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 images found in NOR flash
846 CONFIG_CMD_IMLS_NAND List all images found in NAND flash
847 CONFIG_CMD_IMMAP * IMMR dump support
848 CONFIG_CMD_IMPORTENV * import an environment
849 CONFIG_CMD_INI * import data from an ini file into the env
850 CONFIG_CMD_IRQ * irqinfo
851 CONFIG_CMD_ITEST Integer/string test of 2 values
852 CONFIG_CMD_JFFS2 * JFFS2 Support
853 CONFIG_CMD_KGDB * kgdb
854 CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
855 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
857 CONFIG_CMD_LOADB loadb
858 CONFIG_CMD_LOADS loads
859 CONFIG_CMD_MD5SUM print md5 message digest
860 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
861 CONFIG_CMD_MEMINFO * Display detailed memory information
862 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
864 CONFIG_CMD_MEMTEST mtest
865 CONFIG_CMD_MISC Misc functions like sleep etc
866 CONFIG_CMD_MMC * MMC memory mapped support
867 CONFIG_CMD_MII * MII utility commands
868 CONFIG_CMD_MTDPARTS * MTD partition support
869 CONFIG_CMD_NAND * NAND support
870 CONFIG_CMD_NET bootp, tftpboot, rarpboot
871 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
872 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
873 CONFIG_CMD_PCI * pciinfo
874 CONFIG_CMD_PCMCIA * PCMCIA support
875 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
877 CONFIG_CMD_PORTIO * Port I/O
878 CONFIG_CMD_READ * Read raw data from partition
879 CONFIG_CMD_REGINFO * Register dump
880 CONFIG_CMD_RUN run command in env variable
881 CONFIG_CMD_SANDBOX * sb command to access sandbox features
882 CONFIG_CMD_SAVES * save S record dump
883 CONFIG_CMD_SCSI * SCSI Support
884 CONFIG_CMD_SDRAM * print SDRAM configuration information
885 (requires CONFIG_CMD_I2C)
886 CONFIG_CMD_SETGETDCR Support for DCR Register access
888 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
889 CONFIG_CMD_SHA1SUM print sha1 memory digest
890 (requires CONFIG_CMD_MEMORY)
891 CONFIG_CMD_SOURCE "source" command Support
892 CONFIG_CMD_SPI * SPI serial bus support
893 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
894 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
895 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
896 CONFIG_CMD_TIMER * access to the system tick timer
897 CONFIG_CMD_USB * USB support
898 CONFIG_CMD_CDP * Cisco Discover Protocol support
899 CONFIG_CMD_MFSL * Microblaze FSL support
902 EXAMPLE: If you want all functions except of network
903 support you can write:
905 #include "config_cmd_all.h"
906 #undef CONFIG_CMD_NET
909 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
911 Note: Don't enable the "icache" and "dcache" commands
912 (configuration option CONFIG_CMD_CACHE) unless you know
913 what you (and your U-Boot users) are doing. Data
914 cache cannot be enabled on systems like the 8xx or
915 8260 (where accesses to the IMMR region must be
916 uncached), and it cannot be disabled on all other
917 systems where we (mis-) use the data cache to hold an
918 initial stack and some data.
921 XXX - this list needs to get updated!
925 If this variable is defined, U-Boot will use a device tree
926 to configure its devices, instead of relying on statically
927 compiled #defines in the board file. This option is
928 experimental and only available on a few boards. The device
929 tree is available in the global data as gd->fdt_blob.
931 U-Boot needs to get its device tree from somewhere. This can
932 be done using one of the two options below:
935 If this variable is defined, U-Boot will embed a device tree
936 binary in its image. This device tree file should be in the
937 board directory and called <soc>-<board>.dts. The binary file
938 is then picked up in board_init_f() and made available through
939 the global data structure as gd->blob.
942 If this variable is defined, U-Boot will build a device tree
943 binary. It will be called u-boot.dtb. Architecture-specific
944 code will locate it at run-time. Generally this works by:
946 cat u-boot.bin u-boot.dtb >image.bin
948 and in fact, U-Boot does this for you, creating a file called
949 u-boot-dtb.bin which is useful in the common case. You can
950 still use the individual files if you need something more
955 If this variable is defined, it enables watchdog
956 support for the SoC. There must be support in the SoC
957 specific code for a watchdog. For the 8xx and 8260
958 CPUs, the SIU Watchdog feature is enabled in the SYPCR
959 register. When supported for a specific SoC is
960 available, then no further board specific code should
964 When using a watchdog circuitry external to the used
965 SoC, then define this variable and provide board
966 specific code for the "hw_watchdog_reset" function.
969 CONFIG_VERSION_VARIABLE
970 If this variable is defined, an environment variable
971 named "ver" is created by U-Boot showing the U-Boot
972 version as printed by the "version" command.
973 Any change to this variable will be reverted at the
978 When CONFIG_CMD_DATE is selected, the type of the RTC
979 has to be selected, too. Define exactly one of the
982 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
983 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
984 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
985 CONFIG_RTC_MC146818 - use MC146818 RTC
986 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
987 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
988 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
989 CONFIG_RTC_DS164x - use Dallas DS164x RTC
990 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
991 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
992 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
993 CONFIG_SYS_RV3029_TCR - enable trickle charger on
996 Note that if the RTC uses I2C, then the I2C interface
997 must also be configured. See I2C Support, below.
1000 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1001 CONFIG_PCA953X_INFO - enable pca953x info command
1003 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1004 chip-ngpio pairs that tell the PCA953X driver the number of
1005 pins supported by a particular chip.
1007 Note that if the GPIO device uses I2C, then the I2C interface
1008 must also be configured. See I2C Support, below.
1010 - Timestamp Support:
1012 When CONFIG_TIMESTAMP is selected, the timestamp
1013 (date and time) of an image is printed by image
1014 commands like bootm or iminfo. This option is
1015 automatically enabled when you select CONFIG_CMD_DATE .
1017 - Partition Labels (disklabels) Supported:
1018 Zero or more of the following:
1019 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1020 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1021 Intel architecture, USB sticks, etc.
1022 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1023 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1024 bootloader. Note 2TB partition limit; see
1026 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1028 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1029 CONFIG_CMD_SCSI) you must configure support for at
1030 least one non-MTD partition type as well.
1033 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1034 board configurations files but used nowhere!
1036 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1037 be performed by calling the function
1038 ide_set_reset(int reset)
1039 which has to be defined in a board specific file
1044 Set this to enable ATAPI support.
1049 Set this to enable support for disks larger than 137GB
1050 Also look at CONFIG_SYS_64BIT_LBA.
1051 Whithout these , LBA48 support uses 32bit variables and will 'only'
1052 support disks up to 2.1TB.
1054 CONFIG_SYS_64BIT_LBA:
1055 When enabled, makes the IDE subsystem use 64bit sector addresses.
1059 At the moment only there is only support for the
1060 SYM53C8XX SCSI controller; define
1061 CONFIG_SCSI_SYM53C8XX to enable it.
1063 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1064 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1065 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1066 maximum numbers of LUNs, SCSI ID's and target
1068 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1070 The environment variable 'scsidevs' is set to the number of
1071 SCSI devices found during the last scan.
1073 - NETWORK Support (PCI):
1075 Support for Intel 8254x/8257x gigabit chips.
1078 Utility code for direct access to the SPI bus on Intel 8257x.
1079 This does not do anything useful unless you set at least one
1080 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1082 CONFIG_E1000_SPI_GENERIC
1083 Allow generic access to the SPI bus on the Intel 8257x, for
1084 example with the "sspi" command.
1087 Management command for E1000 devices. When used on devices
1088 with SPI support you can reprogram the EEPROM from U-Boot.
1090 CONFIG_E1000_FALLBACK_MAC
1091 default MAC for empty EEPROM after production.
1094 Support for Intel 82557/82559/82559ER chips.
1095 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1096 write routine for first time initialisation.
1099 Support for Digital 2114x chips.
1100 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1101 modem chip initialisation (KS8761/QS6611).
1104 Support for National dp83815 chips.
1107 Support for National dp8382[01] gigabit chips.
1109 - NETWORK Support (other):
1111 CONFIG_DRIVER_AT91EMAC
1112 Support for AT91RM9200 EMAC.
1115 Define this to use reduced MII inteface
1117 CONFIG_DRIVER_AT91EMAC_QUIET
1118 If this defined, the driver is quiet.
1119 The driver doen't show link status messages.
1121 CONFIG_CALXEDA_XGMAC
1122 Support for the Calxeda XGMAC device
1125 Support for SMSC's LAN91C96 chips.
1127 CONFIG_LAN91C96_BASE
1128 Define this to hold the physical address
1129 of the LAN91C96's I/O space
1131 CONFIG_LAN91C96_USE_32_BIT
1132 Define this to enable 32 bit addressing
1135 Support for SMSC's LAN91C111 chip
1137 CONFIG_SMC91111_BASE
1138 Define this to hold the physical address
1139 of the device (I/O space)
1141 CONFIG_SMC_USE_32_BIT
1142 Define this if data bus is 32 bits
1144 CONFIG_SMC_USE_IOFUNCS
1145 Define this to use i/o functions instead of macros
1146 (some hardware wont work with macros)
1148 CONFIG_DRIVER_TI_EMAC
1149 Support for davinci emac
1151 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1152 Define this if you have more then 3 PHYs.
1155 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1157 CONFIG_FTGMAC100_EGIGA
1158 Define this to use GE link update with gigabit PHY.
1159 Define this if FTGMAC100 is connected to gigabit PHY.
1160 If your system has 10/100 PHY only, it might not occur
1161 wrong behavior. Because PHY usually return timeout or
1162 useless data when polling gigabit status and gigabit
1163 control registers. This behavior won't affect the
1164 correctnessof 10/100 link speed update.
1167 Support for SMSC's LAN911x and LAN921x chips
1170 Define this to hold the physical address
1171 of the device (I/O space)
1173 CONFIG_SMC911X_32_BIT
1174 Define this if data bus is 32 bits
1176 CONFIG_SMC911X_16_BIT
1177 Define this if data bus is 16 bits. If your processor
1178 automatically converts one 32 bit word to two 16 bit
1179 words you may also try CONFIG_SMC911X_32_BIT.
1182 Support for Renesas on-chip Ethernet controller
1184 CONFIG_SH_ETHER_USE_PORT
1185 Define the number of ports to be used
1187 CONFIG_SH_ETHER_PHY_ADDR
1188 Define the ETH PHY's address
1190 CONFIG_SH_ETHER_CACHE_WRITEBACK
1191 If this option is set, the driver enables cache flush.
1194 CONFIG_GENERIC_LPC_TPM
1195 Support for generic parallel port TPM devices. Only one device
1196 per system is supported at this time.
1198 CONFIG_TPM_TIS_BASE_ADDRESS
1199 Base address where the generic TPM device is mapped
1200 to. Contemporary x86 systems usually map it at
1204 At the moment only the UHCI host controller is
1205 supported (PIP405, MIP405, MPC5200); define
1206 CONFIG_USB_UHCI to enable it.
1207 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1208 and define CONFIG_USB_STORAGE to enable the USB
1211 Supported are USB Keyboards and USB Floppy drives
1213 MPC5200 USB requires additional defines:
1215 for 528 MHz Clock: 0x0001bbbb
1219 for differential drivers: 0x00001000
1220 for single ended drivers: 0x00005000
1221 for differential drivers on PSC3: 0x00000100
1222 for single ended drivers on PSC3: 0x00004100
1223 CONFIG_SYS_USB_EVENT_POLL
1224 May be defined to allow interrupt polling
1225 instead of using asynchronous interrupts
1227 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1228 txfilltuning field in the EHCI controller on reset.
1231 Define the below if you wish to use the USB console.
1232 Once firmware is rebuilt from a serial console issue the
1233 command "setenv stdin usbtty; setenv stdout usbtty" and
1234 attach your USB cable. The Unix command "dmesg" should print
1235 it has found a new device. The environment variable usbtty
1236 can be set to gserial or cdc_acm to enable your device to
1237 appear to a USB host as a Linux gserial device or a
1238 Common Device Class Abstract Control Model serial device.
1239 If you select usbtty = gserial you should be able to enumerate
1241 # modprobe usbserial vendor=0xVendorID product=0xProductID
1242 else if using cdc_acm, simply setting the environment
1243 variable usbtty to be cdc_acm should suffice. The following
1244 might be defined in YourBoardName.h
1247 Define this to build a UDC device
1250 Define this to have a tty type of device available to
1251 talk to the UDC device
1254 Define this to enable the high speed support for usb
1255 device and usbtty. If this feature is enabled, a routine
1256 int is_usbd_high_speed(void)
1257 also needs to be defined by the driver to dynamically poll
1258 whether the enumeration has succeded at high speed or full
1261 CONFIG_SYS_CONSOLE_IS_IN_ENV
1262 Define this if you want stdin, stdout &/or stderr to
1266 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1267 Derive USB clock from external clock "blah"
1268 - CONFIG_SYS_USB_EXTC_CLK 0x02
1270 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1271 Derive USB clock from brgclk
1272 - CONFIG_SYS_USB_BRG_CLK 0x04
1274 If you have a USB-IF assigned VendorID then you may wish to
1275 define your own vendor specific values either in BoardName.h
1276 or directly in usbd_vendor_info.h. If you don't define
1277 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1278 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1279 should pretend to be a Linux device to it's target host.
1281 CONFIG_USBD_MANUFACTURER
1282 Define this string as the name of your company for
1283 - CONFIG_USBD_MANUFACTURER "my company"
1285 CONFIG_USBD_PRODUCT_NAME
1286 Define this string as the name of your product
1287 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1289 CONFIG_USBD_VENDORID
1290 Define this as your assigned Vendor ID from the USB
1291 Implementors Forum. This *must* be a genuine Vendor ID
1292 to avoid polluting the USB namespace.
1293 - CONFIG_USBD_VENDORID 0xFFFF
1295 CONFIG_USBD_PRODUCTID
1296 Define this as the unique Product ID
1298 - CONFIG_USBD_PRODUCTID 0xFFFF
1300 - ULPI Layer Support:
1301 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1302 the generic ULPI layer. The generic layer accesses the ULPI PHY
1303 via the platform viewport, so you need both the genric layer and
1304 the viewport enabled. Currently only Chipidea/ARC based
1305 viewport is supported.
1306 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1307 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1308 If your ULPI phy needs a different reference clock than the
1309 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1310 the appropriate value in Hz.
1313 The MMC controller on the Intel PXA is supported. To
1314 enable this define CONFIG_MMC. The MMC can be
1315 accessed from the boot prompt by mapping the device
1316 to physical memory similar to flash. Command line is
1317 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1318 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1321 Support for Renesas on-chip MMCIF controller
1323 CONFIG_SH_MMCIF_ADDR
1324 Define the base address of MMCIF registers
1327 Define the clock frequency for MMCIF
1329 - Journaling Flash filesystem support:
1330 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1331 CONFIG_JFFS2_NAND_DEV
1332 Define these for a default partition on a NAND device
1334 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1335 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1336 Define these for a default partition on a NOR device
1338 CONFIG_SYS_JFFS_CUSTOM_PART
1339 Define this to create an own partition. You have to provide a
1340 function struct part_info* jffs2_part_info(int part_num)
1342 If you define only one JFFS2 partition you may also want to
1343 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1344 to disable the command chpart. This is the default when you
1345 have not defined a custom partition
1347 - FAT(File Allocation Table) filesystem write function support:
1350 Define this to enable support for saving memory data as a
1351 file in FAT formatted partition.
1353 This will also enable the command "fatwrite" enabling the
1354 user to write files to FAT.
1356 CBFS (Coreboot Filesystem) support
1359 Define this to enable support for reading from a Coreboot
1360 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1366 Define this to enable standard (PC-Style) keyboard
1370 Standard PC keyboard driver with US (is default) and
1371 GERMAN key layout (switch via environment 'keymap=de') support.
1372 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1373 for cfb_console. Supports cursor blinking.
1378 Define this to enable video support (for output to
1381 CONFIG_VIDEO_CT69000
1383 Enable Chips & Technologies 69000 Video chip
1385 CONFIG_VIDEO_SMI_LYNXEM
1386 Enable Silicon Motion SMI 712/710/810 Video chip. The
1387 video output is selected via environment 'videoout'
1388 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1391 For the CT69000 and SMI_LYNXEM drivers, videomode is
1392 selected via environment 'videomode'. Two different ways
1394 - "videomode=num" 'num' is a standard LiLo mode numbers.
1395 Following standard modes are supported (* is default):
1397 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1398 -------------+---------------------------------------------
1399 8 bits | 0x301* 0x303 0x305 0x161 0x307
1400 15 bits | 0x310 0x313 0x316 0x162 0x319
1401 16 bits | 0x311 0x314 0x317 0x163 0x31A
1402 24 bits | 0x312 0x315 0x318 ? 0x31B
1403 -------------+---------------------------------------------
1404 (i.e. setenv videomode 317; saveenv; reset;)
1406 - "videomode=bootargs" all the video parameters are parsed
1407 from the bootargs. (See drivers/video/videomodes.c)
1410 CONFIG_VIDEO_SED13806
1411 Enable Epson SED13806 driver. This driver supports 8bpp
1412 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1413 or CONFIG_VIDEO_SED13806_16BPP
1416 Enable the Freescale DIU video driver. Reference boards for
1417 SOCs that have a DIU should define this macro to enable DIU
1418 support, and should also define these other macros:
1424 CONFIG_VIDEO_SW_CURSOR
1425 CONFIG_VGA_AS_SINGLE_DEVICE
1427 CONFIG_VIDEO_BMP_LOGO
1429 The DIU driver will look for the 'video-mode' environment
1430 variable, and if defined, enable the DIU as a console during
1431 boot. See the documentation file README.video for a
1432 description of this variable.
1436 Enable the VGA video / BIOS for x86. The alternative if you
1437 are using coreboot is to use the coreboot frame buffer
1444 Define this to enable a custom keyboard support.
1445 This simply calls drv_keyboard_init() which must be
1446 defined in your board-specific files.
1447 The only board using this so far is RBC823.
1449 - LCD Support: CONFIG_LCD
1451 Define this to enable LCD support (for output to LCD
1452 display); also select one of the supported displays
1453 by defining one of these:
1457 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1459 CONFIG_NEC_NL6448AC33:
1461 NEC NL6448AC33-18. Active, color, single scan.
1463 CONFIG_NEC_NL6448BC20
1465 NEC NL6448BC20-08. 6.5", 640x480.
1466 Active, color, single scan.
1468 CONFIG_NEC_NL6448BC33_54
1470 NEC NL6448BC33-54. 10.4", 640x480.
1471 Active, color, single scan.
1475 Sharp 320x240. Active, color, single scan.
1476 It isn't 16x9, and I am not sure what it is.
1478 CONFIG_SHARP_LQ64D341
1480 Sharp LQ64D341 display, 640x480.
1481 Active, color, single scan.
1485 HLD1045 display, 640x480.
1486 Active, color, single scan.
1490 Optrex CBL50840-2 NF-FW 99 22 M5
1492 Hitachi LMG6912RPFC-00T
1496 320x240. Black & white.
1498 Normally display is black on white background; define
1499 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1501 CONFIG_LCD_ALIGNMENT
1503 Normally the LCD is page-aligned (tyically 4KB). If this is
1504 defined then the LCD will be aligned to this value instead.
1505 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1506 here, since it is cheaper to change data cache settings on
1507 a per-section basis.
1509 CONFIG_CONSOLE_SCROLL_LINES
1511 When the console need to be scrolled, this is the number of
1512 lines to scroll by. It defaults to 1. Increasing this makes
1513 the console jump but can help speed up operation when scrolling
1518 Support drawing of RLE8-compressed bitmaps on the LCD.
1522 Enables an 'i2c edid' command which can read EDID
1523 information over I2C from an attached LCD display.
1525 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1527 If this option is set, the environment is checked for
1528 a variable "splashimage". If found, the usual display
1529 of logo, copyright and system information on the LCD
1530 is suppressed and the BMP image at the address
1531 specified in "splashimage" is loaded instead. The
1532 console is redirected to the "nulldev", too. This
1533 allows for a "silent" boot where a splash screen is
1534 loaded very quickly after power-on.
1536 CONFIG_SPLASH_SCREEN_ALIGN
1538 If this option is set the splash image can be freely positioned
1539 on the screen. Environment variable "splashpos" specifies the
1540 position as "x,y". If a positive number is given it is used as
1541 number of pixel from left/top. If a negative number is given it
1542 is used as number of pixel from right/bottom. You can also
1543 specify 'm' for centering the image.
1546 setenv splashpos m,m
1547 => image at center of screen
1549 setenv splashpos 30,20
1550 => image at x = 30 and y = 20
1552 setenv splashpos -10,m
1553 => vertically centered image
1554 at x = dspWidth - bmpWidth - 9
1556 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1558 If this option is set, additionally to standard BMP
1559 images, gzipped BMP images can be displayed via the
1560 splashscreen support or the bmp command.
1562 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1564 If this option is set, 8-bit RLE compressed BMP images
1565 can be displayed via the splashscreen support or the
1568 - Do compresssing for memory range:
1571 If this option is set, it would use zlib deflate method
1572 to compress the specified memory at its best effort.
1574 - Compression support:
1577 If this option is set, support for bzip2 compressed
1578 images is included. If not, only uncompressed and gzip
1579 compressed images are supported.
1581 NOTE: the bzip2 algorithm requires a lot of RAM, so
1582 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1587 If this option is set, support for lzma compressed
1590 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1591 requires an amount of dynamic memory that is given by the
1594 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1596 Where lc and lp stand for, respectively, Literal context bits
1597 and Literal pos bits.
1599 This value is upper-bounded by 14MB in the worst case. Anyway,
1600 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1601 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1602 a very small buffer.
1604 Use the lzmainfo tool to determinate the lc and lp values and
1605 then calculate the amount of needed dynamic memory (ensuring
1606 the appropriate CONFIG_SYS_MALLOC_LEN value).
1611 The address of PHY on MII bus.
1613 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1615 The clock frequency of the MII bus
1619 If this option is set, support for speed/duplex
1620 detection of gigabit PHY is included.
1622 CONFIG_PHY_RESET_DELAY
1624 Some PHY like Intel LXT971A need extra delay after
1625 reset before any MII register access is possible.
1626 For such PHY, set this option to the usec delay
1627 required. (minimum 300usec for LXT971A)
1629 CONFIG_PHY_CMD_DELAY (ppc4xx)
1631 Some PHY like Intel LXT971A need extra delay after
1632 command issued before MII status register can be read
1642 Define a default value for Ethernet address to use
1643 for the respective Ethernet interface, in case this
1644 is not determined automatically.
1649 Define a default value for the IP address to use for
1650 the default Ethernet interface, in case this is not
1651 determined through e.g. bootp.
1652 (Environment variable "ipaddr")
1654 - Server IP address:
1657 Defines a default value for the IP address of a TFTP
1658 server to contact when using the "tftboot" command.
1659 (Environment variable "serverip")
1661 CONFIG_KEEP_SERVERADDR
1663 Keeps the server's MAC address, in the env 'serveraddr'
1664 for passing to bootargs (like Linux's netconsole option)
1666 - Gateway IP address:
1669 Defines a default value for the IP address of the
1670 default router where packets to other networks are
1672 (Environment variable "gatewayip")
1677 Defines a default value for the subnet mask (or
1678 routing prefix) which is used to determine if an IP
1679 address belongs to the local subnet or needs to be
1680 forwarded through a router.
1681 (Environment variable "netmask")
1683 - Multicast TFTP Mode:
1686 Defines whether you want to support multicast TFTP as per
1687 rfc-2090; for example to work with atftp. Lets lots of targets
1688 tftp down the same boot image concurrently. Note: the Ethernet
1689 driver in use must provide a function: mcast() to join/leave a
1692 - BOOTP Recovery Mode:
1693 CONFIG_BOOTP_RANDOM_DELAY
1695 If you have many targets in a network that try to
1696 boot using BOOTP, you may want to avoid that all
1697 systems send out BOOTP requests at precisely the same
1698 moment (which would happen for instance at recovery
1699 from a power failure, when all systems will try to
1700 boot, thus flooding the BOOTP server. Defining
1701 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1702 inserted before sending out BOOTP requests. The
1703 following delays are inserted then:
1705 1st BOOTP request: delay 0 ... 1 sec
1706 2nd BOOTP request: delay 0 ... 2 sec
1707 3rd BOOTP request: delay 0 ... 4 sec
1709 BOOTP requests: delay 0 ... 8 sec
1711 - DHCP Advanced Options:
1712 You can fine tune the DHCP functionality by defining
1713 CONFIG_BOOTP_* symbols:
1715 CONFIG_BOOTP_SUBNETMASK
1716 CONFIG_BOOTP_GATEWAY
1717 CONFIG_BOOTP_HOSTNAME
1718 CONFIG_BOOTP_NISDOMAIN
1719 CONFIG_BOOTP_BOOTPATH
1720 CONFIG_BOOTP_BOOTFILESIZE
1723 CONFIG_BOOTP_SEND_HOSTNAME
1724 CONFIG_BOOTP_NTPSERVER
1725 CONFIG_BOOTP_TIMEOFFSET
1726 CONFIG_BOOTP_VENDOREX
1727 CONFIG_BOOTP_MAY_FAIL
1729 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1730 environment variable, not the BOOTP server.
1732 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1733 after the configured retry count, the call will fail
1734 instead of starting over. This can be used to fail over
1735 to Link-local IP address configuration if the DHCP server
1738 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1739 serverip from a DHCP server, it is possible that more
1740 than one DNS serverip is offered to the client.
1741 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1742 serverip will be stored in the additional environment
1743 variable "dnsip2". The first DNS serverip is always
1744 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1747 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1748 to do a dynamic update of a DNS server. To do this, they
1749 need the hostname of the DHCP requester.
1750 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1751 of the "hostname" environment variable is passed as
1752 option 12 to the DHCP server.
1754 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1756 A 32bit value in microseconds for a delay between
1757 receiving a "DHCP Offer" and sending the "DHCP Request".
1758 This fixes a problem with certain DHCP servers that don't
1759 respond 100% of the time to a "DHCP request". E.g. On an
1760 AT91RM9200 processor running at 180MHz, this delay needed
1761 to be *at least* 15,000 usec before a Windows Server 2003
1762 DHCP server would reply 100% of the time. I recommend at
1763 least 50,000 usec to be safe. The alternative is to hope
1764 that one of the retries will be successful but note that
1765 the DHCP timeout and retry process takes a longer than
1768 - Link-local IP address negotiation:
1769 Negotiate with other link-local clients on the local network
1770 for an address that doesn't require explicit configuration.
1771 This is especially useful if a DHCP server cannot be guaranteed
1772 to exist in all environments that the device must operate.
1774 See doc/README.link-local for more information.
1777 CONFIG_CDP_DEVICE_ID
1779 The device id used in CDP trigger frames.
1781 CONFIG_CDP_DEVICE_ID_PREFIX
1783 A two character string which is prefixed to the MAC address
1788 A printf format string which contains the ascii name of
1789 the port. Normally is set to "eth%d" which sets
1790 eth0 for the first Ethernet, eth1 for the second etc.
1792 CONFIG_CDP_CAPABILITIES
1794 A 32bit integer which indicates the device capabilities;
1795 0x00000010 for a normal host which does not forwards.
1799 An ascii string containing the version of the software.
1803 An ascii string containing the name of the platform.
1807 A 32bit integer sent on the trigger.
1809 CONFIG_CDP_POWER_CONSUMPTION
1811 A 16bit integer containing the power consumption of the
1812 device in .1 of milliwatts.
1814 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1816 A byte containing the id of the VLAN.
1818 - Status LED: CONFIG_STATUS_LED
1820 Several configurations allow to display the current
1821 status using a LED. For instance, the LED will blink
1822 fast while running U-Boot code, stop blinking as
1823 soon as a reply to a BOOTP request was received, and
1824 start blinking slow once the Linux kernel is running
1825 (supported by a status LED driver in the Linux
1826 kernel). Defining CONFIG_STATUS_LED enables this
1829 - CAN Support: CONFIG_CAN_DRIVER
1831 Defining CONFIG_CAN_DRIVER enables CAN driver support
1832 on those systems that support this (optional)
1833 feature, like the TQM8xxL modules.
1835 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1837 These enable I2C serial bus commands. Defining either of
1838 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1839 include the appropriate I2C driver for the selected CPU.
1841 This will allow you to use i2c commands at the u-boot
1842 command line (as long as you set CONFIG_CMD_I2C in
1843 CONFIG_COMMANDS) and communicate with i2c based realtime
1844 clock chips. See common/cmd_i2c.c for a description of the
1845 command line interface.
1847 CONFIG_HARD_I2C selects a hardware I2C controller.
1849 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1850 bit-banging) driver instead of CPM or similar hardware
1853 There are several other quantities that must also be
1854 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1856 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1857 to be the frequency (in Hz) at which you wish your i2c bus
1858 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1859 the CPU's i2c node address).
1861 Now, the u-boot i2c code for the mpc8xx
1862 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1863 and so its address should therefore be cleared to 0 (See,
1864 eg, MPC823e User's Manual p.16-473). So, set
1865 CONFIG_SYS_I2C_SLAVE to 0.
1867 CONFIG_SYS_I2C_INIT_MPC5XXX
1869 When a board is reset during an i2c bus transfer
1870 chips might think that the current transfer is still
1871 in progress. Reset the slave devices by sending start
1872 commands until the slave device responds.
1874 That's all that's required for CONFIG_HARD_I2C.
1876 If you use the software i2c interface (CONFIG_SOFT_I2C)
1877 then the following macros need to be defined (examples are
1878 from include/configs/lwmon.h):
1882 (Optional). Any commands necessary to enable the I2C
1883 controller or configure ports.
1885 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1889 (Only for MPC8260 CPU). The I/O port to use (the code
1890 assumes both bits are on the same port). Valid values
1891 are 0..3 for ports A..D.
1895 The code necessary to make the I2C data line active
1896 (driven). If the data line is open collector, this
1899 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1903 The code necessary to make the I2C data line tri-stated
1904 (inactive). If the data line is open collector, this
1907 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1911 Code that returns TRUE if the I2C data line is high,
1914 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1918 If <bit> is TRUE, sets the I2C data line high. If it
1919 is FALSE, it clears it (low).
1921 eg: #define I2C_SDA(bit) \
1922 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1923 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1927 If <bit> is TRUE, sets the I2C clock line high. If it
1928 is FALSE, it clears it (low).
1930 eg: #define I2C_SCL(bit) \
1931 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1932 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1936 This delay is invoked four times per clock cycle so this
1937 controls the rate of data transfer. The data rate thus
1938 is 1 / (I2C_DELAY * 4). Often defined to be something
1941 #define I2C_DELAY udelay(2)
1943 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1945 If your arch supports the generic GPIO framework (asm/gpio.h),
1946 then you may alternatively define the two GPIOs that are to be
1947 used as SCL / SDA. Any of the previous I2C_xxx macros will
1948 have GPIO-based defaults assigned to them as appropriate.
1950 You should define these to the GPIO value as given directly to
1951 the generic GPIO functions.
1953 CONFIG_SYS_I2C_INIT_BOARD
1955 When a board is reset during an i2c bus transfer
1956 chips might think that the current transfer is still
1957 in progress. On some boards it is possible to access
1958 the i2c SCLK line directly, either by using the
1959 processor pin as a GPIO or by having a second pin
1960 connected to the bus. If this option is defined a
1961 custom i2c_init_board() routine in boards/xxx/board.c
1962 is run early in the boot sequence.
1964 CONFIG_SYS_I2C_BOARD_LATE_INIT
1966 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1967 defined a custom i2c_board_late_init() routine in
1968 boards/xxx/board.c is run AFTER the operations in i2c_init()
1969 is completed. This callpoint can be used to unreset i2c bus
1970 using CPU i2c controller register accesses for CPUs whose i2c
1971 controller provide such a method. It is called at the end of
1972 i2c_init() to allow i2c_init operations to setup the i2c bus
1973 controller on the CPU (e.g. setting bus speed & slave address).
1975 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1977 This option enables configuration of bi_iic_fast[] flags
1978 in u-boot bd_info structure based on u-boot environment
1979 variable "i2cfast". (see also i2cfast)
1981 CONFIG_I2C_MULTI_BUS
1983 This option allows the use of multiple I2C buses, each of which
1984 must have a controller. At any point in time, only one bus is
1985 active. To switch to a different bus, use the 'i2c dev' command.
1986 Note that bus numbering is zero-based.
1988 CONFIG_SYS_I2C_NOPROBES
1990 This option specifies a list of I2C devices that will be skipped
1991 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1992 is set, specify a list of bus-device pairs. Otherwise, specify
1993 a 1D array of device addresses
1996 #undef CONFIG_I2C_MULTI_BUS
1997 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1999 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2001 #define CONFIG_I2C_MULTI_BUS
2002 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2004 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2006 CONFIG_SYS_SPD_BUS_NUM
2008 If defined, then this indicates the I2C bus number for DDR SPD.
2009 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2011 CONFIG_SYS_RTC_BUS_NUM
2013 If defined, then this indicates the I2C bus number for the RTC.
2014 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2016 CONFIG_SYS_DTT_BUS_NUM
2018 If defined, then this indicates the I2C bus number for the DTT.
2019 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2021 CONFIG_SYS_I2C_DTT_ADDR:
2023 If defined, specifies the I2C address of the DTT device.
2024 If not defined, then U-Boot uses predefined value for
2025 specified DTT device.
2029 Define this option if you want to use Freescale's I2C driver in
2030 drivers/i2c/fsl_i2c.c.
2034 Define this option if you have I2C devices reached over 1 .. n
2035 I2C Muxes like the pca9544a. This option addes a new I2C
2036 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
2037 new I2C Bus to the existing I2C Busses. If you select the
2038 new Bus with "i2c dev", u-bbot sends first the commandos for
2039 the muxes to activate this new "bus".
2041 CONFIG_I2C_MULTI_BUS must be also defined, to use this
2045 Adding a new I2C Bus reached over 2 pca9544a muxes
2046 The First mux with address 70 and channel 6
2047 The Second mux with address 71 and channel 4
2049 => i2c bus pca9544a:70:6:pca9544a:71:4
2051 Use the "i2c bus" command without parameter, to get a list
2052 of I2C Busses with muxes:
2055 Busses reached over muxes:
2057 reached over Mux(es):
2060 reached over Mux(es):
2065 If you now switch to the new I2C Bus 3 with "i2c dev 3"
2066 u-boot first sends the command to the mux@70 to enable
2067 channel 6, and then the command to the mux@71 to enable
2070 After that, you can use the "normal" i2c commands as
2071 usual to communicate with your I2C devices behind
2074 This option is actually implemented for the bitbanging
2075 algorithm in common/soft_i2c.c and for the Hardware I2C
2076 Bus on the MPC8260. But it should be not so difficult
2077 to add this option to other architectures.
2079 CONFIG_SOFT_I2C_READ_REPEATED_START
2081 defining this will force the i2c_read() function in
2082 the soft_i2c driver to perform an I2C repeated start
2083 between writing the address pointer and reading the
2084 data. If this define is omitted the default behaviour
2085 of doing a stop-start sequence will be used. Most I2C
2086 devices can use either method, but some require one or
2089 - SPI Support: CONFIG_SPI
2091 Enables SPI driver (so far only tested with
2092 SPI EEPROM, also an instance works with Crystal A/D and
2093 D/As on the SACSng board)
2097 Enables the driver for SPI controller on SuperH. Currently
2098 only SH7757 is supported.
2102 Enables extended (16-bit) SPI EEPROM addressing.
2103 (symmetrical to CONFIG_I2C_X)
2107 Enables a software (bit-bang) SPI driver rather than
2108 using hardware support. This is a general purpose
2109 driver that only requires three general I/O port pins
2110 (two outputs, one input) to function. If this is
2111 defined, the board configuration must define several
2112 SPI configuration items (port pins to use, etc). For
2113 an example, see include/configs/sacsng.h.
2117 Enables a hardware SPI driver for general-purpose reads
2118 and writes. As with CONFIG_SOFT_SPI, the board configuration
2119 must define a list of chip-select function pointers.
2120 Currently supported on some MPC8xxx processors. For an
2121 example, see include/configs/mpc8349emds.h.
2125 Enables the driver for the SPI controllers on i.MX and MXC
2126 SoCs. Currently i.MX31/35/51 are supported.
2128 - FPGA Support: CONFIG_FPGA
2130 Enables FPGA subsystem.
2132 CONFIG_FPGA_<vendor>
2134 Enables support for specific chip vendors.
2137 CONFIG_FPGA_<family>
2139 Enables support for FPGA family.
2140 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2144 Specify the number of FPGA devices to support.
2146 CONFIG_SYS_FPGA_PROG_FEEDBACK
2148 Enable printing of hash marks during FPGA configuration.
2150 CONFIG_SYS_FPGA_CHECK_BUSY
2152 Enable checks on FPGA configuration interface busy
2153 status by the configuration function. This option
2154 will require a board or device specific function to
2159 If defined, a function that provides delays in the FPGA
2160 configuration driver.
2162 CONFIG_SYS_FPGA_CHECK_CTRLC
2163 Allow Control-C to interrupt FPGA configuration
2165 CONFIG_SYS_FPGA_CHECK_ERROR
2167 Check for configuration errors during FPGA bitfile
2168 loading. For example, abort during Virtex II
2169 configuration if the INIT_B line goes low (which
2170 indicated a CRC error).
2172 CONFIG_SYS_FPGA_WAIT_INIT
2174 Maximum time to wait for the INIT_B line to deassert
2175 after PROB_B has been deasserted during a Virtex II
2176 FPGA configuration sequence. The default time is 500
2179 CONFIG_SYS_FPGA_WAIT_BUSY
2181 Maximum time to wait for BUSY to deassert during
2182 Virtex II FPGA configuration. The default is 5 ms.
2184 CONFIG_SYS_FPGA_WAIT_CONFIG
2186 Time to wait after FPGA configuration. The default is
2189 - Configuration Management:
2192 If defined, this string will be added to the U-Boot
2193 version information (U_BOOT_VERSION)
2195 - Vendor Parameter Protection:
2197 U-Boot considers the values of the environment
2198 variables "serial#" (Board Serial Number) and
2199 "ethaddr" (Ethernet Address) to be parameters that
2200 are set once by the board vendor / manufacturer, and
2201 protects these variables from casual modification by
2202 the user. Once set, these variables are read-only,
2203 and write or delete attempts are rejected. You can
2204 change this behaviour:
2206 If CONFIG_ENV_OVERWRITE is #defined in your config
2207 file, the write protection for vendor parameters is
2208 completely disabled. Anybody can change or delete
2211 Alternatively, if you #define _both_ CONFIG_ETHADDR
2212 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2213 Ethernet address is installed in the environment,
2214 which can be changed exactly ONCE by the user. [The
2215 serial# is unaffected by this, i. e. it remains
2218 The same can be accomplished in a more flexible way
2219 for any variable by configuring the type of access
2220 to allow for those variables in the ".flags" variable
2221 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2226 Define this variable to enable the reservation of
2227 "protected RAM", i. e. RAM which is not overwritten
2228 by U-Boot. Define CONFIG_PRAM to hold the number of
2229 kB you want to reserve for pRAM. You can overwrite
2230 this default value by defining an environment
2231 variable "pram" to the number of kB you want to
2232 reserve. Note that the board info structure will
2233 still show the full amount of RAM. If pRAM is
2234 reserved, a new environment variable "mem" will
2235 automatically be defined to hold the amount of
2236 remaining RAM in a form that can be passed as boot
2237 argument to Linux, for instance like that:
2239 setenv bootargs ... mem=\${mem}
2242 This way you can tell Linux not to use this memory,
2243 either, which results in a memory region that will
2244 not be affected by reboots.
2246 *WARNING* If your board configuration uses automatic
2247 detection of the RAM size, you must make sure that
2248 this memory test is non-destructive. So far, the
2249 following board configurations are known to be
2252 IVMS8, IVML24, SPD8xx, TQM8xxL,
2253 HERMES, IP860, RPXlite, LWMON,
2256 - Access to physical memory region (> 4GB)
2257 Some basic support is provided for operations on memory not
2258 normally accessible to U-Boot - e.g. some architectures
2259 support access to more than 4GB of memory on 32-bit
2260 machines using physical address extension or similar.
2261 Define CONFIG_PHYSMEM to access this basic support, which
2262 currently only supports clearing the memory.
2267 Define this variable to stop the system in case of a
2268 fatal error, so that you have to reset it manually.
2269 This is probably NOT a good idea for an embedded
2270 system where you want the system to reboot
2271 automatically as fast as possible, but it may be
2272 useful during development since you can try to debug
2273 the conditions that lead to the situation.
2275 CONFIG_NET_RETRY_COUNT
2277 This variable defines the number of retries for
2278 network operations like ARP, RARP, TFTP, or BOOTP
2279 before giving up the operation. If not defined, a
2280 default value of 5 is used.
2284 Timeout waiting for an ARP reply in milliseconds.
2288 Timeout in milliseconds used in NFS protocol.
2289 If you encounter "ERROR: Cannot umount" in nfs command,
2290 try longer timeout such as
2291 #define CONFIG_NFS_TIMEOUT 10000UL
2293 - Command Interpreter:
2294 CONFIG_AUTO_COMPLETE
2296 Enable auto completion of commands using TAB.
2298 Note that this feature has NOT been implemented yet
2299 for the "hush" shell.
2302 CONFIG_SYS_HUSH_PARSER
2304 Define this variable to enable the "hush" shell (from
2305 Busybox) as command line interpreter, thus enabling
2306 powerful command line syntax like
2307 if...then...else...fi conditionals or `&&' and '||'
2308 constructs ("shell scripts").
2310 If undefined, you get the old, much simpler behaviour
2311 with a somewhat smaller memory footprint.
2314 CONFIG_SYS_PROMPT_HUSH_PS2
2316 This defines the secondary prompt string, which is
2317 printed when the command interpreter needs more input
2318 to complete a command. Usually "> ".
2322 In the current implementation, the local variables
2323 space and global environment variables space are
2324 separated. Local variables are those you define by
2325 simply typing `name=value'. To access a local
2326 variable later on, you have write `$name' or
2327 `${name}'; to execute the contents of a variable
2328 directly type `$name' at the command prompt.
2330 Global environment variables are those you use
2331 setenv/printenv to work with. To run a command stored
2332 in such a variable, you need to use the run command,
2333 and you must not use the '$' sign to access them.
2335 To store commands and special characters in a
2336 variable, please use double quotation marks
2337 surrounding the whole text of the variable, instead
2338 of the backslashes before semicolons and special
2341 - Commandline Editing and History:
2342 CONFIG_CMDLINE_EDITING
2344 Enable editing and History functions for interactive
2345 commandline input operations
2347 - Default Environment:
2348 CONFIG_EXTRA_ENV_SETTINGS
2350 Define this to contain any number of null terminated
2351 strings (variable = value pairs) that will be part of
2352 the default environment compiled into the boot image.
2354 For example, place something like this in your
2355 board's config file:
2357 #define CONFIG_EXTRA_ENV_SETTINGS \
2361 Warning: This method is based on knowledge about the
2362 internal format how the environment is stored by the
2363 U-Boot code. This is NOT an official, exported
2364 interface! Although it is unlikely that this format
2365 will change soon, there is no guarantee either.
2366 You better know what you are doing here.
2368 Note: overly (ab)use of the default environment is
2369 discouraged. Make sure to check other ways to preset
2370 the environment like the "source" command or the
2373 CONFIG_ENV_VARS_UBOOT_CONFIG
2375 Define this in order to add variables describing the
2376 U-Boot build configuration to the default environment.
2377 These will be named arch, cpu, board, vendor, and soc.
2379 Enabling this option will cause the following to be defined:
2387 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2389 Define this in order to add variables describing certain
2390 run-time determined information about the hardware to the
2391 environment. These will be named board_name, board_rev.
2393 CONFIG_DELAY_ENVIRONMENT
2395 Normally the environment is loaded when the board is
2396 intialised so that it is available to U-Boot. This inhibits
2397 that so that the environment is not available until
2398 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2399 this is instead controlled by the value of
2400 /config/load-environment.
2402 - DataFlash Support:
2403 CONFIG_HAS_DATAFLASH
2405 Defining this option enables DataFlash features and
2406 allows to read/write in Dataflash via the standard
2409 - Serial Flash support
2412 Defining this option enables SPI flash commands
2413 'sf probe/read/write/erase/update'.
2415 Usage requires an initial 'probe' to define the serial
2416 flash parameters, followed by read/write/erase/update
2419 The following defaults may be provided by the platform
2420 to handle the common case when only a single serial
2421 flash is present on the system.
2423 CONFIG_SF_DEFAULT_BUS Bus identifier
2424 CONFIG_SF_DEFAULT_CS Chip-select
2425 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2426 CONFIG_SF_DEFAULT_SPEED in Hz
2430 Define this option to include a destructive SPI flash
2433 - SystemACE Support:
2436 Adding this option adds support for Xilinx SystemACE
2437 chips attached via some sort of local bus. The address
2438 of the chip must also be defined in the
2439 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2441 #define CONFIG_SYSTEMACE
2442 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2444 When SystemACE support is added, the "ace" device type
2445 becomes available to the fat commands, i.e. fatls.
2447 - TFTP Fixed UDP Port:
2450 If this is defined, the environment variable tftpsrcp
2451 is used to supply the TFTP UDP source port value.
2452 If tftpsrcp isn't defined, the normal pseudo-random port
2453 number generator is used.
2455 Also, the environment variable tftpdstp is used to supply
2456 the TFTP UDP destination port value. If tftpdstp isn't
2457 defined, the normal port 69 is used.
2459 The purpose for tftpsrcp is to allow a TFTP server to
2460 blindly start the TFTP transfer using the pre-configured
2461 target IP address and UDP port. This has the effect of
2462 "punching through" the (Windows XP) firewall, allowing
2463 the remainder of the TFTP transfer to proceed normally.
2464 A better solution is to properly configure the firewall,
2465 but sometimes that is not allowed.
2470 This enables a generic 'hash' command which can produce
2471 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2475 Enable the hash verify command (hash -v). This adds to code
2478 CONFIG_SHA1 - support SHA1 hashing
2479 CONFIG_SHA256 - support SHA256 hashing
2481 Note: There is also a sha1sum command, which should perhaps
2482 be deprecated in favour of 'hash sha1'.
2484 - Show boot progress:
2485 CONFIG_SHOW_BOOT_PROGRESS
2487 Defining this option allows to add some board-
2488 specific code (calling a user-provided function
2489 "show_boot_progress(int)") that enables you to show
2490 the system's boot progress on some display (for
2491 example, some LED's) on your board. At the moment,
2492 the following checkpoints are implemented:
2494 - Detailed boot stage timing
2496 Define this option to get detailed timing of each stage
2497 of the boot process.
2499 CONFIG_BOOTSTAGE_USER_COUNT
2500 This is the number of available user bootstage records.
2501 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2502 a new ID will be allocated from this stash. If you exceed
2503 the limit, recording will stop.
2505 CONFIG_BOOTSTAGE_REPORT
2506 Define this to print a report before boot, similar to this:
2508 Timer summary in microseconds:
2511 3,575,678 3,575,678 board_init_f start
2512 3,575,695 17 arch_cpu_init A9
2513 3,575,777 82 arch_cpu_init done
2514 3,659,598 83,821 board_init_r start
2515 3,910,375 250,777 main_loop
2516 29,916,167 26,005,792 bootm_start
2517 30,361,327 445,160 start_kernel
2519 CONFIG_CMD_BOOTSTAGE
2520 Add a 'bootstage' command which supports printing a report
2521 and un/stashing of bootstage data.
2523 CONFIG_BOOTSTAGE_FDT
2524 Stash the bootstage information in the FDT. A root 'bootstage'
2525 node is created with each bootstage id as a child. Each child
2526 has a 'name' property and either 'mark' containing the
2527 mark time in microsecond, or 'accum' containing the
2528 accumulated time for that bootstage id in microseconds.
2533 name = "board_init_f";
2542 Code in the Linux kernel can find this in /proc/devicetree.
2544 Legacy uImage format:
2547 1 common/cmd_bootm.c before attempting to boot an image
2548 -1 common/cmd_bootm.c Image header has bad magic number
2549 2 common/cmd_bootm.c Image header has correct magic number
2550 -2 common/cmd_bootm.c Image header has bad checksum
2551 3 common/cmd_bootm.c Image header has correct checksum
2552 -3 common/cmd_bootm.c Image data has bad checksum
2553 4 common/cmd_bootm.c Image data has correct checksum
2554 -4 common/cmd_bootm.c Image is for unsupported architecture
2555 5 common/cmd_bootm.c Architecture check OK
2556 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2557 6 common/cmd_bootm.c Image Type check OK
2558 -6 common/cmd_bootm.c gunzip uncompression error
2559 -7 common/cmd_bootm.c Unimplemented compression type
2560 7 common/cmd_bootm.c Uncompression OK
2561 8 common/cmd_bootm.c No uncompress/copy overwrite error
2562 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2564 9 common/image.c Start initial ramdisk verification
2565 -10 common/image.c Ramdisk header has bad magic number
2566 -11 common/image.c Ramdisk header has bad checksum
2567 10 common/image.c Ramdisk header is OK
2568 -12 common/image.c Ramdisk data has bad checksum
2569 11 common/image.c Ramdisk data has correct checksum
2570 12 common/image.c Ramdisk verification complete, start loading
2571 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2572 13 common/image.c Start multifile image verification
2573 14 common/image.c No initial ramdisk, no multifile, continue.
2575 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2577 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2578 -31 post/post.c POST test failed, detected by post_output_backlog()
2579 -32 post/post.c POST test failed, detected by post_run_single()
2581 34 common/cmd_doc.c before loading a Image from a DOC device
2582 -35 common/cmd_doc.c Bad usage of "doc" command
2583 35 common/cmd_doc.c correct usage of "doc" command
2584 -36 common/cmd_doc.c No boot device
2585 36 common/cmd_doc.c correct boot device
2586 -37 common/cmd_doc.c Unknown Chip ID on boot device
2587 37 common/cmd_doc.c correct chip ID found, device available
2588 -38 common/cmd_doc.c Read Error on boot device
2589 38 common/cmd_doc.c reading Image header from DOC device OK
2590 -39 common/cmd_doc.c Image header has bad magic number
2591 39 common/cmd_doc.c Image header has correct magic number
2592 -40 common/cmd_doc.c Error reading Image from DOC device
2593 40 common/cmd_doc.c Image header has correct magic number
2594 41 common/cmd_ide.c before loading a Image from a IDE device
2595 -42 common/cmd_ide.c Bad usage of "ide" command
2596 42 common/cmd_ide.c correct usage of "ide" command
2597 -43 common/cmd_ide.c No boot device
2598 43 common/cmd_ide.c boot device found
2599 -44 common/cmd_ide.c Device not available
2600 44 common/cmd_ide.c Device available
2601 -45 common/cmd_ide.c wrong partition selected
2602 45 common/cmd_ide.c partition selected
2603 -46 common/cmd_ide.c Unknown partition table
2604 46 common/cmd_ide.c valid partition table found
2605 -47 common/cmd_ide.c Invalid partition type
2606 47 common/cmd_ide.c correct partition type
2607 -48 common/cmd_ide.c Error reading Image Header on boot device
2608 48 common/cmd_ide.c reading Image Header from IDE device OK
2609 -49 common/cmd_ide.c Image header has bad magic number
2610 49 common/cmd_ide.c Image header has correct magic number
2611 -50 common/cmd_ide.c Image header has bad checksum
2612 50 common/cmd_ide.c Image header has correct checksum
2613 -51 common/cmd_ide.c Error reading Image from IDE device
2614 51 common/cmd_ide.c reading Image from IDE device OK
2615 52 common/cmd_nand.c before loading a Image from a NAND device
2616 -53 common/cmd_nand.c Bad usage of "nand" command
2617 53 common/cmd_nand.c correct usage of "nand" command
2618 -54 common/cmd_nand.c No boot device
2619 54 common/cmd_nand.c boot device found
2620 -55 common/cmd_nand.c Unknown Chip ID on boot device
2621 55 common/cmd_nand.c correct chip ID found, device available
2622 -56 common/cmd_nand.c Error reading Image Header on boot device
2623 56 common/cmd_nand.c reading Image Header from NAND device OK
2624 -57 common/cmd_nand.c Image header has bad magic number
2625 57 common/cmd_nand.c Image header has correct magic number
2626 -58 common/cmd_nand.c Error reading Image from NAND device
2627 58 common/cmd_nand.c reading Image from NAND device OK
2629 -60 common/env_common.c Environment has a bad CRC, using default
2631 64 net/eth.c starting with Ethernet configuration.
2632 -64 net/eth.c no Ethernet found.
2633 65 net/eth.c Ethernet found.
2635 -80 common/cmd_net.c usage wrong
2636 80 common/cmd_net.c before calling NetLoop()
2637 -81 common/cmd_net.c some error in NetLoop() occurred
2638 81 common/cmd_net.c NetLoop() back without error
2639 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2640 82 common/cmd_net.c trying automatic boot
2641 83 common/cmd_net.c running "source" command
2642 -83 common/cmd_net.c some error in automatic boot or "source" command
2643 84 common/cmd_net.c end without errors
2648 100 common/cmd_bootm.c Kernel FIT Image has correct format
2649 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2650 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2651 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2652 102 common/cmd_bootm.c Kernel unit name specified
2653 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2654 103 common/cmd_bootm.c Found configuration node
2655 104 common/cmd_bootm.c Got kernel subimage node offset
2656 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2657 105 common/cmd_bootm.c Kernel subimage hash verification OK
2658 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2659 106 common/cmd_bootm.c Architecture check OK
2660 -106 common/cmd_bootm.c Kernel subimage has wrong type
2661 107 common/cmd_bootm.c Kernel subimage type OK
2662 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2663 108 common/cmd_bootm.c Got kernel subimage data/size
2664 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2665 -109 common/cmd_bootm.c Can't get kernel subimage type
2666 -110 common/cmd_bootm.c Can't get kernel subimage comp
2667 -111 common/cmd_bootm.c Can't get kernel subimage os
2668 -112 common/cmd_bootm.c Can't get kernel subimage load address
2669 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2671 120 common/image.c Start initial ramdisk verification
2672 -120 common/image.c Ramdisk FIT image has incorrect format
2673 121 common/image.c Ramdisk FIT image has correct format
2674 122 common/image.c No ramdisk subimage unit name, using configuration
2675 -122 common/image.c Can't get configuration for ramdisk subimage
2676 123 common/image.c Ramdisk unit name specified
2677 -124 common/image.c Can't get ramdisk subimage node offset
2678 125 common/image.c Got ramdisk subimage node offset
2679 -125 common/image.c Ramdisk subimage hash verification failed
2680 126 common/image.c Ramdisk subimage hash verification OK
2681 -126 common/image.c Ramdisk subimage for unsupported architecture
2682 127 common/image.c Architecture check OK
2683 -127 common/image.c Can't get ramdisk subimage data/size
2684 128 common/image.c Got ramdisk subimage data/size
2685 129 common/image.c Can't get ramdisk load address
2686 -129 common/image.c Got ramdisk load address
2688 -130 common/cmd_doc.c Incorrect FIT image format
2689 131 common/cmd_doc.c FIT image format OK
2691 -140 common/cmd_ide.c Incorrect FIT image format
2692 141 common/cmd_ide.c FIT image format OK
2694 -150 common/cmd_nand.c Incorrect FIT image format
2695 151 common/cmd_nand.c FIT image format OK
2697 - FIT image support:
2699 Enable support for the FIT uImage format.
2701 CONFIG_FIT_BEST_MATCH
2702 When no configuration is explicitly selected, default to the
2703 one whose fdt's compatibility field best matches that of
2704 U-Boot itself. A match is considered "best" if it matches the
2705 most specific compatibility entry of U-Boot's fdt's root node.
2706 The order of entries in the configuration's fdt is ignored.
2708 - Standalone program support:
2709 CONFIG_STANDALONE_LOAD_ADDR
2711 This option defines a board specific value for the
2712 address where standalone program gets loaded, thus
2713 overwriting the architecture dependent default
2716 - Frame Buffer Address:
2719 Define CONFIG_FB_ADDR if you want to use specific
2720 address for frame buffer. This is typically the case
2721 when using a graphics controller has separate video
2722 memory. U-Boot will then place the frame buffer at
2723 the given address instead of dynamically reserving it
2724 in system RAM by calling lcd_setmem(), which grabs
2725 the memory for the frame buffer depending on the
2726 configured panel size.
2728 Please see board_init_f function.
2730 - Automatic software updates via TFTP server
2732 CONFIG_UPDATE_TFTP_CNT_MAX
2733 CONFIG_UPDATE_TFTP_MSEC_MAX
2735 These options enable and control the auto-update feature;
2736 for a more detailed description refer to doc/README.update.
2738 - MTD Support (mtdparts command, UBI support)
2741 Adds the MTD device infrastructure from the Linux kernel.
2742 Needed for mtdparts command support.
2744 CONFIG_MTD_PARTITIONS
2746 Adds the MTD partitioning infrastructure from the Linux
2747 kernel. Needed for UBI support.
2751 Enable building of SPL globally.
2754 LDSCRIPT for linking the SPL binary.
2757 Maximum binary size (text, data and rodata) of the SPL binary.
2759 CONFIG_SPL_TEXT_BASE
2760 TEXT_BASE for linking the SPL binary.
2762 CONFIG_SPL_RELOC_TEXT_BASE
2763 Address to relocate to. If unspecified, this is equal to
2764 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2766 CONFIG_SPL_BSS_START_ADDR
2767 Link address for the BSS within the SPL binary.
2769 CONFIG_SPL_BSS_MAX_SIZE
2770 Maximum binary size of the BSS section of the SPL binary.
2773 Adress of the start of the stack SPL will use
2775 CONFIG_SPL_RELOC_STACK
2776 Adress of the start of the stack SPL will use after
2777 relocation. If unspecified, this is equal to
2780 CONFIG_SYS_SPL_MALLOC_START
2781 Starting address of the malloc pool used in SPL.
2783 CONFIG_SYS_SPL_MALLOC_SIZE
2784 The size of the malloc pool used in SPL.
2786 CONFIG_SPL_FRAMEWORK
2787 Enable the SPL framework under common/. This framework
2788 supports MMC, NAND and YMODEM loading of U-Boot and NAND
2789 NAND loading of the Linux Kernel.
2791 CONFIG_SPL_DISPLAY_PRINT
2792 For ARM, enable an optional function to print more information
2793 about the running system.
2795 CONFIG_SPL_INIT_MINIMAL
2796 Arch init code should be built for a very small image
2798 CONFIG_SPL_LIBCOMMON_SUPPORT
2799 Support for common/libcommon.o in SPL binary
2801 CONFIG_SPL_LIBDISK_SUPPORT
2802 Support for disk/libdisk.o in SPL binary
2804 CONFIG_SPL_I2C_SUPPORT
2805 Support for drivers/i2c/libi2c.o in SPL binary
2807 CONFIG_SPL_GPIO_SUPPORT
2808 Support for drivers/gpio/libgpio.o in SPL binary
2810 CONFIG_SPL_MMC_SUPPORT
2811 Support for drivers/mmc/libmmc.o in SPL binary
2813 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
2814 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
2815 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
2816 Address, size and partition on the MMC to load U-Boot from
2817 when the MMC is being used in raw mode.
2819 CONFIG_SPL_FAT_SUPPORT
2820 Support for fs/fat/libfat.o in SPL binary
2822 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
2823 Filename to read to load U-Boot when reading from FAT
2825 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
2826 Set this for NAND SPL on PPC mpc83xx targets, so that
2827 start.S waits for the rest of the SPL to load before
2828 continuing (the hardware starts execution after just
2829 loading the first page rather than the full 4K).
2831 CONFIG_SPL_NAND_BASE
2832 Include nand_base.c in the SPL. Requires
2833 CONFIG_SPL_NAND_DRIVERS.
2835 CONFIG_SPL_NAND_DRIVERS
2836 SPL uses normal NAND drivers, not minimal drivers.
2839 Include standard software ECC in the SPL
2841 CONFIG_SPL_NAND_SIMPLE
2842 Support for NAND boot using simple NAND drivers that
2843 expose the cmd_ctrl() interface.
2845 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
2846 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
2847 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
2848 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
2849 CONFIG_SYS_NAND_ECCBYTES
2850 Defines the size and behavior of the NAND that SPL uses
2853 CONFIG_SYS_NAND_U_BOOT_OFFS
2854 Location in NAND to read U-Boot from
2856 CONFIG_SYS_NAND_U_BOOT_DST
2857 Location in memory to load U-Boot to
2859 CONFIG_SYS_NAND_U_BOOT_SIZE
2860 Size of image to load
2862 CONFIG_SYS_NAND_U_BOOT_START
2863 Entry point in loaded image to jump to
2865 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
2866 Define this if you need to first read the OOB and then the
2867 data. This is used for example on davinci plattforms.
2869 CONFIG_SPL_OMAP3_ID_NAND
2870 Support for an OMAP3-specific set of functions to return the
2871 ID and MFR of the first attached NAND chip, if present.
2873 CONFIG_SPL_SERIAL_SUPPORT
2874 Support for drivers/serial/libserial.o in SPL binary
2876 CONFIG_SPL_SPI_FLASH_SUPPORT
2877 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
2879 CONFIG_SPL_SPI_SUPPORT
2880 Support for drivers/spi/libspi.o in SPL binary
2882 CONFIG_SPL_RAM_DEVICE
2883 Support for running image already present in ram, in SPL binary
2885 CONFIG_SPL_LIBGENERIC_SUPPORT
2886 Support for lib/libgeneric.o in SPL binary
2889 Linker address to which the SPL should be padded before
2890 appending the SPL payload.
2893 Final target image containing SPL and payload. Some SPLs
2894 use an arch-specific makefile fragment instead, for
2895 example if more than one image needs to be produced.
2900 [so far only for SMDK2400 boards]
2902 - Modem support enable:
2903 CONFIG_MODEM_SUPPORT
2905 - RTS/CTS Flow control enable:
2908 - Modem debug support:
2909 CONFIG_MODEM_SUPPORT_DEBUG
2911 Enables debugging stuff (char screen[1024], dbg())
2912 for modem support. Useful only with BDI2000.
2914 - Interrupt support (PPC):
2916 There are common interrupt_init() and timer_interrupt()
2917 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2918 for CPU specific initialization. interrupt_init_cpu()
2919 should set decrementer_count to appropriate value. If
2920 CPU resets decrementer automatically after interrupt
2921 (ppc4xx) it should set decrementer_count to zero.
2922 timer_interrupt() calls timer_interrupt_cpu() for CPU
2923 specific handling. If board has watchdog / status_led
2924 / other_activity_monitor it works automatically from
2925 general timer_interrupt().
2929 In the target system modem support is enabled when a
2930 specific key (key combination) is pressed during
2931 power-on. Otherwise U-Boot will boot normally
2932 (autoboot). The key_pressed() function is called from
2933 board_init(). Currently key_pressed() is a dummy
2934 function, returning 1 and thus enabling modem
2937 If there are no modem init strings in the
2938 environment, U-Boot proceed to autoboot; the
2939 previous output (banner, info printfs) will be
2942 See also: doc/README.Modem
2944 Board initialization settings:
2945 ------------------------------
2947 During Initialization u-boot calls a number of board specific functions
2948 to allow the preparation of board specific prerequisites, e.g. pin setup
2949 before drivers are initialized. To enable these callbacks the
2950 following configuration macros have to be defined. Currently this is
2951 architecture specific, so please check arch/your_architecture/lib/board.c
2952 typically in board_init_f() and board_init_r().
2954 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
2955 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
2956 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
2957 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
2959 Configuration Settings:
2960 -----------------------
2962 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2963 undefine this when you're short of memory.
2965 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2966 width of the commands listed in the 'help' command output.
2968 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2969 prompt for user input.
2971 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2973 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2975 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2977 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2978 the application (usually a Linux kernel) when it is
2981 - CONFIG_SYS_BAUDRATE_TABLE:
2982 List of legal baudrate settings for this board.
2984 - CONFIG_SYS_CONSOLE_INFO_QUIET
2985 Suppress display of console information at boot.
2987 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2988 If the board specific function
2989 extern int overwrite_console (void);
2990 returns 1, the stdin, stderr and stdout are switched to the
2991 serial port, else the settings in the environment are used.
2993 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2994 Enable the call to overwrite_console().
2996 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2997 Enable overwrite of previous console environment settings.
2999 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3000 Begin and End addresses of the area used by the
3003 - CONFIG_SYS_ALT_MEMTEST:
3004 Enable an alternate, more extensive memory test.
3006 - CONFIG_SYS_MEMTEST_SCRATCH:
3007 Scratch address used by the alternate memory test
3008 You only need to set this if address zero isn't writeable
3010 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3011 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3012 this specified memory area will get subtracted from the top
3013 (end) of RAM and won't get "touched" at all by U-Boot. By
3014 fixing up gd->ram_size the Linux kernel should gets passed
3015 the now "corrected" memory size and won't touch it either.
3016 This should work for arch/ppc and arch/powerpc. Only Linux
3017 board ports in arch/powerpc with bootwrapper support that
3018 recalculate the memory size from the SDRAM controller setup
3019 will have to get fixed in Linux additionally.
3021 This option can be used as a workaround for the 440EPx/GRx
3022 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3025 WARNING: Please make sure that this value is a multiple of
3026 the Linux page size (normally 4k). If this is not the case,
3027 then the end address of the Linux memory will be located at a
3028 non page size aligned address and this could cause major
3031 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3032 Enable temporary baudrate change while serial download
3034 - CONFIG_SYS_SDRAM_BASE:
3035 Physical start address of SDRAM. _Must_ be 0 here.
3037 - CONFIG_SYS_MBIO_BASE:
3038 Physical start address of Motherboard I/O (if using a
3041 - CONFIG_SYS_FLASH_BASE:
3042 Physical start address of Flash memory.
3044 - CONFIG_SYS_MONITOR_BASE:
3045 Physical start address of boot monitor code (set by
3046 make config files to be same as the text base address
3047 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3048 CONFIG_SYS_FLASH_BASE when booting from flash.
3050 - CONFIG_SYS_MONITOR_LEN:
3051 Size of memory reserved for monitor code, used to
3052 determine _at_compile_time_ (!) if the environment is
3053 embedded within the U-Boot image, or in a separate
3056 - CONFIG_SYS_MALLOC_LEN:
3057 Size of DRAM reserved for malloc() use.
3059 - CONFIG_SYS_BOOTM_LEN:
3060 Normally compressed uImages are limited to an
3061 uncompressed size of 8 MBytes. If this is not enough,
3062 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3063 to adjust this setting to your needs.
3065 - CONFIG_SYS_BOOTMAPSZ:
3066 Maximum size of memory mapped by the startup code of
3067 the Linux kernel; all data that must be processed by
3068 the Linux kernel (bd_info, boot arguments, FDT blob if
3069 used) must be put below this limit, unless "bootm_low"
3070 enviroment variable is defined and non-zero. In such case
3071 all data for the Linux kernel must be between "bootm_low"
3072 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3073 variable "bootm_mapsize" will override the value of
3074 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3075 then the value in "bootm_size" will be used instead.
3077 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3078 Enable initrd_high functionality. If defined then the
3079 initrd_high feature is enabled and the bootm ramdisk subcommand
3082 - CONFIG_SYS_BOOT_GET_CMDLINE:
3083 Enables allocating and saving kernel cmdline in space between
3084 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3086 - CONFIG_SYS_BOOT_GET_KBD:
3087 Enables allocating and saving a kernel copy of the bd_info in
3088 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3090 - CONFIG_SYS_MAX_FLASH_BANKS:
3091 Max number of Flash memory banks
3093 - CONFIG_SYS_MAX_FLASH_SECT:
3094 Max number of sectors on a Flash chip
3096 - CONFIG_SYS_FLASH_ERASE_TOUT:
3097 Timeout for Flash erase operations (in ms)
3099 - CONFIG_SYS_FLASH_WRITE_TOUT:
3100 Timeout for Flash write operations (in ms)
3102 - CONFIG_SYS_FLASH_LOCK_TOUT
3103 Timeout for Flash set sector lock bit operation (in ms)
3105 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3106 Timeout for Flash clear lock bits operation (in ms)
3108 - CONFIG_SYS_FLASH_PROTECTION
3109 If defined, hardware flash sectors protection is used
3110 instead of U-Boot software protection.
3112 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3114 Enable TFTP transfers directly to flash memory;
3115 without this option such a download has to be
3116 performed in two steps: (1) download to RAM, and (2)
3117 copy from RAM to flash.
3119 The two-step approach is usually more reliable, since
3120 you can check if the download worked before you erase
3121 the flash, but in some situations (when system RAM is
3122 too limited to allow for a temporary copy of the
3123 downloaded image) this option may be very useful.
3125 - CONFIG_SYS_FLASH_CFI:
3126 Define if the flash driver uses extra elements in the
3127 common flash structure for storing flash geometry.
3129 - CONFIG_FLASH_CFI_DRIVER
3130 This option also enables the building of the cfi_flash driver
3131 in the drivers directory
3133 - CONFIG_FLASH_CFI_MTD
3134 This option enables the building of the cfi_mtd driver
3135 in the drivers directory. The driver exports CFI flash
3138 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3139 Use buffered writes to flash.
3141 - CONFIG_FLASH_SPANSION_S29WS_N
3142 s29ws-n MirrorBit flash has non-standard addresses for buffered
3145 - CONFIG_SYS_FLASH_QUIET_TEST
3146 If this option is defined, the common CFI flash doesn't
3147 print it's warning upon not recognized FLASH banks. This
3148 is useful, if some of the configured banks are only
3149 optionally available.
3151 - CONFIG_FLASH_SHOW_PROGRESS
3152 If defined (must be an integer), print out countdown
3153 digits and dots. Recommended value: 45 (9..1) for 80
3154 column displays, 15 (3..1) for 40 column displays.
3156 - CONFIG_SYS_RX_ETH_BUFFER:
3157 Defines the number of Ethernet receive buffers. On some
3158 Ethernet controllers it is recommended to set this value
3159 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3160 buffers can be full shortly after enabling the interface
3161 on high Ethernet traffic.
3162 Defaults to 4 if not defined.
3164 - CONFIG_ENV_MAX_ENTRIES
3166 Maximum number of entries in the hash table that is used
3167 internally to store the environment settings. The default
3168 setting is supposed to be generous and should work in most
3169 cases. This setting can be used to tune behaviour; see
3170 lib/hashtable.c for details.
3172 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3173 - CONFIG_ENV_FLAGS_LIST_STATIC
3174 Enable validation of the values given to enviroment variables when
3175 calling env set. Variables can be restricted to only decimal,
3176 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3177 the variables can also be restricted to IP address or MAC address.
3179 The format of the list is:
3180 type_attribute = [s|d|x|b|i|m]
3181 access_atribute = [a|r|o|c]
3182 attributes = type_attribute[access_atribute]
3183 entry = variable_name[:attributes]
3186 The type attributes are:
3187 s - String (default)
3190 b - Boolean ([1yYtT|0nNfF])
3194 The access attributes are:
3200 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3201 Define this to a list (string) to define the ".flags"
3202 envirnoment variable in the default or embedded environment.
3204 - CONFIG_ENV_FLAGS_LIST_STATIC
3205 Define this to a list (string) to define validation that
3206 should be done if an entry is not found in the ".flags"
3207 environment variable. To override a setting in the static
3208 list, simply add an entry for the same variable name to the
3211 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3212 If defined, don't allow the -f switch to env set override variable
3215 The following definitions that deal with the placement and management
3216 of environment data (variable area); in general, we support the
3217 following configurations:
3219 - CONFIG_BUILD_ENVCRC:
3221 Builds up envcrc with the target environment so that external utils
3222 may easily extract it and embed it in final U-Boot images.
3224 - CONFIG_ENV_IS_IN_FLASH:
3226 Define this if the environment is in flash memory.
3228 a) The environment occupies one whole flash sector, which is
3229 "embedded" in the text segment with the U-Boot code. This
3230 happens usually with "bottom boot sector" or "top boot
3231 sector" type flash chips, which have several smaller
3232 sectors at the start or the end. For instance, such a
3233 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3234 such a case you would place the environment in one of the
3235 4 kB sectors - with U-Boot code before and after it. With
3236 "top boot sector" type flash chips, you would put the
3237 environment in one of the last sectors, leaving a gap
3238 between U-Boot and the environment.
3240 - CONFIG_ENV_OFFSET:
3242 Offset of environment data (variable area) to the
3243 beginning of flash memory; for instance, with bottom boot
3244 type flash chips the second sector can be used: the offset
3245 for this sector is given here.
3247 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3251 This is just another way to specify the start address of
3252 the flash sector containing the environment (instead of
3255 - CONFIG_ENV_SECT_SIZE:
3257 Size of the sector containing the environment.
3260 b) Sometimes flash chips have few, equal sized, BIG sectors.
3261 In such a case you don't want to spend a whole sector for
3266 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3267 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3268 of this flash sector for the environment. This saves
3269 memory for the RAM copy of the environment.
3271 It may also save flash memory if you decide to use this
3272 when your environment is "embedded" within U-Boot code,
3273 since then the remainder of the flash sector could be used
3274 for U-Boot code. It should be pointed out that this is
3275 STRONGLY DISCOURAGED from a robustness point of view:
3276 updating the environment in flash makes it always
3277 necessary to erase the WHOLE sector. If something goes
3278 wrong before the contents has been restored from a copy in
3279 RAM, your target system will be dead.
3281 - CONFIG_ENV_ADDR_REDUND
3282 CONFIG_ENV_SIZE_REDUND
3284 These settings describe a second storage area used to hold
3285 a redundant copy of the environment data, so that there is
3286 a valid backup copy in case there is a power failure during
3287 a "saveenv" operation.
3289 BE CAREFUL! Any changes to the flash layout, and some changes to the
3290 source code will make it necessary to adapt <board>/u-boot.lds*
3294 - CONFIG_ENV_IS_IN_NVRAM:
3296 Define this if you have some non-volatile memory device
3297 (NVRAM, battery buffered SRAM) which you want to use for the
3303 These two #defines are used to determine the memory area you
3304 want to use for environment. It is assumed that this memory
3305 can just be read and written to, without any special
3308 BE CAREFUL! The first access to the environment happens quite early
3309 in U-Boot initalization (when we try to get the setting of for the
3310 console baudrate). You *MUST* have mapped your NVRAM area then, or
3313 Please note that even with NVRAM we still use a copy of the
3314 environment in RAM: we could work on NVRAM directly, but we want to
3315 keep settings there always unmodified except somebody uses "saveenv"
3316 to save the current settings.
3319 - CONFIG_ENV_IS_IN_EEPROM:
3321 Use this if you have an EEPROM or similar serial access
3322 device and a driver for it.
3324 - CONFIG_ENV_OFFSET:
3327 These two #defines specify the offset and size of the
3328 environment area within the total memory of your EEPROM.
3330 - CONFIG_SYS_I2C_EEPROM_ADDR:
3331 If defined, specified the chip address of the EEPROM device.
3332 The default address is zero.
3334 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3335 If defined, the number of bits used to address bytes in a
3336 single page in the EEPROM device. A 64 byte page, for example
3337 would require six bits.
3339 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3340 If defined, the number of milliseconds to delay between
3341 page writes. The default is zero milliseconds.
3343 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3344 The length in bytes of the EEPROM memory array address. Note
3345 that this is NOT the chip address length!
3347 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3348 EEPROM chips that implement "address overflow" are ones
3349 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3350 address and the extra bits end up in the "chip address" bit
3351 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3354 Note that we consider the length of the address field to
3355 still be one byte because the extra address bits are hidden
3356 in the chip address.
3358 - CONFIG_SYS_EEPROM_SIZE:
3359 The size in bytes of the EEPROM device.
3361 - CONFIG_ENV_EEPROM_IS_ON_I2C
3362 define this, if you have I2C and SPI activated, and your
3363 EEPROM, which holds the environment, is on the I2C bus.
3365 - CONFIG_I2C_ENV_EEPROM_BUS
3366 if you have an Environment on an EEPROM reached over
3367 I2C muxes, you can define here, how to reach this
3368 EEPROM. For example:
3370 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
3372 EEPROM which holds the environment, is reached over
3373 a pca9547 i2c mux with address 0x70, channel 3.
3375 - CONFIG_ENV_IS_IN_DATAFLASH:
3377 Define this if you have a DataFlash memory device which you
3378 want to use for the environment.
3380 - CONFIG_ENV_OFFSET:
3384 These three #defines specify the offset and size of the
3385 environment area within the total memory of your DataFlash placed
3386 at the specified address.
3388 - CONFIG_ENV_IS_IN_REMOTE:
3390 Define this if you have a remote memory space which you
3391 want to use for the local device's environment.
3396 These two #defines specify the address and size of the
3397 environment area within the remote memory space. The
3398 local device can get the environment from remote memory
3399 space by SRIO or PCIE links.
3401 BE CAREFUL! For some special cases, the local device can not use
3402 "saveenv" command. For example, the local device will get the
3403 environment stored in a remote NOR flash by SRIO or PCIE link,
3404 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3406 - CONFIG_ENV_IS_IN_NAND:
3408 Define this if you have a NAND device which you want to use
3409 for the environment.
3411 - CONFIG_ENV_OFFSET:
3414 These two #defines specify the offset and size of the environment
3415 area within the first NAND device. CONFIG_ENV_OFFSET must be
3416 aligned to an erase block boundary.
3418 - CONFIG_ENV_OFFSET_REDUND (optional):
3420 This setting describes a second storage area of CONFIG_ENV_SIZE
3421 size used to hold a redundant copy of the environment data, so
3422 that there is a valid backup copy in case there is a power failure
3423 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3424 aligned to an erase block boundary.
3426 - CONFIG_ENV_RANGE (optional):
3428 Specifies the length of the region in which the environment
3429 can be written. This should be a multiple of the NAND device's
3430 block size. Specifying a range with more erase blocks than
3431 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3432 the range to be avoided.
3434 - CONFIG_ENV_OFFSET_OOB (optional):
3436 Enables support for dynamically retrieving the offset of the
3437 environment from block zero's out-of-band data. The
3438 "nand env.oob" command can be used to record this offset.
3439 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3440 using CONFIG_ENV_OFFSET_OOB.
3442 - CONFIG_NAND_ENV_DST
3444 Defines address in RAM to which the nand_spl code should copy the
3445 environment. If redundant environment is used, it will be copied to
3446 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3448 - CONFIG_SYS_SPI_INIT_OFFSET
3450 Defines offset to the initial SPI buffer area in DPRAM. The
3451 area is used at an early stage (ROM part) if the environment
3452 is configured to reside in the SPI EEPROM: We need a 520 byte
3453 scratch DPRAM area. It is used between the two initialization
3454 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3455 to be a good choice since it makes it far enough from the
3456 start of the data area as well as from the stack pointer.
3458 Please note that the environment is read-only until the monitor
3459 has been relocated to RAM and a RAM copy of the environment has been
3460 created; also, when using EEPROM you will have to use getenv_f()
3461 until then to read environment variables.
3463 The environment is protected by a CRC32 checksum. Before the monitor
3464 is relocated into RAM, as a result of a bad CRC you will be working
3465 with the compiled-in default environment - *silently*!!! [This is
3466 necessary, because the first environment variable we need is the
3467 "baudrate" setting for the console - if we have a bad CRC, we don't
3468 have any device yet where we could complain.]
3470 Note: once the monitor has been relocated, then it will complain if
3471 the default environment is used; a new CRC is computed as soon as you
3472 use the "saveenv" command to store a valid environment.
3474 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3475 Echo the inverted Ethernet link state to the fault LED.
3477 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3478 also needs to be defined.
3480 - CONFIG_SYS_FAULT_MII_ADDR:
3481 MII address of the PHY to check for the Ethernet link state.
3483 - CONFIG_NS16550_MIN_FUNCTIONS:
3484 Define this if you desire to only have use of the NS16550_init
3485 and NS16550_putc functions for the serial driver located at
3486 drivers/serial/ns16550.c. This option is useful for saving
3487 space for already greatly restricted images, including but not
3488 limited to NAND_SPL configurations.
3490 - CONFIG_DISPLAY_BOARDINFO
3491 Display information about the board that U-Boot is running on
3492 when U-Boot starts up. The board function checkboard() is called
3495 - CONFIG_DISPLAY_BOARDINFO_LATE
3496 Similar to the previous option, but display this information
3497 later, once stdio is running and output goes to the LCD, if
3500 Low Level (hardware related) configuration options:
3501 ---------------------------------------------------
3503 - CONFIG_SYS_CACHELINE_SIZE:
3504 Cache Line Size of the CPU.
3506 - CONFIG_SYS_DEFAULT_IMMR:
3507 Default address of the IMMR after system reset.
3509 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3510 and RPXsuper) to be able to adjust the position of
3511 the IMMR register after a reset.
3513 - CONFIG_SYS_CCSRBAR_DEFAULT:
3514 Default (power-on reset) physical address of CCSR on Freescale
3517 - CONFIG_SYS_CCSRBAR:
3518 Virtual address of CCSR. On a 32-bit build, this is typically
3519 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3521 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3522 for cross-platform code that uses that macro instead.
3524 - CONFIG_SYS_CCSRBAR_PHYS:
3525 Physical address of CCSR. CCSR can be relocated to a new
3526 physical address, if desired. In this case, this macro should
3527 be set to that address. Otherwise, it should be set to the
3528 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3529 is typically relocated on 36-bit builds. It is recommended
3530 that this macro be defined via the _HIGH and _LOW macros:
3532 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3533 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3535 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3536 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3537 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3538 used in assembly code, so it must not contain typecasts or
3539 integer size suffixes (e.g. "ULL").
3541 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3542 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3543 used in assembly code, so it must not contain typecasts or
3544 integer size suffixes (e.g. "ULL").
3546 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3547 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3548 forced to a value that ensures that CCSR is not relocated.
3550 - Floppy Disk Support:
3551 CONFIG_SYS_FDC_DRIVE_NUMBER
3553 the default drive number (default value 0)
3555 CONFIG_SYS_ISA_IO_STRIDE
3557 defines the spacing between FDC chipset registers
3560 CONFIG_SYS_ISA_IO_OFFSET
3562 defines the offset of register from address. It
3563 depends on which part of the data bus is connected to
3564 the FDC chipset. (default value 0)
3566 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3567 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3570 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3571 fdc_hw_init() is called at the beginning of the FDC
3572 setup. fdc_hw_init() must be provided by the board
3573 source code. It is used to make hardware dependant
3577 Most IDE controllers were designed to be connected with PCI
3578 interface. Only few of them were designed for AHB interface.
3579 When software is doing ATA command and data transfer to
3580 IDE devices through IDE-AHB controller, some additional
3581 registers accessing to these kind of IDE-AHB controller
3584 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3585 DO NOT CHANGE unless you know exactly what you're
3586 doing! (11-4) [MPC8xx/82xx systems only]
3588 - CONFIG_SYS_INIT_RAM_ADDR:
3590 Start address of memory area that can be used for
3591 initial data and stack; please note that this must be
3592 writable memory that is working WITHOUT special
3593 initialization, i. e. you CANNOT use normal RAM which
3594 will become available only after programming the
3595 memory controller and running certain initialization
3598 U-Boot uses the following memory types:
3599 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
3600 - MPC824X: data cache
3601 - PPC4xx: data cache
3603 - CONFIG_SYS_GBL_DATA_OFFSET:
3605 Offset of the initial data structure in the memory
3606 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3607 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3608 data is located at the end of the available space
3609 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3610 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
3611 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3612 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3615 On the MPC824X (or other systems that use the data
3616 cache for initial memory) the address chosen for
3617 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3618 point to an otherwise UNUSED address space between
3619 the top of RAM and the start of the PCI space.
3621 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
3623 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
3625 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
3627 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
3629 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
3631 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3633 - CONFIG_SYS_OR_TIMING_SDRAM:
3636 - CONFIG_SYS_MAMR_PTA:
3637 periodic timer for refresh
3639 - CONFIG_SYS_DER: Debug Event Register (37-47)
3641 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3642 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3643 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3644 CONFIG_SYS_BR1_PRELIM:
3645 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3647 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3648 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3649 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3650 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3652 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
3653 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
3654 Machine Mode Register and Memory Periodic Timer
3655 Prescaler definitions (SDRAM timing)
3657 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
3658 enable I2C microcode relocation patch (MPC8xx);
3659 define relocation offset in DPRAM [DSP2]
3661 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
3662 enable SMC microcode relocation patch (MPC8xx);
3663 define relocation offset in DPRAM [SMC1]
3665 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
3666 enable SPI microcode relocation patch (MPC8xx);
3667 define relocation offset in DPRAM [SCC4]
3669 - CONFIG_SYS_USE_OSCCLK:
3670 Use OSCM clock mode on MBX8xx board. Be careful,
3671 wrong setting might damage your board. Read
3672 doc/README.MBX before setting this variable!
3674 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
3675 Offset of the bootmode word in DPRAM used by post
3676 (Power On Self Tests). This definition overrides
3677 #define'd default value in commproc.h resp.
3680 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
3681 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
3682 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
3683 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
3684 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
3685 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
3686 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
3687 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
3688 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
3690 - CONFIG_PCI_DISABLE_PCIE:
3691 Disable PCI-Express on systems where it is supported but not
3694 - CONFIG_PCI_ENUM_ONLY
3695 Only scan through and get the devices on the busses.
3696 Don't do any setup work, presumably because someone or
3697 something has already done it, and we don't need to do it
3698 a second time. Useful for platforms that are pre-booted
3699 by coreboot or similar.
3702 Chip has SRIO or not
3705 Board has SRIO 1 port available
3708 Board has SRIO 2 port available
3710 - CONFIG_SYS_SRIOn_MEM_VIRT:
3711 Virtual Address of SRIO port 'n' memory region
3713 - CONFIG_SYS_SRIOn_MEM_PHYS:
3714 Physical Address of SRIO port 'n' memory region
3716 - CONFIG_SYS_SRIOn_MEM_SIZE:
3717 Size of SRIO port 'n' memory region
3719 - CONFIG_SYS_NDFC_16
3720 Defined to tell the NDFC that the NAND chip is using a
3723 - CONFIG_SYS_NDFC_EBC0_CFG
3724 Sets the EBC0_CFG register for the NDFC. If not defined
3725 a default value will be used.
3728 Get DDR timing information from an I2C EEPROM. Common
3729 with pluggable memory modules such as SODIMMs
3732 I2C address of the SPD EEPROM
3734 - CONFIG_SYS_SPD_BUS_NUM
3735 If SPD EEPROM is on an I2C bus other than the first
3736 one, specify here. Note that the value must resolve
3737 to something your driver can deal with.
3739 - CONFIG_SYS_DDR_RAW_TIMING
3740 Get DDR timing information from other than SPD. Common with
3741 soldered DDR chips onboard without SPD. DDR raw timing
3742 parameters are extracted from datasheet and hard-coded into
3743 header files or board specific files.
3745 - CONFIG_FSL_DDR_INTERACTIVE
3746 Enable interactive DDR debugging. See doc/README.fsl-ddr.
3748 - CONFIG_SYS_83XX_DDR_USES_CS0
3749 Only for 83xx systems. If specified, then DDR should
3750 be configured using CS0 and CS1 instead of CS2 and CS3.
3752 - CONFIG_ETHER_ON_FEC[12]
3753 Define to enable FEC[12] on a 8xx series processor.
3755 - CONFIG_FEC[12]_PHY
3756 Define to the hardcoded PHY address which corresponds
3757 to the given FEC; i. e.
3758 #define CONFIG_FEC1_PHY 4
3759 means that the PHY with address 4 is connected to FEC1
3761 When set to -1, means to probe for first available.
3763 - CONFIG_FEC[12]_PHY_NORXERR
3764 The PHY does not have a RXERR line (RMII only).
3765 (so program the FEC to ignore it).
3768 Enable RMII mode for all FECs.
3769 Note that this is a global option, we can't
3770 have one FEC in standard MII mode and another in RMII mode.
3772 - CONFIG_CRC32_VERIFY
3773 Add a verify option to the crc32 command.
3776 => crc32 -v <address> <count> <crc32>
3778 Where address/count indicate a memory area
3779 and crc32 is the correct crc32 which the
3783 Add the "loopw" memory command. This only takes effect if
3784 the memory commands are activated globally (CONFIG_CMD_MEM).
3787 Add the "mdc" and "mwc" memory commands. These are cyclic
3792 This command will print 4 bytes (10,11,12,13) each 500 ms.
3794 => mwc.l 100 12345678 10
3795 This command will write 12345678 to address 100 all 10 ms.
3797 This only takes effect if the memory commands are activated
3798 globally (CONFIG_CMD_MEM).
3800 - CONFIG_SKIP_LOWLEVEL_INIT
3801 [ARM, NDS32, MIPS only] If this variable is defined, then certain
3802 low level initializations (like setting up the memory
3803 controller) are omitted and/or U-Boot does not
3804 relocate itself into RAM.
3806 Normally this variable MUST NOT be defined. The only
3807 exception is when U-Boot is loaded (to RAM) by some
3808 other boot loader or by a debugger which performs
3809 these initializations itself.
3812 Modifies the behaviour of start.S when compiling a loader
3813 that is executed before the actual U-Boot. E.g. when
3814 compiling a NAND SPL.
3816 - CONFIG_ARCH_MAP_SYSMEM
3817 Generally U-Boot (and in particular the md command) uses
3818 effective address. It is therefore not necessary to regard
3819 U-Boot address as virtual addresses that need to be translated
3820 to physical addresses. However, sandbox requires this, since
3821 it maintains its own little RAM buffer which contains all
3822 addressable memory. This option causes some memory accesses
3823 to be mapped through map_sysmem() / unmap_sysmem().
3825 - CONFIG_USE_ARCH_MEMCPY
3826 CONFIG_USE_ARCH_MEMSET
3827 If these options are used a optimized version of memcpy/memset will
3828 be used if available. These functions may be faster under some
3829 conditions but may increase the binary size.
3831 - CONFIG_X86_RESET_VECTOR
3832 If defined, the x86 reset vector code is included. This is not
3833 needed when U-Boot is running from Coreboot.
3836 Freescale QE/FMAN Firmware Support:
3837 -----------------------------------
3839 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
3840 loading of "firmware", which is encoded in the QE firmware binary format.
3841 This firmware often needs to be loaded during U-Boot booting, so macros
3842 are used to identify the storage device (NOR flash, SPI, etc) and the address
3845 - CONFIG_SYS_QE_FMAN_FW_ADDR
3846 The address in the storage device where the firmware is located. The
3847 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3850 - CONFIG_SYS_QE_FMAN_FW_LENGTH
3851 The maximum possible size of the firmware. The firmware binary format
3852 has a field that specifies the actual size of the firmware, but it
3853 might not be possible to read any part of the firmware unless some
3854 local storage is allocated to hold the entire firmware first.
3856 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
3857 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
3858 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
3859 virtual address in NOR flash.
3861 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
3862 Specifies that QE/FMAN firmware is located in NAND flash.
3863 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
3865 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
3866 Specifies that QE/FMAN firmware is located on the primary SD/MMC
3867 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3869 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
3870 Specifies that QE/FMAN firmware is located on the primary SPI
3871 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3873 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
3874 Specifies that QE/FMAN firmware is located in the remote (master)
3875 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
3876 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
3877 window->master inbound window->master LAW->the ucode address in
3878 master's memory space.
3880 Building the Software:
3881 ======================
3883 Building U-Boot has been tested in several native build environments
3884 and in many different cross environments. Of course we cannot support
3885 all possibly existing versions of cross development tools in all
3886 (potentially obsolete) versions. In case of tool chain problems we
3887 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3888 which is extensively used to build and test U-Boot.
3890 If you are not using a native environment, it is assumed that you
3891 have GNU cross compiling tools available in your path. In this case,
3892 you must set the environment variable CROSS_COMPILE in your shell.
3893 Note that no changes to the Makefile or any other source files are
3894 necessary. For example using the ELDK on a 4xx CPU, please enter:
3896 $ CROSS_COMPILE=ppc_4xx-
3897 $ export CROSS_COMPILE
3899 Note: If you wish to generate Windows versions of the utilities in
3900 the tools directory you can use the MinGW toolchain
3901 (http://www.mingw.org). Set your HOST tools to the MinGW
3902 toolchain and execute 'make tools'. For example:
3904 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3906 Binaries such as tools/mkimage.exe will be created which can
3907 be executed on computers running Windows.
3909 U-Boot is intended to be simple to build. After installing the
3910 sources you must configure U-Boot for one specific board type. This
3915 where "NAME_config" is the name of one of the existing configu-
3916 rations; see boards.cfg for supported names.
3918 Note: for some board special configuration names may exist; check if
3919 additional information is available from the board vendor; for
3920 instance, the TQM823L systems are available without (standard)
3921 or with LCD support. You can select such additional "features"
3922 when choosing the configuration, i. e.
3925 - will configure for a plain TQM823L, i. e. no LCD support
3927 make TQM823L_LCD_config
3928 - will configure for a TQM823L with U-Boot console on LCD
3933 Finally, type "make all", and you should get some working U-Boot
3934 images ready for download to / installation on your system:
3936 - "u-boot.bin" is a raw binary image
3937 - "u-boot" is an image in ELF binary format
3938 - "u-boot.srec" is in Motorola S-Record format
3940 By default the build is performed locally and the objects are saved
3941 in the source directory. One of the two methods can be used to change
3942 this behavior and build U-Boot to some external directory:
3944 1. Add O= to the make command line invocations:
3946 make O=/tmp/build distclean
3947 make O=/tmp/build NAME_config
3948 make O=/tmp/build all
3950 2. Set environment variable BUILD_DIR to point to the desired location:
3952 export BUILD_DIR=/tmp/build
3957 Note that the command line "O=" setting overrides the BUILD_DIR environment
3961 Please be aware that the Makefiles assume you are using GNU make, so
3962 for instance on NetBSD you might need to use "gmake" instead of
3966 If the system board that you have is not listed, then you will need
3967 to port U-Boot to your hardware platform. To do this, follow these
3970 1. Add a new configuration option for your board to the toplevel
3971 "boards.cfg" file, using the existing entries as examples.
3972 Follow the instructions there to keep the boards in order.
3973 2. Create a new directory to hold your board specific code. Add any
3974 files you need. In your board directory, you will need at least
3975 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
3976 3. Create a new configuration file "include/configs/<board>.h" for
3978 3. If you're porting U-Boot to a new CPU, then also create a new
3979 directory to hold your CPU specific code. Add any files you need.
3980 4. Run "make <board>_config" with your new name.
3981 5. Type "make", and you should get a working "u-boot.srec" file
3982 to be installed on your target system.
3983 6. Debug and solve any problems that might arise.
3984 [Of course, this last step is much harder than it sounds.]
3987 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3988 ==============================================================
3990 If you have modified U-Boot sources (for instance added a new board
3991 or support for new devices, a new CPU, etc.) you are expected to
3992 provide feedback to the other developers. The feedback normally takes
3993 the form of a "patch", i. e. a context diff against a certain (latest
3994 official or latest in the git repository) version of U-Boot sources.
3996 But before you submit such a patch, please verify that your modifi-
3997 cation did not break existing code. At least make sure that *ALL* of
3998 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3999 just run the "MAKEALL" script, which will configure and build U-Boot
4000 for ALL supported system. Be warned, this will take a while. You can
4001 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4002 environment variable to the script, i. e. to use the ELDK cross tools
4005 CROSS_COMPILE=ppc_8xx- MAKEALL
4007 or to build on a native PowerPC system you can type
4009 CROSS_COMPILE=' ' MAKEALL
4011 When using the MAKEALL script, the default behaviour is to build
4012 U-Boot in the source directory. This location can be changed by
4013 setting the BUILD_DIR environment variable. Also, for each target
4014 built, the MAKEALL script saves two log files (<target>.ERR and
4015 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4016 location can be changed by setting the MAKEALL_LOGDIR environment
4017 variable. For example:
4019 export BUILD_DIR=/tmp/build
4020 export MAKEALL_LOGDIR=/tmp/log
4021 CROSS_COMPILE=ppc_8xx- MAKEALL
4023 With the above settings build objects are saved in the /tmp/build,
4024 log files are saved in the /tmp/log and the source tree remains clean
4025 during the whole build process.
4028 See also "U-Boot Porting Guide" below.
4031 Monitor Commands - Overview:
4032 ============================
4034 go - start application at address 'addr'
4035 run - run commands in an environment variable
4036 bootm - boot application image from memory
4037 bootp - boot image via network using BootP/TFTP protocol
4038 bootz - boot zImage from memory
4039 tftpboot- boot image via network using TFTP protocol
4040 and env variables "ipaddr" and "serverip"
4041 (and eventually "gatewayip")
4042 tftpput - upload a file via network using TFTP protocol
4043 rarpboot- boot image via network using RARP/TFTP protocol
4044 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4045 loads - load S-Record file over serial line
4046 loadb - load binary file over serial line (kermit mode)
4048 mm - memory modify (auto-incrementing)
4049 nm - memory modify (constant address)
4050 mw - memory write (fill)
4052 cmp - memory compare
4053 crc32 - checksum calculation
4054 i2c - I2C sub-system
4055 sspi - SPI utility commands
4056 base - print or set address offset
4057 printenv- print environment variables
4058 setenv - set environment variables
4059 saveenv - save environment variables to persistent storage
4060 protect - enable or disable FLASH write protection
4061 erase - erase FLASH memory
4062 flinfo - print FLASH memory information
4063 nand - NAND memory operations (see doc/README.nand)
4064 bdinfo - print Board Info structure
4065 iminfo - print header information for application image
4066 coninfo - print console devices and informations
4067 ide - IDE sub-system
4068 loop - infinite loop on address range
4069 loopw - infinite write loop on address range
4070 mtest - simple RAM test
4071 icache - enable or disable instruction cache
4072 dcache - enable or disable data cache
4073 reset - Perform RESET of the CPU
4074 echo - echo args to console
4075 version - print monitor version
4076 help - print online help
4077 ? - alias for 'help'
4080 Monitor Commands - Detailed Description:
4081 ========================================
4085 For now: just type "help <command>".
4088 Environment Variables:
4089 ======================
4091 U-Boot supports user configuration using Environment Variables which
4092 can be made persistent by saving to Flash memory.
4094 Environment Variables are set using "setenv", printed using
4095 "printenv", and saved to Flash using "saveenv". Using "setenv"
4096 without a value can be used to delete a variable from the
4097 environment. As long as you don't save the environment you are
4098 working with an in-memory copy. In case the Flash area containing the
4099 environment is erased by accident, a default environment is provided.
4101 Some configuration options can be set using Environment Variables.
4103 List of environment variables (most likely not complete):
4105 baudrate - see CONFIG_BAUDRATE
4107 bootdelay - see CONFIG_BOOTDELAY
4109 bootcmd - see CONFIG_BOOTCOMMAND
4111 bootargs - Boot arguments when booting an RTOS image
4113 bootfile - Name of the image to load with TFTP
4115 bootm_low - Memory range available for image processing in the bootm
4116 command can be restricted. This variable is given as
4117 a hexadecimal number and defines lowest address allowed
4118 for use by the bootm command. See also "bootm_size"
4119 environment variable. Address defined by "bootm_low" is
4120 also the base of the initial memory mapping for the Linux
4121 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4124 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4125 This variable is given as a hexadecimal number and it
4126 defines the size of the memory region starting at base
4127 address bootm_low that is accessible by the Linux kernel
4128 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4129 as the default value if it is defined, and bootm_size is
4132 bootm_size - Memory range available for image processing in the bootm
4133 command can be restricted. This variable is given as
4134 a hexadecimal number and defines the size of the region
4135 allowed for use by the bootm command. See also "bootm_low"
4136 environment variable.
4138 updatefile - Location of the software update file on a TFTP server, used
4139 by the automatic software update feature. Please refer to
4140 documentation in doc/README.update for more details.
4142 autoload - if set to "no" (any string beginning with 'n'),
4143 "bootp" will just load perform a lookup of the
4144 configuration from the BOOTP server, but not try to
4145 load any image using TFTP
4147 autostart - if set to "yes", an image loaded using the "bootp",
4148 "rarpboot", "tftpboot" or "diskboot" commands will
4149 be automatically started (by internally calling
4152 If set to "no", a standalone image passed to the
4153 "bootm" command will be copied to the load address
4154 (and eventually uncompressed), but NOT be started.
4155 This can be used to load and uncompress arbitrary
4158 fdt_high - if set this restricts the maximum address that the
4159 flattened device tree will be copied into upon boot.
4160 For example, if you have a system with 1 GB memory
4161 at physical address 0x10000000, while Linux kernel
4162 only recognizes the first 704 MB as low memory, you
4163 may need to set fdt_high as 0x3C000000 to have the
4164 device tree blob be copied to the maximum address
4165 of the 704 MB low memory, so that Linux kernel can
4166 access it during the boot procedure.
4168 If this is set to the special value 0xFFFFFFFF then
4169 the fdt will not be copied at all on boot. For this
4170 to work it must reside in writable memory, have
4171 sufficient padding on the end of it for u-boot to
4172 add the information it needs into it, and the memory
4173 must be accessible by the kernel.
4175 fdtcontroladdr- if set this is the address of the control flattened
4176 device tree used by U-Boot when CONFIG_OF_CONTROL is
4179 i2cfast - (PPC405GP|PPC405EP only)
4180 if set to 'y' configures Linux I2C driver for fast
4181 mode (400kHZ). This environment variable is used in
4182 initialization code. So, for changes to be effective
4183 it must be saved and board must be reset.
4185 initrd_high - restrict positioning of initrd images:
4186 If this variable is not set, initrd images will be
4187 copied to the highest possible address in RAM; this
4188 is usually what you want since it allows for
4189 maximum initrd size. If for some reason you want to
4190 make sure that the initrd image is loaded below the
4191 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4192 variable to a value of "no" or "off" or "0".
4193 Alternatively, you can set it to a maximum upper
4194 address to use (U-Boot will still check that it
4195 does not overwrite the U-Boot stack and data).
4197 For instance, when you have a system with 16 MB
4198 RAM, and want to reserve 4 MB from use by Linux,
4199 you can do this by adding "mem=12M" to the value of
4200 the "bootargs" variable. However, now you must make
4201 sure that the initrd image is placed in the first
4202 12 MB as well - this can be done with
4204 setenv initrd_high 00c00000
4206 If you set initrd_high to 0xFFFFFFFF, this is an
4207 indication to U-Boot that all addresses are legal
4208 for the Linux kernel, including addresses in flash
4209 memory. In this case U-Boot will NOT COPY the
4210 ramdisk at all. This may be useful to reduce the
4211 boot time on your system, but requires that this
4212 feature is supported by your Linux kernel.
4214 ipaddr - IP address; needed for tftpboot command
4216 loadaddr - Default load address for commands like "bootp",
4217 "rarpboot", "tftpboot", "loadb" or "diskboot"
4219 loads_echo - see CONFIG_LOADS_ECHO
4221 serverip - TFTP server IP address; needed for tftpboot command
4223 bootretry - see CONFIG_BOOT_RETRY_TIME
4225 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4227 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4229 ethprime - controls which interface is used first.
4231 ethact - controls which interface is currently active.
4232 For example you can do the following
4234 => setenv ethact FEC
4235 => ping 192.168.0.1 # traffic sent on FEC
4236 => setenv ethact SCC
4237 => ping 10.0.0.1 # traffic sent on SCC
4239 ethrotate - When set to "no" U-Boot does not go through all
4240 available network interfaces.
4241 It just stays at the currently selected interface.
4243 netretry - When set to "no" each network operation will
4244 either succeed or fail without retrying.
4245 When set to "once" the network operation will
4246 fail when all the available network interfaces
4247 are tried once without success.
4248 Useful on scripts which control the retry operation
4251 npe_ucode - set load address for the NPE microcode
4253 tftpsrcport - If this is set, the value is used for TFTP's
4256 tftpdstport - If this is set, the value is used for TFTP's UDP
4257 destination port instead of the Well Know Port 69.
4259 tftpblocksize - Block size to use for TFTP transfers; if not set,
4260 we use the TFTP server's default block size
4262 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4263 seconds, minimum value is 1000 = 1 second). Defines
4264 when a packet is considered to be lost so it has to
4265 be retransmitted. The default is 5000 = 5 seconds.
4266 Lowering this value may make downloads succeed
4267 faster in networks with high packet loss rates or
4268 with unreliable TFTP servers.
4270 vlan - When set to a value < 4095 the traffic over
4271 Ethernet is encapsulated/received over 802.1q
4274 The following image location variables contain the location of images
4275 used in booting. The "Image" column gives the role of the image and is
4276 not an environment variable name. The other columns are environment
4277 variable names. "File Name" gives the name of the file on a TFTP
4278 server, "RAM Address" gives the location in RAM the image will be
4279 loaded to, and "Flash Location" gives the image's address in NOR
4280 flash or offset in NAND flash.
4282 *Note* - these variables don't have to be defined for all boards, some
4283 boards currenlty use other variables for these purposes, and some
4284 boards use these variables for other purposes.
4286 Image File Name RAM Address Flash Location
4287 ----- --------- ----------- --------------
4288 u-boot u-boot u-boot_addr_r u-boot_addr
4289 Linux kernel bootfile kernel_addr_r kernel_addr
4290 device tree blob fdtfile fdt_addr_r fdt_addr
4291 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4293 The following environment variables may be used and automatically
4294 updated by the network boot commands ("bootp" and "rarpboot"),
4295 depending the information provided by your boot server:
4297 bootfile - see above
4298 dnsip - IP address of your Domain Name Server
4299 dnsip2 - IP address of your secondary Domain Name Server
4300 gatewayip - IP address of the Gateway (Router) to use
4301 hostname - Target hostname
4303 netmask - Subnet Mask
4304 rootpath - Pathname of the root filesystem on the NFS server
4305 serverip - see above
4308 There are two special Environment Variables:
4310 serial# - contains hardware identification information such
4311 as type string and/or serial number
4312 ethaddr - Ethernet address
4314 These variables can be set only once (usually during manufacturing of
4315 the board). U-Boot refuses to delete or overwrite these variables
4316 once they have been set once.
4319 Further special Environment Variables:
4321 ver - Contains the U-Boot version string as printed
4322 with the "version" command. This variable is
4323 readonly (see CONFIG_VERSION_VARIABLE).
4326 Please note that changes to some configuration parameters may take
4327 only effect after the next boot (yes, that's just like Windoze :-).
4330 Callback functions for environment variables:
4331 ---------------------------------------------
4333 For some environment variables, the behavior of u-boot needs to change
4334 when their values are changed. This functionailty allows functions to
4335 be associated with arbitrary variables. On creation, overwrite, or
4336 deletion, the callback will provide the opportunity for some side
4337 effect to happen or for the change to be rejected.
4339 The callbacks are named and associated with a function using the
4340 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4342 These callbacks are associated with variables in one of two ways. The
4343 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4344 in the board configuration to a string that defines a list of
4345 associations. The list must be in the following format:
4347 entry = variable_name[:callback_name]
4350 If the callback name is not specified, then the callback is deleted.
4351 Spaces are also allowed anywhere in the list.
4353 Callbacks can also be associated by defining the ".callbacks" variable
4354 with the same list format above. Any association in ".callbacks" will
4355 override any association in the static list. You can define
4356 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4357 ".callbacks" envirnoment variable in the default or embedded environment.
4360 Command Line Parsing:
4361 =====================
4363 There are two different command line parsers available with U-Boot:
4364 the old "simple" one, and the much more powerful "hush" shell:
4366 Old, simple command line parser:
4367 --------------------------------
4369 - supports environment variables (through setenv / saveenv commands)
4370 - several commands on one line, separated by ';'
4371 - variable substitution using "... ${name} ..." syntax
4372 - special characters ('$', ';') can be escaped by prefixing with '\',
4374 setenv bootcmd bootm \${address}
4375 - You can also escape text by enclosing in single apostrophes, for example:
4376 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4381 - similar to Bourne shell, with control structures like
4382 if...then...else...fi, for...do...done; while...do...done,
4383 until...do...done, ...
4384 - supports environment ("global") variables (through setenv / saveenv
4385 commands) and local shell variables (through standard shell syntax
4386 "name=value"); only environment variables can be used with "run"
4392 (1) If a command line (or an environment variable executed by a "run"
4393 command) contains several commands separated by semicolon, and
4394 one of these commands fails, then the remaining commands will be
4397 (2) If you execute several variables with one call to run (i. e.
4398 calling run with a list of variables as arguments), any failing
4399 command will cause "run" to terminate, i. e. the remaining
4400 variables are not executed.
4402 Note for Redundant Ethernet Interfaces:
4403 =======================================
4405 Some boards come with redundant Ethernet interfaces; U-Boot supports
4406 such configurations and is capable of automatic selection of a
4407 "working" interface when needed. MAC assignment works as follows:
4409 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4410 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4411 "eth1addr" (=>eth1), "eth2addr", ...
4413 If the network interface stores some valid MAC address (for instance
4414 in SROM), this is used as default address if there is NO correspon-
4415 ding setting in the environment; if the corresponding environment
4416 variable is set, this overrides the settings in the card; that means:
4418 o If the SROM has a valid MAC address, and there is no address in the
4419 environment, the SROM's address is used.
4421 o If there is no valid address in the SROM, and a definition in the
4422 environment exists, then the value from the environment variable is
4425 o If both the SROM and the environment contain a MAC address, and
4426 both addresses are the same, this MAC address is used.
4428 o If both the SROM and the environment contain a MAC address, and the
4429 addresses differ, the value from the environment is used and a
4432 o If neither SROM nor the environment contain a MAC address, an error
4435 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4436 will be programmed into hardware as part of the initialization process. This
4437 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4438 The naming convention is as follows:
4439 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4444 U-Boot is capable of booting (and performing other auxiliary operations on)
4445 images in two formats:
4447 New uImage format (FIT)
4448 -----------------------
4450 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4451 to Flattened Device Tree). It allows the use of images with multiple
4452 components (several kernels, ramdisks, etc.), with contents protected by
4453 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4459 Old image format is based on binary files which can be basically anything,
4460 preceded by a special header; see the definitions in include/image.h for
4461 details; basically, the header defines the following image properties:
4463 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4464 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4465 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4466 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4468 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4469 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4470 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4471 * Compression Type (uncompressed, gzip, bzip2)
4477 The header is marked by a special Magic Number, and both the header
4478 and the data portions of the image are secured against corruption by
4485 Although U-Boot should support any OS or standalone application
4486 easily, the main focus has always been on Linux during the design of
4489 U-Boot includes many features that so far have been part of some
4490 special "boot loader" code within the Linux kernel. Also, any
4491 "initrd" images to be used are no longer part of one big Linux image;
4492 instead, kernel and "initrd" are separate images. This implementation
4493 serves several purposes:
4495 - the same features can be used for other OS or standalone
4496 applications (for instance: using compressed images to reduce the
4497 Flash memory footprint)
4499 - it becomes much easier to port new Linux kernel versions because
4500 lots of low-level, hardware dependent stuff are done by U-Boot
4502 - the same Linux kernel image can now be used with different "initrd"
4503 images; of course this also means that different kernel images can
4504 be run with the same "initrd". This makes testing easier (you don't
4505 have to build a new "zImage.initrd" Linux image when you just
4506 change a file in your "initrd"). Also, a field-upgrade of the
4507 software is easier now.
4513 Porting Linux to U-Boot based systems:
4514 ---------------------------------------
4516 U-Boot cannot save you from doing all the necessary modifications to
4517 configure the Linux device drivers for use with your target hardware
4518 (no, we don't intend to provide a full virtual machine interface to
4521 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4523 Just make sure your machine specific header file (for instance
4524 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4525 Information structure as we define in include/asm-<arch>/u-boot.h,
4526 and make sure that your definition of IMAP_ADDR uses the same value
4527 as your U-Boot configuration in CONFIG_SYS_IMMR.
4530 Configuring the Linux kernel:
4531 -----------------------------
4533 No specific requirements for U-Boot. Make sure you have some root
4534 device (initial ramdisk, NFS) for your target system.
4537 Building a Linux Image:
4538 -----------------------
4540 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4541 not used. If you use recent kernel source, a new build target
4542 "uImage" will exist which automatically builds an image usable by
4543 U-Boot. Most older kernels also have support for a "pImage" target,
4544 which was introduced for our predecessor project PPCBoot and uses a
4545 100% compatible format.
4554 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4555 encapsulate a compressed Linux kernel image with header information,
4556 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4558 * build a standard "vmlinux" kernel image (in ELF binary format):
4560 * convert the kernel into a raw binary image:
4562 ${CROSS_COMPILE}-objcopy -O binary \
4563 -R .note -R .comment \
4564 -S vmlinux linux.bin
4566 * compress the binary image:
4570 * package compressed binary image for U-Boot:
4572 mkimage -A ppc -O linux -T kernel -C gzip \
4573 -a 0 -e 0 -n "Linux Kernel Image" \
4574 -d linux.bin.gz uImage
4577 The "mkimage" tool can also be used to create ramdisk images for use
4578 with U-Boot, either separated from the Linux kernel image, or
4579 combined into one file. "mkimage" encapsulates the images with a 64
4580 byte header containing information about target architecture,
4581 operating system, image type, compression method, entry points, time
4582 stamp, CRC32 checksums, etc.
4584 "mkimage" can be called in two ways: to verify existing images and
4585 print the header information, or to build new images.
4587 In the first form (with "-l" option) mkimage lists the information
4588 contained in the header of an existing U-Boot image; this includes
4589 checksum verification:
4591 tools/mkimage -l image
4592 -l ==> list image header information
4594 The second form (with "-d" option) is used to build a U-Boot image
4595 from a "data file" which is used as image payload:
4597 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4598 -n name -d data_file image
4599 -A ==> set architecture to 'arch'
4600 -O ==> set operating system to 'os'
4601 -T ==> set image type to 'type'
4602 -C ==> set compression type 'comp'
4603 -a ==> set load address to 'addr' (hex)
4604 -e ==> set entry point to 'ep' (hex)
4605 -n ==> set image name to 'name'
4606 -d ==> use image data from 'datafile'
4608 Right now, all Linux kernels for PowerPC systems use the same load
4609 address (0x00000000), but the entry point address depends on the
4612 - 2.2.x kernels have the entry point at 0x0000000C,
4613 - 2.3.x and later kernels have the entry point at 0x00000000.
4615 So a typical call to build a U-Boot image would read:
4617 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4618 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4619 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4620 > examples/uImage.TQM850L
4621 Image Name: 2.4.4 kernel for TQM850L
4622 Created: Wed Jul 19 02:34:59 2000
4623 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4624 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4625 Load Address: 0x00000000
4626 Entry Point: 0x00000000
4628 To verify the contents of the image (or check for corruption):
4630 -> tools/mkimage -l examples/uImage.TQM850L
4631 Image Name: 2.4.4 kernel for TQM850L
4632 Created: Wed Jul 19 02:34:59 2000
4633 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4634 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4635 Load Address: 0x00000000
4636 Entry Point: 0x00000000
4638 NOTE: for embedded systems where boot time is critical you can trade
4639 speed for memory and install an UNCOMPRESSED image instead: this
4640 needs more space in Flash, but boots much faster since it does not
4641 need to be uncompressed:
4643 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4644 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4645 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4646 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4647 > examples/uImage.TQM850L-uncompressed
4648 Image Name: 2.4.4 kernel for TQM850L
4649 Created: Wed Jul 19 02:34:59 2000
4650 Image Type: PowerPC Linux Kernel Image (uncompressed)
4651 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4652 Load Address: 0x00000000
4653 Entry Point: 0x00000000
4656 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4657 when your kernel is intended to use an initial ramdisk:
4659 -> tools/mkimage -n 'Simple Ramdisk Image' \
4660 > -A ppc -O linux -T ramdisk -C gzip \
4661 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4662 Image Name: Simple Ramdisk Image
4663 Created: Wed Jan 12 14:01:50 2000
4664 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4665 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4666 Load Address: 0x00000000
4667 Entry Point: 0x00000000
4670 Installing a Linux Image:
4671 -------------------------
4673 To downloading a U-Boot image over the serial (console) interface,
4674 you must convert the image to S-Record format:
4676 objcopy -I binary -O srec examples/image examples/image.srec
4678 The 'objcopy' does not understand the information in the U-Boot
4679 image header, so the resulting S-Record file will be relative to
4680 address 0x00000000. To load it to a given address, you need to
4681 specify the target address as 'offset' parameter with the 'loads'
4684 Example: install the image to address 0x40100000 (which on the
4685 TQM8xxL is in the first Flash bank):
4687 => erase 40100000 401FFFFF
4693 ## Ready for S-Record download ...
4694 ~>examples/image.srec
4695 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4697 15989 15990 15991 15992
4698 [file transfer complete]
4700 ## Start Addr = 0x00000000
4703 You can check the success of the download using the 'iminfo' command;
4704 this includes a checksum verification so you can be sure no data
4705 corruption happened:
4709 ## Checking Image at 40100000 ...
4710 Image Name: 2.2.13 for initrd on TQM850L
4711 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4712 Data Size: 335725 Bytes = 327 kB = 0 MB
4713 Load Address: 00000000
4714 Entry Point: 0000000c
4715 Verifying Checksum ... OK
4721 The "bootm" command is used to boot an application that is stored in
4722 memory (RAM or Flash). In case of a Linux kernel image, the contents
4723 of the "bootargs" environment variable is passed to the kernel as
4724 parameters. You can check and modify this variable using the
4725 "printenv" and "setenv" commands:
4728 => printenv bootargs
4729 bootargs=root=/dev/ram
4731 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4733 => printenv bootargs
4734 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4737 ## Booting Linux kernel at 40020000 ...
4738 Image Name: 2.2.13 for NFS on TQM850L
4739 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4740 Data Size: 381681 Bytes = 372 kB = 0 MB
4741 Load Address: 00000000
4742 Entry Point: 0000000c
4743 Verifying Checksum ... OK
4744 Uncompressing Kernel Image ... OK
4745 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
4746 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4747 time_init: decrementer frequency = 187500000/60
4748 Calibrating delay loop... 49.77 BogoMIPS
4749 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
4752 If you want to boot a Linux kernel with initial RAM disk, you pass
4753 the memory addresses of both the kernel and the initrd image (PPBCOOT
4754 format!) to the "bootm" command:
4756 => imi 40100000 40200000
4758 ## Checking Image at 40100000 ...
4759 Image Name: 2.2.13 for initrd on TQM850L
4760 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4761 Data Size: 335725 Bytes = 327 kB = 0 MB
4762 Load Address: 00000000
4763 Entry Point: 0000000c
4764 Verifying Checksum ... OK
4766 ## Checking Image at 40200000 ...
4767 Image Name: Simple Ramdisk Image
4768 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4769 Data Size: 566530 Bytes = 553 kB = 0 MB
4770 Load Address: 00000000
4771 Entry Point: 00000000
4772 Verifying Checksum ... OK
4774 => bootm 40100000 40200000
4775 ## Booting Linux kernel at 40100000 ...
4776 Image Name: 2.2.13 for initrd on TQM850L
4777 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4778 Data Size: 335725 Bytes = 327 kB = 0 MB
4779 Load Address: 00000000
4780 Entry Point: 0000000c
4781 Verifying Checksum ... OK
4782 Uncompressing Kernel Image ... OK
4783 ## Loading RAMDisk Image at 40200000 ...
4784 Image Name: Simple Ramdisk Image
4785 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4786 Data Size: 566530 Bytes = 553 kB = 0 MB
4787 Load Address: 00000000
4788 Entry Point: 00000000
4789 Verifying Checksum ... OK
4790 Loading Ramdisk ... OK
4791 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
4792 Boot arguments: root=/dev/ram
4793 time_init: decrementer frequency = 187500000/60
4794 Calibrating delay loop... 49.77 BogoMIPS
4796 RAMDISK: Compressed image found at block 0
4797 VFS: Mounted root (ext2 filesystem).
4801 Boot Linux and pass a flat device tree:
4804 First, U-Boot must be compiled with the appropriate defines. See the section
4805 titled "Linux Kernel Interface" above for a more in depth explanation. The
4806 following is an example of how to start a kernel and pass an updated
4812 oft=oftrees/mpc8540ads.dtb
4813 => tftp $oftaddr $oft
4814 Speed: 1000, full duplex
4816 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4817 Filename 'oftrees/mpc8540ads.dtb'.
4818 Load address: 0x300000
4821 Bytes transferred = 4106 (100a hex)
4822 => tftp $loadaddr $bootfile
4823 Speed: 1000, full duplex
4825 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4827 Load address: 0x200000
4828 Loading:############
4830 Bytes transferred = 1029407 (fb51f hex)
4835 => bootm $loadaddr - $oftaddr
4836 ## Booting image at 00200000 ...
4837 Image Name: Linux-2.6.17-dirty
4838 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4839 Data Size: 1029343 Bytes = 1005.2 kB
4840 Load Address: 00000000
4841 Entry Point: 00000000
4842 Verifying Checksum ... OK
4843 Uncompressing Kernel Image ... OK
4844 Booting using flat device tree at 0x300000
4845 Using MPC85xx ADS machine description
4846 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4850 More About U-Boot Image Types:
4851 ------------------------------
4853 U-Boot supports the following image types:
4855 "Standalone Programs" are directly runnable in the environment
4856 provided by U-Boot; it is expected that (if they behave
4857 well) you can continue to work in U-Boot after return from
4858 the Standalone Program.
4859 "OS Kernel Images" are usually images of some Embedded OS which
4860 will take over control completely. Usually these programs
4861 will install their own set of exception handlers, device
4862 drivers, set up the MMU, etc. - this means, that you cannot
4863 expect to re-enter U-Boot except by resetting the CPU.
4864 "RAMDisk Images" are more or less just data blocks, and their
4865 parameters (address, size) are passed to an OS kernel that is
4867 "Multi-File Images" contain several images, typically an OS
4868 (Linux) kernel image and one or more data images like
4869 RAMDisks. This construct is useful for instance when you want
4870 to boot over the network using BOOTP etc., where the boot
4871 server provides just a single image file, but you want to get
4872 for instance an OS kernel and a RAMDisk image.
4874 "Multi-File Images" start with a list of image sizes, each
4875 image size (in bytes) specified by an "uint32_t" in network
4876 byte order. This list is terminated by an "(uint32_t)0".
4877 Immediately after the terminating 0 follow the images, one by
4878 one, all aligned on "uint32_t" boundaries (size rounded up to
4879 a multiple of 4 bytes).
4881 "Firmware Images" are binary images containing firmware (like
4882 U-Boot or FPGA images) which usually will be programmed to
4885 "Script files" are command sequences that will be executed by
4886 U-Boot's command interpreter; this feature is especially
4887 useful when you configure U-Boot to use a real shell (hush)
4888 as command interpreter.
4890 Booting the Linux zImage:
4891 -------------------------
4893 On some platforms, it's possible to boot Linux zImage. This is done
4894 using the "bootz" command. The syntax of "bootz" command is the same
4895 as the syntax of "bootm" command.
4897 Note, defining the CONFIG_SUPPORT_INITRD_RAW allows user to supply
4898 kernel with raw initrd images. The syntax is slightly different, the
4899 address of the initrd must be augmented by it's size, in the following
4900 format: "<initrd addres>:<initrd size>".
4906 One of the features of U-Boot is that you can dynamically load and
4907 run "standalone" applications, which can use some resources of
4908 U-Boot like console I/O functions or interrupt services.
4910 Two simple examples are included with the sources:
4915 'examples/hello_world.c' contains a small "Hello World" Demo
4916 application; it is automatically compiled when you build U-Boot.
4917 It's configured to run at address 0x00040004, so you can play with it
4921 ## Ready for S-Record download ...
4922 ~>examples/hello_world.srec
4923 1 2 3 4 5 6 7 8 9 10 11 ...
4924 [file transfer complete]
4926 ## Start Addr = 0x00040004
4928 => go 40004 Hello World! This is a test.
4929 ## Starting application at 0x00040004 ...
4940 Hit any key to exit ...
4942 ## Application terminated, rc = 0x0
4944 Another example, which demonstrates how to register a CPM interrupt
4945 handler with the U-Boot code, can be found in 'examples/timer.c'.
4946 Here, a CPM timer is set up to generate an interrupt every second.
4947 The interrupt service routine is trivial, just printing a '.'
4948 character, but this is just a demo program. The application can be
4949 controlled by the following keys:
4951 ? - print current values og the CPM Timer registers
4952 b - enable interrupts and start timer
4953 e - stop timer and disable interrupts
4954 q - quit application
4957 ## Ready for S-Record download ...
4958 ~>examples/timer.srec
4959 1 2 3 4 5 6 7 8 9 10 11 ...
4960 [file transfer complete]
4962 ## Start Addr = 0x00040004
4965 ## Starting application at 0x00040004 ...
4968 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
4971 [q, b, e, ?] Set interval 1000000 us
4974 [q, b, e, ?] ........
4975 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
4978 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
4981 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
4984 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
4986 [q, b, e, ?] ...Stopping timer
4988 [q, b, e, ?] ## Application terminated, rc = 0x0
4994 Over time, many people have reported problems when trying to use the
4995 "minicom" terminal emulation program for serial download. I (wd)
4996 consider minicom to be broken, and recommend not to use it. Under
4997 Unix, I recommend to use C-Kermit for general purpose use (and
4998 especially for kermit binary protocol download ("loadb" command), and
4999 use "cu" for S-Record download ("loads" command). See
5000 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5001 for help with kermit.
5004 Nevertheless, if you absolutely want to use it try adding this
5005 configuration to your "File transfer protocols" section:
5007 Name Program Name U/D FullScr IO-Red. Multi
5008 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5009 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5015 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5016 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5018 Building requires a cross environment; it is known to work on
5019 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5020 need gmake since the Makefiles are not compatible with BSD make).
5021 Note that the cross-powerpc package does not install include files;
5022 attempting to build U-Boot will fail because <machine/ansi.h> is
5023 missing. This file has to be installed and patched manually:
5025 # cd /usr/pkg/cross/powerpc-netbsd/include
5027 # ln -s powerpc machine
5028 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5029 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5031 Native builds *don't* work due to incompatibilities between native
5032 and U-Boot include files.
5034 Booting assumes that (the first part of) the image booted is a
5035 stage-2 loader which in turn loads and then invokes the kernel
5036 proper. Loader sources will eventually appear in the NetBSD source
5037 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5038 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5041 Implementation Internals:
5042 =========================
5044 The following is not intended to be a complete description of every
5045 implementation detail. However, it should help to understand the
5046 inner workings of U-Boot and make it easier to port it to custom
5050 Initial Stack, Global Data:
5051 ---------------------------
5053 The implementation of U-Boot is complicated by the fact that U-Boot
5054 starts running out of ROM (flash memory), usually without access to
5055 system RAM (because the memory controller is not initialized yet).
5056 This means that we don't have writable Data or BSS segments, and BSS
5057 is not initialized as zero. To be able to get a C environment working
5058 at all, we have to allocate at least a minimal stack. Implementation
5059 options for this are defined and restricted by the CPU used: Some CPU
5060 models provide on-chip memory (like the IMMR area on MPC8xx and
5061 MPC826x processors), on others (parts of) the data cache can be
5062 locked as (mis-) used as memory, etc.
5064 Chris Hallinan posted a good summary of these issues to the
5065 U-Boot mailing list:
5067 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5068 From: "Chris Hallinan" <clh@net1plus.com>
5069 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5072 Correct me if I'm wrong, folks, but the way I understand it
5073 is this: Using DCACHE as initial RAM for Stack, etc, does not
5074 require any physical RAM backing up the cache. The cleverness
5075 is that the cache is being used as a temporary supply of
5076 necessary storage before the SDRAM controller is setup. It's
5077 beyond the scope of this list to explain the details, but you
5078 can see how this works by studying the cache architecture and
5079 operation in the architecture and processor-specific manuals.
5081 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5082 is another option for the system designer to use as an
5083 initial stack/RAM area prior to SDRAM being available. Either
5084 option should work for you. Using CS 4 should be fine if your
5085 board designers haven't used it for something that would
5086 cause you grief during the initial boot! It is frequently not
5089 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5090 with your processor/board/system design. The default value
5091 you will find in any recent u-boot distribution in
5092 walnut.h should work for you. I'd set it to a value larger
5093 than your SDRAM module. If you have a 64MB SDRAM module, set
5094 it above 400_0000. Just make sure your board has no resources
5095 that are supposed to respond to that address! That code in
5096 start.S has been around a while and should work as is when
5097 you get the config right.
5102 It is essential to remember this, since it has some impact on the C
5103 code for the initialization procedures:
5105 * Initialized global data (data segment) is read-only. Do not attempt
5108 * Do not use any uninitialized global data (or implicitely initialized
5109 as zero data - BSS segment) at all - this is undefined, initiali-
5110 zation is performed later (when relocating to RAM).
5112 * Stack space is very limited. Avoid big data buffers or things like
5115 Having only the stack as writable memory limits means we cannot use
5116 normal global data to share information beween the code. But it
5117 turned out that the implementation of U-Boot can be greatly
5118 simplified by making a global data structure (gd_t) available to all
5119 functions. We could pass a pointer to this data as argument to _all_
5120 functions, but this would bloat the code. Instead we use a feature of
5121 the GCC compiler (Global Register Variables) to share the data: we
5122 place a pointer (gd) to the global data into a register which we
5123 reserve for this purpose.
5125 When choosing a register for such a purpose we are restricted by the
5126 relevant (E)ABI specifications for the current architecture, and by
5127 GCC's implementation.
5129 For PowerPC, the following registers have specific use:
5131 R2: reserved for system use
5132 R3-R4: parameter passing and return values
5133 R5-R10: parameter passing
5134 R13: small data area pointer
5138 (U-Boot also uses R12 as internal GOT pointer. r12
5139 is a volatile register so r12 needs to be reset when
5140 going back and forth between asm and C)
5142 ==> U-Boot will use R2 to hold a pointer to the global data
5144 Note: on PPC, we could use a static initializer (since the
5145 address of the global data structure is known at compile time),
5146 but it turned out that reserving a register results in somewhat
5147 smaller code - although the code savings are not that big (on
5148 average for all boards 752 bytes for the whole U-Boot image,
5149 624 text + 127 data).
5151 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5152 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5154 ==> U-Boot will use P3 to hold a pointer to the global data
5156 On ARM, the following registers are used:
5158 R0: function argument word/integer result
5159 R1-R3: function argument word
5161 R10: stack limit (used only if stack checking if enabled)
5162 R11: argument (frame) pointer
5163 R12: temporary workspace
5166 R15: program counter
5168 ==> U-Boot will use R8 to hold a pointer to the global data
5170 On Nios II, the ABI is documented here:
5171 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5173 ==> U-Boot will use gp to hold a pointer to the global data
5175 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5176 to access small data sections, so gp is free.
5178 On NDS32, the following registers are used:
5180 R0-R1: argument/return
5182 R15: temporary register for assembler
5183 R16: trampoline register
5184 R28: frame pointer (FP)
5185 R29: global pointer (GP)
5186 R30: link register (LP)
5187 R31: stack pointer (SP)
5188 PC: program counter (PC)
5190 ==> U-Boot will use R10 to hold a pointer to the global data
5192 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5193 or current versions of GCC may "optimize" the code too much.
5198 U-Boot runs in system state and uses physical addresses, i.e. the
5199 MMU is not used either for address mapping nor for memory protection.
5201 The available memory is mapped to fixed addresses using the memory
5202 controller. In this process, a contiguous block is formed for each
5203 memory type (Flash, SDRAM, SRAM), even when it consists of several
5204 physical memory banks.
5206 U-Boot is installed in the first 128 kB of the first Flash bank (on
5207 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5208 booting and sizing and initializing DRAM, the code relocates itself
5209 to the upper end of DRAM. Immediately below the U-Boot code some
5210 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5211 configuration setting]. Below that, a structure with global Board
5212 Info data is placed, followed by the stack (growing downward).
5214 Additionally, some exception handler code is copied to the low 8 kB
5215 of DRAM (0x00000000 ... 0x00001FFF).
5217 So a typical memory configuration with 16 MB of DRAM could look like
5220 0x0000 0000 Exception Vector code
5223 0x0000 2000 Free for Application Use
5229 0x00FB FF20 Monitor Stack (Growing downward)
5230 0x00FB FFAC Board Info Data and permanent copy of global data
5231 0x00FC 0000 Malloc Arena
5234 0x00FE 0000 RAM Copy of Monitor Code
5235 ... eventually: LCD or video framebuffer
5236 ... eventually: pRAM (Protected RAM - unchanged by reset)
5237 0x00FF FFFF [End of RAM]
5240 System Initialization:
5241 ----------------------
5243 In the reset configuration, U-Boot starts at the reset entry point
5244 (on most PowerPC systems at address 0x00000100). Because of the reset
5245 configuration for CS0# this is a mirror of the onboard Flash memory.
5246 To be able to re-map memory U-Boot then jumps to its link address.
5247 To be able to implement the initialization code in C, a (small!)
5248 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5249 which provide such a feature like MPC8xx or MPC8260), or in a locked
5250 part of the data cache. After that, U-Boot initializes the CPU core,
5251 the caches and the SIU.
5253 Next, all (potentially) available memory banks are mapped using a
5254 preliminary mapping. For example, we put them on 512 MB boundaries
5255 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5256 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5257 programmed for SDRAM access. Using the temporary configuration, a
5258 simple memory test is run that determines the size of the SDRAM
5261 When there is more than one SDRAM bank, and the banks are of
5262 different size, the largest is mapped first. For equal size, the first
5263 bank (CS2#) is mapped first. The first mapping is always for address
5264 0x00000000, with any additional banks following immediately to create
5265 contiguous memory starting from 0.
5267 Then, the monitor installs itself at the upper end of the SDRAM area
5268 and allocates memory for use by malloc() and for the global Board
5269 Info data; also, the exception vector code is copied to the low RAM
5270 pages, and the final stack is set up.
5272 Only after this relocation will you have a "normal" C environment;
5273 until that you are restricted in several ways, mostly because you are
5274 running from ROM, and because the code will have to be relocated to a
5278 U-Boot Porting Guide:
5279 ----------------------
5281 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5285 int main(int argc, char *argv[])
5287 sighandler_t no_more_time;
5289 signal(SIGALRM, no_more_time);
5290 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5292 if (available_money > available_manpower) {
5293 Pay consultant to port U-Boot;
5297 Download latest U-Boot source;
5299 Subscribe to u-boot mailing list;
5302 email("Hi, I am new to U-Boot, how do I get started?");
5305 Read the README file in the top level directory;
5306 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5307 Read applicable doc/*.README;
5308 Read the source, Luke;
5309 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5312 if (available_money > toLocalCurrency ($2500))
5315 Add a lot of aggravation and time;
5317 if (a similar board exists) { /* hopefully... */
5318 cp -a board/<similar> board/<myboard>
5319 cp include/configs/<similar>.h include/configs/<myboard>.h
5321 Create your own board support subdirectory;
5322 Create your own board include/configs/<myboard>.h file;
5324 Edit new board/<myboard> files
5325 Edit new include/configs/<myboard>.h
5330 Add / modify source code;
5334 email("Hi, I am having problems...");
5336 Send patch file to the U-Boot email list;
5337 if (reasonable critiques)
5338 Incorporate improvements from email list code review;
5340 Defend code as written;
5346 void no_more_time (int sig)
5355 All contributions to U-Boot should conform to the Linux kernel
5356 coding style; see the file "Documentation/CodingStyle" and the script
5357 "scripts/Lindent" in your Linux kernel source directory.
5359 Source files originating from a different project (for example the
5360 MTD subsystem) are generally exempt from these guidelines and are not
5361 reformated to ease subsequent migration to newer versions of those
5364 Please note that U-Boot is implemented in C (and to some small parts in
5365 Assembler); no C++ is used, so please do not use C++ style comments (//)
5368 Please also stick to the following formatting rules:
5369 - remove any trailing white space
5370 - use TAB characters for indentation and vertical alignment, not spaces
5371 - make sure NOT to use DOS '\r\n' line feeds
5372 - do not add more than 2 consecutive empty lines to source files
5373 - do not add trailing empty lines to source files
5375 Submissions which do not conform to the standards may be returned
5376 with a request to reformat the changes.
5382 Since the number of patches for U-Boot is growing, we need to
5383 establish some rules. Submissions which do not conform to these rules
5384 may be rejected, even when they contain important and valuable stuff.
5386 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5388 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5389 see http://lists.denx.de/mailman/listinfo/u-boot
5391 When you send a patch, please include the following information with
5394 * For bug fixes: a description of the bug and how your patch fixes
5395 this bug. Please try to include a way of demonstrating that the
5396 patch actually fixes something.
5398 * For new features: a description of the feature and your
5401 * A CHANGELOG entry as plaintext (separate from the patch)
5403 * For major contributions, your entry to the CREDITS file
5405 * When you add support for a new board, don't forget to add this
5406 board to the MAINTAINERS file, too.
5408 * If your patch adds new configuration options, don't forget to
5409 document these in the README file.
5411 * The patch itself. If you are using git (which is *strongly*
5412 recommended) you can easily generate the patch using the
5413 "git format-patch". If you then use "git send-email" to send it to
5414 the U-Boot mailing list, you will avoid most of the common problems
5415 with some other mail clients.
5417 If you cannot use git, use "diff -purN OLD NEW". If your version of
5418 diff does not support these options, then get the latest version of
5421 The current directory when running this command shall be the parent
5422 directory of the U-Boot source tree (i. e. please make sure that
5423 your patch includes sufficient directory information for the
5426 We prefer patches as plain text. MIME attachments are discouraged,
5427 and compressed attachments must not be used.
5429 * If one logical set of modifications affects or creates several
5430 files, all these changes shall be submitted in a SINGLE patch file.
5432 * Changesets that contain different, unrelated modifications shall be
5433 submitted as SEPARATE patches, one patch per changeset.
5438 * Before sending the patch, run the MAKEALL script on your patched
5439 source tree and make sure that no errors or warnings are reported
5440 for any of the boards.
5442 * Keep your modifications to the necessary minimum: A patch
5443 containing several unrelated changes or arbitrary reformats will be
5444 returned with a request to re-formatting / split it.
5446 * If you modify existing code, make sure that your new code does not
5447 add to the memory footprint of the code ;-) Small is beautiful!
5448 When adding new features, these should compile conditionally only
5449 (using #ifdef), and the resulting code with the new feature
5450 disabled must not need more memory than the old code without your
5453 * Remember that there is a size limit of 100 kB per message on the
5454 u-boot mailing list. Bigger patches will be moderated. If they are
5455 reasonable and not too big, they will be acknowledged. But patches
5456 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob