2 # (C) Copyright 2000 - 2012
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # See file CREDITS for list of people who contributed to this
8 # This program is free software; you can redistribute it and/or
9 # modify it under the terms of the GNU General Public License as
10 # published by the Free Software Foundation; either version 2 of
11 # the License, or (at your option) any later version.
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with this program; if not, write to the Free Software
20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27 This directory contains the source code for U-Boot, a boot loader for
28 Embedded boards based on PowerPC, ARM, MIPS and several other
29 processors, which can be installed in a boot ROM and used to
30 initialize and test the hardware or to download and run application
33 The development of U-Boot is closely related to Linux: some parts of
34 the source code originate in the Linux source tree, we have some
35 header files in common, and special provision has been made to
36 support booting of Linux images.
38 Some attention has been paid to make this software easily
39 configurable and extendable. For instance, all monitor commands are
40 implemented with the same call interface, so that it's very easy to
41 add new commands. Also, instead of permanently adding rarely used
42 code (for instance hardware test utilities) to the monitor, you can
43 load and run it dynamically.
49 In general, all boards for which a configuration option exists in the
50 Makefile have been tested to some extent and can be considered
51 "working". In fact, many of them are used in production systems.
53 In case of problems see the CHANGELOG and CREDITS files to find out
54 who contributed the specific port. The MAINTAINERS file lists board
57 Note: There is no CHANGELOG file in the actual U-Boot source tree;
58 it can be created dynamically from the Git log using:
66 In case you have questions about, problems with or contributions for
67 U-Boot you should send a message to the U-Boot mailing list at
68 <u-boot@lists.denx.de>. There is also an archive of previous traffic
69 on the mailing list - please search the archive before asking FAQ's.
70 Please see http://lists.denx.de/pipermail/u-boot and
71 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
74 Where to get source code:
75 =========================
77 The U-Boot source code is maintained in the git repository at
78 git://www.denx.de/git/u-boot.git ; you can browse it online at
79 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
81 The "snapshot" links on this page allow you to download tarballs of
82 any version you might be interested in. Official releases are also
83 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
86 Pre-built (and tested) images are available from
87 ftp://ftp.denx.de/pub/u-boot/images/
93 - start from 8xxrom sources
94 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
96 - make it easier to add custom boards
97 - make it possible to add other [PowerPC] CPUs
98 - extend functions, especially:
99 * Provide extended interface to Linux boot loader
102 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
103 - create ARMBoot project (http://sourceforge.net/projects/armboot)
104 - add other CPU families (starting with ARM)
105 - create U-Boot project (http://sourceforge.net/projects/u-boot)
106 - current project page: see http://www.denx.de/wiki/U-Boot
112 The "official" name of this project is "Das U-Boot". The spelling
113 "U-Boot" shall be used in all written text (documentation, comments
114 in source files etc.). Example:
116 This is the README file for the U-Boot project.
118 File names etc. shall be based on the string "u-boot". Examples:
120 include/asm-ppc/u-boot.h
122 #include <asm/u-boot.h>
124 Variable names, preprocessor constants etc. shall be either based on
125 the string "u_boot" or on "U_BOOT". Example:
127 U_BOOT_VERSION u_boot_logo
128 IH_OS_U_BOOT u_boot_hush_start
134 Starting with the release in October 2008, the names of the releases
135 were changed from numerical release numbers without deeper meaning
136 into a time stamp based numbering. Regular releases are identified by
137 names consisting of the calendar year and month of the release date.
138 Additional fields (if present) indicate release candidates or bug fix
139 releases in "stable" maintenance trees.
142 U-Boot v2009.11 - Release November 2009
143 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
144 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
150 /arch Architecture specific files
151 /arm Files generic to ARM architecture
152 /cpu CPU specific files
153 /arm720t Files specific to ARM 720 CPUs
154 /arm920t Files specific to ARM 920 CPUs
155 /at91 Files specific to Atmel AT91RM9200 CPU
156 /imx Files specific to Freescale MC9328 i.MX CPUs
157 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
158 /arm925t Files specific to ARM 925 CPUs
159 /arm926ejs Files specific to ARM 926 CPUs
160 /arm1136 Files specific to ARM 1136 CPUs
161 /ixp Files specific to Intel XScale IXP CPUs
162 /pxa Files specific to Intel XScale PXA CPUs
163 /s3c44b0 Files specific to Samsung S3C44B0 CPUs
164 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
165 /lib Architecture specific library files
166 /avr32 Files generic to AVR32 architecture
167 /cpu CPU specific files
168 /lib Architecture specific library files
169 /blackfin Files generic to Analog Devices Blackfin architecture
170 /cpu CPU specific files
171 /lib Architecture specific library files
172 /x86 Files generic to x86 architecture
173 /cpu CPU specific files
174 /lib Architecture specific library files
175 /m68k Files generic to m68k architecture
176 /cpu CPU specific files
177 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
178 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
179 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
180 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
181 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
182 /lib Architecture specific library files
183 /microblaze Files generic to microblaze architecture
184 /cpu CPU specific files
185 /lib Architecture specific library files
186 /mips Files generic to MIPS architecture
187 /cpu CPU specific files
188 /mips32 Files specific to MIPS32 CPUs
189 /xburst Files specific to Ingenic XBurst CPUs
190 /lib Architecture specific library files
191 /nds32 Files generic to NDS32 architecture
192 /cpu CPU specific files
193 /n1213 Files specific to Andes Technology N1213 CPUs
194 /lib Architecture specific library files
195 /nios2 Files generic to Altera NIOS2 architecture
196 /cpu CPU specific files
197 /lib Architecture specific library files
198 /powerpc Files generic to PowerPC architecture
199 /cpu CPU specific files
200 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
201 /mpc5xx Files specific to Freescale MPC5xx CPUs
202 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
203 /mpc8xx Files specific to Freescale MPC8xx CPUs
204 /mpc8220 Files specific to Freescale MPC8220 CPUs
205 /mpc824x Files specific to Freescale MPC824x CPUs
206 /mpc8260 Files specific to Freescale MPC8260 CPUs
207 /mpc85xx Files specific to Freescale MPC85xx CPUs
208 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
209 /lib Architecture specific library files
210 /sh Files generic to SH architecture
211 /cpu CPU specific files
212 /sh2 Files specific to sh2 CPUs
213 /sh3 Files specific to sh3 CPUs
214 /sh4 Files specific to sh4 CPUs
215 /lib Architecture specific library files
216 /sparc Files generic to SPARC architecture
217 /cpu CPU specific files
218 /leon2 Files specific to Gaisler LEON2 SPARC CPU
219 /leon3 Files specific to Gaisler LEON3 SPARC CPU
220 /lib Architecture specific library files
221 /api Machine/arch independent API for external apps
222 /board Board dependent files
223 /common Misc architecture independent functions
224 /disk Code for disk drive partition handling
225 /doc Documentation (don't expect too much)
226 /drivers Commonly used device drivers
227 /examples Example code for standalone applications, etc.
228 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
229 /include Header Files
230 /lib Files generic to all architectures
231 /libfdt Library files to support flattened device trees
232 /lzma Library files to support LZMA decompression
233 /lzo Library files to support LZO decompression
235 /post Power On Self Test
236 /rtc Real Time Clock drivers
237 /tools Tools to build S-Record or U-Boot images, etc.
239 Software Configuration:
240 =======================
242 Configuration is usually done using C preprocessor defines; the
243 rationale behind that is to avoid dead code whenever possible.
245 There are two classes of configuration variables:
247 * Configuration _OPTIONS_:
248 These are selectable by the user and have names beginning with
251 * Configuration _SETTINGS_:
252 These depend on the hardware etc. and should not be meddled with if
253 you don't know what you're doing; they have names beginning with
256 Later we will add a configuration tool - probably similar to or even
257 identical to what's used for the Linux kernel. Right now, we have to
258 do the configuration by hand, which means creating some symbolic
259 links and editing some configuration files. We use the TQM8xxL boards
263 Selection of Processor Architecture and Board Type:
264 ---------------------------------------------------
266 For all supported boards there are ready-to-use default
267 configurations available; just type "make <board_name>_config".
269 Example: For a TQM823L module type:
274 For the Cogent platform, you need to specify the CPU type as well;
275 e.g. "make cogent_mpc8xx_config". And also configure the cogent
276 directory according to the instructions in cogent/README.
279 Configuration Options:
280 ----------------------
282 Configuration depends on the combination of board and CPU type; all
283 such information is kept in a configuration file
284 "include/configs/<board_name>.h".
286 Example: For a TQM823L module, all configuration settings are in
287 "include/configs/TQM823L.h".
290 Many of the options are named exactly as the corresponding Linux
291 kernel configuration options. The intention is to make it easier to
292 build a config tool - later.
295 The following options need to be configured:
297 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
299 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
301 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
302 Define exactly one, e.g. CONFIG_ATSTK1002
304 - CPU Module Type: (if CONFIG_COGENT is defined)
305 Define exactly one of
307 --- FIXME --- not tested yet:
308 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
309 CONFIG_CMA287_23, CONFIG_CMA287_50
311 - Motherboard Type: (if CONFIG_COGENT is defined)
312 Define exactly one of
313 CONFIG_CMA101, CONFIG_CMA102
315 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
316 Define one or more of
319 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
320 Define one or more of
321 CONFIG_LCD_HEARTBEAT - update a character position on
322 the LCD display every second with
325 - Board flavour: (if CONFIG_MPC8260ADS is defined)
328 CONFIG_SYS_8260ADS - original MPC8260ADS
329 CONFIG_SYS_8266ADS - MPC8266ADS
330 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
331 CONFIG_SYS_8272ADS - MPC8272ADS
333 - Marvell Family Member
334 CONFIG_SYS_MVFS - define it if you want to enable
335 multiple fs option at one time
336 for marvell soc family
338 - MPC824X Family Member (if CONFIG_MPC824X is defined)
339 Define exactly one of
340 CONFIG_MPC8240, CONFIG_MPC8245
342 - 8xx CPU Options: (if using an MPC8xx CPU)
343 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
344 get_gclk_freq() cannot work
345 e.g. if there is no 32KHz
346 reference PIT/RTC clock
347 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
350 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
351 CONFIG_SYS_8xx_CPUCLK_MIN
352 CONFIG_SYS_8xx_CPUCLK_MAX
353 CONFIG_8xx_CPUCLK_DEFAULT
354 See doc/README.MPC866
356 CONFIG_SYS_MEASURE_CPUCLK
358 Define this to measure the actual CPU clock instead
359 of relying on the correctness of the configured
360 values. Mostly useful for board bringup to make sure
361 the PLL is locked at the intended frequency. Note
362 that this requires a (stable) reference clock (32 kHz
363 RTC clock or CONFIG_SYS_8XX_XIN)
365 CONFIG_SYS_DELAYED_ICACHE
367 Define this option if you want to enable the
368 ICache only when Code runs from RAM.
373 Specifies that the core is a 64-bit PowerPC implementation (implements
374 the "64" category of the Power ISA). This is necessary for ePAPR
375 compliance, among other possible reasons.
377 CONFIG_SYS_FSL_TBCLK_DIV
379 Defines the core time base clock divider ratio compared to the
380 system clock. On most PQ3 devices this is 8, on newer QorIQ
381 devices it can be 16 or 32. The ratio varies from SoC to Soc.
383 CONFIG_SYS_FSL_PCIE_COMPAT
385 Defines the string to utilize when trying to match PCIe device
386 tree nodes for the given platform.
388 CONFIG_SYS_PPC_E500_DEBUG_TLB
390 Enables a temporary TLB entry to be used during boot to work
391 around limitations in e500v1 and e500v2 external debugger
392 support. This reduces the portions of the boot code where
393 breakpoints and single stepping do not work. The value of this
394 symbol should be set to the TLB1 entry to be used for this
397 CONFIG_SYS_FSL_ERRATUM_A004510
399 Enables a workaround for erratum A004510. If set,
400 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
401 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
403 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
404 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
406 Defines one or two SoC revisions (low 8 bits of SVR)
407 for which the A004510 workaround should be applied.
409 The rest of SVR is either not relevant to the decision
410 of whether the erratum is present (e.g. p2040 versus
411 p2041) or is implied by the build target, which controls
412 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
414 See Freescale App Note 4493 for more information about
417 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
419 This is the value to write into CCSR offset 0x18600
420 according to the A004510 workaround.
422 - Generic CPU options:
423 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
425 Defines the endianess of the CPU. Implementation of those
426 values is arch specific.
428 - Intel Monahans options:
429 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
431 Defines the Monahans run mode to oscillator
432 ratio. Valid values are 8, 16, 24, 31. The core
433 frequency is this value multiplied by 13 MHz.
435 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
437 Defines the Monahans turbo mode to oscillator
438 ratio. Valid values are 1 (default if undefined) and
439 2. The core frequency as calculated above is multiplied
443 CONFIG_SYS_INIT_SP_OFFSET
445 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
446 pointer. This is needed for the temporary stack before
449 CONFIG_SYS_MIPS_CACHE_MODE
451 Cache operation mode for the MIPS CPU.
452 See also arch/mips/include/asm/mipsregs.h.
454 CONF_CM_CACHABLE_NO_WA
457 CONF_CM_CACHABLE_NONCOHERENT
461 CONF_CM_CACHABLE_ACCELERATED
463 CONFIG_SYS_XWAY_EBU_BOOTCFG
465 Special option for Lantiq XWAY SoCs for booting from NOR flash.
466 See also arch/mips/cpu/mips32/start.S.
468 CONFIG_XWAY_SWAP_BYTES
470 Enable compilation of tools/xway-swap-bytes needed for Lantiq
471 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
472 be swapped if a flash programmer is used.
475 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
477 Select high exception vectors of the ARM core, e.g., do not
478 clear the V bit of the c1 register of CP15.
480 CONFIG_SYS_THUMB_BUILD
482 Use this flag to build U-Boot using the Thumb instruction
483 set for ARM architectures. Thumb instruction set provides
484 better code density. For ARM architectures that support
485 Thumb2 this flag will result in Thumb2 code generated by
488 - Linux Kernel Interface:
491 U-Boot stores all clock information in Hz
492 internally. For binary compatibility with older Linux
493 kernels (which expect the clocks passed in the
494 bd_info data to be in MHz) the environment variable
495 "clocks_in_mhz" can be defined so that U-Boot
496 converts clock data to MHZ before passing it to the
498 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
499 "clocks_in_mhz=1" is automatically included in the
502 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
504 When transferring memsize parameter to linux, some versions
505 expect it to be in bytes, others in MB.
506 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
510 New kernel versions are expecting firmware settings to be
511 passed using flattened device trees (based on open firmware
515 * New libfdt-based support
516 * Adds the "fdt" command
517 * The bootm command automatically updates the fdt
519 OF_CPU - The proper name of the cpus node (only required for
520 MPC512X and MPC5xxx based boards).
521 OF_SOC - The proper name of the soc node (only required for
522 MPC512X and MPC5xxx based boards).
523 OF_TBCLK - The timebase frequency.
524 OF_STDOUT_PATH - The path to the console device
526 boards with QUICC Engines require OF_QE to set UCC MAC
529 CONFIG_OF_BOARD_SETUP
531 Board code has addition modification that it wants to make
532 to the flat device tree before handing it off to the kernel
536 This define fills in the correct boot CPU in the boot
537 param header, the default value is zero if undefined.
541 U-Boot can detect if an IDE device is present or not.
542 If not, and this new config option is activated, U-Boot
543 removes the ATA node from the DTS before booting Linux,
544 so the Linux IDE driver does not probe the device and
545 crash. This is needed for buggy hardware (uc101) where
546 no pull down resistor is connected to the signal IDE5V_DD7.
548 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
550 This setting is mandatory for all boards that have only one
551 machine type and must be used to specify the machine type
552 number as it appears in the ARM machine registry
553 (see http://www.arm.linux.org.uk/developer/machines/).
554 Only boards that have multiple machine types supported
555 in a single configuration file and the machine type is
556 runtime discoverable, do not have to use this setting.
558 - vxWorks boot parameters:
560 bootvx constructs a valid bootline using the following
561 environments variables: bootfile, ipaddr, serverip, hostname.
562 It loads the vxWorks image pointed bootfile.
564 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
565 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
566 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
567 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
569 CONFIG_SYS_VXWORKS_ADD_PARAMS
571 Add it at the end of the bootline. E.g "u=username pw=secret"
573 Note: If a "bootargs" environment is defined, it will overwride
574 the defaults discussed just above.
576 - Cache Configuration:
577 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
578 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
579 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
581 - Cache Configuration for ARM:
582 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
584 CONFIG_SYS_PL310_BASE - Physical base address of PL310
585 controller register space
590 Define this if you want support for Amba PrimeCell PL010 UARTs.
594 Define this if you want support for Amba PrimeCell PL011 UARTs.
598 If you have Amba PrimeCell PL011 UARTs, set this variable to
599 the clock speed of the UARTs.
603 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
604 define this to a list of base addresses for each (supported)
605 port. See e.g. include/configs/versatile.h
607 CONFIG_PL011_SERIAL_RLCR
609 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
610 have separate receive and transmit line control registers. Set
611 this variable to initialize the extra register.
613 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
615 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
616 boot loader that has already initialized the UART. Define this
617 variable to flush the UART at init time.
619 CONFIG_SYS_NS16550_BROKEN_TEMT
621 16550 UART set the Transmitter Empty (TEMT) Bit when all output
622 has finished and the transmitter is totally empty. U-Boot waits
623 for this bit to be set to initialize the serial console. On some
624 broken platforms this bit is not set in SPL making U-Boot to
625 hang while waiting for TEMT. Define this option to avoid it.
629 Depending on board, define exactly one serial port
630 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
631 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
632 console by defining CONFIG_8xx_CONS_NONE
634 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
635 port routines must be defined elsewhere
636 (i.e. serial_init(), serial_getc(), ...)
639 Enables console device for a color framebuffer. Needs following
640 defines (cf. smiLynxEM, i8042)
641 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
643 VIDEO_HW_RECTFILL graphic chip supports
646 VIDEO_HW_BITBLT graphic chip supports
647 bit-blit (cf. smiLynxEM)
648 VIDEO_VISIBLE_COLS visible pixel columns
650 VIDEO_VISIBLE_ROWS visible pixel rows
651 VIDEO_PIXEL_SIZE bytes per pixel
652 VIDEO_DATA_FORMAT graphic data format
653 (0-5, cf. cfb_console.c)
654 VIDEO_FB_ADRS framebuffer address
655 VIDEO_KBD_INIT_FCT keyboard int fct
656 (i.e. i8042_kbd_init())
657 VIDEO_TSTC_FCT test char fct
659 VIDEO_GETC_FCT get char fct
661 CONFIG_CONSOLE_CURSOR cursor drawing on/off
662 (requires blink timer
664 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
665 CONFIG_CONSOLE_TIME display time/date info in
667 (requires CONFIG_CMD_DATE)
668 CONFIG_VIDEO_LOGO display Linux logo in
670 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
671 linux_logo.h for logo.
672 Requires CONFIG_VIDEO_LOGO
673 CONFIG_CONSOLE_EXTRA_INFO
674 additional board info beside
677 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
678 a limited number of ANSI escape sequences (cursor control,
679 erase functions and limited graphics rendition control).
681 When CONFIG_CFB_CONSOLE is defined, video console is
682 default i/o. Serial console can be forced with
683 environment 'console=serial'.
685 When CONFIG_SILENT_CONSOLE is defined, all console
686 messages (by U-Boot and Linux!) can be silenced with
687 the "silent" environment variable. See
688 doc/README.silent for more information.
691 CONFIG_BAUDRATE - in bps
692 Select one of the baudrates listed in
693 CONFIG_SYS_BAUDRATE_TABLE, see below.
694 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
696 - Console Rx buffer length
697 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
698 the maximum receive buffer length for the SMC.
699 This option is actual only for 82xx and 8xx possible.
700 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
701 must be defined, to setup the maximum idle timeout for
704 - Pre-Console Buffer:
705 Prior to the console being initialised (i.e. serial UART
706 initialised etc) all console output is silently discarded.
707 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
708 buffer any console messages prior to the console being
709 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
710 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
711 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
712 bytes are output before the console is initialised, the
713 earlier bytes are discarded.
715 'Sane' compilers will generate smaller code if
716 CONFIG_PRE_CON_BUF_SZ is a power of 2
718 - Safe printf() functions
719 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
720 the printf() functions. These are defined in
721 include/vsprintf.h and include snprintf(), vsnprintf() and
722 so on. Code size increase is approximately 300-500 bytes.
723 If this option is not given then these functions will
724 silently discard their buffer size argument - this means
725 you are not getting any overflow checking in this case.
727 - Boot Delay: CONFIG_BOOTDELAY - in seconds
728 Delay before automatically booting the default image;
729 set to -1 to disable autoboot.
730 set to -2 to autoboot with no delay and not check for abort
731 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
733 See doc/README.autoboot for these options that
734 work with CONFIG_BOOTDELAY. None are required.
735 CONFIG_BOOT_RETRY_TIME
736 CONFIG_BOOT_RETRY_MIN
737 CONFIG_AUTOBOOT_KEYED
738 CONFIG_AUTOBOOT_PROMPT
739 CONFIG_AUTOBOOT_DELAY_STR
740 CONFIG_AUTOBOOT_STOP_STR
741 CONFIG_AUTOBOOT_DELAY_STR2
742 CONFIG_AUTOBOOT_STOP_STR2
743 CONFIG_ZERO_BOOTDELAY_CHECK
744 CONFIG_RESET_TO_RETRY
748 Only needed when CONFIG_BOOTDELAY is enabled;
749 define a command string that is automatically executed
750 when no character is read on the console interface
751 within "Boot Delay" after reset.
754 This can be used to pass arguments to the bootm
755 command. The value of CONFIG_BOOTARGS goes into the
756 environment value "bootargs".
758 CONFIG_RAMBOOT and CONFIG_NFSBOOT
759 The value of these goes into the environment as
760 "ramboot" and "nfsboot" respectively, and can be used
761 as a convenience, when switching between booting from
767 When this option is #defined, the existence of the
768 environment variable "preboot" will be checked
769 immediately before starting the CONFIG_BOOTDELAY
770 countdown and/or running the auto-boot command resp.
771 entering interactive mode.
773 This feature is especially useful when "preboot" is
774 automatically generated or modified. For an example
775 see the LWMON board specific code: here "preboot" is
776 modified when the user holds down a certain
777 combination of keys on the (special) keyboard when
780 - Serial Download Echo Mode:
782 If defined to 1, all characters received during a
783 serial download (using the "loads" command) are
784 echoed back. This might be needed by some terminal
785 emulations (like "cu"), but may as well just take
786 time on others. This setting #define's the initial
787 value of the "loads_echo" environment variable.
789 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
791 Select one of the baudrates listed in
792 CONFIG_SYS_BAUDRATE_TABLE, see below.
795 Monitor commands can be included or excluded
796 from the build by using the #include files
797 <config_cmd_all.h> and #undef'ing unwanted
798 commands, or using <config_cmd_default.h>
799 and augmenting with additional #define's
802 The default command configuration includes all commands
803 except those marked below with a "*".
805 CONFIG_CMD_ASKENV * ask for env variable
806 CONFIG_CMD_BDI bdinfo
807 CONFIG_CMD_BEDBUG * Include BedBug Debugger
808 CONFIG_CMD_BMP * BMP support
809 CONFIG_CMD_BSP * Board specific commands
810 CONFIG_CMD_BOOTD bootd
811 CONFIG_CMD_CACHE * icache, dcache
812 CONFIG_CMD_CONSOLE coninfo
813 CONFIG_CMD_CRC32 * crc32
814 CONFIG_CMD_DATE * support for RTC, date/time...
815 CONFIG_CMD_DHCP * DHCP support
816 CONFIG_CMD_DIAG * Diagnostics
817 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
818 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
819 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
820 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
821 CONFIG_CMD_DTT * Digital Therm and Thermostat
822 CONFIG_CMD_ECHO echo arguments
823 CONFIG_CMD_EDITENV edit env variable
824 CONFIG_CMD_EEPROM * EEPROM read/write support
825 CONFIG_CMD_ELF * bootelf, bootvx
826 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
827 CONFIG_CMD_ENV_FLAGS * display details about env flags
828 CONFIG_CMD_EXPORTENV * export the environment
829 CONFIG_CMD_EXT2 * ext2 command support
830 CONFIG_CMD_EXT4 * ext4 command support
831 CONFIG_CMD_SAVEENV saveenv
832 CONFIG_CMD_FDC * Floppy Disk Support
833 CONFIG_CMD_FAT * FAT command support
834 CONFIG_CMD_FDOS * Dos diskette Support
835 CONFIG_CMD_FLASH flinfo, erase, protect
836 CONFIG_CMD_FPGA FPGA device initialization support
837 CONFIG_CMD_GETTIME * Get time since boot
838 CONFIG_CMD_GO * the 'go' command (exec code)
839 CONFIG_CMD_GREPENV * search environment
840 CONFIG_CMD_HASH * calculate hash / digest
841 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
842 CONFIG_CMD_I2C * I2C serial bus support
843 CONFIG_CMD_IDE * IDE harddisk support
844 CONFIG_CMD_IMI iminfo
845 CONFIG_CMD_IMLS List all found images
846 CONFIG_CMD_IMMAP * IMMR dump support
847 CONFIG_CMD_IMPORTENV * import an environment
848 CONFIG_CMD_INI * import data from an ini file into the env
849 CONFIG_CMD_IRQ * irqinfo
850 CONFIG_CMD_ITEST Integer/string test of 2 values
851 CONFIG_CMD_JFFS2 * JFFS2 Support
852 CONFIG_CMD_KGDB * kgdb
853 CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
854 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
856 CONFIG_CMD_LOADB loadb
857 CONFIG_CMD_LOADS loads
858 CONFIG_CMD_MD5SUM print md5 message digest
859 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
860 CONFIG_CMD_MEMINFO * Display detailed memory information
861 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
863 CONFIG_CMD_MISC Misc functions like sleep etc
864 CONFIG_CMD_MMC * MMC memory mapped support
865 CONFIG_CMD_MII * MII utility commands
866 CONFIG_CMD_MTDPARTS * MTD partition support
867 CONFIG_CMD_NAND * NAND support
868 CONFIG_CMD_NET bootp, tftpboot, rarpboot
869 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
870 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
871 CONFIG_CMD_PCI * pciinfo
872 CONFIG_CMD_PCMCIA * PCMCIA support
873 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
875 CONFIG_CMD_PORTIO * Port I/O
876 CONFIG_CMD_READ * Read raw data from partition
877 CONFIG_CMD_REGINFO * Register dump
878 CONFIG_CMD_RUN run command in env variable
879 CONFIG_CMD_SAVES * save S record dump
880 CONFIG_CMD_SCSI * SCSI Support
881 CONFIG_CMD_SDRAM * print SDRAM configuration information
882 (requires CONFIG_CMD_I2C)
883 CONFIG_CMD_SETGETDCR Support for DCR Register access
885 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
886 CONFIG_CMD_SHA1SUM print sha1 memory digest
887 (requires CONFIG_CMD_MEMORY)
888 CONFIG_CMD_SOURCE "source" command Support
889 CONFIG_CMD_SPI * SPI serial bus support
890 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
891 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
892 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
893 CONFIG_CMD_TIMER * access to the system tick timer
894 CONFIG_CMD_USB * USB support
895 CONFIG_CMD_CDP * Cisco Discover Protocol support
896 CONFIG_CMD_MFSL * Microblaze FSL support
899 EXAMPLE: If you want all functions except of network
900 support you can write:
902 #include "config_cmd_all.h"
903 #undef CONFIG_CMD_NET
906 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
908 Note: Don't enable the "icache" and "dcache" commands
909 (configuration option CONFIG_CMD_CACHE) unless you know
910 what you (and your U-Boot users) are doing. Data
911 cache cannot be enabled on systems like the 8xx or
912 8260 (where accesses to the IMMR region must be
913 uncached), and it cannot be disabled on all other
914 systems where we (mis-) use the data cache to hold an
915 initial stack and some data.
918 XXX - this list needs to get updated!
922 If this variable is defined, U-Boot will use a device tree
923 to configure its devices, instead of relying on statically
924 compiled #defines in the board file. This option is
925 experimental and only available on a few boards. The device
926 tree is available in the global data as gd->fdt_blob.
928 U-Boot needs to get its device tree from somewhere. This can
929 be done using one of the two options below:
932 If this variable is defined, U-Boot will embed a device tree
933 binary in its image. This device tree file should be in the
934 board directory and called <soc>-<board>.dts. The binary file
935 is then picked up in board_init_f() and made available through
936 the global data structure as gd->blob.
939 If this variable is defined, U-Boot will build a device tree
940 binary. It will be called u-boot.dtb. Architecture-specific
941 code will locate it at run-time. Generally this works by:
943 cat u-boot.bin u-boot.dtb >image.bin
945 and in fact, U-Boot does this for you, creating a file called
946 u-boot-dtb.bin which is useful in the common case. You can
947 still use the individual files if you need something more
952 If this variable is defined, it enables watchdog
953 support for the SoC. There must be support in the SoC
954 specific code for a watchdog. For the 8xx and 8260
955 CPUs, the SIU Watchdog feature is enabled in the SYPCR
956 register. When supported for a specific SoC is
957 available, then no further board specific code should
961 When using a watchdog circuitry external to the used
962 SoC, then define this variable and provide board
963 specific code for the "hw_watchdog_reset" function.
966 CONFIG_VERSION_VARIABLE
967 If this variable is defined, an environment variable
968 named "ver" is created by U-Boot showing the U-Boot
969 version as printed by the "version" command.
970 Any change to this variable will be reverted at the
975 When CONFIG_CMD_DATE is selected, the type of the RTC
976 has to be selected, too. Define exactly one of the
979 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
980 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
981 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
982 CONFIG_RTC_MC146818 - use MC146818 RTC
983 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
984 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
985 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
986 CONFIG_RTC_DS164x - use Dallas DS164x RTC
987 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
988 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
989 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
990 CONFIG_SYS_RV3029_TCR - enable trickle charger on
993 Note that if the RTC uses I2C, then the I2C interface
994 must also be configured. See I2C Support, below.
997 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
998 CONFIG_PCA953X_INFO - enable pca953x info command
1000 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1001 chip-ngpio pairs that tell the PCA953X driver the number of
1002 pins supported by a particular chip.
1004 Note that if the GPIO device uses I2C, then the I2C interface
1005 must also be configured. See I2C Support, below.
1007 - Timestamp Support:
1009 When CONFIG_TIMESTAMP is selected, the timestamp
1010 (date and time) of an image is printed by image
1011 commands like bootm or iminfo. This option is
1012 automatically enabled when you select CONFIG_CMD_DATE .
1014 - Partition Labels (disklabels) Supported:
1015 Zero or more of the following:
1016 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1017 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1018 Intel architecture, USB sticks, etc.
1019 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1020 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1021 bootloader. Note 2TB partition limit; see
1023 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1025 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1026 CONFIG_CMD_SCSI) you must configure support for at
1027 least one non-MTD partition type as well.
1030 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1031 board configurations files but used nowhere!
1033 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1034 be performed by calling the function
1035 ide_set_reset(int reset)
1036 which has to be defined in a board specific file
1041 Set this to enable ATAPI support.
1046 Set this to enable support for disks larger than 137GB
1047 Also look at CONFIG_SYS_64BIT_LBA.
1048 Whithout these , LBA48 support uses 32bit variables and will 'only'
1049 support disks up to 2.1TB.
1051 CONFIG_SYS_64BIT_LBA:
1052 When enabled, makes the IDE subsystem use 64bit sector addresses.
1056 At the moment only there is only support for the
1057 SYM53C8XX SCSI controller; define
1058 CONFIG_SCSI_SYM53C8XX to enable it.
1060 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1061 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1062 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1063 maximum numbers of LUNs, SCSI ID's and target
1065 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1067 The environment variable 'scsidevs' is set to the number of
1068 SCSI devices found during the last scan.
1070 - NETWORK Support (PCI):
1072 Support for Intel 8254x/8257x gigabit chips.
1075 Utility code for direct access to the SPI bus on Intel 8257x.
1076 This does not do anything useful unless you set at least one
1077 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1079 CONFIG_E1000_SPI_GENERIC
1080 Allow generic access to the SPI bus on the Intel 8257x, for
1081 example with the "sspi" command.
1084 Management command for E1000 devices. When used on devices
1085 with SPI support you can reprogram the EEPROM from U-Boot.
1087 CONFIG_E1000_FALLBACK_MAC
1088 default MAC for empty EEPROM after production.
1091 Support for Intel 82557/82559/82559ER chips.
1092 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1093 write routine for first time initialisation.
1096 Support for Digital 2114x chips.
1097 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1098 modem chip initialisation (KS8761/QS6611).
1101 Support for National dp83815 chips.
1104 Support for National dp8382[01] gigabit chips.
1106 - NETWORK Support (other):
1108 CONFIG_DRIVER_AT91EMAC
1109 Support for AT91RM9200 EMAC.
1112 Define this to use reduced MII inteface
1114 CONFIG_DRIVER_AT91EMAC_QUIET
1115 If this defined, the driver is quiet.
1116 The driver doen't show link status messages.
1118 CONFIG_CALXEDA_XGMAC
1119 Support for the Calxeda XGMAC device
1122 Support for SMSC's LAN91C96 chips.
1124 CONFIG_LAN91C96_BASE
1125 Define this to hold the physical address
1126 of the LAN91C96's I/O space
1128 CONFIG_LAN91C96_USE_32_BIT
1129 Define this to enable 32 bit addressing
1132 Support for SMSC's LAN91C111 chip
1134 CONFIG_SMC91111_BASE
1135 Define this to hold the physical address
1136 of the device (I/O space)
1138 CONFIG_SMC_USE_32_BIT
1139 Define this if data bus is 32 bits
1141 CONFIG_SMC_USE_IOFUNCS
1142 Define this to use i/o functions instead of macros
1143 (some hardware wont work with macros)
1145 CONFIG_DRIVER_TI_EMAC
1146 Support for davinci emac
1148 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1149 Define this if you have more then 3 PHYs.
1152 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1154 CONFIG_FTGMAC100_EGIGA
1155 Define this to use GE link update with gigabit PHY.
1156 Define this if FTGMAC100 is connected to gigabit PHY.
1157 If your system has 10/100 PHY only, it might not occur
1158 wrong behavior. Because PHY usually return timeout or
1159 useless data when polling gigabit status and gigabit
1160 control registers. This behavior won't affect the
1161 correctnessof 10/100 link speed update.
1164 Support for SMSC's LAN911x and LAN921x chips
1167 Define this to hold the physical address
1168 of the device (I/O space)
1170 CONFIG_SMC911X_32_BIT
1171 Define this if data bus is 32 bits
1173 CONFIG_SMC911X_16_BIT
1174 Define this if data bus is 16 bits. If your processor
1175 automatically converts one 32 bit word to two 16 bit
1176 words you may also try CONFIG_SMC911X_32_BIT.
1179 Support for Renesas on-chip Ethernet controller
1181 CONFIG_SH_ETHER_USE_PORT
1182 Define the number of ports to be used
1184 CONFIG_SH_ETHER_PHY_ADDR
1185 Define the ETH PHY's address
1187 CONFIG_SH_ETHER_CACHE_WRITEBACK
1188 If this option is set, the driver enables cache flush.
1191 CONFIG_GENERIC_LPC_TPM
1192 Support for generic parallel port TPM devices. Only one device
1193 per system is supported at this time.
1195 CONFIG_TPM_TIS_BASE_ADDRESS
1196 Base address where the generic TPM device is mapped
1197 to. Contemporary x86 systems usually map it at
1201 At the moment only the UHCI host controller is
1202 supported (PIP405, MIP405, MPC5200); define
1203 CONFIG_USB_UHCI to enable it.
1204 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1205 and define CONFIG_USB_STORAGE to enable the USB
1208 Supported are USB Keyboards and USB Floppy drives
1210 MPC5200 USB requires additional defines:
1212 for 528 MHz Clock: 0x0001bbbb
1216 for differential drivers: 0x00001000
1217 for single ended drivers: 0x00005000
1218 for differential drivers on PSC3: 0x00000100
1219 for single ended drivers on PSC3: 0x00004100
1220 CONFIG_SYS_USB_EVENT_POLL
1221 May be defined to allow interrupt polling
1222 instead of using asynchronous interrupts
1224 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1225 txfilltuning field in the EHCI controller on reset.
1228 Define the below if you wish to use the USB console.
1229 Once firmware is rebuilt from a serial console issue the
1230 command "setenv stdin usbtty; setenv stdout usbtty" and
1231 attach your USB cable. The Unix command "dmesg" should print
1232 it has found a new device. The environment variable usbtty
1233 can be set to gserial or cdc_acm to enable your device to
1234 appear to a USB host as a Linux gserial device or a
1235 Common Device Class Abstract Control Model serial device.
1236 If you select usbtty = gserial you should be able to enumerate
1238 # modprobe usbserial vendor=0xVendorID product=0xProductID
1239 else if using cdc_acm, simply setting the environment
1240 variable usbtty to be cdc_acm should suffice. The following
1241 might be defined in YourBoardName.h
1244 Define this to build a UDC device
1247 Define this to have a tty type of device available to
1248 talk to the UDC device
1251 Define this to enable the high speed support for usb
1252 device and usbtty. If this feature is enabled, a routine
1253 int is_usbd_high_speed(void)
1254 also needs to be defined by the driver to dynamically poll
1255 whether the enumeration has succeded at high speed or full
1258 CONFIG_SYS_CONSOLE_IS_IN_ENV
1259 Define this if you want stdin, stdout &/or stderr to
1263 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1264 Derive USB clock from external clock "blah"
1265 - CONFIG_SYS_USB_EXTC_CLK 0x02
1267 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1268 Derive USB clock from brgclk
1269 - CONFIG_SYS_USB_BRG_CLK 0x04
1271 If you have a USB-IF assigned VendorID then you may wish to
1272 define your own vendor specific values either in BoardName.h
1273 or directly in usbd_vendor_info.h. If you don't define
1274 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1275 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1276 should pretend to be a Linux device to it's target host.
1278 CONFIG_USBD_MANUFACTURER
1279 Define this string as the name of your company for
1280 - CONFIG_USBD_MANUFACTURER "my company"
1282 CONFIG_USBD_PRODUCT_NAME
1283 Define this string as the name of your product
1284 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1286 CONFIG_USBD_VENDORID
1287 Define this as your assigned Vendor ID from the USB
1288 Implementors Forum. This *must* be a genuine Vendor ID
1289 to avoid polluting the USB namespace.
1290 - CONFIG_USBD_VENDORID 0xFFFF
1292 CONFIG_USBD_PRODUCTID
1293 Define this as the unique Product ID
1295 - CONFIG_USBD_PRODUCTID 0xFFFF
1297 - ULPI Layer Support:
1298 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1299 the generic ULPI layer. The generic layer accesses the ULPI PHY
1300 via the platform viewport, so you need both the genric layer and
1301 the viewport enabled. Currently only Chipidea/ARC based
1302 viewport is supported.
1303 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1304 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1305 If your ULPI phy needs a different reference clock than the
1306 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1307 the appropriate value in Hz.
1310 The MMC controller on the Intel PXA is supported. To
1311 enable this define CONFIG_MMC. The MMC can be
1312 accessed from the boot prompt by mapping the device
1313 to physical memory similar to flash. Command line is
1314 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1315 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1318 Support for Renesas on-chip MMCIF controller
1320 CONFIG_SH_MMCIF_ADDR
1321 Define the base address of MMCIF registers
1324 Define the clock frequency for MMCIF
1326 - Journaling Flash filesystem support:
1327 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1328 CONFIG_JFFS2_NAND_DEV
1329 Define these for a default partition on a NAND device
1331 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1332 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1333 Define these for a default partition on a NOR device
1335 CONFIG_SYS_JFFS_CUSTOM_PART
1336 Define this to create an own partition. You have to provide a
1337 function struct part_info* jffs2_part_info(int part_num)
1339 If you define only one JFFS2 partition you may also want to
1340 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1341 to disable the command chpart. This is the default when you
1342 have not defined a custom partition
1344 - FAT(File Allocation Table) filesystem write function support:
1347 Define this to enable support for saving memory data as a
1348 file in FAT formatted partition.
1350 This will also enable the command "fatwrite" enabling the
1351 user to write files to FAT.
1353 CBFS (Coreboot Filesystem) support
1356 Define this to enable support for reading from a Coreboot
1357 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1363 Define this to enable standard (PC-Style) keyboard
1367 Standard PC keyboard driver with US (is default) and
1368 GERMAN key layout (switch via environment 'keymap=de') support.
1369 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1370 for cfb_console. Supports cursor blinking.
1375 Define this to enable video support (for output to
1378 CONFIG_VIDEO_CT69000
1380 Enable Chips & Technologies 69000 Video chip
1382 CONFIG_VIDEO_SMI_LYNXEM
1383 Enable Silicon Motion SMI 712/710/810 Video chip. The
1384 video output is selected via environment 'videoout'
1385 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1388 For the CT69000 and SMI_LYNXEM drivers, videomode is
1389 selected via environment 'videomode'. Two different ways
1391 - "videomode=num" 'num' is a standard LiLo mode numbers.
1392 Following standard modes are supported (* is default):
1394 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1395 -------------+---------------------------------------------
1396 8 bits | 0x301* 0x303 0x305 0x161 0x307
1397 15 bits | 0x310 0x313 0x316 0x162 0x319
1398 16 bits | 0x311 0x314 0x317 0x163 0x31A
1399 24 bits | 0x312 0x315 0x318 ? 0x31B
1400 -------------+---------------------------------------------
1401 (i.e. setenv videomode 317; saveenv; reset;)
1403 - "videomode=bootargs" all the video parameters are parsed
1404 from the bootargs. (See drivers/video/videomodes.c)
1407 CONFIG_VIDEO_SED13806
1408 Enable Epson SED13806 driver. This driver supports 8bpp
1409 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1410 or CONFIG_VIDEO_SED13806_16BPP
1413 Enable the Freescale DIU video driver. Reference boards for
1414 SOCs that have a DIU should define this macro to enable DIU
1415 support, and should also define these other macros:
1421 CONFIG_VIDEO_SW_CURSOR
1422 CONFIG_VGA_AS_SINGLE_DEVICE
1424 CONFIG_VIDEO_BMP_LOGO
1426 The DIU driver will look for the 'video-mode' environment
1427 variable, and if defined, enable the DIU as a console during
1428 boot. See the documentation file README.video for a
1429 description of this variable.
1433 Enable the VGA video / BIOS for x86. The alternative if you
1434 are using coreboot is to use the coreboot frame buffer
1441 Define this to enable a custom keyboard support.
1442 This simply calls drv_keyboard_init() which must be
1443 defined in your board-specific files.
1444 The only board using this so far is RBC823.
1446 - LCD Support: CONFIG_LCD
1448 Define this to enable LCD support (for output to LCD
1449 display); also select one of the supported displays
1450 by defining one of these:
1454 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1456 CONFIG_NEC_NL6448AC33:
1458 NEC NL6448AC33-18. Active, color, single scan.
1460 CONFIG_NEC_NL6448BC20
1462 NEC NL6448BC20-08. 6.5", 640x480.
1463 Active, color, single scan.
1465 CONFIG_NEC_NL6448BC33_54
1467 NEC NL6448BC33-54. 10.4", 640x480.
1468 Active, color, single scan.
1472 Sharp 320x240. Active, color, single scan.
1473 It isn't 16x9, and I am not sure what it is.
1475 CONFIG_SHARP_LQ64D341
1477 Sharp LQ64D341 display, 640x480.
1478 Active, color, single scan.
1482 HLD1045 display, 640x480.
1483 Active, color, single scan.
1487 Optrex CBL50840-2 NF-FW 99 22 M5
1489 Hitachi LMG6912RPFC-00T
1493 320x240. Black & white.
1495 Normally display is black on white background; define
1496 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1498 CONFIG_LCD_ALIGNMENT
1500 Normally the LCD is page-aligned (tyically 4KB). If this is
1501 defined then the LCD will be aligned to this value instead.
1502 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1503 here, since it is cheaper to change data cache settings on
1504 a per-section basis.
1506 CONFIG_CONSOLE_SCROLL_LINES
1508 When the console need to be scrolled, this is the number of
1509 lines to scroll by. It defaults to 1. Increasing this makes
1510 the console jump but can help speed up operation when scrolling
1515 Support drawing of RLE8-compressed bitmaps on the LCD.
1519 Enables an 'i2c edid' command which can read EDID
1520 information over I2C from an attached LCD display.
1522 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1524 If this option is set, the environment is checked for
1525 a variable "splashimage". If found, the usual display
1526 of logo, copyright and system information on the LCD
1527 is suppressed and the BMP image at the address
1528 specified in "splashimage" is loaded instead. The
1529 console is redirected to the "nulldev", too. This
1530 allows for a "silent" boot where a splash screen is
1531 loaded very quickly after power-on.
1533 CONFIG_SPLASH_SCREEN_ALIGN
1535 If this option is set the splash image can be freely positioned
1536 on the screen. Environment variable "splashpos" specifies the
1537 position as "x,y". If a positive number is given it is used as
1538 number of pixel from left/top. If a negative number is given it
1539 is used as number of pixel from right/bottom. You can also
1540 specify 'm' for centering the image.
1543 setenv splashpos m,m
1544 => image at center of screen
1546 setenv splashpos 30,20
1547 => image at x = 30 and y = 20
1549 setenv splashpos -10,m
1550 => vertically centered image
1551 at x = dspWidth - bmpWidth - 9
1553 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1555 If this option is set, additionally to standard BMP
1556 images, gzipped BMP images can be displayed via the
1557 splashscreen support or the bmp command.
1559 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1561 If this option is set, 8-bit RLE compressed BMP images
1562 can be displayed via the splashscreen support or the
1565 - Do compresssing for memory range:
1568 If this option is set, it would use zlib deflate method
1569 to compress the specified memory at its best effort.
1571 - Compression support:
1574 If this option is set, support for bzip2 compressed
1575 images is included. If not, only uncompressed and gzip
1576 compressed images are supported.
1578 NOTE: the bzip2 algorithm requires a lot of RAM, so
1579 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1584 If this option is set, support for lzma compressed
1587 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1588 requires an amount of dynamic memory that is given by the
1591 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1593 Where lc and lp stand for, respectively, Literal context bits
1594 and Literal pos bits.
1596 This value is upper-bounded by 14MB in the worst case. Anyway,
1597 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1598 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1599 a very small buffer.
1601 Use the lzmainfo tool to determinate the lc and lp values and
1602 then calculate the amount of needed dynamic memory (ensuring
1603 the appropriate CONFIG_SYS_MALLOC_LEN value).
1608 The address of PHY on MII bus.
1610 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1612 The clock frequency of the MII bus
1616 If this option is set, support for speed/duplex
1617 detection of gigabit PHY is included.
1619 CONFIG_PHY_RESET_DELAY
1621 Some PHY like Intel LXT971A need extra delay after
1622 reset before any MII register access is possible.
1623 For such PHY, set this option to the usec delay
1624 required. (minimum 300usec for LXT971A)
1626 CONFIG_PHY_CMD_DELAY (ppc4xx)
1628 Some PHY like Intel LXT971A need extra delay after
1629 command issued before MII status register can be read
1639 Define a default value for Ethernet address to use
1640 for the respective Ethernet interface, in case this
1641 is not determined automatically.
1646 Define a default value for the IP address to use for
1647 the default Ethernet interface, in case this is not
1648 determined through e.g. bootp.
1649 (Environment variable "ipaddr")
1651 - Server IP address:
1654 Defines a default value for the IP address of a TFTP
1655 server to contact when using the "tftboot" command.
1656 (Environment variable "serverip")
1658 CONFIG_KEEP_SERVERADDR
1660 Keeps the server's MAC address, in the env 'serveraddr'
1661 for passing to bootargs (like Linux's netconsole option)
1663 - Gateway IP address:
1666 Defines a default value for the IP address of the
1667 default router where packets to other networks are
1669 (Environment variable "gatewayip")
1674 Defines a default value for the subnet mask (or
1675 routing prefix) which is used to determine if an IP
1676 address belongs to the local subnet or needs to be
1677 forwarded through a router.
1678 (Environment variable "netmask")
1680 - Multicast TFTP Mode:
1683 Defines whether you want to support multicast TFTP as per
1684 rfc-2090; for example to work with atftp. Lets lots of targets
1685 tftp down the same boot image concurrently. Note: the Ethernet
1686 driver in use must provide a function: mcast() to join/leave a
1689 - BOOTP Recovery Mode:
1690 CONFIG_BOOTP_RANDOM_DELAY
1692 If you have many targets in a network that try to
1693 boot using BOOTP, you may want to avoid that all
1694 systems send out BOOTP requests at precisely the same
1695 moment (which would happen for instance at recovery
1696 from a power failure, when all systems will try to
1697 boot, thus flooding the BOOTP server. Defining
1698 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1699 inserted before sending out BOOTP requests. The
1700 following delays are inserted then:
1702 1st BOOTP request: delay 0 ... 1 sec
1703 2nd BOOTP request: delay 0 ... 2 sec
1704 3rd BOOTP request: delay 0 ... 4 sec
1706 BOOTP requests: delay 0 ... 8 sec
1708 - BOOTP Random transaction ID:
1709 CONFIG_BOOTP_RANDOM_ID
1711 The standard algorithm to generate a DHCP/BOOTP transaction ID
1712 by using the MAC address and the current time stamp may not
1713 quite unlikely produce duplicate transaction IDs from different
1714 clients in the same network. This option creates a transaction
1715 ID using the rand() function. Provided that the RNG has been
1716 seeded well, this should guarantee unique transaction IDs
1719 - DHCP Advanced Options:
1720 You can fine tune the DHCP functionality by defining
1721 CONFIG_BOOTP_* symbols:
1723 CONFIG_BOOTP_SUBNETMASK
1724 CONFIG_BOOTP_GATEWAY
1725 CONFIG_BOOTP_HOSTNAME
1726 CONFIG_BOOTP_NISDOMAIN
1727 CONFIG_BOOTP_BOOTPATH
1728 CONFIG_BOOTP_BOOTFILESIZE
1731 CONFIG_BOOTP_SEND_HOSTNAME
1732 CONFIG_BOOTP_NTPSERVER
1733 CONFIG_BOOTP_TIMEOFFSET
1734 CONFIG_BOOTP_VENDOREX
1735 CONFIG_BOOTP_MAY_FAIL
1737 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1738 environment variable, not the BOOTP server.
1740 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1741 after the configured retry count, the call will fail
1742 instead of starting over. This can be used to fail over
1743 to Link-local IP address configuration if the DHCP server
1746 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1747 serverip from a DHCP server, it is possible that more
1748 than one DNS serverip is offered to the client.
1749 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1750 serverip will be stored in the additional environment
1751 variable "dnsip2". The first DNS serverip is always
1752 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1755 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1756 to do a dynamic update of a DNS server. To do this, they
1757 need the hostname of the DHCP requester.
1758 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1759 of the "hostname" environment variable is passed as
1760 option 12 to the DHCP server.
1762 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1764 A 32bit value in microseconds for a delay between
1765 receiving a "DHCP Offer" and sending the "DHCP Request".
1766 This fixes a problem with certain DHCP servers that don't
1767 respond 100% of the time to a "DHCP request". E.g. On an
1768 AT91RM9200 processor running at 180MHz, this delay needed
1769 to be *at least* 15,000 usec before a Windows Server 2003
1770 DHCP server would reply 100% of the time. I recommend at
1771 least 50,000 usec to be safe. The alternative is to hope
1772 that one of the retries will be successful but note that
1773 the DHCP timeout and retry process takes a longer than
1776 - Link-local IP address negotiation:
1777 Negotiate with other link-local clients on the local network
1778 for an address that doesn't require explicit configuration.
1779 This is especially useful if a DHCP server cannot be guaranteed
1780 to exist in all environments that the device must operate.
1782 See doc/README.link-local for more information.
1785 CONFIG_CDP_DEVICE_ID
1787 The device id used in CDP trigger frames.
1789 CONFIG_CDP_DEVICE_ID_PREFIX
1791 A two character string which is prefixed to the MAC address
1796 A printf format string which contains the ascii name of
1797 the port. Normally is set to "eth%d" which sets
1798 eth0 for the first Ethernet, eth1 for the second etc.
1800 CONFIG_CDP_CAPABILITIES
1802 A 32bit integer which indicates the device capabilities;
1803 0x00000010 for a normal host which does not forwards.
1807 An ascii string containing the version of the software.
1811 An ascii string containing the name of the platform.
1815 A 32bit integer sent on the trigger.
1817 CONFIG_CDP_POWER_CONSUMPTION
1819 A 16bit integer containing the power consumption of the
1820 device in .1 of milliwatts.
1822 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1824 A byte containing the id of the VLAN.
1826 - Status LED: CONFIG_STATUS_LED
1828 Several configurations allow to display the current
1829 status using a LED. For instance, the LED will blink
1830 fast while running U-Boot code, stop blinking as
1831 soon as a reply to a BOOTP request was received, and
1832 start blinking slow once the Linux kernel is running
1833 (supported by a status LED driver in the Linux
1834 kernel). Defining CONFIG_STATUS_LED enables this
1837 - CAN Support: CONFIG_CAN_DRIVER
1839 Defining CONFIG_CAN_DRIVER enables CAN driver support
1840 on those systems that support this (optional)
1841 feature, like the TQM8xxL modules.
1843 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1845 These enable I2C serial bus commands. Defining either of
1846 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1847 include the appropriate I2C driver for the selected CPU.
1849 This will allow you to use i2c commands at the u-boot
1850 command line (as long as you set CONFIG_CMD_I2C in
1851 CONFIG_COMMANDS) and communicate with i2c based realtime
1852 clock chips. See common/cmd_i2c.c for a description of the
1853 command line interface.
1855 CONFIG_HARD_I2C selects a hardware I2C controller.
1857 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1858 bit-banging) driver instead of CPM or similar hardware
1861 There are several other quantities that must also be
1862 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1864 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1865 to be the frequency (in Hz) at which you wish your i2c bus
1866 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1867 the CPU's i2c node address).
1869 Now, the u-boot i2c code for the mpc8xx
1870 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1871 and so its address should therefore be cleared to 0 (See,
1872 eg, MPC823e User's Manual p.16-473). So, set
1873 CONFIG_SYS_I2C_SLAVE to 0.
1875 CONFIG_SYS_I2C_INIT_MPC5XXX
1877 When a board is reset during an i2c bus transfer
1878 chips might think that the current transfer is still
1879 in progress. Reset the slave devices by sending start
1880 commands until the slave device responds.
1882 That's all that's required for CONFIG_HARD_I2C.
1884 If you use the software i2c interface (CONFIG_SOFT_I2C)
1885 then the following macros need to be defined (examples are
1886 from include/configs/lwmon.h):
1890 (Optional). Any commands necessary to enable the I2C
1891 controller or configure ports.
1893 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1897 (Only for MPC8260 CPU). The I/O port to use (the code
1898 assumes both bits are on the same port). Valid values
1899 are 0..3 for ports A..D.
1903 The code necessary to make the I2C data line active
1904 (driven). If the data line is open collector, this
1907 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1911 The code necessary to make the I2C data line tri-stated
1912 (inactive). If the data line is open collector, this
1915 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1919 Code that returns TRUE if the I2C data line is high,
1922 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1926 If <bit> is TRUE, sets the I2C data line high. If it
1927 is FALSE, it clears it (low).
1929 eg: #define I2C_SDA(bit) \
1930 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1931 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1935 If <bit> is TRUE, sets the I2C clock line high. If it
1936 is FALSE, it clears it (low).
1938 eg: #define I2C_SCL(bit) \
1939 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1940 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1944 This delay is invoked four times per clock cycle so this
1945 controls the rate of data transfer. The data rate thus
1946 is 1 / (I2C_DELAY * 4). Often defined to be something
1949 #define I2C_DELAY udelay(2)
1951 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1953 If your arch supports the generic GPIO framework (asm/gpio.h),
1954 then you may alternatively define the two GPIOs that are to be
1955 used as SCL / SDA. Any of the previous I2C_xxx macros will
1956 have GPIO-based defaults assigned to them as appropriate.
1958 You should define these to the GPIO value as given directly to
1959 the generic GPIO functions.
1961 CONFIG_SYS_I2C_INIT_BOARD
1963 When a board is reset during an i2c bus transfer
1964 chips might think that the current transfer is still
1965 in progress. On some boards it is possible to access
1966 the i2c SCLK line directly, either by using the
1967 processor pin as a GPIO or by having a second pin
1968 connected to the bus. If this option is defined a
1969 custom i2c_init_board() routine in boards/xxx/board.c
1970 is run early in the boot sequence.
1972 CONFIG_SYS_I2C_BOARD_LATE_INIT
1974 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1975 defined a custom i2c_board_late_init() routine in
1976 boards/xxx/board.c is run AFTER the operations in i2c_init()
1977 is completed. This callpoint can be used to unreset i2c bus
1978 using CPU i2c controller register accesses for CPUs whose i2c
1979 controller provide such a method. It is called at the end of
1980 i2c_init() to allow i2c_init operations to setup the i2c bus
1981 controller on the CPU (e.g. setting bus speed & slave address).
1983 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1985 This option enables configuration of bi_iic_fast[] flags
1986 in u-boot bd_info structure based on u-boot environment
1987 variable "i2cfast". (see also i2cfast)
1989 CONFIG_I2C_MULTI_BUS
1991 This option allows the use of multiple I2C buses, each of which
1992 must have a controller. At any point in time, only one bus is
1993 active. To switch to a different bus, use the 'i2c dev' command.
1994 Note that bus numbering is zero-based.
1996 CONFIG_SYS_I2C_NOPROBES
1998 This option specifies a list of I2C devices that will be skipped
1999 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2000 is set, specify a list of bus-device pairs. Otherwise, specify
2001 a 1D array of device addresses
2004 #undef CONFIG_I2C_MULTI_BUS
2005 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2007 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2009 #define CONFIG_I2C_MULTI_BUS
2010 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2012 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2014 CONFIG_SYS_SPD_BUS_NUM
2016 If defined, then this indicates the I2C bus number for DDR SPD.
2017 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2019 CONFIG_SYS_RTC_BUS_NUM
2021 If defined, then this indicates the I2C bus number for the RTC.
2022 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2024 CONFIG_SYS_DTT_BUS_NUM
2026 If defined, then this indicates the I2C bus number for the DTT.
2027 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2029 CONFIG_SYS_I2C_DTT_ADDR:
2031 If defined, specifies the I2C address of the DTT device.
2032 If not defined, then U-Boot uses predefined value for
2033 specified DTT device.
2037 Define this option if you want to use Freescale's I2C driver in
2038 drivers/i2c/fsl_i2c.c.
2042 Define this option if you have I2C devices reached over 1 .. n
2043 I2C Muxes like the pca9544a. This option addes a new I2C
2044 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
2045 new I2C Bus to the existing I2C Busses. If you select the
2046 new Bus with "i2c dev", u-bbot sends first the commandos for
2047 the muxes to activate this new "bus".
2049 CONFIG_I2C_MULTI_BUS must be also defined, to use this
2053 Adding a new I2C Bus reached over 2 pca9544a muxes
2054 The First mux with address 70 and channel 6
2055 The Second mux with address 71 and channel 4
2057 => i2c bus pca9544a:70:6:pca9544a:71:4
2059 Use the "i2c bus" command without parameter, to get a list
2060 of I2C Busses with muxes:
2063 Busses reached over muxes:
2065 reached over Mux(es):
2068 reached over Mux(es):
2073 If you now switch to the new I2C Bus 3 with "i2c dev 3"
2074 u-boot first sends the command to the mux@70 to enable
2075 channel 6, and then the command to the mux@71 to enable
2078 After that, you can use the "normal" i2c commands as
2079 usual to communicate with your I2C devices behind
2082 This option is actually implemented for the bitbanging
2083 algorithm in common/soft_i2c.c and for the Hardware I2C
2084 Bus on the MPC8260. But it should be not so difficult
2085 to add this option to other architectures.
2087 CONFIG_SOFT_I2C_READ_REPEATED_START
2089 defining this will force the i2c_read() function in
2090 the soft_i2c driver to perform an I2C repeated start
2091 between writing the address pointer and reading the
2092 data. If this define is omitted the default behaviour
2093 of doing a stop-start sequence will be used. Most I2C
2094 devices can use either method, but some require one or
2097 - SPI Support: CONFIG_SPI
2099 Enables SPI driver (so far only tested with
2100 SPI EEPROM, also an instance works with Crystal A/D and
2101 D/As on the SACSng board)
2105 Enables the driver for SPI controller on SuperH. Currently
2106 only SH7757 is supported.
2110 Enables extended (16-bit) SPI EEPROM addressing.
2111 (symmetrical to CONFIG_I2C_X)
2115 Enables a software (bit-bang) SPI driver rather than
2116 using hardware support. This is a general purpose
2117 driver that only requires three general I/O port pins
2118 (two outputs, one input) to function. If this is
2119 defined, the board configuration must define several
2120 SPI configuration items (port pins to use, etc). For
2121 an example, see include/configs/sacsng.h.
2125 Enables a hardware SPI driver for general-purpose reads
2126 and writes. As with CONFIG_SOFT_SPI, the board configuration
2127 must define a list of chip-select function pointers.
2128 Currently supported on some MPC8xxx processors. For an
2129 example, see include/configs/mpc8349emds.h.
2133 Enables the driver for the SPI controllers on i.MX and MXC
2134 SoCs. Currently i.MX31/35/51 are supported.
2136 - FPGA Support: CONFIG_FPGA
2138 Enables FPGA subsystem.
2140 CONFIG_FPGA_<vendor>
2142 Enables support for specific chip vendors.
2145 CONFIG_FPGA_<family>
2147 Enables support for FPGA family.
2148 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2152 Specify the number of FPGA devices to support.
2154 CONFIG_SYS_FPGA_PROG_FEEDBACK
2156 Enable printing of hash marks during FPGA configuration.
2158 CONFIG_SYS_FPGA_CHECK_BUSY
2160 Enable checks on FPGA configuration interface busy
2161 status by the configuration function. This option
2162 will require a board or device specific function to
2167 If defined, a function that provides delays in the FPGA
2168 configuration driver.
2170 CONFIG_SYS_FPGA_CHECK_CTRLC
2171 Allow Control-C to interrupt FPGA configuration
2173 CONFIG_SYS_FPGA_CHECK_ERROR
2175 Check for configuration errors during FPGA bitfile
2176 loading. For example, abort during Virtex II
2177 configuration if the INIT_B line goes low (which
2178 indicated a CRC error).
2180 CONFIG_SYS_FPGA_WAIT_INIT
2182 Maximum time to wait for the INIT_B line to deassert
2183 after PROB_B has been deasserted during a Virtex II
2184 FPGA configuration sequence. The default time is 500
2187 CONFIG_SYS_FPGA_WAIT_BUSY
2189 Maximum time to wait for BUSY to deassert during
2190 Virtex II FPGA configuration. The default is 5 ms.
2192 CONFIG_SYS_FPGA_WAIT_CONFIG
2194 Time to wait after FPGA configuration. The default is
2197 - Configuration Management:
2200 If defined, this string will be added to the U-Boot
2201 version information (U_BOOT_VERSION)
2203 - Vendor Parameter Protection:
2205 U-Boot considers the values of the environment
2206 variables "serial#" (Board Serial Number) and
2207 "ethaddr" (Ethernet Address) to be parameters that
2208 are set once by the board vendor / manufacturer, and
2209 protects these variables from casual modification by
2210 the user. Once set, these variables are read-only,
2211 and write or delete attempts are rejected. You can
2212 change this behaviour:
2214 If CONFIG_ENV_OVERWRITE is #defined in your config
2215 file, the write protection for vendor parameters is
2216 completely disabled. Anybody can change or delete
2219 Alternatively, if you #define _both_ CONFIG_ETHADDR
2220 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2221 Ethernet address is installed in the environment,
2222 which can be changed exactly ONCE by the user. [The
2223 serial# is unaffected by this, i. e. it remains
2226 The same can be accomplished in a more flexible way
2227 for any variable by configuring the type of access
2228 to allow for those variables in the ".flags" variable
2229 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2234 Define this variable to enable the reservation of
2235 "protected RAM", i. e. RAM which is not overwritten
2236 by U-Boot. Define CONFIG_PRAM to hold the number of
2237 kB you want to reserve for pRAM. You can overwrite
2238 this default value by defining an environment
2239 variable "pram" to the number of kB you want to
2240 reserve. Note that the board info structure will
2241 still show the full amount of RAM. If pRAM is
2242 reserved, a new environment variable "mem" will
2243 automatically be defined to hold the amount of
2244 remaining RAM in a form that can be passed as boot
2245 argument to Linux, for instance like that:
2247 setenv bootargs ... mem=\${mem}
2250 This way you can tell Linux not to use this memory,
2251 either, which results in a memory region that will
2252 not be affected by reboots.
2254 *WARNING* If your board configuration uses automatic
2255 detection of the RAM size, you must make sure that
2256 this memory test is non-destructive. So far, the
2257 following board configurations are known to be
2260 IVMS8, IVML24, SPD8xx, TQM8xxL,
2261 HERMES, IP860, RPXlite, LWMON,
2264 - Access to physical memory region (> 4GB)
2265 Some basic support is provided for operations on memory not
2266 normally accessible to U-Boot - e.g. some architectures
2267 support access to more than 4GB of memory on 32-bit
2268 machines using physical address extension or similar.
2269 Define CONFIG_PHYSMEM to access this basic support, which
2270 currently only supports clearing the memory.
2275 Define this variable to stop the system in case of a
2276 fatal error, so that you have to reset it manually.
2277 This is probably NOT a good idea for an embedded
2278 system where you want the system to reboot
2279 automatically as fast as possible, but it may be
2280 useful during development since you can try to debug
2281 the conditions that lead to the situation.
2283 CONFIG_NET_RETRY_COUNT
2285 This variable defines the number of retries for
2286 network operations like ARP, RARP, TFTP, or BOOTP
2287 before giving up the operation. If not defined, a
2288 default value of 5 is used.
2292 Timeout waiting for an ARP reply in milliseconds.
2296 Timeout in milliseconds used in NFS protocol.
2297 If you encounter "ERROR: Cannot umount" in nfs command,
2298 try longer timeout such as
2299 #define CONFIG_NFS_TIMEOUT 10000UL
2301 - Command Interpreter:
2302 CONFIG_AUTO_COMPLETE
2304 Enable auto completion of commands using TAB.
2306 Note that this feature has NOT been implemented yet
2307 for the "hush" shell.
2310 CONFIG_SYS_HUSH_PARSER
2312 Define this variable to enable the "hush" shell (from
2313 Busybox) as command line interpreter, thus enabling
2314 powerful command line syntax like
2315 if...then...else...fi conditionals or `&&' and '||'
2316 constructs ("shell scripts").
2318 If undefined, you get the old, much simpler behaviour
2319 with a somewhat smaller memory footprint.
2322 CONFIG_SYS_PROMPT_HUSH_PS2
2324 This defines the secondary prompt string, which is
2325 printed when the command interpreter needs more input
2326 to complete a command. Usually "> ".
2330 In the current implementation, the local variables
2331 space and global environment variables space are
2332 separated. Local variables are those you define by
2333 simply typing `name=value'. To access a local
2334 variable later on, you have write `$name' or
2335 `${name}'; to execute the contents of a variable
2336 directly type `$name' at the command prompt.
2338 Global environment variables are those you use
2339 setenv/printenv to work with. To run a command stored
2340 in such a variable, you need to use the run command,
2341 and you must not use the '$' sign to access them.
2343 To store commands and special characters in a
2344 variable, please use double quotation marks
2345 surrounding the whole text of the variable, instead
2346 of the backslashes before semicolons and special
2349 - Commandline Editing and History:
2350 CONFIG_CMDLINE_EDITING
2352 Enable editing and History functions for interactive
2353 commandline input operations
2355 - Default Environment:
2356 CONFIG_EXTRA_ENV_SETTINGS
2358 Define this to contain any number of null terminated
2359 strings (variable = value pairs) that will be part of
2360 the default environment compiled into the boot image.
2362 For example, place something like this in your
2363 board's config file:
2365 #define CONFIG_EXTRA_ENV_SETTINGS \
2369 Warning: This method is based on knowledge about the
2370 internal format how the environment is stored by the
2371 U-Boot code. This is NOT an official, exported
2372 interface! Although it is unlikely that this format
2373 will change soon, there is no guarantee either.
2374 You better know what you are doing here.
2376 Note: overly (ab)use of the default environment is
2377 discouraged. Make sure to check other ways to preset
2378 the environment like the "source" command or the
2381 CONFIG_ENV_VARS_UBOOT_CONFIG
2383 Define this in order to add variables describing the
2384 U-Boot build configuration to the default environment.
2385 These will be named arch, cpu, board, vendor, and soc.
2387 Enabling this option will cause the following to be defined:
2395 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2397 Define this in order to add variables describing certain
2398 run-time determined information about the hardware to the
2399 environment. These will be named board_name, board_rev.
2401 CONFIG_DELAY_ENVIRONMENT
2403 Normally the environment is loaded when the board is
2404 intialised so that it is available to U-Boot. This inhibits
2405 that so that the environment is not available until
2406 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2407 this is instead controlled by the value of
2408 /config/load-environment.
2410 - DataFlash Support:
2411 CONFIG_HAS_DATAFLASH
2413 Defining this option enables DataFlash features and
2414 allows to read/write in Dataflash via the standard
2417 - Serial Flash support
2420 Defining this option enables SPI flash commands
2421 'sf probe/read/write/erase/update'.
2423 Usage requires an initial 'probe' to define the serial
2424 flash parameters, followed by read/write/erase/update
2427 The following defaults may be provided by the platform
2428 to handle the common case when only a single serial
2429 flash is present on the system.
2431 CONFIG_SF_DEFAULT_BUS Bus identifier
2432 CONFIG_SF_DEFAULT_CS Chip-select
2433 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2434 CONFIG_SF_DEFAULT_SPEED in Hz
2438 Define this option to include a destructive SPI flash
2441 - SystemACE Support:
2444 Adding this option adds support for Xilinx SystemACE
2445 chips attached via some sort of local bus. The address
2446 of the chip must also be defined in the
2447 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2449 #define CONFIG_SYSTEMACE
2450 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2452 When SystemACE support is added, the "ace" device type
2453 becomes available to the fat commands, i.e. fatls.
2455 - TFTP Fixed UDP Port:
2458 If this is defined, the environment variable tftpsrcp
2459 is used to supply the TFTP UDP source port value.
2460 If tftpsrcp isn't defined, the normal pseudo-random port
2461 number generator is used.
2463 Also, the environment variable tftpdstp is used to supply
2464 the TFTP UDP destination port value. If tftpdstp isn't
2465 defined, the normal port 69 is used.
2467 The purpose for tftpsrcp is to allow a TFTP server to
2468 blindly start the TFTP transfer using the pre-configured
2469 target IP address and UDP port. This has the effect of
2470 "punching through" the (Windows XP) firewall, allowing
2471 the remainder of the TFTP transfer to proceed normally.
2472 A better solution is to properly configure the firewall,
2473 but sometimes that is not allowed.
2478 This enables a generic 'hash' command which can produce
2479 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2483 Enable the hash verify command (hash -v). This adds to code
2486 CONFIG_SHA1 - support SHA1 hashing
2487 CONFIG_SHA256 - support SHA256 hashing
2489 Note: There is also a sha1sum command, which should perhaps
2490 be deprecated in favour of 'hash sha1'.
2492 - Show boot progress:
2493 CONFIG_SHOW_BOOT_PROGRESS
2495 Defining this option allows to add some board-
2496 specific code (calling a user-provided function
2497 "show_boot_progress(int)") that enables you to show
2498 the system's boot progress on some display (for
2499 example, some LED's) on your board. At the moment,
2500 the following checkpoints are implemented:
2502 - Detailed boot stage timing
2504 Define this option to get detailed timing of each stage
2505 of the boot process.
2507 CONFIG_BOOTSTAGE_USER_COUNT
2508 This is the number of available user bootstage records.
2509 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2510 a new ID will be allocated from this stash. If you exceed
2511 the limit, recording will stop.
2513 CONFIG_BOOTSTAGE_REPORT
2514 Define this to print a report before boot, similar to this:
2516 Timer summary in microseconds:
2519 3,575,678 3,575,678 board_init_f start
2520 3,575,695 17 arch_cpu_init A9
2521 3,575,777 82 arch_cpu_init done
2522 3,659,598 83,821 board_init_r start
2523 3,910,375 250,777 main_loop
2524 29,916,167 26,005,792 bootm_start
2525 30,361,327 445,160 start_kernel
2527 CONFIG_CMD_BOOTSTAGE
2528 Add a 'bootstage' command which supports printing a report
2529 and un/stashing of bootstage data.
2531 CONFIG_BOOTSTAGE_FDT
2532 Stash the bootstage information in the FDT. A root 'bootstage'
2533 node is created with each bootstage id as a child. Each child
2534 has a 'name' property and either 'mark' containing the
2535 mark time in microsecond, or 'accum' containing the
2536 accumulated time for that bootstage id in microseconds.
2541 name = "board_init_f";
2550 Code in the Linux kernel can find this in /proc/devicetree.
2552 Legacy uImage format:
2555 1 common/cmd_bootm.c before attempting to boot an image
2556 -1 common/cmd_bootm.c Image header has bad magic number
2557 2 common/cmd_bootm.c Image header has correct magic number
2558 -2 common/cmd_bootm.c Image header has bad checksum
2559 3 common/cmd_bootm.c Image header has correct checksum
2560 -3 common/cmd_bootm.c Image data has bad checksum
2561 4 common/cmd_bootm.c Image data has correct checksum
2562 -4 common/cmd_bootm.c Image is for unsupported architecture
2563 5 common/cmd_bootm.c Architecture check OK
2564 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2565 6 common/cmd_bootm.c Image Type check OK
2566 -6 common/cmd_bootm.c gunzip uncompression error
2567 -7 common/cmd_bootm.c Unimplemented compression type
2568 7 common/cmd_bootm.c Uncompression OK
2569 8 common/cmd_bootm.c No uncompress/copy overwrite error
2570 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2572 9 common/image.c Start initial ramdisk verification
2573 -10 common/image.c Ramdisk header has bad magic number
2574 -11 common/image.c Ramdisk header has bad checksum
2575 10 common/image.c Ramdisk header is OK
2576 -12 common/image.c Ramdisk data has bad checksum
2577 11 common/image.c Ramdisk data has correct checksum
2578 12 common/image.c Ramdisk verification complete, start loading
2579 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2580 13 common/image.c Start multifile image verification
2581 14 common/image.c No initial ramdisk, no multifile, continue.
2583 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2585 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2586 -31 post/post.c POST test failed, detected by post_output_backlog()
2587 -32 post/post.c POST test failed, detected by post_run_single()
2589 34 common/cmd_doc.c before loading a Image from a DOC device
2590 -35 common/cmd_doc.c Bad usage of "doc" command
2591 35 common/cmd_doc.c correct usage of "doc" command
2592 -36 common/cmd_doc.c No boot device
2593 36 common/cmd_doc.c correct boot device
2594 -37 common/cmd_doc.c Unknown Chip ID on boot device
2595 37 common/cmd_doc.c correct chip ID found, device available
2596 -38 common/cmd_doc.c Read Error on boot device
2597 38 common/cmd_doc.c reading Image header from DOC device OK
2598 -39 common/cmd_doc.c Image header has bad magic number
2599 39 common/cmd_doc.c Image header has correct magic number
2600 -40 common/cmd_doc.c Error reading Image from DOC device
2601 40 common/cmd_doc.c Image header has correct magic number
2602 41 common/cmd_ide.c before loading a Image from a IDE device
2603 -42 common/cmd_ide.c Bad usage of "ide" command
2604 42 common/cmd_ide.c correct usage of "ide" command
2605 -43 common/cmd_ide.c No boot device
2606 43 common/cmd_ide.c boot device found
2607 -44 common/cmd_ide.c Device not available
2608 44 common/cmd_ide.c Device available
2609 -45 common/cmd_ide.c wrong partition selected
2610 45 common/cmd_ide.c partition selected
2611 -46 common/cmd_ide.c Unknown partition table
2612 46 common/cmd_ide.c valid partition table found
2613 -47 common/cmd_ide.c Invalid partition type
2614 47 common/cmd_ide.c correct partition type
2615 -48 common/cmd_ide.c Error reading Image Header on boot device
2616 48 common/cmd_ide.c reading Image Header from IDE device OK
2617 -49 common/cmd_ide.c Image header has bad magic number
2618 49 common/cmd_ide.c Image header has correct magic number
2619 -50 common/cmd_ide.c Image header has bad checksum
2620 50 common/cmd_ide.c Image header has correct checksum
2621 -51 common/cmd_ide.c Error reading Image from IDE device
2622 51 common/cmd_ide.c reading Image from IDE device OK
2623 52 common/cmd_nand.c before loading a Image from a NAND device
2624 -53 common/cmd_nand.c Bad usage of "nand" command
2625 53 common/cmd_nand.c correct usage of "nand" command
2626 -54 common/cmd_nand.c No boot device
2627 54 common/cmd_nand.c boot device found
2628 -55 common/cmd_nand.c Unknown Chip ID on boot device
2629 55 common/cmd_nand.c correct chip ID found, device available
2630 -56 common/cmd_nand.c Error reading Image Header on boot device
2631 56 common/cmd_nand.c reading Image Header from NAND device OK
2632 -57 common/cmd_nand.c Image header has bad magic number
2633 57 common/cmd_nand.c Image header has correct magic number
2634 -58 common/cmd_nand.c Error reading Image from NAND device
2635 58 common/cmd_nand.c reading Image from NAND device OK
2637 -60 common/env_common.c Environment has a bad CRC, using default
2639 64 net/eth.c starting with Ethernet configuration.
2640 -64 net/eth.c no Ethernet found.
2641 65 net/eth.c Ethernet found.
2643 -80 common/cmd_net.c usage wrong
2644 80 common/cmd_net.c before calling NetLoop()
2645 -81 common/cmd_net.c some error in NetLoop() occurred
2646 81 common/cmd_net.c NetLoop() back without error
2647 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2648 82 common/cmd_net.c trying automatic boot
2649 83 common/cmd_net.c running "source" command
2650 -83 common/cmd_net.c some error in automatic boot or "source" command
2651 84 common/cmd_net.c end without errors
2656 100 common/cmd_bootm.c Kernel FIT Image has correct format
2657 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2658 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2659 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2660 102 common/cmd_bootm.c Kernel unit name specified
2661 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2662 103 common/cmd_bootm.c Found configuration node
2663 104 common/cmd_bootm.c Got kernel subimage node offset
2664 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2665 105 common/cmd_bootm.c Kernel subimage hash verification OK
2666 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2667 106 common/cmd_bootm.c Architecture check OK
2668 -106 common/cmd_bootm.c Kernel subimage has wrong type
2669 107 common/cmd_bootm.c Kernel subimage type OK
2670 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2671 108 common/cmd_bootm.c Got kernel subimage data/size
2672 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2673 -109 common/cmd_bootm.c Can't get kernel subimage type
2674 -110 common/cmd_bootm.c Can't get kernel subimage comp
2675 -111 common/cmd_bootm.c Can't get kernel subimage os
2676 -112 common/cmd_bootm.c Can't get kernel subimage load address
2677 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2679 120 common/image.c Start initial ramdisk verification
2680 -120 common/image.c Ramdisk FIT image has incorrect format
2681 121 common/image.c Ramdisk FIT image has correct format
2682 122 common/image.c No ramdisk subimage unit name, using configuration
2683 -122 common/image.c Can't get configuration for ramdisk subimage
2684 123 common/image.c Ramdisk unit name specified
2685 -124 common/image.c Can't get ramdisk subimage node offset
2686 125 common/image.c Got ramdisk subimage node offset
2687 -125 common/image.c Ramdisk subimage hash verification failed
2688 126 common/image.c Ramdisk subimage hash verification OK
2689 -126 common/image.c Ramdisk subimage for unsupported architecture
2690 127 common/image.c Architecture check OK
2691 -127 common/image.c Can't get ramdisk subimage data/size
2692 128 common/image.c Got ramdisk subimage data/size
2693 129 common/image.c Can't get ramdisk load address
2694 -129 common/image.c Got ramdisk load address
2696 -130 common/cmd_doc.c Incorrect FIT image format
2697 131 common/cmd_doc.c FIT image format OK
2699 -140 common/cmd_ide.c Incorrect FIT image format
2700 141 common/cmd_ide.c FIT image format OK
2702 -150 common/cmd_nand.c Incorrect FIT image format
2703 151 common/cmd_nand.c FIT image format OK
2705 - FIT image support:
2707 Enable support for the FIT uImage format.
2709 CONFIG_FIT_BEST_MATCH
2710 When no configuration is explicitly selected, default to the
2711 one whose fdt's compatibility field best matches that of
2712 U-Boot itself. A match is considered "best" if it matches the
2713 most specific compatibility entry of U-Boot's fdt's root node.
2714 The order of entries in the configuration's fdt is ignored.
2716 - Standalone program support:
2717 CONFIG_STANDALONE_LOAD_ADDR
2719 This option defines a board specific value for the
2720 address where standalone program gets loaded, thus
2721 overwriting the architecture dependent default
2724 - Frame Buffer Address:
2727 Define CONFIG_FB_ADDR if you want to use specific
2728 address for frame buffer. This is typically the case
2729 when using a graphics controller has separate video
2730 memory. U-Boot will then place the frame buffer at
2731 the given address instead of dynamically reserving it
2732 in system RAM by calling lcd_setmem(), which grabs
2733 the memory for the frame buffer depending on the
2734 configured panel size.
2736 Please see board_init_f function.
2738 - Automatic software updates via TFTP server
2740 CONFIG_UPDATE_TFTP_CNT_MAX
2741 CONFIG_UPDATE_TFTP_MSEC_MAX
2743 These options enable and control the auto-update feature;
2744 for a more detailed description refer to doc/README.update.
2746 - MTD Support (mtdparts command, UBI support)
2749 Adds the MTD device infrastructure from the Linux kernel.
2750 Needed for mtdparts command support.
2752 CONFIG_MTD_PARTITIONS
2754 Adds the MTD partitioning infrastructure from the Linux
2755 kernel. Needed for UBI support.
2759 Enable building of SPL globally.
2762 LDSCRIPT for linking the SPL binary.
2765 Maximum binary size (text, data and rodata) of the SPL binary.
2767 CONFIG_SPL_TEXT_BASE
2768 TEXT_BASE for linking the SPL binary.
2770 CONFIG_SPL_RELOC_TEXT_BASE
2771 Address to relocate to. If unspecified, this is equal to
2772 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2774 CONFIG_SPL_BSS_START_ADDR
2775 Link address for the BSS within the SPL binary.
2777 CONFIG_SPL_BSS_MAX_SIZE
2778 Maximum binary size of the BSS section of the SPL binary.
2781 Adress of the start of the stack SPL will use
2783 CONFIG_SPL_RELOC_STACK
2784 Adress of the start of the stack SPL will use after
2785 relocation. If unspecified, this is equal to
2788 CONFIG_SYS_SPL_MALLOC_START
2789 Starting address of the malloc pool used in SPL.
2791 CONFIG_SYS_SPL_MALLOC_SIZE
2792 The size of the malloc pool used in SPL.
2794 CONFIG_SPL_FRAMEWORK
2795 Enable the SPL framework under common/. This framework
2796 supports MMC, NAND and YMODEM loading of U-Boot and NAND
2797 NAND loading of the Linux Kernel.
2799 CONFIG_SPL_DISPLAY_PRINT
2800 For ARM, enable an optional function to print more information
2801 about the running system.
2803 CONFIG_SPL_INIT_MINIMAL
2804 Arch init code should be built for a very small image
2806 CONFIG_SPL_LIBCOMMON_SUPPORT
2807 Support for common/libcommon.o in SPL binary
2809 CONFIG_SPL_LIBDISK_SUPPORT
2810 Support for disk/libdisk.o in SPL binary
2812 CONFIG_SPL_I2C_SUPPORT
2813 Support for drivers/i2c/libi2c.o in SPL binary
2815 CONFIG_SPL_GPIO_SUPPORT
2816 Support for drivers/gpio/libgpio.o in SPL binary
2818 CONFIG_SPL_MMC_SUPPORT
2819 Support for drivers/mmc/libmmc.o in SPL binary
2821 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
2822 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
2823 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
2824 Address, size and partition on the MMC to load U-Boot from
2825 when the MMC is being used in raw mode.
2827 CONFIG_SPL_FAT_SUPPORT
2828 Support for fs/fat/libfat.o in SPL binary
2830 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
2831 Filename to read to load U-Boot when reading from FAT
2833 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
2834 Set this for NAND SPL on PPC mpc83xx targets, so that
2835 start.S waits for the rest of the SPL to load before
2836 continuing (the hardware starts execution after just
2837 loading the first page rather than the full 4K).
2839 CONFIG_SPL_NAND_BASE
2840 Include nand_base.c in the SPL. Requires
2841 CONFIG_SPL_NAND_DRIVERS.
2843 CONFIG_SPL_NAND_DRIVERS
2844 SPL uses normal NAND drivers, not minimal drivers.
2847 Include standard software ECC in the SPL
2849 CONFIG_SPL_NAND_SIMPLE
2850 Support for NAND boot using simple NAND drivers that
2851 expose the cmd_ctrl() interface.
2853 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
2854 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
2855 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
2856 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
2857 CONFIG_SYS_NAND_ECCBYTES
2858 Defines the size and behavior of the NAND that SPL uses
2861 CONFIG_SYS_NAND_U_BOOT_OFFS
2862 Location in NAND to read U-Boot from
2864 CONFIG_SYS_NAND_U_BOOT_DST
2865 Location in memory to load U-Boot to
2867 CONFIG_SYS_NAND_U_BOOT_SIZE
2868 Size of image to load
2870 CONFIG_SYS_NAND_U_BOOT_START
2871 Entry point in loaded image to jump to
2873 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
2874 Define this if you need to first read the OOB and then the
2875 data. This is used for example on davinci plattforms.
2877 CONFIG_SPL_OMAP3_ID_NAND
2878 Support for an OMAP3-specific set of functions to return the
2879 ID and MFR of the first attached NAND chip, if present.
2881 CONFIG_SPL_SERIAL_SUPPORT
2882 Support for drivers/serial/libserial.o in SPL binary
2884 CONFIG_SPL_SPI_FLASH_SUPPORT
2885 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
2887 CONFIG_SPL_SPI_SUPPORT
2888 Support for drivers/spi/libspi.o in SPL binary
2890 CONFIG_SPL_RAM_DEVICE
2891 Support for running image already present in ram, in SPL binary
2893 CONFIG_SPL_LIBGENERIC_SUPPORT
2894 Support for lib/libgeneric.o in SPL binary
2897 Linker address to which the SPL should be padded before
2898 appending the SPL payload.
2901 Final target image containing SPL and payload. Some SPLs
2902 use an arch-specific makefile fragment instead, for
2903 example if more than one image needs to be produced.
2908 [so far only for SMDK2400 boards]
2910 - Modem support enable:
2911 CONFIG_MODEM_SUPPORT
2913 - RTS/CTS Flow control enable:
2916 - Modem debug support:
2917 CONFIG_MODEM_SUPPORT_DEBUG
2919 Enables debugging stuff (char screen[1024], dbg())
2920 for modem support. Useful only with BDI2000.
2922 - Interrupt support (PPC):
2924 There are common interrupt_init() and timer_interrupt()
2925 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2926 for CPU specific initialization. interrupt_init_cpu()
2927 should set decrementer_count to appropriate value. If
2928 CPU resets decrementer automatically after interrupt
2929 (ppc4xx) it should set decrementer_count to zero.
2930 timer_interrupt() calls timer_interrupt_cpu() for CPU
2931 specific handling. If board has watchdog / status_led
2932 / other_activity_monitor it works automatically from
2933 general timer_interrupt().
2937 In the target system modem support is enabled when a
2938 specific key (key combination) is pressed during
2939 power-on. Otherwise U-Boot will boot normally
2940 (autoboot). The key_pressed() function is called from
2941 board_init(). Currently key_pressed() is a dummy
2942 function, returning 1 and thus enabling modem
2945 If there are no modem init strings in the
2946 environment, U-Boot proceed to autoboot; the
2947 previous output (banner, info printfs) will be
2950 See also: doc/README.Modem
2952 Board initialization settings:
2953 ------------------------------
2955 During Initialization u-boot calls a number of board specific functions
2956 to allow the preparation of board specific prerequisites, e.g. pin setup
2957 before drivers are initialized. To enable these callbacks the
2958 following configuration macros have to be defined. Currently this is
2959 architecture specific, so please check arch/your_architecture/lib/board.c
2960 typically in board_init_f() and board_init_r().
2962 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
2963 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
2964 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
2965 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
2967 Configuration Settings:
2968 -----------------------
2970 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2971 undefine this when you're short of memory.
2973 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2974 width of the commands listed in the 'help' command output.
2976 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2977 prompt for user input.
2979 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2981 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2983 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2985 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2986 the application (usually a Linux kernel) when it is
2989 - CONFIG_SYS_BAUDRATE_TABLE:
2990 List of legal baudrate settings for this board.
2992 - CONFIG_SYS_CONSOLE_INFO_QUIET
2993 Suppress display of console information at boot.
2995 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2996 If the board specific function
2997 extern int overwrite_console (void);
2998 returns 1, the stdin, stderr and stdout are switched to the
2999 serial port, else the settings in the environment are used.
3001 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3002 Enable the call to overwrite_console().
3004 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3005 Enable overwrite of previous console environment settings.
3007 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3008 Begin and End addresses of the area used by the
3011 - CONFIG_SYS_ALT_MEMTEST:
3012 Enable an alternate, more extensive memory test.
3014 - CONFIG_SYS_MEMTEST_SCRATCH:
3015 Scratch address used by the alternate memory test
3016 You only need to set this if address zero isn't writeable
3018 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3019 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3020 this specified memory area will get subtracted from the top
3021 (end) of RAM and won't get "touched" at all by U-Boot. By
3022 fixing up gd->ram_size the Linux kernel should gets passed
3023 the now "corrected" memory size and won't touch it either.
3024 This should work for arch/ppc and arch/powerpc. Only Linux
3025 board ports in arch/powerpc with bootwrapper support that
3026 recalculate the memory size from the SDRAM controller setup
3027 will have to get fixed in Linux additionally.
3029 This option can be used as a workaround for the 440EPx/GRx
3030 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3033 WARNING: Please make sure that this value is a multiple of
3034 the Linux page size (normally 4k). If this is not the case,
3035 then the end address of the Linux memory will be located at a
3036 non page size aligned address and this could cause major
3039 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3040 Enable temporary baudrate change while serial download
3042 - CONFIG_SYS_SDRAM_BASE:
3043 Physical start address of SDRAM. _Must_ be 0 here.
3045 - CONFIG_SYS_MBIO_BASE:
3046 Physical start address of Motherboard I/O (if using a
3049 - CONFIG_SYS_FLASH_BASE:
3050 Physical start address of Flash memory.
3052 - CONFIG_SYS_MONITOR_BASE:
3053 Physical start address of boot monitor code (set by
3054 make config files to be same as the text base address
3055 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3056 CONFIG_SYS_FLASH_BASE when booting from flash.
3058 - CONFIG_SYS_MONITOR_LEN:
3059 Size of memory reserved for monitor code, used to
3060 determine _at_compile_time_ (!) if the environment is
3061 embedded within the U-Boot image, or in a separate
3064 - CONFIG_SYS_MALLOC_LEN:
3065 Size of DRAM reserved for malloc() use.
3067 - CONFIG_SYS_BOOTM_LEN:
3068 Normally compressed uImages are limited to an
3069 uncompressed size of 8 MBytes. If this is not enough,
3070 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3071 to adjust this setting to your needs.
3073 - CONFIG_SYS_BOOTMAPSZ:
3074 Maximum size of memory mapped by the startup code of
3075 the Linux kernel; all data that must be processed by
3076 the Linux kernel (bd_info, boot arguments, FDT blob if
3077 used) must be put below this limit, unless "bootm_low"
3078 enviroment variable is defined and non-zero. In such case
3079 all data for the Linux kernel must be between "bootm_low"
3080 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3081 variable "bootm_mapsize" will override the value of
3082 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3083 then the value in "bootm_size" will be used instead.
3085 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3086 Enable initrd_high functionality. If defined then the
3087 initrd_high feature is enabled and the bootm ramdisk subcommand
3090 - CONFIG_SYS_BOOT_GET_CMDLINE:
3091 Enables allocating and saving kernel cmdline in space between
3092 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3094 - CONFIG_SYS_BOOT_GET_KBD:
3095 Enables allocating and saving a kernel copy of the bd_info in
3096 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3098 - CONFIG_SYS_MAX_FLASH_BANKS:
3099 Max number of Flash memory banks
3101 - CONFIG_SYS_MAX_FLASH_SECT:
3102 Max number of sectors on a Flash chip
3104 - CONFIG_SYS_FLASH_ERASE_TOUT:
3105 Timeout for Flash erase operations (in ms)
3107 - CONFIG_SYS_FLASH_WRITE_TOUT:
3108 Timeout for Flash write operations (in ms)
3110 - CONFIG_SYS_FLASH_LOCK_TOUT
3111 Timeout for Flash set sector lock bit operation (in ms)
3113 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3114 Timeout for Flash clear lock bits operation (in ms)
3116 - CONFIG_SYS_FLASH_PROTECTION
3117 If defined, hardware flash sectors protection is used
3118 instead of U-Boot software protection.
3120 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3122 Enable TFTP transfers directly to flash memory;
3123 without this option such a download has to be
3124 performed in two steps: (1) download to RAM, and (2)
3125 copy from RAM to flash.
3127 The two-step approach is usually more reliable, since
3128 you can check if the download worked before you erase
3129 the flash, but in some situations (when system RAM is
3130 too limited to allow for a temporary copy of the
3131 downloaded image) this option may be very useful.
3133 - CONFIG_SYS_FLASH_CFI:
3134 Define if the flash driver uses extra elements in the
3135 common flash structure for storing flash geometry.
3137 - CONFIG_FLASH_CFI_DRIVER
3138 This option also enables the building of the cfi_flash driver
3139 in the drivers directory
3141 - CONFIG_FLASH_CFI_MTD
3142 This option enables the building of the cfi_mtd driver
3143 in the drivers directory. The driver exports CFI flash
3146 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3147 Use buffered writes to flash.
3149 - CONFIG_FLASH_SPANSION_S29WS_N
3150 s29ws-n MirrorBit flash has non-standard addresses for buffered
3153 - CONFIG_SYS_FLASH_QUIET_TEST
3154 If this option is defined, the common CFI flash doesn't
3155 print it's warning upon not recognized FLASH banks. This
3156 is useful, if some of the configured banks are only
3157 optionally available.
3159 - CONFIG_FLASH_SHOW_PROGRESS
3160 If defined (must be an integer), print out countdown
3161 digits and dots. Recommended value: 45 (9..1) for 80
3162 column displays, 15 (3..1) for 40 column displays.
3164 - CONFIG_SYS_RX_ETH_BUFFER:
3165 Defines the number of Ethernet receive buffers. On some
3166 Ethernet controllers it is recommended to set this value
3167 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3168 buffers can be full shortly after enabling the interface
3169 on high Ethernet traffic.
3170 Defaults to 4 if not defined.
3172 - CONFIG_ENV_MAX_ENTRIES
3174 Maximum number of entries in the hash table that is used
3175 internally to store the environment settings. The default
3176 setting is supposed to be generous and should work in most
3177 cases. This setting can be used to tune behaviour; see
3178 lib/hashtable.c for details.
3180 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3181 - CONFIG_ENV_FLAGS_LIST_STATIC
3182 Enable validation of the values given to enviroment variables when
3183 calling env set. Variables can be restricted to only decimal,
3184 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3185 the variables can also be restricted to IP address or MAC address.
3187 The format of the list is:
3188 type_attribute = [s|d|x|b|i|m]
3189 access_atribute = [a|r|o|c]
3190 attributes = type_attribute[access_atribute]
3191 entry = variable_name[:attributes]
3194 The type attributes are:
3195 s - String (default)
3198 b - Boolean ([1yYtT|0nNfF])
3202 The access attributes are:
3208 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3209 Define this to a list (string) to define the ".flags"
3210 envirnoment variable in the default or embedded environment.
3212 - CONFIG_ENV_FLAGS_LIST_STATIC
3213 Define this to a list (string) to define validation that
3214 should be done if an entry is not found in the ".flags"
3215 environment variable. To override a setting in the static
3216 list, simply add an entry for the same variable name to the
3219 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3220 If defined, don't allow the -f switch to env set override variable
3223 The following definitions that deal with the placement and management
3224 of environment data (variable area); in general, we support the
3225 following configurations:
3227 - CONFIG_BUILD_ENVCRC:
3229 Builds up envcrc with the target environment so that external utils
3230 may easily extract it and embed it in final U-Boot images.
3232 - CONFIG_ENV_IS_IN_FLASH:
3234 Define this if the environment is in flash memory.
3236 a) The environment occupies one whole flash sector, which is
3237 "embedded" in the text segment with the U-Boot code. This
3238 happens usually with "bottom boot sector" or "top boot
3239 sector" type flash chips, which have several smaller
3240 sectors at the start or the end. For instance, such a
3241 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3242 such a case you would place the environment in one of the
3243 4 kB sectors - with U-Boot code before and after it. With
3244 "top boot sector" type flash chips, you would put the
3245 environment in one of the last sectors, leaving a gap
3246 between U-Boot and the environment.
3248 - CONFIG_ENV_OFFSET:
3250 Offset of environment data (variable area) to the
3251 beginning of flash memory; for instance, with bottom boot
3252 type flash chips the second sector can be used: the offset
3253 for this sector is given here.
3255 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3259 This is just another way to specify the start address of
3260 the flash sector containing the environment (instead of
3263 - CONFIG_ENV_SECT_SIZE:
3265 Size of the sector containing the environment.
3268 b) Sometimes flash chips have few, equal sized, BIG sectors.
3269 In such a case you don't want to spend a whole sector for
3274 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3275 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3276 of this flash sector for the environment. This saves
3277 memory for the RAM copy of the environment.
3279 It may also save flash memory if you decide to use this
3280 when your environment is "embedded" within U-Boot code,
3281 since then the remainder of the flash sector could be used
3282 for U-Boot code. It should be pointed out that this is
3283 STRONGLY DISCOURAGED from a robustness point of view:
3284 updating the environment in flash makes it always
3285 necessary to erase the WHOLE sector. If something goes
3286 wrong before the contents has been restored from a copy in
3287 RAM, your target system will be dead.
3289 - CONFIG_ENV_ADDR_REDUND
3290 CONFIG_ENV_SIZE_REDUND
3292 These settings describe a second storage area used to hold
3293 a redundant copy of the environment data, so that there is
3294 a valid backup copy in case there is a power failure during
3295 a "saveenv" operation.
3297 BE CAREFUL! Any changes to the flash layout, and some changes to the
3298 source code will make it necessary to adapt <board>/u-boot.lds*
3302 - CONFIG_ENV_IS_IN_NVRAM:
3304 Define this if you have some non-volatile memory device
3305 (NVRAM, battery buffered SRAM) which you want to use for the
3311 These two #defines are used to determine the memory area you
3312 want to use for environment. It is assumed that this memory
3313 can just be read and written to, without any special
3316 BE CAREFUL! The first access to the environment happens quite early
3317 in U-Boot initalization (when we try to get the setting of for the
3318 console baudrate). You *MUST* have mapped your NVRAM area then, or
3321 Please note that even with NVRAM we still use a copy of the
3322 environment in RAM: we could work on NVRAM directly, but we want to
3323 keep settings there always unmodified except somebody uses "saveenv"
3324 to save the current settings.
3327 - CONFIG_ENV_IS_IN_EEPROM:
3329 Use this if you have an EEPROM or similar serial access
3330 device and a driver for it.
3332 - CONFIG_ENV_OFFSET:
3335 These two #defines specify the offset and size of the
3336 environment area within the total memory of your EEPROM.
3338 - CONFIG_SYS_I2C_EEPROM_ADDR:
3339 If defined, specified the chip address of the EEPROM device.
3340 The default address is zero.
3342 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3343 If defined, the number of bits used to address bytes in a
3344 single page in the EEPROM device. A 64 byte page, for example
3345 would require six bits.
3347 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3348 If defined, the number of milliseconds to delay between
3349 page writes. The default is zero milliseconds.
3351 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3352 The length in bytes of the EEPROM memory array address. Note
3353 that this is NOT the chip address length!
3355 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3356 EEPROM chips that implement "address overflow" are ones
3357 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3358 address and the extra bits end up in the "chip address" bit
3359 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3362 Note that we consider the length of the address field to
3363 still be one byte because the extra address bits are hidden
3364 in the chip address.
3366 - CONFIG_SYS_EEPROM_SIZE:
3367 The size in bytes of the EEPROM device.
3369 - CONFIG_ENV_EEPROM_IS_ON_I2C
3370 define this, if you have I2C and SPI activated, and your
3371 EEPROM, which holds the environment, is on the I2C bus.
3373 - CONFIG_I2C_ENV_EEPROM_BUS
3374 if you have an Environment on an EEPROM reached over
3375 I2C muxes, you can define here, how to reach this
3376 EEPROM. For example:
3378 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
3380 EEPROM which holds the environment, is reached over
3381 a pca9547 i2c mux with address 0x70, channel 3.
3383 - CONFIG_ENV_IS_IN_DATAFLASH:
3385 Define this if you have a DataFlash memory device which you
3386 want to use for the environment.
3388 - CONFIG_ENV_OFFSET:
3392 These three #defines specify the offset and size of the
3393 environment area within the total memory of your DataFlash placed
3394 at the specified address.
3396 - CONFIG_ENV_IS_IN_REMOTE:
3398 Define this if you have a remote memory space which you
3399 want to use for the local device's environment.
3404 These two #defines specify the address and size of the
3405 environment area within the remote memory space. The
3406 local device can get the environment from remote memory
3407 space by SRIO or PCIE links.
3409 BE CAREFUL! For some special cases, the local device can not use
3410 "saveenv" command. For example, the local device will get the
3411 environment stored in a remote NOR flash by SRIO or PCIE link,
3412 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3414 - CONFIG_ENV_IS_IN_NAND:
3416 Define this if you have a NAND device which you want to use
3417 for the environment.
3419 - CONFIG_ENV_OFFSET:
3422 These two #defines specify the offset and size of the environment
3423 area within the first NAND device. CONFIG_ENV_OFFSET must be
3424 aligned to an erase block boundary.
3426 - CONFIG_ENV_OFFSET_REDUND (optional):
3428 This setting describes a second storage area of CONFIG_ENV_SIZE
3429 size used to hold a redundant copy of the environment data, so
3430 that there is a valid backup copy in case there is a power failure
3431 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3432 aligned to an erase block boundary.
3434 - CONFIG_ENV_RANGE (optional):
3436 Specifies the length of the region in which the environment
3437 can be written. This should be a multiple of the NAND device's
3438 block size. Specifying a range with more erase blocks than
3439 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3440 the range to be avoided.
3442 - CONFIG_ENV_OFFSET_OOB (optional):
3444 Enables support for dynamically retrieving the offset of the
3445 environment from block zero's out-of-band data. The
3446 "nand env.oob" command can be used to record this offset.
3447 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3448 using CONFIG_ENV_OFFSET_OOB.
3450 - CONFIG_NAND_ENV_DST
3452 Defines address in RAM to which the nand_spl code should copy the
3453 environment. If redundant environment is used, it will be copied to
3454 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3456 - CONFIG_SYS_SPI_INIT_OFFSET
3458 Defines offset to the initial SPI buffer area in DPRAM. The
3459 area is used at an early stage (ROM part) if the environment
3460 is configured to reside in the SPI EEPROM: We need a 520 byte
3461 scratch DPRAM area. It is used between the two initialization
3462 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3463 to be a good choice since it makes it far enough from the
3464 start of the data area as well as from the stack pointer.
3466 Please note that the environment is read-only until the monitor
3467 has been relocated to RAM and a RAM copy of the environment has been
3468 created; also, when using EEPROM you will have to use getenv_f()
3469 until then to read environment variables.
3471 The environment is protected by a CRC32 checksum. Before the monitor
3472 is relocated into RAM, as a result of a bad CRC you will be working
3473 with the compiled-in default environment - *silently*!!! [This is
3474 necessary, because the first environment variable we need is the
3475 "baudrate" setting for the console - if we have a bad CRC, we don't
3476 have any device yet where we could complain.]
3478 Note: once the monitor has been relocated, then it will complain if
3479 the default environment is used; a new CRC is computed as soon as you
3480 use the "saveenv" command to store a valid environment.
3482 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3483 Echo the inverted Ethernet link state to the fault LED.
3485 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3486 also needs to be defined.
3488 - CONFIG_SYS_FAULT_MII_ADDR:
3489 MII address of the PHY to check for the Ethernet link state.
3491 - CONFIG_NS16550_MIN_FUNCTIONS:
3492 Define this if you desire to only have use of the NS16550_init
3493 and NS16550_putc functions for the serial driver located at
3494 drivers/serial/ns16550.c. This option is useful for saving
3495 space for already greatly restricted images, including but not
3496 limited to NAND_SPL configurations.
3498 - CONFIG_DISPLAY_BOARDINFO
3499 Display information about the board that U-Boot is running on
3500 when U-Boot starts up. The board function checkboard() is called
3503 - CONFIG_DISPLAY_BOARDINFO_LATE
3504 Similar to the previous option, but display this information
3505 later, once stdio is running and output goes to the LCD, if
3508 Low Level (hardware related) configuration options:
3509 ---------------------------------------------------
3511 - CONFIG_SYS_CACHELINE_SIZE:
3512 Cache Line Size of the CPU.
3514 - CONFIG_SYS_DEFAULT_IMMR:
3515 Default address of the IMMR after system reset.
3517 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3518 and RPXsuper) to be able to adjust the position of
3519 the IMMR register after a reset.
3521 - CONFIG_SYS_CCSRBAR_DEFAULT:
3522 Default (power-on reset) physical address of CCSR on Freescale
3525 - CONFIG_SYS_CCSRBAR:
3526 Virtual address of CCSR. On a 32-bit build, this is typically
3527 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3529 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3530 for cross-platform code that uses that macro instead.
3532 - CONFIG_SYS_CCSRBAR_PHYS:
3533 Physical address of CCSR. CCSR can be relocated to a new
3534 physical address, if desired. In this case, this macro should
3535 be set to that address. Otherwise, it should be set to the
3536 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3537 is typically relocated on 36-bit builds. It is recommended
3538 that this macro be defined via the _HIGH and _LOW macros:
3540 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3541 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3543 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3544 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3545 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3546 used in assembly code, so it must not contain typecasts or
3547 integer size suffixes (e.g. "ULL").
3549 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3550 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3551 used in assembly code, so it must not contain typecasts or
3552 integer size suffixes (e.g. "ULL").
3554 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3555 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3556 forced to a value that ensures that CCSR is not relocated.
3558 - Floppy Disk Support:
3559 CONFIG_SYS_FDC_DRIVE_NUMBER
3561 the default drive number (default value 0)
3563 CONFIG_SYS_ISA_IO_STRIDE
3565 defines the spacing between FDC chipset registers
3568 CONFIG_SYS_ISA_IO_OFFSET
3570 defines the offset of register from address. It
3571 depends on which part of the data bus is connected to
3572 the FDC chipset. (default value 0)
3574 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3575 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3578 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3579 fdc_hw_init() is called at the beginning of the FDC
3580 setup. fdc_hw_init() must be provided by the board
3581 source code. It is used to make hardware dependant
3585 Most IDE controllers were designed to be connected with PCI
3586 interface. Only few of them were designed for AHB interface.
3587 When software is doing ATA command and data transfer to
3588 IDE devices through IDE-AHB controller, some additional
3589 registers accessing to these kind of IDE-AHB controller
3592 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3593 DO NOT CHANGE unless you know exactly what you're
3594 doing! (11-4) [MPC8xx/82xx systems only]
3596 - CONFIG_SYS_INIT_RAM_ADDR:
3598 Start address of memory area that can be used for
3599 initial data and stack; please note that this must be
3600 writable memory that is working WITHOUT special
3601 initialization, i. e. you CANNOT use normal RAM which
3602 will become available only after programming the
3603 memory controller and running certain initialization
3606 U-Boot uses the following memory types:
3607 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
3608 - MPC824X: data cache
3609 - PPC4xx: data cache
3611 - CONFIG_SYS_GBL_DATA_OFFSET:
3613 Offset of the initial data structure in the memory
3614 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3615 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3616 data is located at the end of the available space
3617 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3618 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
3619 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3620 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3623 On the MPC824X (or other systems that use the data
3624 cache for initial memory) the address chosen for
3625 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3626 point to an otherwise UNUSED address space between
3627 the top of RAM and the start of the PCI space.
3629 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
3631 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
3633 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
3635 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
3637 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
3639 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3641 - CONFIG_SYS_OR_TIMING_SDRAM:
3644 - CONFIG_SYS_MAMR_PTA:
3645 periodic timer for refresh
3647 - CONFIG_SYS_DER: Debug Event Register (37-47)
3649 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3650 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3651 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3652 CONFIG_SYS_BR1_PRELIM:
3653 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3655 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3656 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3657 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3658 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3660 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
3661 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
3662 Machine Mode Register and Memory Periodic Timer
3663 Prescaler definitions (SDRAM timing)
3665 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
3666 enable I2C microcode relocation patch (MPC8xx);
3667 define relocation offset in DPRAM [DSP2]
3669 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
3670 enable SMC microcode relocation patch (MPC8xx);
3671 define relocation offset in DPRAM [SMC1]
3673 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
3674 enable SPI microcode relocation patch (MPC8xx);
3675 define relocation offset in DPRAM [SCC4]
3677 - CONFIG_SYS_USE_OSCCLK:
3678 Use OSCM clock mode on MBX8xx board. Be careful,
3679 wrong setting might damage your board. Read
3680 doc/README.MBX before setting this variable!
3682 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
3683 Offset of the bootmode word in DPRAM used by post
3684 (Power On Self Tests). This definition overrides
3685 #define'd default value in commproc.h resp.
3688 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
3689 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
3690 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
3691 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
3692 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
3693 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
3694 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
3695 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
3696 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
3698 - CONFIG_PCI_DISABLE_PCIE:
3699 Disable PCI-Express on systems where it is supported but not
3702 - CONFIG_PCI_ENUM_ONLY
3703 Only scan through and get the devices on the busses.
3704 Don't do any setup work, presumably because someone or
3705 something has already done it, and we don't need to do it
3706 a second time. Useful for platforms that are pre-booted
3707 by coreboot or similar.
3710 Chip has SRIO or not
3713 Board has SRIO 1 port available
3716 Board has SRIO 2 port available
3718 - CONFIG_SYS_SRIOn_MEM_VIRT:
3719 Virtual Address of SRIO port 'n' memory region
3721 - CONFIG_SYS_SRIOn_MEM_PHYS:
3722 Physical Address of SRIO port 'n' memory region
3724 - CONFIG_SYS_SRIOn_MEM_SIZE:
3725 Size of SRIO port 'n' memory region
3727 - CONFIG_SYS_NDFC_16
3728 Defined to tell the NDFC that the NAND chip is using a
3731 - CONFIG_SYS_NDFC_EBC0_CFG
3732 Sets the EBC0_CFG register for the NDFC. If not defined
3733 a default value will be used.
3736 Get DDR timing information from an I2C EEPROM. Common
3737 with pluggable memory modules such as SODIMMs
3740 I2C address of the SPD EEPROM
3742 - CONFIG_SYS_SPD_BUS_NUM
3743 If SPD EEPROM is on an I2C bus other than the first
3744 one, specify here. Note that the value must resolve
3745 to something your driver can deal with.
3747 - CONFIG_SYS_DDR_RAW_TIMING
3748 Get DDR timing information from other than SPD. Common with
3749 soldered DDR chips onboard without SPD. DDR raw timing
3750 parameters are extracted from datasheet and hard-coded into
3751 header files or board specific files.
3753 - CONFIG_FSL_DDR_INTERACTIVE
3754 Enable interactive DDR debugging. See doc/README.fsl-ddr.
3756 - CONFIG_SYS_83XX_DDR_USES_CS0
3757 Only for 83xx systems. If specified, then DDR should
3758 be configured using CS0 and CS1 instead of CS2 and CS3.
3760 - CONFIG_ETHER_ON_FEC[12]
3761 Define to enable FEC[12] on a 8xx series processor.
3763 - CONFIG_FEC[12]_PHY
3764 Define to the hardcoded PHY address which corresponds
3765 to the given FEC; i. e.
3766 #define CONFIG_FEC1_PHY 4
3767 means that the PHY with address 4 is connected to FEC1
3769 When set to -1, means to probe for first available.
3771 - CONFIG_FEC[12]_PHY_NORXERR
3772 The PHY does not have a RXERR line (RMII only).
3773 (so program the FEC to ignore it).
3776 Enable RMII mode for all FECs.
3777 Note that this is a global option, we can't
3778 have one FEC in standard MII mode and another in RMII mode.
3780 - CONFIG_CRC32_VERIFY
3781 Add a verify option to the crc32 command.
3784 => crc32 -v <address> <count> <crc32>
3786 Where address/count indicate a memory area
3787 and crc32 is the correct crc32 which the
3791 Add the "loopw" memory command. This only takes effect if
3792 the memory commands are activated globally (CONFIG_CMD_MEM).
3795 Add the "mdc" and "mwc" memory commands. These are cyclic
3800 This command will print 4 bytes (10,11,12,13) each 500 ms.
3802 => mwc.l 100 12345678 10
3803 This command will write 12345678 to address 100 all 10 ms.
3805 This only takes effect if the memory commands are activated
3806 globally (CONFIG_CMD_MEM).
3808 - CONFIG_SKIP_LOWLEVEL_INIT
3809 [ARM, NDS32, MIPS only] If this variable is defined, then certain
3810 low level initializations (like setting up the memory
3811 controller) are omitted and/or U-Boot does not
3812 relocate itself into RAM.
3814 Normally this variable MUST NOT be defined. The only
3815 exception is when U-Boot is loaded (to RAM) by some
3816 other boot loader or by a debugger which performs
3817 these initializations itself.
3820 Modifies the behaviour of start.S when compiling a loader
3821 that is executed before the actual U-Boot. E.g. when
3822 compiling a NAND SPL.
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_NO_RESET_VECTOR
3831 If defined, the x86 reset vector code is excluded. You will need
3832 to do this when U-Boot is running from Coreboot.
3834 - CONFIG_X86_NO_REAL_MODE
3835 If defined, x86 real mode code is omitted. This assumes a
3836 32-bit environment where such code is not needed. You will
3837 need to do this when U-Boot is running from Coreboot.
3840 Freescale QE/FMAN Firmware Support:
3841 -----------------------------------
3843 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
3844 loading of "firmware", which is encoded in the QE firmware binary format.
3845 This firmware often needs to be loaded during U-Boot booting, so macros
3846 are used to identify the storage device (NOR flash, SPI, etc) and the address
3849 - CONFIG_SYS_QE_FMAN_FW_ADDR
3850 The address in the storage device where the firmware is located. The
3851 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3854 - CONFIG_SYS_QE_FMAN_FW_LENGTH
3855 The maximum possible size of the firmware. The firmware binary format
3856 has a field that specifies the actual size of the firmware, but it
3857 might not be possible to read any part of the firmware unless some
3858 local storage is allocated to hold the entire firmware first.
3860 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
3861 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
3862 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
3863 virtual address in NOR flash.
3865 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
3866 Specifies that QE/FMAN firmware is located in NAND flash.
3867 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
3869 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
3870 Specifies that QE/FMAN firmware is located on the primary SD/MMC
3871 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3873 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
3874 Specifies that QE/FMAN firmware is located on the primary SPI
3875 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3877 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
3878 Specifies that QE/FMAN firmware is located in the remote (master)
3879 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
3880 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
3881 window->master inbound window->master LAW->the ucode address in
3882 master's memory space.
3884 Building the Software:
3885 ======================
3887 Building U-Boot has been tested in several native build environments
3888 and in many different cross environments. Of course we cannot support
3889 all possibly existing versions of cross development tools in all
3890 (potentially obsolete) versions. In case of tool chain problems we
3891 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3892 which is extensively used to build and test U-Boot.
3894 If you are not using a native environment, it is assumed that you
3895 have GNU cross compiling tools available in your path. In this case,
3896 you must set the environment variable CROSS_COMPILE in your shell.
3897 Note that no changes to the Makefile or any other source files are
3898 necessary. For example using the ELDK on a 4xx CPU, please enter:
3900 $ CROSS_COMPILE=ppc_4xx-
3901 $ export CROSS_COMPILE
3903 Note: If you wish to generate Windows versions of the utilities in
3904 the tools directory you can use the MinGW toolchain
3905 (http://www.mingw.org). Set your HOST tools to the MinGW
3906 toolchain and execute 'make tools'. For example:
3908 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3910 Binaries such as tools/mkimage.exe will be created which can
3911 be executed on computers running Windows.
3913 U-Boot is intended to be simple to build. After installing the
3914 sources you must configure U-Boot for one specific board type. This
3919 where "NAME_config" is the name of one of the existing configu-
3920 rations; see boards.cfg for supported names.
3922 Note: for some board special configuration names may exist; check if
3923 additional information is available from the board vendor; for
3924 instance, the TQM823L systems are available without (standard)
3925 or with LCD support. You can select such additional "features"
3926 when choosing the configuration, i. e.
3929 - will configure for a plain TQM823L, i. e. no LCD support
3931 make TQM823L_LCD_config
3932 - will configure for a TQM823L with U-Boot console on LCD
3937 Finally, type "make all", and you should get some working U-Boot
3938 images ready for download to / installation on your system:
3940 - "u-boot.bin" is a raw binary image
3941 - "u-boot" is an image in ELF binary format
3942 - "u-boot.srec" is in Motorola S-Record format
3944 By default the build is performed locally and the objects are saved
3945 in the source directory. One of the two methods can be used to change
3946 this behavior and build U-Boot to some external directory:
3948 1. Add O= to the make command line invocations:
3950 make O=/tmp/build distclean
3951 make O=/tmp/build NAME_config
3952 make O=/tmp/build all
3954 2. Set environment variable BUILD_DIR to point to the desired location:
3956 export BUILD_DIR=/tmp/build
3961 Note that the command line "O=" setting overrides the BUILD_DIR environment
3965 Please be aware that the Makefiles assume you are using GNU make, so
3966 for instance on NetBSD you might need to use "gmake" instead of
3970 If the system board that you have is not listed, then you will need
3971 to port U-Boot to your hardware platform. To do this, follow these
3974 1. Add a new configuration option for your board to the toplevel
3975 "boards.cfg" file, using the existing entries as examples.
3976 Follow the instructions there to keep the boards in order.
3977 2. Create a new directory to hold your board specific code. Add any
3978 files you need. In your board directory, you will need at least
3979 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
3980 3. Create a new configuration file "include/configs/<board>.h" for
3982 3. If you're porting U-Boot to a new CPU, then also create a new
3983 directory to hold your CPU specific code. Add any files you need.
3984 4. Run "make <board>_config" with your new name.
3985 5. Type "make", and you should get a working "u-boot.srec" file
3986 to be installed on your target system.
3987 6. Debug and solve any problems that might arise.
3988 [Of course, this last step is much harder than it sounds.]
3991 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3992 ==============================================================
3994 If you have modified U-Boot sources (for instance added a new board
3995 or support for new devices, a new CPU, etc.) you are expected to
3996 provide feedback to the other developers. The feedback normally takes
3997 the form of a "patch", i. e. a context diff against a certain (latest
3998 official or latest in the git repository) version of U-Boot sources.
4000 But before you submit such a patch, please verify that your modifi-
4001 cation did not break existing code. At least make sure that *ALL* of
4002 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4003 just run the "MAKEALL" script, which will configure and build U-Boot
4004 for ALL supported system. Be warned, this will take a while. You can
4005 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4006 environment variable to the script, i. e. to use the ELDK cross tools
4009 CROSS_COMPILE=ppc_8xx- MAKEALL
4011 or to build on a native PowerPC system you can type
4013 CROSS_COMPILE=' ' MAKEALL
4015 When using the MAKEALL script, the default behaviour is to build
4016 U-Boot in the source directory. This location can be changed by
4017 setting the BUILD_DIR environment variable. Also, for each target
4018 built, the MAKEALL script saves two log files (<target>.ERR and
4019 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4020 location can be changed by setting the MAKEALL_LOGDIR environment
4021 variable. For example:
4023 export BUILD_DIR=/tmp/build
4024 export MAKEALL_LOGDIR=/tmp/log
4025 CROSS_COMPILE=ppc_8xx- MAKEALL
4027 With the above settings build objects are saved in the /tmp/build,
4028 log files are saved in the /tmp/log and the source tree remains clean
4029 during the whole build process.
4032 See also "U-Boot Porting Guide" below.
4035 Monitor Commands - Overview:
4036 ============================
4038 go - start application at address 'addr'
4039 run - run commands in an environment variable
4040 bootm - boot application image from memory
4041 bootp - boot image via network using BootP/TFTP protocol
4042 bootz - boot zImage from memory
4043 tftpboot- boot image via network using TFTP protocol
4044 and env variables "ipaddr" and "serverip"
4045 (and eventually "gatewayip")
4046 tftpput - upload a file via network using TFTP protocol
4047 rarpboot- boot image via network using RARP/TFTP protocol
4048 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4049 loads - load S-Record file over serial line
4050 loadb - load binary file over serial line (kermit mode)
4052 mm - memory modify (auto-incrementing)
4053 nm - memory modify (constant address)
4054 mw - memory write (fill)
4056 cmp - memory compare
4057 crc32 - checksum calculation
4058 i2c - I2C sub-system
4059 sspi - SPI utility commands
4060 base - print or set address offset
4061 printenv- print environment variables
4062 setenv - set environment variables
4063 saveenv - save environment variables to persistent storage
4064 protect - enable or disable FLASH write protection
4065 erase - erase FLASH memory
4066 flinfo - print FLASH memory information
4067 nand - NAND memory operations (see doc/README.nand)
4068 bdinfo - print Board Info structure
4069 iminfo - print header information for application image
4070 coninfo - print console devices and informations
4071 ide - IDE sub-system
4072 loop - infinite loop on address range
4073 loopw - infinite write loop on address range
4074 mtest - simple RAM test
4075 icache - enable or disable instruction cache
4076 dcache - enable or disable data cache
4077 reset - Perform RESET of the CPU
4078 echo - echo args to console
4079 version - print monitor version
4080 help - print online help
4081 ? - alias for 'help'
4084 Monitor Commands - Detailed Description:
4085 ========================================
4089 For now: just type "help <command>".
4092 Environment Variables:
4093 ======================
4095 U-Boot supports user configuration using Environment Variables which
4096 can be made persistent by saving to Flash memory.
4098 Environment Variables are set using "setenv", printed using
4099 "printenv", and saved to Flash using "saveenv". Using "setenv"
4100 without a value can be used to delete a variable from the
4101 environment. As long as you don't save the environment you are
4102 working with an in-memory copy. In case the Flash area containing the
4103 environment is erased by accident, a default environment is provided.
4105 Some configuration options can be set using Environment Variables.
4107 List of environment variables (most likely not complete):
4109 baudrate - see CONFIG_BAUDRATE
4111 bootdelay - see CONFIG_BOOTDELAY
4113 bootcmd - see CONFIG_BOOTCOMMAND
4115 bootargs - Boot arguments when booting an RTOS image
4117 bootfile - Name of the image to load with TFTP
4119 bootm_low - Memory range available for image processing in the bootm
4120 command can be restricted. This variable is given as
4121 a hexadecimal number and defines lowest address allowed
4122 for use by the bootm command. See also "bootm_size"
4123 environment variable. Address defined by "bootm_low" is
4124 also the base of the initial memory mapping for the Linux
4125 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4128 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4129 This variable is given as a hexadecimal number and it
4130 defines the size of the memory region starting at base
4131 address bootm_low that is accessible by the Linux kernel
4132 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4133 as the default value if it is defined, and bootm_size is
4136 bootm_size - Memory range available for image processing in the bootm
4137 command can be restricted. This variable is given as
4138 a hexadecimal number and defines the size of the region
4139 allowed for use by the bootm command. See also "bootm_low"
4140 environment variable.
4142 updatefile - Location of the software update file on a TFTP server, used
4143 by the automatic software update feature. Please refer to
4144 documentation in doc/README.update for more details.
4146 autoload - if set to "no" (any string beginning with 'n'),
4147 "bootp" will just load perform a lookup of the
4148 configuration from the BOOTP server, but not try to
4149 load any image using TFTP
4151 autostart - if set to "yes", an image loaded using the "bootp",
4152 "rarpboot", "tftpboot" or "diskboot" commands will
4153 be automatically started (by internally calling
4156 If set to "no", a standalone image passed to the
4157 "bootm" command will be copied to the load address
4158 (and eventually uncompressed), but NOT be started.
4159 This can be used to load and uncompress arbitrary
4162 fdt_high - if set this restricts the maximum address that the
4163 flattened device tree will be copied into upon boot.
4164 For example, if you have a system with 1 GB memory
4165 at physical address 0x10000000, while Linux kernel
4166 only recognizes the first 704 MB as low memory, you
4167 may need to set fdt_high as 0x3C000000 to have the
4168 device tree blob be copied to the maximum address
4169 of the 704 MB low memory, so that Linux kernel can
4170 access it during the boot procedure.
4172 If this is set to the special value 0xFFFFFFFF then
4173 the fdt will not be copied at all on boot. For this
4174 to work it must reside in writable memory, have
4175 sufficient padding on the end of it for u-boot to
4176 add the information it needs into it, and the memory
4177 must be accessible by the kernel.
4179 fdtcontroladdr- if set this is the address of the control flattened
4180 device tree used by U-Boot when CONFIG_OF_CONTROL is
4183 i2cfast - (PPC405GP|PPC405EP only)
4184 if set to 'y' configures Linux I2C driver for fast
4185 mode (400kHZ). This environment variable is used in
4186 initialization code. So, for changes to be effective
4187 it must be saved and board must be reset.
4189 initrd_high - restrict positioning of initrd images:
4190 If this variable is not set, initrd images will be
4191 copied to the highest possible address in RAM; this
4192 is usually what you want since it allows for
4193 maximum initrd size. If for some reason you want to
4194 make sure that the initrd image is loaded below the
4195 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4196 variable to a value of "no" or "off" or "0".
4197 Alternatively, you can set it to a maximum upper
4198 address to use (U-Boot will still check that it
4199 does not overwrite the U-Boot stack and data).
4201 For instance, when you have a system with 16 MB
4202 RAM, and want to reserve 4 MB from use by Linux,
4203 you can do this by adding "mem=12M" to the value of
4204 the "bootargs" variable. However, now you must make
4205 sure that the initrd image is placed in the first
4206 12 MB as well - this can be done with
4208 setenv initrd_high 00c00000
4210 If you set initrd_high to 0xFFFFFFFF, this is an
4211 indication to U-Boot that all addresses are legal
4212 for the Linux kernel, including addresses in flash
4213 memory. In this case U-Boot will NOT COPY the
4214 ramdisk at all. This may be useful to reduce the
4215 boot time on your system, but requires that this
4216 feature is supported by your Linux kernel.
4218 ipaddr - IP address; needed for tftpboot command
4220 loadaddr - Default load address for commands like "bootp",
4221 "rarpboot", "tftpboot", "loadb" or "diskboot"
4223 loads_echo - see CONFIG_LOADS_ECHO
4225 serverip - TFTP server IP address; needed for tftpboot command
4227 bootretry - see CONFIG_BOOT_RETRY_TIME
4229 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4231 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4233 ethprime - controls which interface is used first.
4235 ethact - controls which interface is currently active.
4236 For example you can do the following
4238 => setenv ethact FEC
4239 => ping 192.168.0.1 # traffic sent on FEC
4240 => setenv ethact SCC
4241 => ping 10.0.0.1 # traffic sent on SCC
4243 ethrotate - When set to "no" U-Boot does not go through all
4244 available network interfaces.
4245 It just stays at the currently selected interface.
4247 netretry - When set to "no" each network operation will
4248 either succeed or fail without retrying.
4249 When set to "once" the network operation will
4250 fail when all the available network interfaces
4251 are tried once without success.
4252 Useful on scripts which control the retry operation
4255 npe_ucode - set load address for the NPE microcode
4257 tftpsrcport - If this is set, the value is used for TFTP's
4260 tftpdstport - If this is set, the value is used for TFTP's UDP
4261 destination port instead of the Well Know Port 69.
4263 tftpblocksize - Block size to use for TFTP transfers; if not set,
4264 we use the TFTP server's default block size
4266 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4267 seconds, minimum value is 1000 = 1 second). Defines
4268 when a packet is considered to be lost so it has to
4269 be retransmitted. The default is 5000 = 5 seconds.
4270 Lowering this value may make downloads succeed
4271 faster in networks with high packet loss rates or
4272 with unreliable TFTP servers.
4274 vlan - When set to a value < 4095 the traffic over
4275 Ethernet is encapsulated/received over 802.1q
4278 The following image location variables contain the location of images
4279 used in booting. The "Image" column gives the role of the image and is
4280 not an environment variable name. The other columns are environment
4281 variable names. "File Name" gives the name of the file on a TFTP
4282 server, "RAM Address" gives the location in RAM the image will be
4283 loaded to, and "Flash Location" gives the image's address in NOR
4284 flash or offset in NAND flash.
4286 *Note* - these variables don't have to be defined for all boards, some
4287 boards currenlty use other variables for these purposes, and some
4288 boards use these variables for other purposes.
4290 Image File Name RAM Address Flash Location
4291 ----- --------- ----------- --------------
4292 u-boot u-boot u-boot_addr_r u-boot_addr
4293 Linux kernel bootfile kernel_addr_r kernel_addr
4294 device tree blob fdtfile fdt_addr_r fdt_addr
4295 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4297 The following environment variables may be used and automatically
4298 updated by the network boot commands ("bootp" and "rarpboot"),
4299 depending the information provided by your boot server:
4301 bootfile - see above
4302 dnsip - IP address of your Domain Name Server
4303 dnsip2 - IP address of your secondary Domain Name Server
4304 gatewayip - IP address of the Gateway (Router) to use
4305 hostname - Target hostname
4307 netmask - Subnet Mask
4308 rootpath - Pathname of the root filesystem on the NFS server
4309 serverip - see above
4312 There are two special Environment Variables:
4314 serial# - contains hardware identification information such
4315 as type string and/or serial number
4316 ethaddr - Ethernet address
4318 These variables can be set only once (usually during manufacturing of
4319 the board). U-Boot refuses to delete or overwrite these variables
4320 once they have been set once.
4323 Further special Environment Variables:
4325 ver - Contains the U-Boot version string as printed
4326 with the "version" command. This variable is
4327 readonly (see CONFIG_VERSION_VARIABLE).
4330 Please note that changes to some configuration parameters may take
4331 only effect after the next boot (yes, that's just like Windoze :-).
4334 Callback functions for environment variables:
4335 ---------------------------------------------
4337 For some environment variables, the behavior of u-boot needs to change
4338 when their values are changed. This functionailty allows functions to
4339 be associated with arbitrary variables. On creation, overwrite, or
4340 deletion, the callback will provide the opportunity for some side
4341 effect to happen or for the change to be rejected.
4343 The callbacks are named and associated with a function using the
4344 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4346 These callbacks are associated with variables in one of two ways. The
4347 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4348 in the board configuration to a string that defines a list of
4349 associations. The list must be in the following format:
4351 entry = variable_name[:callback_name]
4354 If the callback name is not specified, then the callback is deleted.
4355 Spaces are also allowed anywhere in the list.
4357 Callbacks can also be associated by defining the ".callbacks" variable
4358 with the same list format above. Any association in ".callbacks" will
4359 override any association in the static list. You can define
4360 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4361 ".callbacks" envirnoment variable in the default or embedded environment.
4364 Command Line Parsing:
4365 =====================
4367 There are two different command line parsers available with U-Boot:
4368 the old "simple" one, and the much more powerful "hush" shell:
4370 Old, simple command line parser:
4371 --------------------------------
4373 - supports environment variables (through setenv / saveenv commands)
4374 - several commands on one line, separated by ';'
4375 - variable substitution using "... ${name} ..." syntax
4376 - special characters ('$', ';') can be escaped by prefixing with '\',
4378 setenv bootcmd bootm \${address}
4379 - You can also escape text by enclosing in single apostrophes, for example:
4380 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4385 - similar to Bourne shell, with control structures like
4386 if...then...else...fi, for...do...done; while...do...done,
4387 until...do...done, ...
4388 - supports environment ("global") variables (through setenv / saveenv
4389 commands) and local shell variables (through standard shell syntax
4390 "name=value"); only environment variables can be used with "run"
4396 (1) If a command line (or an environment variable executed by a "run"
4397 command) contains several commands separated by semicolon, and
4398 one of these commands fails, then the remaining commands will be
4401 (2) If you execute several variables with one call to run (i. e.
4402 calling run with a list of variables as arguments), any failing
4403 command will cause "run" to terminate, i. e. the remaining
4404 variables are not executed.
4406 Note for Redundant Ethernet Interfaces:
4407 =======================================
4409 Some boards come with redundant Ethernet interfaces; U-Boot supports
4410 such configurations and is capable of automatic selection of a
4411 "working" interface when needed. MAC assignment works as follows:
4413 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4414 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4415 "eth1addr" (=>eth1), "eth2addr", ...
4417 If the network interface stores some valid MAC address (for instance
4418 in SROM), this is used as default address if there is NO correspon-
4419 ding setting in the environment; if the corresponding environment
4420 variable is set, this overrides the settings in the card; that means:
4422 o If the SROM has a valid MAC address, and there is no address in the
4423 environment, the SROM's address is used.
4425 o If there is no valid address in the SROM, and a definition in the
4426 environment exists, then the value from the environment variable is
4429 o If both the SROM and the environment contain a MAC address, and
4430 both addresses are the same, this MAC address is used.
4432 o If both the SROM and the environment contain a MAC address, and the
4433 addresses differ, the value from the environment is used and a
4436 o If neither SROM nor the environment contain a MAC address, an error
4439 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4440 will be programmed into hardware as part of the initialization process. This
4441 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4442 The naming convention is as follows:
4443 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4448 U-Boot is capable of booting (and performing other auxiliary operations on)
4449 images in two formats:
4451 New uImage format (FIT)
4452 -----------------------
4454 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4455 to Flattened Device Tree). It allows the use of images with multiple
4456 components (several kernels, ramdisks, etc.), with contents protected by
4457 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4463 Old image format is based on binary files which can be basically anything,
4464 preceded by a special header; see the definitions in include/image.h for
4465 details; basically, the header defines the following image properties:
4467 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4468 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4469 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4470 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4472 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4473 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4474 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4475 * Compression Type (uncompressed, gzip, bzip2)
4481 The header is marked by a special Magic Number, and both the header
4482 and the data portions of the image are secured against corruption by
4489 Although U-Boot should support any OS or standalone application
4490 easily, the main focus has always been on Linux during the design of
4493 U-Boot includes many features that so far have been part of some
4494 special "boot loader" code within the Linux kernel. Also, any
4495 "initrd" images to be used are no longer part of one big Linux image;
4496 instead, kernel and "initrd" are separate images. This implementation
4497 serves several purposes:
4499 - the same features can be used for other OS or standalone
4500 applications (for instance: using compressed images to reduce the
4501 Flash memory footprint)
4503 - it becomes much easier to port new Linux kernel versions because
4504 lots of low-level, hardware dependent stuff are done by U-Boot
4506 - the same Linux kernel image can now be used with different "initrd"
4507 images; of course this also means that different kernel images can
4508 be run with the same "initrd". This makes testing easier (you don't
4509 have to build a new "zImage.initrd" Linux image when you just
4510 change a file in your "initrd"). Also, a field-upgrade of the
4511 software is easier now.
4517 Porting Linux to U-Boot based systems:
4518 ---------------------------------------
4520 U-Boot cannot save you from doing all the necessary modifications to
4521 configure the Linux device drivers for use with your target hardware
4522 (no, we don't intend to provide a full virtual machine interface to
4525 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4527 Just make sure your machine specific header file (for instance
4528 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4529 Information structure as we define in include/asm-<arch>/u-boot.h,
4530 and make sure that your definition of IMAP_ADDR uses the same value
4531 as your U-Boot configuration in CONFIG_SYS_IMMR.
4534 Configuring the Linux kernel:
4535 -----------------------------
4537 No specific requirements for U-Boot. Make sure you have some root
4538 device (initial ramdisk, NFS) for your target system.
4541 Building a Linux Image:
4542 -----------------------
4544 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4545 not used. If you use recent kernel source, a new build target
4546 "uImage" will exist which automatically builds an image usable by
4547 U-Boot. Most older kernels also have support for a "pImage" target,
4548 which was introduced for our predecessor project PPCBoot and uses a
4549 100% compatible format.
4558 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4559 encapsulate a compressed Linux kernel image with header information,
4560 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4562 * build a standard "vmlinux" kernel image (in ELF binary format):
4564 * convert the kernel into a raw binary image:
4566 ${CROSS_COMPILE}-objcopy -O binary \
4567 -R .note -R .comment \
4568 -S vmlinux linux.bin
4570 * compress the binary image:
4574 * package compressed binary image for U-Boot:
4576 mkimage -A ppc -O linux -T kernel -C gzip \
4577 -a 0 -e 0 -n "Linux Kernel Image" \
4578 -d linux.bin.gz uImage
4581 The "mkimage" tool can also be used to create ramdisk images for use
4582 with U-Boot, either separated from the Linux kernel image, or
4583 combined into one file. "mkimage" encapsulates the images with a 64
4584 byte header containing information about target architecture,
4585 operating system, image type, compression method, entry points, time
4586 stamp, CRC32 checksums, etc.
4588 "mkimage" can be called in two ways: to verify existing images and
4589 print the header information, or to build new images.
4591 In the first form (with "-l" option) mkimage lists the information
4592 contained in the header of an existing U-Boot image; this includes
4593 checksum verification:
4595 tools/mkimage -l image
4596 -l ==> list image header information
4598 The second form (with "-d" option) is used to build a U-Boot image
4599 from a "data file" which is used as image payload:
4601 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4602 -n name -d data_file image
4603 -A ==> set architecture to 'arch'
4604 -O ==> set operating system to 'os'
4605 -T ==> set image type to 'type'
4606 -C ==> set compression type 'comp'
4607 -a ==> set load address to 'addr' (hex)
4608 -e ==> set entry point to 'ep' (hex)
4609 -n ==> set image name to 'name'
4610 -d ==> use image data from 'datafile'
4612 Right now, all Linux kernels for PowerPC systems use the same load
4613 address (0x00000000), but the entry point address depends on the
4616 - 2.2.x kernels have the entry point at 0x0000000C,
4617 - 2.3.x and later kernels have the entry point at 0x00000000.
4619 So a typical call to build a U-Boot image would read:
4621 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4622 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4623 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4624 > examples/uImage.TQM850L
4625 Image Name: 2.4.4 kernel for TQM850L
4626 Created: Wed Jul 19 02:34:59 2000
4627 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4628 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4629 Load Address: 0x00000000
4630 Entry Point: 0x00000000
4632 To verify the contents of the image (or check for corruption):
4634 -> tools/mkimage -l examples/uImage.TQM850L
4635 Image Name: 2.4.4 kernel for TQM850L
4636 Created: Wed Jul 19 02:34:59 2000
4637 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4638 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4639 Load Address: 0x00000000
4640 Entry Point: 0x00000000
4642 NOTE: for embedded systems where boot time is critical you can trade
4643 speed for memory and install an UNCOMPRESSED image instead: this
4644 needs more space in Flash, but boots much faster since it does not
4645 need to be uncompressed:
4647 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4648 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4649 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4650 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4651 > examples/uImage.TQM850L-uncompressed
4652 Image Name: 2.4.4 kernel for TQM850L
4653 Created: Wed Jul 19 02:34:59 2000
4654 Image Type: PowerPC Linux Kernel Image (uncompressed)
4655 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4656 Load Address: 0x00000000
4657 Entry Point: 0x00000000
4660 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4661 when your kernel is intended to use an initial ramdisk:
4663 -> tools/mkimage -n 'Simple Ramdisk Image' \
4664 > -A ppc -O linux -T ramdisk -C gzip \
4665 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4666 Image Name: Simple Ramdisk Image
4667 Created: Wed Jan 12 14:01:50 2000
4668 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4669 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4670 Load Address: 0x00000000
4671 Entry Point: 0x00000000
4674 Installing a Linux Image:
4675 -------------------------
4677 To downloading a U-Boot image over the serial (console) interface,
4678 you must convert the image to S-Record format:
4680 objcopy -I binary -O srec examples/image examples/image.srec
4682 The 'objcopy' does not understand the information in the U-Boot
4683 image header, so the resulting S-Record file will be relative to
4684 address 0x00000000. To load it to a given address, you need to
4685 specify the target address as 'offset' parameter with the 'loads'
4688 Example: install the image to address 0x40100000 (which on the
4689 TQM8xxL is in the first Flash bank):
4691 => erase 40100000 401FFFFF
4697 ## Ready for S-Record download ...
4698 ~>examples/image.srec
4699 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4701 15989 15990 15991 15992
4702 [file transfer complete]
4704 ## Start Addr = 0x00000000
4707 You can check the success of the download using the 'iminfo' command;
4708 this includes a checksum verification so you can be sure no data
4709 corruption happened:
4713 ## Checking Image at 40100000 ...
4714 Image Name: 2.2.13 for initrd on TQM850L
4715 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4716 Data Size: 335725 Bytes = 327 kB = 0 MB
4717 Load Address: 00000000
4718 Entry Point: 0000000c
4719 Verifying Checksum ... OK
4725 The "bootm" command is used to boot an application that is stored in
4726 memory (RAM or Flash). In case of a Linux kernel image, the contents
4727 of the "bootargs" environment variable is passed to the kernel as
4728 parameters. You can check and modify this variable using the
4729 "printenv" and "setenv" commands:
4732 => printenv bootargs
4733 bootargs=root=/dev/ram
4735 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4737 => printenv bootargs
4738 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4741 ## Booting Linux kernel at 40020000 ...
4742 Image Name: 2.2.13 for NFS on TQM850L
4743 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4744 Data Size: 381681 Bytes = 372 kB = 0 MB
4745 Load Address: 00000000
4746 Entry Point: 0000000c
4747 Verifying Checksum ... OK
4748 Uncompressing Kernel Image ... OK
4749 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
4750 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4751 time_init: decrementer frequency = 187500000/60
4752 Calibrating delay loop... 49.77 BogoMIPS
4753 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
4756 If you want to boot a Linux kernel with initial RAM disk, you pass
4757 the memory addresses of both the kernel and the initrd image (PPBCOOT
4758 format!) to the "bootm" command:
4760 => imi 40100000 40200000
4762 ## Checking Image at 40100000 ...
4763 Image Name: 2.2.13 for initrd on TQM850L
4764 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4765 Data Size: 335725 Bytes = 327 kB = 0 MB
4766 Load Address: 00000000
4767 Entry Point: 0000000c
4768 Verifying Checksum ... OK
4770 ## Checking Image at 40200000 ...
4771 Image Name: Simple Ramdisk Image
4772 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4773 Data Size: 566530 Bytes = 553 kB = 0 MB
4774 Load Address: 00000000
4775 Entry Point: 00000000
4776 Verifying Checksum ... OK
4778 => bootm 40100000 40200000
4779 ## Booting Linux kernel at 40100000 ...
4780 Image Name: 2.2.13 for initrd on TQM850L
4781 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4782 Data Size: 335725 Bytes = 327 kB = 0 MB
4783 Load Address: 00000000
4784 Entry Point: 0000000c
4785 Verifying Checksum ... OK
4786 Uncompressing Kernel Image ... OK
4787 ## Loading RAMDisk Image at 40200000 ...
4788 Image Name: Simple Ramdisk Image
4789 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4790 Data Size: 566530 Bytes = 553 kB = 0 MB
4791 Load Address: 00000000
4792 Entry Point: 00000000
4793 Verifying Checksum ... OK
4794 Loading Ramdisk ... OK
4795 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
4796 Boot arguments: root=/dev/ram
4797 time_init: decrementer frequency = 187500000/60
4798 Calibrating delay loop... 49.77 BogoMIPS
4800 RAMDISK: Compressed image found at block 0
4801 VFS: Mounted root (ext2 filesystem).
4805 Boot Linux and pass a flat device tree:
4808 First, U-Boot must be compiled with the appropriate defines. See the section
4809 titled "Linux Kernel Interface" above for a more in depth explanation. The
4810 following is an example of how to start a kernel and pass an updated
4816 oft=oftrees/mpc8540ads.dtb
4817 => tftp $oftaddr $oft
4818 Speed: 1000, full duplex
4820 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4821 Filename 'oftrees/mpc8540ads.dtb'.
4822 Load address: 0x300000
4825 Bytes transferred = 4106 (100a hex)
4826 => tftp $loadaddr $bootfile
4827 Speed: 1000, full duplex
4829 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4831 Load address: 0x200000
4832 Loading:############
4834 Bytes transferred = 1029407 (fb51f hex)
4839 => bootm $loadaddr - $oftaddr
4840 ## Booting image at 00200000 ...
4841 Image Name: Linux-2.6.17-dirty
4842 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4843 Data Size: 1029343 Bytes = 1005.2 kB
4844 Load Address: 00000000
4845 Entry Point: 00000000
4846 Verifying Checksum ... OK
4847 Uncompressing Kernel Image ... OK
4848 Booting using flat device tree at 0x300000
4849 Using MPC85xx ADS machine description
4850 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4854 More About U-Boot Image Types:
4855 ------------------------------
4857 U-Boot supports the following image types:
4859 "Standalone Programs" are directly runnable in the environment
4860 provided by U-Boot; it is expected that (if they behave
4861 well) you can continue to work in U-Boot after return from
4862 the Standalone Program.
4863 "OS Kernel Images" are usually images of some Embedded OS which
4864 will take over control completely. Usually these programs
4865 will install their own set of exception handlers, device
4866 drivers, set up the MMU, etc. - this means, that you cannot
4867 expect to re-enter U-Boot except by resetting the CPU.
4868 "RAMDisk Images" are more or less just data blocks, and their
4869 parameters (address, size) are passed to an OS kernel that is
4871 "Multi-File Images" contain several images, typically an OS
4872 (Linux) kernel image and one or more data images like
4873 RAMDisks. This construct is useful for instance when you want
4874 to boot over the network using BOOTP etc., where the boot
4875 server provides just a single image file, but you want to get
4876 for instance an OS kernel and a RAMDisk image.
4878 "Multi-File Images" start with a list of image sizes, each
4879 image size (in bytes) specified by an "uint32_t" in network
4880 byte order. This list is terminated by an "(uint32_t)0".
4881 Immediately after the terminating 0 follow the images, one by
4882 one, all aligned on "uint32_t" boundaries (size rounded up to
4883 a multiple of 4 bytes).
4885 "Firmware Images" are binary images containing firmware (like
4886 U-Boot or FPGA images) which usually will be programmed to
4889 "Script files" are command sequences that will be executed by
4890 U-Boot's command interpreter; this feature is especially
4891 useful when you configure U-Boot to use a real shell (hush)
4892 as command interpreter.
4894 Booting the Linux zImage:
4895 -------------------------
4897 On some platforms, it's possible to boot Linux zImage. This is done
4898 using the "bootz" command. The syntax of "bootz" command is the same
4899 as the syntax of "bootm" command.
4901 Note, defining the CONFIG_SUPPORT_INITRD_RAW allows user to supply
4902 kernel with raw initrd images. The syntax is slightly different, the
4903 address of the initrd must be augmented by it's size, in the following
4904 format: "<initrd addres>:<initrd size>".
4910 One of the features of U-Boot is that you can dynamically load and
4911 run "standalone" applications, which can use some resources of
4912 U-Boot like console I/O functions or interrupt services.
4914 Two simple examples are included with the sources:
4919 'examples/hello_world.c' contains a small "Hello World" Demo
4920 application; it is automatically compiled when you build U-Boot.
4921 It's configured to run at address 0x00040004, so you can play with it
4925 ## Ready for S-Record download ...
4926 ~>examples/hello_world.srec
4927 1 2 3 4 5 6 7 8 9 10 11 ...
4928 [file transfer complete]
4930 ## Start Addr = 0x00040004
4932 => go 40004 Hello World! This is a test.
4933 ## Starting application at 0x00040004 ...
4944 Hit any key to exit ...
4946 ## Application terminated, rc = 0x0
4948 Another example, which demonstrates how to register a CPM interrupt
4949 handler with the U-Boot code, can be found in 'examples/timer.c'.
4950 Here, a CPM timer is set up to generate an interrupt every second.
4951 The interrupt service routine is trivial, just printing a '.'
4952 character, but this is just a demo program. The application can be
4953 controlled by the following keys:
4955 ? - print current values og the CPM Timer registers
4956 b - enable interrupts and start timer
4957 e - stop timer and disable interrupts
4958 q - quit application
4961 ## Ready for S-Record download ...
4962 ~>examples/timer.srec
4963 1 2 3 4 5 6 7 8 9 10 11 ...
4964 [file transfer complete]
4966 ## Start Addr = 0x00040004
4969 ## Starting application at 0x00040004 ...
4972 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
4975 [q, b, e, ?] Set interval 1000000 us
4978 [q, b, e, ?] ........
4979 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
4982 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
4985 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
4988 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
4990 [q, b, e, ?] ...Stopping timer
4992 [q, b, e, ?] ## Application terminated, rc = 0x0
4998 Over time, many people have reported problems when trying to use the
4999 "minicom" terminal emulation program for serial download. I (wd)
5000 consider minicom to be broken, and recommend not to use it. Under
5001 Unix, I recommend to use C-Kermit for general purpose use (and
5002 especially for kermit binary protocol download ("loadb" command), and
5003 use "cu" for S-Record download ("loads" command). See
5004 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5005 for help with kermit.
5008 Nevertheless, if you absolutely want to use it try adding this
5009 configuration to your "File transfer protocols" section:
5011 Name Program Name U/D FullScr IO-Red. Multi
5012 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5013 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5019 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5020 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5022 Building requires a cross environment; it is known to work on
5023 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5024 need gmake since the Makefiles are not compatible with BSD make).
5025 Note that the cross-powerpc package does not install include files;
5026 attempting to build U-Boot will fail because <machine/ansi.h> is
5027 missing. This file has to be installed and patched manually:
5029 # cd /usr/pkg/cross/powerpc-netbsd/include
5031 # ln -s powerpc machine
5032 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5033 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5035 Native builds *don't* work due to incompatibilities between native
5036 and U-Boot include files.
5038 Booting assumes that (the first part of) the image booted is a
5039 stage-2 loader which in turn loads and then invokes the kernel
5040 proper. Loader sources will eventually appear in the NetBSD source
5041 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5042 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5045 Implementation Internals:
5046 =========================
5048 The following is not intended to be a complete description of every
5049 implementation detail. However, it should help to understand the
5050 inner workings of U-Boot and make it easier to port it to custom
5054 Initial Stack, Global Data:
5055 ---------------------------
5057 The implementation of U-Boot is complicated by the fact that U-Boot
5058 starts running out of ROM (flash memory), usually without access to
5059 system RAM (because the memory controller is not initialized yet).
5060 This means that we don't have writable Data or BSS segments, and BSS
5061 is not initialized as zero. To be able to get a C environment working
5062 at all, we have to allocate at least a minimal stack. Implementation
5063 options for this are defined and restricted by the CPU used: Some CPU
5064 models provide on-chip memory (like the IMMR area on MPC8xx and
5065 MPC826x processors), on others (parts of) the data cache can be
5066 locked as (mis-) used as memory, etc.
5068 Chris Hallinan posted a good summary of these issues to the
5069 U-Boot mailing list:
5071 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5072 From: "Chris Hallinan" <clh@net1plus.com>
5073 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5076 Correct me if I'm wrong, folks, but the way I understand it
5077 is this: Using DCACHE as initial RAM for Stack, etc, does not
5078 require any physical RAM backing up the cache. The cleverness
5079 is that the cache is being used as a temporary supply of
5080 necessary storage before the SDRAM controller is setup. It's
5081 beyond the scope of this list to explain the details, but you
5082 can see how this works by studying the cache architecture and
5083 operation in the architecture and processor-specific manuals.
5085 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5086 is another option for the system designer to use as an
5087 initial stack/RAM area prior to SDRAM being available. Either
5088 option should work for you. Using CS 4 should be fine if your
5089 board designers haven't used it for something that would
5090 cause you grief during the initial boot! It is frequently not
5093 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5094 with your processor/board/system design. The default value
5095 you will find in any recent u-boot distribution in
5096 walnut.h should work for you. I'd set it to a value larger
5097 than your SDRAM module. If you have a 64MB SDRAM module, set
5098 it above 400_0000. Just make sure your board has no resources
5099 that are supposed to respond to that address! That code in
5100 start.S has been around a while and should work as is when
5101 you get the config right.
5106 It is essential to remember this, since it has some impact on the C
5107 code for the initialization procedures:
5109 * Initialized global data (data segment) is read-only. Do not attempt
5112 * Do not use any uninitialized global data (or implicitely initialized
5113 as zero data - BSS segment) at all - this is undefined, initiali-
5114 zation is performed later (when relocating to RAM).
5116 * Stack space is very limited. Avoid big data buffers or things like
5119 Having only the stack as writable memory limits means we cannot use
5120 normal global data to share information beween the code. But it
5121 turned out that the implementation of U-Boot can be greatly
5122 simplified by making a global data structure (gd_t) available to all
5123 functions. We could pass a pointer to this data as argument to _all_
5124 functions, but this would bloat the code. Instead we use a feature of
5125 the GCC compiler (Global Register Variables) to share the data: we
5126 place a pointer (gd) to the global data into a register which we
5127 reserve for this purpose.
5129 When choosing a register for such a purpose we are restricted by the
5130 relevant (E)ABI specifications for the current architecture, and by
5131 GCC's implementation.
5133 For PowerPC, the following registers have specific use:
5135 R2: reserved for system use
5136 R3-R4: parameter passing and return values
5137 R5-R10: parameter passing
5138 R13: small data area pointer
5142 (U-Boot also uses R12 as internal GOT pointer. r12
5143 is a volatile register so r12 needs to be reset when
5144 going back and forth between asm and C)
5146 ==> U-Boot will use R2 to hold a pointer to the global data
5148 Note: on PPC, we could use a static initializer (since the
5149 address of the global data structure is known at compile time),
5150 but it turned out that reserving a register results in somewhat
5151 smaller code - although the code savings are not that big (on
5152 average for all boards 752 bytes for the whole U-Boot image,
5153 624 text + 127 data).
5155 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5156 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5158 ==> U-Boot will use P3 to hold a pointer to the global data
5160 On ARM, the following registers are used:
5162 R0: function argument word/integer result
5163 R1-R3: function argument word
5165 R10: stack limit (used only if stack checking if enabled)
5166 R11: argument (frame) pointer
5167 R12: temporary workspace
5170 R15: program counter
5172 ==> U-Boot will use R8 to hold a pointer to the global data
5174 On Nios II, the ABI is documented here:
5175 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5177 ==> U-Boot will use gp to hold a pointer to the global data
5179 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5180 to access small data sections, so gp is free.
5182 On NDS32, the following registers are used:
5184 R0-R1: argument/return
5186 R15: temporary register for assembler
5187 R16: trampoline register
5188 R28: frame pointer (FP)
5189 R29: global pointer (GP)
5190 R30: link register (LP)
5191 R31: stack pointer (SP)
5192 PC: program counter (PC)
5194 ==> U-Boot will use R10 to hold a pointer to the global data
5196 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5197 or current versions of GCC may "optimize" the code too much.
5202 U-Boot runs in system state and uses physical addresses, i.e. the
5203 MMU is not used either for address mapping nor for memory protection.
5205 The available memory is mapped to fixed addresses using the memory
5206 controller. In this process, a contiguous block is formed for each
5207 memory type (Flash, SDRAM, SRAM), even when it consists of several
5208 physical memory banks.
5210 U-Boot is installed in the first 128 kB of the first Flash bank (on
5211 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5212 booting and sizing and initializing DRAM, the code relocates itself
5213 to the upper end of DRAM. Immediately below the U-Boot code some
5214 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5215 configuration setting]. Below that, a structure with global Board
5216 Info data is placed, followed by the stack (growing downward).
5218 Additionally, some exception handler code is copied to the low 8 kB
5219 of DRAM (0x00000000 ... 0x00001FFF).
5221 So a typical memory configuration with 16 MB of DRAM could look like
5224 0x0000 0000 Exception Vector code
5227 0x0000 2000 Free for Application Use
5233 0x00FB FF20 Monitor Stack (Growing downward)
5234 0x00FB FFAC Board Info Data and permanent copy of global data
5235 0x00FC 0000 Malloc Arena
5238 0x00FE 0000 RAM Copy of Monitor Code
5239 ... eventually: LCD or video framebuffer
5240 ... eventually: pRAM (Protected RAM - unchanged by reset)
5241 0x00FF FFFF [End of RAM]
5244 System Initialization:
5245 ----------------------
5247 In the reset configuration, U-Boot starts at the reset entry point
5248 (on most PowerPC systems at address 0x00000100). Because of the reset
5249 configuration for CS0# this is a mirror of the onboard Flash memory.
5250 To be able to re-map memory U-Boot then jumps to its link address.
5251 To be able to implement the initialization code in C, a (small!)
5252 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5253 which provide such a feature like MPC8xx or MPC8260), or in a locked
5254 part of the data cache. After that, U-Boot initializes the CPU core,
5255 the caches and the SIU.
5257 Next, all (potentially) available memory banks are mapped using a
5258 preliminary mapping. For example, we put them on 512 MB boundaries
5259 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5260 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5261 programmed for SDRAM access. Using the temporary configuration, a
5262 simple memory test is run that determines the size of the SDRAM
5265 When there is more than one SDRAM bank, and the banks are of
5266 different size, the largest is mapped first. For equal size, the first
5267 bank (CS2#) is mapped first. The first mapping is always for address
5268 0x00000000, with any additional banks following immediately to create
5269 contiguous memory starting from 0.
5271 Then, the monitor installs itself at the upper end of the SDRAM area
5272 and allocates memory for use by malloc() and for the global Board
5273 Info data; also, the exception vector code is copied to the low RAM
5274 pages, and the final stack is set up.
5276 Only after this relocation will you have a "normal" C environment;
5277 until that you are restricted in several ways, mostly because you are
5278 running from ROM, and because the code will have to be relocated to a
5282 U-Boot Porting Guide:
5283 ----------------------
5285 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5289 int main(int argc, char *argv[])
5291 sighandler_t no_more_time;
5293 signal(SIGALRM, no_more_time);
5294 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5296 if (available_money > available_manpower) {
5297 Pay consultant to port U-Boot;
5301 Download latest U-Boot source;
5303 Subscribe to u-boot mailing list;
5306 email("Hi, I am new to U-Boot, how do I get started?");
5309 Read the README file in the top level directory;
5310 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5311 Read applicable doc/*.README;
5312 Read the source, Luke;
5313 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5316 if (available_money > toLocalCurrency ($2500))
5319 Add a lot of aggravation and time;
5321 if (a similar board exists) { /* hopefully... */
5322 cp -a board/<similar> board/<myboard>
5323 cp include/configs/<similar>.h include/configs/<myboard>.h
5325 Create your own board support subdirectory;
5326 Create your own board include/configs/<myboard>.h file;
5328 Edit new board/<myboard> files
5329 Edit new include/configs/<myboard>.h
5334 Add / modify source code;
5338 email("Hi, I am having problems...");
5340 Send patch file to the U-Boot email list;
5341 if (reasonable critiques)
5342 Incorporate improvements from email list code review;
5344 Defend code as written;
5350 void no_more_time (int sig)
5359 All contributions to U-Boot should conform to the Linux kernel
5360 coding style; see the file "Documentation/CodingStyle" and the script
5361 "scripts/Lindent" in your Linux kernel source directory.
5363 Source files originating from a different project (for example the
5364 MTD subsystem) are generally exempt from these guidelines and are not
5365 reformated to ease subsequent migration to newer versions of those
5368 Please note that U-Boot is implemented in C (and to some small parts in
5369 Assembler); no C++ is used, so please do not use C++ style comments (//)
5372 Please also stick to the following formatting rules:
5373 - remove any trailing white space
5374 - use TAB characters for indentation and vertical alignment, not spaces
5375 - make sure NOT to use DOS '\r\n' line feeds
5376 - do not add more than 2 consecutive empty lines to source files
5377 - do not add trailing empty lines to source files
5379 Submissions which do not conform to the standards may be returned
5380 with a request to reformat the changes.
5386 Since the number of patches for U-Boot is growing, we need to
5387 establish some rules. Submissions which do not conform to these rules
5388 may be rejected, even when they contain important and valuable stuff.
5390 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5392 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5393 see http://lists.denx.de/mailman/listinfo/u-boot
5395 When you send a patch, please include the following information with
5398 * For bug fixes: a description of the bug and how your patch fixes
5399 this bug. Please try to include a way of demonstrating that the
5400 patch actually fixes something.
5402 * For new features: a description of the feature and your
5405 * A CHANGELOG entry as plaintext (separate from the patch)
5407 * For major contributions, your entry to the CREDITS file
5409 * When you add support for a new board, don't forget to add this
5410 board to the MAINTAINERS file, too.
5412 * If your patch adds new configuration options, don't forget to
5413 document these in the README file.
5415 * The patch itself. If you are using git (which is *strongly*
5416 recommended) you can easily generate the patch using the
5417 "git format-patch". If you then use "git send-email" to send it to
5418 the U-Boot mailing list, you will avoid most of the common problems
5419 with some other mail clients.
5421 If you cannot use git, use "diff -purN OLD NEW". If your version of
5422 diff does not support these options, then get the latest version of
5425 The current directory when running this command shall be the parent
5426 directory of the U-Boot source tree (i. e. please make sure that
5427 your patch includes sufficient directory information for the
5430 We prefer patches as plain text. MIME attachments are discouraged,
5431 and compressed attachments must not be used.
5433 * If one logical set of modifications affects or creates several
5434 files, all these changes shall be submitted in a SINGLE patch file.
5436 * Changesets that contain different, unrelated modifications shall be
5437 submitted as SEPARATE patches, one patch per changeset.
5442 * Before sending the patch, run the MAKEALL script on your patched
5443 source tree and make sure that no errors or warnings are reported
5444 for any of the boards.
5446 * Keep your modifications to the necessary minimum: A patch
5447 containing several unrelated changes or arbitrary reformats will be
5448 returned with a request to re-formatting / split it.
5450 * If you modify existing code, make sure that your new code does not
5451 add to the memory footprint of the code ;-) Small is beautiful!
5452 When adding new features, these should compile conditionally only
5453 (using #ifdef), and the resulting code with the new feature
5454 disabled must not need more memory than the old code without your
5457 * Remember that there is a size limit of 100 kB per message on the
5458 u-boot mailing list. Bigger patches will be moderated. If they are
5459 reasonable and not too big, they will be acknowledged. But patches
5460 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob