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 /mpc824x Files specific to Freescale MPC824x CPUs
205 /mpc8260 Files specific to Freescale MPC8260 CPUs
206 /mpc85xx Files specific to Freescale MPC85xx CPUs
207 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
208 /lib Architecture specific library files
209 /sh Files generic to SH architecture
210 /cpu CPU specific files
211 /sh2 Files specific to sh2 CPUs
212 /sh3 Files specific to sh3 CPUs
213 /sh4 Files specific to sh4 CPUs
214 /lib Architecture specific library files
215 /sparc Files generic to SPARC architecture
216 /cpu CPU specific files
217 /leon2 Files specific to Gaisler LEON2 SPARC CPU
218 /leon3 Files specific to Gaisler LEON3 SPARC CPU
219 /lib Architecture specific library files
220 /api Machine/arch independent API for external apps
221 /board Board dependent files
222 /common Misc architecture independent functions
223 /disk Code for disk drive partition handling
224 /doc Documentation (don't expect too much)
225 /drivers Commonly used device drivers
226 /examples Example code for standalone applications, etc.
227 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
228 /include Header Files
229 /lib Files generic to all architectures
230 /libfdt Library files to support flattened device trees
231 /lzma Library files to support LZMA decompression
232 /lzo Library files to support LZO decompression
234 /post Power On Self Test
235 /rtc Real Time Clock drivers
236 /tools Tools to build S-Record or U-Boot images, etc.
238 Software Configuration:
239 =======================
241 Configuration is usually done using C preprocessor defines; the
242 rationale behind that is to avoid dead code whenever possible.
244 There are two classes of configuration variables:
246 * Configuration _OPTIONS_:
247 These are selectable by the user and have names beginning with
250 * Configuration _SETTINGS_:
251 These depend on the hardware etc. and should not be meddled with if
252 you don't know what you're doing; they have names beginning with
255 Later we will add a configuration tool - probably similar to or even
256 identical to what's used for the Linux kernel. Right now, we have to
257 do the configuration by hand, which means creating some symbolic
258 links and editing some configuration files. We use the TQM8xxL boards
262 Selection of Processor Architecture and Board Type:
263 ---------------------------------------------------
265 For all supported boards there are ready-to-use default
266 configurations available; just type "make <board_name>_config".
268 Example: For a TQM823L module type:
273 For the Cogent platform, you need to specify the CPU type as well;
274 e.g. "make cogent_mpc8xx_config". And also configure the cogent
275 directory according to the instructions in cogent/README.
278 Configuration Options:
279 ----------------------
281 Configuration depends on the combination of board and CPU type; all
282 such information is kept in a configuration file
283 "include/configs/<board_name>.h".
285 Example: For a TQM823L module, all configuration settings are in
286 "include/configs/TQM823L.h".
289 Many of the options are named exactly as the corresponding Linux
290 kernel configuration options. The intention is to make it easier to
291 build a config tool - later.
294 The following options need to be configured:
296 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
298 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
300 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
301 Define exactly one, e.g. CONFIG_ATSTK1002
303 - CPU Module Type: (if CONFIG_COGENT is defined)
304 Define exactly one of
306 --- FIXME --- not tested yet:
307 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
308 CONFIG_CMA287_23, CONFIG_CMA287_50
310 - Motherboard Type: (if CONFIG_COGENT is defined)
311 Define exactly one of
312 CONFIG_CMA101, CONFIG_CMA102
314 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
315 Define one or more of
318 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
319 Define one or more of
320 CONFIG_LCD_HEARTBEAT - update a character position on
321 the LCD display every second with
324 - Board flavour: (if CONFIG_MPC8260ADS is defined)
327 CONFIG_SYS_8260ADS - original MPC8260ADS
328 CONFIG_SYS_8266ADS - MPC8266ADS
329 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
330 CONFIG_SYS_8272ADS - MPC8272ADS
332 - Marvell Family Member
333 CONFIG_SYS_MVFS - define it if you want to enable
334 multiple fs option at one time
335 for marvell soc family
337 - MPC824X Family Member (if CONFIG_MPC824X is defined)
338 Define exactly one of
339 CONFIG_MPC8240, CONFIG_MPC8245
341 - 8xx CPU Options: (if using an MPC8xx CPU)
342 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
343 get_gclk_freq() cannot work
344 e.g. if there is no 32KHz
345 reference PIT/RTC clock
346 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
349 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
350 CONFIG_SYS_8xx_CPUCLK_MIN
351 CONFIG_SYS_8xx_CPUCLK_MAX
352 CONFIG_8xx_CPUCLK_DEFAULT
353 See doc/README.MPC866
355 CONFIG_SYS_MEASURE_CPUCLK
357 Define this to measure the actual CPU clock instead
358 of relying on the correctness of the configured
359 values. Mostly useful for board bringup to make sure
360 the PLL is locked at the intended frequency. Note
361 that this requires a (stable) reference clock (32 kHz
362 RTC clock or CONFIG_SYS_8XX_XIN)
364 CONFIG_SYS_DELAYED_ICACHE
366 Define this option if you want to enable the
367 ICache only when Code runs from RAM.
372 Specifies that the core is a 64-bit PowerPC implementation (implements
373 the "64" category of the Power ISA). This is necessary for ePAPR
374 compliance, among other possible reasons.
376 CONFIG_SYS_FSL_TBCLK_DIV
378 Defines the core time base clock divider ratio compared to the
379 system clock. On most PQ3 devices this is 8, on newer QorIQ
380 devices it can be 16 or 32. The ratio varies from SoC to Soc.
382 CONFIG_SYS_FSL_PCIE_COMPAT
384 Defines the string to utilize when trying to match PCIe device
385 tree nodes for the given platform.
387 CONFIG_SYS_PPC_E500_DEBUG_TLB
389 Enables a temporary TLB entry to be used during boot to work
390 around limitations in e500v1 and e500v2 external debugger
391 support. This reduces the portions of the boot code where
392 breakpoints and single stepping do not work. The value of this
393 symbol should be set to the TLB1 entry to be used for this
396 CONFIG_SYS_FSL_ERRATUM_A004510
398 Enables a workaround for erratum A004510. If set,
399 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
400 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
402 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
403 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
405 Defines one or two SoC revisions (low 8 bits of SVR)
406 for which the A004510 workaround should be applied.
408 The rest of SVR is either not relevant to the decision
409 of whether the erratum is present (e.g. p2040 versus
410 p2041) or is implied by the build target, which controls
411 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
413 See Freescale App Note 4493 for more information about
416 CONFIG_A003399_NOR_WORKAROUND
417 Enables a workaround for IFC erratum A003399. It is only
418 requred during NOR boot.
420 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
422 This is the value to write into CCSR offset 0x18600
423 according to the A004510 workaround.
425 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
426 This value denotes start offset of M2 memory
427 which is directly connected to the DSP core.
429 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
430 This value denotes start offset of DSP CCSR space.
432 - Generic CPU options:
433 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
435 Defines the endianess of the CPU. Implementation of those
436 values is arch specific.
438 - Intel Monahans options:
439 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
441 Defines the Monahans run mode to oscillator
442 ratio. Valid values are 8, 16, 24, 31. The core
443 frequency is this value multiplied by 13 MHz.
445 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
447 Defines the Monahans turbo mode to oscillator
448 ratio. Valid values are 1 (default if undefined) and
449 2. The core frequency as calculated above is multiplied
453 CONFIG_SYS_INIT_SP_OFFSET
455 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
456 pointer. This is needed for the temporary stack before
459 CONFIG_SYS_MIPS_CACHE_MODE
461 Cache operation mode for the MIPS CPU.
462 See also arch/mips/include/asm/mipsregs.h.
464 CONF_CM_CACHABLE_NO_WA
467 CONF_CM_CACHABLE_NONCOHERENT
471 CONF_CM_CACHABLE_ACCELERATED
473 CONFIG_SYS_XWAY_EBU_BOOTCFG
475 Special option for Lantiq XWAY SoCs for booting from NOR flash.
476 See also arch/mips/cpu/mips32/start.S.
478 CONFIG_XWAY_SWAP_BYTES
480 Enable compilation of tools/xway-swap-bytes needed for Lantiq
481 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
482 be swapped if a flash programmer is used.
485 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
487 Select high exception vectors of the ARM core, e.g., do not
488 clear the V bit of the c1 register of CP15.
490 CONFIG_SYS_THUMB_BUILD
492 Use this flag to build U-Boot using the Thumb instruction
493 set for ARM architectures. Thumb instruction set provides
494 better code density. For ARM architectures that support
495 Thumb2 this flag will result in Thumb2 code generated by
498 CONFIG_ARM_ERRATA_716044
499 CONFIG_ARM_ERRATA_742230
500 CONFIG_ARM_ERRATA_743622
501 CONFIG_ARM_ERRATA_751472
503 If set, the workarounds for these ARM errata are applied early
504 during U-Boot startup. Note that these options force the
505 workarounds to be applied; no CPU-type/version detection
506 exists, unlike the similar options in the Linux kernel. Do not
507 set these options unless they apply!
512 The frequency of the timer returned by get_timer().
513 get_timer() must operate in milliseconds and this CONFIG
514 option must be set to 1000.
516 - Linux Kernel Interface:
519 U-Boot stores all clock information in Hz
520 internally. For binary compatibility with older Linux
521 kernels (which expect the clocks passed in the
522 bd_info data to be in MHz) the environment variable
523 "clocks_in_mhz" can be defined so that U-Boot
524 converts clock data to MHZ before passing it to the
526 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
527 "clocks_in_mhz=1" is automatically included in the
530 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
532 When transferring memsize parameter to linux, some versions
533 expect it to be in bytes, others in MB.
534 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
538 New kernel versions are expecting firmware settings to be
539 passed using flattened device trees (based on open firmware
543 * New libfdt-based support
544 * Adds the "fdt" command
545 * The bootm command automatically updates the fdt
547 OF_CPU - The proper name of the cpus node (only required for
548 MPC512X and MPC5xxx based boards).
549 OF_SOC - The proper name of the soc node (only required for
550 MPC512X and MPC5xxx based boards).
551 OF_TBCLK - The timebase frequency.
552 OF_STDOUT_PATH - The path to the console device
554 boards with QUICC Engines require OF_QE to set UCC MAC
557 CONFIG_OF_BOARD_SETUP
559 Board code has addition modification that it wants to make
560 to the flat device tree before handing it off to the kernel
564 This define fills in the correct boot CPU in the boot
565 param header, the default value is zero if undefined.
569 U-Boot can detect if an IDE device is present or not.
570 If not, and this new config option is activated, U-Boot
571 removes the ATA node from the DTS before booting Linux,
572 so the Linux IDE driver does not probe the device and
573 crash. This is needed for buggy hardware (uc101) where
574 no pull down resistor is connected to the signal IDE5V_DD7.
576 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
578 This setting is mandatory for all boards that have only one
579 machine type and must be used to specify the machine type
580 number as it appears in the ARM machine registry
581 (see http://www.arm.linux.org.uk/developer/machines/).
582 Only boards that have multiple machine types supported
583 in a single configuration file and the machine type is
584 runtime discoverable, do not have to use this setting.
586 - vxWorks boot parameters:
588 bootvx constructs a valid bootline using the following
589 environments variables: bootfile, ipaddr, serverip, hostname.
590 It loads the vxWorks image pointed bootfile.
592 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
593 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
594 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
595 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
597 CONFIG_SYS_VXWORKS_ADD_PARAMS
599 Add it at the end of the bootline. E.g "u=username pw=secret"
601 Note: If a "bootargs" environment is defined, it will overwride
602 the defaults discussed just above.
604 - Cache Configuration:
605 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
606 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
607 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
609 - Cache Configuration for ARM:
610 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
612 CONFIG_SYS_PL310_BASE - Physical base address of PL310
613 controller register space
618 Define this if you want support for Amba PrimeCell PL010 UARTs.
622 Define this if you want support for Amba PrimeCell PL011 UARTs.
626 If you have Amba PrimeCell PL011 UARTs, set this variable to
627 the clock speed of the UARTs.
631 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
632 define this to a list of base addresses for each (supported)
633 port. See e.g. include/configs/versatile.h
635 CONFIG_PL011_SERIAL_RLCR
637 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
638 have separate receive and transmit line control registers. Set
639 this variable to initialize the extra register.
641 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
643 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
644 boot loader that has already initialized the UART. Define this
645 variable to flush the UART at init time.
649 Depending on board, define exactly one serial port
650 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
651 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
652 console by defining CONFIG_8xx_CONS_NONE
654 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
655 port routines must be defined elsewhere
656 (i.e. serial_init(), serial_getc(), ...)
659 Enables console device for a color framebuffer. Needs following
660 defines (cf. smiLynxEM, i8042)
661 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
663 VIDEO_HW_RECTFILL graphic chip supports
666 VIDEO_HW_BITBLT graphic chip supports
667 bit-blit (cf. smiLynxEM)
668 VIDEO_VISIBLE_COLS visible pixel columns
670 VIDEO_VISIBLE_ROWS visible pixel rows
671 VIDEO_PIXEL_SIZE bytes per pixel
672 VIDEO_DATA_FORMAT graphic data format
673 (0-5, cf. cfb_console.c)
674 VIDEO_FB_ADRS framebuffer address
675 VIDEO_KBD_INIT_FCT keyboard int fct
676 (i.e. i8042_kbd_init())
677 VIDEO_TSTC_FCT test char fct
679 VIDEO_GETC_FCT get char fct
681 CONFIG_CONSOLE_CURSOR cursor drawing on/off
682 (requires blink timer
684 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
685 CONFIG_CONSOLE_TIME display time/date info in
687 (requires CONFIG_CMD_DATE)
688 CONFIG_VIDEO_LOGO display Linux logo in
690 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
691 linux_logo.h for logo.
692 Requires CONFIG_VIDEO_LOGO
693 CONFIG_CONSOLE_EXTRA_INFO
694 additional board info beside
697 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
698 a limited number of ANSI escape sequences (cursor control,
699 erase functions and limited graphics rendition control).
701 When CONFIG_CFB_CONSOLE is defined, video console is
702 default i/o. Serial console can be forced with
703 environment 'console=serial'.
705 When CONFIG_SILENT_CONSOLE is defined, all console
706 messages (by U-Boot and Linux!) can be silenced with
707 the "silent" environment variable. See
708 doc/README.silent for more information.
711 CONFIG_BAUDRATE - in bps
712 Select one of the baudrates listed in
713 CONFIG_SYS_BAUDRATE_TABLE, see below.
714 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
716 - Console Rx buffer length
717 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
718 the maximum receive buffer length for the SMC.
719 This option is actual only for 82xx and 8xx possible.
720 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
721 must be defined, to setup the maximum idle timeout for
724 - Pre-Console Buffer:
725 Prior to the console being initialised (i.e. serial UART
726 initialised etc) all console output is silently discarded.
727 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
728 buffer any console messages prior to the console being
729 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
730 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
731 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
732 bytes are output before the console is initialised, the
733 earlier bytes are discarded.
735 'Sane' compilers will generate smaller code if
736 CONFIG_PRE_CON_BUF_SZ is a power of 2
738 - Safe printf() functions
739 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
740 the printf() functions. These are defined in
741 include/vsprintf.h and include snprintf(), vsnprintf() and
742 so on. Code size increase is approximately 300-500 bytes.
743 If this option is not given then these functions will
744 silently discard their buffer size argument - this means
745 you are not getting any overflow checking in this case.
747 - Boot Delay: CONFIG_BOOTDELAY - in seconds
748 Delay before automatically booting the default image;
749 set to -1 to disable autoboot.
750 set to -2 to autoboot with no delay and not check for abort
751 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
753 See doc/README.autoboot for these options that
754 work with CONFIG_BOOTDELAY. None are required.
755 CONFIG_BOOT_RETRY_TIME
756 CONFIG_BOOT_RETRY_MIN
757 CONFIG_AUTOBOOT_KEYED
758 CONFIG_AUTOBOOT_PROMPT
759 CONFIG_AUTOBOOT_DELAY_STR
760 CONFIG_AUTOBOOT_STOP_STR
761 CONFIG_AUTOBOOT_DELAY_STR2
762 CONFIG_AUTOBOOT_STOP_STR2
763 CONFIG_ZERO_BOOTDELAY_CHECK
764 CONFIG_RESET_TO_RETRY
768 Only needed when CONFIG_BOOTDELAY is enabled;
769 define a command string that is automatically executed
770 when no character is read on the console interface
771 within "Boot Delay" after reset.
774 This can be used to pass arguments to the bootm
775 command. The value of CONFIG_BOOTARGS goes into the
776 environment value "bootargs".
778 CONFIG_RAMBOOT and CONFIG_NFSBOOT
779 The value of these goes into the environment as
780 "ramboot" and "nfsboot" respectively, and can be used
781 as a convenience, when switching between booting from
787 When this option is #defined, the existence of the
788 environment variable "preboot" will be checked
789 immediately before starting the CONFIG_BOOTDELAY
790 countdown and/or running the auto-boot command resp.
791 entering interactive mode.
793 This feature is especially useful when "preboot" is
794 automatically generated or modified. For an example
795 see the LWMON board specific code: here "preboot" is
796 modified when the user holds down a certain
797 combination of keys on the (special) keyboard when
800 - Serial Download Echo Mode:
802 If defined to 1, all characters received during a
803 serial download (using the "loads" command) are
804 echoed back. This might be needed by some terminal
805 emulations (like "cu"), but may as well just take
806 time on others. This setting #define's the initial
807 value of the "loads_echo" environment variable.
809 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
811 Select one of the baudrates listed in
812 CONFIG_SYS_BAUDRATE_TABLE, see below.
815 Monitor commands can be included or excluded
816 from the build by using the #include files
817 <config_cmd_all.h> and #undef'ing unwanted
818 commands, or using <config_cmd_default.h>
819 and augmenting with additional #define's
822 The default command configuration includes all commands
823 except those marked below with a "*".
825 CONFIG_CMD_ASKENV * ask for env variable
826 CONFIG_CMD_BDI bdinfo
827 CONFIG_CMD_BEDBUG * Include BedBug Debugger
828 CONFIG_CMD_BMP * BMP support
829 CONFIG_CMD_BSP * Board specific commands
830 CONFIG_CMD_BOOTD bootd
831 CONFIG_CMD_CACHE * icache, dcache
832 CONFIG_CMD_CONSOLE coninfo
833 CONFIG_CMD_CRC32 * crc32
834 CONFIG_CMD_DATE * support for RTC, date/time...
835 CONFIG_CMD_DHCP * DHCP support
836 CONFIG_CMD_DIAG * Diagnostics
837 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
838 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
839 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
840 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
841 CONFIG_CMD_DTT * Digital Therm and Thermostat
842 CONFIG_CMD_ECHO echo arguments
843 CONFIG_CMD_EDITENV edit env variable
844 CONFIG_CMD_EEPROM * EEPROM read/write support
845 CONFIG_CMD_ELF * bootelf, bootvx
846 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
847 CONFIG_CMD_ENV_FLAGS * display details about env flags
848 CONFIG_CMD_EXPORTENV * export the environment
849 CONFIG_CMD_EXT2 * ext2 command support
850 CONFIG_CMD_EXT4 * ext4 command support
851 CONFIG_CMD_SAVEENV saveenv
852 CONFIG_CMD_FDC * Floppy Disk Support
853 CONFIG_CMD_FAT * FAT command support
854 CONFIG_CMD_FDOS * Dos diskette Support
855 CONFIG_CMD_FLASH flinfo, erase, protect
856 CONFIG_CMD_FPGA FPGA device initialization support
857 CONFIG_CMD_FUSE * Device fuse support
858 CONFIG_CMD_GETTIME * Get time since boot
859 CONFIG_CMD_GO * the 'go' command (exec code)
860 CONFIG_CMD_GREPENV * search environment
861 CONFIG_CMD_HASH * calculate hash / digest
862 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
863 CONFIG_CMD_I2C * I2C serial bus support
864 CONFIG_CMD_IDE * IDE harddisk support
865 CONFIG_CMD_IMI iminfo
866 CONFIG_CMD_IMLS List all images found in NOR flash
867 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
868 CONFIG_CMD_IMMAP * IMMR dump support
869 CONFIG_CMD_IMPORTENV * import an environment
870 CONFIG_CMD_INI * import data from an ini file into the env
871 CONFIG_CMD_IRQ * irqinfo
872 CONFIG_CMD_ITEST Integer/string test of 2 values
873 CONFIG_CMD_JFFS2 * JFFS2 Support
874 CONFIG_CMD_KGDB * kgdb
875 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
876 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
878 CONFIG_CMD_LOADB loadb
879 CONFIG_CMD_LOADS loads
880 CONFIG_CMD_MD5SUM * print md5 message digest
881 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
882 CONFIG_CMD_MEMINFO * Display detailed memory information
883 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
885 CONFIG_CMD_MEMTEST * mtest
886 CONFIG_CMD_MISC Misc functions like sleep etc
887 CONFIG_CMD_MMC * MMC memory mapped support
888 CONFIG_CMD_MII * MII utility commands
889 CONFIG_CMD_MTDPARTS * MTD partition support
890 CONFIG_CMD_NAND * NAND support
891 CONFIG_CMD_NET bootp, tftpboot, rarpboot
892 CONFIG_CMD_NFS NFS support
893 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
894 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
895 CONFIG_CMD_PCI * pciinfo
896 CONFIG_CMD_PCMCIA * PCMCIA support
897 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
899 CONFIG_CMD_PORTIO * Port I/O
900 CONFIG_CMD_READ * Read raw data from partition
901 CONFIG_CMD_REGINFO * Register dump
902 CONFIG_CMD_RUN run command in env variable
903 CONFIG_CMD_SANDBOX * sb command to access sandbox features
904 CONFIG_CMD_SAVES * save S record dump
905 CONFIG_CMD_SCSI * SCSI Support
906 CONFIG_CMD_SDRAM * print SDRAM configuration information
907 (requires CONFIG_CMD_I2C)
908 CONFIG_CMD_SETGETDCR Support for DCR Register access
910 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
911 CONFIG_CMD_SHA1SUM * print sha1 memory digest
912 (requires CONFIG_CMD_MEMORY)
913 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
914 CONFIG_CMD_SOURCE "source" command Support
915 CONFIG_CMD_SPI * SPI serial bus support
916 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
917 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
918 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
919 CONFIG_CMD_TIMER * access to the system tick timer
920 CONFIG_CMD_USB * USB support
921 CONFIG_CMD_CDP * Cisco Discover Protocol support
922 CONFIG_CMD_MFSL * Microblaze FSL support
923 CONFIG_CMD_XIMG Load part of Multi Image
926 EXAMPLE: If you want all functions except of network
927 support you can write:
929 #include "config_cmd_all.h"
930 #undef CONFIG_CMD_NET
933 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
935 Note: Don't enable the "icache" and "dcache" commands
936 (configuration option CONFIG_CMD_CACHE) unless you know
937 what you (and your U-Boot users) are doing. Data
938 cache cannot be enabled on systems like the 8xx or
939 8260 (where accesses to the IMMR region must be
940 uncached), and it cannot be disabled on all other
941 systems where we (mis-) use the data cache to hold an
942 initial stack and some data.
945 XXX - this list needs to get updated!
947 - Regular expression support:
949 If this variable is defined, U-Boot is linked against
950 the SLRE (Super Light Regular Expression) library,
951 which adds regex support to some commands, as for
952 example "env grep" and "setexpr".
956 If this variable is defined, U-Boot will use a device tree
957 to configure its devices, instead of relying on statically
958 compiled #defines in the board file. This option is
959 experimental and only available on a few boards. The device
960 tree is available in the global data as gd->fdt_blob.
962 U-Boot needs to get its device tree from somewhere. This can
963 be done using one of the two options below:
966 If this variable is defined, U-Boot will embed a device tree
967 binary in its image. This device tree file should be in the
968 board directory and called <soc>-<board>.dts. The binary file
969 is then picked up in board_init_f() and made available through
970 the global data structure as gd->blob.
973 If this variable is defined, U-Boot will build a device tree
974 binary. It will be called u-boot.dtb. Architecture-specific
975 code will locate it at run-time. Generally this works by:
977 cat u-boot.bin u-boot.dtb >image.bin
979 and in fact, U-Boot does this for you, creating a file called
980 u-boot-dtb.bin which is useful in the common case. You can
981 still use the individual files if you need something more
986 If this variable is defined, it enables watchdog
987 support for the SoC. There must be support in the SoC
988 specific code for a watchdog. For the 8xx and 8260
989 CPUs, the SIU Watchdog feature is enabled in the SYPCR
990 register. When supported for a specific SoC is
991 available, then no further board specific code should
995 When using a watchdog circuitry external to the used
996 SoC, then define this variable and provide board
997 specific code for the "hw_watchdog_reset" function.
1000 CONFIG_VERSION_VARIABLE
1001 If this variable is defined, an environment variable
1002 named "ver" is created by U-Boot showing the U-Boot
1003 version as printed by the "version" command.
1004 Any change to this variable will be reverted at the
1009 When CONFIG_CMD_DATE is selected, the type of the RTC
1010 has to be selected, too. Define exactly one of the
1013 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1014 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1015 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1016 CONFIG_RTC_MC146818 - use MC146818 RTC
1017 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1018 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1019 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1020 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1021 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1022 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1023 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1024 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1027 Note that if the RTC uses I2C, then the I2C interface
1028 must also be configured. See I2C Support, below.
1031 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1032 CONFIG_PCA953X_INFO - enable pca953x info command
1034 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1035 chip-ngpio pairs that tell the PCA953X driver the number of
1036 pins supported by a particular chip.
1038 Note that if the GPIO device uses I2C, then the I2C interface
1039 must also be configured. See I2C Support, below.
1041 - Timestamp Support:
1043 When CONFIG_TIMESTAMP is selected, the timestamp
1044 (date and time) of an image is printed by image
1045 commands like bootm or iminfo. This option is
1046 automatically enabled when you select CONFIG_CMD_DATE .
1048 - Partition Labels (disklabels) Supported:
1049 Zero or more of the following:
1050 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1051 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1052 Intel architecture, USB sticks, etc.
1053 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1054 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1055 bootloader. Note 2TB partition limit; see
1057 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1059 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1060 CONFIG_CMD_SCSI) you must configure support for at
1061 least one non-MTD partition type as well.
1064 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1065 board configurations files but used nowhere!
1067 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1068 be performed by calling the function
1069 ide_set_reset(int reset)
1070 which has to be defined in a board specific file
1075 Set this to enable ATAPI support.
1080 Set this to enable support for disks larger than 137GB
1081 Also look at CONFIG_SYS_64BIT_LBA.
1082 Whithout these , LBA48 support uses 32bit variables and will 'only'
1083 support disks up to 2.1TB.
1085 CONFIG_SYS_64BIT_LBA:
1086 When enabled, makes the IDE subsystem use 64bit sector addresses.
1090 At the moment only there is only support for the
1091 SYM53C8XX SCSI controller; define
1092 CONFIG_SCSI_SYM53C8XX to enable it.
1094 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1095 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1096 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1097 maximum numbers of LUNs, SCSI ID's and target
1099 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1101 The environment variable 'scsidevs' is set to the number of
1102 SCSI devices found during the last scan.
1104 - NETWORK Support (PCI):
1106 Support for Intel 8254x/8257x gigabit chips.
1109 Utility code for direct access to the SPI bus on Intel 8257x.
1110 This does not do anything useful unless you set at least one
1111 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1113 CONFIG_E1000_SPI_GENERIC
1114 Allow generic access to the SPI bus on the Intel 8257x, for
1115 example with the "sspi" command.
1118 Management command for E1000 devices. When used on devices
1119 with SPI support you can reprogram the EEPROM from U-Boot.
1121 CONFIG_E1000_FALLBACK_MAC
1122 default MAC for empty EEPROM after production.
1125 Support for Intel 82557/82559/82559ER chips.
1126 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1127 write routine for first time initialisation.
1130 Support for Digital 2114x chips.
1131 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1132 modem chip initialisation (KS8761/QS6611).
1135 Support for National dp83815 chips.
1138 Support for National dp8382[01] gigabit chips.
1140 - NETWORK Support (other):
1142 CONFIG_DRIVER_AT91EMAC
1143 Support for AT91RM9200 EMAC.
1146 Define this to use reduced MII inteface
1148 CONFIG_DRIVER_AT91EMAC_QUIET
1149 If this defined, the driver is quiet.
1150 The driver doen't show link status messages.
1152 CONFIG_CALXEDA_XGMAC
1153 Support for the Calxeda XGMAC device
1156 Support for SMSC's LAN91C96 chips.
1158 CONFIG_LAN91C96_BASE
1159 Define this to hold the physical address
1160 of the LAN91C96's I/O space
1162 CONFIG_LAN91C96_USE_32_BIT
1163 Define this to enable 32 bit addressing
1166 Support for SMSC's LAN91C111 chip
1168 CONFIG_SMC91111_BASE
1169 Define this to hold the physical address
1170 of the device (I/O space)
1172 CONFIG_SMC_USE_32_BIT
1173 Define this if data bus is 32 bits
1175 CONFIG_SMC_USE_IOFUNCS
1176 Define this to use i/o functions instead of macros
1177 (some hardware wont work with macros)
1179 CONFIG_DRIVER_TI_EMAC
1180 Support for davinci emac
1182 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1183 Define this if you have more then 3 PHYs.
1186 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1188 CONFIG_FTGMAC100_EGIGA
1189 Define this to use GE link update with gigabit PHY.
1190 Define this if FTGMAC100 is connected to gigabit PHY.
1191 If your system has 10/100 PHY only, it might not occur
1192 wrong behavior. Because PHY usually return timeout or
1193 useless data when polling gigabit status and gigabit
1194 control registers. This behavior won't affect the
1195 correctnessof 10/100 link speed update.
1198 Support for SMSC's LAN911x and LAN921x chips
1201 Define this to hold the physical address
1202 of the device (I/O space)
1204 CONFIG_SMC911X_32_BIT
1205 Define this if data bus is 32 bits
1207 CONFIG_SMC911X_16_BIT
1208 Define this if data bus is 16 bits. If your processor
1209 automatically converts one 32 bit word to two 16 bit
1210 words you may also try CONFIG_SMC911X_32_BIT.
1213 Support for Renesas on-chip Ethernet controller
1215 CONFIG_SH_ETHER_USE_PORT
1216 Define the number of ports to be used
1218 CONFIG_SH_ETHER_PHY_ADDR
1219 Define the ETH PHY's address
1221 CONFIG_SH_ETHER_CACHE_WRITEBACK
1222 If this option is set, the driver enables cache flush.
1226 Support TPM devices.
1229 Support for i2c bus TPM devices. Only one device
1230 per system is supported at this time.
1232 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1233 Define the the i2c bus number for the TPM device
1235 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1236 Define the TPM's address on the i2c bus
1238 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1239 Define the burst count bytes upper limit
1242 Support for generic parallel port TPM devices. Only one device
1243 per system is supported at this time.
1245 CONFIG_TPM_TIS_BASE_ADDRESS
1246 Base address where the generic TPM device is mapped
1247 to. Contemporary x86 systems usually map it at
1251 At the moment only the UHCI host controller is
1252 supported (PIP405, MIP405, MPC5200); define
1253 CONFIG_USB_UHCI to enable it.
1254 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1255 and define CONFIG_USB_STORAGE to enable the USB
1258 Supported are USB Keyboards and USB Floppy drives
1260 MPC5200 USB requires additional defines:
1262 for 528 MHz Clock: 0x0001bbbb
1266 for differential drivers: 0x00001000
1267 for single ended drivers: 0x00005000
1268 for differential drivers on PSC3: 0x00000100
1269 for single ended drivers on PSC3: 0x00004100
1270 CONFIG_SYS_USB_EVENT_POLL
1271 May be defined to allow interrupt polling
1272 instead of using asynchronous interrupts
1274 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1275 txfilltuning field in the EHCI controller on reset.
1277 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1278 interval for usb hub power-on delay.(minimum 100msec)
1281 Define the below if you wish to use the USB console.
1282 Once firmware is rebuilt from a serial console issue the
1283 command "setenv stdin usbtty; setenv stdout usbtty" and
1284 attach your USB cable. The Unix command "dmesg" should print
1285 it has found a new device. The environment variable usbtty
1286 can be set to gserial or cdc_acm to enable your device to
1287 appear to a USB host as a Linux gserial device or a
1288 Common Device Class Abstract Control Model serial device.
1289 If you select usbtty = gserial you should be able to enumerate
1291 # modprobe usbserial vendor=0xVendorID product=0xProductID
1292 else if using cdc_acm, simply setting the environment
1293 variable usbtty to be cdc_acm should suffice. The following
1294 might be defined in YourBoardName.h
1297 Define this to build a UDC device
1300 Define this to have a tty type of device available to
1301 talk to the UDC device
1304 Define this to enable the high speed support for usb
1305 device and usbtty. If this feature is enabled, a routine
1306 int is_usbd_high_speed(void)
1307 also needs to be defined by the driver to dynamically poll
1308 whether the enumeration has succeded at high speed or full
1311 CONFIG_SYS_CONSOLE_IS_IN_ENV
1312 Define this if you want stdin, stdout &/or stderr to
1316 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1317 Derive USB clock from external clock "blah"
1318 - CONFIG_SYS_USB_EXTC_CLK 0x02
1320 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1321 Derive USB clock from brgclk
1322 - CONFIG_SYS_USB_BRG_CLK 0x04
1324 If you have a USB-IF assigned VendorID then you may wish to
1325 define your own vendor specific values either in BoardName.h
1326 or directly in usbd_vendor_info.h. If you don't define
1327 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1328 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1329 should pretend to be a Linux device to it's target host.
1331 CONFIG_USBD_MANUFACTURER
1332 Define this string as the name of your company for
1333 - CONFIG_USBD_MANUFACTURER "my company"
1335 CONFIG_USBD_PRODUCT_NAME
1336 Define this string as the name of your product
1337 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1339 CONFIG_USBD_VENDORID
1340 Define this as your assigned Vendor ID from the USB
1341 Implementors Forum. This *must* be a genuine Vendor ID
1342 to avoid polluting the USB namespace.
1343 - CONFIG_USBD_VENDORID 0xFFFF
1345 CONFIG_USBD_PRODUCTID
1346 Define this as the unique Product ID
1348 - CONFIG_USBD_PRODUCTID 0xFFFF
1350 - ULPI Layer Support:
1351 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1352 the generic ULPI layer. The generic layer accesses the ULPI PHY
1353 via the platform viewport, so you need both the genric layer and
1354 the viewport enabled. Currently only Chipidea/ARC based
1355 viewport is supported.
1356 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1357 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1358 If your ULPI phy needs a different reference clock than the
1359 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1360 the appropriate value in Hz.
1363 The MMC controller on the Intel PXA is supported. To
1364 enable this define CONFIG_MMC. The MMC can be
1365 accessed from the boot prompt by mapping the device
1366 to physical memory similar to flash. Command line is
1367 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1368 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1371 Support for Renesas on-chip MMCIF controller
1373 CONFIG_SH_MMCIF_ADDR
1374 Define the base address of MMCIF registers
1377 Define the clock frequency for MMCIF
1379 - USB Device Firmware Update (DFU) class support:
1381 This enables the USB portion of the DFU USB class
1384 This enables the command "dfu" which is used to have
1385 U-Boot create a DFU class device via USB. This command
1386 requires that the "dfu_alt_info" environment variable be
1387 set and define the alt settings to expose to the host.
1390 This enables support for exposing (e)MMC devices via DFU.
1393 This enables support for exposing NAND devices via DFU.
1395 CONFIG_SYS_DFU_DATA_BUF_SIZE
1396 Dfu transfer uses a buffer before writing data to the
1397 raw storage device. Make the size (in bytes) of this buffer
1398 configurable. The size of this buffer is also configurable
1399 through the "dfu_bufsiz" environment variable.
1401 CONFIG_SYS_DFU_MAX_FILE_SIZE
1402 When updating files rather than the raw storage device,
1403 we use a static buffer to copy the file into and then write
1404 the buffer once we've been given the whole file. Define
1405 this to the maximum filesize (in bytes) for the buffer.
1406 Default is 4 MiB if undefined.
1408 - Journaling Flash filesystem support:
1409 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1410 CONFIG_JFFS2_NAND_DEV
1411 Define these for a default partition on a NAND device
1413 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1414 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1415 Define these for a default partition on a NOR device
1417 CONFIG_SYS_JFFS_CUSTOM_PART
1418 Define this to create an own partition. You have to provide a
1419 function struct part_info* jffs2_part_info(int part_num)
1421 If you define only one JFFS2 partition you may also want to
1422 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1423 to disable the command chpart. This is the default when you
1424 have not defined a custom partition
1426 - FAT(File Allocation Table) filesystem write function support:
1429 Define this to enable support for saving memory data as a
1430 file in FAT formatted partition.
1432 This will also enable the command "fatwrite" enabling the
1433 user to write files to FAT.
1435 CBFS (Coreboot Filesystem) support
1438 Define this to enable support for reading from a Coreboot
1439 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1445 Define this to enable standard (PC-Style) keyboard
1449 Standard PC keyboard driver with US (is default) and
1450 GERMAN key layout (switch via environment 'keymap=de') support.
1451 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1452 for cfb_console. Supports cursor blinking.
1455 Enables a Chrome OS keyboard using the CROS_EC interface.
1456 This uses CROS_EC to communicate with a second microcontroller
1457 which provides key scans on request.
1462 Define this to enable video support (for output to
1465 CONFIG_VIDEO_CT69000
1467 Enable Chips & Technologies 69000 Video chip
1469 CONFIG_VIDEO_SMI_LYNXEM
1470 Enable Silicon Motion SMI 712/710/810 Video chip. The
1471 video output is selected via environment 'videoout'
1472 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1475 For the CT69000 and SMI_LYNXEM drivers, videomode is
1476 selected via environment 'videomode'. Two different ways
1478 - "videomode=num" 'num' is a standard LiLo mode numbers.
1479 Following standard modes are supported (* is default):
1481 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1482 -------------+---------------------------------------------
1483 8 bits | 0x301* 0x303 0x305 0x161 0x307
1484 15 bits | 0x310 0x313 0x316 0x162 0x319
1485 16 bits | 0x311 0x314 0x317 0x163 0x31A
1486 24 bits | 0x312 0x315 0x318 ? 0x31B
1487 -------------+---------------------------------------------
1488 (i.e. setenv videomode 317; saveenv; reset;)
1490 - "videomode=bootargs" all the video parameters are parsed
1491 from the bootargs. (See drivers/video/videomodes.c)
1494 CONFIG_VIDEO_SED13806
1495 Enable Epson SED13806 driver. This driver supports 8bpp
1496 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1497 or CONFIG_VIDEO_SED13806_16BPP
1500 Enable the Freescale DIU video driver. Reference boards for
1501 SOCs that have a DIU should define this macro to enable DIU
1502 support, and should also define these other macros:
1508 CONFIG_VIDEO_SW_CURSOR
1509 CONFIG_VGA_AS_SINGLE_DEVICE
1511 CONFIG_VIDEO_BMP_LOGO
1513 The DIU driver will look for the 'video-mode' environment
1514 variable, and if defined, enable the DIU as a console during
1515 boot. See the documentation file README.video for a
1516 description of this variable.
1520 Enable the VGA video / BIOS for x86. The alternative if you
1521 are using coreboot is to use the coreboot frame buffer
1528 Define this to enable a custom keyboard support.
1529 This simply calls drv_keyboard_init() which must be
1530 defined in your board-specific files.
1531 The only board using this so far is RBC823.
1533 - LCD Support: CONFIG_LCD
1535 Define this to enable LCD support (for output to LCD
1536 display); also select one of the supported displays
1537 by defining one of these:
1541 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1543 CONFIG_NEC_NL6448AC33:
1545 NEC NL6448AC33-18. Active, color, single scan.
1547 CONFIG_NEC_NL6448BC20
1549 NEC NL6448BC20-08. 6.5", 640x480.
1550 Active, color, single scan.
1552 CONFIG_NEC_NL6448BC33_54
1554 NEC NL6448BC33-54. 10.4", 640x480.
1555 Active, color, single scan.
1559 Sharp 320x240. Active, color, single scan.
1560 It isn't 16x9, and I am not sure what it is.
1562 CONFIG_SHARP_LQ64D341
1564 Sharp LQ64D341 display, 640x480.
1565 Active, color, single scan.
1569 HLD1045 display, 640x480.
1570 Active, color, single scan.
1574 Optrex CBL50840-2 NF-FW 99 22 M5
1576 Hitachi LMG6912RPFC-00T
1580 320x240. Black & white.
1582 Normally display is black on white background; define
1583 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1585 CONFIG_LCD_ALIGNMENT
1587 Normally the LCD is page-aligned (tyically 4KB). If this is
1588 defined then the LCD will be aligned to this value instead.
1589 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1590 here, since it is cheaper to change data cache settings on
1591 a per-section basis.
1593 CONFIG_CONSOLE_SCROLL_LINES
1595 When the console need to be scrolled, this is the number of
1596 lines to scroll by. It defaults to 1. Increasing this makes
1597 the console jump but can help speed up operation when scrolling
1602 Support drawing of RLE8-compressed bitmaps on the LCD.
1606 Enables an 'i2c edid' command which can read EDID
1607 information over I2C from an attached LCD display.
1609 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1611 If this option is set, the environment is checked for
1612 a variable "splashimage". If found, the usual display
1613 of logo, copyright and system information on the LCD
1614 is suppressed and the BMP image at the address
1615 specified in "splashimage" is loaded instead. The
1616 console is redirected to the "nulldev", too. This
1617 allows for a "silent" boot where a splash screen is
1618 loaded very quickly after power-on.
1620 CONFIG_SPLASHIMAGE_GUARD
1622 If this option is set, then U-Boot will prevent the environment
1623 variable "splashimage" from being set to a problematic address
1624 (see README.displaying-bmps and README.arm-unaligned-accesses).
1625 This option is useful for targets where, due to alignment
1626 restrictions, an improperly aligned BMP image will cause a data
1627 abort. If you think you will not have problems with unaligned
1628 accesses (for example because your toolchain prevents them)
1629 there is no need to set this option.
1631 CONFIG_SPLASH_SCREEN_ALIGN
1633 If this option is set the splash image can be freely positioned
1634 on the screen. Environment variable "splashpos" specifies the
1635 position as "x,y". If a positive number is given it is used as
1636 number of pixel from left/top. If a negative number is given it
1637 is used as number of pixel from right/bottom. You can also
1638 specify 'm' for centering the image.
1641 setenv splashpos m,m
1642 => image at center of screen
1644 setenv splashpos 30,20
1645 => image at x = 30 and y = 20
1647 setenv splashpos -10,m
1648 => vertically centered image
1649 at x = dspWidth - bmpWidth - 9
1651 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1653 If this option is set, additionally to standard BMP
1654 images, gzipped BMP images can be displayed via the
1655 splashscreen support or the bmp command.
1657 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1659 If this option is set, 8-bit RLE compressed BMP images
1660 can be displayed via the splashscreen support or the
1663 - Do compresssing for memory range:
1666 If this option is set, it would use zlib deflate method
1667 to compress the specified memory at its best effort.
1669 - Compression support:
1672 If this option is set, support for bzip2 compressed
1673 images is included. If not, only uncompressed and gzip
1674 compressed images are supported.
1676 NOTE: the bzip2 algorithm requires a lot of RAM, so
1677 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1682 If this option is set, support for lzma compressed
1685 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1686 requires an amount of dynamic memory that is given by the
1689 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1691 Where lc and lp stand for, respectively, Literal context bits
1692 and Literal pos bits.
1694 This value is upper-bounded by 14MB in the worst case. Anyway,
1695 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1696 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1697 a very small buffer.
1699 Use the lzmainfo tool to determinate the lc and lp values and
1700 then calculate the amount of needed dynamic memory (ensuring
1701 the appropriate CONFIG_SYS_MALLOC_LEN value).
1706 The address of PHY on MII bus.
1708 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1710 The clock frequency of the MII bus
1714 If this option is set, support for speed/duplex
1715 detection of gigabit PHY is included.
1717 CONFIG_PHY_RESET_DELAY
1719 Some PHY like Intel LXT971A need extra delay after
1720 reset before any MII register access is possible.
1721 For such PHY, set this option to the usec delay
1722 required. (minimum 300usec for LXT971A)
1724 CONFIG_PHY_CMD_DELAY (ppc4xx)
1726 Some PHY like Intel LXT971A need extra delay after
1727 command issued before MII status register can be read
1737 Define a default value for Ethernet address to use
1738 for the respective Ethernet interface, in case this
1739 is not determined automatically.
1744 Define a default value for the IP address to use for
1745 the default Ethernet interface, in case this is not
1746 determined through e.g. bootp.
1747 (Environment variable "ipaddr")
1749 - Server IP address:
1752 Defines a default value for the IP address of a TFTP
1753 server to contact when using the "tftboot" command.
1754 (Environment variable "serverip")
1756 CONFIG_KEEP_SERVERADDR
1758 Keeps the server's MAC address, in the env 'serveraddr'
1759 for passing to bootargs (like Linux's netconsole option)
1761 - Gateway IP address:
1764 Defines a default value for the IP address of the
1765 default router where packets to other networks are
1767 (Environment variable "gatewayip")
1772 Defines a default value for the subnet mask (or
1773 routing prefix) which is used to determine if an IP
1774 address belongs to the local subnet or needs to be
1775 forwarded through a router.
1776 (Environment variable "netmask")
1778 - Multicast TFTP Mode:
1781 Defines whether you want to support multicast TFTP as per
1782 rfc-2090; for example to work with atftp. Lets lots of targets
1783 tftp down the same boot image concurrently. Note: the Ethernet
1784 driver in use must provide a function: mcast() to join/leave a
1787 - BOOTP Recovery Mode:
1788 CONFIG_BOOTP_RANDOM_DELAY
1790 If you have many targets in a network that try to
1791 boot using BOOTP, you may want to avoid that all
1792 systems send out BOOTP requests at precisely the same
1793 moment (which would happen for instance at recovery
1794 from a power failure, when all systems will try to
1795 boot, thus flooding the BOOTP server. Defining
1796 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1797 inserted before sending out BOOTP requests. The
1798 following delays are inserted then:
1800 1st BOOTP request: delay 0 ... 1 sec
1801 2nd BOOTP request: delay 0 ... 2 sec
1802 3rd BOOTP request: delay 0 ... 4 sec
1804 BOOTP requests: delay 0 ... 8 sec
1806 - DHCP Advanced Options:
1807 You can fine tune the DHCP functionality by defining
1808 CONFIG_BOOTP_* symbols:
1810 CONFIG_BOOTP_SUBNETMASK
1811 CONFIG_BOOTP_GATEWAY
1812 CONFIG_BOOTP_HOSTNAME
1813 CONFIG_BOOTP_NISDOMAIN
1814 CONFIG_BOOTP_BOOTPATH
1815 CONFIG_BOOTP_BOOTFILESIZE
1818 CONFIG_BOOTP_SEND_HOSTNAME
1819 CONFIG_BOOTP_NTPSERVER
1820 CONFIG_BOOTP_TIMEOFFSET
1821 CONFIG_BOOTP_VENDOREX
1822 CONFIG_BOOTP_MAY_FAIL
1824 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1825 environment variable, not the BOOTP server.
1827 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1828 after the configured retry count, the call will fail
1829 instead of starting over. This can be used to fail over
1830 to Link-local IP address configuration if the DHCP server
1833 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1834 serverip from a DHCP server, it is possible that more
1835 than one DNS serverip is offered to the client.
1836 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1837 serverip will be stored in the additional environment
1838 variable "dnsip2". The first DNS serverip is always
1839 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1842 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1843 to do a dynamic update of a DNS server. To do this, they
1844 need the hostname of the DHCP requester.
1845 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1846 of the "hostname" environment variable is passed as
1847 option 12 to the DHCP server.
1849 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1851 A 32bit value in microseconds for a delay between
1852 receiving a "DHCP Offer" and sending the "DHCP Request".
1853 This fixes a problem with certain DHCP servers that don't
1854 respond 100% of the time to a "DHCP request". E.g. On an
1855 AT91RM9200 processor running at 180MHz, this delay needed
1856 to be *at least* 15,000 usec before a Windows Server 2003
1857 DHCP server would reply 100% of the time. I recommend at
1858 least 50,000 usec to be safe. The alternative is to hope
1859 that one of the retries will be successful but note that
1860 the DHCP timeout and retry process takes a longer than
1863 - Link-local IP address negotiation:
1864 Negotiate with other link-local clients on the local network
1865 for an address that doesn't require explicit configuration.
1866 This is especially useful if a DHCP server cannot be guaranteed
1867 to exist in all environments that the device must operate.
1869 See doc/README.link-local for more information.
1872 CONFIG_CDP_DEVICE_ID
1874 The device id used in CDP trigger frames.
1876 CONFIG_CDP_DEVICE_ID_PREFIX
1878 A two character string which is prefixed to the MAC address
1883 A printf format string which contains the ascii name of
1884 the port. Normally is set to "eth%d" which sets
1885 eth0 for the first Ethernet, eth1 for the second etc.
1887 CONFIG_CDP_CAPABILITIES
1889 A 32bit integer which indicates the device capabilities;
1890 0x00000010 for a normal host which does not forwards.
1894 An ascii string containing the version of the software.
1898 An ascii string containing the name of the platform.
1902 A 32bit integer sent on the trigger.
1904 CONFIG_CDP_POWER_CONSUMPTION
1906 A 16bit integer containing the power consumption of the
1907 device in .1 of milliwatts.
1909 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1911 A byte containing the id of the VLAN.
1913 - Status LED: CONFIG_STATUS_LED
1915 Several configurations allow to display the current
1916 status using a LED. For instance, the LED will blink
1917 fast while running U-Boot code, stop blinking as
1918 soon as a reply to a BOOTP request was received, and
1919 start blinking slow once the Linux kernel is running
1920 (supported by a status LED driver in the Linux
1921 kernel). Defining CONFIG_STATUS_LED enables this
1924 - CAN Support: CONFIG_CAN_DRIVER
1926 Defining CONFIG_CAN_DRIVER enables CAN driver support
1927 on those systems that support this (optional)
1928 feature, like the TQM8xxL modules.
1930 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1932 These enable I2C serial bus commands. Defining either of
1933 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1934 include the appropriate I2C driver for the selected CPU.
1936 This will allow you to use i2c commands at the u-boot
1937 command line (as long as you set CONFIG_CMD_I2C in
1938 CONFIG_COMMANDS) and communicate with i2c based realtime
1939 clock chips. See common/cmd_i2c.c for a description of the
1940 command line interface.
1942 CONFIG_HARD_I2C selects a hardware I2C controller.
1944 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1945 bit-banging) driver instead of CPM or similar hardware
1948 There are several other quantities that must also be
1949 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1951 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1952 to be the frequency (in Hz) at which you wish your i2c bus
1953 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1954 the CPU's i2c node address).
1956 Now, the u-boot i2c code for the mpc8xx
1957 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1958 and so its address should therefore be cleared to 0 (See,
1959 eg, MPC823e User's Manual p.16-473). So, set
1960 CONFIG_SYS_I2C_SLAVE to 0.
1962 CONFIG_SYS_I2C_INIT_MPC5XXX
1964 When a board is reset during an i2c bus transfer
1965 chips might think that the current transfer is still
1966 in progress. Reset the slave devices by sending start
1967 commands until the slave device responds.
1969 That's all that's required for CONFIG_HARD_I2C.
1971 If you use the software i2c interface (CONFIG_SOFT_I2C)
1972 then the following macros need to be defined (examples are
1973 from include/configs/lwmon.h):
1977 (Optional). Any commands necessary to enable the I2C
1978 controller or configure ports.
1980 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1984 (Only for MPC8260 CPU). The I/O port to use (the code
1985 assumes both bits are on the same port). Valid values
1986 are 0..3 for ports A..D.
1990 The code necessary to make the I2C data line active
1991 (driven). If the data line is open collector, this
1994 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1998 The code necessary to make the I2C data line tri-stated
1999 (inactive). If the data line is open collector, this
2002 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2006 Code that returns true if the I2C data line is high,
2009 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2013 If <bit> is true, sets the I2C data line high. If it
2014 is false, it clears it (low).
2016 eg: #define I2C_SDA(bit) \
2017 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2018 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2022 If <bit> is true, sets the I2C clock line high. If it
2023 is false, it clears it (low).
2025 eg: #define I2C_SCL(bit) \
2026 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2027 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2031 This delay is invoked four times per clock cycle so this
2032 controls the rate of data transfer. The data rate thus
2033 is 1 / (I2C_DELAY * 4). Often defined to be something
2036 #define I2C_DELAY udelay(2)
2038 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2040 If your arch supports the generic GPIO framework (asm/gpio.h),
2041 then you may alternatively define the two GPIOs that are to be
2042 used as SCL / SDA. Any of the previous I2C_xxx macros will
2043 have GPIO-based defaults assigned to them as appropriate.
2045 You should define these to the GPIO value as given directly to
2046 the generic GPIO functions.
2048 CONFIG_SYS_I2C_INIT_BOARD
2050 When a board is reset during an i2c bus transfer
2051 chips might think that the current transfer is still
2052 in progress. On some boards it is possible to access
2053 the i2c SCLK line directly, either by using the
2054 processor pin as a GPIO or by having a second pin
2055 connected to the bus. If this option is defined a
2056 custom i2c_init_board() routine in boards/xxx/board.c
2057 is run early in the boot sequence.
2059 CONFIG_SYS_I2C_BOARD_LATE_INIT
2061 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2062 defined a custom i2c_board_late_init() routine in
2063 boards/xxx/board.c is run AFTER the operations in i2c_init()
2064 is completed. This callpoint can be used to unreset i2c bus
2065 using CPU i2c controller register accesses for CPUs whose i2c
2066 controller provide such a method. It is called at the end of
2067 i2c_init() to allow i2c_init operations to setup the i2c bus
2068 controller on the CPU (e.g. setting bus speed & slave address).
2070 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2072 This option enables configuration of bi_iic_fast[] flags
2073 in u-boot bd_info structure based on u-boot environment
2074 variable "i2cfast". (see also i2cfast)
2076 CONFIG_I2C_MULTI_BUS
2078 This option allows the use of multiple I2C buses, each of which
2079 must have a controller. At any point in time, only one bus is
2080 active. To switch to a different bus, use the 'i2c dev' command.
2081 Note that bus numbering is zero-based.
2083 CONFIG_SYS_I2C_NOPROBES
2085 This option specifies a list of I2C devices that will be skipped
2086 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2087 is set, specify a list of bus-device pairs. Otherwise, specify
2088 a 1D array of device addresses
2091 #undef CONFIG_I2C_MULTI_BUS
2092 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2094 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2096 #define CONFIG_I2C_MULTI_BUS
2097 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2099 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2101 CONFIG_SYS_SPD_BUS_NUM
2103 If defined, then this indicates the I2C bus number for DDR SPD.
2104 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2106 CONFIG_SYS_RTC_BUS_NUM
2108 If defined, then this indicates the I2C bus number for the RTC.
2109 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2111 CONFIG_SYS_DTT_BUS_NUM
2113 If defined, then this indicates the I2C bus number for the DTT.
2114 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2116 CONFIG_SYS_I2C_DTT_ADDR:
2118 If defined, specifies the I2C address of the DTT device.
2119 If not defined, then U-Boot uses predefined value for
2120 specified DTT device.
2124 Define this option if you want to use Freescale's I2C driver in
2125 drivers/i2c/fsl_i2c.c.
2129 Define this option if you have I2C devices reached over 1 .. n
2130 I2C Muxes like the pca9544a. This option addes a new I2C
2131 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
2132 new I2C Bus to the existing I2C Busses. If you select the
2133 new Bus with "i2c dev", u-bbot sends first the commandos for
2134 the muxes to activate this new "bus".
2136 CONFIG_I2C_MULTI_BUS must be also defined, to use this
2140 Adding a new I2C Bus reached over 2 pca9544a muxes
2141 The First mux with address 70 and channel 6
2142 The Second mux with address 71 and channel 4
2144 => i2c bus pca9544a:70:6:pca9544a:71:4
2146 Use the "i2c bus" command without parameter, to get a list
2147 of I2C Busses with muxes:
2150 Busses reached over muxes:
2152 reached over Mux(es):
2155 reached over Mux(es):
2160 If you now switch to the new I2C Bus 3 with "i2c dev 3"
2161 u-boot first sends the command to the mux@70 to enable
2162 channel 6, and then the command to the mux@71 to enable
2165 After that, you can use the "normal" i2c commands as
2166 usual to communicate with your I2C devices behind
2169 This option is actually implemented for the bitbanging
2170 algorithm in common/soft_i2c.c and for the Hardware I2C
2171 Bus on the MPC8260. But it should be not so difficult
2172 to add this option to other architectures.
2174 CONFIG_SOFT_I2C_READ_REPEATED_START
2176 defining this will force the i2c_read() function in
2177 the soft_i2c driver to perform an I2C repeated start
2178 between writing the address pointer and reading the
2179 data. If this define is omitted the default behaviour
2180 of doing a stop-start sequence will be used. Most I2C
2181 devices can use either method, but some require one or
2184 - SPI Support: CONFIG_SPI
2186 Enables SPI driver (so far only tested with
2187 SPI EEPROM, also an instance works with Crystal A/D and
2188 D/As on the SACSng board)
2192 Enables the driver for SPI controller on SuperH. Currently
2193 only SH7757 is supported.
2197 Enables extended (16-bit) SPI EEPROM addressing.
2198 (symmetrical to CONFIG_I2C_X)
2202 Enables a software (bit-bang) SPI driver rather than
2203 using hardware support. This is a general purpose
2204 driver that only requires three general I/O port pins
2205 (two outputs, one input) to function. If this is
2206 defined, the board configuration must define several
2207 SPI configuration items (port pins to use, etc). For
2208 an example, see include/configs/sacsng.h.
2212 Enables a hardware SPI driver for general-purpose reads
2213 and writes. As with CONFIG_SOFT_SPI, the board configuration
2214 must define a list of chip-select function pointers.
2215 Currently supported on some MPC8xxx processors. For an
2216 example, see include/configs/mpc8349emds.h.
2220 Enables the driver for the SPI controllers on i.MX and MXC
2221 SoCs. Currently i.MX31/35/51 are supported.
2223 - FPGA Support: CONFIG_FPGA
2225 Enables FPGA subsystem.
2227 CONFIG_FPGA_<vendor>
2229 Enables support for specific chip vendors.
2232 CONFIG_FPGA_<family>
2234 Enables support for FPGA family.
2235 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2239 Specify the number of FPGA devices to support.
2241 CONFIG_SYS_FPGA_PROG_FEEDBACK
2243 Enable printing of hash marks during FPGA configuration.
2245 CONFIG_SYS_FPGA_CHECK_BUSY
2247 Enable checks on FPGA configuration interface busy
2248 status by the configuration function. This option
2249 will require a board or device specific function to
2254 If defined, a function that provides delays in the FPGA
2255 configuration driver.
2257 CONFIG_SYS_FPGA_CHECK_CTRLC
2258 Allow Control-C to interrupt FPGA configuration
2260 CONFIG_SYS_FPGA_CHECK_ERROR
2262 Check for configuration errors during FPGA bitfile
2263 loading. For example, abort during Virtex II
2264 configuration if the INIT_B line goes low (which
2265 indicated a CRC error).
2267 CONFIG_SYS_FPGA_WAIT_INIT
2269 Maximum time to wait for the INIT_B line to deassert
2270 after PROB_B has been deasserted during a Virtex II
2271 FPGA configuration sequence. The default time is 500
2274 CONFIG_SYS_FPGA_WAIT_BUSY
2276 Maximum time to wait for BUSY to deassert during
2277 Virtex II FPGA configuration. The default is 5 ms.
2279 CONFIG_SYS_FPGA_WAIT_CONFIG
2281 Time to wait after FPGA configuration. The default is
2284 - Configuration Management:
2287 If defined, this string will be added to the U-Boot
2288 version information (U_BOOT_VERSION)
2290 - Vendor Parameter Protection:
2292 U-Boot considers the values of the environment
2293 variables "serial#" (Board Serial Number) and
2294 "ethaddr" (Ethernet Address) to be parameters that
2295 are set once by the board vendor / manufacturer, and
2296 protects these variables from casual modification by
2297 the user. Once set, these variables are read-only,
2298 and write or delete attempts are rejected. You can
2299 change this behaviour:
2301 If CONFIG_ENV_OVERWRITE is #defined in your config
2302 file, the write protection for vendor parameters is
2303 completely disabled. Anybody can change or delete
2306 Alternatively, if you #define _both_ CONFIG_ETHADDR
2307 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2308 Ethernet address is installed in the environment,
2309 which can be changed exactly ONCE by the user. [The
2310 serial# is unaffected by this, i. e. it remains
2313 The same can be accomplished in a more flexible way
2314 for any variable by configuring the type of access
2315 to allow for those variables in the ".flags" variable
2316 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2321 Define this variable to enable the reservation of
2322 "protected RAM", i. e. RAM which is not overwritten
2323 by U-Boot. Define CONFIG_PRAM to hold the number of
2324 kB you want to reserve for pRAM. You can overwrite
2325 this default value by defining an environment
2326 variable "pram" to the number of kB you want to
2327 reserve. Note that the board info structure will
2328 still show the full amount of RAM. If pRAM is
2329 reserved, a new environment variable "mem" will
2330 automatically be defined to hold the amount of
2331 remaining RAM in a form that can be passed as boot
2332 argument to Linux, for instance like that:
2334 setenv bootargs ... mem=\${mem}
2337 This way you can tell Linux not to use this memory,
2338 either, which results in a memory region that will
2339 not be affected by reboots.
2341 *WARNING* If your board configuration uses automatic
2342 detection of the RAM size, you must make sure that
2343 this memory test is non-destructive. So far, the
2344 following board configurations are known to be
2347 IVMS8, IVML24, SPD8xx, TQM8xxL,
2348 HERMES, IP860, RPXlite, LWMON,
2351 - Access to physical memory region (> 4GB)
2352 Some basic support is provided for operations on memory not
2353 normally accessible to U-Boot - e.g. some architectures
2354 support access to more than 4GB of memory on 32-bit
2355 machines using physical address extension or similar.
2356 Define CONFIG_PHYSMEM to access this basic support, which
2357 currently only supports clearing the memory.
2362 Define this variable to stop the system in case of a
2363 fatal error, so that you have to reset it manually.
2364 This is probably NOT a good idea for an embedded
2365 system where you want the system to reboot
2366 automatically as fast as possible, but it may be
2367 useful during development since you can try to debug
2368 the conditions that lead to the situation.
2370 CONFIG_NET_RETRY_COUNT
2372 This variable defines the number of retries for
2373 network operations like ARP, RARP, TFTP, or BOOTP
2374 before giving up the operation. If not defined, a
2375 default value of 5 is used.
2379 Timeout waiting for an ARP reply in milliseconds.
2383 Timeout in milliseconds used in NFS protocol.
2384 If you encounter "ERROR: Cannot umount" in nfs command,
2385 try longer timeout such as
2386 #define CONFIG_NFS_TIMEOUT 10000UL
2388 - Command Interpreter:
2389 CONFIG_AUTO_COMPLETE
2391 Enable auto completion of commands using TAB.
2393 Note that this feature has NOT been implemented yet
2394 for the "hush" shell.
2397 CONFIG_SYS_HUSH_PARSER
2399 Define this variable to enable the "hush" shell (from
2400 Busybox) as command line interpreter, thus enabling
2401 powerful command line syntax like
2402 if...then...else...fi conditionals or `&&' and '||'
2403 constructs ("shell scripts").
2405 If undefined, you get the old, much simpler behaviour
2406 with a somewhat smaller memory footprint.
2409 CONFIG_SYS_PROMPT_HUSH_PS2
2411 This defines the secondary prompt string, which is
2412 printed when the command interpreter needs more input
2413 to complete a command. Usually "> ".
2417 In the current implementation, the local variables
2418 space and global environment variables space are
2419 separated. Local variables are those you define by
2420 simply typing `name=value'. To access a local
2421 variable later on, you have write `$name' or
2422 `${name}'; to execute the contents of a variable
2423 directly type `$name' at the command prompt.
2425 Global environment variables are those you use
2426 setenv/printenv to work with. To run a command stored
2427 in such a variable, you need to use the run command,
2428 and you must not use the '$' sign to access them.
2430 To store commands and special characters in a
2431 variable, please use double quotation marks
2432 surrounding the whole text of the variable, instead
2433 of the backslashes before semicolons and special
2436 - Commandline Editing and History:
2437 CONFIG_CMDLINE_EDITING
2439 Enable editing and History functions for interactive
2440 commandline input operations
2442 - Default Environment:
2443 CONFIG_EXTRA_ENV_SETTINGS
2445 Define this to contain any number of null terminated
2446 strings (variable = value pairs) that will be part of
2447 the default environment compiled into the boot image.
2449 For example, place something like this in your
2450 board's config file:
2452 #define CONFIG_EXTRA_ENV_SETTINGS \
2456 Warning: This method is based on knowledge about the
2457 internal format how the environment is stored by the
2458 U-Boot code. This is NOT an official, exported
2459 interface! Although it is unlikely that this format
2460 will change soon, there is no guarantee either.
2461 You better know what you are doing here.
2463 Note: overly (ab)use of the default environment is
2464 discouraged. Make sure to check other ways to preset
2465 the environment like the "source" command or the
2468 CONFIG_ENV_VARS_UBOOT_CONFIG
2470 Define this in order to add variables describing the
2471 U-Boot build configuration to the default environment.
2472 These will be named arch, cpu, board, vendor, and soc.
2474 Enabling this option will cause the following to be defined:
2482 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2484 Define this in order to add variables describing certain
2485 run-time determined information about the hardware to the
2486 environment. These will be named board_name, board_rev.
2488 CONFIG_DELAY_ENVIRONMENT
2490 Normally the environment is loaded when the board is
2491 intialised so that it is available to U-Boot. This inhibits
2492 that so that the environment is not available until
2493 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2494 this is instead controlled by the value of
2495 /config/load-environment.
2497 - DataFlash Support:
2498 CONFIG_HAS_DATAFLASH
2500 Defining this option enables DataFlash features and
2501 allows to read/write in Dataflash via the standard
2504 - Serial Flash support
2507 Defining this option enables SPI flash commands
2508 'sf probe/read/write/erase/update'.
2510 Usage requires an initial 'probe' to define the serial
2511 flash parameters, followed by read/write/erase/update
2514 The following defaults may be provided by the platform
2515 to handle the common case when only a single serial
2516 flash is present on the system.
2518 CONFIG_SF_DEFAULT_BUS Bus identifier
2519 CONFIG_SF_DEFAULT_CS Chip-select
2520 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2521 CONFIG_SF_DEFAULT_SPEED in Hz
2525 Define this option to include a destructive SPI flash
2528 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2530 Define this option to use the Bank addr/Extended addr
2531 support on SPI flashes which has size > 16Mbytes.
2533 - SystemACE Support:
2536 Adding this option adds support for Xilinx SystemACE
2537 chips attached via some sort of local bus. The address
2538 of the chip must also be defined in the
2539 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2541 #define CONFIG_SYSTEMACE
2542 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2544 When SystemACE support is added, the "ace" device type
2545 becomes available to the fat commands, i.e. fatls.
2547 - TFTP Fixed UDP Port:
2550 If this is defined, the environment variable tftpsrcp
2551 is used to supply the TFTP UDP source port value.
2552 If tftpsrcp isn't defined, the normal pseudo-random port
2553 number generator is used.
2555 Also, the environment variable tftpdstp is used to supply
2556 the TFTP UDP destination port value. If tftpdstp isn't
2557 defined, the normal port 69 is used.
2559 The purpose for tftpsrcp is to allow a TFTP server to
2560 blindly start the TFTP transfer using the pre-configured
2561 target IP address and UDP port. This has the effect of
2562 "punching through" the (Windows XP) firewall, allowing
2563 the remainder of the TFTP transfer to proceed normally.
2564 A better solution is to properly configure the firewall,
2565 but sometimes that is not allowed.
2570 This enables a generic 'hash' command which can produce
2571 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2575 Enable the hash verify command (hash -v). This adds to code
2578 CONFIG_SHA1 - support SHA1 hashing
2579 CONFIG_SHA256 - support SHA256 hashing
2581 Note: There is also a sha1sum command, which should perhaps
2582 be deprecated in favour of 'hash sha1'.
2587 This enables the RSA algorithm used for FIT image verification
2588 in U-Boot. See doc/uImage/signature for more information.
2590 The signing part is build into mkimage regardless of this
2594 - Show boot progress:
2595 CONFIG_SHOW_BOOT_PROGRESS
2597 Defining this option allows to add some board-
2598 specific code (calling a user-provided function
2599 "show_boot_progress(int)") that enables you to show
2600 the system's boot progress on some display (for
2601 example, some LED's) on your board. At the moment,
2602 the following checkpoints are implemented:
2604 - Detailed boot stage timing
2606 Define this option to get detailed timing of each stage
2607 of the boot process.
2609 CONFIG_BOOTSTAGE_USER_COUNT
2610 This is the number of available user bootstage records.
2611 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2612 a new ID will be allocated from this stash. If you exceed
2613 the limit, recording will stop.
2615 CONFIG_BOOTSTAGE_REPORT
2616 Define this to print a report before boot, similar to this:
2618 Timer summary in microseconds:
2621 3,575,678 3,575,678 board_init_f start
2622 3,575,695 17 arch_cpu_init A9
2623 3,575,777 82 arch_cpu_init done
2624 3,659,598 83,821 board_init_r start
2625 3,910,375 250,777 main_loop
2626 29,916,167 26,005,792 bootm_start
2627 30,361,327 445,160 start_kernel
2629 CONFIG_CMD_BOOTSTAGE
2630 Add a 'bootstage' command which supports printing a report
2631 and un/stashing of bootstage data.
2633 CONFIG_BOOTSTAGE_FDT
2634 Stash the bootstage information in the FDT. A root 'bootstage'
2635 node is created with each bootstage id as a child. Each child
2636 has a 'name' property and either 'mark' containing the
2637 mark time in microsecond, or 'accum' containing the
2638 accumulated time for that bootstage id in microseconds.
2643 name = "board_init_f";
2652 Code in the Linux kernel can find this in /proc/devicetree.
2654 Legacy uImage format:
2657 1 common/cmd_bootm.c before attempting to boot an image
2658 -1 common/cmd_bootm.c Image header has bad magic number
2659 2 common/cmd_bootm.c Image header has correct magic number
2660 -2 common/cmd_bootm.c Image header has bad checksum
2661 3 common/cmd_bootm.c Image header has correct checksum
2662 -3 common/cmd_bootm.c Image data has bad checksum
2663 4 common/cmd_bootm.c Image data has correct checksum
2664 -4 common/cmd_bootm.c Image is for unsupported architecture
2665 5 common/cmd_bootm.c Architecture check OK
2666 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2667 6 common/cmd_bootm.c Image Type check OK
2668 -6 common/cmd_bootm.c gunzip uncompression error
2669 -7 common/cmd_bootm.c Unimplemented compression type
2670 7 common/cmd_bootm.c Uncompression OK
2671 8 common/cmd_bootm.c No uncompress/copy overwrite error
2672 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2674 9 common/image.c Start initial ramdisk verification
2675 -10 common/image.c Ramdisk header has bad magic number
2676 -11 common/image.c Ramdisk header has bad checksum
2677 10 common/image.c Ramdisk header is OK
2678 -12 common/image.c Ramdisk data has bad checksum
2679 11 common/image.c Ramdisk data has correct checksum
2680 12 common/image.c Ramdisk verification complete, start loading
2681 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2682 13 common/image.c Start multifile image verification
2683 14 common/image.c No initial ramdisk, no multifile, continue.
2685 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2687 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2688 -31 post/post.c POST test failed, detected by post_output_backlog()
2689 -32 post/post.c POST test failed, detected by post_run_single()
2691 34 common/cmd_doc.c before loading a Image from a DOC device
2692 -35 common/cmd_doc.c Bad usage of "doc" command
2693 35 common/cmd_doc.c correct usage of "doc" command
2694 -36 common/cmd_doc.c No boot device
2695 36 common/cmd_doc.c correct boot device
2696 -37 common/cmd_doc.c Unknown Chip ID on boot device
2697 37 common/cmd_doc.c correct chip ID found, device available
2698 -38 common/cmd_doc.c Read Error on boot device
2699 38 common/cmd_doc.c reading Image header from DOC device OK
2700 -39 common/cmd_doc.c Image header has bad magic number
2701 39 common/cmd_doc.c Image header has correct magic number
2702 -40 common/cmd_doc.c Error reading Image from DOC device
2703 40 common/cmd_doc.c Image header has correct magic number
2704 41 common/cmd_ide.c before loading a Image from a IDE device
2705 -42 common/cmd_ide.c Bad usage of "ide" command
2706 42 common/cmd_ide.c correct usage of "ide" command
2707 -43 common/cmd_ide.c No boot device
2708 43 common/cmd_ide.c boot device found
2709 -44 common/cmd_ide.c Device not available
2710 44 common/cmd_ide.c Device available
2711 -45 common/cmd_ide.c wrong partition selected
2712 45 common/cmd_ide.c partition selected
2713 -46 common/cmd_ide.c Unknown partition table
2714 46 common/cmd_ide.c valid partition table found
2715 -47 common/cmd_ide.c Invalid partition type
2716 47 common/cmd_ide.c correct partition type
2717 -48 common/cmd_ide.c Error reading Image Header on boot device
2718 48 common/cmd_ide.c reading Image Header from IDE device OK
2719 -49 common/cmd_ide.c Image header has bad magic number
2720 49 common/cmd_ide.c Image header has correct magic number
2721 -50 common/cmd_ide.c Image header has bad checksum
2722 50 common/cmd_ide.c Image header has correct checksum
2723 -51 common/cmd_ide.c Error reading Image from IDE device
2724 51 common/cmd_ide.c reading Image from IDE device OK
2725 52 common/cmd_nand.c before loading a Image from a NAND device
2726 -53 common/cmd_nand.c Bad usage of "nand" command
2727 53 common/cmd_nand.c correct usage of "nand" command
2728 -54 common/cmd_nand.c No boot device
2729 54 common/cmd_nand.c boot device found
2730 -55 common/cmd_nand.c Unknown Chip ID on boot device
2731 55 common/cmd_nand.c correct chip ID found, device available
2732 -56 common/cmd_nand.c Error reading Image Header on boot device
2733 56 common/cmd_nand.c reading Image Header from NAND device OK
2734 -57 common/cmd_nand.c Image header has bad magic number
2735 57 common/cmd_nand.c Image header has correct magic number
2736 -58 common/cmd_nand.c Error reading Image from NAND device
2737 58 common/cmd_nand.c reading Image from NAND device OK
2739 -60 common/env_common.c Environment has a bad CRC, using default
2741 64 net/eth.c starting with Ethernet configuration.
2742 -64 net/eth.c no Ethernet found.
2743 65 net/eth.c Ethernet found.
2745 -80 common/cmd_net.c usage wrong
2746 80 common/cmd_net.c before calling NetLoop()
2747 -81 common/cmd_net.c some error in NetLoop() occurred
2748 81 common/cmd_net.c NetLoop() back without error
2749 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2750 82 common/cmd_net.c trying automatic boot
2751 83 common/cmd_net.c running "source" command
2752 -83 common/cmd_net.c some error in automatic boot or "source" command
2753 84 common/cmd_net.c end without errors
2758 100 common/cmd_bootm.c Kernel FIT Image has correct format
2759 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2760 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2761 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2762 102 common/cmd_bootm.c Kernel unit name specified
2763 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2764 103 common/cmd_bootm.c Found configuration node
2765 104 common/cmd_bootm.c Got kernel subimage node offset
2766 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2767 105 common/cmd_bootm.c Kernel subimage hash verification OK
2768 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2769 106 common/cmd_bootm.c Architecture check OK
2770 -106 common/cmd_bootm.c Kernel subimage has wrong type
2771 107 common/cmd_bootm.c Kernel subimage type OK
2772 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2773 108 common/cmd_bootm.c Got kernel subimage data/size
2774 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2775 -109 common/cmd_bootm.c Can't get kernel subimage type
2776 -110 common/cmd_bootm.c Can't get kernel subimage comp
2777 -111 common/cmd_bootm.c Can't get kernel subimage os
2778 -112 common/cmd_bootm.c Can't get kernel subimage load address
2779 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2781 120 common/image.c Start initial ramdisk verification
2782 -120 common/image.c Ramdisk FIT image has incorrect format
2783 121 common/image.c Ramdisk FIT image has correct format
2784 122 common/image.c No ramdisk subimage unit name, using configuration
2785 -122 common/image.c Can't get configuration for ramdisk subimage
2786 123 common/image.c Ramdisk unit name specified
2787 -124 common/image.c Can't get ramdisk subimage node offset
2788 125 common/image.c Got ramdisk subimage node offset
2789 -125 common/image.c Ramdisk subimage hash verification failed
2790 126 common/image.c Ramdisk subimage hash verification OK
2791 -126 common/image.c Ramdisk subimage for unsupported architecture
2792 127 common/image.c Architecture check OK
2793 -127 common/image.c Can't get ramdisk subimage data/size
2794 128 common/image.c Got ramdisk subimage data/size
2795 129 common/image.c Can't get ramdisk load address
2796 -129 common/image.c Got ramdisk load address
2798 -130 common/cmd_doc.c Incorrect FIT image format
2799 131 common/cmd_doc.c FIT image format OK
2801 -140 common/cmd_ide.c Incorrect FIT image format
2802 141 common/cmd_ide.c FIT image format OK
2804 -150 common/cmd_nand.c Incorrect FIT image format
2805 151 common/cmd_nand.c FIT image format OK
2807 - FIT image support:
2809 Enable support for the FIT uImage format.
2811 CONFIG_FIT_BEST_MATCH
2812 When no configuration is explicitly selected, default to the
2813 one whose fdt's compatibility field best matches that of
2814 U-Boot itself. A match is considered "best" if it matches the
2815 most specific compatibility entry of U-Boot's fdt's root node.
2816 The order of entries in the configuration's fdt is ignored.
2818 CONFIG_FIT_SIGNATURE
2819 This option enables signature verification of FIT uImages,
2820 using a hash signed and verified using RSA. See
2821 doc/uImage.FIT/signature.txt for more details.
2823 - Standalone program support:
2824 CONFIG_STANDALONE_LOAD_ADDR
2826 This option defines a board specific value for the
2827 address where standalone program gets loaded, thus
2828 overwriting the architecture dependent default
2831 - Frame Buffer Address:
2834 Define CONFIG_FB_ADDR if you want to use specific
2835 address for frame buffer. This is typically the case
2836 when using a graphics controller has separate video
2837 memory. U-Boot will then place the frame buffer at
2838 the given address instead of dynamically reserving it
2839 in system RAM by calling lcd_setmem(), which grabs
2840 the memory for the frame buffer depending on the
2841 configured panel size.
2843 Please see board_init_f function.
2845 - Automatic software updates via TFTP server
2847 CONFIG_UPDATE_TFTP_CNT_MAX
2848 CONFIG_UPDATE_TFTP_MSEC_MAX
2850 These options enable and control the auto-update feature;
2851 for a more detailed description refer to doc/README.update.
2853 - MTD Support (mtdparts command, UBI support)
2856 Adds the MTD device infrastructure from the Linux kernel.
2857 Needed for mtdparts command support.
2859 CONFIG_MTD_PARTITIONS
2861 Adds the MTD partitioning infrastructure from the Linux
2862 kernel. Needed for UBI support.
2867 Adds commands for interacting with MTD partitions formatted
2868 with the UBI flash translation layer
2870 Requires also defining CONFIG_RBTREE
2872 CONFIG_UBI_SILENCE_MSG
2874 Make the verbose messages from UBI stop printing. This leaves
2875 warnings and errors enabled.
2880 Adds commands for interacting with UBI volumes formatted as
2881 UBIFS. UBIFS is read-only in u-boot.
2883 Requires UBI support as well as CONFIG_LZO
2885 CONFIG_UBIFS_SILENCE_MSG
2887 Make the verbose messages from UBIFS stop printing. This leaves
2888 warnings and errors enabled.
2892 Enable building of SPL globally.
2895 LDSCRIPT for linking the SPL binary.
2897 CONFIG_SPL_MAX_FOOTPRINT
2898 Maximum size in memory allocated to the SPL, BSS included.
2899 When defined, the linker checks that the actual memory
2900 used by SPL from _start to __bss_end does not exceed it.
2901 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2902 must not be both defined at the same time.
2905 Maximum size of the SPL image (text, data, rodata, and
2906 linker lists sections), BSS excluded.
2907 When defined, the linker checks that the actual size does
2910 CONFIG_SPL_TEXT_BASE
2911 TEXT_BASE for linking the SPL binary.
2913 CONFIG_SPL_RELOC_TEXT_BASE
2914 Address to relocate to. If unspecified, this is equal to
2915 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2917 CONFIG_SPL_BSS_START_ADDR
2918 Link address for the BSS within the SPL binary.
2920 CONFIG_SPL_BSS_MAX_SIZE
2921 Maximum size in memory allocated to the SPL BSS.
2922 When defined, the linker checks that the actual memory used
2923 by SPL from __bss_start to __bss_end does not exceed it.
2924 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2925 must not be both defined at the same time.
2928 Adress of the start of the stack SPL will use
2930 CONFIG_SPL_RELOC_STACK
2931 Adress of the start of the stack SPL will use after
2932 relocation. If unspecified, this is equal to
2935 CONFIG_SYS_SPL_MALLOC_START
2936 Starting address of the malloc pool used in SPL.
2938 CONFIG_SYS_SPL_MALLOC_SIZE
2939 The size of the malloc pool used in SPL.
2941 CONFIG_SPL_FRAMEWORK
2942 Enable the SPL framework under common/. This framework
2943 supports MMC, NAND and YMODEM loading of U-Boot and NAND
2944 NAND loading of the Linux Kernel.
2946 CONFIG_SPL_DISPLAY_PRINT
2947 For ARM, enable an optional function to print more information
2948 about the running system.
2950 CONFIG_SPL_INIT_MINIMAL
2951 Arch init code should be built for a very small image
2953 CONFIG_SPL_LIBCOMMON_SUPPORT
2954 Support for common/libcommon.o in SPL binary
2956 CONFIG_SPL_LIBDISK_SUPPORT
2957 Support for disk/libdisk.o in SPL binary
2959 CONFIG_SPL_I2C_SUPPORT
2960 Support for drivers/i2c/libi2c.o in SPL binary
2962 CONFIG_SPL_GPIO_SUPPORT
2963 Support for drivers/gpio/libgpio.o in SPL binary
2965 CONFIG_SPL_MMC_SUPPORT
2966 Support for drivers/mmc/libmmc.o in SPL binary
2968 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
2969 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
2970 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
2971 Address, size and partition on the MMC to load U-Boot from
2972 when the MMC is being used in raw mode.
2974 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
2975 Sector to load kernel uImage from when MMC is being
2976 used in raw mode (for Falcon mode)
2978 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
2979 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
2980 Sector and number of sectors to load kernel argument
2981 parameters from when MMC is being used in raw mode
2984 CONFIG_SPL_FAT_SUPPORT
2985 Support for fs/fat/libfat.o in SPL binary
2987 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
2988 Filename to read to load U-Boot when reading from FAT
2990 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
2991 Filename to read to load kernel uImage when reading
2992 from FAT (for Falcon mode)
2994 CONFIG_SPL_FAT_LOAD_ARGS_NAME
2995 Filename to read to load kernel argument parameters
2996 when reading from FAT (for Falcon mode)
2998 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
2999 Set this for NAND SPL on PPC mpc83xx targets, so that
3000 start.S waits for the rest of the SPL to load before
3001 continuing (the hardware starts execution after just
3002 loading the first page rather than the full 4K).
3004 CONFIG_SPL_NAND_BASE
3005 Include nand_base.c in the SPL. Requires
3006 CONFIG_SPL_NAND_DRIVERS.
3008 CONFIG_SPL_NAND_DRIVERS
3009 SPL uses normal NAND drivers, not minimal drivers.
3012 Include standard software ECC in the SPL
3014 CONFIG_SPL_NAND_SIMPLE
3015 Support for NAND boot using simple NAND drivers that
3016 expose the cmd_ctrl() interface.
3018 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3019 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3020 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3021 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3022 CONFIG_SYS_NAND_ECCBYTES
3023 Defines the size and behavior of the NAND that SPL uses
3026 CONFIG_SYS_NAND_U_BOOT_OFFS
3027 Location in NAND to read U-Boot from
3029 CONFIG_SYS_NAND_U_BOOT_DST
3030 Location in memory to load U-Boot to
3032 CONFIG_SYS_NAND_U_BOOT_SIZE
3033 Size of image to load
3035 CONFIG_SYS_NAND_U_BOOT_START
3036 Entry point in loaded image to jump to
3038 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3039 Define this if you need to first read the OOB and then the
3040 data. This is used for example on davinci plattforms.
3042 CONFIG_SPL_OMAP3_ID_NAND
3043 Support for an OMAP3-specific set of functions to return the
3044 ID and MFR of the first attached NAND chip, if present.
3046 CONFIG_SPL_SERIAL_SUPPORT
3047 Support for drivers/serial/libserial.o in SPL binary
3049 CONFIG_SPL_SPI_FLASH_SUPPORT
3050 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3052 CONFIG_SPL_SPI_SUPPORT
3053 Support for drivers/spi/libspi.o in SPL binary
3055 CONFIG_SPL_RAM_DEVICE
3056 Support for running image already present in ram, in SPL binary
3058 CONFIG_SPL_LIBGENERIC_SUPPORT
3059 Support for lib/libgeneric.o in SPL binary
3061 CONFIG_SPL_ENV_SUPPORT
3062 Support for the environment operating in SPL binary
3064 CONFIG_SPL_NET_SUPPORT
3065 Support for the net/libnet.o in SPL binary.
3066 It conflicts with SPL env from storage medium specified by
3067 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3070 Image offset to which the SPL should be padded before appending
3071 the SPL payload. By default, this is defined as
3072 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3073 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3074 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3077 Final target image containing SPL and payload. Some SPLs
3078 use an arch-specific makefile fragment instead, for
3079 example if more than one image needs to be produced.
3081 CONFIG_FIT_SPL_PRINT
3082 Printing information about a FIT image adds quite a bit of
3083 code to SPL. So this is normally disabled in SPL. Use this
3084 option to re-enable it. This will affect the output of the
3085 bootm command when booting a FIT image.
3090 [so far only for SMDK2400 boards]
3092 - Modem support enable:
3093 CONFIG_MODEM_SUPPORT
3095 - RTS/CTS Flow control enable:
3098 - Modem debug support:
3099 CONFIG_MODEM_SUPPORT_DEBUG
3101 Enables debugging stuff (char screen[1024], dbg())
3102 for modem support. Useful only with BDI2000.
3104 - Interrupt support (PPC):
3106 There are common interrupt_init() and timer_interrupt()
3107 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3108 for CPU specific initialization. interrupt_init_cpu()
3109 should set decrementer_count to appropriate value. If
3110 CPU resets decrementer automatically after interrupt
3111 (ppc4xx) it should set decrementer_count to zero.
3112 timer_interrupt() calls timer_interrupt_cpu() for CPU
3113 specific handling. If board has watchdog / status_led
3114 / other_activity_monitor it works automatically from
3115 general timer_interrupt().
3119 In the target system modem support is enabled when a
3120 specific key (key combination) is pressed during
3121 power-on. Otherwise U-Boot will boot normally
3122 (autoboot). The key_pressed() function is called from
3123 board_init(). Currently key_pressed() is a dummy
3124 function, returning 1 and thus enabling modem
3127 If there are no modem init strings in the
3128 environment, U-Boot proceed to autoboot; the
3129 previous output (banner, info printfs) will be
3132 See also: doc/README.Modem
3134 Board initialization settings:
3135 ------------------------------
3137 During Initialization u-boot calls a number of board specific functions
3138 to allow the preparation of board specific prerequisites, e.g. pin setup
3139 before drivers are initialized. To enable these callbacks the
3140 following configuration macros have to be defined. Currently this is
3141 architecture specific, so please check arch/your_architecture/lib/board.c
3142 typically in board_init_f() and board_init_r().
3144 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3145 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3146 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3147 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3149 Configuration Settings:
3150 -----------------------
3152 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3153 undefine this when you're short of memory.
3155 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3156 width of the commands listed in the 'help' command output.
3158 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3159 prompt for user input.
3161 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3163 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3165 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3167 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3168 the application (usually a Linux kernel) when it is
3171 - CONFIG_SYS_BAUDRATE_TABLE:
3172 List of legal baudrate settings for this board.
3174 - CONFIG_SYS_CONSOLE_INFO_QUIET
3175 Suppress display of console information at boot.
3177 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3178 If the board specific function
3179 extern int overwrite_console (void);
3180 returns 1, the stdin, stderr and stdout are switched to the
3181 serial port, else the settings in the environment are used.
3183 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3184 Enable the call to overwrite_console().
3186 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3187 Enable overwrite of previous console environment settings.
3189 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3190 Begin and End addresses of the area used by the
3193 - CONFIG_SYS_ALT_MEMTEST:
3194 Enable an alternate, more extensive memory test.
3196 - CONFIG_SYS_MEMTEST_SCRATCH:
3197 Scratch address used by the alternate memory test
3198 You only need to set this if address zero isn't writeable
3200 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3201 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3202 this specified memory area will get subtracted from the top
3203 (end) of RAM and won't get "touched" at all by U-Boot. By
3204 fixing up gd->ram_size the Linux kernel should gets passed
3205 the now "corrected" memory size and won't touch it either.
3206 This should work for arch/ppc and arch/powerpc. Only Linux
3207 board ports in arch/powerpc with bootwrapper support that
3208 recalculate the memory size from the SDRAM controller setup
3209 will have to get fixed in Linux additionally.
3211 This option can be used as a workaround for the 440EPx/GRx
3212 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3215 WARNING: Please make sure that this value is a multiple of
3216 the Linux page size (normally 4k). If this is not the case,
3217 then the end address of the Linux memory will be located at a
3218 non page size aligned address and this could cause major
3221 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3222 Enable temporary baudrate change while serial download
3224 - CONFIG_SYS_SDRAM_BASE:
3225 Physical start address of SDRAM. _Must_ be 0 here.
3227 - CONFIG_SYS_MBIO_BASE:
3228 Physical start address of Motherboard I/O (if using a
3231 - CONFIG_SYS_FLASH_BASE:
3232 Physical start address of Flash memory.
3234 - CONFIG_SYS_MONITOR_BASE:
3235 Physical start address of boot monitor code (set by
3236 make config files to be same as the text base address
3237 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3238 CONFIG_SYS_FLASH_BASE when booting from flash.
3240 - CONFIG_SYS_MONITOR_LEN:
3241 Size of memory reserved for monitor code, used to
3242 determine _at_compile_time_ (!) if the environment is
3243 embedded within the U-Boot image, or in a separate
3246 - CONFIG_SYS_MALLOC_LEN:
3247 Size of DRAM reserved for malloc() use.
3249 - CONFIG_SYS_BOOTM_LEN:
3250 Normally compressed uImages are limited to an
3251 uncompressed size of 8 MBytes. If this is not enough,
3252 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3253 to adjust this setting to your needs.
3255 - CONFIG_SYS_BOOTMAPSZ:
3256 Maximum size of memory mapped by the startup code of
3257 the Linux kernel; all data that must be processed by
3258 the Linux kernel (bd_info, boot arguments, FDT blob if
3259 used) must be put below this limit, unless "bootm_low"
3260 enviroment variable is defined and non-zero. In such case
3261 all data for the Linux kernel must be between "bootm_low"
3262 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3263 variable "bootm_mapsize" will override the value of
3264 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3265 then the value in "bootm_size" will be used instead.
3267 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3268 Enable initrd_high functionality. If defined then the
3269 initrd_high feature is enabled and the bootm ramdisk subcommand
3272 - CONFIG_SYS_BOOT_GET_CMDLINE:
3273 Enables allocating and saving kernel cmdline in space between
3274 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3276 - CONFIG_SYS_BOOT_GET_KBD:
3277 Enables allocating and saving a kernel copy of the bd_info in
3278 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3280 - CONFIG_SYS_MAX_FLASH_BANKS:
3281 Max number of Flash memory banks
3283 - CONFIG_SYS_MAX_FLASH_SECT:
3284 Max number of sectors on a Flash chip
3286 - CONFIG_SYS_FLASH_ERASE_TOUT:
3287 Timeout for Flash erase operations (in ms)
3289 - CONFIG_SYS_FLASH_WRITE_TOUT:
3290 Timeout for Flash write operations (in ms)
3292 - CONFIG_SYS_FLASH_LOCK_TOUT
3293 Timeout for Flash set sector lock bit operation (in ms)
3295 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3296 Timeout for Flash clear lock bits operation (in ms)
3298 - CONFIG_SYS_FLASH_PROTECTION
3299 If defined, hardware flash sectors protection is used
3300 instead of U-Boot software protection.
3302 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3304 Enable TFTP transfers directly to flash memory;
3305 without this option such a download has to be
3306 performed in two steps: (1) download to RAM, and (2)
3307 copy from RAM to flash.
3309 The two-step approach is usually more reliable, since
3310 you can check if the download worked before you erase
3311 the flash, but in some situations (when system RAM is
3312 too limited to allow for a temporary copy of the
3313 downloaded image) this option may be very useful.
3315 - CONFIG_SYS_FLASH_CFI:
3316 Define if the flash driver uses extra elements in the
3317 common flash structure for storing flash geometry.
3319 - CONFIG_FLASH_CFI_DRIVER
3320 This option also enables the building of the cfi_flash driver
3321 in the drivers directory
3323 - CONFIG_FLASH_CFI_MTD
3324 This option enables the building of the cfi_mtd driver
3325 in the drivers directory. The driver exports CFI flash
3328 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3329 Use buffered writes to flash.
3331 - CONFIG_FLASH_SPANSION_S29WS_N
3332 s29ws-n MirrorBit flash has non-standard addresses for buffered
3335 - CONFIG_SYS_FLASH_QUIET_TEST
3336 If this option is defined, the common CFI flash doesn't
3337 print it's warning upon not recognized FLASH banks. This
3338 is useful, if some of the configured banks are only
3339 optionally available.
3341 - CONFIG_FLASH_SHOW_PROGRESS
3342 If defined (must be an integer), print out countdown
3343 digits and dots. Recommended value: 45 (9..1) for 80
3344 column displays, 15 (3..1) for 40 column displays.
3346 - CONFIG_FLASH_VERIFY
3347 If defined, the content of the flash (destination) is compared
3348 against the source after the write operation. An error message
3349 will be printed when the contents are not identical.
3350 Please note that this option is useless in nearly all cases,
3351 since such flash programming errors usually are detected earlier
3352 while unprotecting/erasing/programming. Please only enable
3353 this option if you really know what you are doing.
3355 - CONFIG_SYS_RX_ETH_BUFFER:
3356 Defines the number of Ethernet receive buffers. On some
3357 Ethernet controllers it is recommended to set this value
3358 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3359 buffers can be full shortly after enabling the interface
3360 on high Ethernet traffic.
3361 Defaults to 4 if not defined.
3363 - CONFIG_ENV_MAX_ENTRIES
3365 Maximum number of entries in the hash table that is used
3366 internally to store the environment settings. The default
3367 setting is supposed to be generous and should work in most
3368 cases. This setting can be used to tune behaviour; see
3369 lib/hashtable.c for details.
3371 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3372 - CONFIG_ENV_FLAGS_LIST_STATIC
3373 Enable validation of the values given to enviroment variables when
3374 calling env set. Variables can be restricted to only decimal,
3375 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3376 the variables can also be restricted to IP address or MAC address.
3378 The format of the list is:
3379 type_attribute = [s|d|x|b|i|m]
3380 access_atribute = [a|r|o|c]
3381 attributes = type_attribute[access_atribute]
3382 entry = variable_name[:attributes]
3385 The type attributes are:
3386 s - String (default)
3389 b - Boolean ([1yYtT|0nNfF])
3393 The access attributes are:
3399 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3400 Define this to a list (string) to define the ".flags"
3401 envirnoment variable in the default or embedded environment.
3403 - CONFIG_ENV_FLAGS_LIST_STATIC
3404 Define this to a list (string) to define validation that
3405 should be done if an entry is not found in the ".flags"
3406 environment variable. To override a setting in the static
3407 list, simply add an entry for the same variable name to the
3410 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3411 If defined, don't allow the -f switch to env set override variable
3414 - CONFIG_SYS_GENERIC_BOARD
3415 This selects the architecture-generic board system instead of the
3416 architecture-specific board files. It is intended to move boards
3417 to this new framework over time. Defining this will disable the
3418 arch/foo/lib/board.c file and use common/board_f.c and
3419 common/board_r.c instead. To use this option your architecture
3420 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3421 its config.mk file). If you find problems enabling this option on
3422 your board please report the problem and send patches!
3424 - CONFIG_SYS_SYM_OFFSETS
3425 This is set by architectures that use offsets for link symbols
3426 instead of absolute values. So bss_start is obtained using an
3427 offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
3428 directly. You should not need to touch this setting.
3430 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3431 This is set by OMAP boards for the max time that reset should
3432 be asserted. See doc/README.omap-reset-time for details on how
3433 the value can be calulated on a given board.
3435 The following definitions that deal with the placement and management
3436 of environment data (variable area); in general, we support the
3437 following configurations:
3439 - CONFIG_BUILD_ENVCRC:
3441 Builds up envcrc with the target environment so that external utils
3442 may easily extract it and embed it in final U-Boot images.
3444 - CONFIG_ENV_IS_IN_FLASH:
3446 Define this if the environment is in flash memory.
3448 a) The environment occupies one whole flash sector, which is
3449 "embedded" in the text segment with the U-Boot code. This
3450 happens usually with "bottom boot sector" or "top boot
3451 sector" type flash chips, which have several smaller
3452 sectors at the start or the end. For instance, such a
3453 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3454 such a case you would place the environment in one of the
3455 4 kB sectors - with U-Boot code before and after it. With
3456 "top boot sector" type flash chips, you would put the
3457 environment in one of the last sectors, leaving a gap
3458 between U-Boot and the environment.
3460 - CONFIG_ENV_OFFSET:
3462 Offset of environment data (variable area) to the
3463 beginning of flash memory; for instance, with bottom boot
3464 type flash chips the second sector can be used: the offset
3465 for this sector is given here.
3467 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3471 This is just another way to specify the start address of
3472 the flash sector containing the environment (instead of
3475 - CONFIG_ENV_SECT_SIZE:
3477 Size of the sector containing the environment.
3480 b) Sometimes flash chips have few, equal sized, BIG sectors.
3481 In such a case you don't want to spend a whole sector for
3486 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3487 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3488 of this flash sector for the environment. This saves
3489 memory for the RAM copy of the environment.
3491 It may also save flash memory if you decide to use this
3492 when your environment is "embedded" within U-Boot code,
3493 since then the remainder of the flash sector could be used
3494 for U-Boot code. It should be pointed out that this is
3495 STRONGLY DISCOURAGED from a robustness point of view:
3496 updating the environment in flash makes it always
3497 necessary to erase the WHOLE sector. If something goes
3498 wrong before the contents has been restored from a copy in
3499 RAM, your target system will be dead.
3501 - CONFIG_ENV_ADDR_REDUND
3502 CONFIG_ENV_SIZE_REDUND
3504 These settings describe a second storage area used to hold
3505 a redundant copy of the environment data, so that there is
3506 a valid backup copy in case there is a power failure during
3507 a "saveenv" operation.
3509 BE CAREFUL! Any changes to the flash layout, and some changes to the
3510 source code will make it necessary to adapt <board>/u-boot.lds*
3514 - CONFIG_ENV_IS_IN_NVRAM:
3516 Define this if you have some non-volatile memory device
3517 (NVRAM, battery buffered SRAM) which you want to use for the
3523 These two #defines are used to determine the memory area you
3524 want to use for environment. It is assumed that this memory
3525 can just be read and written to, without any special
3528 BE CAREFUL! The first access to the environment happens quite early
3529 in U-Boot initalization (when we try to get the setting of for the
3530 console baudrate). You *MUST* have mapped your NVRAM area then, or
3533 Please note that even with NVRAM we still use a copy of the
3534 environment in RAM: we could work on NVRAM directly, but we want to
3535 keep settings there always unmodified except somebody uses "saveenv"
3536 to save the current settings.
3539 - CONFIG_ENV_IS_IN_EEPROM:
3541 Use this if you have an EEPROM or similar serial access
3542 device and a driver for it.
3544 - CONFIG_ENV_OFFSET:
3547 These two #defines specify the offset and size of the
3548 environment area within the total memory of your EEPROM.
3550 - CONFIG_SYS_I2C_EEPROM_ADDR:
3551 If defined, specified the chip address of the EEPROM device.
3552 The default address is zero.
3554 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3555 If defined, the number of bits used to address bytes in a
3556 single page in the EEPROM device. A 64 byte page, for example
3557 would require six bits.
3559 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3560 If defined, the number of milliseconds to delay between
3561 page writes. The default is zero milliseconds.
3563 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3564 The length in bytes of the EEPROM memory array address. Note
3565 that this is NOT the chip address length!
3567 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3568 EEPROM chips that implement "address overflow" are ones
3569 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3570 address and the extra bits end up in the "chip address" bit
3571 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3574 Note that we consider the length of the address field to
3575 still be one byte because the extra address bits are hidden
3576 in the chip address.
3578 - CONFIG_SYS_EEPROM_SIZE:
3579 The size in bytes of the EEPROM device.
3581 - CONFIG_ENV_EEPROM_IS_ON_I2C
3582 define this, if you have I2C and SPI activated, and your
3583 EEPROM, which holds the environment, is on the I2C bus.
3585 - CONFIG_I2C_ENV_EEPROM_BUS
3586 if you have an Environment on an EEPROM reached over
3587 I2C muxes, you can define here, how to reach this
3588 EEPROM. For example:
3590 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
3592 EEPROM which holds the environment, is reached over
3593 a pca9547 i2c mux with address 0x70, channel 3.
3595 - CONFIG_ENV_IS_IN_DATAFLASH:
3597 Define this if you have a DataFlash memory device which you
3598 want to use for the environment.
3600 - CONFIG_ENV_OFFSET:
3604 These three #defines specify the offset and size of the
3605 environment area within the total memory of your DataFlash placed
3606 at the specified address.
3608 - CONFIG_ENV_IS_IN_REMOTE:
3610 Define this if you have a remote memory space which you
3611 want to use for the local device's environment.
3616 These two #defines specify the address and size of the
3617 environment area within the remote memory space. The
3618 local device can get the environment from remote memory
3619 space by SRIO or PCIE links.
3621 BE CAREFUL! For some special cases, the local device can not use
3622 "saveenv" command. For example, the local device will get the
3623 environment stored in a remote NOR flash by SRIO or PCIE link,
3624 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3626 - CONFIG_ENV_IS_IN_NAND:
3628 Define this if you have a NAND device which you want to use
3629 for the environment.
3631 - CONFIG_ENV_OFFSET:
3634 These two #defines specify the offset and size of the environment
3635 area within the first NAND device. CONFIG_ENV_OFFSET must be
3636 aligned to an erase block boundary.
3638 - CONFIG_ENV_OFFSET_REDUND (optional):
3640 This setting describes a second storage area of CONFIG_ENV_SIZE
3641 size used to hold a redundant copy of the environment data, so
3642 that there is a valid backup copy in case there is a power failure
3643 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3644 aligned to an erase block boundary.
3646 - CONFIG_ENV_RANGE (optional):
3648 Specifies the length of the region in which the environment
3649 can be written. This should be a multiple of the NAND device's
3650 block size. Specifying a range with more erase blocks than
3651 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3652 the range to be avoided.
3654 - CONFIG_ENV_OFFSET_OOB (optional):
3656 Enables support for dynamically retrieving the offset of the
3657 environment from block zero's out-of-band data. The
3658 "nand env.oob" command can be used to record this offset.
3659 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3660 using CONFIG_ENV_OFFSET_OOB.
3662 - CONFIG_NAND_ENV_DST
3664 Defines address in RAM to which the nand_spl code should copy the
3665 environment. If redundant environment is used, it will be copied to
3666 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3668 - CONFIG_ENV_IS_IN_UBI:
3670 Define this if you have an UBI volume that you want to use for the
3671 environment. This has the benefit of wear-leveling the environment
3672 accesses, which is important on NAND.
3674 - CONFIG_ENV_UBI_PART:
3676 Define this to a string that is the mtd partition containing the UBI.
3678 - CONFIG_ENV_UBI_VOLUME:
3680 Define this to the name of the volume that you want to store the
3683 - CONFIG_ENV_UBI_VOLUME_REDUND:
3685 Define this to the name of another volume to store a second copy of
3686 the environment in. This will enable redundant environments in UBI.
3687 It is assumed that both volumes are in the same MTD partition.
3689 - CONFIG_UBI_SILENCE_MSG
3690 - CONFIG_UBIFS_SILENCE_MSG
3692 You will probably want to define these to avoid a really noisy system
3693 when storing the env in UBI.
3695 - CONFIG_ENV_IS_IN_MMC:
3697 Define this if you have an MMC device which you want to use for the
3700 - CONFIG_SYS_MMC_ENV_DEV:
3702 Specifies which MMC device the environment is stored in.
3704 - CONFIG_SYS_MMC_ENV_PART (optional):
3706 Specifies which MMC partition the environment is stored in. If not
3707 set, defaults to partition 0, the user area. Common values might be
3708 1 (first MMC boot partition), 2 (second MMC boot partition).
3710 - CONFIG_ENV_OFFSET:
3713 These two #defines specify the offset and size of the environment
3714 area within the specified MMC device.
3716 If offset is positive (the usual case), it is treated as relative to
3717 the start of the MMC partition. If offset is negative, it is treated
3718 as relative to the end of the MMC partition. This can be useful if
3719 your board may be fitted with different MMC devices, which have
3720 different sizes for the MMC partitions, and you always want the
3721 environment placed at the very end of the partition, to leave the
3722 maximum possible space before it, to store other data.
3724 These two values are in units of bytes, but must be aligned to an
3725 MMC sector boundary.
3727 - CONFIG_ENV_OFFSET_REDUND (optional):
3729 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
3730 hold a redundant copy of the environment data. This provides a
3731 valid backup copy in case the other copy is corrupted, e.g. due
3732 to a power failure during a "saveenv" operation.
3734 This value may also be positive or negative; this is handled in the
3735 same way as CONFIG_ENV_OFFSET.
3737 This value is also in units of bytes, but must also be aligned to
3738 an MMC sector boundary.
3740 - CONFIG_ENV_SIZE_REDUND (optional):
3742 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
3743 set. If this value is set, it must be set to the same value as
3746 - CONFIG_SYS_SPI_INIT_OFFSET
3748 Defines offset to the initial SPI buffer area in DPRAM. The
3749 area is used at an early stage (ROM part) if the environment
3750 is configured to reside in the SPI EEPROM: We need a 520 byte
3751 scratch DPRAM area. It is used between the two initialization
3752 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3753 to be a good choice since it makes it far enough from the
3754 start of the data area as well as from the stack pointer.
3756 Please note that the environment is read-only until the monitor
3757 has been relocated to RAM and a RAM copy of the environment has been
3758 created; also, when using EEPROM you will have to use getenv_f()
3759 until then to read environment variables.
3761 The environment is protected by a CRC32 checksum. Before the monitor
3762 is relocated into RAM, as a result of a bad CRC you will be working
3763 with the compiled-in default environment - *silently*!!! [This is
3764 necessary, because the first environment variable we need is the
3765 "baudrate" setting for the console - if we have a bad CRC, we don't
3766 have any device yet where we could complain.]
3768 Note: once the monitor has been relocated, then it will complain if
3769 the default environment is used; a new CRC is computed as soon as you
3770 use the "saveenv" command to store a valid environment.
3772 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3773 Echo the inverted Ethernet link state to the fault LED.
3775 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3776 also needs to be defined.
3778 - CONFIG_SYS_FAULT_MII_ADDR:
3779 MII address of the PHY to check for the Ethernet link state.
3781 - CONFIG_NS16550_MIN_FUNCTIONS:
3782 Define this if you desire to only have use of the NS16550_init
3783 and NS16550_putc functions for the serial driver located at
3784 drivers/serial/ns16550.c. This option is useful for saving
3785 space for already greatly restricted images, including but not
3786 limited to NAND_SPL configurations.
3788 - CONFIG_DISPLAY_BOARDINFO
3789 Display information about the board that U-Boot is running on
3790 when U-Boot starts up. The board function checkboard() is called
3793 - CONFIG_DISPLAY_BOARDINFO_LATE
3794 Similar to the previous option, but display this information
3795 later, once stdio is running and output goes to the LCD, if
3798 Low Level (hardware related) configuration options:
3799 ---------------------------------------------------
3801 - CONFIG_SYS_CACHELINE_SIZE:
3802 Cache Line Size of the CPU.
3804 - CONFIG_SYS_DEFAULT_IMMR:
3805 Default address of the IMMR after system reset.
3807 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3808 and RPXsuper) to be able to adjust the position of
3809 the IMMR register after a reset.
3811 - CONFIG_SYS_CCSRBAR_DEFAULT:
3812 Default (power-on reset) physical address of CCSR on Freescale
3815 - CONFIG_SYS_CCSRBAR:
3816 Virtual address of CCSR. On a 32-bit build, this is typically
3817 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3819 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3820 for cross-platform code that uses that macro instead.
3822 - CONFIG_SYS_CCSRBAR_PHYS:
3823 Physical address of CCSR. CCSR can be relocated to a new
3824 physical address, if desired. In this case, this macro should
3825 be set to that address. Otherwise, it should be set to the
3826 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3827 is typically relocated on 36-bit builds. It is recommended
3828 that this macro be defined via the _HIGH and _LOW macros:
3830 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3831 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3833 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3834 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3835 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3836 used in assembly code, so it must not contain typecasts or
3837 integer size suffixes (e.g. "ULL").
3839 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3840 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3841 used in assembly code, so it must not contain typecasts or
3842 integer size suffixes (e.g. "ULL").
3844 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3845 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3846 forced to a value that ensures that CCSR is not relocated.
3848 - Floppy Disk Support:
3849 CONFIG_SYS_FDC_DRIVE_NUMBER
3851 the default drive number (default value 0)
3853 CONFIG_SYS_ISA_IO_STRIDE
3855 defines the spacing between FDC chipset registers
3858 CONFIG_SYS_ISA_IO_OFFSET
3860 defines the offset of register from address. It
3861 depends on which part of the data bus is connected to
3862 the FDC chipset. (default value 0)
3864 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3865 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3868 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3869 fdc_hw_init() is called at the beginning of the FDC
3870 setup. fdc_hw_init() must be provided by the board
3871 source code. It is used to make hardware dependant
3875 Most IDE controllers were designed to be connected with PCI
3876 interface. Only few of them were designed for AHB interface.
3877 When software is doing ATA command and data transfer to
3878 IDE devices through IDE-AHB controller, some additional
3879 registers accessing to these kind of IDE-AHB controller
3882 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3883 DO NOT CHANGE unless you know exactly what you're
3884 doing! (11-4) [MPC8xx/82xx systems only]
3886 - CONFIG_SYS_INIT_RAM_ADDR:
3888 Start address of memory area that can be used for
3889 initial data and stack; please note that this must be
3890 writable memory that is working WITHOUT special
3891 initialization, i. e. you CANNOT use normal RAM which
3892 will become available only after programming the
3893 memory controller and running certain initialization
3896 U-Boot uses the following memory types:
3897 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
3898 - MPC824X: data cache
3899 - PPC4xx: data cache
3901 - CONFIG_SYS_GBL_DATA_OFFSET:
3903 Offset of the initial data structure in the memory
3904 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3905 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3906 data is located at the end of the available space
3907 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3908 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
3909 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3910 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3913 On the MPC824X (or other systems that use the data
3914 cache for initial memory) the address chosen for
3915 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3916 point to an otherwise UNUSED address space between
3917 the top of RAM and the start of the PCI space.
3919 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
3921 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
3923 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
3925 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
3927 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
3929 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3931 - CONFIG_SYS_OR_TIMING_SDRAM:
3934 - CONFIG_SYS_MAMR_PTA:
3935 periodic timer for refresh
3937 - CONFIG_SYS_DER: Debug Event Register (37-47)
3939 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3940 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3941 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3942 CONFIG_SYS_BR1_PRELIM:
3943 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3945 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3946 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3947 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3948 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3950 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
3951 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
3952 Machine Mode Register and Memory Periodic Timer
3953 Prescaler definitions (SDRAM timing)
3955 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
3956 enable I2C microcode relocation patch (MPC8xx);
3957 define relocation offset in DPRAM [DSP2]
3959 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
3960 enable SMC microcode relocation patch (MPC8xx);
3961 define relocation offset in DPRAM [SMC1]
3963 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
3964 enable SPI microcode relocation patch (MPC8xx);
3965 define relocation offset in DPRAM [SCC4]
3967 - CONFIG_SYS_USE_OSCCLK:
3968 Use OSCM clock mode on MBX8xx board. Be careful,
3969 wrong setting might damage your board. Read
3970 doc/README.MBX before setting this variable!
3972 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
3973 Offset of the bootmode word in DPRAM used by post
3974 (Power On Self Tests). This definition overrides
3975 #define'd default value in commproc.h resp.
3978 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
3979 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
3980 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
3981 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
3982 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
3983 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
3984 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
3985 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
3986 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
3988 - CONFIG_PCI_DISABLE_PCIE:
3989 Disable PCI-Express on systems where it is supported but not
3992 - CONFIG_PCI_ENUM_ONLY
3993 Only scan through and get the devices on the busses.
3994 Don't do any setup work, presumably because someone or
3995 something has already done it, and we don't need to do it
3996 a second time. Useful for platforms that are pre-booted
3997 by coreboot or similar.
3999 - CONFIG_PCI_INDIRECT_BRIDGE:
4000 Enable support for indirect PCI bridges.
4003 Chip has SRIO or not
4006 Board has SRIO 1 port available
4009 Board has SRIO 2 port available
4011 - CONFIG_SRIO_PCIE_BOOT_MASTER
4012 Board can support master function for Boot from SRIO and PCIE
4014 - CONFIG_SYS_SRIOn_MEM_VIRT:
4015 Virtual Address of SRIO port 'n' memory region
4017 - CONFIG_SYS_SRIOn_MEM_PHYS:
4018 Physical Address of SRIO port 'n' memory region
4020 - CONFIG_SYS_SRIOn_MEM_SIZE:
4021 Size of SRIO port 'n' memory region
4023 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4024 Defined to tell the NAND controller that the NAND chip is using
4026 Not all NAND drivers use this symbol.
4027 Example of drivers that use it:
4028 - drivers/mtd/nand/ndfc.c
4029 - drivers/mtd/nand/mxc_nand.c
4031 - CONFIG_SYS_NDFC_EBC0_CFG
4032 Sets the EBC0_CFG register for the NDFC. If not defined
4033 a default value will be used.
4036 Get DDR timing information from an I2C EEPROM. Common
4037 with pluggable memory modules such as SODIMMs
4040 I2C address of the SPD EEPROM
4042 - CONFIG_SYS_SPD_BUS_NUM
4043 If SPD EEPROM is on an I2C bus other than the first
4044 one, specify here. Note that the value must resolve
4045 to something your driver can deal with.
4047 - CONFIG_SYS_DDR_RAW_TIMING
4048 Get DDR timing information from other than SPD. Common with
4049 soldered DDR chips onboard without SPD. DDR raw timing
4050 parameters are extracted from datasheet and hard-coded into
4051 header files or board specific files.
4053 - CONFIG_FSL_DDR_INTERACTIVE
4054 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4056 - CONFIG_SYS_83XX_DDR_USES_CS0
4057 Only for 83xx systems. If specified, then DDR should
4058 be configured using CS0 and CS1 instead of CS2 and CS3.
4060 - CONFIG_ETHER_ON_FEC[12]
4061 Define to enable FEC[12] on a 8xx series processor.
4063 - CONFIG_FEC[12]_PHY
4064 Define to the hardcoded PHY address which corresponds
4065 to the given FEC; i. e.
4066 #define CONFIG_FEC1_PHY 4
4067 means that the PHY with address 4 is connected to FEC1
4069 When set to -1, means to probe for first available.
4071 - CONFIG_FEC[12]_PHY_NORXERR
4072 The PHY does not have a RXERR line (RMII only).
4073 (so program the FEC to ignore it).
4076 Enable RMII mode for all FECs.
4077 Note that this is a global option, we can't
4078 have one FEC in standard MII mode and another in RMII mode.
4080 - CONFIG_CRC32_VERIFY
4081 Add a verify option to the crc32 command.
4084 => crc32 -v <address> <count> <crc32>
4086 Where address/count indicate a memory area
4087 and crc32 is the correct crc32 which the
4091 Add the "loopw" memory command. This only takes effect if
4092 the memory commands are activated globally (CONFIG_CMD_MEM).
4095 Add the "mdc" and "mwc" memory commands. These are cyclic
4100 This command will print 4 bytes (10,11,12,13) each 500 ms.
4102 => mwc.l 100 12345678 10
4103 This command will write 12345678 to address 100 all 10 ms.
4105 This only takes effect if the memory commands are activated
4106 globally (CONFIG_CMD_MEM).
4108 - CONFIG_SKIP_LOWLEVEL_INIT
4109 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4110 low level initializations (like setting up the memory
4111 controller) are omitted and/or U-Boot does not
4112 relocate itself into RAM.
4114 Normally this variable MUST NOT be defined. The only
4115 exception is when U-Boot is loaded (to RAM) by some
4116 other boot loader or by a debugger which performs
4117 these initializations itself.
4120 Modifies the behaviour of start.S when compiling a loader
4121 that is executed before the actual U-Boot. E.g. when
4122 compiling a NAND SPL.
4124 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4125 Only for 85xx systems. If this variable is specified, the section
4126 .resetvec is not kept and the section .bootpg is placed in the
4127 previous 4k of the .text section.
4129 - CONFIG_ARCH_MAP_SYSMEM
4130 Generally U-Boot (and in particular the md command) uses
4131 effective address. It is therefore not necessary to regard
4132 U-Boot address as virtual addresses that need to be translated
4133 to physical addresses. However, sandbox requires this, since
4134 it maintains its own little RAM buffer which contains all
4135 addressable memory. This option causes some memory accesses
4136 to be mapped through map_sysmem() / unmap_sysmem().
4138 - CONFIG_USE_ARCH_MEMCPY
4139 CONFIG_USE_ARCH_MEMSET
4140 If these options are used a optimized version of memcpy/memset will
4141 be used if available. These functions may be faster under some
4142 conditions but may increase the binary size.
4144 - CONFIG_X86_RESET_VECTOR
4145 If defined, the x86 reset vector code is included. This is not
4146 needed when U-Boot is running from Coreboot.
4149 Defines the MPU clock speed (in MHz).
4151 NOTE : currently only supported on AM335x platforms.
4153 Freescale QE/FMAN Firmware Support:
4154 -----------------------------------
4156 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4157 loading of "firmware", which is encoded in the QE firmware binary format.
4158 This firmware often needs to be loaded during U-Boot booting, so macros
4159 are used to identify the storage device (NOR flash, SPI, etc) and the address
4162 - CONFIG_SYS_QE_FMAN_FW_ADDR
4163 The address in the storage device where the firmware is located. The
4164 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4167 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4168 The maximum possible size of the firmware. The firmware binary format
4169 has a field that specifies the actual size of the firmware, but it
4170 might not be possible to read any part of the firmware unless some
4171 local storage is allocated to hold the entire firmware first.
4173 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4174 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4175 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4176 virtual address in NOR flash.
4178 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4179 Specifies that QE/FMAN firmware is located in NAND flash.
4180 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4182 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4183 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4184 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4186 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4187 Specifies that QE/FMAN firmware is located on the primary SPI
4188 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4190 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4191 Specifies that QE/FMAN firmware is located in the remote (master)
4192 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4193 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4194 window->master inbound window->master LAW->the ucode address in
4195 master's memory space.
4197 Building the Software:
4198 ======================
4200 Building U-Boot has been tested in several native build environments
4201 and in many different cross environments. Of course we cannot support
4202 all possibly existing versions of cross development tools in all
4203 (potentially obsolete) versions. In case of tool chain problems we
4204 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4205 which is extensively used to build and test U-Boot.
4207 If you are not using a native environment, it is assumed that you
4208 have GNU cross compiling tools available in your path. In this case,
4209 you must set the environment variable CROSS_COMPILE in your shell.
4210 Note that no changes to the Makefile or any other source files are
4211 necessary. For example using the ELDK on a 4xx CPU, please enter:
4213 $ CROSS_COMPILE=ppc_4xx-
4214 $ export CROSS_COMPILE
4216 Note: If you wish to generate Windows versions of the utilities in
4217 the tools directory you can use the MinGW toolchain
4218 (http://www.mingw.org). Set your HOST tools to the MinGW
4219 toolchain and execute 'make tools'. For example:
4221 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4223 Binaries such as tools/mkimage.exe will be created which can
4224 be executed on computers running Windows.
4226 U-Boot is intended to be simple to build. After installing the
4227 sources you must configure U-Boot for one specific board type. This
4232 where "NAME_config" is the name of one of the existing configu-
4233 rations; see boards.cfg for supported names.
4235 Note: for some board special configuration names may exist; check if
4236 additional information is available from the board vendor; for
4237 instance, the TQM823L systems are available without (standard)
4238 or with LCD support. You can select such additional "features"
4239 when choosing the configuration, i. e.
4242 - will configure for a plain TQM823L, i. e. no LCD support
4244 make TQM823L_LCD_config
4245 - will configure for a TQM823L with U-Boot console on LCD
4250 Finally, type "make all", and you should get some working U-Boot
4251 images ready for download to / installation on your system:
4253 - "u-boot.bin" is a raw binary image
4254 - "u-boot" is an image in ELF binary format
4255 - "u-boot.srec" is in Motorola S-Record format
4257 By default the build is performed locally and the objects are saved
4258 in the source directory. One of the two methods can be used to change
4259 this behavior and build U-Boot to some external directory:
4261 1. Add O= to the make command line invocations:
4263 make O=/tmp/build distclean
4264 make O=/tmp/build NAME_config
4265 make O=/tmp/build all
4267 2. Set environment variable BUILD_DIR to point to the desired location:
4269 export BUILD_DIR=/tmp/build
4274 Note that the command line "O=" setting overrides the BUILD_DIR environment
4278 Please be aware that the Makefiles assume you are using GNU make, so
4279 for instance on NetBSD you might need to use "gmake" instead of
4283 If the system board that you have is not listed, then you will need
4284 to port U-Boot to your hardware platform. To do this, follow these
4287 1. Add a new configuration option for your board to the toplevel
4288 "boards.cfg" file, using the existing entries as examples.
4289 Follow the instructions there to keep the boards in order.
4290 2. Create a new directory to hold your board specific code. Add any
4291 files you need. In your board directory, you will need at least
4292 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4293 3. Create a new configuration file "include/configs/<board>.h" for
4295 3. If you're porting U-Boot to a new CPU, then also create a new
4296 directory to hold your CPU specific code. Add any files you need.
4297 4. Run "make <board>_config" with your new name.
4298 5. Type "make", and you should get a working "u-boot.srec" file
4299 to be installed on your target system.
4300 6. Debug and solve any problems that might arise.
4301 [Of course, this last step is much harder than it sounds.]
4304 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4305 ==============================================================
4307 If you have modified U-Boot sources (for instance added a new board
4308 or support for new devices, a new CPU, etc.) you are expected to
4309 provide feedback to the other developers. The feedback normally takes
4310 the form of a "patch", i. e. a context diff against a certain (latest
4311 official or latest in the git repository) version of U-Boot sources.
4313 But before you submit such a patch, please verify that your modifi-
4314 cation did not break existing code. At least make sure that *ALL* of
4315 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4316 just run the "MAKEALL" script, which will configure and build U-Boot
4317 for ALL supported system. Be warned, this will take a while. You can
4318 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4319 environment variable to the script, i. e. to use the ELDK cross tools
4322 CROSS_COMPILE=ppc_8xx- MAKEALL
4324 or to build on a native PowerPC system you can type
4326 CROSS_COMPILE=' ' MAKEALL
4328 When using the MAKEALL script, the default behaviour is to build
4329 U-Boot in the source directory. This location can be changed by
4330 setting the BUILD_DIR environment variable. Also, for each target
4331 built, the MAKEALL script saves two log files (<target>.ERR and
4332 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4333 location can be changed by setting the MAKEALL_LOGDIR environment
4334 variable. For example:
4336 export BUILD_DIR=/tmp/build
4337 export MAKEALL_LOGDIR=/tmp/log
4338 CROSS_COMPILE=ppc_8xx- MAKEALL
4340 With the above settings build objects are saved in the /tmp/build,
4341 log files are saved in the /tmp/log and the source tree remains clean
4342 during the whole build process.
4345 See also "U-Boot Porting Guide" below.
4348 Monitor Commands - Overview:
4349 ============================
4351 go - start application at address 'addr'
4352 run - run commands in an environment variable
4353 bootm - boot application image from memory
4354 bootp - boot image via network using BootP/TFTP protocol
4355 bootz - boot zImage from memory
4356 tftpboot- boot image via network using TFTP protocol
4357 and env variables "ipaddr" and "serverip"
4358 (and eventually "gatewayip")
4359 tftpput - upload a file via network using TFTP protocol
4360 rarpboot- boot image via network using RARP/TFTP protocol
4361 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4362 loads - load S-Record file over serial line
4363 loadb - load binary file over serial line (kermit mode)
4365 mm - memory modify (auto-incrementing)
4366 nm - memory modify (constant address)
4367 mw - memory write (fill)
4369 cmp - memory compare
4370 crc32 - checksum calculation
4371 i2c - I2C sub-system
4372 sspi - SPI utility commands
4373 base - print or set address offset
4374 printenv- print environment variables
4375 setenv - set environment variables
4376 saveenv - save environment variables to persistent storage
4377 protect - enable or disable FLASH write protection
4378 erase - erase FLASH memory
4379 flinfo - print FLASH memory information
4380 nand - NAND memory operations (see doc/README.nand)
4381 bdinfo - print Board Info structure
4382 iminfo - print header information for application image
4383 coninfo - print console devices and informations
4384 ide - IDE sub-system
4385 loop - infinite loop on address range
4386 loopw - infinite write loop on address range
4387 mtest - simple RAM test
4388 icache - enable or disable instruction cache
4389 dcache - enable or disable data cache
4390 reset - Perform RESET of the CPU
4391 echo - echo args to console
4392 version - print monitor version
4393 help - print online help
4394 ? - alias for 'help'
4397 Monitor Commands - Detailed Description:
4398 ========================================
4402 For now: just type "help <command>".
4405 Environment Variables:
4406 ======================
4408 U-Boot supports user configuration using Environment Variables which
4409 can be made persistent by saving to Flash memory.
4411 Environment Variables are set using "setenv", printed using
4412 "printenv", and saved to Flash using "saveenv". Using "setenv"
4413 without a value can be used to delete a variable from the
4414 environment. As long as you don't save the environment you are
4415 working with an in-memory copy. In case the Flash area containing the
4416 environment is erased by accident, a default environment is provided.
4418 Some configuration options can be set using Environment Variables.
4420 List of environment variables (most likely not complete):
4422 baudrate - see CONFIG_BAUDRATE
4424 bootdelay - see CONFIG_BOOTDELAY
4426 bootcmd - see CONFIG_BOOTCOMMAND
4428 bootargs - Boot arguments when booting an RTOS image
4430 bootfile - Name of the image to load with TFTP
4432 bootm_low - Memory range available for image processing in the bootm
4433 command can be restricted. This variable is given as
4434 a hexadecimal number and defines lowest address allowed
4435 for use by the bootm command. See also "bootm_size"
4436 environment variable. Address defined by "bootm_low" is
4437 also the base of the initial memory mapping for the Linux
4438 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4441 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4442 This variable is given as a hexadecimal number and it
4443 defines the size of the memory region starting at base
4444 address bootm_low that is accessible by the Linux kernel
4445 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4446 as the default value if it is defined, and bootm_size is
4449 bootm_size - Memory range available for image processing in the bootm
4450 command can be restricted. This variable is given as
4451 a hexadecimal number and defines the size of the region
4452 allowed for use by the bootm command. See also "bootm_low"
4453 environment variable.
4455 updatefile - Location of the software update file on a TFTP server, used
4456 by the automatic software update feature. Please refer to
4457 documentation in doc/README.update for more details.
4459 autoload - if set to "no" (any string beginning with 'n'),
4460 "bootp" will just load perform a lookup of the
4461 configuration from the BOOTP server, but not try to
4462 load any image using TFTP
4464 autostart - if set to "yes", an image loaded using the "bootp",
4465 "rarpboot", "tftpboot" or "diskboot" commands will
4466 be automatically started (by internally calling
4469 If set to "no", a standalone image passed to the
4470 "bootm" command will be copied to the load address
4471 (and eventually uncompressed), but NOT be started.
4472 This can be used to load and uncompress arbitrary
4475 fdt_high - if set this restricts the maximum address that the
4476 flattened device tree will be copied into upon boot.
4477 For example, if you have a system with 1 GB memory
4478 at physical address 0x10000000, while Linux kernel
4479 only recognizes the first 704 MB as low memory, you
4480 may need to set fdt_high as 0x3C000000 to have the
4481 device tree blob be copied to the maximum address
4482 of the 704 MB low memory, so that Linux kernel can
4483 access it during the boot procedure.
4485 If this is set to the special value 0xFFFFFFFF then
4486 the fdt will not be copied at all on boot. For this
4487 to work it must reside in writable memory, have
4488 sufficient padding on the end of it for u-boot to
4489 add the information it needs into it, and the memory
4490 must be accessible by the kernel.
4492 fdtcontroladdr- if set this is the address of the control flattened
4493 device tree used by U-Boot when CONFIG_OF_CONTROL is
4496 i2cfast - (PPC405GP|PPC405EP only)
4497 if set to 'y' configures Linux I2C driver for fast
4498 mode (400kHZ). This environment variable is used in
4499 initialization code. So, for changes to be effective
4500 it must be saved and board must be reset.
4502 initrd_high - restrict positioning of initrd images:
4503 If this variable is not set, initrd images will be
4504 copied to the highest possible address in RAM; this
4505 is usually what you want since it allows for
4506 maximum initrd size. If for some reason you want to
4507 make sure that the initrd image is loaded below the
4508 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4509 variable to a value of "no" or "off" or "0".
4510 Alternatively, you can set it to a maximum upper
4511 address to use (U-Boot will still check that it
4512 does not overwrite the U-Boot stack and data).
4514 For instance, when you have a system with 16 MB
4515 RAM, and want to reserve 4 MB from use by Linux,
4516 you can do this by adding "mem=12M" to the value of
4517 the "bootargs" variable. However, now you must make
4518 sure that the initrd image is placed in the first
4519 12 MB as well - this can be done with
4521 setenv initrd_high 00c00000
4523 If you set initrd_high to 0xFFFFFFFF, this is an
4524 indication to U-Boot that all addresses are legal
4525 for the Linux kernel, including addresses in flash
4526 memory. In this case U-Boot will NOT COPY the
4527 ramdisk at all. This may be useful to reduce the
4528 boot time on your system, but requires that this
4529 feature is supported by your Linux kernel.
4531 ipaddr - IP address; needed for tftpboot command
4533 loadaddr - Default load address for commands like "bootp",
4534 "rarpboot", "tftpboot", "loadb" or "diskboot"
4536 loads_echo - see CONFIG_LOADS_ECHO
4538 serverip - TFTP server IP address; needed for tftpboot command
4540 bootretry - see CONFIG_BOOT_RETRY_TIME
4542 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4544 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4546 ethprime - controls which interface is used first.
4548 ethact - controls which interface is currently active.
4549 For example you can do the following
4551 => setenv ethact FEC
4552 => ping 192.168.0.1 # traffic sent on FEC
4553 => setenv ethact SCC
4554 => ping 10.0.0.1 # traffic sent on SCC
4556 ethrotate - When set to "no" U-Boot does not go through all
4557 available network interfaces.
4558 It just stays at the currently selected interface.
4560 netretry - When set to "no" each network operation will
4561 either succeed or fail without retrying.
4562 When set to "once" the network operation will
4563 fail when all the available network interfaces
4564 are tried once without success.
4565 Useful on scripts which control the retry operation
4568 npe_ucode - set load address for the NPE microcode
4570 tftpsrcport - If this is set, the value is used for TFTP's
4573 tftpdstport - If this is set, the value is used for TFTP's UDP
4574 destination port instead of the Well Know Port 69.
4576 tftpblocksize - Block size to use for TFTP transfers; if not set,
4577 we use the TFTP server's default block size
4579 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4580 seconds, minimum value is 1000 = 1 second). Defines
4581 when a packet is considered to be lost so it has to
4582 be retransmitted. The default is 5000 = 5 seconds.
4583 Lowering this value may make downloads succeed
4584 faster in networks with high packet loss rates or
4585 with unreliable TFTP servers.
4587 vlan - When set to a value < 4095 the traffic over
4588 Ethernet is encapsulated/received over 802.1q
4591 The following image location variables contain the location of images
4592 used in booting. The "Image" column gives the role of the image and is
4593 not an environment variable name. The other columns are environment
4594 variable names. "File Name" gives the name of the file on a TFTP
4595 server, "RAM Address" gives the location in RAM the image will be
4596 loaded to, and "Flash Location" gives the image's address in NOR
4597 flash or offset in NAND flash.
4599 *Note* - these variables don't have to be defined for all boards, some
4600 boards currenlty use other variables for these purposes, and some
4601 boards use these variables for other purposes.
4603 Image File Name RAM Address Flash Location
4604 ----- --------- ----------- --------------
4605 u-boot u-boot u-boot_addr_r u-boot_addr
4606 Linux kernel bootfile kernel_addr_r kernel_addr
4607 device tree blob fdtfile fdt_addr_r fdt_addr
4608 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4610 The following environment variables may be used and automatically
4611 updated by the network boot commands ("bootp" and "rarpboot"),
4612 depending the information provided by your boot server:
4614 bootfile - see above
4615 dnsip - IP address of your Domain Name Server
4616 dnsip2 - IP address of your secondary Domain Name Server
4617 gatewayip - IP address of the Gateway (Router) to use
4618 hostname - Target hostname
4620 netmask - Subnet Mask
4621 rootpath - Pathname of the root filesystem on the NFS server
4622 serverip - see above
4625 There are two special Environment Variables:
4627 serial# - contains hardware identification information such
4628 as type string and/or serial number
4629 ethaddr - Ethernet address
4631 These variables can be set only once (usually during manufacturing of
4632 the board). U-Boot refuses to delete or overwrite these variables
4633 once they have been set once.
4636 Further special Environment Variables:
4638 ver - Contains the U-Boot version string as printed
4639 with the "version" command. This variable is
4640 readonly (see CONFIG_VERSION_VARIABLE).
4643 Please note that changes to some configuration parameters may take
4644 only effect after the next boot (yes, that's just like Windoze :-).
4647 Callback functions for environment variables:
4648 ---------------------------------------------
4650 For some environment variables, the behavior of u-boot needs to change
4651 when their values are changed. This functionailty allows functions to
4652 be associated with arbitrary variables. On creation, overwrite, or
4653 deletion, the callback will provide the opportunity for some side
4654 effect to happen or for the change to be rejected.
4656 The callbacks are named and associated with a function using the
4657 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4659 These callbacks are associated with variables in one of two ways. The
4660 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4661 in the board configuration to a string that defines a list of
4662 associations. The list must be in the following format:
4664 entry = variable_name[:callback_name]
4667 If the callback name is not specified, then the callback is deleted.
4668 Spaces are also allowed anywhere in the list.
4670 Callbacks can also be associated by defining the ".callbacks" variable
4671 with the same list format above. Any association in ".callbacks" will
4672 override any association in the static list. You can define
4673 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4674 ".callbacks" envirnoment variable in the default or embedded environment.
4677 Command Line Parsing:
4678 =====================
4680 There are two different command line parsers available with U-Boot:
4681 the old "simple" one, and the much more powerful "hush" shell:
4683 Old, simple command line parser:
4684 --------------------------------
4686 - supports environment variables (through setenv / saveenv commands)
4687 - several commands on one line, separated by ';'
4688 - variable substitution using "... ${name} ..." syntax
4689 - special characters ('$', ';') can be escaped by prefixing with '\',
4691 setenv bootcmd bootm \${address}
4692 - You can also escape text by enclosing in single apostrophes, for example:
4693 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4698 - similar to Bourne shell, with control structures like
4699 if...then...else...fi, for...do...done; while...do...done,
4700 until...do...done, ...
4701 - supports environment ("global") variables (through setenv / saveenv
4702 commands) and local shell variables (through standard shell syntax
4703 "name=value"); only environment variables can be used with "run"
4709 (1) If a command line (or an environment variable executed by a "run"
4710 command) contains several commands separated by semicolon, and
4711 one of these commands fails, then the remaining commands will be
4714 (2) If you execute several variables with one call to run (i. e.
4715 calling run with a list of variables as arguments), any failing
4716 command will cause "run" to terminate, i. e. the remaining
4717 variables are not executed.
4719 Note for Redundant Ethernet Interfaces:
4720 =======================================
4722 Some boards come with redundant Ethernet interfaces; U-Boot supports
4723 such configurations and is capable of automatic selection of a
4724 "working" interface when needed. MAC assignment works as follows:
4726 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4727 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4728 "eth1addr" (=>eth1), "eth2addr", ...
4730 If the network interface stores some valid MAC address (for instance
4731 in SROM), this is used as default address if there is NO correspon-
4732 ding setting in the environment; if the corresponding environment
4733 variable is set, this overrides the settings in the card; that means:
4735 o If the SROM has a valid MAC address, and there is no address in the
4736 environment, the SROM's address is used.
4738 o If there is no valid address in the SROM, and a definition in the
4739 environment exists, then the value from the environment variable is
4742 o If both the SROM and the environment contain a MAC address, and
4743 both addresses are the same, this MAC address is used.
4745 o If both the SROM and the environment contain a MAC address, and the
4746 addresses differ, the value from the environment is used and a
4749 o If neither SROM nor the environment contain a MAC address, an error
4752 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4753 will be programmed into hardware as part of the initialization process. This
4754 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4755 The naming convention is as follows:
4756 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4761 U-Boot is capable of booting (and performing other auxiliary operations on)
4762 images in two formats:
4764 New uImage format (FIT)
4765 -----------------------
4767 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4768 to Flattened Device Tree). It allows the use of images with multiple
4769 components (several kernels, ramdisks, etc.), with contents protected by
4770 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4776 Old image format is based on binary files which can be basically anything,
4777 preceded by a special header; see the definitions in include/image.h for
4778 details; basically, the header defines the following image properties:
4780 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4781 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4782 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4783 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4785 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4786 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4787 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4788 * Compression Type (uncompressed, gzip, bzip2)
4794 The header is marked by a special Magic Number, and both the header
4795 and the data portions of the image are secured against corruption by
4802 Although U-Boot should support any OS or standalone application
4803 easily, the main focus has always been on Linux during the design of
4806 U-Boot includes many features that so far have been part of some
4807 special "boot loader" code within the Linux kernel. Also, any
4808 "initrd" images to be used are no longer part of one big Linux image;
4809 instead, kernel and "initrd" are separate images. This implementation
4810 serves several purposes:
4812 - the same features can be used for other OS or standalone
4813 applications (for instance: using compressed images to reduce the
4814 Flash memory footprint)
4816 - it becomes much easier to port new Linux kernel versions because
4817 lots of low-level, hardware dependent stuff are done by U-Boot
4819 - the same Linux kernel image can now be used with different "initrd"
4820 images; of course this also means that different kernel images can
4821 be run with the same "initrd". This makes testing easier (you don't
4822 have to build a new "zImage.initrd" Linux image when you just
4823 change a file in your "initrd"). Also, a field-upgrade of the
4824 software is easier now.
4830 Porting Linux to U-Boot based systems:
4831 ---------------------------------------
4833 U-Boot cannot save you from doing all the necessary modifications to
4834 configure the Linux device drivers for use with your target hardware
4835 (no, we don't intend to provide a full virtual machine interface to
4838 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4840 Just make sure your machine specific header file (for instance
4841 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4842 Information structure as we define in include/asm-<arch>/u-boot.h,
4843 and make sure that your definition of IMAP_ADDR uses the same value
4844 as your U-Boot configuration in CONFIG_SYS_IMMR.
4847 Configuring the Linux kernel:
4848 -----------------------------
4850 No specific requirements for U-Boot. Make sure you have some root
4851 device (initial ramdisk, NFS) for your target system.
4854 Building a Linux Image:
4855 -----------------------
4857 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4858 not used. If you use recent kernel source, a new build target
4859 "uImage" will exist which automatically builds an image usable by
4860 U-Boot. Most older kernels also have support for a "pImage" target,
4861 which was introduced for our predecessor project PPCBoot and uses a
4862 100% compatible format.
4871 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4872 encapsulate a compressed Linux kernel image with header information,
4873 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4875 * build a standard "vmlinux" kernel image (in ELF binary format):
4877 * convert the kernel into a raw binary image:
4879 ${CROSS_COMPILE}-objcopy -O binary \
4880 -R .note -R .comment \
4881 -S vmlinux linux.bin
4883 * compress the binary image:
4887 * package compressed binary image for U-Boot:
4889 mkimage -A ppc -O linux -T kernel -C gzip \
4890 -a 0 -e 0 -n "Linux Kernel Image" \
4891 -d linux.bin.gz uImage
4894 The "mkimage" tool can also be used to create ramdisk images for use
4895 with U-Boot, either separated from the Linux kernel image, or
4896 combined into one file. "mkimage" encapsulates the images with a 64
4897 byte header containing information about target architecture,
4898 operating system, image type, compression method, entry points, time
4899 stamp, CRC32 checksums, etc.
4901 "mkimage" can be called in two ways: to verify existing images and
4902 print the header information, or to build new images.
4904 In the first form (with "-l" option) mkimage lists the information
4905 contained in the header of an existing U-Boot image; this includes
4906 checksum verification:
4908 tools/mkimage -l image
4909 -l ==> list image header information
4911 The second form (with "-d" option) is used to build a U-Boot image
4912 from a "data file" which is used as image payload:
4914 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4915 -n name -d data_file image
4916 -A ==> set architecture to 'arch'
4917 -O ==> set operating system to 'os'
4918 -T ==> set image type to 'type'
4919 -C ==> set compression type 'comp'
4920 -a ==> set load address to 'addr' (hex)
4921 -e ==> set entry point to 'ep' (hex)
4922 -n ==> set image name to 'name'
4923 -d ==> use image data from 'datafile'
4925 Right now, all Linux kernels for PowerPC systems use the same load
4926 address (0x00000000), but the entry point address depends on the
4929 - 2.2.x kernels have the entry point at 0x0000000C,
4930 - 2.3.x and later kernels have the entry point at 0x00000000.
4932 So a typical call to build a U-Boot image would read:
4934 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4935 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4936 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4937 > examples/uImage.TQM850L
4938 Image Name: 2.4.4 kernel for TQM850L
4939 Created: Wed Jul 19 02:34:59 2000
4940 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4941 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4942 Load Address: 0x00000000
4943 Entry Point: 0x00000000
4945 To verify the contents of the image (or check for corruption):
4947 -> tools/mkimage -l examples/uImage.TQM850L
4948 Image Name: 2.4.4 kernel for TQM850L
4949 Created: Wed Jul 19 02:34:59 2000
4950 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4951 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4952 Load Address: 0x00000000
4953 Entry Point: 0x00000000
4955 NOTE: for embedded systems where boot time is critical you can trade
4956 speed for memory and install an UNCOMPRESSED image instead: this
4957 needs more space in Flash, but boots much faster since it does not
4958 need to be uncompressed:
4960 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4961 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4962 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4963 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4964 > examples/uImage.TQM850L-uncompressed
4965 Image Name: 2.4.4 kernel for TQM850L
4966 Created: Wed Jul 19 02:34:59 2000
4967 Image Type: PowerPC Linux Kernel Image (uncompressed)
4968 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4969 Load Address: 0x00000000
4970 Entry Point: 0x00000000
4973 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4974 when your kernel is intended to use an initial ramdisk:
4976 -> tools/mkimage -n 'Simple Ramdisk Image' \
4977 > -A ppc -O linux -T ramdisk -C gzip \
4978 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4979 Image Name: Simple Ramdisk Image
4980 Created: Wed Jan 12 14:01:50 2000
4981 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4982 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4983 Load Address: 0x00000000
4984 Entry Point: 0x00000000
4987 Installing a Linux Image:
4988 -------------------------
4990 To downloading a U-Boot image over the serial (console) interface,
4991 you must convert the image to S-Record format:
4993 objcopy -I binary -O srec examples/image examples/image.srec
4995 The 'objcopy' does not understand the information in the U-Boot
4996 image header, so the resulting S-Record file will be relative to
4997 address 0x00000000. To load it to a given address, you need to
4998 specify the target address as 'offset' parameter with the 'loads'
5001 Example: install the image to address 0x40100000 (which on the
5002 TQM8xxL is in the first Flash bank):
5004 => erase 40100000 401FFFFF
5010 ## Ready for S-Record download ...
5011 ~>examples/image.srec
5012 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5014 15989 15990 15991 15992
5015 [file transfer complete]
5017 ## Start Addr = 0x00000000
5020 You can check the success of the download using the 'iminfo' command;
5021 this includes a checksum verification so you can be sure no data
5022 corruption happened:
5026 ## Checking Image at 40100000 ...
5027 Image Name: 2.2.13 for initrd on TQM850L
5028 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5029 Data Size: 335725 Bytes = 327 kB = 0 MB
5030 Load Address: 00000000
5031 Entry Point: 0000000c
5032 Verifying Checksum ... OK
5038 The "bootm" command is used to boot an application that is stored in
5039 memory (RAM or Flash). In case of a Linux kernel image, the contents
5040 of the "bootargs" environment variable is passed to the kernel as
5041 parameters. You can check and modify this variable using the
5042 "printenv" and "setenv" commands:
5045 => printenv bootargs
5046 bootargs=root=/dev/ram
5048 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5050 => printenv bootargs
5051 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5054 ## Booting Linux kernel at 40020000 ...
5055 Image Name: 2.2.13 for NFS on TQM850L
5056 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5057 Data Size: 381681 Bytes = 372 kB = 0 MB
5058 Load Address: 00000000
5059 Entry Point: 0000000c
5060 Verifying Checksum ... OK
5061 Uncompressing Kernel Image ... OK
5062 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
5063 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5064 time_init: decrementer frequency = 187500000/60
5065 Calibrating delay loop... 49.77 BogoMIPS
5066 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5069 If you want to boot a Linux kernel with initial RAM disk, you pass
5070 the memory addresses of both the kernel and the initrd image (PPBCOOT
5071 format!) to the "bootm" command:
5073 => imi 40100000 40200000
5075 ## Checking Image at 40100000 ...
5076 Image Name: 2.2.13 for initrd on TQM850L
5077 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5078 Data Size: 335725 Bytes = 327 kB = 0 MB
5079 Load Address: 00000000
5080 Entry Point: 0000000c
5081 Verifying Checksum ... OK
5083 ## Checking Image at 40200000 ...
5084 Image Name: Simple Ramdisk Image
5085 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5086 Data Size: 566530 Bytes = 553 kB = 0 MB
5087 Load Address: 00000000
5088 Entry Point: 00000000
5089 Verifying Checksum ... OK
5091 => bootm 40100000 40200000
5092 ## Booting Linux kernel at 40100000 ...
5093 Image Name: 2.2.13 for initrd on TQM850L
5094 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5095 Data Size: 335725 Bytes = 327 kB = 0 MB
5096 Load Address: 00000000
5097 Entry Point: 0000000c
5098 Verifying Checksum ... OK
5099 Uncompressing Kernel Image ... OK
5100 ## Loading RAMDisk Image at 40200000 ...
5101 Image Name: Simple Ramdisk Image
5102 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5103 Data Size: 566530 Bytes = 553 kB = 0 MB
5104 Load Address: 00000000
5105 Entry Point: 00000000
5106 Verifying Checksum ... OK
5107 Loading Ramdisk ... OK
5108 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
5109 Boot arguments: root=/dev/ram
5110 time_init: decrementer frequency = 187500000/60
5111 Calibrating delay loop... 49.77 BogoMIPS
5113 RAMDISK: Compressed image found at block 0
5114 VFS: Mounted root (ext2 filesystem).
5118 Boot Linux and pass a flat device tree:
5121 First, U-Boot must be compiled with the appropriate defines. See the section
5122 titled "Linux Kernel Interface" above for a more in depth explanation. The
5123 following is an example of how to start a kernel and pass an updated
5129 oft=oftrees/mpc8540ads.dtb
5130 => tftp $oftaddr $oft
5131 Speed: 1000, full duplex
5133 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5134 Filename 'oftrees/mpc8540ads.dtb'.
5135 Load address: 0x300000
5138 Bytes transferred = 4106 (100a hex)
5139 => tftp $loadaddr $bootfile
5140 Speed: 1000, full duplex
5142 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5144 Load address: 0x200000
5145 Loading:############
5147 Bytes transferred = 1029407 (fb51f hex)
5152 => bootm $loadaddr - $oftaddr
5153 ## Booting image at 00200000 ...
5154 Image Name: Linux-2.6.17-dirty
5155 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5156 Data Size: 1029343 Bytes = 1005.2 kB
5157 Load Address: 00000000
5158 Entry Point: 00000000
5159 Verifying Checksum ... OK
5160 Uncompressing Kernel Image ... OK
5161 Booting using flat device tree at 0x300000
5162 Using MPC85xx ADS machine description
5163 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5167 More About U-Boot Image Types:
5168 ------------------------------
5170 U-Boot supports the following image types:
5172 "Standalone Programs" are directly runnable in the environment
5173 provided by U-Boot; it is expected that (if they behave
5174 well) you can continue to work in U-Boot after return from
5175 the Standalone Program.
5176 "OS Kernel Images" are usually images of some Embedded OS which
5177 will take over control completely. Usually these programs
5178 will install their own set of exception handlers, device
5179 drivers, set up the MMU, etc. - this means, that you cannot
5180 expect to re-enter U-Boot except by resetting the CPU.
5181 "RAMDisk Images" are more or less just data blocks, and their
5182 parameters (address, size) are passed to an OS kernel that is
5184 "Multi-File Images" contain several images, typically an OS
5185 (Linux) kernel image and one or more data images like
5186 RAMDisks. This construct is useful for instance when you want
5187 to boot over the network using BOOTP etc., where the boot
5188 server provides just a single image file, but you want to get
5189 for instance an OS kernel and a RAMDisk image.
5191 "Multi-File Images" start with a list of image sizes, each
5192 image size (in bytes) specified by an "uint32_t" in network
5193 byte order. This list is terminated by an "(uint32_t)0".
5194 Immediately after the terminating 0 follow the images, one by
5195 one, all aligned on "uint32_t" boundaries (size rounded up to
5196 a multiple of 4 bytes).
5198 "Firmware Images" are binary images containing firmware (like
5199 U-Boot or FPGA images) which usually will be programmed to
5202 "Script files" are command sequences that will be executed by
5203 U-Boot's command interpreter; this feature is especially
5204 useful when you configure U-Boot to use a real shell (hush)
5205 as command interpreter.
5207 Booting the Linux zImage:
5208 -------------------------
5210 On some platforms, it's possible to boot Linux zImage. This is done
5211 using the "bootz" command. The syntax of "bootz" command is the same
5212 as the syntax of "bootm" command.
5214 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5215 kernel with raw initrd images. The syntax is slightly different, the
5216 address of the initrd must be augmented by it's size, in the following
5217 format: "<initrd addres>:<initrd size>".
5223 One of the features of U-Boot is that you can dynamically load and
5224 run "standalone" applications, which can use some resources of
5225 U-Boot like console I/O functions or interrupt services.
5227 Two simple examples are included with the sources:
5232 'examples/hello_world.c' contains a small "Hello World" Demo
5233 application; it is automatically compiled when you build U-Boot.
5234 It's configured to run at address 0x00040004, so you can play with it
5238 ## Ready for S-Record download ...
5239 ~>examples/hello_world.srec
5240 1 2 3 4 5 6 7 8 9 10 11 ...
5241 [file transfer complete]
5243 ## Start Addr = 0x00040004
5245 => go 40004 Hello World! This is a test.
5246 ## Starting application at 0x00040004 ...
5257 Hit any key to exit ...
5259 ## Application terminated, rc = 0x0
5261 Another example, which demonstrates how to register a CPM interrupt
5262 handler with the U-Boot code, can be found in 'examples/timer.c'.
5263 Here, a CPM timer is set up to generate an interrupt every second.
5264 The interrupt service routine is trivial, just printing a '.'
5265 character, but this is just a demo program. The application can be
5266 controlled by the following keys:
5268 ? - print current values og the CPM Timer registers
5269 b - enable interrupts and start timer
5270 e - stop timer and disable interrupts
5271 q - quit application
5274 ## Ready for S-Record download ...
5275 ~>examples/timer.srec
5276 1 2 3 4 5 6 7 8 9 10 11 ...
5277 [file transfer complete]
5279 ## Start Addr = 0x00040004
5282 ## Starting application at 0x00040004 ...
5285 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5288 [q, b, e, ?] Set interval 1000000 us
5291 [q, b, e, ?] ........
5292 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5295 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5298 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5301 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5303 [q, b, e, ?] ...Stopping timer
5305 [q, b, e, ?] ## Application terminated, rc = 0x0
5311 Over time, many people have reported problems when trying to use the
5312 "minicom" terminal emulation program for serial download. I (wd)
5313 consider minicom to be broken, and recommend not to use it. Under
5314 Unix, I recommend to use C-Kermit for general purpose use (and
5315 especially for kermit binary protocol download ("loadb" command), and
5316 use "cu" for S-Record download ("loads" command). See
5317 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5318 for help with kermit.
5321 Nevertheless, if you absolutely want to use it try adding this
5322 configuration to your "File transfer protocols" section:
5324 Name Program Name U/D FullScr IO-Red. Multi
5325 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5326 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5332 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5333 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5335 Building requires a cross environment; it is known to work on
5336 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5337 need gmake since the Makefiles are not compatible with BSD make).
5338 Note that the cross-powerpc package does not install include files;
5339 attempting to build U-Boot will fail because <machine/ansi.h> is
5340 missing. This file has to be installed and patched manually:
5342 # cd /usr/pkg/cross/powerpc-netbsd/include
5344 # ln -s powerpc machine
5345 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5346 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5348 Native builds *don't* work due to incompatibilities between native
5349 and U-Boot include files.
5351 Booting assumes that (the first part of) the image booted is a
5352 stage-2 loader which in turn loads and then invokes the kernel
5353 proper. Loader sources will eventually appear in the NetBSD source
5354 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5355 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5358 Implementation Internals:
5359 =========================
5361 The following is not intended to be a complete description of every
5362 implementation detail. However, it should help to understand the
5363 inner workings of U-Boot and make it easier to port it to custom
5367 Initial Stack, Global Data:
5368 ---------------------------
5370 The implementation of U-Boot is complicated by the fact that U-Boot
5371 starts running out of ROM (flash memory), usually without access to
5372 system RAM (because the memory controller is not initialized yet).
5373 This means that we don't have writable Data or BSS segments, and BSS
5374 is not initialized as zero. To be able to get a C environment working
5375 at all, we have to allocate at least a minimal stack. Implementation
5376 options for this are defined and restricted by the CPU used: Some CPU
5377 models provide on-chip memory (like the IMMR area on MPC8xx and
5378 MPC826x processors), on others (parts of) the data cache can be
5379 locked as (mis-) used as memory, etc.
5381 Chris Hallinan posted a good summary of these issues to the
5382 U-Boot mailing list:
5384 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5385 From: "Chris Hallinan" <clh@net1plus.com>
5386 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5389 Correct me if I'm wrong, folks, but the way I understand it
5390 is this: Using DCACHE as initial RAM for Stack, etc, does not
5391 require any physical RAM backing up the cache. The cleverness
5392 is that the cache is being used as a temporary supply of
5393 necessary storage before the SDRAM controller is setup. It's
5394 beyond the scope of this list to explain the details, but you
5395 can see how this works by studying the cache architecture and
5396 operation in the architecture and processor-specific manuals.
5398 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5399 is another option for the system designer to use as an
5400 initial stack/RAM area prior to SDRAM being available. Either
5401 option should work for you. Using CS 4 should be fine if your
5402 board designers haven't used it for something that would
5403 cause you grief during the initial boot! It is frequently not
5406 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5407 with your processor/board/system design. The default value
5408 you will find in any recent u-boot distribution in
5409 walnut.h should work for you. I'd set it to a value larger
5410 than your SDRAM module. If you have a 64MB SDRAM module, set
5411 it above 400_0000. Just make sure your board has no resources
5412 that are supposed to respond to that address! That code in
5413 start.S has been around a while and should work as is when
5414 you get the config right.
5419 It is essential to remember this, since it has some impact on the C
5420 code for the initialization procedures:
5422 * Initialized global data (data segment) is read-only. Do not attempt
5425 * Do not use any uninitialized global data (or implicitely initialized
5426 as zero data - BSS segment) at all - this is undefined, initiali-
5427 zation is performed later (when relocating to RAM).
5429 * Stack space is very limited. Avoid big data buffers or things like
5432 Having only the stack as writable memory limits means we cannot use
5433 normal global data to share information beween the code. But it
5434 turned out that the implementation of U-Boot can be greatly
5435 simplified by making a global data structure (gd_t) available to all
5436 functions. We could pass a pointer to this data as argument to _all_
5437 functions, but this would bloat the code. Instead we use a feature of
5438 the GCC compiler (Global Register Variables) to share the data: we
5439 place a pointer (gd) to the global data into a register which we
5440 reserve for this purpose.
5442 When choosing a register for such a purpose we are restricted by the
5443 relevant (E)ABI specifications for the current architecture, and by
5444 GCC's implementation.
5446 For PowerPC, the following registers have specific use:
5448 R2: reserved for system use
5449 R3-R4: parameter passing and return values
5450 R5-R10: parameter passing
5451 R13: small data area pointer
5455 (U-Boot also uses R12 as internal GOT pointer. r12
5456 is a volatile register so r12 needs to be reset when
5457 going back and forth between asm and C)
5459 ==> U-Boot will use R2 to hold a pointer to the global data
5461 Note: on PPC, we could use a static initializer (since the
5462 address of the global data structure is known at compile time),
5463 but it turned out that reserving a register results in somewhat
5464 smaller code - although the code savings are not that big (on
5465 average for all boards 752 bytes for the whole U-Boot image,
5466 624 text + 127 data).
5468 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5469 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5471 ==> U-Boot will use P3 to hold a pointer to the global data
5473 On ARM, the following registers are used:
5475 R0: function argument word/integer result
5476 R1-R3: function argument word
5478 R10: stack limit (used only if stack checking if enabled)
5479 R11: argument (frame) pointer
5480 R12: temporary workspace
5483 R15: program counter
5485 ==> U-Boot will use R8 to hold a pointer to the global data
5487 On Nios II, the ABI is documented here:
5488 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5490 ==> U-Boot will use gp to hold a pointer to the global data
5492 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5493 to access small data sections, so gp is free.
5495 On NDS32, the following registers are used:
5497 R0-R1: argument/return
5499 R15: temporary register for assembler
5500 R16: trampoline register
5501 R28: frame pointer (FP)
5502 R29: global pointer (GP)
5503 R30: link register (LP)
5504 R31: stack pointer (SP)
5505 PC: program counter (PC)
5507 ==> U-Boot will use R10 to hold a pointer to the global data
5509 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5510 or current versions of GCC may "optimize" the code too much.
5515 U-Boot runs in system state and uses physical addresses, i.e. the
5516 MMU is not used either for address mapping nor for memory protection.
5518 The available memory is mapped to fixed addresses using the memory
5519 controller. In this process, a contiguous block is formed for each
5520 memory type (Flash, SDRAM, SRAM), even when it consists of several
5521 physical memory banks.
5523 U-Boot is installed in the first 128 kB of the first Flash bank (on
5524 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5525 booting and sizing and initializing DRAM, the code relocates itself
5526 to the upper end of DRAM. Immediately below the U-Boot code some
5527 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5528 configuration setting]. Below that, a structure with global Board
5529 Info data is placed, followed by the stack (growing downward).
5531 Additionally, some exception handler code is copied to the low 8 kB
5532 of DRAM (0x00000000 ... 0x00001FFF).
5534 So a typical memory configuration with 16 MB of DRAM could look like
5537 0x0000 0000 Exception Vector code
5540 0x0000 2000 Free for Application Use
5546 0x00FB FF20 Monitor Stack (Growing downward)
5547 0x00FB FFAC Board Info Data and permanent copy of global data
5548 0x00FC 0000 Malloc Arena
5551 0x00FE 0000 RAM Copy of Monitor Code
5552 ... eventually: LCD or video framebuffer
5553 ... eventually: pRAM (Protected RAM - unchanged by reset)
5554 0x00FF FFFF [End of RAM]
5557 System Initialization:
5558 ----------------------
5560 In the reset configuration, U-Boot starts at the reset entry point
5561 (on most PowerPC systems at address 0x00000100). Because of the reset
5562 configuration for CS0# this is a mirror of the onboard Flash memory.
5563 To be able to re-map memory U-Boot then jumps to its link address.
5564 To be able to implement the initialization code in C, a (small!)
5565 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5566 which provide such a feature like MPC8xx or MPC8260), or in a locked
5567 part of the data cache. After that, U-Boot initializes the CPU core,
5568 the caches and the SIU.
5570 Next, all (potentially) available memory banks are mapped using a
5571 preliminary mapping. For example, we put them on 512 MB boundaries
5572 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5573 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5574 programmed for SDRAM access. Using the temporary configuration, a
5575 simple memory test is run that determines the size of the SDRAM
5578 When there is more than one SDRAM bank, and the banks are of
5579 different size, the largest is mapped first. For equal size, the first
5580 bank (CS2#) is mapped first. The first mapping is always for address
5581 0x00000000, with any additional banks following immediately to create
5582 contiguous memory starting from 0.
5584 Then, the monitor installs itself at the upper end of the SDRAM area
5585 and allocates memory for use by malloc() and for the global Board
5586 Info data; also, the exception vector code is copied to the low RAM
5587 pages, and the final stack is set up.
5589 Only after this relocation will you have a "normal" C environment;
5590 until that you are restricted in several ways, mostly because you are
5591 running from ROM, and because the code will have to be relocated to a
5595 U-Boot Porting Guide:
5596 ----------------------
5598 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5602 int main(int argc, char *argv[])
5604 sighandler_t no_more_time;
5606 signal(SIGALRM, no_more_time);
5607 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5609 if (available_money > available_manpower) {
5610 Pay consultant to port U-Boot;
5614 Download latest U-Boot source;
5616 Subscribe to u-boot mailing list;
5619 email("Hi, I am new to U-Boot, how do I get started?");
5622 Read the README file in the top level directory;
5623 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5624 Read applicable doc/*.README;
5625 Read the source, Luke;
5626 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5629 if (available_money > toLocalCurrency ($2500))
5632 Add a lot of aggravation and time;
5634 if (a similar board exists) { /* hopefully... */
5635 cp -a board/<similar> board/<myboard>
5636 cp include/configs/<similar>.h include/configs/<myboard>.h
5638 Create your own board support subdirectory;
5639 Create your own board include/configs/<myboard>.h file;
5641 Edit new board/<myboard> files
5642 Edit new include/configs/<myboard>.h
5647 Add / modify source code;
5651 email("Hi, I am having problems...");
5653 Send patch file to the U-Boot email list;
5654 if (reasonable critiques)
5655 Incorporate improvements from email list code review;
5657 Defend code as written;
5663 void no_more_time (int sig)
5672 All contributions to U-Boot should conform to the Linux kernel
5673 coding style; see the file "Documentation/CodingStyle" and the script
5674 "scripts/Lindent" in your Linux kernel source directory.
5676 Source files originating from a different project (for example the
5677 MTD subsystem) are generally exempt from these guidelines and are not
5678 reformated to ease subsequent migration to newer versions of those
5681 Please note that U-Boot is implemented in C (and to some small parts in
5682 Assembler); no C++ is used, so please do not use C++ style comments (//)
5685 Please also stick to the following formatting rules:
5686 - remove any trailing white space
5687 - use TAB characters for indentation and vertical alignment, not spaces
5688 - make sure NOT to use DOS '\r\n' line feeds
5689 - do not add more than 2 consecutive empty lines to source files
5690 - do not add trailing empty lines to source files
5692 Submissions which do not conform to the standards may be returned
5693 with a request to reformat the changes.
5699 Since the number of patches for U-Boot is growing, we need to
5700 establish some rules. Submissions which do not conform to these rules
5701 may be rejected, even when they contain important and valuable stuff.
5703 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5705 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5706 see http://lists.denx.de/mailman/listinfo/u-boot
5708 When you send a patch, please include the following information with
5711 * For bug fixes: a description of the bug and how your patch fixes
5712 this bug. Please try to include a way of demonstrating that the
5713 patch actually fixes something.
5715 * For new features: a description of the feature and your
5718 * A CHANGELOG entry as plaintext (separate from the patch)
5720 * For major contributions, your entry to the CREDITS file
5722 * When you add support for a new board, don't forget to add this
5723 board to the MAINTAINERS file, too.
5725 * If your patch adds new configuration options, don't forget to
5726 document these in the README file.
5728 * The patch itself. If you are using git (which is *strongly*
5729 recommended) you can easily generate the patch using the
5730 "git format-patch". If you then use "git send-email" to send it to
5731 the U-Boot mailing list, you will avoid most of the common problems
5732 with some other mail clients.
5734 If you cannot use git, use "diff -purN OLD NEW". If your version of
5735 diff does not support these options, then get the latest version of
5738 The current directory when running this command shall be the parent
5739 directory of the U-Boot source tree (i. e. please make sure that
5740 your patch includes sufficient directory information for the
5743 We prefer patches as plain text. MIME attachments are discouraged,
5744 and compressed attachments must not be used.
5746 * If one logical set of modifications affects or creates several
5747 files, all these changes shall be submitted in a SINGLE patch file.
5749 * Changesets that contain different, unrelated modifications shall be
5750 submitted as SEPARATE patches, one patch per changeset.
5755 * Before sending the patch, run the MAKEALL script on your patched
5756 source tree and make sure that no errors or warnings are reported
5757 for any of the boards.
5759 * Keep your modifications to the necessary minimum: A patch
5760 containing several unrelated changes or arbitrary reformats will be
5761 returned with a request to re-formatting / split it.
5763 * If you modify existing code, make sure that your new code does not
5764 add to the memory footprint of the code ;-) Small is beautiful!
5765 When adding new features, these should compile conditionally only
5766 (using #ifdef), and the resulting code with the new feature
5767 disabled must not need more memory than the old code without your
5770 * Remember that there is a size limit of 100 kB per message on the
5771 u-boot mailing list. Bigger patches will be moderated. If they are
5772 reasonable and not too big, they will be acknowledged. But patches
5773 bigger than the size limit should be avoided.
projects / kernel / u-boot.git / blob