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_MISC Misc functions like sleep etc
865 CONFIG_CMD_MMC * MMC memory mapped support
866 CONFIG_CMD_MII * MII utility commands
867 CONFIG_CMD_MTDPARTS * MTD partition support
868 CONFIG_CMD_NAND * NAND support
869 CONFIG_CMD_NET bootp, tftpboot, rarpboot
870 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
871 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
872 CONFIG_CMD_PCI * pciinfo
873 CONFIG_CMD_PCMCIA * PCMCIA support
874 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
876 CONFIG_CMD_PORTIO * Port I/O
877 CONFIG_CMD_READ * Read raw data from partition
878 CONFIG_CMD_REGINFO * Register dump
879 CONFIG_CMD_RUN run command in env variable
880 CONFIG_CMD_SANDBOX * sb command to access sandbox features
881 CONFIG_CMD_SAVES * save S record dump
882 CONFIG_CMD_SCSI * SCSI Support
883 CONFIG_CMD_SDRAM * print SDRAM configuration information
884 (requires CONFIG_CMD_I2C)
885 CONFIG_CMD_SETGETDCR Support for DCR Register access
887 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
888 CONFIG_CMD_SHA1SUM print sha1 memory digest
889 (requires CONFIG_CMD_MEMORY)
890 CONFIG_CMD_SOURCE "source" command Support
891 CONFIG_CMD_SPI * SPI serial bus support
892 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
893 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
894 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
895 CONFIG_CMD_TIMER * access to the system tick timer
896 CONFIG_CMD_USB * USB support
897 CONFIG_CMD_CDP * Cisco Discover Protocol support
898 CONFIG_CMD_MFSL * Microblaze FSL support
901 EXAMPLE: If you want all functions except of network
902 support you can write:
904 #include "config_cmd_all.h"
905 #undef CONFIG_CMD_NET
908 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
910 Note: Don't enable the "icache" and "dcache" commands
911 (configuration option CONFIG_CMD_CACHE) unless you know
912 what you (and your U-Boot users) are doing. Data
913 cache cannot be enabled on systems like the 8xx or
914 8260 (where accesses to the IMMR region must be
915 uncached), and it cannot be disabled on all other
916 systems where we (mis-) use the data cache to hold an
917 initial stack and some data.
920 XXX - this list needs to get updated!
924 If this variable is defined, U-Boot will use a device tree
925 to configure its devices, instead of relying on statically
926 compiled #defines in the board file. This option is
927 experimental and only available on a few boards. The device
928 tree is available in the global data as gd->fdt_blob.
930 U-Boot needs to get its device tree from somewhere. This can
931 be done using one of the two options below:
934 If this variable is defined, U-Boot will embed a device tree
935 binary in its image. This device tree file should be in the
936 board directory and called <soc>-<board>.dts. The binary file
937 is then picked up in board_init_f() and made available through
938 the global data structure as gd->blob.
941 If this variable is defined, U-Boot will build a device tree
942 binary. It will be called u-boot.dtb. Architecture-specific
943 code will locate it at run-time. Generally this works by:
945 cat u-boot.bin u-boot.dtb >image.bin
947 and in fact, U-Boot does this for you, creating a file called
948 u-boot-dtb.bin which is useful in the common case. You can
949 still use the individual files if you need something more
954 If this variable is defined, it enables watchdog
955 support for the SoC. There must be support in the SoC
956 specific code for a watchdog. For the 8xx and 8260
957 CPUs, the SIU Watchdog feature is enabled in the SYPCR
958 register. When supported for a specific SoC is
959 available, then no further board specific code should
963 When using a watchdog circuitry external to the used
964 SoC, then define this variable and provide board
965 specific code for the "hw_watchdog_reset" function.
968 CONFIG_VERSION_VARIABLE
969 If this variable is defined, an environment variable
970 named "ver" is created by U-Boot showing the U-Boot
971 version as printed by the "version" command.
972 Any change to this variable will be reverted at the
977 When CONFIG_CMD_DATE is selected, the type of the RTC
978 has to be selected, too. Define exactly one of the
981 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
982 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
983 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
984 CONFIG_RTC_MC146818 - use MC146818 RTC
985 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
986 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
987 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
988 CONFIG_RTC_DS164x - use Dallas DS164x RTC
989 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
990 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
991 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
992 CONFIG_SYS_RV3029_TCR - enable trickle charger on
995 Note that if the RTC uses I2C, then the I2C interface
996 must also be configured. See I2C Support, below.
999 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1000 CONFIG_PCA953X_INFO - enable pca953x info command
1002 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1003 chip-ngpio pairs that tell the PCA953X driver the number of
1004 pins supported by a particular chip.
1006 Note that if the GPIO device uses I2C, then the I2C interface
1007 must also be configured. See I2C Support, below.
1009 - Timestamp Support:
1011 When CONFIG_TIMESTAMP is selected, the timestamp
1012 (date and time) of an image is printed by image
1013 commands like bootm or iminfo. This option is
1014 automatically enabled when you select CONFIG_CMD_DATE .
1016 - Partition Labels (disklabels) Supported:
1017 Zero or more of the following:
1018 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1019 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1020 Intel architecture, USB sticks, etc.
1021 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1022 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1023 bootloader. Note 2TB partition limit; see
1025 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1027 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1028 CONFIG_CMD_SCSI) you must configure support for at
1029 least one non-MTD partition type as well.
1032 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1033 board configurations files but used nowhere!
1035 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1036 be performed by calling the function
1037 ide_set_reset(int reset)
1038 which has to be defined in a board specific file
1043 Set this to enable ATAPI support.
1048 Set this to enable support for disks larger than 137GB
1049 Also look at CONFIG_SYS_64BIT_LBA.
1050 Whithout these , LBA48 support uses 32bit variables and will 'only'
1051 support disks up to 2.1TB.
1053 CONFIG_SYS_64BIT_LBA:
1054 When enabled, makes the IDE subsystem use 64bit sector addresses.
1058 At the moment only there is only support for the
1059 SYM53C8XX SCSI controller; define
1060 CONFIG_SCSI_SYM53C8XX to enable it.
1062 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1063 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1064 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1065 maximum numbers of LUNs, SCSI ID's and target
1067 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1069 The environment variable 'scsidevs' is set to the number of
1070 SCSI devices found during the last scan.
1072 - NETWORK Support (PCI):
1074 Support for Intel 8254x/8257x gigabit chips.
1077 Utility code for direct access to the SPI bus on Intel 8257x.
1078 This does not do anything useful unless you set at least one
1079 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1081 CONFIG_E1000_SPI_GENERIC
1082 Allow generic access to the SPI bus on the Intel 8257x, for
1083 example with the "sspi" command.
1086 Management command for E1000 devices. When used on devices
1087 with SPI support you can reprogram the EEPROM from U-Boot.
1089 CONFIG_E1000_FALLBACK_MAC
1090 default MAC for empty EEPROM after production.
1093 Support for Intel 82557/82559/82559ER chips.
1094 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1095 write routine for first time initialisation.
1098 Support for Digital 2114x chips.
1099 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1100 modem chip initialisation (KS8761/QS6611).
1103 Support for National dp83815 chips.
1106 Support for National dp8382[01] gigabit chips.
1108 - NETWORK Support (other):
1110 CONFIG_DRIVER_AT91EMAC
1111 Support for AT91RM9200 EMAC.
1114 Define this to use reduced MII inteface
1116 CONFIG_DRIVER_AT91EMAC_QUIET
1117 If this defined, the driver is quiet.
1118 The driver doen't show link status messages.
1120 CONFIG_CALXEDA_XGMAC
1121 Support for the Calxeda XGMAC device
1124 Support for SMSC's LAN91C96 chips.
1126 CONFIG_LAN91C96_BASE
1127 Define this to hold the physical address
1128 of the LAN91C96's I/O space
1130 CONFIG_LAN91C96_USE_32_BIT
1131 Define this to enable 32 bit addressing
1134 Support for SMSC's LAN91C111 chip
1136 CONFIG_SMC91111_BASE
1137 Define this to hold the physical address
1138 of the device (I/O space)
1140 CONFIG_SMC_USE_32_BIT
1141 Define this if data bus is 32 bits
1143 CONFIG_SMC_USE_IOFUNCS
1144 Define this to use i/o functions instead of macros
1145 (some hardware wont work with macros)
1147 CONFIG_DRIVER_TI_EMAC
1148 Support for davinci emac
1150 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1151 Define this if you have more then 3 PHYs.
1154 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1156 CONFIG_FTGMAC100_EGIGA
1157 Define this to use GE link update with gigabit PHY.
1158 Define this if FTGMAC100 is connected to gigabit PHY.
1159 If your system has 10/100 PHY only, it might not occur
1160 wrong behavior. Because PHY usually return timeout or
1161 useless data when polling gigabit status and gigabit
1162 control registers. This behavior won't affect the
1163 correctnessof 10/100 link speed update.
1166 Support for SMSC's LAN911x and LAN921x chips
1169 Define this to hold the physical address
1170 of the device (I/O space)
1172 CONFIG_SMC911X_32_BIT
1173 Define this if data bus is 32 bits
1175 CONFIG_SMC911X_16_BIT
1176 Define this if data bus is 16 bits. If your processor
1177 automatically converts one 32 bit word to two 16 bit
1178 words you may also try CONFIG_SMC911X_32_BIT.
1181 Support for Renesas on-chip Ethernet controller
1183 CONFIG_SH_ETHER_USE_PORT
1184 Define the number of ports to be used
1186 CONFIG_SH_ETHER_PHY_ADDR
1187 Define the ETH PHY's address
1189 CONFIG_SH_ETHER_CACHE_WRITEBACK
1190 If this option is set, the driver enables cache flush.
1193 CONFIG_GENERIC_LPC_TPM
1194 Support for generic parallel port TPM devices. Only one device
1195 per system is supported at this time.
1197 CONFIG_TPM_TIS_BASE_ADDRESS
1198 Base address where the generic TPM device is mapped
1199 to. Contemporary x86 systems usually map it at
1203 At the moment only the UHCI host controller is
1204 supported (PIP405, MIP405, MPC5200); define
1205 CONFIG_USB_UHCI to enable it.
1206 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1207 and define CONFIG_USB_STORAGE to enable the USB
1210 Supported are USB Keyboards and USB Floppy drives
1212 MPC5200 USB requires additional defines:
1214 for 528 MHz Clock: 0x0001bbbb
1218 for differential drivers: 0x00001000
1219 for single ended drivers: 0x00005000
1220 for differential drivers on PSC3: 0x00000100
1221 for single ended drivers on PSC3: 0x00004100
1222 CONFIG_SYS_USB_EVENT_POLL
1223 May be defined to allow interrupt polling
1224 instead of using asynchronous interrupts
1226 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1227 txfilltuning field in the EHCI controller on reset.
1230 Define the below if you wish to use the USB console.
1231 Once firmware is rebuilt from a serial console issue the
1232 command "setenv stdin usbtty; setenv stdout usbtty" and
1233 attach your USB cable. The Unix command "dmesg" should print
1234 it has found a new device. The environment variable usbtty
1235 can be set to gserial or cdc_acm to enable your device to
1236 appear to a USB host as a Linux gserial device or a
1237 Common Device Class Abstract Control Model serial device.
1238 If you select usbtty = gserial you should be able to enumerate
1240 # modprobe usbserial vendor=0xVendorID product=0xProductID
1241 else if using cdc_acm, simply setting the environment
1242 variable usbtty to be cdc_acm should suffice. The following
1243 might be defined in YourBoardName.h
1246 Define this to build a UDC device
1249 Define this to have a tty type of device available to
1250 talk to the UDC device
1253 Define this to enable the high speed support for usb
1254 device and usbtty. If this feature is enabled, a routine
1255 int is_usbd_high_speed(void)
1256 also needs to be defined by the driver to dynamically poll
1257 whether the enumeration has succeded at high speed or full
1260 CONFIG_SYS_CONSOLE_IS_IN_ENV
1261 Define this if you want stdin, stdout &/or stderr to
1265 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1266 Derive USB clock from external clock "blah"
1267 - CONFIG_SYS_USB_EXTC_CLK 0x02
1269 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1270 Derive USB clock from brgclk
1271 - CONFIG_SYS_USB_BRG_CLK 0x04
1273 If you have a USB-IF assigned VendorID then you may wish to
1274 define your own vendor specific values either in BoardName.h
1275 or directly in usbd_vendor_info.h. If you don't define
1276 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1277 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1278 should pretend to be a Linux device to it's target host.
1280 CONFIG_USBD_MANUFACTURER
1281 Define this string as the name of your company for
1282 - CONFIG_USBD_MANUFACTURER "my company"
1284 CONFIG_USBD_PRODUCT_NAME
1285 Define this string as the name of your product
1286 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1288 CONFIG_USBD_VENDORID
1289 Define this as your assigned Vendor ID from the USB
1290 Implementors Forum. This *must* be a genuine Vendor ID
1291 to avoid polluting the USB namespace.
1292 - CONFIG_USBD_VENDORID 0xFFFF
1294 CONFIG_USBD_PRODUCTID
1295 Define this as the unique Product ID
1297 - CONFIG_USBD_PRODUCTID 0xFFFF
1299 - ULPI Layer Support:
1300 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1301 the generic ULPI layer. The generic layer accesses the ULPI PHY
1302 via the platform viewport, so you need both the genric layer and
1303 the viewport enabled. Currently only Chipidea/ARC based
1304 viewport is supported.
1305 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1306 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1307 If your ULPI phy needs a different reference clock than the
1308 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1309 the appropriate value in Hz.
1312 The MMC controller on the Intel PXA is supported. To
1313 enable this define CONFIG_MMC. The MMC can be
1314 accessed from the boot prompt by mapping the device
1315 to physical memory similar to flash. Command line is
1316 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1317 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1320 Support for Renesas on-chip MMCIF controller
1322 CONFIG_SH_MMCIF_ADDR
1323 Define the base address of MMCIF registers
1326 Define the clock frequency for MMCIF
1328 - Journaling Flash filesystem support:
1329 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1330 CONFIG_JFFS2_NAND_DEV
1331 Define these for a default partition on a NAND device
1333 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1334 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1335 Define these for a default partition on a NOR device
1337 CONFIG_SYS_JFFS_CUSTOM_PART
1338 Define this to create an own partition. You have to provide a
1339 function struct part_info* jffs2_part_info(int part_num)
1341 If you define only one JFFS2 partition you may also want to
1342 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1343 to disable the command chpart. This is the default when you
1344 have not defined a custom partition
1346 - FAT(File Allocation Table) filesystem write function support:
1349 Define this to enable support for saving memory data as a
1350 file in FAT formatted partition.
1352 This will also enable the command "fatwrite" enabling the
1353 user to write files to FAT.
1355 CBFS (Coreboot Filesystem) support
1358 Define this to enable support for reading from a Coreboot
1359 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1365 Define this to enable standard (PC-Style) keyboard
1369 Standard PC keyboard driver with US (is default) and
1370 GERMAN key layout (switch via environment 'keymap=de') support.
1371 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1372 for cfb_console. Supports cursor blinking.
1377 Define this to enable video support (for output to
1380 CONFIG_VIDEO_CT69000
1382 Enable Chips & Technologies 69000 Video chip
1384 CONFIG_VIDEO_SMI_LYNXEM
1385 Enable Silicon Motion SMI 712/710/810 Video chip. The
1386 video output is selected via environment 'videoout'
1387 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1390 For the CT69000 and SMI_LYNXEM drivers, videomode is
1391 selected via environment 'videomode'. Two different ways
1393 - "videomode=num" 'num' is a standard LiLo mode numbers.
1394 Following standard modes are supported (* is default):
1396 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1397 -------------+---------------------------------------------
1398 8 bits | 0x301* 0x303 0x305 0x161 0x307
1399 15 bits | 0x310 0x313 0x316 0x162 0x319
1400 16 bits | 0x311 0x314 0x317 0x163 0x31A
1401 24 bits | 0x312 0x315 0x318 ? 0x31B
1402 -------------+---------------------------------------------
1403 (i.e. setenv videomode 317; saveenv; reset;)
1405 - "videomode=bootargs" all the video parameters are parsed
1406 from the bootargs. (See drivers/video/videomodes.c)
1409 CONFIG_VIDEO_SED13806
1410 Enable Epson SED13806 driver. This driver supports 8bpp
1411 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1412 or CONFIG_VIDEO_SED13806_16BPP
1415 Enable the Freescale DIU video driver. Reference boards for
1416 SOCs that have a DIU should define this macro to enable DIU
1417 support, and should also define these other macros:
1423 CONFIG_VIDEO_SW_CURSOR
1424 CONFIG_VGA_AS_SINGLE_DEVICE
1426 CONFIG_VIDEO_BMP_LOGO
1428 The DIU driver will look for the 'video-mode' environment
1429 variable, and if defined, enable the DIU as a console during
1430 boot. See the documentation file README.video for a
1431 description of this variable.
1435 Enable the VGA video / BIOS for x86. The alternative if you
1436 are using coreboot is to use the coreboot frame buffer
1443 Define this to enable a custom keyboard support.
1444 This simply calls drv_keyboard_init() which must be
1445 defined in your board-specific files.
1446 The only board using this so far is RBC823.
1448 - LCD Support: CONFIG_LCD
1450 Define this to enable LCD support (for output to LCD
1451 display); also select one of the supported displays
1452 by defining one of these:
1456 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1458 CONFIG_NEC_NL6448AC33:
1460 NEC NL6448AC33-18. Active, color, single scan.
1462 CONFIG_NEC_NL6448BC20
1464 NEC NL6448BC20-08. 6.5", 640x480.
1465 Active, color, single scan.
1467 CONFIG_NEC_NL6448BC33_54
1469 NEC NL6448BC33-54. 10.4", 640x480.
1470 Active, color, single scan.
1474 Sharp 320x240. Active, color, single scan.
1475 It isn't 16x9, and I am not sure what it is.
1477 CONFIG_SHARP_LQ64D341
1479 Sharp LQ64D341 display, 640x480.
1480 Active, color, single scan.
1484 HLD1045 display, 640x480.
1485 Active, color, single scan.
1489 Optrex CBL50840-2 NF-FW 99 22 M5
1491 Hitachi LMG6912RPFC-00T
1495 320x240. Black & white.
1497 Normally display is black on white background; define
1498 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1500 CONFIG_LCD_ALIGNMENT
1502 Normally the LCD is page-aligned (tyically 4KB). If this is
1503 defined then the LCD will be aligned to this value instead.
1504 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1505 here, since it is cheaper to change data cache settings on
1506 a per-section basis.
1508 CONFIG_CONSOLE_SCROLL_LINES
1510 When the console need to be scrolled, this is the number of
1511 lines to scroll by. It defaults to 1. Increasing this makes
1512 the console jump but can help speed up operation when scrolling
1517 Support drawing of RLE8-compressed bitmaps on the LCD.
1521 Enables an 'i2c edid' command which can read EDID
1522 information over I2C from an attached LCD display.
1524 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1526 If this option is set, the environment is checked for
1527 a variable "splashimage". If found, the usual display
1528 of logo, copyright and system information on the LCD
1529 is suppressed and the BMP image at the address
1530 specified in "splashimage" is loaded instead. The
1531 console is redirected to the "nulldev", too. This
1532 allows for a "silent" boot where a splash screen is
1533 loaded very quickly after power-on.
1535 CONFIG_SPLASH_SCREEN_ALIGN
1537 If this option is set the splash image can be freely positioned
1538 on the screen. Environment variable "splashpos" specifies the
1539 position as "x,y". If a positive number is given it is used as
1540 number of pixel from left/top. If a negative number is given it
1541 is used as number of pixel from right/bottom. You can also
1542 specify 'm' for centering the image.
1545 setenv splashpos m,m
1546 => image at center of screen
1548 setenv splashpos 30,20
1549 => image at x = 30 and y = 20
1551 setenv splashpos -10,m
1552 => vertically centered image
1553 at x = dspWidth - bmpWidth - 9
1555 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1557 If this option is set, additionally to standard BMP
1558 images, gzipped BMP images can be displayed via the
1559 splashscreen support or the bmp command.
1561 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1563 If this option is set, 8-bit RLE compressed BMP images
1564 can be displayed via the splashscreen support or the
1567 - Do compresssing for memory range:
1570 If this option is set, it would use zlib deflate method
1571 to compress the specified memory at its best effort.
1573 - Compression support:
1576 If this option is set, support for bzip2 compressed
1577 images is included. If not, only uncompressed and gzip
1578 compressed images are supported.
1580 NOTE: the bzip2 algorithm requires a lot of RAM, so
1581 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1586 If this option is set, support for lzma compressed
1589 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1590 requires an amount of dynamic memory that is given by the
1593 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1595 Where lc and lp stand for, respectively, Literal context bits
1596 and Literal pos bits.
1598 This value is upper-bounded by 14MB in the worst case. Anyway,
1599 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1600 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1601 a very small buffer.
1603 Use the lzmainfo tool to determinate the lc and lp values and
1604 then calculate the amount of needed dynamic memory (ensuring
1605 the appropriate CONFIG_SYS_MALLOC_LEN value).
1610 The address of PHY on MII bus.
1612 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1614 The clock frequency of the MII bus
1618 If this option is set, support for speed/duplex
1619 detection of gigabit PHY is included.
1621 CONFIG_PHY_RESET_DELAY
1623 Some PHY like Intel LXT971A need extra delay after
1624 reset before any MII register access is possible.
1625 For such PHY, set this option to the usec delay
1626 required. (minimum 300usec for LXT971A)
1628 CONFIG_PHY_CMD_DELAY (ppc4xx)
1630 Some PHY like Intel LXT971A need extra delay after
1631 command issued before MII status register can be read
1641 Define a default value for Ethernet address to use
1642 for the respective Ethernet interface, in case this
1643 is not determined automatically.
1648 Define a default value for the IP address to use for
1649 the default Ethernet interface, in case this is not
1650 determined through e.g. bootp.
1651 (Environment variable "ipaddr")
1653 - Server IP address:
1656 Defines a default value for the IP address of a TFTP
1657 server to contact when using the "tftboot" command.
1658 (Environment variable "serverip")
1660 CONFIG_KEEP_SERVERADDR
1662 Keeps the server's MAC address, in the env 'serveraddr'
1663 for passing to bootargs (like Linux's netconsole option)
1665 - Gateway IP address:
1668 Defines a default value for the IP address of the
1669 default router where packets to other networks are
1671 (Environment variable "gatewayip")
1676 Defines a default value for the subnet mask (or
1677 routing prefix) which is used to determine if an IP
1678 address belongs to the local subnet or needs to be
1679 forwarded through a router.
1680 (Environment variable "netmask")
1682 - Multicast TFTP Mode:
1685 Defines whether you want to support multicast TFTP as per
1686 rfc-2090; for example to work with atftp. Lets lots of targets
1687 tftp down the same boot image concurrently. Note: the Ethernet
1688 driver in use must provide a function: mcast() to join/leave a
1691 - BOOTP Recovery Mode:
1692 CONFIG_BOOTP_RANDOM_DELAY
1694 If you have many targets in a network that try to
1695 boot using BOOTP, you may want to avoid that all
1696 systems send out BOOTP requests at precisely the same
1697 moment (which would happen for instance at recovery
1698 from a power failure, when all systems will try to
1699 boot, thus flooding the BOOTP server. Defining
1700 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1701 inserted before sending out BOOTP requests. The
1702 following delays are inserted then:
1704 1st BOOTP request: delay 0 ... 1 sec
1705 2nd BOOTP request: delay 0 ... 2 sec
1706 3rd BOOTP request: delay 0 ... 4 sec
1708 BOOTP requests: delay 0 ... 8 sec
1710 - DHCP Advanced Options:
1711 You can fine tune the DHCP functionality by defining
1712 CONFIG_BOOTP_* symbols:
1714 CONFIG_BOOTP_SUBNETMASK
1715 CONFIG_BOOTP_GATEWAY
1716 CONFIG_BOOTP_HOSTNAME
1717 CONFIG_BOOTP_NISDOMAIN
1718 CONFIG_BOOTP_BOOTPATH
1719 CONFIG_BOOTP_BOOTFILESIZE
1722 CONFIG_BOOTP_SEND_HOSTNAME
1723 CONFIG_BOOTP_NTPSERVER
1724 CONFIG_BOOTP_TIMEOFFSET
1725 CONFIG_BOOTP_VENDOREX
1726 CONFIG_BOOTP_MAY_FAIL
1728 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1729 environment variable, not the BOOTP server.
1731 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1732 after the configured retry count, the call will fail
1733 instead of starting over. This can be used to fail over
1734 to Link-local IP address configuration if the DHCP server
1737 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1738 serverip from a DHCP server, it is possible that more
1739 than one DNS serverip is offered to the client.
1740 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1741 serverip will be stored in the additional environment
1742 variable "dnsip2". The first DNS serverip is always
1743 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1746 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1747 to do a dynamic update of a DNS server. To do this, they
1748 need the hostname of the DHCP requester.
1749 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1750 of the "hostname" environment variable is passed as
1751 option 12 to the DHCP server.
1753 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1755 A 32bit value in microseconds for a delay between
1756 receiving a "DHCP Offer" and sending the "DHCP Request".
1757 This fixes a problem with certain DHCP servers that don't
1758 respond 100% of the time to a "DHCP request". E.g. On an
1759 AT91RM9200 processor running at 180MHz, this delay needed
1760 to be *at least* 15,000 usec before a Windows Server 2003
1761 DHCP server would reply 100% of the time. I recommend at
1762 least 50,000 usec to be safe. The alternative is to hope
1763 that one of the retries will be successful but note that
1764 the DHCP timeout and retry process takes a longer than
1767 - Link-local IP address negotiation:
1768 Negotiate with other link-local clients on the local network
1769 for an address that doesn't require explicit configuration.
1770 This is especially useful if a DHCP server cannot be guaranteed
1771 to exist in all environments that the device must operate.
1773 See doc/README.link-local for more information.
1776 CONFIG_CDP_DEVICE_ID
1778 The device id used in CDP trigger frames.
1780 CONFIG_CDP_DEVICE_ID_PREFIX
1782 A two character string which is prefixed to the MAC address
1787 A printf format string which contains the ascii name of
1788 the port. Normally is set to "eth%d" which sets
1789 eth0 for the first Ethernet, eth1 for the second etc.
1791 CONFIG_CDP_CAPABILITIES
1793 A 32bit integer which indicates the device capabilities;
1794 0x00000010 for a normal host which does not forwards.
1798 An ascii string containing the version of the software.
1802 An ascii string containing the name of the platform.
1806 A 32bit integer sent on the trigger.
1808 CONFIG_CDP_POWER_CONSUMPTION
1810 A 16bit integer containing the power consumption of the
1811 device in .1 of milliwatts.
1813 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1815 A byte containing the id of the VLAN.
1817 - Status LED: CONFIG_STATUS_LED
1819 Several configurations allow to display the current
1820 status using a LED. For instance, the LED will blink
1821 fast while running U-Boot code, stop blinking as
1822 soon as a reply to a BOOTP request was received, and
1823 start blinking slow once the Linux kernel is running
1824 (supported by a status LED driver in the Linux
1825 kernel). Defining CONFIG_STATUS_LED enables this
1828 - CAN Support: CONFIG_CAN_DRIVER
1830 Defining CONFIG_CAN_DRIVER enables CAN driver support
1831 on those systems that support this (optional)
1832 feature, like the TQM8xxL modules.
1834 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1836 These enable I2C serial bus commands. Defining either of
1837 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1838 include the appropriate I2C driver for the selected CPU.
1840 This will allow you to use i2c commands at the u-boot
1841 command line (as long as you set CONFIG_CMD_I2C in
1842 CONFIG_COMMANDS) and communicate with i2c based realtime
1843 clock chips. See common/cmd_i2c.c for a description of the
1844 command line interface.
1846 CONFIG_HARD_I2C selects a hardware I2C controller.
1848 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1849 bit-banging) driver instead of CPM or similar hardware
1852 There are several other quantities that must also be
1853 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1855 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1856 to be the frequency (in Hz) at which you wish your i2c bus
1857 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1858 the CPU's i2c node address).
1860 Now, the u-boot i2c code for the mpc8xx
1861 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1862 and so its address should therefore be cleared to 0 (See,
1863 eg, MPC823e User's Manual p.16-473). So, set
1864 CONFIG_SYS_I2C_SLAVE to 0.
1866 CONFIG_SYS_I2C_INIT_MPC5XXX
1868 When a board is reset during an i2c bus transfer
1869 chips might think that the current transfer is still
1870 in progress. Reset the slave devices by sending start
1871 commands until the slave device responds.
1873 That's all that's required for CONFIG_HARD_I2C.
1875 If you use the software i2c interface (CONFIG_SOFT_I2C)
1876 then the following macros need to be defined (examples are
1877 from include/configs/lwmon.h):
1881 (Optional). Any commands necessary to enable the I2C
1882 controller or configure ports.
1884 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1888 (Only for MPC8260 CPU). The I/O port to use (the code
1889 assumes both bits are on the same port). Valid values
1890 are 0..3 for ports A..D.
1894 The code necessary to make the I2C data line active
1895 (driven). If the data line is open collector, this
1898 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1902 The code necessary to make the I2C data line tri-stated
1903 (inactive). If the data line is open collector, this
1906 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1910 Code that returns TRUE if the I2C data line is high,
1913 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1917 If <bit> is TRUE, sets the I2C data line high. If it
1918 is FALSE, it clears it (low).
1920 eg: #define I2C_SDA(bit) \
1921 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1922 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1926 If <bit> is TRUE, sets the I2C clock line high. If it
1927 is FALSE, it clears it (low).
1929 eg: #define I2C_SCL(bit) \
1930 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1931 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1935 This delay is invoked four times per clock cycle so this
1936 controls the rate of data transfer. The data rate thus
1937 is 1 / (I2C_DELAY * 4). Often defined to be something
1940 #define I2C_DELAY udelay(2)
1942 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1944 If your arch supports the generic GPIO framework (asm/gpio.h),
1945 then you may alternatively define the two GPIOs that are to be
1946 used as SCL / SDA. Any of the previous I2C_xxx macros will
1947 have GPIO-based defaults assigned to them as appropriate.
1949 You should define these to the GPIO value as given directly to
1950 the generic GPIO functions.
1952 CONFIG_SYS_I2C_INIT_BOARD
1954 When a board is reset during an i2c bus transfer
1955 chips might think that the current transfer is still
1956 in progress. On some boards it is possible to access
1957 the i2c SCLK line directly, either by using the
1958 processor pin as a GPIO or by having a second pin
1959 connected to the bus. If this option is defined a
1960 custom i2c_init_board() routine in boards/xxx/board.c
1961 is run early in the boot sequence.
1963 CONFIG_SYS_I2C_BOARD_LATE_INIT
1965 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1966 defined a custom i2c_board_late_init() routine in
1967 boards/xxx/board.c is run AFTER the operations in i2c_init()
1968 is completed. This callpoint can be used to unreset i2c bus
1969 using CPU i2c controller register accesses for CPUs whose i2c
1970 controller provide such a method. It is called at the end of
1971 i2c_init() to allow i2c_init operations to setup the i2c bus
1972 controller on the CPU (e.g. setting bus speed & slave address).
1974 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1976 This option enables configuration of bi_iic_fast[] flags
1977 in u-boot bd_info structure based on u-boot environment
1978 variable "i2cfast". (see also i2cfast)
1980 CONFIG_I2C_MULTI_BUS
1982 This option allows the use of multiple I2C buses, each of which
1983 must have a controller. At any point in time, only one bus is
1984 active. To switch to a different bus, use the 'i2c dev' command.
1985 Note that bus numbering is zero-based.
1987 CONFIG_SYS_I2C_NOPROBES
1989 This option specifies a list of I2C devices that will be skipped
1990 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1991 is set, specify a list of bus-device pairs. Otherwise, specify
1992 a 1D array of device addresses
1995 #undef CONFIG_I2C_MULTI_BUS
1996 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1998 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2000 #define CONFIG_I2C_MULTI_BUS
2001 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2003 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2005 CONFIG_SYS_SPD_BUS_NUM
2007 If defined, then this indicates the I2C bus number for DDR SPD.
2008 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2010 CONFIG_SYS_RTC_BUS_NUM
2012 If defined, then this indicates the I2C bus number for the RTC.
2013 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2015 CONFIG_SYS_DTT_BUS_NUM
2017 If defined, then this indicates the I2C bus number for the DTT.
2018 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2020 CONFIG_SYS_I2C_DTT_ADDR:
2022 If defined, specifies the I2C address of the DTT device.
2023 If not defined, then U-Boot uses predefined value for
2024 specified DTT device.
2028 Define this option if you want to use Freescale's I2C driver in
2029 drivers/i2c/fsl_i2c.c.
2033 Define this option if you have I2C devices reached over 1 .. n
2034 I2C Muxes like the pca9544a. This option addes a new I2C
2035 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
2036 new I2C Bus to the existing I2C Busses. If you select the
2037 new Bus with "i2c dev", u-bbot sends first the commandos for
2038 the muxes to activate this new "bus".
2040 CONFIG_I2C_MULTI_BUS must be also defined, to use this
2044 Adding a new I2C Bus reached over 2 pca9544a muxes
2045 The First mux with address 70 and channel 6
2046 The Second mux with address 71 and channel 4
2048 => i2c bus pca9544a:70:6:pca9544a:71:4
2050 Use the "i2c bus" command without parameter, to get a list
2051 of I2C Busses with muxes:
2054 Busses reached over muxes:
2056 reached over Mux(es):
2059 reached over Mux(es):
2064 If you now switch to the new I2C Bus 3 with "i2c dev 3"
2065 u-boot first sends the command to the mux@70 to enable
2066 channel 6, and then the command to the mux@71 to enable
2069 After that, you can use the "normal" i2c commands as
2070 usual to communicate with your I2C devices behind
2073 This option is actually implemented for the bitbanging
2074 algorithm in common/soft_i2c.c and for the Hardware I2C
2075 Bus on the MPC8260. But it should be not so difficult
2076 to add this option to other architectures.
2078 CONFIG_SOFT_I2C_READ_REPEATED_START
2080 defining this will force the i2c_read() function in
2081 the soft_i2c driver to perform an I2C repeated start
2082 between writing the address pointer and reading the
2083 data. If this define is omitted the default behaviour
2084 of doing a stop-start sequence will be used. Most I2C
2085 devices can use either method, but some require one or
2088 - SPI Support: CONFIG_SPI
2090 Enables SPI driver (so far only tested with
2091 SPI EEPROM, also an instance works with Crystal A/D and
2092 D/As on the SACSng board)
2096 Enables the driver for SPI controller on SuperH. Currently
2097 only SH7757 is supported.
2101 Enables extended (16-bit) SPI EEPROM addressing.
2102 (symmetrical to CONFIG_I2C_X)
2106 Enables a software (bit-bang) SPI driver rather than
2107 using hardware support. This is a general purpose
2108 driver that only requires three general I/O port pins
2109 (two outputs, one input) to function. If this is
2110 defined, the board configuration must define several
2111 SPI configuration items (port pins to use, etc). For
2112 an example, see include/configs/sacsng.h.
2116 Enables a hardware SPI driver for general-purpose reads
2117 and writes. As with CONFIG_SOFT_SPI, the board configuration
2118 must define a list of chip-select function pointers.
2119 Currently supported on some MPC8xxx processors. For an
2120 example, see include/configs/mpc8349emds.h.
2124 Enables the driver for the SPI controllers on i.MX and MXC
2125 SoCs. Currently i.MX31/35/51 are supported.
2127 - FPGA Support: CONFIG_FPGA
2129 Enables FPGA subsystem.
2131 CONFIG_FPGA_<vendor>
2133 Enables support for specific chip vendors.
2136 CONFIG_FPGA_<family>
2138 Enables support for FPGA family.
2139 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2143 Specify the number of FPGA devices to support.
2145 CONFIG_SYS_FPGA_PROG_FEEDBACK
2147 Enable printing of hash marks during FPGA configuration.
2149 CONFIG_SYS_FPGA_CHECK_BUSY
2151 Enable checks on FPGA configuration interface busy
2152 status by the configuration function. This option
2153 will require a board or device specific function to
2158 If defined, a function that provides delays in the FPGA
2159 configuration driver.
2161 CONFIG_SYS_FPGA_CHECK_CTRLC
2162 Allow Control-C to interrupt FPGA configuration
2164 CONFIG_SYS_FPGA_CHECK_ERROR
2166 Check for configuration errors during FPGA bitfile
2167 loading. For example, abort during Virtex II
2168 configuration if the INIT_B line goes low (which
2169 indicated a CRC error).
2171 CONFIG_SYS_FPGA_WAIT_INIT
2173 Maximum time to wait for the INIT_B line to deassert
2174 after PROB_B has been deasserted during a Virtex II
2175 FPGA configuration sequence. The default time is 500
2178 CONFIG_SYS_FPGA_WAIT_BUSY
2180 Maximum time to wait for BUSY to deassert during
2181 Virtex II FPGA configuration. The default is 5 ms.
2183 CONFIG_SYS_FPGA_WAIT_CONFIG
2185 Time to wait after FPGA configuration. The default is
2188 - Configuration Management:
2191 If defined, this string will be added to the U-Boot
2192 version information (U_BOOT_VERSION)
2194 - Vendor Parameter Protection:
2196 U-Boot considers the values of the environment
2197 variables "serial#" (Board Serial Number) and
2198 "ethaddr" (Ethernet Address) to be parameters that
2199 are set once by the board vendor / manufacturer, and
2200 protects these variables from casual modification by
2201 the user. Once set, these variables are read-only,
2202 and write or delete attempts are rejected. You can
2203 change this behaviour:
2205 If CONFIG_ENV_OVERWRITE is #defined in your config
2206 file, the write protection for vendor parameters is
2207 completely disabled. Anybody can change or delete
2210 Alternatively, if you #define _both_ CONFIG_ETHADDR
2211 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2212 Ethernet address is installed in the environment,
2213 which can be changed exactly ONCE by the user. [The
2214 serial# is unaffected by this, i. e. it remains
2217 The same can be accomplished in a more flexible way
2218 for any variable by configuring the type of access
2219 to allow for those variables in the ".flags" variable
2220 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2225 Define this variable to enable the reservation of
2226 "protected RAM", i. e. RAM which is not overwritten
2227 by U-Boot. Define CONFIG_PRAM to hold the number of
2228 kB you want to reserve for pRAM. You can overwrite
2229 this default value by defining an environment
2230 variable "pram" to the number of kB you want to
2231 reserve. Note that the board info structure will
2232 still show the full amount of RAM. If pRAM is
2233 reserved, a new environment variable "mem" will
2234 automatically be defined to hold the amount of
2235 remaining RAM in a form that can be passed as boot
2236 argument to Linux, for instance like that:
2238 setenv bootargs ... mem=\${mem}
2241 This way you can tell Linux not to use this memory,
2242 either, which results in a memory region that will
2243 not be affected by reboots.
2245 *WARNING* If your board configuration uses automatic
2246 detection of the RAM size, you must make sure that
2247 this memory test is non-destructive. So far, the
2248 following board configurations are known to be
2251 IVMS8, IVML24, SPD8xx, TQM8xxL,
2252 HERMES, IP860, RPXlite, LWMON,
2255 - Access to physical memory region (> 4GB)
2256 Some basic support is provided for operations on memory not
2257 normally accessible to U-Boot - e.g. some architectures
2258 support access to more than 4GB of memory on 32-bit
2259 machines using physical address extension or similar.
2260 Define CONFIG_PHYSMEM to access this basic support, which
2261 currently only supports clearing the memory.
2266 Define this variable to stop the system in case of a
2267 fatal error, so that you have to reset it manually.
2268 This is probably NOT a good idea for an embedded
2269 system where you want the system to reboot
2270 automatically as fast as possible, but it may be
2271 useful during development since you can try to debug
2272 the conditions that lead to the situation.
2274 CONFIG_NET_RETRY_COUNT
2276 This variable defines the number of retries for
2277 network operations like ARP, RARP, TFTP, or BOOTP
2278 before giving up the operation. If not defined, a
2279 default value of 5 is used.
2283 Timeout waiting for an ARP reply in milliseconds.
2287 Timeout in milliseconds used in NFS protocol.
2288 If you encounter "ERROR: Cannot umount" in nfs command,
2289 try longer timeout such as
2290 #define CONFIG_NFS_TIMEOUT 10000UL
2292 - Command Interpreter:
2293 CONFIG_AUTO_COMPLETE
2295 Enable auto completion of commands using TAB.
2297 Note that this feature has NOT been implemented yet
2298 for the "hush" shell.
2301 CONFIG_SYS_HUSH_PARSER
2303 Define this variable to enable the "hush" shell (from
2304 Busybox) as command line interpreter, thus enabling
2305 powerful command line syntax like
2306 if...then...else...fi conditionals or `&&' and '||'
2307 constructs ("shell scripts").
2309 If undefined, you get the old, much simpler behaviour
2310 with a somewhat smaller memory footprint.
2313 CONFIG_SYS_PROMPT_HUSH_PS2
2315 This defines the secondary prompt string, which is
2316 printed when the command interpreter needs more input
2317 to complete a command. Usually "> ".
2321 In the current implementation, the local variables
2322 space and global environment variables space are
2323 separated. Local variables are those you define by
2324 simply typing `name=value'. To access a local
2325 variable later on, you have write `$name' or
2326 `${name}'; to execute the contents of a variable
2327 directly type `$name' at the command prompt.
2329 Global environment variables are those you use
2330 setenv/printenv to work with. To run a command stored
2331 in such a variable, you need to use the run command,
2332 and you must not use the '$' sign to access them.
2334 To store commands and special characters in a
2335 variable, please use double quotation marks
2336 surrounding the whole text of the variable, instead
2337 of the backslashes before semicolons and special
2340 - Commandline Editing and History:
2341 CONFIG_CMDLINE_EDITING
2343 Enable editing and History functions for interactive
2344 commandline input operations
2346 - Default Environment:
2347 CONFIG_EXTRA_ENV_SETTINGS
2349 Define this to contain any number of null terminated
2350 strings (variable = value pairs) that will be part of
2351 the default environment compiled into the boot image.
2353 For example, place something like this in your
2354 board's config file:
2356 #define CONFIG_EXTRA_ENV_SETTINGS \
2360 Warning: This method is based on knowledge about the
2361 internal format how the environment is stored by the
2362 U-Boot code. This is NOT an official, exported
2363 interface! Although it is unlikely that this format
2364 will change soon, there is no guarantee either.
2365 You better know what you are doing here.
2367 Note: overly (ab)use of the default environment is
2368 discouraged. Make sure to check other ways to preset
2369 the environment like the "source" command or the
2372 CONFIG_ENV_VARS_UBOOT_CONFIG
2374 Define this in order to add variables describing the
2375 U-Boot build configuration to the default environment.
2376 These will be named arch, cpu, board, vendor, and soc.
2378 Enabling this option will cause the following to be defined:
2386 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2388 Define this in order to add variables describing certain
2389 run-time determined information about the hardware to the
2390 environment. These will be named board_name, board_rev.
2392 CONFIG_DELAY_ENVIRONMENT
2394 Normally the environment is loaded when the board is
2395 intialised so that it is available to U-Boot. This inhibits
2396 that so that the environment is not available until
2397 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2398 this is instead controlled by the value of
2399 /config/load-environment.
2401 - DataFlash Support:
2402 CONFIG_HAS_DATAFLASH
2404 Defining this option enables DataFlash features and
2405 allows to read/write in Dataflash via the standard
2408 - Serial Flash support
2411 Defining this option enables SPI flash commands
2412 'sf probe/read/write/erase/update'.
2414 Usage requires an initial 'probe' to define the serial
2415 flash parameters, followed by read/write/erase/update
2418 The following defaults may be provided by the platform
2419 to handle the common case when only a single serial
2420 flash is present on the system.
2422 CONFIG_SF_DEFAULT_BUS Bus identifier
2423 CONFIG_SF_DEFAULT_CS Chip-select
2424 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2425 CONFIG_SF_DEFAULT_SPEED in Hz
2429 Define this option to include a destructive SPI flash
2432 - SystemACE Support:
2435 Adding this option adds support for Xilinx SystemACE
2436 chips attached via some sort of local bus. The address
2437 of the chip must also be defined in the
2438 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2440 #define CONFIG_SYSTEMACE
2441 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2443 When SystemACE support is added, the "ace" device type
2444 becomes available to the fat commands, i.e. fatls.
2446 - TFTP Fixed UDP Port:
2449 If this is defined, the environment variable tftpsrcp
2450 is used to supply the TFTP UDP source port value.
2451 If tftpsrcp isn't defined, the normal pseudo-random port
2452 number generator is used.
2454 Also, the environment variable tftpdstp is used to supply
2455 the TFTP UDP destination port value. If tftpdstp isn't
2456 defined, the normal port 69 is used.
2458 The purpose for tftpsrcp is to allow a TFTP server to
2459 blindly start the TFTP transfer using the pre-configured
2460 target IP address and UDP port. This has the effect of
2461 "punching through" the (Windows XP) firewall, allowing
2462 the remainder of the TFTP transfer to proceed normally.
2463 A better solution is to properly configure the firewall,
2464 but sometimes that is not allowed.
2469 This enables a generic 'hash' command which can produce
2470 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2474 Enable the hash verify command (hash -v). This adds to code
2477 CONFIG_SHA1 - support SHA1 hashing
2478 CONFIG_SHA256 - support SHA256 hashing
2480 Note: There is also a sha1sum command, which should perhaps
2481 be deprecated in favour of 'hash sha1'.
2483 - Show boot progress:
2484 CONFIG_SHOW_BOOT_PROGRESS
2486 Defining this option allows to add some board-
2487 specific code (calling a user-provided function
2488 "show_boot_progress(int)") that enables you to show
2489 the system's boot progress on some display (for
2490 example, some LED's) on your board. At the moment,
2491 the following checkpoints are implemented:
2493 - Detailed boot stage timing
2495 Define this option to get detailed timing of each stage
2496 of the boot process.
2498 CONFIG_BOOTSTAGE_USER_COUNT
2499 This is the number of available user bootstage records.
2500 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2501 a new ID will be allocated from this stash. If you exceed
2502 the limit, recording will stop.
2504 CONFIG_BOOTSTAGE_REPORT
2505 Define this to print a report before boot, similar to this:
2507 Timer summary in microseconds:
2510 3,575,678 3,575,678 board_init_f start
2511 3,575,695 17 arch_cpu_init A9
2512 3,575,777 82 arch_cpu_init done
2513 3,659,598 83,821 board_init_r start
2514 3,910,375 250,777 main_loop
2515 29,916,167 26,005,792 bootm_start
2516 30,361,327 445,160 start_kernel
2518 CONFIG_CMD_BOOTSTAGE
2519 Add a 'bootstage' command which supports printing a report
2520 and un/stashing of bootstage data.
2522 CONFIG_BOOTSTAGE_FDT
2523 Stash the bootstage information in the FDT. A root 'bootstage'
2524 node is created with each bootstage id as a child. Each child
2525 has a 'name' property and either 'mark' containing the
2526 mark time in microsecond, or 'accum' containing the
2527 accumulated time for that bootstage id in microseconds.
2532 name = "board_init_f";
2541 Code in the Linux kernel can find this in /proc/devicetree.
2543 Legacy uImage format:
2546 1 common/cmd_bootm.c before attempting to boot an image
2547 -1 common/cmd_bootm.c Image header has bad magic number
2548 2 common/cmd_bootm.c Image header has correct magic number
2549 -2 common/cmd_bootm.c Image header has bad checksum
2550 3 common/cmd_bootm.c Image header has correct checksum
2551 -3 common/cmd_bootm.c Image data has bad checksum
2552 4 common/cmd_bootm.c Image data has correct checksum
2553 -4 common/cmd_bootm.c Image is for unsupported architecture
2554 5 common/cmd_bootm.c Architecture check OK
2555 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2556 6 common/cmd_bootm.c Image Type check OK
2557 -6 common/cmd_bootm.c gunzip uncompression error
2558 -7 common/cmd_bootm.c Unimplemented compression type
2559 7 common/cmd_bootm.c Uncompression OK
2560 8 common/cmd_bootm.c No uncompress/copy overwrite error
2561 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2563 9 common/image.c Start initial ramdisk verification
2564 -10 common/image.c Ramdisk header has bad magic number
2565 -11 common/image.c Ramdisk header has bad checksum
2566 10 common/image.c Ramdisk header is OK
2567 -12 common/image.c Ramdisk data has bad checksum
2568 11 common/image.c Ramdisk data has correct checksum
2569 12 common/image.c Ramdisk verification complete, start loading
2570 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2571 13 common/image.c Start multifile image verification
2572 14 common/image.c No initial ramdisk, no multifile, continue.
2574 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2576 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2577 -31 post/post.c POST test failed, detected by post_output_backlog()
2578 -32 post/post.c POST test failed, detected by post_run_single()
2580 34 common/cmd_doc.c before loading a Image from a DOC device
2581 -35 common/cmd_doc.c Bad usage of "doc" command
2582 35 common/cmd_doc.c correct usage of "doc" command
2583 -36 common/cmd_doc.c No boot device
2584 36 common/cmd_doc.c correct boot device
2585 -37 common/cmd_doc.c Unknown Chip ID on boot device
2586 37 common/cmd_doc.c correct chip ID found, device available
2587 -38 common/cmd_doc.c Read Error on boot device
2588 38 common/cmd_doc.c reading Image header from DOC device OK
2589 -39 common/cmd_doc.c Image header has bad magic number
2590 39 common/cmd_doc.c Image header has correct magic number
2591 -40 common/cmd_doc.c Error reading Image from DOC device
2592 40 common/cmd_doc.c Image header has correct magic number
2593 41 common/cmd_ide.c before loading a Image from a IDE device
2594 -42 common/cmd_ide.c Bad usage of "ide" command
2595 42 common/cmd_ide.c correct usage of "ide" command
2596 -43 common/cmd_ide.c No boot device
2597 43 common/cmd_ide.c boot device found
2598 -44 common/cmd_ide.c Device not available
2599 44 common/cmd_ide.c Device available
2600 -45 common/cmd_ide.c wrong partition selected
2601 45 common/cmd_ide.c partition selected
2602 -46 common/cmd_ide.c Unknown partition table
2603 46 common/cmd_ide.c valid partition table found
2604 -47 common/cmd_ide.c Invalid partition type
2605 47 common/cmd_ide.c correct partition type
2606 -48 common/cmd_ide.c Error reading Image Header on boot device
2607 48 common/cmd_ide.c reading Image Header from IDE device OK
2608 -49 common/cmd_ide.c Image header has bad magic number
2609 49 common/cmd_ide.c Image header has correct magic number
2610 -50 common/cmd_ide.c Image header has bad checksum
2611 50 common/cmd_ide.c Image header has correct checksum
2612 -51 common/cmd_ide.c Error reading Image from IDE device
2613 51 common/cmd_ide.c reading Image from IDE device OK
2614 52 common/cmd_nand.c before loading a Image from a NAND device
2615 -53 common/cmd_nand.c Bad usage of "nand" command
2616 53 common/cmd_nand.c correct usage of "nand" command
2617 -54 common/cmd_nand.c No boot device
2618 54 common/cmd_nand.c boot device found
2619 -55 common/cmd_nand.c Unknown Chip ID on boot device
2620 55 common/cmd_nand.c correct chip ID found, device available
2621 -56 common/cmd_nand.c Error reading Image Header on boot device
2622 56 common/cmd_nand.c reading Image Header from NAND device OK
2623 -57 common/cmd_nand.c Image header has bad magic number
2624 57 common/cmd_nand.c Image header has correct magic number
2625 -58 common/cmd_nand.c Error reading Image from NAND device
2626 58 common/cmd_nand.c reading Image from NAND device OK
2628 -60 common/env_common.c Environment has a bad CRC, using default
2630 64 net/eth.c starting with Ethernet configuration.
2631 -64 net/eth.c no Ethernet found.
2632 65 net/eth.c Ethernet found.
2634 -80 common/cmd_net.c usage wrong
2635 80 common/cmd_net.c before calling NetLoop()
2636 -81 common/cmd_net.c some error in NetLoop() occurred
2637 81 common/cmd_net.c NetLoop() back without error
2638 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2639 82 common/cmd_net.c trying automatic boot
2640 83 common/cmd_net.c running "source" command
2641 -83 common/cmd_net.c some error in automatic boot or "source" command
2642 84 common/cmd_net.c end without errors
2647 100 common/cmd_bootm.c Kernel FIT Image has correct format
2648 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2649 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2650 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2651 102 common/cmd_bootm.c Kernel unit name specified
2652 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2653 103 common/cmd_bootm.c Found configuration node
2654 104 common/cmd_bootm.c Got kernel subimage node offset
2655 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2656 105 common/cmd_bootm.c Kernel subimage hash verification OK
2657 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2658 106 common/cmd_bootm.c Architecture check OK
2659 -106 common/cmd_bootm.c Kernel subimage has wrong type
2660 107 common/cmd_bootm.c Kernel subimage type OK
2661 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2662 108 common/cmd_bootm.c Got kernel subimage data/size
2663 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2664 -109 common/cmd_bootm.c Can't get kernel subimage type
2665 -110 common/cmd_bootm.c Can't get kernel subimage comp
2666 -111 common/cmd_bootm.c Can't get kernel subimage os
2667 -112 common/cmd_bootm.c Can't get kernel subimage load address
2668 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2670 120 common/image.c Start initial ramdisk verification
2671 -120 common/image.c Ramdisk FIT image has incorrect format
2672 121 common/image.c Ramdisk FIT image has correct format
2673 122 common/image.c No ramdisk subimage unit name, using configuration
2674 -122 common/image.c Can't get configuration for ramdisk subimage
2675 123 common/image.c Ramdisk unit name specified
2676 -124 common/image.c Can't get ramdisk subimage node offset
2677 125 common/image.c Got ramdisk subimage node offset
2678 -125 common/image.c Ramdisk subimage hash verification failed
2679 126 common/image.c Ramdisk subimage hash verification OK
2680 -126 common/image.c Ramdisk subimage for unsupported architecture
2681 127 common/image.c Architecture check OK
2682 -127 common/image.c Can't get ramdisk subimage data/size
2683 128 common/image.c Got ramdisk subimage data/size
2684 129 common/image.c Can't get ramdisk load address
2685 -129 common/image.c Got ramdisk load address
2687 -130 common/cmd_doc.c Incorrect FIT image format
2688 131 common/cmd_doc.c FIT image format OK
2690 -140 common/cmd_ide.c Incorrect FIT image format
2691 141 common/cmd_ide.c FIT image format OK
2693 -150 common/cmd_nand.c Incorrect FIT image format
2694 151 common/cmd_nand.c FIT image format OK
2696 - FIT image support:
2698 Enable support for the FIT uImage format.
2700 CONFIG_FIT_BEST_MATCH
2701 When no configuration is explicitly selected, default to the
2702 one whose fdt's compatibility field best matches that of
2703 U-Boot itself. A match is considered "best" if it matches the
2704 most specific compatibility entry of U-Boot's fdt's root node.
2705 The order of entries in the configuration's fdt is ignored.
2707 - Standalone program support:
2708 CONFIG_STANDALONE_LOAD_ADDR
2710 This option defines a board specific value for the
2711 address where standalone program gets loaded, thus
2712 overwriting the architecture dependent default
2715 - Frame Buffer Address:
2718 Define CONFIG_FB_ADDR if you want to use specific
2719 address for frame buffer. This is typically the case
2720 when using a graphics controller has separate video
2721 memory. U-Boot will then place the frame buffer at
2722 the given address instead of dynamically reserving it
2723 in system RAM by calling lcd_setmem(), which grabs
2724 the memory for the frame buffer depending on the
2725 configured panel size.
2727 Please see board_init_f function.
2729 - Automatic software updates via TFTP server
2731 CONFIG_UPDATE_TFTP_CNT_MAX
2732 CONFIG_UPDATE_TFTP_MSEC_MAX
2734 These options enable and control the auto-update feature;
2735 for a more detailed description refer to doc/README.update.
2737 - MTD Support (mtdparts command, UBI support)
2740 Adds the MTD device infrastructure from the Linux kernel.
2741 Needed for mtdparts command support.
2743 CONFIG_MTD_PARTITIONS
2745 Adds the MTD partitioning infrastructure from the Linux
2746 kernel. Needed for UBI support.
2750 Enable building of SPL globally.
2753 LDSCRIPT for linking the SPL binary.
2756 Maximum binary size (text, data and rodata) of the SPL binary.
2758 CONFIG_SPL_TEXT_BASE
2759 TEXT_BASE for linking the SPL binary.
2761 CONFIG_SPL_RELOC_TEXT_BASE
2762 Address to relocate to. If unspecified, this is equal to
2763 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2765 CONFIG_SPL_BSS_START_ADDR
2766 Link address for the BSS within the SPL binary.
2768 CONFIG_SPL_BSS_MAX_SIZE
2769 Maximum binary size of the BSS section of the SPL binary.
2772 Adress of the start of the stack SPL will use
2774 CONFIG_SPL_RELOC_STACK
2775 Adress of the start of the stack SPL will use after
2776 relocation. If unspecified, this is equal to
2779 CONFIG_SYS_SPL_MALLOC_START
2780 Starting address of the malloc pool used in SPL.
2782 CONFIG_SYS_SPL_MALLOC_SIZE
2783 The size of the malloc pool used in SPL.
2785 CONFIG_SPL_FRAMEWORK
2786 Enable the SPL framework under common/. This framework
2787 supports MMC, NAND and YMODEM loading of U-Boot and NAND
2788 NAND loading of the Linux Kernel.
2790 CONFIG_SPL_DISPLAY_PRINT
2791 For ARM, enable an optional function to print more information
2792 about the running system.
2794 CONFIG_SPL_INIT_MINIMAL
2795 Arch init code should be built for a very small image
2797 CONFIG_SPL_LIBCOMMON_SUPPORT
2798 Support for common/libcommon.o in SPL binary
2800 CONFIG_SPL_LIBDISK_SUPPORT
2801 Support for disk/libdisk.o in SPL binary
2803 CONFIG_SPL_I2C_SUPPORT
2804 Support for drivers/i2c/libi2c.o in SPL binary
2806 CONFIG_SPL_GPIO_SUPPORT
2807 Support for drivers/gpio/libgpio.o in SPL binary
2809 CONFIG_SPL_MMC_SUPPORT
2810 Support for drivers/mmc/libmmc.o in SPL binary
2812 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
2813 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
2814 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
2815 Address, size and partition on the MMC to load U-Boot from
2816 when the MMC is being used in raw mode.
2818 CONFIG_SPL_FAT_SUPPORT
2819 Support for fs/fat/libfat.o in SPL binary
2821 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
2822 Filename to read to load U-Boot when reading from FAT
2824 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
2825 Set this for NAND SPL on PPC mpc83xx targets, so that
2826 start.S waits for the rest of the SPL to load before
2827 continuing (the hardware starts execution after just
2828 loading the first page rather than the full 4K).
2830 CONFIG_SPL_NAND_BASE
2831 Include nand_base.c in the SPL. Requires
2832 CONFIG_SPL_NAND_DRIVERS.
2834 CONFIG_SPL_NAND_DRIVERS
2835 SPL uses normal NAND drivers, not minimal drivers.
2838 Include standard software ECC in the SPL
2840 CONFIG_SPL_NAND_SIMPLE
2841 Support for NAND boot using simple NAND drivers that
2842 expose the cmd_ctrl() interface.
2844 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
2845 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
2846 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
2847 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
2848 CONFIG_SYS_NAND_ECCBYTES
2849 Defines the size and behavior of the NAND that SPL uses
2852 CONFIG_SYS_NAND_U_BOOT_OFFS
2853 Location in NAND to read U-Boot from
2855 CONFIG_SYS_NAND_U_BOOT_DST
2856 Location in memory to load U-Boot to
2858 CONFIG_SYS_NAND_U_BOOT_SIZE
2859 Size of image to load
2861 CONFIG_SYS_NAND_U_BOOT_START
2862 Entry point in loaded image to jump to
2864 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
2865 Define this if you need to first read the OOB and then the
2866 data. This is used for example on davinci plattforms.
2868 CONFIG_SPL_OMAP3_ID_NAND
2869 Support for an OMAP3-specific set of functions to return the
2870 ID and MFR of the first attached NAND chip, if present.
2872 CONFIG_SPL_SERIAL_SUPPORT
2873 Support for drivers/serial/libserial.o in SPL binary
2875 CONFIG_SPL_SPI_FLASH_SUPPORT
2876 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
2878 CONFIG_SPL_SPI_SUPPORT
2879 Support for drivers/spi/libspi.o in SPL binary
2881 CONFIG_SPL_RAM_DEVICE
2882 Support for running image already present in ram, in SPL binary
2884 CONFIG_SPL_LIBGENERIC_SUPPORT
2885 Support for lib/libgeneric.o in SPL binary
2888 Linker address to which the SPL should be padded before
2889 appending the SPL payload.
2892 Final target image containing SPL and payload. Some SPLs
2893 use an arch-specific makefile fragment instead, for
2894 example if more than one image needs to be produced.
2899 [so far only for SMDK2400 boards]
2901 - Modem support enable:
2902 CONFIG_MODEM_SUPPORT
2904 - RTS/CTS Flow control enable:
2907 - Modem debug support:
2908 CONFIG_MODEM_SUPPORT_DEBUG
2910 Enables debugging stuff (char screen[1024], dbg())
2911 for modem support. Useful only with BDI2000.
2913 - Interrupt support (PPC):
2915 There are common interrupt_init() and timer_interrupt()
2916 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2917 for CPU specific initialization. interrupt_init_cpu()
2918 should set decrementer_count to appropriate value. If
2919 CPU resets decrementer automatically after interrupt
2920 (ppc4xx) it should set decrementer_count to zero.
2921 timer_interrupt() calls timer_interrupt_cpu() for CPU
2922 specific handling. If board has watchdog / status_led
2923 / other_activity_monitor it works automatically from
2924 general timer_interrupt().
2928 In the target system modem support is enabled when a
2929 specific key (key combination) is pressed during
2930 power-on. Otherwise U-Boot will boot normally
2931 (autoboot). The key_pressed() function is called from
2932 board_init(). Currently key_pressed() is a dummy
2933 function, returning 1 and thus enabling modem
2936 If there are no modem init strings in the
2937 environment, U-Boot proceed to autoboot; the
2938 previous output (banner, info printfs) will be
2941 See also: doc/README.Modem
2943 Board initialization settings:
2944 ------------------------------
2946 During Initialization u-boot calls a number of board specific functions
2947 to allow the preparation of board specific prerequisites, e.g. pin setup
2948 before drivers are initialized. To enable these callbacks the
2949 following configuration macros have to be defined. Currently this is
2950 architecture specific, so please check arch/your_architecture/lib/board.c
2951 typically in board_init_f() and board_init_r().
2953 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
2954 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
2955 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
2956 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
2958 Configuration Settings:
2959 -----------------------
2961 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2962 undefine this when you're short of memory.
2964 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2965 width of the commands listed in the 'help' command output.
2967 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2968 prompt for user input.
2970 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2972 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2974 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2976 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2977 the application (usually a Linux kernel) when it is
2980 - CONFIG_SYS_BAUDRATE_TABLE:
2981 List of legal baudrate settings for this board.
2983 - CONFIG_SYS_CONSOLE_INFO_QUIET
2984 Suppress display of console information at boot.
2986 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2987 If the board specific function
2988 extern int overwrite_console (void);
2989 returns 1, the stdin, stderr and stdout are switched to the
2990 serial port, else the settings in the environment are used.
2992 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2993 Enable the call to overwrite_console().
2995 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2996 Enable overwrite of previous console environment settings.
2998 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2999 Begin and End addresses of the area used by the
3002 - CONFIG_SYS_ALT_MEMTEST:
3003 Enable an alternate, more extensive memory test.
3005 - CONFIG_SYS_MEMTEST_SCRATCH:
3006 Scratch address used by the alternate memory test
3007 You only need to set this if address zero isn't writeable
3009 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3010 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3011 this specified memory area will get subtracted from the top
3012 (end) of RAM and won't get "touched" at all by U-Boot. By
3013 fixing up gd->ram_size the Linux kernel should gets passed
3014 the now "corrected" memory size and won't touch it either.
3015 This should work for arch/ppc and arch/powerpc. Only Linux
3016 board ports in arch/powerpc with bootwrapper support that
3017 recalculate the memory size from the SDRAM controller setup
3018 will have to get fixed in Linux additionally.
3020 This option can be used as a workaround for the 440EPx/GRx
3021 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3024 WARNING: Please make sure that this value is a multiple of
3025 the Linux page size (normally 4k). If this is not the case,
3026 then the end address of the Linux memory will be located at a
3027 non page size aligned address and this could cause major
3030 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3031 Enable temporary baudrate change while serial download
3033 - CONFIG_SYS_SDRAM_BASE:
3034 Physical start address of SDRAM. _Must_ be 0 here.
3036 - CONFIG_SYS_MBIO_BASE:
3037 Physical start address of Motherboard I/O (if using a
3040 - CONFIG_SYS_FLASH_BASE:
3041 Physical start address of Flash memory.
3043 - CONFIG_SYS_MONITOR_BASE:
3044 Physical start address of boot monitor code (set by
3045 make config files to be same as the text base address
3046 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3047 CONFIG_SYS_FLASH_BASE when booting from flash.
3049 - CONFIG_SYS_MONITOR_LEN:
3050 Size of memory reserved for monitor code, used to
3051 determine _at_compile_time_ (!) if the environment is
3052 embedded within the U-Boot image, or in a separate
3055 - CONFIG_SYS_MALLOC_LEN:
3056 Size of DRAM reserved for malloc() use.
3058 - CONFIG_SYS_BOOTM_LEN:
3059 Normally compressed uImages are limited to an
3060 uncompressed size of 8 MBytes. If this is not enough,
3061 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3062 to adjust this setting to your needs.
3064 - CONFIG_SYS_BOOTMAPSZ:
3065 Maximum size of memory mapped by the startup code of
3066 the Linux kernel; all data that must be processed by
3067 the Linux kernel (bd_info, boot arguments, FDT blob if
3068 used) must be put below this limit, unless "bootm_low"
3069 enviroment variable is defined and non-zero. In such case
3070 all data for the Linux kernel must be between "bootm_low"
3071 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3072 variable "bootm_mapsize" will override the value of
3073 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3074 then the value in "bootm_size" will be used instead.
3076 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3077 Enable initrd_high functionality. If defined then the
3078 initrd_high feature is enabled and the bootm ramdisk subcommand
3081 - CONFIG_SYS_BOOT_GET_CMDLINE:
3082 Enables allocating and saving kernel cmdline in space between
3083 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3085 - CONFIG_SYS_BOOT_GET_KBD:
3086 Enables allocating and saving a kernel copy of the bd_info in
3087 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3089 - CONFIG_SYS_MAX_FLASH_BANKS:
3090 Max number of Flash memory banks
3092 - CONFIG_SYS_MAX_FLASH_SECT:
3093 Max number of sectors on a Flash chip
3095 - CONFIG_SYS_FLASH_ERASE_TOUT:
3096 Timeout for Flash erase operations (in ms)
3098 - CONFIG_SYS_FLASH_WRITE_TOUT:
3099 Timeout for Flash write operations (in ms)
3101 - CONFIG_SYS_FLASH_LOCK_TOUT
3102 Timeout for Flash set sector lock bit operation (in ms)
3104 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3105 Timeout for Flash clear lock bits operation (in ms)
3107 - CONFIG_SYS_FLASH_PROTECTION
3108 If defined, hardware flash sectors protection is used
3109 instead of U-Boot software protection.
3111 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3113 Enable TFTP transfers directly to flash memory;
3114 without this option such a download has to be
3115 performed in two steps: (1) download to RAM, and (2)
3116 copy from RAM to flash.
3118 The two-step approach is usually more reliable, since
3119 you can check if the download worked before you erase
3120 the flash, but in some situations (when system RAM is
3121 too limited to allow for a temporary copy of the
3122 downloaded image) this option may be very useful.
3124 - CONFIG_SYS_FLASH_CFI:
3125 Define if the flash driver uses extra elements in the
3126 common flash structure for storing flash geometry.
3128 - CONFIG_FLASH_CFI_DRIVER
3129 This option also enables the building of the cfi_flash driver
3130 in the drivers directory
3132 - CONFIG_FLASH_CFI_MTD
3133 This option enables the building of the cfi_mtd driver
3134 in the drivers directory. The driver exports CFI flash
3137 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3138 Use buffered writes to flash.
3140 - CONFIG_FLASH_SPANSION_S29WS_N
3141 s29ws-n MirrorBit flash has non-standard addresses for buffered
3144 - CONFIG_SYS_FLASH_QUIET_TEST
3145 If this option is defined, the common CFI flash doesn't
3146 print it's warning upon not recognized FLASH banks. This
3147 is useful, if some of the configured banks are only
3148 optionally available.
3150 - CONFIG_FLASH_SHOW_PROGRESS
3151 If defined (must be an integer), print out countdown
3152 digits and dots. Recommended value: 45 (9..1) for 80
3153 column displays, 15 (3..1) for 40 column displays.
3155 - CONFIG_SYS_RX_ETH_BUFFER:
3156 Defines the number of Ethernet receive buffers. On some
3157 Ethernet controllers it is recommended to set this value
3158 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3159 buffers can be full shortly after enabling the interface
3160 on high Ethernet traffic.
3161 Defaults to 4 if not defined.
3163 - CONFIG_ENV_MAX_ENTRIES
3165 Maximum number of entries in the hash table that is used
3166 internally to store the environment settings. The default
3167 setting is supposed to be generous and should work in most
3168 cases. This setting can be used to tune behaviour; see
3169 lib/hashtable.c for details.
3171 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3172 - CONFIG_ENV_FLAGS_LIST_STATIC
3173 Enable validation of the values given to enviroment variables when
3174 calling env set. Variables can be restricted to only decimal,
3175 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3176 the variables can also be restricted to IP address or MAC address.
3178 The format of the list is:
3179 type_attribute = [s|d|x|b|i|m]
3180 access_atribute = [a|r|o|c]
3181 attributes = type_attribute[access_atribute]
3182 entry = variable_name[:attributes]
3185 The type attributes are:
3186 s - String (default)
3189 b - Boolean ([1yYtT|0nNfF])
3193 The access attributes are:
3199 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3200 Define this to a list (string) to define the ".flags"
3201 envirnoment variable in the default or embedded environment.
3203 - CONFIG_ENV_FLAGS_LIST_STATIC
3204 Define this to a list (string) to define validation that
3205 should be done if an entry is not found in the ".flags"
3206 environment variable. To override a setting in the static
3207 list, simply add an entry for the same variable name to the
3210 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3211 If defined, don't allow the -f switch to env set override variable
3214 The following definitions that deal with the placement and management
3215 of environment data (variable area); in general, we support the
3216 following configurations:
3218 - CONFIG_BUILD_ENVCRC:
3220 Builds up envcrc with the target environment so that external utils
3221 may easily extract it and embed it in final U-Boot images.
3223 - CONFIG_ENV_IS_IN_FLASH:
3225 Define this if the environment is in flash memory.
3227 a) The environment occupies one whole flash sector, which is
3228 "embedded" in the text segment with the U-Boot code. This
3229 happens usually with "bottom boot sector" or "top boot
3230 sector" type flash chips, which have several smaller
3231 sectors at the start or the end. For instance, such a
3232 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3233 such a case you would place the environment in one of the
3234 4 kB sectors - with U-Boot code before and after it. With
3235 "top boot sector" type flash chips, you would put the
3236 environment in one of the last sectors, leaving a gap
3237 between U-Boot and the environment.
3239 - CONFIG_ENV_OFFSET:
3241 Offset of environment data (variable area) to the
3242 beginning of flash memory; for instance, with bottom boot
3243 type flash chips the second sector can be used: the offset
3244 for this sector is given here.
3246 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3250 This is just another way to specify the start address of
3251 the flash sector containing the environment (instead of
3254 - CONFIG_ENV_SECT_SIZE:
3256 Size of the sector containing the environment.
3259 b) Sometimes flash chips have few, equal sized, BIG sectors.
3260 In such a case you don't want to spend a whole sector for
3265 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3266 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3267 of this flash sector for the environment. This saves
3268 memory for the RAM copy of the environment.
3270 It may also save flash memory if you decide to use this
3271 when your environment is "embedded" within U-Boot code,
3272 since then the remainder of the flash sector could be used
3273 for U-Boot code. It should be pointed out that this is
3274 STRONGLY DISCOURAGED from a robustness point of view:
3275 updating the environment in flash makes it always
3276 necessary to erase the WHOLE sector. If something goes
3277 wrong before the contents has been restored from a copy in
3278 RAM, your target system will be dead.
3280 - CONFIG_ENV_ADDR_REDUND
3281 CONFIG_ENV_SIZE_REDUND
3283 These settings describe a second storage area used to hold
3284 a redundant copy of the environment data, so that there is
3285 a valid backup copy in case there is a power failure during
3286 a "saveenv" operation.
3288 BE CAREFUL! Any changes to the flash layout, and some changes to the
3289 source code will make it necessary to adapt <board>/u-boot.lds*
3293 - CONFIG_ENV_IS_IN_NVRAM:
3295 Define this if you have some non-volatile memory device
3296 (NVRAM, battery buffered SRAM) which you want to use for the
3302 These two #defines are used to determine the memory area you
3303 want to use for environment. It is assumed that this memory
3304 can just be read and written to, without any special
3307 BE CAREFUL! The first access to the environment happens quite early
3308 in U-Boot initalization (when we try to get the setting of for the
3309 console baudrate). You *MUST* have mapped your NVRAM area then, or
3312 Please note that even with NVRAM we still use a copy of the
3313 environment in RAM: we could work on NVRAM directly, but we want to
3314 keep settings there always unmodified except somebody uses "saveenv"
3315 to save the current settings.
3318 - CONFIG_ENV_IS_IN_EEPROM:
3320 Use this if you have an EEPROM or similar serial access
3321 device and a driver for it.
3323 - CONFIG_ENV_OFFSET:
3326 These two #defines specify the offset and size of the
3327 environment area within the total memory of your EEPROM.
3329 - CONFIG_SYS_I2C_EEPROM_ADDR:
3330 If defined, specified the chip address of the EEPROM device.
3331 The default address is zero.
3333 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3334 If defined, the number of bits used to address bytes in a
3335 single page in the EEPROM device. A 64 byte page, for example
3336 would require six bits.
3338 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3339 If defined, the number of milliseconds to delay between
3340 page writes. The default is zero milliseconds.
3342 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3343 The length in bytes of the EEPROM memory array address. Note
3344 that this is NOT the chip address length!
3346 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3347 EEPROM chips that implement "address overflow" are ones
3348 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3349 address and the extra bits end up in the "chip address" bit
3350 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3353 Note that we consider the length of the address field to
3354 still be one byte because the extra address bits are hidden
3355 in the chip address.
3357 - CONFIG_SYS_EEPROM_SIZE:
3358 The size in bytes of the EEPROM device.
3360 - CONFIG_ENV_EEPROM_IS_ON_I2C
3361 define this, if you have I2C and SPI activated, and your
3362 EEPROM, which holds the environment, is on the I2C bus.
3364 - CONFIG_I2C_ENV_EEPROM_BUS
3365 if you have an Environment on an EEPROM reached over
3366 I2C muxes, you can define here, how to reach this
3367 EEPROM. For example:
3369 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
3371 EEPROM which holds the environment, is reached over
3372 a pca9547 i2c mux with address 0x70, channel 3.
3374 - CONFIG_ENV_IS_IN_DATAFLASH:
3376 Define this if you have a DataFlash memory device which you
3377 want to use for the environment.
3379 - CONFIG_ENV_OFFSET:
3383 These three #defines specify the offset and size of the
3384 environment area within the total memory of your DataFlash placed
3385 at the specified address.
3387 - CONFIG_ENV_IS_IN_REMOTE:
3389 Define this if you have a remote memory space which you
3390 want to use for the local device's environment.
3395 These two #defines specify the address and size of the
3396 environment area within the remote memory space. The
3397 local device can get the environment from remote memory
3398 space by SRIO or PCIE links.
3400 BE CAREFUL! For some special cases, the local device can not use
3401 "saveenv" command. For example, the local device will get the
3402 environment stored in a remote NOR flash by SRIO or PCIE link,
3403 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3405 - CONFIG_ENV_IS_IN_NAND:
3407 Define this if you have a NAND device which you want to use
3408 for the environment.
3410 - CONFIG_ENV_OFFSET:
3413 These two #defines specify the offset and size of the environment
3414 area within the first NAND device. CONFIG_ENV_OFFSET must be
3415 aligned to an erase block boundary.
3417 - CONFIG_ENV_OFFSET_REDUND (optional):
3419 This setting describes a second storage area of CONFIG_ENV_SIZE
3420 size used to hold a redundant copy of the environment data, so
3421 that there is a valid backup copy in case there is a power failure
3422 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3423 aligned to an erase block boundary.
3425 - CONFIG_ENV_RANGE (optional):
3427 Specifies the length of the region in which the environment
3428 can be written. This should be a multiple of the NAND device's
3429 block size. Specifying a range with more erase blocks than
3430 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3431 the range to be avoided.
3433 - CONFIG_ENV_OFFSET_OOB (optional):
3435 Enables support for dynamically retrieving the offset of the
3436 environment from block zero's out-of-band data. The
3437 "nand env.oob" command can be used to record this offset.
3438 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3439 using CONFIG_ENV_OFFSET_OOB.
3441 - CONFIG_NAND_ENV_DST
3443 Defines address in RAM to which the nand_spl code should copy the
3444 environment. If redundant environment is used, it will be copied to
3445 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3447 - CONFIG_SYS_SPI_INIT_OFFSET
3449 Defines offset to the initial SPI buffer area in DPRAM. The
3450 area is used at an early stage (ROM part) if the environment
3451 is configured to reside in the SPI EEPROM: We need a 520 byte
3452 scratch DPRAM area. It is used between the two initialization
3453 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3454 to be a good choice since it makes it far enough from the
3455 start of the data area as well as from the stack pointer.
3457 Please note that the environment is read-only until the monitor
3458 has been relocated to RAM and a RAM copy of the environment has been
3459 created; also, when using EEPROM you will have to use getenv_f()
3460 until then to read environment variables.
3462 The environment is protected by a CRC32 checksum. Before the monitor
3463 is relocated into RAM, as a result of a bad CRC you will be working
3464 with the compiled-in default environment - *silently*!!! [This is
3465 necessary, because the first environment variable we need is the
3466 "baudrate" setting for the console - if we have a bad CRC, we don't
3467 have any device yet where we could complain.]
3469 Note: once the monitor has been relocated, then it will complain if
3470 the default environment is used; a new CRC is computed as soon as you
3471 use the "saveenv" command to store a valid environment.
3473 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3474 Echo the inverted Ethernet link state to the fault LED.
3476 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3477 also needs to be defined.
3479 - CONFIG_SYS_FAULT_MII_ADDR:
3480 MII address of the PHY to check for the Ethernet link state.
3482 - CONFIG_NS16550_MIN_FUNCTIONS:
3483 Define this if you desire to only have use of the NS16550_init
3484 and NS16550_putc functions for the serial driver located at
3485 drivers/serial/ns16550.c. This option is useful for saving
3486 space for already greatly restricted images, including but not
3487 limited to NAND_SPL configurations.
3489 - CONFIG_DISPLAY_BOARDINFO
3490 Display information about the board that U-Boot is running on
3491 when U-Boot starts up. The board function checkboard() is called
3494 - CONFIG_DISPLAY_BOARDINFO_LATE
3495 Similar to the previous option, but display this information
3496 later, once stdio is running and output goes to the LCD, if
3499 Low Level (hardware related) configuration options:
3500 ---------------------------------------------------
3502 - CONFIG_SYS_CACHELINE_SIZE:
3503 Cache Line Size of the CPU.
3505 - CONFIG_SYS_DEFAULT_IMMR:
3506 Default address of the IMMR after system reset.
3508 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3509 and RPXsuper) to be able to adjust the position of
3510 the IMMR register after a reset.
3512 - CONFIG_SYS_CCSRBAR_DEFAULT:
3513 Default (power-on reset) physical address of CCSR on Freescale
3516 - CONFIG_SYS_CCSRBAR:
3517 Virtual address of CCSR. On a 32-bit build, this is typically
3518 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3520 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3521 for cross-platform code that uses that macro instead.
3523 - CONFIG_SYS_CCSRBAR_PHYS:
3524 Physical address of CCSR. CCSR can be relocated to a new
3525 physical address, if desired. In this case, this macro should
3526 be set to that address. Otherwise, it should be set to the
3527 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3528 is typically relocated on 36-bit builds. It is recommended
3529 that this macro be defined via the _HIGH and _LOW macros:
3531 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3532 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3534 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3535 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3536 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3537 used in assembly code, so it must not contain typecasts or
3538 integer size suffixes (e.g. "ULL").
3540 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3541 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3542 used in assembly code, so it must not contain typecasts or
3543 integer size suffixes (e.g. "ULL").
3545 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3546 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3547 forced to a value that ensures that CCSR is not relocated.
3549 - Floppy Disk Support:
3550 CONFIG_SYS_FDC_DRIVE_NUMBER
3552 the default drive number (default value 0)
3554 CONFIG_SYS_ISA_IO_STRIDE
3556 defines the spacing between FDC chipset registers
3559 CONFIG_SYS_ISA_IO_OFFSET
3561 defines the offset of register from address. It
3562 depends on which part of the data bus is connected to
3563 the FDC chipset. (default value 0)
3565 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3566 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3569 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3570 fdc_hw_init() is called at the beginning of the FDC
3571 setup. fdc_hw_init() must be provided by the board
3572 source code. It is used to make hardware dependant
3576 Most IDE controllers were designed to be connected with PCI
3577 interface. Only few of them were designed for AHB interface.
3578 When software is doing ATA command and data transfer to
3579 IDE devices through IDE-AHB controller, some additional
3580 registers accessing to these kind of IDE-AHB controller
3583 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3584 DO NOT CHANGE unless you know exactly what you're
3585 doing! (11-4) [MPC8xx/82xx systems only]
3587 - CONFIG_SYS_INIT_RAM_ADDR:
3589 Start address of memory area that can be used for
3590 initial data and stack; please note that this must be
3591 writable memory that is working WITHOUT special
3592 initialization, i. e. you CANNOT use normal RAM which
3593 will become available only after programming the
3594 memory controller and running certain initialization
3597 U-Boot uses the following memory types:
3598 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
3599 - MPC824X: data cache
3600 - PPC4xx: data cache
3602 - CONFIG_SYS_GBL_DATA_OFFSET:
3604 Offset of the initial data structure in the memory
3605 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3606 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3607 data is located at the end of the available space
3608 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3609 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
3610 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3611 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3614 On the MPC824X (or other systems that use the data
3615 cache for initial memory) the address chosen for
3616 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3617 point to an otherwise UNUSED address space between
3618 the top of RAM and the start of the PCI space.
3620 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
3622 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
3624 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
3626 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
3628 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
3630 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3632 - CONFIG_SYS_OR_TIMING_SDRAM:
3635 - CONFIG_SYS_MAMR_PTA:
3636 periodic timer for refresh
3638 - CONFIG_SYS_DER: Debug Event Register (37-47)
3640 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3641 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3642 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3643 CONFIG_SYS_BR1_PRELIM:
3644 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3646 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3647 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3648 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3649 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3651 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
3652 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
3653 Machine Mode Register and Memory Periodic Timer
3654 Prescaler definitions (SDRAM timing)
3656 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
3657 enable I2C microcode relocation patch (MPC8xx);
3658 define relocation offset in DPRAM [DSP2]
3660 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
3661 enable SMC microcode relocation patch (MPC8xx);
3662 define relocation offset in DPRAM [SMC1]
3664 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
3665 enable SPI microcode relocation patch (MPC8xx);
3666 define relocation offset in DPRAM [SCC4]
3668 - CONFIG_SYS_USE_OSCCLK:
3669 Use OSCM clock mode on MBX8xx board. Be careful,
3670 wrong setting might damage your board. Read
3671 doc/README.MBX before setting this variable!
3673 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
3674 Offset of the bootmode word in DPRAM used by post
3675 (Power On Self Tests). This definition overrides
3676 #define'd default value in commproc.h resp.
3679 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
3680 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
3681 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
3682 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
3683 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
3684 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
3685 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
3686 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
3687 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
3689 - CONFIG_PCI_DISABLE_PCIE:
3690 Disable PCI-Express on systems where it is supported but not
3693 - CONFIG_PCI_ENUM_ONLY
3694 Only scan through and get the devices on the busses.
3695 Don't do any setup work, presumably because someone or
3696 something has already done it, and we don't need to do it
3697 a second time. Useful for platforms that are pre-booted
3698 by coreboot or similar.
3701 Chip has SRIO or not
3704 Board has SRIO 1 port available
3707 Board has SRIO 2 port available
3709 - CONFIG_SYS_SRIOn_MEM_VIRT:
3710 Virtual Address of SRIO port 'n' memory region
3712 - CONFIG_SYS_SRIOn_MEM_PHYS:
3713 Physical Address of SRIO port 'n' memory region
3715 - CONFIG_SYS_SRIOn_MEM_SIZE:
3716 Size of SRIO port 'n' memory region
3718 - CONFIG_SYS_NDFC_16
3719 Defined to tell the NDFC that the NAND chip is using a
3722 - CONFIG_SYS_NDFC_EBC0_CFG
3723 Sets the EBC0_CFG register for the NDFC. If not defined
3724 a default value will be used.
3727 Get DDR timing information from an I2C EEPROM. Common
3728 with pluggable memory modules such as SODIMMs
3731 I2C address of the SPD EEPROM
3733 - CONFIG_SYS_SPD_BUS_NUM
3734 If SPD EEPROM is on an I2C bus other than the first
3735 one, specify here. Note that the value must resolve
3736 to something your driver can deal with.
3738 - CONFIG_SYS_DDR_RAW_TIMING
3739 Get DDR timing information from other than SPD. Common with
3740 soldered DDR chips onboard without SPD. DDR raw timing
3741 parameters are extracted from datasheet and hard-coded into
3742 header files or board specific files.
3744 - CONFIG_FSL_DDR_INTERACTIVE
3745 Enable interactive DDR debugging. See doc/README.fsl-ddr.
3747 - CONFIG_SYS_83XX_DDR_USES_CS0
3748 Only for 83xx systems. If specified, then DDR should
3749 be configured using CS0 and CS1 instead of CS2 and CS3.
3751 - CONFIG_ETHER_ON_FEC[12]
3752 Define to enable FEC[12] on a 8xx series processor.
3754 - CONFIG_FEC[12]_PHY
3755 Define to the hardcoded PHY address which corresponds
3756 to the given FEC; i. e.
3757 #define CONFIG_FEC1_PHY 4
3758 means that the PHY with address 4 is connected to FEC1
3760 When set to -1, means to probe for first available.
3762 - CONFIG_FEC[12]_PHY_NORXERR
3763 The PHY does not have a RXERR line (RMII only).
3764 (so program the FEC to ignore it).
3767 Enable RMII mode for all FECs.
3768 Note that this is a global option, we can't
3769 have one FEC in standard MII mode and another in RMII mode.
3771 - CONFIG_CRC32_VERIFY
3772 Add a verify option to the crc32 command.
3775 => crc32 -v <address> <count> <crc32>
3777 Where address/count indicate a memory area
3778 and crc32 is the correct crc32 which the
3782 Add the "loopw" memory command. This only takes effect if
3783 the memory commands are activated globally (CONFIG_CMD_MEM).
3786 Add the "mdc" and "mwc" memory commands. These are cyclic
3791 This command will print 4 bytes (10,11,12,13) each 500 ms.
3793 => mwc.l 100 12345678 10
3794 This command will write 12345678 to address 100 all 10 ms.
3796 This only takes effect if the memory commands are activated
3797 globally (CONFIG_CMD_MEM).
3799 - CONFIG_SKIP_LOWLEVEL_INIT
3800 [ARM, NDS32, MIPS only] If this variable is defined, then certain
3801 low level initializations (like setting up the memory
3802 controller) are omitted and/or U-Boot does not
3803 relocate itself into RAM.
3805 Normally this variable MUST NOT be defined. The only
3806 exception is when U-Boot is loaded (to RAM) by some
3807 other boot loader or by a debugger which performs
3808 these initializations itself.
3811 Modifies the behaviour of start.S when compiling a loader
3812 that is executed before the actual U-Boot. E.g. when
3813 compiling a NAND SPL.
3815 - CONFIG_ARCH_MAP_SYSMEM
3816 Generally U-Boot (and in particular the md command) uses
3817 effective address. It is therefore not necessary to regard
3818 U-Boot address as virtual addresses that need to be translated
3819 to physical addresses. However, sandbox requires this, since
3820 it maintains its own little RAM buffer which contains all
3821 addressable memory. This option causes some memory accesses
3822 to be mapped through map_sysmem() / unmap_sysmem().
3824 - CONFIG_USE_ARCH_MEMCPY
3825 CONFIG_USE_ARCH_MEMSET
3826 If these options are used a optimized version of memcpy/memset will
3827 be used if available. These functions may be faster under some
3828 conditions but may increase the binary size.
3830 - CONFIG_X86_RESET_VECTOR
3831 If defined, the x86 reset vector code is included. This is not
3832 needed when U-Boot is running from Coreboot.
3835 Freescale QE/FMAN Firmware Support:
3836 -----------------------------------
3838 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
3839 loading of "firmware", which is encoded in the QE firmware binary format.
3840 This firmware often needs to be loaded during U-Boot booting, so macros
3841 are used to identify the storage device (NOR flash, SPI, etc) and the address
3844 - CONFIG_SYS_QE_FMAN_FW_ADDR
3845 The address in the storage device where the firmware is located. The
3846 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3849 - CONFIG_SYS_QE_FMAN_FW_LENGTH
3850 The maximum possible size of the firmware. The firmware binary format
3851 has a field that specifies the actual size of the firmware, but it
3852 might not be possible to read any part of the firmware unless some
3853 local storage is allocated to hold the entire firmware first.
3855 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
3856 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
3857 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
3858 virtual address in NOR flash.
3860 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
3861 Specifies that QE/FMAN firmware is located in NAND flash.
3862 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
3864 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
3865 Specifies that QE/FMAN firmware is located on the primary SD/MMC
3866 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3868 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
3869 Specifies that QE/FMAN firmware is located on the primary SPI
3870 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3872 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
3873 Specifies that QE/FMAN firmware is located in the remote (master)
3874 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
3875 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
3876 window->master inbound window->master LAW->the ucode address in
3877 master's memory space.
3879 Building the Software:
3880 ======================
3882 Building U-Boot has been tested in several native build environments
3883 and in many different cross environments. Of course we cannot support
3884 all possibly existing versions of cross development tools in all
3885 (potentially obsolete) versions. In case of tool chain problems we
3886 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3887 which is extensively used to build and test U-Boot.
3889 If you are not using a native environment, it is assumed that you
3890 have GNU cross compiling tools available in your path. In this case,
3891 you must set the environment variable CROSS_COMPILE in your shell.
3892 Note that no changes to the Makefile or any other source files are
3893 necessary. For example using the ELDK on a 4xx CPU, please enter:
3895 $ CROSS_COMPILE=ppc_4xx-
3896 $ export CROSS_COMPILE
3898 Note: If you wish to generate Windows versions of the utilities in
3899 the tools directory you can use the MinGW toolchain
3900 (http://www.mingw.org). Set your HOST tools to the MinGW
3901 toolchain and execute 'make tools'. For example:
3903 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3905 Binaries such as tools/mkimage.exe will be created which can
3906 be executed on computers running Windows.
3908 U-Boot is intended to be simple to build. After installing the
3909 sources you must configure U-Boot for one specific board type. This
3914 where "NAME_config" is the name of one of the existing configu-
3915 rations; see boards.cfg for supported names.
3917 Note: for some board special configuration names may exist; check if
3918 additional information is available from the board vendor; for
3919 instance, the TQM823L systems are available without (standard)
3920 or with LCD support. You can select such additional "features"
3921 when choosing the configuration, i. e.
3924 - will configure for a plain TQM823L, i. e. no LCD support
3926 make TQM823L_LCD_config
3927 - will configure for a TQM823L with U-Boot console on LCD
3932 Finally, type "make all", and you should get some working U-Boot
3933 images ready for download to / installation on your system:
3935 - "u-boot.bin" is a raw binary image
3936 - "u-boot" is an image in ELF binary format
3937 - "u-boot.srec" is in Motorola S-Record format
3939 By default the build is performed locally and the objects are saved
3940 in the source directory. One of the two methods can be used to change
3941 this behavior and build U-Boot to some external directory:
3943 1. Add O= to the make command line invocations:
3945 make O=/tmp/build distclean
3946 make O=/tmp/build NAME_config
3947 make O=/tmp/build all
3949 2. Set environment variable BUILD_DIR to point to the desired location:
3951 export BUILD_DIR=/tmp/build
3956 Note that the command line "O=" setting overrides the BUILD_DIR environment
3960 Please be aware that the Makefiles assume you are using GNU make, so
3961 for instance on NetBSD you might need to use "gmake" instead of
3965 If the system board that you have is not listed, then you will need
3966 to port U-Boot to your hardware platform. To do this, follow these
3969 1. Add a new configuration option for your board to the toplevel
3970 "boards.cfg" file, using the existing entries as examples.
3971 Follow the instructions there to keep the boards in order.
3972 2. Create a new directory to hold your board specific code. Add any
3973 files you need. In your board directory, you will need at least
3974 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
3975 3. Create a new configuration file "include/configs/<board>.h" for
3977 3. If you're porting U-Boot to a new CPU, then also create a new
3978 directory to hold your CPU specific code. Add any files you need.
3979 4. Run "make <board>_config" with your new name.
3980 5. Type "make", and you should get a working "u-boot.srec" file
3981 to be installed on your target system.
3982 6. Debug and solve any problems that might arise.
3983 [Of course, this last step is much harder than it sounds.]
3986 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3987 ==============================================================
3989 If you have modified U-Boot sources (for instance added a new board
3990 or support for new devices, a new CPU, etc.) you are expected to
3991 provide feedback to the other developers. The feedback normally takes
3992 the form of a "patch", i. e. a context diff against a certain (latest
3993 official or latest in the git repository) version of U-Boot sources.
3995 But before you submit such a patch, please verify that your modifi-
3996 cation did not break existing code. At least make sure that *ALL* of
3997 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3998 just run the "MAKEALL" script, which will configure and build U-Boot
3999 for ALL supported system. Be warned, this will take a while. You can
4000 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4001 environment variable to the script, i. e. to use the ELDK cross tools
4004 CROSS_COMPILE=ppc_8xx- MAKEALL
4006 or to build on a native PowerPC system you can type
4008 CROSS_COMPILE=' ' MAKEALL
4010 When using the MAKEALL script, the default behaviour is to build
4011 U-Boot in the source directory. This location can be changed by
4012 setting the BUILD_DIR environment variable. Also, for each target
4013 built, the MAKEALL script saves two log files (<target>.ERR and
4014 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4015 location can be changed by setting the MAKEALL_LOGDIR environment
4016 variable. For example:
4018 export BUILD_DIR=/tmp/build
4019 export MAKEALL_LOGDIR=/tmp/log
4020 CROSS_COMPILE=ppc_8xx- MAKEALL
4022 With the above settings build objects are saved in the /tmp/build,
4023 log files are saved in the /tmp/log and the source tree remains clean
4024 during the whole build process.
4027 See also "U-Boot Porting Guide" below.
4030 Monitor Commands - Overview:
4031 ============================
4033 go - start application at address 'addr'
4034 run - run commands in an environment variable
4035 bootm - boot application image from memory
4036 bootp - boot image via network using BootP/TFTP protocol
4037 bootz - boot zImage from memory
4038 tftpboot- boot image via network using TFTP protocol
4039 and env variables "ipaddr" and "serverip"
4040 (and eventually "gatewayip")
4041 tftpput - upload a file via network using TFTP protocol
4042 rarpboot- boot image via network using RARP/TFTP protocol
4043 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4044 loads - load S-Record file over serial line
4045 loadb - load binary file over serial line (kermit mode)
4047 mm - memory modify (auto-incrementing)
4048 nm - memory modify (constant address)
4049 mw - memory write (fill)
4051 cmp - memory compare
4052 crc32 - checksum calculation
4053 i2c - I2C sub-system
4054 sspi - SPI utility commands
4055 base - print or set address offset
4056 printenv- print environment variables
4057 setenv - set environment variables
4058 saveenv - save environment variables to persistent storage
4059 protect - enable or disable FLASH write protection
4060 erase - erase FLASH memory
4061 flinfo - print FLASH memory information
4062 nand - NAND memory operations (see doc/README.nand)
4063 bdinfo - print Board Info structure
4064 iminfo - print header information for application image
4065 coninfo - print console devices and informations
4066 ide - IDE sub-system
4067 loop - infinite loop on address range
4068 loopw - infinite write loop on address range
4069 mtest - simple RAM test
4070 icache - enable or disable instruction cache
4071 dcache - enable or disable data cache
4072 reset - Perform RESET of the CPU
4073 echo - echo args to console
4074 version - print monitor version
4075 help - print online help
4076 ? - alias for 'help'
4079 Monitor Commands - Detailed Description:
4080 ========================================
4084 For now: just type "help <command>".
4087 Environment Variables:
4088 ======================
4090 U-Boot supports user configuration using Environment Variables which
4091 can be made persistent by saving to Flash memory.
4093 Environment Variables are set using "setenv", printed using
4094 "printenv", and saved to Flash using "saveenv". Using "setenv"
4095 without a value can be used to delete a variable from the
4096 environment. As long as you don't save the environment you are
4097 working with an in-memory copy. In case the Flash area containing the
4098 environment is erased by accident, a default environment is provided.
4100 Some configuration options can be set using Environment Variables.
4102 List of environment variables (most likely not complete):
4104 baudrate - see CONFIG_BAUDRATE
4106 bootdelay - see CONFIG_BOOTDELAY
4108 bootcmd - see CONFIG_BOOTCOMMAND
4110 bootargs - Boot arguments when booting an RTOS image
4112 bootfile - Name of the image to load with TFTP
4114 bootm_low - Memory range available for image processing in the bootm
4115 command can be restricted. This variable is given as
4116 a hexadecimal number and defines lowest address allowed
4117 for use by the bootm command. See also "bootm_size"
4118 environment variable. Address defined by "bootm_low" is
4119 also the base of the initial memory mapping for the Linux
4120 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4123 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4124 This variable is given as a hexadecimal number and it
4125 defines the size of the memory region starting at base
4126 address bootm_low that is accessible by the Linux kernel
4127 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4128 as the default value if it is defined, and bootm_size is
4131 bootm_size - Memory range available for image processing in the bootm
4132 command can be restricted. This variable is given as
4133 a hexadecimal number and defines the size of the region
4134 allowed for use by the bootm command. See also "bootm_low"
4135 environment variable.
4137 updatefile - Location of the software update file on a TFTP server, used
4138 by the automatic software update feature. Please refer to
4139 documentation in doc/README.update for more details.
4141 autoload - if set to "no" (any string beginning with 'n'),
4142 "bootp" will just load perform a lookup of the
4143 configuration from the BOOTP server, but not try to
4144 load any image using TFTP
4146 autostart - if set to "yes", an image loaded using the "bootp",
4147 "rarpboot", "tftpboot" or "diskboot" commands will
4148 be automatically started (by internally calling
4151 If set to "no", a standalone image passed to the
4152 "bootm" command will be copied to the load address
4153 (and eventually uncompressed), but NOT be started.
4154 This can be used to load and uncompress arbitrary
4157 fdt_high - if set this restricts the maximum address that the
4158 flattened device tree will be copied into upon boot.
4159 For example, if you have a system with 1 GB memory
4160 at physical address 0x10000000, while Linux kernel
4161 only recognizes the first 704 MB as low memory, you
4162 may need to set fdt_high as 0x3C000000 to have the
4163 device tree blob be copied to the maximum address
4164 of the 704 MB low memory, so that Linux kernel can
4165 access it during the boot procedure.
4167 If this is set to the special value 0xFFFFFFFF then
4168 the fdt will not be copied at all on boot. For this
4169 to work it must reside in writable memory, have
4170 sufficient padding on the end of it for u-boot to
4171 add the information it needs into it, and the memory
4172 must be accessible by the kernel.
4174 fdtcontroladdr- if set this is the address of the control flattened
4175 device tree used by U-Boot when CONFIG_OF_CONTROL is
4178 i2cfast - (PPC405GP|PPC405EP only)
4179 if set to 'y' configures Linux I2C driver for fast
4180 mode (400kHZ). This environment variable is used in
4181 initialization code. So, for changes to be effective
4182 it must be saved and board must be reset.
4184 initrd_high - restrict positioning of initrd images:
4185 If this variable is not set, initrd images will be
4186 copied to the highest possible address in RAM; this
4187 is usually what you want since it allows for
4188 maximum initrd size. If for some reason you want to
4189 make sure that the initrd image is loaded below the
4190 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4191 variable to a value of "no" or "off" or "0".
4192 Alternatively, you can set it to a maximum upper
4193 address to use (U-Boot will still check that it
4194 does not overwrite the U-Boot stack and data).
4196 For instance, when you have a system with 16 MB
4197 RAM, and want to reserve 4 MB from use by Linux,
4198 you can do this by adding "mem=12M" to the value of
4199 the "bootargs" variable. However, now you must make
4200 sure that the initrd image is placed in the first
4201 12 MB as well - this can be done with
4203 setenv initrd_high 00c00000
4205 If you set initrd_high to 0xFFFFFFFF, this is an
4206 indication to U-Boot that all addresses are legal
4207 for the Linux kernel, including addresses in flash
4208 memory. In this case U-Boot will NOT COPY the
4209 ramdisk at all. This may be useful to reduce the
4210 boot time on your system, but requires that this
4211 feature is supported by your Linux kernel.
4213 ipaddr - IP address; needed for tftpboot command
4215 loadaddr - Default load address for commands like "bootp",
4216 "rarpboot", "tftpboot", "loadb" or "diskboot"
4218 loads_echo - see CONFIG_LOADS_ECHO
4220 serverip - TFTP server IP address; needed for tftpboot command
4222 bootretry - see CONFIG_BOOT_RETRY_TIME
4224 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4226 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4228 ethprime - controls which interface is used first.
4230 ethact - controls which interface is currently active.
4231 For example you can do the following
4233 => setenv ethact FEC
4234 => ping 192.168.0.1 # traffic sent on FEC
4235 => setenv ethact SCC
4236 => ping 10.0.0.1 # traffic sent on SCC
4238 ethrotate - When set to "no" U-Boot does not go through all
4239 available network interfaces.
4240 It just stays at the currently selected interface.
4242 netretry - When set to "no" each network operation will
4243 either succeed or fail without retrying.
4244 When set to "once" the network operation will
4245 fail when all the available network interfaces
4246 are tried once without success.
4247 Useful on scripts which control the retry operation
4250 npe_ucode - set load address for the NPE microcode
4252 tftpsrcport - If this is set, the value is used for TFTP's
4255 tftpdstport - If this is set, the value is used for TFTP's UDP
4256 destination port instead of the Well Know Port 69.
4258 tftpblocksize - Block size to use for TFTP transfers; if not set,
4259 we use the TFTP server's default block size
4261 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4262 seconds, minimum value is 1000 = 1 second). Defines
4263 when a packet is considered to be lost so it has to
4264 be retransmitted. The default is 5000 = 5 seconds.
4265 Lowering this value may make downloads succeed
4266 faster in networks with high packet loss rates or
4267 with unreliable TFTP servers.
4269 vlan - When set to a value < 4095 the traffic over
4270 Ethernet is encapsulated/received over 802.1q
4273 The following image location variables contain the location of images
4274 used in booting. The "Image" column gives the role of the image and is
4275 not an environment variable name. The other columns are environment
4276 variable names. "File Name" gives the name of the file on a TFTP
4277 server, "RAM Address" gives the location in RAM the image will be
4278 loaded to, and "Flash Location" gives the image's address in NOR
4279 flash or offset in NAND flash.
4281 *Note* - these variables don't have to be defined for all boards, some
4282 boards currenlty use other variables for these purposes, and some
4283 boards use these variables for other purposes.
4285 Image File Name RAM Address Flash Location
4286 ----- --------- ----------- --------------
4287 u-boot u-boot u-boot_addr_r u-boot_addr
4288 Linux kernel bootfile kernel_addr_r kernel_addr
4289 device tree blob fdtfile fdt_addr_r fdt_addr
4290 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4292 The following environment variables may be used and automatically
4293 updated by the network boot commands ("bootp" and "rarpboot"),
4294 depending the information provided by your boot server:
4296 bootfile - see above
4297 dnsip - IP address of your Domain Name Server
4298 dnsip2 - IP address of your secondary Domain Name Server
4299 gatewayip - IP address of the Gateway (Router) to use
4300 hostname - Target hostname
4302 netmask - Subnet Mask
4303 rootpath - Pathname of the root filesystem on the NFS server
4304 serverip - see above
4307 There are two special Environment Variables:
4309 serial# - contains hardware identification information such
4310 as type string and/or serial number
4311 ethaddr - Ethernet address
4313 These variables can be set only once (usually during manufacturing of
4314 the board). U-Boot refuses to delete or overwrite these variables
4315 once they have been set once.
4318 Further special Environment Variables:
4320 ver - Contains the U-Boot version string as printed
4321 with the "version" command. This variable is
4322 readonly (see CONFIG_VERSION_VARIABLE).
4325 Please note that changes to some configuration parameters may take
4326 only effect after the next boot (yes, that's just like Windoze :-).
4329 Callback functions for environment variables:
4330 ---------------------------------------------
4332 For some environment variables, the behavior of u-boot needs to change
4333 when their values are changed. This functionailty allows functions to
4334 be associated with arbitrary variables. On creation, overwrite, or
4335 deletion, the callback will provide the opportunity for some side
4336 effect to happen or for the change to be rejected.
4338 The callbacks are named and associated with a function using the
4339 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4341 These callbacks are associated with variables in one of two ways. The
4342 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4343 in the board configuration to a string that defines a list of
4344 associations. The list must be in the following format:
4346 entry = variable_name[:callback_name]
4349 If the callback name is not specified, then the callback is deleted.
4350 Spaces are also allowed anywhere in the list.
4352 Callbacks can also be associated by defining the ".callbacks" variable
4353 with the same list format above. Any association in ".callbacks" will
4354 override any association in the static list. You can define
4355 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4356 ".callbacks" envirnoment variable in the default or embedded environment.
4359 Command Line Parsing:
4360 =====================
4362 There are two different command line parsers available with U-Boot:
4363 the old "simple" one, and the much more powerful "hush" shell:
4365 Old, simple command line parser:
4366 --------------------------------
4368 - supports environment variables (through setenv / saveenv commands)
4369 - several commands on one line, separated by ';'
4370 - variable substitution using "... ${name} ..." syntax
4371 - special characters ('$', ';') can be escaped by prefixing with '\',
4373 setenv bootcmd bootm \${address}
4374 - You can also escape text by enclosing in single apostrophes, for example:
4375 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4380 - similar to Bourne shell, with control structures like
4381 if...then...else...fi, for...do...done; while...do...done,
4382 until...do...done, ...
4383 - supports environment ("global") variables (through setenv / saveenv
4384 commands) and local shell variables (through standard shell syntax
4385 "name=value"); only environment variables can be used with "run"
4391 (1) If a command line (or an environment variable executed by a "run"
4392 command) contains several commands separated by semicolon, and
4393 one of these commands fails, then the remaining commands will be
4396 (2) If you execute several variables with one call to run (i. e.
4397 calling run with a list of variables as arguments), any failing
4398 command will cause "run" to terminate, i. e. the remaining
4399 variables are not executed.
4401 Note for Redundant Ethernet Interfaces:
4402 =======================================
4404 Some boards come with redundant Ethernet interfaces; U-Boot supports
4405 such configurations and is capable of automatic selection of a
4406 "working" interface when needed. MAC assignment works as follows:
4408 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4409 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4410 "eth1addr" (=>eth1), "eth2addr", ...
4412 If the network interface stores some valid MAC address (for instance
4413 in SROM), this is used as default address if there is NO correspon-
4414 ding setting in the environment; if the corresponding environment
4415 variable is set, this overrides the settings in the card; that means:
4417 o If the SROM has a valid MAC address, and there is no address in the
4418 environment, the SROM's address is used.
4420 o If there is no valid address in the SROM, and a definition in the
4421 environment exists, then the value from the environment variable is
4424 o If both the SROM and the environment contain a MAC address, and
4425 both addresses are the same, this MAC address is used.
4427 o If both the SROM and the environment contain a MAC address, and the
4428 addresses differ, the value from the environment is used and a
4431 o If neither SROM nor the environment contain a MAC address, an error
4434 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4435 will be programmed into hardware as part of the initialization process. This
4436 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4437 The naming convention is as follows:
4438 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4443 U-Boot is capable of booting (and performing other auxiliary operations on)
4444 images in two formats:
4446 New uImage format (FIT)
4447 -----------------------
4449 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4450 to Flattened Device Tree). It allows the use of images with multiple
4451 components (several kernels, ramdisks, etc.), with contents protected by
4452 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4458 Old image format is based on binary files which can be basically anything,
4459 preceded by a special header; see the definitions in include/image.h for
4460 details; basically, the header defines the following image properties:
4462 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4463 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4464 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4465 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4467 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4468 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4469 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4470 * Compression Type (uncompressed, gzip, bzip2)
4476 The header is marked by a special Magic Number, and both the header
4477 and the data portions of the image are secured against corruption by
4484 Although U-Boot should support any OS or standalone application
4485 easily, the main focus has always been on Linux during the design of
4488 U-Boot includes many features that so far have been part of some
4489 special "boot loader" code within the Linux kernel. Also, any
4490 "initrd" images to be used are no longer part of one big Linux image;
4491 instead, kernel and "initrd" are separate images. This implementation
4492 serves several purposes:
4494 - the same features can be used for other OS or standalone
4495 applications (for instance: using compressed images to reduce the
4496 Flash memory footprint)
4498 - it becomes much easier to port new Linux kernel versions because
4499 lots of low-level, hardware dependent stuff are done by U-Boot
4501 - the same Linux kernel image can now be used with different "initrd"
4502 images; of course this also means that different kernel images can
4503 be run with the same "initrd". This makes testing easier (you don't
4504 have to build a new "zImage.initrd" Linux image when you just
4505 change a file in your "initrd"). Also, a field-upgrade of the
4506 software is easier now.
4512 Porting Linux to U-Boot based systems:
4513 ---------------------------------------
4515 U-Boot cannot save you from doing all the necessary modifications to
4516 configure the Linux device drivers for use with your target hardware
4517 (no, we don't intend to provide a full virtual machine interface to
4520 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4522 Just make sure your machine specific header file (for instance
4523 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4524 Information structure as we define in include/asm-<arch>/u-boot.h,
4525 and make sure that your definition of IMAP_ADDR uses the same value
4526 as your U-Boot configuration in CONFIG_SYS_IMMR.
4529 Configuring the Linux kernel:
4530 -----------------------------
4532 No specific requirements for U-Boot. Make sure you have some root
4533 device (initial ramdisk, NFS) for your target system.
4536 Building a Linux Image:
4537 -----------------------
4539 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4540 not used. If you use recent kernel source, a new build target
4541 "uImage" will exist which automatically builds an image usable by
4542 U-Boot. Most older kernels also have support for a "pImage" target,
4543 which was introduced for our predecessor project PPCBoot and uses a
4544 100% compatible format.
4553 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4554 encapsulate a compressed Linux kernel image with header information,
4555 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4557 * build a standard "vmlinux" kernel image (in ELF binary format):
4559 * convert the kernel into a raw binary image:
4561 ${CROSS_COMPILE}-objcopy -O binary \
4562 -R .note -R .comment \
4563 -S vmlinux linux.bin
4565 * compress the binary image:
4569 * package compressed binary image for U-Boot:
4571 mkimage -A ppc -O linux -T kernel -C gzip \
4572 -a 0 -e 0 -n "Linux Kernel Image" \
4573 -d linux.bin.gz uImage
4576 The "mkimage" tool can also be used to create ramdisk images for use
4577 with U-Boot, either separated from the Linux kernel image, or
4578 combined into one file. "mkimage" encapsulates the images with a 64
4579 byte header containing information about target architecture,
4580 operating system, image type, compression method, entry points, time
4581 stamp, CRC32 checksums, etc.
4583 "mkimage" can be called in two ways: to verify existing images and
4584 print the header information, or to build new images.
4586 In the first form (with "-l" option) mkimage lists the information
4587 contained in the header of an existing U-Boot image; this includes
4588 checksum verification:
4590 tools/mkimage -l image
4591 -l ==> list image header information
4593 The second form (with "-d" option) is used to build a U-Boot image
4594 from a "data file" which is used as image payload:
4596 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4597 -n name -d data_file image
4598 -A ==> set architecture to 'arch'
4599 -O ==> set operating system to 'os'
4600 -T ==> set image type to 'type'
4601 -C ==> set compression type 'comp'
4602 -a ==> set load address to 'addr' (hex)
4603 -e ==> set entry point to 'ep' (hex)
4604 -n ==> set image name to 'name'
4605 -d ==> use image data from 'datafile'
4607 Right now, all Linux kernels for PowerPC systems use the same load
4608 address (0x00000000), but the entry point address depends on the
4611 - 2.2.x kernels have the entry point at 0x0000000C,
4612 - 2.3.x and later kernels have the entry point at 0x00000000.
4614 So a typical call to build a U-Boot image would read:
4616 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4617 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4618 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4619 > examples/uImage.TQM850L
4620 Image Name: 2.4.4 kernel for TQM850L
4621 Created: Wed Jul 19 02:34:59 2000
4622 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4623 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4624 Load Address: 0x00000000
4625 Entry Point: 0x00000000
4627 To verify the contents of the image (or check for corruption):
4629 -> tools/mkimage -l examples/uImage.TQM850L
4630 Image Name: 2.4.4 kernel for TQM850L
4631 Created: Wed Jul 19 02:34:59 2000
4632 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4633 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4634 Load Address: 0x00000000
4635 Entry Point: 0x00000000
4637 NOTE: for embedded systems where boot time is critical you can trade
4638 speed for memory and install an UNCOMPRESSED image instead: this
4639 needs more space in Flash, but boots much faster since it does not
4640 need to be uncompressed:
4642 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4643 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4644 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4645 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4646 > examples/uImage.TQM850L-uncompressed
4647 Image Name: 2.4.4 kernel for TQM850L
4648 Created: Wed Jul 19 02:34:59 2000
4649 Image Type: PowerPC Linux Kernel Image (uncompressed)
4650 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4651 Load Address: 0x00000000
4652 Entry Point: 0x00000000
4655 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4656 when your kernel is intended to use an initial ramdisk:
4658 -> tools/mkimage -n 'Simple Ramdisk Image' \
4659 > -A ppc -O linux -T ramdisk -C gzip \
4660 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4661 Image Name: Simple Ramdisk Image
4662 Created: Wed Jan 12 14:01:50 2000
4663 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4664 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4665 Load Address: 0x00000000
4666 Entry Point: 0x00000000
4669 Installing a Linux Image:
4670 -------------------------
4672 To downloading a U-Boot image over the serial (console) interface,
4673 you must convert the image to S-Record format:
4675 objcopy -I binary -O srec examples/image examples/image.srec
4677 The 'objcopy' does not understand the information in the U-Boot
4678 image header, so the resulting S-Record file will be relative to
4679 address 0x00000000. To load it to a given address, you need to
4680 specify the target address as 'offset' parameter with the 'loads'
4683 Example: install the image to address 0x40100000 (which on the
4684 TQM8xxL is in the first Flash bank):
4686 => erase 40100000 401FFFFF
4692 ## Ready for S-Record download ...
4693 ~>examples/image.srec
4694 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4696 15989 15990 15991 15992
4697 [file transfer complete]
4699 ## Start Addr = 0x00000000
4702 You can check the success of the download using the 'iminfo' command;
4703 this includes a checksum verification so you can be sure no data
4704 corruption happened:
4708 ## Checking Image at 40100000 ...
4709 Image Name: 2.2.13 for initrd on TQM850L
4710 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4711 Data Size: 335725 Bytes = 327 kB = 0 MB
4712 Load Address: 00000000
4713 Entry Point: 0000000c
4714 Verifying Checksum ... OK
4720 The "bootm" command is used to boot an application that is stored in
4721 memory (RAM or Flash). In case of a Linux kernel image, the contents
4722 of the "bootargs" environment variable is passed to the kernel as
4723 parameters. You can check and modify this variable using the
4724 "printenv" and "setenv" commands:
4727 => printenv bootargs
4728 bootargs=root=/dev/ram
4730 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4732 => printenv bootargs
4733 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4736 ## Booting Linux kernel at 40020000 ...
4737 Image Name: 2.2.13 for NFS on TQM850L
4738 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4739 Data Size: 381681 Bytes = 372 kB = 0 MB
4740 Load Address: 00000000
4741 Entry Point: 0000000c
4742 Verifying Checksum ... OK
4743 Uncompressing Kernel Image ... OK
4744 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
4745 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4746 time_init: decrementer frequency = 187500000/60
4747 Calibrating delay loop... 49.77 BogoMIPS
4748 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
4751 If you want to boot a Linux kernel with initial RAM disk, you pass
4752 the memory addresses of both the kernel and the initrd image (PPBCOOT
4753 format!) to the "bootm" command:
4755 => imi 40100000 40200000
4757 ## Checking Image at 40100000 ...
4758 Image Name: 2.2.13 for initrd on TQM850L
4759 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4760 Data Size: 335725 Bytes = 327 kB = 0 MB
4761 Load Address: 00000000
4762 Entry Point: 0000000c
4763 Verifying Checksum ... OK
4765 ## Checking Image at 40200000 ...
4766 Image Name: Simple Ramdisk Image
4767 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4768 Data Size: 566530 Bytes = 553 kB = 0 MB
4769 Load Address: 00000000
4770 Entry Point: 00000000
4771 Verifying Checksum ... OK
4773 => bootm 40100000 40200000
4774 ## Booting Linux kernel at 40100000 ...
4775 Image Name: 2.2.13 for initrd on TQM850L
4776 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4777 Data Size: 335725 Bytes = 327 kB = 0 MB
4778 Load Address: 00000000
4779 Entry Point: 0000000c
4780 Verifying Checksum ... OK
4781 Uncompressing Kernel Image ... OK
4782 ## Loading RAMDisk Image at 40200000 ...
4783 Image Name: Simple Ramdisk Image
4784 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4785 Data Size: 566530 Bytes = 553 kB = 0 MB
4786 Load Address: 00000000
4787 Entry Point: 00000000
4788 Verifying Checksum ... OK
4789 Loading Ramdisk ... OK
4790 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
4791 Boot arguments: root=/dev/ram
4792 time_init: decrementer frequency = 187500000/60
4793 Calibrating delay loop... 49.77 BogoMIPS
4795 RAMDISK: Compressed image found at block 0
4796 VFS: Mounted root (ext2 filesystem).
4800 Boot Linux and pass a flat device tree:
4803 First, U-Boot must be compiled with the appropriate defines. See the section
4804 titled "Linux Kernel Interface" above for a more in depth explanation. The
4805 following is an example of how to start a kernel and pass an updated
4811 oft=oftrees/mpc8540ads.dtb
4812 => tftp $oftaddr $oft
4813 Speed: 1000, full duplex
4815 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4816 Filename 'oftrees/mpc8540ads.dtb'.
4817 Load address: 0x300000
4820 Bytes transferred = 4106 (100a hex)
4821 => tftp $loadaddr $bootfile
4822 Speed: 1000, full duplex
4824 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4826 Load address: 0x200000
4827 Loading:############
4829 Bytes transferred = 1029407 (fb51f hex)
4834 => bootm $loadaddr - $oftaddr
4835 ## Booting image at 00200000 ...
4836 Image Name: Linux-2.6.17-dirty
4837 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4838 Data Size: 1029343 Bytes = 1005.2 kB
4839 Load Address: 00000000
4840 Entry Point: 00000000
4841 Verifying Checksum ... OK
4842 Uncompressing Kernel Image ... OK
4843 Booting using flat device tree at 0x300000
4844 Using MPC85xx ADS machine description
4845 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4849 More About U-Boot Image Types:
4850 ------------------------------
4852 U-Boot supports the following image types:
4854 "Standalone Programs" are directly runnable in the environment
4855 provided by U-Boot; it is expected that (if they behave
4856 well) you can continue to work in U-Boot after return from
4857 the Standalone Program.
4858 "OS Kernel Images" are usually images of some Embedded OS which
4859 will take over control completely. Usually these programs
4860 will install their own set of exception handlers, device
4861 drivers, set up the MMU, etc. - this means, that you cannot
4862 expect to re-enter U-Boot except by resetting the CPU.
4863 "RAMDisk Images" are more or less just data blocks, and their
4864 parameters (address, size) are passed to an OS kernel that is
4866 "Multi-File Images" contain several images, typically an OS
4867 (Linux) kernel image and one or more data images like
4868 RAMDisks. This construct is useful for instance when you want
4869 to boot over the network using BOOTP etc., where the boot
4870 server provides just a single image file, but you want to get
4871 for instance an OS kernel and a RAMDisk image.
4873 "Multi-File Images" start with a list of image sizes, each
4874 image size (in bytes) specified by an "uint32_t" in network
4875 byte order. This list is terminated by an "(uint32_t)0".
4876 Immediately after the terminating 0 follow the images, one by
4877 one, all aligned on "uint32_t" boundaries (size rounded up to
4878 a multiple of 4 bytes).
4880 "Firmware Images" are binary images containing firmware (like
4881 U-Boot or FPGA images) which usually will be programmed to
4884 "Script files" are command sequences that will be executed by
4885 U-Boot's command interpreter; this feature is especially
4886 useful when you configure U-Boot to use a real shell (hush)
4887 as command interpreter.
4889 Booting the Linux zImage:
4890 -------------------------
4892 On some platforms, it's possible to boot Linux zImage. This is done
4893 using the "bootz" command. The syntax of "bootz" command is the same
4894 as the syntax of "bootm" command.
4896 Note, defining the CONFIG_SUPPORT_INITRD_RAW allows user to supply
4897 kernel with raw initrd images. The syntax is slightly different, the
4898 address of the initrd must be augmented by it's size, in the following
4899 format: "<initrd addres>:<initrd size>".
4905 One of the features of U-Boot is that you can dynamically load and
4906 run "standalone" applications, which can use some resources of
4907 U-Boot like console I/O functions or interrupt services.
4909 Two simple examples are included with the sources:
4914 'examples/hello_world.c' contains a small "Hello World" Demo
4915 application; it is automatically compiled when you build U-Boot.
4916 It's configured to run at address 0x00040004, so you can play with it
4920 ## Ready for S-Record download ...
4921 ~>examples/hello_world.srec
4922 1 2 3 4 5 6 7 8 9 10 11 ...
4923 [file transfer complete]
4925 ## Start Addr = 0x00040004
4927 => go 40004 Hello World! This is a test.
4928 ## Starting application at 0x00040004 ...
4939 Hit any key to exit ...
4941 ## Application terminated, rc = 0x0
4943 Another example, which demonstrates how to register a CPM interrupt
4944 handler with the U-Boot code, can be found in 'examples/timer.c'.
4945 Here, a CPM timer is set up to generate an interrupt every second.
4946 The interrupt service routine is trivial, just printing a '.'
4947 character, but this is just a demo program. The application can be
4948 controlled by the following keys:
4950 ? - print current values og the CPM Timer registers
4951 b - enable interrupts and start timer
4952 e - stop timer and disable interrupts
4953 q - quit application
4956 ## Ready for S-Record download ...
4957 ~>examples/timer.srec
4958 1 2 3 4 5 6 7 8 9 10 11 ...
4959 [file transfer complete]
4961 ## Start Addr = 0x00040004
4964 ## Starting application at 0x00040004 ...
4967 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
4970 [q, b, e, ?] Set interval 1000000 us
4973 [q, b, e, ?] ........
4974 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
4977 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
4980 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
4983 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
4985 [q, b, e, ?] ...Stopping timer
4987 [q, b, e, ?] ## Application terminated, rc = 0x0
4993 Over time, many people have reported problems when trying to use the
4994 "minicom" terminal emulation program for serial download. I (wd)
4995 consider minicom to be broken, and recommend not to use it. Under
4996 Unix, I recommend to use C-Kermit for general purpose use (and
4997 especially for kermit binary protocol download ("loadb" command), and
4998 use "cu" for S-Record download ("loads" command). See
4999 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5000 for help with kermit.
5003 Nevertheless, if you absolutely want to use it try adding this
5004 configuration to your "File transfer protocols" section:
5006 Name Program Name U/D FullScr IO-Red. Multi
5007 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5008 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5014 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5015 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5017 Building requires a cross environment; it is known to work on
5018 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5019 need gmake since the Makefiles are not compatible with BSD make).
5020 Note that the cross-powerpc package does not install include files;
5021 attempting to build U-Boot will fail because <machine/ansi.h> is
5022 missing. This file has to be installed and patched manually:
5024 # cd /usr/pkg/cross/powerpc-netbsd/include
5026 # ln -s powerpc machine
5027 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5028 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5030 Native builds *don't* work due to incompatibilities between native
5031 and U-Boot include files.
5033 Booting assumes that (the first part of) the image booted is a
5034 stage-2 loader which in turn loads and then invokes the kernel
5035 proper. Loader sources will eventually appear in the NetBSD source
5036 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5037 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5040 Implementation Internals:
5041 =========================
5043 The following is not intended to be a complete description of every
5044 implementation detail. However, it should help to understand the
5045 inner workings of U-Boot and make it easier to port it to custom
5049 Initial Stack, Global Data:
5050 ---------------------------
5052 The implementation of U-Boot is complicated by the fact that U-Boot
5053 starts running out of ROM (flash memory), usually without access to
5054 system RAM (because the memory controller is not initialized yet).
5055 This means that we don't have writable Data or BSS segments, and BSS
5056 is not initialized as zero. To be able to get a C environment working
5057 at all, we have to allocate at least a minimal stack. Implementation
5058 options for this are defined and restricted by the CPU used: Some CPU
5059 models provide on-chip memory (like the IMMR area on MPC8xx and
5060 MPC826x processors), on others (parts of) the data cache can be
5061 locked as (mis-) used as memory, etc.
5063 Chris Hallinan posted a good summary of these issues to the
5064 U-Boot mailing list:
5066 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5067 From: "Chris Hallinan" <clh@net1plus.com>
5068 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5071 Correct me if I'm wrong, folks, but the way I understand it
5072 is this: Using DCACHE as initial RAM for Stack, etc, does not
5073 require any physical RAM backing up the cache. The cleverness
5074 is that the cache is being used as a temporary supply of
5075 necessary storage before the SDRAM controller is setup. It's
5076 beyond the scope of this list to explain the details, but you
5077 can see how this works by studying the cache architecture and
5078 operation in the architecture and processor-specific manuals.
5080 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5081 is another option for the system designer to use as an
5082 initial stack/RAM area prior to SDRAM being available. Either
5083 option should work for you. Using CS 4 should be fine if your
5084 board designers haven't used it for something that would
5085 cause you grief during the initial boot! It is frequently not
5088 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5089 with your processor/board/system design. The default value
5090 you will find in any recent u-boot distribution in
5091 walnut.h should work for you. I'd set it to a value larger
5092 than your SDRAM module. If you have a 64MB SDRAM module, set
5093 it above 400_0000. Just make sure your board has no resources
5094 that are supposed to respond to that address! That code in
5095 start.S has been around a while and should work as is when
5096 you get the config right.
5101 It is essential to remember this, since it has some impact on the C
5102 code for the initialization procedures:
5104 * Initialized global data (data segment) is read-only. Do not attempt
5107 * Do not use any uninitialized global data (or implicitely initialized
5108 as zero data - BSS segment) at all - this is undefined, initiali-
5109 zation is performed later (when relocating to RAM).
5111 * Stack space is very limited. Avoid big data buffers or things like
5114 Having only the stack as writable memory limits means we cannot use
5115 normal global data to share information beween the code. But it
5116 turned out that the implementation of U-Boot can be greatly
5117 simplified by making a global data structure (gd_t) available to all
5118 functions. We could pass a pointer to this data as argument to _all_
5119 functions, but this would bloat the code. Instead we use a feature of
5120 the GCC compiler (Global Register Variables) to share the data: we
5121 place a pointer (gd) to the global data into a register which we
5122 reserve for this purpose.
5124 When choosing a register for such a purpose we are restricted by the
5125 relevant (E)ABI specifications for the current architecture, and by
5126 GCC's implementation.
5128 For PowerPC, the following registers have specific use:
5130 R2: reserved for system use
5131 R3-R4: parameter passing and return values
5132 R5-R10: parameter passing
5133 R13: small data area pointer
5137 (U-Boot also uses R12 as internal GOT pointer. r12
5138 is a volatile register so r12 needs to be reset when
5139 going back and forth between asm and C)
5141 ==> U-Boot will use R2 to hold a pointer to the global data
5143 Note: on PPC, we could use a static initializer (since the
5144 address of the global data structure is known at compile time),
5145 but it turned out that reserving a register results in somewhat
5146 smaller code - although the code savings are not that big (on
5147 average for all boards 752 bytes for the whole U-Boot image,
5148 624 text + 127 data).
5150 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5151 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5153 ==> U-Boot will use P3 to hold a pointer to the global data
5155 On ARM, the following registers are used:
5157 R0: function argument word/integer result
5158 R1-R3: function argument word
5160 R10: stack limit (used only if stack checking if enabled)
5161 R11: argument (frame) pointer
5162 R12: temporary workspace
5165 R15: program counter
5167 ==> U-Boot will use R8 to hold a pointer to the global data
5169 On Nios II, the ABI is documented here:
5170 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5172 ==> U-Boot will use gp to hold a pointer to the global data
5174 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5175 to access small data sections, so gp is free.
5177 On NDS32, the following registers are used:
5179 R0-R1: argument/return
5181 R15: temporary register for assembler
5182 R16: trampoline register
5183 R28: frame pointer (FP)
5184 R29: global pointer (GP)
5185 R30: link register (LP)
5186 R31: stack pointer (SP)
5187 PC: program counter (PC)
5189 ==> U-Boot will use R10 to hold a pointer to the global data
5191 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5192 or current versions of GCC may "optimize" the code too much.
5197 U-Boot runs in system state and uses physical addresses, i.e. the
5198 MMU is not used either for address mapping nor for memory protection.
5200 The available memory is mapped to fixed addresses using the memory
5201 controller. In this process, a contiguous block is formed for each
5202 memory type (Flash, SDRAM, SRAM), even when it consists of several
5203 physical memory banks.
5205 U-Boot is installed in the first 128 kB of the first Flash bank (on
5206 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5207 booting and sizing and initializing DRAM, the code relocates itself
5208 to the upper end of DRAM. Immediately below the U-Boot code some
5209 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5210 configuration setting]. Below that, a structure with global Board
5211 Info data is placed, followed by the stack (growing downward).
5213 Additionally, some exception handler code is copied to the low 8 kB
5214 of DRAM (0x00000000 ... 0x00001FFF).
5216 So a typical memory configuration with 16 MB of DRAM could look like
5219 0x0000 0000 Exception Vector code
5222 0x0000 2000 Free for Application Use
5228 0x00FB FF20 Monitor Stack (Growing downward)
5229 0x00FB FFAC Board Info Data and permanent copy of global data
5230 0x00FC 0000 Malloc Arena
5233 0x00FE 0000 RAM Copy of Monitor Code
5234 ... eventually: LCD or video framebuffer
5235 ... eventually: pRAM (Protected RAM - unchanged by reset)
5236 0x00FF FFFF [End of RAM]
5239 System Initialization:
5240 ----------------------
5242 In the reset configuration, U-Boot starts at the reset entry point
5243 (on most PowerPC systems at address 0x00000100). Because of the reset
5244 configuration for CS0# this is a mirror of the onboard Flash memory.
5245 To be able to re-map memory U-Boot then jumps to its link address.
5246 To be able to implement the initialization code in C, a (small!)
5247 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5248 which provide such a feature like MPC8xx or MPC8260), or in a locked
5249 part of the data cache. After that, U-Boot initializes the CPU core,
5250 the caches and the SIU.
5252 Next, all (potentially) available memory banks are mapped using a
5253 preliminary mapping. For example, we put them on 512 MB boundaries
5254 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5255 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5256 programmed for SDRAM access. Using the temporary configuration, a
5257 simple memory test is run that determines the size of the SDRAM
5260 When there is more than one SDRAM bank, and the banks are of
5261 different size, the largest is mapped first. For equal size, the first
5262 bank (CS2#) is mapped first. The first mapping is always for address
5263 0x00000000, with any additional banks following immediately to create
5264 contiguous memory starting from 0.
5266 Then, the monitor installs itself at the upper end of the SDRAM area
5267 and allocates memory for use by malloc() and for the global Board
5268 Info data; also, the exception vector code is copied to the low RAM
5269 pages, and the final stack is set up.
5271 Only after this relocation will you have a "normal" C environment;
5272 until that you are restricted in several ways, mostly because you are
5273 running from ROM, and because the code will have to be relocated to a
5277 U-Boot Porting Guide:
5278 ----------------------
5280 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5284 int main(int argc, char *argv[])
5286 sighandler_t no_more_time;
5288 signal(SIGALRM, no_more_time);
5289 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5291 if (available_money > available_manpower) {
5292 Pay consultant to port U-Boot;
5296 Download latest U-Boot source;
5298 Subscribe to u-boot mailing list;
5301 email("Hi, I am new to U-Boot, how do I get started?");
5304 Read the README file in the top level directory;
5305 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5306 Read applicable doc/*.README;
5307 Read the source, Luke;
5308 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5311 if (available_money > toLocalCurrency ($2500))
5314 Add a lot of aggravation and time;
5316 if (a similar board exists) { /* hopefully... */
5317 cp -a board/<similar> board/<myboard>
5318 cp include/configs/<similar>.h include/configs/<myboard>.h
5320 Create your own board support subdirectory;
5321 Create your own board include/configs/<myboard>.h file;
5323 Edit new board/<myboard> files
5324 Edit new include/configs/<myboard>.h
5329 Add / modify source code;
5333 email("Hi, I am having problems...");
5335 Send patch file to the U-Boot email list;
5336 if (reasonable critiques)
5337 Incorporate improvements from email list code review;
5339 Defend code as written;
5345 void no_more_time (int sig)
5354 All contributions to U-Boot should conform to the Linux kernel
5355 coding style; see the file "Documentation/CodingStyle" and the script
5356 "scripts/Lindent" in your Linux kernel source directory.
5358 Source files originating from a different project (for example the
5359 MTD subsystem) are generally exempt from these guidelines and are not
5360 reformated to ease subsequent migration to newer versions of those
5363 Please note that U-Boot is implemented in C (and to some small parts in
5364 Assembler); no C++ is used, so please do not use C++ style comments (//)
5367 Please also stick to the following formatting rules:
5368 - remove any trailing white space
5369 - use TAB characters for indentation and vertical alignment, not spaces
5370 - make sure NOT to use DOS '\r\n' line feeds
5371 - do not add more than 2 consecutive empty lines to source files
5372 - do not add trailing empty lines to source files
5374 Submissions which do not conform to the standards may be returned
5375 with a request to reformat the changes.
5381 Since the number of patches for U-Boot is growing, we need to
5382 establish some rules. Submissions which do not conform to these rules
5383 may be rejected, even when they contain important and valuable stuff.
5385 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5387 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5388 see http://lists.denx.de/mailman/listinfo/u-boot
5390 When you send a patch, please include the following information with
5393 * For bug fixes: a description of the bug and how your patch fixes
5394 this bug. Please try to include a way of demonstrating that the
5395 patch actually fixes something.
5397 * For new features: a description of the feature and your
5400 * A CHANGELOG entry as plaintext (separate from the patch)
5402 * For major contributions, your entry to the CREDITS file
5404 * When you add support for a new board, don't forget to add this
5405 board to the MAINTAINERS file, too.
5407 * If your patch adds new configuration options, don't forget to
5408 document these in the README file.
5410 * The patch itself. If you are using git (which is *strongly*
5411 recommended) you can easily generate the patch using the
5412 "git format-patch". If you then use "git send-email" to send it to
5413 the U-Boot mailing list, you will avoid most of the common problems
5414 with some other mail clients.
5416 If you cannot use git, use "diff -purN OLD NEW". If your version of
5417 diff does not support these options, then get the latest version of
5420 The current directory when running this command shall be the parent
5421 directory of the U-Boot source tree (i. e. please make sure that
5422 your patch includes sufficient directory information for the
5425 We prefer patches as plain text. MIME attachments are discouraged,
5426 and compressed attachments must not be used.
5428 * If one logical set of modifications affects or creates several
5429 files, all these changes shall be submitted in a SINGLE patch file.
5431 * Changesets that contain different, unrelated modifications shall be
5432 submitted as SEPARATE patches, one patch per changeset.
5437 * Before sending the patch, run the MAKEALL script on your patched
5438 source tree and make sure that no errors or warnings are reported
5439 for any of the boards.
5441 * Keep your modifications to the necessary minimum: A patch
5442 containing several unrelated changes or arbitrary reformats will be
5443 returned with a request to re-formatting / split it.
5445 * If you modify existing code, make sure that your new code does not
5446 add to the memory footprint of the code ;-) Small is beautiful!
5447 When adding new features, these should compile conditionally only
5448 (using #ifdef), and the resulting code with the new feature
5449 disabled must not need more memory than the old code without your
5452 * Remember that there is a size limit of 100 kB per message on the
5453 u-boot mailing list. Bigger patches will be moderated. If they are
5454 reasonable and not too big, they will be acknowledged. But patches
5455 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob