gd_t) available to all
3833 functions. We could pass a pointer to this data as argument to _all_
3834 functions, but this would bloat the code. Instead we use a feature of
3835 the GCC compiler (Global Register Variables) to share the data: we
3836 place a pointer (gd) to the global data into a register which we
3837 reserve for this purpose.
3839 When choosing a register for such a purpose we are restricted by the
3840 relevant (E)ABI specifications for the current architecture, and by
3841 GCC's implementation.
3843 For PowerPC, the following registers have specific use:
3845 R2: reserved for system use
3846 R3-R4: parameter passing and return values
3847 R5-R10: parameter passing
3848 R13: small data area pointer
3852 (U-Boot also uses R14 as internal GOT pointer.)
3854 ==> U-Boot will use R2 to hold a pointer to the global data
3856 Note: on PPC, we could use a static initializer (since the
3857 address of the global data structure is known at compile time),
3858 but it turned out that reserving a register results in somewhat
3859 smaller code - although the code savings are not that big (on
3860 average for all boards 752 bytes for the whole U-Boot image,
3861 624 text + 127 data).
3863 On Blackfin, the normal C ABI (except for P5) is followed as documented here:
3864 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
3866 ==> U-Boot will use P5 to hold a pointer to the global data
3868 On ARM, the following registers are used:
3870 R0: function argument word/integer result
3871 R1-R3: function argument word
3873 R10: stack limit (used only if stack checking if enabled)
3874 R11: argument (frame) pointer
3875 R12: temporary workspace
3878 R15: program counter
3880 ==> U-Boot will use R8 to hold a pointer to the global data
3882 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3883 or current versions of GCC may "optimize" the code too much.
3888 U-Boot runs in system state and uses physical addresses, i.e. the
3889 MMU is not used either for address mapping nor for memory protection.
3891 The available memory is mapped to fixed addresses using the memory
3892 controller. In this process, a contiguous block is formed for each
3893 memory type (Flash, SDRAM, SRAM), even when it consists of several
3894 physical memory banks.
3896 U-Boot is installed in the first 128 kB of the first Flash bank (on
3897 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3898 booting and sizing and initializing DRAM, the code relocates itself
3899 to the upper end of DRAM. Immediately below the U-Boot code some
3900 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
3901 configuration setting]. Below that, a structure with global Board
3902 Info data is placed, followed by the stack (growing downward).
3904 Additionally, some exception handler code is copied to the low 8 kB
3905 of DRAM (0x00000000 ... 0x00001FFF).
3907 So a typical memory configuration with 16 MB of DRAM could look like
3910 0x0000 0000 Exception Vector code
3913 0x0000 2000 Free for Application Use
3919 0x00FB FF20 Monitor Stack (Growing downward)
3920 0x00FB FFAC Board Info Data and permanent copy of global data
3921 0x00FC 0000 Malloc Arena
3924 0x00FE 0000 RAM Copy of Monitor Code
3925 ... eventually: LCD or video framebuffer
3926 ... eventually: pRAM (Protected RAM - unchanged by reset)
3927 0x00FF FFFF [End of RAM]
3930 System Initialization:
3931 ----------------------
3933 In the reset configuration, U-Boot starts at the reset entry point
3934 (on most PowerPC systems at address 0x00000100). Because of the reset
3935 configuration for CS0# this is a mirror of the onboard Flash memory.
3936 To be able to re-map memory U-Boot then jumps to its link address.
3937 To be able to implement the initialization code in C, a (small!)
3938 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3939 which provide such a feature like MPC8xx or MPC8260), or in a locked
3940 part of the data cache. After that, U-Boot initializes the CPU core,
3941 the caches and the SIU.
3943 Next, all (potentially) available memory banks are mapped using a
3944 preliminary mapping. For example, we put them on 512 MB boundaries
3945 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3946 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3947 programmed for SDRAM access. Using the temporary configuration, a
3948 simple memory test is run that determines the size of the SDRAM
3951 When there is more than one SDRAM bank, and the banks are of
3952 different size, the largest is mapped first. For equal size, the first
3953 bank (CS2#) is mapped first. The first mapping is always for address
3954 0x00000000, with any additional banks following immediately to create
3955 contiguous memory starting from 0.
3957 Then, the monitor installs itself at the upper end of the SDRAM area
3958 and allocates memory for use by malloc() and for the global Board
3959 Info data; also, the exception vector code is copied to the low RAM
3960 pages, and the final stack is set up.
3962 Only after this relocation will you have a "normal" C environment;
3963 until that you are restricted in several ways, mostly because you are
3964 running from ROM, and because the code will have to be relocated to a
3968 U-Boot Porting Guide:
3969 ----------------------
3971 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3975 int main (int argc, char *argv[])
3977 sighandler_t no_more_time;
3979 signal (SIGALRM, no_more_time);
3980 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3982 if (available_money > available_manpower) {
3983 pay consultant to port U-Boot;
3987 Download latest U-Boot source;
3989 Subscribe to u-boot mailing list;
3992 email ("Hi, I am new to U-Boot, how do I get started?");
3996 Read the README file in the top level directory;
3997 Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
3998 Read the source, Luke;
4001 if (available_money > toLocalCurrency ($2500)) {
4004 Add a lot of aggravation and time;
4007 Create your own board support subdirectory;
4009 Create your own board config file;
4013 Add / modify source code;
4017 email ("Hi, I am having problems...");
4019 Send patch file to Wolfgang;
4024 void no_more_time (int sig)
4033 All contributions to U-Boot should conform to the Linux kernel
4034 coding style; see the file "Documentation/CodingStyle" and the script
4035 "scripts/Lindent" in your Linux kernel source directory. In sources
4036 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
4037 spaces before parameters to function calls) is actually used.
4039 Source files originating from a different project (for example the
4040 MTD subsystem) are generally exempt from these guidelines and are not
4041 reformated to ease subsequent migration to newer versions of those
4044 Please note that U-Boot is implemented in C (and to some small parts in
4045 Assembler); no C++ is used, so please do not use C++ style comments (//)
4048 Please also stick to the following formatting rules:
4049 - remove any trailing white space
4050 - use TAB characters for indentation, not spaces
4051 - make sure NOT to use DOS '\r\n' line feeds
4052 - do not add more than 2 empty lines to source files
4053 - do not add trailing empty lines to source files
4055 Submissions which do not conform to the standards may be returned
4056 with a request to reformat the changes.
4062 Since the number of patches for U-Boot is growing, we need to
4063 establish some rules. Submissions which do not conform to these rules
4064 may be rejected, even when they contain important and valuable stuff.
4066 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4068 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4069 see http://lists.denx.de/mailman/listinfo/u-boot
4071 When you send a patch, please include the following information with
4074 * For bug fixes: a description of the bug and how your patch fixes
4075 this bug. Please try to include a way of demonstrating that the
4076 patch actually fixes something.
4078 * For new features: a description of the feature and your
4081 * A CHANGELOG entry as plaintext (separate from the patch)
4083 * For major contributions, your entry to the CREDITS file
4085 * When you add support for a new board, don't forget to add this
4086 board to the MAKEALL script, too.
4088 * If your patch adds new configuration options, don't forget to
4089 document these in the README file.
4091 * The patch itself. If you are using git (which is *strongly*
4092 recommended) you can easily generate the patch using the
4093 "git-format-patch". If you then use "git-send-email" to send it to
4094 the U-Boot mailing list, you will avoid most of the common problems
4095 with some other mail clients.
4097 If you cannot use git, use "diff -purN OLD NEW". If your version of
4098 diff does not support these options, then get the latest version of
4101 The current directory when running this command shall be the parent
4102 directory of the U-Boot source tree (i. e. please make sure that
4103 your patch includes sufficient directory information for the
4106 We prefer patches as plain text. MIME attachments are discouraged,
4107 and compressed attachments must not be used.
4109 * If one logical set of modifications affects or creates several
4110 files, all these changes shall be submitted in a SINGLE patch file.
4112 * Changesets that contain different, unrelated modifications shall be
4113 submitted as SEPARATE patches, one patch per changeset.
4118 * Before sending the patch, run the MAKEALL script on your patched
4119 source tree and make sure that no errors or warnings are reported
4120 for any of the boards.
4122 * Keep your modifications to the necessary minimum: A patch
4123 containing several unrelated changes or arbitrary reformats will be
4124 returned with a request to re-formatting / split it.
4126 * If you modify existing code, make sure that your new code does not
4127 add to the memory footprint of the code ;-) Small is beautiful!
4128 When adding new features, these should compile conditionally only
4129 (using #ifdef), and the resulting code with the new feature
4130 disabled must not need more memory than the old code without your
4133 * Remember that there is a size limit of 100 kB per message on the
4134 u-boot mailing list. Bigger patches will be moderated. If they are
4135 reasonable and not too big, they will be acknowledged. But patches
4136 bigger than the size limit should be avoided.
projects / people / ms / u-boot.git / blob