2 # (C) Copyright 2000 - 2012
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
57 Note: There is no CHANGELOG file in the actual U-Boot source tree;
58 it can be created dynamically from the Git log using:
66 In case you have questions about, problems with or contributions for
67 U-Boot you should send a message to the U-Boot mailing list at
68 <u-boot@lists.denx.de>. There is also an archive of previous traffic
69 on the mailing list - please search the archive before asking FAQ's.
70 Please see http://lists.denx.de/pipermail/u-boot and
71 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
74 Where to get source code:
75 =========================
77 The U-Boot source code is maintained in the git repository at
78 git://www.denx.de/git/u-boot.git ; you can browse it online at
79 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
81 The "snapshot" links on this page allow you to download tarballs of
82 any version you might be interested in. Official releases are also
83 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
86 Pre-built (and tested) images are available from
87 ftp://ftp.denx.de/pub/u-boot/images/
93 - start from 8xxrom sources
94 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
96 - make it easier to add custom boards
97 - make it possible to add other [PowerPC] CPUs
98 - extend functions, especially:
99 * Provide extended interface to Linux boot loader
102 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
103 - create ARMBoot project (http://sourceforge.net/projects/armboot)
104 - add other CPU families (starting with ARM)
105 - create U-Boot project (http://sourceforge.net/projects/u-boot)
106 - current project page: see http://www.denx.de/wiki/U-Boot
112 The "official" name of this project is "Das U-Boot". The spelling
113 "U-Boot" shall be used in all written text (documentation, comments
114 in source files etc.). Example:
116 This is the README file for the U-Boot project.
118 File names etc. shall be based on the string "u-boot". Examples:
120 include/asm-ppc/u-boot.h
122 #include <asm/u-boot.h>
124 Variable names, preprocessor constants etc. shall be either based on
125 the string "u_boot" or on "U_BOOT". Example:
127 U_BOOT_VERSION u_boot_logo
128 IH_OS_U_BOOT u_boot_hush_start
134 Starting with the release in October 2008, the names of the releases
135 were changed from numerical release numbers without deeper meaning
136 into a time stamp based numbering. Regular releases are identified by
137 names consisting of the calendar year and month of the release date.
138 Additional fields (if present) indicate release candidates or bug fix
139 releases in "stable" maintenance trees.
142 U-Boot v2009.11 - Release November 2009
143 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
144 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
150 /arch Architecture specific files
151 /arm Files generic to ARM architecture
152 /cpu CPU specific files
153 /arm720t Files specific to ARM 720 CPUs
154 /arm920t Files specific to ARM 920 CPUs
155 /at91 Files specific to Atmel AT91RM9200 CPU
156 /imx Files specific to Freescale MC9328 i.MX CPUs
157 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
158 /arm925t Files specific to ARM 925 CPUs
159 /arm926ejs Files specific to ARM 926 CPUs
160 /arm1136 Files specific to ARM 1136 CPUs
161 /ixp Files specific to Intel XScale IXP CPUs
162 /pxa Files specific to Intel XScale PXA CPUs
163 /s3c44b0 Files specific to Samsung S3C44B0 CPUs
164 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
165 /lib Architecture specific library files
166 /avr32 Files generic to AVR32 architecture
167 /cpu CPU specific files
168 /lib Architecture specific library files
169 /blackfin Files generic to Analog Devices Blackfin architecture
170 /cpu CPU specific files
171 /lib Architecture specific library files
172 /x86 Files generic to x86 architecture
173 /cpu CPU specific files
174 /lib Architecture specific library files
175 /m68k Files generic to m68k architecture
176 /cpu CPU specific files
177 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
178 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
179 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
180 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
181 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
182 /lib Architecture specific library files
183 /microblaze Files generic to microblaze architecture
184 /cpu CPU specific files
185 /lib Architecture specific library files
186 /mips Files generic to MIPS architecture
187 /cpu CPU specific files
188 /mips32 Files specific to MIPS32 CPUs
189 /xburst Files specific to Ingenic XBurst CPUs
190 /lib Architecture specific library files
191 /nds32 Files generic to NDS32 architecture
192 /cpu CPU specific files
193 /n1213 Files specific to Andes Technology N1213 CPUs
194 /lib Architecture specific library files
195 /nios2 Files generic to Altera NIOS2 architecture
196 /cpu CPU specific files
197 /lib Architecture specific library files
198 /powerpc Files generic to PowerPC architecture
199 /cpu CPU specific files
200 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
201 /mpc5xx Files specific to Freescale MPC5xx CPUs
202 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
203 /mpc8xx Files specific to Freescale MPC8xx CPUs
204 /mpc8220 Files specific to Freescale MPC8220 CPUs
205 /mpc824x Files specific to Freescale MPC824x CPUs
206 /mpc8260 Files specific to Freescale MPC8260 CPUs
207 /mpc85xx Files specific to Freescale MPC85xx CPUs
208 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
209 /lib Architecture specific library files
210 /sh Files generic to SH architecture
211 /cpu CPU specific files
212 /sh2 Files specific to sh2 CPUs
213 /sh3 Files specific to sh3 CPUs
214 /sh4 Files specific to sh4 CPUs
215 /lib Architecture specific library files
216 /sparc Files generic to SPARC architecture
217 /cpu CPU specific files
218 /leon2 Files specific to Gaisler LEON2 SPARC CPU
219 /leon3 Files specific to Gaisler LEON3 SPARC CPU
220 /lib Architecture specific library files
221 /api Machine/arch independent API for external apps
222 /board Board dependent files
223 /common Misc architecture independent functions
224 /disk Code for disk drive partition handling
225 /doc Documentation (don't expect too much)
226 /drivers Commonly used device drivers
227 /examples Example code for standalone applications, etc.
228 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
229 /include Header Files
230 /lib Files generic to all architectures
231 /libfdt Library files to support flattened device trees
232 /lzma Library files to support LZMA decompression
233 /lzo Library files to support LZO decompression
235 /post Power On Self Test
236 /rtc Real Time Clock drivers
237 /tools Tools to build S-Record or U-Boot images, etc.
239 Software Configuration:
240 =======================
242 Configuration is usually done using C preprocessor defines; the
243 rationale behind that is to avoid dead code whenever possible.
245 There are two classes of configuration variables:
247 * Configuration _OPTIONS_:
248 These are selectable by the user and have names beginning with
251 * Configuration _SETTINGS_:
252 These depend on the hardware etc. and should not be meddled with if
253 you don't know what you're doing; they have names beginning with
256 Later we will add a configuration tool - probably similar to or even
257 identical to what's used for the Linux kernel. Right now, we have to
258 do the configuration by hand, which means creating some symbolic
259 links and editing some configuration files. We use the TQM8xxL boards
263 Selection of Processor Architecture and Board Type:
264 ---------------------------------------------------
266 For all supported boards there are ready-to-use default
267 configurations available; just type "make <board_name>_config".
269 Example: For a TQM823L module type:
274 For the Cogent platform, you need to specify the CPU type as well;
275 e.g. "make cogent_mpc8xx_config". And also configure the cogent
276 directory according to the instructions in cogent/README.
279 Configuration Options:
280 ----------------------
282 Configuration depends on the combination of board and CPU type; all
283 such information is kept in a configuration file
284 "include/configs/<board_name>.h".
286 Example: For a TQM823L module, all configuration settings are in
287 "include/configs/TQM823L.h".
290 Many of the options are named exactly as the corresponding Linux
291 kernel configuration options. The intention is to make it easier to
292 build a config tool - later.
295 The following options need to be configured:
297 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
299 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
301 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
302 Define exactly one, e.g. CONFIG_ATSTK1002
304 - CPU Module Type: (if CONFIG_COGENT is defined)
305 Define exactly one of
307 --- FIXME --- not tested yet:
308 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
309 CONFIG_CMA287_23, CONFIG_CMA287_50
311 - Motherboard Type: (if CONFIG_COGENT is defined)
312 Define exactly one of
313 CONFIG_CMA101, CONFIG_CMA102
315 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
316 Define one or more of
319 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
320 Define one or more of
321 CONFIG_LCD_HEARTBEAT - update a character position on
322 the LCD display every second with
325 - Board flavour: (if CONFIG_MPC8260ADS is defined)
328 CONFIG_SYS_8260ADS - original MPC8260ADS
329 CONFIG_SYS_8266ADS - MPC8266ADS
330 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
331 CONFIG_SYS_8272ADS - MPC8272ADS
333 - Marvell Family Member
334 CONFIG_SYS_MVFS - define it if you want to enable
335 multiple fs option at one time
336 for marvell soc family
338 - MPC824X Family Member (if CONFIG_MPC824X is defined)
339 Define exactly one of
340 CONFIG_MPC8240, CONFIG_MPC8245
342 - 8xx CPU Options: (if using an MPC8xx CPU)
343 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
344 get_gclk_freq() cannot work
345 e.g. if there is no 32KHz
346 reference PIT/RTC clock
347 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
350 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
351 CONFIG_SYS_8xx_CPUCLK_MIN
352 CONFIG_SYS_8xx_CPUCLK_MAX
353 CONFIG_8xx_CPUCLK_DEFAULT
354 See doc/README.MPC866
356 CONFIG_SYS_MEASURE_CPUCLK
358 Define this to measure the actual CPU clock instead
359 of relying on the correctness of the configured
360 values. Mostly useful for board bringup to make sure
361 the PLL is locked at the intended frequency. Note
362 that this requires a (stable) reference clock (32 kHz
363 RTC clock or CONFIG_SYS_8XX_XIN)
365 CONFIG_SYS_DELAYED_ICACHE
367 Define this option if you want to enable the
368 ICache only when Code runs from RAM.
373 Specifies that the core is a 64-bit PowerPC implementation (implements
374 the "64" category of the Power ISA). This is necessary for ePAPR
375 compliance, among other possible reasons.
377 CONFIG_SYS_FSL_TBCLK_DIV
379 Defines the core time base clock divider ratio compared to the
380 system clock. On most PQ3 devices this is 8, on newer QorIQ
381 devices it can be 16 or 32. The ratio varies from SoC to Soc.
383 CONFIG_SYS_FSL_PCIE_COMPAT
385 Defines the string to utilize when trying to match PCIe device
386 tree nodes for the given platform.
388 CONFIG_SYS_PPC_E500_DEBUG_TLB
390 Enables a temporary TLB entry to be used during boot to work
391 around limitations in e500v1 and e500v2 external debugger
392 support. This reduces the portions of the boot code where
393 breakpoints and single stepping do not work. The value of this
394 symbol should be set to the TLB1 entry to be used for this
397 CONFIG_SYS_FSL_ERRATUM_A004510
399 Enables a workaround for erratum A004510. If set,
400 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
401 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
403 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
404 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
406 Defines one or two SoC revisions (low 8 bits of SVR)
407 for which the A004510 workaround should be applied.
409 The rest of SVR is either not relevant to the decision
410 of whether the erratum is present (e.g. p2040 versus
411 p2041) or is implied by the build target, which controls
412 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
414 See Freescale App Note 4493 for more information about
417 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
419 This is the value to write into CCSR offset 0x18600
420 according to the A004510 workaround.
422 - Generic CPU options:
423 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
425 Defines the endianess of the CPU. Implementation of those
426 values is arch specific.
428 - Intel Monahans options:
429 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
431 Defines the Monahans run mode to oscillator
432 ratio. Valid values are 8, 16, 24, 31. The core
433 frequency is this value multiplied by 13 MHz.
435 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
437 Defines the Monahans turbo mode to oscillator
438 ratio. Valid values are 1 (default if undefined) and
439 2. The core frequency as calculated above is multiplied
443 CONFIG_SYS_INIT_SP_OFFSET
445 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
446 pointer. This is needed for the temporary stack before
449 CONFIG_SYS_MIPS_CACHE_MODE
451 Cache operation mode for the MIPS CPU.
452 See also arch/mips/include/asm/mipsregs.h.
454 CONF_CM_CACHABLE_NO_WA
457 CONF_CM_CACHABLE_NONCOHERENT
461 CONF_CM_CACHABLE_ACCELERATED
463 CONFIG_SYS_XWAY_EBU_BOOTCFG
465 Special option for Lantiq XWAY SoCs for booting from NOR flash.
466 See also arch/mips/cpu/mips32/start.S.
468 CONFIG_XWAY_SWAP_BYTES
470 Enable compilation of tools/xway-swap-bytes needed for Lantiq
471 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
472 be swapped if a flash programmer is used.
475 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
477 Select high exception vectors of the ARM core, e.g., do not
478 clear the V bit of the c1 register of CP15.
480 CONFIG_SYS_THUMB_BUILD
482 Use this flag to build U-Boot using the Thumb instruction
483 set for ARM architectures. Thumb instruction set provides
484 better code density. For ARM architectures that support
485 Thumb2 this flag will result in Thumb2 code generated by
488 - Linux Kernel Interface:
491 U-Boot stores all clock information in Hz
492 internally. For binary compatibility with older Linux
493 kernels (which expect the clocks passed in the
494 bd_info data to be in MHz) the environment variable
495 "clocks_in_mhz" can be defined so that U-Boot
496 converts clock data to MHZ before passing it to the
498 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
499 "clocks_in_mhz=1" is automatically included in the
502 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
504 When transferring memsize parameter to linux, some versions
505 expect it to be in bytes, others in MB.
506 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
510 New kernel versions are expecting firmware settings to be
511 passed using flattened device trees (based on open firmware
515 * New libfdt-based support
516 * Adds the "fdt" command
517 * The bootm command automatically updates the fdt
519 OF_CPU - The proper name of the cpus node (only required for
520 MPC512X and MPC5xxx based boards).
521 OF_SOC - The proper name of the soc node (only required for
522 MPC512X and MPC5xxx based boards).
523 OF_TBCLK - The timebase frequency.
524 OF_STDOUT_PATH - The path to the console device
526 boards with QUICC Engines require OF_QE to set UCC MAC
529 CONFIG_OF_BOARD_SETUP
531 Board code has addition modification that it wants to make
532 to the flat device tree before handing it off to the kernel
536 This define fills in the correct boot CPU in the boot
537 param header, the default value is zero if undefined.
541 U-Boot can detect if an IDE device is present or not.
542 If not, and this new config option is activated, U-Boot
543 removes the ATA node from the DTS before booting Linux,
544 so the Linux IDE driver does not probe the device and
545 crash. This is needed for buggy hardware (uc101) where
546 no pull down resistor is connected to the signal IDE5V_DD7.
548 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
550 This setting is mandatory for all boards that have only one
551 machine type and must be used to specify the machine type
552 number as it appears in the ARM machine registry
553 (see http://www.arm.linux.org.uk/developer/machines/).
554 Only boards that have multiple machine types supported
555 in a single configuration file and the machine type is
556 runtime discoverable, do not have to use this setting.
558 - vxWorks boot parameters:
560 bootvx constructs a valid bootline using the following
561 environments variables: bootfile, ipaddr, serverip, hostname.
562 It loads the vxWorks image pointed bootfile.
564 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
565 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
566 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
567 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
569 CONFIG_SYS_VXWORKS_ADD_PARAMS
571 Add it at the end of the bootline. E.g "u=username pw=secret"
573 Note: If a "bootargs" environment is defined, it will overwride
574 the defaults discussed just above.
576 - Cache Configuration:
577 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
578 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
579 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
581 - Cache Configuration for ARM:
582 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
584 CONFIG_SYS_PL310_BASE - Physical base address of PL310
585 controller register space
590 Define this if you want support for Amba PrimeCell PL010 UARTs.
594 Define this if you want support for Amba PrimeCell PL011 UARTs.
598 If you have Amba PrimeCell PL011 UARTs, set this variable to
599 the clock speed of the UARTs.
603 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
604 define this to a list of base addresses for each (supported)
605 port. See e.g. include/configs/versatile.h
607 CONFIG_PL011_SERIAL_RLCR
609 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
610 have separate receive and transmit line control registers. Set
611 this variable to initialize the extra register.
613 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
615 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
616 boot loader that has already initialized the UART. Define this
617 variable to flush the UART at init time.
619 CONFIG_SYS_NS16550_BROKEN_TEMT
621 16550 UART set the Transmitter Empty (TEMT) Bit when all output
622 has finished and the transmitter is totally empty. U-Boot waits
623 for this bit to be set to initialize the serial console. On some
624 broken platforms this bit is not set in SPL making U-Boot to
625 hang while waiting for TEMT. Define this option to avoid it.
629 Depending on board, define exactly one serial port
630 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
631 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
632 console by defining CONFIG_8xx_CONS_NONE
634 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
635 port routines must be defined elsewhere
636 (i.e. serial_init(), serial_getc(), ...)
639 Enables console device for a color framebuffer. Needs following
640 defines (cf. smiLynxEM, i8042)
641 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
643 VIDEO_HW_RECTFILL graphic chip supports
646 VIDEO_HW_BITBLT graphic chip supports
647 bit-blit (cf. smiLynxEM)
648 VIDEO_VISIBLE_COLS visible pixel columns
650 VIDEO_VISIBLE_ROWS visible pixel rows
651 VIDEO_PIXEL_SIZE bytes per pixel
652 VIDEO_DATA_FORMAT graphic data format
653 (0-5, cf. cfb_console.c)
654 VIDEO_FB_ADRS framebuffer address
655 VIDEO_KBD_INIT_FCT keyboard int fct
656 (i.e. i8042_kbd_init())
657 VIDEO_TSTC_FCT test char fct
659 VIDEO_GETC_FCT get char fct
661 CONFIG_CONSOLE_CURSOR cursor drawing on/off
662 (requires blink timer
664 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
665 CONFIG_CONSOLE_TIME display time/date info in
667 (requires CONFIG_CMD_DATE)
668 CONFIG_VIDEO_LOGO display Linux logo in
670 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
671 linux_logo.h for logo.
672 Requires CONFIG_VIDEO_LOGO
673 CONFIG_CONSOLE_EXTRA_INFO
674 additional board info beside
677 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
678 a limited number of ANSI escape sequences (cursor control,
679 erase functions and limited graphics rendition control).
681 When CONFIG_CFB_CONSOLE is defined, video console is
682 default i/o. Serial console can be forced with
683 environment 'console=serial'.
685 When CONFIG_SILENT_CONSOLE is defined, all console
686 messages (by U-Boot and Linux!) can be silenced with
687 the "silent" environment variable. See
688 doc/README.silent for more information.
691 CONFIG_BAUDRATE - in bps
692 Select one of the baudrates listed in
693 CONFIG_SYS_BAUDRATE_TABLE, see below.
694 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
696 - Console Rx buffer length
697 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
698 the maximum receive buffer length for the SMC.
699 This option is actual only for 82xx and 8xx possible.
700 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
701 must be defined, to setup the maximum idle timeout for
704 - Pre-Console Buffer:
705 Prior to the console being initialised (i.e. serial UART
706 initialised etc) all console output is silently discarded.
707 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
708 buffer any console messages prior to the console being
709 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
710 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
711 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
712 bytes are output before the console is initialised, the
713 earlier bytes are discarded.
715 'Sane' compilers will generate smaller code if
716 CONFIG_PRE_CON_BUF_SZ is a power of 2
718 - Safe printf() functions
719 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
720 the printf() functions. These are defined in
721 include/vsprintf.h and include snprintf(), vsnprintf() and
722 so on. Code size increase is approximately 300-500 bytes.
723 If this option is not given then these functions will
724 silently discard their buffer size argument - this means
725 you are not getting any overflow checking in this case.
727 - Boot Delay: CONFIG_BOOTDELAY - in seconds
728 Delay before automatically booting the default image;
729 set to -1 to disable autoboot.
730 set to -2 to autoboot with no delay and not check for abort
731 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
733 See doc/README.autoboot for these options that
734 work with CONFIG_BOOTDELAY. None are required.
735 CONFIG_BOOT_RETRY_TIME
736 CONFIG_BOOT_RETRY_MIN
737 CONFIG_AUTOBOOT_KEYED
738 CONFIG_AUTOBOOT_PROMPT
739 CONFIG_AUTOBOOT_DELAY_STR
740 CONFIG_AUTOBOOT_STOP_STR
741 CONFIG_AUTOBOOT_DELAY_STR2
742 CONFIG_AUTOBOOT_STOP_STR2
743 CONFIG_ZERO_BOOTDELAY_CHECK
744 CONFIG_RESET_TO_RETRY
748 Only needed when CONFIG_BOOTDELAY is enabled;
749 define a command string that is automatically executed
750 when no character is read on the console interface
751 within "Boot Delay" after reset.
754 This can be used to pass arguments to the bootm
755 command. The value of CONFIG_BOOTARGS goes into the
756 environment value "bootargs".
758 CONFIG_RAMBOOT and CONFIG_NFSBOOT
759 The value of these goes into the environment as
760 "ramboot" and "nfsboot" respectively, and can be used
761 as a convenience, when switching between booting from
767 When this option is #defined, the existence of the
768 environment variable "preboot" will be checked
769 immediately before starting the CONFIG_BOOTDELAY
770 countdown and/or running the auto-boot command resp.
771 entering interactive mode.
773 This feature is especially useful when "preboot" is
774 automatically generated or modified. For an example
775 see the LWMON board specific code: here "preboot" is
776 modified when the user holds down a certain
777 combination of keys on the (special) keyboard when
780 - Serial Download Echo Mode:
782 If defined to 1, all characters received during a
783 serial download (using the "loads" command) are
784 echoed back. This might be needed by some terminal
785 emulations (like "cu"), but may as well just take
786 time on others. This setting #define's the initial
787 value of the "loads_echo" environment variable.
789 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
791 Select one of the baudrates listed in
792 CONFIG_SYS_BAUDRATE_TABLE, see below.
795 Monitor commands can be included or excluded
796 from the build by using the #include files
797 <config_cmd_all.h> and #undef'ing unwanted
798 commands, or using <config_cmd_default.h>
799 and augmenting with additional #define's
802 The default command configuration includes all commands
803 except those marked below with a "*".
805 CONFIG_CMD_ASKENV * ask for env variable
806 CONFIG_CMD_BDI bdinfo
807 CONFIG_CMD_BEDBUG * Include BedBug Debugger
808 CONFIG_CMD_BMP * BMP support
809 CONFIG_CMD_BSP * Board specific commands
810 CONFIG_CMD_BOOTD bootd
811 CONFIG_CMD_CACHE * icache, dcache
812 CONFIG_CMD_CONSOLE coninfo
813 CONFIG_CMD_CRC32 * crc32
814 CONFIG_CMD_DATE * support for RTC, date/time...
815 CONFIG_CMD_DHCP * DHCP support
816 CONFIG_CMD_DIAG * Diagnostics
817 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
818 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
819 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
820 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
821 CONFIG_CMD_DTT * Digital Therm and Thermostat
822 CONFIG_CMD_ECHO echo arguments
823 CONFIG_CMD_EDITENV edit env variable
824 CONFIG_CMD_EEPROM * EEPROM read/write support
825 CONFIG_CMD_ELF * bootelf, bootvx
826 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
827 CONFIG_CMD_ENV_FLAGS * display details about env flags
828 CONFIG_CMD_EXPORTENV * export the environment
829 CONFIG_CMD_EXT2 * ext2 command support
830 CONFIG_CMD_EXT4 * ext4 command support
831 CONFIG_CMD_SAVEENV saveenv
832 CONFIG_CMD_FDC * Floppy Disk Support
833 CONFIG_CMD_FAT * FAT command support
834 CONFIG_CMD_FDOS * Dos diskette Support
835 CONFIG_CMD_FLASH flinfo, erase, protect
836 CONFIG_CMD_FPGA FPGA device initialization support
837 CONFIG_CMD_GETTIME * Get time since boot
838 CONFIG_CMD_GO * the 'go' command (exec code)
839 CONFIG_CMD_GREPENV * search environment
840 CONFIG_CMD_HASH * calculate hash / digest
841 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
842 CONFIG_CMD_I2C * I2C serial bus support
843 CONFIG_CMD_IDE * IDE harddisk support
844 CONFIG_CMD_IMI iminfo
845 CONFIG_CMD_IMLS List all found images
846 CONFIG_CMD_IMMAP * IMMR dump support
847 CONFIG_CMD_IMPORTENV * import an environment
848 CONFIG_CMD_INI * import data from an ini file into the env
849 CONFIG_CMD_IRQ * irqinfo
850 CONFIG_CMD_ITEST Integer/string test of 2 values
851 CONFIG_CMD_JFFS2 * JFFS2 Support
852 CONFIG_CMD_KGDB * kgdb
853 CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
854 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
856 CONFIG_CMD_LOADB loadb
857 CONFIG_CMD_LOADS loads
858 CONFIG_CMD_MD5SUM print md5 message digest
859 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
860 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
862 CONFIG_CMD_MISC Misc functions like sleep etc
863 CONFIG_CMD_MMC * MMC memory mapped support
864 CONFIG_CMD_MII * MII utility commands
865 CONFIG_CMD_MTDPARTS * MTD partition support
866 CONFIG_CMD_NAND * NAND support
867 CONFIG_CMD_NET bootp, tftpboot, rarpboot
868 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
869 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
870 CONFIG_CMD_PCI * pciinfo
871 CONFIG_CMD_PCMCIA * PCMCIA support
872 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
874 CONFIG_CMD_PORTIO * Port I/O
875 CONFIG_CMD_READ * Read raw data from partition
876 CONFIG_CMD_REGINFO * Register dump
877 CONFIG_CMD_RUN run command in env variable
878 CONFIG_CMD_SAVES * save S record dump
879 CONFIG_CMD_SCSI * SCSI Support
880 CONFIG_CMD_SDRAM * print SDRAM configuration information
881 (requires CONFIG_CMD_I2C)
882 CONFIG_CMD_SETGETDCR Support for DCR Register access
884 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
885 CONFIG_CMD_SHA1SUM print sha1 memory digest
886 (requires CONFIG_CMD_MEMORY)
887 CONFIG_CMD_SOURCE "source" command Support
888 CONFIG_CMD_SPI * SPI serial bus support
889 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
890 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
891 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
892 CONFIG_CMD_TIMER * access to the system tick timer
893 CONFIG_CMD_USB * USB support
894 CONFIG_CMD_CDP * Cisco Discover Protocol support
895 CONFIG_CMD_MFSL * Microblaze FSL support
898 EXAMPLE: If you want all functions except of network
899 support you can write:
901 #include "config_cmd_all.h"
902 #undef CONFIG_CMD_NET
905 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
907 Note: Don't enable the "icache" and "dcache" commands
908 (configuration option CONFIG_CMD_CACHE) unless you know
909 what you (and your U-Boot users) are doing. Data
910 cache cannot be enabled on systems like the 8xx or
911 8260 (where accesses to the IMMR region must be
912 uncached), and it cannot be disabled on all other
913 systems where we (mis-) use the data cache to hold an
914 initial stack and some data.
917 XXX - this list needs to get updated!
921 If this variable is defined, U-Boot will use a device tree
922 to configure its devices, instead of relying on statically
923 compiled #defines in the board file. This option is
924 experimental and only available on a few boards. The device
925 tree is available in the global data as gd->fdt_blob.
927 U-Boot needs to get its device tree from somewhere. This can
928 be done using one of the two options below:
931 If this variable is defined, U-Boot will embed a device tree
932 binary in its image. This device tree file should be in the
933 board directory and called <soc>-<board>.dts. The binary file
934 is then picked up in board_init_f() and made available through
935 the global data structure as gd->blob.
938 If this variable is defined, U-Boot will build a device tree
939 binary. It will be called u-boot.dtb. Architecture-specific
940 code will locate it at run-time. Generally this works by:
942 cat u-boot.bin u-boot.dtb >image.bin
944 and in fact, U-Boot does this for you, creating a file called
945 u-boot-dtb.bin which is useful in the common case. You can
946 still use the individual files if you need something more
951 If this variable is defined, it enables watchdog
952 support for the SoC. There must be support in the SoC
953 specific code for a watchdog. For the 8xx and 8260
954 CPUs, the SIU Watchdog feature is enabled in the SYPCR
955 register. When supported for a specific SoC is
956 available, then no further board specific code should
960 When using a watchdog circuitry external to the used
961 SoC, then define this variable and provide board
962 specific code for the "hw_watchdog_reset" function.
965 CONFIG_VERSION_VARIABLE
966 If this variable is defined, an environment variable
967 named "ver" is created by U-Boot showing the U-Boot
968 version as printed by the "version" command.
969 Any change to this variable will be reverted at the
974 When CONFIG_CMD_DATE is selected, the type of the RTC
975 has to be selected, too. Define exactly one of the
978 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
979 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
980 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
981 CONFIG_RTC_MC146818 - use MC146818 RTC
982 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
983 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
984 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
985 CONFIG_RTC_DS164x - use Dallas DS164x RTC
986 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
987 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
988 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
989 CONFIG_SYS_RV3029_TCR - enable trickle charger on
992 Note that if the RTC uses I2C, then the I2C interface
993 must also be configured. See I2C Support, below.
996 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
997 CONFIG_PCA953X_INFO - enable pca953x info command
999 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1000 chip-ngpio pairs that tell the PCA953X driver the number of
1001 pins supported by a particular chip.
1003 Note that if the GPIO device uses I2C, then the I2C interface
1004 must also be configured. See I2C Support, below.
1006 - Timestamp Support:
1008 When CONFIG_TIMESTAMP is selected, the timestamp
1009 (date and time) of an image is printed by image
1010 commands like bootm or iminfo. This option is
1011 automatically enabled when you select CONFIG_CMD_DATE .
1013 - Partition Labels (disklabels) Supported:
1014 Zero or more of the following:
1015 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1016 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1017 Intel architecture, USB sticks, etc.
1018 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1019 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1020 bootloader. Note 2TB partition limit; see
1022 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1024 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1025 CONFIG_CMD_SCSI) you must configure support for at
1026 least one non-MTD partition type as well.
1029 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1030 board configurations files but used nowhere!
1032 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1033 be performed by calling the function
1034 ide_set_reset(int reset)
1035 which has to be defined in a board specific file
1040 Set this to enable ATAPI support.
1045 Set this to enable support for disks larger than 137GB
1046 Also look at CONFIG_SYS_64BIT_LBA.
1047 Whithout these , LBA48 support uses 32bit variables and will 'only'
1048 support disks up to 2.1TB.
1050 CONFIG_SYS_64BIT_LBA:
1051 When enabled, makes the IDE subsystem use 64bit sector addresses.
1055 At the moment only there is only support for the
1056 SYM53C8XX SCSI controller; define
1057 CONFIG_SCSI_SYM53C8XX to enable it.
1059 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1060 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1061 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1062 maximum numbers of LUNs, SCSI ID's and target
1064 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1066 The environment variable 'scsidevs' is set to the number of
1067 SCSI devices found during the last scan.
1069 - NETWORK Support (PCI):
1071 Support for Intel 8254x/8257x gigabit chips.
1074 Utility code for direct access to the SPI bus on Intel 8257x.
1075 This does not do anything useful unless you set at least one
1076 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1078 CONFIG_E1000_SPI_GENERIC
1079 Allow generic access to the SPI bus on the Intel 8257x, for
1080 example with the "sspi" command.
1083 Management command for E1000 devices. When used on devices
1084 with SPI support you can reprogram the EEPROM from U-Boot.
1086 CONFIG_E1000_FALLBACK_MAC
1087 default MAC for empty EEPROM after production.
1090 Support for Intel 82557/82559/82559ER chips.
1091 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1092 write routine for first time initialisation.
1095 Support for Digital 2114x chips.
1096 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1097 modem chip initialisation (KS8761/QS6611).
1100 Support for National dp83815 chips.
1103 Support for National dp8382[01] gigabit chips.
1105 - NETWORK Support (other):
1107 CONFIG_DRIVER_AT91EMAC
1108 Support for AT91RM9200 EMAC.
1111 Define this to use reduced MII inteface
1113 CONFIG_DRIVER_AT91EMAC_QUIET
1114 If this defined, the driver is quiet.
1115 The driver doen't show link status messages.
1117 CONFIG_CALXEDA_XGMAC
1118 Support for the Calxeda XGMAC device
1121 Support for SMSC's LAN91C96 chips.
1123 CONFIG_LAN91C96_BASE
1124 Define this to hold the physical address
1125 of the LAN91C96's I/O space
1127 CONFIG_LAN91C96_USE_32_BIT
1128 Define this to enable 32 bit addressing
1131 Support for SMSC's LAN91C111 chip
1133 CONFIG_SMC91111_BASE
1134 Define this to hold the physical address
1135 of the device (I/O space)
1137 CONFIG_SMC_USE_32_BIT
1138 Define this if data bus is 32 bits
1140 CONFIG_SMC_USE_IOFUNCS
1141 Define this to use i/o functions instead of macros
1142 (some hardware wont work with macros)
1144 CONFIG_DRIVER_TI_EMAC
1145 Support for davinci emac
1147 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1148 Define this if you have more then 3 PHYs.
1151 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1153 CONFIG_FTGMAC100_EGIGA
1154 Define this to use GE link update with gigabit PHY.
1155 Define this if FTGMAC100 is connected to gigabit PHY.
1156 If your system has 10/100 PHY only, it might not occur
1157 wrong behavior. Because PHY usually return timeout or
1158 useless data when polling gigabit status and gigabit
1159 control registers. This behavior won't affect the
1160 correctnessof 10/100 link speed update.
1163 Support for SMSC's LAN911x and LAN921x chips
1166 Define this to hold the physical address
1167 of the device (I/O space)
1169 CONFIG_SMC911X_32_BIT
1170 Define this if data bus is 32 bits
1172 CONFIG_SMC911X_16_BIT
1173 Define this if data bus is 16 bits. If your processor
1174 automatically converts one 32 bit word to two 16 bit
1175 words you may also try CONFIG_SMC911X_32_BIT.
1178 Support for Renesas on-chip Ethernet controller
1180 CONFIG_SH_ETHER_USE_PORT
1181 Define the number of ports to be used
1183 CONFIG_SH_ETHER_PHY_ADDR
1184 Define the ETH PHY's address
1186 CONFIG_SH_ETHER_CACHE_WRITEBACK
1187 If this option is set, the driver enables cache flush.
1190 CONFIG_GENERIC_LPC_TPM
1191 Support for generic parallel port TPM devices. Only one device
1192 per system is supported at this time.
1194 CONFIG_TPM_TIS_BASE_ADDRESS
1195 Base address where the generic TPM device is mapped
1196 to. Contemporary x86 systems usually map it at
1200 At the moment only the UHCI host controller is
1201 supported (PIP405, MIP405, MPC5200); define
1202 CONFIG_USB_UHCI to enable it.
1203 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1204 and define CONFIG_USB_STORAGE to enable the USB
1207 Supported are USB Keyboards and USB Floppy drives
1209 MPC5200 USB requires additional defines:
1211 for 528 MHz Clock: 0x0001bbbb
1215 for differential drivers: 0x00001000
1216 for single ended drivers: 0x00005000
1217 for differential drivers on PSC3: 0x00000100
1218 for single ended drivers on PSC3: 0x00004100
1219 CONFIG_SYS_USB_EVENT_POLL
1220 May be defined to allow interrupt polling
1221 instead of using asynchronous interrupts
1223 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1224 txfilltuning field in the EHCI controller on reset.
1227 Define the below if you wish to use the USB console.
1228 Once firmware is rebuilt from a serial console issue the
1229 command "setenv stdin usbtty; setenv stdout usbtty" and
1230 attach your USB cable. The Unix command "dmesg" should print
1231 it has found a new device. The environment variable usbtty
1232 can be set to gserial or cdc_acm to enable your device to
1233 appear to a USB host as a Linux gserial device or a
1234 Common Device Class Abstract Control Model serial device.
1235 If you select usbtty = gserial you should be able to enumerate
1237 # modprobe usbserial vendor=0xVendorID product=0xProductID
1238 else if using cdc_acm, simply setting the environment
1239 variable usbtty to be cdc_acm should suffice. The following
1240 might be defined in YourBoardName.h
1243 Define this to build a UDC device
1246 Define this to have a tty type of device available to
1247 talk to the UDC device
1250 Define this to enable the high speed support for usb
1251 device and usbtty. If this feature is enabled, a routine
1252 int is_usbd_high_speed(void)
1253 also needs to be defined by the driver to dynamically poll
1254 whether the enumeration has succeded at high speed or full
1257 CONFIG_SYS_CONSOLE_IS_IN_ENV
1258 Define this if you want stdin, stdout &/or stderr to
1262 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1263 Derive USB clock from external clock "blah"
1264 - CONFIG_SYS_USB_EXTC_CLK 0x02
1266 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1267 Derive USB clock from brgclk
1268 - CONFIG_SYS_USB_BRG_CLK 0x04
1270 If you have a USB-IF assigned VendorID then you may wish to
1271 define your own vendor specific values either in BoardName.h
1272 or directly in usbd_vendor_info.h. If you don't define
1273 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1274 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1275 should pretend to be a Linux device to it's target host.
1277 CONFIG_USBD_MANUFACTURER
1278 Define this string as the name of your company for
1279 - CONFIG_USBD_MANUFACTURER "my company"
1281 CONFIG_USBD_PRODUCT_NAME
1282 Define this string as the name of your product
1283 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1285 CONFIG_USBD_VENDORID
1286 Define this as your assigned Vendor ID from the USB
1287 Implementors Forum. This *must* be a genuine Vendor ID
1288 to avoid polluting the USB namespace.
1289 - CONFIG_USBD_VENDORID 0xFFFF
1291 CONFIG_USBD_PRODUCTID
1292 Define this as the unique Product ID
1294 - CONFIG_USBD_PRODUCTID 0xFFFF
1296 - ULPI Layer Support:
1297 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1298 the generic ULPI layer. The generic layer accesses the ULPI PHY
1299 via the platform viewport, so you need both the genric layer and
1300 the viewport enabled. Currently only Chipidea/ARC based
1301 viewport is supported.
1302 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1303 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1304 If your ULPI phy needs a different reference clock than the
1305 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1306 the appropriate value in Hz.
1309 The MMC controller on the Intel PXA is supported. To
1310 enable this define CONFIG_MMC. The MMC can be
1311 accessed from the boot prompt by mapping the device
1312 to physical memory similar to flash. Command line is
1313 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1314 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1317 Support for Renesas on-chip MMCIF controller
1319 CONFIG_SH_MMCIF_ADDR
1320 Define the base address of MMCIF registers
1323 Define the clock frequency for MMCIF
1325 - Journaling Flash filesystem support:
1326 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1327 CONFIG_JFFS2_NAND_DEV
1328 Define these for a default partition on a NAND device
1330 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1331 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1332 Define these for a default partition on a NOR device
1334 CONFIG_SYS_JFFS_CUSTOM_PART
1335 Define this to create an own partition. You have to provide a
1336 function struct part_info* jffs2_part_info(int part_num)
1338 If you define only one JFFS2 partition you may also want to
1339 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1340 to disable the command chpart. This is the default when you
1341 have not defined a custom partition
1343 - FAT(File Allocation Table) filesystem write function support:
1346 Define this to enable support for saving memory data as a
1347 file in FAT formatted partition.
1349 This will also enable the command "fatwrite" enabling the
1350 user to write files to FAT.
1352 CBFS (Coreboot Filesystem) support
1355 Define this to enable support for reading from a Coreboot
1356 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1362 Define this to enable standard (PC-Style) keyboard
1366 Standard PC keyboard driver with US (is default) and
1367 GERMAN key layout (switch via environment 'keymap=de') support.
1368 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1369 for cfb_console. Supports cursor blinking.
1374 Define this to enable video support (for output to
1377 CONFIG_VIDEO_CT69000
1379 Enable Chips & Technologies 69000 Video chip
1381 CONFIG_VIDEO_SMI_LYNXEM
1382 Enable Silicon Motion SMI 712/710/810 Video chip. The
1383 video output is selected via environment 'videoout'
1384 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1387 For the CT69000 and SMI_LYNXEM drivers, videomode is
1388 selected via environment 'videomode'. Two different ways
1390 - "videomode=num" 'num' is a standard LiLo mode numbers.
1391 Following standard modes are supported (* is default):
1393 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1394 -------------+---------------------------------------------
1395 8 bits | 0x301* 0x303 0x305 0x161 0x307
1396 15 bits | 0x310 0x313 0x316 0x162 0x319
1397 16 bits | 0x311 0x314 0x317 0x163 0x31A
1398 24 bits | 0x312 0x315 0x318 ? 0x31B
1399 -------------+---------------------------------------------
1400 (i.e. setenv videomode 317; saveenv; reset;)
1402 - "videomode=bootargs" all the video parameters are parsed
1403 from the bootargs. (See drivers/video/videomodes.c)
1406 CONFIG_VIDEO_SED13806
1407 Enable Epson SED13806 driver. This driver supports 8bpp
1408 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1409 or CONFIG_VIDEO_SED13806_16BPP
1412 Enable the Freescale DIU video driver. Reference boards for
1413 SOCs that have a DIU should define this macro to enable DIU
1414 support, and should also define these other macros:
1420 CONFIG_VIDEO_SW_CURSOR
1421 CONFIG_VGA_AS_SINGLE_DEVICE
1423 CONFIG_VIDEO_BMP_LOGO
1425 The DIU driver will look for the 'video-mode' environment
1426 variable, and if defined, enable the DIU as a console during
1427 boot. See the documentation file README.video for a
1428 description of this variable.
1432 Enable the VGA video / BIOS for x86. The alternative if you
1433 are using coreboot is to use the coreboot frame buffer
1440 Define this to enable a custom keyboard support.
1441 This simply calls drv_keyboard_init() which must be
1442 defined in your board-specific files.
1443 The only board using this so far is RBC823.
1445 - LCD Support: CONFIG_LCD
1447 Define this to enable LCD support (for output to LCD
1448 display); also select one of the supported displays
1449 by defining one of these:
1453 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1455 CONFIG_NEC_NL6448AC33:
1457 NEC NL6448AC33-18. Active, color, single scan.
1459 CONFIG_NEC_NL6448BC20
1461 NEC NL6448BC20-08. 6.5", 640x480.
1462 Active, color, single scan.
1464 CONFIG_NEC_NL6448BC33_54
1466 NEC NL6448BC33-54. 10.4", 640x480.
1467 Active, color, single scan.
1471 Sharp 320x240. Active, color, single scan.
1472 It isn't 16x9, and I am not sure what it is.
1474 CONFIG_SHARP_LQ64D341
1476 Sharp LQ64D341 display, 640x480.
1477 Active, color, single scan.
1481 HLD1045 display, 640x480.
1482 Active, color, single scan.
1486 Optrex CBL50840-2 NF-FW 99 22 M5
1488 Hitachi LMG6912RPFC-00T
1492 320x240. Black & white.
1494 Normally display is black on white background; define
1495 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1497 CONFIG_LCD_ALIGNMENT
1499 Normally the LCD is page-aligned (tyically 4KB). If this is
1500 defined then the LCD will be aligned to this value instead.
1501 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1502 here, since it is cheaper to change data cache settings on
1503 a per-section basis.
1505 CONFIG_CONSOLE_SCROLL_LINES
1507 When the console need to be scrolled, this is the number of
1508 lines to scroll by. It defaults to 1. Increasing this makes
1509 the console jump but can help speed up operation when scrolling
1514 Support drawing of RLE8-compressed bitmaps on the LCD.
1518 Enables an 'i2c edid' command which can read EDID
1519 information over I2C from an attached LCD display.
1521 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1523 If this option is set, the environment is checked for
1524 a variable "splashimage". If found, the usual display
1525 of logo, copyright and system information on the LCD
1526 is suppressed and the BMP image at the address
1527 specified in "splashimage" is loaded instead. The
1528 console is redirected to the "nulldev", too. This
1529 allows for a "silent" boot where a splash screen is
1530 loaded very quickly after power-on.
1532 CONFIG_SPLASH_SCREEN_ALIGN
1534 If this option is set the splash image can be freely positioned
1535 on the screen. Environment variable "splashpos" specifies the
1536 position as "x,y". If a positive number is given it is used as
1537 number of pixel from left/top. If a negative number is given it
1538 is used as number of pixel from right/bottom. You can also
1539 specify 'm' for centering the image.
1542 setenv splashpos m,m
1543 => image at center of screen
1545 setenv splashpos 30,20
1546 => image at x = 30 and y = 20
1548 setenv splashpos -10,m
1549 => vertically centered image
1550 at x = dspWidth - bmpWidth - 9
1552 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1554 If this option is set, additionally to standard BMP
1555 images, gzipped BMP images can be displayed via the
1556 splashscreen support or the bmp command.
1558 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1560 If this option is set, 8-bit RLE compressed BMP images
1561 can be displayed via the splashscreen support or the
1564 - Do compresssing for memory range:
1567 If this option is set, it would use zlib deflate method
1568 to compress the specified memory at its best effort.
1570 - Compression support:
1573 If this option is set, support for bzip2 compressed
1574 images is included. If not, only uncompressed and gzip
1575 compressed images are supported.
1577 NOTE: the bzip2 algorithm requires a lot of RAM, so
1578 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1583 If this option is set, support for lzma compressed
1586 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1587 requires an amount of dynamic memory that is given by the
1590 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1592 Where lc and lp stand for, respectively, Literal context bits
1593 and Literal pos bits.
1595 This value is upper-bounded by 14MB in the worst case. Anyway,
1596 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1597 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1598 a very small buffer.
1600 Use the lzmainfo tool to determinate the lc and lp values and
1601 then calculate the amount of needed dynamic memory (ensuring
1602 the appropriate CONFIG_SYS_MALLOC_LEN value).
1607 The address of PHY on MII bus.
1609 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1611 The clock frequency of the MII bus
1615 If this option is set, support for speed/duplex
1616 detection of gigabit PHY is included.
1618 CONFIG_PHY_RESET_DELAY
1620 Some PHY like Intel LXT971A need extra delay after
1621 reset before any MII register access is possible.
1622 For such PHY, set this option to the usec delay
1623 required. (minimum 300usec for LXT971A)
1625 CONFIG_PHY_CMD_DELAY (ppc4xx)
1627 Some PHY like Intel LXT971A need extra delay after
1628 command issued before MII status register can be read
1638 Define a default value for Ethernet address to use
1639 for the respective Ethernet interface, in case this
1640 is not determined automatically.
1645 Define a default value for the IP address to use for
1646 the default Ethernet interface, in case this is not
1647 determined through e.g. bootp.
1648 (Environment variable "ipaddr")
1650 - Server IP address:
1653 Defines a default value for the IP address of a TFTP
1654 server to contact when using the "tftboot" command.
1655 (Environment variable "serverip")
1657 CONFIG_KEEP_SERVERADDR
1659 Keeps the server's MAC address, in the env 'serveraddr'
1660 for passing to bootargs (like Linux's netconsole option)
1662 - Gateway IP address:
1665 Defines a default value for the IP address of the
1666 default router where packets to other networks are
1668 (Environment variable "gatewayip")
1673 Defines a default value for the subnet mask (or
1674 routing prefix) which is used to determine if an IP
1675 address belongs to the local subnet or needs to be
1676 forwarded through a router.
1677 (Environment variable "netmask")
1679 - Multicast TFTP Mode:
1682 Defines whether you want to support multicast TFTP as per
1683 rfc-2090; for example to work with atftp. Lets lots of targets
1684 tftp down the same boot image concurrently. Note: the Ethernet
1685 driver in use must provide a function: mcast() to join/leave a
1688 - BOOTP Recovery Mode:
1689 CONFIG_BOOTP_RANDOM_DELAY
1691 If you have many targets in a network that try to
1692 boot using BOOTP, you may want to avoid that all
1693 systems send out BOOTP requests at precisely the same
1694 moment (which would happen for instance at recovery
1695 from a power failure, when all systems will try to
1696 boot, thus flooding the BOOTP server. Defining
1697 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1698 inserted before sending out BOOTP requests. The
1699 following delays are inserted then:
1701 1st BOOTP request: delay 0 ... 1 sec
1702 2nd BOOTP request: delay 0 ... 2 sec
1703 3rd BOOTP request: delay 0 ... 4 sec
1705 BOOTP requests: delay 0 ... 8 sec
1707 - DHCP Advanced Options:
1708 You can fine tune the DHCP functionality by defining
1709 CONFIG_BOOTP_* symbols:
1711 CONFIG_BOOTP_SUBNETMASK
1712 CONFIG_BOOTP_GATEWAY
1713 CONFIG_BOOTP_HOSTNAME
1714 CONFIG_BOOTP_NISDOMAIN
1715 CONFIG_BOOTP_BOOTPATH
1716 CONFIG_BOOTP_BOOTFILESIZE
1719 CONFIG_BOOTP_SEND_HOSTNAME
1720 CONFIG_BOOTP_NTPSERVER
1721 CONFIG_BOOTP_TIMEOFFSET
1722 CONFIG_BOOTP_VENDOREX
1723 CONFIG_BOOTP_MAY_FAIL
1725 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1726 environment variable, not the BOOTP server.
1728 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1729 after the configured retry count, the call will fail
1730 instead of starting over. This can be used to fail over
1731 to Link-local IP address configuration if the DHCP server
1734 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1735 serverip from a DHCP server, it is possible that more
1736 than one DNS serverip is offered to the client.
1737 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1738 serverip will be stored in the additional environment
1739 variable "dnsip2". The first DNS serverip is always
1740 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1743 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1744 to do a dynamic update of a DNS server. To do this, they
1745 need the hostname of the DHCP requester.
1746 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1747 of the "hostname" environment variable is passed as
1748 option 12 to the DHCP server.
1750 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1752 A 32bit value in microseconds for a delay between
1753 receiving a "DHCP Offer" and sending the "DHCP Request".
1754 This fixes a problem with certain DHCP servers that don't
1755 respond 100% of the time to a "DHCP request". E.g. On an
1756 AT91RM9200 processor running at 180MHz, this delay needed
1757 to be *at least* 15,000 usec before a Windows Server 2003
1758 DHCP server would reply 100% of the time. I recommend at
1759 least 50,000 usec to be safe. The alternative is to hope
1760 that one of the retries will be successful but note that
1761 the DHCP timeout and retry process takes a longer than
1764 - Link-local IP address negotiation:
1765 Negotiate with other link-local clients on the local network
1766 for an address that doesn't require explicit configuration.
1767 This is especially useful if a DHCP server cannot be guaranteed
1768 to exist in all environments that the device must operate.
1770 See doc/README.link-local for more information.
1773 CONFIG_CDP_DEVICE_ID
1775 The device id used in CDP trigger frames.
1777 CONFIG_CDP_DEVICE_ID_PREFIX
1779 A two character string which is prefixed to the MAC address
1784 A printf format string which contains the ascii name of
1785 the port. Normally is set to "eth%d" which sets
1786 eth0 for the first Ethernet, eth1 for the second etc.
1788 CONFIG_CDP_CAPABILITIES
1790 A 32bit integer which indicates the device capabilities;
1791 0x00000010 for a normal host which does not forwards.
1795 An ascii string containing the version of the software.
1799 An ascii string containing the name of the platform.
1803 A 32bit integer sent on the trigger.
1805 CONFIG_CDP_POWER_CONSUMPTION
1807 A 16bit integer containing the power consumption of the
1808 device in .1 of milliwatts.
1810 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1812 A byte containing the id of the VLAN.
1814 - Status LED: CONFIG_STATUS_LED
1816 Several configurations allow to display the current
1817 status using a LED. For instance, the LED will blink
1818 fast while running U-Boot code, stop blinking as
1819 soon as a reply to a BOOTP request was received, and
1820 start blinking slow once the Linux kernel is running
1821 (supported by a status LED driver in the Linux
1822 kernel). Defining CONFIG_STATUS_LED enables this
1825 - CAN Support: CONFIG_CAN_DRIVER
1827 Defining CONFIG_CAN_DRIVER enables CAN driver support
1828 on those systems that support this (optional)
1829 feature, like the TQM8xxL modules.
1831 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1833 These enable I2C serial bus commands. Defining either of
1834 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1835 include the appropriate I2C driver for the selected CPU.
1837 This will allow you to use i2c commands at the u-boot
1838 command line (as long as you set CONFIG_CMD_I2C in
1839 CONFIG_COMMANDS) and communicate with i2c based realtime
1840 clock chips. See common/cmd_i2c.c for a description of the
1841 command line interface.
1843 CONFIG_HARD_I2C selects a hardware I2C controller.
1845 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1846 bit-banging) driver instead of CPM or similar hardware
1849 There are several other quantities that must also be
1850 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1852 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1853 to be the frequency (in Hz) at which you wish your i2c bus
1854 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1855 the CPU's i2c node address).
1857 Now, the u-boot i2c code for the mpc8xx
1858 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1859 and so its address should therefore be cleared to 0 (See,
1860 eg, MPC823e User's Manual p.16-473). So, set
1861 CONFIG_SYS_I2C_SLAVE to 0.
1863 CONFIG_SYS_I2C_INIT_MPC5XXX
1865 When a board is reset during an i2c bus transfer
1866 chips might think that the current transfer is still
1867 in progress. Reset the slave devices by sending start
1868 commands until the slave device responds.
1870 That's all that's required for CONFIG_HARD_I2C.
1872 If you use the software i2c interface (CONFIG_SOFT_I2C)
1873 then the following macros need to be defined (examples are
1874 from include/configs/lwmon.h):
1878 (Optional). Any commands necessary to enable the I2C
1879 controller or configure ports.
1881 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1885 (Only for MPC8260 CPU). The I/O port to use (the code
1886 assumes both bits are on the same port). Valid values
1887 are 0..3 for ports A..D.
1891 The code necessary to make the I2C data line active
1892 (driven). If the data line is open collector, this
1895 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1899 The code necessary to make the I2C data line tri-stated
1900 (inactive). If the data line is open collector, this
1903 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1907 Code that returns TRUE if the I2C data line is high,
1910 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1914 If <bit> is TRUE, sets the I2C data line high. If it
1915 is FALSE, it clears it (low).
1917 eg: #define I2C_SDA(bit) \
1918 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1919 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1923 If <bit> is TRUE, sets the I2C clock line high. If it
1924 is FALSE, it clears it (low).
1926 eg: #define I2C_SCL(bit) \
1927 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1928 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1932 This delay is invoked four times per clock cycle so this
1933 controls the rate of data transfer. The data rate thus
1934 is 1 / (I2C_DELAY * 4). Often defined to be something
1937 #define I2C_DELAY udelay(2)
1939 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1941 If your arch supports the generic GPIO framework (asm/gpio.h),
1942 then you may alternatively define the two GPIOs that are to be
1943 used as SCL / SDA. Any of the previous I2C_xxx macros will
1944 have GPIO-based defaults assigned to them as appropriate.
1946 You should define these to the GPIO value as given directly to
1947 the generic GPIO functions.
1949 CONFIG_SYS_I2C_INIT_BOARD
1951 When a board is reset during an i2c bus transfer
1952 chips might think that the current transfer is still
1953 in progress. On some boards it is possible to access
1954 the i2c SCLK line directly, either by using the
1955 processor pin as a GPIO or by having a second pin
1956 connected to the bus. If this option is defined a
1957 custom i2c_init_board() routine in boards/xxx/board.c
1958 is run early in the boot sequence.
1960 CONFIG_SYS_I2C_BOARD_LATE_INIT
1962 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1963 defined a custom i2c_board_late_init() routine in
1964 boards/xxx/board.c is run AFTER the operations in i2c_init()
1965 is completed. This callpoint can be used to unreset i2c bus
1966 using CPU i2c controller register accesses for CPUs whose i2c
1967 controller provide such a method. It is called at the end of
1968 i2c_init() to allow i2c_init operations to setup the i2c bus
1969 controller on the CPU (e.g. setting bus speed & slave address).
1971 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1973 This option enables configuration of bi_iic_fast[] flags
1974 in u-boot bd_info structure based on u-boot environment
1975 variable "i2cfast". (see also i2cfast)
1977 CONFIG_I2C_MULTI_BUS
1979 This option allows the use of multiple I2C buses, each of which
1980 must have a controller. At any point in time, only one bus is
1981 active. To switch to a different bus, use the 'i2c dev' command.
1982 Note that bus numbering is zero-based.
1984 CONFIG_SYS_I2C_NOPROBES
1986 This option specifies a list of I2C devices that will be skipped
1987 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1988 is set, specify a list of bus-device pairs. Otherwise, specify
1989 a 1D array of device addresses
1992 #undef CONFIG_I2C_MULTI_BUS
1993 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1995 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1997 #define CONFIG_I2C_MULTI_BUS
1998 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2000 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2002 CONFIG_SYS_SPD_BUS_NUM
2004 If defined, then this indicates the I2C bus number for DDR SPD.
2005 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2007 CONFIG_SYS_RTC_BUS_NUM
2009 If defined, then this indicates the I2C bus number for the RTC.
2010 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2012 CONFIG_SYS_DTT_BUS_NUM
2014 If defined, then this indicates the I2C bus number for the DTT.
2015 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2017 CONFIG_SYS_I2C_DTT_ADDR:
2019 If defined, specifies the I2C address of the DTT device.
2020 If not defined, then U-Boot uses predefined value for
2021 specified DTT device.
2025 Define this option if you want to use Freescale's I2C driver in
2026 drivers/i2c/fsl_i2c.c.
2030 Define this option if you have I2C devices reached over 1 .. n
2031 I2C Muxes like the pca9544a. This option addes a new I2C
2032 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
2033 new I2C Bus to the existing I2C Busses. If you select the
2034 new Bus with "i2c dev", u-bbot sends first the commandos for
2035 the muxes to activate this new "bus".
2037 CONFIG_I2C_MULTI_BUS must be also defined, to use this
2041 Adding a new I2C Bus reached over 2 pca9544a muxes
2042 The First mux with address 70 and channel 6
2043 The Second mux with address 71 and channel 4
2045 => i2c bus pca9544a:70:6:pca9544a:71:4
2047 Use the "i2c bus" command without parameter, to get a list
2048 of I2C Busses with muxes:
2051 Busses reached over muxes:
2053 reached over Mux(es):
2056 reached over Mux(es):
2061 If you now switch to the new I2C Bus 3 with "i2c dev 3"
2062 u-boot first sends the command to the mux@70 to enable
2063 channel 6, and then the command to the mux@71 to enable
2066 After that, you can use the "normal" i2c commands as
2067 usual to communicate with your I2C devices behind
2070 This option is actually implemented for the bitbanging
2071 algorithm in common/soft_i2c.c and for the Hardware I2C
2072 Bus on the MPC8260. But it should be not so difficult
2073 to add this option to other architectures.
2075 CONFIG_SOFT_I2C_READ_REPEATED_START
2077 defining this will force the i2c_read() function in
2078 the soft_i2c driver to perform an I2C repeated start
2079 between writing the address pointer and reading the
2080 data. If this define is omitted the default behaviour
2081 of doing a stop-start sequence will be used. Most I2C
2082 devices can use either method, but some require one or
2085 - SPI Support: CONFIG_SPI
2087 Enables SPI driver (so far only tested with
2088 SPI EEPROM, also an instance works with Crystal A/D and
2089 D/As on the SACSng board)
2093 Enables the driver for SPI controller on SuperH. Currently
2094 only SH7757 is supported.
2098 Enables extended (16-bit) SPI EEPROM addressing.
2099 (symmetrical to CONFIG_I2C_X)
2103 Enables a software (bit-bang) SPI driver rather than
2104 using hardware support. This is a general purpose
2105 driver that only requires three general I/O port pins
2106 (two outputs, one input) to function. If this is
2107 defined, the board configuration must define several
2108 SPI configuration items (port pins to use, etc). For
2109 an example, see include/configs/sacsng.h.
2113 Enables a hardware SPI driver for general-purpose reads
2114 and writes. As with CONFIG_SOFT_SPI, the board configuration
2115 must define a list of chip-select function pointers.
2116 Currently supported on some MPC8xxx processors. For an
2117 example, see include/configs/mpc8349emds.h.
2121 Enables the driver for the SPI controllers on i.MX and MXC
2122 SoCs. Currently i.MX31/35/51 are supported.
2124 - FPGA Support: CONFIG_FPGA
2126 Enables FPGA subsystem.
2128 CONFIG_FPGA_<vendor>
2130 Enables support for specific chip vendors.
2133 CONFIG_FPGA_<family>
2135 Enables support for FPGA family.
2136 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2140 Specify the number of FPGA devices to support.
2142 CONFIG_SYS_FPGA_PROG_FEEDBACK
2144 Enable printing of hash marks during FPGA configuration.
2146 CONFIG_SYS_FPGA_CHECK_BUSY
2148 Enable checks on FPGA configuration interface busy
2149 status by the configuration function. This option
2150 will require a board or device specific function to
2155 If defined, a function that provides delays in the FPGA
2156 configuration driver.
2158 CONFIG_SYS_FPGA_CHECK_CTRLC
2159 Allow Control-C to interrupt FPGA configuration
2161 CONFIG_SYS_FPGA_CHECK_ERROR
2163 Check for configuration errors during FPGA bitfile
2164 loading. For example, abort during Virtex II
2165 configuration if the INIT_B line goes low (which
2166 indicated a CRC error).
2168 CONFIG_SYS_FPGA_WAIT_INIT
2170 Maximum time to wait for the INIT_B line to deassert
2171 after PROB_B has been deasserted during a Virtex II
2172 FPGA configuration sequence. The default time is 500
2175 CONFIG_SYS_FPGA_WAIT_BUSY
2177 Maximum time to wait for BUSY to deassert during
2178 Virtex II FPGA configuration. The default is 5 ms.
2180 CONFIG_SYS_FPGA_WAIT_CONFIG
2182 Time to wait after FPGA configuration. The default is
2185 - Configuration Management:
2188 If defined, this string will be added to the U-Boot
2189 version information (U_BOOT_VERSION)
2191 - Vendor Parameter Protection:
2193 U-Boot considers the values of the environment
2194 variables "serial#" (Board Serial Number) and
2195 "ethaddr" (Ethernet Address) to be parameters that
2196 are set once by the board vendor / manufacturer, and
2197 protects these variables from casual modification by
2198 the user. Once set, these variables are read-only,
2199 and write or delete attempts are rejected. You can
2200 change this behaviour:
2202 If CONFIG_ENV_OVERWRITE is #defined in your config
2203 file, the write protection for vendor parameters is
2204 completely disabled. Anybody can change or delete
2207 Alternatively, if you #define _both_ CONFIG_ETHADDR
2208 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2209 Ethernet address is installed in the environment,
2210 which can be changed exactly ONCE by the user. [The
2211 serial# is unaffected by this, i. e. it remains
2214 The same can be accomplished in a more flexible way
2215 for any variable by configuring the type of access
2216 to allow for those variables in the ".flags" variable
2217 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2222 Define this variable to enable the reservation of
2223 "protected RAM", i. e. RAM which is not overwritten
2224 by U-Boot. Define CONFIG_PRAM to hold the number of
2225 kB you want to reserve for pRAM. You can overwrite
2226 this default value by defining an environment
2227 variable "pram" to the number of kB you want to
2228 reserve. Note that the board info structure will
2229 still show the full amount of RAM. If pRAM is
2230 reserved, a new environment variable "mem" will
2231 automatically be defined to hold the amount of
2232 remaining RAM in a form that can be passed as boot
2233 argument to Linux, for instance like that:
2235 setenv bootargs ... mem=\${mem}
2238 This way you can tell Linux not to use this memory,
2239 either, which results in a memory region that will
2240 not be affected by reboots.
2242 *WARNING* If your board configuration uses automatic
2243 detection of the RAM size, you must make sure that
2244 this memory test is non-destructive. So far, the
2245 following board configurations are known to be
2248 IVMS8, IVML24, SPD8xx, TQM8xxL,
2249 HERMES, IP860, RPXlite, LWMON,
2252 - Access to physical memory region (> 4GB)
2253 Some basic support is provided for operations on memory not
2254 normally accessible to U-Boot - e.g. some architectures
2255 support access to more than 4GB of memory on 32-bit
2256 machines using physical address extension or similar.
2257 Define CONFIG_PHYSMEM to access this basic support, which
2258 currently only supports clearing the memory.
2263 Define this variable to stop the system in case of a
2264 fatal error, so that you have to reset it manually.
2265 This is probably NOT a good idea for an embedded
2266 system where you want the system to reboot
2267 automatically as fast as possible, but it may be
2268 useful during development since you can try to debug
2269 the conditions that lead to the situation.
2271 CONFIG_NET_RETRY_COUNT
2273 This variable defines the number of retries for
2274 network operations like ARP, RARP, TFTP, or BOOTP
2275 before giving up the operation. If not defined, a
2276 default value of 5 is used.
2280 Timeout waiting for an ARP reply in milliseconds.
2284 Timeout in milliseconds used in NFS protocol.
2285 If you encounter "ERROR: Cannot umount" in nfs command,
2286 try longer timeout such as
2287 #define CONFIG_NFS_TIMEOUT 10000UL
2289 - Command Interpreter:
2290 CONFIG_AUTO_COMPLETE
2292 Enable auto completion of commands using TAB.
2294 Note that this feature has NOT been implemented yet
2295 for the "hush" shell.
2298 CONFIG_SYS_HUSH_PARSER
2300 Define this variable to enable the "hush" shell (from
2301 Busybox) as command line interpreter, thus enabling
2302 powerful command line syntax like
2303 if...then...else...fi conditionals or `&&' and '||'
2304 constructs ("shell scripts").
2306 If undefined, you get the old, much simpler behaviour
2307 with a somewhat smaller memory footprint.
2310 CONFIG_SYS_PROMPT_HUSH_PS2
2312 This defines the secondary prompt string, which is
2313 printed when the command interpreter needs more input
2314 to complete a command. Usually "> ".
2318 In the current implementation, the local variables
2319 space and global environment variables space are
2320 separated. Local variables are those you define by
2321 simply typing `name=value'. To access a local
2322 variable later on, you have write `$name' or
2323 `${name}'; to execute the contents of a variable
2324 directly type `$name' at the command prompt.
2326 Global environment variables are those you use
2327 setenv/printenv to work with. To run a command stored
2328 in such a variable, you need to use the run command,
2329 and you must not use the '$' sign to access them.
2331 To store commands and special characters in a
2332 variable, please use double quotation marks
2333 surrounding the whole text of the variable, instead
2334 of the backslashes before semicolons and special
2337 - Commandline Editing and History:
2338 CONFIG_CMDLINE_EDITING
2340 Enable editing and History functions for interactive
2341 commandline input operations
2343 - Default Environment:
2344 CONFIG_EXTRA_ENV_SETTINGS
2346 Define this to contain any number of null terminated
2347 strings (variable = value pairs) that will be part of
2348 the default environment compiled into the boot image.
2350 For example, place something like this in your
2351 board's config file:
2353 #define CONFIG_EXTRA_ENV_SETTINGS \
2357 Warning: This method is based on knowledge about the
2358 internal format how the environment is stored by the
2359 U-Boot code. This is NOT an official, exported
2360 interface! Although it is unlikely that this format
2361 will change soon, there is no guarantee either.
2362 You better know what you are doing here.
2364 Note: overly (ab)use of the default environment is
2365 discouraged. Make sure to check other ways to preset
2366 the environment like the "source" command or the
2369 CONFIG_ENV_VARS_UBOOT_CONFIG
2371 Define this in order to add variables describing the
2372 U-Boot build configuration to the default environment.
2373 These will be named arch, cpu, board, vendor, and soc.
2375 Enabling this option will cause the following to be defined:
2383 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2385 Define this in order to add variables describing certain
2386 run-time determined information about the hardware to the
2387 environment. These will be named board_name, board_rev.
2389 - DataFlash Support:
2390 CONFIG_HAS_DATAFLASH
2392 Defining this option enables DataFlash features and
2393 allows to read/write in Dataflash via the standard
2396 - Serial Flash support
2399 Defining this option enables SPI flash commands
2400 'sf probe/read/write/erase/update'.
2402 Usage requires an initial 'probe' to define the serial
2403 flash parameters, followed by read/write/erase/update
2406 The following defaults may be provided by the platform
2407 to handle the common case when only a single serial
2408 flash is present on the system.
2410 CONFIG_SF_DEFAULT_BUS Bus identifier
2411 CONFIG_SF_DEFAULT_CS Chip-select
2412 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2413 CONFIG_SF_DEFAULT_SPEED in Hz
2415 - SystemACE Support:
2418 Adding this option adds support for Xilinx SystemACE
2419 chips attached via some sort of local bus. The address
2420 of the chip must also be defined in the
2421 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2423 #define CONFIG_SYSTEMACE
2424 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2426 When SystemACE support is added, the "ace" device type
2427 becomes available to the fat commands, i.e. fatls.
2429 - TFTP Fixed UDP Port:
2432 If this is defined, the environment variable tftpsrcp
2433 is used to supply the TFTP UDP source port value.
2434 If tftpsrcp isn't defined, the normal pseudo-random port
2435 number generator is used.
2437 Also, the environment variable tftpdstp is used to supply
2438 the TFTP UDP destination port value. If tftpdstp isn't
2439 defined, the normal port 69 is used.
2441 The purpose for tftpsrcp is to allow a TFTP server to
2442 blindly start the TFTP transfer using the pre-configured
2443 target IP address and UDP port. This has the effect of
2444 "punching through" the (Windows XP) firewall, allowing
2445 the remainder of the TFTP transfer to proceed normally.
2446 A better solution is to properly configure the firewall,
2447 but sometimes that is not allowed.
2452 This enables a generic 'hash' command which can produce
2453 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2457 Enable the hash verify command (hash -v). This adds to code
2460 CONFIG_SHA1 - support SHA1 hashing
2461 CONFIG_SHA256 - support SHA256 hashing
2463 Note: There is also a sha1sum command, which should perhaps
2464 be deprecated in favour of 'hash sha1'.
2466 - Show boot progress:
2467 CONFIG_SHOW_BOOT_PROGRESS
2469 Defining this option allows to add some board-
2470 specific code (calling a user-provided function
2471 "show_boot_progress(int)") that enables you to show
2472 the system's boot progress on some display (for
2473 example, some LED's) on your board. At the moment,
2474 the following checkpoints are implemented:
2476 - Detailed boot stage timing
2478 Define this option to get detailed timing of each stage
2479 of the boot process.
2481 CONFIG_BOOTSTAGE_USER_COUNT
2482 This is the number of available user bootstage records.
2483 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2484 a new ID will be allocated from this stash. If you exceed
2485 the limit, recording will stop.
2487 CONFIG_BOOTSTAGE_REPORT
2488 Define this to print a report before boot, similar to this:
2490 Timer summary in microseconds:
2493 3,575,678 3,575,678 board_init_f start
2494 3,575,695 17 arch_cpu_init A9
2495 3,575,777 82 arch_cpu_init done
2496 3,659,598 83,821 board_init_r start
2497 3,910,375 250,777 main_loop
2498 29,916,167 26,005,792 bootm_start
2499 30,361,327 445,160 start_kernel
2501 CONFIG_CMD_BOOTSTAGE
2502 Add a 'bootstage' command which supports printing a report
2503 and un/stashing of bootstage data.
2505 CONFIG_BOOTSTAGE_FDT
2506 Stash the bootstage information in the FDT. A root 'bootstage'
2507 node is created with each bootstage id as a child. Each child
2508 has a 'name' property and either 'mark' containing the
2509 mark time in microsecond, or 'accum' containing the
2510 accumulated time for that bootstage id in microseconds.
2515 name = "board_init_f";
2524 Code in the Linux kernel can find this in /proc/devicetree.
2526 Legacy uImage format:
2529 1 common/cmd_bootm.c before attempting to boot an image
2530 -1 common/cmd_bootm.c Image header has bad magic number
2531 2 common/cmd_bootm.c Image header has correct magic number
2532 -2 common/cmd_bootm.c Image header has bad checksum
2533 3 common/cmd_bootm.c Image header has correct checksum
2534 -3 common/cmd_bootm.c Image data has bad checksum
2535 4 common/cmd_bootm.c Image data has correct checksum
2536 -4 common/cmd_bootm.c Image is for unsupported architecture
2537 5 common/cmd_bootm.c Architecture check OK
2538 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2539 6 common/cmd_bootm.c Image Type check OK
2540 -6 common/cmd_bootm.c gunzip uncompression error
2541 -7 common/cmd_bootm.c Unimplemented compression type
2542 7 common/cmd_bootm.c Uncompression OK
2543 8 common/cmd_bootm.c No uncompress/copy overwrite error
2544 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2546 9 common/image.c Start initial ramdisk verification
2547 -10 common/image.c Ramdisk header has bad magic number
2548 -11 common/image.c Ramdisk header has bad checksum
2549 10 common/image.c Ramdisk header is OK
2550 -12 common/image.c Ramdisk data has bad checksum
2551 11 common/image.c Ramdisk data has correct checksum
2552 12 common/image.c Ramdisk verification complete, start loading
2553 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2554 13 common/image.c Start multifile image verification
2555 14 common/image.c No initial ramdisk, no multifile, continue.
2557 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2559 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2560 -31 post/post.c POST test failed, detected by post_output_backlog()
2561 -32 post/post.c POST test failed, detected by post_run_single()
2563 34 common/cmd_doc.c before loading a Image from a DOC device
2564 -35 common/cmd_doc.c Bad usage of "doc" command
2565 35 common/cmd_doc.c correct usage of "doc" command
2566 -36 common/cmd_doc.c No boot device
2567 36 common/cmd_doc.c correct boot device
2568 -37 common/cmd_doc.c Unknown Chip ID on boot device
2569 37 common/cmd_doc.c correct chip ID found, device available
2570 -38 common/cmd_doc.c Read Error on boot device
2571 38 common/cmd_doc.c reading Image header from DOC device OK
2572 -39 common/cmd_doc.c Image header has bad magic number
2573 39 common/cmd_doc.c Image header has correct magic number
2574 -40 common/cmd_doc.c Error reading Image from DOC device
2575 40 common/cmd_doc.c Image header has correct magic number
2576 41 common/cmd_ide.c before loading a Image from a IDE device
2577 -42 common/cmd_ide.c Bad usage of "ide" command
2578 42 common/cmd_ide.c correct usage of "ide" command
2579 -43 common/cmd_ide.c No boot device
2580 43 common/cmd_ide.c boot device found
2581 -44 common/cmd_ide.c Device not available
2582 44 common/cmd_ide.c Device available
2583 -45 common/cmd_ide.c wrong partition selected
2584 45 common/cmd_ide.c partition selected
2585 -46 common/cmd_ide.c Unknown partition table
2586 46 common/cmd_ide.c valid partition table found
2587 -47 common/cmd_ide.c Invalid partition type
2588 47 common/cmd_ide.c correct partition type
2589 -48 common/cmd_ide.c Error reading Image Header on boot device
2590 48 common/cmd_ide.c reading Image Header from IDE device OK
2591 -49 common/cmd_ide.c Image header has bad magic number
2592 49 common/cmd_ide.c Image header has correct magic number
2593 -50 common/cmd_ide.c Image header has bad checksum
2594 50 common/cmd_ide.c Image header has correct checksum
2595 -51 common/cmd_ide.c Error reading Image from IDE device
2596 51 common/cmd_ide.c reading Image from IDE device OK
2597 52 common/cmd_nand.c before loading a Image from a NAND device
2598 -53 common/cmd_nand.c Bad usage of "nand" command
2599 53 common/cmd_nand.c correct usage of "nand" command
2600 -54 common/cmd_nand.c No boot device
2601 54 common/cmd_nand.c boot device found
2602 -55 common/cmd_nand.c Unknown Chip ID on boot device
2603 55 common/cmd_nand.c correct chip ID found, device available
2604 -56 common/cmd_nand.c Error reading Image Header on boot device
2605 56 common/cmd_nand.c reading Image Header from NAND device OK
2606 -57 common/cmd_nand.c Image header has bad magic number
2607 57 common/cmd_nand.c Image header has correct magic number
2608 -58 common/cmd_nand.c Error reading Image from NAND device
2609 58 common/cmd_nand.c reading Image from NAND device OK
2611 -60 common/env_common.c Environment has a bad CRC, using default
2613 64 net/eth.c starting with Ethernet configuration.
2614 -64 net/eth.c no Ethernet found.
2615 65 net/eth.c Ethernet found.
2617 -80 common/cmd_net.c usage wrong
2618 80 common/cmd_net.c before calling NetLoop()
2619 -81 common/cmd_net.c some error in NetLoop() occurred
2620 81 common/cmd_net.c NetLoop() back without error
2621 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2622 82 common/cmd_net.c trying automatic boot
2623 83 common/cmd_net.c running "source" command
2624 -83 common/cmd_net.c some error in automatic boot or "source" command
2625 84 common/cmd_net.c end without errors
2630 100 common/cmd_bootm.c Kernel FIT Image has correct format
2631 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2632 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2633 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2634 102 common/cmd_bootm.c Kernel unit name specified
2635 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2636 103 common/cmd_bootm.c Found configuration node
2637 104 common/cmd_bootm.c Got kernel subimage node offset
2638 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2639 105 common/cmd_bootm.c Kernel subimage hash verification OK
2640 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2641 106 common/cmd_bootm.c Architecture check OK
2642 -106 common/cmd_bootm.c Kernel subimage has wrong type
2643 107 common/cmd_bootm.c Kernel subimage type OK
2644 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2645 108 common/cmd_bootm.c Got kernel subimage data/size
2646 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2647 -109 common/cmd_bootm.c Can't get kernel subimage type
2648 -110 common/cmd_bootm.c Can't get kernel subimage comp
2649 -111 common/cmd_bootm.c Can't get kernel subimage os
2650 -112 common/cmd_bootm.c Can't get kernel subimage load address
2651 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2653 120 common/image.c Start initial ramdisk verification
2654 -120 common/image.c Ramdisk FIT image has incorrect format
2655 121 common/image.c Ramdisk FIT image has correct format
2656 122 common/image.c No ramdisk subimage unit name, using configuration
2657 -122 common/image.c Can't get configuration for ramdisk subimage
2658 123 common/image.c Ramdisk unit name specified
2659 -124 common/image.c Can't get ramdisk subimage node offset
2660 125 common/image.c Got ramdisk subimage node offset
2661 -125 common/image.c Ramdisk subimage hash verification failed
2662 126 common/image.c Ramdisk subimage hash verification OK
2663 -126 common/image.c Ramdisk subimage for unsupported architecture
2664 127 common/image.c Architecture check OK
2665 -127 common/image.c Can't get ramdisk subimage data/size
2666 128 common/image.c Got ramdisk subimage data/size
2667 129 common/image.c Can't get ramdisk load address
2668 -129 common/image.c Got ramdisk load address
2670 -130 common/cmd_doc.c Incorrect FIT image format
2671 131 common/cmd_doc.c FIT image format OK
2673 -140 common/cmd_ide.c Incorrect FIT image format
2674 141 common/cmd_ide.c FIT image format OK
2676 -150 common/cmd_nand.c Incorrect FIT image format
2677 151 common/cmd_nand.c FIT image format OK
2679 - FIT image support:
2681 Enable support for the FIT uImage format.
2683 CONFIG_FIT_BEST_MATCH
2684 When no configuration is explicitly selected, default to the
2685 one whose fdt's compatibility field best matches that of
2686 U-Boot itself. A match is considered "best" if it matches the
2687 most specific compatibility entry of U-Boot's fdt's root node.
2688 The order of entries in the configuration's fdt is ignored.
2690 - Standalone program support:
2691 CONFIG_STANDALONE_LOAD_ADDR
2693 This option defines a board specific value for the
2694 address where standalone program gets loaded, thus
2695 overwriting the architecture dependent default
2698 - Frame Buffer Address:
2701 Define CONFIG_FB_ADDR if you want to use specific
2702 address for frame buffer.
2703 Then system will reserve the frame buffer address to
2704 defined address instead of lcd_setmem (this function
2705 grabs the memory for frame buffer by panel's size).
2707 Please see board_init_f function.
2709 - Automatic software updates via TFTP server
2711 CONFIG_UPDATE_TFTP_CNT_MAX
2712 CONFIG_UPDATE_TFTP_MSEC_MAX
2714 These options enable and control the auto-update feature;
2715 for a more detailed description refer to doc/README.update.
2717 - MTD Support (mtdparts command, UBI support)
2720 Adds the MTD device infrastructure from the Linux kernel.
2721 Needed for mtdparts command support.
2723 CONFIG_MTD_PARTITIONS
2725 Adds the MTD partitioning infrastructure from the Linux
2726 kernel. Needed for UBI support.
2730 Enable building of SPL globally.
2733 LDSCRIPT for linking the SPL binary.
2736 Maximum binary size (text, data and rodata) of the SPL binary.
2738 CONFIG_SPL_TEXT_BASE
2739 TEXT_BASE for linking the SPL binary.
2741 CONFIG_SPL_RELOC_TEXT_BASE
2742 Address to relocate to. If unspecified, this is equal to
2743 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2745 CONFIG_SPL_BSS_START_ADDR
2746 Link address for the BSS within the SPL binary.
2748 CONFIG_SPL_BSS_MAX_SIZE
2749 Maximum binary size of the BSS section of the SPL binary.
2752 Adress of the start of the stack SPL will use
2754 CONFIG_SPL_RELOC_STACK
2755 Adress of the start of the stack SPL will use after
2756 relocation. If unspecified, this is equal to
2759 CONFIG_SYS_SPL_MALLOC_START
2760 Starting address of the malloc pool used in SPL.
2762 CONFIG_SYS_SPL_MALLOC_SIZE
2763 The size of the malloc pool used in SPL.
2765 CONFIG_SPL_FRAMEWORK
2766 Enable the SPL framework under common/. This framework
2767 supports MMC, NAND and YMODEM loading of U-Boot and NAND
2768 NAND loading of the Linux Kernel.
2770 CONFIG_SPL_DISPLAY_PRINT
2771 For ARM, enable an optional function to print more information
2772 about the running system.
2774 CONFIG_SPL_INIT_MINIMAL
2775 Arch init code should be built for a very small image
2777 CONFIG_SPL_LIBCOMMON_SUPPORT
2778 Support for common/libcommon.o in SPL binary
2780 CONFIG_SPL_LIBDISK_SUPPORT
2781 Support for disk/libdisk.o in SPL binary
2783 CONFIG_SPL_I2C_SUPPORT
2784 Support for drivers/i2c/libi2c.o in SPL binary
2786 CONFIG_SPL_GPIO_SUPPORT
2787 Support for drivers/gpio/libgpio.o in SPL binary
2789 CONFIG_SPL_MMC_SUPPORT
2790 Support for drivers/mmc/libmmc.o in SPL binary
2792 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
2793 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
2794 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
2795 Address, size and partition on the MMC to load U-Boot from
2796 when the MMC is being used in raw mode.
2798 CONFIG_SPL_FAT_SUPPORT
2799 Support for fs/fat/libfat.o in SPL binary
2801 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
2802 Filename to read to load U-Boot when reading from FAT
2804 CONFIG_SPL_NAND_BASE
2805 Include nand_base.c in the SPL. Requires
2806 CONFIG_SPL_NAND_DRIVERS.
2808 CONFIG_SPL_NAND_DRIVERS
2809 SPL uses normal NAND drivers, not minimal drivers.
2812 Include standard software ECC in the SPL
2814 CONFIG_SPL_NAND_SIMPLE
2815 Support for NAND boot using simple NAND drivers that
2816 expose the cmd_ctrl() interface.
2818 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
2819 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
2820 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
2821 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
2822 CONFIG_SYS_NAND_ECCBYTES
2823 Defines the size and behavior of the NAND that SPL uses
2826 CONFIG_SYS_NAND_U_BOOT_OFFS
2827 Location in NAND to read U-Boot from
2829 CONFIG_SYS_NAND_U_BOOT_DST
2830 Location in memory to load U-Boot to
2832 CONFIG_SYS_NAND_U_BOOT_SIZE
2833 Size of image to load
2835 CONFIG_SYS_NAND_U_BOOT_START
2836 Entry point in loaded image to jump to
2838 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
2839 Define this if you need to first read the OOB and then the
2840 data. This is used for example on davinci plattforms.
2842 CONFIG_SPL_OMAP3_ID_NAND
2843 Support for an OMAP3-specific set of functions to return the
2844 ID and MFR of the first attached NAND chip, if present.
2846 CONFIG_SPL_SERIAL_SUPPORT
2847 Support for drivers/serial/libserial.o in SPL binary
2849 CONFIG_SPL_SPI_FLASH_SUPPORT
2850 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
2852 CONFIG_SPL_SPI_SUPPORT
2853 Support for drivers/spi/libspi.o in SPL binary
2855 CONFIG_SPL_RAM_DEVICE
2856 Support for running image already present in ram, in SPL binary
2858 CONFIG_SPL_LIBGENERIC_SUPPORT
2859 Support for lib/libgeneric.o in SPL binary
2862 Final target image containing SPL and payload. Some SPLs
2863 use an arch-specific makefile fragment instead, for
2864 example if more than one image needs to be produced.
2869 [so far only for SMDK2400 boards]
2871 - Modem support enable:
2872 CONFIG_MODEM_SUPPORT
2874 - RTS/CTS Flow control enable:
2877 - Modem debug support:
2878 CONFIG_MODEM_SUPPORT_DEBUG
2880 Enables debugging stuff (char screen[1024], dbg())
2881 for modem support. Useful only with BDI2000.
2883 - Interrupt support (PPC):
2885 There are common interrupt_init() and timer_interrupt()
2886 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2887 for CPU specific initialization. interrupt_init_cpu()
2888 should set decrementer_count to appropriate value. If
2889 CPU resets decrementer automatically after interrupt
2890 (ppc4xx) it should set decrementer_count to zero.
2891 timer_interrupt() calls timer_interrupt_cpu() for CPU
2892 specific handling. If board has watchdog / status_led
2893 / other_activity_monitor it works automatically from
2894 general timer_interrupt().
2898 In the target system modem support is enabled when a
2899 specific key (key combination) is pressed during
2900 power-on. Otherwise U-Boot will boot normally
2901 (autoboot). The key_pressed() function is called from
2902 board_init(). Currently key_pressed() is a dummy
2903 function, returning 1 and thus enabling modem
2906 If there are no modem init strings in the
2907 environment, U-Boot proceed to autoboot; the
2908 previous output (banner, info printfs) will be
2911 See also: doc/README.Modem
2913 Board initialization settings:
2914 ------------------------------
2916 During Initialization u-boot calls a number of board specific functions
2917 to allow the preparation of board specific prerequisites, e.g. pin setup
2918 before drivers are initialized. To enable these callbacks the
2919 following configuration macros have to be defined. Currently this is
2920 architecture specific, so please check arch/your_architecture/lib/board.c
2921 typically in board_init_f() and board_init_r().
2923 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
2924 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
2925 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
2926 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
2928 Configuration Settings:
2929 -----------------------
2931 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2932 undefine this when you're short of memory.
2934 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2935 width of the commands listed in the 'help' command output.
2937 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2938 prompt for user input.
2940 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2942 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2944 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2946 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2947 the application (usually a Linux kernel) when it is
2950 - CONFIG_SYS_BAUDRATE_TABLE:
2951 List of legal baudrate settings for this board.
2953 - CONFIG_SYS_CONSOLE_INFO_QUIET
2954 Suppress display of console information at boot.
2956 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2957 If the board specific function
2958 extern int overwrite_console (void);
2959 returns 1, the stdin, stderr and stdout are switched to the
2960 serial port, else the settings in the environment are used.
2962 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2963 Enable the call to overwrite_console().
2965 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2966 Enable overwrite of previous console environment settings.
2968 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2969 Begin and End addresses of the area used by the
2972 - CONFIG_SYS_ALT_MEMTEST:
2973 Enable an alternate, more extensive memory test.
2975 - CONFIG_SYS_MEMTEST_SCRATCH:
2976 Scratch address used by the alternate memory test
2977 You only need to set this if address zero isn't writeable
2979 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2980 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2981 this specified memory area will get subtracted from the top
2982 (end) of RAM and won't get "touched" at all by U-Boot. By
2983 fixing up gd->ram_size the Linux kernel should gets passed
2984 the now "corrected" memory size and won't touch it either.
2985 This should work for arch/ppc and arch/powerpc. Only Linux
2986 board ports in arch/powerpc with bootwrapper support that
2987 recalculate the memory size from the SDRAM controller setup
2988 will have to get fixed in Linux additionally.
2990 This option can be used as a workaround for the 440EPx/GRx
2991 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2994 WARNING: Please make sure that this value is a multiple of
2995 the Linux page size (normally 4k). If this is not the case,
2996 then the end address of the Linux memory will be located at a
2997 non page size aligned address and this could cause major
3000 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3001 Enable temporary baudrate change while serial download
3003 - CONFIG_SYS_SDRAM_BASE:
3004 Physical start address of SDRAM. _Must_ be 0 here.
3006 - CONFIG_SYS_MBIO_BASE:
3007 Physical start address of Motherboard I/O (if using a
3010 - CONFIG_SYS_FLASH_BASE:
3011 Physical start address of Flash memory.
3013 - CONFIG_SYS_MONITOR_BASE:
3014 Physical start address of boot monitor code (set by
3015 make config files to be same as the text base address
3016 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3017 CONFIG_SYS_FLASH_BASE when booting from flash.
3019 - CONFIG_SYS_MONITOR_LEN:
3020 Size of memory reserved for monitor code, used to
3021 determine _at_compile_time_ (!) if the environment is
3022 embedded within the U-Boot image, or in a separate
3025 - CONFIG_SYS_MALLOC_LEN:
3026 Size of DRAM reserved for malloc() use.
3028 - CONFIG_SYS_BOOTM_LEN:
3029 Normally compressed uImages are limited to an
3030 uncompressed size of 8 MBytes. If this is not enough,
3031 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3032 to adjust this setting to your needs.
3034 - CONFIG_SYS_BOOTMAPSZ:
3035 Maximum size of memory mapped by the startup code of
3036 the Linux kernel; all data that must be processed by
3037 the Linux kernel (bd_info, boot arguments, FDT blob if
3038 used) must be put below this limit, unless "bootm_low"
3039 enviroment variable is defined and non-zero. In such case
3040 all data for the Linux kernel must be between "bootm_low"
3041 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3042 variable "bootm_mapsize" will override the value of
3043 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3044 then the value in "bootm_size" will be used instead.
3046 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3047 Enable initrd_high functionality. If defined then the
3048 initrd_high feature is enabled and the bootm ramdisk subcommand
3051 - CONFIG_SYS_BOOT_GET_CMDLINE:
3052 Enables allocating and saving kernel cmdline in space between
3053 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3055 - CONFIG_SYS_BOOT_GET_KBD:
3056 Enables allocating and saving a kernel copy of the bd_info in
3057 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3059 - CONFIG_SYS_MAX_FLASH_BANKS:
3060 Max number of Flash memory banks
3062 - CONFIG_SYS_MAX_FLASH_SECT:
3063 Max number of sectors on a Flash chip
3065 - CONFIG_SYS_FLASH_ERASE_TOUT:
3066 Timeout for Flash erase operations (in ms)
3068 - CONFIG_SYS_FLASH_WRITE_TOUT:
3069 Timeout for Flash write operations (in ms)
3071 - CONFIG_SYS_FLASH_LOCK_TOUT
3072 Timeout for Flash set sector lock bit operation (in ms)
3074 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3075 Timeout for Flash clear lock bits operation (in ms)
3077 - CONFIG_SYS_FLASH_PROTECTION
3078 If defined, hardware flash sectors protection is used
3079 instead of U-Boot software protection.
3081 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3083 Enable TFTP transfers directly to flash memory;
3084 without this option such a download has to be
3085 performed in two steps: (1) download to RAM, and (2)
3086 copy from RAM to flash.
3088 The two-step approach is usually more reliable, since
3089 you can check if the download worked before you erase
3090 the flash, but in some situations (when system RAM is
3091 too limited to allow for a temporary copy of the
3092 downloaded image) this option may be very useful.
3094 - CONFIG_SYS_FLASH_CFI:
3095 Define if the flash driver uses extra elements in the
3096 common flash structure for storing flash geometry.
3098 - CONFIG_FLASH_CFI_DRIVER
3099 This option also enables the building of the cfi_flash driver
3100 in the drivers directory
3102 - CONFIG_FLASH_CFI_MTD
3103 This option enables the building of the cfi_mtd driver
3104 in the drivers directory. The driver exports CFI flash
3107 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3108 Use buffered writes to flash.
3110 - CONFIG_FLASH_SPANSION_S29WS_N
3111 s29ws-n MirrorBit flash has non-standard addresses for buffered
3114 - CONFIG_SYS_FLASH_QUIET_TEST
3115 If this option is defined, the common CFI flash doesn't
3116 print it's warning upon not recognized FLASH banks. This
3117 is useful, if some of the configured banks are only
3118 optionally available.
3120 - CONFIG_FLASH_SHOW_PROGRESS
3121 If defined (must be an integer), print out countdown
3122 digits and dots. Recommended value: 45 (9..1) for 80
3123 column displays, 15 (3..1) for 40 column displays.
3125 - CONFIG_SYS_RX_ETH_BUFFER:
3126 Defines the number of Ethernet receive buffers. On some
3127 Ethernet controllers it is recommended to set this value
3128 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3129 buffers can be full shortly after enabling the interface
3130 on high Ethernet traffic.
3131 Defaults to 4 if not defined.
3133 - CONFIG_ENV_MAX_ENTRIES
3135 Maximum number of entries in the hash table that is used
3136 internally to store the environment settings. The default
3137 setting is supposed to be generous and should work in most
3138 cases. This setting can be used to tune behaviour; see
3139 lib/hashtable.c for details.
3141 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3142 - CONFIG_ENV_FLAGS_LIST_STATIC
3143 Enable validation of the values given to enviroment variables when
3144 calling env set. Variables can be restricted to only decimal,
3145 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3146 the variables can also be restricted to IP address or MAC address.
3148 The format of the list is:
3149 type_attribute = [s|d|x|b|i|m]
3150 access_atribute = [a|r|o|c]
3151 attributes = type_attribute[access_atribute]
3152 entry = variable_name[:attributes]
3155 The type attributes are:
3156 s - String (default)
3159 b - Boolean ([1yYtT|0nNfF])
3163 The access attributes are:
3169 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3170 Define this to a list (string) to define the ".flags"
3171 envirnoment variable in the default or embedded environment.
3173 - CONFIG_ENV_FLAGS_LIST_STATIC
3174 Define this to a list (string) to define validation that
3175 should be done if an entry is not found in the ".flags"
3176 environment variable. To override a setting in the static
3177 list, simply add an entry for the same variable name to the
3180 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3181 If defined, don't allow the -f switch to env set override variable
3184 The following definitions that deal with the placement and management
3185 of environment data (variable area); in general, we support the
3186 following configurations:
3188 - CONFIG_BUILD_ENVCRC:
3190 Builds up envcrc with the target environment so that external utils
3191 may easily extract it and embed it in final U-Boot images.
3193 - CONFIG_ENV_IS_IN_FLASH:
3195 Define this if the environment is in flash memory.
3197 a) The environment occupies one whole flash sector, which is
3198 "embedded" in the text segment with the U-Boot code. This
3199 happens usually with "bottom boot sector" or "top boot
3200 sector" type flash chips, which have several smaller
3201 sectors at the start or the end. For instance, such a
3202 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3203 such a case you would place the environment in one of the
3204 4 kB sectors - with U-Boot code before and after it. With
3205 "top boot sector" type flash chips, you would put the
3206 environment in one of the last sectors, leaving a gap
3207 between U-Boot and the environment.
3209 - CONFIG_ENV_OFFSET:
3211 Offset of environment data (variable area) to the
3212 beginning of flash memory; for instance, with bottom boot
3213 type flash chips the second sector can be used: the offset
3214 for this sector is given here.
3216 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3220 This is just another way to specify the start address of
3221 the flash sector containing the environment (instead of
3224 - CONFIG_ENV_SECT_SIZE:
3226 Size of the sector containing the environment.
3229 b) Sometimes flash chips have few, equal sized, BIG sectors.
3230 In such a case you don't want to spend a whole sector for
3235 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3236 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3237 of this flash sector for the environment. This saves
3238 memory for the RAM copy of the environment.
3240 It may also save flash memory if you decide to use this
3241 when your environment is "embedded" within U-Boot code,
3242 since then the remainder of the flash sector could be used
3243 for U-Boot code. It should be pointed out that this is
3244 STRONGLY DISCOURAGED from a robustness point of view:
3245 updating the environment in flash makes it always
3246 necessary to erase the WHOLE sector. If something goes
3247 wrong before the contents has been restored from a copy in
3248 RAM, your target system will be dead.
3250 - CONFIG_ENV_ADDR_REDUND
3251 CONFIG_ENV_SIZE_REDUND
3253 These settings describe a second storage area used to hold
3254 a redundant copy of the environment data, so that there is
3255 a valid backup copy in case there is a power failure during
3256 a "saveenv" operation.
3258 BE CAREFUL! Any changes to the flash layout, and some changes to the
3259 source code will make it necessary to adapt <board>/u-boot.lds*
3263 - CONFIG_ENV_IS_IN_NVRAM:
3265 Define this if you have some non-volatile memory device
3266 (NVRAM, battery buffered SRAM) which you want to use for the
3272 These two #defines are used to determine the memory area you
3273 want to use for environment. It is assumed that this memory
3274 can just be read and written to, without any special
3277 BE CAREFUL! The first access to the environment happens quite early
3278 in U-Boot initalization (when we try to get the setting of for the
3279 console baudrate). You *MUST* have mapped your NVRAM area then, or
3282 Please note that even with NVRAM we still use a copy of the
3283 environment in RAM: we could work on NVRAM directly, but we want to
3284 keep settings there always unmodified except somebody uses "saveenv"
3285 to save the current settings.
3288 - CONFIG_ENV_IS_IN_EEPROM:
3290 Use this if you have an EEPROM or similar serial access
3291 device and a driver for it.
3293 - CONFIG_ENV_OFFSET:
3296 These two #defines specify the offset and size of the
3297 environment area within the total memory of your EEPROM.
3299 - CONFIG_SYS_I2C_EEPROM_ADDR:
3300 If defined, specified the chip address of the EEPROM device.
3301 The default address is zero.
3303 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3304 If defined, the number of bits used to address bytes in a
3305 single page in the EEPROM device. A 64 byte page, for example
3306 would require six bits.
3308 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3309 If defined, the number of milliseconds to delay between
3310 page writes. The default is zero milliseconds.
3312 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3313 The length in bytes of the EEPROM memory array address. Note
3314 that this is NOT the chip address length!
3316 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3317 EEPROM chips that implement "address overflow" are ones
3318 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3319 address and the extra bits end up in the "chip address" bit
3320 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3323 Note that we consider the length of the address field to
3324 still be one byte because the extra address bits are hidden
3325 in the chip address.
3327 - CONFIG_SYS_EEPROM_SIZE:
3328 The size in bytes of the EEPROM device.
3330 - CONFIG_ENV_EEPROM_IS_ON_I2C
3331 define this, if you have I2C and SPI activated, and your
3332 EEPROM, which holds the environment, is on the I2C bus.
3334 - CONFIG_I2C_ENV_EEPROM_BUS
3335 if you have an Environment on an EEPROM reached over
3336 I2C muxes, you can define here, how to reach this
3337 EEPROM. For example:
3339 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
3341 EEPROM which holds the environment, is reached over
3342 a pca9547 i2c mux with address 0x70, channel 3.
3344 - CONFIG_ENV_IS_IN_DATAFLASH:
3346 Define this if you have a DataFlash memory device which you
3347 want to use for the environment.
3349 - CONFIG_ENV_OFFSET:
3353 These three #defines specify the offset and size of the
3354 environment area within the total memory of your DataFlash placed
3355 at the specified address.
3357 - CONFIG_ENV_IS_IN_REMOTE:
3359 Define this if you have a remote memory space which you
3360 want to use for the local device's environment.
3365 These two #defines specify the address and size of the
3366 environment area within the remote memory space. The
3367 local device can get the environment from remote memory
3368 space by SRIO or PCIE links.
3370 BE CAREFUL! For some special cases, the local device can not use
3371 "saveenv" command. For example, the local device will get the
3372 environment stored in a remote NOR flash by SRIO or PCIE link,
3373 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3375 - CONFIG_ENV_IS_IN_NAND:
3377 Define this if you have a NAND device which you want to use
3378 for the environment.
3380 - CONFIG_ENV_OFFSET:
3383 These two #defines specify the offset and size of the environment
3384 area within the first NAND device. CONFIG_ENV_OFFSET must be
3385 aligned to an erase block boundary.
3387 - CONFIG_ENV_OFFSET_REDUND (optional):
3389 This setting describes a second storage area of CONFIG_ENV_SIZE
3390 size used to hold a redundant copy of the environment data, so
3391 that there is a valid backup copy in case there is a power failure
3392 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3393 aligned to an erase block boundary.
3395 - CONFIG_ENV_RANGE (optional):
3397 Specifies the length of the region in which the environment
3398 can be written. This should be a multiple of the NAND device's
3399 block size. Specifying a range with more erase blocks than
3400 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3401 the range to be avoided.
3403 - CONFIG_ENV_OFFSET_OOB (optional):
3405 Enables support for dynamically retrieving the offset of the
3406 environment from block zero's out-of-band data. The
3407 "nand env.oob" command can be used to record this offset.
3408 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3409 using CONFIG_ENV_OFFSET_OOB.
3411 - CONFIG_NAND_ENV_DST
3413 Defines address in RAM to which the nand_spl code should copy the
3414 environment. If redundant environment is used, it will be copied to
3415 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3417 - CONFIG_SYS_SPI_INIT_OFFSET
3419 Defines offset to the initial SPI buffer area in DPRAM. The
3420 area is used at an early stage (ROM part) if the environment
3421 is configured to reside in the SPI EEPROM: We need a 520 byte
3422 scratch DPRAM area. It is used between the two initialization
3423 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3424 to be a good choice since it makes it far enough from the
3425 start of the data area as well as from the stack pointer.
3427 Please note that the environment is read-only until the monitor
3428 has been relocated to RAM and a RAM copy of the environment has been
3429 created; also, when using EEPROM you will have to use getenv_f()
3430 until then to read environment variables.
3432 The environment is protected by a CRC32 checksum. Before the monitor
3433 is relocated into RAM, as a result of a bad CRC you will be working
3434 with the compiled-in default environment - *silently*!!! [This is
3435 necessary, because the first environment variable we need is the
3436 "baudrate" setting for the console - if we have a bad CRC, we don't
3437 have any device yet where we could complain.]
3439 Note: once the monitor has been relocated, then it will complain if
3440 the default environment is used; a new CRC is computed as soon as you
3441 use the "saveenv" command to store a valid environment.
3443 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3444 Echo the inverted Ethernet link state to the fault LED.
3446 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3447 also needs to be defined.
3449 - CONFIG_SYS_FAULT_MII_ADDR:
3450 MII address of the PHY to check for the Ethernet link state.
3452 - CONFIG_NS16550_MIN_FUNCTIONS:
3453 Define this if you desire to only have use of the NS16550_init
3454 and NS16550_putc functions for the serial driver located at
3455 drivers/serial/ns16550.c. This option is useful for saving
3456 space for already greatly restricted images, including but not
3457 limited to NAND_SPL configurations.
3459 Low Level (hardware related) configuration options:
3460 ---------------------------------------------------
3462 - CONFIG_SYS_CACHELINE_SIZE:
3463 Cache Line Size of the CPU.
3465 - CONFIG_SYS_DEFAULT_IMMR:
3466 Default address of the IMMR after system reset.
3468 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3469 and RPXsuper) to be able to adjust the position of
3470 the IMMR register after a reset.
3472 - CONFIG_SYS_CCSRBAR_DEFAULT:
3473 Default (power-on reset) physical address of CCSR on Freescale
3476 - CONFIG_SYS_CCSRBAR:
3477 Virtual address of CCSR. On a 32-bit build, this is typically
3478 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3480 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3481 for cross-platform code that uses that macro instead.
3483 - CONFIG_SYS_CCSRBAR_PHYS:
3484 Physical address of CCSR. CCSR can be relocated to a new
3485 physical address, if desired. In this case, this macro should
3486 be set to that address. Otherwise, it should be set to the
3487 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3488 is typically relocated on 36-bit builds. It is recommended
3489 that this macro be defined via the _HIGH and _LOW macros:
3491 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3492 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3494 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3495 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3496 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3497 used in assembly code, so it must not contain typecasts or
3498 integer size suffixes (e.g. "ULL").
3500 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3501 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3502 used in assembly code, so it must not contain typecasts or
3503 integer size suffixes (e.g. "ULL").
3505 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3506 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3507 forced to a value that ensures that CCSR is not relocated.
3509 - Floppy Disk Support:
3510 CONFIG_SYS_FDC_DRIVE_NUMBER
3512 the default drive number (default value 0)
3514 CONFIG_SYS_ISA_IO_STRIDE
3516 defines the spacing between FDC chipset registers
3519 CONFIG_SYS_ISA_IO_OFFSET
3521 defines the offset of register from address. It
3522 depends on which part of the data bus is connected to
3523 the FDC chipset. (default value 0)
3525 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3526 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3529 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3530 fdc_hw_init() is called at the beginning of the FDC
3531 setup. fdc_hw_init() must be provided by the board
3532 source code. It is used to make hardware dependant
3536 Most IDE controllers were designed to be connected with PCI
3537 interface. Only few of them were designed for AHB interface.
3538 When software is doing ATA command and data transfer to
3539 IDE devices through IDE-AHB controller, some additional
3540 registers accessing to these kind of IDE-AHB controller
3543 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3544 DO NOT CHANGE unless you know exactly what you're
3545 doing! (11-4) [MPC8xx/82xx systems only]
3547 - CONFIG_SYS_INIT_RAM_ADDR:
3549 Start address of memory area that can be used for
3550 initial data and stack; please note that this must be
3551 writable memory that is working WITHOUT special
3552 initialization, i. e. you CANNOT use normal RAM which
3553 will become available only after programming the
3554 memory controller and running certain initialization
3557 U-Boot uses the following memory types:
3558 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
3559 - MPC824X: data cache
3560 - PPC4xx: data cache
3562 - CONFIG_SYS_GBL_DATA_OFFSET:
3564 Offset of the initial data structure in the memory
3565 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3566 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3567 data is located at the end of the available space
3568 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3569 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
3570 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3571 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3574 On the MPC824X (or other systems that use the data
3575 cache for initial memory) the address chosen for
3576 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3577 point to an otherwise UNUSED address space between
3578 the top of RAM and the start of the PCI space.
3580 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
3582 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
3584 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
3586 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
3588 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
3590 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3592 - CONFIG_SYS_OR_TIMING_SDRAM:
3595 - CONFIG_SYS_MAMR_PTA:
3596 periodic timer for refresh
3598 - CONFIG_SYS_DER: Debug Event Register (37-47)
3600 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3601 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3602 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3603 CONFIG_SYS_BR1_PRELIM:
3604 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3606 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3607 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3608 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3609 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3611 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
3612 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
3613 Machine Mode Register and Memory Periodic Timer
3614 Prescaler definitions (SDRAM timing)
3616 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
3617 enable I2C microcode relocation patch (MPC8xx);
3618 define relocation offset in DPRAM [DSP2]
3620 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
3621 enable SMC microcode relocation patch (MPC8xx);
3622 define relocation offset in DPRAM [SMC1]
3624 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
3625 enable SPI microcode relocation patch (MPC8xx);
3626 define relocation offset in DPRAM [SCC4]
3628 - CONFIG_SYS_USE_OSCCLK:
3629 Use OSCM clock mode on MBX8xx board. Be careful,
3630 wrong setting might damage your board. Read
3631 doc/README.MBX before setting this variable!
3633 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
3634 Offset of the bootmode word in DPRAM used by post
3635 (Power On Self Tests). This definition overrides
3636 #define'd default value in commproc.h resp.
3639 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
3640 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
3641 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
3642 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
3643 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
3644 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
3645 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
3646 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
3647 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
3649 - CONFIG_PCI_DISABLE_PCIE:
3650 Disable PCI-Express on systems where it is supported but not
3653 - CONFIG_PCI_ENUM_ONLY
3654 Only scan through and get the devices on the busses.
3655 Don't do any setup work, presumably because someone or
3656 something has already done it, and we don't need to do it
3657 a second time. Useful for platforms that are pre-booted
3658 by coreboot or similar.
3661 Chip has SRIO or not
3664 Board has SRIO 1 port available
3667 Board has SRIO 2 port available
3669 - CONFIG_SYS_SRIOn_MEM_VIRT:
3670 Virtual Address of SRIO port 'n' memory region
3672 - CONFIG_SYS_SRIOn_MEM_PHYS:
3673 Physical Address of SRIO port 'n' memory region
3675 - CONFIG_SYS_SRIOn_MEM_SIZE:
3676 Size of SRIO port 'n' memory region
3678 - CONFIG_SYS_NDFC_16
3679 Defined to tell the NDFC that the NAND chip is using a
3682 - CONFIG_SYS_NDFC_EBC0_CFG
3683 Sets the EBC0_CFG register for the NDFC. If not defined
3684 a default value will be used.
3687 Get DDR timing information from an I2C EEPROM. Common
3688 with pluggable memory modules such as SODIMMs
3691 I2C address of the SPD EEPROM
3693 - CONFIG_SYS_SPD_BUS_NUM
3694 If SPD EEPROM is on an I2C bus other than the first
3695 one, specify here. Note that the value must resolve
3696 to something your driver can deal with.
3698 - CONFIG_SYS_DDR_RAW_TIMING
3699 Get DDR timing information from other than SPD. Common with
3700 soldered DDR chips onboard without SPD. DDR raw timing
3701 parameters are extracted from datasheet and hard-coded into
3702 header files or board specific files.
3704 - CONFIG_FSL_DDR_INTERACTIVE
3705 Enable interactive DDR debugging. See doc/README.fsl-ddr.
3707 - CONFIG_SYS_83XX_DDR_USES_CS0
3708 Only for 83xx systems. If specified, then DDR should
3709 be configured using CS0 and CS1 instead of CS2 and CS3.
3711 - CONFIG_ETHER_ON_FEC[12]
3712 Define to enable FEC[12] on a 8xx series processor.
3714 - CONFIG_FEC[12]_PHY
3715 Define to the hardcoded PHY address which corresponds
3716 to the given FEC; i. e.
3717 #define CONFIG_FEC1_PHY 4
3718 means that the PHY with address 4 is connected to FEC1
3720 When set to -1, means to probe for first available.
3722 - CONFIG_FEC[12]_PHY_NORXERR
3723 The PHY does not have a RXERR line (RMII only).
3724 (so program the FEC to ignore it).
3727 Enable RMII mode for all FECs.
3728 Note that this is a global option, we can't
3729 have one FEC in standard MII mode and another in RMII mode.
3731 - CONFIG_CRC32_VERIFY
3732 Add a verify option to the crc32 command.
3735 => crc32 -v <address> <count> <crc32>
3737 Where address/count indicate a memory area
3738 and crc32 is the correct crc32 which the
3742 Add the "loopw" memory command. This only takes effect if
3743 the memory commands are activated globally (CONFIG_CMD_MEM).
3746 Add the "mdc" and "mwc" memory commands. These are cyclic
3751 This command will print 4 bytes (10,11,12,13) each 500 ms.
3753 => mwc.l 100 12345678 10
3754 This command will write 12345678 to address 100 all 10 ms.
3756 This only takes effect if the memory commands are activated
3757 globally (CONFIG_CMD_MEM).
3759 - CONFIG_SKIP_LOWLEVEL_INIT
3760 [ARM, NDS32, MIPS only] If this variable is defined, then certain
3761 low level initializations (like setting up the memory
3762 controller) are omitted and/or U-Boot does not
3763 relocate itself into RAM.
3765 Normally this variable MUST NOT be defined. The only
3766 exception is when U-Boot is loaded (to RAM) by some
3767 other boot loader or by a debugger which performs
3768 these initializations itself.
3771 Modifies the behaviour of start.S when compiling a loader
3772 that is executed before the actual U-Boot. E.g. when
3773 compiling a NAND SPL.
3775 - CONFIG_USE_ARCH_MEMCPY
3776 CONFIG_USE_ARCH_MEMSET
3777 If these options are used a optimized version of memcpy/memset will
3778 be used if available. These functions may be faster under some
3779 conditions but may increase the binary size.
3781 - CONFIG_X86_NO_RESET_VECTOR
3782 If defined, the x86 reset vector code is excluded. You will need
3783 to do this when U-Boot is running from Coreboot.
3785 - CONFIG_X86_NO_REAL_MODE
3786 If defined, x86 real mode code is omitted. This assumes a
3787 32-bit environment where such code is not needed. You will
3788 need to do this when U-Boot is running from Coreboot.
3791 Freescale QE/FMAN Firmware Support:
3792 -----------------------------------
3794 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
3795 loading of "firmware", which is encoded in the QE firmware binary format.
3796 This firmware often needs to be loaded during U-Boot booting, so macros
3797 are used to identify the storage device (NOR flash, SPI, etc) and the address
3800 - CONFIG_SYS_QE_FMAN_FW_ADDR
3801 The address in the storage device where the firmware is located. The
3802 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3805 - CONFIG_SYS_QE_FMAN_FW_LENGTH
3806 The maximum possible size of the firmware. The firmware binary format
3807 has a field that specifies the actual size of the firmware, but it
3808 might not be possible to read any part of the firmware unless some
3809 local storage is allocated to hold the entire firmware first.
3811 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
3812 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
3813 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
3814 virtual address in NOR flash.
3816 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
3817 Specifies that QE/FMAN firmware is located in NAND flash.
3818 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
3820 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
3821 Specifies that QE/FMAN firmware is located on the primary SD/MMC
3822 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3824 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
3825 Specifies that QE/FMAN firmware is located on the primary SPI
3826 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3828 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
3829 Specifies that QE/FMAN firmware is located in the remote (master)
3830 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
3831 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
3832 window->master inbound window->master LAW->the ucode address in
3833 master's memory space.
3835 Building the Software:
3836 ======================
3838 Building U-Boot has been tested in several native build environments
3839 and in many different cross environments. Of course we cannot support
3840 all possibly existing versions of cross development tools in all
3841 (potentially obsolete) versions. In case of tool chain problems we
3842 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3843 which is extensively used to build and test U-Boot.
3845 If you are not using a native environment, it is assumed that you
3846 have GNU cross compiling tools available in your path. In this case,
3847 you must set the environment variable CROSS_COMPILE in your shell.
3848 Note that no changes to the Makefile or any other source files are
3849 necessary. For example using the ELDK on a 4xx CPU, please enter:
3851 $ CROSS_COMPILE=ppc_4xx-
3852 $ export CROSS_COMPILE
3854 Note: If you wish to generate Windows versions of the utilities in
3855 the tools directory you can use the MinGW toolchain
3856 (http://www.mingw.org). Set your HOST tools to the MinGW
3857 toolchain and execute 'make tools'. For example:
3859 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3861 Binaries such as tools/mkimage.exe will be created which can
3862 be executed on computers running Windows.
3864 U-Boot is intended to be simple to build. After installing the
3865 sources you must configure U-Boot for one specific board type. This
3870 where "NAME_config" is the name of one of the existing configu-
3871 rations; see boards.cfg for supported names.
3873 Note: for some board special configuration names may exist; check if
3874 additional information is available from the board vendor; for
3875 instance, the TQM823L systems are available without (standard)
3876 or with LCD support. You can select such additional "features"
3877 when choosing the configuration, i. e.
3880 - will configure for a plain TQM823L, i. e. no LCD support
3882 make TQM823L_LCD_config
3883 - will configure for a TQM823L with U-Boot console on LCD
3888 Finally, type "make all", and you should get some working U-Boot
3889 images ready for download to / installation on your system:
3891 - "u-boot.bin" is a raw binary image
3892 - "u-boot" is an image in ELF binary format
3893 - "u-boot.srec" is in Motorola S-Record format
3895 By default the build is performed locally and the objects are saved
3896 in the source directory. One of the two methods can be used to change
3897 this behavior and build U-Boot to some external directory:
3899 1. Add O= to the make command line invocations:
3901 make O=/tmp/build distclean
3902 make O=/tmp/build NAME_config
3903 make O=/tmp/build all
3905 2. Set environment variable BUILD_DIR to point to the desired location:
3907 export BUILD_DIR=/tmp/build
3912 Note that the command line "O=" setting overrides the BUILD_DIR environment
3916 Please be aware that the Makefiles assume you are using GNU make, so
3917 for instance on NetBSD you might need to use "gmake" instead of
3921 If the system board that you have is not listed, then you will need
3922 to port U-Boot to your hardware platform. To do this, follow these
3925 1. Add a new configuration option for your board to the toplevel
3926 "boards.cfg" file, using the existing entries as examples.
3927 Follow the instructions there to keep the boards in order.
3928 2. Create a new directory to hold your board specific code. Add any
3929 files you need. In your board directory, you will need at least
3930 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
3931 3. Create a new configuration file "include/configs/<board>.h" for
3933 3. If you're porting U-Boot to a new CPU, then also create a new
3934 directory to hold your CPU specific code. Add any files you need.
3935 4. Run "make <board>_config" with your new name.
3936 5. Type "make", and you should get a working "u-boot.srec" file
3937 to be installed on your target system.
3938 6. Debug and solve any problems that might arise.
3939 [Of course, this last step is much harder than it sounds.]
3942 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3943 ==============================================================
3945 If you have modified U-Boot sources (for instance added a new board
3946 or support for new devices, a new CPU, etc.) you are expected to
3947 provide feedback to the other developers. The feedback normally takes
3948 the form of a "patch", i. e. a context diff against a certain (latest
3949 official or latest in the git repository) version of U-Boot sources.
3951 But before you submit such a patch, please verify that your modifi-
3952 cation did not break existing code. At least make sure that *ALL* of
3953 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3954 just run the "MAKEALL" script, which will configure and build U-Boot
3955 for ALL supported system. Be warned, this will take a while. You can
3956 select which (cross) compiler to use by passing a `CROSS_COMPILE'
3957 environment variable to the script, i. e. to use the ELDK cross tools
3960 CROSS_COMPILE=ppc_8xx- MAKEALL
3962 or to build on a native PowerPC system you can type
3964 CROSS_COMPILE=' ' MAKEALL
3966 When using the MAKEALL script, the default behaviour is to build
3967 U-Boot in the source directory. This location can be changed by
3968 setting the BUILD_DIR environment variable. Also, for each target
3969 built, the MAKEALL script saves two log files (<target>.ERR and
3970 <target>.MAKEALL) in the <source dir>/LOG directory. This default
3971 location can be changed by setting the MAKEALL_LOGDIR environment
3972 variable. For example:
3974 export BUILD_DIR=/tmp/build
3975 export MAKEALL_LOGDIR=/tmp/log
3976 CROSS_COMPILE=ppc_8xx- MAKEALL
3978 With the above settings build objects are saved in the /tmp/build,
3979 log files are saved in the /tmp/log and the source tree remains clean
3980 during the whole build process.
3983 See also "U-Boot Porting Guide" below.
3986 Monitor Commands - Overview:
3987 ============================
3989 go - start application at address 'addr'
3990 run - run commands in an environment variable
3991 bootm - boot application image from memory
3992 bootp - boot image via network using BootP/TFTP protocol
3993 bootz - boot zImage from memory
3994 tftpboot- boot image via network using TFTP protocol
3995 and env variables "ipaddr" and "serverip"
3996 (and eventually "gatewayip")
3997 tftpput - upload a file via network using TFTP protocol
3998 rarpboot- boot image via network using RARP/TFTP protocol
3999 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4000 loads - load S-Record file over serial line
4001 loadb - load binary file over serial line (kermit mode)
4003 mm - memory modify (auto-incrementing)
4004 nm - memory modify (constant address)
4005 mw - memory write (fill)
4007 cmp - memory compare
4008 crc32 - checksum calculation
4009 i2c - I2C sub-system
4010 sspi - SPI utility commands
4011 base - print or set address offset
4012 printenv- print environment variables
4013 setenv - set environment variables
4014 saveenv - save environment variables to persistent storage
4015 protect - enable or disable FLASH write protection
4016 erase - erase FLASH memory
4017 flinfo - print FLASH memory information
4018 nand - NAND memory operations (see doc/README.nand)
4019 bdinfo - print Board Info structure
4020 iminfo - print header information for application image
4021 coninfo - print console devices and informations
4022 ide - IDE sub-system
4023 loop - infinite loop on address range
4024 loopw - infinite write loop on address range
4025 mtest - simple RAM test
4026 icache - enable or disable instruction cache
4027 dcache - enable or disable data cache
4028 reset - Perform RESET of the CPU
4029 echo - echo args to console
4030 version - print monitor version
4031 help - print online help
4032 ? - alias for 'help'
4035 Monitor Commands - Detailed Description:
4036 ========================================
4040 For now: just type "help <command>".
4043 Environment Variables:
4044 ======================
4046 U-Boot supports user configuration using Environment Variables which
4047 can be made persistent by saving to Flash memory.
4049 Environment Variables are set using "setenv", printed using
4050 "printenv", and saved to Flash using "saveenv". Using "setenv"
4051 without a value can be used to delete a variable from the
4052 environment. As long as you don't save the environment you are
4053 working with an in-memory copy. In case the Flash area containing the
4054 environment is erased by accident, a default environment is provided.
4056 Some configuration options can be set using Environment Variables.
4058 List of environment variables (most likely not complete):
4060 baudrate - see CONFIG_BAUDRATE
4062 bootdelay - see CONFIG_BOOTDELAY
4064 bootcmd - see CONFIG_BOOTCOMMAND
4066 bootargs - Boot arguments when booting an RTOS image
4068 bootfile - Name of the image to load with TFTP
4070 bootm_low - Memory range available for image processing in the bootm
4071 command can be restricted. This variable is given as
4072 a hexadecimal number and defines lowest address allowed
4073 for use by the bootm command. See also "bootm_size"
4074 environment variable. Address defined by "bootm_low" is
4075 also the base of the initial memory mapping for the Linux
4076 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4079 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4080 This variable is given as a hexadecimal number and it
4081 defines the size of the memory region starting at base
4082 address bootm_low that is accessible by the Linux kernel
4083 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4084 as the default value if it is defined, and bootm_size is
4087 bootm_size - Memory range available for image processing in the bootm
4088 command can be restricted. This variable is given as
4089 a hexadecimal number and defines the size of the region
4090 allowed for use by the bootm command. See also "bootm_low"
4091 environment variable.
4093 updatefile - Location of the software update file on a TFTP server, used
4094 by the automatic software update feature. Please refer to
4095 documentation in doc/README.update for more details.
4097 autoload - if set to "no" (any string beginning with 'n'),
4098 "bootp" will just load perform a lookup of the
4099 configuration from the BOOTP server, but not try to
4100 load any image using TFTP
4102 autostart - if set to "yes", an image loaded using the "bootp",
4103 "rarpboot", "tftpboot" or "diskboot" commands will
4104 be automatically started (by internally calling
4107 If set to "no", a standalone image passed to the
4108 "bootm" command will be copied to the load address
4109 (and eventually uncompressed), but NOT be started.
4110 This can be used to load and uncompress arbitrary
4113 fdt_high - if set this restricts the maximum address that the
4114 flattened device tree will be copied into upon boot.
4115 For example, if you have a system with 1 GB memory
4116 at physical address 0x10000000, while Linux kernel
4117 only recognizes the first 704 MB as low memory, you
4118 may need to set fdt_high as 0x3C000000 to have the
4119 device tree blob be copied to the maximum address
4120 of the 704 MB low memory, so that Linux kernel can
4121 access it during the boot procedure.
4123 If this is set to the special value 0xFFFFFFFF then
4124 the fdt will not be copied at all on boot. For this
4125 to work it must reside in writable memory, have
4126 sufficient padding on the end of it for u-boot to
4127 add the information it needs into it, and the memory
4128 must be accessible by the kernel.
4130 fdtcontroladdr- if set this is the address of the control flattened
4131 device tree used by U-Boot when CONFIG_OF_CONTROL is
4134 i2cfast - (PPC405GP|PPC405EP only)
4135 if set to 'y' configures Linux I2C driver for fast
4136 mode (400kHZ). This environment variable is used in
4137 initialization code. So, for changes to be effective
4138 it must be saved and board must be reset.
4140 initrd_high - restrict positioning of initrd images:
4141 If this variable is not set, initrd images will be
4142 copied to the highest possible address in RAM; this
4143 is usually what you want since it allows for
4144 maximum initrd size. If for some reason you want to
4145 make sure that the initrd image is loaded below the
4146 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4147 variable to a value of "no" or "off" or "0".
4148 Alternatively, you can set it to a maximum upper
4149 address to use (U-Boot will still check that it
4150 does not overwrite the U-Boot stack and data).
4152 For instance, when you have a system with 16 MB
4153 RAM, and want to reserve 4 MB from use by Linux,
4154 you can do this by adding "mem=12M" to the value of
4155 the "bootargs" variable. However, now you must make
4156 sure that the initrd image is placed in the first
4157 12 MB as well - this can be done with
4159 setenv initrd_high 00c00000
4161 If you set initrd_high to 0xFFFFFFFF, this is an
4162 indication to U-Boot that all addresses are legal
4163 for the Linux kernel, including addresses in flash
4164 memory. In this case U-Boot will NOT COPY the
4165 ramdisk at all. This may be useful to reduce the
4166 boot time on your system, but requires that this
4167 feature is supported by your Linux kernel.
4169 ipaddr - IP address; needed for tftpboot command
4171 loadaddr - Default load address for commands like "bootp",
4172 "rarpboot", "tftpboot", "loadb" or "diskboot"
4174 loads_echo - see CONFIG_LOADS_ECHO
4176 serverip - TFTP server IP address; needed for tftpboot command
4178 bootretry - see CONFIG_BOOT_RETRY_TIME
4180 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4182 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4184 ethprime - controls which interface is used first.
4186 ethact - controls which interface is currently active.
4187 For example you can do the following
4189 => setenv ethact FEC
4190 => ping 192.168.0.1 # traffic sent on FEC
4191 => setenv ethact SCC
4192 => ping 10.0.0.1 # traffic sent on SCC
4194 ethrotate - When set to "no" U-Boot does not go through all
4195 available network interfaces.
4196 It just stays at the currently selected interface.
4198 netretry - When set to "no" each network operation will
4199 either succeed or fail without retrying.
4200 When set to "once" the network operation will
4201 fail when all the available network interfaces
4202 are tried once without success.
4203 Useful on scripts which control the retry operation
4206 npe_ucode - set load address for the NPE microcode
4208 tftpsrcport - If this is set, the value is used for TFTP's
4211 tftpdstport - If this is set, the value is used for TFTP's UDP
4212 destination port instead of the Well Know Port 69.
4214 tftpblocksize - Block size to use for TFTP transfers; if not set,
4215 we use the TFTP server's default block size
4217 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4218 seconds, minimum value is 1000 = 1 second). Defines
4219 when a packet is considered to be lost so it has to
4220 be retransmitted. The default is 5000 = 5 seconds.
4221 Lowering this value may make downloads succeed
4222 faster in networks with high packet loss rates or
4223 with unreliable TFTP servers.
4225 vlan - When set to a value < 4095 the traffic over
4226 Ethernet is encapsulated/received over 802.1q
4229 The following image location variables contain the location of images
4230 used in booting. The "Image" column gives the role of the image and is
4231 not an environment variable name. The other columns are environment
4232 variable names. "File Name" gives the name of the file on a TFTP
4233 server, "RAM Address" gives the location in RAM the image will be
4234 loaded to, and "Flash Location" gives the image's address in NOR
4235 flash or offset in NAND flash.
4237 *Note* - these variables don't have to be defined for all boards, some
4238 boards currenlty use other variables for these purposes, and some
4239 boards use these variables for other purposes.
4241 Image File Name RAM Address Flash Location
4242 ----- --------- ----------- --------------
4243 u-boot u-boot u-boot_addr_r u-boot_addr
4244 Linux kernel bootfile kernel_addr_r kernel_addr
4245 device tree blob fdtfile fdt_addr_r fdt_addr
4246 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4248 The following environment variables may be used and automatically
4249 updated by the network boot commands ("bootp" and "rarpboot"),
4250 depending the information provided by your boot server:
4252 bootfile - see above
4253 dnsip - IP address of your Domain Name Server
4254 dnsip2 - IP address of your secondary Domain Name Server
4255 gatewayip - IP address of the Gateway (Router) to use
4256 hostname - Target hostname
4258 netmask - Subnet Mask
4259 rootpath - Pathname of the root filesystem on the NFS server
4260 serverip - see above
4263 There are two special Environment Variables:
4265 serial# - contains hardware identification information such
4266 as type string and/or serial number
4267 ethaddr - Ethernet address
4269 These variables can be set only once (usually during manufacturing of
4270 the board). U-Boot refuses to delete or overwrite these variables
4271 once they have been set once.
4274 Further special Environment Variables:
4276 ver - Contains the U-Boot version string as printed
4277 with the "version" command. This variable is
4278 readonly (see CONFIG_VERSION_VARIABLE).
4281 Please note that changes to some configuration parameters may take
4282 only effect after the next boot (yes, that's just like Windoze :-).
4285 Callback functions for environment variables:
4286 ---------------------------------------------
4288 For some environment variables, the behavior of u-boot needs to change
4289 when their values are changed. This functionailty allows functions to
4290 be associated with arbitrary variables. On creation, overwrite, or
4291 deletion, the callback will provide the opportunity for some side
4292 effect to happen or for the change to be rejected.
4294 The callbacks are named and associated with a function using the
4295 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4297 These callbacks are associated with variables in one of two ways. The
4298 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4299 in the board configuration to a string that defines a list of
4300 associations. The list must be in the following format:
4302 entry = variable_name[:callback_name]
4305 If the callback name is not specified, then the callback is deleted.
4306 Spaces are also allowed anywhere in the list.
4308 Callbacks can also be associated by defining the ".callbacks" variable
4309 with the same list format above. Any association in ".callbacks" will
4310 override any association in the static list. You can define
4311 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4312 ".callbacks" envirnoment variable in the default or embedded environment.
4315 Command Line Parsing:
4316 =====================
4318 There are two different command line parsers available with U-Boot:
4319 the old "simple" one, and the much more powerful "hush" shell:
4321 Old, simple command line parser:
4322 --------------------------------
4324 - supports environment variables (through setenv / saveenv commands)
4325 - several commands on one line, separated by ';'
4326 - variable substitution using "... ${name} ..." syntax
4327 - special characters ('$', ';') can be escaped by prefixing with '\',
4329 setenv bootcmd bootm \${address}
4330 - You can also escape text by enclosing in single apostrophes, for example:
4331 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4336 - similar to Bourne shell, with control structures like
4337 if...then...else...fi, for...do...done; while...do...done,
4338 until...do...done, ...
4339 - supports environment ("global") variables (through setenv / saveenv
4340 commands) and local shell variables (through standard shell syntax
4341 "name=value"); only environment variables can be used with "run"
4347 (1) If a command line (or an environment variable executed by a "run"
4348 command) contains several commands separated by semicolon, and
4349 one of these commands fails, then the remaining commands will be
4352 (2) If you execute several variables with one call to run (i. e.
4353 calling run with a list of variables as arguments), any failing
4354 command will cause "run" to terminate, i. e. the remaining
4355 variables are not executed.
4357 Note for Redundant Ethernet Interfaces:
4358 =======================================
4360 Some boards come with redundant Ethernet interfaces; U-Boot supports
4361 such configurations and is capable of automatic selection of a
4362 "working" interface when needed. MAC assignment works as follows:
4364 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4365 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4366 "eth1addr" (=>eth1), "eth2addr", ...
4368 If the network interface stores some valid MAC address (for instance
4369 in SROM), this is used as default address if there is NO correspon-
4370 ding setting in the environment; if the corresponding environment
4371 variable is set, this overrides the settings in the card; that means:
4373 o If the SROM has a valid MAC address, and there is no address in the
4374 environment, the SROM's address is used.
4376 o If there is no valid address in the SROM, and a definition in the
4377 environment exists, then the value from the environment variable is
4380 o If both the SROM and the environment contain a MAC address, and
4381 both addresses are the same, this MAC address is used.
4383 o If both the SROM and the environment contain a MAC address, and the
4384 addresses differ, the value from the environment is used and a
4387 o If neither SROM nor the environment contain a MAC address, an error
4390 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4391 will be programmed into hardware as part of the initialization process. This
4392 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4393 The naming convention is as follows:
4394 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4399 U-Boot is capable of booting (and performing other auxiliary operations on)
4400 images in two formats:
4402 New uImage format (FIT)
4403 -----------------------
4405 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4406 to Flattened Device Tree). It allows the use of images with multiple
4407 components (several kernels, ramdisks, etc.), with contents protected by
4408 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4414 Old image format is based on binary files which can be basically anything,
4415 preceded by a special header; see the definitions in include/image.h for
4416 details; basically, the header defines the following image properties:
4418 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4419 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4420 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4421 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4423 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4424 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4425 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4426 * Compression Type (uncompressed, gzip, bzip2)
4432 The header is marked by a special Magic Number, and both the header
4433 and the data portions of the image are secured against corruption by
4440 Although U-Boot should support any OS or standalone application
4441 easily, the main focus has always been on Linux during the design of
4444 U-Boot includes many features that so far have been part of some
4445 special "boot loader" code within the Linux kernel. Also, any
4446 "initrd" images to be used are no longer part of one big Linux image;
4447 instead, kernel and "initrd" are separate images. This implementation
4448 serves several purposes:
4450 - the same features can be used for other OS or standalone
4451 applications (for instance: using compressed images to reduce the
4452 Flash memory footprint)
4454 - it becomes much easier to port new Linux kernel versions because
4455 lots of low-level, hardware dependent stuff are done by U-Boot
4457 - the same Linux kernel image can now be used with different "initrd"
4458 images; of course this also means that different kernel images can
4459 be run with the same "initrd". This makes testing easier (you don't
4460 have to build a new "zImage.initrd" Linux image when you just
4461 change a file in your "initrd"). Also, a field-upgrade of the
4462 software is easier now.
4468 Porting Linux to U-Boot based systems:
4469 ---------------------------------------
4471 U-Boot cannot save you from doing all the necessary modifications to
4472 configure the Linux device drivers for use with your target hardware
4473 (no, we don't intend to provide a full virtual machine interface to
4476 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4478 Just make sure your machine specific header file (for instance
4479 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4480 Information structure as we define in include/asm-<arch>/u-boot.h,
4481 and make sure that your definition of IMAP_ADDR uses the same value
4482 as your U-Boot configuration in CONFIG_SYS_IMMR.
4485 Configuring the Linux kernel:
4486 -----------------------------
4488 No specific requirements for U-Boot. Make sure you have some root
4489 device (initial ramdisk, NFS) for your target system.
4492 Building a Linux Image:
4493 -----------------------
4495 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4496 not used. If you use recent kernel source, a new build target
4497 "uImage" will exist which automatically builds an image usable by
4498 U-Boot. Most older kernels also have support for a "pImage" target,
4499 which was introduced for our predecessor project PPCBoot and uses a
4500 100% compatible format.
4509 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4510 encapsulate a compressed Linux kernel image with header information,
4511 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4513 * build a standard "vmlinux" kernel image (in ELF binary format):
4515 * convert the kernel into a raw binary image:
4517 ${CROSS_COMPILE}-objcopy -O binary \
4518 -R .note -R .comment \
4519 -S vmlinux linux.bin
4521 * compress the binary image:
4525 * package compressed binary image for U-Boot:
4527 mkimage -A ppc -O linux -T kernel -C gzip \
4528 -a 0 -e 0 -n "Linux Kernel Image" \
4529 -d linux.bin.gz uImage
4532 The "mkimage" tool can also be used to create ramdisk images for use
4533 with U-Boot, either separated from the Linux kernel image, or
4534 combined into one file. "mkimage" encapsulates the images with a 64
4535 byte header containing information about target architecture,
4536 operating system, image type, compression method, entry points, time
4537 stamp, CRC32 checksums, etc.
4539 "mkimage" can be called in two ways: to verify existing images and
4540 print the header information, or to build new images.
4542 In the first form (with "-l" option) mkimage lists the information
4543 contained in the header of an existing U-Boot image; this includes
4544 checksum verification:
4546 tools/mkimage -l image
4547 -l ==> list image header information
4549 The second form (with "-d" option) is used to build a U-Boot image
4550 from a "data file" which is used as image payload:
4552 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4553 -n name -d data_file image
4554 -A ==> set architecture to 'arch'
4555 -O ==> set operating system to 'os'
4556 -T ==> set image type to 'type'
4557 -C ==> set compression type 'comp'
4558 -a ==> set load address to 'addr' (hex)
4559 -e ==> set entry point to 'ep' (hex)
4560 -n ==> set image name to 'name'
4561 -d ==> use image data from 'datafile'
4563 Right now, all Linux kernels for PowerPC systems use the same load
4564 address (0x00000000), but the entry point address depends on the
4567 - 2.2.x kernels have the entry point at 0x0000000C,
4568 - 2.3.x and later kernels have the entry point at 0x00000000.
4570 So a typical call to build a U-Boot image would read:
4572 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4573 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4574 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4575 > examples/uImage.TQM850L
4576 Image Name: 2.4.4 kernel for TQM850L
4577 Created: Wed Jul 19 02:34:59 2000
4578 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4579 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4580 Load Address: 0x00000000
4581 Entry Point: 0x00000000
4583 To verify the contents of the image (or check for corruption):
4585 -> tools/mkimage -l examples/uImage.TQM850L
4586 Image Name: 2.4.4 kernel for TQM850L
4587 Created: Wed Jul 19 02:34:59 2000
4588 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4589 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4590 Load Address: 0x00000000
4591 Entry Point: 0x00000000
4593 NOTE: for embedded systems where boot time is critical you can trade
4594 speed for memory and install an UNCOMPRESSED image instead: this
4595 needs more space in Flash, but boots much faster since it does not
4596 need to be uncompressed:
4598 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4599 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4600 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4601 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4602 > examples/uImage.TQM850L-uncompressed
4603 Image Name: 2.4.4 kernel for TQM850L
4604 Created: Wed Jul 19 02:34:59 2000
4605 Image Type: PowerPC Linux Kernel Image (uncompressed)
4606 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4607 Load Address: 0x00000000
4608 Entry Point: 0x00000000
4611 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4612 when your kernel is intended to use an initial ramdisk:
4614 -> tools/mkimage -n 'Simple Ramdisk Image' \
4615 > -A ppc -O linux -T ramdisk -C gzip \
4616 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4617 Image Name: Simple Ramdisk Image
4618 Created: Wed Jan 12 14:01:50 2000
4619 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4620 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4621 Load Address: 0x00000000
4622 Entry Point: 0x00000000
4625 Installing a Linux Image:
4626 -------------------------
4628 To downloading a U-Boot image over the serial (console) interface,
4629 you must convert the image to S-Record format:
4631 objcopy -I binary -O srec examples/image examples/image.srec
4633 The 'objcopy' does not understand the information in the U-Boot
4634 image header, so the resulting S-Record file will be relative to
4635 address 0x00000000. To load it to a given address, you need to
4636 specify the target address as 'offset' parameter with the 'loads'
4639 Example: install the image to address 0x40100000 (which on the
4640 TQM8xxL is in the first Flash bank):
4642 => erase 40100000 401FFFFF
4648 ## Ready for S-Record download ...
4649 ~>examples/image.srec
4650 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4652 15989 15990 15991 15992
4653 [file transfer complete]
4655 ## Start Addr = 0x00000000
4658 You can check the success of the download using the 'iminfo' command;
4659 this includes a checksum verification so you can be sure no data
4660 corruption happened:
4664 ## Checking Image at 40100000 ...
4665 Image Name: 2.2.13 for initrd on TQM850L
4666 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4667 Data Size: 335725 Bytes = 327 kB = 0 MB
4668 Load Address: 00000000
4669 Entry Point: 0000000c
4670 Verifying Checksum ... OK
4676 The "bootm" command is used to boot an application that is stored in
4677 memory (RAM or Flash). In case of a Linux kernel image, the contents
4678 of the "bootargs" environment variable is passed to the kernel as
4679 parameters. You can check and modify this variable using the
4680 "printenv" and "setenv" commands:
4683 => printenv bootargs
4684 bootargs=root=/dev/ram
4686 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4688 => printenv bootargs
4689 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4692 ## Booting Linux kernel at 40020000 ...
4693 Image Name: 2.2.13 for NFS on TQM850L
4694 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4695 Data Size: 381681 Bytes = 372 kB = 0 MB
4696 Load Address: 00000000
4697 Entry Point: 0000000c
4698 Verifying Checksum ... OK
4699 Uncompressing Kernel Image ... OK
4700 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
4701 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4702 time_init: decrementer frequency = 187500000/60
4703 Calibrating delay loop... 49.77 BogoMIPS
4704 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
4707 If you want to boot a Linux kernel with initial RAM disk, you pass
4708 the memory addresses of both the kernel and the initrd image (PPBCOOT
4709 format!) to the "bootm" command:
4711 => imi 40100000 40200000
4713 ## Checking Image at 40100000 ...
4714 Image Name: 2.2.13 for initrd on TQM850L
4715 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4716 Data Size: 335725 Bytes = 327 kB = 0 MB
4717 Load Address: 00000000
4718 Entry Point: 0000000c
4719 Verifying Checksum ... OK
4721 ## Checking Image at 40200000 ...
4722 Image Name: Simple Ramdisk Image
4723 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4724 Data Size: 566530 Bytes = 553 kB = 0 MB
4725 Load Address: 00000000
4726 Entry Point: 00000000
4727 Verifying Checksum ... OK
4729 => bootm 40100000 40200000
4730 ## Booting Linux kernel at 40100000 ...
4731 Image Name: 2.2.13 for initrd on TQM850L
4732 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4733 Data Size: 335725 Bytes = 327 kB = 0 MB
4734 Load Address: 00000000
4735 Entry Point: 0000000c
4736 Verifying Checksum ... OK
4737 Uncompressing Kernel Image ... OK
4738 ## Loading RAMDisk Image at 40200000 ...
4739 Image Name: Simple Ramdisk Image
4740 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4741 Data Size: 566530 Bytes = 553 kB = 0 MB
4742 Load Address: 00000000
4743 Entry Point: 00000000
4744 Verifying Checksum ... OK
4745 Loading Ramdisk ... OK
4746 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
4747 Boot arguments: root=/dev/ram
4748 time_init: decrementer frequency = 187500000/60
4749 Calibrating delay loop... 49.77 BogoMIPS
4751 RAMDISK: Compressed image found at block 0
4752 VFS: Mounted root (ext2 filesystem).
4756 Boot Linux and pass a flat device tree:
4759 First, U-Boot must be compiled with the appropriate defines. See the section
4760 titled "Linux Kernel Interface" above for a more in depth explanation. The
4761 following is an example of how to start a kernel and pass an updated
4767 oft=oftrees/mpc8540ads.dtb
4768 => tftp $oftaddr $oft
4769 Speed: 1000, full duplex
4771 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4772 Filename 'oftrees/mpc8540ads.dtb'.
4773 Load address: 0x300000
4776 Bytes transferred = 4106 (100a hex)
4777 => tftp $loadaddr $bootfile
4778 Speed: 1000, full duplex
4780 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4782 Load address: 0x200000
4783 Loading:############
4785 Bytes transferred = 1029407 (fb51f hex)
4790 => bootm $loadaddr - $oftaddr
4791 ## Booting image at 00200000 ...
4792 Image Name: Linux-2.6.17-dirty
4793 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4794 Data Size: 1029343 Bytes = 1005.2 kB
4795 Load Address: 00000000
4796 Entry Point: 00000000
4797 Verifying Checksum ... OK
4798 Uncompressing Kernel Image ... OK
4799 Booting using flat device tree at 0x300000
4800 Using MPC85xx ADS machine description
4801 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4805 More About U-Boot Image Types:
4806 ------------------------------
4808 U-Boot supports the following image types:
4810 "Standalone Programs" are directly runnable in the environment
4811 provided by U-Boot; it is expected that (if they behave
4812 well) you can continue to work in U-Boot after return from
4813 the Standalone Program.
4814 "OS Kernel Images" are usually images of some Embedded OS which
4815 will take over control completely. Usually these programs
4816 will install their own set of exception handlers, device
4817 drivers, set up the MMU, etc. - this means, that you cannot
4818 expect to re-enter U-Boot except by resetting the CPU.
4819 "RAMDisk Images" are more or less just data blocks, and their
4820 parameters (address, size) are passed to an OS kernel that is
4822 "Multi-File Images" contain several images, typically an OS
4823 (Linux) kernel image and one or more data images like
4824 RAMDisks. This construct is useful for instance when you want
4825 to boot over the network using BOOTP etc., where the boot
4826 server provides just a single image file, but you want to get
4827 for instance an OS kernel and a RAMDisk image.
4829 "Multi-File Images" start with a list of image sizes, each
4830 image size (in bytes) specified by an "uint32_t" in network
4831 byte order. This list is terminated by an "(uint32_t)0".
4832 Immediately after the terminating 0 follow the images, one by
4833 one, all aligned on "uint32_t" boundaries (size rounded up to
4834 a multiple of 4 bytes).
4836 "Firmware Images" are binary images containing firmware (like
4837 U-Boot or FPGA images) which usually will be programmed to
4840 "Script files" are command sequences that will be executed by
4841 U-Boot's command interpreter; this feature is especially
4842 useful when you configure U-Boot to use a real shell (hush)
4843 as command interpreter.
4845 Booting the Linux zImage:
4846 -------------------------
4848 On some platforms, it's possible to boot Linux zImage. This is done
4849 using the "bootz" command. The syntax of "bootz" command is the same
4850 as the syntax of "bootm" command.
4852 Note, defining the CONFIG_SUPPORT_INITRD_RAW allows user to supply
4853 kernel with raw initrd images. The syntax is slightly different, the
4854 address of the initrd must be augmented by it's size, in the following
4855 format: "<initrd addres>:<initrd size>".
4861 One of the features of U-Boot is that you can dynamically load and
4862 run "standalone" applications, which can use some resources of
4863 U-Boot like console I/O functions or interrupt services.
4865 Two simple examples are included with the sources:
4870 'examples/hello_world.c' contains a small "Hello World" Demo
4871 application; it is automatically compiled when you build U-Boot.
4872 It's configured to run at address 0x00040004, so you can play with it
4876 ## Ready for S-Record download ...
4877 ~>examples/hello_world.srec
4878 1 2 3 4 5 6 7 8 9 10 11 ...
4879 [file transfer complete]
4881 ## Start Addr = 0x00040004
4883 => go 40004 Hello World! This is a test.
4884 ## Starting application at 0x00040004 ...
4895 Hit any key to exit ...
4897 ## Application terminated, rc = 0x0
4899 Another example, which demonstrates how to register a CPM interrupt
4900 handler with the U-Boot code, can be found in 'examples/timer.c'.
4901 Here, a CPM timer is set up to generate an interrupt every second.
4902 The interrupt service routine is trivial, just printing a '.'
4903 character, but this is just a demo program. The application can be
4904 controlled by the following keys:
4906 ? - print current values og the CPM Timer registers
4907 b - enable interrupts and start timer
4908 e - stop timer and disable interrupts
4909 q - quit application
4912 ## Ready for S-Record download ...
4913 ~>examples/timer.srec
4914 1 2 3 4 5 6 7 8 9 10 11 ...
4915 [file transfer complete]
4917 ## Start Addr = 0x00040004
4920 ## Starting application at 0x00040004 ...
4923 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
4926 [q, b, e, ?] Set interval 1000000 us
4929 [q, b, e, ?] ........
4930 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
4933 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
4936 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
4939 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
4941 [q, b, e, ?] ...Stopping timer
4943 [q, b, e, ?] ## Application terminated, rc = 0x0
4949 Over time, many people have reported problems when trying to use the
4950 "minicom" terminal emulation program for serial download. I (wd)
4951 consider minicom to be broken, and recommend not to use it. Under
4952 Unix, I recommend to use C-Kermit for general purpose use (and
4953 especially for kermit binary protocol download ("loadb" command), and
4954 use "cu" for S-Record download ("loads" command). See
4955 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
4956 for help with kermit.
4959 Nevertheless, if you absolutely want to use it try adding this
4960 configuration to your "File transfer protocols" section:
4962 Name Program Name U/D FullScr IO-Red. Multi
4963 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
4964 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
4970 Starting at version 0.9.2, U-Boot supports NetBSD both as host
4971 (build U-Boot) and target system (boots NetBSD/mpc8xx).
4973 Building requires a cross environment; it is known to work on
4974 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
4975 need gmake since the Makefiles are not compatible with BSD make).
4976 Note that the cross-powerpc package does not install include files;
4977 attempting to build U-Boot will fail because <machine/ansi.h> is
4978 missing. This file has to be installed and patched manually:
4980 # cd /usr/pkg/cross/powerpc-netbsd/include
4982 # ln -s powerpc machine
4983 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
4984 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
4986 Native builds *don't* work due to incompatibilities between native
4987 and U-Boot include files.
4989 Booting assumes that (the first part of) the image booted is a
4990 stage-2 loader which in turn loads and then invokes the kernel
4991 proper. Loader sources will eventually appear in the NetBSD source
4992 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
4993 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
4996 Implementation Internals:
4997 =========================
4999 The following is not intended to be a complete description of every
5000 implementation detail. However, it should help to understand the
5001 inner workings of U-Boot and make it easier to port it to custom
5005 Initial Stack, Global Data:
5006 ---------------------------
5008 The implementation of U-Boot is complicated by the fact that U-Boot
5009 starts running out of ROM (flash memory), usually without access to
5010 system RAM (because the memory controller is not initialized yet).
5011 This means that we don't have writable Data or BSS segments, and BSS
5012 is not initialized as zero. To be able to get a C environment working
5013 at all, we have to allocate at least a minimal stack. Implementation
5014 options for this are defined and restricted by the CPU used: Some CPU
5015 models provide on-chip memory (like the IMMR area on MPC8xx and
5016 MPC826x processors), on others (parts of) the data cache can be
5017 locked as (mis-) used as memory, etc.
5019 Chris Hallinan posted a good summary of these issues to the
5020 U-Boot mailing list:
5022 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5023 From: "Chris Hallinan" <clh@net1plus.com>
5024 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5027 Correct me if I'm wrong, folks, but the way I understand it
5028 is this: Using DCACHE as initial RAM for Stack, etc, does not
5029 require any physical RAM backing up the cache. The cleverness
5030 is that the cache is being used as a temporary supply of
5031 necessary storage before the SDRAM controller is setup. It's
5032 beyond the scope of this list to explain the details, but you
5033 can see how this works by studying the cache architecture and
5034 operation in the architecture and processor-specific manuals.
5036 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5037 is another option for the system designer to use as an
5038 initial stack/RAM area prior to SDRAM being available. Either
5039 option should work for you. Using CS 4 should be fine if your
5040 board designers haven't used it for something that would
5041 cause you grief during the initial boot! It is frequently not
5044 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5045 with your processor/board/system design. The default value
5046 you will find in any recent u-boot distribution in
5047 walnut.h should work for you. I'd set it to a value larger
5048 than your SDRAM module. If you have a 64MB SDRAM module, set
5049 it above 400_0000. Just make sure your board has no resources
5050 that are supposed to respond to that address! That code in
5051 start.S has been around a while and should work as is when
5052 you get the config right.
5057 It is essential to remember this, since it has some impact on the C
5058 code for the initialization procedures:
5060 * Initialized global data (data segment) is read-only. Do not attempt
5063 * Do not use any uninitialized global data (or implicitely initialized
5064 as zero data - BSS segment) at all - this is undefined, initiali-
5065 zation is performed later (when relocating to RAM).
5067 * Stack space is very limited. Avoid big data buffers or things like
5070 Having only the stack as writable memory limits means we cannot use
5071 normal global data to share information beween the code. But it
5072 turned out that the implementation of U-Boot can be greatly
5073 simplified by making a global data structure (gd_t) available to all
5074 functions. We could pass a pointer to this data as argument to _all_
5075 functions, but this would bloat the code. Instead we use a feature of
5076 the GCC compiler (Global Register Variables) to share the data: we
5077 place a pointer (gd) to the global data into a register which we
5078 reserve for this purpose.
5080 When choosing a register for such a purpose we are restricted by the
5081 relevant (E)ABI specifications for the current architecture, and by
5082 GCC's implementation.
5084 For PowerPC, the following registers have specific use:
5086 R2: reserved for system use
5087 R3-R4: parameter passing and return values
5088 R5-R10: parameter passing
5089 R13: small data area pointer
5093 (U-Boot also uses R12 as internal GOT pointer. r12
5094 is a volatile register so r12 needs to be reset when
5095 going back and forth between asm and C)
5097 ==> U-Boot will use R2 to hold a pointer to the global data
5099 Note: on PPC, we could use a static initializer (since the
5100 address of the global data structure is known at compile time),
5101 but it turned out that reserving a register results in somewhat
5102 smaller code - although the code savings are not that big (on
5103 average for all boards 752 bytes for the whole U-Boot image,
5104 624 text + 127 data).
5106 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5107 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5109 ==> U-Boot will use P3 to hold a pointer to the global data
5111 On ARM, the following registers are used:
5113 R0: function argument word/integer result
5114 R1-R3: function argument word
5116 R10: stack limit (used only if stack checking if enabled)
5117 R11: argument (frame) pointer
5118 R12: temporary workspace
5121 R15: program counter
5123 ==> U-Boot will use R8 to hold a pointer to the global data
5125 On Nios II, the ABI is documented here:
5126 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5128 ==> U-Boot will use gp to hold a pointer to the global data
5130 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5131 to access small data sections, so gp is free.
5133 On NDS32, the following registers are used:
5135 R0-R1: argument/return
5137 R15: temporary register for assembler
5138 R16: trampoline register
5139 R28: frame pointer (FP)
5140 R29: global pointer (GP)
5141 R30: link register (LP)
5142 R31: stack pointer (SP)
5143 PC: program counter (PC)
5145 ==> U-Boot will use R10 to hold a pointer to the global data
5147 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5148 or current versions of GCC may "optimize" the code too much.
5153 U-Boot runs in system state and uses physical addresses, i.e. the
5154 MMU is not used either for address mapping nor for memory protection.
5156 The available memory is mapped to fixed addresses using the memory
5157 controller. In this process, a contiguous block is formed for each
5158 memory type (Flash, SDRAM, SRAM), even when it consists of several
5159 physical memory banks.
5161 U-Boot is installed in the first 128 kB of the first Flash bank (on
5162 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5163 booting and sizing and initializing DRAM, the code relocates itself
5164 to the upper end of DRAM. Immediately below the U-Boot code some
5165 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5166 configuration setting]. Below that, a structure with global Board
5167 Info data is placed, followed by the stack (growing downward).
5169 Additionally, some exception handler code is copied to the low 8 kB
5170 of DRAM (0x00000000 ... 0x00001FFF).
5172 So a typical memory configuration with 16 MB of DRAM could look like
5175 0x0000 0000 Exception Vector code
5178 0x0000 2000 Free for Application Use
5184 0x00FB FF20 Monitor Stack (Growing downward)
5185 0x00FB FFAC Board Info Data and permanent copy of global data
5186 0x00FC 0000 Malloc Arena
5189 0x00FE 0000 RAM Copy of Monitor Code
5190 ... eventually: LCD or video framebuffer
5191 ... eventually: pRAM (Protected RAM - unchanged by reset)
5192 0x00FF FFFF [End of RAM]
5195 System Initialization:
5196 ----------------------
5198 In the reset configuration, U-Boot starts at the reset entry point
5199 (on most PowerPC systems at address 0x00000100). Because of the reset
5200 configuration for CS0# this is a mirror of the onboard Flash memory.
5201 To be able to re-map memory U-Boot then jumps to its link address.
5202 To be able to implement the initialization code in C, a (small!)
5203 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5204 which provide such a feature like MPC8xx or MPC8260), or in a locked
5205 part of the data cache. After that, U-Boot initializes the CPU core,
5206 the caches and the SIU.
5208 Next, all (potentially) available memory banks are mapped using a
5209 preliminary mapping. For example, we put them on 512 MB boundaries
5210 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5211 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5212 programmed for SDRAM access. Using the temporary configuration, a
5213 simple memory test is run that determines the size of the SDRAM
5216 When there is more than one SDRAM bank, and the banks are of
5217 different size, the largest is mapped first. For equal size, the first
5218 bank (CS2#) is mapped first. The first mapping is always for address
5219 0x00000000, with any additional banks following immediately to create
5220 contiguous memory starting from 0.
5222 Then, the monitor installs itself at the upper end of the SDRAM area
5223 and allocates memory for use by malloc() and for the global Board
5224 Info data; also, the exception vector code is copied to the low RAM
5225 pages, and the final stack is set up.
5227 Only after this relocation will you have a "normal" C environment;
5228 until that you are restricted in several ways, mostly because you are
5229 running from ROM, and because the code will have to be relocated to a
5233 U-Boot Porting Guide:
5234 ----------------------
5236 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5240 int main(int argc, char *argv[])
5242 sighandler_t no_more_time;
5244 signal(SIGALRM, no_more_time);
5245 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5247 if (available_money > available_manpower) {
5248 Pay consultant to port U-Boot;
5252 Download latest U-Boot source;
5254 Subscribe to u-boot mailing list;
5257 email("Hi, I am new to U-Boot, how do I get started?");
5260 Read the README file in the top level directory;
5261 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5262 Read applicable doc/*.README;
5263 Read the source, Luke;
5264 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5267 if (available_money > toLocalCurrency ($2500))
5270 Add a lot of aggravation and time;
5272 if (a similar board exists) { /* hopefully... */
5273 cp -a board/<similar> board/<myboard>
5274 cp include/configs/<similar>.h include/configs/<myboard>.h
5276 Create your own board support subdirectory;
5277 Create your own board include/configs/<myboard>.h file;
5279 Edit new board/<myboard> files
5280 Edit new include/configs/<myboard>.h
5285 Add / modify source code;
5289 email("Hi, I am having problems...");
5291 Send patch file to the U-Boot email list;
5292 if (reasonable critiques)
5293 Incorporate improvements from email list code review;
5295 Defend code as written;
5301 void no_more_time (int sig)
5310 All contributions to U-Boot should conform to the Linux kernel
5311 coding style; see the file "Documentation/CodingStyle" and the script
5312 "scripts/Lindent" in your Linux kernel source directory.
5314 Source files originating from a different project (for example the
5315 MTD subsystem) are generally exempt from these guidelines and are not
5316 reformated to ease subsequent migration to newer versions of those
5319 Please note that U-Boot is implemented in C (and to some small parts in
5320 Assembler); no C++ is used, so please do not use C++ style comments (//)
5323 Please also stick to the following formatting rules:
5324 - remove any trailing white space
5325 - use TAB characters for indentation and vertical alignment, not spaces
5326 - make sure NOT to use DOS '\r\n' line feeds
5327 - do not add more than 2 consecutive empty lines to source files
5328 - do not add trailing empty lines to source files
5330 Submissions which do not conform to the standards may be returned
5331 with a request to reformat the changes.
5337 Since the number of patches for U-Boot is growing, we need to
5338 establish some rules. Submissions which do not conform to these rules
5339 may be rejected, even when they contain important and valuable stuff.
5341 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5343 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5344 see http://lists.denx.de/mailman/listinfo/u-boot
5346 When you send a patch, please include the following information with
5349 * For bug fixes: a description of the bug and how your patch fixes
5350 this bug. Please try to include a way of demonstrating that the
5351 patch actually fixes something.
5353 * For new features: a description of the feature and your
5356 * A CHANGELOG entry as plaintext (separate from the patch)
5358 * For major contributions, your entry to the CREDITS file
5360 * When you add support for a new board, don't forget to add this
5361 board to the MAINTAINERS file, too.
5363 * If your patch adds new configuration options, don't forget to
5364 document these in the README file.
5366 * The patch itself. If you are using git (which is *strongly*
5367 recommended) you can easily generate the patch using the
5368 "git format-patch". If you then use "git send-email" to send it to
5369 the U-Boot mailing list, you will avoid most of the common problems
5370 with some other mail clients.
5372 If you cannot use git, use "diff -purN OLD NEW". If your version of
5373 diff does not support these options, then get the latest version of
5376 The current directory when running this command shall be the parent
5377 directory of the U-Boot source tree (i. e. please make sure that
5378 your patch includes sufficient directory information for the
5381 We prefer patches as plain text. MIME attachments are discouraged,
5382 and compressed attachments must not be used.
5384 * If one logical set of modifications affects or creates several
5385 files, all these changes shall be submitted in a SINGLE patch file.
5387 * Changesets that contain different, unrelated modifications shall be
5388 submitted as SEPARATE patches, one patch per changeset.
5393 * Before sending the patch, run the MAKEALL script on your patched
5394 source tree and make sure that no errors or warnings are reported
5395 for any of the boards.
5397 * Keep your modifications to the necessary minimum: A patch
5398 containing several unrelated changes or arbitrary reformats will be
5399 returned with a request to re-formatting / split it.
5401 * If you modify existing code, make sure that your new code does not
5402 add to the memory footprint of the code ;-) Small is beautiful!
5403 When adding new features, these should compile conditionally only
5404 (using #ifdef), and the resulting code with the new feature
5405 disabled must not need more memory than the old code without your
5408 * Remember that there is a size limit of 100 kB per message on the
5409 u-boot mailing list. Bigger patches will be moderated. If they are
5410 reasonable and not too big, they will be acknowledged. But patches
5411 bigger than the size limit should be avoided.
projects / kernel / u-boot.git / blob